PHENIX RPC in China. Xiaomei LI. Science and Technology on Nuclear Data Laboratory China Institute of Atomic Energy

Transcription

1 PHENIX RPC in China Xiaomei LI Science and Technology on Nuclear Data Laboratory China Institute of Atomic Energy

2 Outline 1.Motivation of the PHENIX Forward Upgrade 2.Study of PHENIX-RPC in China 3.Laboratory construction at CIAE 4.The task of PHENIX-China group

3 1. Motivation of the PHENIX Forward Upgrade

4 Motivation of the PHENIX Forward. Upgrade Add RPC ( Resistive Plate Chamber) as a fast muon trigger to study the quark-gluon structure of the proton by observing W-bosons from colliding polarized proton beams at RHIC.

5 Motivation of the PHENIX Forward Upgrade 1.a fast online measurement of the muon momentum to reject low momentum muons from hadron decays in jets 2.on a coarse timing measurements to remove background correlated with the incoming proton beam bunches.

6 PHENIX Trigger Needs Design Luminosity s = 500 GeV σ=60mb L = 2x10 32 /cm 2 /s Total X-sec rate=12mhz DAQ LIMIT =1-2kHz(forμarm) RF~ ( s= 200 GeV ) is inadequate Required RF ~ 10,000

7 2. Study of PHENIX RPC Detector in China

8 Structure of RPC Bakelite resistivity cm Gas Gap: 2 mm Gas pressure : ~ 1 Atm Gas mixture: F134a, Isobutane, SF 6 HV electrodes : 100 m graphite Read-out strips

9 The Basics of RPC Advantage: easy and cheap Two modes: Avalanche and Streamer PHENIX-RPC will work at avalanche mode to ensure the proper operation at very high rate.

10 RPC Prototype Made in China Size: cm 3 Graphite coat: cm 2 Double gas-gaps: 2 mm each Read-out strip placed between the two gas-gaps bakelite resistivity: ~ cm

11 Beam Test at RHIC Run5 RPC1 RPC2 RPC1 Grounded to Platform RPC2 Grounded to MUID Gas Panel

12 Test Result at BNL Shielding SC1 SC1 RPC RPC Cosmic &&RPC Cosmic Top View Beam test location Cosmic ray test result

13 3. Laboratory construction at CIAE

14 Laboratory construction at CIAE Main goals: Train students and technicians for future QA and assembly Test prototypes Research & Development

15 Laboratory construction at CIAE located at the building of HI-13 tandem accelerator

16 The New prototype (No.1) Two new prototypes: The resistivities of the bakelites of prototypes are around cm. The sizes are same as PHENIX RPC2A design.

17 The New Prototype (No.2) The upstream of Prototype No.2 is separated into two parts and the readout strips are jointed with ground by matched resistances.

18 Laboratory construction at CIAE The RPC test multilayer: m 3, 9 detector supporting layers in total, can test 5-7 RPCs at the same time.

19 Laboratory construction at CIAE Has equipped gas system, electronics and DAQ system.

20 Experimental Set-up 示波器 高压电源 塑料闪烁体 RPC 塑料闪烁体 恒比定时器 门延迟发生器 前置放大器 恒比定时器 恒比定时器 门延迟发生器 F134a C 4 H 10 SF 6 配气仪 计算机 多道分析器 逻辑单元纳米延时线 Start stop 时幅转换器

21 Prototype Test at CIAE Current gas mixture: 90.1% F134a, 9% Isobutane and 0.9% SF 6 Time resolution <2.0 ns

22 Comparing the Signals from Avalanche Mode and Streamer Mode RPC working voltage=9800v RPC working voltage=10200v Avalanche mode Streamer mode The chambers have high noises from 9000V to 9800 V

23 Prototype Test at CIAE We changed HV and the ratio of the gases to study time resolution. For different gas mixtures, we got best time resolutions at different HVs. The HV of the best resolution moves ahead as the ratio of SF6 increases

24 4. The Task of PHENIX-China group

25 Some Collaborators GSU UIUC Korea Uni. CIAE Prototype Development & QA Gas mixing Position resolution Chamber Production Mechanical components Assembly & QA

26 The Task of PHENIX-China group The RPC chambers is manufactured at Korea University and all other mechanical parts are made in China. CIAE will also take care of the QA and assembly.

27 Time Line Summer 2009 Summer 2010 Summer 2011 RPCs RPC 3 North & South RPC 1 North & South RPC 2 North & South?

28 CIHENP group

29 Thanks!