Development of Monoenergetic Photon Source in the Energe Range below 100 keV by the X-ray Fluorescence Method

형광 X 선을 이용한 100 KeV 이하의 에너지 영역에서의 단색 Photon 선원개발에 관한 연구

The development of mono energetic photon sources using $K_{\alpha}$ fluorescence X-ray of pure material was carried out in the energy range below 100 keV. The monoenergetic photons are very useful in the calibration of the radiation measuring instruments and can be produced as the $K_{\alpha}$ fluorescence X-ray by irradiating the bremsstrahlung to the thin pure metal foils called ‘radiators’. In this experiment, several radiators such as $_{47}Ag,\;_{50}Sn,\;_{68}Er,\;_{70}Yb,\;and\;_{82}Pb$ provide the wide monoenergetic photon energy ranging from 20 keV to 80 keV. By the spectrometry with HpGe LEPS, spectral purity factors which measure the monochrometicity for the $K_{\alpha}$ fluorescence X-ray, were determined as $0.64{\sim}0.94$. Dosimetry for the purpose of the determination of the exposure rate with a 600cc thin window ionization chamber, which was calibrated by the standard free-air ionization chamber, was performed. Exposure rates ranging $8.3{\sim}232.5mR/h$ was obtained according to the $K_{\alpha}$ fluorescence X-ray energy for each radiator.

고순도 물질의 $K_{\alpha}$형광 X-선을 이용하여 100 keV 이하에서의 단색 Photon 선원을 개발하였다. 단색 Photon은 방사선 측정기기의 교정에 매우 유용한 것으로 얇은 금속박막의 Radiator에 제동복사선을 조사하여 얻을 수 있다. 본 실험에서는 $_{47}Ag,\;_{50}Sn,\;_{68}Er,\;_{70}Yb,\;_{82}Pb$, 등의 Radiator를 사용하여 20 keV 에서 80 keV의 범위에서 단색 Photon을 얻어내어 고순도 HpGe LEPS로 0.64-0.94에 이르는 단색도를 얻어내었고 600cc 얇은창이온전리함을 사용하여 8.3mR/h 에서 232. 5mR/h에 이르는 선량률을 얻어 내였다.