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We have newly developed a large-scale equilibrium database for real-time magnetic coordinate mapping system in the Large Helical Device. Thousands of free-boundary equilibria for each vacuum configuration have been calculated under wide ranges of central beta, pressure peaking factor, toroidal current and current peaking factor. We have also prepared a line of sight database which tabulates pre-calculated mapping results for all equilibria along several selected lines of sight to accelerate the mapping procedure. A user library has been developed to retrieve results of the inverse mapping as well as additional equilibrium parameters from the databases. A mapping program iteratively searches for the best-fitted equilibrium so as to minimize the discrepancy between inboard and outboard side of an electron temperature profile measured by the Thomson scattering diagnostic. Real-time mapping of all the time slices of the Thomson data enables us to provide time evolutions of equilibrium parameters and electron temperature/density profiles as functions of effective minor radius, which can be applied specifically for subsequent analyses of transport phenomena based on experiments.

The present report describes developmental, phenotypic and functional features of unconventional CD4+ TCR alpha beta lymphocytes. In C57BL/6 mice, the majority of liver lymphocytes expressing intermediate intensity of TCR alpha beta (TCR alpha beta int) are CD4+ NK1.1+ and express a highly restricted TCR V beta repertoire, dominated by V beta 8 with some contribution by V beta 7 and V beta 2. Although these cells express the CD4 co-receptor, they are present in H2-1 A beta (A beta)-/- gene disruption mutants but are markedly reduced in beta 2-microglobulin (beta 2m)-/- mutant mice and hence are beta 2m dependent. Thymocytes expressing the CD4+ NK1.1+ TCR alpha beta phenotype are also beta 2m contingent, suggesting that these two T lymphocyte populations are related. The CD4+ NK1.1+ TCR alpha beta lymphocytes in liver and thymus share several markers such as LFA-1+, CD44+, CD5+, LECAM-1- and IL-2R alpha-. The CD4+ NK1.1+ TCR alpha beta int liver lymphocytes were not detected in athymic nu/nu mice. We conclude that beta 2m expression is crucial for development of the CD4+ NK1.1+ TCR alpha beta int liver lymphocytes and that thymus plays a major role. CD4+ TCR alpha beta int liver lymphocytes were also identified in NK1.1- mouse strains, there lacking the NK1.1 marker. We assume that the NK1.1 molecule is a characteristic marker of the CD4+ TCR alpha beta int liver lymphocytes in NK1.1+ mouse strains, although its expression is not obligatory for their development. The liver lymphocytes from beta 2m+/-, but not from beta 2m-/-, mice are potent IL-4 producers in response to CD3 or TCR alpha beta engagement and the IL-4 production by liver lymphocytes was markedly reduced by treatment with anti-NK1.1 mAb. We conclude that the CD4+ NK1.1+ TCR alpha beta int liver lymphocytes are capable of producing IL-4 in response to TCR stimulation.

Conversion of Salmonella typhimurium to L-forms, both in vitro and in vivo, resulted in the expression of proteins cross-reacting to the mycobacterial 65,000 MW heat-shock protein (hsp). Immunization of C3H/HeJ mice with a protective dose of stable L-form S. typhimurium induced gamma delta T cells in the liver, in accordance with the multiplication of L-form Salmonella in Kupffer cells. The number of gamma delta T cells decreased after the intracellular growth of L-form Salmonella plateaued. Persistance of the L-forms in Kupffer cells, however, allowed hepatic gamma delta T cells to increase within 48 hr of infection with virulent S. typhimurium. Thus, the intrahepatic colonization of L-form Salmonella seems to keep gamma delta T cells on standby, but the emergence of these T cells does not correlate with the expression of L-form hsp. In addition, Kupffer cells colonized by L-forms constitutively synthesized mRNA for interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha). These results suggest that conversion of S. typhimurium to L-forms in phagocytic cells builds up and maintains acquired resistance, conferred by live-cell vaccines of S. typhimurium, against murine typhoid.

