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116 (22 ) 32 talks, 37 Posters● 3 Summary talks

https://indico.cern.ch/conferenceDisplay.py?confId=164917

H,[
Talk Session● 3 Summary talks• SiPM overview• SiPM application• SiPM readout● Sessions• SiPM (12 Talks)• SiPM Application (7 Talks)• SiPM Vacuum photodetectors (5 Talks)• New Devices (2 Talks)f<*\)C?HTC/()●• Electronics (6 talks)• dSiPM• Timing Resolution• UV sensitive SiPM
• Analog Memory

SiPM GeneralPhotoDet 2012

LAL Orsay, June 2012

The SiPM Physics and Technology- a Review G.Collazuol
Department of Physics and Astronomy, University of Padova and INFN

Overview- Introduction- Key physics and technology features- I-V characteristics- Device response- Noises- Photo-detection efficiency- Timing properties- Summary and Future1

Close up of a cell – custom process
Shallow-Junction APD
Example of implementation

Optical window
note: light absorption in Si, SiO2

C.Piemonte NIM A 568 (2006) 224
Shallow n+ layer(0.1 µm)n+polysilicon RQ

Opticallydead region
Opticalisolationp(fully) depleted region(4 µm)

G.Collazuol - PhotoDet 2012

Substrate
low resistivity contact(500 µm)

Trench(filled)π epitaxial≈p+• n+ on p abrupt junction structure• Anti-reflective coating (ARC)• Very thin (100nm) n+ layer: “low” doping→ minimize Auger and SHR recombination• Thin high-field region: “high” doping p layer→ limited by tunneling breakdown→ fixes VBD junction well below VBD at edge
• RQ by poly-silicon• Trenches for optical insulation (cross-talk)• Fill factor: 20% - 80%

Active volume• no≈micro-plasma's
high quality epitaxial• doping / E field profile
engineering

Optimization forblue light (420nm)≈
Critical region:• Leakage current• Surface charges• Guard Ring for- preventing earlyedge-breakdown- isolating cells- tuning E field shape→impact on Fill Factor

6

CMOS vs Custom processes“Standard” CMOS processes
high E field• shallow implant depths(low Vbd)• high doping concentrations• shallow trench isolation (STI)• deep well implants (flash extension)• no extra gettering and high T annealing• non optimized optical stacks• design rule restrictions

tunnelinglattice stress(defects/traps)

high DCR

limited PDE(often p-on-n)limited timing performances(long diffusion tails)

G.Collazuol - PhotoDet 2012

Recent progresses in CMOS APDs due to:1) high voltage (flash) extension often available in standard processes• deep wells (needed for the high voltages used in flash memories)2) Additional processes (custom) available:• buried implants• deep trench isolation• optical stack optimization
Key elements for CMOS SiPMs• APD cell isolation from CMOS circuitry• guard ring (again)
7

Close up of a CMOS cell
APD integration into CMOS
Example of implementation T.Frach in US patent 2010/0127314
Note • extended CMOS processes exploited• careful design of cell isolation and guard ring
shallow isolation(STI/LOCOS)
contactwithburiedlayer

optical window

APD cell isolated
by multiple wellsfrom CMOS circuitry

anode (p+)
sgn+ (field enhancem.)
epitaxial n (active region)
buried n (isolation layer)dExample of
NMOS FETof the RO
electronics

G.Collazuol - PhotoDet 2012

epitaxial pp++ substrate

deep isolation trench(oxide/polysilicon filling)buried isolation layer(also protection from substrateradiation induced carriers)

substrate(gettering sites)
8Basic electrical model
Fast Capacitor (cell) discharge andslow recharge (roughly speaking)iquenching
time

DIODE

currents internal / external

VBD

RQ

CD

VD

VBIAS

RS

ilatch1-exp(-t/τd)exp(-t/τq)

Rise time

99% recovery time ~ 5 τQ

τd = R d C dFall time (recovery)≪τq = RqCdt

G.Collazuol - PhotoDet 2012

Recovery time:

T dependence due to Rq
Cd is independent of T

Rise time: T dependent (to lesser extent) due to RdGain~C ∆V → independent of T
at fixed Over-Voltage (∆V = Vbias-Vbd)
26

SiPM equivalent circuit (detailed model)
slow

Single cell model → (Rd||Cd)+(Rq||Cq)
SiPM + load → (||Zcell)||Cgrid + Zload

fast

Signal = slow pulse (τd (rise),τslow (fall)) ++ fast pulse (τd (rise),τfast (fall))•τd (rise)~Rd(Cq+Cd)(fast; parasitic spike)•τfast (fall) = Rload Ctot•τslow (fall) = Rq (Cq+Cd) (slow; cell recovery)

Rd

F.Corsi, et al. NIM A572 (2007) 416
S.Seifert et al. IEEE TNS 56 (2009) 3726
Cq → fast current supply path in the beginning of avalanche

G.Collazuol - PhotoDet 2012

Vmax

Pulse shape

Sp.Charge Rd x Cd,q filtered by parasitic
inductance, stray C, ... (Low Pass)• Rise: Exponential• Fall: Sum of 2 exponentials
Cd = 10fF
Cq = Cd
Cg = 10pF
Rq= 400kΩ
Rq= 50Ω−t
C q τ−t Rload C dQτV (t)≃(e +e )C q +C d C tot
Rq C q +C d
FAST

SLOW

for Rload << Rq

where Q = ∆V (Cq+Cd) is the total charge released by the cell
→ 'prompt' charge on Ctot is Qfast = Q Cq/(Cq+Cd)
27

Pulse shape−t
C q τ−t Rload C d
Q R load C q τ−t
C d τ−tQτV (t ) ≃
(
e +
e ) =
(τ e + τ
e )
fast
slow
C q +C d C tot
Rq C q +C d
C q +C dfast→ gainG = ∫ dt

slow

fast

Δ V (C d +C q ) independentV (t)= Q / qe =of Rq
q e R load
qe

slow

Note: valid for
low impedance load
Rload << Rq• τfast = Rload Ctot
• τslow = Rq (Cq+Cd)

Q slow C d∼→ charge ratio
Q fast C q

Vmax → peak voltage on Rload V max ∼ Rload (Q fast Q slow dependent on Rqτ fast + τ slow ) (increasing with 1/R )G.Collazuol - PhotoDet 2012q

Cd = 10fF
Cq = Cd
Cg = 10pF
Rq= 400kΩ
Rq= 50Ωmax→ peak height ratio

V slow

C d C tot R load

V fast

2
q

∼
max

C Rq

increasing with Cd and 1/Rq

28

Optimizing signal shape for timing
slow

Single cell model → (Rd||Cd)+(Rq||Cq)
SiPM + load → (||Zcell)||Cgrid + Zload

fast

Signal = slow pulse (τd (rise),τq-slow (fall)) ++ fast pulse (τd (rise),τq-fast (fall))•τd (rise)~Rd(Cq+Cd)(fast; parasitic spike)•τq-fast (fall) = Rload Ctot
•τq-slow (fall) = Rq (Cq+Cd) (slow; cell recovery)

