Beam Loss Detection

Beam Loss Detection

Workshop on Machine Protection, Focusing on Linear Accelerator Complexes 1

Bernd DehningCERN BE/BI

B.Dehning: 07.06.2012

Extensively used for operation verification and machine tuning 1 Hz Logging (12 integration times, 40 us to 83 s)

Integration times < 1s: maximum during the last second is logged short losses are recorded and loss duration can be reconstructed (20% accuracy)

Also used for Online Display

BLM System – Online Display

LHCbBeamDumps

Collimation

BLM System Knowledge Flow


Beam Loss Measurement System Layouts

B.Dehning: 07.06.2012


Ionisation chamber Function: observation and interlock 3700 installed Over 90 % connected to interlock/dump

system Secondary emission detector

Function: observation 300 installed

6

Reliability: Failure Rate and Checks

Systems parallel + survey + functional check:1. in case of system failure dump beam (failsafe)2. verification of functionality: simulate measurement and

comparison with expected result => as good as new

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0 50 100 150 200 250 300time [a.u.]

failu

re ra

te [a

. u.]

constant f. r.systems parallelsystems parallel + surv.systems parallel + surv. + check

B.Dehning: 07.06.2012

Workshop on Machine Protection, Focusing on Linear Accelerator Complexes

Key implementation to obtain low failure rate


7

02_FAQ=0.0336 w=0.00275

False Alarm

Channel _FAQ=0.00513 w=0.000427

Channel FalseAlarm

DigFEE _FAQ=0.000125 w=1.04e-5

Digital FEEFalse Alarm

TunnnelPS_FAQ=0.0191 w=0.00158

False alarmgenerated bytunnel Power

Supply

BEE _FAQ=9.35e -5 w=7.79e-6

Back EndElectronic

False Alarm

Crate _FAQ=7.12e-6 w=5.99e-7

Crateselectronics

False Alarms

VMEunit _FAQ=0.00946 w=0.000784

VME unitFalse Alarms

OL_equiv _FA

642 redudantOptical link ,

w

r=5.30677 e-007 tau =12

Q=3.18e-6 w=5.31e -7

Memory .01

MechanicalFailure (325)

r =9. 2713e- 011 n=325 m =1

Q=3.62e-7 w=3.01e-8

Memory .02

ElectricalFailure (325)

r =3. 0858 e-011 n=325 m =1

Q=1.2e-7 w=1e-8

HTcon _FA_CQ=4.82e-5 w=4.02e-6

HT connectorsFalse Alarms,

Continuous check

Page 11

IC_FA_CQ=0.000368 w=3.07e-5

IonizationChamber False

Alarm,Continuous check

Page 12

Channel _FA_10pAQ=0.00472 w=0.000392

CFC FalseAlarm , 10pA

check

Page 13

PSarc_FA_CQ=2.5e-5 w=2.08e-6

Arc PowerSupplies False


Page 16

PSSS_FA_CQ=0.0191 w=0.00158

Straight SectionPS False Alarm,

Continuous check

Page 17

PSVME_FA_CQ=9.75e-9 w=1.95e-8

PS VME FalseAlarm,

Continuous check

Page 20

VMEfans_FA_CQ=0.00946 w=0.000784

VME fantray FalseAlarm,

Continuous check

Page 21

BEE _FA_CQ=8.58e-5 w=7.15e-6

Back Endelectronic False


Page 18

BEE _FA_LQ=7.71e-6 w=6.43e-7


Alarm, Loggingcheck

Crate _FA_CQ=5.47e-6 w=4.62e-7

Crates electronicsFalse Alarms,

Continuous check

Page 19

CombFPGA_FA_LQ=1.65e -6 w=1.37e-7

Combiner FPGAFalse Alarm,

Loggin check

Memory_FA_LQ=4.82e-7 w=4.02e-8

No thresholds(325)

FPGARXen _FA_LQ=7.14e-6 w=5.95e-7

No energyupdating from

combiner

TransceiverEn _FA_LQ=9.55e -8 w=7.96e-9

Wrong energysignal fromtransceiver

DigFEE _FA_CQ=0.000108 w=8.97e-6

Digital FEE FalseAlarm,

Continuous check

Page 14

DigFEE_FA_10pAQ=1.74e-5 w=1.45e-6

Digital FEEFalse Alarm ,10pA check

Page 15

FPGARX.0.3_1

Wrong energyfrom Combiner

(325)

r=1.83e-009 n=325 m=1Q=7.14e-6 w=5.95e-7

Transceiver .0.6_1

Data Bit Error(325)

r=2.448e-011 n=325 m=1Q=9.55e -8 w=7.96e-9

Combiner FPGA.02_1

Internal error

r=5.49e-009 n=25 m=1Q=1.65e -6 w=1.37e-7

CombBPin_FA_LQ=1.65e -6 w=1.37e-7

Wrongcombinerbackplane

OL_equiv_FA:r= r(OL_FA)* n

tau=missiontime

To run with lifetime= mission time (12

h)

