Lab1& Lab2: Hands-on SiPMwith the

CAEN Silicon Photomultiplier Kit:a flexible and modular system for

sensor testing & education

M. Caccia & R. SantoroUniversita’ dell’Insubria @ Como

massimo.caccia@uninsubria.itromualdo.santro@uninsubria.it

INFIERI, July 14th – 25th , 2014

Si-Photon Multiplayer

SiPM is a High density (up to 104/mm2 ) matrix of diodes with a common output, working in Geiger-Müller regime

Common bias is applied to all cells (few % over breakdown voltage)

Each cell has its own quenching resistor (from 100kΩto several MΩ)

When a cell is fired an avalanche starts with a multiplicative factor of about 105-106

The output is a fast signal (trise~ ns; tfall ~ 50 ns) sum of signals produced by individual cells

SiPM works as an analog photon detector

typical Signal from SiPM

Si-Photon Multiplayer:

Why they are so appealing?

high detection efficiency (single photo-electron discrimination)

compactness and robustness low operating voltage and power

consumption low cost withstanding to magnetic field

that’s the main reasons why they start to be widely used in different fields i.e. medical applications, homeland security, spectrometry, high energy physics …

RAPSODI Main objectives:SiPM development and optimization for three different applications: Dosimetry

in Mammography, Radon Monitoring, illicit traffic of radioactive material

2006–

2008

RAPSODI. Prototypes of an easy-to-use, flexible, modular kit for the characterization of SiPM

2009Licensing of the background knowledge to CAEN.

First announcement at the IEEE NSS, Orlando.

2010Establishment of a Joint Development Laboratory to finalize the

development of the kit and its applications. Kit on the move at IEEE NSS at Knoxville

2011 Early development of the educational project

2013 First Educational Applications completed

…and educational

the project was born as a by-product of RAPSODI (RAdiation Protection with Silicon Optoelectronic Devices and Instruments): FP6 founded project

An overview of the kit

The building blocks of the kit:

1. The SP5600: Power Supply and amplification Unit (with a bit of logic on board)

2 channel mother & daughter architecture

every channel features:

Independent biasing (max 120 V, 100 μA) 2 stage amplification [500 MHz bandwidth,

tunable gain up to ~ 50 db] discriminator ( ±2V)

active feedback control on Vbias for Gain stabilization (granularity: 0.1 oC)

coincidence logic

The building blocks of the kit:

1. The SP5600: Power Supply and amplification Unit (with a bit of logic on board)

2 channel mother & daughter architecture

every channel features:

Independent biasing (max 120 V, 100 μA) 2 stage amplification [500 MHz bandwidth,

tunable gain up to ~ 50 db] discriminator ( ±2V)

active feedback control on Vbias for Gain stabilization (granularity: 0.1 oC)

coincidence logic

The 720 desktop Digitizer

Featuring the Digital Pulse processor

The building blocks of the kit:

2. Signal recording: Digitization

Main characteristics

2 channels stand-alone 250 Ms/s, 12 bits (up to 5 Gs/s) ±1V input range

Reference LED:

λpeak = 420 nm peak current 120 mA luminous intensity = 9500 mcd

@20mA 30o half-view angle

τ ~ 5 ns

Single Photon Timing spectrum

The building blocks of the kit:

3. The FAST LED, an essential tool for sensor testing

6 x 6 mm2 SiPM 1 CsI crystal, 6 x 6 x 30 mm3

The building blocks of the kit:

4. The Gamma Ray Spectrometer

137Cs (662 KeV) with ≈ 10% FWHM

> 0.5 ph

> 1.5 ph

> 2.5 ph

0.5 ph

1.5 ph

2.5 ph

Th

resh

old

scan

150 x 150 x 10 mm3 plastic scintillator tile wls fiber => 2 channels in coincidence

Single channel Dark Count Rate

Count rate in coincidence

The building blocks of the kit:

5. The Cosmic (ray) Tile

The building blocks of the kit:

6. Dedicated LabView Control Software

The Educational project

The SiPM kit offers the possibility to perform a series of experiments well suited to undergraduates (& possibly beyond):

1. Hands-on photon counting statistics (it can be introduced and performed at different levels, from an introduction to stochastic processes for [bright] high school students to advanced data analysis aimed for doctoral students) [arXiv:1308.3622]

2. γspectrometry (with a series of classical small experiments)

3. A simple method for measuring after-pulsing [arXiv:1406.6278]

4. Measuring the maximum counting frequency in a SiPM based system for Poissonian distributed events [note in preparation]

5. Hands-on Poissonian processes (counting statistics & time domain) [next in line]

More experiments in the pipeline:

6. Cosmic ray experiments [proof of concept]

7. Introduction to PET and TOF-PET [tbc]

8. Exemplary illustration of NonDestructiveTesting [requires an X-ray tube]

… and the best is possibly yet to come....