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Androgens are produced locally in breast carcinoma tissues by androgen‑producing enzymes such as 5α‑reductase type 1 (5αRed1) and affect not only breast cancer cells but the tumor microenvironment as well. Tumor‑associated macrophages (TAMs) are primary components of the tumor microenvironment and contribute to tumor progression. Although previous studies suggest that androgen/androgen receptor (AR) signaling in macrophages has important roles in human diseases, androgen action on TAMs has remained largely unknown. We immunolocalized macrophage marker CD163 as well as AR and 5αRed1 in 116 breast carcinomas and correlated them with clinicopathological parameters and clinical outcomes. Moreover, we examined the roles of androgens on macrophages in breast cancer progression using cell lines 4T1 (mouse breast cancer) and RAW264.7 (macrophage) in a tumor‑bearing female BALB/c mouse model. Double immunohistochemistry revealed that AR was sporadically expressed in the macrophages in breast carcinoma tissues. Macrophage infiltration was significantly correlated with an aggressive phenotype of breast carcinomas and worse prognosis, especially in the 5αRed1‑positive group. In a sphere‑forming assay using 4T1 and RAW‑AR cells, which stably express AR, the sphere size was significantly increased due to androgens when 4T1 cells were cocultured with RAW‑AR cells. Furthermore, in vivo experiments revealed that tumor growth and Ki67, a cell proliferation marker, were increased when androgens were stably produced in breast cancer cells and AR was expressed in macrophages. In conclusion, AR is expressed in intratumoral macrophages and is associated with an aggressive phenotype of breast carcinomas, especially when breast cancer cells actively produce androgens. Thus, androgens may enhance the ability of macrophages to promote breast cancer progression.

A transition from an interchange mode to a non-resonant mode is found in the nonlinear magnetohydrodynamic simulation for the partial collapse in a large helical device (LHD) plasma with a net toroidal current. This transition can occur when the magnetic shear is weak and the rotational transform is close to unity in the core region. In this transition, the mode number of the dominant Fourier component is reduced. As a result of the nonlinear evolution, the (m, n) = (1, 1) component can be dominant, where m and n are the poloidal and the toroidal mode numbers, respectively. This transition is considered to be a candidate to explain the observation in the LHD experiments with the net toroidal current that show partial collapses are caused by the (1, 1) mode.

Dentritic spines are small membrane protrusions. Their regulation is thought to be important for memory storage, but the links between dentric spines and memory have been largely correlational because of a luck of techniques for manipulating individual spines. To overcome this problem, we have developed a novel synaptic optoprobe, AS-PaRac1, which is unique not only because it specifically labels recently potentiated spines, but also because it becomes possible to selectively shrink spines containing AS-PaRac1. This indicates that AS-PaRac1 can be use to specifically visualize the recently "written spines" and that the erasure of these spines is possible upon excitation with blue light. Using in vivo two-photon imaging, synaptic potentiation was visualized during active remodeling of the neocortex. Upon learning a motor skill, AS-PaRac1 expression was induced in a relatively small number of neurons, in which approximately 8% of spines were tagged by AS-PaRac1. The labeled spines were broadly distributed throughout the dendritic tree. Excitation with blue light induced shrinkage of learning related spines and disrupted the acquired motor learning. In contrast, the erasure of a similar number of learning-irrelevant spines did not affect task performance. This novel light-dependent tool will open up new areas of memory research, and will additionally shed light on the neural networks that determine who we are.

All-optical gas sensor consisting of graphene covered silicon microring resonator is proposed. Ammonia gas increases the Fermi level of graphene. The gas concentration can be detected by the resonant-wavelength shift by microring resonator.

Integrated optic ammonia gas sensor using graphene covered silicon microring resonator is proposed. Ammonia gas adsorption increases the Fermi energy of graphene. The gas concentration is detected by the resonant-wavelength shift of microring resonator. The NH3 gas concentration from 0.5 to 1000 ppm is shown to be measured by the resonant wavelength from 1551.75 to 1551.27 nm. By applying voltage to the graphene, the Fermi energy is controlled to adjust the sensitivity and the range of detectable concentration.

