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Photon Detector Workshop at Kobe, 27-29 June 2007 Timing properties of MCP-PMT - Time resolution - Lifetime - Rate dependence K.Inami (Nagoya university, Japan)
Photon Detector Workshop at Kobe, 27-29 June 2007
Timing properties of MCP-PMT
- Time resolution- Lifetime- Rate dependence
K.Inami (Nagoya university, Japan)
2007/6/27-29 Photon Detector WS at Kobe 2
Introduction
~400mm
Linear-array type photon detector
LX
20mm
Quartz radiatorx
y
z
Photon device for TOP counterCherenkov ring imaging counter with precise timing measurement (NIM A 440 (2000) 124)
Barrel PID upgrade for Super B factory
Single photon sensitivityGood transit time spread (TTS<50ps)Operational under 1.5T B-fieldPosition sensitive (~5mm)High detection efficiency
MCP-PMT is a best solution!
2007/6/27-29 Photon Detector WS at Kobe 3
MCP-PMTMicro-Channel-Plate
Tiny electron multipliersDiameter ~10µm, length ~400µm
High gain~106 for two-stage type
→ Fast time responsePulse raise time ~500ps, TTS < 50ps
can operate under high magnetic field (~1T)
Photo-cathode MCP plates Anode
Photon
Single photonChannel
~400µm
φ~10µm
Input electron
HV
MCP channel
2007/6/27-29 Photon Detector WS at Kobe 4
MCP-PMT for single photonTiming properties under B=0~1.5T parallel to PMT
HPK6 BINP8 HPK10 Burle25
1012513Bias angle (deg.)
bi-alkalimulti-alkalimulti-alkalimulti-alkaliphoto-cathode
2500360032003600Max. H.V. (V)
24261826Q.E.(%) (λ=408nm)
40434040Length-diameter ratio
251086MCP hole diameter(µm)50x50251811Effective size(mm)
71x715230.545PMT size(mm)
Burle2585011-501
HPK10R3809U-50-25X
BINP8N4428
HPK6R3809U-50-11X
MCP-PMT
2007/6/27-29 Photon Detector WS at Kobe 5
MCP-PMT for single photon (2)Setup
Single photon is generated by laser (408nm).B-field is parallel to tube axis.
HPK PLP-02Width 36ps
18GHz0~10dB
1.5GHz36dB
Philips 708
2007/6/27-29 Photon Detector WS at Kobe 6
MCP-PMT (output)Hamamatsu R3809U-50 (multi-alkali photo-cathode)
ADC (count/0.25pC)
0
200
400
600
100 120 140N
um
ber
of
Even
tsTDC (count/25psec)
0
500
1000
1500
-20
Nu
mb
er
of
Ev
en
ts
200
σ=46psfor single photon
single photon peak
Window size : 25mmφ
HPK10
MCP hole 10µmφ
HPK6
Window : 11mmφ
MCP hole 6µmφ0
200
400
600
800
1000
1200
100 110 120 130ADC (1bin/0.25pC)
even
t
0
200
400
600
800
1000
-20 -10 0 10 20
30.4psec
TDC(25ps/count)
even
tGain ~ 106
2007/6/27-29 Photon Detector WS at Kobe 7
105
106
107
0 0.2 0.4 0.6 0.8 1.2 1.4 1.61B (T)
Gai
n
HPK6: 3.6kVBINP8: 3.2kVHPK10: 3.4kVBurle25: 2.5kV
Pulse shape (B=0T)Fast raise time (~500ps)Broad shape for BINP8
Due to mismatch with H.V. supply and readout cableNo influence for time resolution
Gain v.s. B-fieldSmall hole diameter shows high stability against B-field.Explained by relation btw hole size and Larmor radius of electron motion under B-field.
1ns
500ps 1ns
10mV20mV
1ns
2mV 2mV
HPK6 BINP8
HPK10 Burle25
Pulse response
2007/6/27-29 Photon Detector WS at Kobe 8
MCP-PMT in B-fieldADC spectra with different angles under B=1.5T
Gain depends on the angle.Behaviors are slightly different.
