Transcript CVD diamond used for: (heat spreader material?) heavy ion beam monitor

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
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Diamond as beam monitor
Pb67+ up to 2,5*109 Ions pro bunch.
Here bunch split into 4 sub-bunches
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Time resolution in sub ns range
Diamond
signal [V]
500ns
Bunch of 2*108 Oxygen ions
with beam transformer
and diamond strip detector
Beam transformer [mV]
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Diamond can be bonded to metal
GND
HV+Signal
Metallization
Target
(Xenon, 14 bar)
Beam
Beampipe
(Vacuum)
Diamond
(300um)
Diffusion
Bonding:
Diffusion Bonding
Flange
Contact
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Simple sensor design proven in beam
Vacuumwindow
Solderpin
for cable
Diamond diffusion bonded
in metal vacuum flange
diamond
Advantages:
signal
[V]
1 cm
40 ns
14..12.2006
[ns]
RD42 Meeting, CERN
• no hybrid needed
• radiation hard
• mechanically robust
• Al-metallization done without
masks
• Guard ring = diffusion bond
Left: signals from cyclotron showing
the 26 MHz bunches. Each bunch
has about 106 protons, so the signal
can be directly displayed on the scope
without amplifier, even with 10m cable
Width given by spread in bunches
W. de Boer, Univ. of Karlsruhe
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LHC beam loss and background
Monitoring at CMS
BCM1
IP
BCM2
“heat spreader”
CVD diamond radhard tunnelcard
LHC ionization chambers
for beam loss monitoring
14..12.2006
RD42 Meeting, CERN
Beam loss at
KA cyclotron
W. de Boer, Univ. of Karlsruhe
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Beam test with BCM electronics for LHC
(developed in Bernd Dehning’s group at CERN)
8 channel
tunnel cards
with optical
fiber output
40 us sampling
time
16 channel
VME readout
cards
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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CFC Card – working principle
ADC values
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 times
the capacitor was discharged, which is a measure of the sensor current.
Additionally an ADC converts the integrator voltages into digital values
which can be used to calculate the slope of the discharge and therefore the current,
this is important for low detector currents.
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Test at KA cyclotron
diamond
CFC-Card
USB readout
electronics
current to frequency converter
range: 10pA – 1mA
low-noise readout
radiation hard design
KAZ
Karlsruher cyclotron
26MeV protons
14..12.2006
RD42 Meeting, CERN
sensor signal
versus time
W. de Boer, Univ. of Karlsruhe
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System Test at cyclotron in Karlsruhe
1scan
5=5scans
36cm
2=2scans
38cm
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3=3scans
31cm
RD42 Meeting, CERN
4=4scans
29cm
W. de Boer, Univ. of Karlsruhe
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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
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Layout CMS Beam Loss Monitoring
Tunnel card with CFC from LHC Beam
Monitoring Group (Dehning, Effinger)
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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BCM2 sensor
pCVD 350µm 10x10mm
mounted in a box of aluminum for shielding
metalization visible from both sides
contact with bond wires and silver epoxy
glue
CMS sensor from Bob Stone, Rutgers
metalization: Tungsten-Titanium
measured CCD: 250µm

HV
14..12.2006
Signal
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Decrease of CCD vs fluence with 26 MeV protons
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Radiation damage in Diamond
200 MeV
Si total
C total
Si inelastic
n
Si elastic
C inelastic
C elastic
14..12.2006
RD42 Meeting, CERN
p
Z
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Total
Ions
417
910
1384
1021
1225
265
493
398
909
270
383
662
11152
46107
6559
Z
6
5
4
3
2
1
Total
10 GeV protons
Ion
NIEL
698
0.8
869
0.77
584
0.44
1133
0.55
10625
2.01
30465
0.24
44374
4.81
W. de Boer, Univ. of Karlsruhe
NIEL
4.2
9.06
12.47
8.86
8.45
1.41
2.09
1.31
2.36
0.55
0.66
0.67
4.4
0.9
57.38
Si
C
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Radiation monitoring components
BSC
Z=± 1.9m, r=4.3cm
BCM1
Z=± 1.9m, r=4.3cm
Cherenkov
Fibres
Fibre Based
Radiation Monitors
14..12.2006
RD42 Meeting, CERN
BCM2
Z=± 14.4m, r=29cm
W. de Boer, Univ. of Karlsruhe
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CMS Flux Maps
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
14..12.2006
RD42 Meeting, CERN
High neutron
flux for BCM2
W. de Boer, Univ. of Karlsruhe
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BCM1 and BCM2
CMS Rad mon
RADMON
HF Plug
TOTEM T1
TOTEM T2
IP
BCM2
Sensors
BSC Scintillators
(On front of HF)
Fibre loop
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RD42 Meeting, CERN
BCM Sensor
Carriage+ BCM1
Fibre Coils
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BCM1: Mechanical Structure
Tracker Bulkhead
BCM1 Carriage
BCM1
Pixel Rail System
Beampipe
14..12.2006
RD42 Meeting, CERN
W. de Boer, Univ. of Karlsruhe
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Machine Protection Systems and Interfaces
Beam Current
Monitors
DCCT Dipole
Current 1
DCCT Dipole
Current 2
RF turn clock
Current
Safe LHC
Parameters
Energy
Beam Energy
Tracking
Injection
Kickers
Beam Dump
Trigger
Discharge
Switches
Cryogenics
Power Converters
AUG
UPS
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Powering
Interlock
System
NC Magnet Interlocks
BPMs for dx/dt + dy/dt
dI/dt beam current
dI/dt magnet current
Screens
RF + Damper
LHC Experiments
Vacuum System
Operators
Software Interlocks
auxiliary
circuits
Timing
RD42 Meeting, CERN
TL collimators
BPMs for Beam Dump
LHC
Beam
Interlock
System
essential
circuits
SPS Extraction
Interlocks
BLMs aperture
BLMs arc
Collimators / Absorbers
Beam Dumping
System
Access Safety
System
Quench
Protection
Energy
SafeBeam
Flag
Energy
PM Trigger
W. de Boer, Univ. of Karlsruhe
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