Robert PakVTX Meeting

Sept. 7, 2004

VTX

dxVTX

Robert PakVTX Meeting

Sept. 7, 2004

PHENIX Central Region

From VTX Proposal

(dims in mm)

HBD is standalone

Robert PakVTX Meeting

Sept. 7, 2004

VTX Barrel Geometry

14 cm

GEANT by VR

2.5 cm

Robert PakVTX Meeting

Sept. 7, 2004

VTX Barrel Specs

Not updated in proposal

Robert PakVTX Meeting

Sept. 7, 2004

VTX Endcap Geometry

Robert PakVTX Meeting

Sept. 7, 2004

How VTX fits

VTX layout changed, but envelope remains the same

Lots of comments about this

Robert PakVTX 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

Robert PakVTX Meeting

Sept. 7, 2004

Be Beam Pipe Quote

Robert PakVTX 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 1st pixel layer • General agreement this is OK

Robert PakVTX 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

Robert PakVTX 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

Robert PakVTX Meeting

Sept. 7, 2004

Alternate Mounting Scheme

TPC mounts from top CM yoke.

VTX Si detectorcomes in from bottom, much like MVD does now.

Translate or clamshell?

From: van Hecke

Robert PakVTX 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

Robert PakVTX 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/cm2 for strip layers; Vince concurred• 0.70 W/cm2 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

Robert PakVTX 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

Robert PakVTX 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

Robert PakVTX 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

Robert PakVTX Meeting

Sept. 7, 2004

VTX Design Issues Revisited

• Circulated revised spec sheet:• Cooling system operating temperature: < 10o C (Junkichi)• Current draw from Junji and Dave:

power/area [W/cm 2̂] 0.47 0.47 0.21 0.21 readout chips onlypower [W] 131 262 415 719supply voltage [V] 1.8 1.8 2.5 2.5current [A] 73 146 166 288power/area [W/cm 2̂] 0.70 0.70 0.35 0.35 Robert's excel numberpower [W] 195 390 687 1191supply voltage [V] 1.8 1.8 2.5 2.5current [A] 108 217 275 476

layer 1 2 3 4detector type Pixel Pixel Stripixel Stripixelradius [cm] 2.5 5.0 10.0 14.0z-length [cm] 21.8 21.8 31.8 38.2area [cm 2̂] 279 557 1963 3403

What’s correct?