Access to the MHD second stability regime has been achieved in the ATF torsatron. Experimental p values (j3 0 < 3%, with fast ions contributing « j of the pressure at high p) are well above the theoretical transition value (p c « 1.3% for ideal modes) required to reach this regime. The relatively low p c results from operation with peaked pressure profiles. The measured magnetic fluctuations decrease with increasing /?, and the pressure profile broadens. This behavior is consistent with theoretical predictions for p self-stabilization of resistive interchange modes. PACS numbers: 52.55.Hc, 52.30.Jb, 52.35.PyThe ideal magnetohydrodynamic (MHD) second stability regime has attracted increasing attention in toroidal confinement fusion research 1 ' 2 because it offers the hope of operation at high p=2fiop/B 2 (the ratio of the plasma kinetic pressure to the magnetic pressure) with favorable confinement, which would improve the prospects for a viable D-T fusion reactor. This theory predicts that the changes in the internal magnetic surfaces (plasma axis shift and shape) caused by an increase in plasma pressure act to stabilize instabilities driven by unfavorable field-line curvature. l As a result, the plasma can become more stable as p increases ("/? self-stabilization"), with an accompanying reduction in the anomalous transport induced by the curvature-driven instabilities. In this Letter we describe experiments in which operation in the second stability regime has been achieved at relatively low p in a torsatron (a type of stellarator).Because of their external control of magnetic configuration and the absence of plasma current, stellarators are well suited for exploring the second stability regime and studying p self-stabilization. In stellarators with significant shear (dx/dr > 0, where % is the rotational transform and r is the plasma minor radius) the dominant instabilities are interchange modes. 3,4 These modes can be stabilized by the magnetic well produced by the outward magnetic axis shift at finite p (Shafranov shift), and this p self-stabilization effect can open a stable path to the second stability regime. 5 ' 6 The ATF torsatron design was optimized to explore this possibili- ty. 7ATF is an / -2, twelve-field-period torsatron with major radius /?o™2.10 m, average minor radius a *=0.27 m, magnetic field on axis 5o<2T, central rotational transform £o«0.3, and edge transform ^f l «l. For the profile assumed in the ATF design studies 6 the p selfstabilization effect should dominate at /?o«5%. Electron-beam field mapping in early 1988 revealed substantial magnetic islands (6 cm wide at the x ™ T surface and smaller at other rational surfaces). 8 These islands, now corrected, acted as a magnetic limiter and effectively reduced the plasma radius to r p *=*0.6d (increasing the effective aspect ratio A from 8 to 10) and the effective edge transform Xa » 0.5. This led to a large increase in the Shafranov shift id/accp^A/xl) that enhanced the self-stabilization effect and afforded the results reported here, which ...

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In 1985, members of the veterinary profession and four other professional groups in New Zealand were surveyed to establish their attitudes towards the developing commercialisation of their professions, and particularly towards advertising. This survey was repeated in 1988, and again in 1994. The results of the three surveys are presented in this paper. There was a sharp movement towards acceptance of advertising, and toward a competitive orientation in general, between 1985 and 1988, with a consolidation of these changes during the following 6 years. The acceptance of the idea of an openly competitive profession now has widespread support among veterinarians. Similarly, there is general support for the use of most kinds of informative advertising, with many practitioners viewing advertising as a business building tool, but with the advertising of fees remaining an area over which there is still considerable caution. Although clients are seen as more demanding than in the past, the client-practitioner relationship is still expected to be an enduring one. We suggest that, in view of the relaxed attitudes towards advertising that now exists among members of the veterinary profession, control of advertising should cease to be a concern to the profession.

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