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A case of 55-year-old man pathologically proven as neoplastic angioendotheliosis was reported. He initially developed sensory disturbance and motor weakness in the lower extremities. After admission, he showed progressive deterioration of higher brain functions with moderate fever. Routine laboratory examinations revealed elevated serum LDH level and erythrocyte sedimentation rate without leukocytosis or increased serum globulin level. Immunological tests were normal, except positive RA. Immunocytochemical investigation of tumor cells in the blood vessel gave the results that these cells appeared to be derived from B cells. Southern blot analyses of the brain samples revealed clear positive bands corresponding to JC virus DNA in the blot. JC virus has been known to infect the endothelial cells of the blood vessel as well as urethral epithelial cells. We discussed the possible mechanism of the selective growth of tumor cells in the blood vessel in terms of possible JC virus infection to the endothelial cells of the blood vessel and abnormal recognition between tumor cells and endothelial cells.

46-year-old male patient was born in Niigata Prefecture and thereafter lived in Tokyo. In late January 1985, he noticed swelling of the bilateral inguinal lymph-nodes followed by fever and lumbago. In February, he consulted a local doctor and hepatosplenomegaly, marked leukocytosis and renal dysfunction were pointed out and he was referred to our hospital on February 22nd. The clinical laboratory data on admission were as follows; WBC 23,200/microliter, serum-Ca 18.4 mg/dl, BUN 85.3 mg/dl, creatinine 5.4 mg/dl, antibody to ATLV x160. ATL was diagnosed by biopsy of lymph nodes and examinations of peripheral blood and bone marrow hemogram. Remission was achieved in March by the treatment with adriacin. Renal failure and hypercalcemia also improved. However his respiratory dysfunction gradually worsened. The chest radiographies++ showed pulmonary edema, although there was no clinical evidence of heart failure. When his condition became stable, TBLB was performed and revealed extensive deposition of calcium along alveolar septae, suggesting that pulmonary edema was induced by the metastatic calcification of the lung. After the second treatment for ATL, he died of pneumonia. The autopsy showed calcium deposition not only in the lung but in pyramids of the kidney and in sub-serous layer of the small intestine. There was no tumor cell invasion into the bone or parathyroid gland. High urinary c-AMP together with normal levels of PTH suggested that the hypercalcemia in this case was induced by PTH-related protein. It was concluded that careful treatment for hypercalcemia is important as regards the occurrence of pulmonary edema.

A transition to a high electron temperature state in the core accompanied by an electron internal transport barrier (eITB) was clearly observed in neutral beam (NB) sustained plasmas with strongly focused on-axis electron cyclotron heating (ECH) in Large Helical Device (LHD). During stepwise injection of ECH power, the core electron temperature started to build up spontaneously and became high temperature in the core (high-Te state), while the temperature outside of ρ 0.3 drastically decreased. The transition dynamics of the core temperature is analyzed by the time evolution of electron temperature profiles and heat flux changes based on the data from multi-channel electron cyclotron emission. Effect of an initial island size (m/n=2/1) on the high-Te transition was experimentally investigated by controlling the width by an external coil field. The results show that the island size possibly affects a threshold value of ECH power and collisionality on the high-Te transition.

High-ion-temperature (exceeding 5 keV) hydrogen plasmas have been successfully produced in the Large Helical Device [Iiyoshi et al., Nucl. Fusion 39, 1245 (1999); Motojima et al., Nucl. Fusion 47, S668 (2007)] with the ion heat confinement improvement in the core region. The experimental ion heat diffusivity at the core region is found to be almost independent of the ion temperature, T_i (even decreasing as T_i increases). The neoclassical (NC) ripple transport is suppressed by the ambipolar radial electric field, E_r (

An on-chip automatic erase technique using an internal voltage generator has been developed and has proved to operate well in 1-Mb-flash EEPROM. This technology permits accurate control of erasure and guarantees the performance after erasure of the true single-transistor-per-cell type of flash EEPROM. Device implementation is described

In the Large Helical Device, the stray microwave radiation is monitored by using so-called sniffer probes during electron cyclotron heating. In monitoring the stray radiation, we changed the microwave beam injection angle and search the O-X-B mode-conversion window to excite electron Bernstein waves (EBWs). When the microwave beam is injected toward the vicinity of the predicted O-X-B mode-conversion window, the electron temperature rises in the central part of overdense plasmas. In that case, the stray radiation level near the injection antenna becomes low. These results indicate that monitoring the stray radiation near the injection antenna is helpful in confirming the effectiveness of excitation of EBWs simply without precise analysis.

