Dielectric barrier discharge (DBD) plasma has been utilized as a sustainable technology to enhance seed germination in various plant species. The objective of this research was to identify the mechanism of physicochemical properties and antioxidant enzyme activities to promote kangkong (Ipomoea aquatica Forssk.) seed germination using different durations of DBD plasma treatments. Seeds were exposed to atmospheric DBD plasma from 5 to 20 min, compared to non-treated seeds as the control. According to SEM images, the seed surface had cracks and grew wider as a result of the prolonged DBD plasma treatments. A longer DBD plasma treatment exhibited a lower water contact angle and increased water absorption. DBD plasma treatments strongly improved germination percentages and hydrogen peroxide (H₂O₂) contents. Seeds treated with DBD plasma for 20 min showed the highest malondialdehyde (MDA) content and the lowest field emergence. Catalase (CAT) activity increased under DBD plasma treatments for 5 and 10 min. Ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities were not statistically different among the treatments. This finding suggested that DBD plasma treatments stimulated the germination of kangkong seeds by modifying the seed surface, and upregulating H₂O₂ content and CAT activity. Five minutes was an appropriate time to treat DBD plasma.

The presence of helically trapped fast ions in helical ripples in the large helical device (LHD), resulting from a perpendicularly injected positive-ion-source-based neutral beam (P-NB)-heated plasma and/or from ion cyclotron range of frequency (ICRF) wave-heated plasma, poses a significant concern due to the system’s lack of symmetry. In response to this challenge, compact neutron emission spectrometers (CNESs) have been strategically developed in the LHD, featuring a perpendicular line of sight relative to the plasma’s magnetic field. The first perpendicular CNES offered a vertical field of view through the deuterium plasma and incorporated a liquid (EJ-301) scintillation detector optimized for efficient operation at a high neutron emission rate. The second perpendicular CNES was operated using a Cs2LiYCl6:Ce scintillation detector enriched with 7Li (CLYC7), providing a horizontal field of view through the deuterium plasma and effectively operating in a region characterized by relatively low neutron emission rates. During plasma heating through P-NB, both perpendicular CNESs showed a neutron energy distribution, featuring a double-humped profile with two peaks at energy of approximately 2.30 and 2.74 MeV. Furthermore, the deuterium-deuterium neutron energy spectrum expected to be obtained by perpendicular CNES was calculated using the 5-D orbit following code DELTA5D and considering the Larmor motion effect. The results revealed that the experimentally obtained neutron energies were almost consistent with the neutron energies calculated based on the orbit following model. These peaks aligned with the Larmor motion of deuterons resulting from P-NB injection at the helical ripple of the LHD. In addition, we conducted neutron spectroscopy involving deuterium-deuterium interactions in a deuterium plasma simultaneously heated by both P-NB and ICRF wave, characterized by a high neutron emission rate, using perpendicular CNES based on EJ-301. The observation revealed a broadening in spectrum width, attributed to the additional ICRF wave heating.

Thailand Tokamak-1 is a small size tokamak, formerly known as HT-6M and belong to Institute of Plasma Physics, Chinese Academy of Science (ASIPP, China). The HT-6M was donated to Thailand Institute of Nuclear Technology (TINT, Thailand) and will undergo a reconstruction in order to re-commission again. For the reconstruction of power supply for magnet systems, three circuits have been designed based on capacitor discharge for the toroidal field magnet coil, the heating field magnet coils, and the vertical field magnet coils. With a simulation of new circuit design, the TT-1 will have toroidal magnet field about 1.5 T for a flattop duration of 100 ms with Ohmic heating and vertical magnetic field of the same duration.

The compact neutron emission spectrometers (CNES) based on conventional liquid (EJ-301) scintillation detectors were characterized in this work. The CNESs were employed for deuterium-deuterium neutron emission spectroscopy in the Large Helical Device (LHD). Prior to the installation, the EJ-301 scintillation detectors were characterized at the Fast Neutron Laboratory of Tohoku University. In order to discriminate the neutron and γ-ray signals, the charge comparison method was used. The neutron energy spectrum was successfully unfolded from the measured recoil proton energy spectrum of the EJ-301 scintillation detector using the derivative unfolding technique. The detector’s energy resolution was examined. In the LHD, EJ-301 based CNESs with both tangential and perpendicular line-of-sight were employed to characterization. Furthermore, the characterization of the CNES was performed in the deuterium-deuterium experiment campaign. The operational capabilities of CNESs in the LHD were examined. Deuterium-deuterium neutron emission spectroscopy in various approaches of neutral beam (NB)-heated plasmas was conducted using CNES. Because of the high energy of the injected fast-ions from tangential NB injection, an investigation of the Doppler effect on deuterium-deuterium neutron energy was conducted. The upper and lower shifted deuterium-deuterium neutron energies were observed when the fast-ions moved towards and away from the tangential CNES, respectively. As expected, no notable energy shift was observed from fast-ions injected by the perpendicular NB injection. Additionally, the five-dimensional orbit following code DELTA5D, which takes into account Larmor motion effects and the detector’s energy resolution, was utilized to compute the expected deuterium-deuterium neutron energy spectrum that would be measured by the CNES. There was a concurrence between the calculations and experimental results.

Plasma-activated water (PAW) is an eco-friendly technology with potential to improve seed germination and nutritional quality in microgreens. This study investigated the effects of PAW on three cultivars of kangkong (Ipomoea aquatica Forssk.). PAW activated for 10 min (PAW10) significantly enhanced seed germination and vigor, with effects comparable to those of a 15-min treatment. PAW10 treatment not only improved the accumulation of bioactive compounds—including total phenolics, flavonoids, ascorbic acid, chlorophylls, and carotenoids—but also enhanced antioxidant activity. These improvements were accompanied by elevated hydrogen peroxide (H₂O₂) levels and increased enzymatic activities, specifically catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). Principal component analysis revealed cultivar-specific responses to PAW10. The Senafore 20 (SF) cultivar showed the most pronounced increases in antioxidant and antiglycation activities, as well as key bioactive compounds. The Phai-ngern (PN) cultivar exhibited elevated SOD activity and fiber content, while the Senee 20 (SN) cultivar showed minimal changes. These findings suggest that PAW10 effectively promotes germination and antioxidant-related biochemical responses in kangkong microgreens, with varying responses depending on cultivar. This study highlights PAW treatment as a promising approach to improve microgreen production and antioxidant capacity, supporting sustainable agriculture.