A possible scenario to observe a knock-on tail using anisotropic neutron emission spectrum in a proton-beam injected deuterium plasma is presented. On the basis of the ion trajectory analysis in ...ITER-like magnetic configuration, Boltzmann collision integral and Fokker-Planck simulation, the knock-on tail formation in deuteron distribution function due to nuclear elastic scattering, and the resulting modification of the "double differential" neutron emission spectrum are examined. As a result of the beam injection with a specific direction, the neutron emission spectrum is modified in 2-D phase space. It is shown that the ratio of neutron emission rate with >2.8-MeV energy to the 2.45-MeV peak is increased almost 10 times compared with the 1-D modified neutron emission spectrum integrated over the emission angle, which implies the improvement of the accuracy in the neutron measurement. By using the anisotropic neutron emission adjusting the relative positions between beam-injection port and the neutron detector, the possibility to catch the knock-on tail for various plasma conditions can be increased.
Full vertical profiles of visible bremsstrahlung continuum have been measured for diagnostics of effective ion charge, Zeff , with parallel optical fiber arrays at horizontally elongated plasma cross ...section in the Large Helical Device (LHD). Measured bremsstrahlung profiles were asymmetric due to non-uniform bremsstrahlung emissions located in the stochastic magnetic field layer. Then, the Zeff profile analysis has been done only for a magnetic configuration with relatively thin stochastic magnetic field layer, i.e. for plasmas at magnetic axis position of Rax = 3.60 m. The effect of the non-uniform bremsstrahlung emission disappears in the lower half profile at Rax = 3.60 m, while the Zeff profile analysis is extremely difficult in other magnetic configurations due to the presence of the non-uniform bremsstrahlung emission over the entire vertical profile from top to bottom. To improve the difficult situation in the Zeff diagnostic the fan array optical fiber system was newly installed at vertically elongated plasma cross section for full horizontal profile measurement. It is found that the non-uniform bremsstrahlung emissions disappear from the signal and the observed bremsstrahlung profile is almost symmetric between inboard and outboard radial profiles. The analysis on the Zeff profile has been carried out based on the plasma equilibrium database in LHD, TSMAP. A preliminary result is obtained in high-density discharges, which shows a flat Zeff profile and values of Zeff ∼ 1.
In fusion plasmas, energetic ions play a crucial role in plasma heating. Nuclear elastic scattering (NES) is a non-Coulombic scattering process that affects the energy transport between energetic and ...bulk ions. In the Large Helical Device (LHD), energetic protons produced by neutral beam injection (180 keV) formed a knock-on tail (KT) in deuterons via NES, and the DD neutron emission rate increased by one order of magnitude in relatively high-electron-temperature plasmas. Furthermore, the effect of NES among ion cyclotron range of frequency (ICRF) tail protons and bulk deuterons was investigated at high-electron-temperature plasmas in the LHD. It was found that DD neutron emission rate was increased by a factor of 2 to 4. Changes in ion temperature and plasma density cannot be the only reasons for the increase in DD neutron emission rate. The increment in DD neutron emission rate was reproduced by the Fokker-Planck simulation using the Boltzmann collision integral for NES by assuming the ICRF-tail protons having a high-temperature Maxwellian.
We have recently incorporated the occupation probability formalism (OPF) in the simulation model C. Stehlé and S. Jacquemot, Astron. Astrophys. 271, 348 (1993) to have a smooth transition from ...discrete lines to continuum spectrum in the wavelength range near the Balmer series limit. We have analyzed spectra measured for the hydrogen pellet ablation cloud in the Large Helical Device with the revised model, and have found that the electron density in the ablation cloud has a close correlation with the electron temperature of the background plasma. This type of correlation is first confirmed in the present analysis and should give a new insight in the simulation studies of pellet ablation for the magnetically confined fusion plasma.
The compact neutron energy spectrometer (CNES), based on the Cs2LiYCl6 : Ce with a 7Li-enrichment (CLYC7) scintillator, has been developed for a neutron energy diagnostic in large helical device ...(LHD) plasma in the 2020 experimental campaign. The CNES, installed on a tangential sightline, is utilized to measure neutron energy spectra from tangentially-injected negative-ion-based neutral beam (N-NB) heated deuterium plasmas. In this paper, an initial result of the Doppler-shifted neutron spectrum is reported.
