Background: Absolute light yield measurement based on single photoelectron (SPE) approach remain susceptible to random coincidences between pulsed excitation trigger and the photomultiplier tube (PMT) response. Few studies have reported a quantitative comparison of SPE-based light-yield estimation before and after random-coincidence suppression. To address this, we developed a simplified digitizer-based setup to quantify the light yield using a predefined time window to suppress random-coincidence events. Materials and Methods: SPE spectra were measured by stimulating a PMT with a dim light emitting diode, and the anode signals were recorded using a high-speed digitizer. Event timestamps were used to select correlated signals within the time window. A 2.54 cm×2.54 cm (1˝×1˝) CsI(Tl) scintillator was sequentially coupled to R2228 and R1924A PMTs under identical configurations to verify the consistency of the measured light yield across the two PMTs. Results and Discussion: Suppressing random coincidences eliminated bias in SPE estimation, which otherwise led to an ~11% overestimation in light yield. The CsI(Tl) light yield was determined as 50,000±2,000 photons/MeV and 51,000±2,000 photons/MeV for R2228 and R1924A PMT, respectively. This digitizer-based SPE approach provides a reliable and reproducible method for light yield measurement. Conclusion: We demonstrated a simplified digitizer-based SPE measurement method, applying a time-window filter to reject random coincidence events. This approach enables accurate estimation of the SPE charge and, consequently, a reliable and reproducible light yield evaluation, which have been confirmed with consistent results obtained by the two PMTs.
목차
ABSTRACT Introduction Materials and Methods 1. Experimental Setup 2. Light Yield Measurement Procedure Using Two PMTs Results and Discussion 1. Effect of Random-Coincidence Suppression on SPE-Based Light Yield Estimation 2. Comparison of Measured Light Yield with a Second PMT Conclusion Article Information References
Jihwan Boo [ Department of Energy Systems Engineering, Seoul National University, Seoul, Republic of Korea ]
Nam Young Kim [ epartment of Radiation Oncology, Yonsei Cancer Center, Seoul, Republic of Korea ]
Geehyun Kim [ Department of Energy Systems Engineering, Seoul National University, Seoul, Republic of Korea; Department of Nuclear Engineering, Seoul National University, Seoul, Republic of Korea;Institute of Engineering Research, Seoul National University, Seoul, Republic of Korea ]
Corresponding Author
대한방사선방어학회 [Korean Association For Radiation Protection]
설립연도
1975
분야
자연과학>기타자연과학
소개
회원 상호간의 협조와 친목을 도모함으로써 방사선방어에 관한 제반연구 및 발전에 이바지함을 물론 학술의 국제교류 및 국제학술단체와의 상호협력 증진에 기여함을 목적으로 하며, 이 목적을 달성하기 위하여 다음 각 호의 사업을 한다.
1. 방사선방어에 관한 학술연구발표회 및 강연회 등의 개최
2. 학회지 및 방사선방어에 관한 학술간행물의 발행 및 배포
3. 방사선방어에 관한 학술의 국제교류 및 협력
4. 방사선방어에 관한 국제학술자료의 조사, 수집 및 번역
5. 방사선방어에 관한 조사 및 연구용역
6. 회원의 연구활동을 위한 제반협조
7. 기타 본 학회의 목적 달성에 필요한 사항
간행물
간행물명
방사선방어학회지 [Journal of Radiation Protection and Research]