Transcript 10 psec Time-Of-Flight Counter T. Ohshima (Nagoya U.)

TIMING PROPERTIES OF MCP-PMT
DEVICES
- s<10 psec TOF Counter T. Ohshima (Nagoya U.)
1. TOP counter and TOF counter
2. R&D of MCP-PMT’s
3. TOF counter
■ New Approaches
■ Beam test (1)
■ Beam test (2)
■ Know-how
Footnote: MCP-PMTにもとずく 10 psec TOF counter R&Dの報告である。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
1. TOP counter and TOF counter
Photon device for TOP counter
M. Akatsu et al, NIM A440 (2000) 124-135; T. Ohshima ICFA Instr. Bull. 20 (2000) 2
Single photon sensitive
high detection efficiency
Y. Enari et al, NIM A547 (2005) 490-503
Fine-mesh multi-anode PMT
M. Hirose et al, NIM A460 (2001) 326-335
Hybrid Avalanche Photo-Diode
Quantum Efficiency
S. Matsui et al, NIM A463 (2001) 220-226
Collection Efficiency
photocathode material
Fast timing TTS < 50 ps
Linear array multi-anode PMT
Micro-Channel Plate PMT
M. Akatsu et al, NIM A528 (2004) 763-775
cathode – 1st MCP gap
Structure of MCP-PMT
Position resolution ~ 1 mm
Multi-anode structure
Cross-talk
Operational under 1.5 T
Long life-time
Ion-feedback layer
Rate dependence
vacuum
1. HPK10 (3809U-50-25X),
2. HPK6 (3809U-50-11X)
3. BINP (multialkali)
(GaAs extended)
4. Burle (85001-501)
< 10 ps TOF counter
TOP counterのphoton detectorの開発が動機。要請する性能を満たすもの⇒PMT, HAPD & MCPへ。この過程でMCP-PMTの光時間分解能を活用しTOF counetrを発想。
回路を除くと5 psの分解能をすでに得る。 By doing R&D on these issues, most of them are now in satisfaction. In the course of R&D studies,
we come across an idea to have less 10 ps TOF counter.
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(Single photon pulses)
(Transite Time Spread) TTS
●Multi-anode linear-array PMT (L16 & L24)
●Hybrid Avalanche Photo-Diode
●Micro-Channel-Plate PMT
70-80; 120 ps
150 ps
30-40 ps
HAPD(HPK R7110U-07)
L16(HPK R5900-L16)
PMT(HPK H7195)
1 ns/div
L24(HPK R6135-L24X)
MCP(HPK10 3809U-50-25X)
Footnote: これまで開発研究した光検出器の１光子に対する信号と測定TTS。信号の立ち上がりの速さを比較せよ。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
Points for TOF counter
一
Fluctuations of
1. TTS
2. Decay-time (Td  TTS)
3. Light-path (Tγ  TTS)
4. Nγ Photo-statistics 1/Nγ is
varied only
at Td, Tγ << TS.
六
二
五
四
三
七
time
photon signals
quartz: n=1.47;
q=45o (for GeV/c
particles)
1. 30-40 ps (MCP-PMT), 70-80 ps (L16)
2. Cherenkov light
3. Normal incidence (a timing spread due to quartz thickness = 1-2 ps for 1 cm quartz.)
⇒ s = (30x2–30) ps /1cm/(12Nγ) = 9 ps/ Nγ/ 1 cm)
4. 50 detected photons/1 cm quartz
For short path, no chromaticity effect.
s = 30-40 ps/ 50 = 5-6 ps
Footnote: TOF精度を決める要因。⇒MCP-PMY/Cherenkov/path/# photons （時間広がりがなく、多量の光子が＝１．＆４．）
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(Test circuit)
矩形波で測定
測定回路の寄与＝ 8.8psec
弐
壱
using single photons from a light-pulser
Divider
divider
Divider
参
HPK C5594:
bandwidth=50 kHz-1.5 GHz
gain=36dB (@0.1 GHz)
NF = 5 dB
HUBER+SUHNER SMA cable
MULTIFLEX MF 141：
Impedance=50 ohm
Operating frequency= 18 GHz
Capacitance=95 pF/m
Time delay= 4.7 ns/m
Attenuation= a f(GHz)^1/2 + b f(GHz) (a=0.37320), (b=0.02790)
Footnote: TOF精度を決める要因。⇒回路系の精度（実測値＝7-9 psec）。ビームテストではatt.&ampは不要。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(MCP-PMT’s)
NIM A528 (2004) 763-775, by M. Akatsu et al, “MCP-PMT timing property for single photons”
multialkali
multialkali
MCP(Micro-Channel Plate)
チャンネル径
Footnote: 開発研究のMCP-PMT性能比較。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(ADC spectra)
• HPK10 R3809U-50-25X
Gain=106
s=46ps
Single photon peak
(pedestal = 100count)
• BINP N4963
Gain=3x106
s=34ps
（１光子照射,HV:3.2kV)
Single photon peak
(pedestal = 100count)
Footnote: ADC & TDC spectra
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(Gain vs TTS)
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2. R&D of MCP-PMT’s
(TTS vs B)
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3. TOF counter
Cerenkov radiator
(TOF by HPK10)
Since the light-pulser’s jitter yields an essential contribution on the measurement,
TTS=46 ps, N = 200/ 4 cm quartz,
s0 = 46/ 200 = 3 ps
⇒ sexpected = 9 ps
including circuit fluctuation of 9 ps.
