1、Oct.2001, Beijing,MRPC，USTC,1,MRPC -High Time Resolution Detector R&D at USTC CHINA Chen, Hongfang 2001/Oct.,Oct.2001, Beijing.,2,Introduction,.,Particle identification for the experiment is a key ingredient . To identify particle in the momentum range 0.5-2 GeV/c , a time of flight array should hav
2、e following characters: 1. Excellent Time Resolution. TOF time resolution of 60-100ps will much expending the PID momentum range. 2. The time of flight detector should to be segmented as needed. 3. Large Area and Low CostMulti-gap resistive plate chamber (MRPC) based on the technology developed at C
3、ERN LAA , Alice group. It will be much cheaper than using scintillating detector.,Oct.2001, Beijing,MRPC，USTC,3,Working Principle of Multi-gap Resistive Plate Chamber,Oct.2001, Beijing,MRPC，USTC,4,R&D at USTC 1.The Single Cell MRPC inner glass 4*4 cm2 ,electrode 3*3cm2 built at USTC in Sept. 2000,Oc
4、t.2001, Beijing,MRPC，USTC,5,MRPC Beam Test at CERN,Starting Time Resolution: start 30ps Beam Size: 1.5 mm, Momentum: 7GeV/c,USTC,Oct.2001, Beijing,MRPC，USTC,6,T-A correlation of single cell MRPC(5 gaps 0.22mm) Beam Test at CERN Nov. 2000 ( Working gas 90% Freon+5%i-C4H10,5%SF6),Oct.2001, Beijing,MRP
5、C，USTC,7,Single cell MRPC time after T-A correction ( inner glass 4*4 cm2 electrode 3*3cm2 ),Oct.2001, Beijing,MRPC，USTC,8,Efficiency and time resolution along horizontal position ( inner glass 4*4 cm2 electrode 3*3cm2 ),Oct.2001, Beijing,MRPC，USTC,9,Efficiency and time resolution VS. HV and thresho
6、ld ( inner glass 4*4 cm2 electrode 3*3cm2 ),Oct.2001, Beijing,MRPC，USTC,10,2. 2*6 pad MRPC side view-1 gap : 0.25 mm USTC(2.2) April 2001 outer glass 1.8mm, inner glass 0.7mm (made in Shanghai) pad size 3.1*3 cm,Oct.2001, Beijing,MRPC，USTC,11,2*6 pad MRPC side view-2 gap : 0.25 mm,Oct.2001, Beijing,
7、MRPC，USTC,12,The Pad of the Chamber pad size 3*3.1cm, gap between pad 0.3cm,Oct.2001, Beijing,MRPC，USTC,13,The MRPC with 2*6 pad,Oct.2001, Beijing,MRPC，USTC,14,Efficiency,time resolution and time walk as a function of applied HV for pad-4 of the MRPC (USTC 2.2),Oct.2001, Beijing,MRPC，USTC,15,Result
8、of the 6*0.25mm MRPC,Oct.2001, Beijing,MRPC，USTC,16,Result of the 6*0.25mm MRPC,Oct.2001, Beijing,MRPC，USTC,17,Efficiency and time resolution as a function of position (X scan for pad 2 and pad 3),Oct.2001, Beijing,MRPC，USTC,18,Efficiency and time resolution along Z scan for pad 1 of the MRPC USTC 1
9、.0.0,Oct.2001, Beijing,MRPC，USTC,19,p - identification testing at T-10 (d=277cm),Oct.2001, Beijing,MRPC，USTC,20,3. Structure of the double MRPC(USTC 3.2) gap : 0.22mm , tested at CERN June 2001 cathode(outer electrode) -HV, anode(middle electrode) +HV signal of cathode connect together, signal of an
10、ode connect together,Oct.2001, Beijing,MRPC，USTC,21,Raw time distribution and T-A correlation 5*0.22mm gap double chamber,Oct.2001, Beijing,MRPC，USTC,22,Time distribution after T-A correction,Oct.2001, Beijing,MRPC，USTC,23,Efficiency/Time resolution vs. HV,Oct.2001, Beijing,MRPC，USTC,24,Efficiency a
11、t different position,Oct.2001, Beijing,MRPC，USTC,25,Effect of inclined beam / 1. Inclined in direction _ _ a) Hit near the center of pad with 6*0.22mm RICE Left: =0o ,=67.8ps; Right: =20o, =70.5ps,Oct.2001, Beijing,MRPC，USTC,26,b) beam hit at near the edge of pad with 6*0.22mm RICE Left: =0o ,=77.5p
12、s; Right: =20o, =90.8ps,Oct.2001, Beijing,MRPC，USTC,27,2. Effect of inclined beam in (near the center of pad, with 6*0.22mm RICE) _ Left: =0o ,=63.7ps; Right: =20.5o, =65.3ps,Oct.2001, Beijing,MRPC，USTC,28,Oct.2001, Beijing,MRPC，USTC,29,Oct.2001, Beijing,MRPC，USTC,30,SUMMARY,Properties of MRPC From
13、the CERN PS test beam data.Time resolution Efficiency6*0.25mm gap 60-70 ps , 97% 2*5*0.22 mm gap 50-60 ps 99%,Oct.2001, Beijing,MRPC，USTC,31,Some Comment,Alice TOF module :active area 120*10cm2 , 6 gaps pad size : 3.5*2.5 cm2 =60-70 ps , 97% for MIPs Active area 160*12cm2, pad 160*5 cm2 (P. Fonte I-LIP Portugal) 2 *2gaps 0.3mm=50-80 ps , 95% for MIPsposition resolution along the strip 1.2 cm Proposal for BES endcap TOF,
