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The toluene solvate crystal of the titled highly congested aromatic ketone-ester compound has been subjected to crystal structural analysis from the viewpoints of the clarification of distribution feature of effective non-classical hydrogen bonds and the retention and perturbation of the symmetric nature. The two independent molecules of the title naphthalene derivative, which bears two aroyl groups at the adjacent inner positions and two benzoyloxy groups at the neighboring β-positions, and one disordered solvent toluene molecule are incorporated in the asymmetric unit of P21/c (Z′= 2). In the packing of the solvate crystal, the solvent toluene molecule plays the multi roles of hydrogen donor/acceptor for C–H…π non-classical hydrogen bonds and hydrogen donor for C–H…O = C ones. On the other hand, the role of other benzene rings of the parts of the title compound molecules is confined. The 4-methylbenzoyl groups situated at the molecular inner positions mainly play the role of the hydrogen donor of C–H…π non-classical hydrogen bond. The benzoyloxy groups that extend outward from the molecular body mainly act as the hydrogen acceptors of C–H…O and C–H…π non-classical hydrogen bonds. The naphthalene ring moderately contributes as the hydrogen acceptor for C–H…π non-classical hydrogen bonds and as the hydrogen donor for C–H…O non-classical hydrogen bonds. The roles of the toluene molecule are not limited to a simple filler for the void among the major constituent molecules but proved to position at the pseudo-centrosymmetric center of the counter-configurated pair of molecules of the independent major component compounds to concentrate the effective non-classical hydrogen bonds.

The ablation and assimilation of cryogenic pure H_{2} and mixed H_{2}+Ne pellets, which are foreseen to be used by the ITER tokamak for mitigating thermal and electromagnetic loads of major disruptions, are observed by spatially and temporally resolved measurements. It is experimentally demonstrated that a small fraction (here ≈5%) of neon added to hydrogenic pellets enhances the core density assimilation with reduced outward transport for the low magnetic-field side injection. This is consistent with theoretical expectations that line radiation increased by doped neon in dense plasmoids suppresses the plasmoid pressure and reduces the E[over →]×B[over →] transport of the ablated material.

Background:Opioid and benzodiazepine use and abuse is a national healthcare crisis to which patients with cancer are particularly vulnerable. Long-term use and risk factors for opioid and benzodiazepine use in patients with breast cancer is poorly characterized.Methods:We conducted a retrospective population-based study of patients with breast cancer diagnosed between 2008 and 2015 undergoing curative-intent treatment identified through the SEER-Medicare linked database. Primary outcomes were new persistent opioid use and new persistent benzodiazepine use. Factors associated with new opioid and benzodiazepine use were investigated by univariate and multivariable logistic regression.Results:Among opioid-naïve patients, new opioid use was observed in 22,418 (67.4%). Of this group, 611 (2.7%) developed persistent opioid use at 3 months and 157 (0.7%) at 6 months after treatment. Risk factors for persistent use at 3 and 6 months included stage III disease (odds ratio [OR], 2.16; 95% CI, 1.49–3.12, and OR, 3.48; 95% CI, 1.58–7.67), surgery plus chemotherapy (OR, 1.44; 95% CI, 1.10–1.88, and OR, 2.28; 95% CI, 1.40–3.71), surgery plus chemoradiation therapy (OR, 1.47; 95% CI, 1.10–1.96, and OR, 2.34; 95% CI, 1.38–3.96), and initial tramadol use (OR, 2.66; 95% CI, 2.05–3.46, and OR, 3.12; 95% CI, 1.93–5.04). Among benzodiazepine-naïve patients, new benzodiazepine use was observed in 955 (10.3%), and 111 (11.6%) developed new persistent use at 3 months. Tamoxifen use was statistically significantly associated with new persistent benzodiazepine use at 3 months.Conclusions:A large percentage of patients receiving curative-intent treatment of breast cancer were prescribed new opioids; however, only a small number developed new persistent opioid use. In contrast, a smaller proportion of patients received a new benzodiazepine prescription; however, new persistent use after completion of treatment was more likely and particularly related to concurrent treatment with tamoxifen.