Achieving steady-state plasma operation at high plasma temperatures is one of the important goals of worldwide magnetic fusion research. A high temperature of approximately 2 keV, and steady-state plasma-sustainment operation of the Large Helical Device (LHD) [O. Motojima, K. Akaishi, H. Chikaraishi et al., Nucl. Fusion 40, 599 (2000)] is reported. High-temperature plasmas were created and maintained for more than 30 min with a world record injected heating power of 1.3 GJ. The three-dimensional heat-deposition profile of the LHD helical divertor was modified and during long-pulse discharges it effectively dispersed the heat load using a magnetic-axis swing technique developed at the LHD. A sweep of only 3 cm of the major radius of the magnetic axis position (less than 1% of the major radius of the LHD) was enough to disperse the divertor heat load. The modification of the heat-load profile was explained well by field-line tracing. The steady-state plasma was heated and sustained mainly by hydrogen minority ion heating using ion cyclotron range of frequencies. The operation lasted until a sudden increase of radiation loss occurred, presumably because of wall metal flakes dropping into the plasma. The sustained line-averaged electron density was approximately 0.7?0.8×10^19 m^?3. The average input power was 680 kW, and the plasma duration was 31 min 45 s. This successful long operation shows that the heliotron configuration has a high potential as a steady-state fusion reactor.

Carbonization was successfully applied to Heliotron-E. Iron-inpurity radiations were strongly reduced with the carbonized wall. Main impacts of the metal reduction on plasma behaviors are sustainment of stored energy during high power, long pulse heating by NBI, achievement of a quasi-steady discharge with a low helical field and high beta, and highest electron density with pellet injection in a quasi-steady state. Hydrogen recycling was very high with the carbonized wall and low density operation was impossible. Helium glow discharge was found to be effective to control the hydrogen recycling with a carbon-tiled wall.

Electron-cyclotron and neutral-beam heating have been used to produce currentless plasma with $〈\ensuremath{\beta}〉\ensuremath{\approx}(1\ensuremath{-}2)%$ in the Heliotron-$E$ device. For moderately peaked profiles, magnetohydrodynamic activity that peaks at the $t=1$ surface has been observed. The characteristics of the fluctuations are consistent with theoretical expectations for an $m=1$ pressure-driven instability. The magnetohydrodynamic activity is associated with particle and energy losses but has not yet been directly linked to global confinement.

Recent results of the heating experiment on the Heliotron E plasma are reported. Two heating methods are applied; electron cyclotron resonance heating (ECRH) and neutral injection (NBI) heating. In the ECRH experiment, a currentless high-temperature plasma is produced with the use of a gyrotron capable of delivering an output power of 200 kW for 40-ms duration at 28 GHz. The electron and the ion temperatures at the center −Te(0) and Ti(0) − 1.1 keV and 120 eV, respectively, and the average density n e of 5 × 1012 cm−3 is obtained. The NBI heating has produced the plasma which has the temperatures of Te(0) ∼ Te(0) ∼ 660 eV and the density n e of 3 × 1013 by the NBI power of about 1.6 MW. The heating efficiency has been found to be about 2 ( eV ·P abs ( kW ) n e (10 13 cm −3 ), where P abs is the absorbed neutral beam power, for bot perpendicular and 28° co- and counter-injection angles from the normal direction of the torus. The central beta value reaches about 1%.