Phagocytosed M. tuberculosis either multiply inside the endocytic compartment of mononuclear phagocytes or they are destroyed by the host cell. Due to this macrophage-shelter (ab)used by mycobacteria, tuberculosis is controlled by the cellular immune response. Protection against mycobacteria depends on alpha/beta T-cells expressing the CD4 or CD8 phenotype. T-cell-mediated immunity amplifies macrophage capacities to kill and digest the bacilli. Specific alpha/beta T-cells produce several cytokines that attract and activate macrophages and additional lymphocytes, such as: interferon-gamma (IFN-gamma) which has the capacity to activate several antimicrobial properties of macrophages; tumour necrosis factor-alpha (TNF-alpha) a key cytokine involved in granuloma formation; interleukins 2, 6 and 8 (IL-2; IL-6 and IL-8); and interleukin 12 (IL-12), a candidate cytokine for the induction of Th1 cells. Furthermore, CD4+ and CD8+ T-cells display cytotoxic activity, which permits them to control mycobacterial growth through destruction of the infected cells. Escaping bacteria are subsequently ingested and destroyed by surrounding macrophages activated by T-cells. There is evidence to associate gamma/delta T-cells with antimycobacterial immunity, such as their preferential accumulation in inflammatory lesions, in necrotic areas of tuberculous lymphadenitis, and potent in vitro stimulation by M. tuberculosis components. In addition, M. tuberculosis activated gamma/delta T-cells are cytolytic and secrete several cytokines. Hence, clinical tuberculosis is associated with T-cell reactivity which controls the local concentrations of tubercle bacilli. Taken together, the cellular response, cytokine regulation, and the definition of target molecules are important aspects for the understanding of pathological immune mechanisms in tuberculosis.

The secretion of tumor necrosis factor (TNF)-alpha from macrophages is regulated by both priming and triggering signals. We found that macrophages from mice lacking gamma delta T cells [T cell receptor (TCR) delta-/- mice], which lack the gene encoding the delta chain, produced only small amounts of TNF-alpha in response to lipopolysaccharide (LPS) and showed a reduced level of expression of CD14. Pre-incubation of macrophages from TCR delta-/- mice with gamma delta T cells from their TCR delta +/- littermates restored their capacity to produce TNF-alpha in response to LPS. The priming activity of gamma delta T cells was in part inhibited by neutralizing anti-interferon (IFN)-gamma monoclonal antibodies. Collectively, these results suggest that gamma delta T cells play a role in priming macrophages to a steady state of activation via IFN-gamma secretion, which allows them to produce TNF-alpha when exposed to LPS.

Elevated plasma intermediate density lipoprotein (IDL) is one of the features of uremic dyslipidemia which is potentially atherogenic. We examined the effects of pravastatin, an HMG-CoA reductase inhibitor, on IDL levels as well as other lipoprotein parameters in 19 uremic patients treated with hemodialysis (HD, n = 11) or continuous ambulatory peritoneal dialysis (CAPD, n = 8). The patients were administered 5 mg/day pravastatin for the initial 4 weeks and 10 mg/day for the subsequent 12 weeks. In the analysis of the total subjects, IDL-cholesterol was reduced by 31% as well as low density lipoprotein (LDL)-cholesterol. Cholesterol in very low density lipoprotein (VLDL) also decreased whereas that in high density lipoprotein (HDL) did not. Significant decrease of serum triglycerides was due mainly to reduced IDL- and LDL-triglycerides. Apolipoprotein (apo) A-I did not change, whereas apo A-II, B, C-II, C-III, E, and B/A-I ratio were significantly lowered. Pravastatin did not affect measured activity of lecithin: cholesterol acyltransferase, post-heparin plasma lipoprotein lipase or hepatic triglyceride lipase. HD and CAPD patients responded almost equally to the treatment. IDL elevation was present independent of serum total cholesterol, and it was lowered by pravastatin even in non-hypercholesterolemic subjects. There was no critical adverse effect besides transient and asymptomatic increase of serum creatine kinase level. We conclude that pravastatin can be a safe and effective approach to the management of dyslipidemia in uremic patients who have an elevated level of IDL.

The antiemetic efficacy of a combination of granisetron and clonazepam was investigated in 39 gynecological cancer patients treated with cisplatin. Granisetron (3 mg/body/day) was administered by intravenous drip infusion before and 24 hours after anticancer drug administration, and clonazepam was taken orally twice a day. With a combination of granisetron and clonazepam, excellent efficacy was found in 87% (34/39) of the cases. Delayed emesis occurred in 38% (13/34), but the degree of nausea was mild. Clinically, antiemetic therapy with a combination of granisetron and clonazepam demonstrated superior antiemetic effects and seems to be useful for controlling nausea and vomiting associated with cancer chemotherapy.

