Background: Gamma-ray spectrometry helps in radiation shielding problems and different applications of radioisotopes. Experimental arrangements including broad beam geometries are widely used. The aim is to investigate and evaluate the γ-ray spectra via attenuation by environmental materials. Materials and Methods: The photo peak to nominated parts in the γ-ray spectra and the attenuation coefficients μb ⁄ρ from broad beam geometries are measured for the materials water, soil, sand and cement at the energies 0.662, 1.25, and 1.332 MeV with a 3" × 3" NaI(Tl) detector. Results and Discussion: The γ-ray spectra vary according to changes in the effective atomic number Zeff of the attenuator, the photon energy and the solid angle. The peak to total ratios are the most sensitive parts to variations in the experimental conditions and overturn in the region 0.663 MeV to 1.332 MeV. This is indicated as inversion trend. The results are discussed in view of Zeff and the experimental conditions. The intensity build-up is larger at the lower energy and larger scattering angles in agreement with Klein-Nishina formula and other results. The buildup factor B is 1 at high γ-energies and small scattering angles. Conclusion: The sensitivity to material characteristics decrease gradually from peak: to total, to Compton valley, to Compton plateau ratios. Rigorous collimation is necessary at small energies. Cement, of the largest Zeff , is characterized by the maximum broad beam mass attenuation coefficients μb ⁄ρ. The obtained results provide information to decide for the suitable experimental set-up based on aim of the work.
목차
ABSTRACT Introduction Materials and Methods Results and Discussion 1. The peak ratios as function of effective atomic numbers 2. The peak ratios as function of energy 3. The mass attenuation coefficients 4. The full width at half maximum and the centroids Conclusions Acknowledgements References
키워드
Gamma ray spectrometryNaI(Tl) detector performanceBuild-up factorPhoto peak ratios
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]