BESIII端盖TOF升级 MRPC性能测试 第二次微结构气体探测器研究研讨会 Beijing, China, Jan. 5-6, 2012 BESIII端盖TOF升级 MRPC性能测试 Yongjie Sun Center of Particle Physics and Technology University of Science and Technology of China

BESIII ETOF MRPC Beam Test Outline Introduction Beam test of the MRPC Prototypes two-end readout MRPC single-end readout MRPC Summary and outlook 2019/5/30 BESIII ETOF MRPC Beam Test

Current ETOF and upgrade Target μ: 110ps Electron: 148ps π: 138ps (average 1.1GeV for 2 σ π/K separation, but varying is from 0.9 to 1.3 GeV) MRPC ETOF Not too affected by scattering Total <80ps Non-intrinsic: 50ps MRPC: 50ps >1.4GeV for 2 σ π/K separation The drawings are from Sun SS calibration result for almost all present data The red line is representing the time resolution of 80ps X3.38, that is 95% confidence level 2019/5/30 BESIII ETOF MRPC Beam Test

BESIII ETOF MRPC Beam Test The conceptual design 36-overlapping modules for each E-cap Module shape: trapezium Gas gap: 2×6×0.22mm, in 2 stacks Total thickness: < 25mm (including gas box and hold structure) Readout: single / two ends Strips: 2.5cm wide, 8.6 – 14.1cm long 4mm wide gap between strips 24 channels for each module 4mm 8.6cm 14.1cm 2.5cm 2019/5/30 BESIII ETOF MRPC Beam Test

BESIII ETOF MRPC Beam Test Beam test at BEPC E3 line ~600MeV/c Proton / Pion π p Electronics: NINO+HPTDC Work gas: 90%Freon+5%i-C4H10+5%SF6 Goals of the test: Joint performance test: 50 ps ? Readout method study: single or two ends readout ? Strip length dependence ? At 600MeV/c, π is Minimum Ionization Particle, p is not. π / p can be identified by the charge spectrum of T1 or T2. Proton events were used for better statistics. 2019/5/30 BESIII ETOF MRPC Beam Test

Two-end readout: HV Scan Proton different particles' efficiency plateau HV>=6.8kV: Time resolution: <45ps For Proton: HV>=6.4kV, efficiency>98% For Pion: HV>=7.0kV, efficiency>98% 2019/5/30 BESIII ETOF MRPC Beam Test

Two-end readout: FEE Threshold Scan Proton Time Resolution: <45ps For Th>150mV: time resolution changes little with threshold increase 2019/5/30 BESIII ETOF MRPC Beam Test

Two-end readout: Pad Scan Proton 1 12 Time resolution:<45ps Strip length independent. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout MRPC Beam Two single-end readout MRPC prototypes were tested together to compare their performance. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: HV Scan For proton: HV>=5.8kV,efficiency>98% For Pion: HV>=6.6kV,efficiency>98% different particles' efficiency plateau 2019/5/30 BESIII ETOF MRPC Beam Test

HV Scan results: comparison Proton Single-end readout time resolution: < 50ps ( trigger witdth = 2cm  intrinsic: ~40ps ) Under work HV: two-end readout shows better time resolution than single-end readout (without T-P correction). Two-end readout need higher work HV. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: cross-pad scan trigger size: 5×2 cm2 1 2 3 4 5 6 7 8 9 10 11 12 The boxes represent the hit positions. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: cross-pad scan Proton Two prototypes have similar performance. Pad7 shows better time resolution than pad1/pad12. Strip length seems affect the time resolution of single-end readout. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: along pad6 scan 1 2 3 4 5 6 7 8 9 10 11 12 Hit area: 5×2 cm2 The boxes represent the hit positions. Scan step:1 cm. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: along pad6 scan Proton Time resolution:<50ps Hit postion(along pad6) seems affect single-end readout time resolution. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: along pad11 scan Hit area: 5×2 cm2 1 2 3 4 5 6 7 8 9 10 11 12 The boxes represent the hit positions Scan step:1cm. 2019/5/30 BESIII ETOF MRPC Beam Test

Single-end readout: along pad11 scan Proton Pad11 time resolution is not as good as pad6 in overall. For pad11, the influence of hit position is not so clear. 2019/5/30 BESIII ETOF MRPC Beam Test

BESIII ETOF MRPC Beam Test Summary and outlook Three MRPC prototypes show very good performance Two-end readout: time resolution (proton): <45ps efficiency: >98% Single-end readout: the two prototypes almost have the same performance time resolution(proton): ~50ps (without T-P correction) efficency: >98% Two-end readout: strip length does not affect the time resolution Single-end readout: strip length has some relation with the time resolution Due to the hit position uncertainty is less, the time resolution of two-end readout is better than single-end readout. MRPC: main performance satisfy ETOF upgrade requirements. More specific work needed to improve the performance. Thank you 2019/5/30 BESIII ETOF MRPC Beam Test

Comparison between proton and pion At 600MeV/c: proton time resolution is systematically better than pion (MIP) 2019/5/30 BESIII ETOF MRPC Beam Test

BESIII ETOF MRPC Beam Test 2019/5/30 BESIII ETOF MRPC Beam Test