Development of an imaging plate as a heavy-nuclide detector

It is very important for the study of nucleosynthesis in supernova explosion to be able to measure the abundance of heavy nuclides in cosmic rays. There are not, however, efficient large-area detectors with which to make such measurements. To address this need, we are developing a new type of heavy nuclide detector using an Imaging Plate which is manufactured by Fuji Film Co. Ltd. This film has a position resolution of 25 μm and a sensitivity 1000 times higher than X-ray film. Moreover it is easy to enlarge since the area of one plate can be 20×25 cm² and the accumulated cosmic-ray-interaction information can be read out in about 10 minutes. To measure the characteristics of the Imaging Plate for heavy nuclides, we irradiated it with several kinds of nuclides using an accelerator in the National Institute of Radiological Sciences. These tests demonstrated that the imaging plate was able to separate carbon, silicon, and argon nuclides