The production of fatty acid methyl esters (FAMEs) from waste activated bleaching earth (ABE) discarded by the crude oil refining industry using lipase from Candida cylindracea was investigated in a 50-L pilot plant. Diesel oil or kerosene was used as an organic solvent for the transesterification of triglycerides embedded in the waste ABE. When 1% (w/w) lipase was added to waste ABE, the FAME content reached 97% (w/w) after reaction for 12 h at 25 °C with an agitation rate of 30 rpm. The FAME production rate was strongly dependent upon the amount of enzyme added. Mixtures of FAME and diesel oil at ratios of 45:55 (BDF-45) and 35:65 (BDF-35) were assessed and compared with the European specifications for biodiesel as automotive diesel fuel, as defined by pr EN 14214. The biodiesel quality of BDF-45 met the EN 14214 standard. BDF-45 was used as generator fuel, and the exhaust emissions were compared with those of diesel oil. The CO and SO2 contents were reduced, but nitrogen oxide emission increased by 10%. This is the first report of a pilot plant study of lipase-catalyzed FAME production using waste ABE as a raw material. This result demonstrates a promising reutilization method for the production of FAME from industrial waste resources containing vegetable oils for use as a biodiesel fuel.

The enzymatic transesterification of rapeseed oil and methanol with activated bleaching earth (ABE) as a medium was investigated in a solvent-free system. The initial fatty acid methyl ester (FAME) production rate in the solvent-free system was 2.3-fold lower than that in the organic solvent system, but there was not much difference between the overall reaction rates in the solvent and solvent-free systems. When ABE was added to the reaction mixture consisting of rapeseed oil, methanol and lipase, the repeated batch production of FAME was conducted for nine cycles without a significant inactivation of lipase. However, it was only repeated six times in the rapeseed oil-fed batch process, because of the inactivation of lipase. The FAME yield based on used lipase in the repeated batch process was 55.8 g FAME per gram used lipase, which was two-fold higher than that of the oil-fed batch process.

Twelve kinds of silica particles, with particle sizes of 1.6–700 μm and specific surface areas of 14–620 m 2 /g support, were investigated as lipase-immobilizing supports for the production of fatty acid methyl ester (FAME). When the particle size and specific surface area of silica particles became smaller, the maximum enzymatic reaction rate was at a high level. Scanning electron microscopy revealed that the surfaces of lipase-immobilizing silica particles were coated by a lipase layer. At higher lipase loading than 20%, the lipase formed multilayers or wrinkled sheets on the silica surface and some of them peeled off. Lipase activity was proportional to the increase in the enzyme loading on silica particle until 30%, but the FAME formation rate was proportioned to the enzyme loading until 20%, and remained at a maximum level at lipase loading higher than 20%. The lipase-immobilizing silica particle did not lose activity following agitation rate at a 150 rpm for 8 h and 118 d of storage at room temperature. When lipase-immobilizing silica P-707 with at a specific surface area of 300 m 2 /g was used, the FAME conversion remained at 80% until the 16–20th cycle, and decreased to 20% after the 33rd cycle. The lipase immobilized on P-707 produced 57 g FAME per gram of lipase. Total FAME production increased with an increase in the specific surface area of silica particles, but it was not influenced by particle size over 40 μm. During the progress of a long-term esterification reaction, the outer layer lipase was first inactivated, and then the inner layer of lipase was inactivated.

JT-60 data processing system (DPS) possesses three-level hierarchy. At the top level of hierarchy is JT-60 inter-shot processor (MSP-ISP), which is a mainframe computer, provides communication with the JT-60 supervisory control system and supervises the internal communication inside the DPS. The middle level of hierarchy has minicomputers and the bottom level of hierarchy has individual diagnostic subsystems, which consist of the CAMAC and VME modules. To meet the demand for advanced diagnostics, the DPS has been progressed in stages from a three-level hierarchy system, which was dependent on the processing power of the MSP-ISP, to a two-level hierarchy system, which is decentralized data processing system (New-DPS) by utilizing the UNIX-based workstations and network technology. At present, replacing the MSP-ISP with a UNIX-based workstation is under way as a final phase in building the New-DPS project. This replacement will be accomplished by October 2005. In addition, remote experiment in JT-60 is considered to be an important issue in extension of the collaborative research among the nuclear fusion community. Technical environments for this task have been developed. The participant from a remote site can set discharge parameters with assistance of the dedicated machine operating status-information tools.

