SPS North Area Operation Shutdown Lectures - 2006 Morning session Introduction and test beams Ilias...

SPS North Area Operation Shutdown Lectures - 2006

Morning sessionMorning session Introduction and test beams Ilias Efthymiopoulos

Afternoon sessionAfternoon session M2 muon beam – COMPASS Lau Gatignon Neutrino beam – CNGS Edda Gschwendtner

And…

PS East Area operation M. Delrieux (17 March – PM) nTOF/FTN line operation not operational in 2006

The SPS North Area Beams

OutlineOutline Introduction (6)

The EHN1 Beams (18)

Design highlights (12)

Operational aspects (4)

Safety Issues (8)

Access System

Ilias Efthymiopoulos AB/ATB-EASPS Training Lecture Program

March 2006

21/03/2003 ie-spstraining Shutdown Lectures 2006 - 3

Introduction (1/6)

The proton beam (400 GeV/c) from SPS is slowly extracted to the North Area at LSS2

The extracted beam is transported in the TT20 tunnel 11% slope to arrive into TCC2 – then horizontal ; ~10m underground

The primary proton beam is split in three parts directed towards to the North Area primary targets: T2, T4 and T6

11% slope


Introduction (2/6)

The splitters – how they work!The splitters – how they work!

Optimized beam optics to minimize losses Small H (~9m) and large v(~23Km)

The beam splitters are among the “hottest” objects in TCC2

B

Field-free region

Horizontally deflected by the B-field

Continues straight - no B-field

Losses

T2 T4 T6


Introduction (3/6)

The SPS North Area BeamsThe SPS North Area Beams The three proton beams are directed onto the primary targets:

T2 H2 and H4 beam lines

T4 H6, H8, and P0 beam lines

T6 M2 beam line

and Experimental Areas:and Experimental Areas: ECN3: underground experimental hall, can receive the primary proton beam

with high intensity in ECN3

EHN1: surface experimental hall, can receive secondary beams and/or attenuated primary proton beams

EHN2: surface experimental hall, receives the secondary beams or intense muon beam


Introduction (4/6)

CCC

EHN1

BA81(ps building)

BA80(ps building)

TCC2 access

TCC2 targets

(underground)

EHN2

(COMPASS)

ECN3

(NA48)

CRN(obsolete)


Introduction (5/6)

CMS

CERF/SC-RP

LHCb ATLAS TOTEM

CALICE/ILC

GLAST, DREAM, AMS,…

ALICE

CRYSTALS/LHC Coll.

NA49

6.5 Km of beam lines

About 1000 equipment installed


Introduction (6/6)

2006 will be a very interesting year for operations…

SPS Secondary Beam Lines - Experiments/Tests

0

5

10

15

20

25

30

35

2001 2002 2003 2004 2005 2006

Year

Total

LHC-Experiments

Tests

FT-Experiments

SPS Secondary Beam Lines - Sub-periods (user slots)

0

10

20

30

40

50

60

70

80

90

100

2001 2002 2003 2004 2005 2006

Year

Total

West Area

Indium Run (40 days)(14 additional sub-periods)

Extrapolation for 2006(keep weekly tests)

Extrapolation for 2006(all requests - shorter time slices or new areas)


The EHN1 beams (1/18)

The SPS North Area was originally designed to house long-lasting experiments demands for high quality of beams: high intensity, high energy, high resolution

In the recent years most of the users are “tests” in particular of LHC detectors with permanent or “semi-permanent” BIG installations several users from astroparticle experiments

The test users have very different requirements from the big experiments: scan the full energy range ; typically [10, 300] GeV/c

with sometimes increased precision (linearity) requirements

use beams of all particle types {electrons, pions, protons, muons} with as good as possible separation and identification

and, sometimes request high (or very high) rates

and all that during the few (or even one!) week(s) of their allocated time!

Rapidly changing environment, quite demanding on beam conditions and tunes



Target Beam Characteristics

T2 H2 High-energy, high-resolution secondary beam.

