Agilent 400/54 Premium Shielded NMR Magnet System · Parts List and Order Form 50 Parts Quotation...

Agilent 400/54 Premium Shielded NMR Magnet System

System Overview

Agilent Technologies

Notices© Agilent Technologies, Inc. 2012

No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or transla-tion into a foreign language) without prior agreement and written consent fromAgilent Technologies, Inc. as governed by United States and international copyright laws.

Manual Part Number

9100380100

Edition

Revision A, April 2012

Printed in USA

Agilent Technologies, Inc.5301 Stevens Creek Boulevard Santa Clara, CA 95051 USA

Warranty

The material contained in this docu-ment is provided “as is,” and is sub-ject to being changed, without notice, in future editions. Further, to the max-imum extent permitted by applicable law, Agilent disclaims all warranties, either express or implied, with regard to this manual and any information contained herein, including but not limited to the implied warranties of merchantability and fitness for a par-ticular purpose. Agilent shall not be liable for errors or for incidental or consequential damages in connection with the furnishing, use, or perfor-mance of this document or of any information contained herein. Should Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms, the warranty terms in the sep-arate agreement shall control.

Technology Licenses

The hardware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Restricted Rights Legend

If software is for use in the performance of a U.S. Government prime contract or sub-contract, Software is delivered and licensed as “Commercial computer soft-ware” as defined in DFAR 252.227-7014 (June 1995), or as a “commercial item” as defined in FAR 2.101(a) or as “Restricted computer software” as defined in FAR 52.227-19 (June 1987) or any equivalent agency regulation or contract clause. Use, duplication or disclosure of Software is subject to Agilent Technologies’ standard commercial license terms, and non-DOD Departments and Agencies of the U.S. Gov-ernment will receive no greater than Restricted Rights as defined in FAR 52.227-19(c)(1-2) (June 1987). U.S. Govern-ment users will receive no greater than Limited Rights as defined in FAR 52.227-14 (June 1987) or DFAR 252.227-7015 (b)(2) (November 1995), as applicable in any technical data.

Safety Notices

CAUTION

A CAUTION notice denotes a haz-ard. It calls attention to an operat-ing procedure, practice, or the like that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met.

WARNING

A WARNING notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly per-formed or adhered to, could result in personal injury or death. Do not proceed beyond a WARNING notice until the indicated condi-tions are fully understood and met.

Contents

1 Introduction

400/54 Premium Shielded NMR Mag

Safety Warnings 6

Compliance Notice 8

Contact Information 9

Europe 9USA 9Agilent website (all countries) 9

Important Notice 10

Disclaimer 10

2 Installation and Operation Safety

Introduction 12

Nature of the Magnetic Field 13

Hazards Presented by the Magnetic Field 14

Magnetic Field Safety Requirements 15

Exclusion Zone (5-gauss line) 15Magnetic Attraction Zone 16Occupational exposure to magnetic fields 16

Nature of Liquid Cryogens 17

Hazards Presented by Cryogens 18

Siting Requirements 20

Vents or quench ducts 20Adequate ventilation during magnet installation 21Oxygen monitor 21Routine maintenance involving transfer of cryogens 22Advice 22

Electrical Safety 23

Safe Access When Working at Height 24

Considerations for the Outbreak of Fire 25

General Safety — Potential Hazards 27

Handling cryogens (liquid helium and liquid nitrogen) 27Vacuum hazards 27Magnetic field 28Air quality 28System mechanical stability 29

net System Product Overview 1

3 Maintenance

2

Commissioning and Decommissioning the Magnet 32

General safety note 32

Cryostat Maintenance 35

General maintenance 35

Cryogenic Fills 38

Safety during cryogen fills 38How to perform a routine LN2 fill 38How to perform a standard helium fill (top-up) 40

Parts List and Order Form 50

Parts Quotation Request 51Information Sheet 53

4 Reference

Nitrogen Probe Calibration Chart — 400/54 Premium Shielded 56

Helium Probe Calibration Chart — 400/54 Premium Shielded 57

Temperature Sensors — 400/54/ASP 59

Platinum resistor thermometers (PT100) 59Allen-Bradley temperature sensors 59Location of temperature sensors 59

Wiring Diagram 60

10-pin seal pin designations, 400/54/ASP 60 19-way shim socket pin designations – 400/54/ASP 62

5 Agilent E5025 Cryogen Monitor

Safety 66

Compliance Notice 67

Overview 68

Description and Operating Principle 70

Technical specification 72

The Top-Level USER Menu 73

Manually reading the helium probes 73Changing to the Helium Fill mode 73Checking both Helium probe readings 74

The Secondary Level SET-UP Menu 75

Entering the secondary level SET-UP menu 75Functions available on the secondary level SET-UP menu 75

Cryogen Monitor User Interface 79

400/54 Premium Shielded NMR Magnet System Product Overview

400/54 Premium Shielded NMR Mag

Modes of operation 79Application start-up 80Reader-mode user interface 80N2 and He Level history plot windows 82Writer-mode user interface 83

Errors and Alarms 85

Ethernet Communication 86

Ethernet 86

6 Technical Specifications

System Description 88

The Superconducting Magnet 89

General description 89Magnet specifications 90Superconducting shim coils 90

The Cryostat 92

General Description 92Specifications 92

Customer Interface Drawings 94

System Components 96

Superconducting magnet system components 96Standard ancillary parts provided with the system 96

net System Product Overview 3

4

Agilent 400/54 Premium Shielded NMR Magnet SystemSystem Overview

1Introduction

Safety Warnings 6

Compliance Notice 8

Contact Information 9

Important Notice 10

5Agilent Technologies

1 Introduction

Safety Warnings

6

WARNING This device produces a high magnetic field. The stray field surrounding the magnet extends far beyond the confines of the vessel. The existence of this field produces several hazards. In particular, make sure people with cardiac pacemakers avoid the region of field. The FDA guideline for cardiac pacemakers is currently 5 gauss. Fields higher than this can cause malfunction of the pacemaker. The field will interfere with sensitive electronic devices and will erase magnetic storage devices such as tapes and credit cards.

WARNING Ferromagnetic objects in the vicinity of the magnet will become magnetized and will be attracted toward the magnet. The force on such objects is proportional to their mass so that even large objects will move toward the magnet with considerable velocity.

WARNING Under fault conditions, it is possible for large amounts of helium and/or nitrogen to be released from the system (for example, during a magnet quench). Under these conditions, the gas is very cold and can cause “cold burns”. If the gas is not vented properly, asphyxiation is possible due to the displacement of oxygen within the room. It is the responsibility of the user to ensure adequate venting of the gas is provided and adequate ventilation within the final installation site.

NOTE It is the responsibility of the user to take all necessary precautions to prevent accident or loss from use of the magnet. Agilent Technologies accepts no responsibility for any loss or damage caused either directly or indirectly from use of the magnet. Every effort is made that the information contained in this manual is correct. However, Agilent Technologies accepts no responsibility for any inaccurate statements or omissions.


Introduction 1

400/54 Premium Shielded NMR Magne

WARNING Limit the magnet power supply to the operating current of the magnet plus 10%. Energize the magnet only after completion of cooling.

NOTE Agilent Technologies makes available technical information and parts for repair or maintenance where appropriate.

t System Product Overview 7

1 Introduction

Compliance Notice

8

Marking by the symbol indicates compliance of this device to the PED (Pressure Equipment Directive) directive of the European Community. This unit is to be installed and operated as detailed. Any modification or maintenance procedure undertaken which is not approved by Agilent

Technologies UK Ltd could nullify the marking of this product and lead to prosecution. A 'Declaration Of Conformity' in accordance with the above directive has been made and is located at Agilent Technologies, Yarnton, Oxfordshire, UK.


Introduction 1

Contact Information

Europe


Address:

Agilent Technologies UK Ltd.

6 Mead Road

Oxford Industrial Estate

Yarnton, Oxfordshire OX5 1QU

Telephone Numbers:

To find contact information for your country, click the following link, select your country, and then click Go.

http://www.chem.agilent.com/en- us/ContactUS/Pages/ContactUs.aspx

USA

Address:

Agilent Technologies, Inc.

5301 Stevens Creek Blvd.

Santa Clara, CA 95051

Telephone Numbers:

Toll Free: +1 (800) 227 9770

Agilent website (all countries)

To find contact information for your location, click the following link, select your country, and then click Go.

http://www.chem.agilent.com/en- us/ContactUS/Pages/ContactUs.aspx


http://www.chem.agilent.com/en-us/ContactUS/Pages/ContactUs.aspx

http://www.chem.agilent.com/en-us/ContactUS/Pages/ContactUs.aspx

1 Introduction

Important Notice

10

Inspect goods immediately on arrival for possible transit damage, and notify Agilent Technologies within three days of receipt of goods. Failure to do this invalidates any possible claim.

Disclaimer

Every precaution has been taken in the preparation of this publication. Agilent Technologies assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.



2Installation and Operation Safety

Introduction 12

Nature of the Magnetic Field 13

Hazards Presented by the Magnetic Field 14

Magnetic Field Safety Requirements 15

Nature of Liquid Cryogens 17

Hazards Presented by Cryogens 18

Siting Requirements 20

Electrical Safety 23

Safe Access When Working at Height 24

Considerations for the Outbreak of Fire 25

General Safety — Potential Hazards 27



Introduction

12

The site for a superconducting magnet system must meet national, state, and local safety regulations. For magnet systems, site safety issues primarily relate to magnetic fringe fields and handling liquid cryogens. This section summarizes these potential dangers and makes recommendations for the facility.


