Status of TPC/HBD for PHENIX Craig Woody BNL DC Upgrades Meeting February 12, 2002

C.Woody, DC Upgrades Meeting, 2/12/022 New Physics to be Addressed with the TPC/HBD Low mass dilepton pairs provides tracking through non-uniform residual magnetic field electron id for p T < 200 MeV by dE/dx and cherenkov reduces mass in front of detector by requiring fewer layers of silicon for tracking and vertex finding reduces mass seen by all outer detectors can be used for both HI and pp running Heavy flavor (c,b) production used in conjunction with the vertex detector, reduces requirements on the number of layers of silicon Jet studies and g -jet correlations provides 2 p tracking over | h | < 0.7 improves momentum resolution ( d p T /p T ~.02), paricularly at low p T Rare processes designed to work at highest HI and pp luminosities

C.Woody, DC Upgrades Meeting, 2/12/023 TPC tracking coverage Df=2p -0.7<|h|<0.7 dp T /p T ~ 0.02 Inner Coil creates a “field free” (∫Bdl=0) region inside the Central Magnet PHENIX Inner Detector will be installed during 2002 shutdown

C.Woody, DC Upgrades Meeting, 2/12/024 Field Integral Momentum resolution in TPC 300 mm single point resolution in x,y,z (Simulation by N. Smirnoff) dp T /p T =0.02 PHENIX ± Field Configuration Z (m) Tracking in the Central Region in PHENIX

C.Woody, DC Upgrades Meeting, 2/12/025 Simulation by J. Heuser Pixel barrels (50 mm x 425 mm) Strip barrels (100 mm x 5 cm) Pixel disks (50 mm x 200 mm) e dca D eX primary vertex ct 0 = 125 mm ct ± = 317 mm 1.0% X 0 per layer 500 mm Be Beam Pipe 1.2<|h|< 2.4 |h|< 1.2 Proposed Silicon Tracker in PHENIX

C.Woody, DC Upgrades Meeting, 2/12/026 Dileptons in High Energy Heavy Ion Collisions R.Rapp, Jaipur Conference Low Mass Electron Pairs at CERN

C.Woody, DC Upgrades Meeting, 2/12/027 Low Mass Electron Pairs at RHIC Dilepton spectra from central Au-Au collisions at full RHIC energy R.Rapp, Jaipur Conference Y. Akiba

C.Woody, DC Upgrades Meeting, 2/12/028 Study the electronic and optical properties of gases (CF 4, CH 4, …) Detector design (field cage, readout plane, construct prototype) Investigate readout detector options (GEM, mMega, MWPC w/pads) Design of integrated readout electronics Monte Carlo simulation studies R&D Topics

C.Woody, DC Upgrades Meeting, 2/12/029 Measurements by Bob Azmoun, Stony Brook Constructed gas cell with MgF 2 window Setup to measure VUV transmission of gases

C.Woody, DC Upgrades Meeting, 2/12/0210 VUV Spectrometer Gas Transparency Measurements C.Lu & K.T. McDonald, NIM A343(1994) B. Azmoun (Stony Brook) CF purity

C.Woody, DC Upgrades Meeting, 2/12/0211 Photocathodes CsI CVD Diamond

C.Woody, DC Upgrades Meeting, 2/12/0212 A HV UV MgF2 window CsI or CVD photocathode Setup to Measure Photocathodes Need CsI photocathodes vacuum or gas

C.Woody, DC Upgrades Meeting, 2/12/0213 TPC Drift Cell presently being fabricated at MDC

C.Woody, DC Upgrades Meeting, 2/12/0214 Ordering new GEM foils to be used with TPC Drift Cell Results with GEM Detector Energy resolution < 20% ( 55 Fe) variation over 10x10cm 2 (12 points) Ar/CO 2 gas mixture very stable G~ 2 x 10 4 typical G ~ 6x10 4 max no sparks over > 8hrs Tested mixtures of Ar+CH4 (95/5 - 50/50) N. Smirnov (Yale)

