1. Progress in CALICE tile HCAL and LCcal ECAL R&D
Felix Sefkow
DESY
ALCPG Workshop at SLAC
January 7, 2004

2. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Imaging Calorimetry
Precision physics: best possible detector
Particle flow: best jet energies ↔ minimum calorimetry
Imaging calorimeter:
new ideas & technologies
challenging granularities
sensitivity to (de)tails: need test beam data
Prepare to make the best choice
ZHH g qqbbbb
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

3. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
This talk
LCcal: hybrid ECAL
combine the virtues of scintillator and silicon for energy and position measurements
CALICE: the analogue HCAL branch
explore to how to best use amplitude and position information of scintillator tiles for particle flow
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

4. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Outline
LCcal test beam results
CALICE
reconstruction software studies
test beam studies with the minical
preparation of the physics prototype
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

5. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
CALICE collaboration
164 Physicists, 26 Institutes, 9 Countries: 3 Regions
Si W ECAL: see
France, UK, Czech, Russia, Korea H.Videau’s talk
Analogue tile scintillator HCAL:
Germany, Czech, Russia
Digital HCAL options: see
Scintillator: US G.Blazey’s & V.Zutshi’s talks
RPCs: US, Russia , Korea L.Xia’s talk
GEMs: US A.White’s talk
“EFLOW”, software: “all”
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

6. Cluster reconstruction in hadronic showers
use energy deposition pattern to classify,
longitudinal sampling crucial - at all depths
V.Morgunov
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

7. Optimize prototype geometry
vary depth and width of fine segmented area
3, 6, and 12 cm
for flexibility
V.Morgunov, A.Raspereza
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

8. Two showers: cluster separation↔
vary transverse gran.
cluster overlap for 3x3 cm tiles very close to 1x1 cm case
prototype with ~8000 channel will work like one with 3x3 cm everywhere (35k ch. equiv.)
V.Morgunov, A.Raspereza
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

9. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Tail catcher
de-tails matter – 10 or 15 % to be 20GeV
A.Raspereza
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

10. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
TailC Segmentation
study resolution:
affects mostly constant term
stochastic term %
other considerations: particle ID & PFLOW
→ freedom for optimization
A.Raspereza
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

11. More software work started
from cluster to full shower reconstruction and two-particle separation
test beam run strategy
Move to Mokka framework and LCIO
real data entities added and LCIO converter for minical data ready
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

12. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
MiniCAL
Main goals:
Gain experinece with larger # of channels
Develop hardware understanding in simulations
27 layers
SiPMs and APDs, MA-PMs for reference
Cosmics and DESY electrons (1…6GeV)
2 cm
steel
0.5 cm
active
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

13. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Detector Cassettes
SiPMs mounted directly
on tile, single tile readout
Tile size:
5x5x0.5 cm3 e+
1-loop fiber placed in groove (not glued)
Single tiles covered by 3M reflector
1 cell = 3 tiles
combined in depth
for PM and APD
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

14. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Calibration (PMs)
with cosmics and e beam “MIP”
PM PM PM 3
reproducibility at 6-8% level – after LED monitoring correction (per PM)
single channel monitoring prepared
exercise; LED monitoring mandatory for APD runs
E.Garutti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

15. The Silicon Photomultiplier
A pixilated solid state Geiger counter
1000 pixels on 1mm2
Gain few x 10**6, efficiency %
At V bias voltage
R 50 h
pixel
Ubias Al
Depletion
Region
2 m
substrate
Resistor
Rn=400 k
20m
42m
0 pe
1 pe
2 pe
3 pe
4 pe
B.Dolgoshein
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

16. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Si PM noise
low noise confirmed with 108 channel minical: 4*10-3 hits /event above ½ MIP
corresponds to 24 Hz per channel or < 1 hit / event in physics prototype
(70 ns gate)
(150 ns gate)
B.Dolgoshein
E.Garutti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

17. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Si PM calibration
spread for 108 SiPM + tiles
(Ru106 source)
B.Dolgoshein
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

18. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Energy resolution
Fit function:
Fit values for PM / MC
a =  /  0.1
b =  /  0.1
Si PMs and PMs similar, MC to be refined
E.Garutti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

19. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
SiPM non-linearity, MC
implement max # pixels
ph.e statistics in MC:
Beam position
A.Raspereza
red and
black points
should agree
B.Dolgoshein
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

20. Measured SiPM saturation
longer pulses (WLF)
effective max # of pixels > 1024
B.Dolgoshein
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

21. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Data vs MC status
linearity resolution
E/E
1/E, GeV
B.Dolgoshein
E.Garutti
shower shapes and low E part to be worked on
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

22. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Electronics tests
not having to resolve single ph.e peaks for calibration significantly loosens demands on FEE
study possible use of (modestly modified) ECAL chip
18 channel ASIC with MUX output to ADC
first prel.
tests:
broadening
due to
SiPM noise
corr. to
0.6 ph.e
Si PM on Dubna test board
with LAL HCAL chip
I.Tyapkin
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

23. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
APDs
lower gain, higher efficiency
critical: stability/monitoring
low noise preamps
stable (10-4) HV p/s at hand, tested
LED monitoring being prepared
4 different preamps available and tested
APD S8550
signal dependence on Ubias, T
at high gain:
15%/V, 11%/K
J.Cvach
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

24. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Gain spread
Characteristics of 40 APD tested
@ CERN (CMS test room):
quantum efficiency = 77.5% (500nm)
 stable at 1% level
capacitance ~30pF at 400V
gain vs voltage:
 ~50% gain variation at V = 415V
 reduced with APD pre-selection
 no single APD voltage adjustment
on board required
E.Garutti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

25. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
APD Homogeneity test
U=405V, M= 200, T=290C
U=410V, M=130 , T=29.50C
12 APD tested
homogeneity 6%
1 APD used to
read out 3-4 tiles
G.Eigen
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

26. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
APDs in the minical
beam
cell 1
cell 2
cell 3
absorber plate
window
tile 5x5 cm2
5.5 cm
Beam
Facing minical from beam side
LAL preamp
Beam positioned in the tile centre with accuracy better than ± 1 cm
Ebeam = 1 – 6 GeV in 1 GeV steps, T = 25°C, Ubias = 415 V
J.Cvach
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

27. Energy resolution with APDs
Good linearity, small systematic deviation in the slope
Fit values PM APD MC
P ± ± 0.2
P2(%) ± ± 0.1
reasons for worse resolution:
noise of APD
lower tile light yield (estimate: 17 ph.e./tile)
tile alignment ( alignment with beam)
calibration
J.Cvach
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

28. Pre-amp Boards (source test)
Charge sensitive Minsk preamp Voltage sensitive Prague preamp
ped
Sr MIP
Sr MIP
ped
LED
LED
- gate adjustment : 90% signal contained
300 ns ns
noise comparison: s(ped)/(MIP-ped)
5.0/85 = /82 = 0.15
MIP resolution: s(MIP)/(MIP-ped)
36.4/85 = /82 = 0.52
G.Eigen,
E.Garutti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

29. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Mechanical structure
K.Gadow
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

30. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Layer structure
adjustable gaps
2*2mm module box part of absorber
2*1mm flatness tolerrance
K.Gadow
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

31. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Moving parts
K.Gadow
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

32. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
RPC prototyping
at IHEP, Protvino:
Design of 1 m2 RPC plane
Top view
Bottom view
no SS cups
1000x1030 mm2 - lateral dimensions
970 x 970 mm2 – glass area
960 x 960 mm2 – sensitive area
Weight ~ 40 kg
96x96 = 9216 pads in total
8 anode RPC PCBs of 240x530 mm2
24x48 = 1152 pads on each
test uniformity
other activities:
optimization
RPC minical
test beam electronics
prepare RPC test in B=5T magnet at DESY
V.Ammosov
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

33. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
RPC optimization
Comparison avalanche vs. streamer mode
pad multiplicity and energy resolution
Geant 3 m= 2
1.4 1
V.Ammosov
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

34. CALICE tile HCAL summary
Transition from table-top R&D to proto-typing
Ongoing minical e testbeam program
successful operation of 108 SiPMs
progress in detector understanding and simulation
ingredients for coming APD tests at hand
Physics prototype is taking shape
granularity defined, explore analogue and semi-digital option
electronics being specified following minical experience
versatile stack mechanics designed (for tiles, RPCs & more)
A hadron calorimeter test beam experimental program with a rich potential ahead
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

35. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
LCcal collaboration
INFN R&D project,
DESY R&D project PRC R&D 00/02
Contributors (Como, LNF, Padova, Trieste): M. Alemi, M.Bettini, S. Bertolucci, E. Borsato, M. Caccia, P.Checchia, C. Fanin, J. Marczewski, S. Miscetti, B. Nadalout, M. Nicoletto, M. Prest, R. Peghin, L. Ramina, E. Vallazza.
thanks to S.Miscetti and A.Bulgheroni for their slides
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

36. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Calorimeter Layout
Total of 45 layers
27 X0
The general details of the calorimeters have been already described in the plenary session of yesterday afternoon by Stefano Miscetti and so let me recall you only few details about the geometrical topics. The calorimeter is made by 45 layers corresponding to about 27 times the radiation length. The sandwich is made by an absorber followed by a scintillator layer coupled with the outside world by wavelength shifting optical fibers. There are also three silicon detectors layers at 2, 6 an 12 radiation length respectively that are the main subject of my talk.
Absorber
Silicon pad detectors
25 x 25 x 0.3 cm3
Scintillator
3 layers
725 Pads ~ 1 x 1 cm2
2, 6 and 12 X0
25 Cells 5 x 5 cm2
A.Bulgheroni
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

37. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Silicon sensors
3rd batch: ~ 18
2nd batch: ~ 15
1st batch: ~ 10
problems with impurities and leakage solved
theoretical expectation SNR ~ 22
mostly FEE
A.Bulgheroni
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

38. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
Beam tests
at Frascati
and CERN
S.Miscetti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

39. Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report
More test beam results
position resolution
beam multiplicity?
e / π separation
longit. and lateral shower shape
S.Miscetti
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

40. Shower reconstruction: Two track separationPH
@ 2X0
In the next few slides I would like to show you the capability of our setup to record 3D images of the shower development within the calorimeter. In this first example the forward strips tracker triggered two particles impinging on the detectors and the two showers produced can be easily separated. Both in the lego as well in the box plot the 3d image on the 1st and on the 2nd layer is presented. The distance between the two hits is roughly a couple of centimetres.
@ 6X0
Tracked particle
Pad
Pad
Ghost tracks
30 GeV e-
A.Bulgheroni
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

41. Granularity considerations
x [cm]
x [cm]
This effect becomes even much more evident looking the behaviour of the residual versus one of the two coordinates (say x). In the first layer, represented on the left, a periodic structure is shown with a period corresponding to the pad size, while this effect completely disappears on the second and on the last layer.
1st layer
2nd layer
x [cm]
x [cm]
Pad size ~ Shower size
0.9 ~ 0.7
can improve resolution with smaller pads
Pad size < Shower size
0.9 < 1.6
A.Bulgheroni
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report

42. LCcal summary and plans
Test beam program successfully completed
Energy and position resolution as expected
Finalizing analysis: shower reconstruction,…
Next:
include in general LC simulation and reconstruction framework
combined test with HCAL
engineering study for full detector
ALCPG SLAC, Jan 7, 2004
Felix Sefkow CALICE Tile HCAL and LCcal ECAL Report