Detector for GlueX

1. Detector for GlueX Beamline Hall D GlueX Detector Software Trigger Computing Environment Physics PRL JLab PAC 23 Jan 20, 2003

2. What is needed? • 9-GeV polarized photon beam • Coherent bremsstrahlung beam • Hermetic detector for multi-particle charged and neutral final statesCharged • Solenoid-based detector • Select events of interest with high sensitivity • High DAQ rate capability with software trigger • Analysis environment for successful PWA

3. Construction Site

4. Status of Civil Design • Credible optics design • Layout that provides room for detectors and access to equipment • Beam containment proposal • Concept for civil design • GEANT Calculations show that the shielding satisfies radiation protection guidelines

5. Hall D site layout

6. Flux Photon beam energy (GeV) Coherent bremsstrahlung beam Delivers the necessary polarization, energy and flux concentrated in the region of interest P = 40% Linear Polarization Photon beam energy (GeV)

7. To certify PWA - consistency checks will be made among different final states for the same decay mode, for example: Should give same results Hybrid decays GlueX will be sensitive to a wide variety of decay modes - the measurements of which will be compared against theory predictions. Gluonic excitations transfer angular momentum in their decays to the internal angular momentum of quark pairs not to the relative angularmomentum of daughter meson pairs - this needs testing. For example, for hybrids: favored Measure many decay modes! not-favored

8. GlueX detector

9. Solenoid ships from Los Alamos

10. Unloading at IUCF

11. Exploded view of the GlueX detector CERENKOV TOF Pb-GLASS DET 12.00 TARGET VTX CDC FDC • The components are extracted by “4 ft” from each other for maintenance.

12. Particle kinematics g p→ X p→ K+K─p+p─p Most forward particle All particles

13. GlueX Detector

14. Central tracking Straw tube chamber Vertex Counter

15. Forward drift chambers

16. Charged particle resolution

17. p0 h Mass gg Calorimetry Pb Glass Barrel Built by IU for BNL Exp 852 Pb/SciFi detector based on KLOE s/E = 4.4 %/ √E, threshold = 20 MeV st = 250 ps

18. gp → K*K*p, Eg = 9 GeV Particle identification Time-of-flight, Cerenkov counter, and constraints for exclusive events

19. Hall D Prototype (IHEP Run 2001) R. Heinz / IU

20. PID with Cerenkov and forward TOF TOF s =100 ps resolution gp → K+Kp+pp, Eg = 9 GeV n= 1.0014 n= 1.0024

21. Gottfried-Jackson frame: Acceptance in In the rest frame of X Mass [X] = 1.4 GeV the decay angles are Mass [X] = 1.7 GeV Decay Angles theta, phi Mass [X] = 2.0 GeV assuming 9 GeV photon beam Acceptance is high and uniform

22. Output of Level 3 software trigger Trigger Rates

23. Luminosity limits GlueX raw rates will be well below currently running CLAS electron beam experiments

24. DAQ architecture 40 VME front-end crates Gigabit switch 8 event builders 8 100-Mbit switches 200 Level 3 Filter Nodes 4 event recorders 4 tape silos

25. Fully pipeline system of electronics • Deadtimeless • Expandable • No delay cables Flash ADCs: 13000 channels TDCs : 8000 channels (Non-pipeline: Limits photon flux < 107/s, incurs deadtime, requires delay cables)

26. Data Volume per experiment per year (Raw data - in units of 109 bytes) But: collaboration sizes! Ian Bird

27. Data Handling and Reduction Data rate up by 10, computer costs down by > 5  GlueX Computing Effort ~ 2 x CLAS

28. 1 PB/year DAQ Level 3 Farm Event Reconstruction Computing Model Tier “2” Centers Calibration Tier “1” Center (Jlab) 20 MB/s Physics Data 0.2 PB/yr Physics Analysis 70 MB/s Physics Analysis 100 MB/s 20 MB/s Tier “2” Simulation Center Monte Carlo 0.2 PB

29. p r g X p p p n a2 p2 h=+1 h=-1 fGJ h=+1 h=-1 h=+1 m3p [GeV/c2] Detector designed for PWA Double blind studies of 3p final states Linear Polarization

