Upload
shing
View
38
Download
0
Embed Size (px)
DESCRIPTION
Test and start‐up procedures . Eva Barbara Holzer, CERN LHC BLM Audit CERN, June 10, 2008. Beam energy. Calibration. magnet. detector. tunnel elec. surface elec. BIC. LBDS. Particle shower. Environmental test. Functional test. Dependability design of BLM system. - PowerPoint PPT Presentation
Citation preview
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 1
Eva Barbara Holzer, CERN
LHC BLM Audit
CERN, June 10, 2008
Test and start‐up procedures
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 2
PhD thesis (G. Guaglio, Reliability of the Beam Loss Monitors System for the Large Hadron Collider at CERN, PhDThesis, Universit´e Clermont Ferrand II - Blaise Pascal, 2005.)
Fail safe design: “The most probable failure of the component does not generate the worst consequence (= risk to damage a magnet).”
1.Choice of reliable and radiation tolerant components environmental tests of tunnel electronics:
Temperature 15 – 50 degree Dose & single event no single event effects observed during tests,
dose corresponding to 20 years of operation
2. Redundancy and voting (when single components are not reliable enough)
3. Constant monitoring of availability and drift of readout channels (Functional Tests)
Dependability design of BLM system
Calibration
Functional testEnvironmental test
Beam energy
detector LBDSBICsurface elec.tunnel elec.magnet
Particle shower
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 3
Functional Tests PhD thesis G. Guaglio
Radioactive source test
Functional tests before installation
Barcode check (visual, serial numbers)
HV modulation test
Double optical line comparison
10 pA test
System component identity check
Beam inhibit lines tests
DetectorTunnel
electronicsSurface
electronicsCombiner
Inspection frequency:
Reception Installation and yearly maintenance Before (each) fill Parallel with beam
Current source test
Threshold table data base comparison
Functional checks – Monitoring of drifts
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 4
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Cable identification check (sticker, visual) Cable continuity check; particularly verify if there are no conductors
swapped Test of insulation, connection and current limits (bad connection
introduces offset current The crate shall be equipped with a test card to record the measurements. Offset current with HV on shall be below 0.5 pA on all channels. MTF recording
Leakage Current {M, 5m, T, HWC} (10-BLM P6: LC(offset) w/cable&M-r)
manually manually test card in tunnel rack
monitor tunnel rack slot
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 5
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Tests of insulation, correct interconnections and current limits Signal cable disconnected from monitor, current source connected.
Correct channel connection checked by observing channel by channel the current signal at the test card
In case the measured currents are outside the limits the corresponding cable are changed
MTF recording
Current Source {M, 5m, T, HWC} (10-BLM P7: Signal via source w/cable)
manually manually test card in tunnel rack
cable of monitor
tunnel rack slot
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 6
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Before each fill Threshold table, channel parameters (e.g. electronics card number)
and channel mapping (matrix for maskable/unmaskable and connected/unconnected) are compared to the one stored in the data base
ThresholdComparator & Combine&Servey (Combiner) vs DB Comparison {F, 5m, -, HWC QUICK} (60-BLM P1: Threshold/Ch Matrix Test)
Sequencer, man. (after th. ch.)
combiner RBAC TC & combiner
ELSA DB
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 7
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Beam permit transmission from all threshold comparators to the last combiner card
Before each fill For maskable and un-maskable channels
TC to CS (Combiner)Transmission {F, 5m, -, HWC QUICK} (60-BLM P3: UBP Check BLETC to
BLECS)
Sequencer (timeout), Expert
combiner combiner TC last combiner
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 8
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Technically possible, but not yet foreseen Before each fill For maskable and un-maskable channels Beam permit transmission from last combiner card to the “controls
interlock beam user” (the interface to the BIC in the VME crate). Last combiner BLM interface to BIC Toggle of redundant lines
CS to CIBU Transmission (responsibility of BIS) {F, 5m, -, HWC
QUICK} (60-BLM P4: UBP Check BLECS to CIBU)
BIS BIS BIS last combiner BLM interface to BIC
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 9
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Lab test, details not finalized (see talk by Ch. Zamantzas) Tested all 16 channels, all 12 running sums and all 32 energy values
of one threshold comparator, each time a new firm ware is installed – test of firmware.