Molecular drivers are increasingly identified as therapeutic targets for non-small cell lung cancer (NSCLC). This review focuses on the role of ROS1 inhibitors in treating relapsed/metastatic ROS-1 altered (ROS1+) NSCLC. Four FDA-approved drugs have significant activity against ROS1+ NSCLC: crizotinib, ciritinib, lorlatinib, and entrectinib. Each drug yields an overall response rates exceeding 60% with ciritinib, lorlatinib, and entrectinib possessing intracranial activity. The drugs have manageable toxicity profiles. ROS1 alterations are rare molecular drivers of NSCLC that can be effectively treated with a variety of ROS1-targetd drugs. New agents are being identified that may treat resistance mutations.

Molecular drivers are increasingly identified as therapeutic targets for non-small cell lung cancer (NSCLC). This review focuses on the role of ROS1 inhibitors in treating relapsed/metastatic ROS-1 altered (ROS1+) NSCLC.Four FDA-approved drugs have significant activity against ROS1+ NSCLC: crizotinib, ciritinib, lorlatinib, and entrectinib. Each drug yields an overall response rates exceeding 60% with ciritinib, lorlatinib, and entrectinib possessing intracranial activity. The drugs have manageable toxicity profiles. ROS1 alterations are rare molecular drivers of NSCLC that can be effectively treated with a variety of ROS1-targetd drugs. New agents are being identified that may treat resistance mutations.

Summary Deep learning has the potential to estimate velocity models directly from shot gathers, which would reduce the turn-around time of seismic inversion. Our study addresses two challenges in implementing deep learning techniques for seismic inversion: the practical generation of a large amount of training data and the search for the best neural network architecture. First, we propose a flexible system which parametrically generates velocity models to create a large-scale, complex and fully synthetic training dataset, without using a target subsurface model. Using this system, we created 300,000 synthetic velocity models for our experiments. Second, we employ neural architecture search techniques to design a suitable neural network using Optuna, an automatic hyperparameter optimisation framework. We incorporated the residual network into an encoder–decoder model and optimised its architecture. Thus, we obtained an optimal neural network model consisting of more than 100 hidden layers. We evaluated our model using the Marmousi2 model and the 1994 Amoco statics test dataset. The model demonstrated comprehensible estimations of the benchmark velocity models.

Summary What is known and objective In Japan, although topiroxostat, a selective xanthine oxidoreductase inhibitor, has been used for the treatment of patients with hyperuricemia including gout, no published randomized controlled studies evaluating the dose-dependent relationship with respect to the serum urate-lowering efficacy have been reported. The aim of this study was to evaluate the dose-dependent relationship with serum urate-lowering efficacy and safety of topiroxostat in Japanese hyperuricemic patients including gout. Methods We conducted an exploratory, phase 2a, multicentre, randomized, double-blind, 8-week, placebo-controlled study in Japanese hyperuricemic patients with or without gout. The study arms were placebo and topiroxostat 40, 60, 80 or 120 mg/day. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit. Results and discussion One hundred and eighty-seven eligible patients were randomized and 186 received at least one dose of the study drug. The study results demonstrated a dose-dependent serum urate reduction effect ranging from 40 to 120 mg/day (P < 0·001, Jonckheere–Terpstra test). The mean per cent change in serum urate level from baseline at the final visit was −30·8% in the 120-mg group and 1·6% with placebo, with a between-group difference of −32·4% ([95% confidence interval, −38·9% to −25·9%]; P < 0·001). Incidences of overall adverse events (AEs) in the topiroxostat groups were comparable to those in the placebo group; however, the incidence of AEs in the 120-mg group was statistically lower than that in the placebo group. The incidences of gouty arthritis were not statistically but numerically higher in the topiroxostat 80- and 120-mg groups. What is new and conclusions A dose-dependent serum urate-lowering efficacy of topiroxostat was observed in Japanese hyperuricemic male patients with or without gout. Further clinical studies aimed at evaluating the long-term safety and clinical efficacy are warranted.

We have been developing a conduction cooled 3T HTS(REBCO)-MRI system. The prototype system of 100 mm DSV (diameter spherical volume) was designed and made.The MRI image of a mouse fetus (25 mm long) was obtained successfully with 2.9 T under a power supply driven operation. However, the HTS(ReBCO)-MRI magnet still had a considerable magnetic field fluctuation for clear MRI imaging due to a long-lasting attenuation of screening current induced on the superconducting tapes. To solve this problem, we introduced a power supply system consists of a exciter power supply and a small trimming current supply, which compensates the magnetic field deviation due to the screening current, in parallel. We measured and evaluated the magnetic field stability of a commercial 3T-LTS-MRI magnet under both the power supply driven operation with proposed system and the persistent current operation. The availability of the power supply system was discussed using an experimental HTS-MRI system.