Pulse shape
G.Collazuol - PhotoDet 2012

Vmax
Cd = 10fF
Cq = Cd
Cg = 10pF
Rq= 400kΩ
Rq= 50Ω

Rd

−t

−t

FAST

SLOW

Cq 
Rload C dQV t ≃e eC q C d C tot
Rq C q C d

Q fast C q~→ charge ratio
Q slow C d→ peak height ratio

V max
fast

C 2q R q~max
V slow C d C tot Rload

increasing with Rq and 1/Rload(and Cq of course)

Increasing Cq/Cd or/and Rq/Rload→ spike enhancement→ better timing73

Overview of Multicell Geiger-mode
Avalanche Photodiodes (SiPM)
Applications
Gabriela Llosá,Instituto de Física Corpuscular - IFIC (CSIC-UV), Valencia, Spain

IRIS grouphttp://ific.uv.es/iris

Photodet 2012, Orsay, 13-15 June 2011

Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 2012

1

CMS Outer Hadron Calorimeter (HO) upgrade●●

Replace HO HPD (susceptible to discharge atintermediate B fields) with SiliconPhotoMultipliers (SiPM)●

SiPM PDE >2x HPDs and gain a factor of 50 to 500 larger;●

Compact and Vbias ~100V compared to ~10KV for HPDs;●

Not affected by magnetic fields

Scintillator/wavelengthshifting fiber.

Board with 18 MPPCs and Peltier on
the back. Temp stabilization system.

3 mm x 3 mm
SiPMs

Components (2200 SIPMs, 160 SIPM
Mounting Boards, 160 Control Boards)
built and tested. Electronics will becomplete by the end of 2012.
● The full HO SIPM system will be
installed during the LHC LS1 shutdown in
A. Sharma/Jim Freeman. FDFP 20122013.
●

Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 2012

9

BELLE II Particle ID detector upgrade
●

●

●

●

Proximity focusing Aerogel RICH considered for theforward particle ID detector upgrade.
Req: limited space, mag field 1.5 T, rad damage(neutrons).
Light guides to concentrate light on MPPCs. Pyramidal
light concentrators (different options considered).
Module with 64, 1 mm2 MPPCs and light guide array.

S. Korpar et al.
NIMA. In press.

Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 2012

18

PEBS
●

●

Positron Electron Balloon Spectrometer formeasurement of cosmic ray electron and positron flux up
to the TeV scale.
●

Cheaper than space detectors●

Multiple flights●

Reoptimization between flights

A. Bay et al.
NIM A 2011

ECAL aimed at rejecting proton background. Large area,
high resol, low power and low weight. (PEBS1 ECAL:
Weight ~2000 kg Power Consumption ~900 W).
●●●

Gabriela Llosá

Scintillating bars (7.75 x 3 x 837 mm3), optically isolated withembedded WLS fibres. Tungsten absorber plates.
MPPCs (Hamamatsu) adapted, 1.4 x 1.4 mm2, 25 x 25m2
microcell size.

●

Readout with SPIROC chip.

●

Monitoring system and temp controller with Peltier.

Proton rejection better than 10-3 up to 50 GeVPhotodet 2012, Orsay, 13-15 June 2012

22

MU-RAY telescope●●●

Study density variations in volcanoes through muonradiography. Resol (optimal ~10 m) can be better thanwith gravimetric techniques- eventual anomalies.
Detect horizontal muons through volcano. Energy loss inrock. Need to know the morphology.
Telescope: Tracking capability with millirad resolution,
low cost, low consumption, resistant, temp var > 60ºC.

G. Ambrosi et al.
NIMA 2011.
R. D'Alessandro
et al. FDFP 2012

Principal investigators INFN and Univ. Naples
Pictures courtesy R. D'Alessandro.
Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 201226

SiPMs in PET: innovative designs
Several layers of 0.8 mm
crystals

PS-SiPMs

Crystals of
0.5 mmresolved

Song et al.
PMB 2010

Mc Clish et al.
2010 IEEE NSSMIC Conf Rec

0.5 mm crystals resolved

Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 201231

SiPMs in PET: full working ring
Small animal PET ringTwo types of LGSO
crystals (phoswich)
1.1mm x 1.2mm x 5mm
1.1mm x 1.2mm x 6mm
Images of mice obtained
Yamamoto et al.
PMB 2010

Already tested in PET/MR
applications.
(Presented in PSMR 2012)

Gabriela Llosá

Photodet 2012, Orsay, 13-15 June 201236

SiPMs in PET: PET/MR●●●

Simultaneous combination of PET
and MR imaging modalities.
Provides very high resolution
anatomical reference with noadditional radiation (as CT).
SiPMs: 'photodetectors of choice'.

Hyperimage + Sublima
Gabriela Llosá●

SiPMs from FBK-irst●

PETA3 ASIC

Photodet 2012, Orsay, 13-15 June 2012

C. Piemonte et al.
PSMR 2012
37

KX7FO
PET
http://agenda.infn.it/conferenceOtherViews.py?confId=3899

Delayed avalanche in SiPMs andespecially MPPCs
Fabrice Retiere and Kyle Boone(Undergraduate student)
With help from Y. Iwai (Hamamatsu)

Cross-talk and after-pulse• Cross-talk– Prompt = by definition– Origin: photons produced in
the avalanche absorbed inneighboring high field region• After-pulse

13/06/2012

p+

p+

n+

n+

n substrate– Delayed = by definition– “Usual” origin: carrier
produced in the avalanche
trapped on impurities– Alternative origin: photons
absorbed in bulk
• Delay due to diffusion• Lets test this hypothesis

3

Use external light source
Spectrum of photons emitted in MPPC avalanches• Setup– Light sources: 404, 437,
637, 820nm• Pulse width and jitter<80ps• 820nm lent to us by
Hamamatsu thanks to Y.
Iwai

R. Mirzoyan , R.Kosyra H.-G.Moser ,NIMA 610 (2009) 98–100
13/06/2012– MPPC (or other SiPM)– High speed amplifier– Oscilloscope to record
waveforms– Temperature controlledchamber4Analysis method
T2K MPPC, 20C, ∆V~1.5V• Look for pulses within a 1us
window• Accept only events with 1
pulse to avoid after-pulse– Set the light level to maximize
efficiency• Subtract out the noise
contribution– Measure prior to light pulse• Normalize distribution toone• Fit prompt peak by the
convolution of an Gaussianand exponential
13/06/20125

Look beyond the prompt pulse
Evidence for delayed avalanches
T2K MPPC, -60C, ∆V~1.5V

13/06/2012

T2K MPPC, 20C, ∆V~1.5V

Time of the prompt peak set to 0.3 ns to show well on the logX plot

6

Dark noise is an issue at 20C
T2K MPPC, ∆V~1.5V, 820 nm
20C
-60C

• Large correction in thetail. Limit the statisticalaccuracy• Prompt peak a bit wider
at 20C• Tail does not seem tochange– Expected because thecoefficient of diffusion
vary weakly withtemperature

