1 Geiger mode APDs as photon detector for the PANDA TOF and

Geiger mode APDs as photon detector
for the PANDA TOF and DIRC
systems
By Victoria Rebyakova
and Richard Peschke
(AntiProton ANnihilation at DArmstadt)
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The PANDA Project
Antiproton proton annihilation in the energy range of 1-15 GeV
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Facility for
Antiproton and
Ion Research
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Physics at PANDA
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Charmonium (cc) spectroscopy
Gluonic excitations (charmed hybrids, glueballs) in
the charmonium mass range (3–5 GeV/c2)
Search for modifications of meson properties in the
nuclear medium and the possible relationship to the
partial restoration of chiral symmetry for light quarks.
Precision γ-ray spectroscopy of single and double
hypernuclei
CP violation
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PANDA detector
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Requirements for detectors
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full angular coverage and good angular
resolution
particle identification in a large range of
particles (γ -rays, leptons, muons, kaons,
etc.) and energies
high resolution in a wide range of energies
high rate compatibility especially for the
close-to-target and forward detectors
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Particle Identification:
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Target & Forward
Spectrometer
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TOF wall
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Time of Flight system
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Simulation. Time-of-flight vs. particle
momentum at primary beam energy of 5GeV.
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The time resolution aimed at is σ ≤ 200 ps.
Characteristics:
Saint Cobain BC 418
Wavelength of
max.emision 391 nm
Decay time 1.4 ns
refrection index n = 1:58.
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Detector of
Internally
Reflected
Cherenkov light
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DIRC
Quartz bars with a high refraction index n=1.47.
•, Relativistic particles
(v>c/n) emits light in a
cone with an opening
angle of:
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cos(θ ) =
10
βn
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Different types of APDs
Hamamatsu 3x3 mm²
Sens L 3x3 mm²
Hamamatsu 1x1 mm²
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APDs
Geiger mode is a method for operating an APD at a reverse
bias voltage higher than the breakdown voltage.
Geiger modes and quenching resistor
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MPPC
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Avalanche photodiods
(APDs)
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Semiconductor light
sensitive diodes
Single Photon detection
Independent of
Magnetic fields
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Negatives
Very hight darkcounting
rate (MHz)
Not suitable as trigger.
Î External trigger is
necessary
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Measurement of Dark signals
Type
Voltage/
V
Dark
counting
(0.5
threshold)
/kHz
Dark
counting
(1.5
threshold)
/kHz
Single
photon
Signal
/mV
Double
photon
Signal
/mV
Breakthrough
voltage /V
a
/kHz/V
Hamamatsu
S10362-11025C 4
70.6
300.0
2.0
0.65
272
1.22
560
68.42
261.43
Hamamatsu
S10362-11050C
70.0
446.2
54.3
0.77
1.6
69.50
811.20
Hamamatsu
S10362-11100C 2
69.4
Sens L
SPMMicro
3020x05
30.0
900
800
Sens L
SPMMicro
3035x05
701.0
96.3
0.79
1.3
68.72
1802.9
2
700
3100
450
4.89[1]
12.041
29.95
2898.7
Rate, kHz
600
500
400
300
29.0
1120
140
2.561
4.581
29.91
3767.1
200
100
68,0
Hamamatsu
S10362-33100C 1 white
70.0
2620
870
9.81
17.81
69.4
4614
Hamamatsu
S10362-33025C 1 white
72.1
510
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3.21
8.601
69.1
633.33
Hamamatsu
S10362-33050C 1 white
71.4
4470
880
8.91
19.011
69.9
2990
[1]
With preamplifier
68,5
69,0
69,5
70,0
70,5
71,0
71,5
Voltage, V
Counting rate as function of Ubias
Ham black 025C
⎛
⎞
R = R (U ) = a⎜⎜U − U breakthrough ⎟⎟ = 261.42 ⋅ (U − 68.42 )
⎝
⎠
To characterise the APDs we have measured the rate as function
of threshold and Signal height.
Hamamatsu 050C
Sens L SPMMicro 3035x05
Sens L SPMMicro 3020x05
Different APD from the same type
(Sens L SPMMicro 3020x05)
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Measurements with LED
(~570nm)
frequency /Hz
6500
APD
PMT
6000
0.46
ratio
APD Ham 050c
fit
0.44
5500
0.42
5000
0.4
4500
4000
0.38
3500
0.36
3000
0.34
2500
0.32
2000
0.3
1500
0.28
1000
0.26
500
Pulse in nVs
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54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
Comparison between PMT and ADP
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0.24
frequency /kHz
10
100
1000
counting rate vs. frequency
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Measurements with scintillator
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Measurements with Cherenkov
radiator
Measure time 1000s
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Coincidence between PMTs & APDs.
- blue line - coincidence between PMTs
- other lines - signals from APDs
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Conclusion
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APDs are useful with external trigger
APDs are able to see less light than PMTs
With APDs we are able to see Cherenkov
light
But it is very hard to separate real signal from
noise
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Outlook
We have to investigate
the Cherenkov radiation
with higher flux
Î We need beam time!!!
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a more quantitative
value of how good we
are able to measure
Cherenkov and
scintillation light
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Acknowledgments
Many thanks to our Tutors
Prof. Dr. Herbert Orth and Dr. Carsten Schwarz
To Heide Rinnert and Jőrn Knoll
To Tina Herbst, David von Lindenfels, Paul Seyfert,
Ivan Burenkov, Alexey Berzutskiy
And all the other summer students
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End ?
No!
Beam time measurement
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Proton beam with variable energies1-2,5GeV
Up to 106 protons per packet
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Quantitative measurements with the
Quartz bar
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Result
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We are able to see Cherenkov light
Again the separation von the noise is the
problem
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Measurements with
Scintillator
Attention!
logarithmic
Scale
Signal to noise
rate ≈100
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More quantitative
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Pulse shape
What can we see from this?
In the average 8 photons are hitting
the APD
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Is there more structure?
What do we
see here?
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Results
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We are not just able to measure events we
are able to count photons.
we will be able to create a self triggering
photon detector.
For the work with Scintillator the APD will be
suitable.
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