Particle control with pump limiters has been successfully demonstrated in a variety of tokamaks. This experiment has obtained, for the first time, experimental data on pump limiter operation in a heliotron configuration. A movable pump limiter module was installed on a horizontal midplane port of Heliotron-E. The limiter module was installed on a horizontal midplane port of Heliotron-E. The limiter assembly consists of a TiC-coated graphite head with single-sided particle collection and active pumping. The location of the limiter is varied from near the vacuum vessel wall or up to 8 cm inside the last closed magnetic flux surface. This flexibility permits the study of a heliotron plasma that is limited either by the magnetic separatrix or by a material limiter. In the configuration investigated, only very low pressures are observed in the pump limiter when it is located outside the last closed flux surface, indicating that the scrape-off layer density is very low ( 11 cm −3 ). For limiter positions inside the last closed flux surface, pressures of 2–6 mTorr are observed (similar to comparable tokamak operation). Erosion patterns on the vacuum vessel, as well as hot spots on the limiter head, indicate that the particle flow out of the confined plasma exhibits complicated patterns. This suggests that for efficient particle collection in a stellarator, pump limiters must be matched to the particle flow patterns.

Shear Alfven wave heating experiments are reported in which a bulk electron heating of the toroidal plasma for a high initial temperature plasma ( T e >50 eV) and a local electron heating for a lower temperature plasma were observed. The results indicate the excitation of the kinetic shear Alfven wave and are consistent with the theoretical calculation of the damping length of the wave.

Parametric studies of volume averaged electron temperature (Te) and global electron energy confinement time ?Ee of ohmically heated Heliotron E plasmas have been performed using a data acquisition computer system. The scaling laws (Te) ? (IOH · B/ne)0.5 and ?Ee ?ne-0.4 · B/IOH1.5 are obtained directly by a code which fits the exponents of the plasma parameters to the electron temperature and confinement time. The ohmically heated plasma confinement time ?Ee is shown to be related to the drift parameter ? (= VDe/VTe). The dependences of the energy confinement time on other plasma parameters is also presented. An investigation is made of the correlation between MHD activity and the confinement.

Measurements of neutral density in ECRH, Ohmically heated and neutral beam heated plasmas on the Heliotron E device are described. Profiles of neutral density determined by the vertically scanned charge exchange neutral flux are compared with the results of the Monte Carlo simulation. In Ohmic and ECRH plasmas, the obtained profiles agree well with the simulation results using Franck-Condon neutral (∼3 eV) as incident particles. In NBI case, the recycling particle with higher energy (typically ∼30 eV) dominates the particle source. The dependence of the neutral density on the average electron density is represented by the parameter I p . Although the neutral density in Ohmic and ECRH plasmas decreases as \bar N e increases, NBI plasma does not have such dependence. The global particle confinement time is estimated, and τ p decreases as I p increases.

A simple and sensitive assay for GM1 ganglioside (GM1) beta-galactosidase activity was devised by direct measurement of released D-galactose using high-performance liquid chromatography (HPLC). GM1 beta-galactosidase activity in crude samples such as brain homogenates could be measured by this method. After incubation of brain homogenate for 1 h with GM1 at 37 degrees C and pH 4.4 in the presence of sodium taurodeoxycholate, the reaction was terminated by heating at 100 degrees C for 2 min and the supernatant from the centrifuged sample was analysed directly by HPLC. D-Galactose isolated by HPLC was converted into a fluorescent compound by a post-column reaction with arginine at 150 degrees C and the fluorescence intensity at 430 nm was measured with excitation at 320 nm. By this method 10 pmol of D-galactose could be measured and the fluorescence intensity was linear up to 1 mmol of D-galactose. Using this method, the optimal conditions for the activity of this enzyme were re-examined. As an application, the enzyme activity in the brain of a patient with GM1 gangliosidosis was examined. This method can be applied to any natural substrates, glycolipids or glycoproteins, the terminal galactose of which is hydrolysed by this enzyme.

The transport of a currentless ECRH plasma in Heliotron E is studied numerically, using a 1-D transport code with an assumed RF power deposition profile. The investigated parameter range is as follows: 300 Te 1000 eV, Ti 120 eV, 2 < e< 10 X 1012 cm−3 and PRF ≈ 90 kW at B = I T. Four typical models for the transport coefficients are used in the numerical calculations. It is found that a neoclassical model results in a remarkable discrepancy of the time evolution of the electron temperature Te(r) and density ne(r) profiles with regard to the measured values. The neoclassical model which includes the effects of the helical field ripple seems to simulate the saturation of Te(0), in agreement with the experimental results. This saturation is due to the dependence of . However, a consistent description of Te(r) and ne(r) cannot be given by this model. In order to reproduce the measured profiles, it is necessary to use radially increasing transport coefficients. Adding Alcator-like anomalous transport terms (independent of Te) to the neoclassical transport model, it is found that e and PRF dependences of Te(0) can be adequately explained. The fourth model investigated has a temperature-dependent . For ions the e dependence of an anomaly factor, ,is also examined.

