Report on Beam Loss Monitors
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Transcript of Report on Beam Loss Monitors
14.06.2004 LEADE, Bernd Dehning 1
Report on Beam Loss Monitors
Specification
Type of detectors
Location of detectors
Status of developments, production and tests
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Loss Levels and Required Accuracy
Relative loss levels
450 GeV 7 TeV
Damage to components
320/5 1000/25
Quench level 1 1
Beam dump threshold for quench prevention
0.3 0.3/0.4
Warning 0.1 0.1/0.25
Absolute precision (calibration)
< factor 2 initial < factor 5)
Relative precision for quench prevention
< 25%
Functional specification:https://edms.cern.ch/file/328146/2.0/LHC-BLM-ES-0001-20-00.pdf
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Reliability and Time Resolution
Type Area of use Criticality Time resolution
BLMC Collimation sections
yes 1 turn
BLMS Critical aperture limits or critical positions
yes 1 turn(89 us)
BLMA All along the rings (ARC, …)
no 2.5 ms (7.4.4)
BLMB Primary collimators
no 1 turnbunch-by-bunch
Definition (specs): By criticality, we mean that the system must be 100% operational to allow beam injection and that the beam is dumped if it fails.
In case of a non working monitor this monitor has to be repaired before the next injection
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Quench and Damage Levels
Detection of shower particles outside the cryostat or near the collimators to determine the coil temperature increase due to particle losses
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
1.E+14
1.E+15
1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06
duration of loss [ms]
qu
ench
lev
els
[pro
ton
/s]
Special & Collimator
Arc
Damage levels Quench level and observation range450 GeV
7 TeV
Bending magnet
Dynamic108
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Loss Detectors
Ionisation chamber few litre volume
Secondary emissionmonitor
diameter = 8.9 cm, length 60 cm, 1.5 litre
diameter = 8.9 cm, length 15 cm
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Location of Detectors (I)1. Distinguish between beams2. Observe losses due to magnet misalignments3. Observe losses due to orbit changes and emittance growth
Impact of protons in the centre of the quad. magnet
Exact longitudinal position not defined yet
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IR TAS or
BPM Q1
TRIPLET two
beam
TRIPLET abs
TAN (1+5)
or D2
(2+8)
TCL 1
TCL 2
XRP 4
locations
MSI one side
TDI one side
TCD D
one side
TCL i
one side
MSD TCD Q
TCD S
Q5 Collimator
DIS Q8
prot
DIS Q 11
prot
DIS xx
ion
DIS xx cap ion
1 SI +
SS
2 * SI
SS SI +
SS SI
SI SI SI
2 SI +
SS
2 * SI
--- SI +
SS
SI +
SS
SI +
SS
SI +
SS
2 * SI +
SS
SI +
SS
SI +
SS SI
3
xxx CI +
CS
SI SI SI
4
5 SI +
SS
2 * SI
SS SI +
SS SI SI
4 * SI
SI SI SI
6
SI +
SS
SI +
SS
SI +
SS
SI +
SS
7
xxx CI +
CS
SI SI SI
8 SI +
SS
2 * SI
--- SI +
SS
SI +
SS
SI +
SS
SI +
SS
2 * SI +
SS
SI +
SS
SI +
SS
Location of Detectors (I) (One side of IP only, has to be
multiplied by two to get the number per IP, if not indicated differently. Only one beam, if not indicated differently)
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Status of BLM’s
Current tofrequencyconverter
Multi-plexerLASER
DiodeDemulti-plexer
Thresholdcomparator
BIC (Dump)Beam PermitBeam EnergyVME Bus
Analogue Electronics Digital Electronics
Below Quad. in ARC
Ionization Chamber orSEM
At surface (SR, SX)
Ionisation chamber and SEM: final tests with proto production contracts in
preparation Installation start in 09/2005
Current to frequency converter: Prototype tests in SPS
( - 11/2004) Radiation tests at PSI (06/2004)
Transmission link (optical): GOL/GOH from CMS DIODE/TLK proto in 11/2004
Threshold comparator DAB TRIUMF BPM/BLM Proto 08/2004
Complete Proto system 12/2004
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Notation:(BLMS: Monitors in the Straight Sections, Triplett, D1, D2)
Functional specificatio
n
Engineering specification
time remarks
BLMA BLMAI 2.5x10-3 to 100s
Monitors at all quadrupole magnets, ARC (except if other
specified)
BLMB BLMB Every bunch Monitors with single bunch resolution
BLMC BLMCI + BLMCS (CI+CS)
1x10-4 to 100s
Monitors in the collimation area (I: ionisation chambers,
S: secondary emission monitors)
BLMS BLMSI (SI) 1x10-4 to 100s
Special location ionisation chamber
(low region of dynamic range)
BLMS* BLMSS (SS) 1x10-4 to 100s
Special location secondary emission monitors
(high region of dynamic range)