Background correction method for portable thyroid dose monitor using gamma-ray spectrometer developed at JAEA in high dose rate environment

Tanimura, Yoshihiko   ; Yoshitomi, Hiroshi   ; Nishino, Sho   ; Takahashi, Masa 

A portable thyroid dose monitoring system has been developed at the Japan Atomic Energy Agency (JAEA) to assess the thyroid equivalent dose for workers and members of the public in a high dose rate environment. The background (B.G.) photon correction is required for an accurate measurement in a high dose rate environment at an early stage after a nuclear accident. We developed the B.G. photon correction method using cylindrical PMMA phantoms.