1 US CMS DOE/NSF Review: May 8-10, 2001 1 WBS 4.0 The Electromagnetic Calorimeter Roger Rusack The University of Minnesota US-CMS L2 ECAL Manager

1US CMS DOE/NSF Review: May 8-10, 2001 1

WBS 4.0 The Electromagnetic CalorimeterWBS 4.0 The Electromagnetic CalorimeterWBS 4.0 The Electromagnetic CalorimeterWBS 4.0 The Electromagnetic Calorimeter

Roger Rusack

The University of Minnesota

US-CMS L2 ECAL Manager


OutlineOutlineOutlineOutline

Subsystem overviewProblems and Solutions

Current StatusChangesConcerns


The constructionThe constructionThe constructionThe construction

ECAL Barrel and Endcaps

Supermodule

VFE ModulesGrid

Crystals

Services

36 supermodules 1700 crystals per super-module

~20,000 crystals in endcap


VFE readoutVFE readoutVFE readoutVFE readout

ADC

Energy

Light

Light

Current

Current

Voltage

Voltage Bits

Bits

Light

Avalanche photodiode

FPPA

Bit-serializer

Electro-optics


CalibrationCalibrationCalibrationCalibration

Seven month period of operation in 2006 at low luminosity. CMS goal to observe the Higgs.

• At low luminosity physics channels for calibration are limited by rates.

• Need to start with crystals calibrated to 1%.

• Calibrate every crystal in beam between now and installation.


Calibration ScheduleCalibration ScheduleCalibration ScheduleCalibration Schedule

• Module 0 tests October – Novemebr 2001 to debug whole calibration process.

• Supermodule calibration• SM1 3.5 months in 2002. • SM2 to SM11 2002.• SM12 to SM24 and DEE1 2003• SM25 to SM36 and DEE2 2004

• Sufficient to remeasure ~10 SM’s in 2004.

• Fits with V31 planning.• Install in SX5 EB+ (SM1 – SM18) in 8/2004.• Install in UX5 EB+ (SM1 – SM18) in 11/2004.


Issues at last ReviewIssues at last ReviewIssues at last ReviewIssues at last Review

Crystal production.

Supermodule Mechanics

APD Radiation hardness

Honeywell Bit-serializer


SM Construction ScheduleSM Construction ScheduleSM Construction ScheduleSM Construction Schedule

Production of crystals sets the pace of the supermodule construction at the end.

Module 0’ tests paced by electro-optic components.

Calibration of supermodules paced by electronics delivery at start.

Initial pace set by APD production.


Improvements to the crystal process increased rate of production.

• New method: 2-crystals per boule.

• All Russian crystals to be made this way.

CrystalsCrystalsCrystalsCrystals

36 mm64

mm


Double EE

Double EB

Single EE

Crystal BoulesCrystal BoulesCrystal BoulesCrystal Boules


CMS-ECALCrystal production

0

10000

20000

30000

40000

50000

60000

70000

1/1/

01

3/1/

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5/1/

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7/1/

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9/1/

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11/1

/01

1/1/

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3/1/

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7/1/

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9/1/

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/02

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3/1/

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5/1/

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7/1/

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9/1/

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/03

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3/1/

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7/1/

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9/1/

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1/1/

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3/1/

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5/1/

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7/1/

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9/1/

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11/1

/05

1/1/

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3/1/

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5/1/

06

Barrel

Endcap

SM1 done

EB+ done

EB- done

Dee 1

Dee 2

Dee 3

Dee 4

EB + install

EB - install

EE+ inst EE- inst

Crystal Production

Supermodule Construction

Crystal Production

Crystal ProductionCrystal ProductionCrystal ProductionCrystal Production


MechanicsMechanicsMechanicsMechanics

Major problems last year: Prototype grid failed tolerance requirements.• Tolerance is critical for barrel assembly.

Major redesign of the way grid is made.• Dropped idea of welding three pieces together.• Now simpler bolted solution.• Better cooling.

2 of 4 module prototypes delivered and meet specifications.

Have on order parts for SM1 and SM2.Problem solved


MechanicsMechanicsMechanicsMechanics

Alveola are now tied on their front face

Grid are made by 3 bolted pieces


Bit-SerializerBit-SerializerBit-SerializerBit-Serializer

Last year two failed runs at Honeywelland then 3” ‘safe’ mode run failed.

