Energy and Primary Mass Determination Using Multiple Solid State Detectors

Primary mass identification of energetic ions and neutrals (10 < E < 1000 keV) has been investigated for spacecraft applications using multiple solid state detectors of various dead zone thicknesses. The ion identification is based on comparison of the flux and energy spectrum measured between detectors using an iterative procedure. This technique permits simultaneous mass and energy determination with large geometrical factors (e.g. 10 cm2 ster) and at low cost. However, certain limitations exist related to statistics and resolution. Energy loss curves (dE/dx) are presented and compared to experimental data. Using this technique ion spectra were measured during the launch of Nike Apache 14.542 into a ring current precipitation event at middle latitudes and the results are found to agree well with theoretical energy loss curves. A spacecraft ion mass spectrometer design using multiple solid state detectors in a 7K Gauss magnetic field is presented which features high mass and energy resolution.