13/06/2012

7

Over-voltage dependence
T2K MPPC, 820 nm, -60C

13/06/20128

Summary• Delayed avalanches clearlyvisible at 637 and 820 nm– Late avalanche probability
increase with ∆V– Timing distribution mostly
unaffected by ∆V– Weak dependence withtemperature– More late avalanches for
Hamamatsu than Excelitas• Phenomena consistent withholes created in the bulk
diffusing back to junction– Simulations can reproduce
the data– Several free parameters
because junction structure is
unknown• Phenomena can explain
after-pulsing– Required x2 photon flux
however

13/06/201217

Study of MPPC
with Multiwavelength Laser
Microscope system
Koji YOSHIMURA and Isamu NAKAMURA
for KEK Detector R&D GroupNDIP2011 July 8, 2011, Lyon

Motivation
Why is multi-wavelength light usuful for study PPDs?
Variety of applications which cover different range of wave length
Understanding of sensor structure and mechanism
Orme’s Study (PD’09)

PhotoDet June 13, 2012, LALGeiger Efficiency[V/cm]

Compare theavalanche prob.
between e and h.

Field strength~ 3x105

SurfaceehSubstrate
Depth

Multipl. Layer

Impact ionization prob.

Simulation Results
electron: saturated
Avalanche Probability

Direction of E

1
0.9

Electron Seed
Hole Seed

0.8
0.7
0.6
0.5
0.4
0.3

e

0.2

h
1 order of magnitude
diﬀerence

0.1
0
70

72

74

76

78
80
82
Bias Voltage [V]hole: linear

H.Otono, et al., PANIC08

Power Monitor

ND Filter

Beam splitter

Beam splitter

OPHIR PE10
Power Meter
PhotoDet June 13, 2012, LAL

New stage for sample switching
Reference PMT

Laser

MPPC

150 mm span
PhotoDet June 13, 2012, LAL

PDE vs Wavelength
PDE (%)

PDE vs Wavelength
50

Very Preliminary40

30Over voltage
0.25 - 1.1 V

20

10

0
400

Reference
450

500

550

600

650

700

750
800
Wave length (nm)PhotoDet June 13, 2012, LAL

PDE vs Bias voltage
PDE (%)

PDE vs HV
50

Very Preliminary

40

30

20

10

0
0

0.2

0.4

0.6

0.8

1
1.2
Over voltage (V)PhotoDet June 13, 2012, LAL

Normalized PDE
Normalized PDE

PDE vs HV
4

Very Preliminary

3.5

3

2.5

2

1.5

1

0.5
0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1
1.2
Over voltage (V)PhotoDet June 13, 2012, LAL

dSiPM

Initial Experience with Digital SiPMs
in Detectors for Time-of-Flight PET

D. R. Schaart, G. Borghi, H. T. van Dam, G. J. van der Lei, S. Seifert, V. Tabacchini
PhotoDet 2012, Orsay, 14-Jun-2012
Dennis R. Schaart
Delft University of Technology

1

SiPM arrays – some examples
18 mm

Hamamatsu

This image cannot currently be displayed.

FBKirst

16 mm

46 mm

Philips Digital Photon Counting

SensL

48 mm

Individual readout of array elements => position-sensitive light sensor
Dennis R. Schaart
Delft University of Technology

3

Digital SiPMs
Analog Silicon Photomultiplier
Vbias

Readout ASIC...

Discriminator

TDC

Time

∫

ADC

EnergyShaper
SiPM

dSiPM provides adigital timestamp andthe photon count foreach light pulse,
without the need ofany analog front-end
electronics

Digital Silicon Photomultiplier
Vbias

Vbias

Cell
Electronics

...

Cell
Electronics

Recharge

Detector + Readout...

Trigger
Network

TDC
PhotonCounter

Time
EnergyFrom: Thomas Frach, IEEE NSS/MIC, Orlando, FL October 28, 20095

dSiPM array• dSiPM pixels: 64 (8x8)32 mm• Microcells per pixel:- 6396 (DPC-6400-44-22)- 3200 (DPC-3200-44-22)• Silicon dies: 16 (4x4)• Sub-pixels per pixel: 4 (2x2)• Array size: 32 mm x 32 mm

32 mm

1 pixel

1 dieMagnifying glass shows 1 Si die
Dennis R. Schaart
Delft University of Technology

6Test setup: initial timing measurements
3 mm x 3 mm x 5 mm LSO:Ce,CadSiPM array

Exit hole Ø 0.5 mm

Na-22

dSiPM array

Stepper motors X and Y

Tungsten collimator

Flatcable

Flatcable
Daughterboard
Motherboard

Temperature chamberUSB
Dennis R. Schaart
Delft University of Technology

PC
8

Timing resolution

Two coincident detectors:•

DPC-3200-44-22 dSiPM arrays•3 x 3 x 5 mm3 LSO:Ce,Ca crystals

Timing spectra at different positions of one of the two detectors. The step size is
20 mm. The average coincidence resolving time (CRT) is 123 ps FWHM.
Dennis R. Schaart
Delft University of Technology

9Monolithic scintillator detectors
front

z

crystallight sensor

x

back

Light distribution
depends on theentry point on thefront surface…

…and on the depthof interaction (DOI).

Dennis R. Schaart
Delft University of Technology

10Monolithic scintillator detectors
Compared to segmented crystals:• Intrinsic depth of interaction (DOI),
even with single-sided readout• High sensitivity (100% packing
fraction)• Easier crystal surface processing
and detector assembly• Fewer reflections of scintillation
photons before reaching sensor• Fewer losses• Smaller transient time spread=> intrinsically better characteristics?
Dennis R. Schaart
Delft University of Technology

11

The monolithic scintillator 2.0
Monolithic TOF/DOI detector with improved performance due to Ca co-doped LSO
scintillator, digital photon counting (dSiPM), and optimized readout algorithms

24 mm x 24 mm x 10 mm LSO:Ce,Ca
scintillator on PDPC digital SiPM array

Dennis R. Schaart
Delft University of Technology

Faster & more accurate nearest-neighbour
algorithm, H.T. van Dam et al, IEEE Trans
Nucl Sci 58, 2139-2147, 201112

Spatial resolution
20 mm thick crystal• 16 x 16 x 20 mm3 LSO:Ce,Ca• DPC-3200-44-22 array• Smoothed k-NN method*
nref = 100
Point Spread
Function (PSF)• Measured at -25 °C• Crystal average:• x: 1.89 mm FWHM
• y: 1.79 mm FWHM
• Uncorrected for beam
diameter* H.T. van Dam et al, IEEE Trans Nucl Sci 58,
2139-2147, 2011

Preliminary results

17

Coincidence resolving time
10 mm thick crystal• 24 x 24 x 10 mm3 LSO:Ce,Ca• DPC-3200-44-22 array
146 ps FWHM

