Fast wake-up trigger for

the TOF detector on NICA-MPD

Lucio F. Rebolledo H.

October 22, 2019

NICA days 2019

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Content

• Detector concept

• Mechanical structure

• Scintillator

• Front-End design

• Conclusions

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NICA MPDFast wake up trigger detector

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Wake up detector

concept

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• The main goal of this inner beam counter detector is to provide a fast wake-up trigger signal for the Time-Of-Flight (TOF) detector of MPD in low multiplicity events.

• 20 square plastic scintillator cells of 20x20x3 mm3 and 1,280 SiPM covering an effective sensitive area of 128,000 mm2.

• Cylinder 60 cm length.

• Inner diameter is 25 cm, outer diameter is 27 cm.

• Required time resolution of 30 ps

• Stripe of sensors

• 16 sensor stripes

• 20 cells per stripe, made of:

• BC422 Scintillator of 20x20x3 mm3

• 4- 3x3mm2 SiPMs

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Figure1: Schematics of MBB detector

Characteristics

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Mechanical Structure

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Mechanical structure

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• Carbon fiber material.

• Skeleton based on CERN ITS design.

• Stripe sensor supported on pyramidal

structure.

• Current work on structural strength.

• 3D printing is under construction for

prototyping

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OPTION 1:

Mechanical structure

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• Carbon fiber material

• Skeleton based “U” form

• Current work on structural strength

• 3D printing is under construction for

prototyping

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OPTION 2:

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Scintillator simulations

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BC-404

•20x20x3 mm3 Scintillators.

•Black squares (scorers) represent

the photosensors.

•Scintillator material BC404.

•Average time resolution of 8 ps.

•Option D) have better photon

detection characteristics.

•Four SiPM’s, equally spaced, will be

used as scorers.

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Proposed Scintillator

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BC422 BC404

RISE TIME (ns) 0.35 0.7

DECAY TIME

(ns)

1.6 1.8

PULSE WIDTH,

FWHM (ns)

1.3 2.2

Front-End design

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Front-endTrigger generation

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Proposed SiPM

• SensL MicroFJ-30035

• Rise Time = 90ps

• (2.5 V Over-voltage)

• FWHM = 1.5ns

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• SensL MicroFJ-30035 (3x3 mm2)

• Breakdown voltage max (Vbr):

24.7V

• Photon Detection Efficiency (PDE):

• 38% Vbr+2.5 V

• 50% Vbr+6.0 V

• Gain: 6.3x1016

• Crosstalk: 8%

SiPM dynamical range

• MicroFJ-30035

• Dynamic range:

• Min: 0.1 mA @ 0.1 nW

• Max: 20 mA @ 50 nW

• Linear: 50 mA @ 100 nW

• Noise level: 1mV

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Sensor stripe

• 20 cells (Scintillator + Photo detectors card)

• Flexible PCB Backplane (minimize material)

• Each Photo detector card with 4 SiPM’s

• fast output connection

• Single “serial array” output

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Serial array

• Expected time resolution enhancement with serial

interconnections

BC422 S10362-33-050C

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Development of High Precision Timing Counter Based on Plastic

Scintillator with SiPM Readout, Paolo W. Cattaneo, Matteo De

Gerone, Flavio Gatti, Member, IEEE, Miki Nishimura, Wataru Ootani,

Massimo Rossella, and Yusuke Uchiyama, IEEE TRANSACTIONS

ON NUCLEAR SCIENCE,VOL.61 , NO.5 , FEBRUARY 2014

Parallel

interconnection

• MICROFC-60035

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Rise Time FWHM

Single SIPM 1 ns 3.2 ns

Two SIPM 3.9 ns 16.8 ns

Triggering circuit

• ADCMP573 Analog

Comparator

• 35 ps typical output rise/fall

• 10 ps deterministic jitter (DJ)

• 200 fs random jitter (RJ)

• 15 ps overdrive and slew rate

dissipation

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TRB3 Platform•TRB platform Trigger and Readout Board

•TDC channels .…………………. 260 (8 ps)

•Max hit rate …………………..… 50 MHz

•Connectivity ……………………. 95 Mbytes

•TRB Network for internal communication

• Direct GbE connection for data and slow control;

no CPU on board, all implemented in FPGA

•Usable for large system as well as stand alone

system: just 48V and GbE are needed to take data

•Can be used as a pure digital board, for example

as a data/trigger hub

•Applications: The time information encoded in the

discriminated detector signal can be measured with

FPGA-TDCs: Leading edge and pulse width

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GbE Connectivity

• TRB3 Designed to be used as

• Stand-alone measurement device

• Part of a complex system

• Different communication solutions

• Based on 3.2 GBps optical links

• Links configured by groups of 4

• Managed by central FPGA

• Transmission of collected data

• Board or Whole system control

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Future work

• Mechanical structure construction for prototyping.

• Tests with the front end for time resolution estimation.

• Time resolution estimation for SiPM’s, Front-end and

Scintillator with the goal to achieve the 30 ps time

resolution.

• Construction of the triggering circuit for a single strip and

full triggering system.

• Front-end interconnection with TRB3 for processing.

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Thank you!

Questions?

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