the sipm status on r&d in munich
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The SiPM status on R&D in Munich. Nepomuk Otte MPI für Physik München. outline. working principle status in Munich measurement results single photon resolution gain time resolution recovery time crosstalk summary. SiPM – the working principle. - PowerPoint PPT PresentationTRANSCRIPT
The SiPMstatus on R&D in Munich
Nepomuk Otte
MPI für Physik München
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
outline
• working principle• status in Munich• measurement results
– single photon resolution– gain– time resolution– recovery time– crosstalk
• summary
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
SiPM – the working principle
APD in geiger mode is a single photon counting device
combine many small pixels into a matrix and connect them in parallel gain dynamic range in addition to single photon resolution
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
SiPM status in Munich
SiPM from MEPhI• 1mm2 with 576 pixels are in Munich
and are being studied (see results on the following slides)
• 9mm2 already in Munich
- test station is being setup (cooling needed)
development at HLLIDEA: use fully depleted Si with backside irradiation (no dead space)
• simulations are in progress
-APD in geiger mode
-APD in proportional mode
• test structures at the end of this year
• first prototypes at the end of next year
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
gain
slope gives pixel capacity (C = 41fF)
gain comparable to PMT‘s
eQGain
picture
a capacity is discharged by a certain amount of charge
)( breakdownbias UUCQ
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
time resolution
pixels fired ofnumber 1
t
timeresolution imroves with number of fired pixelst
J. Barral
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
no well defined deadtimebetter: “recovery time”
pixel is not dead while it isrecharging to bias voltage
recovery time
t
eU 1
with a dark count rate of 106 counts/s at room temperature1‰ of all pixels will always be “dead”
s 1
J. Barral
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
single photon resolution
very low excess noise factor leads to multiple photon resolution
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
crosstalk
Hot-Carrier Luminescence 105 avalanche carriers 3 emitted photons
A. Lacaita et al, IEEE TED (1993)
photons generated in the avalanche travel into a neighbouring cell and initiate another geiger brakedown
ways to reduce crosstalk: reduce gain and/or absorb photons between pixels
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
quantum efficieny
determined by• intrinsic QE of Si• detection efficiency
(depending on overvoltage)• active area (≈25%)
P. Buzhan et al. NIM A 504 (2003) 48-52
52 53 54 55 56 57 58 59 60
0
2
4
6
8
10
12
Model: ExpGrow2 Equation: y = y0 + A1*exp((x-x0)/t1) + A2*exp((x-x0)/t2) y0 2119.18427x0 -1096.07597A1 -0.4014t1 117.11843A2 0.00467t2 82.53056
SiPM Z246 (576 pixels). T = +19 0CParameters measurement conditions. Yellow LED L53SYC (l=595nm), wavegide, duration of electrical impulse igniting the LED t
impulse=10ns, amplifier LeCroy 612AM (k
I=30), ADC Lecroy 2249A, t
gate=50ns
Dar
k ra
te f 1e
, MH
z
Bias voltage U, V
52 53 54 55 56 57 58 59 60
4
6
8
10
12
14
Model: ExpDecay1 Equation: y = y0 + A1*exp(-(x-x0)/t1)y0 17.3601x0 42.205A1 -52.75392t1 6.87142
Effi
cien
cy ,
%
Bias voltage U, V
52 53 54 55 56 57 58 59 60
5
10
15
20
25
30
Model: linear Equation: y=a+b*x a -160.94956b 3.22447
Pix
el g
ain
k pixe
l, 105
Bias voltage U, V
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
summary and outlook• we are developing SiPMs in two different ways:
– in collaboration with MEPhI and Pulsar (B. Dolgoshein et al.)– with the semiconductor laboratory attached to MPI (WHI) and MPE
• SiPM is a promising replacement candidate for conventional photomultipliers high gain (106) QESiPM ≈ QEPMT; expect boost by the application of microlenses multiple photoelectron resolution up to ≈ 60 photo electrons mechanical robust possibility of mass production reduction in costs insensitiv to magnetic fields low power consumption < 40µW per 1 mm2
dark count rate crosstalk
• R&D goals: increase SiPM size from 1 mm up to (3-5)mm increase in QE up to 70%
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
crosstalk at a gain of 5105
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
Dark noise
• noise sources– thermal generation– tunneling
• cooling needed to satisfy EUSO requirements– count rate drops below
10kHz when operated at -50°C and gain >106
22°C
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
Principle of operation
1. photon is absorbed in the depleted semiconductor
2. photo electron drifts into high field region and initiates an avalanche breakdown
3. passive quenching by resistor4. deadtime ≈10-7 s given by the
time constant to recharge the pixel‘s capacity
P. Buzhan et al. http://www.slac-stanford.edu/pubs/icfa/fall01.html
Nepomuk Otte ([email protected]) Max-Planck-Institute for physics Munich
Photon detector requirements for EUSO
• overall photon detection efficiency > 50%(only about thousand photons per event)
• sensitive range 330 nm to 400 nm(fluorescence light of N2 molecules)
• single photon counting with time resolution <10 ns(to avoid photon pileup)
• dynamic range 100 phe/mm2
(to detect the Cherenkov flash)• dark noise < 106 counts/s/mm2
(so light of night sky is limiting)• active detector area 4mm x 4mm with as small as possible dead area
(given by the resolution of the EUSO optics)