1. Robert Pak VTX Meeting Sept. 7, 2004 VTX

2. Robert Pak VTX Meeting Sept. 7, 2004 PHENIX Central Region From VTX Proposal (dims in mm) HBD is standalone

3. Robert Pak VTX Meeting Sept. 7, 2004 VTX Barrel Geometry 14 cm GEANT by VR 2.5 cm

4. Robert Pak VTX Meeting Sept. 7, 2004 VTX Barrel Specs Not updated in proposal

5. Robert Pak VTX Meeting Sept. 7, 2004 VTX Endcap Geometry

6. Robert Pak VTX Meeting Sept. 7, 2004 How VTX fits VTX layout changed, but envelope remains the same Lots of comments about this

7. Robert Pak VTX Meeting Sept. 7, 2004  = 1.17  = 0.88  = 0.70  = 0.35 Planar GEM tracking chambers Provides tracking coverage over -2.6 <  < 2.6  = 2.6 Space for the TPC is being squeezed by the need to bring out services for the VTX and the need for space for the readout electronics 10-15 cm From: C. Woody

8. Robert Pak VTX Meeting Sept. 7, 2004 Be Beam Pipe Quote

9. Robert Pak VTX Meeting Sept. 7, 2004 Mylar Sleeve Proper grounding & isolation of Si detector Image charge from circulating beam Aluminized Mylar sleeve around Be beam pipe Few  m’s thick to hold down material budget Grounded w/ braid through magnet No interference with other sub-systems; nothing else between beam pipe and 1 st pixel layer General agreement this is OK

10. Robert Pak VTX Meeting Sept. 7, 2004 VTX Mechanical Support Structure Frame for barrel & end caps (HYTEC and LANL) External support structure in central magnet (BNL) Mechanical tolerances/distortions: < 25  m internally ~4x this amount relative to the rest of the detector From CAD Survey Group (F. Karl): 50 – 100  m on the bench 100 – 200  m in the hall

11. Robert Pak VTX Meeting Sept. 7, 2004 VTX Mech Support Structure (cont) Modular design is necessary: Easily removable from IR Barrel and end caps mount separately Mounted off of pole tips/nose cone calorimeter To maintain specified tolerances Alternate scheme proposed at Vanderbilt Meeting

12. Robert Pak VTX Meeting Sept. 7, 2004 Alternate Mounting Scheme TPC mounts from top CM yoke. VTX Si detector comes in from bottom, much like MVD does now. Translate or clamshell? From: van Hecke

13. Robert Pak VTX Meeting Sept. 7, 2004 Engineering for VTX Decision on mounting scheme requires engineering PHENIX hiring engineer to replace P. Kroon (retiring) Work on PHENIX central region, which includes VTX Engineering specific to VTX will be done at LANL(?) In consultation with new PHENIX engineer Point of contact with HYTEC

14. Robert Pak VTX Meeting Sept. 7, 2004 VTX Design Issues Circulated spec sheet compiled by D. Lee for CDR: Heat Load (mainly due to readout chips): 0.35 W/cm 2 for strip layers; Vince concurred 0.70 W/cm 2 for pixel layers; Hiroaki concurred Consistent with nos. in proposal Mechanical tolerances/distortions: < 25  m Disassembly/configuration options: D. Lee has discussed modularity with HYTEC Need to finalize before next round with HYTEC

15. Robert Pak VTX Meeting Sept. 7, 2004 VTX Auxiliary Systems Services routed radially at the pole tips: Power for Si detectors (proper grounding & isolation): Si HV & LV power supplies (Stony Brook & RIKEN) UPS (BNL) Cooling system for Si Dry Air System Bleed boil off from LN2 buggy into enclosure Radiation Monitoring TLDs & Chipmunks

16. Robert Pak VTX Meeting Sept. 7, 2004 Routing for Services Power, cooling and signal services are brought in at both ends, using the entire perimeter. From: van Hecke

17. Robert Pak VTX Meeting Sept. 7, 2004 Infrastructure for VTX Electronics racks Platforms above central magnet Cooling for electronics Power for aux sys (proper grounding & isolation): Clean & dirty power 110V & 208V Ballpark estimate: pixels draw 60A and strips draw 400A UPS

18. Robert Pak VTX Meeting Sept. 7, 2004 VTX Design Issues Revisited Circulated revised spec sheet: Cooling system operating temperature: < 10 o C (Junkichi) Current draw from Junji and Dave: What’s correct?