• Measured at -25 °C• Corrected for electronic
skews of individual Si dies
(50 ps laser measurement)

Timing measurement against 85 ps FWHM
reference detector
Preliminary results• Corrected for mean opticaltransit time, given the (x,y)
interaction position18

Sub-mm resolution, TOF & DOI !
Summary of first results with LSO:Ce,Camonolithic scintillators on digital SiPM arrays:• Coincidence resolving time ≤ 200 ps FWHM
• < 1 mm FWHM resolution (height = 10 mm)• < 2 mm FWHM resolution (height = 20 mm)• 11% - 12% FWHM energy resolution• Intrinsic depth-of-interaction (DOI) information⇒ A highly promising detector concept
for clinical PET/CT and PET/MRI
Dennis R. Schaart
Delft University of Technology

20Technical Evaluation Kit●

Our evaluation kit is made of :●2 DLS 3200 sensor with 3200 cells per pixel●

2 DLS 6400 sensor with 6400 cells per pixel●

4 kapton cables●

One base to connect the tiles●

One power supply●

One computer for detector configuration and dataacquisition

Few characteristics

DLS 6400

DLS3200

Cell size [μm2]30 x 50

59.4 x 64

Fill factor [%]54

78 (→ 84)

PDE [%] @ 420 nm

30

43 (→ 47)

DCR [MHz/pixel] @20°C

<5

<10

Op. voltage [V]< 35

Temp. dep of PDE [% / K]

- 0.3313th-15th Junel 2012MPPC :
3600 cells
3x3 mm2

M. Heller, PhotoDet 2012 in Orsay

32 mm
16

Timing Resolution

PhotoDet 2012

LAL Orsay, June 2012

The SiPM Physics and Technology- a Review G.Collazuol
Department of Physics and Astronomy, University of Padova and INFN

Overview- Introduction- Key physics and technology features- I-V characteristics- Device response- Noises- Photo-detection efficiency- Timing properties- Summary and Future1

GM-APD avalanche development(1) Avalanche “seed”: free-carrier
concentration rises exponentiallyby "longitudinal" multiplication

Longitudinal
multiplication
Duration ~ few ps
Internal current
up to ~ few µA(1') Electric field locally lowered(by space charge R effect)
towards breakdown level
Multiplication is self-sustaining
Avalanche current steady until
new multiplication triggeredin near regions

A.Spinelli
Ph.D thesis (1996)
time (ps)Simulation w/o quenching:→ steady current reached

G.Collazuol - PhotoDet 2012x100

(2) Avalanche spreads"transversally" across the junction(diffusion speed ~up to 50µm/ns
enhanced by multiplication)

Transverse
multiplication
Duration ~ few 100ps
Internal current
up to ~ several 10µA

Photon @ center of the cell

Photon @ edge(2') Passive quenching mechanism
effective after transverse
avalanche size ~10µm(if no quench, avalanche spreads over
the whole active depletion volume→ avalanche current reaches a final
saturation steady state value)

time (ns)57

GM-APD avalanche transverse propagation
Avalanche transverse propagation by a kindof shock wave: the wavefront carries ahigh density of carriers and high E field gradients(inside: carriers' density lower and E field decreasing
toward breakdown level)

r

∆r



dS d
D
= 2  r t  r=2  v diff  r=4   r
dt dt
Rate of current production:dI dI dS
D=~
dt dS dt R sp  G.Collazuol - PhotoDet 2012

V biasdI=J =dS
R sp  S Internal current rising front:
the faster it grows, the lower the jitter
dI/dt → understand/engineer timing
features of SiPM cells

S = surface of wavefront (ring of area 2π r∆r)
Rsp (S) = space charge resistance ~ w2/2ε v~ O(50 kΩ µm2)
vdiff ~ O(some 10µm/ns)

D = transverse diffusion coefficient ~ O(µm2/ns)
τ = longitudinal (exponential) buildup time ~ O(few ps)~11− E max / E breakdown n→ timing resolution improves at high Vbias→ E field profile affects τ and Rsp (wider E field profile → smaller R)(should be engineered when aiming at ultra-fast timing)→ T dependence of timing through τ and D→ slower growth at GAPD cell edges → higher jitter at edges
reduced length of the propagation front

SiPM cell58

GM-APD timing jitter: fast and slow components
1) Fast component: gaussianwith time scale O(100ps)
Statistical fluctuations in the avalanche:• Longitudinal build-up (minor contribution)• Transversal propagation (main contribution):- via multiplication assisted diffusion(dominating in few µm thin devices)
A.Lacaita et al. APL and El.Lett. 1990

G.Collazuol - PhotoDet 2012

- via photon assisted propagation(dominating in thick devices – O(100µm))
PP.Webb, R.J. McIntyre RCA Eng. 1982
A.Lacaita et al. APL 1992

Fluctuations due toa) impact ionization statisticsb) variance of longitudinal positionof photo-generation: finite drift
time even at saturated velocity
note: saturated ve ~ 3 vh
(n-on-p are faster in general)→ Jitter at minimum → O(10ps)(very low threshold → not easy)

Fluctuations due toc) variance of the transverse
diffusion speed vdiffd) variance of transverse positionof photo-generation: slopeof current rising front depends
on transverse position

Multiplication assisted
diffusion

Photon assisted
propagation→ Jitter → O(100ps)(usually threshold set high)59

GM-APD timing jitter: fast and slow components
2) Slow component: non-gaussian tails with time scale O(ns)Carriers photo-generated in the neutral regions above/beneath thejunction and reaching the electric field region by diffusion

G.Collazuol - PhotoDet 2012

G.Ripamonti, S.Cova Sol.State Electronics (1985)

tail lifetime: τ ~ L2 / π2 D ~ up to some ns
L = effective neutral layer thickness
D = diffusion coefficient

S.Cova et al. NIST Workshop on SPD (2003)→ Neutral regions underneath the junction : timing tails for long wavelengths→ Neutral regions in APD entrance: timing tails for short wavelengths
60

PDE vs timing optimization
1.0

k=ratio of hole (β) to electron (α)
ionization coefficient (increasing
with E field)

narrow avalanche region,
high E: - small w- high k = b/aw=high fieldregion width

increasing k

0.8
0.6

P01PbeE field

C.H.Tan et al IEEE J.Quantum Electronics 13 (4) (2007) 906

electroninjection

0.2
0.0

better for TIMING

0

20

depth

40

60

80

% increase in α ∗ w

ttb<t b(ps)> (ps)

E field

better for PDE

100

∼δV/V

decreasing w

1000

100

(a)
10

- small k = b/a
depth

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.12

0.14

decreasing w

b

100

10

b

wide avalanche region,
low E: - wide w

jitter(<t 2rms(ps)>-< t > 2 ) 1/2 (ps)G.Collazuol - PhotoDet 2012

k=1 (R P L)
k=0.5 (R P L)
k=0.1 (R P L)
recurrencetechnique

0.4

1

(b)
0.02

0.04

0.06

0.08

0.10

δ V/V

Plots are courtesy of C.H.Tan

61

C. de La Taille
CTO. CNRS/IN2P3

SiPM readout electronics overview

Charge and Current preamps
Charge preamp
Capacitive feedback Cf
Vout/Iin = - 1/jωCf
Perfect integrator : vout=Q/Cf∫
Difficult to accomodate large
SiPM signals (200 pC)
Lowest noise configuration
Need Rf to empty Cf

