????????????PHENIX???? Aerogel Cherenkov Counter ?????????

1
????????????PHENIX????Aerogel Cherenkov
Counter?????????
??13?? ???? ?1?? ???? ????? 980319 ???? 980290
???? ???? ???? ????
1.PHENIX?? 2.??????? 3.KEK????? 4.ACC??????????? 5
.???
2
QGP? PHENIX??
Quark Gluon Plasma ?????????????
????????????????QGP???????
??????RHIC(200A GeV )?AuAu???? (??????26
GeV/f? ????????????)
QGP??????
PHENIX?? QGP??????????????????
???????????????? ??????????(Jet Quench??)
?? TOF?RICH???????????? ???????????
TOF
TOF(???????)p/K separation 2.5GeV/c??
K/P separation 5GeV/c??
RICH(Ring Imaging Cherenkov Counter)
p/K separation 517GeV/c??
K/P separation 17GeV/c??
?????????????????????
RICH
3
PHENIX???????
Cherenkov???????
?GeV/c?????????????????????????????????
?? Aerogel ?? ??
1.001 1.006 1.07 1.31.7 1.4


Aerogel ? ????
Aerogel Cherenkov Counter ?????
17GeV -
???????n 1.01?????????????
4
???????
Aerogel Cherenkov Counter(ACC)??????
????????KEK??????????
1.ACC??????????????
?????? ????
2.?????????????????????????
???????
KEK??? ????
???? Aerogel????CHECK
ACC??????
5
Aerogel?????????
Aerogel???

• ???? ?????????????95 ???
• ???????????????????
  ?????????(1.0061.07)
• Rayleigh????????????????? ????

???????????
?????????????????????? ????????????????????????
????????????????

• ?????????????????1
• ??????
• ????????????1/? ???

2
10
6
????? ? Quality check ?
1.????????????
??? ???
? 1.007 1.0070.002
? 1.015 1.0180.002
? 1.015 1.0170.003
? 1.020 1.0200.001
? 1.020 1.0210.001
???????
?n/(n-1) 6
2.?????? ??????????? , ? ???cm
??????????????
???cm
1.007 1.018 1.020
355 0.6 1.0 1.3
415 ? 2.0 4.4
532 6.4 5.6 8.3
index
?? nm
7
??????????
????????????????????? ?? 2mm thick aluminum
, aerogel??? 11x11x12cm³ PMT R6233
(Hamamatsu) , ????(??) Goretex / Millipore /
Tyvek
1. Type A (????)
?????????????????????????
??????????1cm????? (?????)
Rayleigh ????????
?????????
2. Type B (????)
??????????????
???????(????????)?????PMT?????
???????????? 10cm ?? (?????)
8
????? ?PMT????
KEK????????????????(PMT) R6233 ???
PMT????????????????????????????????????? PMT??????
???????????????????
PMT?ADC(??)?????????????
????????????
?????? ??????
????(415nm)?????????????
HV 1800V 4.2 pe
9
KEK?????
???? ACC ??????????? (Type A , B)
???????
Set Up
?????4GeV/C?2????
???? ST1nST2nDF1nDF2nVETO TOF ST13 ???
???? DF1,2 (0.5cm)
3.09
10
KEK???????? (1) ? PID ?
TOF?????????
Log(z)
ß 0.9989
ß 0.9544
TOF vs. ACC??? (3GeV/C)
(3GeV/c?p???(?)???(?)??? ACC?????, n 1.017 )
????????????PID???? 13?????? (PMT1?)
11
KEK???????? (2) -?????-
PID??????????????????
Npe-???
Npe-??? (n1.017)
m 0.14 n 1.017
m 0.14 p 3.0
?????????????
????????? ?????????
12
KEK???????? (3) ??????
? 3GeV/c ? 2GeV/c ? 1GeV/c
p????????
????????
1GeV/c 2GeV/c 3GeV/c
1 0.993 0.999 1.000
3 0.918 0.999 0.998
5 0.732 0.993 0.995
7 0.467 0.959 0.985
???
???????????? d-ray ????????
??????????? ?????????
??????
13
KEK???????? (4) ??????
??? GeV/c e ???? ??? ?? ????
1.0 0.988 1.3 13.0
2.0 0.995 4.6 25.0
3.0 0.988 6.6 26.7
e???????????????????????????? 0.001
? p???????? ? ????????
p?????????????????????????????????????????????????
??????????e????
14
Type A ? Type B ??? (1)
??????? (type A)
PMT???? cm
????????(???)
??????????????????? ???????????????????????? ?PMT?
????????????????????
Type A ???????? ??? 5.5 0.3 cm (Tyvek)
7.0 0.3 cm (Goretex)
15
Type A ? Type B ??? (2)
??????? (type A)
??????? (type B)
????????1.5????????
??????2?????
??????????(???????)
??????????
PMT1????????????????????? ?????????Type
A??????????
16
Type A ? Type B ??? (3)
Aerogel ????? (PMT1?)
TypeB?TypeA???????? ?? 20cm????TypeB????? ?????
?
??????? (TypeA)
????????????? ????????
? ? ? ?? ? ??
17
???
Aerogel Cherenkov Counter ???????????p??????

??????? ????Type A??????27??98.8?????e????
(3GeV/c
?p???/??) Aerogel?????????????????????????PMT????
?????????????????????????Type A / ????Type B
????????? ????????????(????????UV-PMT??)???????
????????