BEPCII??????

1
BEPCII??????

• ?????????????????
• ??3??

2
?, ??
??L?????
?????Bhabha e e-?e e- ? ????? ee-?ee-
2? ???Bhabha??ee- ?ee-
????I??????,C3.111036?????I I- ,?????? I??????
3
????????Bhabha
4
??
????????????1????????????3???????? ???????Bunch-by
bunch?????
???????????,?????????
5
?????
6
(No Transcript)
7
(No Transcript)
8
RD

• ?????????????,??GEANT4???(??????????
• ?????R7400U-06)????????????,??
• ????????????????????
• ??????????????????????
• ?????????????????
• ??????????
• ????????????????????
• ?????BBBREM???100000???,??????????????????????????

9
??????
?????????????????????????????????92.9 ?82.3?
??????????????xy???????
10
???????????
???????????????,????????PMT???? ??????????????
???????,?100000????,?????????????? ?????1???????55
083?54964
11
?, ????
1?????????????????
12
400MeV???????(?)?ADC?(?)
????(??????)????????
13
TDC?
????200ps
14
??
????
ADC
????????????????7.65.9?6.14.5
2 ?????
15
?????0.25ns
16
????????????????
Energy (MeV) Number of Photoelectron Number of Photoelectron Calibration factor
Energy (MeV) Simulation e- beam test Calibration factor
400 60.838.1 28.817.5 0.4740.413
500 83.146.2 33.520.7 0.4030.335
600 97.153.0 38.020.2 0.3910.298
????????????????????????????????? ??????,?????????
???0.4230.203
17

• BEPCII?????????
• ????????

18
(No Transcript)
19
(No Transcript)
20
?????????

• bunch by bunch??
• Bunch by bunch???,????????????????????,??????
  ????????????????????????????????????????????????
  ????????????????????????????????????,????????,???
  ????

21
????(???)
???????,??????????????????????????????????????
???????????????????????(???????????)
????8ns????????(???)??????????????8ns?????
????8ns????????(??)??????????????8ns???
22
??????
??????????????????????x-0.7mm?y-0.02mm?
23

• BEPCII?????????
• ????????

24
??????????????
???????????????????????(???????????)
50???????????????????????(???????????) ??????????
25
????(????)
??????????????????????(???????????)
?????????????????????????
26
????(????)
????????????
27
?????????
?????? , , , ????????????????????
?????????? 1??????????????? 2????????
3?
28
?????????(?I5.11mA,I-5.02mA????)
?(mV) 100 200 300 400 500 600 800 1000 1200 1400
nT 25991 19946 16245 13535 11281 9226 6036 3305 1509 649
n? 26261 20105 16351 13608 11332 9260 6051 3309 1510 649
102.5 89.7 80.9 73.8 67.3 60.9 49.2 36.4 24.6 16.1
857 575 420 306 250 192 120 58 17.5 0
18.5 15.2 13.0 11.1 10.0 8.8 6.9 4.8 2.6 0
31775 24413 19914 16628 13853 11335 7414 4064 1866 811
130.2 113.7 102.4 93.3 85.0 77.0 62.1 45.9 24.7 20.1
0.0041 0.0047 0.0051 0.0056 0.0061 0.0068 0.0084 0.0113 0.0132 0.026
????????????,???400mV,5mA/bunch
???????????????
29
???????
1?PMT???????
The PMT gain and gain spread
The type of PMT 03HB1453 06CB2090 06CB2093 06CB2096 AT3186 old03 old06
The mean value of PMT gain(105) 2.86 6.92 1.88 3.10 3.78 4.57 6.07
The error of PMT gain (104) 0.035 0.11 0.011 0.050 0.060 0.013 0.032
The sigma of PMT gain (105) 0.439 1.148 0.334 0.501 0.690 0.721 0.822
?????????????PMT,???????????PMT
30
???????
2????????????
2box ???
3box ???
31
???????
3?PMT????????????
????VS??(????)
32
???????

• ???????????????????????PMT?????????
• ?????????PMT?????????????PMT???????????Npe
• ???????PMT?????????? ,?????????????(??????
  ???????Npe)??????????,???????????????(160mb),?????
  ????eff,???????????,LNsb/ ?eff?
• ???????PMT???????????????????????????Npe????Npe,??
  ???????Npe ?Npe?Npe- ?Npe??????????effl??effh,???
  ????????????

33
?????-??-???-??
34
???????
???????,??????????,???(??/mA????????????
????,????????
35
???????(???I5.11mA,I-5.02mA????)
?(mV) 200 300 400 500 600 800 1000
nT 19946 16245 13535 11281 9226 6036 3305
n? 20105 16351 13608 11332 9260 6051 3309
nsb 24413 19914 16628 13853 11335 7414 4064
L(1029) 7.72 3.66 -2.79 9.06 5.60 -3.68 10.10 8.13 -4.56 10.85 10.89 -5.35 10.95 13.62 -5.75 10.23 18.36 -5.99 7.62 18.65 -4.84
36
????
???????????????,????????????? ???200mV,???????5X5
mA2,??
37
??!