TY - GEN
T1 - Timing Performance of Organic Scintillators for Positron Annihilation Lifetime Spectroscopy
AU - Fang, Ming
AU - Bartholomew, Nathan
AU - Fulvio, Angela DI
N1 - Publisher Copyright:
© 2019 IEEE.
PY - 2019/10
Y1 - 2019/10
N2 - Positron Annihilation Lifetime Spectroscopy (PALS) is a diagnostic method used mostly in material science to investigate solid-state materials' microstructure by measuring the positron lifetime in the material. Typical analog electronics-based PALS experiment is complicated to set up. We report the development of a PALS experimental setup which encompasses organic scintillators and fast digitizers. We interpolated the digital waveform to recover the pulse shape and implemented a constant-fraction discrimination (CFD) timing algorithm to calculate the pulse arrival time. We compared the time resolution performance of three different organic scintillator pairs: BC418, EJ276, and EJ309. We achieved an excellent time resolution of 194.5 1.2 ps using BC418 scintillators, which allows for discrimination ±between different positron lifetime components. We used the optimized experimental setup and used it to determine the lifetimes of positron in two quartz samples. The measured positron lifetimes in quartz are 157 ± 1 ps, 285 ± 1 ps and 1.115± 1 ns, which compares well with the positron annihilation lifetime that characterizes quartz. The system will be used to investigate the nature and density of defects in scintillation crystals.
AB - Positron Annihilation Lifetime Spectroscopy (PALS) is a diagnostic method used mostly in material science to investigate solid-state materials' microstructure by measuring the positron lifetime in the material. Typical analog electronics-based PALS experiment is complicated to set up. We report the development of a PALS experimental setup which encompasses organic scintillators and fast digitizers. We interpolated the digital waveform to recover the pulse shape and implemented a constant-fraction discrimination (CFD) timing algorithm to calculate the pulse arrival time. We compared the time resolution performance of three different organic scintillator pairs: BC418, EJ276, and EJ309. We achieved an excellent time resolution of 194.5 1.2 ps using BC418 scintillators, which allows for discrimination ±between different positron lifetime components. We used the optimized experimental setup and used it to determine the lifetimes of positron in two quartz samples. The measured positron lifetimes in quartz are 157 ± 1 ps, 285 ± 1 ps and 1.115± 1 ns, which compares well with the positron annihilation lifetime that characterizes quartz. The system will be used to investigate the nature and density of defects in scintillation crystals.
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U2 - 10.1109/NSS/MIC42101.2019.9059732
DO - 10.1109/NSS/MIC42101.2019.9059732
M3 - Conference contribution
AN - SCOPUS:85083582306
T3 - 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2019
BT - 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2019
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2019
Y2 - 26 October 2019 through 2 November 2019
ER -