Current preamp
Resistive feedback Rf
Vout/Iin = - Rf
Keeps signal shape
Need Cf for stability

V= -1/Cf ∫ i(t)dt
15 jun 2012

V= -Rf i(t)CdLT Photodet conferenceHigh speed configurations• Open loop configurations : current conveyors, RF amplifiers• Usually designed at transistor level MOS or SiGe (ex PETIROC)•

Current conveyors

•
•
•
•

Small Zin : current sensitive input
Large Zout : current driven output
Unity gain current conveyor
E.g. : (super) common-baseconfiguration
Low input impedance : Rin=1/gm
Transimpedance : Rc
Bandwitdth : 1/2πRcCμ > 1 GHz

•
•
•

I in

15 jun 2012

Cd•

RF amplifiers

•
•
•
•
•
•

Large Zin : voltage sensitive input
Large Zout : current driven output
Current conversion with resistor RS
E.g. common-emitter configuration
Transimpedance : -gmRcRs
Bandwitdth : 1/2πRsCt

I in

Cd

CdLT Photodet conference

RS=50 Ω

Noise and jitter• Electronics noise dominated by series noise en
–
–
–
–
–

Large detector capacitanceFor voltage preamp and load resistor RL,
Output rms noise Vn²=(en²+4kTRs) G² π/2*BW-3dB
Typical values : Rs=50 Ω, en=1 nV/√Hz Vn=1 mV for G=10, BW=1GHz
For current sensitive preamps, possible noise peaking due to Cd• Jitter– Part due to electronics noise :– σt = σv / (dV/dt)– Minimized by increasing BW

15 jun 2012

CdLT Photodet conferenceA few (personal) comments• Strong push for high speed front-end > GHz– Essential for timing measurements– Several configurations to get GBW > 10 GHz– Optimum use of SiGe bipolar transiistors• Voltage sensitive front-end– Easiest : 50Ω termination, many commercial amplifiers (mini circuit…)– Beware of power dissipation– Easy multi-gain (time and charge)• Current sensitive front-end– Potentially lower noise, lower input impdance– Largest GBW product• In all cases, importance of reducing stray inductance

15 jun 2012

CdLT Photodet conferenceTiming resolution of MPPCs
13th June, 2012
Akito Kobayashi
Shinshu University

Setup

TDC

Clock gene
Start

Gate gene
LED Driver

×63 gainHigh speed amp
leading edge
Discri

LED

Gate gene

Stop

MPPC

Thermostatic chamber• We can control drive pulse height for the LED by keeping
the width of 15ns.
• We have tested four different pixel sizes of the MPPC.
• Signal shape into the discriminator is degraded byamplifier response at high intensity light.
2.5V

4Setup view
LED

LED

5cm
MPPC

For the plastic package

5cm
MPPC

For the ceramic package• LED located from MPPC about 5cm.
• MPPC sensor positions is the same for two kinds ofpackages.

5

Timing resolution
40ps• Timing resolutions are around 40 ps.
• Resolution becomes slightly better with increasing
amount of light.
• Data points of 400pixel , 1600pixel , 2500pixel aligned 8
except 100pixel.

Threshold dependence result• Timing resolution was bitter at lower
threhsold.

10

SiPM Photodetectors for Highest Time
Resolution in PET
Cern/PH Lab27 TOF-PET Group
Stefan Gundacker, E. Auffray, N. Di Vara, B. Frisch,
H. Hillemanns, P. Jarron, T. Meyer, K.Pauwels, P. Lecoq

1

Scintillator-ra y s511X keVgamma
5 0 - 1 0 0 krayseV

LSO:Ce, 0.4% Ca(2x2x5mm3)

t

SiPM

Readout
Electronics
NINO

voltage

Photodetector

current

Using NINO for TOF-PETt

Photodetector output, NINO inputtThreshold at
A exp(-t/τ)A
Timewalk

Pulse Width~ τ ln(A/at)

Pulse width is nonlinear
function of the charge.
NINO outputt

F. Powolny et al., IEEE Transactions, pp. 2465-2474, October 2008
Photodet 2012, June 13-15, 2012 – LAL Orsay, France

3

Stefan GUNDACKER

Data Analysis
Crystal:LSO:Ce,0.4% Ca
2x2x5mm3

SiPM:
Hamamatsu 50μ

Acquire pulse width and delay timetrends of both channels withoscilloscope. After selecting thephotopeak on both sides wededuce the time resolution.
vertical projection

FWHM=142±4ps

horizontal projection

6
Photodet 2012, June 13-15, 2012 – LAL Orsay, France

Stefan GUNDACKER

Parameters to optimize
Threshold voltage of NINO chip

Bias voltage of SiPM

These two parameters can be scanned in order to optimize forthe three different types of MPPCs (25μm, 50μm and 100μm
SPAD size)
7
Photodet 2012, June 13-15, 2012 – LAL Orsay, France

Stefan GUNDACKER

Optimization Results
SPAD Size[µm]

Fill Factor
[%]

<Vop>
[V]

VBD
[V]

Bias
[V]

NINO
Threshold
[mV]

CTR
FWHM
[ps]

25

30.8

71.47

69.2

73.0

40

202±4

50

61.5

72.10

70.5

72.2

40

142±4

100

78.5

70.84

69.3

70.3

40

192±8

Dark Count rate vs. Bias overvoltage

100μm

25μm
50μm

Optimum timing
performance for the 50μm
type, due to low DCR andgood fill factor.
The 100μm type cannot be
operated at optimum bias
voltages, because of rapid
increase in DCR.
Lower fill factor for the
25μm directly degrades
timing because of photon
statistics.
13

Photodet 2012, June 13-15, 2012 – LAL Orsay, France

Stefan GUNDACKER

SensL New Fast
Timing SPM
Kevin O’Neill (SensL)
Nikolai Pavlov (SensL)
Sergei Dolinsky (GE)Carl Jackson (SensL)1

Introduction – Fast Pulses with SPM• SensL’s new technology creates fast pulses without sacrificing PDE• This new technology is described in SensL’s international patentapplication no. WO2011117309• MicroFM family sampling now with general availability Q3 2012

2

FM Signal with L(Y)SO Output• Superior ability
to trigger fromthe first
photoelectron• Lessdependence on
PDE

4FM Coincidence Resolving Time
 SensL new FM series SPM demonstrates <250ps coincidence resolved

timing–Over wide range of timing thresholds–

Over wide range of operating voltages and temperatures• LYSO3x3x15mm3• 3mm devices