A new temperature controlled material probe was designed for the exposure of W samples to He plasma in the LHD (Large Helical Device). TEM (Transmission Electron Microscopy) analysis allowed the study of the impact of He irradiation under high temperatures (up to 600 °C) on W microstructure: bubbles and dislocation loops are formed at the surface. A heavily damaged layer rich in both damages is formed at the very surface layer whose thickness increases with the incident fluence; beyond this layer, bubbles are observed much deeper than expected, rising concerns about the consequences for the material properties conservation. Nano-indentation measurements showed that the hardness of exposed tungsten indeed increases as the dislocation loops are formed and large bubbles appear in the material.

Petroleum in the Surma basin, NE Bangladesh (part of the Bengal Basin) ranges from waxy crude oils to condensates. The origin and source rocks of these hydrocarbons were investigated based on the distributions of saturated and aromatic hydrocarbons in 20 oil samples from seven oil and gas fields. The relative compositions of pristane, phytane and adjacent n-alkanes suggest that the source rock was deposited in a non-marine setting. The abundance and similar distribution of biphenyls, cadalene and bicadinanes in most of the crude oils and condensates indicates a significant supply of higher-plant derived organic matter to the source rocks. Maturity levels of the crude oils and condensates from the Surma basin correspond to calculated vitrinite reflectance (Rc) values of 1.0–1.3%, indicating hydrocarbon expulsion from the source rock at a comparatively high maturity level. The Rc values of oils from the Titas field in the southern margin of the Surma basin are relatively low (0.8–1.0%). Some oils were severely biodegraded. The similar distribution of diamondoid hydrocarbons in both biodegraded and non-biodegraded oils indicated similar types of source rocks and similar maturity levels to those of oils from the Surma basin. The Oligocene Jenam Shale and/or underlying non-marine deposits located at greater depths may be potential source rocks. The diversity of the petroleum in the Surma basin was likely due to evaporative fractionation, resulting in residual waxy oils and lighter condensates which subsequently underwent tertiary migration and re-accumulation. Evaporative fractionation due to modification of the reservoir structure occurred during and after the Pliocene, when large-scale tectonic deformation occurred in and around the Bengal Basin.

Summary What is known and objective There are no clinical reports that have compared topiroxostat, a selective xanthine oxidase inhibitor, with allopurinol in serum urate-lowering efficacy. The aim of this study was to compare the efficacy and safety of topiroxostat and allopurinol in Japanese hyperuricemic patients with or without gout. Methods A phase 3, multicentre, randomized, double-blind, double-dummy, active-controlled, parallel-group study conducted in Japan. Patients who had inadequate serum urate levels (a gout patient: serum urate level ≥416·4 μmol/L; an asymptomatic hyperuricemic patient with specific complications (urinary lithiasis, hypertension, hyperlipidemia and/or diabetes): serum urate level ≥475·8 μmol/L; and an asymptomatic hyperuricemic patient with no specific complications: serum urate level ≥535·3 μmol/L) were randomized to topiroxostat 120 mg/day or allopurinol 200 mg/day, with an equal allocation ratio, for 16 weeks. To prevent the onset of gouty arthritis by rapid serum urate reduction, these doses were increased in a stepwise manner. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit. Results and discussion Overall, 206 patients were randomly assigned to topiroxostat and allopurinol. Two hundred and three patients (allopurinol: n = 105, topiroxostat: n = 98) received at least one dose of the study drug and had their serum urate level assessed at least once. The baseline characteristics were comparable between groups. The mean age of patients was 53·0 ± 11·4 years and 99% of patients were male. The primary efficacy endpoint was −34·3 ± 11·1% in the allopurinol group (n = 105) and −36·3 ± 12·7% in the topiroxostat group (n = 98). Non-inferiority of the serum urate-lowering efficacy of topiroxostat to allopurinol was proved by the predefined non-inferiority margin (95% confidence interval, −5·3 to 1·3%). The overall incidences of adverse events and adverse drug reactions were similar between both groups. What is new and conclusion Topiroxostat 120 mg/day provides non-inferior serum urate reduction compared with allopurinol 200 mg/day and is well tolerated in Japanese hyperuricemic patients with or without gout.