Tungsten (W) is one of the major impurities in ITER and future DEMO reactors. However, diagnosing ion density, temperature, and spatial distribution for tungsten ions in low charge states such as ...W17+-W27+ is difficult due to a lack of spectral line data. In this study, we observed tungsten Unresolved Transition Array (UTA) spectra around W20+ in Large Helical Device. Furthermore, the emission spectra of tungsten ions ranging from W19+-W23+ were also measured using Compact electron Beam Ion Trap (CoBIT). Two spectral peaks were detected in the CoBIT experimental setup. Subsequently, these peaks were theoretically identified as 5s-5p and 5p3/2-5d transitions using Flexible Atomic Code (FAC). The identified peaks are useful for impurity diagnostics of ITER edge plasma.
Fast ion diagnostic is one of the most crucial plasma diagnostics for nuclear fusion investigation. A new diagnostic method for fast ions has been proposed using visible spectra of 3He produced by a ...deuteron-deuteron reaction. This diagnostic method has a better energy resolution than methods using neutron/γ-ray and is superior to conventional spectroscopy in measuring high energy (MeV order) ions. This diagnostic method has been predicted using numerical analysis for ITER, but no verification experiments have been performed yet. In this study, we examined the measurability of this diagnostic method in the large helical device (LHD) deuterium plasma. Although very dependent on the measurement geometry and the spectrometer performance, it may be possible to measure the fast 3He visible spectrum.
Mushrooms of the genus
Agaricus are a common folk remedy against carcinoma. The active ingredients, polysaccharides and protein-polysaccharide complexes containing β-glucan, have been isolated and ...shown to have indirect tumor-suppressing activity via an immunological activation.
The diffusible fraction of a hot-water extract of
Agaricus blazei Murrill (ABM) powder was fractionated by HPLC based on the anti-tumor activity against leukemic cells
in vitro. The structure of the anti-tumor substance was determined by NMR and MS analyses.
We purified a tumorcidal substance from the diffusible fraction of ABM and identified it as agaritine, β-
N-(γ-
l(+)-glutamyl)-4-(hydroxymethyl) phenylhydrazine, having a molecular mass of 267
Da. This compound inhibited the proliferation of leukemic cell lines such as U937, MOLT4, HL60 and K562 with IC
50 values of 2.7, 9.4, 13.0, and 16.0
μg/mL, respectively, but showed no significant effect on normal lymphatic cells at concentrations up to 40
μg/mL. Although agaritine has been suspected of having genotoxic or carcinogenic properties, agaritine did not activate the
umu gene of
Salmonella, which reacts to carcinogens.
The results indicate that agaritine from ABM has direct anti-tumor activity against leukemic tumor cells
in vitro. This is in contrast to the carcinogenic activity previously ascribed to this compound. Our results also show that this activity is distinct from that of β-glucan, which indirectly suppresses proliferation of tumor cells.
BACKGROUND: Agaricus blazei Murrill (ABM) has been shown to exhibit immunostimulatory and anti-cancer activities; however, its mechanism of action is poorly understood. We recently found that the ...diffusible fraction of hot-water extract of ABM exhibits anti-tumor activity toward leukemic cells, and identified it as agaritine, a hydrazine-containing compound. In the present study, we examined the morphological and cytochemical effects of agaritine on U937 cells to elucidate the tumoricidal mechanism of agaritine. METHODS: Surface expression of phosphatidylserine (evaluated by annexin V binding), Fas antigen, DNA cleavage using TUNEL staining, changes in caspase activities and cytochrome c release, before and after treatment with agaritine, were examined using U937 cells. RESULTS: Nuclear damage, DNA fragmentation, was observed by Wright–Giemsa, TUNEL staining and agarose gel electrophoresis when U937 cells were incubated with 10μg/mL of agaritine for 48h. Flow cytometric analysis indicated that agaritine augments the proportion of annexin V-positive U937 cells without significant change in Fas antigen expression. Activities of caspase-3, -8 and -9 were gradually increased after the addition of agaritine. In the presence of caspase-3 or granzyme B inhibitor, except for the caspase-8 inhibitor, annexin V expression was significantly decreased, suggesting that mainly caspase-3 and -9 participate in the apoptotic pathway. Furthermore, cytochrome c release was detected by western blotting analysis after agaritine treatment. CONCLUSIONS: These results strongly suggest that the ABM constituent agaritine moderately induces apoptosis in U937 leukemic cells via caspase activation through cytochrome c release from mitochondria. GENERAL SIGNIFICANCE: This is the first report suggesting that the anti-tumor effect of agaritine is mediated through apoptosis. The present results might provide helpful suggestions for the design of anti-tumor drugs toward leukemia patients.
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