Observed CRT
between two
detectors(i.e.‘folded’)5

UV Sensitive SiPM

Characterization of Hamamatsu
MPPC for use in liquid xenon
scintillation detectors
F. Neves, F. Balau, V. Solovov, V. Chepel, R. Martins,
A. Pereira, M.I. Lopes
LIP–Coimbra & Department of Physics of the University of Coimbra,
PortugalSiPM in LXe: Pro & Contra
A SiPM is an array of avalanche photodiodes (pixels)
working Independently in Geiger mode. The device
output signal is the linear sum of all pixels.
Advantages:✔ High gain;✔ Good single photoelectron resolution;✔ Low noise at low temperatures;✔ High radio-purity and low mass;✔ Insensitive to external electric fields;+V

Disadvantages:✗ Low linearity range (dependent on the number of pixels);✗ Crosstalk and afterpulsing (but devices are evolving...) ;✗ Small area (growing and arrays are already available...) ;Unknowns:● QE/PDE @ 175 nm?
● Robustness (cooling/warming, pressure variations)● Xe purity impact
PhotoDet 2012 - June 13-15 - LAL Orsay, France3

Windowless SiPM
Manufacturer

Hamamatsu

Type

S10362-33-100X

Number of pixels

30x30

Effective active area

3x3 mmFill factor

78.5 %

Peak sensitivity

440 nmSpectral response range

320-900 nm

Dark counts
Time resolution (1 pe)
Gain

room

~2 MHz-35 oC12.7 KHz

0.6 ns (FWHM)
2 x 106

PhotoDet 2012 - June 13-15 - LAL Orsay, France4

QE measurement: SiPM
Peltiercell

Cooling with a Peltier cell:● Single stage: 17W;●
∆T = -62 oC (2.5W);●
Prec: 0.02 oC rms.

quartzwindow

175 nmfilterAmαXechargeSiPM

PTFE

Signal formating:● Shaping: 2 µs;● Gate: 6 µs.

Xe prop. scintillation lamp
PA

A

in

ADC

in

PA

A

gate

+V

HV

GG

PhotoDet 2012 - June 13-15 - LAL Orsay, France

DISC

5

SiPM PDE & QE estimate
λ=175 nm, T=-35°C

Nphe

QE

PMT

20.4

20%

SiPM

2.1

2.6%

PDE
2.0%

What about liquid xenon?
Aprile et al.,Nucl. Instr. Meth. A556 (2006) 215-218
PDE = 5.5% → QE = 22%

VS

Akimov et al.,Nuc. Exp. Tech., v.52 (2009) 345-351
PDE < 1% for the same SiPM!

PhotoDet 2012 - June 13-15 - LAL Orsay, France

9

WLS coating
TPB (Tetraphenyl butadiene)
Efficiently absorbs VUV and re-emits in blue region●QE of ~100% for 175 nm incoming light (C.H. Lallyet al., Nucl. Instr. Meth. - B, v.117, pp. 421–427)●Successfully used in LAr (P K Lightfoot et al., 2009,
JINST 4 P04002)●

Hamamatsu SiPM
S10362-33-100X
3 mm x 3 mm

LXe
10.7mmDiaphragm ø1 mm

Emission spectrum of TBP(W. M. Burton and B. A. PowellAppl. Opt. v.12, pp. 87-89)

241Am source on a gold-plated support

PhotoDet 2012 - June 13-15 - LAL Orsay, France

12

WLS coating@ SiPM gain of ~2 x 106 :46 ph.e / α – uncoated220 phe / α – TPB uncoated
About x5 improvement
PhotoDet 2012 - June 13-15 - LAL Orsay, France

14SummaryIn this work we present the performance results for windowless SiPM
(Hamamatsu) operating at temperatures down to -100ºC:
A intrinsic noise of <1 Hz for a threshold of ≥1 pe has been measured
at -100ºC;
The SiPMs maintain a good single electron response at high gain (>10 6)and low temperature;
The standard SiPM with window is not sensitive to xenon light;
A QE of ~2.6% (PDE ~ 2%) at 175 nm has been measured using xenon
proportional scintillation light source;
Works immersed in liquid xenon with the same estimated PDE (2%)
A glass plate coated with TPB in front of SiPM improves PDE by at leasta factor of 5, but probably causes optical feedback

PhotoDet 2012 - June 13-15 - LAL Orsay, France

15

PhotoDet2012 Int. Workshop on New Photon-detectors

Evaluation ofhigh UV sensitive SiPMs
from MEPhI/MPI for use in liquid argon.

June 13-15, 2012
LAL Orsay

L.Bezrukov, B.Lubsandorzhiev, N.Lubsandorzhiev,
INR RAS
B.Dolgoshein, E.Popova, P.Buzhan, A.Ilyin,
A.Stifutkin, A.Pleshko, MEPHI
R.Mirzoyan, MPI
A.Zhukov, MIET

Phase I of GERDA experiment has been successfully completed
One of the tasks for Phase II is:
Liquid Argon instrumentation:
LAr – from passive to active shielding
Detection of LAr scintillation
WLS + Cryogenic PMT:

Cryogenic SIPMs for direct LAr light
redout:•several designs underconsideration•MC in progress•VUV sensitive (128 nm)•Large area (1cm2)

WLS +Cryogenic SiPMs:•MC study just started•under preparation for testing in LAr,
•MC shows ~100 noise from 228Th
suppression

June 13-15 2012

UV SiPMs from MEPhI/MPI
can be the possible candidates

Evaluation of high UV sensitive SiPMs
from MEPhI/MPI

5

UV SiPMs from MEPhI/MPI/Excelitas collaboration(produced at Zelenograd, Russia)
100 micron pixel size (100B type), geometrical efficiency 80%

Spectral sensitivity

CrosstalkMeasurements at MEPHI and MPI
700,3
PDE for U=38V (U=4,7V)

60
50
Crosstalk xt

PDE, %

0,2

40
30
20
10
0
300

Comparison with reference
XP2020 (error=17%) at MEPHIPIN 10x10 at MEPhI (error=7%) at MEPHIPIN 18x18 at MPI (error=15%) at MPI

2

3x3mm
2
1x1mm

0,1

0,0

350

400

450

500

550

600

650

0

1

Wavelength , nm

2

3
4
Overvoltage U, V

5

6•Dark rate at room temperature is 400-800 kHz/mm2•Gain temperature stability is 0.5%/C
June 13-15 2012

Evaluation of high UV sensitive SiPMs
from MEPhI/MPI

6

GERDA requirements. Task 1: VUV sensitivity•AR coating•High internal quantum efficiency (abs. length for 128nm ≈5 nm)
actual MEPhI/MPI/Excelitas SiPMs
Internal QE
ARC transparency
100

100

80

Internal QE, %Transmittance, %

80

60

40

60
40
20

20
200

400

600

800

1000

0
200

300

Wavelength , nm

400

500

600

700

800

900 1000

Wavelength , nm

internal QE aready is quite high
ARC should be shifted to 128nm
Task 1 seems to be possible to solve
June 13-15 2012