A core density collapse (CDC) phenomenon is a rapid collapse events observed in super dense core (SDC) plasma with internal diffusion barrier (IDB) in the Large Helical Device (LHD). By CDC, the central beta is decreased by up to 50%. The collapse starts from the edge region of the plasma. CDCs appear with plasma parameters where the high–n ballooning modes are unstable at ϱ ∼ 0.8. With less collisional conditions, m = 1 type oscillations are observed with similar beta profile. The origin of the m = 1 oscillations is not clarified (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Edge cooling experiments with a tracer-encapsulated solid pellet in the large helical device (LHD) show a significant rise in core electron temperature (the maximum rise is around 1 keV) as well as in many tokamaks. This experimental result indicates the possible presence of the nonlocality of electron heat transport in plasmas where turbulence as a cause of anomalous transport dominates. The nonlocal electron temperature rise in the LHD takes place in almost the same parametric domain (e.g. in a low density) as in the tokamaks. Meanwhile, the experimental results of LHD show some new aspects of nonlocal electron temperature rise, for example the delay in the nonlocal rise of core electron temperature relative to the pellet penetration time increases with the increase both in the collisionality in the core plasma and the electron temperature gradient scale length in the outer region of the plasma.

To investigate the relationship of dental status to food diversity among older Japanese.A community-based cross-sectional study conducted in the town of Tosa, Kochi Prefecture, Japan.The study participants were 252 Japanese (84 men and 168 women, average age 81.2 years) and dentate participants were classified into three groups: 1-9 teeth, 10-19 teeth and 20 or more teeth. Food diversity was assessed as a validated measure of dietary quality using the 11-item Food Diversity Score Kyoto (FDSK-11), which evaluates frequency of consumption of 11 main food groups. Multivariable analysis of the differences in FDSK-11 score ranging from 0 to 11, with a higher score indicating greater food diversity, among the three dental status groups was conducted using general linear models. All the performed analyses were stratified by gender.There was no association between dental status and food diversity score in models for men. In contrast, women with ≤ 9 teeth and with 10-19 teeth had significantly lower FDSK-11 scores than women with ≥ 20 teeth after adjusting for confounders (p0.001 and p = 0.009, respectively). Additionally, there was a trend toward lower scores for FDSK-11 with fewer teeth (p = 0.001).A less varied diet, as indicated by low FDSK-11 score, was observed in female participants with fewer teeth. Tooth loss was associated with poor diet quality among older Japanese women.

A repetitive pellet injector has been developed and pellet refuelling experiments have been launched on the Large Helical Device (LHD) in a new regime characterized by high density steady state operation. In order to suppress the disturbance to the core plasma as much as possible, we employ relatively small and slow pellets. The size and velocity of the pellets are typically 2.5?mm in diameter and 250?m?s?1, respectively. The pellets were injected into neutral beam heated plasmas with repetition frequency of 10?Hz. The density rise per pellet is 1.5 ? 1019?m?3 and the pellet penetration depth, which is normalized by the plasma minor radius, is typically less than 0.5. Quasi-steady-state operation was achieved at plasma parameters of , Te = Ti = 1.0?keV. Repetitive pellet fuelling showed improved energy confinement compared with massive gas puff fuelling in the high density regime in common with previous transient pellet injection experiments, and it can sustain such an improved confinement property.

Steady state divertor operation with high performance plasmas (ne ~ 0.7 × 1019 cm−3, Ti ~ 2 keV) was demonstrated for half an hour in the Large Helical Device (LHD), the superconducting helical device (R = 3.6–3.9 m, a = 0.6 m, B = 3 T, l/m = 2/10). The high performance plasmas have been sustained with an averaged heating power of 680 kW and achieved an injected energy of 1.3 GJ. This required both advanced technological integration of heating systems and divertor heat flux control. In particular, optimization of divertor heat flux distribution along the divertor leg trace on divertor plates and real-time magnetic axis sweeping (R = 3.67–3.7 m) have allowed LHD to access a steady state regime with a margin of safety for the actively cooled divertor plates. The distribution of divertor heat load along the traces was investigated with calorimetric measurements and it was found that there was a localized heat load connected with the loss of high-energy ions produced by ion cyclotron radio frequency near-fields. Orbit analysis shows that the behaviour of high-energy ions is qualitatively in good agreement with the experimental result. Long-pulse discharges were terminated by radiation collapse due to penetration of metallic flakes into the plasma.