A negative-ion-based neutral beam injection (NBI) system, in which large caesium-seeded negative-ion sources are utilized, has operated reliably in the Large Helical Device (LHD) since it was operational in 1998. The injection power of the hydrogen beam has been increased up to 13.1 MW with three injectors. In one injector with modified ion sources utilizing a multi-slotted grounded grid, the injection power reached 5.7 MW with an energy of 184 keV, which exceeds the designed value of 180 keV and 5 MW. Individual control of the local arc-discharge with independently divided arc and filament power supplies is effective in improving beam uniformity in a large negative ion source. The injection duration has been extended to 120 s, during which the LHD plasma is sustained by the NBI alone with a reduced power of 0.2–0.3 MW using one ion source with a cooled plasma grid. These results demonstrate that the injection performance of the negative-ion-based NBI is comparable to that of the conventional positive-ion-based NBI. The progress of the negative-NBI in the LHD is reviewed in detail from the point of view of the improvement of the negative ion sources.

The JFT-2M tokamak has been modified three times during the Advanced Material Tokamak Experiment (AMTEX) program to investigate the compatibility of the low-activation ferritic steel F82H with tokamak plasmas as structural material for future reactors. The ferritic steel plates/wall were installed inside and/or outside of the vacuum vessel to reduce the ripple of the toroidal magnetic field step by step through three modifications. This paper focuses on engineering aspects of these modifications: electromagnetic analysis to find a suitable way to attach these plates, installation procedure to keep small tolerances, and a three-dimensional magnetic field measurement device used to obtain information of the actual shape of the vacuum vessel used as a standard installation surface. To maintain good surface conditions of the ferritic steel plates/wall that rust easily, careful treatment was executed before the installation. To reduce oxygen impurities further, a boronization system with trimethyl boron, which is safe and easy to operate, was developed.

The diagnostic system of JFT-2M has consisted of about 30 individual diagnostic instruments, which were used to study plasma production, control, equilibrium, stability, confinement, plasma heating...

In JFT-2M, the toroidal magnetic field (TF) ripple was reduced by ferritic insert. Two kinds of ripple reduction were carried out. In the first case, ferritic steel was installed between the TF coil (TFC) and the vacuum vessel, just under the TFCs outside the vacuum vessel. In the second one, ferritic steel was installed inside the vacuum vessel covering almost the whole inside wall. The ripple was successfully reduced in both cases. The temperature increment on the first wall, which indicates the ripple-induced loss of fast ions, was measured by infrared television and was also reduced. The effect of the localized larger ripple was also investigated by attaching additional ferritic steel. A new version of the orbit-following Monte Carlo (OFMC) code was developed including the three-dimensional complex structure of the TF ripple and the nonaxisymmetric first-wall geometry. The experimental results and the new OFMC calculation were consistent.

Compatibility between plasma and reduced activation ferritic steel, which is the leading candidate for the structural material of a fusion demonstration reactor, has been investigated in the Advanced Material Tokamak EXperiment (AMTEX). Ferritic plates (FPs) were installed progressively in the JFT-2M tokamak. The effect of ferromagnetism on plasma production, control, confinement, and stability has been investigated. Impurity release behavior has also been investigated. Even when the inside vacuum vessel wall was fully covered with the FPs and the tokamak plasma was operated close to the wall, no deleterious effect was observed, and the normalized beta could be increased up to ~3.5. Thus, encouraging results are obtained for application of this material to the demonstration reactor.

The dependence of helium production on radiation hardening and -embrittlement has been examined in a reduced-activation martensitic F82H steel (8Cr–2W–0.2V–0.04Ta–0.1C) irradiated at 250 °C to 2.3 dpa. In this study, 10 B and 11 B-doped specimens were irradiated to minimize the errors from the effect of B on mechanical properties by comparing the results. The specimens used were 10 B-doped, 10 B + 11 B-doped and 11 B-doped F82H steels. The total amounts of doping boron were about 60 mass ppm. The range of helium concentration produced in the specimens was from about 5 to about 330 appm. Tensile and fracture toughness tests were performed after neutron irradiation. 50 MeV-He 2+ irradiation was also performed to implant about 85 appm He atoms at 120 °C by AVF cyclotron to 0.03 dpa, and small punch testing was performed to obtain ductile-to-brittle transition temperatures (DBTT). Radiation hardening of the neutron-irradiated specimens increased slightly with increasing helium production. The 100 MPa m 1/2 DBTT for the F82H + 11 B, F82H + 10 B + 11 B, and F82H + 10 B specimens were 40, 110, and 155 °C, respectively. The shifts of DBTT due to helium production were evaluated as about 70 °C by 190 appm He and 115 °C by 330 appm He. In cyclotron experiment using standard F82H, a similar DBTT shift due to He was measured. These results suggest that helium production can increase the DBTT.