In patients with a moderate degree of renal insufficiency, restriction of dietary phosphate suppresses PTH secretion by increasing serum calcitriol. However, this may not operate in advanced renal failure. The present study was designed to evaluate the influence of serum phosphate levels on PTH secretion in oral 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] pulse therapy. 22 patients with secondary hyperparathyroidism [carboxy-terminal PTH (c-PTH) concentration: 19.5+/-13.9 ng/ml, mean +/-SD] received oral doses of 1,25(OH)2D3 (3.0-4.0 micrograms) twice a week, each at the end of hemodialysis, for 12 weeks. Doses of phosphate binders remained unchanged throughout this period. Patients were divided into two groups: group A (11 subjects) with mean serum phosphate levels of less than 6.0 mg/dl and group B (11 subjects) with levels of 6.0 mg/dl and above. There was no significant difference in the average corrected serum calcium levels. The reduction in serum intact PTH levels was greater in group A than in group B. A negative correlation (r = -0.48; p0.05) was observed between mean serum phosphate levels and the percent decrease in serum c-PTH levels. The findings of this study indicate an important role for dietary phosphate reduction in oral 1,25(OH)2D3 pulse therapy and suggest that serum phosphate reduction may play a part in suppressing PTH secretion through a mechanism independent of 1,25(OH)2D3 and plasma calcium levels.

The liver comprises unique T cells differentiating extrathymically and expressing an intermediate intensity of alpha beta T-cell receptor (TcR) and a high intensity of leucocyte function antigen-1 (LFA-1). To elucidate the functional roles of the intermediate alpha beta TcR cells in host defence against bacterial infection, we examined the effects of depletion of the intermediate alpha beta TcR cells by in vivo administration of monoclonal antibodies (mAb) to intercellular adhesion molecule-1 (ICAM-1)/LFA-1 and alpha beta TcR on the bacterial growth in the liver after infection with Salmonella chorelaesuis in mice. Pretreatment with mAb to LFA-1 (200 micrograms/mouse) together with mAb to ICAM-1 (200 micrograms/mouse), which could preferentially deplete the intermediate alpha beta TcR cells and gamma delta TcR cells in the liver, resulted in a severely reduced ability to resolve acute phase of Salmonella infection in the liver. Pretreatment with a low dose of anti-alpha beta TcR mAb (60 micrograms/mouse), which depleted only bright alpha beta TcR cells, did not affect the bacterial growth in the liver at the early stage after Salmonella infection, while the depleting of both intermediate and bright alpha beta TcR cells by pretreatment with a high dose of anti-alpha beta TcR mAb (120 micrograms/mouse) allowed the bacteria to multiply exaggeratedly in the liver at this stage. These results suggest that intermediate alpha beta TcR cells may play an important role in protection at the early stage after Salmonella infection in liver and that the interaction of ICAM-1/LFA-1 is critically involved in protective roles of extrathymic T cells bearing intermediate alpha beta TcR in liver at the early stage after Salmonella infection.

A high-performance data acquisition (DAQ) system has been developed for steady-state fusion experiments at the Large Helical Device (LHD). Its significant characteristics are 110 MB s−1 continuous DAQ capability and the performance scalability using an unlimited number of DAQ units. Incoming data streams are first transferred temporarily onto the shared random access memory, and then cut into definite time chunks to be stored. They are also thinned out to 1/N to be served for the real-time monitoring clients. In LHD steady-state experiment, the DAQ cluster has established the world record for acquiring 90 GB/shot. The established technology of this steady-state acquisition and store can contribute to the ITER experiments whose data amount is estimated in the range 100 or 1000 GB/shot. This system also acquires experimental data from multiple remote sites through the fusion-dedicated virtual private network in Japan. The speed lowering problem in long-distance TCP/IP data transfer has been improved by the packet pacing optimization. The demonstrated collaboration scheme will be analogous to that of ITER and the supporting machines.

This study was conducted to investigate the effects of sex hormones upon the nature of soluble immune response suppressor (SIRS) produced by concanavalin A-stimulated Lyt-2+ T cells. Conventional SIRS affected IgM PFC only. However, SIRS made with progesterone (20-400 ng/ml or Prog-SIRS) suppressed IgM PFC, one-way MLR, and generation CTL; and SIRS made with estrogen (0.2-50 ng/ml or Est-SIRS) enhanced these responses. The factor(s) (MW 40,000-55,000) to stimulate macrophages to produce the second soluble factor (M phi-SF) was isolated from all preparations by gel filtration. Furthermore, Est-SIRS contained a factor(s) (MW 10,000-30,000) to enhance IgM PFC, MLR, and mitogen-induced blastogenesis of both T and B cells; and Prog-SIRS possessed the suppressive factor(s) to IgM PFC, MLR, and mitogen-induced T-cell proliferation. These activities were not impaired by 2-mercaptoethanol. Moreover, the suppressive activity of Prog-SIRS was completely absorbed by T cells only, but the enhancing activity of Est-SIRS was not completely absorbed by a single-cell population. These data suggest that progesterone can contribute to the suppression of allograft rejection through soluble factors, and estrogen can enhance host responses which may be affected by several soluble factors during pregnancy.

