1 HFT Wieman 11/6/2004

2 Outline  Development Status uMIMOSTAR pixel detectors uMIMOSA5 Electronic Readout uLadder mechanics uBeam pipe  Interface issues uExternal tracking requirements uMechanical interface uCalibration concept

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4 MIMOSTAR1 back from foundry  Prototype 128X  m pixels (640X640 for the full size with 4 ms frame read time)  Final design features such as JTAG controlled internal biasing levels and multiple testing modes  Received chip from foundry in October 04, testing to start at LEPSI/IReS

5 LEPSI/IReS MIMOSA V testing at LBNL  Developing readout skills at LBNL with a single MIMOSA V chip  MIMOSA V is an earlier device developed at LEPSI/IReS prior to the STAR work  Noise and leakage currents as previously measured by the Strasburg developers  Design in progress for a multi-chip ladder using the MIMOSA V Lara Pierpoint Fabrice Retiere Fred Bieser Robin Gareus Howard Matis Leo Greiner

6 Electronic/Mechanical Ladder Work – MIMOSA V  Multi chip design  Readout with Off ladder ADCs  Low mass mechanical development Leo Greiner

7 Ladder structure and X 0 budget  Unidirectional carbon fiber skins separated by reticulated vitreous carbon (RVC) foam.  Very stiff uFoam separation gives large moment of inertia with little added mass uCarbon provides large Young’s modulus with low Z uWith single end support expected to have < 10  m gravitational deflection  Ladder mass 2.7gm (a sheet of copier paper weighs 4.7 gm)  Carbon ladder structure 0.12% X 0 Cable = 0.10% 50µm Si Detector = % Carrier (flat with RVC) = 0.12 % Total for single ladder = 0.27%* (500µm beam pipe = 0.142%) *RDO chip will add another 0.053% if in final design. More information on cable design/constraints at More information on material radiation length at Leo Greiner

8 Beam pipe concept required for HFT, discussions started with Brush Wellman mm

9 Beam pipe concept required for HFT, central region Beam pipe supports attach here

10 Ghost Tracks – pointing accuracy – hit density  Ghosts tracks, i.e. connecting the wrong hit to a track depends on uHit density on the tracking layer uTrack projection uncertainty to the layer Associate the closest hit to the track and the probability of a false association is: where Eugene Yamamoto’s plot This is not an efficiency – ghost trade off unless you set a limiting window

11 Mechanical Interface 3 point kinematic connection to support structure Two roll in rails Kinematic structure concept to replace earlier arm design

12 Alignment and spatial calibration procedure  Map all detector surfaces for each 4 ladder arm assembly with the vision coordinate machine  Assemble the 6 arm assemblies and map their relative positions  Install in STAR preserving all relative positions  If outside tracker alignment is fully known use a few tracks to determine the 6 parameters defining position of HFT within the outer tracker  If the outside tracker is not spatially calibrated do it with tracking through the HFT BarBar vertex detector in the vision coordinate measuring machine

13 Kinematic assembly – constrained to repeatedly assemble to same the same location Allows assembly in vision coordinate machine to be the same as in the installed position Ball in cylinder pair kinematic mounts 6 mount points used in assembly around beam pipe 3 mount points for each arm