CSNSM SPACIROC S Ahmad P Barrillon S Blin

CSNSM SPACIROC S. Ahmad, P. Barrillon, S. Blin, S. Dagoret, F. Dulucq, C. de La Taille IN 2 P 3 -OMEGA LAL Orsay, France Y. Kawasaki - RIKEN, Japan I. Hirokazu – JAXA, Japan

Overview SPACIROC - Spatial Photomultiplier Array Counting and Integrating Read. Out Chip Ø Ø Ø Readout chip for 64 channels MAPMT Low-power & radiation hardened Co-designed by LAL/JAXA/RIKEN JEM-EUSO : • Extremely High Energy Cosmic Ray(EECR) observer onboard of International Space Station • Observing extensive air shower created by the EECRs EUSO-BALLOON : • A prototype (1 PDM) with electronics and mechanics as close as possible to the one of JEMEUSO • Project CNES + IRAP (Toulouse), APC and LAL supported by the whole JEM-EUSO collaboration • Goal: Launch in 2014 Technological demonstrator (PDM + software) Study of the background Tests of the DAQ and the algorithms (trigger et switch) Detection of an atmospheric shower

JEM–EUSO – Front End ASIC • 64 channels photon counting – Single photon counting 100% trigger efficiency: 1/3 pe – Double pulse resolution : 10 ns • Charges to Time (Q-to-T) converters – Variable trigger pulse width – Pixels charge measurement: 2 p. C – 200 p. C • Data acquisition & Readout to be done within 2. 5 µs (GTU) – Readout Clock : 40 MHz • Radiation hardness • Power budget : <1 m. W/channel

SPACIROC – Status • SPACIROC 1: Technology: AMS 0. 35µm Si. Ge – Chip arrival: Mid-July – Test: September 4. 6 mm – Submitted in March 2010 – Dimensions : 4. 6 mm x 4. 1 mm (19 mm²) – Power supply: 0 -3 V – Naked Die: 1700 chips – Packaging : CQFP 240 (proto) CQFP 160 (Euso-balloon production) • SPACIROC 2: 4. 1 mm Technology: AMS 0. 35µm Si. Ge – Submitted in November 2011 – Chip arrival: February 2012 – Dimensions : 4. 6 mm x 4. 6 mm (21 mm 2) – Power supply: 0 -3 V – Packaging : CQFP 208 (proto) 4

SPACIROC – Slow Control Cell Slow control cell: • 1 Scan DFF + triple Data latch • Majority voter • Bit error detection • Non-destructive data readout • Bigger layout : SEL protection, . . . 16µm Layout Bascule DFF 18µm 32µm Layout Slow Control Cell Spaciroc 114µm 5

SPACIROC – Design & Architecture

SPACIROC – Design & Architecture 1) Photon Counting • 64 channels (pixels) – Fast triggering @100 MHz • 3 different triggers available § Trig_PA: output directly from preamplifier § Trig_FSU : Maroc 3 unipolar fast shaper § Trig_VFS : new optimised fast triggering shaper 2) Q-to-T (based on KI 02 ASIC – JAXA/RIKEN) • 8 channels : each for 8 -pixel sum preamplifier signals • Input dynamic range: 16 p. C – 1600 p. C (MAPMT gain 106) 3) Digital • Photon counting : 64 x 8 -bit counter , 8 serialized outputs • Q-to-T: 8 x 7 -bit counter + 1 x 8 -bit counter , 1 serialized output 7

Photon Counting - Architecture vth SPACIROC 2 R=10 k. W + buffer Input from MAPMT 64 anodes <10 ns Q vth SPACIROC 2 VFS Discri modified

SPACIROC 1: 64 channels Scurves PA 50 f. C Average Threshold = 941. 6 DAC (2. 509 V); RMS = 1. 8 DAC (~2 m. V) FSU 55 f. C Average Threshold =93. 7 DAC ; RMS = 2. 5 DAC LSB VFS 132 f. C Average Threshold =170. 9 DAC ; RMS = 17. 7 DAC LSB

SPACIROC 1: PA Measurement – Ch 32 Gain = 0. 32 m. V/f. C Min Input = 10 f. C 5*Noise = 3. 7 f. C Pedestal = 2. 529 V s=1. 1 m. V Double pulse separation : 36 ns

SPACIROC 1: FSU Measurement – Ch 32 Gain = 0. 944 m. V/f. C Min Input = 15 f. C 5*Noise = 10 f. C Pedestal = 1. 03 V s=1. 99 m. V Double pulse separation : 30 ns

SPACIROC 1: VFS Measurement – Ch 32 Gain = 1. 29 m. V/f. C Min Input = 23 f. C 5*Noise = 4. 35 f. C Double pulse separation : 15 ns