Evaluation of high UV sensitive SiPMs
from MEPhI/MPI

7

Summary:
 MEPhI/MPI/Excelitas UV SiPMs look likepromising candidates for LAr
instrumentation usage in GERDA
experiment
It requires developments of: VUV SiPM
 large area> 10mm2 SiPMs
 precise experimental methods for
extraction of SiPM SPICE-parameters
June 13-15 2012

Evaluation of high UV sensitive SiPMs
from MEPhI/MPI

18

Development of PPD Sensitive to
Deep UV Scintillation Photons ofLiquid Xenon
W. Ootani, X. Bai, T. Chiba, Y. Fujii, T. Iwamoto, D. Kaneko, T. Mori,
H. Natori, R. Sawada and Y. Uchiyama
ICEPP, University of Tokyo
S. Mihara and H. Nishiguchi
KEK, High Energy Accelerator Research Organization
A. Stoykov
Paul Scherrer Institut
International Workshop On New Photon-detectors 2012, June 13-15, 2012, LAL Orsay

1How It Would Look Like
216 PMTs on γ entrance face~4000 PPDs on γ entrance face
CG

5

PDE for VUVPDE for VUV is nearly zero for commercial
device.
✤ Low transmission for VUV to sensitive layer
due to✤✤Protection coating (epoxy resin/silicon rubber)✤

Insensitive layer (p+ contact layer with ~zero field)✤✤

Absorption length in Si for VUV photon: ~5nm

High reflectivity for VUV on Si surface

VUV
Protection coating✤

Possible solution✤

Remove protection coating✤

Thinner p+ contact layer✤

Optimize reflection/refractive index on sensor
surfaceE field

p+
pn++

8

Development of UV-Enhanced
MPPC✤

UV-enhanced MPPC is under develpment in collaboration with
Hamamatsu.
✤

Remove protection coating✤

Optimize MPPC parameters✤

Thinner p+ contact layer

Anti-reflection coating✤ Refractive index of surface material✤✤✤

Quench resistor✤

Pixel size✤...

Currently sensor size: 3×3mm2

9Prototypes of UV-enhanced MPPC✤

Prototypes of UV-enhanced MPPC of various types are being tested.

✤

Sensor size: 3×3mm2, pixel pitch: 50!mType

p+ contact layer

Reflection/refractive index

Athinner

Anti-reflection

Bthinner

Anti-reflection

Cthinner

Anti-reflection

Dthinner

Anti-reflectionEthinner

Anti-reflection

Fthinner

Anti-reflection

G

normalRefractive index

H

normalRefractive index

Sorry, but we can’t show details of the parameters. (we don’t know either!)10

PDE
Estimation of absolute PDE✤✤

PDE = (Observed # of p.e.) / (expected # of photons) for alpha event

PDE includes effects of optical crosstalk and afterpulsing.
Raw PDE✤

0.2

T=165K

0.18

A
B
C
D
F
F (100#m)
G-1
G-2
H

0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
0

1

2

3

4

Over voltage [V]14

PDE
Effective PDE after subtracting effect of optical crosstalk (5-20% prob.) andafterpulsing (10-30% prob.)✤

Effective PDE ~10% achieved for best samples (type G)✤

Small contribution from NIR component of LXe scintillation (~1% level)
included.
Effective PDE✤

0.2

T=165K

0.18

A
B
C
D
F
F (100#m)
G-1
G-2
H

0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
0

1

2

3

4

Over voltage [V]15

Summary and Outlook✤

MPPC sensitive to LXe scintillation photons is under development incollaboration with Hamamatsu for possible upgrade of MEG LXe "detector.

✤

Prototypes of UV-enhanced MPPC show promising performance (PDE of~10% for best sample) although there are still some issues to be addressed.

✤

Next steps✤✤

Further improvement of performance✤

Improvement of PDE✤

Optimization of MPPC parameters such as pixel pitch and quench
resistor

Production of large area prototype (~12×12mm2)✤

We plan to build LXe detector prototype with 100#-LXe and ~600 large
area MPPCs by spring next year and to perform a beam test.

✤

We aim at the construction of the final detector with ~4000 MPPCs within
next year.
21Analog Memory

C. de La Taille
CTO. CNRS/IN2P3

SiPM readout electronics overview

Waveform digitizers [S. Ritt]
FADCs
•
•
•
•

8 bits – 3 GS/s – 1.9 W
 24 Gbits/s
10 bits – 3 GS/s – 3.6 W  30 Gbits/s
12 bits – 3.6 GS/s – 3.9 W  43.2 Gbits/s
14 bits – 0.4 GS/s – 2.5 W  5.6 Gbits/s

4 channels
5 GSPS
1 GHz BW
8 bit (6-7)
15k€

24x1.8 Gbits/s

1.8 GHz!

4 channels
5 GSPS
1 GHz BW11.5 bits
900€
USB Power

1/10 k€/ch
PX1500-4:
2 Channel
3 GS/s8 bitsStefan Ritt

CdLT Photodet conference 15 jun 2012

18/33

Switched Capacitor Array (Analog Memory)
10-100 mW

0.2-2 ns

Inverter “Domino” ring chainIN
Waveform
stored

Clock

Out
FADC
33 MHz

Shift Register“Time stretcher”
GHz  MHzdtd

dts
Stefan Ritt

CdLT Photodet conference 15 jun 2012

19/33

How is timing resolution affected?
voltage noise Du
signal height U
timing uncertainty Dt

Assumes zero
aperture jitter

Du
1
Dt 

U
3 f s  f 3dB

U

Du

fs

f3db

Dt

100 mV

1 mV

2 GSPS

300 MHz∼10 psoptimized SNR:

1V

1 mV

2 GSPS

300 MHz1 ps

next generation:

1V

1 mV

10 GSPS

3 GHz

0.1 pstoday:

Stefan Ritt

CdLT Photodet conference 15 jun 2012

20/33

Switched Capacitor Arrays for Particle Physics

E. Delagnes
D. Breton
CEA Saclay

G. Varner, Univ. of Hawaii

STRAW3LABRADOR3

TARGET

AFTER

SAM

NECTAR0

H. Frisch et al., Univ. Chicago

PSEC1 - PSEC4
Poster 232• 0.25 mm TSMC
• Many chips for different projects(Belle, Anita, IceCube …)• 0.35 mm AMS• T2K TPC, Antares, Hess2,
CTA

www.phys.hawaii.edu/~idlab/

matacq.free.fr

DRS1

DRS2

DRS3

DRS4

2002

2004

2007

2008

Stefan Ritt

• 0.25 mm UMC• Universal chip for many applications• MEG experiment, MAGIC, Veritas,
TOF-PET
Poster 15, 106

CdLT Photodet conference 15 jun 2012

• 0.13 mm IBM• Large Area Picosecond
Photo-Detectors Project(LAPPD)

psec.uchicago.edu

Stefan Ritt
R. Dinapoli
PSI, Switzerland

drs.web.psi.ch
22/33

Things you can buy• DRS4 chip (PSI)• 32+2 channels• 12 bit 5 GSPS
• > 500 MHz analog BW• 1024 sample points/chn.
• 110 ms dead time