Because of the different bias angle of MCP hole HPK6: 13deg, 6µm, BINP8: 5deg, 8µm
0
0.02
0.04
0.06
100 150 200 250 300
0.05
0.1
0.15
0.2
100 120 140 160 1800
ADC channel (/0.25pC)
φ=0o
φ=30o
φ=45o
φ=60o
φ=0o
φ=15o
φ=30o
φ=45o
ADC channel (/0.25pC)
# of
eve
nt (
arbi
trar
y) HPK6 BINP8
Photo-cathode MCP plates Anode
Photon
Bφ
2007/6/27-29 Photon Detector WS at Kobe 9
20
40
60
80
100
120
0 0.2 0.4 0.6 0.8 1.2 1.4 1.61B (T)
TT
S (p
s)
HPK6: HV 3.6kVBINP8: HV 3.2kVHPK10: HV 3.6kVBurle25:HV 2.5kV
0
20
40
60
80
100
120
10 6 107
BINP8HPK6
HPK10Burle25
Gain
TT
S(ps
)
Single photon
Single photon
Time responseTTS v.s. B-field
Small hole diameter shows high stability and good resolution.
TTS v.s. GainFor several HV and B-field conditions30~40ps resolution was obtained for gain>106
Hole size need <~10µmto get time resolution of ~30ps under 1.5T B-field.
2007/6/27-29 Photon Detector WS at Kobe 10
LifetimeHow long can we use MCP-PMT under high hit rate?
(Nucl. Instr. Meth. A564 (2006) 204.)
Light load by LED pulse (1~5kHz)20~100 p.e. /pulse (monitored by normal PMT)
55-60%65%XX OOAl protection
40-6037%Correction eff.
5deg13degBias angle
30~40ps29ps3~4x1061.5x1061.9x106Gain
34psTTS
16-20%19%21%Quantum eff. at 400nm
Multi-alkali (NaKSbCs)Photo-cathode
18mmφ11mmφEffective area
Russian (x5)HPK (x2)
2007/6/27-29 Photon Detector WS at Kobe 11
Lifetime - Q.E. -
0
0.5
1
0 10 20 30Integrated irradiation(x1013 photons/cm2)
Rel
ativ
e Q
.E.
λ=400nm
Time in Super-B factory (year)0 5 10 15
Relative Q.E. by single photon laser
Without Al protectionDrop <50% within 1yr.
With Al protectionLong lifeNot enough for Russian PMTs
Enough lifetime for HPK’s MCP-PMT with Al protection layer
HPK w/ AlHPK w/o AlRussian w/ AlRussian w/o Al
2007/6/27-29 Photon Detector WS at Kobe 12
Lifetime - Q.E. vs wavelangth -Q.E. after lifetime test (Ratio of Q.E. btw. before,after)
Large Q.E. drop at longer wavelengthNumber of Cherenkov photons；only 13% drop (HPK w/Al)
Number of generated Cherenkov photon:~1/λ2
10-2
10-1
1
10
200 300 400 500 600 700 800 900λ(nm)
Q.E
.(%
)
HPK w/ AlHPK w/o Al
BINP w/ Al (#32)BINP w/ Al (#35)BINP w/ Al (#38)BINP w/o Al (#6)BINP w/o Al (#11)BINP before
HPK before
10-3
10-2
10-1
1
200 300 400 500 600 700 800 900λ(nm)
Rel
ativ
e Q
.E.
HPK w/ AlHPK w/o Al
BINP w/ Al (#32)BINP w/ Al (#35)BINP w/ Al (#38)BINP w/o Al (#6)BINP w/o Al (#11)
2007/6/27-29 Photon Detector WS at Kobe 13
Lifetime - Gain -
0
0.25
0.5
0.75
1
0 10 20 30Integrated irradiation(x1013 photons/cm2)
Rel
ativ
e G
ain
Time in Super-B factory (year)0 5 10 15
Estimate from output charge for single photon irradiation
<1013photons/cm2
Drop fast
>1013photons/cm2
Drop slowly
Single photon detection: OKCan recover gain by increasing HV
HPK w/ AlHPK w/o AlRussian w/ AlRussian w/o Al
2007/6/27-29 Photon Detector WS at Kobe 14
Lifetime - T.T.S. -
0
20
40
60
80
100
0 10 20 30Integrated irradiation(x1013 photons/cm2)
TT
S(p
s)
Russian w/o Al (#6)
HPK w/o Al
Russian w/ Al(#32)
HPK w/ Al
－before－after
σ=31psσ=36ps
σ=43psσ=32ps
σ=34psσ=34ps
σ=29psσ=33ps
HPK w/ AlHPK w/o AlRussian w/ AlRussian w/o Al
Time resolution for single photonNo degradation!Keep ~35ps
2007/6/27-29 Photon Detector WS at Kobe 15
Multi-anode MCP-PMT (1)
NoAl protection layer
2Number of MCP stage
4 channel linear arrayAnode
27.5 x 27.5 x 14.8 mmSize
22 x 22 mm(64%)Effective area
0.3 mmAnode gaps
5.3 x 22 mmAnode size (1ch)
~60%Aperture
10 µmMCP Channel diameter
~20%(λ=350nm)Q.E.
