The breaking of up-down symmetry of trapped particle orbits by a toroidal electrical field
- Imperial College, London (United Kingdom)
A breaking of the up-down symmetry due to the inductive electric field E{sub {phi}} is analyzed in detail for particles describing quasi-banana orbits in the large aspect ratio approximation. Time independent and time dependent electric fields are considered. In the first case it is proved that the classical {del}B drift and the breaking of up-down symmetry due to E{sub {phi}} lead to a net inward radial drift, which agrees with the well known Ware pinch formula. The weak points of previous treatments of the Ware pinch, e.g. taking only leading terms in the Taylor expansion of A{sub {phi}}, are discussed. Yet the results obtained here lead to the same pinch formula, even for banana orbits with large amplitude of poloidal angle and for more general conditions than previously considered. A more general formula for a time dependent E{sub {phi}} has also been found. Our results show from a very general basis that the corresponding polarization drift does not play any role in the inward pinch; however the second time derivative of the inductive electric field E{sub {phi}} could increase or decrease significantly the usual Ware pinch.
- OSTI ID:
- 489421
- Report Number(s):
- CONF-960354-; TRN: 97:011565
- Resource Relation:
- Conference: International Sherwood fusion theory conference, Philadelphia, PA (United States), 18-20 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of 1996 international Sherwood fusion theory conference; PB: 244 p.
- Country of Publication:
- United States
- Language:
- English
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