Alternatively can be used to transport: attenuated primary beam of protons, electrons from -conversion, polarized protons for decay, enriched low-intensity beam of anti-protons, or K+

Main parameters: Pmax= 400 (450) GeV/c, Acc.=1.5 Sr, p/pmax= ±2.0 %

H4 High-energy, high-resolution secondary beam.

Alternatively can be used to transport: primary protons, electrons from -conversion, polarized protons for decay, enriched low-intensity beam of anti-protons, or K+

Main parameters: Pmax= 330 (450) GeV/c, Acc.=1.5 Sr, p/pmax= ±1.4 %

T4 H6 High-energy secondary beam.

Main parameters: Pmax= 203 GeV/c, Acc.= 2.0 Sr, p/pmax= ±1.5 %

H8 High-energy, high-resolution secondary beam.

Alternatively can be used to transport an attenuated primary proton beam

Main parameters: Pmax= 400(450) GeV/c, Acc.= 2.5 Sr, p/pmax= ±1.5 %



Particle production downstream the primary target

Protons : remnant of the incoming primary beams the target actually serves as attenuator ~40% of the initial incoming intensity of the beam

Pions(hadrons) : produced in hadronic interactions Typical scale: interaction length (int)

Electrons : produced in electromagnetic processes Typical length scale : radiation length (X0)

Muons : produced in the decay of pions At the target and also along the beam line

Target Development of hadronic

shower

Primary p beam

(400 GeV/c)Secondary particles ( 400

GeV/c)

Attenuated proton

beam



Target material and lengthTarget material and length The proton intensity on each target can go up to 1013 protons/pulse

limited by target and TAX absorber construction (i.e. cooling, etc.)

The material with largest ratio: Xo/int is preferred Beryllium

Increasing the target length: more production but also more re-absorption lower the energy of the outgoing particles

Optimal choice ~ 1 interaction lengthOptimal choice ~ 1 interaction length

Material Xo

(cm)

int

(cm)

Xo/int

BerylliumCopperLead

35.31.500.56

40.715.017.1

0.870.100.03



The target head Beam position monitors TBIU (upstream) , TBID (downstream)

mounted on same girder as the target head for better alignment

beam steering onto the target using BSM located ~30m upstream of the target

T4 targetPosition H (mm) V (mm) L (mm) Material

0

1

2

3

4

5

EMPTY160

3

160

160

120

2

2

2

10

300

300

200

100

40

Be

Be

Be

Be

Pb

T2 targetPosition H (mm) V (mm) L (mm) Material

0

1

2

3

4

5

EMPTY160

160

160

160

120

2

2

2

2

2

300

500

180

100

40

Be

Be

Be

Be

Be

<x> = -0.2 mm<y> = -0.4 mm



T6 target

(M2, COMPASS)

T4 target

(H6, H8, P0)

T2 target

(H2, H4)

Wobbling magnets



Special cases – tertiary beams from neutralsSpecial cases – tertiary beams from neutrals Neutral particles (, K0, 0) are also produced at the target

And …

1. Convert the photons using a lead sheet to produce e+, e- pairs That way we can produce the purest electron/positron beams !!!

2. Let short lived neutrals (K0, 0) to decay in air to produce p or beams Using the energy and decay kinematics can enhance the p, content of the beam

Use a strong magnet to sweep away all charged particles

Let the neutrals fly through towards the beam line direction

Use the first magnet of the beam to select the sign of particles to transport



Special cases – Muon beam characteristicsSpecial cases – Muon beam characteristics Muon beams are formed by the decay of pions (or)

Decay kinematics: At the pion center of mass system:

At the laboratory frame – boost

Limiting cases:

Conclusion: the muon beam energy is in the

interval [0.57,1.0] of the initial pion beam energy

(p*, E*)

cMeVm

mmE

cMeVm

mmp

1102

302

22*

22*

*** cos pEE

EE

EE

57.01cos

0.11cos

min

max

0.157.0

E

E 0.157.0

E

E


The EHN1 beams (9/18) – Production rates

Absolute electron/positron production rates from Be targets

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

0 50 100 150 200 250 300 350

P(GeV/c)

e+-

/sr

1012

po

t

500mm

300 mm

100 mm

Hadron beamsHadron beams Electron beamsElectron beams

Pa

rtic

le p

rod

uct

ion

by

40

0 G

eV

/c p

roto

ns

on

Be

ta

rge

ts,

H.W

.Ath

ert

on

et.

al.


