U-SCOPEの実用化研究と実地試験

原子燃料公社試作1号機を中心として

抄録

Characteristics of the U-Scope in general and some special characteristics of the first trial set of U-Scope No.1 of the Atomic Fuel Corp. are discussed and compared with the prototype constructed in the Univ. of Tokyo. Many improvements in electioiic circuits and mechanical constructions raised to some extent the possibility of finding out very weak radioactive sources in fields. With the prototype of U-Scope special patterns, the Simple and Compound patterns by isolated point sources of radioactive substances, are almost perfectly solved in the previous papers, -Journal of Applied Physics, Japan 27, No. 7 (1958); Proceedings of the II Geneve Conference on the Peaceful Use of Atomic Energy, 3 (1958)-with many illustrations and there a response function η (cf. II. 2. a (1)) performed an excellent role in the explanation of the constitution of these patterns. However, Diffused and Background Patterns by outcrops of granitic rocks, slates and so on, and those by scattered sources, for example, debris of stone fragments and gravel on the road, cannot be explained simply by the response function mentioned above.
To make it possible to solve these complicated problems the following three concepts are introduced:
(1) Substitution of equivalent radioactive surface charge on the outcrop for the actual source
(2) The integral response function Y=∫2α -2α η d ø
(3) The fundamental formulae for the calculation of responsibility of U-Scope for scattered sources of radioactivity.
This way of conducting the analysis is well supported by the outcome of discussions concerning the experiments carried out at Tokai, the Lake Biwa, and at the Bay of Kojima in March of 1959.