Radiation detection using single event upsets in memory chips
A photon incident upon Silicon whose energy is greater than the bandgap in Si (1.12eV) will produce an electron-hole pair by lifting an electron from the valance band into the conduction band, leaving a hole in the valance band. If this occurs in a block of pure Si, the electron-hole pairs will merely recombine. However, if this process occurs near the depletion region of a p-n junction, the electric field will separate the electron-hole pairs. This causes a voltage difference to develop between the p and n regions. If an external circuit is connected across the p and n regions, a current will flow; this is the basis for solar cells.
The present study focuses on building X-Ray detectors using commercial-off-the-shelf Si devices that were not designed to be used as X-Ray detectors. Solar cells are designed to work with photons in the visible portion of the spectrum. However photons with any energy greater than 1.12eV can produce electron hole pairs in Si, therefore X-Rays (∼8keV) will also produce electron hole pairs, although most of the incident energy will be wasted. Several different solar cell based X-Ray detectors were designed and tested. One of these designs was employed to perform a basic physics experiment.
Memory chips are also constructed using p-n junctions. Stray electron hole pairs produced by incident radiation can corrupt the data in the memory. Several different types of memory were studied. The susceptibility of these chips to radiation induced errors and the survival rate of these chips following irradiation was investigated. The inherent suitability of various types of memory to use as a detector was also evaluated.
0552: Nuclear physics