The EHN1 beams (10/18) – target station wobbling

AIMAIM Additional degrees of freedom increase the flexibility in using a target station

Produce “several” secondary beams from the same target when the primary beam hits the target basically “all” the particles are produced in a

large variety of angles and energies the most energetic particles are in the forward direction

should not forget: The very intense primary proton beam has to be dumped in a controlled way

The secondary beams of the chosen momentum have to go into the directions foreseen by the beam geometry (i.e. inside the vacuum tube of each beam line)

SolutionSolution: : “wobbling” : hit the target under variable angle


The EHN1 beams (11/18) – target station wobbling

TargetSPS protons

TAX B10-order approximation:0-order approximation:

TargetSPS protons

TAX B11st -order approximation:1st -order approximation:

B1

Target

SPS protons

TAX B12nd -order approximation:2nd -order approximation:

B1

• single secondary or primary beam

• fixed production angle

• two secondary beams

• one could be the primary beam

• fixed production angles

• two secondary beams

• one could be the primary beam

• variable production angles


The EHN1 beams (12/18) – T4 target station


The EHN1 beams (13/18) – TAX absorber attenuator


The EHN1 beams (14/18) –– TAX absorber attenuator

Preparation and installation of new TAX blocks for T4.


The EHN1 beams (15/18) – T4 Wobbling

Example 1: primary proton beam in P0 H8, H6 secondary beams



Example 1: primary proton beam in P0 H8, H6 secondary beams

Presently the most frequent case

“standard wobbling” settings:

H8 H6

Energy (GeV/c) @ 0 mrad prod. angle

Energy (GeV/c)

Prod. Angle (mrad)

+180 +120 +100 +80

0 -5.46 -13.36

+20 +10 +20 +6

-1.58 8.58

-15.13 -250 -100

-200 -120 -60

-0.33 8.06 2.15

-10.23



Example 2: P0 beam OFF primary protons in H8 – “micro-beam” H6 secondary beam



Safety - Survey survey (monitor) the current in the “wobbling” magnets and the position

of the TBIU, TBID monitors should be automatically done A program called WOBSU should be running continuously

for planned changes to the target station magnets (wobbling changes) a manual INHIBIT signal for the extraction has to be set at the CCC

Wobbling changes: initiated by the EA physicist upon the user requests presented and discussed in the EATC meeting, documented in the

minutes settings file prepared and communicated by the EA physicist performed by the operators on the agreed time

re-tuning of the the beam lines after the wobbling changes is often required


Design highlights (1/12)

The momentum selection is done in the vertical plane

“upstream” V-BENDs (B1, B2)between the primary target and the momentum acceptance collimator

“downstream” V-BENDs (B3, B4)

the main spectrometer of the beam momentum definition



View of the H8 and H6 beam lines in TT81 tunnel.



Beam optics modes:Beam optics modes: High Resolution: used in the past to increase the momentum

resolution of the beam line Required additional hardware (spectrometer chambers), not available

anymore.

High Transmission: allows having the maximum particle flux at a given momentum

Filter Mode : has a focus on both planes at ~130m of the beam line, which allows using an intermediate (tertiary) target Heavily used now days to produce tertiary beams !

