Zhangbu Xu (BNL) Ming Shao (USTC) eSTAR Concept Kinematics and Acceptance eSTAR Detector Simulations Why GTRD GEM TRD detector R&D progress Summary GEM Based TRD R&D Progress

2 Physics Deliverables (EIC whitepaper) 1.Proton Spin 2.Motion of partons 3.Imagining 4.Dense Gluonic QCD matter 5.Quark Hadronization

3 RHIC: eight key unanswered questions Hot QCD Matter Partonic structure 6: Spin structure of the nucleon 7: How to go beyond leading twist and collinear factorization? 8: What are the properties of cold nuclear matter? 1: Properties of the sQGP 2: Mechanism of energy loss: weak or strong coupling? 3: Is there a critical point, and if so, where? 4: Novel symmetry properties 5: Exotic particles

4 Current STAR Experiment MRPC ToF Barrel BBC PMD FPD FMSFMS EMC Barrel EMC End Cap DAQ1000 FGT COMPLETE Ongoing MTD R&D HFT TPC FHC HLT pp2pp’ triggercomputing

5 STAR Concept  Large Coverage  Low Material  Electron and hadron ID with gas detector and TOF, EMC  Extend this concept to hadron direction GEM tracker (VFGT) Forward Calorimetry  Extend this concept to electron direction Re-instrument inner TPC TRD+TOF Crystal Calorimeter (BSO) Evolution, not a revolution!

6 DIS – eSTAR Kinematics Resolution! Jets PID ugprade x

7 STAR Upgrade --- Huan Huang STAR forward instrumentation upgrade Forward instrumentation optimized for p+A and transverse spin physics – Charged-particle tracking – e/h and γ/π 0 discrimination – Baryon/meson separation eSTAR specific upgrades: EToF: e, π, K identification, ETRD: electron ID and hadron tracking BSO: 5 GeV, 10 GeV electron beams Re-instrument HFT FHC (E864) ~ 6 GEM disks Tracking: 2.5 < η < 4 RICH/Threshold Baryon/meson separation? nucleus electron >2016 W-Powder EMCal FHC (E864) Pb-Sc HCal Forward Calorimeter System (FCS) BSO iTPC ETTIE

8 Proven STAR Capabilities

9 Simulation Geometry

10 A Pythia Simulation Event Only TPC and ETTIE are shown

11 Occupancy and pile-up ii) Beam speciesSqrt(s)Peak Luminosity (cm -2 s -1 ) Cross section (cm 2 ) Nch/d  Track density (dNch/d  MHz) Hit density impact hit finding Space charge impact tracking e+p5x Au+Au100x1005x x MinorCorrected to good precision p+p100x1005x x MinorCorrected to good precision p+p250x2501.5x x Significant for inner Corrected to acceptable DIS: Q 2 ~>1 GeV 2 QED α=1/137 and low multiplicity  an order of magnitude lower pile-up than RHIC

12 eSTAR Acceptance 5x25010x250 GEANT Simulation with eSTAR geometry Inclusive Acceptance: Scattered Electron in x-Q 2 TPC hits>15 BSO and TRD Efficiency assumed 90%

13 x-Q 2 coverage (with x resolution <20%) Energy resolution A ep ep iTPC+TRD p T =2GeV/c Without iTPC without vertex

14 First Stage eRHIC electron/hadron PID Electron coverage: 1>eta>-2.5 PID e/h: 1000 Low material: photon conversion e  h INT report (arXiv: ) Fig.7.18.

15 TPC Inner Sector Upgrade  Staggered readout Only 13 maximum possible points  Issues in Tracking: recognition and resolution Only reads ~20% of possible gas path length  Inner sectors essentially not used in dE/dx  Essentially limits TPC effective acceptance to |η|<1 Inner TPC Upgrade: 1. MWPC (SDU/SINAP) ATLAS sTGC Chinese 973 project 2. Mechanics (LBL/BNL) Eric Anderson 3. Electronics (BNL/ALICE) 4. Schedule (2017)  =±1  =±1.2  =±2

16 TRD+TOF at Endcap (-2<  <-1)  Inner tracking  TPC (endcap region): TRD + TOF/Absorber sandwich Within <70cm space inside endcap TOF as start-time for BTOF and MTD TOF + dE/dx for electron ID TOF for hadron PID Extend track pathlength with precise points High-precision dE/dx (Xe+CO2) TRD Ming Shao (USTC) TPC IP Inner Tracking Iron Endcap TRD TOF / Absorber

