Study experimental time resolution limits of recent ASICs at Weeroc with different SiPMs and scintillators

Abstract

Medical applications, such as Positron Emission Tomography (PET), and space applications, such as Light Detection and Ranging (LIDAR), are in need of highly specialized ASICs. Weeroc, in collaboration with different partners, is highly involved in developing a new generation of front-end ASICs. In the context of a joined LIDAR project among Weeroc, CNES, and Airbus, Weeroc is working on the development of Liroc, an ASIC for space LIDAR application. Weeroc is also working on advancing ASICs for medical applications with Radioroc under development and intended to be used for PET applications. This study experimentally evaluates the time resolution limits of these ASICs in different configurations, with some of the most recent silicon photomultiplier (SiPM) technologies available on the market, coupled to different scintillation crystals. The best single-photon time resolution (SPTR) was achieved using FBK NUV-HD SiPMs with an FWHM of 90 ps with Liroc and 73 ps with Radioroc. Furthermore, the coincidence time resolution (CTR) of Radioroc was studied with different crystal sizes. Using a large LYSO:Ce,Ca crystal of (3 × 3 × 20 mm3) with Broadcom Near UltraViolet-Metal in Trench (NUV-MT) yields a CTR of 127 ps (FWHM). The best CTR of Radioroc was determined to 83 ps (FWHM) with Broadcom NUV-MT SiPMs coupled to LYSO:Ce,Ca (2 × 2 × 3 mm3)) from Taiwan Applied Crystal (TAC).

Advances in Perovskite Nanocrystals and Nanocomposites for Scintillation Applications

“…Even more recently, Cova et al 193 and Sorokin and co-workers 233 prepared respectively 0.5 and 2 wt% nanocomposites of CsPbBr 3 PNCs by solvent evaporation in PMMA. As shown in Figure 10g,h, they measured a largely ultrafast kinetics with effective scintillation time τ eff ≈ 1.81 ns by soft X-ray excitation and τ eff ≈ 1.4 ns using 238 Pu and 239 Pu radionuclides as alpha particle excitation sources, with both ascribed to the recombination of multi-excitons and charged excitons formed under ionizing radiation, in full agreement with previous results. 63,159 ■ SUMMARY AND OPEN CHALLENGES…”

“…Despite this, HEP detectors share the fundamental principles of TOF-PET scintillators, aiming to combine ultrafast scintillation with high LY for higher time resolution in radiation detection. To date, the lowest CTRs measured with coincidence setups under laboratory conditions at 511 keV are 127 ps for long crystals (3 × 3 × 20 mm 3 ) and 83 ps for small crystals (2 × 2 × 3 mm 3 ) of LYSO:Ce,Ca, while the best commercial TOF-PET scanners have a time resolution of 210 ps, corresponding to a spatial resolution of 30–40 mm along the line of response before any image reconstruction algorithm is applied. As predicted by Lecoq et al, the conventional scintillation mechanism , and the resulting relaxation mechanisms fundamentally limit the achievable time resolution and require a paradigm shift in scintillating materials to pave the way toward 10 ps CTRs that would enable one millimeter diagnostic precision in TOF-PET.…”