Tertiary beams provide more flexibility to the users and relaxes the coupling between the beam lines due to wobble choice. keep longer periods with the same wobble setting



Tertiary beamsTertiary beams Produced in two distinct ways:

H6, H8: use a second target (filter) beam line tuned for two energies:

E1 (high energy) : from the primary target until the filter momentum selection by the “down” vertical BENDs

E2 (< E1) : from the filter until the experiment momentum selection by BEND-3 and BEND-4 (up vertical bends)

H2, H4: from the conversion or decay of secondary neutral particles

tertiary muon beams of well defined momenta are produced by stopping pions in a closed collimator before the last bending magnets of the beam line



Op

era

tion

al asp

ect

s



Op

era

tion

al asp

ect

s



introduce a target (filter) after the “upstream” bends

tertiary beams have typically lower rates

choice of target material can enhance/select different particles Cu, Poly, Pb

XCON fine positioning filter/converter



Tertiary beams H2 , H4Tertiary beams H2 , H4 use the B3 magnet of the wobbling

as sweeping magnet charged particles are absorbed in

the TAX neutral particles go through and hit

the converter

note: neutral particles can have zero or

non zero production angle

use the converter on Pb (CONVERTER=LEAD): to

produce electrons (e+, e-) COPNVERTER=AIR (no

converter) to let K0, 0 , to decay K0 + + - 0 p + -

use B1 of the beam line to select the charge and particle for the tertiary beam to the experiment



Electron beamsElectron beamsSecondary beams electrons produced at the primary

target rate goes down with energy

increase

longer targets help electron production rate ~proportional to target length

at high energies (120 GeV/c) can be separated from hadrons by synchrotron radiation

mixed beams pion (hadron) contamination for lower energies user CEDAR or treshold

Cherenkov counters for tagging

Tertiary beams H6, H8: use Pb as secondary

target few mm, or ~1-2 radiation lengths

(X0) radiation length: distance in matter

where electrons loose ~1/e of their

energy hadrons loose ~nothing

H2, H4: electrons from photon conversion high purity beams!



Electron beam separation by synchrotron radiation at high energies

Electron beam – E0-DE

@150 GeV/c 149.197 GeV/c

Electron beam- E0

Electron beam- E0

41mrad angle – DE@180 GeV/c = 200 MeV

41mrad angle – DE@180 GeV/c = 200 MeV

Hadron beam – no energy loss



Hadron beamsHadron beams

Secondary beams hadrons are produced at the

primary target for positive sign beam a good

fraction of the total hadron rate is protons

using an absorber (~1-2 X0 of Pb) in the beam we can eliminate any electron contamination

Tertiary beams H6, H8: use secondary target of

Cu, (CH)n

~1 interaction length I

interaction length: characterizes the average longitudinal distribution of hadronic showers a high energy hadron has 1-

1/e probability to interact within one lI

I >> X0 for most of materials

H2, H4: hadrons produced in the decay of neutral mesons 0 p + -, K0 ++ -



Muon beamsMuon beams

Secondary beams muons produced directly at the

target area or by the decay of pions muon momentum: 57-100% of the

parent pion momentum

to produce a pure muon beam for the experiment, is enough to close out of beam axis the last collimators of the beam line

closing the collimator upstream of the last bend of the line we can obtain momentum selected muons

rule of thump: muons in a 1010cm2 trigger represent ~1% of the hadron/pion flux there is another ~1% in a cone

about 1 1m2 around the beam axis

106 muons / 10 10 cm2 trigger 1.3 uSv/h

Tertiary beams muons present only for tertiary

beams in the energy range 57-100% of the secondary beam momentum


Operational aspects (1/4)

Beam tuningBeam tuning Goal: deliver good quality of beam to the experiment!

sufficient rate, spot size, particle purity,…

Tuning the beam is required each time we change something: energy, wobbling, user

Very important: start from an already prepared beam file by the EA physicists

be sure it corresponds to the present wobbling settings

be sure it can fulfil the user requirements typically the users know “their” files, but good to check it yourself as well!!!



The first stepsThe first steps consult the logbook of the beam line

most of the files have been used already in the past new files represent minor variations of existing files

treat each plane independently start with the vertical plane which is the most important to get the beam to

the experimental hall

select your observation point a scintillator counter close to the end of the beam line

provided the beam can reache it!!



