PHENIX Vertex Detector with Conventional Strip Sensors Abhay Deshpande Stony Brook University

6/9/2008Si Strip: Backup Plan2 Conventional Strip Option (CSO) Why consider this option? Philosophy behind this development and the strategy that has developed Status –Hardware: options available –Path forward: Prototype goals & tests Module building options available Studies of physics impact Possible impact on schedule & cost Issues, concerns & decisions Summary

6/9/2008Si Strip: Backup Plan3 Why consider Conventional Strips? Strip-Pixel design (one-sided, two dimensional read-out ) was novel –Challenging… but possible –Realized by not only its proponents but also by the reviewers… All performance milestones for strip-pixel project reached, although perhaps some what slower –Most recent: A full module with the ROC3-with stripixel sensor has been produced, shown to operate well, despite the difficulties (Akiba & Nouicer’s presentations) We have seen the MIP peak! Although all this has been possible, design and assembly issues for the ROC3 as well as stripixel system performance issues remain a concern

6/9/2008Si Strip: Backup Plan4 Why consider Conventional Strips? It seems only prudent to step back and consider if there are other options available as “back-up” which could be used if Stripixel Sensor does not work Conventional Strip Planning Task Force initiated –Alan Dion (chair) and 3 members –Charge: Develop a concrete plan of strip detector using conventional sensors in the next few months Choice of sensor Physics impact evaluation ROC and Ladder configuration Testing plan Budget Schedule

6/9/2008Si Strip: Backup Plan5 Philosophy --> Strategy Build up on the experience gained so far –Use the developed parts of the project (ROCs) –Minimal R&D for cost and time saving Replace stripixel with available conventional strip sensor that matches closest to our present sensor in its physics requirements and dimensional needs Proceed to build modules using the ROC and the sensor Proceed with the same tests that were originally proposed in the stripixels Evaluate Signal/Noise and compare to VTX performance specs Evaluate the ability to produce strip layers with alternate sensor within project constraints

6/9/2008Si Strip: Backup Plan6 Realization

6/9/2008Si Strip: Backup Plan7 Possible Realization While “past performance is never a proof of future results”, FNAL has shown that SVX4 + HPK off the shelf sensors have worked –We could try to be as close to this model as possible HPK has 3 x 6 cm strip sensors (80  m pitch) made for ATLAS, which could be used for initial tests –2 sensors may be available immediately (free) –5 more sensors may be available at minimal cost If ATLAS sensors work, we could ask HPK to produce slightly modified (size: 3 x 3 cm) sensors for our purpose Other options under investigation (SBU/D0)

6/9/2008Si Strip: Backup Plan8 A possible realization SVX4 3 cm Pitch adapter hybrid Sensor 3 cm

6/9/2008Si Strip: Backup Plan9 Sensor module Glue and wire-bond the hybrid to the sensor

6/9/2008Si Strip: Backup Plan10 RCC board, connectors, RCC flex cables

6/9/2008Si Strip: Backup Plan11 4 sensor modules to read 2 views

6/9/2008Si Strip: Backup Plan12 Final configuration on to the ladder…

6/9/2008Si Strip: Backup Plan13 Building up confidence that we have a viable fall-back plan Gain experience with conventional sensor Single and Multiple hybrids, modules tested independently and finally together on a ladder… These tests will be similar to those planned for the stripixel sensor Signal/Noise ratio compared with the stripixel sensors –Study with beam test

6/9/2008Si Strip: Backup Plan14 Impact on Physics

6/9/2008Si Strip: Backup Plan15 Monte Carlo studies Preliminary stand alone tracking studies initiated Early results: –Two layers with stereo angles are needed for high multiplicity collisions –90 0 stereo angle gives slightly worse tracking efficiency but better vertex resolution than the original strip-pixel sensors (80 x 80  vs. 80 x 1000  ) –Small(er) stereo angle gives worse efficiency and no better vertex than strip-pixel sensors If the “90 0 option” is chosen, it will have consequence for the ROC design

6/9/2008Si Strip: Backup Plan16 Tracking efficiency for 2 Sensors crossed at 90 o

6/9/2008Si Strip: Backup Plan17 Momentum Resolution for 2 sensors crossed at 90 o

Preliminary plan Obtain existing sensors from HPK for tests with ROC3 Develop layout of sensor+module Hold technical review ~August 2008 (same for as for stripixel) –Possible outcome: purchase of pre-production sensors & ROCx design Assemble conventional sensor+ROCx => Module Assemble modules with non-ROC FEE + Stave => Ladder

Preliminary Schedule WBS: About 2 months delay: Conservative (?) This is only the pre-production delay Production: Delivery, QA, module construction: too early to estimate

6/9/2008Si Strip: Backup Plan20 Preliminary cost guestimate Based on the known costs of 3x6cm sensors recently costed for FVTX project in PHENIX –$600 including HPK R&D –For 3x3 unit the cost can be approximately $300 We need 246 working modules with 4 sensors each  1000 sensors $300K + (contingency+ yield) ~ $500K These will become more firm as we communicate with HPK specifically for this in near futureThese will become more firm as we communicate with HPK specifically for this in near future

6/9/2008Si Strip: Backup Plan21 Issues & Concerns Conventional Strip Sensor Option should work but –Will ROC-on-Sensor design (proposed) work? –What (minimal) design modifications might be needed? –What is the true impact to the project schedule? –What will be the total cost of going this way? All these need to be addressed and an informed decision needs to be made

6/9/2008Si Strip: Backup Plan22Summary While the strip-pixel design is going forward, concerns related to large scale automated production have been raised based on the experience on building the first modules. This prompted us to look at alternative options using the conventional strip sensor in the project Early studies of feasibility, realization and physics impact for the CSO have started and look optimistic, but more are needed: –Prototyping, testing, physics impact –Cost & schedule impact Expect to finish most of the studies in the next few months after which through a technical review a decision could be made on the final design Until major concerns on the stripixel are alleviated the backup option will be pursued

6/9/2008Si Strip: Backup Plan24 Schedule Impact (preliminary estimate) Sensor ROCx

6/9/2008Si Strip: Backup Plan25 Schedule: preliminary Impact estimate WBS: About 2 months delay: Conservative (?) This is only the pre-production delay Production: Delivery, QA, module construction: too early to estimate