A low-power test system using a vector network analyzer is constructed to evaluate the performance of phase correcting mirrors in a matching optics unit (MOU). The MOU is used in order to facilitate the good coupling of a millimeter wave beam from a gyrotron into corrugated waveguides. The newly developed diagnostic system allows us to make measurements not only of intensity-, but also of phase-profiles of millimeter wave beams and opens a new range of possibilities for designing and testing high-precision quasi-optical systems. Low-power tests are carried out to evaluate the performance of the newly designed MOU by reversely injecting a Gaussian beam from the output port of the MOU. The output beam from the input port of the MOU is measured with the analyzer. In this inverse process, the injected Gaussian beam should be converted to the real beam pattern radiated from the gyrotron. Using correlation analysis, the measured- and calculated-electric fields are compared in their amplitude- and phase-profiles. Good agreement between the measurement and the calculation is obtained. Therefore, it is judged that the phase-correcting mirrors in the MOU will work correctly in upcoming high-power tests.

F82H (Fe–8Cr–2W) and its variant doped with 2%Ni were irradiated up to 20 dpa at 300 °C in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Post irradiation tensile testing was performed at room temperature. During testing, the images of the specimens including the necked region were continuously recorded. Tests on cold worked material were also carried out for comparison. From the load–displacement curves and the strain distributions obtains from the images, flow stress levels and strain hardening behavior was evaluated. A preliminary constitutive equation for the plastic deformation of irradiated F82H is presented. The results suggest that the irradiation mainly causes defect-induced hardening while it did not strongly affect strain hardening at the same flow stress level for F82H irradiated at 300 °C. The strain hardening of Ni doped specimens was, however, strongly affected by irradiation. Results provide basics to determine allowable stress levels at temperatures below 400 °C.

Low activation ferritic steel plates were installed in the JFT-2M tokamak to fully cover the inside wall of the vacuum vessel (ferritic inside wall; FIW) as a simulation of the blanket wall of the fusion demonstration reactor. After the physics and engineering design concerns with the ripple reduction, the electro-magnetic force and so on, FIW was installed with a tolerance of a few mm. The ripple reduction was confirmed from the detailed measurement. Tokamak discharges were obtained without changing control system, as predicted theoretically. The reduction of ripple loss of fast ions was clearly demonstrated by both experiments and calculations. Compatibility of FIW with high normalized beta plasma up to 3.3 was demonstrated at relatively far wall position. Preliminary investigation showed that the slowdown of the growth rate occurred with closer wall position, which presumably corresponds to wall stabilization effect.

In the JT-60 tokamak at JAERI, an environment for remote participation is planning to be developed by concentrating ideas of experts of nuclear fusion research from research organizations and universities distributed throughout the country. We are constructing a hierarchical collaborative remote research system, which consists of remote experiment, remote analysis and remote diagnostic. In remote collaboration, it is important to share information, atmosphere and presence between the participants as well as to maintain the security of the system. To implement a collaborative environment, a video conferencing system, a video streaming system and remote analysis system called “VizAnalysis” have been developed for the communication. To assist the remote participation for the fusion research, the document management system based on the web browser called “VizSquare” has been developed. In JT-60, security and authentication methods utilizing a computer network and a new communication tool have been developed, and they are applicable to the remote participation of ITER.

Data processing system for JT-60 is constructed by mini-computers, microcomputers and CAMACs for the control and the data acquisition of plasma diagnostics. However, it is difficult to apply this system to the remote diagnostics using the internet, because the old microcomputers used for over 15 years has no internet connectivity. Therefore, the data processing subsystem using mini-computers and microcomputers should be replaced, keeping the consistency with the main computer. The workstation based on UNIX-OS is a useful candidate for replacing those computers, since it is excellent in the network communication, the cost and the stability. We therefore the replaced microcomputers controlled and monitored the diagnostic CAMAC system, and executed its data acquisition. The new workstation-based system was simple system, which consisted of the serial highway driver module for controlling CAMAC and CPU module with SPARC CPU in VMEbus. By these replacements, the difficulty in the remote control has been solved by using the network and screen control of X Window. The maintainability is also improved and the function enhancement becomes easier. In this paper, basic design for replacing mini-computer and microcomputer with the UNIX workstation will be described.