Measurements of atomic hydrogen density profiles in Heliotron E plasmas were performed, where attention was focussed on the anisotropy of the profiles in the poloidal cross section. Obtained penetration profiles of atomic hydrogen agreed well with the Monte Carlo code calculations of the penetration of Franck-Condon neutrals when averaged electron densities \bar n e are larger than 10 19 m -3 . For \bar n e

Plasma heating experiment is performed using a low-frequency shear Alfv\'en wave in the Heliotron-$D$ device. The excitation of the wave is confirmed, and an efficient plasma heating is observed; electrons are heated up to about 2 times and ions more than 1.5 times of the initial temperatures by applying an rf pulse of 400-kW power level.

A currentless plasma with a volume-averaged beta value of 2% has been produced with neutral beam heating. Target plasmas were created by second harmonic resonance heating with electron cyclotron waves (150–350 kW and 53.2 GHz) at a magnetic field strength of 0.94 T. Neutral beam injection (23–30 keV and 1.3−2.6 MW) was used to heat the plasma further. MHD stable and unstable high-beta plasmas were observed. The Q-mode plasmas were produced with the help of intense neutral gas puffing. Properties of the MHD activity and confinement of high-beta plasmas are discussed and compared with theoretical studies.

Measurements of neutral-hydrogen density by laser fluorescence spectroscopy on Heliotron E revealed the anisotropy of its distribution in the poloidal cross section and the dependence of the anisotropy on the average electron density for the first time. This indicates the relative importance of the recycling of charged particles localized at divertor traces and that of charge-exchanged neutrals distributed over a surface. These results are used to calculate the global particle confinement time, which is to be correlated with the measurements of H α emission intensity and the electron density fluctuations, the initial results of which are also shown.

The first biased limiter experiment has been done in Heliotron E, which is a typical stellarator / heliotron type device. This experiment investigates the boundary physics of the currentless plasmas, which are produced in the magnetic limiter (divertor) configuration. We analyze the experimental results related to the surface potential, recycling process, and plasma parameters using a material limiter which was biased from the vacuum chamber. The boundary density profile was measured by a thermal Li beam probe to investigate the effect of the biased limiter.

An observation has been made of the laser-induced fluorescence of Fe I near the wall of Heliotron E to obtain information of the metal impurities released from the wall. The electron cyclotron-resonance and the neutral beam injection heatings are operated in a currentless plasma. The iron atom density is found to increase in the later period of the neutral beam injection. This result is compared with that of the measured charge-exchange neutral flux. The impurity-production mechanism is discussed.

Impurity transport in currentless Heliotron E plasmas is examined. The main aim of the experiment is to clarify the density dependence of impurity transport both in electron cyclotron heated (ECH) and neutral beam injected (NBI) plasmas. In experiments with a stationary electron density, the confinement time of impurities is determined as a function of the line averaged electron density. The inherent difference between ECH and NBI plasmas, observed in an earlier measurement, seems to have been masked by the operating conditions. From a direct comparison between NBI plasmas and simultaneous ECH and NBI heated plasmas of the same density, a pumping-out effect of impurities by the ECH pulse is established. From numerical analyses, the unexpected discrepancy between observed and calculated VUV spectral data can be explained by a charge exchange process. The observed impurity transport is found to be well described by a model which incorporates the effects of radial diffusion and inward convection. The inward flow does not seem to be due to the plasma potential because the flow is also observed in ECH plasmas where the heating power is expected to contribute to a reversed potential. The flow velocity is of the order of the classical friction between background ions and seems to play only a minor role in various aspects of impurity transport in NBI plasmas, such as impurity accumulation. The variety in impurity transport in Heliotron E plasmas is best understood by changes in the diffusion coefficient.