Magnetic configurations of LHD are characterized by the presence of chaotic magnetic field, the so-called ergodic layer, surrounding the core plasma. H-mode-like discharges have been obtained at an outwardly shifted configuration of Rax = 4.00 m with a thick ergodic layer, where the ι/2π = 1 position is located in the middle of the ergodic layer. A clear density rise and a reduction of magnetic fluctuation were observed. ELM-like Hα bursts also appeared with a radial propagation of density bursts. These H-mode-like discharges can be triggered by changing PNBI(

Self-sustained detachment has been obtained in the Large Helical Device (LHD). Strong hydrogen gas puffing of ~200 Pa m3 s−1 after a density feedback phase detaches the plasma from the divertor plates with high reproducibility. High electron density of over 1 × 1020 m−3 is sustained without gas puffing until the heating beam stops and a high-density flat top for 2 s has been demonstrated. Throughout the self-sustained detachment phase, the minor radius of the hot plasma column shrinks to ~90% of the last-closed-flux-surface, which corresponds to the rational surface. This new state has been named the 'Serpens mode', for self-regulated plasma edge 'neath the last-closed-flux-surface. Global energy confinement of the Serpens mode is compared with the international stellarator scaling 1995 (ISS95) and the recently established scaling for high-density LHD plasmas (HD scaling), where shrinking confinement volume and shallow penetration of the heating beams are taken into account. Although the energy confinement of the Serpens mode seems deteriorated compared with ISS95, as in the case of high-density attached plasmas, it is consistent with the HD scaling. This suggests that the energy confinement properties of detached plasmas in LHD are similar to those in high-density attached plasmas.

In the Large Helical Device (LHD), two different divertor configurations, i.e. helical divertor (HD) and local island divertor (LID), are utilized to control the edge plasma. The HD with two X-points is an intrinsic divertor for heliotron devices, accompanied with a relatively thick ergodic layer outside the confinement region. Edge and divertor plasma behavior from low density to high density regimes is presented, referring to the divertor detachment. The effect of the ergodic layer on the edge transport is also discussed. On the other hand, the LID is an advanced divertor concept which realizes a high pumping efficiency by the combination of an externally induced magnetic island and a closed pumping system. Experimental results to confirm the fundamental divertor performance of the LID are presented.

A variety of electron density (ne) profiles have been observed in the Large Helical Device (LHD). The density profiles change dramatically with heating power and toroidal magnetic field (Bt). The particle transport coefficients, i.e. diffusion coefficient (D) and convection velocity (V) are experimentally obtained in the standard configuration from density modulation experiments. The values of D and V are estimated separately in the core and edge. The diffusion coefficients are found to be a function of electron temperature (Te), and vary with Bt. Edge diffusion coefficients are proportional to . Non-zero V is observed, and it is found that the electron temperature gradient can drive particle convection, particularly in the core region. The convection velocity both in the core and edge reverses direction from inward to outward as the Te gradient increases. However, the toroidal magnetic field also significantly affects the value and direction of V. The density fluctuation profiles are measured by a two-dimensional phase contrast interferometer. It was found that fluctuations which are localized in the edge propagate towards the ion diamagnetic direction in the laboratory frame, while the phase velocity of fluctuations around mid-radius is close to the plasma poloidal Er × Bt rotation velocity. The fluctuation level becomes larger as particle flux becomes larger in the edge region.

Magnetic island formation is experimentally investigated in the Large Helical Device. The (m, n) = (1, 1) vacuum magnetic island is generated by using the local island diverter field, where m and n are the poloidal and toroidal mode numbers, respectively. The island width depends on plasma parameters (the electron temperature and the β) and the magnetic axis position. In the case of Rax = 3.53 m the magnetic island in the plasma is larger than that in the vacuum field. Here, Rax is the major radius of the magnetic axis. In the case of Rax = 3.6 m the magnetic island is not generated when the error field is less than the threshold which is increased as the β is increased. Evidence of island current is obtained when the magnetic island is formed due to a small error field. However, the mechanism that generates the island is not yet known.