sobserved = 10.6 ps
⇒ With different TTS [ L16(TTS=80 ps) & MCP(TTS=46 ps) ] and
similar Nγ’s, sobserved = 11-12 ps is attained,where the circuit
fluctuations (7-9 ps) dominate the ambiguity.
Footnote: HPK10 TOFのビームテスト。期待値＝９ ｐｓ ｖｓ。測定値＝１０．６ ｐｓ。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3. TOF counter
(TOF－PMT w/o Radiator)
NIM A547 (2005) 490, Y.Enari et al, Cross-Talk of a Multi-Anode PMT and Attainment of a s sim 10 ps TOF counter
HPK10(TTS=46 ps)
By hitting an MCP-PMT
directly by charged beam,
TOF resolution of
s = 13.6 ps was attained.
Footnote: HPK10を単独でビーム照射。分解能＝１３．６ psec。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3. TOF counter
(TOF-PMT w/o Radiator (continue))
● window thickness = 4 mm ⇒
Nγexpected = 25 photons vs. Nγdetected = 50 photons
MCP had a 4 mm-thick quartz window, so that about 20-25 detectable photo-electrons were expected while we observed about twice.
At the time, it was inferred that the extra photons more than the expectation might be yielded by MCP layer itself.
However, the measured and readout system resolutions of 13.6 ps and 9 ps indicate the intrinsic resolution of the MPC be 10 ps,
which corresponds about detectable 20 photo-electrons.
Where these extra photo-electrons come from is a mystery. Anyway, MCP itself provides 10 ps resolution.
Inspection: s0 = [ 13.62 – 92 ]1/2 = 10 ps
= 46 ps/ 21 (photons)
21 photons vs. 25 / 50 photons
⇒ Timing of photons from the 1st MCP plate is 100 ps earlier than those
from photo-cathode, but its gain would be lower so that effective # of
photons would be less than 25.
⇒ Yield of 25 photons is really from the MCP?
Footnote: 実測値＝１３．６ psec。GaAs photo-cathodeにすればphoton数は２倍、分解能＝１０ psecが期待できる。MCP-PMT自体が高分解能TOF counter
として働く。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3. TOF counter
(TOF-PMT w/o Radiator (continue))
In a case the most photons produced at the window,
equipping thicker window, 10 mm, would improve
TOF resolution better than 10 ps.
25x10/4=60 photons,
46 ps/ 60 =6 ps;
s =  62+72 = 9 ps
Circuit error
When MCP has a thick quartz window, say, 10 mm, then 60 photo-electrons and 6 ps resolution are expected.
Including readout system uncertainty, suppose to be it 7 ps, results in 9 ps accuracy in total.
If MCP having better TTS and better circuit are prepared, the resolution will be improved.
MCP-PMT
(TTS=46 ps)
Footnote: MCP-PMT(HPK10)のwindowを 10 mmのquartzとする。また、回路系の分解能＝９→７ psecとする。
そうすると、MCP-PMT単独で分解能＝９ psecが期待できる。ただし、GaAsP photo-cathodeを想定していない。
また、HPK10(TTS=４６ psec）でなく、HPK6（TTS=30 psec）ならばwindowは５．６ mmでよい。 総体として、回路系の分解能を改良することが最重要。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3. TOF counter
(10 ps TOF-Counter)
s=30ps/ 60(110)
=3-4 ps
with 7 ps circuit error
MCP-PMT
(TTS=30 ps)
s= 8 ps
particle
Or, put 10 mm-thick quartz in front of MCP, for instance, with 30 ps TTS.
3-4 ps intrinsic resolution is attained.
Readout system uncertainty would dominate the resolution of 8 ps.
