{'fraction_non_alphanumeric': 0.029789719626168224, 'fraction_numerical': 0.02453271028037383, 'mean_word_length': 5.206521739130435, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Studies on high energy particle irradiation on Micro Sun Sensors for space applications

High accuracy micro sun sensors (angular resolution better than 0.1°) for space applications are designed and developed using n+/p junction twin triangular silicon photo detectors (planar process) anodically bonded with micro-optics (Corning 7740) having an etch cavity depth of around 100 µm on one side and a 300 µm wide slit patterned on high optical density black chrome on the other side. This sensor configuration determines sun angle by taking differential current outputs from the individual photo-detectors. A normalization technique adopted makes the output independent of flux variations, ambient temperature fluctuations and cosine effect of incidence. Micro sun sensor devices, whose field of view (FOV) is around ±50°, are characterized for sensor performance, which include mainly sensitivity and non-linearity in the linear range of ±25°. Achieved sensitivity and non-linearity of these devices are 140 mV/deg and better than 10% respectively. Further, the effect of gamma and electron irradiation on the sensor performance is studied. Few devices were subjected to gamma radiation (Dose:100 krad), with a rate of 23 rad/s using Co-60 source and found that the degradation in the short circuit current density is around 0.158% and 1.58% respectively. The devices which have undergone electron irradiation of energy 8 MeV with a fluence of 2×1013/cm2, and their post sensor performance evaluation revealed that sun presence, non-linearity and sensitivity are varied. The high energy particle irradiation effect was studied with the help of analytical models and the variation is substantiated quantitatively.