Watch out !!Watch out !! electrons do not like material!

remove triggers or other detectors from the beam line, otherwise you may simply kill the whole beam

be careful when you try to measure/monitor things, since you may disturb the users

referring to logbook is fine but be sure you are comparing apples

with apples

follow the particles, consistent particle rates use as much as possible normalized

rates: rate/pot monitor beam losses, be sure you are

looking at the beam not at its halo similar rates at different places

along the beam line scintillator counters are typically =

100mm but NOT ALL; Exp. Scalers can vary a lot!

switching beam files: secondary beams have high rates

acceptance collimators close tertiary beams have low rates

acceptance collimators wide open

therefore:

switching from tertiary to secondary beam, load FIRST the collimators and then the magnetsO

pera

tion

al asp

ect

s



ImportantImportant Think before acting

To first order, all beam lines are quite similar however there are some

differences which need time to become familiar with

Time is important for you and the users there is always a limit to how good

a beam can be; let the users decide

Some users are quite experienced with their beam, and can do many things alone

Good documentation is vital beam line snapshot:

status of magnets/files/wobbling settings

status of collimators, target, absorber

rates in few counters (start, middle, end of beam line)

Don’t be afraid to ask for help

Op

era

tion

al asp

ect

s


Safety Issues (1/8)

Radiation Safety IssuesRadiation Safety Issues

Direct in-beam exposure should be avoided at all cases!

Hadron or electron beams containing >108 particles/burst are dangerous should be always dumped in special (thick) dumps (controlled losses)

serious irradiation to persons standing close to unshielded loss points unshielded loss points will cause excessively high radiation levels in the

experimental hall and cause dose rate limits at the CERN boundaries any in-beam exposure for even one pulse will cause observable biological damage beam line & areas should be completely shielded

Hadron or electron beams containing >106 particles/burst should be treated with respect unshielded loss points will cause limiting radiation levels in the experimental halls

and at the CERN boundaries all loss points must be completely shielded (dumps) any in-beam exposure is still serious and will cause significant administrative

actions


Safety Issues (2/8)

Radiation Safety IssuesRadiation Safety Issues

Hadron or electron beams containing <104 particles/burst could be allowed to travel in open areas still in-beam exposure should be avoided

Heavy ion beams of any intensity cannot be allowed to travel through open areas accidental in-beam exposure is dangerous and must be completely

avoided


Safety Issues (3/8)

SC/RP Central DAQSC/RP Central DAQ All installed radiation alarm

monitors can be read remotely Data are stored in a database

for further retreival The parameters for each

monitor are accessible can only be set/modified by

authorized persons (TIS/RP)


Safety Issues (4/8)


Safety Issues (5/8)

Additional radiation sources in the areas Additional radiation sources in the areas

Radioactive sources Used by the experiments for their detector calibration Transport/installation under the TIS/RP responsibility Normally a garage position should be available

sometimes the source is in interlock with the area access system Warning panels at the door of the experimental areaLasers Used by the experiments for their detector calibration Normally setup certified by TIS/RPRadioactive detectors Uranium calorimeters (not anymore “a la mode”!) “hot” detectors after irradiation tests

transport/installation under TIS/RP supervision

Note Setups are modified quite often by the users

it can happen that information on the changes arrives very late


Safety Issues (6/8)

DumpsDumps Used to orderly stop the

hadron/electron beams muons go through but undergo

multiple scattering ==> larger cone

Typically formed by 2-3 m of iron with at least 80cm in

each direction from the beam impact point

one or two concrete blocks (80cm each) in each direction

Several dumps can exist in a beam line provide separation between

different experimental areas motorized or build in

fixed dump at the end of each line

For high intensity beams the dump is made re-entrant, the particles are dumped into a hole, in order to reduce the particle backsplash

For very high intensities or for special beams (neutrino or muon beams) the dumps consist of many meters of iron, concrete and/or earth shielding examples: M2, P0/NA48, WANF, CNGS


