Stellarator equilibria with reactor relevant energetic particle losses

Stellarator configurations with reactor relevant energetic particle losses are constructed by simultaneously optimizing for quasisymmetry and an analytically derived metric (Γ_c), which attempts to align contours of the second adiabatic invariant J∥, with magnetic surfaces. Results show that with this optimization scheme it is possible to generate quasihelically symmetric equilibria on the scale of ARIES-CS which completely eliminate all collisionless alpha particle losses within normalized radius r/a = 0.3. We show that the best performance is obtained by reducing losses at the trapped-passing boundary. Energetic particle transport can be improved even when neoclassical transport, as calculated using the metric ɛ_eff, is degraded. Several quasihelically symmetric equilibria with different aspect ratios are presented, all with excellent energetic particle confinement.