1 / 27

Test beam results of a prototype for PHENIX FOCAL

Test beam results of a prototype for PHENIX FOCAL. Sanghoon Lim ( 林 相勳 ) Yonsei University, KOREA ATHIC 2010 20, October, 2010. Outline. Introduction to PHENIX FOCAL Mechanical design Physics motivation. Test beam 09’ @ CERN Test beam setup Results. FVTX. FOCAL.

skyla
Download Presentation

Test beam results of a prototype for PHENIX FOCAL

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Test beam results of a prototype for PHENIX FOCAL Sanghoon Lim (林 相勳) Yonsei University, KOREA ATHIC 2010 20, October, 2010

  2. Outline • Introduction to PHENIX FOCAL • Mechanical design • Physics motivation • Test beam 09’ @ CERN • Test beam setup • Results Sanghoon Lim ATHIC2010

  3. FVTX FOCAL Introduction to PHENIX FOCAL The PHENIX experiment at RHIC has been specifically designed to study rare processes at a high rate but with limited acceptance. FOCAL will replace the copper nosecone with a high density, high granularity Si-W tracking calorimeter. Sanghoon Lim ATHIC2010

  4. FOCAL Overview MPC FoCal EMC FoCal MPC FOCAL 0 f coverage 2p -3 -2 -1 0 1 2 3 h • Small space in front of nosecone • 40cm from vertex • 20cm deep • FOCAL acceptance • 1.6 < η < 2.5 • d-going side in d+Aucollisons Sanghoon Lim ATHIC2010

  5. FOCAL design Transverse View • 4mm W plates ~1X0 • 525μm Si pad 15x15mm2— 21 layers Instrumented region • 300μm Si strips (4X+4Y) — 8 layers 1 “brick” Longitudinal View Sanghoon Lim ATHIC2010

  6. FOCAL building brick Micro-module Ceramic spacer INTC board Silicon sensor Cu foils + PCB • Tungsten • High density for compactness • Silicon • Compactness • Segmentation is easy • Read-out • 16x4x3 pad per brick • 128x2x4 strips per brick Test beam setup (CERN2009) Beam S0 S1 S2 Sanghoon Lim ATHIC2010

  7. Muon Arms Central Arms Searching gluon saturation RCP in d+Au collisions • Nuclear modification factor: • Increasing suppression with η • Consistent with the onset of gluon saturation at small-x in the Au nucleus. • Need to study this in more detail by • identifying particles • expanding forward coverage BRAHMS: PRL93(2004) 242303 Gluon PDF can be directly accessed from direct-γ Sanghoon Lim ATHIC2010

  8. Identifying π0and γ – Strip tracking • Highly segmented layers of x/y strips into first segment. • Measure the development of the shower at its infancy • With a resolution to distinguish individual γ tracks 4(X+Y)strip layers Catch the shower, before it’s too late Sanghoon Lim ATHIC2010

  9. High energy π0 reconstruction Single Particle Simulation • Reconstruction of single γ and π0’s with FOCAL • Good separation of γ peak and π0 mass peak • Low mass peak from π0’s • Large-angle decays • One γ dominating(asymmetric energy) γ π0 Sanghoon Lim ATHIC2010

  10. Test beam @ CERN • When : 2009, June 17th - 29th (13 days) • Where : PS T10 (1-6GeV) • SPS H2 (20-100GeV) • To study detector performance and response to EM-particle Beam direction The beam passes through 3 scintillatorsat sizes 14x14, 4x4 and 2x2(cm2) Sanghoon Lim ATHIC2010

  11. Preparation in KOREA • Pad sensor production • IV, CV check • Micromodule production • Cosmic muon test • To check sensors working properly Micromodule Cosmic test setup Sanghoon Lim ATHIC2010

  12. Purse shape determination • Pulse shape is determined by preamp electronics (all channels share similar shape). • Energy in each channel is extracted by fitting with 2 parameters. • amplitude – deposited energy • t0 – start time Sanghoon Lim ATHIC2010

  13. Electron selection Electron Hadron • Using the different shower characteristics between electron and pion, hadron events (~20%) are rejects in SPS data. • We defined energy dependent electron selection cut using ratio of energy sum in segment 2 to all segments. Sanghoon Lim ATHIC2010

  14. Position dependent inefficiency correction Center of gravity of jth segment ->weighted sum over the segment Fit function : • We observe large inefficiency around sensor boundary. • We also considered small pad to pad efficiency variation. Sanghoon Lim ATHIC2010

  15. Resolution — Line shape 6GeV(PS), electron 75GeV(SPS), electron • Energy distribution fits with Gaussian function . • In the 75GeV plot, low energy tail is highly suppressed by using electron ID cut. • But, still have some low energy tail. Sanghoon Lim ATHIC2010

  16. Linearity & Resolution — Energy dependence • We observe a good linearity. • Deviation from the fit is by less than 2.5%. • Obtained resolution is . Sanghoon Lim ATHIC2010

  17. Energy deposition profile • Longitudinal and lateral profile for 6GeV electron beam(red) are well matched with GEANT4 simulation results(blue). Longitudinal energy profile Lateral energy profile Sanghoon Lim ATHIC2010

  18. Position measurement Fit function : • From the simulated relation between xCG and xtrue function for incident position of beam is obtained. • Incident position resolution is 2.0mm(~0.15 pad). Sanghoon Lim ATHIC2010

  19. summary • PHENIX FOCAL upgrade will provide much extended coverage for interesting physics topics • New measurements of the gluon PDF at low-x • Direct photon measurement • Test beam at CERN in June 2009. • Good linearity and energy resolution • Energy deposition profile is consistent with the GEANT4 simulation Sanghoon Lim ATHIC2010

  20. THANK YOU

  21. Back up Sanghoon Lim ATHIC2010

  22. Purse shape determination • Pulse shape is determined by preamp electronics (all channels share similar shape). • We select a channel with the largest pulse for a given event. Subsequently, we aligned time bins with the largest pulse over many events and averaged. Normalized pulse shape 6GeV, electron Sanghoon Lim ATHIC2010

  23. Test beam setup Beam Pad Carrier Board 4 pad sensors with 4x4 of 15x15mm pads S2, S1, S0 Segments 4mm Tungsten plate 21 layers of ~500u Si pads 15ⅹ15 mm2 7 layers of ~300u 0.5mm wide Si strips(4X + 4Y) Sanghoon Lim ATHIC2010

  24. Pad sensor micromodule Ceramic spacer INTC board Silicon sensor Cu foils + PCB Sanghoon Lim ATHIC2010

  25. Pad sensor electronics Flexible cable preamps Motherboards in crate Summing board • 10m differential cable to ADC (12bit 65MHz) • 16ns between samples • 20 samples per event • Signals from 7 pads(same lateral position) in the same segments are summed. • Total pads : 84 sensors (2x2x7x3)  192 towers (8x8x3) Sanghoon Lim ATHIC2010

  26. Energy deposition profile study 75GeV, Clean beam, electron ID Matrix sum With electron ID cut, low energy tail is highly suppressed but still exist… Some shower events exhibits larger lateral size… Upstream interaction? Sanghoon Lim ATHIC2010

  27. Profile study using Geant4 simulation No material 0.1 X0 0.2 X0 0.3 X0 • We did geant4 simulation with some material placed 10m upstream of detector. • Simulation results with 0.3X0 of material is well consistent with real data. Sanghoon Lim ATHIC2010

More Related