A Study on the Energy and Time Characteristics of $BaF_2$ Scintillation Detector

$BaF_2$ 검출기의 시간과 에너지 특성연구

he scintillation detector having $BaF^2$ crystal with 3.6cm dia${\times}$2.0 cm thick was provided. The energy and timing characteristics were measured and compared with NaI(Tl) scintillation detectors, which widely used in unclear medicine. In order to measure the energy spectrum, the radioactive sources used were $^{22}Na,\;^{54}Mn,\;^{57}Co,\;^{137}Cs$ and the source to detector distance was 7cm. For the timing characteristic, NaI(Tl)(1" ${\times}$ 1")-$BaF^2$ and NaI(Tl)(3" ${\times}$ 3")-$BaF^2$ timing coincidence systems were prepared and the used source was $^{22}Na$ emitting 511keV annihilation photons. For the 511keV gamma-ray emitted from $^{22}Na$, It was revealed that the timing response of the $BaF^2$ detector was faster than NaI(Tl)(1" ${\times}$ 1") and NaI(Tl)(3" ${\times}$ 3") detector used in this experimental investigation. The energy characteristics of the $BaF^2$ detector had a good values for about 500keV energy range.

3.6cm${\times}$2.0cm (지름 ${\times}$ 두께) 크기의 $BaF^2$ 섬광체로 검출기를 제작하여 감마 카메라등 의료용 진단장치에서 센서로 사용되고 있는 NaI(씨)검출기와 방사선 검출특성을 비교하여 보았다. 특정에 사용된 선원은 $^{22}Na,\;^{54}Mn,\;^{57}Co,\;^{137}Cs$의 ${\gamma}$선 방출선원으로 검출기와 선원간의 거리를 7cm로 유지하였다. 시간특성을 분석하기 위하여 511keV의 양전자 방출선원을 사용하여 NaI(Tl)(1" ${\times}$ 1"), NaI(Tl)(3" ${\times}$ 3")순으로 $BaF^2$가 가장 빠르게 나타났으며, $BaF^2$ 검출기의 효율은 500keV에서 가장 높게 측정되었다.