Scintillator HCAL read-out andout and calibration HCAL read-out andout and calibration Felix Sefkow...
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Transcript of Scintillator HCAL read-out andout and calibration HCAL read-out andout and calibration Felix Sefkow...
Scintillator HCAL read-out andread out and calibration
Felix Sefkow
TILC08 at Sendai, Japan March 4, 2008
Outline
• Test beam
• Calibration and monitoring methods
N d t l t i d t t• New read-out electronics under test
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 2
Scintillator HCAL prototypep yp
• Steel scintillator sandwich• 38 layers, 2cm steel absorbers• Scintillator tiles 3x3x0.5cm3
• 7608 SiPMs (MEPhI / Pulsar)7608 SiPMs (MEPhI / Pulsar)
Versatile calibration and monitoring system
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 3
Test beam experiencep
• Established the scintillator SiPM technology on large scale (7608 SiPMs)– Robust and stable operation, 95% up-time, 1.6% dead channels (mostly solder)– Noise occupancy 10-3 as expected 0 8 MIP = 25 MeV / hit
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 4
– Noise occupancy 10 3 as expected, 0.8 MIP = 25 MeV / hit– Imaging capability nicely demonstrated, millions of events collected
Analysis ongoingy g g
• Electromagnetic showers: Verify detector model and calibration dprocedures
• Hadrons: test simulation models and particle flow performance
Ongoing thesis workN.Wattimena O. Wendt
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 5
Next: technical prototypep yp
• Goal: A compact and realistic (i e scaleable) scintillator HCAL
• Integration issues
• Goal: A compact and realistic (i.e. scaleable) scintillator HCAL structure with embedded electronics
– Readout architecture– Ultra-low power ASICs– Calibration system
Til d SiPM i t ti– Tile and SiPM integration– Absorber mechanics with
minimal cracks• See V Zutshi’s talkSee V.Zutshi s talk
• Feed-back from test beam essential
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 6
essential– Calibration concept
Calibration
• Pixel photo-diode is non-linear: need p2 reference scales– MIP: muon test beam– Gain: low intensity LED light
• Energy deposition– E[MIP] = A / AMIP * f ( A / Apixel)
• Saturation correction fSaturat on correct on f– From test benchSATURATION CURVE SIPMS WAFER 4-11
Light, MIP
Res
pons
e, p
ixel
s
0
200
400
600
800
1000
1200
1400
0 50 100 150 200 250
G i
SATURATION CURVE SIPMS WAFER 4-11
Light, MIP
Res
pons
e, p
ixel
s
0
200
400
600
800
1000
1200
1400
0 50 100 150 200 250
Gain
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 7
SATURATION CURVE SIPMS WAFER 4-11
Light, MIP
Res
pons
e, p
ixel
s
0
200
400
600
800
1000
1200
1400
0 50 100 150 200 250
Temperature and voltagep g
• Signal (charge) depends on gain and Geiger efficiency: A ~ ε * Gg g p g g y• Both depend on overvoltage ΔU = Ubias – Ubreakdown
• Breakdown voltage Ubreakdown depends on temperature
Figures: S.Uozumi• For x = A, G: dx/dT = - dx/dU * dUbreakdown/dT
R ti f lit d d i ffi i t i th f U d T
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 8
• Ratio of amplitude and gain coefficient is the same for U and T dependence
Voltage dependenceg p
• Measured for A and G at ITEP test bench, stored in data base• Reproduced in CERN test beam set-up
ITEP
CERN
This and following slides:
N F
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 9
N.Feege,A.Kaplan
Temperature dependencep p
• Measured in test-beam only
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 10Red: low ΔU group
Amplitude and gain coeff.sp g
• Check model: dA/dT / dG/dT = dA/dU / dG/dU ?
• Mean (norm) -4.0 -1.7 5.6 -2.6 %/(K or 0.1V) • RMS (norm) 2.8* 0.4 0.8 0.4
mean spread
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 11
Correction methods
• Temperature correction: x = x0 [ 1 + dx/xdT (T-T0) ] , x = A, Gp– Instantaneous, but non-local
• Gain correction A = A0 [ 1 + { dA/AdU / dG/GdU } (G-G0) ]0 [ { } ( 0) ]– Local, but not instantaneous
• Combination of both – all to be triedCombination of both all to be tried– Success not guarenteed – may introduce additional errors
V lt dj st t U U ( G G ) / dG/dU• Voltage adjustment U = U0 + ( G – G0) / dG/dU– More radical, but most effective
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 12
Bias working pointg p
• Critical for signal / noise optimization, not recoverable offline
Derived from Li h i ld A/GLight yield = A/G
N.D’Ascenzo
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 13
Voltage adjustmentg j
• Test beam preparation at DESY vs. CERN
observedTemperature-corrected
Required bias adjustment
Voltage-corrected(prediction)
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 14
q j mfrom observed gain shift
(average per layer)
Auto-calibration
• With single photo-electron (pixel) peaks the pixel photo-diode provides its own reference scale
P i i t l f it i t t• Promising tool for monitoring temperature-induced response variations
• Opens possibilities for further simplification• Opens possibilities for further simplification of calorimeter design – No external reference– Small amplitudesp– Loose stability requirements
• Stability of saturation correction
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 15
– Under study, so far OK