A powerful neutral beam system with six high current H− ion sources achieved a total power of 10.3 MW in the large helical device (LHD). We describe the present status of the ion sources, and the results of studies of cesium consumption, tungsten filament lifetime, and the velocity spectrum of the beam. Maximum power and beam energy in those ion sources range from 3.5 to 4.4 MW and 165 to 180 keV (design energy), respectively. The maximum H− current is ∼25 A. Much progress on beam acceleration and plasma uniformity was facilitated by a new accelerator and new arc power supply system with careful Cs seeding. Cs consumption for 1/2 year of operation ranges from 3.9 to 10.6 g per one source (over 2×104 shots). It is converted to the rate of 0.17–1.5 mg per one shot per source. It is considered that Cs deposition on the inside surface of the plasma source could be from 0.11 to 1.0 monolayer per one shot per source. This is of the same order as the expected optimum coverage of ∼0.7. Filament weight loss was me...

In this article we describe the first results of beam injection using an improved negative ion source, which consists of a set of steering and multislot grounded grids. The set of the grids is designed to achieve high power beam injection for the large helical device (LHD). The main purpose in replacing the conventional multiaperture with multislot grids is to reduce the heat load onto the grid. By adopting the multislot grid, the frequency of voltage breakdown at the acceleration gap decreased considerably and the maximum beam energy attained was 180 keV, which is one of the target values of the LHD neutral beam injector (NBI). The maximum injection power reached 4.4 MW, consequently. The heat load onto the multislot grid was water calorimetrically measured and the load is suppressed by 50% compared to the multiaperture case. In the condition for maximum injection power, the beam profile obtained in the accelerator with the multislot grounded grid becomes vertically elongated due to the asymmetric electric field close to the grid slot. Although some part of this elongated beam is lost at the injection port, the multislot grid has enough performance for beam injection.

In order to investigate the influence of shot peening on the surface durability of sintered powder metal gears, the plasma case-hardened sintered powder metal gears shot-peened with different shot diameter and shot hardness were fatigue-tested using a gear testing machine. The hardness, the compressive residual stress and the surface roughness of the gears increased by the shot peening. The pores near the tooth surface of the shot-peened gears were obviously deformed excect for those of the lightest shot-peened gear in this study. The failure mode of the unpeened gear was pitting, and those of the shot-peened gears was mainly spalling. The failure depth agreed almost with the depth where the amplitude A (τyz/HV) of the ratio of orthogonal shear stress to Vickers hardness became peak near the tooth surface. In these experiments the surface durability of the lightest shot-peened gear was highest comparing with those of the other gears. Therefore, it can be proposed that the light shot peening, which does not cause too large surface roughness and the deformed sharp pore, has to be selected in order to improve the surface durability of sintered powder metal gears.

Compatibility between the plasma and low activation ferritic steel, which is a candidate material for fusion demonstration reactors, has been investigated step by step in the JFT-2M tokamak. We have entered the third stage of the Advanced Material Tokamak EXperiment (AMTEX), where the inside of the vacuum vessel wall is completely covered with ferritic steel plates ferritic inside wall (FIW). The effects of a FIW on the plasma production, impurity release, the operation region, and H-mode characteristics have been investigated. No negative effect has been observed up to now. A high normalized beta plasma of βN ~ 3, having both an internal transport barrier and a steady H-mode edge was obtained. A remarkable reduction in ripple trapped loss from 0.26 MW m−2 (without ferritic steel) to less than 0.01 MW m−2 was demonstrated by the optimization of the thickness profile of FIW. A code to calculate fast ion losses, taking into account the full three-dimensional magnetic structure was developed, and values obtained using the code showed good agreement with experimental results. Thus, encouraging results are obtained for the use of this material in the demo-reactor.

To measure the electron temperature profile of tokamak plasma in a high confinement mode with edge localized mode (ELMy H-mode), a method of data analysis is presented on the fast-scanning Fourier transform spectrometer (FTS), and results in the JT-60U tokamak are described. In the ELMy H-mode, where the FTS interferogram of electron cyclotron emission (ECE) becomes incomplete due to nonthermal emission pulses of ELM, the spectrum of ECE is estimated by using the maximum entropy method (MEM) of nonparametric type. The optimization of the regularization parameter is studied in terms of adopting the generalized cross validation (GCV) from the linear regularization of Tikhonov–Phillips. A study is also performed on a method to remove the nonthermal emission pulses from interferogram data before the MEM analysis, and on an extension of minimum cross entropy in order to meet with the missing of interferogram values in the region of zero path difference. From the application to experimental data of many shots, it is found that the electron temperature profiles can be automatically measured using the FTS during the ELMy H-mode operation of the tokamak.

