1. 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

2. 2 US CMS DOE/NSF Review: May 8-10, 2001 2 OutlineOutline Subsystem overview Problems and Solutions Current Status Changes Concerns

3. 3 US CMS DOE/NSF Review: May 8-10, 2001 3 The construction ECAL Barrel and Endcaps Supermodule VFE Modules Grid Crystals Services 36 supermodules 1700 crystals per super-module ~20,000 crystals in endcap

4. 4 US CMS DOE/NSF Review: May 8-10, 2001 4 VFE readout ADC Energy  Light  Current  Voltage  Bits  Light Avalanche photodiode FPPA Bit-serializer Electro- optics

5. 5 US CMS DOE/NSF Review: May 8-10, 2001 5 CalibrationCalibration 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.

6. 6 US CMS DOE/NSF Review: May 8-10, 2001 6 Calibration 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 DEE22004 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.

7. 7 US CMS DOE/NSF Review: May 8-10, 2001 7 Issues at last Review Crystal production. Supermodule Mechanics APD Radiation hardness Honeywell Bit-serializer

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

9. 9 US CMS DOE/NSF Review: May 8-10, 2001 9 Improvements to the crystal process increased rate of production. New method: 2-crystals per boule. All Russian crystals to be made this way. Crystals 36 mm 64 mm

10. 10 US CMS DOE/NSF Review: May 8-10, 2001 10 Double EE Double EB Single EE Crystal Boules

11. 11 US CMS DOE/NSF Review: May 8-10, 2001 11 Crystal Production Supermodule Construction Crystal Production

12. 12 US CMS DOE/NSF Review: May 8-10, 2001 12 MechanicsMechanics 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

13. 13 US CMS DOE/NSF Review: May 8-10, 2001 13 MechanicsMechanics Alveola are now tied on their front face Grid are made by 3 bolted pieces

14. 14 US CMS DOE/NSF Review: May 8-10, 2001 14 Bit-SerializerBit-Serializer Last year two failed runs at Honeywell and 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 driver Mods for ECAL. Submission May 2001 Will not be ready for Module 0’ Cheaper…

15. 15 US CMS DOE/NSF Review: May 8-10, 2001 15 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-Optics Methode Spinner

16. 16 US CMS DOE/NSF Review: May 8-10, 2001 16 FPPA2000 (UHF1x) ADC Energy  Light  Current  Voltage  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.

17. 17 US CMS DOE/NSF Review: May 8-10, 2001 17 FPPAFPPA

18. 18 US CMS DOE/NSF Review: May 8-10, 2001 18 FPPAFPPA Circuit functions as designed. Noise level is 4 × higher than anticipated. OK for module 0’ tests – will need another engineering run

19. 19 US CMS DOE/NSF Review: May 8-10, 2001 19 APD’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 2×10 13 neutrons/cm 2 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

20. 20 US CMS DOE/NSF Review: May 8-10, 2001 20 Radiation Damage to APD’s Time Current

21. 21 US CMS DOE/NSF Review: May 8-10, 2001 21 Changes to APD’s Move n + in away from p Increase gap

22. 22 US CMS DOE/NSF Review: May 8-10, 2001 22 Californium Source

23. 23 US CMS DOE/NSF Review: May 8-10, 2001 23 Neutron Irradiation Every APD has survived neutron irradiation 135 irradiated so far

24. 24 US CMS DOE/NSF Review: May 8-10, 2001 24 MonitorMonitor 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.

25. 25 US CMS DOE/NSF Review: May 8-10, 2001 25 Monitor Light Source

26. 26 US CMS DOE/NSF Review: May 8-10, 2001 26 Cost estimate changes Major cost changes. Honeywell to IBM switch. ($640k) Peter Denes -- Princeton to LBL. $350k Extra engineering effort.$100k Spinner development contract$110k Productization of FPPA$150k Californium cost change$ 75k

27. 27 US CMS DOE/NSF Review: May 8-10, 2001 27 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.

28. 28 US CMS DOE/NSF Review: May 8-10, 2001 28 ConcernsConcerns 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.