1. SCT Week 2 Oct 2002N.P. Hessey NIKHEF1 Status ATLAS SCT 2002 NIKHEF Contributions to ATLAS: Magnets – discussed by Frank Trigger DCS Muon MDT and alignment – Covered by next talk SCT Talk Outline: SCT Progress Past Year NIKHEF SCT Work Past Year Future NIKHEF Work

2. SCT Week 2 Oct 2002N.P. Hessey NIKHEF2 ATLAS Detector

3. SCT Week 2 Oct 2002N.P. Hessey NIKHEF3 SCT Progress – Barrel 1 st Carbon Fibre Cylinder Delivered Mostly in spec, some difficulties achieving the very high precision machining requirements they had Ready to start mounting brackets Some delay because of last minute change in layout for clearances Modules UK and Japan sites qualified for production Nordic Group and USA have made modules but still not perfect Japan in routine production since summer 2002 and now speeding up UK started routine production System Test Many modules run simultaneously With good grounding and shielding, no extra noise and good rejection of external noise

4. SCT Week 2 Oct 2002N.P. Hessey NIKHEF4 Barrel System Test

5. SCT Week 2 Oct 2002N.P. Hessey NIKHEF5 SCT Progress - Endcap Modules Hybrids: K4/K5/KB/Filters story Mid 2001 realised K4 had serious problems Started program to be sure of solving it 1. Investigate/understand the problem: difficult with binary (hit-or-miss) readout At NIKHEF we realised it is a feedback from Digital Power Supply to Analogue side 2. Fix K4 (NIKHEF) Filters in digital power supply Worked well on NIKHEF modules, but could not rescue a Liverpool module 3. New version: K5 (Freiburg) 4 layer  6 layer + better AGND plane Now working well 4. Fit Barrel Hybrid on Endcap Module: KB (Geneva) Worked as well as Barrel Modules (still some feedback) Cooling finally worked well, but more material and ?cost? Would have been a lot of extra engineering work Decided early 2002 to go ahead with K5

6. SCT Week 2 Oct 2002N.P. Hessey NIKHEF6 Feedback Model (S. Peeters simulation)

7. SCT Week 2 Oct 2002N.P. Hessey NIKHEF7 Feedback Reduction with Filter Glued on Chip S-curves Before Filter: After Filter: Filter Circuit glued to ABCD Chip Joop Roverkamp/Henk Peek

8. SCT Week 2 Oct 2002N.P. Hessey NIKHEF8 Radiation Hardness of Endcap Modules June 2002: Two Endcap Modules Irradiated Very noisy, out of spec Optimists: Maybe they got overcooked? August 2002: Two more irradiated…behaviour much better, well inside spec Pessimists: Maybe the August ones were undercooked The Pessimists were right Status now: Some chips out of spec on irradiation; most OK/on the edge Are Endcap modules worse than Barrel? (I.e., is K5 bad?) Don’t know any mechanism why they should be Hybrid power supply lines all OK after irradiation Could be statistics? Barrel were lucky? Fix: We can raise threshold from 1 fC to 1.2 fC Fixes noise rate; little effect on efficiency or tracking Raise bias to 450 or 500 V: Regains full charge collectione efficiency; Modules hold this HV

9. SCT Week 2 Oct 2002N.P. Hessey NIKHEF9 NIKHEF SCT Progress In addition to feedback also has calculated the fundamental noise limit Many significant contributions Many input parameters, some were unknown and had to be measured End result: Modules are 10-20 % noisier than predicted Best quality chips are closer to prediction Conclusion: we have a good hybrid, close to ideal But…still some things not understood, e.g. anti-noise at low signals Module Noise Model – Simon Peeters Chip-0 Output Noise:

10. SCT Week 2 Oct 2002N.P. Hessey NIKHEF10 Module Manufacture – 5 Inner K5 Modules Made Aim was to test K5 and develop assembly techniques and QA All are in specs; most important parameter within ~1 micron Sent to test centres 3 to system test 1 for thermal tests 1 for irradiation

11. SCT Week 2 Oct 2002N.P. Hessey NIKHEF11 Discs Order placed with PCI in July 2002 First 2 Discs Delivered Last Week DU01: In Spec DU02: Not flat enough Needs work with PCI to see what can be done Cylinder and Wings contract imminent NIKHEF Cylinder due July 2003 Cheap-O Prototype Torlon Inserts Succesful ~300 per disc; low X0 Now glued to disc Next: machine flat Send to UK for Services tests Flatness of DU01, side 1: ~0.4 mm

12. SCT Week 2 Oct 2002N.P. Hessey NIKHEF12 Cheap-O – with inserts, ready for measurement

13. SCT Week 2 Oct 2002N.P. Hessey NIKHEF13 Tooling to machine discs flat Discs ~0.5 mm flat; Modules need better: For placement; For Services Clearances We machine inserts to 0.1 mm flatness Stiff-back rohacell sandwich made Most fittings made Ready Feb 2003

14. SCT Week 2 Oct 2002N.P. Hessey NIKHEF14 Future NIKHEF Work NIKHEF Site Qualification We make five more modules in Jan/Feb If all OK, we are ready to receive components and start manufacture These 5 modules can go into ATLAS Endcap Module Production Officially starts April Hybrid delayed though…looks optimistic Discs Sort out flatness Finalise disc layout details Test services, inserts etc.; incorporate minor improvements Start machining discs

15. SCT Week 2 Oct 2002N.P. Hessey NIKHEF15 Disc Assmbly H026: Glue inserts add services

16. SCT Week 2 Oct 2002N.P. Hessey NIKHEF16 H023/24/25 Assembly Module assembly Modules-to-disc Disc-to-Cylinder Testing C3F8 Evaporative Cooling Whole disc readout

17. SCT Week 2 Oct 2002N.P. Hessey NIKHEF17 The End – 2005 Ship One Endcap to CERN