Development of a New Active Personal Dosimeter for Use in Space Radiation Environments

A new solid state detector, known as Medipix, developed by a consortium of academic institutions has been evolved from a technology originally created for use at the LHC at CERN in Geneva, Switzerland. This technology is being harnessed for use as an active personal dosimeter for space radiation applications. The pixel based technology embeds the entire required readout electronics for each pixel withing the pixel´s 55 micron square footprint. That allows the seamless tiling of multiple arrays of detectors. Prototypes have been exposed to heavy ion beams at the HIMAC facility in Japan and at the Texas A&M cyclotron in the US. The results are very encouraging. Extensive experience is being gained in using the detectors with appropriate converters for simultaneous neutron dosimetry as well. Ultimate versions may be deployed that are both wireless and self-contained, as well as having a package size comparable to current passive personal dosimeters. Prospect are excellent for building them into spacesuits, which would provide ground-based real-time monitoring of the detailed doses being taken by crew members during such high-risk periods as EVAs. These dosimeters could also be used as active area monitors in a variety of both space and ground-based applications.