30. An imperfect understanding of the detector can lead to “leakage” of strength from a strong partial wave into a weak one. STRONG: a1(1260) (JPC=1++) Break the GlueX Detector (in MC). Look for Signal strength in Exotic 1-+ Under extreme distortions, ~1% leakage! Leakage

31. Ongoing R&D effort • Solenoid – shipped to IUCF for refurbishment • Tracking – testing straw chamber; fabricating endplate prototype (CMU) • Vertex - study of fiber characteristics (ODU/FIU) • Barrel calorimeter – beam tests at TRIUMPF; fabricated first test element of the Pb/SciFi matrix (Regina) • Cerenkov counter – magnetic shield studies (RPI) • Time-of-flight wall – results of beam tests at IHEP show s<50 ps (IU) • Computing– developing architecture design for Hall D computing • Electronics– prototypes of pipeline TDC and FLASH ADC (Jlab/IU) • Trigger – Studies of algorithm optimization for Level 1(CNU) • Photon tagger – benchmarks of crystal radiators using X-rays (Glasgow/UConn) • Civil– beam height optimized; electron beam optics shortens length of construction; new radiation calculations completed (Jlab)

32. 7 • Benchmarks of Diamond Crystals High Quality Poor Quality Stone 1482A Slice 2 (10mmx10mm X-ray rocking curve) Stone 1407 Slice 1 (4mm x 4 mm X-ray rocking curve) Richard Jones / Uconn R.T. Jones, Newport News, Mar 21, 2002

33. cosmics b gun Straw Tube chamber work Graduate Students: Zeb Krahn and Mike Smith Built a b-gun using a 10 mCi 106Ru Source Getting coincidences with both cosmics and b’s ArCO2 90-10 ArEthane 50-50 Carnegie Mellon University

34. Building a Prototype Endplate Build endplates as 8 sections with tounge and groove. Checking achievable accuracy

35. Barrel calorimeter prototyping Hybrid pmts can operate in fields up to 2 Tesla Pb/SciFi prototype University of Regina

36. FLASH ADC Prototype 250 MHz, 8-bit FADC Paul Smith / IU

37. s = 59 ps TDC counts Pipeline TDC First prototype results: high resolution mode Jlab DAQ and Fast Electronics Groups

38. the magnet is usable, • to optimize many of the detector choices, • to ensure that the novel designs are feasible, and to validate cost estimates.” Cassel review of Hall D concluded “The experimental program proposed in the Hall D Project is well-suited for definitive searches for exotic states that are required according to our current understanding of QCD” “An R&D program is required to ensure that Working with input from many groups on electronics, DAQ, computing, civil, RadCon, engineering, and detector systems.

39. Hall D Budget Budget assumes that in addition to the construction cost, the Physics operations Budget will increase by 30% to support a Hall D group. Budget estimates are under review as we update the GlueX Design report. No substantial changes since 3/01.

40. What is Needed? • PWA requires that the entire event be identified - all particles detected, measured and identified. • The detector should be hermetic for neutral and charged particles, with excellent resolution and particle ID capability. • The beam energy should be sufficiently high to produce mesons in the desired mass range with excellent acceptance. • Too high an energy will introduce backgrounds, reduce cross-sections of interest and make it difficult to achieve above experimental goals. • PWA also requires high statistics and linearly polarized photons. • Linear polarization will be discussed. At 108 photons/sec and a 30-cm LH2 target a 1 µb cross section will yield 600M events/yr. We want sensitivity to sub-nanobarn production cross-sections.

41. Missing mass resolution g p→ X p→ K+K─p+p─p0p

43. Hall D schematic

44. Outline • Site and civil construction • Detector Requirements • Recent developments • DAQ • Electronics • Offline Computing

45. Pipeline TDC based on COMPAS F1 chip • Resolution • 4 channels per chip of high resolution (60 ps least count) • 8 channels per chip of low resolution (120 ps least count) • Density per board • 32 channels of low resolution inputs • 64 channels of high resolution inputs • Packaging in VME64x • Dynamic range – 16 bits (~ 4 ms) • Development by JLab Fast Electronics and DAQ groups (F. Barbosa and E. Jastrzembski)