Multipixel Geiger mode Multipixel Geiger mode photo-sensors photo-sensors (MRS APD’s) (MRS APD’s)

Yury KudenkoYury Kudenko

ISS meeting, KEK, 25 January 2006

INR, Moscow

22

Near Detectors at 280mNear Detectors at 280m

Magnet + Side-MRD

Magnet + Side-MRD

P0D TPC TPC TPCFG

D

Pb-

P0D

EM calorimeter

EM calorimeter

EM

cal

ori

met

er

Muo

nID

hod

osco

pe

FG

D+

H2O

3m1m

1m

PMT

Iron

Tracker : SciBar type Extruded Scintillator + Wave Length Shifting Fiber

Veto all surface by plastic scintillator (Fibers goes through holes.)

3m

1m

1m

Off-axis (~2Off-axis (~2oo))

On-axis (0o)

19m

Super-K

Beam center

37m

ND280m hall

- ~ 105 WLS fiber channels- individual readout

33

Principles of MRS APD Principles of MRS APD operationoperation

Number of pixels 450 - 4000

Qpixel = Cpixel x V = Cpixel x (Vbias - Vbreakdown)Cpixel 50fmF V few volts Qpixel 2x106 electrons

Depletion region 2mDrift velosity 107 cm/sField (2-3)x105 V/cm

CPTA, Moscow (MRS APD)MePhi/PULSAR, Moscow (SiPM)Dubna

limited Geiger mode

PMT: diameter 20 mm

MRS: active area 1x1mm2

diam 1 mm

Multipixel Geiger mode APD’s invented in Russia in 1980’s

44

MRS APDMRS APD

One pixel ~ 40 x 40 m2

55

MRS APDMRS APD

New devices - Dark noise rate- PDE- Dynamic range, linearity of signal- Temperature effects- Long time stability - Lifetime - Recovery time

- Diameter of active area 1.1 mm- Number of pixels 556 - Geometrical efficiency 70-80 %- Photon detection efficiency at th=0.5 p.e. and dark rate ~1MHz 10-15% - Bias voltage range 25-75 V- Gain 106 - 107

- Sensitivity to magnetic field ( 9T) no- Cross talk 4-6%- Auto calibration and control separated p.e. peaks - Dark noise rate (th =0.5 p.e) 1 MHz

LED signal

66

1pe

2pe

3pe

Dark noise rateThreshold, p.e. Dark rate, MHz 0.5 1.0 1.5 ~0.1 2.5 0.01

Dark noise rateDark noise rate

Temperature dependence~70 – 100 kHz/deg

77

Photon detection efficiency (PDE)Photon detection efficiency (PDE)PDE=εpixel × QE × εGeiger

30-70% 60-80% 50-80%

PDE=12%

1 MHzTypical PDE ~12% (at 1 MHz (th=0,5 p.e.)New CPTA devices PDE ~15%

88

Linearity and cross talk Linearity and cross talk MRS APD, 556 pixels

The same LED signal to MRS APD and PMTthrough Y11 fiber

Crosstalk

Bias voltage = 40.0 VDark rate (0.5p.e) ~ 1MHzCrosstalk = 5-6%

99

Temperature effectsTemperature effects

PDE gradient ~ -1.8%/deg

Dark noise rate gradient ~70-90 kHz/deg

1010

Stability and lifetime study Stability and lifetime study

l.y. measurement

After temp correction

For 2 years ~150 CPTA devices are studied 3 dead

High temperature test

On-going test:10 devices are at 80 deg and HV for 15 days All OK

1111

Recovery time

t

Large pulse >600 p.e.

Dec’05 MRS #1710-002

Second pulse ~100 p.e.

First pulse:Black – 50 p.eRed - 100 p.e.Green - 300 p.e.Second: - 100 p.e.

1212

Beam test of SMRD detectorBeam test of SMRD detector

Beam test at KEK, Nov 2005. Sci/WLS/(both end MRS readout) detector1.4 GeV/c pions and protons

l.y. from one end of slab

Ped

Extruded scintillator (Vladimir, Russia)Chemical reflectorFiber KURARAY Y11, double clad, 1 mm

SMRD: about 5000 extruded scintillator slabs ~ 90 cm x 20 cm x 1.0 cm

8p.e.

1313

Beam test resultsBeam test results

S-type SMRD detector:l.y. (sum of 2 ends) 152 p.e. MIP efficiency >99%Timing at 15 p.e. ~ 1.7 ns () Space resolution ~12 cm ()

Beam scan along the slab

Time resolution

1414

Summary and outlook

Status Perspectives Diameter 1.1mm 1.1, 1.2-1.5 mmPDE 12-15% OK, R&D 20% Dark noise rate ~1 MHz (0.5 p.e.) manufacturers aim to decrease 100 kHz (1.5 p.e) OK Time resolution 1- 3 ns () with Y11 OK, both end readout to suppress noise Cross talk 4-6% OKGain 106 – 107 OK Linearity range 200 p.e. 600 pixels OK, 1000-2000 pixels 20-30 p.e. 100 pixels OK for SMRD, on-axis Long term stability ~1000 hrs, 1-2% OK, more tests Lifetime 3 of 450 are dead looks not bad, study is ongoingTemperature Dark noise rate +(70-90) kHz/deg PDE -1.8%/deg 22-25 deg OK, low temp is better Recovery time 1-5 s OK- Great progress in development of

Multi-pixel Silicon devices for last 2-3 years- Such devices are now considered as

base-line photo-sensors for the T2K near detector at 280 m