Experiments aiming at 'day long operation at high performance' have been carried out in TRIAM-1M. The record value of the discharge duration was updated to 5 h and 16 min. Steady-state tokamak operation is studied under the localized plasma wall interaction conditions. The distributions of the heat load, the particle recycling flux and impurity source are investigated to understand the co-deposition and wall pumping. The formation and sustainment of an internal transport barrier (ITB) in enhanced current drive mode has been investigated by controlling the lower hybrid driven current profile by changing the phase spectrum. An ITER relevant remote steering antenna for electron cyclotron wave injection was installed and a relativistic Doppler resonance of the oblique propagating extraordinary wave with energetic electrons driven by lower hybrid waves was studied.

No abstract

Real-time radiation dose management is important because staff members working in interventional radiology may be exposed to relatively high doses of primary and scattered radiation from the body of a patient. In this study, we investigated the dependence of energy and dose rate of the commercially available semiconductor detector named Pocket Geiger (POKEGA) for personal monitoring in diagnostic X-rays. In the energy-dependence study, a suitable metal filter and the threshold level were examined for energy compensation using a Monte Carlo calculation code. Moreover, the energy dependence of the POKEGA with an optimal metal filter was compared with that of commercially available active personal dosimeters (APDs). With an aluminum filter, the difference of the ratio of the absorbed dose of silicon to that of air was ±7% for a tube voltage of 70-110 kV and a cutoff energy of 23 keV in the calculation. The energy response of the APDs, except the PDM-122B-SHC and the POKEGA, met the required JIS standard from 50 to 110 kV. In the dose rate-dependence study, a high linearity was observed up to 2.2 mGy h using the POKEGA with an aluminum filter.

No abstract

Understanding the properties of slice sensitivity profile (SSP), or slice thickness, is crucial for an accurate and highly reproducible diagnosis using tomosynthesis imaging. The objectives of the present study are therefore to quantitatively evaluate how the SSP with the use of a small metal bead is affected by different settings of the height from the table and the height of the center of rotation (COR) in tomosynthesis imaging except for the digital breast tomosynthesis, and visually verify the effects on tomosynthesis images. The reconstruction filters used were three types of filtered back-projection and iterative reconstructions. The SSP was measured from the full width at half maximum (FWHM-SSP) of the profile curve of the bead in the perpendicular direction (z direction) relative to the table. Two types of anthropomorphic phantoms simulating the human body, with bones and soft tissues, were used to study the effects of different settings for the COR height. In all reconstruction filters, the FWHM-SSP changed as the height of the bead varied when the bead and COR were set to the same height from the table. If the bead and the COR were set to different heights, the FWHM-SSP increased (decreased) when the height of the bead was set to be greater (less) than the height of the COR. These changes were also confirmed on the anthropomorphic phantom images of the bones and soft tissues.