Safety Issues (7/8)

Motorized dumpsMotorized dumpsXTDX – horizontal 2-3m of cast iron several blocks one next to the other

variable configuration replace by concrete the last block

for better neutron absorbtion No concrete shielding around it

reinforced shielding in the area

XTDV – vertical 3.2m of cast iron Is embedded in concrete shielding

> 80cm in each direction


Safety Issues (8/8)

FencesFences Used to mark the limits of the controlled areas

at least 2m height should not be possible to climb over no ladders allowed at any point against the fences

At least 1-2 m away from the nominal beam axis exact size/shape depends on the size of the experiment

Modification to dumps or fences Can ONLY be initiated by the responsible physicist Have to be approved by TIS/RP and RSO

presented in AB Safety Committee for approval During SPS operation if for whatever reason the dumps or fences of the areas

have to be modified, the MANUAL VETO of the beam line should be set


The access system (1/8)

Beamline and Experimental Area Beamline and Experimental Area classificationclassification

Secondary beam areas EHN1 (H2, H4, H6, H8) EHN2 (P61/M2) access granted locally interlock system per beam

line/area

Primary beam areas TCC2 (north area targets) ECN3 (P0) same access rules as SPS

machine and target zones



The access system is used to prevent in-beam exposure for the personnel For EA can be separated in two categories: Beam lines and Experimental areas

Experimental Area Perimeter defined by concrete blocks and/or fences

typically at least 1m from the beam axis, exact shape depends on detector/installation size high intensity (>106/ppp) proton or heavy-ion beams and exp. areas are completely shielded

with concrete visibility to the area should not be blocked

Doors to access each area the main one (PPE) and at least one emergency escape door (PPX, PPG)

Several can exist in a single beam line connected to the same or different interlock chains

Access to downstream areas depend on beam conditions provided there is a dump (XTDV, XTDX, “manual”) in between

Beam Line The beam line: from the target tunnel exp.area(hall) dump A beam line can contain a single or several interlock chains of experimental areas



PPE146 – H6A Big but “empty”

PPE146

PPX146

XTDV

PAX monitor



PPE168 – H8B Large area with four doors and a search point Big and complicated detector installations Radioactive sources, gas distribution (including flammable)

PPX168 PPE168

PPG168

PPX168 Search point

PAX monitor

Beam dumpMagnet interlock

XTDV dump



Safety elementsSafety elements Physical elements that provide information for the access system

Doors: allow access to the experimental areas and underground tunnels

Dumps: motorized dumps to separate experimental areas in the same beam line

TAX: motorized blocks “dumps with holes” to attenuate or dump the beam

Magnets: stop the transport of a beam; (“champ null” detector, current limit, interlock)

Equipment: has to be present and in a given configuration

Special case: radiation monitors can stop the beam if above threshold, but not included in the access system

Status information available on the control room



Interlock chainsInterlock chains Hardware system to define a status of a beam line

receives/treats information form various safety elements specialized electronics and network

Hierarchical organization per beam line (several chains in each beam line) tunnel (several beam lines) building/tunnels/area (TTC2=North) SPS veto

Interlock signal based on information from at least two safety elements



Software Interlock chains - MatricesSoftware Interlock chains - Matrices Implemented into NODAL (CESAR) system

Should correspond to the actual hardware configuration matrices describing the configuration of each interlock chain

Used to facilitate the users/operators avoid mistakes that can cause access alarms fast help and monitor of the access system

however Mainly intended for high-level commands/programs

direct calls to the hardware (ie. move a TAX or XTDV) may still be possible

Software interlocks are not considered as SAFE

Note: Hardware for the interlock system maintained by M.Grill (ST/MA) Annual inspection before SPS startup



Safety ElementsSafety ElementsDoorsDoors Control the access to experimental areas and

beam lines

Users have to take a key to open the door must use the key to enter AND exit the area

At least one PPE and one PPX in each area marked at PPE xxx, PPX xxx (PPG xxx)

