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BRM Report forCMS Management Board
Meeting Richard Hall-Wilton (CERN - TS/LEA)
On Behalf of the CMS Beam Conditions and Radiation Monitoring Group
Institutes involved:
Auckland, Canterbury, CERN, DESY-HH, DESY-Zeuthen, Karlsruhe, Princeton, Rutgers, Tennessee, UCLA,
UC-Davis, Vienna, Uni Hamburg
14th September 2007
BRM Group• BRM Group is run as a sub-project within CMS
Technical Coordination• Project leaders: Austin Ball + Emmanuel Tsesmelis• Approx 40 People involved within last 18 months:
Thomas Aumeyr, Ed Bartz, Austin Ball, Alan Bell, Anthony Butler, Joel Butler, Phil Butler, Maria Chamizo, Jesse Cornelissen, Wim De Boer, Elies Ennabli, Stephan
Farry, Alexander Furgeri, Alexei Garmash, Richard Gray, Richard Hall-Wilton, Mark Hashimoto, Matthew Hollingsworth, Uwe Holm, Rob Knegjens, David Krofcheck, Wolfgang Lange, Jose Lazo-Flores, Alick Macpherson, Daniel Marlow, Steffen
Mueller, Heinz Prause, Nuno Rodrigues, Vladimir Ryjov, David Schaffner, Steve Schnetzer, Patrice Siegrist, Jeff Spalding, Stefan Spanier, David Stickland, Robert Stone, Wojciech Szklarz, Emmanuel Tsesmelis, Rainer Wallny, Sam Whitehead,
Jenny Williams, Wolfram Zeuner
Includes experts previously involved in Radiation Monitoring at experiments at LEP, HERA, TEVATRON, BABAR
Core group of 8-10 people at CERN
3
Beam + Radiation Monitoring Functionality Provide monitoring of the beam-induced radiation field within the UXC55 cavern
and the adjacent straight sections. Provide information on the state of the machine, and hence helps determine
whether sub-detectors should be turned on. Provide real-time fast diagnosis of beam conditions and initiate protection
procedures in the advent of dangerous conditions for the CMS detector System features include:
Active whenever there is beam in LHC Ability to initiate beam aborts Provision of warning & abort signals to CMS subdetectors (ie ramp down
LV and HV) Postmortem reporting Provision of online and offline beam diagnostic information to CMS + LHC Bench-marking of integrated dose and activation level calculations Integration of all online beam diagnostic information (including
subdetectors). Updating at ≥1 Hz
Statement of CMS Policy: CMS requires that if LHC is running then the CMS Protection System (BCM)
must be operational to ensure safety of the Detector.
Clarification is needed for signal and data exchange with LHC, GUIs for CMS and LHC
Subsystem Location Sampling time
Function Readout + Interface
PassivesTLD + Alanine
In CMS and UXC
Long term Monitoring ---
RADMON 18 monitors around CMS
1s Monitoring Standard LHC
BCM2Diamonds
At rear of HFz=±14.4m
40 us Protection CMS + Standard LHC
BCM1L Diamonds
Pixel Volumez=±1.8m
Sub orbit~ 5us
Protection CMS + Standard LHC
BSCScintillator
Front of HFz=±10.9,14.4 m
(sub-)Bunch by bunch
Monitoring CMS Standalone
BCM1FDiamonds
Pixel volume z=±1.8m
(sub-)Bunch by bunch
Monitoring + protection
CMS Standalone
BPTXBeam Pickup
175m from IP5
200ps Monitoring CMS Standalone
Systems are independent of CMS DAQ, and on LHC UPS power
Incr
ease
d tim
e re
solu
tion
Emphasis on detectors that are
relative flux monitorsBRM Subsystem Hardware Summary
5
BPTX: 175m
RADMON: 18 monitors around UXC
BCM1BSC1
BCM2+BSC2
1.8m
10.9m
14.4mPASSIVES: Everywhere
Beam Conditions Monitor Carriage
• Design of carriage complete, and currently under construction• Design allows for co-habitation of PLT• Fabrication at ADCO, Germany• Delivery mid-November
• Installation cassette conceptual design completed• Finalised by end September• Produced during October
Protection Systems
Protection Systems - Beam Conditions Monitor
CVD Diamond used extensively elsewhere for radiation monitoring- CDF, BaBar, Belle
CMS Diamonds have also been installed in CDF
Development program ongoing since many years within CMS
diamonds (+BLMs)
Example from CDF:• LHC Beam Loss Monitor readout chosen
• Robust, reliable, extensively tested• Trusted by LHC• Implementation approved through
AB/BI technical board• BRM group have developed excellent
working relationship with BLM group and AB/BI, AB/CO, AB/OP
• Output to beam ABORT is fully hard-wired
• Similarly hard-wired warning/alarm levels for sub-detectors exist• eg for tracker, pixels, etc.• To be able to take action (turn off hv,
lv) in the event of the onset of adverse beam conditions
9
BCM1L: Leakage current monitoring•Consists of 4 units per end mounted on the BCM Carriage.