Quartz (10mm)
Nγ=60(60+50) photons
Footnote: 10 mmのquartz輻射体を設ける。 Photon数は６０（quartzから）と５０（PMTから）であり、回路系の分解能＝９→７ psecとする。
その結果、分解能＝８ psecが期待できる。MCP-PMTをHPK６(TTS=３０ psec）でなくHPK１０（TTS=４６ psec）とすると分解能＝８－９ psecが期待できる。
ただし、GaAsP photo-cathodeを想定していない。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3.4 TOF counter
(2nd BEAM-TEST: 5 ps TOF Beam-Test)
Up to here, the attained resolution was limited mostly by the uncertainty of readout circuit..
 Aims
(1) Study of TOF resolution using SPC (Becker & Hickl GmbH’s)
Time-Correlated Single Photon Counting Modules (SPC-134):
- channel resolution = 813 fs
- electrical time resolution = 4 ps RMS
- repetition rates upto 200 MHz
This SPC includes CFD, TAC, ADC, and MCA (Micro Channel Analyzer).
(2) Study of extra photons (from MCP itself?)
回路系の分解能 7-8 ps。これが分解能を決めている。SPC（分解能４ｐｓ）を当面使用して、MCP-PMTの分解能をstudy。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
Using HPK6 (TTS=30 ps) with 3 mm-thick window instead HPK10.
 SET-UP
 LOGIC CIRCUIT The thickness of quartz radiator is varied.
We don’t need any other readout electronics for MCP’s; only the common stop signal is prepared by scintillation counters.
- cable: SMA, BNC
- discri: 300 MHz
- SPC-134: 0.86/count (CFD-TAC-ADC)
- AMP: 50 k-1.5 GHz
- ATTN: < 18 GHz
- power splitter:
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2nd BEAM-TEST: “5 ps TOF Beam-Test” (cont.)
For SINGLE PHOTONS
ADC, TDC and st (~30 ps)
(CAMAC)
raw signals
GAIN, TTS and CE vs HV
st for single photons(spc used)
Pulser (single photon) による測定
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
2nd BEAM-TEST: “5 ps TOF Beam-Test” (cont.)
For 3 GeV/c PIONS
Circuit resolution ( s t = 4.1 ps )
TOF w/o radiator ( s t = 7.7 ps )
Beam による測定。 SPCの分解能。 No radiator & 10 mm crystal。
TOF w radiator ( s t = 6.2 ps )
6.2(ps)2 – 4.1 (ps) 2 = 4.7 (ps) 2
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
Although the number of the photo-electrons increases by using thicker quartz, the resolution gradually deteriorates.
It is because the uncertainty of the light path due to the quartz thickness.
 s t vs RADIATOR THICKNESS
■
N vs RADIATOR THICKNESS
ADC distribution of MCP-plate alone
Almost 1 photo-electrons is seen on an average.
The extra photo-electrons are not produced at MCP, it might be at the MCP window.
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3.3 TOF counter
チェレンコフ光子数 
(Know-How: Window materials)
1
2
In order to have larger number of photo-electrons, a consideration of the window material is important.
Photon yields iare a few times different between HPK(3-4mm quatrz) and BINP(1mm Borosi).
Quartz/ Borosilicate
Quartz 3-4 mm
Borosilicate 1mm
Footnote: quartz, borosilicate windowで検出できる光の波長特性が変わる。輻射体が短い場合はchromaticityも効かないので、quartzがよい。
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
3.3 TOF counter
(Know-How： Photocathode materials)
In order to further improve the resolution, we need more photo-electrons. Using thicker radiator rather deteriorates the resolution. Our detector
equips already 10 mm-thick quartz. How to increase the number of photo-electrons?
Cherenk
ov
∝ 1/2
Not only QE but also -range depend on material.
Footnote: Bi-alkaliはほうけい酸ガラスで、multi-alkaliはquartzか？
The choice of photo-cathode material is quite essential. GaAsP indicates much higher QE and wider sensitive frequency range.
BINP serves Blue extended GaAs window, which also has a good property.
Suitable choice of the material would improved TOF resolution by enlarging the number of photo-electrons.
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
LIFT-TIME
No time to talk
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima
4. Summary
By R&D
We have developed MCP-PMT’s which satisfies the most of
our requirements.
sTTS = 30 ps & st = 5 ps is obtained by a beam test.
R&D of MCP-PMT is now focused on
GaAsP photocathode &
Lifetime improvement
R&D of readout circuits is focused on
Highly stable CFD &
TDC
Very-fast TOF Workshop, U of Chicago, Nov.18.2005.; Takayoshi Ohshima