Door status defines the status of the area BUT NOT of the beam line free: people can enter without key key access: to enter you have to take a key beam ON/OFF: no access, beam can be

present in the area

Timeout (~1min) if a door is left open more than 1min switches

automatically to free state

In complicated areas the PPExxx door is combined with a search point acts like a door forces the area patrol to pass by that point

Access Rules to Experimental Areas One person one key

no more than 8 people at a time in the area if so, the door/area must go in free mode

Change of door/area states: free key access

search of the area by SPS operators and the GLIMOS of the experiment

key access beam (beam key access) press the end of access system

verify that the above rule was not violated via computer system

key access free via computer system door open timeout

Emergency button (“force the door”) stops the beam drops the interlock chain of the door AND the next higher level interlock chain



PPExxx Door

door handle

door and area status and control panel

keys



Dumps – Motorized XTDV, XTDXDumps – Motorized XTDV, XTDX Used to separate experimental areas in the same beam line

attached to the interlock chain of the downstream area Motorized XTDV, XTDX dumps, 2-3m of Fe Two positions defined: IN/OUT Before moving a dump the beam must be stopped

this to avoid spraying particles as the edge of the dump crosses the beam

MagnetsMagnets Power converter level

interlock on polarity current limitation

Direct measurement of the magnetic field zero magnetic field detection (“champ null”) can be very tricky if we have to transport low energy beams



TAXs – Target AttenuatorTAXs – Target Attenuator Massive blocks of material (Al-Cu-Fe)

different configurations depending on the beam line 3.2m long located downstream the primary targets

Combined function: dump: stop proton/hadron beam

can be quite “hot”; ~5 Sv/hr at the end of shutdown attenuator: let the full (big hole) or attenuated beam (small holes with some material insert) to

go through Fully motorized with remote control

two motors (XTAXxxxyyy) per beam Movement split in ranges

SMALL range: move around the small holes

empty or with material insert

used for the primary proton beams MEDIUM range: LARGE range:

can move the full range including the big empty holes used for secondary or ion beams A

ccess

syst

em





EquipmentEquipment

MicroCollimator in H8 Beam Line Combined setup:

set of two collimators: XCRH and XCRV

their support table: XCRT an IN/OUT collimator: XCIO

Used for the “micro-beam” option in H8 attenuated primary proton beam in

H8


The access system (14/8)In

terl

ock C

hain

– N

ort

h A

rea

Inte

rlock C

hain

– N

ort

h A

rea



Interlock chain status Interlock chain status The chains can be:SAFE If all the elements in

the chain are in the SAFE state it means we can

have access to the area

orUNSAFE If any of the

elements in the chain is in UNSAFE state we can’t have

access the beam is

present



Door Status and Control Door Status and Control DisplayDisplay

Displays the status of the PPE doors

Allows monitoring and control of their state

The doors can be in one of the following states

FREE (green) No access control

KEY ACCESS (yellow) Access with key Limited number of

people

CLOSED (red) Beam present



Search and secure procedureSearch and secure procedure Is needed in order to switch from

Free to Key access an Exp. Area

The search is conducted by the search leader

normally the GLIMOS of the experiment and other authorized persons(s)

The defined procedure should be rigorously followed

Procedure:1. Ask all the persons present in the area to

exit and close all the doors (PPE, PPX, PPG)

2. Verify that all fences and blocks defining the perimeter of the area are in place

3. Remove all ladders or any other equipment can be used by people to climb over the fences

4. Go to the PPE door and call the PCR to switch it from “Free Access” to “Key Access”

5. Leave one person at the PPE door and start the search. All persons entering the area must take a key. Audible devices can be used during the search to warn people. Take your time and look carefully everywhere

6. If there is a “Search Box” you must re-arm it although there is a time-out to do so, don’t

rush! it is more to force you to look into that area

not just to turn the key!

