14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 1
CVD diamonds as beam monitors
CVD diamond used for:
• heavy ion beam monitor
•beam exit window for primary beams (heat spreader material?)
•Beam Loss Monitor for CMS
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 2
Pb67+ up to 2,5*109 Ions pro bunch. Here bunch split into 4 sub-bunches
Diamond as beam monitor
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 3
Diamond signal [V]
Beam transformer [mV]
Bunch of 2*108 Oxygen ionswith beam transformerand diamond strip detector
500ns
Time resolution in sub ns range
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 4
Beampipe(Vacuum)
Target (Xenon, 14 bar)
Diamond(300um)
FlangeDiffusion Bonding
Diffusion Bonding:
Metallization
GND
HV+Signal
Diamond can be bonded to metal
Beam
Contact
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 5
Simple sensor design proven in beam
Diamond diffusion bondedin metal vacuum flange
Advantages:
• no hybrid needed• radiation hard• mechanically robust• Al-metallization done without masks• Guard ring = diffusion bond
[ns]
Left: signals from cyclotron showingthe 26 MHz bunches. Each bunchhas about 106 protons, so the signalcan be directly displayed on the scopewithout amplifier, even with 10m cable.Width given by spread in bunches
diamond
signal
Vacuumwindow Solderpinfor cable
1 cm
40 ns
[V ]
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 6
IP
BCM1
BCM2
“heat spreader”CVD diamondradhard tunnelcard
LHC ionization chambersfor beam loss monitoring
Beam loss atKA cyclotron
LHC beam loss and backgroundMonitoring at CMS
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 7
Beam test with BCM electronics for LHC(developed in Bernd Dehning’s group at CERN)
8 channeltunnel cardswith opticalfiber output40 us samplingtime
16 channelVME readoutcards
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 8
CFC Card – working principle
Principle: after reset: C is discharged with detector current. To continuously check the card an additional current source of 10 pA discharges as well, so at least every 20s a trigger will be given to a
counter indicating that C was discharged below the threshold. Every 40 us the counter on the board is readout telling how many timesthe capacitor was discharged, which is a measure of the sensor current.Additionally an ADC converts the integrator voltages into digital valueswhich can be used to calculate the slope of the discharge and therefore the current, this is important for low detector currents.
ADC values
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 9
CFC-CardUSB readout electronics
diamond
KAZKarlsruher cyclotron
26MeV protons
current to frequency converter range: 10pA – 1mAlow-noise readoutradiation hard design
Test at KA cyclotron
sensor signalversus time
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 10
5=5scans36cm
4=4scans29cm
3=3scans31cm
2=2scans38cm
1scan
System Test at cyclotron in Karlsruhe
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 11
Beam Condition Monitoring at LHC• BCM at LHC is done by roundabout 3700 gas ionization
chambers which are placed round the ring• if their signal gets too large a beam dump is requested
to prevent a quenching of the superconducting magnets or damage on the machinery
• there is no space inside the 4 caverns for this chambers, so another solution was needed to monitor the beam without interruption
• For CMS this is the BeamRadiationMonitoring System consisting of 6 subsystems of which 3 are diamond based and places inside the CMS detector
• BCM2 consists of 16 (opt 32) pCVD diamonds, which are placed near the beam pipe
• the readout of BCM2 is solely based on the same electronics as the gas ionization chambers, so the data is immediately available via the LHC software
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 12
Tunnel card with CFC from LHC Beam Monitoring Group (Dehning, Effinger)
Layout CMS Beam Loss Monitoring
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 13
BCM2 sensorpCVD 350µm 10x10mmmounted in a box of aluminum for shielding metalization visible from both sidescontact with bond wires and silver epoxy glueCMS sensor from Bob Stone, Rutgersmetalization: Tungsten-Titaniummeasured CCD: 250µm
HV Signal
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 14
Decrease of CCD vs fluence with 26 MeV protons
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 15
Z Ions NIEL14 417 4.213 910 9.0612 1384 12.4711 1021 8.8610 1225 8.459 265 1.418 493 2.097 398 1.316 909 2.365 270 0.554 383 0.663 662 0.672 11152 4.41 46107 0.9Total 6559 57.38
10 GeV protonsZ Ion NIEL6 698 0.85 869 0.774 584 0.443 1133 0.552 10625 2.011 30465 0.24Total 44374 4.81
Radiation damage in Diamond
npSi elastic
Si inelastic
Si total
C total
C elastic
C inelastic
Si
C
200 MeV
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 16
BCM2Z=± 14.4m, r=29cm
BCM1Z=± 1.9m, r=4.3cm
BSCZ=± 1.9m, r=4.3cm
Fibre Based Radiation Monitors
Cherenkov Fibres
Radiation monitoring components
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 17
Charged particle flux at 1034
BCM1 ~ 1x107cm-2s-1
0.25 cm-2 per BX
Neutron flux at 1034 BCM1 ~ 1x107cm-2s-1
0.25cm-2 per BX
High neutron flux for BCM2
CMS Flux Maps
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 18
TOTEM T2IP
TOTEM T1HF Plug
BCM Sensor Carriage+ BCM1
BSC Scintillators (On front of HF)
BCM2 Sensors
Fibre loopFibre Coils
CMS Rad mon RADMON
BCM1 and BCM2
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 19
Tracker Bulkhead
BCM1 Carriage
Pixel Rail SystemBeampipe
BCM1
BCM1: Mechanical Structure
14..12.2006 RD42 Meeting, CERN W. de Boer, Univ. of Karlsruhe 20
Beam Energy Tracking
Beam Dumping System
DCCT Dipole Current 1
DCCT Dipole Current 2
RF turn clock
LHCBeam
Interlock System
Access Safety System
Beam DumpTrigger
SPS ExtractionInterlocks
Injection Kickers
essentialcircuits
auxiliarycircuits
Safe LHCParameters
Beam Current Monitors Current
EnergyEnergy
SafeBeamFlag
Energy
TL collimators
Timing PM Trigger
BLMs aperture
BPMs for Beam Dump
LHC Experiments
Collimators / Absorbers
NC Magnet Interlocks
Vacuum System
RF + Damper
dI/dt beam current
BLMs arc
BPMs for dx/dt + dy/dt
dI/dt magnet current
OperatorsSoftware Interlocks
Screens
Powering Interlock System
Quench Protection
Power Converters
Discharge Switches
AUGUPS
Cryogenics
Machine Protection Systems and Interfaces