On each channels, each running sum and at each energy in the threshold comparator is brought above the abort threshold (increasing the signal and/or lowering the threshold value).
Check if firmware correctly identifies the channel above threshold.
Remove Beam Permit {F, 5m, -, HWC} (60-BLM P2: TTable User Beam Permit T)
manually manually TC TC TC
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 10
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
The LHC energy information is sent via the “slow timing” to the CISV (VME card) and from there to the combiner (CS) (which distributes it to all TC in parallel)
Continuous check of: Transmission by CRC (cyclic redundancy check) Toggle bit to indicate updates; if timeout -> energy set to max.
value
Beam Energy Reception {F, 5m, -, HWC QUICK} (80-BLM)
continuous combiner combiner CISV combiner
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 11
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Check the connectivity up to the surface card before every fill The bias current is increased by 100 pA and the 1.3 second running
sum is measured and checked. Modulate the high tension with a sine wave Acquire modulated monitor signal, and check MTF recording
High Voltage Modulation {F, 1m, -, HWC QUICK} (40-BLM)
sequencer (timeout), expert
combiner combiner monitor (gas not checked)
DB
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 12
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Continuous check of the tunnel electronics : each minute the integrated injected current offset is checked
The bias current is increased in a control loop(possibility to correct for eventual offset in the electronics – e.g. ageing effects) so that a 10 pA offset is measured.
FPGA in CFC verifies signal levels MTF recording
10 pA Test {F, -, -, HWC CONTINOUS} (30-BLM, P2:10pA/1.3 sec run.sum)
continuos analogue tunnel el.
FPGA of CFC analogue tunnel el.
FPGA of CFC
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 13
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Functional test of full acquisition chain with Radioactive Source The procedure is described in a dedicated document made in
collaboration with TIS. The purpose is to create a signal on the chamber with the RA source
and check its presence in the corresponding DAB card channels in the surface electronics and the DB.
MTF recording
Radioactive Source Test {M, 5m, -, HWC} (50-BLM)
manually manually TIMBER (DB viewer)
monitor DB
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 14
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
The 40 us and 1.3 s running sum are measured with possible interference sources switched ON and OFF
Possible interference sources are: Collimator jaw motors Kicker magnets Injection line magnets
EMC Test {F, 2h, -, HWC} (70-BLM)
manually manually expert application
monitor DB
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 15
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Continuous 2 lines with CRC of transmission Decision matrix
Double Optical Line comparison
Continuous TC TC FPGA of CFC TC
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 16
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Continuous Check of software versions (FPGA of TC and CS) Check of electronics serial numbers
Channel / Card assignment SW check
Continuous FPGA TC & CS
TC & CS tunnel el., TC, CS
TC, CS
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 17
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
During machine checkout For each octant BLM takes away beam permit (by toggle functionality) Measure the delay (by time stamps) between the BLM initiating and
the dump system receiving the beam dump request Reporting in MTF
Transmission Time of Beam Permit Disabling
manually manually combiner & LBDS
combiner LBDS
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 18
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
During machine checkout Ramp dipole in 4 sectors and observe DB logging of beam energy
values Reporting in MTF
Change of Threshold Value with Beam Energy
manually manually DB, Manual dipole setting DB
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 19
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
Pilot beam of 5109 p+ at 450 GeV Decrease thresholds (trim application) to very low value Create local bump to force a beam dump request with very low level
of losses Measure delay between signal over threshold and the beam dump :