Installation and Operation Safety 2

Nature of the Magnetic Field


The greatest hazard presented by a superconducting magnet is the fringe magnetic field. Once the magnet is energized, the magnetic field is always present, even when all power to the system is turned off. This magnetic field extends above, below and to the sides of the magnet. It extends through doors, walls ceilings, and floors.

The strength of the magnetic field increases as the magnet is approached. Objects and people at risk from the magnetic field are considered safe outside the 5 gauss line.

NOTE A magnet that has been de-energized but remains at liquid helium temperatures still exhibits a small residual magnetic field. Make measurements of this field, and restrict public access as per national and state requirements. (See “Magnetic Field Safety Requirements” on page 15.)

Occasionally, fault conditions cause magnets to lose their superconducting properties, which in turn causes their magnetic fields to collapse. For a magnet that is actively shielded, before the magnetic field collapses it can momentarily “bloom” slightly beyond its normal dimensions. For further details on this subject for any specific magnet, consult Agilent Technologies.



Hazards Presented by the Magnetic Field

14

The strong magnetic field creates hazards because it strongly attracts ferromagnetic metal alloys. Ferromagnetic metal alloys contain iron, nickel, or cobalt. They are used in most types of tools and equipment and in some surgical implants.

The strong magnetic field can cause the following hazards:

• Projectiles

• Displacement of surgical implants

• Stoppage of electrical and mechanical implants and devices

WARNING If a loose metal object (such as a wrench or pen) gets too close to the magnet, it can become a projectile as the force of the magnetic field pulls the object towards the magnetic center. This metal projectile can seriously injure anyone standing between it and the magnet.

WARNING Ferromagnetic metals are sometimes used in surgical implants and prosthetic devices. The magnetic field can twist metallic implants out of place, causing tissue damage and pain to the person in whom they are implanted, creating a life-threatening situation. Some cardiac pacemakers, biostimulators, and neurostimulators are mechanically activated and can stop in the presence of the magnetic field. This situation can also create a life-threatening situation.



Magnetic Field Safety Requirements


NOTE National and state legislation & requirements differ around the world. In the USA, follow the requirements and guidance issued by the Food & Drug Administration (FDA). In Europe, European Commission (EC) Directive 2004/40/EC applies; follow the guidance issued by the International Commission on Non Ionizing Radiation Protection (ICNIRP).

NOTE Before 1st April 2005, the advisory body for the United Kingdom was the National Radiological Protection Board (NRPB) - a member of ICNIRP. From 1st April 2005 the NRPB merged with the United Kingdom Health Protection Agency (HPA), and became its Radiation Protection Division.

Control the hazards described in the previous sections of this document by establishing two secure and clearly marked zones:

• The Exclusion Zone

• The Magnetic Attraction Zone

Exclusion Zone (5-gauss line)

The exclusion zone comprises the area (rooms and hallways for example) inside the 5- gauss line of the magnet. Prevent individuals with cardiac or other mechanically active implants from entering this area.

The magnetic field surrounds the magnet in a three- dimensional fashion. Limit access and warn individuals who are potentially at risk, not only at the same floor as the magnet, but also at the levels above and below the magnet.

Enforce the exclusion zone with a combination of warning signs and physical barriers. The following figure shows the warning sign recommended by Agilent Technologies.


16


Figure 1 Warning sign

Magnetic Attraction Zone

NOTE At magnetic field strengths of approximately ten gauss or more, magnetic media can become wiped or damaged.

The “magnetic attraction zone” is established to prevent ferromagnetic objects from becoming projectiles; it is usually confined to the room that houses the magnet. The magnetic attraction zone threshold is usually at a magnetic field strength of 30 gauss.

Occupational exposure to magnetic fields

WARNING Do not allow ferromagnetic objects inside the Magnetic Attraction Zone.

Consult national and state enforcement and advisory bodies to ensure that any exposure limits are not infringed for (nonpatient) occupational workers.



Nature of Liquid Cryogens


A superconducting magnet uses two types of cryogens: liquid helium and liquid nitrogen. Helium is a naturally occurring, inert gas that becomes a liquid at approximately 4K. It is colorless, odorless, nonflammable, and nontoxic. In order to remain in a superconducting state, the magnet is immersed in liquid helium.

Nitrogen is a naturally occurring gas that becomes liquid at approximately 77K. It is also colorless, odorless, nonflammable, and nontoxic. It is used to cool the shield that surrounds the liquid helium reservoir.

During normal operation, liquid cryogens evaporate and require replenishment on a regular basis.

CAUTIONIt

Cryogens are delivered to the site in Dewars; these Dewars, including any carriers, must be nonmagnetic.



Hazards Presented by Cryogens

18

Helium and nitrogen in both their liquid and gaseous forms, present the following hazards:

• A large quantity of gas released in an area that is not well ventilated can cause asphyxiation.

• Liquids or cold gases can cause cryogenic burns.

• The filling procedure produces an oxygen- rich liquid, which is a fire hazard when it drops on a combustible material.

The extremely low temperature of the liquids and their cold vapors can cause severe frostbite, or a cryogenic burn. These low temperatures are mainly a danger during the filling process, when the fill line and other equipment freezes.

WARNING Touching the fill line or any other piece of equipment during a transfer can freeze the skin or cause it to stick to the surface of the equipment.

To prevent cryogenic burns, wear safety footwear, protective gloves, and a face shield. Long- sleeved clothing and long trousers or pants are also recommended.

During the filling process, atmospheric air condenses on the fill line or pipes, leaving an oxygen- rich liquid, or even liquid oxygen. If this drips onto a combustible material, like oil or grease, it can cause a fire.

WARNING Liquid oxygen can spontaneously ignite upon contact with oils or greases.

For these reasons, note the following recommendations:

• Exclude all sources of ignition from magnet rooms.

• Keep all tools and equipment used for transferring cryogenic liquids clean and free from oils and grease.

• Exclude all sources of ignition from the magnet room, which is also designated as a No Smoking zone.




WARNING Helium or nitrogen gas released in an area that is not well ventilated can displace air and reduce the oxygen content to an unsafe level, leading to asphyxiation.

Also note that, when cold, gaseous helium remains lighter than air, but gaseous nitrogen is heavier than air. The greatest risk of asphyxiation is during commissioning of the magnet. However, after the magnet is in service, a risk of asphyxiation can still occur during a “quench”.

A “quench” occurs when the magnet loses its superconductivity, and warms the liquid helium, causing it to turn to gas. This large amount of gas escapes through the magnet venting. The following section describes the safety recommendations that prevent the possibility of asphyxiation after a magnet quench.



Siting Requirements

Vents or quench ducts

20

In order to reduce the risk of asphyxiation in the event of a quench, vent the helium exhaust from the magnet to the outside of the building. Make sure the ducting to the outside of the building is of large enough diameter to avoid excessive pressure build- up due to the flow impedance of the duct. (This exhaust ducting is often referred to as a “quench duct”.) Only allow service personnel to have access to the exit end of the quench duct. In addition, protect the exit opening from the ingress of rain, snow, or any debris which can block the system. Inspect the quench duct exit periodically to ensure that the presence of debris does not restrict the gas flow.

It is also essential to ensure that any gas which vents from the quench duct cannot be drawn into any air conditioning or ventilation system intakes. Carefully locate the exit of the duct to prevent this situation from happening in all atmospheric conditions and winds.

Although “quenches” are short- lived and infrequent phenomena. However, as quench gases are liberated, the temperature of the quench duct can become low enough to cause cold burns on unprotected skin. This cold can also damage electrical wiring or other services routed close enough to touch the quench duct. (Do not route water pipes near quench ducts.) Make sure that quench ducts are protected with suitable proprietary thermal insulation, such as fiberglass cladding or the equivalent. Make sure that the thermal insulation is:

• Fire resistant (due to the possibility of condensation of liquid oxygen)

• At least 50 mm thick

• Resistant to deterioration upon contact with water (Frost formed on the pipe within the thermal insulation eventually thaws.)

If a quench duct fails during a quench, gas can release rapidly into the magnet room, causing the pressure to rise (and create an asphyxiation hazard there). This pressure rise can prevent an exit through inward- opening doors along escape routes. For safety, make sure that exit doors always open outwards, away from the magnet.

Provide a secondary escape route for large volumes of




quench gases by installing a passive vent opening directly from the magnet room to the outside. Make sure that this opening has, as a minimum, the same cross- sectional area as a quench duct. An opening measuring 400mm x 400mm is normally sufficient. To ensure that this passive vent is fail- safe, do not include active control for the vent opening; do not use fans or mechanical shutters.

Adequate ventilation during magnet installation

During the installation and cooling of superconducting magnets, large volumes of nitrogen or helium gases are sometimes generated. Although these gases are inert, if generated in large enough quantities, they can create dangerous circumstances if they displace the oxygen in the room. The following table provides examples:

Table 1 Examples of gas generation

Magnet Type

Quantity of liberated N2

gas during precool

Time taken to liberate N2 gas during precool

Quantity of liberated He gas during filling

Time taken to evolve He gas during filling

Quantity of He gas liberated during a “quench”

Time to liberate He gas during a “quench”

800/89 3400 m3 40 hours 1750 m3 14 hours 800 m3 1 min

900/52 13600 m3 160 hours 7000 m3 56 hours 315 m3 1.5 min

4T940 5400 m3 48 hours 5400 m3 72 hours 900 m3 10 min

Oxygen monitor

WARNING Adequate means of transporting evolved gases from the magnet out of the magnet room and also good ventilation of the magnet room is essential.

NOTE An oxygen monitor is recommended for the magnet room. See the Site Planning Guide for recommendations. Make sure the audio/visual alarm connected to an oxygen monitor is visible/audible outside the magnet room as well as inside it.

