Hiroshi Tominaga

Simultaneous Utilization of Neutrons and γ-rays from 252Cf for Measurement of Moisture and Density

A new method for moisture and density determination which is applicable to a large heterogeneous object has been developed, using transmission of fast neutrons and γ-rays from 252Cf, followed by simultaneous detection of these radiations with an organic scintillator having pulse shape discrimination properties. An on-line test of the method in coke of an ironmaking process revealed that the precision of moisture determination was improved several times compared with ordinary neutron moisture gauges.

Effect of spectrum smoothing on peak area determinations

Abstract The effect of a smoothing by digital filter on the determination of spectral peak areas has been studied quantitatively by means of the numerical experiments with a computer. Gaussian shape filters were employed. For the method of Covells partial peak area determination, the least-squares analysis using a standard peak, and the subtraction of polynomial background, statistical and systematic errors are comparatively observed especially in the case of a single small peak on the curved background.

Rapid determination of multi-elements in thin specimens by X-ray spectrometry

Abstract A simple X-ray method of multi-elements determination for thin specimens has been developed in which troublesome preparation of the thin film standards is not required. The X-ray flourescence count rate of each element is calibrated by calculation with both the count rate of the pure element in saturation thickness and the effective mass-absorption coefficient. Corrections for matrix-absorption effects, if necessary, are made by using a pure-element target.

A Digital Pulse-Shape Discriminating Unit for Neutron-Gamma Discrimination with NE213

A fast and stable digital pulse-shape discriminating unit has been developed for the moisture gauge using 252Cf as radiation source. This unit performs digital discrimination between neutrons and gamma-rays in conbination with the liquid scintillator NE213. Modern digital integrated circuits such as flash type A-D converter, a digital divider, a digital comparator and digital controled gated integrators compose the discrimination circuit. Neutrons and gamma-rays events are separately accumulated and applied for automatic stabilization by an integrated single-chip computer. The discriminating charastics are controled not only manually but also under a host computer by way of the GPIB. The performances of available event rates and long term stability are estimated around 100 kcps and 0.5 % respectively The actual circuit configuration and features are discussed in detail.

Determination of fluorine in glasses by cyclic activation analysis using a californium-252 neutron source

A cyclic activation analysis method with a 100 μg252Cf source was developed for the determination of low concentrations of fluorine in glasses containing high concentrations of oxygen. Factors influencing errors in the analysis were investigated quantitatively. The activation cross-section of19F(n, α)16N for252Cf fission neutrons was determined. A brief description is given of the cyclic activation, analysis apparatus, and also the modified optimization of the cyclic operation. The usefulness of the analysis is demonstrated by application to a fluorine volatilization study.

Economic Scale of Utilization of Radiation (I): Industry Comparison between Japan and the U.S.A

Utilization of radiation in the industrial field has been enlarged due to the variety of technologies. In the present paper, the economic scale between the U.S.A. and Japan is compared with selected industrial parameters such as sterilization, semiconductors, radiographic testing (RT) and radial tire production because the very large industrial markets make a whole comparison difficult. The economic scale revealed was about 56b

A simplified procedure in radioisotope dilution method for the mercury inventory of electrolytic chlorine cells

(1

Neutron and Gamma Simultaneous Radiography Using a 2 5 2Cf Isotopic Neutron Source

=121¥) for the U.S.A. and 39b

Apparatus for measuring neutrons and gamma rays

for Japan. The former is large in magnitude by a factor of 1.4. With respect to the relative ratio versus the GDP, the former was 0.7% and 0.9% for the latter. This implied that utilization of radiation in industry is large in magnitude and is expected to be further developed. Regarding electron beam (EB) accelerators, for example, 648 units were installed in North America and 308 units for Japan during the past 29 years. The large number of the former is attributed to use in curing and heat shrinkable tubes (film).

Use of Radioisotope X-Ray Technique in Photographic Dosimetry

Abstract Concerning the radioisotope dilution method for determining the mercury amount in electrolytic cells in the soda industry, a simple and safe procedure with high accuracy was investigated. The procedure developed is based on the scrupulous supply by the Japan Atomic Energy Research Institute of the aliquots of radioactive mercury, i.e. 197 Hg, precisely weighed and the standard reference sample accurately diluted. The intended purpose is achieved with the s.d. in the determination less than 1%