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We started to develop a new space dosimeter named 'Position Sensitive Tissue Equivalent Proportional Counter (PS-TEPC)' with tissue equivalency and position sensitivity. This detector consists of the Micro Pixel Chamber (micro-PIC) which is a kind of the micro-pattern gas detector. Heavy ions irradiation experiments were performed at HIMAC (Heavy Ion Medical Accelerator in Chiba) of NIRS (National Institute for Radiological Sciences) using the detector with the sensitive volume of 26 x 26 x 55 cu mm., 資料番号: AA0063349082

The scintillating fiber camera is a type of three-dimensional track detector. Using this camera, we can observe the scintillation track produced along the path of a charged particle, and from its scintillation yield can determine the linear energy transfer (LET) distribution of the charged particle. Such observations are also possible for recoil (charged) particles produced by fast neutrons. From these data, we can estimate the LET distribution of individual charged particles or that of recoil particles produced by neutrons; and finally, we can estimate the dose equivalent due to charged particles and/or fast neutrons. For use as a dosimeter for fast neutrons produced by the interaction between cosmic-ray particles and wall materials of a manned spaceship in space, a 52 mm cubic scintillating fiber camera with a 75 mm diameter gated-image intensifier with a maximum counting rate of 30 Hz was constructed. The dosimeter consists of a stack of scintillation fibers with a sensitive volume of 52 mm x 52 mm x 52 mm and a 75 mm diameter image intensifier for readout from the scintillation fibers. The scintillation yields were measured for high-energy heavy ions such as carbon and argon ions. An energy resolution of 12 percent full-width half-maximum (FWHM) was obtained for penetrated argon ions of 650 MeV/n. These results demonstrate that this type detector is very useful as a dosimeter for high-energy cosmic rays and their secondary neutrons., 資料番号: AA0049500032, レポート番号: JAXA-SP-06-006

The space environment which must be considered in the spacecraft design can be classified into five categories: vacuum, neutral gas, plasma, radiation, and micrometeoroid/orbital debris. The radiation is placed in it as the important environment because it has a large effect on the lifetime of the satellite and affects health of crew member. We studied the measurement of light particles (electron, proton, helium) and neutron in the 2004 FY. This paper describes the study result of neutron dosimetry device., 資料番号: AA0049054027, レポート番号: JAXA-SP-05-008

It is essential to evaluate the radiation risk for astronaut in space. The development of a new space dosimeter named 'Position Sensitive Tissue Equivalent Proportional Counter' (PS-TEPC) is started. This detector has good properties of both exiting dosimeters such as TEPC in NASA and Real-time Radiation Monitoring Device-3 (RRMD-3) based on a Si telescope. A novel technique named Micro PIxel Chamber (Micro-PIC) makes it feasible., 資料番号: AA0048095062