The oxygen monitor sounds an alarm when the oxygen level in the room rises above or falls below a safe level. This alarm happens if the ventilation system malfunctions, either during a quench or during a normal boil- off, and a large


22


amount of helium gas is released into the room.

Routine maintenance involving transfer of cryogens

Advice

WARNING For safety reasons, allow only personnel with formal maintenance training to perform routine maintenance tasks involving transfer of cryogenic liquids.

If you have any queries concerning your siting requirement, advice can be obtained from the Installation Manager at Agilent Technologies.



Electrical Safety


Always observe the following precautions and safe practices:

WARNING Electric shock hazard. Isolate or disconnect equipment from mains supply before opening this unit for any reason.

WARNING For continued protection against risk of fire or electric shock, always replace fuses with the same type, rating, and UL listing.

CAUTION Magnets power supplies contain internal protection fuses, follow the guidelines in the trouble-shooting section of the magnet manual before replacement of these devices.

CAUTION Your magnet power supply has been preset to a voltage range suitable for the national supply of your country. If any fuses require replacement, always use the correct type and rating.



Safe Access When Working at Height

24

Safe access to the top of magnets is important for routine topping up of cryogens; the frequency of doing so varies from magnet to magnet, but can be needed as often as weekly. Safe access to the top of magnets is also essential for installation work. Normal ladders and stepladders are not best suited to this task: They often fail to offer a secure platform when working on top of magnets and performing tasks that require the use of both hands.

Select and purchase suitable access equipment before the arrival of the magnet. Make sure that all equipment is nonferrous and immune to magnetic attraction. To aid in choosing the height and size of access equipment in advance of the magnet arrival, refer to the magnet System Interface Drawing that is sent in advance to all customers.



Considerations for the Outbreak of Fire


Specific precautions regarding fire safety vary depending on legislation and regulations in the country where the magnet is installed. The considerations discussed in the following sections are intended to help customers review their site fire precautions following the installation of a superconducting magnet. These considerations are advisory in nature.

There are two types of fire that can affect a magnet room – small fires and large fires. In this document “small fires” are defined as fires of a size that personnel can choose to fight with a first aid fire extinguisher. “Large fires” are defined here as major fires that only professional fire fighters are qualified to extinguish.

Small fires. Most premises already have fire and emergency procedures in place, in accordance with current safety legislation. Make sure any fire extinguisher provided in a magnet room, or taken into a magnet room in response to a fire, is of nonferromagnetic construction. Otherwise, it can become attracted to the magnet, causing personal injury, and becoming useless for fire fighting purposes.

Large fires. Most premises already have fire and emergency procedures in place, in accordance with current safety legislation. For maximum safety, invite the Fire Department (or Fire Brigade) for a liaison visit to inspect the building layout and the hazards associated with superconducting magnets. It is important for the Fire Department (or Brigade) to understand – before attending a major fire at a magnet lab – the hazards in addition to flames and smoke that these installations represent. The hazards to discuss with professional fire fighters include the following:

Magnetic attraction of ferrous equipment. Assuming the magnetic field warning signs are still intact when fire fighters, most firemen do not understand the strength of magnetic attraction that superconducting magnets generate. These magnetic fields can attract firefighting equipment and endanger the firefighters themselves.

Quenches. Quench ducts can fail in a large fire or be broken by falling debris, liberating quench gases into the magnet room, creating a risk of asphyxiation for any fire fighters present. Magnet rooms with several vertical magnets,


26


which do not possess dedicated quench ducts, can be faced with more than one magnet quenching simultaneously, venting large quantities of nitrogen or helium gas into the magnet room. Because these gases are inert, with nitrogen comprising 80% of the air we breathe, as few as three breaths of 100% inert gas can cause asphyxiation. Magnet rooms of very large volumes can represent a lower risk than magnet rooms of small volumes. However, always advise fire fighters of the asphyxiation hazard, and suggest they wear breathing apparatus when fighting a fire in a magnet room.

Explosions. In a disaster scenario, magnets very close to or enveloped in flames get very hot, causing them to quench and rapidly release inert gases, possibly faster than their pipes and fittings normally permit. In the worse case, a magnet can become over pressurized and explode. If magnets become physically hot in a fire, Treat them in a similar way to hot compressed gas cylinders: hosed down and kept cool.

Fire Doors and Exits. Make sure fire doors and exits from magnet rooms open outwards. In a disaster scenario, if large quantities of gas are vented into the magnet room, the pressure in the room can rise, making inward- opening doors difficult to open. This situation can make access difficult for fire fighters, or potentially fatal for anyone still inside the magnet room.

WARNING Although large fires are unlikely, always evacuate all staff before a fire becomes fully established, following standard fire procedures or evacuation plans.



General Safety — Potential Hazards

Handling cryogens (liquid helium and liquid nitrogen)


Vacuum hazards

WARNING For safety reasons, allow only personnel with formal training to perform routine maintenance tasks involving the transfer of cryogenic liquids.

Wear safety goggles, loose fitting nonabsorbent gloves, long trousers, a long-sleeved shirt, and nonferrous safety footwear.

Ensure adequate ventilation and oxygen monitoring of the area consistent with the volume of cryogens being used. If the oxygen level in the room falls below 19.5%, do not allow personnel to enter the area without self-contained breathing apparatus or airline respirators.

Do not smoke. Ensure that other sources of ignition are not present. Liquid oxygen can condense on cold surfaces and cause a fire hazard.

Never measure the helium level by “dipping” or “thumping” the helium can; always use the integral level probes in order to gauge the volume of liquid remaining.

WARNING Keep cryostat exhaust ports free from blockages such as ice.

Ensure all safety devices (relief valves and drop-off plate) are maintained in working order.

Do NOT tamper with any vacuum seals or attempt to unscrew vacuum feed-through connections.



Magnetic field

28

WARNING Siting of the magnet must be consistent with local legislation on allowable levels of stray magnetic field.

Do not allow people with heart pacemakers or metallic body implants within the vicinity of the magnet (within the 5G (0.5 mT) line).

Keep gas cylinders away from the magnet (outside the 5G (0.5 mT) line).

Keep all other large ferromagnetic objects away from the magnet. Use steel tools near the magnet only with great care and when nonmagnetic alternatives are not available.

Due to the nature of shielded magnets, there are very high field gradients close to the magnet. These fields are particularly high at the ends of the bore tube (for example, directly underneath and on top of vertical magnets, and at each end of horizontal magnets).

In the rare event of a magnet quench, it is possible for the magnetic field to bloom momentarily beyond its normal limit, attracting ferromagnetic objects towards the magnet. For this reason, do not place or store ferromagnetic objects within 1 meter of the cryostat.

Air quality

CAUTION Keep all forms of magnetic storage media outside the 10G (1 mT) line, including credit cards, computer hard disks, and floppy disks. Mechanical watches are also at risk.

WARNING Maintain adequate ventilation of the room in which the system is located.

See “Handling cryogens (liquid helium and liquid nitrogen) ” on page 27.

Oil mist from rotary vane vacuum pumps is a potential health hazard: vent the exhaust from pumps to the outdoors. Make sure any flexible hoses used for this purpose are kink-resistant and have a push-on engagement with the exhaust port of the vacuum pump. (Do not clamp hoses onto pumps.)



System mechanical stability


WARNING The antivibration legs supplied with the system MUST be leveled and bolted to the floor using the relevant holes in the base fixing plate. Perform this operation at the beginning of the magnet installation, before the magnet is energized.

Do not stand on the legs hoods at any time, to avoid affecting the stability of the system. Protective leg hood covers are fitted to prevent this situation from happening.


30




3Maintenance

Commissioning and Decommissioning the Magnet 32

Cryostat Maintenance 35

Cryogenic Fills 38

Parts List and Order Form 50


3 Maintenance

Commissioning and Decommissioning the Magnet

General safety note

32

For reasons of safety and to avoid damage to the internal fixtures in the cryostat, allow only skilled and suitably trained personnel to remove the system from the crate or detransit the magnet. Do not allow untrained personnel to attempt these tasks.

Storing transit fixtures

Once the system has been detransited, safely store the transit fixtures for future use. If the magnet is moved, these fixtures are required to prevent damage during transportation. Transit bungs are individually machined to fit each system and are not easily replaced if lost. See the following table for a list of all of these transit features. Space is provided in this table to record the storage location of each item for future reference.

Table 2 Transit features

Transit feature Part number Quantity Storage location

Transit bung DNC119812 3

Blanking plate DNC318628 1

O-ring P171126030 3

Screws and washers - -

Decommissioning of the magnet

Only allow suitably trained personnel to move or ship the magnet. If all the transits are not correctly fitted on the system, or if it is packed or shipped incorrectly, the system can be damaged. Contact Agilent Technologies for information about services for decommissioning and recommissioning magnets.

Energization direction

All Agilent Technologies magnets are energized in a standard direction as defined in this section, unless otherwise requested by the customer at the time of ordering.

The magnet is energized such that the North is at the top of


Maintenance 3


the magnet, and the South is at the bottom. The following procedure describes the method for determining the energization direction.

1 Align the compass to geographic north outside of the building, away from all magnetizable structures. Note which end of the needle points to geographic north. (Geographic north pole coincides with magnetic south pole.) In the following steps, this end of the needle is referred to as the “N end of the needle”.

2 Approach the ends of the magnet with the compass, continuously observing the needle. Keep the compass away from the magnetized elements, because they can demagnetize the compass needle.

3 Proceed as described above. The “N end of the needle” must point to the bottom of the magnet (pointing up the bore tube from the floor). This is the S end of the magnet. The reverse is checked at the top of the magnet (the “S end of the needle” must point down towards the bore tube from the top of the magnet, indicating that this is the N end of the magnet).

