PowerPoint

ALICEPWO

20103222010@

2010/3/222010 JPS1LHC/ALICE/PHOS

2010/3/222010 JPS2Heavy Ion Collisions at LHC2010/3/222010 JPS33/22/2010JPS 20103

p+p s =14 TeVPb+PbsNN=5.5 TeV

EnergyLHC = 28 x RHIC =320 x SPS = 1000 x AGS3/22/2010JPS 201044

Detector:Size: 16 x 26 metersWeight: 10,000 tonsCollaboration:> 1000 Members> 100 Institutes > 30 countries

4

PHOS

//

PHOS

(QGP)100 QGP!!

3/22/2010JPS 2010PbWO4 CrystalFast Signal (~nsec)Operation at -25degSmall Moliere Radius (2cm) Good 2 photon Separation

PHOS

5PbWO4 CrystalFast Signal (~nsec)Operation at -25degSmall Moliere Radius (2cm) Good 2 photon SeparationAvalanche Photo Diode (APD)High Q.E.(60%-80%)Thin photo-sensorOperational in magnetic field

PbW04 crystal18cm2.2x2.2cm2

APD: Hamamatsu S8148/S8664-555x5mm2x2cm5PHOS164*56=3584PWOAPD()CSP()

PHOS:PWO -> ->

APD-> (PMT)(10^4~10^6)(10~10^4)

Charge Sensitive Preamplifier(CSP)5ALICEPHOS

PHOS

PHOS

3/22/2010JPS 20106PHOS

63/22/2010JPS 20107HV-1500 V, -1550 V

PHOS

PHOS

7PHOSTest BenchPWO -> APD -> CSP -> (FEE)

Test BenchPHOS

Test Bench2PWOAPDCSP-25

// (1)PWO(2)(3)

3/22/2010JPS 20109

ADC countADC count100 ns / count100 ns / count

ADC countADC count100 ns / count100 ns / count9PWO-> APD-> CSP(p0)-> FEE(70 counts)

3/22/2010JPS 201010PWOPWO()()

8(A) 2(B)

= 20rate ~ 1.34 10-4 sec-1 ( 12 events / crystal) PWO() 0.5 1 0

1.5 20 0.8

0.6 1 0.2

: > Threshold(A): < Threshold(B)

= ()103/22/2010JPS 201011rate ~ 3.35 10-3 sec-1 ( 290 events / crystal) 3 33

2 3 1

2 10 7

1 5 3

: > Threshold(A): > Threshold(C)

= () + ()()

8(A) 4(C)

p0 = 10+5+7 = 2211JPS 201012

Threshold(A) > 8 [ADC count]

Threshold(C) > 4 [ADC count]

29

: 30.3

: 18.4

/ E: 0.27 (@ )

APD

()3/22/2010

Threshold(A) > 8 [ADC count]

Threshold(B) < 2 [ADC count]

29

: 32.3

: 22.9

/ E: 0.14 (@ )

12291

3/22/2010JPS 201013APD(1)

Threshold(A) > 8 [ADC count]

Threshold(C) > 4 [ADC count]

29

: 39.1

: 4.6

/ E: 0.20 (@ )

Threshold(A) > 8 [ADC count]

Threshold(B) < 2 [ADC count]

29

: 38.1

: 6.2

/ E: 0.14 (@ )HV*133/22/2010JPS 201014APD(2)

Threshold(A) > 8 [ADC count]

Threshold(C) > 4 [ADC count]

29

: 32.8

: 1.3

/ E: 0.21 (@ )

Threshold(A) > 8 [ADC count]

Threshold(B) < 2 [ADC count]

29

: 31.6

: 2.0

/ E: 0.18 (@ )HV*14/()(@ )0.73/22/2010JPS 20101515PHOS

MIP6.3%3.9%250.7

ALICE3/22/2010JPS 201016Back up3/22/2010JPS 2010173/22/2010JPS 201018[g/cm3][cm][cm][ns][NaI]PWO8.280.892.05~150.01BGO7.131.122.43000.15NaI3.672.594.52501.00CsI4.531.853.85650.40PWO: : 18

PWOAPD CSPFEE board

(1) (2) APD(3) CSP(4) FEE3/22/2010JPS 20101919PHOS / 3/22/2010JPS 201020

PWOAPD CSPFEE board

(1) (2) (3)

ALICEL3PHOS: 3584/1 module: 2920FEE board

3/22/2010JPS 201022

p0:

P1:

p2:

p3:

p4: Sampling ADC1522f(x)=Amp*t^N*exp(-N*t)+Ped, where t=(x-Tpre)/Tau

(MIP)

E=dE/dx L=9.4[MeV/cm] 18[cm]=169.2[MeV](34[ADC count] @ 50)3/22/2010JPS 201023

PbW04 crystalL = 18cm2.2x2.2cm2dE/dx = 9.4 MeV/cm

1[ADC count] 5[MeV]

PWO

E/E ~ 0.14 E/E ~ 0.203/22/2010JPS 201024243/22/2010JPS 201025PWOAPDCSPFEE: ~4GeVPWOLED: ~eVPWOLED25HVHV(1)HV(2)195k109k103k179.59APDHV3/22/2010JPS 20102626HVLEDAPDHV-p034[ADC count]APDHV

HVp034APD(@ (0,13))LEDp020105p034180HVHV3/22/2010JPS 20102727/Threshold(A)

3/22/2010JPS 201028

99%Threshold(A)

4~10 ADC count(20~50 MeV @ gain 50)020p028Threshold8.68.39.94.91.49.55.84.84.97.44.58.78.14.79.08.37.98.24.24.97.38.48.58.37.98.28.45.18.47.93/22/2010JPS 201029Threshold(A)Threshold(B,C)2.04.0 [ADC count]100%((7,12))()Test Bench()29APD311345319348-3523583463603363163553483523413063123073363393093123153423323003133033423283/22/2010JPS 201030[V]HV30APD342334310370-3453753723733553523673633673553363103363583603392852903203422882933333203003/22/2010JPS 201031[V]HV(1)31APD335327304368-3363793783783563423693663723543223043243603603252872903143442952923233243033/22/2010JPS 201032[V]HV(2)32