[en] Phosphorylation and dephosphorylation, which are the most remarkable post-translational modifications, are considered to be important chemical reactions that control the activation of proteins. First, we examine the phosphorylation analysis method by measuring the infrared absorption peak of the phosphate group that is observed at about 1070 cm^-1 (9.4 μm) with Fourier Transform-Infrared Spectrometer (FT-IR). Next, we attempt to control the quantity of phosphorylation, that is to say an action like dephosphorylation without enzyme reactions, by irradiating 9.4 μm-Free Electron Laser (9.4 μm-FEL). FEL irradiation has an effect of some kind on the organization of infrared absorption of a phosphate group. We would now like to go on to develop this photochemical reaction like dephosphorylation by examining under several conditions and in detail

[en] An accelerator-based neutron source with a combination of DC accelerator (IBA Proton-Dynamitron) and a lithium target has been developed at the Nagoya University (NUANS). Proton beam is extracted from an ECR ion source, accelerated in the Dynamitron up to 2.8 MeV with the maximum current of 15 mA (42 kW), and transported to the target through the beamline. In 2017, all the components of the NUANS such as beamline, target and BSA were constructed, and neutron irradiation experiments were started. For the safety of the accelerator system and sufficient neutron production for BNCT, a beam transport analysis was performed by a linear optics model. As a result of the optimization of beam conditions by this analysis, we achieved transport of high beam current of 8 mA. (author)

[en] The lithium thick target bombed with low-energy protons is one of the promising neutron sources for the Boron Neutron Capture Therapy (BNCT). The benchmark calculations of the neutron Thick Target Yield (TTY) of the lithium target are conducted by the Particle and Heavy Ion Transport Code System PHITS with ACE formatted files of JENDL-4.0/HE and ENDF/B-VII and the DROSG-2000 code for the incident proton energy of around 3 MeV. Also, neutron TTY of the lithium thick target with a titanium window is evaluated for the Nagoya University Accelerator-driven Neutron Source (NUANS). Finally, the TTY evaluated with PHITS is applied for the neuron transport calculation for the Beam Shaping Assembly (BSA) of NUANS. As a conclusion, it is considered that ENDF/B-VII is more feasible than JENDL-4.0/HE for the ⁷Li(p,n)⁷Be reaction around 3 MeV of the proton energy. (author)

[en] An optical fiber-based neutron detector using a small piece of a scintillator can be an effective way for real-time neutron monitoring in an intense neutron field, such as BNCT. The neutron sensitivity of the detector can be arbitrarily selected from 10^-6 to 10^-3 cps/(n/cm²/s) by controlling the mass of the scintillator. The detector output linearity was confirmed up to 450 kcps, when using a Li glass scintillator. It was nearly 9 times larger than the upper limit in the detector using a Eu:LiCaAlF₆ or LiF/Eu:CaF₂ scintillator. No deterioration was observed in neutron irradiation up to thermal neutron fluence of 2×10¹² n/cm². (author)

[en] Development of an accelerator-driven compact neutron source for BNCT, Boron Neutron Capture Therapy, has started in Nagoya University. We will show the results of improved design around the neutron beam exit of the Beam Shaping Assembly. We proposed a use of an “Extension collimator” that can make it easier to set a patient in a comfortable position during the neutron irradiation. Additionally, we could greatly improve performance of the collimator by using a new nozzle structure called as “Ni implant nozzle”. We, consequently, achieved the neutron beam characteristics that almost satisfied all of the recommended values reported in IAEA-TECDOC-1223. (author)

[en] There is a worldwide trend to develop accelerator-based neutron sources for boron neutron capture therapy (BNCT), known as AB-BNCT, that can be installed in hospitals, as research reactors are being decommissioned [I-1]. An AB-BNCT system generally consists of a ‘proton accelerator’, ‘neutron generating target’, and ‘beam shaping assembly’ (BSA) that reduces the neutron energy to the therapeutic range. The basic requirements for the AB-BNCT system installed in a hospital are as follows: • Sufficient neutrons with a low impact on normal cells; • Agreeable patient positioning during treatment; • Low radiation exposure of medical workers; • Low activation accelerator and facility; • Affordable construction and operation costs. To satisfy those requirements, an AB-BNCT System Research Laboratory for academic– industrial partnerships at Nagoya University’s Graduate School of Engineering was inaugurated on November 1, 2013, to develop a neutron source equipped with an electrostatic accelerator and a sealed Li target (an AB-BNCT system).

[en] Neutrons are generated in a fusion plasma and induce various radionuclides via a nuclear reaction with fusion reactor materials. Evaluating the kinds of nuclide and the amount of induced radioactivity is important for decommissioning planning and regular maintenance. In this study, we verified a long-term prediction model of induced radioactivity in the large helical device (LHD) model by comparing induced radioactivity generated during deuterium plasma experiments in LHD with results calculated using a high-energy particle-induced radioactivity code. The metals employed for activation were SUS316L, Co, Mo, and Ni. During the deuterium plasma experiments, these materials were placed on an 8-O port of the LHD, and the induced radioactivity was measured weekly. To computed induced radioactivity using DCHAIN-SP, the neutron energy spectrum was computed using the LHD model with the Monte-Carlo simulation code PHITS. Although the calculated and measured radioactivity of ⁵⁸Co and ⁵⁴Mo agreed well, the calculated values of ⁶⁰Co and ⁹⁹Mo were underestimated. However, low-energy components could be improved by incorporating peripheral devices into the LHD model, resulting in more accurate radioactivity predictions. (author)

[en] Information of confined energetic ions can be obtained by the neutron measurement because neutrons are mainly emitted from the reactions between energetic and thermal ions in current deuterium plasmas. The large helical device (LHD) has several neutron measurement systems, and energetic-particle physics studies have been performed based on the neutron measurement.

[en] The application of imaging plate (IP) method using indium foils to measure the distribution of fast neutron in large area was evaluated in this work. The radioactive nuclides of indium were individually quantified by high-purity germanium detector (HPGe) and chronological IP measurements. The detection efficiencies of each radioactive nuclide for various thicknesses of foil mylar polyester film were summarized. The scope of application for proposed method were clearly dependent on the flux ratio of fast and thermal neutron, limiting the applicable region only being close to the neutron source. (author)

[en] Highlights: • First experimental verification of NUANS for BNCT was conducted. • Spatial distribution of the thermal neutron flux in the water phantom was measured. • Calculated energy spectrum was verified based on indirect experimental results. • Epithermal neutron flux was 1.49 × 10⁷ n/cm²/s at a proton current of 0.25 mA. As the commissioning phase of the Nagoya University Accelerator-driven Neutron Source for boron neutron capture therapy, in-phantom thermal neutron flux measurements were conducted using a small LiF/Eu:CaF scintillator detector and activation foils. The spatial distribution of the measured thermal neutron flux agreed with the Monte Carlo simulation results. Based on this comparison, the free-in-air neutron spectrum, calculated at the exit aperture, was verified and the epithermal neutron flux, at a 0.25 mA proton current, was evaluated as (1.49 ± 0.10) × 10 n/(cm² s).