4 Repeat by aligning the compass to geographic north outside the building, away from all magnetizable structures. Ensure that the same end, the “N end of the needle”, points to the geographic north as before. This confirms that the compass was not demagnetized, and the measurement was successful.


34

3 Maintenance

Figure 2 Magnet orientation


Maintenance 3

Cryostat Maintenance

General maintenance


Regular maintenance tasks are essential for the efficient and reliable operation of this system. These tasks generally include checking cryogens, making sure that the system is leak- tight, and checking that none of the parts are worn or damaged. A routine maintenance schedule is recommended.

Daily

• Check flow- rates and note cryogen levels to see whether refills are required. If a manostat is not fitted to the system, flow rates depend on atmospheric pressure changes. Average flow rate is achieved over longer periods of time (for example, one week).

Weekly

• Check that all safety valves are free and are not iced- up.

• Check that all seals are air- tight, especially after a helium top- up.

• Check that the cryogen levels in the log are consistent (dropping regularly). If ice develops on the helium probe, a false reading can occur, and the level will cease to drop. If this is suspected, contact Agilent Technologies for advice.

Monthly and annually (for systems with fitted quench ducting)

• Check monthly that quench ducting (where fitted) remains unobstructed.

• Check at least annually that the burst disk is intact. Replace if necessary.

During/after every nitrogen fill

• Check the o- rings on the accessories fitted to the nitrogen turrets for wear and tear. If they become excessively worn or broken, replace them.

During/after every helium fill

• Check the o- rings on the bung and baffle assembly for wear and tear. If any sign of wear is seen, replace the o- ring.


36

3 Maintenance

• Check the condition of the baffles. If they become torn or cannot be straightened, then consider a replacement set.

• Check that the nitrogen vent is clear and is not iced- up.

• Check that the cryogen monitor was reset to the minimum sample rate (“normal”).

• Check that the siphon entry fitting is tight. (Wait for the ice to melt before checking.)

• Check that all seals are correctly made and are leak- tight. (Check that the o- ring and carrier between the manifold and nonreturn valve was correctly tightened with the clamp, and that the bung and baffles were correctly fitted with compression seals.) The correct compression seal arrangement is shown in the following figure.

Figure 3 Compression seal arrangement

Cryogen and service log

It is good practice to keep a log of cryogen usage and maintenance. An increase in cryogen consumption over time can indicate that the vacuum space needs to be repumped. A reduction in boil- off can indicate a leak or blockage. In addition, it is useful to calculate the helium transfer efficiency during a helium fill. Calculate the efficiency by comparing the volume of helium used from the Dewar, to the volume increase in the magnet helium can (75% to 85% is usual for a 2m span siphon). A degradation in helium transfer efficiency can indicate poor vacuum in the transfer siphon, or a damaged siphon.

A suggested layout for a cryogen and service log is shown in the following table:


Maintenance 3


Table 3 Cryogen and service log example

Date Helium Nitrogen Notes/Service details

Level probe (%)

Quantity used for refill Level probe (%)

Quantity used for refill

3 Nov YY 27 - 20 -

1 Dec YY 22 - 20 -

3 Jan YY 18 - 10 -

3 Feb YY 13 - 10 -

5 Mar YY 9 - 10 -

3 Apr YY 99 ~60 liters F ~90 liters Helium and Nitrogen top-up

Servicing

If you have any concerns about your system, contact Agilent Technologies for technical advice or to arrange a service visit. A list of contacts is provided at the beginning of this manual.

In order to avoid any difficulties and potential safety issues, use only Agilent Technologies approved parts on the system.


3 Maintenance

Cryogenic Fills

Safety during cryogen fills

38

WARNING For safety reasons, only allow formally trained personnel to perform cryogenic top-ups.

How to perform a routine LN2 fill

WARNING Wear safety goggles and loose fitting nonabsorbent gloves.

Ensure adequate ventilation and oxygen monitoring of the area consistent with the volume of cryogens being used. If the oxygen level in the room falls below 19.5%, do not let personnel enter the area without self contained breathing apparatus or air line respirators.

Do not smoke. Liquid oxygen can condense on cold surfaces and cause a fire hazard.

Never measure the helium level in the magnet cryostat by “dipping” or “thumping” the helium can.

WARNING Do not let the pressure in the nitrogen can exceed 5 psi. Ensure that the transport vessel has suitable pressure control.

The procedure given in this section assumes that there is some liquid nitrogen left in the nitrogen can. Cooling and filling an empty nitrogen can requires additional precautions. Contact Agilent Technologies if you suspect that the liquid nitrogen has run out.

The initial precool of the magnet helium can and nitrogen can is a skilled task. Allow only suitably qualified personnel to perform this task.

CAUTION It is important to stop the transfer once LN2 is seen to issue from the nitrogen can. If the system is left unattended, it is possible to freeze the OVC o-rings and cause a catastrophic loss of vacuum.


Maintenance 3


Make sure that the liquid nitrogen reservoir is refilled regularly and liquid nitrogen remains in the reservoir at all times. Refer to the Nitrogen Probe Calibration Chart for information on when to refill the nitrogen can, typical refill volumes, and minimum nitrogen hold times. See “Nitrogen Probe Calibration Chart — 400/54 Premium Shielded ” on page 56.

To refill the reservoir, the nitrogen fill adaptor and the nitrogen transfer line (2.5m provided as standard) are required, as well as a nonmagnetic nitrogen storage Dewar of suitable capacity. If the nitrogen Dewar is not of the self- pressurizing type, then a regulated nonmagnetic cylinder of helium or nitrogen gas is also needed.

To improve transfer efficiency, fit insulation to the transfer line. Simple, cheap, easily available, and replaceable expanded foam pipe lagging works well. Trials showed that

Armaflex Tuffcoat® insulation (20mm internal diameter, and 13mm insulation thickness), although slightly more expensive, was the most effective at improving nitrogen transfer efficiency. Use a suitable waterproof tape to preserve the integrity of the insulation, and to prevent air/water ingress into the lagging at the joints and the ends. All insulation freezes during the nitrogen transfer, and if moved when cold, it cracks. Repeated freeze/thawing also degrades the insulation. Allow the insulation to thaw before removing, and replace as necessary.

The top- up procedure is simple.

1 Provide two free turrets for the fill by removing the heat sinks and/or the nitrogen safety valve (small silver- colored valve) from the turrets.

2 Connect the liquid outlet of the storage Dewar to one of these ports via the transfer line with the nitrogen fill adapter connected.

3 Connect a length of reinforced plastic tube (or similar) to the other port, which will be used to exhaust. Position the top of the tube to direct the exhausting nitrogen away from the cryostat, personnel and sensitive equipment.

4 Liquid nitrogen is transferred using a backpressure in the storage Dewar of about 6 psig. Continue the transfer until liquid starts to overflow from the free port of the system nitrogen reservoir; this transfer takes about 30 minutes on most systems.


40

3 Maintenance

5 After the fill, check that the o- rings are in good condition and return the heat sinks/valves to the turrets.

6 Tighten the grub screw on the safety valve (if present).

7 Finally, check that the digital nitrogen monitor is reading full. If not, follow the simple instructions for recalibrating the nitrogen probe, outlined in the cryogen monitor manuals section of this manual.

How to perform a standard helium fill (top-up)

The calibration charts and minimum levels for the helium probes are given in Chapter 4, “Reference”. A separate Helium Level Chart was also provided for your reference to locate near the magnet.

This system has two helium turrets, one with 10- pin seals fitted, the other with none. Fill from the side without the 10- pin seals (recommended). However, if logistically difficult, you can perform top- ups from the other side, provided sufficient care is taken not to damage the electrical wires in the neck.

Figure 4 Recommended turret for helium fills

For the helium top- up, the helium siphon, phase separator, and the helium fill adapter (all provided) are required, as well as a nonmagnetic helium storage Dewar of appropriate capacity.

Follow these instructions carefully to ensure that the magnet is topped up quickly, cleanly and efficiently. Following these instructions minimizes any exposure of the helium can to air, avoids damage to connectors and baffles, helps maintain

RecommendedTurret


Maintenance 3


the original helium hold- time, and keeps the helium can clean and free of ice. It is important that the helium can remains leak tight at all times, so the compression seals must be fitted correctly as shown.

Figure 5 Compression seal arrangement

1 Determine the amount of liquid helium required to top- up the helium can. The volume is determined from the helium level chart provided. Arrange to have enough liquid helium in a NONMAGNETIC storage Dewar available to fill the helium can entirely, plus transfer losses (normally transfers are 75% to 85% efficient). The liquid level in the helium transfer Dewar (NOT the magnet) is determined with a “dipstick” or “thumper- tube”. This part is only included with selected products, however they are available for purchase from Agilent Technologies.

WARNING Make sure all the nitrogen ports are well sealed before starting to helium fill. The liquid nitrogen can become supercooled due to the thermal linking within the cryostat. This results in zero boil off, which can allow air to cryopump into the nitrogen can, forming air-ice and blocking the exhaust ports, and creating a serious safety hazard.


42

3 Maintenance

Figure 6 Location of nitrogen ports

2 Check that all seals on the helium manifold are correctly fitted and tight before starting.

Figure 7 Locations of helium manifold seals

3 Set the cryogen monitor for the helium to read on “Fill” mode. (See monitor manual for instructions.)


Maintenance 3


4 Fit the adapter and fittings to the siphon in advance. Push the knurled compression nut, the o- ring, and the special fill adapter (part number AUC330649), in this order, onto the leg of the siphon, which will go into the cryostat. Push them all of the way to the top of the siphon leg (the junction with the right- angled bend).