KI(8 -Pixel-Sum) - Architecture Δt

SPACIROC 1: Mapmt measurements Photon Counting KI Test setup: HVPS: K=1000 V & Cockroft Walton MAPMT: Hamamatsu R 11265 -M 64 MAPMT Gain: 1. 106 (1 p. e=0. 16 p. C) DC LED : λ=378 nm Photon Counting pileup: 30 p. e KI range: 6. 4 -198 p. C

SPACIROC 1 issues & bugs – Power consumption: • Due to design bugs, unused component can’t be turned off. – In baseline mode(Trig_FSU), VFS shapers & Trig_PA discri are always ON! Non negligeable useless power dissipation. – PC: Noise problem: • Noise polluting some inputs – PC: Double pulse separation: • Off target for 10 ns. Probably unachievable. – PC : Trig_PA • Expected signal & gain too low compared to simulations – Very sensitive to layout parasitic capacitances – PC: Trig_VFS: • VFS has no turned OFF switch! • Discri has very uneven behavior due to process disparity 15

Comparison SPACIROC 1 SPACIROC 2 • Consumption – Trig_pa: 0. 68 m. W/ch – Trig_fsu: 0. 83 m. W/ch – Trig_vfs: 0. 72 m. W/ch – Trig_pa: 1. 08 m. W/ch – Trig_fsu: 1. 07 m. W/ch – Trig_vfs: 0. 96 m. W/ch • Pedestals – Pa: mean= 2. 522 V ; rms=1 m. V – Fsu: mean= 1. 038 V ; rms=1 m. V – Vfs: mean= 1. 037 V; rms=1 m. V – – Pa: mean= 2. 5 V ; rms=<1 m. V Pa_buff: mean= 1. 72 V rms=<1 m. V Fsu: mean=1. 03 V ; rms=1 m. V Vfs: mean=1. 06 V ; rms=1 m. V FSU noise improved 16

Conclusion SPACIROC: • Good behaviour for first prototype • • Good baseline for Photon Counting SC cells & Digital modules working as expected 4 COB ASICs integration (UFFO-EC board) Will be used for EUSO-Balloon (CQFP 160) UFFO – EC SPACIROC 2: Photon Counting: • Trig FSU (Baseline): • Double pulse separation : 30 ns • Gain = 1 m. V/f. C • Min input = 30 f. C • Trig_PA: • Double pulse separation : 36 ns • Gain = 0. 32 m. V/f. C • Min input = 30 f. C • Trig_VFS: • Double pulse separation : 15 ns • Gain = 1. 3 m. V/f. C • Min input = 60 f. C KI: • 8 -pixel-sum: • Input test: 1. 6 – 160 p. C • Saturation starts at 40 p ü Eliminate all power consumption problems ü Bringing down power consumption by 30% ü Improve double pulse separation ü Replace Trig_VFS discri ü Improve Trig_PA & KI performances 17

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Noise measurements SPACIROC 2 SPACIROC 1 PA: 218µV PA: 239µV PA after buffer: 280µV VFS: 1. 3 m. V VFS: 1. 9 m. V FSU: 1. 47 m. V FSU: 1. 27 m. V 19

SPACIROC – Digital Overview 8 x digital module for Photon. Counting 1 x digital module for KI 9 x Serialized Data Out line Data. Out 8 x 8 -bit counter 8 x 7 -bit counter + 1 x 8 -bit counter Data. Out Power Consumption: • Photon Counting : 0. 105 m. W/ch – 0. 585 mw/ch • KI: 0. 175 m. W/ch – 0. 233 m. W/ch 20

SPACIROC – Slow Control Cell Slow control cell: • 1 Scan DFF + triple Data latch • Majority voter • Bit error detection • Non-destructive data readout • Bigger layout : SEL protection, . . . 16µm Layout Bascule DFF 18µm 32µm Layout Slow Control Cell Spaciroc 114µm 21

Photon Counting – Simulations • Triggers for 80 f. C input charge (1/2 pe for PMT gain =106) Trig_FSU Vth=1. 2 v Δt<10 ns Trig_PA Vth=2. 35 v Δt<5 ns Trig_VFS Vth=1. 2 v Δt<5 ns

Photon Counting – Simulations • Triggers for 160 f. C input charge (1 pe for PMT gain =106) Trig_FSU Vth=1. 2 v Δt<10 ns Trig_PA Vth=2. 35 v Δt<15 ns Trig_VFS Vth=1. 2 v Δt<5 ns

KI 8 -Pixel-Sum – Simulations • Input : 2. 4 p. C – 240 p. C 2. 4 p. C 11 p. C 52 p. C 240 p. C