Fusion-Fission Hybrid Reactor Studies for the Straight Field Line Mirror

Abstract

A comparatively small mirror fusion hybrid device may be developed for industrial transmutation and energy production from spent nuclear waste. This opportunity ensues from the large fission to fusion energy multiplication ratio, Q_r = P_fis/P_fus ≤ 150, in a subcritical fusion device surrounded by a fission mantle with the neutron multiplicity k_eff ≈ 0.97. The geometry of mirror machines is almost perfectly suited for a hybrid reactor application, and the requirements for plasma confinement can be dramatically relaxed in correspondence with a high value of Q_r. Steady state power production in a mirror hybrid seems possible if the electron temperature reaches 500 eV. A moderately low fusion Q factor, the ratio of fusion power to the power necessary to sustain the plasma, could be sufficient, i.e. Q ≈ 0.15. Theoretical predictions for the straight field line mirror (SFLM) concept are presented, including results from radio frequency heating, neutron Monte Carlo and magnetic coil computations. Means to achieve an electron temperature of 500 eV are briefly discussed. The basic study considers a 25 m long confinement region with 40 cm plasma radius with 10 MW fusion power and a power production of 1.5 GW thermal.