Status of photon sensor studyat Niigata University-- SiPM and MPPC --

Photon sensor mini workshop05/9/16 (Fri) @Kyoto University

Niigata University HEP-LabSayaka IBA

Editha P. Jacosalem (Mindanao-U), Hiroaki Ono, Noriko Nakajima, Hitoshi Miyata

Contents

1. Study at Niigata university

2. SiPM study

1. Signal

2. Sensor signal uniformity dependence

3. MPPC study

1. Signal

2. Laser intensity dependence

3. Sensor signal uniformity dependence

4. Summary and future plan

Fine segmentation scintillatorRead out by photon sensor

-> Study of photon sensor (by Iba) Scintillator (by Editha-san)

1. Study at Niigata university Present design of GLD Calorimeter We might need smaller segmentation calorimeter

10x40x2mm strip type scinti

X, Z-layer strip scinti: 10x200x2mm Tile-layer: 40x40x1mmThis granularity will be checked by simulation soon

MPPC

MPPC

MPPC

2. SiPM Study

SiPM from RussiaWire Bonding

2mm

2mm

34x34=1156pixels

1.2mm

1.2mm

K

A

about 30um

Using SiPM for read out

Micro Avalanche Photo Diode (APD) Each pixel in Geiger mode

Compact Suitable for WLS fiber readout

34x34=1156 pixels in small area

Pixel Size : 30x30um

High Gain : ~106

Operational at low voltage : 60~70V

YAG Laser Wave length & power: 532nm (10mJ/cm2), 1064nm (20mJ/cm2) Use filter : down to10-8

Trigger : from Laser systemPulse width : <10nsecSpot size : <2um Precision of laser position : ±2umOutput Circuit

YAG laser　 & scan table

system

Logic

Setup

Signal of laser(1064nm, 532nm)

532nm signal is smaller than 1064nm

532nm result has many noise than 1064nm Rise time : ~10ns Fall time : ~200ns

1064nm　 65.0V

532nm65.0V

532nm66.0V

20mV 10mV

10mV

50nsec 50nsec

50nsec

Laser wave length : 1064nm Sensor bias : 66.5V 49points (7x7points) were measured Deviation (RMS) : ~28% Laser output fluctuation range : ~10% Central part showed higher PH

Laser hitting area(3x3=9 pixel) 5x5 pixel area

Sensor signal uniformity dependent

Fluctuation histogram

Cross sectional view

Cross section of X-axis line 4 and Y-axis line 4

Y-axisline 4

X-axis line4

Cutting X-axis line-4

Cutting Y-axis line-4

3. MPPC Study

MPPC from HPK MPPC :Multi Pixels Photon Counter Made by HPK and under

development

Compact device Works with much lower voltage than

PMT (~50V) Suitable for wavelength shifter fiber

We have two types of MPPC 100pixels : 10x10pixels 400pixels : 20x20pixels

MPPC 400pixels

MPPC 100pixels (10x10pixels)

~85um

~100um

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

Signal

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 oscilloscopeMPPC : 100pixels

From ADC signalMPPC : 100pixe ｌ s

0pixel (0photon)

1pixel (1photon)

2pixel (2photon)

signal

trigger

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

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≧Efficiency = # of 0 or 1photon event / # of All events 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)

Pulse height = 1photon mean value – 0photon mean value

Deviation of PH (RMS) : 10% Laser long term fluctuation : 5%≦

Pulse Height

1photon mean

0photon mean

Pulse height vs Pixel position

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

Efficiency = #of 0photon (or 1photon) event / #of all photon events≧ Edge of sensor shows low signal efficiency Central area of sensor has good efficiency

Efficiency : 0photon Efficiency : 1photon≧

Intensity dependence at other points

Efficiency : 0photon position X=8,Y=9 eff: poorposition X=4,Y=3 eff: good

position X=5,Y=10 eff: too bad

Intensity

Eff.

Efficiency of more than 1photon event vs. Laser intensity

160160

160

flat region

flat region

Efficiency : 0photon position X=8,Y=9 eff: poor

position X=4,Y=3 eff: good

position X=5,Y=10 eff: too bad

Intensity

Eff.

Pulse height vs. Laser intensity

160

160160

down

4. Summary and future plan

SiPM study (position dependence) PH uniformity was 28%(RMS), while laser fluctuation was 10% Edge part showed low PH

MPPC study (pixel position & intensity dependence) 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 sho

wed inefficiency in the light collection For poor efficiency pixels, their efficiency don’t increase and PH d

ecreases as intensity increases Future of Niigata study

Try to connect scintillator strip and MPC through Wavelength-shifter fiber and to do beta-ray test

Measure more detail for 400pixels