02_FAQ=0.0336 w=0.00275

False Alarm

Channel _FAQ=0.00513 w=0.000427

Channel FalseAlarm

DigFEE _FAQ=0.000125 w=1.04e-5




Supply

BEE _FAQ=9.35e -5 w=7.79e-6

Back EndElectronic

False Alarm

Crate _FAQ=7.12e-6 w=5.99e-7

Crateselectronics

False Alarms

VMEunit _FAQ=0.00946 w=0.000784


OL_equiv _FA


w

r=5.30677 e-007 tau =12

Q=3.18e-6 w=5.31e -7

Memory .01


r =9. 2713e- 011 n=325 m =1

Q=3.62e-7 w=3.01e-8

Memory .02


r =3. 0858 e-011 n=325 m =1

Q=1.2e-7 w=1e-8



Continuous check

Page 11

IC_FA_CQ=0.000368 w=3.07e-5



Page 12

Channel _FA_10pAQ=0.00472 w=0.000392


check

Page 13




Page 16

PSSS_FA_CQ=0.0191 w=0.00158


Continuous check

Page 17


PS VME FalseAlarm,

Continuous check

Page 20

VMEfans_FA_CQ=0.00946 w=0.000784


Continuous check

Page 21

BEE _FA_CQ=8.58e-5 w=7.15e-6



Page 18

BEE _FA_LQ=7.71e-6 w=6.43e-7


Alarm, Loggingcheck



Continuous check

Page 19



Loggin check


No thresholds(325)



combiner



DigFEE _FA_CQ=0.000108 w=8.97e-6


Continuous check

Page 14



Page 15

FPGARX.0.3_1


(325)

r=1.83e-009 n=325 m=1Q=7.14e-6 w=5.95e-7

Transceiver .0.6_1

Data Bit Error(325)

r=2.448e-011 n=325 m=1Q=9.55e -8 w=7.96e-9

Combiner FPGA.02_1

Internal error

r=5.49e-009 n=25 m=1Q=1.65e -6 w=1.37e-7




tau=missiontime


h)

