Two types of single electron transistor devices are proposed as cryogenic radiation detectors. One is a super conducting tunnel junction coupled with the single electron transistor for a high sensitivity detector. The other is a position sensitive detector consisted of four single electron transistors and a micro bolometer which has 100 nm position resolution estimated by a heat flow calculation. Here are presented preliminary consideration on the device design and fabrication method.

  For general research and industrial applications with radiations, especially photons, InSb compound semiconductor detectors are under development. The InSb detectors will be operated at moderately low temperature with sensitive areas larger than the ones of superconductor detectors. The expected energy resolution of InSb detectors is better than 60eV for 6keV photons. The current-voltage curves, measured energy spectra of alpha particles, rise times of p-InSb and undoped InSb detectors are discussed. As an application of InSb detector, neutron detection was performed with ³He converter at 4.2K.

  We describ the pixellated detectors which used compound semiconductor TlBr crystals. TlBr is a very promising compound semiconductor for fabrication of X- and γ-ray detectors. Our studies made an effort to fabricated 9 channel pixellated detectors with sufficient detection efficiency and good charge collection efficiency. Pixellated X- and γ-ray detectors were fabricated from TlBr crystals. Spectrometric performance of the pixellated TlBr detectors was tested by irradiating them with ²⁴¹Am (59.5keV), ⁵⁷Co (12keV) and ¹³⁷Cs (662keV) gamma-ray sources. Each of the anode pixels of the detector was connected to each charge sensitive preamplifier and the guard ring was grounded. The energy resolution (FWHM) in a best channel obtained for the pixel of the TlBr detector at -20℃ were 4keV, 7 keV and 10 keV for 59.5 keV, 122 keV and 662 keV gamma-rays, respectively. In an application of the pixellated TlBr detectors , the time stability, operating temperature of the TlBr detectors should be the subject of our future researches.

  Recent state for development of CdTe-based radiation detectors is reviewed. The progress of the technologies such as the crystal growth of CdTe and CdZnTe, the deposition of electrodes on the crystal, the design of read out ASIC, and the bonding between crystal and ASIC, opened the way for the development of imaging devices for practical uses. A X-ray imager for non destructive inspections and a gamma ray imager for small animal radioisotope experiments or nuclear medicine are presented as examples.

  Personal radiation dose has decreased as years pass by. This requires a personal dosemeter with higher sensitivity. Recently new dosemeters have been developed, such as the Luxel badge that is composed of Aluminum Oxide (Al₂O₃:C) as a detector element with an optically stimulated luminescence process for a measuring method, and the DIS dosemeter containing an MOSFET type analogue EEPROM. These dosemeters have 10 to 100 times lower detection limit than the old film badge.

  Then some trials have been conducted to use these dosemeters for measuring environmental doses. Here I will present the technical specifications like detection principles of these dosemeters and some examples of data obtained from application to the environmental dose measurement.

  RPL glass dosemeter has been recently recognized to have a good performance as accumulation dosemeter and has been routinely used for personal dosimetry and environmental radiation monitoring. Furthermore, its applicable field is being extending to medical radiation measurement.

  The history of RPL glass dosemeter is very long. It was born in USA in 1950s and after that it was improved in Japan. And it was used as personal dosemeter in 1970s. But, in those days, RPL glass dosemeter was not suitable to low dose measurement due to some handling problems. So, its use had been reduced gradually.

  The author has broken through any past problems, by mainly realizing the pulsed UV excitation method. In this paper, the development history, principle & features, and the development good results of the pulsed UV excitation method are summarized, including the introduction of recent RPL glass dosimetry products.