1 / 20

Development of SiPM-Based PET System Demonstrator: Advances in 4x4 and 8x8 Matrices

This study details the progress in developing a SiPM-based PET system demonstrator at the University of Pisa and INFN. We present new results from 4x4 SiPM matrices and initial results from 8x8 matrices, highlighting improvements in readout systems using the MAROC2 and VA-TA ASICs. The framework includes front-end ASIC capabilities for better trigger and digitization performance. Extensive characterization of SiPM matrices shows excellent uniformity and promising photon detection efficiency. The results aim to inform future advancements in PET technology.

ryo
Télécharger la présentation

Development of SiPM-Based PET System Demonstrator: Advances in 4x4 and 8x8 Matrices

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pisa activities II part Maria GiuseppinaBisogni Universita’ di Pisa and INFN Sezionedi Pisa

  2. Outline • SiPM 4x4 matrices new results • 8x8 matrices first results • New DAQ system

  3. SiPM Matrices and arrays readout • Framework: development of a SiPM based PET system demonstrator based on • Matrices of SiPM pixels (FBK-irst) • Final target  8 x 8 ; Currently available  4 x 4 • Front-End ASIC with trigger and digitization capabilities (Politecnico di Bari) • Final target  32 channel ; Currently available  8 channel • Meanwhile, readout of SiPM matrices employing different systems: • Readout system from LAL-Orsay (MAROC2 ASIC). • Readout system for PET applications employing the VA-TA ASICs from gamma medica-IDEAS (SiPM0)

  4. 1 mm 4 mm SiPM 4x4 matrices from FBK-irst Composed of 16 (4x4) pixel elements in a common substrate 1 mm pixels in 1.06 mm pitch • Structure: n+-p-p -p+ optimized for blue light: Shallow n+ layer + specific antireflective coating. • Each pixel: 625 (25 x 25) microcells, 40mm x 40mm size. • Polysilicon quenching resistor. • Fill factor 44%. Bonded SiPM array SiPM array SiPM pixel

  5. 4x4 Matrices Characterization • Full characterization of first run performed at LAL, Orsay. • Excellent uniformity. • Breakdown voltage 30.5V ; svar= 0.5% • Gain @33V 1.46x106; svar= 4% • Mean dark rate @33V (DV=2.5V): 1.98 MHz • PDE @ 33V 8-10% from 420 to 680 nm wavelength. Expected PDE >15% for the results shown here (run II and DV=4V) N. Dinu et al. Pixel 2008 workshop, Fermilab, September 2008.

  6. Readout: MAROC2 ASIC • Developed at Laboratoire de l'Accelerateur Lineaire, Orsay. • 64 channels • low noise preamplifier w variable gain (6 bits) • Slow shaper (~20-150 ns, adjustable) • Fast shaper (15 ns) + 3 discriminators =>Trigger signal. • Designed for MAPMT – not optimized for SiPMs, but allows us to make the tests satisfactorily.

  7. Readout: Test board • Altera FPGA • USB Port • ADC on the board. • ASIC calibration input. • LabVIEW software for data acquisition

  8. Experimental Results • Results with pixilated crystals • Results matrix + crystal array • Results with continuous crystals • Results matrix + slab • Position determination • G. Llosa et al., IEEE- MIC2008, paper M02-1 • Submitted to TNS on march 23

  9. Position determination • Coincidence with a 2nd detector: 1 mm x 1 mm x 1 mm crystal coupled to a SiPM • Source close to the matrix, far from 2nd detector • Move together source and 2nd detector. 2nd detector 30 mm 2 mm

  10. Position determination setup

  11. Position determination- crystal array + 1 mm + 2 mm Hitmap for different source positions with crystal array + 0.5 mm + 1.5 mm

  12. Position determination-black slab • Matrix + LYSO crystal 4mmx4mmx5mm painted black • Center of gravity algorithm – problems at the edges • Difficulties due to the small size of the devices

  13. Position determination-black slab • Hitmap • Algoritmo “center of gravity”

  14. Edge distortions

  15. Statistics • 12 wafers. Alcune di questi hanno un leakage alto, sintomo di dark count alto. • Ogni fetta contiene 12 matrici con read-out da un lato e 4 matrici con read-out da entrambe i lati • matrici con read-out da un lato: • 32 matrici con tutti elementi funzionanti • 22 con 1 elemento su 64 non funzionante • 8 con 2 elementi su 64 non funzionanti • matrici con read-out da 2 lati: • 10 matrici con tutti elementi funzionanti • 8 con 1 elemento su 64 non funzionante • 3 con 2 elementi su 64 non funzionanti • Wafers 9,10,11 a Perugia per IV test dopo il taglio • Wafers 12, 14, 15 a Pisa • Wafer 14: 16 linear array 1x8

  16. Wafer 12 C4 all chns working

  17. Matrix 8x8 first Na22 coincidence spectrum

  18. DASIPM3 new set-up Designer A. Soldani Servizio Progettazione Meccanica INFN Pisa

  19. New DAQ System B side 64 chns A side 64 chns Conceptual Design from Ing. Giovanni Franchi from AGE Scientific

More Related