title: Determination of HPGe peak efficiency for voluminous gamma-ray sources by using an effective solid angle method.
abstract: A code called EXVol has been developed to obtain the absolute peak efficiency for an extended or voluminous γ-ray source. The method is based on the concept of effective solid angles. Several efficiency curves that have been determined semi-empirically for voluminous sources are compared with the experimental values based on certified reference volume sources. To study the geometric and matrix effects, standard γ-ray sources of several media, volumes and shapes were measured using HPGe detectors with three different efficiencies. For the n-type detector of 32% relative efficiency, the relative deviations are less than ±10%; this performance is similar to that of existing programs for similar purposes. The EXVol code is able to calculate the detection efficiency within approximately five minutes or less. Systematic errors based on EXVol input parameters, which are mainly due to the inherent uncertainty in the detector's characteristic dimensions provided by the vendor, are studied to obtain more accurate specifications of the detectors.
authors: Seoul National University, Daehak-dong, Gwanak-gu, Seoul, 151-742 Republic of Korea. Electronic address: kangmy@snu.ac.kr.
authors: M Y
authors: MY
authors: Kang
authors: Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon, 305- 353 Republic of Korea.
authors: G M
authors: GM
authors: Sun
authors: Seoul National University, Daehak-dong, Gwanak-gu, Seoul, 151-742 Republic of Korea; Korea Atomic Energy Research Institute (KAERI), Yuseong, Daejeon, 305- 353 Republic of Korea.
authors: Junhyuck
authors: J
authors: Kim
authors: Seoul National University, Daehak-dong, Gwanak-gu, Seoul, 151-742 Republic of Korea.
authors: H D
authors: HD
authors: Choi
keywords: Attenuation effect; Detection efficiency; Effective solid angle; Voluminous γ-ray source