The isolation and determination of biological activities of the active component of Corynebacterium kutscheri were attempted in the present investigation. The antitumor effect was confined to the subcellular particle fraction of this bacterium and was associated with a molecule of glycoprotein nature (40,000-38,000 Daltons) isolated from this fraction by affinity chromatography with concanavalin A-Sepharose 4B. This substance exerted mitogenic activity on C3H/HeJ splenocytes and T cells, stimulatory activity on macrophages, and further exhibited antitumor effect on P388 leukemia in CDF1 mice. The Winn assay disclosed that the antitumor effect induced by this substance was dependent on L3T4+ T cells. Furthermore, both the mitogenic and antitumor activity of this moiety were resistant to heating at 100 degrees C for 30 min or RNase digestion, but sensitive to trypsin digestion, or low or high pH. These results indicate that the antitumor effect of C. kutscheri is attributable to the heat-stable glycoprotein moiety which can directly stimulate T cells and macrophages.

Cardiovascular mortality is higher in dialysis patients than the nonuremic population. This has been taken to indicate that dialysis patients have accelerated atherosclerosis [1]. We have recently revealed that atherosclerosis in hemodialysis patients is advanced morphologically, showing a greater intima media thickness in the carotid and femoral arteries in dialysis patients than healthy control subjects by high-resolution B mode ultrasonography [2]. Lipoprotein abnormality is one of the major risk factors for atherosclerosis in the general population, and recent studies [3–6] reemphasize the importance of triglyceride-rich lipoproteins such as partially lipolyzed very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL). These lipoprotein classes are significantly elevated in patients with chronic renal failure [7–9].

Two outbred mouse strains, ddY and CF1, were tested for their ability to be protected against infection with Salmonella typhimurium by several types of salmonella vaccines. These strains have the same levels of innate susceptibility to S. typhimurium, and also have the same capacity to develop delayed-type hypersensitivity (DTH) to salmonella antigens. Both the crude ribosomal fraction (CRF) and live-cell vaccines conferred acquired resistance on both strains, characterized by greater responses of T cells to salmonella antigens. Mice of the ddY strain were also protected by the purified transfer RNA (tRNA) vaccine, which was free of O antigens, but CF1 mice were not, despite the presence of T-cell reactivity with salmonella antigens. Neither strain was protected by the phenol-water-extracted lipopolysaccharide (LPS). The tRNA-immunized CF1 mice were protected by transfer of antiserum to CRF, but not by transfer of anti-LPS antibody. This antiserum to CRF, however, did not transfer acquired resistance into non-immune mice of either strain. These observations suggest that CF1 mice may require an antibody to another non-O antigen existing in CRF to develop acquired resistance, and that stimulation of the defence system by tRNA may be essential to the development of acquired resistance in CF1 mice.

In order to compare the potential of salmonella vaccines prepared from Salmonella typhimurium to provide the longer-lasting protection from the aspects of cell-mediated immunity, groups of mice were immunized with optimal doses of the following preparations: live cells, ribosome-rich extract, acetone-killed cells, and heat-killed cells. At various intervals post-immunization, mouse peritoneal macrophages and splenic T cells were tested for biological activities. The capacity of each vaccine to confer mouse protection against a lethal challenge with S. typhimurium correlated with the degree of macrophage activation engendered by each of them in the early stage of immunization. In the late stage of immunization, the level of mouse protection conferred by each vaccine was found to be based on the capacity of T cells to respond to salmonella antigens, which correlated with the degree of adoptive immunity by T cells. The live-cell and ribosomal vaccines were superior to killed-cell vaccines in inducing the cell-mediated protection. Thus, the longer-lasting immunity provided by the live-cell and ribosomal vaccines can be accounted for by the fact that T cells of mice immunized with both vaccines have the persistent reactivity to salmonella antigens.

