A train detector utilizing radio-isotopes was tentatively manufactured and tested on the Shimogawara-line during the period from February to March in 1963. Since the train speed on the line was below 60 km/h and the test period was too short, further tests were carried out in order to confirm its ability under more practical conditions. A type of ground spot detector, composed of a Radio-Isotope 137 Cs of 25 mCi (milli-curie) laid inside a track, and a stainless steel cathode halogen Geiger tube of 40 mm phi time 400 mm in length fixed on the floor of a car was perfectly operated even when the car passed over the isotope at a speed of 200 km/h. Another type with the isotope 60 Co of 100 alpha Gi (micro-curie) laid inside a track, and with a scintillation radiation detector fixed beneath the floor of a car, was also operated satisfactory at a speed of 200 km/h. As for the train detector of gamma-reflection type, in which both of the isotope 137 Cs of 25 mCi and a Geiger tube are laid inside a track, its performance was good both on narrow gauge lines and on the new Tokaido line. In its life test for a long period, it could detect train passages of about 14,000 times without even one miss or over-counting.

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    TOKYO,   Japan 
  • Authors:
    • Kobayashi, A
    • Nakaya, R
  • Publication Date: 1967-6

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  • Accession Number: 00033157
  • Record Type: Publication
  • Report/Paper Numbers: Quart Rpt
  • Files: TRIS
  • Created Date: Jun 16 1973 12:00AM