02_FAQ=0.0336 w=0.00275

False Alarm

Channel _FAQ=0.00513 w=0.000427

Channel FalseAlarm

DigFEE _FAQ=0.000125 w=1.04e-5




Supply

BEE _FAQ=9.35e -5 w=7.79e-6

Back EndElectronic

False Alarm

Crate _FAQ=7.12e-6 w=5.99e-7

Crateselectronics

False Alarms

VMEunit _FAQ=0.00946 w=0.000784


OL_equiv _FA


02_FAQ=0.0336 w=0.00275

False Alarm

Channel _FAQ=0.00513 w=0.000427

Channel FalseAlarm

DigFEE _FAQ=0.000125 w=1.04e-5




Supply

BEE _FAQ=9.35e -5 w=7.79e-6

Back EndElectronic

False Alarm

Crate _FAQ=7.12e-6 w=5.99e-7

Crateselectronics

False Alarms

VMEunit _FAQ=0.00946 w=0.000784


OL_equiv _FA


w

r=5.30677 e-007 tau =12

Q=3.18e-6 w=5.31e -7

Memory .01


r =9. 2713e- 011 n=325 m =1

Q=3.62e-7 w=3.01e-8

Memory .02


r =3. 0858 e-011 n=325 m =1

Q=1.2e-7 w=1e-8



Continuous check

Page 11

IC_FA_CQ=0.000368 w=3.07e-5


w

r=5.30677 e-007 tau =12

Q=3.18e-6 w=5.31e -7

Memory .01


r =9. 2713e- 011 n=325 m =1

Q=3.62e-7 w=3.01e-8

Memory .02


r =3. 0858 e-011 n=325 m =1

Q=1.2e-7 w=1e-8



Continuous check

Page 11

IC_FA_CQ=0.000368 w=3.07e-5



Page 12

Channel _FA_10pAQ=0.00472 w=0.000392


check

Page 13




Page 16

PSSS_FA_CQ=0.0191 w=0.00158


Continuous check

Page 17


PS VME FalseAlarm,

Continuous check

Page 20

VMEfans_FA_CQ=0.00946 w=0.000784


Continuous check

Page 21

BEE _FA_CQ=8


Page 12

Channel _FA_10pAQ=0.00472 w=0.000392


check

Page 13




Page 16

PSSS_FA_CQ=0.0191 w=0.00158


Continuous check

Page 17


PS VME FalseAlarm,

Continuous check

Page 20

VMEfans_FA_CQ=0.00946 w=0.000784


Continuous check

Page 21

BEE _FA_CQ=8.58e-5 w=7.15e-6



Page 18

BEE _FA_LQ=7.71e-6 w=6.43e-7


Alarm, Loggingcheck



Continuous check

Page 19



Loggin check


No thresholds(325)


No energy

.58e-5 w=7.15e-6



Page 18

BEE _FA_LQ=7.71e-6 w=6.43e-7


Alarm, Loggingcheck



Continuous check

Page 19



Loggin check


No thresholds(325)



combiner



DigFEE _FA_CQ=0.000108 w=8.97e-6


Continuous check

Page 14



Page 15

FPGARX.0.3_1


(325)

r=1.83e-009 n=325 m=1Q=7.14e-6 w=5.95e-7

Transceiver .0.6_1

Data Bit Error(325)

r=2.448e-011 n=325 m

updating fromcombiner



DigFEE _FA_CQ=0.000108 w=8.97e-6


Continuous check

Page 14



Page 15

FPGARX.0.3_1


(325)

r=1.83e-009 n=325 m=1Q=7.14e-6 w=5.95e-7

Transceiver .0.6_1

Data Bit Error(325)

r=2.448e-011 n=325 m=1Q=9.55e -8 w=7.96e-9

Combiner FPGA.02_1

Internal error

r=5.49e-009 n=25 m=1Q=1.65e -6 w=1.37e-7




tau=missiontime


h)

B.Dehning: 07.06.2012

Reliability: Fault Tree Analysis

The probability to have an Failure Mode A, Pr{A}, is calculated per each Failure Modes of the FMECA, given the hazard rate, the repair rate and the inspection period .

OR Gate

EVENT1 EVENT2

OR Gate

EVENT1 EVENT2

DamageRisk

BlindFEE

BlindBEE

AND Gate

EVENT1 EVENT2

AND Gate

EVENT1 EVENT2

False Alarmby

transmission

Opticalline

1

Opticalline

2

Almost 160 Failure Modes have been defined for the BLMS using the FMD-97 standard.Three Ends Effects:1. Damage Risk: probability not to be ready in case of dangerous loss. 2. False Alarm: probability to generate a false alarm.3. Warning: probability to generate a maintenance request

following a failure of a redundant component.

Used program: Isograph, includes component catalogue

Steps taken for a Failsafe System: Error-free Communication

B.Dehning: 07.06.2012


The steps taken to ensure a reliable communication link: Double (redundant) optical link

CRC-32 error check algorithm All single-bit errors. All double-bit errors. Any odd number of errors. Any burst error with a length less than the length of CRC. For longer bursts Pr = 1.16415*10-10 probability of undetected error.

224 bits of data plus 32 bits of CRC remainder = 256 bits

8b/10b encoding Clock data recovery (CDR) - guarantees transition density. DC-balanced serial stream - ones and zeros are equal/DC is zero. Error detection – four times more characters. Special characters used for control – sync, frame.

256 bits of data are encoded in 320 bits = 64 extra bits

Steps taken for a Failsafe System: Avoiding Human Errors

B.Dehning: 07.06.2012


To avoid misplacement of electronic cards or threshold and masking tables

Tunnel Card ID Unique number embedded in the FPGA (16bit) Included in every transmitted frame Compared with the one stored in the LSA DB

Surface Card Serial number Unique number embedded in a IC (64bit) Compared with the one stored in the LSA DB

Steps taken for a Failsafe System: System Failures

B.Dehning: 07.06.2012


To avoid loss of data Frame ID

Surface FPGA checks for missing frames Incrementing number included at every transmission

Optical link is always active 8b/10b encoding sends “commas” when no data Disconnection is detected in max 25ns

