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