Post on 18-Jan-2016
description
BESIII宇宙线实验
朱科军高能物理研究所
BEPCII Project
Luminosity: 3~10×1032cm-2s-1 @ 3.77GeV
Milestones Barrel EMC and electronics was ready on 11/30/2007 Trigger system for EMC was ready on 11/30/2007 Started MUON test since 12/3/2007 Barrel TOF and electronics was ready on 12/20/2007 MDC and electronics was ready on 1/2/2008 Cosmic ray w/o end-cap seen on 1/6/2008 End-cap of EMC and TOF was ready on 2/12/2008 Cosmic ray with full detector seen on 2/14/2008 Cosmic ray data taking finished on 3/16/2008 Moved to the BEPCII IR by mid-April, 2008 Data taking is expected around mid-June, 2008.
System overview
TOF Electronics
MDC Electronics
TOF Trigger
MDC Trigger
Global Trigger &
Fast Control
MDC Electronics
Fanout
T0
Optical Fiber Cable
L1*
EMC Electronics
MU Electronics
MU Trigger
EMC Trigger
MDC Electronics
Fanout
MDC Electronics
Fanout
MDC Electronics
Fanout
触发条件和定时 00 to 15 :::::: EMC 00 : NCluster >= 1 01 : NCluster >= 2 02 : Barrel Cluster back to back 03 : Endcap Cluster back to back 04 : Cluster Balance in Z direction 05 : Barrel Cluster Balance in Phi direction 06 : Endcap Cluster phi Balance 07 : Barrel total Energy Higher threshold 08 : Endcap total Energy Higher threshold 09 : total Energy Lower threshold 10 : total Energy Middle threshold 11 : Energy Balance in "Z" direction 12 : Barrel Energy difference Balance 13 : Endcap Energy difference Balance 14 : Energy Block Balance 15 : Endcap Energy Balance
16 to 21 :::::: TOF 16 : Endcap TOF back to back 17 : Barrel TOF back to back 18 : NETOF >= 2 19 : NETOF >= 1 20 : NBTOF >= 2 21 : NBTOF >= 1 (0x15) 32 to 37 :::::: MUON 32 : MUON Back to Back 3478 33 : MUON Back to Back 37 38 to 47 :::::: MDC 38 : Short Track back to back 39 : NStrk >= N 40 : NStrk >= 2 41 : NStrk >= 1 42 : Long Track back to back 43 : NLtrk >= N 44 : NLtrk >= 2 45 : NLtrk >= 1 46 : NItrk >= 1 47 : NItrk >= 2
触发道 0x1 => EMC Ncluster >= 1 0x2 => NBTOF >= 1 0x4 => BTOF back to back 0x8 => EMC Cluster back to back 0x10 => Short Track Back to Back 0x20 => Long Track Back to Back && BTOF Back to
Back 0x100 => BTOF back to back && Ncluster >= 1 0x200 => random trigger 0x400 => Long Track Back to Back && NCluster >= 1 0x800 => NLtrk >= 1 0x1000 => MUON Back to Back 3478 0x2000 => MUON Back to Back 37 0x4000 => NBTOF >= 1 && NClus >= 1 0x8000 => NLtrk >= N
Run2414: 2008-03-06 18:17 to 03-07 09:00
Trigger channels: 0x441cEndcap Cluster phi Balance
Long Track Back to Back && NCluster >= 1
ETOF back to back
EMC Cluster back to back
BTOF back to back
Timing: 0x8022a11Barrel TOF back to back
Long Track back to back
Barrel Cluster back to back
时间低阈的选取
在 3# 厅进行的宇宙线测试中，按噪声水平 1% 为标准，设置的时间低阈为内室 110 ； 台阶 70 ； 大端板 50内室 120 ； 台阶 80 ； 大端板 60 ( 数据分析得到的理想低阈 )
当前条件下，如果按 1% 的标准，时间低阈应为内室 100 ； 台阶 70 ； 大端板 40
随机触发，设置时间道高低阈相等，在不同时间阈值下测量漂移室各通道的时间计数，计数值阈触发数之比反映了漂移室在该时间阈下的噪声计数水平
Hitmap and distribution of T and Q (run1963)
T hitmap Q hitmap
T distribution Q distribution
Drift distance (mm)
Dri
ft ti
me
(ns)
Time-to-distance relation(layer 12)
Drift time (ns)
Ent
ries
Distribution of drift time(layer 12)
Results of calibration and reconstruction
Spatial resolution(after calibration and alignment)
• HV: 2150V
• T threshold:
120/150(inner section), 80/110(stepped section), 60/80(outer section)
Spatial resolution vs layer
Efficiency vs layer
TOF Calibration Using Cosmic Ray Data
Time Difference of Each Counter
The distribution of sum time of two end. The fitting function isError Function.