To ensure recognition of system failures and beam dump requests

FPGA Outputs (Beam Dump signals) as frequency At a dump request, reset, or failure the transmitted frequency will be altered

Beam Permit lines are daisy-chained between cards Custom VME backplane Dummy cards on empty slots to close circuit

Verification using Emulator Module

In situ test of the TC in VME crate by emulation of output signals of CFC

Arbitrary Tx data Comparison of different TC firmware versions Playback of LHC capture data for analysis

Tx errors CRC, CID, FID

Wrong configuration Errors in physical layer

Manual testing procedure Results read out in Expert application

B.Dehning: 07.06.2012


Verification using custom programs

B.Dehning: 07.06.2012


Exhaustive verification of the behavior of the Threshold Comparator block

Check all permutations and their ability to trigger a beam dump request

Flash modified threshold table targeting one table field at each iteration.

16 cards/crate 16 detectors/TC card 12 integration windows/detector 32 beam energy levels 98’304 test cases/crate

VME readout check The same test case repeated 500’000 times

Internal (VME crate) beam permit check

B.Dehning: 07.06.2012


Check the beam permit lines (BPL) inside the crate

Check the BPL between the crates (on the same IP)

Check results are saved in the database

BLECSU

BLETCN°1

BLETCN°16

BLETCN°2

U

M M M

Last BLECS

CIBUS

U

All lines to ‘FALSE’

Energy link

last BLECS had received the last dump request and notify all the other BLECS

1

2

3

Send the card number which have to provoke the dump and U or M

The BLECS provoke the dump which is transmitted to the last BLECS before the CIBUS

Combiner card inside the LHC BLM system

Beam Loss Monitors (4000)

Interlock Interfaces (16) [CIBUS] TE-MPE-MI (B. Puccio, B. Todd)

Beam Energy Receivers (8) [CISV]Hardware:BE-CO-HT (P. Alvarez)Responsible:TE-MPE-MI (B. Puccio)Energy measurements:

Tunnel Cards (700)

Threshold Comparators (350) Combiner and Survey (25)

Operational applications (2) Expert applications (2) Diagnostics application,phase and amplitude

for the connectivity check

Settings applications (2)

Tunnel Card test benches (5) around the LHC ring

HV HV

BLM HV supplies

B.Dehning: 07.06.2012 14


Connectivity check

The high voltage is modulated with a 30V/60mHz signalA current is induced in the monitors and measured by the system

The phase and amplitude are calculated and compared to predefined thresholds in the BLECS card.

The raw and filtered data is kept into the SRAM and can be retrieve with the Diagnostic application

Internal thresholds settingsoverview in the diagnostic tool.(unique for each monitor)

Last full period in saved in the SRAM and processed

B.Dehning: 07.06.2012 15


1. Check of cabling2. Check of components,

R- C filter

3. Check of chamber capacity

4. Check of stablity of signal, pA to nA

5. Not checked: gas gain

of chamber

High Voltage Modulation Results

B.Dehning: 07.06.2012




18B.Dehning: 07.06.2012

Software Overview, Management of Settings

Safety given by: Comparison of settings at

DB and front-end Safe transmission of

settings

front - end


19B.Dehning: 07.06.2012

Software Overview, Management of Settings

Safety given by: Comparison of settings at

DB and front-end Safe transmission of

settings

front - end

1. Modular design of data base very useful (if changes are needed limited impact)

1. MTF: history of equipment e.g. ionisation chamber, electronic cards, …

2. Layout: description of links between equipment3. LSA: reference for all data needed in the front-end (some imported

from MTF and Layout) 2. Storage of data in frontend in FPGA memory (even here corruptions

observed)3. Master for comparison is the front-end (this allows immediate beam

inhibit)4. Design very early defined in PhD thesis on reliability (root was followed

during project)5. Issue of design: protection and measurement functionality are

implemented in same front-end (review remark). 1. Critical, because of upgrades are more often needed on

measurement functionality compared to protection functionality2. New design: locking of FPGA firmware, which has protection

functionality (partial solution)3. Occupation of FPGA by firmware too large, first estimate of

occupation will be about 30% for new BLM systems


Noise and Fast Database Access

Important for availability (false dumps) and dynamic range

Main source of noise: long cables (up to 800 m in straight section)