Figure 8 Fitting of adapter and fittings to the siphon

5 Fit the phase separator or “deflector tip” (part number DTU400032) to the bottom of the siphon leg to go into the helium can. If necessary, fit the siphon extension piece to the siphon leg that will be inserted into the Dewar.

Figure 9 Phase separator connection and siphon extension fitting

6 Loosen the nut on the top hat assembly on the magnet, but do not remove.


44

3 Maintenance

7 Precool the siphon.

8 Insert the transfer line into the transfer Dewar top seal and then open the top valve.

9 Insert the transfer siphon into the liquid in the Dewar, which causes the liquid to boil and the pressure to rise. As the siphon cools, the vapor becomes denser and more opaque, and eventually the transition is made from vapor to liquid. This process usually takes a couple of minutes. The liquid vaporizes immediately on contact with air.

If during this process, the transfer line develops frost or is cold to touch, then the transfer siphon may have insufficient vacuum or may be damaged. If insufficient vacuum is suspected, then stop the helium fill until the problem with the transfer siphon is resolved. If there is insufficient vacuum in the transfer siphon, then pump it down using a vacuum pump connected to the siphon, using a siphon pump out tool (part number P222000008, available from Agilent Technologies). If the siphon is damaged and has a touch, then a replacement is probably required.

Figure 10 Top seal of the Dewar


Maintenance 3


Figure 11 Inserting transfer line into the top seal of the Dewar

CAUTION Failure to precool the siphon can quench the magnet as the warm siphon is inserted into the helium can. If the siphon is suspected to be soft or have a touch, do not insert into the helium can, as it can also cause the magnet to quench.

10 After the siphon precool is complete and helium liquid is issuing from the phase separator, remove the helium nonreturn valve from the manifold.

11 Remove the fill side bung and baffle assembly, and insert the siphon and adapter assembly, screwing down the nut to ensure a good compression seal.


46

3 Maintenance

Figure 12 Remove helium nonreturn valve and fill side bung and baffle assembly

Figure 13 Insert siphon and adapter assembly

12 Gently push the siphon into the helium can until you feel it touch a barrier (connector). Then withdraw it about 50 mm (~2 inches).

13 Continually monitor the helium level to ensure that the fill is progressing well.


Maintenance 3


Figure 14 Side view of the helium siphon inserted into both magnet and transfer Dewar for a helium transfer

14 When full, take the pressure off the transfer Dewar to stop the transfer.

15 Refit the helium nonreturn valve to the manifold.

Figure 15 Helium siphon in the transfer Dewar showing it lifted from the base of the Dewar

16 Inspect the bung and baffle assembly for damage and ensure that it is warm and dry (no water droplets) before refitting.


48

3 Maintenance

17 Remove the siphon and adapter, and replace the bung and baffle assembly, tightening the nut to form a good compression seal. If the baffles appear to be damaged such that they are broken or cannot be restraightened, then consider a replacement set. You can order a replacement set using the parts order form in “Parts List and Order Form” on page 50. The use of damaged baffles (or omitting the baffles completely) can result in reduced performance of the system.

Figure 16 Replacing bung and baffle assembly

18 Remember to change the helium probe reading back to “normal” again.

19 Once the turret and top- hat assembly is warmed up after the fill, recheck the o- ring seal and retighten if necessary.


Maintenance 3


Figure 17 Recheck o-ring seal

CAUTION Because of the excellent cryogenic efficiency of the cryostat in normal operation, it is common for the helium and/or nitrogen boil-off to fall to zero immediately after a transfer or after magnet energization. There is then a serious risk of air entering the helium and/or nitrogen reservoir. However, if the procedures in this guide are followed correctly, you can avoid any associated problems.


3 Maintenance

Parts List and Order Form

50

The following lists give part numbers for replacement parts for use with this magnet. You can photocopy the forms and then fax or send them to the Sales Department at Agilent Technologies for quotation. The parts listed are the general consumables and ancillaries required for normal operation. Contact the service department for any other parts required.

Remember to copy both the order form and the contact details, and send them to the Sales Department.

For addresses, fax numbers, and telephone numbers, see “Contact Information” on page 9.


Maintenance 3

Parts Quotation Request


Part Description Quantity required

P171037624 M 37.6ID X 2.4 SO-ring used on nitrogen heat sink assemblyO-ring used on nitrogen fill adapter ANC327909

P170OR2050 BS 014 .489ID x.070 SO-ring used on nitrogen safety valve AUC500209

P170OR3050 BS 112 .487ID X.103 SO-ring used on the nitrogen probeSmall O-ring of the helium fill adapter AUC330649 and siphon

P170OR3100 BS 120 .987ID X .103SO-ring used on the bung and baffle assemblyLarge O-ring of the helium fill adapter AUC330649

P171042114 Silicone o-ring, circle sealManifold quench valve seal

KC25AV Aluminum NW25 centering ring (with Viton O-ring fitted)Manifold O-ring seals

DUC400015 Seal nut for P170OR3050

DTU400032 Phase separator

DUC400007 Seal nut 25.4mm for P170OR3100

KQ25AW Black NW25 wing-nut clamp for KC25AV

ANC300397 Single nitrogen port ice preventor (heatsink) with non-return valve fitted

ANC345286 Nitrogen port double heatsink and gas flow gauge assembly

AHC340869 Nitrogen turret filling cap assembly

ATU142515 2.5m Nitrogen transfer line – flare fitting

AUC500209 Nitrogen safety valve (small silver valve)

AUC330649 Helium fill adapter (seal body assembly)

AUC500207 Helium non-return valve

P222000072 Helium transfer siphon, 2m span (and extension tube)

P222000008 Helium siphon pump-out tool

ANC331172 Bung and baffle assembly, for 400/54/ASP, 400/54/AR, 400/89/ASP, 500/54/ASP, 600/54/ASC, 500/54/AR, 600/54/AR

ANC330617 Bung and baffle assembly, for 500/89/AS


3 Maintenance

C0557001 E5025 Cable, PSU 2V 15W, short

C0608040 E5025 interface connection cable

AZZ346425 Helium dipstick - for use in helium storage dewar only

ATU327906 5m Nitrogen transfer line – flare fitting, optional longer length

P200000041 3” Burst disk, 5psi, for optional quench manifold

52 400/54 Premium Shielded NMR Magnet System Product Overview

Maintenance 3

Information Sheet


Please fax this information sheet with your order to the Sales Department at Agilent Technologies at the Fax number or address listed in “Contact Information” on page 9.

Magnet Serial Number(see serial number plate on cryostat, or system manual)

Name:

Site:

Contact Address:

Telephone number:

Fax number:

Email address:


54

3 Maintenance



4Reference

Nitrogen Probe Calibration Chart — 400/54 Premium Shielded 56

Helium Probe Calibration Chart — 400/54 Premium Shielded 57

Temperature Sensors — 400/54/ASP 59

Wiring Diagram 60


4 Reference

Nitrogen Probe Calibration Chart — 400/54 Premium Shielded

56

The E5025 indicates a refill in the 5% range (with a max. of 6.0 liters remaining).

The nitrogen remaining in the can at this time will last a minimum of 39 hours.

The refill volume will be in the range 56.5 to 62.5 liters.

Table 4 Nitrogen probe calibration chart

Nitrogen probe digital readout (%)

Height range on probe for digital reading (mm)

Volume range remaining (l)

min max min. max.

0 0 15 0.0 3.0

5 15 45 3.0 6.0

10 45 74 6.0 9.1

15 74 104 9.1 12.1

20 104 134 12.1 15.2

25 134 163 15.2 18.2

30 163 193 18.2 21.3

35 193 223 21.3 24.3

40 223 252 24.3 27.4

45 252 282 27.4 30.4

50 282 312 30.4 33.5

55 312 342 33.5 36.5

60 342 371 36.5 39.6

65 371 401 39.6 42.6

70 401 431 42.6 45.7

75 431 460 45.7 45.7

80 460 490 45.7 51.8

85 490 520 51.8 54.8

90 520 549 54.8 57.9

95 549 579 57.9 60.9

F 579 594 60.9 62.5


Reference 4

Helium Probe Calibration Chart — 400/54 Premium Shielded


Table 5 Helium probe calibration chart — 400/54 premium shielded

Probe reading Helium level in cryostat

(%) (mm) (mm) (liters remaining)

100 455 537 123.8

100 455 532 122.4

95 433 515 117.7

90 412 494 111.6

85 390 472 105.5

80 368 450 100.3

77 353 435 96.1 Min level for energizing/shimming

75 346 428 94.2

70 325 407 88.1

65 303 385 83.3

60 281 363 78.4

55 259 341 73.6

50 238 320 68.7

45 216 298 63.9

40 194 276 59.0

35 172 254 54.2

30 151 233 49.4

25 129 211 44.5

20 107 189 39.7

10 64 146 30.0

5 42 124 25.1

0 20 102 20.3 Min Refill Level

-20 16 98 19.4

-40 12 94 18.5

-60 8 90 17.6

-80 4 86 16.7

-100 0 82 15.8

-100 0 0 0.0


58

4 Reference

There is a ‘dead volume’ between the top of the helium can and the top of the helium level probe that is not shown by the helium level meter.


Reference 4

Temperature Sensors — 400/54/ASP


Temperature sensors have been fitted to this system for use on installation and for diagnostic purposes. Two sorts of temperature sensors are fitted, Platinum resistor thermometers and Allen Bradley temperature sensors. Platinum resistor thermometers (PT100) are useful for measuring temperatures between room temperature and 77K. Allen- Bradley temperature sensors are more accurate at lower temperatures (below 77K) to liquid helium temperatures.

