Post on 03-Jan-2016
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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