학술논문
Spontaneous fission decay constant of.sup.238U determined by SSNTD method using CR-39 and DAP plates
Document Type
Report
Source
Nuclear Instruments and Methods in Physics Research, A. Dec 15, 2005, Vol. 555 Issue 1-2, p386, 10 p.
Subject
Language
English
ISSN
0168-9002
Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.nima.2005.09.014 Byline: Tetsu Yoshioka (a)(b), Takao Tsuruta (a)(c), Hideki Iwano (b), Tohru Danhara (b) Keywords: Spontaneous fission decay constant; Alpha emission decay constant;.sup.238U; Solid-state nuclear track detector (SSNTD); CR-39; Diallyl phthalate (DAP); Bulk-etching rate; Track-etching rate; Thin source Abstract: This paper presents a simple method for determining the spontaneous fission decay constant (I'.sub.f) of.sup.238U using a combination of CR-39 and diallyl phthalate (DAP) plates as solid-state nuclear track detectors (SSNTD). In this method, thin U-sources were prepared by depositing natural uranium onto 10-cm.sup.2 stainless steel plates. Alpha-particle tracks originated from.sup.238U were detected in the 2I geometry of CR-39 detectors that had been attached to U-sources for 120-426min. Spontaneous fission tracks, on the other hand, were detected using DAP detectors in the same geometry that had been attached to U-sources for 50-238 days. Based on precise measurements of bulk-etching and track-etching rates of the two detectors, track registration efficiencies and critical angles were determined to be 0.740[+ or -]0.072 and 15.1[degrees] for CR-39, and 0.995[+ or -]0.035 and 0.26[degrees] for DAP, respectively. Using these correction values and specific activities (or track densities) measured for each detector, a mean value of I'.sub.f was calculated to be (8.51[+ or -]0.18)x10.sup.-17 yr.sup.-1 in proportion to the alpha emission decay constant of 1.55[+ or -]1.25x10.sup.-10 yr.sup.-1. Author Affiliation: (a) Interdisciplinary Graduate School of Science and Engineering, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan (b) Kyoto Fission-Track Co., Ltd., Minamitajiri-cho 44-4, Omiya, Kita-ku, Kyoto 603-8832, Japan (c) Atomic Energy Research Institute, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan Article History: Received 16 April 2005; Revised 30 August 2005; Accepted 2 September 2005