Platinum resistor thermometers (PT100)

These sensors have a nominal resistance of 100 Ohms at 0°C (273K) which falls linearly to a typical resistance of 20 Ohms at 77K.

Allen-Bradley temperature sensors

Allen- Bradley temperature sensors are individually calibrated, and are specific to each system.

Location of temperature sensors

The temperature sensors fitted to this system are outlined below.

ensors
Table 6 Location of temperature s
Sensor type Location Access

Calibrated Allen Bradley

Gas-cooled shield ABDE 10-pin seal on side of cryostat

PT100 Magnet baseplate EFHJ 10-pin seal 2 on helium turret (blue nut)

Uncalibrated Allen Bradley

Magnet Baseplate KL 10-pin seal 1 on helium turret (black nut)


4 Reference

Wiring Diagram

10-pin seal pin designations, 400/54/ASP

60

Figure 18 Pin Arrangement in the 10-pin connectors on the magnet

Table 7 OVC 10-pin seal

Pin Function

A GCS AB270 I+

B GCS AB270 V+

C -

D GCS AB270 V-

E GCS AB270 I-

F -

H -

J -

K -

L -


Reference 4


Table 8 Blue 10-pin seal nut on helium turret (red wire)

Pin Function

A

B Main Switch Heater

C

D

E Baseplate PT100 V+

F Baseplate PT100 I+

H Baseplate PT100 V-

J Baseplate PT100 I-

K B0 Shim Switch Heater

L B0 Shim Switch Heater

Table 9 Black 10-pin seal nut on helium turret (black wire)

Pin Function

A Fixed Helium Probe V+

B Fixed Helium Probe I+

C Fixed Helium Probe V-

D Fixed Helium Probe I-

E Spare Helium Probe V+

F Spare Helium Probe I+

H Spare Helium Probe V-

J Spare Helium Probe I-

K Baseplate Allen Bradley

L Baseplate Allen Bradley


62

4 Reference

Figure 19 View directly down onto the current lead turret showing positions of the three 10-pin connectors

19-way shim socket pin designations – 400/54/ASP

Figure 20 Pin Arrangement in the 19-way connector on the shim lead


Reference 4


Table 10 19-way shim socket pin designations

Pin Function

A Z1 Switch Heater

B Z2 Switch Heater

C X Switch Heater

D Y Switch Heater

E ZX Switch Heater

F ZY Switch Heater

G XY Switch Heater

H X2-Y2 Switch Heater

J Switch Heater Common

K B0 Series Switch Heater

L Z3 Switch Heater

M Main Switch Heater

N B0 Switch Heater

P Magnet Volts +

R Magnet Volts -

S Shim Current Circuit -

T Shim Current Circuit -

U Shim Current Circuit +

V Shim Current Circuit +


64

4 Reference



5Agilent E5025 Cryogen Monitor

Safety 66

Compliance Notice 67

Overview 68

Description and Operating Principle 70

The Top-Level USER Menu 73

The Secondary Level SET-UP Menu 75

Cryogen Monitor User Interface 79

Errors and Alarms 85

Ethernet Communication 86



Safety

66

Refer to accompanying documents.

WARNING This equipment must be connected to an earthed mains supply. For continued protection against risk of fire or electric shock, replace fuses with the same type, rating and UL listing.

CAUTION This equipment is not suitable for use in areas with flammable mixtures.


Agilent E5025 Cryogen Monitor 5

Compliance Notice


Marking by the symbol indicates compliance of this device to the EMC (electromagnetic compatibility) and LV (low voltage) directives of the European Community. This unit is to be installed and operated as detailed. Any modification or maintenance procedure undertaken which is not approved by Agilent Technologies UK Ltd could nullify

the marking of this product and lead to prosecution. A 'Declaration Of Conformity' in accordance with the above directive has been made and is located at Agilent Technologies, Yarnton, Oxfordshire, UK.



Overview

68

The E5025 is a small, single case, low- cost instrument that can be used to measure liquid nitrogen and liquid helium levels, primarily for 400- 700 MHz Agilent NMR magnet systems.

The following figure shows a cross section of a typical vertical bore magnet system. The liquid helium and nitrogen cryogen levels are displayed in terms of the percentage of refill volume remaining:

• F (100%) = reservoir is full

• 0% = refill is required now

Figure 21 Helium and Nitrogen refill volumes

This instrument mounts on the nitrogen level probe on top of the magnet, shown in the following figure. Power is provided by a universal PSU. An interconnect cable carries




power from the PSU to the unit and also has a short cable branching out of each end. The branch at the E5025 end connects over to the Helium level probe. The PSU end branches into an Ethernet connector to use with a network.

Whenever a nitrogen or helium level measurement is performed, the result is stored in a circular buffer. This buffer can be downloaded from the unit over an Ethernet link.

Helium readings are automatically acquired every eight hours or once a day, and can also be manually acquired at any time. The unit also has a helium filling mode where measurements are performed every 30 seconds. This mode is useful for providing up- to- date level readings during helium top- ups, however it is not desirable during normal use, as the increased duty cycle of the probe heater will boil off additional helium cryogens.

Figure 22 Unit installed on top of the Nitrogen turret of a 400-MHz magnet



Description and Operating Principle

70

The E5025 is a single instrument mounted on top of the nitrogen probe which monitors the levels of both the liquid nitrogen and liquid helium cryogens inside the magnet cryostat.

This manual describes units

with software version 6 and

newer.

When the unit is first switched on, it displays an “E5025” start- up message followed by the software version number. It then scrolls through the helium and nitrogen level probes and states whether they are enabled or disabled. Finally it takes a reading of the cryogen levels and displays the result.

The cryogen display mode displays the level of both nitrogen and helium in% of remaining refill volume.

Figure 23 The E5025 front panel

The buttons on the front panel have the following functions:

+ Increments a value. From the cryogen level display, this button is used

to enter the ‘user’ menu (see “The Top- Level USER Menu” on page 73). It is also used to confirm the result or user choice of an action.

- Used to scroll down a menu or to decrement a value.

The nitrogen level is shown on the left side of the display and measures in 5% increments, with 100% full being displayed as “F”. Once the level reaches the 5% increment, the nitrogen display flashes to indicate a low level. The nitrogen probe is read approximately every 5 seconds.

The helium level is shown on the right side of the display. The monitor measures the immersed length of the probe and then converts it to a percentage reading, which is displayed.




• 100% corresponds to full• 0% means that the level has dropped to the refill level

for the magnet

The accuracy of helium level readings is approximately 2mm (better than 1%). Below the refill level, the display outputs a negative reading which moves to –100% as the level drops to the bottom of the helium level probe. If the level falls below the refill level (0%) then the helium display flashes to indicate a low level and that a fill is required.

The unit is preprogrammed to read the helium level probes every eight hours at the internal clock preset times of 01:00, 09:00 and 17:00. As a stand- alone unit, the internal clock is factory set to GMT timezone. If connected to a console (with the appropriate software), then the internal clock is changed to the time registering on the console.

Users of the E5025 have access to a number of set- up items via the front panel buttons. Two menu levels provide a top level “user” menu and a secondary level “set- up” menu. Each menu is traversable in the down direction only.

Note when pressing the buttons on the display:

• A finger on or off button delay of about 1/3 second is implemented, therefore do not press buttons too quickly.

• A flashing display indicates an error or alarm situation. There is a regular period, every five or so seconds, when the flashing is held off for a time of 3 seconds. If the display is in flash mode, use the three- second nonflashing period to press buttons.

• Buttons are scanned several times per second. However it is possible the press can be missed when the instrument is carrying out internal operations. In this situation, release the buttons and try again.

• All commands have an automatic time- out of approximately 30 seconds, after which the unit returns to the cryogen display mode. Any value chosen for adjustment but not “entered” is ignored and the original value remains. Likewise any action is abandoned.



Technical specification

Helium probes supported Dual, standard type, max length 1.25m with 121 /m wire.

Nitrogen probes supported • 400 to 800 MHz Agilent NMR magnets

User data display 8-digit red LED

User status display All status information is communicated via the 8-digit LED display.

User controls three push buttons: +, , and -

Configuration / calibration of Nitrogen and Helium probes

Can be performed via front panel. A portable computer with an Ethernet connection can also be used.

Default calibration For 400/54/ASP Premium Shielded magnet

Data logging • Cryogen levels are logged in the unit after every read operation, and can be downloaded to computer via RS-232 or Ethernet.

• Estimated endurance: nine months.

Level read interval • Nitrogen levels are refreshed every cycle (~5 secs) and recorded every eight hours (or manual reading) coincident with the helium readings.

• He level levels are recorded every 8 hours during normal operation and every 30 seconds during fill mode.

Nitrogen refill volume display resolution

• 0% to 100% in 5% steps.• 0% = bottom of refill volume • F = 100% or full • Display reading level flashes for levels ~ 5%

Helium refill volume display resolution

• 0% to 100% in 1% steps • 0% = bottom of refill volume • Display reading level flashes for levels ~ 0%

Absolute helium physical resolution (that is, resolution that the unit can measure)

< ±2mm

Head unit size 76mm wide, 44mm tall, 125mm long

Head unit mass Approx. 250g

Primary PSU size 50mm wide, 40mm tall, 95mm long

Power requirements • 15 Watts power consumption • Universal mains input (100-240V 50/60Hz)

Connector A Underside, central, TNC for connection to nitrogen level probe, and for unit mounting

Connector B Underside, far end, transverse, 15 D type, for power and helium level probe

Connector C RJ45, back panel, for Ethernet communication

72 400/54 Premium Shielded NMR Magnet System Product Overview


The Top-Level USER Menu


This top- level menu allows you to take manual readings of the helium level probes or to change to the “fill” mode to take frequent helium readings during helium filling.