7. Return all the keys to the PPE door and press the “End of Access” button



North Area Beam InterlockNorth Area Beam Interlock

Proton extraction to the North is allowed only if the North Area is in SAFE mode

North Area SAFE when ALL the corresponding Beam Lines are in safe mode

Beam Line SAFE if - either the nominal beam energy is limited

below the energy of primary protons ie. cannot transport primary

protons

-

or the beam intensity is limited by beam attenuators (TAX's or combination of TAX's and other beam elements)

Ion beam extraction can always be done Particle type identification from CPS

“Oxygen Interlock” signal Manual operation – “ion key”



Example H8 Beam Line:Example H8 Beam Line:

x in a position means that 1 or 0 is allowed

ElementActual Status

Normal status

Micro Beam

(primary protons)

Protons

(secondary)

Ions

Beam Line SAFE

UNSAFE

0

1

1

0

1

0

x

xTAX TAXMOT(6) NO RGE

ALARM1 1 1 1

Magnets BEND LIMITED

NON LIMITED

0

1

0

1

1

0

0

1Micro collimator table TABLE201 SAFE

UNSAFE

0

1

1

0

0

1

0

1Micro collimator XCRH201 SAFE

UNSAFE

1

1

1

0

x

x

x

xXCRV201 SAFE

UNSAFE

1

1

1

0

x

x

x

xProtection collimator XCIO200 SAFE

UNSAFE

0

1

1

0

0

1

0

1



TAX RangesTAX Ranges SMALL/MEDIUM Range

only small holes or holes with insert attenuated beam

LARGE Range big and/or empty holes possible

no attenuation



TAX RangesTAX Ranges status and setting in NODAL CESAR

READ actual position (readout) TAXDT set position (default, BIM-0). The position to reach at the end of an

access SELECT.RGE selected range (set) ENABLE.RGE allowed (enabled) range based on the beam type in the

machine/beamline CONTROL.RGE control unit status (values: COMPUTER, LOCAL, LOCKED) ACTUAL.RGE actual range (readout)



BEND LimitsBEND Limits

Interlock condition on the maximum allowed current for the main BENDs of a beam line

LIMITED: Ilimit < ISPS the primary SPS beam cannot be

transported

UNLIMITED: Ilimit ISPS

the primary SPS beam can be transported

North Area



Manual VetoManual Veto “Key” to veto an interlock chain of a beam

line blocks the presence of the beam in an exp.

area, regardless the status of the existing safety elements of the chain

Normal status of all exp. area chains during shutdown

Has to be set each time there is work foreseen that can modify the status of an exp. area

Can ONLY be lifted with the agreement (signature) of the EA physicist.

The EA physicist must patrol the exp. area before signing to lift the Manual Veto verify that its perimeter is correctly closed the safety elements (dumps, doors, magnets)

are present and functionali.e. must verify that the access system can function

correctly



Changes to the access systemChanges to the access system Changes to the access system (new conditions from the users,

modification in the beam line or exp. area) are initiated and are under the responsibility of the EA physicist

The EA physicist takes care that all the parties involved are consulted and agree on the proposed changes EA and BI beam line experts access system experts, ST/MA (M. Grill) TIS/RP and AB/RSO

All modifications are discussed in the EATC meetings and documented in the minutes 1st meeting of the year: summary of all modifications during the shutdown during operation, in the meeting before the SPS period concerned


Items not discussed

SPS Page-1 – what it means every number there?

Timing –events and their distribution

Beam Instrumentation Collimators, FISCs, WireChambers, Cherenkovs, CEDARs,…

You can find all that and answer all your questions in two week’s time:

Dry-Run-2 – week 13 (27-31 March)Dry-Run-2 – week 13 (27-31 March)

Full commissioning exercise of the North Area beamsFull commissioning exercise of the North Area beams

Prepare and test the maximum possible before the beam starts.

New in 2006: BI hardware renovation, CESAR software, FESA-2, advanced software applications, and all kinds of goodies!!!!

Date post:	19-Dec-2015
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SPS North Area Operation Shutdown Lectures - 2006 Morning session Introduction and test beams Ilias...

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