Flux, energy, and particle lifetime measurements for well-formed FRCs: Appendix D

Experimental flux, energy and particle lifetimes are reported for a wide range of plasma conditions (T/sub i/ = 100 to 800 eV, r/sub s/ = 3.5 to 7 cm) in the slow risetime TRX-2 field-reversed theta pinch. The lifetimes exhibit a scaling with the parameter r/sub s//rho/sub io//sup 1/2/ to an exponent of between 2.7 and 3.6. This favorable scaling, especially for the flux lifetimes, implies an average plasma resistivity which scales as the drift parameter v/sub E//v/sub i/ to some power greater than unity. For present small devices, typical flux diffusion coefficients are about 4 m2/sec and, based on the above scaling, would decrease rapidly in larger devices with smaller pressure gradient scale lengths. The above scaling is obtained only for well-formed FRCs with low levels of formation turbulence, and it remains to be seen if this low turbulence level can be maintained in larger, less kinetic, FRCs