Jerome Axensalva BE/OP 1

CLIC DETECTOR PAC RING SHIELDING CONCEPT

16/12/2011 MDI meeting

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Introduction 1:At its both ends, the CLIC detectors must be shielded to avoid radiation leaks in the experimental cavern, this can be achieved by filling the gap between the detector and the cavern walls with dedicated material.

Jerome Axensalva BE/OP

General Layout. Drawing by Nicolas Siegrist

16/12/2011 MDI meeting

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Introduction 2: To allow the detectors to be moved in and out the cavern and to insure the maximum tightness against radiations (no gap between the cavern wall and the detectors), it is foreseen that this radiation shielding can be extended and retracted.

Jerome Axensalva BE/OPShielding layout. Drawings by Nicolas Siegrist

16/12/2011 MDI meeting

Jerome Axensalva BE/OP 4

Constraints we have around the demanded shielding:- The first 100 mm of depth of the yoke material.- 4 fixed concentric coil rings.- Cavern wall (not shown).- If any other, please specify…!

16/12/2011 MDI meeting

Jerome Axensalva BE/OP 5

What is required:A Moveable Shielding System Between the Coil Rings to Fill the 50 mm Gap.

16/12/2011 MDI meeting

Shielding in extended position Shielding in retracted position

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What is proposed 1:We need a supporting system for the moveable shielding rings -> screwed sliding pins in the yoke…

Jerome Axensalva BE/OP16/12/2011 MDI meeting

Shielding supporting pins

Jerome Axensalva BE/OP 7

What is proposed 2:…to guide and support the shielding rings…

16/12/2011 MDI meeting

Shielding support

Jerome Axensalva BE/OP 8

What is Proposed 3:… and finally a translation equipment to perform the 50 mm In and Out stroke -> double effect hydraulic cylinders. ! Note, that, at this point, grooving's in the yoke are needed to run the hydraulic piping to the inner shielding rings.

16/12/2011 MDI meetingYoke grooving and hydraulic equipment

Jerome Axensalva BE/OP 9

What is Proposed 4:Note that the shielding rings are also grooved to house the hydraulic cylinders. Low friction material is in place at the interface between the sliding pins and the shield to minimize the risk of jamming.

16/12/2011 MDI meeting

Shielding viewed from backward with yoke material hidden

Jerome Axensalva BE/OP 10

Manufacturing consideration:The rings are difficult to manufacture and transport in one single piece (Ø max ~ 11 m)…A reasonable solution is to split them into 3 equal sectors and re-assemble them once on the detectors.

16/12/2011 MDI meeting

Jerome Axensalva BE/OP 11

Test Bench:Preliminary tests are proposed on a prototype system to validate the hydraulic and sliding systems…

16/12/2011 MDI meeting

Test bench assembly

Jerome Axensalva BE/OP 12

Test Bench:…and we also need to perform endurance tests on components: hydraulics, low friction pads, motion sensors, etc…

16/12/2011 MDI meeting

Test bench assembly

Jerome Axensalva BE/OP 13

Test Bench:View from the bottom, grooves for hydraulic piping

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Test bench: grooves in the dummy shield part and hydraulic piping

Jerome Axensalva BE/OP 14

Test Bench:Hydraulic cylinders.

16/12/2011 MDI meeting

Test budget: ~ 15.000 kCHF

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Questions:• Is this concept compatible with the yoke’s magnetic field (Threads,

Grooves, Piping fixes, … ) ? • Do we really have 100 mm of the yoke’s material available ?• Can we anticipate a clearance between the fixed coils rings and the

moveable shield rings of 5 mm ?• Need to evaluate the stress and deformations of the yoke around the

sliding pins threads -> need to know the exact yoke material.• Radiation levels compatible with the hydraulic components ? (piston rings

of the hydraulic cylinders are made of synthetic material).• Failure mode(s) ? Redundancy ?• Seismic constraints ? Cavern wall movements transmitted to the

detectors ? (hydraulic circuits opened/relieved or not during operation) ? • …

16/12/2011 MDI meeting