巻号一覧
16 巻 (1981)
- 4 号 p. 277-
- 3 号 p. 201-
- 2 号 p. 83-
- 1 号 p. 1-
16 巻, 2 号
選択された号の論文の10件中1～10を表示しています
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中島 敬行, 古田 定昭1981 年 16 巻 2 号 p. 83-97
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーIn order to measure the energy spectra due to environmental gamma-rays and to assess doses due to gamma-rays and to cosmic-rays at sea level, a 3″φ spherical plastic scintillation detector was constructed. The calibration between energy and pulse-height due to photon was made detecting the Compton scattering electrons and photons. The 30×30 response matrix of the detection system was constituted for gamma-rays to evaluate energy spectra due to environmental gamma-rays. Monte Carlo programme was used to compute a set of standard pulse-height distributions due to gamma-rays with monochromatic energy. The environmental gamma-ray spectra analyzed using the response matrix was deformed slightly to higher energy sides. Therefore, the dose rate derived from the spectrum was higher by approximate 10%.
Based on the cosmic-ray flux density, a simple method was discussed to evaluate dose equivalent to exposure rate. Cosmic ray flux density is a quantity that is definitely measurable. Stopping powers of μ-meson and electron were averaged on their spectra estimated at sea level. And then the stopping powers were averaged again according to the respective flux density at sea level. The cosmic ray doses equivalent to exposure rate measured outdoor and indoor were comparatively coincided those estimated by other method. The present simple method was found effective especially in estimation of cosmic-ray dose as monitoring work.抄録全体を表示PDF形式でダウンロード (1573K) -
天野 光, 笠井 篤1981 年 16 巻 2 号 p. 99-103
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーBeryllium-7, cosmic ray produced radioactivity, its monthly average concentration in the lower atmosphere and monthly fallout rate were measured in Tokai, Japan. Then, the monthly variations were compared with those of fission products due to nuclear detonations in the atmosphere. The concentration of 7Be in the lower atmosphere ranged from 0.5×10-1pCi/m3 to 2.5×10-1pCi/m3 in Tokai between the observed period, 1975-1977. The fallout rate of 7Be vibrated widely, its range was from the detection limits to 1.2×104pCi/m2. The monthly variations were not always the same with variations of the fission products. Fallout rate of 7Be depended on the rain strongly.
The concentration of 7Be in the rain was measured, too. Then the range was from 9.2 pCi/l to 1.9×102pCi/l between the observed period 1976. 9-1977. 2.抄録全体を表示PDF形式でダウンロード (582K) -
蘇 献章, 蔡 昭明1981 年 16 巻 2 号 p. 105-109
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーRegistration of α-tracks and fast-neutron-induced recoil tracks by the electrochemical etching (ECE) technique as applied to sensitive Lexan polycarbonate foils has provided a simple, sensitive, and inexpensive means of neutron dosimetry. The application of this ECE technique to the amplification of alpha particle tracks in 250-μm-thick Lexan polycarbonate foils was studied here. The intention is to produce permanently stable tracks which are suitable for α particle detection.
The detection efficiency for α particles as a function of etching time under conditions of 1, 000V, 2kHZ, 22°C, and 50% alcoholic KOH solution was shown. It seems that the track registration efficiency is not proportional to the specific ionization in the polycarbonate foil. From the study on the relative frequency of track diameter distribution it is evident that the track diameter depends only on the latent track position in the foil.抄録全体を表示PDF形式でダウンロード (2329K) -
福井 正美1981 年 16 巻 2 号 p. 111-121
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーA number of models of sorption have been used to describe the transport of chemicals through porous media, some representing an equilibrium between the concentration in adsorbed and in solution phase, and some modeling the kinetics to equlibrium.
Though analytical solutions for the material balance equation were obtained in linear isotherm systems, some concentration distributions were not expected by them under practical soil conditions. In this study, the finite difference method using quasilinearization technique was applied to solve the palabolic partial differential equation which describes the transport of solutes, and contains the nonlinear sorption equations.
These models well describe the shapes of the concentration curves rather than the linear models. So, this numerical approximation appears to have broad and practical utility so as to choose the sorption model of radionuclides to soils and/or to predict the contamination spread accurately in case of the accidental release of radionuclides from a repository into a subsurface aquifaer.抄録全体を表示PDF形式でダウンロード (1210K) -
下 道国, 小川 逸男, 尾川 哲男1981 年 16 巻 2 号 p. 123-133
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーThe air concentration of radon short-lived daughter products (Rn-Dts) differs considerably with location and time. This fact is the reason why the estimation of radiation doses to the respiratory system due to Rn-Dts is difficult from the viewpoint of population doses. Hence, we attempted to define an equiconcentration area with a uniform air concentration of Rn-Dts. Many points at which we measured Rn-Dts concentration were selected at the inner area within a 30km radius around the reference pointof the campus. Measurements of Rn-Dts concentrations have been carried out between the reference point and a point for comparison at same time. Similar measurements have been continued successively. The values observed at every point within the 15km radius around the reference point were consistent with that observed at the reference point with an error of 20 percent of the concentration ratio of Rn-Dts and above the correlation coefficient of 0.80. The values obtained at every point, excerpt for two points on the granits zone and 100m above sea level, agreed with that observed atthe reference point within an error of 50 percent of concentration ratio of Rn-Dts and over the correlation coefficient of 0.45.抄録全体を表示PDF形式でダウンロード (1145K) -
バックグラウンド推定法の原理松田 秀晴, 古川 滋子, 上西 時司, 湊 進1981 年 16 巻 2 号 p. 135-139
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーA new method for evaluating weak leakage gamma-ray dose without background measurement was developed. A pulse height distribution obtained by a 3″φ×3″ NaI (Tl) scintillation spectrometer was converted to the incident gamma-ray energy spectrum by the response matrix method. Weak leakage gamma-ray dose rate with background was directly calculated from the energy spectrum. On the other background exposure rate was evaluated from natural activity concentrations deduced by the peak of 40K, 214Bi (U) and 208Tl (Th) in the energy spectrum. The results of measurement showed that this method was practically satisfiable technique.抄録全体を表示PDF形式でダウンロード (602K) -
熊澤 蕃, 伊藤 精, 西 健雄, 沼宮内 弼雄1981 年 16 巻 2 号 p. 141-144
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (424K) -
木村 捷二郎, 佐々木 将博, 筒井 天尊1981 年 16 巻 2 号 p. 145-149
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (601K) -
北原 義久, 成田 脩, 篠原 邦彦, 浅野 智宏1981 年 16 巻 2 号 p. 151-163
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (1946K) -
シリカゲルに吸着されたトリチウムの簡易測定法新野 二男1981 年 16 巻 2 号 p. 165-167
発行日: 1981年
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (294K)
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