The active component in crude ribosomal fraction (CRF) of Salmonella typhimurium, capable of inducing protective antibody, was partially purified by two series of chromatography (Sephadex G-150 and DEAE-Sepharose CL6B) after sodium dodecyl sulphate (SDS)-treated CRF was precipitated with ammonium sulphate. The major active component was eluted by 0.4-0.45 M NaCl from DEAE-Sepharose CL6B, and its molecular weight was 43,000 as determined by SDS-polyacrylamide gel electrophoresis. Immunization with the fraction containing 43,000 component alone did not always confer protection on CF1 mice, but its administration together with either the purified transfer RNA (tRNA) or Freund's complete adjuvant (FCA) was much more effective against infection with S. typhimurium. Antibody to the fraction containing 43,000 component was not only free in serum but also associated with peritoneal cells. Macrophages that had been exposed to the antibody had enhanced anti-bacterial activity. Western blot analysis showed that 43,000 component did not react to antiserum to lipopolysaccharide (LPS), but to antiserum to CRF. The antibody elicited by non-O antigenic component and the cell-mediated resistance stimulated by the adjuvant effect of RNA together confer effective protection on CF1 mice.

The effect of local injection of formalin-killed Corynebacterium kutscheri (FK.CK) on mouse survival after the intraperitoneal inoculation of Ehrlich ascites carcinoma in outbred ddY mice or P388 leukemia cells in inbred CDF1 mice was investigated. Treatment of mice in the dose range of greater than 10(6) organisms per mouse conferred the substantial protection on both mice. The initial phase of antitumor effect consisted of the marked increase in the number of peritoneal exudate cells and the enhanced cytotoxicity of peritoneal exudate cells. The Winn assay disclosed that antitumor effect by which tumor-burden mice could survive was attributable to nonadherent splenocytes whose activity was impaired by treatment with anti-T cell serum and complement. A single injection of FK.CK induced the cytotoxicity to three different murine tumor cells in serum of treated mice without a boosting injection of endotoxin. Furthermore, the generation of effector cells and serum cytotoxicity seemed to be paralleled by that of the delayed-type hypersensitivity to this organism. Thus, the antitumor resistance induced by C. kutscheri is considered to be in part T cell mediated.

In the Large Helical Device (LHD), upgrading of the key hardware system since the last EPS conference has led to (1) higher Te (Te(0) = 4.4 keV at ne = 5.3×1018 m-3 and Pabs = 1.8 MW); (2) higher confinement (τE = 0.3 s, Te(0) = 1.1 keV at ne = 6.5×1019 m-3 and Pabs = 2.0 MW); (3) higher stored energy Wpdia = 880 kJ; and (4) the highest β value in helical devices (2.4% at B = 1.3 T). The energy confinement was systematically higher than that predicted by the International Stellarator Scaling 95 up to a factor of 1.6. Ion cyclotron range of frequencies (ICRF) power up to 1.3 MW was reliably injected into the plasma without significant impurity contamination and a plasma with stored energy of 200 kJ was sustained for 5 s by ICRF alone. Long pulse discharges greater than 1 min in duration have been successfully achieved with ICRF power alone and with neutral beam injection (NBI) power alone. With NBI heating an 80 s discharge was achieved with a heating power of 0.5 MW at 2.75 T. The electron density was maintained at around 1.6×1019 m-3 by controlled gas puffing. The central electron and ion temperatures were kept around 1.5 keV. With ICRF heating, a similar long pulse discharge was achieved for 68 s with a heating power of 0.85 MW. The sustained plasma parameters are: Wp~110 kJ, Te(0)~Ti(0) = 2.0 keV and ne = 1.0×1019 m-3. During these discharges, no increase in radiation power has been observed.

The data acquisition (DAQ) and management system of the Large Helical Device (LHD), named the LABCOM system, has been in development since 1995. The recently acquired data have grown to 7 gigabytes...

Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond the stability criterion for the Mercier (high-n) mode. While the stability against an interchange mode is violated in the inward-shifted configuration due to an enhancement of the magnetic hill, the neoclassical transport and confinement of high-energy particle are, in contrast, improved by this inward shift. Mitigation of the unfavourable effects of MHD instability has led to a significant extension of the operational regime. Achievements of the stored energy of I MJ and the volume-averaged beta of 3% are representative results from this finding. A confinement enhancement factor above the international stellarator scaling ISS95 is also maintained around 1.5 towards a volume-averaged beta, (beta), of 3%. Configuration studies on confinement and MHD characteristics emphasize the superiority of the inward-shifted geometry to other geometries. The emergence of coherent modes appears to be consistent with the linear ideal MHD theory; however, the inward-shifted configuration has reduced heat transport in spite of a larger amplitude of magnetic fluctuation than the outward-shifted configuration. While neoclassical helical ripple transport becomes visible for the outward-shifted configuration in the collisionless regime, the inward-shifted configuration does not show any degradation of confinement deep in the collisionless regime (nu* < 0.1). The distinguished characteristics observed in the inward-shifted configuration help in creating a new perspective of MHD stability and related transport in net current-free plasmas. The first result of the pellet launching at different locations is also reported.