In the Large Helical Device (LHD) programme, one of the key research issues is to enhance helical plasma performance through edge plasma control. For the first time in the LHD programme, the edge plasma control was performed with a local island divertor (LID) that is a closed divertor, utilizing an m/n = 1/1 island generated externally by which 20 small perturbation coils, and fundamental LID functions were demonstrated experimentally. It was found that the outward heat and particle fluxes crossing the island separatrix flow along the field lines to the rear of the divertor head, where carbon plates are placed to receive the heat and particle loads. Accordingly, high efficient pumping was demonstrated, which is considered to be the key in realizing high temperature divertor operations, resulting in an improvement in energy confinement. In this experiment, relatively good energy confinement is achieved in the high density regime at a magnetic axis position, Rax, of 3.75?m. Results of edge modelling are also presented by using the EMC3-EIRENE code.

A local island divertor (LID) experiment has begun on LHD, with the aims of controlling edge recycling and improving the plasma confinement. The fundamental divertor functions of the LID have been demonstrated in the recent experiments. From the particle flux profile measurements on the LID head it was found that the particles diffusing out from the core region are well guided along the island separatrix to the LID head. Owing to the closed configuration around the LID head, evidence of the high efficient pumping was observed, together with a strong capacity to screen impurities. The first results of edge modeling using the EMC3-EIRENE code are also presented.

In the HT-7 superconducting tokamak, long-pulse discharge was generated by synergy of high power LHCD (300–600 kW, 2.45 GHz) and high power IBW (200–350 kW, 27 MHz) heating. Recently, a new set of actively cooled toroidal double-ring graphite limiters at bottom and top of the vacuum vessel has been developed for long-pulse operation in the HT-7. Based on the understanding of plasma surface interactions, nearly full non-inductive current driven plasma (Ip = 120–180 kA, BT = 1.5–2 T, Te(0) = 2–4 keV, and 〈ne〉 = 1–2.5 × 1019 m−3) was achieved with the operational pulse length of 1–10 s. For lower performance operation, more than 60 s of long-pulse plasma was obtained by the LHCD in 2003 on the HT-7 tokamak.

A repetitive pellet injector has been developed for investigation of refueling issues towards the steady-state operation in Large Helical Device (LHD). Continuous operation of more than 10000 pellet launching at 10 Hz has been demonstrated. The maximum repeating rate is 11 Hz. No technical constraint for longer operation has been found. The reliability of pellet launch has exceeded 99.9%. The initial application to the NBI-heated plasmas has been successful in the last experimental campaign of LHD. Although the pulse length is limited by the operational constraint of NBI, the plasma with a density of 8 × 1019 m-3 has been sustained for 2 s by the pellet injection at 10 Hz. A prospect for the future experiment is discussed on the basis of the initial result.

Hydrogen ice pellets have been injected using two different location configurations, namely outer port injection and coil side injection, in the large helical device. The behaviour of the pellet ablation has been observed using a fast camera, which possesses high spatial and time resolution. Striking toroidal deflection of the pellet trajectory is observed. The deflection is in the direction of tangential neutral beam injection. The toroidal velocity ultimately reaches 1000 m s−1 or more. The possibility of a rocket effect due to a unilateral ablation by the fast ions is discussed. The effective penetration depth of the pellet, which is measured by images, agrees with the prediction from the neutral-gas-shielding model. The penetration depth is compared with the measured deposition profile of the pellet.

Characteristics of MHD instabilities and their impacts on plasma confinement are studied in current free plasmas of the Large Helical Device. Spontaneous L?H transition is often observed in high beta plasmas close to 2% at low toroidal fields (Bt ? 0.75?T). The stored energy starts to rise rapidly just after the transition accompanying the clear rise in the electron density but quickly saturates due to the growth of the m = 2/n = 3 mode (m and n: poloidal and toroidal mode numbers), the rational surface of which is located in the edge barrier region, and edge localized mode (ELM) like activities having fairly small amplitude but high repetition frequency. Even in low beta plasmas without L?H transitions, ELM-like activities are sometimes induced in high performance plasmas with a steep edge pressure gradient and transiently reduce the stored energy up to 10%. Energetic ion driven MHD modes such as Alfv?n eigenmodes (AEs) are studied in a very wide range of characteristic parameters (the averaged beta of energetic ions, ?b?, and the ratio of energetic ion velocity to the Alfv?n velocity, Vb?/VA), of which range includes all tokamak data. In addition to the observation of toroidicity induced AEs (TAEs), coherent magnetic fluctuations of helicity induced AEs (HAEs) have been detected for the first time in NBI heated plasmas. The transition of a core-localized TAE to a global AE (GAE) is also observed in a discharge with temporal evolution of the rotational transform profile, having a similarity to the phenomenon observed in a reversed shear tokamak. At low magnetic fields, bursting TAEs transiently induce a significant loss of energetic ions, up to 40% of injected beams, but on the other hand play an important role in triggering the formation of transport barriers in the core and edge regions.

