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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 β_N ~ 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.

The utility of ICRF heating in the LHD was demonstrated in the third campaign carried out in 1999. This paper summarizes the investigations made in 2000 with a focus on the optimization of ICRF heating. The flexibility of the LHD magnetic configuration was fully utilized as a key factor in the investigations. The experiments include (a) scan of magnetic field intensity, (b) scan of aspect ratio, (c) scan of magnetic axis shift, (d) scan of quadrupole magnetic field, and (e) cancellation of magnetic island. The performance of the ICRF heating was thus optimized with respect to magnetic parameters, while optimization was achieved mainly with respect to heating regime and wall conditioning in the third campaign. Some of these parameters are directly related to the orbit of trapped particles. Therefore, the relation between particle orbits and the performance of ICRF heating is also addressed in this paper based on analyses of the high-energy tail of ions.

We evaluated the diagnostic accuracy of a new method for quantitative analysis of myocardial perfusion at exercise using 99mTc-tetrofosmin tomographic imaging. 99mTc-tetrofosmin imaging of an exercise-rest sequence was performed in 30 patients with coronary artery disease (CAD) and eight age-matched control subjects. The exercise-induced myocardial count increase was calculated as the relative value (per cent increase ratio, IR) to that at rest by correcting for physical decay for 99mTc and injected doses and by a subtraction technique. Exercise and rest 99mTc-tetrofosmin images were assessed visually and quantitatively using the per cent peak count and IR of the myocardial count at exercise. Segments with significant coronary stenosis (diameter stenosis 75 or more) showed a significantly lower IR than did those without significant coronary stenosis in the CAD patients (37±19 vs 63±21, P<0.05). The diagnostic efficacy of visual analysis for detecting coronary stenosis was as follows: sensitivity, 58.1 and specificity, 81.4. When IR 37 was used for detecting significant coronary stenosis, sensitivity and specificity increased to 74.2 and 93.2, respectively. Furthermore, the quantitative analysis significantly (P0.04) improved the overall diagnostic accuracy from 73.3 to 86.7 compared to that of visual assessment. Thus, augmentation of myocardial 99mTc-tetrofosmin uptake at exercise is blunted in the myocardium with significant coronary stenosis. The calculation of myocardial count increase at exercise relative to that at rest can improve the diagnostic value of 99mTc-tetrofosmin SPECT imaging and may contribute to more accurate quantification of myocardial ischaemia and impaired tracer uptake in coronary artery disease.

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 of trapped 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.

ObjectiveTo investigate whether coronary stenting limits myocardial injury and preserves left ventricular function.Design and settingProspective multicentre case-control study of primary percutaneous transluminal coronary angioplasty (PTCA) with and without stenting, performed in seven cardiovascular centres.Subjects and methods45 consecutive patients with acute myocardial infarction who were treated with successful primary stenting (Stent group) and did not have restenosis were paired with 45 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting, also with no restenosis (POBA group).ResultsIn comparison with the POBA group, the Stent group--especially those patients with a left anterior descending coronary artery lesion--had a smaller hypokinesis area (mean (SD): 15.1 (20.0) v 34.4 (24.3) chords), reduced hypokinesis area/risk area (25.2 (31.9)% v 58.8 (40.1)%), and a larger ejection fraction (63.3 (10.2)% v 51.7 (11.7)%) evaluated by quantitative left ventriculography using the centreline method. In the Stent group, the correlation between risk area and hypokinesis area was significantly shifted downward. Multiple logistic regression analysis on infarct size limitation (hypokinesis area/risk area &lt; 50%) identified preinfarction angina in all subjects and preinfarction angina and stenting in patients with left anterior descending coronary artery leasions as explanatory factors.ConclusionsPrimary PTCA using a coronary stent is effective in preventing myocardial injury and restoring left ventricular function in patients with anterior acute myocardial infarction.

The development of the manless operation of the slab and coil yards, which is realized in the new hot strip mill at Keihin Works, N.K.K., is described. The stock yard of steel works had been one of the most difficult process to automate for many reasons and it was needed to develop or to adopt the following ideas tu uvuruurau thu difficulties.(1)The simplest yard layout and handling equipment(2)Standardization of material management(3)Safe and reliable handling methods

NKK has developed a new tension control method for the hot strip finishing mill, and applied it to Keihin Works. The behavior of the interstand tension by the looper control was evaluated by simulation and it was concluded that the mass moment of looper inertia should be reduced drastically. To achieve this, a full stand looperless rolling technique using statistical scheme was developed for the large-sectioned material use. Hence, loopers were scaled down by 2/3 only for the small-sectioned material use, and the optimum looper control technique under modern control theory was applied. Consequently, a 40% reduction in the longitudinal thickness variation of the product strip has been achieved.

Optical parametric chirped-pulse amplification (OPCPA) operation with low gain by seeding with high-energy, clean pulses is shown to significantly improve the contrast to better than 10^−10to10^−11 in a high-intensity Ti:sapphire laser system that is based on chirped-pulse amplification. In addition to the high-contrast broadband, high-energy output from the final amplifier is achieved with a flat-topped spatial profile of filling factor near 77%. This is the result of pump beam spatial profile homogenization with diffractive optical elements. Final pulse energies exceed 30 J, indicating capability for reaching peak powers in excess of 500 TW.