four channels data acquisition system for silicon photomultipliers mateusz baszczyk, piotr dorosz,...

Four Channels Data Acquisition System for Silicon Photomultipliers

Mateusz Baszczyk, Piotr Dorosz, Sebastian Głąb,Wojciech Kucewicz, Łukasz Mik, Maria Sapor

Department of Electronics,AGH – University of Science and Technology,Al. Mickiewicza 30, 30-059 Krakow, Polande-mail kucewicz@agh.edu.plsglab@agh.edu.pl

Agenda

• Fluorescence;• Silicon Photomultiplier description;• Description of previous measurement system;• Four channel data acquisition system;• Results;• Summary;• Future work.

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Why do we measure fluorescence light intensity?

• Dye-labelled cells can be count by fluorescence light intensity measurement;

• At low concentrations the fluorescence intensity is generally proportional to the concentrations of fluorophore.

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Fluorescein and Bio-Tek filters spectra

fluorescein resorufin

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Optical block

Blue LED

S500LLB4G-H+

485/20nm optical filter

1.5 ml cuvette with fluorescein solution

530/25nm optical filter

5mm diameter optical channel

5mm diameter optical collimator

and fiber cable with 940um core

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Silicon Photomultiplier

The idea appears in the late 90-ties:•„Photon Detection with High Gain Avalanche Photodiode Arrays” S. Vasile, P. Gothoskar, R. Farrell, D. Sdrulla•„Silicon avalanche photodiodes on the base of metal-resistor-semiconductor (MRS) structures” V. Saveliev, V. Golovin 6

Structure

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Current - Voltage Characteristic

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Photodiode Operation Mode

1 photon generates 1 electron-hole pair9

Avalanche Operation Mode

1 photon generates 10-200 electron-hole pairs10

Geiger Operation Mode

1 photon generates 105 - 106 electron-hole pairs11

Typical SiPM Parameters

sensL s1020 Hamamatsu S10362-11-025C

Spectral Range (λ) 400-1100 nm 320-900 nm

Peak Spectral Response (λ) 490 nm 440 nm

Breakdown Voltage (Vbr) 28.6 V ---

Operating Voltage (V) 30.6 V 70.82 V

Microcell Gain 106 2.75 · 105

SPM Pixel Active Area Φ 1 mm Φ 1 mm

Number of Pixels 400 1600

Dark Rate (MHz) 0.42 0.3

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Previous Measurement System For Fluorescence

Picosecond 2600C

generator

Cuvette holderwith

specimen

GPAamplifier

QDC device

PC with Labview

application

excitationfilter

emissionfilter

Agilent33250

generator

trigger signal gate pulses

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First Measurement System For Fluorescence

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Acquisition System

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Acquisition System

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Front-end ASIC

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Front-end ASIC

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Front-end ASIC

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Linearity – high gain

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Linearity – low gain

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Measurement results

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Measurement results

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Measurement results

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Measurement results

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Measurement results

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Measurement results

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Light Intensity

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Light Intensity

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Light Intensity

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Without Coincidence

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Coincidence

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Results of fluorescence light measurements

976.6 [pg/ml]61.05 [pg/ml]

y = -572500 x² + 223.6 x + 6458000 – fluoresceiny = -373800 x² + 170.3 x + 14030000 – resorufin

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Influence of Temperature and Bias

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Dark Current Rate

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Influence of Temperature and Bias

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Conclusions

• We have designed, built and optimized readout system for detection of single photons;

• We have tested readout circuit with light and confirmed that it is linear;

• We can distinguish a dozen or so photons and eliminate thermal generation from measurement data;

• System with silicon photomultiplier has a good sensitivity and can be used to measure fluorescence light intensity for fluorescein concentration from 1ug/ml to about 60pg/ml and resorufin at the level of 1ng/ml up to 1ug/ml.

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Future work

• Stabilization system compensating temperature influence on SiPM gain by varying supply voltage;

• Measurements of fluorescent dyes in microbioreactors.

scanning probe

micro-bioreactor

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Thank you for your attention

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