1. Readout scheme for the Baby-MIND detector
E. Noah1, A. Blondel1, Y. Favre1, Y. Kudenko2, O. Mineev2, R. Tsenov2
1University of Geneva, Switzerland
2INR, Russia
PD15: Moscow: Troitsk: 6-9 July 2015

2. Outline The Baby-MIND detector Detector module characteristics
Choice of photosensors
Module light yield with CITIROC
Baby MIND Front End Board

3. The Baby-MIND detector
EHN1 extension
Muon spectrometer consisting of magnetized plates of iron interleaved with plastic scintillator detector modules.
Modularity in magnetization design simplifies proposed use at various facililities, downstream of:
WAGASCI at J-PARC (2016 onwards) : anti-nu selection efficiencies > 90%.
LAr (WA105) (2017 onwards): Use of MIND detectors integrated from start of studies or Long Baseline experiments in Europe (LBNO): muon charge ID and momentum, tail catching of hadronic showers. Baby MIND could provide partial acceptance for events in 6×6×6m3 of WA105 LAr.
J-PARC
Baby-MIND
positioned here
Wagasci
Side MRDs

4. Optical readout of plastic scintillator planes
PMT
PMT-based: MICE-EMR installed at RAL Sep. 2013
SiPM-based: AIDA Baby MIND
Implemented for several thousand channels first at T2K ND280
SiPM

5. Plastic scintillator bars:
Detector modules
Poster: The design, construction and testing of TASD: A. Mefodiev et al.
Plastic scintillator bars:
Extruded scintillator slabs produced at Uniplast company, Vladimir, RU:
polysterene-based, 1.5% paraterphenyl (PTP) and 0.01% POPOP.
Slabs etched with chemical agent (Uniplast) to create a mm layer that acts as a diffusive layer
Custom optical connectors (INR design for AIDA)
Kuraray Y11 WLS fiber in 2mm deep groove
Dimensions: 900 x 10 x 7 mm3
Module characteristics :
2 planes, X/Y
Each plane: 84 plastic scintillator bars
1st prototype Nov. 2014
Photosensor connector: INR design
Optical cement light transmission
WLS fiber: St. Gobain & Kuraray Y11
Light yield measured for > 9000 bars

6. Photosensors Options tested: Selection: MPPC/ASD40/KETEK/SensL
Several MPPC variants
Selection:
Hamamatsu MPPC S C
1 × 1 mm2
25 mm cell size
3000 delivered by 6 Mar. 2015
MPPC test data by Hamamatsu
Vop [V]
25oC
Dark cnts [kHz]
thres.: 0.5 p.e.
WLS fiber and MPPC alignment

7. Calibration & digitization
Lab.
Cosmic m, radiosource 6
SiPM 5
Individual bar characterization: n bars 4 3
Module QA: n/m bars 2
Charged particle 1
Beamline
Scintillation
Light trapping efficiency in WLS fiber
Light attenuation in WLS fiber
Optical connector insertion loss
SiPM response
Electronics response
Cosmic m?
m,p,e,p

8. Bar light yield test: post module assembly
Channel configuration: channels under test ch0-15
ch15
ch7
ch23
ch0
ch8
ch16
ch27
ch24
ch31
ch28
Setup in dark room
25oC

9. Module characterisation with CITIROC evaluation board
ADC
[12-bit]
FPGA
MPPC
x32
Plastic
Scint. bars
x32
Delay
usb
LabVIEW

10. CITIROC shaper time constant
OR32/Hold delay
40 ns
50 ns
60 ns

11. Regime: Dynamic range (HG): > 1600 p.e. with LG.
Varying Pre-amp Feedback capacitance
Feedback capa.
= 1 [arb.]
48.2 ADC/p.e.
Regime:
high enough gain to resolve indivual p.e. peaks whilst avoiding saturation
Dynamic range (HG):
12-bit ADC
Baseline ~950
19.3 ADC/p.e.
160 p.e.
> 1600 p.e. with LG.
Feedback capa.
= 4 [arb.]
32.2 ADC/p.e.
Feedback capa.
= 6 [arb.]
25.6 ADC/p.e.
Feedback capa.
= 8 [arb.]
19.3 ADC/p.e.

12. Light yield: sum of both ends of bar
Bar pos.
[#]
Bar ID
Bar INR
[p.e.]
Module 1
6421
124.4
145.2 2
6411
125.4
155.4 3
6422
119.0
138.7 4
6410
134.6
153.6 5
6414
112.9
142.5 6
6409
118.6
136.6 7
6412
129.4
146.2 8
6413
183

13. “Optical” crosstalk: light yield in adjacent bars
ch15
ch7
ch23
ch0
ch8
L.y. cuts:
Ch3>70p.e.
Ch11>70p.e.
Ch19>70p.e.
ch16
ch27
ch24
ch31
ch28

14. “Optical” crosstalk: l.y. sum of both ends collected in adjacent bars

15. Baby MIND electronics chain

16. Baby MIND FEB FEB characteristics :
96 SiPM channels (mini coax. connectors), 84 used for Baby MIND
3 CITIROC ASICs (32 ch charge ampl., trigs, ext. common HV + independent 0/4V)
12-bits 8-ch ADC 40Ms/s/ch
2 x 6Gb/s transceiver (800Mb/s for Baby MIND)
USB3.0 (5Gb/s) µC for lab, calib. & maintenance
LV & HV power supplies
Altera ARIA 5 FPGA (mid-range), firmware :
84 ch. Timing meas (2/2.5ns resolution)
Charge meas. (from 12-bits ADC)
Baseline computation (filtering)
USB3.0 gateway
Gigabit protocol for readout (exp.)
Baby MIND FEB (Photo by Y. Favre 12 March 2015)
PCB:
8 layers
120µm space/width lines
Impedance & length control (TDC)
Schedule:
First prototype FEB 11 March 2015
Firmware development ongoing
~ 30 Baby MIND FEBs Dec. 2015

17. FEB firmware architecture

18. Baby MIND spectrometer modules:
Summary
Baby MIND spectrometer modules:
all 9400 bars measured for light yield at INR before assembly into modules at UniGe
choice of photosensor made, 3000 MPPC S C delivered by March 2015 with good QA data
Test procedure for module characterization
Electronics:
CITIROC tested with evaluation board from Omega Microelectronics (8-bit DAC for Vop, Pre-amp gain, shaper, discriminator, Or32 Mask)
FEB produced (3 CITIROC/FEB)
Firmware architecture done (documented)
Firmware implementation ongoing

19. thanks to
F. Cadoux, M. Dementjoz, S. Fedotov, A. Khotyantsev, A. Kleimenova, A. Mefodiev, L. Nicola, T. Ovsiannikova, N. Yershov to you for your attention

20. Back-up

21. Tested SiPM parameters at INR

22. Tested SiPM performance at INR

23. Tests of 1 x 1 mm2 MPPC at INR “New” MPPC 50mm cell size
same optical cross-talk and afterpulsing for both, sensitive area difference:
1x1 mm2 = 16.4 p.e.
1.3x1.3 mm2 = 17.2 p.e.

24. Hamamatsu options tested

25. Hamamatsu options vs readout

26. Hamamatsu MPPC S12571-025C spec.

27. Hamamatsu MPPC S12571-025C: gain and PDE