1. PHENIX Silicon Vertex Tracker

2. Mechanical Requirements Stability requirement, short and long25 µm Low radiation length<0.5% Low CTE High stiffness-to-weight ratio Room temperature operation -- desirable Cooling – H2O desirable Kinematically mounted off Central Magnet

3. PHENIX Silicon Vertex Tracker Mechanical Specifications Central Barrel layer radius2.5,6,8,10 cm layer length30 cm pixel size50 μm x 425 μm strips80 μm x 3cm pixels( 1 st layer)~1.9M strips(2,3,4 layer)~165k azimuthal coverage320 deg End caps(each) inner radius2.5 cm outer radius18cm disk z position(at z= 2.5cm)20,26,32,38 cm pixel size 50 μm x 4 mm total pixels~2.0M azimuthal coverage360 deg

4. PHENIX Silicon Vertex Tracker Simulated Performance Barrel occupancy 1 st layer 1% 2 nd layer11.5% 3 rd layer 7.2% 4 th layer 4.8% resolution DCA<100 µm Endcaps occupancy all disks<3% resolution<100 µm

5. PHENIX Silicon Vertex Tracker Integration Designed to coexist with TPC < 20 cm radius. Clam shell design to fit around beam pipe. Radiation length ~ 1% per layer goal Barrel and end cap sections are separate units ( i.e. ATLAS type) Staging Option 1 Phase One --year 1 Design for barrel with strips first – no pixels or end caps Phase Two - after year 1 Second design for complete barrel and end caps Option 2 Design for barrel with option to add pixels, add end caps later

6. N-type single-sided strip sensor developed by BNL (Z. Li) Thickness : 400um (0.43 % X0), 250um (0.26% X0) for mass prod. Size : 3cm*6cm, Pitch : 80um, 2-dim readout : x- and u-direction #ch per sensor : 384 ch/dir * 4 dir =1536 ch Drawn by Yuji Goto Silicon Strip Sensor x u x u

7. Prototype Sensor Module Prototype module development is on going. Performance of the sensor will be tested w/ cosmic ray and beam at KEK. Readout chip : VA2 (Viking 128 ch CMOS, analog multiplexer, 1us peaking time) Draft Only this

8. Toward Ladder Structure in Vertex Tracker Barrel layer length: ~30cm #chip : 12 readout chip/sensor #sensor : 4 or 5 sensor/ladder Cooling : dependent on readout chip Ex. SVX3D : 3.5mW/ch * 128ch/chip * 60sensor/ladder = 27 W/ladder Liquid cooling will be required. Cabling : Cu(Al) / Polyimide hybrid for low material budget Ladder material : ex. CFRP (Carbon Reinforced Polymer) Total material budget goal : 1% X0 per layer

9. Mock-up of Barrel Support Structure Material : CFRP (Carbon-Fiber Reinforced Polymer) Pictures and drawings : http://rarfaxp.riken.go.jp/~tojo/20020729/mockup20020729.htmhttp://rarfaxp.riken.go.jp/~tojo/20020729/mockup20020729.htm Precision, strength, deformation and material budget will be measured.

10. ATLAS Vertex Detector Support and cooling structures for ATLAS vertex detectors Thermo-mechanical design -dimensional stability, low Z, high stiffness, heat removal capacity B-layer services end section (2) center frame section disks (10) internal end-cone (2) interior barrel layers 050cm

11. ATLAS: Support Frame Support Frame End Section –All GFRP Construction XN80/CE Facings XN50/CE Honeycomb –High dimensional accuracy (<.001”) Finished Prototype Load Test (Prism) Prototype Frame During Fabrication

12. ATLAS: Silicon Detector Backplanes Pixel detector support & cooling –Extreme stability ( < 10 µm @ -15ºC) –High heat flux (10,000 W/m 2 ), active cooling circuit –Low mass ( < 2 kg/m 2 ) –High stiffness ( > 100 Hz ) all carbon-carbon tube ~3.2 mm ID 0.25 mm wall thickness facing overhang tube extensions mounting points 0 10 cm

13. PHENIX Silicon Vertex Tracker