BCM1_L mezzanine board tested using final LHC Beam Loss Monitor readout chain
BCM1Z=±1.8m, r=4.3cm
Assembly will start soon at PrincetonReady to mount on carriage end this year
Protection systems:
ABORT GAP
10
BCM2
• Behind TOTEM T2• Mounted on CASTOR installation table
• BCM2 sensors profile (per end)• Inner Diamonds (4) sensitive to luminosity products• Outer diamonds (8) sensitive to incoming background (shielded from IP)
• Standard LHC Beam Loss Monitor readout • Diamonds Frontend readout via rad. hard LHC readout for BLM• Backend Readout: DAB64 cards, FESA• For LHC looks identical to Beam Loss Monitors
BCM2 & BSC2Z=± 14.4m, r=5, 29cm
All components needed in handAssembly, calibration and testing ongoing at KarlsruheInstallation schedule on time
From Day 0, will be active in ABORT
BSC2
BCM2
Monitoring Systems
12
PPOPTO
Counting Room
Off DetectorOn BCM1 Carriage
BCM1F: Bunch by bunch monitoring
BCM1F readout chain tested with final design sensor, FE boardAssembly, testing, calibration of FE boards about to start at CERNWill be ready to mount when carriage arrives mid-Nov
Amplifier JK16 rad hard
• Sensor - 5x5x0.504mm• Source – Sr90• FE - 16mV/fC, AC coupled
3fC responseJK16(Ch.1) and AOH
(Ch.2)
MIP Sensitive
TRK AOH
Single Crystal Diamond
13
$ Simple standalone system: No front end electronics
$ Simple to commission$ Monitoring Independent of CMS DAQ statusWill need replacement at some point
Readout:$PMTs mounted on side of HF, readout over long
cables (80m) to USC.$ADC & discriminator + TDC readout
$ Same back end as BCM1F
CMS Beam Scintillator Counters
BSC Paddles
BSC Disks
BSC1 --- 11 000 cm2 BSC2 --- 1 000 cm2
Z=+/-14.4 mZ=+/-10.9 m
Beampipe
Beampipe
Inner radius - 5 cmInner radius - 15 cm
Output to CMS (+LHC?): statistical measurements
•Rate monitoring on sub orbit scales + bunch by bunch, inc. Abort gap monitoring•Relative time measurements: incoming vs outgoing particles•Should be sensitive during 450 GeV + pilot beam
$ Installation on schedule
Monitoring: BPTX• Trigger on orbit marker
• Measure phase between bunch and 40MHz Expt clock • Check filling scheme; bunches in correct RF buckets.• Check abort gap is empty.• Check for satellite bunches in neighbouring RF buckets• Measure the intensity (or amplitude) of each bunch • Measure the period of the clock
• Scope-based readout chosen jointly with ATLAS• Will also check phases of different clocks• Calculate z position of IP• Technical Trigger input• Sensitive to first beam
Beam Timing for the Experiments
LHC Beam Position Monitor
Analog Signal: ~1ns FWHMOrbit length= 89us Samples entire orbit Sampling at 5GSamples/sec =>200ps sampling
SPS Testbeam - June
24.97 +/- 0.05 ns
Measured Clock Period
Predicted and measured amplitudes
agree
BPTX: Beam pickup 175m upstream IP
Time
15
RADMON Units (In conjunction with TS-LEA) Measures
Dose, dose rate using RadFETs Hadron (E>20 MeV) flux and fluence, SEU rate via SRAM 1 MeV equiv neutron fluence via pin diodes (α >100keV fluence)
18 Monitors deployed around CMS (UXC +USC) Data reported back to the RADMON database Installation of RADMON infrastructure started
Used for Online benchmark points for verification of simulations
Passive Dosimeters (In conjunction with DESY-HH, Uni Hamburg) TLDs, Alanine Provide detailed radiation mapping after Pilot run
RADMON and Passive Monitors
TLD~4mm
dia
16
Interface with CMS AND LHC Database
Software Framework used by BRM based upon AB/CO standards
Interface to LHC database(s) is Beam Loss Monitor standard
Interface to CMS database(s) is DCS
Machine Technical Network CMS Technical Network
“BRM5” “BRM4”
StaticDisplays
DB
DataStoredlocally
PVSSDCS PC
orBCM Volt PC
DataStoredlocally
BRMPublisher
DCSDB
DIP relayData from BCMCrate through
FESA and CMW
StaticDisplays
DIP publisher
DIP listener
BRM Listener
CMWCCCDIP
publisher
Collaborating with Luminosity Group for combined display