LED on board
• Attractive option - if auto-Attractive option - if auto-calibration of SiPM sufficient
• Proof-of-principle test borad, check for cross-talkcheck for cross-talk, uniformity, dynamic range,…
First tests:
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 16
M.Reinecke, DESYFirst tests:
electrical cross-talk small
Estimate Crosstalk
Scope in averagingdmode
Light in Tile 1Light in Tile 1
Crosstalk to tile 2 and tile 4
≈40mV
≈1mV
Crosstalk ≈ 2 5%
tile 2 and tile 4
Very encouragingOngoing optimization and measurements Crosstalk ≈ 2.5%
Consistent with optical XTg g p
(ligt uniformity, dyn. range,…)
Felix Sefkow TILC08, Sendai, March 3-7, 2008
Scintillator HCAL readout & calibration
17Mathias Reinecke EUDET annual meeting – Paris 8.-10. Oct. 2007
LEDs: to be continued
• Uniformity not yet sufficient (LED LED i i )(LED to LED variation)– Do not want to –remote-
control or tune each driver– Discussions with manufacturerDiscussions with manufacturer– Could in principle be solved
with pre-selection • Driver uniformity?y
• Dynamic range – the more, the merrier
A Lucaci
• Systematic investigation using CALICE DAQ
A.Lucaci, S.Weber
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 18
– ILC-SiPM ASIC and CRC
New ASIC on the test benches
• Auto-triggering and time measurementsgg g• ADC and TDC integrated• Power pulsing, low (continuous) power DAC
50 -100nsGain
selection
Slow Shaper
Slow Depth 16
Low gain Preamplifier
Analog memory1.5pF 0.1pF-1.5pF
Gain
LAL
50-100ns
15ns
HOLD
Shaper
Fast Shaper
Charge measurement
12-bit Wilkinso
nADCDepth 16
High gain Preamplifier
15pF
0.1pF-1.5pF
Conversion
READ
Variable delay
IN
Discri
DESY
4-bit threshold adjustmentDAC
output
Time
Trigger
Depth 168-bit DAC0-5V
80 µsdelayDiscriFlag TDC
Analo
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 19
10-bit DACTime
measurementTDC ramp 300ns/5 µs
Common to the 36 channels
g outpu
t
Analogue partg p
pedestal
1,166
Gain uniformity
1,158
1,16
1,162
1,164
DC
vol
tage
(V)
109
110
111
112
113
114
Vout
(mV)
1,152
1,154
1,156
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35
Channel
D
106
107
108
109
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35
Channel
G i d d t l if it d
L.Raux, S.Callier0.15
0.10
Cf=100fF Cf=100fF Cf=200fF Cf=300fF Cf=400fF Cf=500fF Cf=600fF Cf=700fF Cf=800fF
High gain charge output at different Cf Qinj= 1.5pC
• Gain and pedestal uniformity good (as expected from SiGe 0.35)
• Somewhat smaller gain and larger i th i i l ti
0.05
0.00
Vou
t (V
)
Cf=900fF Cf=1pF Cf=1.1pF Cf=1.2F Cf=1.3pF Cf=1.4pF Cf=1.5pF
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 20
noise than in simulation500400300200100
Time (x10-9s)
Input DACp
• SiPM bias adjustmentj• Must be extremely low power (~10µW), since always on!• Non-linearity ~2%, just OK
DAC linearity
5
ch0ch1ch2ch30 02
0,03
2,5
3
3,5
4
4,5
5
age
(V)
ch3ch4ch5ch6ch7ch8ch9ch10ch110 01
0
0,01
0,02
0 50 100 150 200 250 300
0
0,5
1
1,5
2
2,5
Volta ch12
ch13ch14ch15ch16ch17ch18ch19
-0,03
-0,02
-0,01
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 21
0 50 100 150 200 250 300
DAC
ch20ch21ch22
-0,04
L.Raux, S.Callier
Autotriggergg
• Fast shaper (10ns) and discriminatorC t i 0 5• Can triger on 0.5 p.e.
• Small threshold dispersion• Cross-talk 0.3%• Time walk 6ns
trigger time walk vs injected charge
60
62
64
)
S-curves
80
90
100
Série1
Série2
Série3
Série4
Série5
Série6
Série7
Série8
Sé i 950
52
54
56
58
time
(in
ns)
50
60
70
80
ger e
ffici
ency
Série9
Série10
Série11
Série12
Série13
Série14
Série15
Série16
Série17
0 1000 2000 3000 4000 5000
charge (in fC)
10
20
30
40
trig
g
Série18
Série19
Série20
Série21
Série22
Série23
Série24
Série25
Sé i 26
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 22
0388 390 392 394 396 398 400 402 404 406 408
DAC value
Série26
Série27
Série28
Série29
Série30
L.Raux, S.Callier
SPIROC meets SiPM
R.Fabbri, B.Lutz
• Still a lot of tests to be done• Understand response with auto-trigger, control thresholds
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 23
• Internal ADC not yet usable
Summaryy
• A nice concept for the 2nd generation HCAL prototype with b dd d l i d lib i i iembedded electronics and calibration system is emerging
• Readout with many new features( )– Auto-trigger (zero-suppression)
– On-chip digitization– Time measurement
Power pulsing– Power pulsing
• Auto-calibration of PPDs is a very powerful tool – but remains a challenge for sensor and electronics designchallenge for sensor and electronics design
• Test beam experience vital and rich source to develop calibration concept
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 24
concept
Back up slidesBack-up slides
Felix Sefkow TILC08, Sendai, March 3-7, 2008
Scintillator HCAL readout & calibration 25
Integrated layer designg y g
Reflector Foil100
Polyimide Foil100
HBU Interface500MCSector
wall
100µm 100µm PCB800µm
500µm gapASICTQFP-1001mm high
Top Plate600µm steel
Spacer1.7mm
Top Plate fixing
DESY
SiPMC t ABolt with innerM3 threadwelded to bottom
SiPMTile3mm
Bottom Plate600µm
Component Area:900µm high
HBU height:6.1mm
AbsorberPlates(st l)
Felix Sefkow TILC08, Sendai, March 3-7, 2008 Scintillator HCAL readout & calibration 26
plate6. mm(4.9mm without covers => absorber) (steel)
integrated