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

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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

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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