Hard X-ray observation of solar flares with balloon-borne CdTe spectrometer

这项研究的目的是研制气球携带的碲化镉探测器光谱仪，并在当前太阳活动高峰期观测太阳耀斑硬X射线。2001年夏季完成了具有16个探测器的光谱仪的研制，2001年10月29日在ISAS的三陆气球中心发射了ISAS气球B80-6，并成功地进行了42公里高度的观测。虽然不幸的是没有探测到太阳耀斑，但仪器工作正常，并获得了高质量的背景数据。探测器冷却到-10℃，光谱分辨率为2,503keV，与常规探测器相比是相当好的。该仪器是在日本海中打捞上来的。在成功演示该仪器的性能后，于2002年5月24日进行了第二次飞行实验。在日本夏令时15：30探测到1.2级耀斑。我们相信，这是第一次用CdTe探测器探测到来自天体的硬X射线。16个探测器在整个观测过程中工作正常，屏蔽线的发射线允许我们确认能量增益和分辨率没有下降。耀斑的初始部分也被NASA RHESS卫星观测到，这颗卫星携带了锗探测器和调制准直器，两个结果都很好地吻合。初步分析表明，观测到的光谱与50mK的热谱符合得很好，正在用Nobeama射电日光仪获取的射电数据进行详细的研究。

The purpose of the research is to develop the balloon-borne Cadmium telluride detector spectrometer, and to observe solar flare hard X-rays during the current solar maximum. The development of the spectrometer with 16 detections was completed in the summer of 2001, and the ISAS balloon B80-6 was launched in 2001 October 29 from the Sanriku Balloon Center of ISAS, and the observation at 42 km altitude was successfully carried out. Though solar flares were unfortunately not detected, the instrument worked fine, and high-quality background data was taken. The detector was cooled down to -10 degree C, and the spectral resolution was 2,503 KeV, which was quite good as compared with conventional detectors. The instrument was recovered in the Japan sea. Following the successful demonstration of the instrument performance, the second flight experiment was done in 2002 May 24. An M1.2 flare was detected at 15:30 JST. We believe that this is the first detection of hard X-rays from celestial sources with the CdTe detectors. 16 detectors worked fine throughout the observation, and the emission lines from the shield lead allow us to confirm that there was no degradation in energy gain and resolution. The initial portion of the flare was also observbed with NASA RHESS satellite,which carried germanium detector and modulation collimator, and both results coincided very well. An initial analysis showed that the observed spectra were well fitted by 50 MK thermal spectra, and detailed study is going on with radio data taken with the Nobeyama radio heliograph.