C.Woody, DC Upgrades Meeting, 2/12/0215 Measurement Setup in Instrumentation Micromega results 55Fe FWHM = 26% 5.4 keV CF 4 I.Giomataris,G.Smith,B.Yu

C.Woody, DC Upgrades Meeting, 2/12/0216 Track density in pp dN ch /dy = 2.6 L x s = 2 x x 60 mb ( S s = 500 GeV) = 12 MHz (min bias) 12 MHz => 12 events/ m sec => ~50 m.b. events per drift time 12 MHz x 2.6 trks x 1.5 = 47 x 10 6 trks/sec = ~ 47 trks/ m sec Au-Au L ~ 8 x cm -2 s -1 O-O L ~ 1.6 x cm -2 s -1 p-p L ~ 2 x cm -2 s -1 (possibly -> 4 x cm -2 s -1 ) Track density in HI dN ch /dy = 150 (min bias) L x s = 8 x x 7.2 b = 58 kHz 58kHz x 150 trks x 1.5 = 13 x 10 6 trks/sec = 13 trks/ m sec 47 trks/ m sec x 4 m sec = 188 trks 188 trks x 35 pts(max)/trk x 12 bytes/pt ~ 80 kB Rate Issues for TPC

C.Woody, DC Upgrades Meeting, 2/12/0217 Number of channels A plane = p ( ) = 8247 cm 2 A pad = 1.0 x 0.2 = 0.2 cm 2 N pad = 8247/0.2 = 41,233 x 2 = ~ 80K chs Readout Speed in PHENIX Buffer size < 40 beam clock ticks 40 x 100 ns (10 MHz) = 4 msec (EMCAL pushes this to 6.4 msec) Readout time < 40 msec (25 KHz in DCM) 800 Kb => 6.4 x 10 6 bits/40 x sec = 1.6 x bits/sec = 160 Gbits/sec (20 Gb/sec) => 160 1Gbit fibers (TEC has 128) => 40 DCMs (TEC has 28) Data Volume 4 msec/20 ns => 200 time samples (8 bits) 80K x 200b ~ 16 Mb Assume zero suppression of 1/20 => 800 Kb (actual hit rate gives 80 Kb => 1/200) Trigger Expect actual trigger rate in pp to be ~10 4 Hz at L = 2 x (trigger rate of interesting events including W,Z,charm is only ~ 10 3 Hz) If data volume after final zero suppression is 80 Kb, then 80 Kb x 10 4 /sec => 800 Mb/sec => need Level 3 trigger Data Volume and Readout Speed for TPC

C.Woody, DC Upgrades Meeting, 2/12/ Completion of Baseline Detector Install North Muon Spectrometer Upgrade TEC to TRD Silicon strip detectors Prototype silicon pixel detector Prototype HBD (upgradable to TPC) Prototype aerogel detector Complete silicon pixel detectors Complete TPC/HBD Complete aerogel detector R&D presently supported by various institutional funds (LDRDs,RIKEN) requires ~ 3-4 $M over 3-4 yrs needs DOE funding to continue Construction Staged approach, with detectors requiring less R&D to be implemented first Rough estimate of detector construction costs ~ $10-15M NSAC plan shows $80M in RHIC II detector upgrades over 7 years starting in FY05 Time Scale and Cost

C.Woody, DC Upgrades Meeting, 2/12/0219 Summary TPC/HBD/SVT are an integrated part of the upgrade of the central part of the PHENIX detector Time scale for HBD/Si strips and TPC/Si pixels are different, driven mainly by electronics development and infrastructure. This leads to a natural upgrade process, assuming one can accommodate infrastructure issues. R&D on both TPC and HBD detectors is well under way Needed for R&D proposal Serious simulation effort Serious estimate of effort needed in electronics and DAQ