x 2x dxe
2
1xD
22
')( )/()'(
Mean value vs counter number
Sigma value vs counter number
T0 Extract
σ=317ps σ=164ps
σ=283psOriginal T0
T0 after calibration
T0 Difference before and after T0 extract
Delta T distribution before and after T0 extract
Single End Readout Time Resolution (Preliminary!)
East and West end readout time resolution with unit/ps
Using time difference of each counter and T0 extraction, with an approximation of β ＝ 0.99, the single end readout time resolution are shown.
• event Selection
– EMCb2b
– Energy of digi>10MeV, and only two digis
• Check ADC(MeV) distribution for each crystal
– First calibrated by using relative light yield data,
– and comparison with the MCdata
• Finally give the Preliminarycalibration constant for every crystal
How to calibrate by using cosmic rawdata
Hitmap of sample events
宇宙线事例： EMC b2b 触发 选择只击中两块晶体的事例
ADC (MeV) vs nphi
Barrel light yield by PMT
crystal-per
lightyieldlightyield lightyield
meanCalibConst
PMT RLY calibrationNo calibration
No-calib
Sig/mean=
32.57/239.7=13.6%
PMT RLY calib
Sig/mean=
26.95/265.8=10.1%
Cosmic RLY calib
Sig/mean=
29.59/265=11.2%
Fiber RLY calib
Sig/mean=
29.01/262.3=11.1%
Barrel_all
Preliminary results only using relative light yield data
Gaus_landau fitting
adc2-28l-2930
Mean=267MeV
Phi=29&30
Mean/RMS=
187.6/19.55
RawDataMCData
C1=Mean_mc/Mean_raw~188/267=0.7
1Cyieldlight relative
yield)light iveMean(relattCalib.Cons
First calibration by Cosmic rawdata
Cosmic_mc Cosmic_rawdata , barrel_all
The22&phi29
Sig/mean=
11.38/182.1
=6.25%
Barrel_all
Sig/mean=
12.34/184.4
=6.7%
Only relative light yield by PMT testSig/Mean=27/265.9=10.1%
relative light yield by PMT test +mc_calibSig/Mean=16.7/183.4=9.1%
Preliminary results using relative light yield data & MC_calib
Barrel_all Barrel_28cm Barrel_24cmBarrel_ntheta2
1Barrel_nthe21&
nphi29
Cosmic Rawdata
32.57/239.7=13.6%
32.56/239.6
=13.6%
27.57/247.7
=11.1%
22.84/228.7
=10%
Relatvie light yield
calib(PMT)
27/265.9
=10.1%
26.63/266.2
=10%
21.28/216.1
=9.85%
24.97/266.8
=9.36%
26.5/293.9
=9%
Relatvie light yield
calib(PMT) +mc_calib
16.7/183.4
=9.1%
16.52/183.6
=9%
15.23/158.3
=9.6%
16.23/182.4
=8.9%
16.55/183.6
=9%
Mc simulation 12.23/184.2=
6.64%11.93/184.3
=6.47%
10.95/158.4
=6.91%
11.75/183.1
=6.42%6.25%
Sigma/mean by Gaus+landau fit
Preliminary results
By layer By segment
Hit map
Hit maps show pretty well, noise and dead channel have been checked and repaired
Counting rate
Trigger rate: 75~90Hz, Counting rate of MUC at 10-4 Hz/cm2 level
总结 BESIII 宇宙线调试总的来说进展顺利 已获取一定数量的宇宙线事例供离线进
行软件调试和探测器性能的初步研究，帮助查找硬件中存在的问题
下月初进行第二轮宇宙线测试 准备迎接对撞取数
谢谢