Transcript Creation of the hadronic calorimeter prototype for ILC

Construction of the hadronic calorimeter
prototype for ILC
(CALICE collaboration)
or experience with
Geiger mode operating multipixel
photodiodes (SiPM)
V. Rusinov, ITEP, Moscow
Representing the CALICE collaboration
10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS
Novosibirsk, February28-March5,2008
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Contents
• scintillator layers creation
• main impressions from SiPM
• possible further applications
• desirable properties for new generation
of SiPM
• conclusions
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
SiPM – common name and the detector from this producer
- Producer: MEPhI-Pulsar
-1×1 mm2, 1156 pixel
-Operating voltage:30-70 Volts
-More than 12000 SiPMs were studied
42m
20m
pixel
h
LED + β-source
Al
Depletion
Region
2 m
R 50
Substrate
See yesterday’s talks by D. Renker
and Yu. Musienko
Ubias
V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
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Detector unit:
Scheme of assembling
- 3×3, 6×6,12×12cm2
- uniformity
- cross-talk
- drop between tiles
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Test bench for SiPM parameter measurement
Set up is realized in CAMAC standard
LED
driver
It includes:
PC driven
generator
16 channel computer driven power supply
to feed SiPM’s
- 5 mV resolution
- 110 V max
- 100 μA maximal output current
16 channel computer read-out digital
voltmeter to monitor
- SiPM bias voltage
- SiPM current
- temperature during test
measurement accuracy
voltage
– 5 mV
current
– 5 nA
temperature – 0.2O
DATA
Digital voltmeter
BASE
Remote control
16 channel
power supply
Steering
program
…….
16 ch
X~100
PMT
12 bit
gate
PC driven generator to produce LED and
random triggers and ignite LED
ADC
Tested SiPMs
16 channel 12 bit ADC 0.25pC/count
sensitivity
16 ch amp
16 ch
12 bit
ADC
PMT to monitor LED light
15 SiPMs can be tested simultaniously
Measurements are done at 2 kHz trigger
rate
A software package was developed to make easy interface between user and hardware, to
perform measurements and to save results in data base
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Picture from PC screen, one of 8 steps of HV tuning.
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
SiPM parameter distributions
Result of selection
Rejected reason:
Gain – 2.8%
Noise at ½ pixel – 5.5%
Noise at ½ MIP – 22.6%
Cross talk – 3.5%
Current – 0.5%
Current RMS – 1.4%
Yield of good SiPM’s > 70%
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
What detector has been used, comparison with other SiPM
(See the talk of Yu. Musienko with
recent SiPM achievements)
Characteristics of SiPM used for CALICE HCAL prototype are far from
today's record values
But…
V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
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1. Do not forget that the work on HCAL prototype for CALICE has been done in 20042007; the SiPM’s for it were developed in 2003. At that time HAMAMATSU (MPPC)
(which now produce the devices with record parameters) wasn’t manufacturing it at all.
This business growing extremely fast
2. And more important. The existing SiPM characteristics are
sufficient and furthermore adequate for our goals
Let me illustrate it.
This is one of our results – light yield
distribution from MIP for all tiles. Looking
only on mean value (over all three tile
sizes) of the LY = 13.5 pixels.
What it means?
SiPM has 1156 pixels and therefore has
limited dynamic range.
Having 13.5 pixels per MIP we can measure
energy per cell up to ~ 200 MIP.
More efficient detector leads to reduction of
this range.
Thus, we don’t need higher sensitivity
SiPM - only for given task, of course
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Noise rate
Mean value for SiPM’s used is equal to 2 MHz, and it looks terrible.
But the noise drops fast with threshold increase.
random trigger
So, if
Threshold=0.5 MIP
noise rate=1.8kHZ
It leads to
3 noise events from all 8000 channels
for 200 nsec gate
and with a such threshold we have
93% efficiency of the whole detector
1p.e.
2p.e.
Ped.
3p.e.
The better detectors could give more
flexibility in threshold choice and could add
few percent in efficiency. But, nevertheless,
characteristics of SiPM’s from MEPhI –
PULSAR were quite adequate for our goals.
And - of course – for some other tasks.
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Impressions from dealing with SiPM
Advantages
•
•
•
•
•
•
•
•
Small size
compact and high
granulated detector
Low operating voltage
Fast
Large gain, simple electronic
Self-calibration possibility
Insensitivity to magnetic field
Reliability – problems solved
Price (?)
