Performance of MPPC using laser system Photon sensor workshop @ KEK 2005.12.26-27 Niigata university , ILC calorimeter group Sayaka IBA, Hiroaki ONO, Paul Anthony RAMIREZ Takahiko ITIKAWA, Hitoshi MIYATA
Dec 18, 2015
Performance of MPPC using laser system
Photon sensor workshop @ KEK2005.12.26-27
Niigata university , ILC calorimeter groupSayaka IBA, Hiroaki ONO, Paul Anthony RAMIREZ
Takahiko ITIKAWA, Hitoshi MIYATA
Contents
1. Study of Niigata university
2. New photon sensor -- MPPC --
3. Laser system and setup
4. Performance of first version MPPC1. Signal
2. Pixel signal uniformity (gain & efficiency)
3. Break down voltage
5. Development of MPPC
6. Readout from scintillator using WLS fiber
7. Summary and future plan
Fine segmentation scintillatorRead out by photon sensor
1. Study at Niigata university
Present design of GLD Calorimeter We might need smaller segmentation c
alorimeter Ex. 10x40x2mm strip type scinti
X, Z-layer strip scinti: 10x200x2mm Tile-layer: 40x40x2mmThis granularity will be checked by simulation soon
2. New photon sensor --MPPC-- MPPC :Multi Pixels Photon Counter Made by HPK and under development
Compact device Gain is 106~
Same level as PMT Don’t need other amplifier
Works with much lower voltage than PMT Suitable for wavelength shifter fiber Useful under magnetic field
PMT can’t work under magnetic field
Type of MPPC (100pixels) First version (First MPPC) Type#: 1-53-1A-11
MPPC overview
MPPC 100pixels (10x10pixels)
~85um
~100um
3. Laser system and setup
Output circuit
YAG LaserLogic readout
YAG Laser Wave length & power: 532nm (10mJ/cm2), 1064nm (20mJ/cm2) Filter : Laser intensity is down to10-8
Trigger : from Laser systemPulse width : <10nsecLaser beam minimum spot size : <2um Precision of laser position : ±2um
MPPC
MPPC
4. Performance of first version MPPC
Rise time : ~10ns, Fall time : ~500ns + tail From the ADC graph, we calculated the Charge output of 1pixel
which is ~ 2.5pc and Gain is ~1.6x107 for 100pixels MPPC
10mV
500nsec
View from oscilloscope From ADC signal
0pixel (0photon)
1pixel (1photon)
2pixel (2photon)
signal
trigger
Signal for laser 1pixel injection
Why does MPPC yield above 2pe signal from 1pixel ? Cross talk
Laser light inject other pixels avalanche electron goes to other
pixels inside semiconductor
Pulse Height
1photon mean
0photon mean
0pe1pe
From cross talk
Efficiency =# of 0 or 1photon events
# of All events
Gain =PH(ADCcount)x-0.25(pc/ADCcount)
1.6x10-19(pc)
PulseHeight = 1photon mean – 0photon mean
Measurement performance
Pixel signal uniformity in one pixel (Position dependence between two pixels) Checked efficiency between two
pixels as uniformity measurement Scanned 7points between two
pixels Wavelength : 532nm Sensor bias : 49.0V
Efficiency of more than 1photon event becomes minimum at the boundary line between 2pixels
Efficiency vs Position▲ : Efficiency of 0photon event● : Efficiency of 1photon event≧
pixel pixel
Sensor signal uniformity dependent on the pixel locations
Injected laser single photon to each pixel and got response Measurement conditions
MPPC : 100pixels Sensor bias : 49.0V Laser wavelength : 532nm, Intensity : 160 Laser hitting area is smaller than 1pixel area Measured points are 50points that are shown as gray area
~30um
~35um
Laser hitting area (smaller than 1pixel)
~85um
Measured points : 50points(Gray pixels)
Deviation of PH (RMS) : 10% Laser long term fluctuation : 5%≦
Pulse Height
1photon mean
0photon mean
Pulse height vs Pixel positionSensor bias: 49.0V
Distribution of the PH
# of pixels
Cross sectional view (Central part)
Cross section of X-axis (line-5 + line-6) and Y-axis (line-5 + line-6) which are shown in previous slide Central part of sensor