A microbeam system is under construction in the Dynamitron laboratory at Tohoku University for the purpose of applying X-rays produced by a microproton beam as monochromatic X-ray point source to biological and materials research etc. The system consists of a dedicated beam line with a doublet quadrupole and a slit-system of microslits, divergence-defining slits and baffle slits connected to the 4.5 MV Dynamitron accelerator’s energy analyzing system, which was a newly installed second analyzing magnet. The demagnification factors are 8.0 and 27.5 for horizontal and vertical planes, respectively. Performance of the microbeam system was tested by beam scanning across the surface of a copper mesh sample (1000 lines/inch) and measuring the X-ray spectrum. A beam spot size of 2 × 2 μm 2 , which is larger than the design goal, is currently obtained. We are now adjusting the whole system to achieve a beam spot size of 1 × 1 μm 2 .

Significant progress has been made with ion cyclotron range of frequencies (ICRF) heating in the Large Helical Device. This is mainly due to better confinement of the helically trapped particles and less accumulation of impurities in the region of the plasma core. During the past two years, ICRF heating power has been increased from 1.35 to 2.7 MW. Various wave-mode tests were carried out using minority-ion heating, second-harmonic heating, slow-wave heating and high-density fast-wave heating at the fundamental cyclotron frequency. This fundamental heating mode extended the plasma density range of effective ICRF heating to a value of 1×1020 m−3. This use of the heating mode was its first successful application in large fusion devices. Using the minority-ion mode gave the best performance, and the stored energy reached 240 kJ using ICRF alone. This was obtained for the inward-shifted magnetic axis configuration. The improvement associated with the axis-shift was common for both bulk plasma and highly accelerated particles. For the minority-ion mode, high-energy ions up to 500 keV were observed by concentrating the heating power near the plasma axis. The confinement properties of high-energy particles were studied for different magnetic axis configurations, using the power-modulation technique. It confirmed that with the inward-shifted configuration the confinement of high-energy particles was better than with the normal configuration. By increasing the distance of the plasma to the vessel wall to about 2 cm, the impurity influx was sufficiently reduced to allow sustainment of the plasma with ICRF heating alone for more than 2 min.

Internal transport barriers with respect to electron thermal transport (eITB) were observed in the large helical device, when the electron cyclotron resonance heating (ECH) power was highly localized on the centre of a plasma sustained by neutral beam injection. The eITB is characterized by a high central electron temperature of 6–8 keV with an extremely steep gradient, as high as 55 keV m−1 and a low electron thermal diffusivity within a normalized average radius ρ≈0.3 as well as by the existence of clear thresholds for the ECH power and plasma collisionality.

The behaviour of high-energy ions accelerated by an ion cyclotron range of frequency (ICRF) electric field in the large helical device (LHD) is discussed. A better confinement performance of high-energy ions in the inward-shifted magnetic axis configuration was experimentally verified by measuring their energy spectrum and comparing it with the effective temperature determined by an electron slowing down process. In the standard magnetic axis configuration a saturation of the measured tail temperature was observed as the effective temperature was increased. The ratio between these two quantities is a measure of the quality of transfer efficiency from high-energy ions to a bulk plasma; when this efficiency was compared with Monte Carlo simulations the results agreed fairly well. The ratio of the stored energy of the high-energy ions to that of the bulk plasma was measured using an ICRF heating power modulation method; it was deduced from phase differences between total and bulk plasma stored energies and the modulated ICRF heating power. The measured high energy fraction agreed with that calculated using the injected ICRF heating power, the transfer efficiency determined in the experiment and the confinement scaling of the LHD plasma.

The convergence properties of stereo acoustic echo cancelers with preprocessing are examined. We first elucidated the conditions of the paths from the talker to the microphones under which the nonuniqueness problem occurs. The degree of nonuniqueness was found to depend on the primeness of the paths. Next, the convergence rates of the acoustic echo cancelers with preprocessing were analyzed based on the independence theory for general cases and on the cyclostationarity of the input signal for the input-sliding method. The derived rates that depended on both of the period of the input signal and the order of the adaptive filter agreed well with the results of computer simulations.