Static Display for LHC - use AB/CO Standards Displays - developed with AB/CO
BRM Data
Lumi Data
ABORT Threshold Determination
• Setting suitable Abort thresholds to protect sub-detectors depends upon:
• Sub-Detector safety/damage levels
• BCM detector response
• Relation between loss rates measured at BCM location and the sub-detector location
• Sub-Detector safety/damage/comfort levels:
• Have contact persons for Pixels, Tracker, ZDC
• Will broaden this dialogue over the coming months with other interested sub-detectors
• Thresholds will need tuning, particularly at the beginning
• Developing framework to be able to do this simply
Ch: 1 Sum: 8
Time [s]3380 3390 3400 3410 3420 3430 3440
I [A]
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-910×
Cross Calibration of Detectors
Be-Target
Be-Target
BLM
BCM
Other stuff
Steffen Mueller BRM Meeting 27. June 2007 10
Calibration results• BLM:
S=46.4 (+/- 0.53)nA/8.5e7N/(cm**2 s)*DC+ 3.68 (+/- 3.18)nA
Response: 8.65e-18C/N
This is compatible to the simulated response from Markus: 3.5e-18C/N (preliminary.
Assumptions: single energy Neutrons 22MeV, parallel beam)
• BCM2:
S=37.96 (+/- 0.65)nA/1.4e8N/(cm**2 s) * DC + 8.66 (+/- 3.9)nA
Response: 270.2e-18C/N
0
100
200
300
400
500
600
0 2 4 6 8 10 12
dete
cto
r curr
ent / nA
deutoron current / uA
ionisation chamber, 60cm from targetBCM2 diamond, 58cm from target
BLM
Preliminary Results
Testbeam programme just started for cross-calibration of diamonds with BLM
neutrons in Louvain
Starting slice test all sub-systems in PS (T11)
Ch: 3 Sum: 8
Time [s]3380 3390 3400 3410 3420 3430 3440
I [A]
0.2
0.25
0.3
0.35
0.4
-910×
1: Passives, Alanine
2: BCM2 diamond, P27
3: Prototype diamond
4: BLM tube
5: Passives, Alanine
6: BSC
PRELIMINARYBLM Raw Data BCM2
200pA predicted
Louvain
SPS
Simulations• Aim to understand how relative rates
seen in BCM locations correlate to rates in, eg, pixel detector
• Trying to determine particle species and spectra that will be seen by diamonds
• Initial results seem to confirm expected shadowing of outer BCM2 diamonds from collision products
• In dialogue with other groups working on simulations of backgrounds
Outer Position: Shielded from IPPRELIMINARY
Inner position: Unshielded from IPPRELIMINARY
Two locations for BCM2 monitoring r =5cm and r= 29cm
Outer position has ~O(100) increase in sensitivity to beam halo
Example: BCM2
Summary• Beam and Radiation Monitoring system will provide protection for CMS from beam accidents
and give an overview of the machine background conditions from day 0
• All sub-systems of the BRM are on schedule for installation
• BSC will need upgrade as some point
• Clarification needed on remit of the group
• Especially injection inhibit, signal and data exchange with the machine
• Present manpower (just) sufficient to complete the hardware project
• In particular, excellent progress made this summer with influx of summer students
• Very good working atmosphere within the group
• However concern about manpower volatility looking forward
• Continuing need for people to maintain and operate BRM
• Loosing key people now
• Majority of group has uncertainty about participation within the group within the next year
• Support provided from groups involved is much appreciated, but needs to be maintained
BACKUP
24
BCM: Beam Conditions Monitors
1
3
2
CMS BCM Units BCM1L: Leakage current monitor Location: z=±1.8m, r=4.5cm 4 stations in ϕ, 8 sensors total Sensor: 1cm2 PCVD Diamond Readout: 200kHz / 5us No front end electronics
BCM1F: Fast BCM unit Location: z=±1.8m, r=4.3cm 4 stations in ϕ, 8 sensors total Sensor: Single Crystal Diamond Electronics: Analog+ optical Readout: bunch by bunch (Asynch)
BCM2: Leakage current monitor Location: z=± 14.4m, r=29cm, 5cm 8 stations in ϕ, 24 sensors total Sensor: 1cm2 PCVD Diamond Readout: 25kHz / 40 us 16 Sensors shielded from IP Off detectors electronics
1
2
3
2 Sensor Locations, 3 Monitoring Timescales