Characterization of imperfections in scintillator crystals using gamma-ray induced positron annihilation lifetime spectroscopy

Kitaura, Mamoru; Taira, Yoshitaka; Watanabe, Shinta

doi:10.1016/j.omx.2022.100156

Cited by 3 publications

(2 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The good footwork unique to small-scale facilities has promoted the development of quantum beams like optical vortices, pulsed-gamma ray using SR light, and so on by accelerator researchers, which is highly unique even from an international perspective [39][40][41][42][43][44][45][46][47]. In the future, it would be interesting to develop the SR facility as a giant quantum simulator for controlling quantum states and measuring quantum information using multiple undulator light sources.…”

Section: History Of Uvsormentioning

confidence: 99%

Prospects required for future light-source facilities: a case of UVSOR synchrotron facility

et al. 2023

View full text Add to dashboard Cite

The synchrotron radiation facility is a large-scale public infrastructure that provides advanced light sources and is used for various academic research and application development. For 40 years, UVSOR synchrotron facility has been leading the field as a facility that has developed and utilized cutting-edge light source technology in the low-photon-energy regime. The next UVSOR synchrotron facility aims to establish a center for quantum photon science research through the development of unexplored evaluation technologies by advanced use of light sources and a measurement and analysis support environment. The science of molecular dynamics with spatio-temporal hierarchies for evaluating and controlling the functions of complex systems will be pioneered. The assets of the UVSOR synchrotron radiation facility and the fundamental measurement and analysis technology of the Institute for Molecular Science will be inherited effectively and progressively. We plan to contribute to strengthening the foundation of many fundamental disciplines to create next-generation industrial applications.

show abstract

Section: History Of Uvsormentioning

confidence: 99%

Prospects required for future light-source facilities: a case of UVSOR synchrotron facility

et al. 2023

View full text Add to dashboard Cite

show abstract

“…In a two-dimensional angular correlation device, arrays composed of multiple NaI (TI) scintillators are used. Lifetime spectrum measurements performed with a plastic scintillator or BaF 2 scintillator achieve a very good timing effect because they have very short decay times [2]. Doppler broadening spectrum measurements with Ge (Li) or HpGe semiconductor detectors achieve 511 keV annihilation radiation energy near the 1.0-1.5 keV energy peak broadening because these devices have far better energy resolution than NaI (TI) scintillators [3].…”

Section: Introductionmentioning

confidence: 99%

Calculation method based on a BGO+SiPM detector for ^13N gas coincidence detection efficiency

Chen

et al. 2023

J. Inst.

View full text Add to dashboard Cite

To reduce the lower detection limit of 13N gas, we design a γ-γ coincidence measuring instrument including two detectors, a sampling vessel, and a summation and coincidence circuit in this work. The detector uses a 13 cm × 5 cm oversized Bi4Ge3O12 (BGO) scintillator and 172 silicon photomultiplier (SiPM) tubes, which greatly reduce the instrument size while improving the coincidence detection efficiency. The 13N gas coincidence detection efficiency is improved by installing a multilayer metal absorber plate inside the cylindrical sampling vessel. Due to the short half-life of 13N gas, it cannot be stored for a long time; additionally, it is difficult to obtain. It is not possible to directly scale the coincidence detection efficiency of this instrument using a 13N gas source with known activity in engineering projects. Based on the spatial distribution of the relative efficiency of the sampling vessel and the absolute efficiency of the reference point, we use a combination of 22Na solid point source experiments and Monte Carlo simulations to calculate the coincidence detection efficiency of this instrument for 13N gas in this work; the coincidence detection efficiency is approximately 4%, which meets the engineering design requirements.

show abstract

Development of gamma-ray-induced positron age–momentum correlation measurement

Taira

Yamamoto

Sugita

et al. 2022

Review of Scientific Instruments

View full text Add to dashboard Cite

In conventional positron annihilation spectroscopy using radioisotopes, source contributions are unavoidable since positrons annihilate in the material covering the radioisotopes. Part of the positrons annihilate within the radioisotopes even when radioisotopes are deposited directly on a sample. Gamma-ray-induced positron annihilation spectroscopy makes it possible to measure only the spectra of a sample without source contributions since positrons are directly generated inside the sample from the gamma rays by pair production and annihilate inside the same sample. In this study, a new positron age–momentum correlation measurement system using ultrashort pulsed gamma rays is developed. The gamma rays with an energy of 6.6 MeV are generated by the inverse Thomson scattering of laser photons by high-energy electrons and are irradiated to the sample. The laser pulse can fully control the timing of gamma-ray generation. This characteristic and the use of a digital oscilloscope with a 12-bit vertical resolution enable us to develop a simple measurement system. Time-resolved momentum distributions for stainless steel with no defects and deformed interstitial free steel show the explicit differences reflecting the type of defect; for BaF2 single crystals, the results have been interpreted by considering the formation of positronium.

show abstract

Characterization of imperfections in scintillator crystals using gamma-ray induced positron annihilation lifetime spectroscopy

Cited by 3 publications

References 47 publications

Prospects required for future light-source facilities: a case of UVSOR synchrotron facility

Prospects required for future light-source facilities: a case of UVSOR synchrotron facility

Calculation method based on a BGO+SiPM detector for ^13N gas coincidence detection efficiency

Development of gamma-ray-induced positron age–momentum correlation measurement

Contact Info

Product

Resources

About