We have studied the growth of the Zn1−xMnxTe film on the GaAs(1 0 0) substrate by use of hot-wall epitaxy (HWE) system. The growth rate is rather slow and the epitaxial Zn1−xMnxTe films with thickness of about 230 nm are obtained after 6 h deposition. Mn composition can be easily controlled in the range of x=0–0.33 by changing the Mn source temperature (650–680 °C). It, however, is found that the structural quality of the films degrades with increasing Mn composition. Obtained Zn1−xMnxTe films showed photoluminescence originating in Mn2+ ions.

Ion temperature at the plasma centre has been measured from Doppler broadening of Ti XXI (2.61 A) and Ar XVII (3.95 A) x-ray lines using a newly installed crystal spectrometer with CCD detector in ECH, NBI and ICRF plasmas of Large Helical Device (LHD). The ion temperature obtained in a range of 0.6 and 3.5 keV was analysed with electron density and compared with electron temperature. A new parameter range of Ti>Te was found in low-density (ne

Divertor plasma characteristics in the Large Helical Device (LHD) have been investigated mainly by using Langmuir probes. The three-dimensional structure of the helical divertor, which is naturally produced in the heliotron-type magnetic configuration, is clearly seen in the measured particle and power deposition profiles on the divertor plates. These observations are consistent with the numerical results of field line tracing. The particle flux to the divertor plates increases almost linearly with the line averaged density. The high-recycling regime and divertor detachment, which are observed in tokamaks, have not been observed even during high density discharges with low input power. Both electron density and temperature decrease with increasing radius in the stochastic layer with open field lines, and at the divertor plate they become fairly low compared with those at the last closed flux surface. This means the reduction of pressure along the magnetic field lines occurs in the open field line region in LHD.

The energy confinement time of net current-free plasmas in the Large Helical Device (LHD) is comparable to ELMy H-mode with q = 4.5 on the scale of IPB98(y,2). Broad temperature with high edge pressure, which is of robust nature in LHD, recalls the pedestal structure in tokamak H-mode. Basic parameter dependence is, however, weak gyro-Bohm in both edge and core regions. This suggests that one physical model could explain the observed profile. The edge temperature is proportional to the square root of heating power and inversely proportional to the square root of edge density. This means that edge pressure and its gradient are not limited and can be increased by heating power.

The improvement in the particle confinement of pellet shots on the Large Helical Device (LHD) was found after methane (CH4) mixed hydrogen gas-puff discharges. Only four discharges introducing ∼20 Pa m 3 of CH4 caused the reduction in the radiation loss and the level of metal impurities, together with the enhanced recycling, which is expected as the real time carbonization effect. The decay rate of the electron density was mitigated in the pellet shot after CH4 discharges. Transport analysis shows 60% reduction in the particle transport coefficient at half the averaged minor radius.

During the first two years of the LHD experiment the following results have been achieved: (i) higher Te (Te(0) = 4.4 keV at ne = 5.3 × 1018 m-3 and Pabs = 1.8 MW); (ii) higher confinement (τE = 0.3 s, Te(0) = 1.1 keV at ne = 6.5 × 1019 m-3 and Pabs = 2.0 MW); (iii) higher stored energy, Wpdia = 880 kJ at B = 2.75 T. High performance plasmas have been realized in the inward shifted magnetic axis configuration (R = 3.6 m) where helical symmetry is recovered and the particle orbit properties are improved by a trade-off of MHD stability properties due to the appearance of a magnetic hill. Energy confinement was systematically higher than that predicted by the International Stellarator Scaling 95 by up to a factor of 1.6 and was comparable with the ELMy H mode confinement capability in tokamaks. This confinement improvement is attributed to configuration control (inward shift of the magnetic axis) and to the formation of a high edge temperature. The average beta value achieved reached 2.4% at B = 1.3 T, the highest beta value ever obtained in a helical device, and so far no degradation of confinement by MHD phenomena has been observed. The inward shifted configuration has also led to successful ICRF minority ion heating. ICRF powers up to 1.3 MW were reliably injected into the plasma without significant impurity contamination, and a plasma with a stored energy of 200 kJ was sustained for 5 s by ICRF alone. As another important result, long pulse discharges of more than 1 min were successfully achieved separately with an NBI heating of 0.5 MW and with an ICRF heating of 0.85 MW.