High-Energy Proton Telescope for ORBITALS
The High-Energy Proton Telescope (HEPT) is being developed for detecting and measuring the energy and distribution of protons in the magnetosphere, one of the ten detectors (6 of them Canadian designs) on the Canadian small satellite mission proposal ORBITALS. The HEPT detector project is headed by Prof. Robert Fedosejevs and Prof. Ying Y. Tsui from the Department of Electrical and Computer Engineering and the design and testing of the detector is being directed by Dr. Sean Kirkwood.
The proposed HEPT detector will consist of 2 telescopes heads capable of measuring protons with an energy range of 6 – 120 MeV and electrons with an energy range of 2 – 20 MeV. The first detector, the low energy head, will measure protons with energies between 6 MeV and 26 MeV and the high energy head will measure protons with energies between 26 MeV and 120 MeV and the full electron range. The detectors are a linear array of large-radius silicon diodes that measure the energy based on the amount of charge deposited when the high-energy particles enter through the front entrance aperture.
For the current Phase A portion of the mission, we have constructed a prototype (see figure) that has three silicon detectors: two fully-depleted PIPS (Passivated, Implanted Planar Silicon) and a SSB (Silicon Surface Barrier) detector. Adjustable thickness degrader plates can be inserted between the detector elements to simulate additional missing detector elements in the final detector. The instrument is designed to enable detection of up to 200,000 events/sec, which is the rate expected for the peak flux during a solar flare as the mission is planned for the next solar cycle due in 2011.