A semiempirical formation model for field-reversed configurations

Recent data from the FRX-C [Proceedings of the 7th Symposium on the Physics and Technology of Compact Toroids (Los Alamos National Laboratory, Los Alamos, NM, 1986), p.142] and FRX-C/LSM [Proceedings of the 14th European Conference on Controlled Fusion and Plasma Physics (European Physical Society, Madrid, 1987), p. 485] field-reversed theta pinches are presented concerning heating, internal flux, and particle retention after formation. These results extend the data base of field-reversed configuration plasmas to larger dimensions. Good agreement is found for collisionless plasmas with some existing formation laws [Fusion Technol. 9, 48 (1986)] and the main result is confirmation of improved internal flux retention for plasmas of larger radius. Some simple semiempirical laws are proposed, which allow a global analytical formation model. This model should provide reasonable estimates of the equilibrium parameters of field-reversed configurations formed in theta pinches.