17 GEM based TRD – R&D  Advantage Few ion feedback to drift volume High rate Better position resolution Less space charge effect dE/dx Drift along magnetic field ALICE TRD Readout: MWPC -> GEM Multiple time bin readout New type thick GEM 0.2mm 0.5mm Prototype TRD with miniDrift GEM (27 time bins) Cosmic ray test results Plan test beam at FermiLab with other EIC R&D projects in October (T1037) Setups at USTC and BNL

18 Pathlength and dE/dx Gas volume for tracking and dE/dx dE/dx important for electron and hadron PID TR is part of dE/dx in tracking Page 3 committee Report TRD alone

19 dE/dx is crucial in PID Andronic et al. NIMA 2004 silicon followed by a straw tube/TR system? To what extent is the TPC tracking sufficient for this as part of an electron ID system?

20 Students in the Lab Shuai YangSabita Das

21 WTRD and GTRD Checking the data match of wire chamber and TGEM Wire Chamber: STAR TPC readout (107ns per time bin) GEM: STAR FGT/GMT APV readout (26.7ns per time bin)

22 Sigma of residual (regular GEM: 200μm, Thick GEM(thin gap): 300μm) (with thin gap) Cosmic Ray Tracking(online)

23 GEM based TRD Cosmic Ray Test System y z x GEM0 GEM1(TGEM) GEM2 Three GEMs are aligned (Δx=0; Δy=0) cm 12.3cm 51.0cm (0,0,0)

24 Cosmic Ray Tracking(online) TGEM(thick gap) X- axis:strip Y- axis:pad TGEM’s HV = 3650V

25 Gain uniformity and stability Test at Yale with Fe source Results with cosmic ray

26 HV Scan and Drift Velocity Measurements comparisons ALICE Wire TRD Results from journal

27 Tracklet Reconstruction TGEM Search one cluster for each time bin(the APV has 27 time bin; 26.7ns/tb) Calculate the x(y) of cluster using Center of gravity method for each selected time bin If the cluster number of one event >=3, fit these points to obtain the slope. x(y) v*time bin number Slope obtained from TGEM v is the TGEM drift velocity Meetings discussing the methods

28 Tracking Slope in x tgem_slopex1: using the method 1 to obtain slope02_x = (x 0 – x 2 ) / (z 0 – z 2 ) The thickness of ionization gap is ~ 1cm, so the resolution of slope provided by TGEM is consistent with TGEM’s spatial resolution

29 Tracking Slope in y

30 USTC Test Stand Copper shield THGEM Rail HV, Shaper X-ray source Yi Zhou, Prof. Ming Shao, Cheng Li, Hongfang Chen

31 THGEM foils IHEP (8 tested)

32 Plans Radiator from ALICE (GSI) Design new gas box (BNL/Yale) Test beam at FermiLab T1037: consortium EIC Tracking and PID USTC/IHEP: large foil New APV readout: IU The various groups should talk to each other even more.

33 Summary  Progress on TRD cosmic ray test results: Gain uniformity Stability Tracklet with Drift volume for TRD Angular Resolution  eSTAR a possible option for first-stage EIC detector (Electron E<~10 GeV)  Need forward upgrades for eSTAR GEM based TRD a good option for endcap to extend tracking and PID  R&D projects and EIC simulation in progress

34 Tracking with Kalman Filter ii)  ~ -1.2 p T = 1GeV/c 10 MC tracks STAR Computing Group: in progress TRD TPC Other upgrades possible improve the tracking resolution: Inner TPC Upgrade Precision Tracker at |r|<50cm

35 iTPC Benefit to electron ID Improve dE/dx resolution and acceptance

36 Improve electron PID with iTPC Purity, Efficiency, acceptance Bingchu Huang

37 Last Committee report  1) Future presentations on this work would benefit from a written text summarizing the results and referencing the prior reports and milestones.  2) The Committee heard a number of proposals for forward tracking and PID, some using GEMs in a number of functions. It would be good to understand the extent to which these various efforts are in synergy, are mutually exclusive, utilize overlapping technology, or are in some sort of collaboration already.  3) To what extent is the TPC tracking sufficient for this as part of an electron ID system? Would additional tracking layers, as part of a larger GEM (or other) system, have some advantage? Is there room for such additional layers?  4) What is the optimization of TRD, including the number of measurements, efficiency vs rejection, and use of other tracking layers in the available space?  5) The ATLAS tracking uses silicon followed by a straw tube/TR system. Conceptually there is some relationship to the present proposal. Can you learn anything from the ATLAS experience to help you better understand the usefulness or design of the system proposed here?