Energetic particle deposition to the wall due to toroidal magnetic field (TF) ripple was assessed for a 2 GW fusion power reactor. When the present allowance for the loss is applied, the alpha particle flux to the wall can be as high as 2×10 18 m −2 s −1 in the reactor, eroding tungsten by ∼20 μm per year. The peak particle fluence over a 2-year operation cycle can reach 10 26 m −2 , probably being larger than a critical fluence for blister formation. The result suggests that, for the steady-state tokamak fusion reactor, we should introduce a new design methodology of determining an acceptable level of TF ripple on the basis of particle fluence to the wall, instead of the present one based on a tolerable heat flux.

Compatibility of a low activation ferritic steel, F82H, with plasma has been investigated in the JFT-2M tokamak with three stages. The tokamak experiments in the third stage have just started, where the vacuum vessel is fully covered with the ferritic steel. Prior to the tokamak experiment, vacuum properties of F82H were investigated using a test-stand. The outgas rate is less than 6×10 −8 Pa m 3 /sm 2 after baking at 120 °C for 10 days. As is predicted from the results, the base pressure of 6×10 −6 Pa, which is the same as the previous level, was obtained in JFT-2M. In spite of the magnetic effect, the Taylor discharge was obtained without any difficulties and removal of oxygen was clearly observed. Tokamak discharges were obtained with the ferritic steel wall. The improved confinement mode (H-mode) was obtained with a neutral beam of 800 kW with a single-null divertor configuration. Within the preliminary results, the radiation loss did not increase due to the ferritic steel wall.

The compatibility of the low activation ferritic steel with a fusion plasma has been investigated in the JFT-2M tokamak. The program consists of three stages. In the first stage, the reduction of fast ion losses was well demonstrated by ferritic steel plates (FPs) outside the vacuum vessel (VV). In the second stage, 20% of the inner surface of the VV was covered by the FPs. The plasma control, stability, and impurity release were preliminary investigated. No deteriorative effect on the plasma was observed at least in the following conditions: partial covering of 20% and the normalized beta value less than 2.8. First boronization was applied to JFT-2M leading to a remarkable decrease of the oxygen impurity. After the boronization, plasmas with the highest normalized beta in JFT-2M were obtained. Thus encouraging results were gained for this stage. In the third stage, the VV was fully covered by FPs, where the ripple reduction and the plasma stability will be investigated as a full scale testing.

The JT-60U data processing system is a large computer complex gradually modernized by utilizing progressive computer and network technology. A main computer using state-of-the-art CMOS technology c...

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so ...

Fusion plasma performance and confinement studies on JT-60 and JT-60U are reviewed. With the main aim of providing a physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has b...

Ripple loss reduction resulting in reduced losses of fast ions was demonstrated successfully at the JFT-2M tokamak by installing ferritic plates between the vacuum vessel and toroidal field coils. This paper describes the comparison between the experimental results and computation based on the orbit following a Monte Carlo code. They are in qualitatively good agreement in the cases where the toroidal distribution of the toroidal field ripple is almost periodic (e.g. ferritic plate installed resulting in a complex periodic structure of the magnetic ripple), but differ in the case of toroidally small average ripple exhibiting non-periodic large local ones (e.g. ferritic plate installed resulting in a more complex non-periodic structure of the magnetic ripple).

Research activities of the Japanese tokamaks JT-60U, JFT-2M, and TRIAM-1M are described. The recent JT-60 program is focused on the establishment of a scientific basis of advanced steady-state oper...

A folded waveguide (FWG) antenna was used in the ion cyclotron range of frequency (ICRF) on the large helical device (LHD) in the National Institute for Fusion Science. The FWG antenna is a waveguide antenna folded several times in order to make its size smaller. The FWG antenna in the LHD is designed so that slow waves are excited preferentially. It was used in the fourth experimental campaign in 2000-2001 for the purpose of plasma production and plasmas with an average electron density up to 3.0×1018 m-3 were obtained. This will be a high enough density for initial plasmas of neutral beam injection or ICRF to obtain plasmas with higher densities and temperatures. This is the first demonstration of the utility of an FWG antenna in magnetic confinement devices. Further investigations were made in order to understand the mechanism of plasma production. The maximum achievable plasma density increased with injection power and gas-puffing rate, and became saturated. The density became higher as the magnetic field strength was increased. Such experimental observations were explained by the wave accessibility conditions of a shear Alfven wave.