Cutting X-axis line-5▲ + line-6▲
Cutting Y-axis line-5▲ + line-6▲
X-axisline-5 +6
Y-axisline-5+6
Cross sectional view (Edge part)
X-axisline-9 +10
Y-axisline-9+10
Cutting X-axis line-9▲ + line-10▲
Cutting Y-axis line-9▲ + line-10▲
Cross section of X-axis (line-9 + line-10) and Y-axis (line-9 + line-10) Edge of sensor
We can see that pulse height level and deviation look same as previous slide
Position dependence of efficiency
Compare efficiencies between 0photon events and more than 1photon events
Edge of sensor shows low signal efficiency Central area of sensor has good efficiency
Efficiency : 0photon Sensor bias : 49.0V
Efficiency : 1photon≧Sensor bias : 49.0V
Break down voltage
MPPC 100pixel MPPC works best performance
under Geiger mode Enough laser beam incident
(saturation was occurred at best operation voltage)
If it down the voltage, some pixel become Geiger mode
48.4VLaser : same as above(saturation)
49.1VLaser : saturation
~80pe
~10pe
Sensor : First MPPC100pixels (no type#)
At 48.4V 100pixels
10pixelsGeiger mode
90pixelsAvalanche mode
Break down V = Start Geiger mode V
It is different break down voltage at each pixel !!
Efficiency : 0photon position X=8,Y=9 eff: poor
position X=5,Y=6 eff: excellent
position X=5,Y=10 eff: too bad
49.1V
49.1V49.0V
The part of 1photon appearance is difference ->Breakdown voltage is difference
Eff.
Bias(V)
Summary of first MPPC
We measured two types of Hamamatsu MPPC which are under development : 100pixels, first type
PH uniformity was 10% (RMS), while laser long term fluctuation was less than 5%
Central part of a sensor had good efficiency while edge part showed inefficiency in the light collection
Breakdown voltage Breakdown voltage = start Geiger mode voltage Sensor bias depend on Efficiency The part of 1photon appearance was difference (~100mV) at
each pixel : breakdown voltage was difference, too Best operation voltage range was delicate (~200mV)
5. Development of MPPC
1-53-1A-11 (100pixels) First MPPC(100pixels)
Best operation V
(Best operation range)
49.9V~50.3V
(<400mV)
49.0V~49.1V
(<200mV)
Gain (average value) 1.60x107 (20pixels) 1.41x107 (50pixels)
Deviation of PH for each pixel
2%
(RMS of 20pixels)
10%
(RMS of 50pixels)
Efficiency for average of all pixels
22% (50.0V, RMS of 20pixels)
59% (49.0V, RMS of 50pixels)
Deviation of efficiency for each pixel
22% (50.0V, RMS of 20pixels)
66% (49.0V, RMS of 50pixels)
Break down voltage range
<200mV (49.9V~50.0V)
at 3pixels
<200mV (49.0V~49.1V)
at 6pixels
Deviation of PH
Deviation = RMS / Mean value
Deviation of PH for each pixel : 10% 2%, better than first MPPC
Deviation: 2%
Histogram of deviation for pulse height
Deviation: 10%
Using 50pixels data Using 20pixels
7. Final summary and future plan
Laser intensity dependence For getting the best laser
intensity corresponding to 1photon injection
Measurement conditions MPPC : 100pixels Pixel position : center
(X=5,Y=6) Laser hitting area : within the
1pixel Wavelength : 532nm Used filter : for laser intensity
down to10-8
We think laser intensity 160 corresponds to 1photon injection, because this value is beginning of max of 1photon and min of 0photon
Efficiency of 0pe, 1pe vs. Laser intensity● : Efficiency of 0photon event▲ : Efficiency of more than 1photon event
Laser intensity 160for 1photon injection
6. Readout from scintillator using WLS fiber
We connected scintillator and MPPC through wavelength sifter fiber and tried beta ray test
Measurement conditions Scintillator : 10x40x2mm strip type Source : 90Sr (beta-ray) WLS fiber : Φ1.0mm, length 20cm, Y-11 (Kuraray) Trigger : scintillator + PMT MPPC : first MPPC (100pixels)
Setup