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  • Author or Editor: Shoji Takahashi x
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Abstract  

A socio-economic networking (SEN) of the public funded basic research (PFBR) in the Japan Atomic Energy Research Institute (JAERI) was studied by the bibliometric method combined with the international nuclear database INIS. As PFBR, Material Science (MS) research of JAERI is chosen. The appropriateness of the present bibliometric method is discussed. The authors believe that this method is applicable to studying the socio-economic effect on PFBR. The shortcoming of it is, however, the use of the inevitable usage of biased EBRF (ranked keywords), accompanied with the feeling of unfairness. The authors confirm that the S-matrix has a potential capability to show the quantitative magnitude of co-operation among research institutions avoiding significant bias.

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Abstract  

Three types of high-purity germanium (HPGe) detector systems for low-level radioactivity measurement were constructed in the laboratory near sea level. An anti-Compton system was set up by combining a large volume HPGe (rel. eff. 115%) with a well type NaI(Tl). The detection limit (D.L.) of 137Cs of an ashed oyster sample for the anti-Compton mode of 115% Ge was 0.023 Bq/sample for 8·104 s counting, whereas 0.035 Bq/sample for the normal mode. Under similar measuring conditions, D.L. of 137Cs for a medium volume HPGe (rel. eff. 51%) was 0.042 Bq/sample. A low-background Ge-LEPS (Low Energy Photon Spectrometer) was sufficiently sensitive for low level measurements of 210Pb, 234Th and other low energy gamma-emitters. The detection limit for 210Pb in the sample shape of 60 mm diameter by 2 mm thick was about 0.05 Bq/sample for 5.0·105 s background counting. Using this LEPS, it was found that 210Pb behaves similarly to 7Be in both air and precipitation (snowfall).

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