• To get into the USER menu from the cryogen display mode, press .

• To scroll down the menu, press .

• To make a selection, press after a question.

• Scrolling down the menu eventually cycles back to the cryogen display mode.

Manually reading the helium probes

From the cryogen display mode, press the button once. The unit displays “rEAd ?” Press again to select this option.

The unit performs helium readings of the probes that are switched on, displaying “rEAd P1” and “rEAd P2” as appropriate while it is carrying out the operation. Each reading takes approximately 15 seconds. Once the operation is completed, the unit reverts to the cryogen display mode with the updated readings. If both probes are on, then P1 is displayed as default (unless set otherwise from the set- up menu). If only one probe is switched on, then the selected probe is displayed.

Changing to the Helium Fill mode

From the cryogen display mode, press the button once. The unit displays “rEAd ?” Press once to scroll down the menu to display “FiLL ?”. Press to select this option. To confirm, the unit displays “Fill On” for a few seconds, and performs helium readings before reverting to the cryogen display mode. In this mode, the helium level probes are read every 60 seconds. The cryogen display mode now indicates an “F” after the Helium reading to denote that it is in Fill mode.

While the unit is set to Helium Fill mode, the helium consumption increases. It is preferable to revert to normal readings as soon as the fill is complete. To revert to normal helium readings (every eight hours), follow the described procedure again. The unit displays “Fill oFF” for a few seconds before reverting to the cryogen display mode.


74


If the unit is inadvertently left in Helium Fill mode, it automatically reverts to the normal helium probe readings after 90 minutes.

It is not necessary to turn on helium fill mode when performing a nitrogen top- up, since the nitrogen display is updated with a new nitrogen level measurement approximately every 5 seconds during normal operation.

Checking both Helium probe readings

If both helium probes are ON then the option “HELiU ?” is available by pressing twice to scroll down the menu. Selecting this option makes the unit display the most recent helium level measurement for each probe consecutively, P1 first followed by P2. The display then reverts to the default display of P1 (unless set otherwise from the Set- up menu).



The Secondary Level SET-UP Menu


This secondary level menu changes the parameters and set- up of the unit. These values are preset at the factory for the magnet type before shipment.

Entering the secondary level SET-UP menu

CAUTION During normal operation, there is no need to access the secondary level SET-UP menu other than to perform a recalibration of the nitrogen probe.

Incorrect use of the SET-UP menu can damage the unit.

1 From the cryogen display mode, press the and buttons simultaneously. The unit displays “SEt UP ?”

2 Press and a confirmation “SurE ?” is displayed.

3 Press to enter the menu.

4 To scroll down the menu, press the button.

Scrolling down through the menu eventually returns to the cryogen display mode.

Functions available on the secondary level SET-UP menu

This section describes each item in the secondary level SET- UP menu in the order they appear on the display.

To change a value for any function:

1 Press to select the function when it appears on the display.

2 When the current value is displayed, press the and buttons as necessary to select the desired value.

3 Press to save the new value and exit to the Cryogen Display mode.

4 You may be presented with a prompt to confirm the action before the unit returns to the cryogen display mode.

If the display is allowed to auto time- out back to the cryogen display mode (after approximately 15 seconds) without saving, then the value is unchanged and any actions are ignored.


76


P1SEC?

Sets the duration (in seconds) so that the helium probe heater is energized for performing a level reading (min. 3 secs, max. 20 secs). The unit assumes that both P1 and P2 probes are equivalent and changes the heater time for both probes.

P1Cur ?

The heater current (in mA) for both the helium probes (min. 85mA, max. 125mA).

rEFiLL ?

The refill level (in mm) on the probe, that is, the 0% position.

P1 LEn ?

The nominal active length (in mm) of both helium probes. Note that this value does not include the heater length

P1 rES ?

The resistivity of the probe wire (in Ohms/m).

P1 on ?

Enables the P1 helium probe.

P1 oFF ?

Disables the P1 level probe. It is useful to be able to deselect a probe if it is faulty and causes the unit to flash a warning on the display permanently. When selected, the monitor displays the P2 reading. If both probes are disabled, the unit displays “oFF”.

P2 on ?

Enables the P2 helium probe.

P2 oFF ?

Disables the P2 level probe. It is useful to be able to deselect a probe if it is faulty and causes the unit to flash a warning on the display permanently. When selected, the monitor displays the P1 reading. If both probes are disabled, the unit displays “oFF”.




diSP P1 ?

Selects P1 to be displayed in the cryogen display mode. This option is only available when both the probes are enabled.

diSP P2 ?

Selects P2 to be displayed in the cryogen display mode. This option is only available when both the probes are enabled.

n2 on ?

Enables the nitrogen level probe.

In order for the nitrogen to read correctly once enabled, perform a calibration while the nitrogen vessel is full (see CAL n2 ? below).

n2 oFF ?

Disables the nitrogen level probe. The nitrogen reading is displayed as “oFF”.

CAL n2 ?

Performs a calibration of the nitrogen probe. Make sure that the nitrogen vessel is FULL when the routine is run. Otherwise it will calibrate incorrectly. The unit displays “CAL n2 - ” during calibration, then returns to Cryogen Display mode.

FAC CAL?

Recalls the factory saved calibration values. It does not reset the P1 or P2 display settings.

The unit displays “rECAL - ” during calibration and confirms “donE” when completed, then returns to Cryogen Display mode.

iP 1 0 ?

Sets the IP address of the unit to: IP address [10.0.0.241], Gateway [10.0.0.1], Subnet mask [255.255.255.0].

iP 1 72 ?

Sets the IP address of the unit to: IP address [172.16.0.241], Gateway [172.16.0.1], Subnet mask [255.255.255.0].


78


Magnet profiles

The remaining commands are used to set the helium probe calibration parameters P1 SEC, P1Cur, rEFiLL, and P1Len to any of a number of preset magnet types, such as 489ASP ? for the Premium Shielded 400- MHz 89- mm magnet.

If you must reset the profile, refer to the System Section of the magnet manual for the correct profile name.



Cryogen Monitor User Interface


This section describes the user interface to the E5025 cryogen monitor hardware. This version of the Cryogen Monitor user interface software requires VnmrJ 3.0 or later.

Modes of operation

The Cryogen monitor software can be run in “server”, “writer”, or “reader” execution modes and can be started either from within VnmrJ or as a stand- alone Java process from a command shell.

Server execution mode

The “server” (or “master”) execution mode provides a direct communication link to the monitor hardware (via a TCP socket). The server process can either be run in the background or with a graphical user interface. It is responsible for periodically querying the Cryogen monitor hardware for cryogen levels and writing the results to a history file. This file can be used to construct plots and other data presentation features used by all application modes that support a user interface.

Nonserver execution modes

In nonserver modes, the user interface is chosen automatically to be either “writer” or “reader” depending on whether the current user has write access to files in the /vnmr directory (for example, is logged on as vnmr1).

In the “writer” interface, controls can be used to set preferences for features such as cryogen levels for notification states and the maximum number of days to retain history. The user interface also includes a button that can be used to launch a “server” process in the background, if one is not currently active.



Application start-up

80

You can open the Cryogen Monitor software interface in either of the ways described in the following section.

Running from VnmrJ

To open the cryogen interface from VnmrJ:

1 Configure the Cryogen Monitor to be Present using the System “config” window, as shown.

2 Select View Cryogens from the VnmrJ Tools menu to open the Cryogen Monitor software interface.

Starting from a command shell

To start the user interface application outside of VnmrJ:

1 Enter the following in a command shell:

> /vnmr/bin/cryomon [-vnmrj]

- vnmrj is an optional argument that causes the interface to adopt the same look- and- feel as when the interface is opened from VnmrJ. Otherwise, the currently selected system theme is used.

Reader-mode user interface

When the Cryogen Monitor application is opened in “reader” mode, the following main interface panel is shown:

Figure 24 Cryogen Monitor interface panel — reader mode

The information available for Nitrogen and Helium status is the same. It consists of a progress bar that shows the current level, a History button that displays a graph of the log file, and an Update button used to select between one of




three date- time events.

Progress bar

The progress bar displays the current level of the corresponding Cryogen (% of maximum level). The color of the indicator changes when the level falls within the range of one of three set- point values:

History button

When you press the Nitrogen or Helium History button, a graph of the level history for the associated Cryogen is displayed. See “N2 and He Level history plot windows” on page 82.

Update button

When you press the Update button, the software rereads the level history file and updates any open plots and date event values. Under normal operation, this reading is only done when the application starts up or every hour while the interface is open.

Date-Time events

This pull- down menu and associated text field can be used to display one of three cases:

Fill (green) The level where the Cryogen is scheduled to be refilled during normal maintenance.

Warn (yellow) Indicates that the level dropped below a threshold that is considered to be worthy of attention (but not necessarily critical).

Alert (red) Indicates that the level dropped below a level where there can be serious consequences (such as a magnet quench) unless immediate action is taken.

Last The date and time of the last level measurement in the log file.

First The date and time of the first- level measurement in the log file.


82


Fill The date and time where the level is predicted to drop to the normal maintenance “Fill” level. The fill date is estimated by using the current time and the slope from the last fill event in the history file.

N2 and He Level history plot windows

These plot windows are the same for N2 and He and are opened by pressing the History button in the corresponding control line in the main interface panel:

Figure 25 Helium level history plot

• The black trace displays the level history with solids points showing where an actual measurement was taken. Helium levels are measured at eight hour intervals. Nitrogen levels are measured every hour.

• The vertical (Y) axis shows percent capacity and the horizontal (X) axis shows time (and date).