The charge density wave induced energy gap has been observed by tunneling measurements over the nearly-commensurate phase of IT-TaS2. The energy gap stays near 0.5eV from 215K up to around 280K, and above this temperature it decreases with increasing the temperature. In addition to the structures giving the energy gap, a group of peak structures connected with the charge density waves have been observed in the dI/dV vs. V curves of the tunneling junctions, though the origin of those is not clarified yet. Connections of the energy gap with the electronic properties of this material are discussed.

In order to investigate the production mechanism of iron atoms from the vacuum vessel wall, a coaxial laser induced fluorescence spectroscopic system, which uses only one diagnostic port, has been developed at Heliotron-E. The neutral iron atoms near the wall were measured in currentless plasmas initiated by ECH and heated by neutral beam injection, and compared to the charge exchange neutral fluxes. The generation mechanisms and the relation between iron outflux form the wall and iron density in the plasma are discussed.

This paper describes preliminary results on the Heliotron E device, which is the biggest machine among the asymmetric toroidal systems. The Heliotron E is designed to investigate the “proof of principle” of the heliotron field configuration. The major and average minor radius are 2.2 m and 20 cm, respectively. In the preliminary experiments at the low helical field Bh = 10 kG, we obtain the high beta plasma s (0) of 1%.

For the choice of super-conducting (SC) vs. normal-conducting (NC) magnet system as a next large helical system device in Japan, 1=2/m=10 Heliotron configuration with major radius of 4m, magnetic field of 4T are surveyed with regard to 1) the design flexibility for short-pulsed/high-beta experiments, 2) the possibility for long-pulsed experiments, 3) the accessibility to the machine for heating and diagnostics, and 4) the schedule/cost for its construction. As for SC design, a strong emphasis has been put on the steady-state operation with divertor. On the other hand, the NC version is characterized by the flexible control of shaping magnetic field, toroidal electric field and leakage magnetic field with 4 pair poloidal field coils. After the detailed comparisons, we conculuded the SC machine is appropriate for the main device in a new Toki Fusion Institute.

Confinement of a plasma initiated and heated by electron cyclotron resonance frequency waves has been studied in Heliotron E. The observed plasma parameters were Te = 500 eV − 100 eV, Ti= 100 eV, ne = 4 × 1012 cm−3 at B = 10 kG. The electron energy decay time was 40±8 msec and the particle confinement time was estimated to be more than 70 msec. These results show a considerable improvement in energy confinement over the ohmically heated plasmas. The ECRH plasma discharge process in Heliotron E was also studied both by the experiment and by the ray trajectory calculations.

The heating systems for the new large helical device which has been designed as a joint effort among Japanese universities are reported. The conceptional design of the heating devices and basic hardware structures are discussed. ECH heating system (112 GH z ) with maximum power of around 10MW is proposed to produce and heat the net current-less plasma. For the further heatings, NBI (20 MW, 100 kV, H 0 ) and ICRF (9 MW, 30–90 MH z ) heating systems have been considered. High energy particle loss, which is a fairly serious problem in helical configurations (stellarator/heliotron), have been analyzed numerically. Monte-Carlo calculation shows that, for tangential injection, the beam energy over 100 kV is necessary to obtain the thermalization efficiency of above 60% inside the half radius. On the fast-wave (ICRF) heating, theoretical analysis of the wave field and velocity distribution function, which includes the loss cone effect, has been developed. In the case of 3 He minority heating, the orbit loss problem becomes small than in the case of proton minority heating. From these theoretical analysis and hardware considerations, the required thermalized power of around 20 MW can be obtained by ECH, NBI and ICRF heatings.

The electron power deposition profile has been estimated experimentally during the ion cyclotron range of frequency (ICRF) heating and the electron cyclotron resonance heating (ECRH) in the compact helical system (CHS). The time evolution of the local electron temperature is measured from the second harmonic electron cyclotron emission (ECE) using super heterodyne radiometer. The absorbed power by electrons has been derived from the change in the slopes of the local electron temperature just before and after the input power is turned off. The power deposition profiles of electrons are compared with results from the calculation code in ICRF experiment. Those results show good agreement. In the ECRH experiment the input power is modulated to reduce the power deposition profile. Those analyses give results that the input power is absorbed around {rho}=0.6. 4 refs., 4 figs.