Kazushi Terada

Feasibility study of SPECT system for online dosimetry imaging in boron neutron capture therapy.

A single collimator version of a proposed PG-SPECT system was manufactured and experimentally tested. Combining this experimental data with Monte Carlo simulation, the viability of Ge and CdTe semiconductors detectors was calculated. It was determined that the best detector of the ones compared would be a CdTe detector of 2-3mm, aided by the benefit of adding a Compton-suppression anti-coincidence timing detector.

Feasibility study on pinhole camera system for online dosimetry in boron neutron capture therapy.

The feasibility of a pinhole camera system for online dosimetry in boron neutron capture therapy (BNCT) was studied. A prototype system was designed and built. Prompt γ-rays from the (10)B(n,α)(7)Li reaction from a phantom irradiated with neutrons were detected with the prototype system. An image was reconstructed from the experimental data. The reconstructed image showed a good separation of the two borated regions in the phantom. The counting rates and signal-to-noise ratio when using the system in actual BNCT applications are also discussed.

Measurements of keV-neutron capture cross sections and capture gamma-ray spectra of 105Pd

The neutron capture cross sections and capture gamma-ray spectra of 105Pd were measured in the region from 15 to 100 keV and at 585 keV. A neutron time-of-flight method was utilised with an anti-Compton NaI(Tl) spectrometer and a 1.5-ns pulsed neutron source by the 7Li(p,n)7Be reaction. The capture yields were obtained by applying a pulse-height weighting technique to the observed net capture gamma-ray pulse-height spectra. The capture cross sections of 105Pd were derived with errors less than 5%, using the standard capture cross sections of 197Au. The evaluated capture cross sections of JENDL-4.0 and ENDF/B-VII.1 were compared with the present results. The evaluations of JENDL-4.0 and ENDF/B-VII.1 were larger than the present results by 3%–15% in the region from 15 to 100 keV and at 585 keV. The capture gamma-ray spectra of 105Pd were also derived by unfolding the observed net capture gamma-ray pulse-height spectra. The multiplicities of capture gamma rays of 105Pd were obtained from the capture gamma-ray spectra.

SYSTEMA TIC MEASUREMENTS OF keV-NEUTRON CAPTURE CROSS SECTIONS AND CAPTURE GAMMA-RAY SPECTRA OF Pd ISOTOPES

The capture cross sections and capture γ-ray spectra of 104,105Pd were measured in the neutron energy region of 15–100 keV as a part of systematic series of measurements. A neutron time-of-flight method was adopted, using a ns pulsed neutron source via the 7Li(p,n)7Be reaction. The capture γ-rays from the samples were measured with an antiCompton NaI(Tl) spectrometer. The capture yields were obtained by applying a pulseheight weighting technique to the net capture γ-ray pulse-height spectra. The capture cross sections of 104,105Pd were derived with errors less than 5%, using the standard capture cross sections of 197Au. The capture γ-ray spectra of 104,105Pd were also derived by unfolding the respective observed capture γ-ray pulse-height spectra.