TIMING PROPERTIES OF MCP-PMT DEVICES - s<10 psec TOF Counter - T. Ohshima (Nagoya U.)

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TIMING PROPERTIES OF MCP-PMT DEVICES- slt10 psec
TOF Counter -T. Ohshima (Nagoya U.)

• 1. TOP counter and TOF counter
• 2. RD of MCP-PMTs
• 3. TOF counter
• New Approaches
• Beam test (1)
• Beam test (2)
• Know-how

Footnote MCP-PMT????? 10 psec TOF counter
RD???????
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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

• HPK10 (3809U-50-25X),
• HPK6 (3809U-50-11X)
• BINP (multialkali)
• (GaAs extended)
• 4. Burle (85001-501)

lt 10 ps TOF counter
TOP counter?photon detector????????????????????PMT
, HAPD MCP???????MCP-PMT???????????TOF
counetr???? ??????5 ps??????????? By doing RD on
these issues, most of them are now in
satisfaction. In the course of RD studies, we
come across an idea to have less 10 ps TOF
counter.
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2. RD of MCP-PMTs (Single photon pulses)

• 
  (Transite Time Spread) TTS
• ?Multi-anode linear-array PMT (L16 L24)
  70-80 120 ps
• ?Hybrid Avalanche Photo-Diode
  150 ps
• ?Micro-Channel-Plate PMT
  30-40 ps

Footnote ???????????????1???????????TTS?????????
?????????
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Points for TOF counter

• Fluctuations of  
• TTS
• Decay-time (Td ? TTS)
• Light-path (T? ? TTS)
• N?

time
?
photon signals
Photo-statistics 1/?N? is varied only
at Td, T? ltlt TS.
quartz n1.47 q45o (for GeV/c
particles)
?
?
?
?
?
?
Footnote TOF??????????MCP-PMY/Cherenkov/path/
photons (???????????????1.4.)
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2. RD of MCP-PMTs (Test circuit)
?????? ??????? 8.8psec
?
?
using single photons from a light-pulser
Divider
HUBERSUHNER SMA cable MULTIFLEX MF 141
Impedance50 ohm Operating frequency 18 GHz
Capacitance95 pF/m Time delay 4.7 ns/m
Attenuation a f(GHz)1/2 b f(GHz)
(a0.37320), (b0.02790)
?
HPK C5594 bandwidth50 kHz-1.5 GHz gain36dB
(_at_0.1 GHz) NF 5 dB
Footnote TOF????????????????(???7-9
psec)?????????att.amp????
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2. RD of MCP-PMTs (MCP-PMTs)
NIM A528 (2004) 763-775, by M. Akatsu et al,
MCP-PMT timing property for single photons
Footnote ?????MCP-PMT?????
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2. RD of MCP-PMTs (ADC spectra)
Footnote ADC TDC spectra
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2. RD of MCP-PMTs (Gain vs TTS)
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2. RD of MCP-PMTs (TTS vs B)
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3. TOF counter (TOF by HPK10)
Cerenkov radiator
Since the light-pulsers jitter yields an
essential contribution on the measurement,
TTS46 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(TTS80 ps)
MCP(TTS46 ps) and similar N?s, sobserved
11-12 ps is attained,where the circuit
fluctuations (7-9 ps) dominate the ambiguity.
Footnote HPK10 TOF???????????9 ps vs????10.6
ps?
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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
Footnote HPK10?????????????13.6 psec?
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3. TOF counter (TOF-PMT w/o Radiator (continue))

• ? window thickness 4 mm ?
• N?expected 25 photons vs. N?detected 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 ???13.6 psec?GaAs photo-cathode????pho
ton??2?????10 psec???????MCP-PMT???????TOF
counter ??????
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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.

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.
Footnote MCP-PMT(HPK10)?window? 10
mm?quartz??????????????9?7 psec???? ??????MCP-PMT
??????9 psec???????????GaAsP photo-cathode???????
?? ???HPK10(TTS46 psec)????HPK6(TTS30
psec)???window?5.6 mm???? ????????????????????????
?
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3. TOF counter (10 ps TOF-Counter)
MCP-PMT (TTS30 ps)
s30ps/? 60(110) 3-4 ps with 7 ps circuit
error
s 8 ps

• particle

Quartz (10mm) N?60(6050) photons
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.
Footnote 10 mm?quartz???????? Photon??60(quartz??
)?50(PMT??)???????????9?7 psec???? ????????8
psec???????MCP-PMT?HPK6(TTS30 psec)???HPK10(TTS4
6 psec)???????8-9 psec??????? ????GaAsP
photo-cathode?????????
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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
• Study of TOF resolution using SPC (Becker Hickl
  GmbHs)
• Time-Correlated Single Photon Counting
  Modules (SPC-134)
• - channel resolution 813 fs
• - electrical time resolution 4 ps RMS
• - repetition rates upto 200 MHz
• (2) Study of extra photons (from MCP itself?)

This SPC includes CFD, TAC, ADC, and MCA (Micro
Channel Analyzer).
??????? 7-8 ps??????????????SPC(???4ps)????????MCP
-PMT?????study?
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Using HPK6 (TTS30 ps) with 3 mm-thick window
instead HPK10.

• SET-UP
• LOGIC CIRCUIT The thickness of quartz radiator is
  varied.
• We dont need
  any other readout electronics for MCPs 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 lt 18 GHz

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2nd BEAM-TEST 5 ps TOF Beam-Test (cont.)

• For SINGLE PHOTONS ADC,
  TDC and st (30 ps)
• raw signals
• GAIN, TTS and CE vs HV
• 
  
  st for single photons(spc
  used)
• 
  
  

(CAMAC)
Pulser (single photon) ?????
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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 ) TOF w
  radiator ( s t 6.2 ps )

6.2(ps)2 4.1 (ps) 2 4.7 (ps) 2
Beam ?????? SPC????? No radiator 10 mm crystal?
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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.
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.
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3.3 TOF counter (Know-How Window materials)
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).  
Footnote quartz, borosilicate
window??????????????????????????chromaticity??????
??quartz????
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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?  
Footnote Bi-alkali???????????multi-alkali?quartz
??
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.
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LIFT-TIME
No time to talk
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4. Summary

• By RD
• We have developed MCP-PMTs which satisfies the
  most of
• our requirements.
• sTTS 30 ps st 5 ps is obtained by a beam
  test.
• RD of MCP-PMT is now focused on
• GaAsP photocathode
• Lifetime improvement
• RD of readout circuits is focused on
• Highly stable CFD
• TDC