title: 4πβ(PS)-4πγ(GE) list-mode coincidence counter and its applications.
abstract: We developed a 4πβ-4πγ counter composed of a 4π plastic scintillation detector and a well-type Ge detector, employing digital coincidence counting and data storage in list-mode. In both of the β- and γ-channels, the amplified pulses from a linear amplifier feed the input channel of the digitizer directly via delay circuits. A signal from the peak-hold of each channel is fed to a sliding scale ADC (14bits, 200MHz clock) after peak detection and converted into 13bit digital data, registered along with a time stamp and event channel allowing various data analysis to be implemented offline. When employing multiple gamma window settings, a weighted average of each apparent efficiency might be introduced to improve the efficiency functions. This idea was investigated along with reasonable estimates of the weighing factors, and activity measurements of (59)Fe using this system are presented.
authors.affiliation: Japan Radioisotope Association, 2-28-45, Hon-komagome, Bunkyo, Tokyo 113-8941, Japan. Electronic address: tyamada@jrias.or.jp.
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 1-1-1 Umezono, Ttsukuba, Ibaraki 305-8568, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawada
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 1-1-1 Umezono, Ttsukuba, Ibaraki 305-8568, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
keywords: (59)Fe activity standardization; 4π plastic scintillator; Coincidence counting; Efficiency-extrapolation with multiple window setting; Weighted average of individual efficiencies; Well-type Ge detector