Three strikes and…

Switched to CERN solution:Giga-optical link. Made in 0.25 process.

Bit error rate test in the 800Mbit/s G-Link mode: 20 hours error free

transmission

Problems with VCSEL driverMods for ECAL. Submission May 2001

Will not be ready for Module 0’

Cheaper…


We need this component in final form for the 2001 calibration test.

• Used to send output of serializer to upper level readout.

• Slow getting components from Methode

• Started second parallel development with Spinner

Major Issues May 2000.

Electro-OpticsElectro-OpticsElectro-OpticsElectro-Optics

Methode

Spinner


FPPA2000 (UHF1x)FPPA2000 (UHF1x)FPPA2000 (UHF1x)FPPA2000 (UHF1x)

ADC

Energy

Light

Light

Current

Current

Voltage

Voltage Bits

Bits

Light

40 MHz Multi-ranging sample-and-hold Intersil UHF-1X process

Joint Lyon-Princeton (LBL) design

1000 parts made. Early results look good. Detailed studies on large quantity now at Lyon.


FPPAFPPAFPPAFPPA


FPPAFPPAFPPAFPPA

Circuit functions as designed.Noise level is 4 × higher than anticipated.

OK for module 0’ tests – will need another engineering run


APD’sAPD’sAPD’sAPD’s

Problem all last year with radiation damage.• APD’s survival goal is 0.1% level to ensure energy

resolution required to observe the Higgs.• 5% failure rate seen in proton beam at PSI.• Requirements 2×1013 neutrons/cm2 and 10 kGy gammas

over 10 years.• Proton beam delivers full dose in 2 hours.

Changes• Compared neutron with protons. With neutrons 100%

survival. • Effect of ionizing dose is rate dependent.• Improve APD design


Radiation Damage to APD’sRadiation Damage to APD’sRadiation Damage to APD’sRadiation Damage to APD’s

0

10

20

30

40

50

60

0 1000 2000 3000 4000 5000 6000 7000

time [sec]

APD #220

APD #222

APD #234

APD #241

Time

Curr

en

t


Changes to APD’sChanges to APD’sChanges to APD’sChanges to APD’s

Move n+ in away from p

Increase gap


Californium SourceCalifornium SourceCalifornium SourceCalifornium Source


Neutron IrradiationNeutron IrradiationNeutron IrradiationNeutron IrradiationNeutron irradiation

0

5

10

15

20

25

30

35

40

0:00:00 24:00:00 48:00:00 72:00:00 96:00:00 120:00:00 144:00:00 168:00:00 192:00:00 216:00:00

Time Hours

Cu

rren

t

Every APD has survived neutron irradiation

135 irradiated so far


MonitorMonitorMonitorMonitor

Ti:Saphire laser pumped by a Nd:YLF laser.

• Light output at 440 or 490 nm.

• Used to monitor changes to the crystal response between calibration cycles.

• Two lasers required to ensure continuous operation during supermodule calibration.

• Ship first laser August ’01

• Second one early 2002.


Monitor Light SourceMonitor Light SourceMonitor Light SourceMonitor Light Source


Cost estimate changesCost estimate changesCost estimate changesCost estimate changes

Major cost changes.

Honeywell to IBM switch. ($640k)

Peter Denes -- Princeton to LBL. $350kExtra engineering effort. $100kSpinner development contract $110kProductization of FPPA $150kCalifornium cost change $ 75k


L2 and L3 milestones.L2 and L3 milestones.L2 and L3 milestones.L2 and L3 milestones.

Delays in mechanics and APD and Electronics in production

ML2 - Module 0 complete - 8 month delay.ML2 - SM1 completed – 15 month delay.


ConcernsConcernsConcernsConcerns

Points to watch in near future.• Production of the electro-optics components

for Module 0’.

• Production start of FPPA.

• Bit-serializer and SEU effects.

• Establish procedures for electronics radiation hardness QA/QC.

• Readiness for calibration.

Documents

1 US CMS DOE/NSF Review: May 8-10, 2001 1 WBS 4.0 The Electromagnetic Calorimeter Roger Rusack The University of Minnesota US-CMS L2 ECAL Manager