Use of a Zero-Dimensional RFP Model to Simulate Behavior of CPRF and ZT-40M: Annual Progress Report.

摘要

An improved zero-dimensional code has been developed and used for comparison with ZT-40M and for parametric studies of the behavior of ZT-H. The code includes equations for energy balance for electrons and ions. Particle density and current are specified quantities. Impurities are treated using a coronal non-equilibrium model. Particle leakage and recycling are included for plasma and impurities. A single particle lifetime is used. The energy confinement times for electrons and ions are specified as multiplicative coefficients times the Ohmic energy confinement time. Energy loss by electrons is assumed to dominate. Ohmic heating is enhanced by an anomaly factor, and an ion heating term is included by use of a multiplicative factor times Ohmic heating. A single set of coefficients is found to simulate a variety of ZT-40M runs with different currents and wall conditions. Both flat top and ramp current waveforms are studied. The resulting model is applied to predict ZT-H behavior for both 2 MA and 4 MA operation. Parametric analysis was performed to evaluate the effect to varying I/N from 3 x 10 sup -14 to 6 x 10 sup -14 ; of varying the recycle time from 5 ms to 1000 ms; and of using two different energy confinement laws, one involving beta /sub theta/ as a calculated parameter, and one for beta /sub theta/ = 0.10. Low temperatures were obtained for short recycle times and low I/N values. Significantly improved performance was found for the beta /sub theta/ = 0.10 case. 4 figs., 9 tabs. (ERA citation 14:002519)