• MATACQ chip (CEA/IN2P3)• 4 channels• 14 bit 2 GSPS
• 300 MHz analog BW• 2520 sample points/chn.
• 650 ms dead time

• SAM Chip (CEA/IN2PD)• 2 channels• 12 bit 3.2 GSPS
• 300 MHz analog BW• 256 sample points/chn.
• On-board spectroscopy• DRS4 Evaluation Board• 4 channels• 12 bit 5 GSPS
• 750 MHz analog BW• 1024 sample points/chn.
• 500 events/sec over USB 2.0
Stefan Ritt

CdLT Photodet conference 15 jun 2012

24/33

Plansread
pointer
digital readout
latch
latch
latch

• Storage of 128 events• Accommodate long trigger latencies• Quasi dead time-free up to a few MHz,• Possibility to skip segments→ second level trigger

FPGA

counter

DRS5 (PSI)• Self-trigger writing of 128 short 32-bin
segments (4096 bins total)

analog readout• Attractive replacement for CFG+TDC• First version planned for 2013

CEA/Saclay• Dual gain channels• Dynamic power management (Read/Writeparts)• Region-of-interest readout
Stefan Ritt

CdLT Photodet conference 15 jun 2012

triggerwrite
pointer
25/33

Comments• Trends– Reduce dead time
– increase analog bandwidth– Increase depth, give more latency– Include high speed low noise preamps (NECTAR…)• Comments– Unbeatable for pulse shape analysis or discrimination– Ultra low timing measurements (ps)– More power hungry than dedicated front-end (many CdV/dt…), needs
careful study for large systems (>> kch)

15 jun 2012

CdLT Photodet conferenceMiscellanea

Lifetime reasurements of recent
microchannel­plate PMTs

Alexander Britting, Wolfgang Eyrich, Albert Lehmann, Fred Uhlig
supported by BMBF and GSI

13.06.2012

Microchannel Plate PMTs


Typical pore sizes: 6 – 25µm

Fast signals:


Rise time: 0.5 – 1.5ns

TTS < 50ps

Gain > 106 with 2 MCP stages

Low dark count rate

27.5 mm

Hamamatsu
R10754X­06­L4
13.06.2012

Alexander Britting

59 mm

PHOTONIS
XP 85112/A1­HGL
5Methods to increase lifetimeHamamatsu:
Protection layer

Between MCP layers (latest models)

Photonis:

In front of first MCP layer→ reduction of collect. efficiency

Improved vacuum
Treatment of MCP surfaces:

T. Mori, Lifetime of HPK Square­shape MCP­PMT, Fast Timing
Workshop, Cracow (Dec. 2010)Electron scrubbing (XP85112/A1, XP85112/A1­HGL)Atomic layer deposition (XP85112/A1­HGL)

BINP:


Protection layer in front of first MCP (old models)Electron scrubbing and improved vacuum (#1359, #3548)

New photo cathode → higher darkcount rate

13.06.2012

Alexander Britting

6Quantum efficiency

Latest models of MCP­PMTs (solid dots) have drasticallyincreased lifetime compared with older ones (open dots)!
13.06.2012

Alexander Britting

16

Spectral QEHam. R10754X­01­M16
degrades faster for higher
wavelengths
Phot. XP85112/A1­HGL is still
unaffected
Recently developed new cath.
( Na 2 KSb Cs Cs 3 Sb )degrades almost constantly
for any wavelength!

13.06.2012

Alexander Britting

14

A new design of large area
MCP-PMTfor the next generation neutrino experiments
Yuekun Heng
IHEP, Beijing
Representing the collaboration

2012/6/13

PhotoDec 20121

• Big demanding for PMT–Large area
–Big quantity: low prices–Low Radiation Background–High QE

2012/6/13

PhotoDec 2012

5

The new design of a large area PMTHigh photon detection efficiency＋ Low cost

＋ Single photoelectron Detection

1) Using two sets of Microchannel plates (MCPs) to replace the dynode chain2) Using transmission photocathode (front hemisphere)~ 4π viewing angle!!
and reflective photocathode (back hemisphere)• Quantum Efficiency:
photonelectron•

Transmission photocathode: 20%•

Reflection photocathode: 40%• MCP Collection Efficiency: 60%
Photon detection efficiency:
20% * 60% = 12%

70% * 40% * 60% = 17%

Total Photon Detection Efficiency: ~30%
2012/6/13

Photon Detection Efficiency:PhotoDec
14% 2012
 30% ; ×~2 at least !

11

The Low radioactive background glass

2012/6/13

PhotoDec 201216

Cathode

2012/6/13

PhotoDec 2012

18

MCP
Method of HV setting

Test equipment for M• HV• Coating• length-diameter ra

Coating MgF2
and MnO

2012/6/13

New
Equipment
for MCP test

Assembly of
two MCPs

PhotoDec 201219

Prototypes

2012/6/13

PhotoDec 201220

8” ellipse MCP-PMT--Electron Multiplier:8”
prototypetransmission

small size MCP (φ=18mm)--photocathode area:transmission + reflection
photocathodeThe photoelectron collected by theelectron multiplier MCPd？

The overview of the prototype

2012/6/13

PhotoDec 201224

The development of the multi PPD readout
electronics with EASIROC and SiTCP

R. Honda, K. Miwa
Tohoku University
I. Nakamura, M. Tanaka, K. Yoshimura
T.Uchida (Open-It), M.Ikeno (Open-It)
KEK

PD12 Orsay FranceIntroduction -EASIROCEASIROC (Extended Analogue SiPM Integrated Read Out Chip)






32 channels inputs
HV adjustment (4.5 V, 8 bit)
Amp, shaper, discriminator
Analog (serial)
discriminator (parallel) outputs.

Shaper(variable shaping time)
25 → 175 ns

Double gain (1:10)
High gain(10 → 150)

Low gain(1 → 15)

AnalogDigital
HV adjustment(8 bit DAC)
Common threshold(10 bit DAC)PD12 Orsay France

Developed by
Omega/IN2P3

The evaluation board with EASIROC
The evaluation board with EASIROC
I/O components

MPPC input

Analog I/OMPPC input (32 ch)
HV inputAnalog output / probe output
Digital I/O
NIM level input x5 (400 Mbps)

NIM level output x4 (~ 1Gbps)

LVDS output (640Mbps)
SiTCP

EASIROC
ADC(AD9220)FPGA(SPARTAN6)

On board ADC and TDC
AD9220●Digital MHTDC in FPGALVDS output

Power supply●±6 V
SOY (general purpose SiTCP board)is needed to use SiTCP.
Bandwidth: 100 Mpbs.

SOY2012.03.24
日本物理学会 関西学院
PD12 Orsay France

#eN PD workshop

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● 2015 Russia()
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