HvH, DNP Oct The FVTX detector in PHENIX Hubert van Hecke, Los Alamos National Laboratory for the PHENIX collaboration Vtx (Mannel) Fvtx (HvH) RPC (Wei) TOF (Belmont) RPC gas (Wood) RPC (Kim) RPC (Meredith) Computing (Love) Forward Silicon Vertex Detector, one of a number of detector upgrades

HvH, DNP Oct FVTX team R. K. Choudhury, P. Shukla, D. Dutta, A. K. Mohanty, Bhabha Atomic Research Centre, India; R. Pak, K.A. Drees, Brookhaven National Laboratory; H. Pereira, Saclay, France; M. Finger, M. Finger, Charles University, Prague, Czech Republic; J. Klaus, Czech Technical University, Prague, Czech Republic; P. Mikes, J. Popule, L. Tomasek, M. Tomasek, V. Vrba; Institute of Physics, Academy of Sciences, Prague, Czech Republic; B. Cole, E. Mannel, D. Winter, W. Zajc, Columbia University; J.C. Hill, J.G. Lajoie, C.A. Ogilvie, A. Lebedev, H. Pei, G. Skank,A. Semenov, G. Sleege, F. Wei, Iowa State University; Naohito Saito, KEK, Japan; T. Murakami, K. Tanida, Kyoto University, Japan; J.G. Boissevain, M.L. Brooks, S. Butsyk, G. Grim, H.W. van Hecke, J. Kapustinsky, A. Klein, G.J. Kunde, D.M. Lee, M.J. Leitch, H. Liu, M.X. Liu, P.L. McGaughey, A.K. Purwar, W.E. Sondheim, Los Alamos National Laboratory; Hisham Albataineh, G. Kyle, V. Papavassiliou, S. Pate, X.R. Wang, New Mexico State University; T. Alho, M. Bondila, R. Diaz, D. J. Kim, J. Rak, University of Jyvaskyla, Finland; B. Bassalleck, D.E. Fields, M. Hoeferkamp, M. Malik, K. Spendier, J. Berndt, University of New Mexico, Albuquerque; J.H. Kang, Y. Kweon, Yonsei University, Korea

HvH, DNP Oct Goals of the FVTX Use heavy quarks (c,b) to study  properties of the QGP  q, g contributions to p spin  Drell-Yan Signal channel:  b->B->   c->D->   J/ ,  ’->     ++ -- B,D have finite lifetimes, so they can be identified with a vertex tracker

HvH, DNP Oct Separate signal from backgrounds Solution: D, B mesons travel ~1mm (with boost) before semileptonic decay to muons Mean ,K decay distance is much larger By measuring the DCA to the primary vertex, we can separate D, B decays from prompt muons and from long-lived decays from , K The problem: backgrounds (  ->  and K->  ) overwhelm the signal

HvH, DNP Oct Detector Specifications Need sufficient DCA resolution (~100um) Need occupancy low enough to find tracks in central AuAu events (<few %) Need enough hits to reconstruct a track (>=3 hits) Need to match tracks with Muon System:  =

HvH, DNP Oct Model the detector SensorHDI Geant-3-based simulations cm 1664 strips 13 chips 2.8mm strip 11.2mm strip 75-um strips

HvH, DNP Oct Other materials Materials that affect us: - barrel silicon layers (4) - support and cooling structures - cabling and connectors - beam pipe - electronics board

HvH, DNP Oct DCA resolutions Since the barrel pixels are // to the beampipe (orthogonal to the FVTX mini-strips, using them greatly improves phi resolution

HvH, DNP Oct Occupancy Max track density in central Au+Au ~7/cm 2 Max. strip occupancy ~ 2.8% -> choose 75  m strips /cm 2

HvH, DNP Oct Using DCA cuts, plus   and isolation cuts, we can now improve the signal/background for D,B->  Open charm, bottom signal

HvH, DNP Oct Simulated RHIC-II p+p run - better background. rejection - better mass resolution - separate  ’ Without FVTX With FVTX Improved resolution + background reduction

HvH, DNP Oct Mechanical design and prototypes Silicon sensor prototype from ON Semiconductor, CZ, under test at UNM Main unit: ‘wedge’ Carbon backing Kapton HDI Silicon Readout chips Min Tº = 15ºC Max Tº = 20.3ºC Max deflection 10.4μm Heat flow studies Mechanical distortion studies

HvH, DNP Oct Mechanical design ~80% done Wedge -> Disk -> Cage assembly Thermally conducting silicone Honeycomb support panel Wedges front and back Cooling in let 15°C Cooling out 16.1°C Support cage 40 cm

HvH, DNP Oct Readout chain 1)FVTX readout chips 2)ROC read-out card nearby 3)FEM front-end module outside experimental hall

HvH, DNP Oct ) Readout chip (FPHX) Readout chip being designed at FNAL Derived from FPIX family of chips (BTeV), with (small) modifications ‘Pushes’ data to ROC - total bandwidth up to ~3.5 Tbps Low power: 100  W/channel, 50W total / 4 disks 2x13 chips per wedge, 128 channels / chip Total # channels: ~1.0M

HvH, DNP Oct ) ROC - readout card - One ROC combines data from 26 FPHX chips, send zero-supressed data to FEM over optical link - Download masks and thresholds to FPHX - Send clocks - Control calibration board - Implemented in rad-hard Actel FPGA 8-chip HDI USB Interfa ce Actel Starter Board prototype

HvH, DNP Oct ) FEM: front-end-module - FEM buffers data by beam crossing, 64 clocks deep - Deliver event upon LVL-1 trigger to Phenix DAQ - Send clocks down to IR - Implemented in Xilinx FPGA

HvH, DNP Oct Calibration using FPIX chips and readout cardprototype: Threshold / noise ~ 18:1 Test with prototype readout chip and ROC

HvH, DNP Oct Status and outlook Software: - Simulations and analysis - in hand Hardware: - Silicon detector prototypes undergoing tests - FPHX chip being layed out - HDI (Kapton interconnects) being layed out - Readout electronics chain prototyped and running - Mechanical design ~80% done - Construction start in FY08 - Installation in Phenix in summer 2011

HvH, DNP Oct backups

HvH, DNP Oct External mount

HvH, DNP Oct Acceptance Since the event vertex spans ~+-10 cm in z, we can use the barrel hits for some events. skip

HvH, DNP Oct Can we match muon arm tracks with a FVTX track? 3 GeV muon: 75% correct match 9 GeV muons; 93% correct match Use the chi2 of the Kalman track fitter : skip