THE ENERGY DEPENDENCY OF RESPONSE ON PLASTIC SCINTILLATOR TO THE RANGE OF THE PHOTON ENERGY FROM 28 keV_eff TO 98 keV_eff

Abstract

As one of studies of the medical exposure, a series of studies on the measurement of integral dose by plastic scintillator which can be a phantom has been carried out by Murai et al.
In this paper, we studied the energy dependency of plastic scintillator to photon with the energy range from 28 keV_eff to 98 keV_eff.
The scintillator consists to solid organic fluorescent substance in the base of polystyrene with the density of 1.05.
We used three types of scintillators, two cylindrical types (1.96cm∅×3cm and 1.05cm∅×3cm) and a thin plate type (0.3cm×1.8cm×3cm).
The response of sensitivity of the scintillators to the exposure and to the tissue energy absorption was discussed.
We calculated the correction factor g which made the same intrinsic sensitivity to the different type of the scintillators and discused theoretically the relationship between the exposure and the photo-electric current of the measurement.
The response in the energy range from 30 keV to 50 keV measured in the present study was 10% higher than one theoretically calculated.
It was supposed that the intrinsic efficiency of the fluorescence to the absorbed dose was higer in the energy range.