The JT-60 data processing system is a large computer complex, gradually being modernized by utilizing progressing computer and network technologies. There were three major changes in our system recently. A VME-based fast data acquisition system (FDS) has been developed to enlarge a transient mass-data storage system (TMDS). It can acquire the data of 6 MB per channel with 1 or 5 μs sampling. Now there are three FDSs with 29 channels. The TMDS, which was composed of a mini-computer and 61 channels of 6 MB memory modules with 5-μs sampling, has been replaced with a new system based on the technology of the VME-based fast data acquisition system. One of the outdated auxiliary crate controllers with micro-processor (ACM), which controls CAMAC modules in the crate on the serial highway, acquires data from them and transfers data to the main computer, has been replaced by a workstation with a VMEbus byte-serial highway driver. The combination of a workstation and a VMEbus byte-serial highway driver has been developed and used to replace many mini-computers in our system. A workstation with a digital linear tape (DLT) library has been introduced as final data storage. The conversion of a few terabytes of raw data tapes for a cartridge tape library (CTL), which is attached to a mainframe computer, Fujitsu GS8300, will be started by using data conversion software prepared to handle mainframe data on the workstation.

A 20-channel electron cyclotron emission (ECE) detection system for the grating polychromator in JT-60U has been developed to measure electron temperature and its perturbations. Indium antimonide (InSb) detectors aligned in a row are cooled by liquid helium held by a 50 cm-diam cryostat, in which a hold time of the liquid helium reaches 7 weeks. Twenty-channel preamplifiers are dc-coupled ones, which enable to measure low-frequency ECE. From the comparison between the new system and the existing 20-channel detector system, where a refrigerator for cooling InSb detectors and ac-coupled preamplifiers are used, it is found that the signal-to-noise ratio is improved, and that small perturbations can be detected. By using this system, the electron temperature and its perturbations near the internal transport barrier in a reversed shear discharge are measured in detail.

In the JFT-2M tokamak, discharges exhibiting good performance have been produced by counterNBI after boronization. An improved core confinement mode under an H-mode edge condition is sustained for -5~~E With H89p - 1.5 and pN - 2.0 at a line-averaged electron density of around 70%-80% of the Greenwald density limit. It is found that the q-profile changes from a monotonic one having qo ~ 1 to a zero or weak negative central magnetic shear configuration having I < qmin ~ qo < 3 during improved core confinement mode using counter-NBI under an H-mode edge condition. The central electron temperature very clearly increases when the sawtooth activity disappears, while the previous result without boronization exhibited a significant degradation of the energy confinement due to the accumulation of impurities. The mechanism governing the improved core confinement mode including the density peaking and/or ITB formation due to negative shear is presently unclear.

In the medium size tokamak JFT-2M, ferritic steel plates (FPs) were inserted in order to reduce the toroidal field ripple, which caused fast ion losses. A 2D infrared TV (IRTV) system with time and spatial resolutions appropriate for measuring the first wall temperature increment caused by the ripple ion losses was developed. An IR thermal-imaging camera was used in the present study; this device provided a field rate of 60 fields/sec and a detectable temperature range of 0-500oC with a resolution of 0.2oC. The PtSi detector, sensitive to 3˜5 µm IR radiation, was arrayed in 256 × 256 pixels. The optical system consisted of an IR-lens, a turning mirror, and a sapphire vacuum window with a distance from the camera position to the target wall of 3.5 m, resulting in spatial resolution of ˜3 mm. The target wall consisted of ˜9 cm × ˜15 cm carbon tiles. By using this system, local hot spots due to the ripple-trapped and banana drift losses were observed when fast ions were produced by tangential NBI (36 kV, ˜0.5 MW). The peak temperature increment reached ˜75oC and ˜150oC on the ripple-trapped and banana drift loss regions, respectively. In the optimized condition with FP insertion, the temperature increment was reduced to an almost negligible level for the ripple-trapped loss regions. The corresponding increment for the banana drift loss regions was also minimized. These IRTV data clearly demonstrate the efficacy of FPs for the reduction of fast ion losses.

Application testing of the low activation ferritic steel to plasma is in progress in the JFT-2M tokamak. The toroidal field ripple reduction with ferritic insertion between the vacuum vessel and the toroidal field coils (1st stage) was successfully demonstrated. So far, no deteriorating effects of ferritic boards (FBs) inside the vacuum vessel has been observed in the pre-testing on compatibility with plasma (2nd stage). The density limit was improved by more than a factor of 1.6 after boronization with inside FBs. Design and preparation works are in progress for the testing on compatibility with plasma (3rd stage), where inside wall of the vacuum vessel will be fully covered with ferritic steel.