Neutral beam injection (NBI) heating started in the second experimental campaign of the Large Helical Device (September to December 1998) by two tangential beam lines. With 100 keV hydrogen, the beam port through power of up to 3.7 MW was injected for 1 s typically. The energy confinement was systematically better than that predicted by the International Stellerator Scaling 95 up to a factor of 1.5. The temperature pedestal observed contributes to this enhancement. We have also demonstrated a long pulse discharge by NBI in the LHD. By injecting 0.7 MW of beam, a plasma with a density of 0.3 × 1019 m-3 was sustained for 22 s. A unique oscillating phenomenon of plasma quantities with a long time scale was observed in the long pulse discharge. One of the topics of NB discharge is that the plasma can be started up by NB alone. This technique is unique for helical systems that have a vacuum magnetic field confining high energy ions, and it is useful for helical systems to be free from the constraint of magnetic field strength that must coincide with the frequency required by electron cyclotron resonance heating (ECH).

In the first four years of the LHD experiment, several encouraging results have emerged, the most significant of which is that MHD stability and good transport are compatible in the inward shifted axis configuration. The observed energy confinement at this optimal configuration is consistent with ISS95 scaling with an enhancement factor of 1.5. The confinement enhancement over the smaller heliotron devices is attributed to the high edge temperature. We find that the plasma with an average beta of 3% is stable in this configuration, even though the theoretical stability conditions of Mercier modes and pressure driven low-n modes are violated. In the low density discharges heated by NBI and ECR, internal transport barrier (ITB) and an associated high central temperature (> 10 keV) are seen. The radial electric field measured in these discharges is positive (electron root) and expected to play a key role in the formation of the ITB. The positive electric field is also found to suppress the ion thermal diffusivity as predicted by neoclassical transport theory. The width of the externally imposed island (n/m = 1/1) is found to decrease when the plasma is collisionless with finite beta and increase when the plasma is collisional. The ICRF heating in LHD is successful and a high energy tail (up to 500 keV) has been detected for minority ion heating, demonstrating good confinement of the high energy particles. The magnetic field line structure unique to the heliotron edge configuration is confirmed by measuring the plasma density and temperature profiles on the divertor plate. A long pulse (2 min) discharge with an ICRF power of 0.4 MW has been demonstrated and the energy confinement characteristics are almost the same as those in short pulse discharges.

The most important finding in the Large Helical Device (LHD) experiments so far is that an inward-shifted configuration exhibits good plasma performance with a scaling similar to that of ELMy H-mode tokamaks. The inward-shifted configuration has been predicted to have unfavourable magnetohydrodynamic (MHD) properties, even though it has significantly better particle-orbit properties. However, no serious confinement degradation due to the MHD activities was observed, resolving favourably the potential conflict between stability and confinement. Neoclassical transport loss can be suppressed even in a low-collisionality regime, and in this way the inward-shifted configuration was shown to make the LHD plasma properties favourable. Then, it is very important to realize more improved plasma performance and higher temperature plasmas for extending the plasma-parameter regime in order to obtain data that can be extrapolated to a reactor. In the fifth campaign in 2001–2002, an increase in the heating power achieved an electron temperature Te of over 10 keV and an ion temperature Ti of 5 keV. A Te profile, which is characteristic of internal transport barriers, was also observed when the electron cyclotron resonance heating power was highly focused on the centre of the plasma sustained by neutral beam injection.

The experimental results from the Large Helical Device (LHD) heliotron / torsatron of the first two years are reviewed. The world's largest superconducting helical coils have been driven up to 2.9 Tesla on the axis which is close to the designed value (3 T) The obtained plasma performances are better than those predicted by the database from the medium-size helical devices. These improvements are attributed mainly to the optimization of a magnetic field configuration which can be controlled by shifting the magnetic axis inward than that of standard case. This configuration improves particle orbits oftrapped high energy ions resulting in success of ICRF heating in LHD. Efforts have also been made on steady state plasma operation, and long pulse discharges more than one minute have been achieved both by ICRF and NBI. It should be noted that the feature of no current-disruption in helical plasma makes the discharges easy.