Aim: factor 10 between noise and threshold

Thresholds decrease with increasing energy

noise reduction before 7 TeV operation Single pair shielded cables,

noise reduction: > factor 5 Development of kGy

radiation hard readout to avoid long cablesNoise estimate in design phase with test

installations at comparable locations


Daily Checks

B.Dehning: 07.06.2012


Temperature and failure rate

Survey of BLM thresholds

B.Dehning: 07.06.2012


Detailed Analysis of Modulation Result – Preventive Action

B.Dehning: 07.06.2012



Now: C++ program and SVN storage Future: all values and functional dependence in ORACLE


Now: C++ program and SVN storage Future: all values and functional dependence in ORACLE

Reserve Slides

B.Dehning: 07.06.2012



29B.Dehning: 07.06.2012

Literature

http://cern.ch/blm LHC

Reliability issues, thesis, G. Guaglio Reliability issues, R. Filippini et al., PAC 05 Front end electronics, analog, thesis, W. Friesenbichler Front end electronics, analog-digital, E. Effinger et al. Digital signal treatment, thesis, C. Zamantzas Balancing Safety and Availability for an Electronic

Protection System, S. Wagner et al., to be published, ESREL 2008

30

Reliability: Safety System Design Approach

Damage(system integrity)

Quench(operationalEfficiency)

Scaling:

frequency of events

xconsequence

FailsafeRedundancy

SurveyFunctional Check

Meantime

between failures

Methods: Stop of next

injectionExtraction of

beam

Reduction of operational efficiency

Safety ProtectionRisk Availability

SILALARP

Systems:Beam loss MonitorsQuench

protectionsystem

Interlocksystem

¨Dump system

Design issues:Reliable

componentsRedundancy,

votingMonitoring of

drifts1 10-8 to1 10-7 1/h

B.Dehning: 07.06.2012



31B.Dehning: 07.06.2012

Reliability: Settings and Checks from Database to Frontend

Setting storage in Oracle database

Settings: Threshold values Voltages, currents,

phase limits for automatic test

Serial numbers for ever equipment in the acquisition chain

Software version numbers

Comparison of frontend settings with database every 12 hours or after every update

If positive hardware base beam permit given

If negative after retry, manual intervention (no beam permit)

Corruption in frontend are more likely as in reference database, therefore =>

Request for comparison issued by front-end, most reliable (no software layers in between)


32

Resonance Crossing – SEM signal Issue

No signal from secondary emission monitors expected: due to ionisation in air at non insulated wire connection (patch boxes)

B.Dehning: 07.06.2012

Beam

ionisation chambers

secondary emission monitors

Optimized tools are very help full during commissioning (design during test phases)

B.Dehning: 07.06.2012


The BLM Acquisition System

Real-Time Processing BEE FPGA Altera’s Stratix EP1S40 (medium size,

SRAM based) Mezzanine card for the optical links 3 x 2 MB SRAMs for temporary data

storage NV-RAM for system settings and threshold

table storage

Analog front-end FEE Current to Frequency Converters (CFCs) Analogue to Digital Converters (ADCs) Tunnel FPGAs:

Actel’s 54SX/A radiation tolerant. Communication links:

Gigabit Optical Links.


34B.Dehning: 07.06.2012

Post Mortem Data (some examples)

PM application: BLM data of 0.082 seconline available

Longer PM buffer: BLM data of 1.72 secoffine available

43000 values (40 us)

2000 values (40 us)

Loss in a bending magnet

Monitors

Time

Extensively used for operation verification and machine tuning 1 Hz Logging (12 integration times)

Integration times < 1s: maximum during the last second is logged short losses are recorded and loss duration can be reconstructed (20%

accuracy) Also used for Online Display

BLM Published Data – Logging Data – Online Display• Change of the thresholds:

• As function of loss duration• As function of beam energy

• Will also be implemented for warm magnet and equipment protection

Energy integration time

Extensively used for operation verification and machine tuning 1 Hz Logging (12 integration times)

Integration times < 1s: maximum during the last second is logged short losses are recorded and loss duration can be reconstructed (20%

accuracy) Also used for Online Display

BLM Published Data – Logging Data – Online Display

Fit to data in the plan signal versusintegration time => interception straight line parameterization => loss duration

Storage of several running sums allows reconstruction of duration of loss event (reduction of network traffic and data storage place)

BLM Published Data – Logging Data – Online DisplayPost Mortem Data: Event triggered read out of all acquisition buffers1. Online (after 10 s 2000 values with 40 us integration time 2. Off line 43000 values


