Equilibrium constraints applied to RMF-driven compact toroid devices

The rotating-magnetic-field technique is being considered as a possible means of generating and sustaining a field-reversed configuration (FRC). In this report analytical expressions for the time evolution of the rotating-field and ohmically-heated-plasma parameters are derived for a loss-less equilibrium FRC. The parameters for proof-of-concept and reactor-size devices are presented

RMF concept: a rotating-magnetic-field technique for driving steady plasma currents in compact toroid devices

The generation and/or sustaining of a Compact Toroid (CT) configuration using the RMF technique is a relatively new and unknown concept. In this report the basic principles, historical development, and current theoretical understanding of this concept are reviewed. Significant experimental and theoretical results, potential problem areas, and recommendations for the direction of future work are discussed. An illustrative analysis of the application of the RMF technique to a CT reactor is presented. The results of a recent experiment, the Rotamak, in which a Spheromak-like CT plasma was produced using the RMF technique, are presented

Coaxial slow source: a quasi-static FRC formation concept

The electromagnetics of one of several techniques for generating FRCs in a coaxial configuration has been presented. It has been shown that the discussed design satisfies all the electromagnetic requirements for a slow source. The next major issue is the investigation of the plasma physics which will ultimately determine the viability of this concept

Equilibrium and power balance constraints on a quasi-static, ohmically-heated FRC

In present experiments, FRC's (field-reversed configurations) are generated on dynamic time scales using pulsed high-power theta-pinch technology, which does not easily extrapolate to reactor-size devices. The attractiveness of FRC reactor scenarios would be enhanced by the development of quasi-static (i.e. formation time >> Alfven time) formation techniques requiring moderate power levels. In this report the quasi-static formation of FRC plasmas is analytically investigated. The set of equations which yield the time evolution of the ohmically-heated-plasa parameters, under the constraints of radial equilibrium and plasma energy losses, are presented. Subject to the simplifying assumptions used in the model, this equation set is completely general and would apply to any ohmically-heated FRC. A sample calculation is presented in which the FRC azimuthal current, I/sub theta/, is generted by the rotating-magnetic-field (RMF) technique

Percutaneous transluminal coronary angioplasty: clinical and quality of life outcomes one year later.

Background: The quality of life status of patients prior to and following percutaneous transluminal coronary angioplasty (PTCA) has not been comprehensively investigated. Aim: This study was carried out to determine the effect that PTCA has on patients' quality of life. Methods: Data on 209 patients were collected one day pre‐PTCA and at a mean of two and 11 months post‐PTCA. Data on symptomatic status, functional capacity, life satisfaction and psychological well‐being were analysed quantitatively. Clinical outcomes, patient perception of PTCA and employment status wee analysed by descriptive statistics. Results: Highly significant improvement in all quality of life measures was found at the early follow‐up (p < .001). This improvement was sustained at the late follow‐up. At the late follow‐up, 58% of patients felt that PTCA had been very beneficial to their health and well‐being, and 79% of workers had returned to work. PTCA was primarily successful in 91% of vessels dilated. There were no procedural‐related deaths, 12 patients (6%) developed acute occlusion and three patients (1.5%) experienced myocardial infarction (MI). A symptomatic restenosis rate of 16% was found, including 19 patients (9%) requiring repeat PTCA and 14 (7%) undergoing coronary artery bypass grafting (CABG). Conclusion: These findings suggest that, after PTCA, the majority of patients experienced improved quality of life which was sustained one year later

FRC studies on FRX-B

Recent experimental studies of Field-Reversed Configurations (FRC) on the FRX-B device have included (1) characterization of FRC formation with regard to loss of bias flux, (2) examination of FRC equilibria through separatrix profiles, (3) formation of FRC's with different end-mirror configurations, and (4) extension of FRC parameter range. Studies on loss of bias flux during the pre-ionization (PI) phase of FRC formation are presented in another paper dedicated solely to PI considerations. Loss of bias flux during the reversal phase of FRC formation is reviewed in the first section of this paper. Use of barrier fields during the reversal phase to enhance trapping of bias flux is included in the third section of this paper. In addition to barrier field studies, results from different mirror configurations are also discussed in the third section. A critical diagnostic for interpretation of the results from the different machine modifications is the excluded-flux probe array. Analysis of excluded-flux measurements to obtain the FRC separatrix profile is described in the second section. Finally, preliminary results of FRX-B operation in an extended range of plasma parameters is briefly discussed in the fourth section

Clinical results and quality of life after percutaneous transluminal coronary angioplasty: A preliminary report

To evaluate the effect of percutaneous transluminal coronary angioplasty (PTCA) on quality of life, data on symptomatic status, functional capacity, life satisfaction, and psychological wellness were collected on 102 patients at 1 day pre‐PTCA and 2 months post‐PTCA, and on the first 50 of these patients at 10 months post‐PTCA. There were highly significant changes (