the whole chain from the chamber to the LBDS, via the LBIS, is tested
MPS Functionality of BLM (without quenching)
manually manually BLM system simulations (magnet + monitor)
BLM system & LBDS
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 20
initiated controlled & verified
meas. device start point end point
Calibration Beam energy
detector LBDSLBISsurface elec.tunnel elec.magnet
DB
43 bunches of 41010 p+ at 450 GeV (below damage limit) Steer the beam in the chosen magnet Check level of losses and BLM readings at the quench level Repeat for MQM, MQTL, MQ and MB If no quench occurs the threshold DB values have to be reduced Test justification and description in Chamonix XV proceedings, 2006,
Magnet Quenches with Beam (A. Koschik) A: transient losses and B: steady state losses
Provoked Quench (Transient + Steady State)
manually manually BLM system simulations (magnet + monitor)
BLM system
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 21
THE END
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 22
impact location unforeseen beam impact positionsunforeseen aperture locations
enthalpy (Cu, NiTi) (fast) erroneous geometrymodel errors
heat conductivity (slow) erroneous geometrymodel errors
coil energy deposition erroneous geometry (peak, average)Geant, FLUKA errors
detector energy deposition (slow / fast) erroneous geometryerroneous Geant
detector signal (slow, fast) steady high loss rate (saturation)fast high loss rate (saturation)steady low loss rate (leakage current)
transmission (Cu) erroneous cablinginterruptionsmall signalslarge signals
digitalisation (slow) small values (ADC)large values (CFC)
digitalisation (fast) large values (CFC)
transmission (opt.) erroneous cablinginterruptiondata integrity
threshold comparison (fast, slow) reception of data erroneousFPGA comparison small-large valueserroneous threshold values
BLM beam permit, (un)mask able, A/B (two redundant lines)matrix wronglink blocked TC to Combiner
transmission CIBU, mask able, A/B erroneous cablingtransmission CIBU, un-mask able, A/B interruption
ground connection
survey of internal voltages and currents HV, CFC, TC, VME crate, HV crate
EMC noise
energy reception beam energy
implemented? Defined? (jan2008) not impl.? not defined part. impl. implemented? not defined impl.test is controlled and verified by manual manual manual combiner combiner analogue FE FPGA combiner manual
measurement devicetest card in tunnel rack?
test card in tunnel rack?
expert application?
combiner combiner analogue FE crate CPU? combinerexpert aplication
combiner & FPGA
test starting point in the BLM signal chain monitorcable of monitor
monitormonitor (gas not checked)
analogue FE analogue FEoptical transmitter
analogue FE FPGA FPGA FPGA last combiner monitorSMP (safe machine oarameters)
test end point in the BLM signal chain mini-rack slot mini-rack slot DB? DB FPGA DB? opt. receiver FPGA DB? FPGA last combinerBLM interface to BIC
DB? combiner
test initiated by manually manually manuallySequencer Expert
Sequencer Expert
continous continous continousSequencer, manually after th. Change
Sequencer, Expert
BIS manually continous
Before each start-up and after change in installation Before each fill Parallel with beam
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 23
The BIS (Beam Interlock System) Architecture
Three ring-type systems:• LHC Beam 1 & Beam 2• SPS
Four tree-type systems:• LHC injection (Beam 1 & 2)• SPS extraction (BA4 & BA6)
User Permit A
User Permit B
Beam Permit Info
Test
Monitor
<1200m
USERINTERFACE
ELECTRONICS
BEAMINTERLOCK
CONTROLLERELECTRONICS
true false
‘DC’ Signals
Encoded Data Frames
User Permit A
User Permit B
Beam Permit Info
USERSYSTEM
ELECTRONICS
<4m
Permit Loop Beam-1 Anti-Clockwise
Permit Loop Beam-1 Clockwise
Permit Loop Beam-2 Clockwise
Permit Loop Beam-2 Anti-Clockwise
To/FromNext/
PreviousBICs
<6000mCurrent Loops RS485 Channels Fibre Optics
1 2 3
CIBU
Eva Barbara HolzerLHC BLM Audit, CERN June 10, 2008 24
Calibration / Threshold determination
BLM signal
Number of locally lost beam particles
Deposited energy in the machine component
Fraction of quench and damage level of the machine component
Proton loss locations
Hadronic showers
Chamber response Hadronic showers (energy deposition in magnet)
Quench and damage levels as function of loss duration (heat flow in magnet)Threshold values
Machine component Loss location Detector position Beam energy Loss duration