MRPC -High Time Resolution Detector R&D at USTC CHINA Chen, Hongfang 2001/Oct. Oct.2001, Beijing MRPC，USTC

Introduction 1. Excellent Time Resolution. 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 have 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 Cost Multi-gap resistive plate chamber (MRPC) based on the technology developed at CERN LAA , Alice group. It will be much cheaper than using scintillating detector. . Oct.2001, Beijing.

Working Principle of Multi-gap Resistive Plate Chamber Oct.2001, Beijing MRPC，USTC

R&D at USTC 1. The Single Cell MRPC inner glass 4. 4 cm2 ,electrode 3 R&D at USTC 1.The Single Cell MRPC inner glass 4*4 cm2 ,electrode 3*3cm2 built at USTC in Sept. 2000 Oct.2001, Beijing MRPC，USTC

MRPC Beam Test at CERN Starting Time Resolution: start ~30ps Beam Size: ~ 1.5 mm, Momentum: 7GeV/c USTC Oct.2001, Beijing MRPC，USTC

T-A correlation of single cell MRPC(5 gaps 0 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 MRPC，USTC

Single cell MRPC time after T-A correction ( inner glass 4 Single cell MRPC time after T-A correction ( inner glass 4*4 cm2 electrode 3*3cm2 ) Oct.2001, Beijing MRPC，USTC

Efficiency and time resolution along horizontal position ( inner glass 4*4 cm2 electrode 3*3cm2 ) Oct.2001, Beijing MRPC，USTC

Efficiency and time resolution VS. HV and threshold ( inner glass 4 Efficiency and time resolution VS. HV and threshold ( inner glass 4*4 cm2 electrode 3*3cm2 ) Oct.2001, Beijing MRPC，USTC

2. 2. 6 pad MRPC side view-1 gap : 0. 25 mm USTC(2 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

2*6 pad MRPC side view-2 gap : 0.25 mm Oct.2001, Beijing MRPC，USTC

The Pad of the Chamber pad size 3*3.1cm, gap between pad 0.3cm Oct.2001, Beijing MRPC，USTC

The MRPC with 2*6 pad Oct.2001, Beijing MRPC，USTC

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

Result of the 6*0.25mm MRPC Oct.2001, Beijing MRPC，USTC

Result of the 6*0.25mm MRPC Oct.2001, Beijing MRPC，USTC

Efficiency and time resolution as a function of position (X scan for pad 2 and pad 3) Oct.2001, Beijing MRPC，USTC

Efficiency and time resolution along Z scan for pad 1 of the MRPC USTC 1.0.0 Oct.2001, Beijing MRPC，USTC

p -π identification testing at T-10 (d=277cm) Oct.2001, Beijing MRPC，USTC

3. Structure of the ‘double’ MRPC(USTC 3. 2) gap : 0 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 anode connect together Oct.2001, Beijing MRPC，USTC

Raw time distribution and T-A correlation 5*0.22mm gap double chamber Oct.2001, Beijing MRPC，USTC

Time distribution after T-A correction Oct.2001, Beijing MRPC，USTC

Efficiency/Time resolution vs. HV Oct.2001, Beijing MRPC，USTC

Efficiency at different position Oct.2001, Beijing MRPC，USTC

Effect of inclined beam / 1 Effect of inclined beam / 1. Inclined in Φ direction ____ ____ a) Hit near the center of pad with 6*0.22mm RICE Left: Φ=0o ,σ=67.8ps; Right: Φ=20o, σ=70.5ps Oct.2001, Beijing MRPC，USTC

b) beam hit at near the edge of pad with 6. 22mm RICE Left: Φ=0o ,σ=77 b) beam hit at near the edge of pad with 6*0.22mm RICE Left: Φ=0o ,σ=77.5ps; Right: Φ=20o, σ=90.8ps Oct.2001, Beijing MRPC，USTC

2. Effect of inclined beam in θ \ (near the center of pad, with 6 2. Effect of inclined beam in θ \ (near the center of pad, with 6*0.22mm RICE) _____ Left: θ =0o ,σ=63.7ps; Right: θ =20.5o, σ=65.3ps Oct.2001, Beijing MRPC，USTC

Oct.2001, Beijing MRPC，USTC

Oct.2001, Beijing MRPC，USTC

From the CERN PS test beam data. SUMMARY Properties of MRPC From the CERN PS test beam data. Time resolution Efficiency 6*0.25mm gap σ~60-70 ps , >97% 2*5*0.22 mm gap 50-60 ps >99% Oct.2001, Beijing MRPC，USTC

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 MIPs position resolution along the strip ~1.2 cm Proposal for BES endcap TOF Oct.2001, Beijing MRPC，USTC