Limitations
• Low radiation hardness*
• Strong voltage (temperature)
dependence**
• Limited dynamic range
• High noise level
In conclusion of this part. It was really a pleasure to work with MEPhI – PULSAR
team: Boris Dolgoshein, Sergey Klemin, Elena Popova and other people, who
developed SiPM’s and produced many thousands of them!
*
Peak resolution up to ~ 1krad protons, 500 krad e (or gamma), 5×10 10 fast neutrons/cm2;
recovery for some of detectors; necessary to think separately in each case
** d(MIP)/dT=-4.5%/K ; d(MIP)/dV=7%/V
the dependence from only one value!
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Our HCAL prototype is working! The unique granularity
allows to separate closest showers
Reconstruction algorithm:
(V. Morgunov)
applied to HCAL only.
Clusters grouped
according to topology and
hit amplitude.
Separate:
EM and HAD shower
components
+ neutrons (= isolated hits)
Event with 2 hadrons after reconstruction.
Two showers separated in depth are
visible
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Detector unit: scintillating tile+ WLS+ SiPM gives possibility to construct
HCAL . But for scalable prototype we still search other solutions.
Example 1:
How to make calorimeter with >106 channels?
One of the first possible steps is
to read out light directly from tile without WLS
scintillator
SiPM
2 problems right away:
• low light
• response non-uniformity
glue
MC simulation by E. Tarkovsky (ITEP)
Result from ITEP proton beam
We can equalize the response only by cutting the peak, but the light
problem will grow. New detectors are necessary.
V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
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Example 2. Scintillating strip as detector unit
-Time measurements.
D1
Strip with
WLSF
Trigger
counters
D2
1.2 mm Y11
1 mm BCF 92
Delays t12=t1-t2, t1T=t1-tT, t2T=t2tT have been measured
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
Example 3. Scintillating strip as detector unit.
- Light Yield and Efficiency
2000x25x10
2 SiPM’s
mm3
1000x40x10 mm3
coated with TiO2 white paint
Ø1.2 mm Kuraray Y11 WLS fiber
glued into a groove
MRS APD + mirror at opposite end
Strip efficiency and noise vs threshold
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk
, March 4, 2008
Possible directions
and
Activities
1.
Direct light reading from tile.
what do we want from SiPM
Requirements to detector
1.
2.
Energy measurement up to hundreds MIP,
large dynamic range (>103 pixel), high
efficiency in blue light (>20%), low noise
(<100 Hz at ½ MIP), larger area, flat
packaging.
No energy measurement, 102 pixel, small
area (1-1.5 mm2), high efficiency in green
(>30%), not so strong requirements to noise
level.
2.
Long scintillating strips with WLS:
•
•
•
muon detector
veto or trigger wall
time (or coordinate) measurements
3.
Neutrino detector based on scintillating
strips and WLS
( ν + p = n + e +)
Neutron detector based on scintillator
doped with B10 and WLS
3.-4. Energy measurement from ½ MIP, 103 pixel,
small area (1-1.5 mm2), high efficiency in
green (>30%), lowest noise level (to start with
low threshold).
Gamma detection in liquid Xe
5.
4.
5.
No energy, 102 pixel, large area (16, 25 mm2),
sensitivity to UV, any noise
One of main impressions from SiPM – non-universality.
New task requires new detectors.
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
It is clearly seen - various detectors are needed
MRS APD from CPTA, Moscow
1mm2 green MRS with ε=30%
4 mm2 ------------------------- 25%
4 mm2 blue MRS with ε=25%
Noise rate~ 2.5 MHz/mm2
Efficiency - good for different purposes
Noise – not so good yet
So, we continue to work with producer,
hoping to get better and various detectors
The cooperation with Russian producers looks perspective due to
easy communication and fast response. Important to have a possibility
to order what you really need together with a possibility to buy in
a good shop (HAMAMATSU) what they have
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
CONCLUSION
• The active layers construction for HCAL prototype
was a big and interesting work for our group, the
8000-channel device was finished last summer
• We have obtained an unique experience with
more than 10000 SiPM’s and positive impressions of them
• We principally know how to produce HCAL based on unit
described (tile – WLS – SiPM) and we are searching other
possibilities
• We see further possible applications for such kind of
detectors
And – thanks to organizers!
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V. Rusinov 10-th INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS Novosibirsk, March 4, 2008
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