38B.Dehning: 07.06.2012

Quench and Damage Levels

• High dynamic range dynamic• Arc: 108

• Collimation: 1013 second detector

• Change of the thresholds:• As function of loss

duration• As function of beam

energy

Energy integration time

246 GeV

7 TeV

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]

quen

ch le

vels

[pro

ton/

s]

total quench levels at 450 GeVtotal quench levels at 7 TeV

He heat flow

He heat reserve

heat flow between cable and He

heat reserve of cable


39B.Dehning: 07.06.2012

Post Mortem Data (some examples), Zoom

Loss from primary event+

dump system loss

B.Dehning: 07.06.2012


Eva Barbara HolzerTIPP 2011 June 10, 2011 42

Main purpose: prevent damage and quench

3600 Ionization chambers (IC) interlock (97%) and observation

300 Secondary emission monitors (SEM) for observation

Beam Loss Measurement System Layout


Extensively used for operation verification and machine tuning 1 Hz Logging (nearly all 12 integration times)

Integration times < 1s: maximum during the last second is logged short losses are recorded and loss duration can be reconstructed

(20% accuracy) Also used for Online Display

BLM Published Data – Logging Data


Specifications Time resolution ½ turn, 40 us Average calculation loss:

12 values, 40 us to 83 s Max amplitude 23 Gy/s Min amplitude

1E-4 Gy/s @ 40 us 3E-7 Gy/s @ 1.3 s

Dynamic 2E5 @ 40 us ~ 1E8 @ 1.3 s

Damage level 2000 Gy/s @ 1 ms

All channels could be connected to the interlock system

Thresholds Loss duration dependent, 12

values Energy dependent, 32 values About 1.5 E6 thresholds


Quench and Damage Levels

450 GeV 3.5 TeV 5.0 TeV 7.0 TeVQuadrupole and bending magnet thresholds

B.Dehning: 07.06.2012

Eva Barbara HolzerTIPP 2011 June 10, 2011 45Workshop on Machine Protection, Focusing on Linear Accelerator Complexes

System settings& data flow

Beam permit

signal flowB.Dehning: 07.06.2012

Eva Barbara HolzerTIPP 2011 June 10, 2011 46Workshop on Machine Protection, Focusing on Linear Accelerator Complexes

46B.Dehning: 07.06.2012

Radioactive source test

Functional tests before installation

Barcode check

HV modulation test

Double optical line comparison

Offset to check connectivity (10 pA test)

System component identity check

Beam inhibit lines tests

Detector

Tunnel electronics

Surface electronic

sCombiner

Inspection frequency:

Reception Installation and yearly maintenance Before (each) fill Parallel with beam

Current source test

Threshold table data base comparison

Functional Tests Overview PhD thesis G. Guaglio


47B.Dehning: 07.06.2012

Ionisation Chamber and Secondary Emission Monitor

Stainless steal cylinder Parallel electrodes distance 0.5

cm Diameter 8.9 cm Voltage 1.5 kV Low pass filter at the HV input

IC: Al electrodes Length 60 cm Ion collection time 85 us N2 gas filling at 1.1 bar Sensitive volume 1.5 l

SEM: Ti electrodes Components UHV

compatible Steel vacuum fired Detector contains 170 cm2

of NEG St707 to keep the vacuum < 10-4 mbar during 20 years

Signal Ratio: IC/SEM = 60000


Mostly, onset of system degradation detected by regular offline checks before malfunction

Number of failures regarded manageable (no availability issue)

Hardware Failures (since Feb. 2010)

12 IC with bad soldering

(out of 3600)

9 GOH with low power

1 damaged connector

out of 1500

7 CFC with ‘noisy’ components

2 cards with bad solderingout of 750

12 with ‘weak’ receivers

out of 1500

2 with failed SRAM

out of 350

3 failed CPU RIO3

out of 25

1 VME Power Supply, out of 25

12

19

14

4

Specification: Beam Loss Durations and Protection Systems

4 turns (356 s)

10 ms

10 s

100 s

LOSS DURATION

Ultra-fast loss

Fast losses

Intermediate losses

Slow losses

Steady state losses

PROTECTION SYSTEM

Passive Components

+ BLM (damage and quench prevention)

+ Quench Protection System, QPS (damage protection only)

+ Cryogenic System

Since not active protection possible for ultra-fast losses => passive system

Classification loss signals to be used for functional and technical specificationB.Dehning:

07.06.2012 49Workshop on Machine Protection, Focusing on Linear Accelerator

Complexes

Documents

Beam Loss Detection