• The three colored traces (fill, warn, and alert) show the corresponding levels and can be set independently for N2 and He from the “master” application interface.

• Resize the plot windows by dragging one of the four corners following a left mouse button click.

• To expand a region of the data (zoom in), draw a rectangle in a down right direction using a left mouse click- and- drag operation.

• To zoom out (expand) draw a rectangle in the reverse order (that is, draw a rectangle using an up- left motion).




• Pressing the Fit button in the plot window or the History button in the main interface panel sets the display to show all the data in the history file.

Writer-mode user interface

When the Writer cryomon user interface is first started, the software checks whether a server instance of the cryomon application is currently running in the background. If no server is running, you are prompted to start one. Answer Yes to start a new server instance.

Figure 26 Prompt to start cryogen monitor service

The main user interface panel in Writer- mode is similar to that of the Reader- mode interface. The only difference is the presence of an Options menu, which allows you to access the set of advanced feature controls described in the next section.

Figure 27 Cryogen Monitor interface panel — writer mode

Advanced Features

When you mark the Advanced check box item in the Options menu, an Advanced section is displayed in the master interface panel, as shown in the next figure:


84


Figure 28 Cryogen Monitor —advanced features

The advanced features are described in the following:

Level adjustment controls The values associated with the “fill”, “warn”, and “alert” levels can be set using the slider and associated pull down controls in the first line in the advanced features subpanel.

These settings are saved in a file called cryomon.prefs in the /vnmr/cryo/cryomon folder.

History controls The “MaxDays” field can be used to change the maximum number of days that the software saves level and status history. (The default value is 1000 days.) Clicking Clear causes the history file to be reset so that it contains only its last entry.

Server status The Server status button displays whether a server application is currently active in the background. This is displayed if such a process was running when the interface was first started from VnmrJ or if you answered, “yes” in the initial pop- up dialog. In these cases, the server status button is inactive (pressed in) and shows the text “running”. Otherwise, the button is active (not pressed) and displays the text “Start”.



Errors and Alarms


If the unit detects an error or a low cryogen level, the display flashes to indicate that attention is required.

The instrument has a measurement cycle period of 5 seconds, at which time it measures the level of liquid nitrogen and then rewrites the display. Helium level is read automatically three times daily, at 01:00 hrs, 09:00 hrs, 17:00 hrs. If the helium part of the display flashes a message “c”, then the monitor requires calibration. In the unlikely event that you see this message, contact Agilent for assistance.

Any command change takes effect at the end of the next 5- second cycle. Therefore, it can take up to 3 cycles (15 seconds) to accept a new menu value and remeasure. Then on the final cycle error, conditions are reassessed.

• Nitrogen errors or alarms cause the left side of the display to flash.

• Helium errors or alarms cause the right side of the display to flash.

• When the entire display flashes, there is a problem with both cryogens.

When the display is flashing an error, the display is periodically held steady for a few seconds, which allows you to more easily read the display and access the menus.

Using the menu system causes the flashing to stop. The flashing resumes when you exit the menu. If you alter a menu item value that brings the flashing to an end, there is a delay of at least 10 seconds before the instrument remeasures and refreshes the display flash status.

If the Helium display is flashing and a parameter was altered, you must manually perform a Helium read in the USER menu to force an update of the Helium environment.



Ethernet Communication

86

The E5025 has a built- in Ethernet port.

Ethernet

Service cable C0608040 includes an Ethernet cable which can be used to connect the E5025 unit to the VNMRS console.

Ethernet communication is primarily via Telnet (port 23) over TCP- IP protocol.

The E5025 also responds to ICMP “ping” requests.

The unit can be set to two different address profiles via the front panel:

Profile A Profile B

IP address 10.0.0.241 172.16.0.241

Gateway 10.0.0.1 172.16.0.1

Subnet mask 255.255.255.0 255.255.255.0



6Technical Specifications

System Description 88

The Superconducting Magnet 89

The Cryostat 92

Customer Interface Drawings 94

System Components 96



System Description

88

The 400/54/ASP magnet utilizes Agilent Premium Shielded magnet technology which features outstanding fringe field containment to minimize laboratory space requirements.

External field perturbations are efficiently attenuated. Pneumatic antivibration support legs are supplied as standard across the product line to allow siting in a wide range of environments.


Technical Specifications 6

The Superconducting Magnet

General description


The Agilent Premium Shielded configuration means that this magnet has all the excellent characteristics of a standard magnet but with a significantly reduced stray field. The magnet and screen are wound from multi- filamentary NbTi conductor. The windings are placed on precision- machined formers and then fully vacuum impregnated for robustness and long- term reliability.

The magnet is designed to exacting standards of homogeneity. Proprietary jointing techniques for NbTi materials ensure the best field stability. Inevitably, winding tolerances and small amounts of environmental influence distort the central field. Corrections for these distortions are made in the first instance by superconducting shim coils located on a former surrounding the main coil. Final corrections are made by room temperature correction coils placed in the bore of the system, supplied by the customer.

The magnet coils are fully protected from accidental damage due to a magnet quench by a passive resistor/diode network located within the helium reservoir.

The magnet is designed to conservative levels of stress and mechanical stability to ensure reliable and stable operation. In addition, the use of high quality superconducting wire ensures that a top quality magnet system is delivered.



Magnet specifications

90

Table 11 Magnet specifications

Magnet type Compensated self-screened solenoid

Central field 9.4 Tesla (400 MHz 1H)

Field stability Less than 0.02 ppm/hour drift (8 Hz/hour 1H)

Operating current 97.4 Amps (nominal)

Typical time to energise magnet to full field

Less than 160 min.

Stored Energy 0.18 MJ

Fringe field (5-Gauss line)* 0.55 m radially and 1.0 m axially

Superconducting shim coils

WARNING *In the event of a quench, it is possible for the magnetic field to momentarily bloom beyond this limit. For further details consult the Safety Considerations for the Installation and Operation of Magnet Systems document.

Table 12 Coil details

Shims provided Z0, Z1, Z2, Z3, X, Y, ZX, ZY, XY, X2-Y2

Coupling All shims are designed to be decoupled from main coil

Orthogonality All shims are designed to be fully orthogonal

'X' axis alignment Nominally coincident with line through main necks




Figure 29 Fringe field



The Cryostat

General Description

92

The cryostat is of conventional design, consisting of a central all- welded stainless- steel helium vessel, surrounded by a gas- cooled radiation shield and liquid nitrogen reservoir. The complete assembly is contained in a stainless- steel outer vacuum vessel with two service turrets located on top of the cryostat. The turrets provide access to the helium reservoir for the demountable magnet leads, helium level probe, and helium transfer siphon. The outer vessel has a bottom- flange closure constructed from aluminium, which is sealed to the main body, and bore- tube by compressed o- ring seals. The system is designed to be shipped without disassembly to facilitate quicker and easier installation.

Specifications

The cryostat is generally as shown in drawing CNZ331842, Issue F.

System finish

Dimensions

See customer interface drawings.

Table 13 System finish

Cryostat Light gray (RAL 7047), semi-gloss.

Stand and T-plate (where supplied) Charcoal gray (RAL 7011) semi-gloss.

Table 14 Cryostat dimensions

Minimum ceiling heightwith low ceiling installation equipment

2.94m2.61m

System assembly Lift from below

Weight, magnet and cryostat 450 kg

Weight, operational including legs and cryogens

630 kg




Liquid helium cryogen details

Liquid nitrogen cryogen details

Table 15 Shipping information

Crate dimensions (magnet and ancillaries)

127 x 109 x 171(h) cm615kg (approx.)

Crate dimensions (antivibration legs) 140 x 105 x 52(h) cm (approx.)180kg (approx.)

Table 16 Liquid helium

Siphon leg diameter 0.5" (12.7mm)

Volume for initial installation (includes cooling the magnet from 77K to 4.2K plus the volume required to completely fill Helium reservoir and to refill Helium reservoir after magnet energization.)

400 liters (approx.)

Recommended helium refill volume during normal operation

95 liters

Helium hold time during normal operation (static magnetic field, leads withdrawn)

> 270 days

Table 17 Liquid nitrogen

Total volume of nitrogen required for installation

700 liters (approx.)

(a) For precool of magnet 500 liters (approx.)

(b) For cool and fill of nitrogen can 200 liters (approx.)

Volume of reservoir 62.5 liters

Refill volume 58 liters

Nitrogen hold time in static condition Greater than 14 days



Customer Interface Drawings

94

Figure 30 CNZ331842F drawing 1 of 2




Figure 31 CNZ331842F drawing 2 of 2



System Components

Superconducting magnet system components

96

Table 18 System components

Qty Description

1 ea. Main magnet (consisting of main coil, superconducting shim coils, screen coils, and cryostat)

1 ea. Fixed liquid helium level probe (spare included)

Standard ancillary parts provided with the system

Table 19 Standard parts provided with system

Qty Description Part number

1 ea. Standard manifold and safety valve assembly

1 ea. Helium fill adapter, seal nut, washer, and O-rings

1 set Transit fittings

1 ea. System manual 9100380100

1 ea. Nitrogen level probe AUE334195

1 set Heat sink and flow meter assembly ANC345286

1 set Helium transfer siphon and extension tube P22200072

1 set Transfer siphon maintenance parts AKZ510817

1 ea. Nitrogen transfer line (2.5 m) and nitrogen turret fitting ATU142515

1 set 1049mm AV legs P217000234

3 ea. Welded stand hood and cover ANC133067DNC133066

1 ea. E5025 He and N2 level monitor E5025


Agilent Technologies

© Agilent Technologies, Inc.

Printed in USA, April 2012

*9100380100*

9100380100

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