Parametric studies of tandem mirror reactors

To increase net power plant efficiency and reduce the recirculating power fraction, a tandem mirror reactor should have Q approx. 10. With this in mind, we solve a set of space and time independent power balance equations including quasi-neutrality requirement for electrons, plug ions, and central cell ions. We investigate the effect of finite radial confinement time on Q, and the impact of plug diameter to length ratio (plug aspect ratio) on the physical dimensions and neutron wall loading of the machine. The preliminary study shows that a Q = 10, 3000 MW/sub th/ reactor is possible with an injected deuterium beam energy of 1.5 MeV, and a maximum plug magnetic field of 16.5 T. When the plug aspect ratio is 1, the central cell length is about 200 m and the neutron wall loading is 0.9 MW/m2. If a fatter plug plasma is feasible, e.g., with an aspect ratio of 2, then the solenoid length can be reduced to about 100 m and the neutron wall loading can be increased by 20%. In either case, at Q = 10, the recirculating power fraction is reduced to 20%, compared to approx. 36% at Q = 5