Balloon-borne Hard X-ray Spectrometer for Flare Observations

摘要

We present the design and initial flight results of a balloon-borne hard X-ray detector system for observing high-resolution spectra of solar flares. The instrument is designed to achieve a 3 keV energy resolution over the energy range of 15-120 keV. The instrument uses sixteen 10 x 10 x 0.5 mm cadmium telluride (CdTe) detectors with indium electrodes that act as Schottky barriers. Pre-flight tests confirmed that all detectors exceeded the target 3 keV resolution. The detector system is designed to optimize radiative cooling in order to achieve the operating temperature of 0°C without refrigeration mechanisms. The first flight took place on August 29, 2001 and while no major flares were observed, the instrument operation was verified and a detector temperature of ―3 °C was achieved. The second flight took place on May 24, 1974 and during the 8 hours of level flight at an altitude of 41 km, we succeeded in observing a class M1.1 solar flare.