公开(公告)号：JPS55116286A

公开(公告)日：1980-09-06

申请号：JP2344279

申请日：1979-03-02

Applicant: ALOKA CO LTD

Inventor： IKEDA TERUO ,  MATSUBARA SHIYOUHEI

IPC: G01T1/20

Abstract: PURPOSE:To remove detection errors and improve detection precision by forming a thin metal film on the incidence surface of radiations of a scintillator and preventing the incidence of Cherenkov ray onto the scintillator. CONSTITUTION:Intake pipe 10, to which a fluid, such as water, containing radioactive substances, is drawn is provided with plastic scintillator 12 of the radiation detector. The incidence surface of radiations 12a, of scintillator 12 is fitted with thin metal film 14 made of aluminum or silver, and thereby the direct contact between flowing water 16, to be measured, in intake pipe 10, and scintillator 12 is prevented. Consequently, since the Cherenkov ray produced along the range of radiations when high-energy, radiations such as beta rays, are discharged in flowing water 16, is reflected or absorbed by thin metal film 14, the radiations in flowing water 16 are not affected by the Cherenkov ray and can be detected with high precision.