Space-based Time of Flight (TOF) mass spectrometer for suprathermal-through-energetic ion measurements-development status and prospects

Detection of the composition, energy spectrum, flux and angular distribution of ions in space at the range of tens of keV to several MeV has crucial scientific research and application value. Since the 1980s, the first space-based suprathermal-through-energetic ions detector on the basis of secondary electron emission (SEE) and TOF x E method (energetic TOF mass spectrometer) has been invented, it is still widely applied to a variety of space missions nowadays. This review paper focuses on the technical principles, development history, current situations of energetic TOF mass spectrometers, and research tends in the coming future. On the other hand, influencing factors of mass resolution and anti-interference capability, of that are two key parameters of energetic TOF mass spectrometers are analyzed. Meanwhile, the possibility of improving these two parameters are discussed by applying graphene foil and diamond detector. Nevertheless, China hasn't yet mastered this technique up to the date. On the threshold of Chinese deep space missions, scientific research and application requirements of it have been raised. Regarding to various of future space missions, the Chinese research orientations of energetic TOF mass spectrometers should focus on both uni-directional high resolution and multi-directional multielement modes. At the same time, through introducing new technologies, like graphene foil and diamond detector, furthers the detection performance and adaptability for different space missions. Chinese deep space missions, scientific research and application requirements of it have been raised.