Multi-alkaliPhoto cathode
22(effective area)27.5mm
1ch
2ch
3ch
4ch
SL10R&D with Hamamatsu for TOP counter
• Large effective area 64% by square shape• Position information 4ch linear anode (5mm pitch)
2007/6/27-29 Photon Detector WS at Kobe 16
Multi-anode (2)Single photon detectionFast raise time: ~400psGain=1.5x106 @B=1.5TT.T.S.(single photon): ~30ps @B=1.5TPosition resoltion: <5mmCorrection eff.: ~50%
Nucl. Instr. Meth. A528 (2004) 768.
Basic performance is OK!Same as single anode MCP-PMT
Raise time～400ps
tdc(time walk collection)
0
1000
2000
3000
4000
5000
6000
-25 -20 -15 -10 -5 0 5 10 15 20 25
ID
Entries
Mean
RMS
3542
19316
1.479
4.464
319.3 / 9
Constant 4725. 52.34
Mean -0.5600 0.1162E-01
Sigma 1.150 0.8783E-02
1bin/25ps
coun
t
T.T.S.: σ~30ps
2007/6/27-29 Photon Detector WS at Kobe 17
Rate dependenceGain vs. photon rate
For high intensity beamGain drop for high rate
>105 count/cm2/sDue to lack of elections inside MCP holesDepending on RC variables
10-2
10-1
1
1 10 102
103
104
105
106
107
108
109
SL10HPK6BINP
Ndet(count/cm2/sec)
Super B-factory@L=2x10 /cm /sec
35 2R
elat
ive
Gai
n24~393116MCP capacitance
(pF/cm2)
380~100014396MCP resistance (MΩ cm2)
BINPHPK6SL10
MCP
MCP channel
Electrode Enough for TOP counter
2007/6/27-29 Photon Detector WS at Kobe 18
High resolution TOFStructure
Small-size quartz (cm~mm length)Cherenkov light (Decay time ~ 0) extremely reduce time dispersion compared to scintillation (τ ~ ns)
MCP-PMT (multi-alkali photo-cathode)TTS ~ 30ps even for single photongives enough time resolution for smaller number of detectable photons
Readout electronicsσelec.: 4psTime-correlated Single Photon Counting Modules (SPC-134, Becker & Hickl GMbH’s)
CFD, TAC and ADC Channel width = 813fsElectrical time resolution = 4ps RMS
Test counter
2007/6/27-29 Photon Detector WS at Kobe 19
Beam test setup3GeV/c π− beam
at KEK-PS π2 line
PMT: R3809U-50-11XQuartz radiator
10φx40zmm with Al evaporation
0
100
200
300
40 80 120
4.1ps
Even
tsTDC (ch/0.814ps)
Elec. resolutionBeamTrig.1
Trig.2TOF1 TOF2
30cm
Trig.1 Coinc. Discri.Divider
Trig.2
TOF2
TOF1PowerSpliter
Discri.
Discri.Divider
Start Stop
π, 3GeV/c-
SPC-134
2007/6/27-29 Photon Detector WS at Kobe 20
Beam test resultWith 10mm quartz radiator
+3mm quartz windowNumber of photons ~ 180Time resolution = 6.2psIntrinsic resolution ~ 4.7ps
Without quartz radiator3mm quartz windowNumber of photons ~ 80
Expectation ~ 20 photo-electrons
Time resolution = 7.7ps
Even
ts
100
200
300
400
40 80 120 1400TDC (ch/0.814ps)
6.2ps
100
200
300
40 80 120 1400
TDC
7.7ps
(ch/0.814ps)Ev
ents
2007/6/27-29 Photon Detector WS at Kobe 21
SummaryMCP-PMT studies
Good time resolution of ~35ps for single photonEven under B=1.5T
Gain~106 with <10µm MCP holeLong lifetime (<10% QE drop) until 3x1014photons/cm2
Need Al protection layerGain degradation if Ndet >105 counts/cm2/s
Enough performance for TOP counter in super B factory
High resolution TOF; ~5ps time resolutionAn apprication of fast MCP-PMT
ReferencesM. Akatsu et.al., Nucl. Instr. Meth. A528 (2004) 768.K. Inami et.al., Nucl. Instr. Meth. A560 (2006) 303.N. Kishimoto et.al., Nucl. Instr. Meth. A564 (2006) 204.