Magnetic effect of ferritic steel board (FB) on the plasma was experimentally investigated in the JFT-2M tokamak. Clear deterioration by the error field was not observed even in the condition of toroidally unbalanced placement of FBs outside vacuum vessel (VV). Deteriorating effects were not observed with the FBs inside VV for the operational region and the control of plasma, although slight discrepancy in the relation of vertical-coil current and equilibrium was found. Compatibility of FBs with high normalized-beta plasma (β N up to 2.7) was demonstrated after boronization.

In order to investigate the effect of polarization change on measurements of electron temperature profile from electron cyclotron emission (ECE) in a tokamak plasma, we have calculated the spatial evolution of the electric field of ECE propagating in the plasma. In the case of almost on-axis propagation, the Boyd's prediction is a good approximation, that is, the electric vector rotates with magnetic field. On the other hand, along horizontal sight line far from the axis the Boyd's prediction has a discrepancy of 3% from the numerical results. The effect of the polarization change is important for the measurement of ECE imaging in large tokamaks.

An electron cyclotron emission (ECE) measurement system has been developed to obtain electron temperature with high time and spatial resolution for JT-60U plasmas. The system consists of three different diagnostic systems. These systems have different advantages and have been used complementarily. Several kinds of calibration are periodically carried out in the systems to secure reliable measurements. In order to reduce the transmission loss, a corrugated waveguide transmission line was installed and the reduction of the loss of ca. 3 dB was attained. As preliminary applications toward the operation of future fusion reactors, the feedback control of electron temperature profile and the automatic determination of the sawtooth inversion radius with an adaptive neural network were successfully demonstrated.

Applicability of the low-activation ferritic steel (F82H), which is one of the candidate materials for next generation fusion devices, has been tested in JFT-2M. Ferritic steel boards (FB) were installed between toroidal field coils (TFC) and the vacuum vessel at all toroidal sections. The experiment and the calculation show that the ripple amplitude decreases from 2.2% to 1.1% by the FB installation at R =1.6 m. The ripple reduction results in the reduction of fast ion loss and in the shift of the ripple loss to the outer region. No undesirable effect to the energy confinement and the plasma control was observed. The FB will be installed inside the vacuum vessel in the near future. In preparation, surface coating tests, mainly concerning with an in situ boron coating, are carried out.

Non-dimensional transport studies have been carried out for NBI heated ELMy H-mode plasmas in JT-60U. In a high-δ (triangularity) case, both the electron thermal diffusivity, χe, and the ion thermal diffusivity, χi, show gyroBohm-like diffusion, χe/χBohm, χi/χBohm∝(ρ*)0.7-0.9, where ρ* is the normalized Larmor radius. The dependence of the energy confinement on the normalized collision frequency, ν*, was also studied. The weak ν* dependence of the energy confinement time, τE/τBohm∝(1/ν*)~0.3, was also obtained in the high-δ case. On the assumption of the same ν* dependence of τE/τBohm, the ρ* dependence of χ* in the low-δ case is compatible with the high-δ case. When the ELM activity is strong enough to affect the global energy confinement, however, the ion energy confinement was significantly degraded, although the electron energy confinement still follows the gyroBohm-like diffusion.

In order to test the effect of the toroidal field ripple on the fast ion losses, ferritic steel boards were inserted between the vacuum vessel and the toroidal field coil in the JFT-2M tokamak. The experimental and computational results show that the ripple amplitude is reduced from 2.2 to 1.1%. The ion losses are monitored from the increase in the wall temperature measured by the infrared TV. The region of the ripple trapped ion losses moves to outer side by about 6 cm and the increment of the wall temperature due to the ion loss of ripple trapped and banana drift is reduced. The ripple loss of the fast ions is reduced by ferritic steel insertion for the first time in the world. No deleterious effect of the ferritic insertion on plasma production and plasma control has been observed so far.

Although lymphoscintigraphy is a useful method of detecting the sentinel nodes of malignancy, conventional lymphoscintigraphy images only the sentinel nodes without revealing their anatomical location. We, therefore, used scattered photons to attempt to outline the body contours of patients with either breast or esophageal cancer. Lymphoscintigraphy was performed 3 to 4 hours after the injection of 111 MBq of 99mTc tin colloid into the peritumoral region. Images were obtained with dual-energy windows of 130 to 150 keV for the primary photons and 70 to 110 keV for the scattered photons. The images constructed from the scattered photons clearly showed the contours of the body, and the fusion images constructed from the primary and scattered photons allowed for easy identification of the location of the sentinel nodes. The results of this study confirm that images obtained from scattered photons on lymphoscintigraphy are helpful in identifying the anatomical location of sentinel nodes.