title: Improvements of the standardization of (134)Cs by the critical window setting for 605keV photopeak.
abstract: In the standardization of (134)Cs by the 4πβ-γ coincidence method with a γ-window at 605keV, the satellite components of 563keV and 569keV overlapping the 605keV peak cause a steep slope and non-linearity of the efficiency extrapolation function. By shifting the lower threshold of a γ-window higher, the satellite components are eliminated, and the slope tends to horizontal. Nearly flat efficiency curves were obtained by using a CeBr3 scintillator for detecting γ-photons, as well as a NaI(Tl) scintillator.
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan. Electronic address: a.yunoki@aist.go.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Yunoki
authors.affiliation: National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Yasushi
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, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hino
keywords: (134)Cs; 605keV peak window; Horizontal efficiency functions; Rejection of 593keV and 569keV satellite components; Shifting lower level of the window