A drift orbit model for relativistic test electrons has been incorporated into the MARS-F code (Liu et al 2000 Phys. Plasmas7 3681), in order to study the runaway electron (RE) behavior in the presence of magneto-hydrodynamic perturbations computed by MARS-F. By implementing the model directly into the MARS-F curve-linear magnetic coordinates, maximal accuracy in representing the full field perturbation is preserved. The updated code is utilized to study the high current RE beam loss in a post-disruption DIII-D plasma, revealing that a fast growing, n = 1 (n is the toroidal mode number) resistive kink instability, at ∼100 Gauss level, can induce significant fraction of RE loss, largely by perturbing drift orbits of REs. A ∼1000 Gauss perturbation fully terminates the RE beam, as found in both experiment and modeling. The 3D field induced loss increases with the perturbation amplitude but decreases with the particle energy. The loss fraction is generally not sensitive to the initial particle pitch angle. The particle velocity change, due to electric field acceleration/deceleration, small pitch angle scattering, synchrotron radiation and Bremsstrahlung, further perturbs the RE trajectory but plays a minor role in prompt RE loss within microseconds time scale. Therefore, the dominant dependencies are simply the RE energy and instability strength. For comparison, a resonant magnetic perturbation field, generated by 4 kAt n = 3 even parity I-coil currents in DIII-D and with the plasma response field included, is found to induce almost no loss for the same RE beam.
3D场致DIII-D逃逸电子丢失及其与RMP场致丢失的对比研究。采用真实3D扰动场对DIII-D逃逸电子束的3D场致丢失进行了建模研究。实验与建模均发现，~1000 Gauss的扰动足以完全终止逃逸电子束，而~1000 Gauss的3D场完全终止逃逸电子束。建模发现，~1000 Gauss的扰动会完全终止逃逸电子束，这与实验和建模结果一致。3D场致丢失随扰动幅度增大而增加，但随粒子能量增大而减小。丢失份额通常对初始粒子投掷角不敏感。由于电场加速/减速、小角度散射、同步辐射和轫致辐射引起的粒子速度变化会进一步扰动逃逸电子轨迹，但在微秒时间尺度内对快速丢失过程作用次要。因此，主要依赖因素仅为逃逸电子能量和扰动强度。对比发现，由DIII-D中4 kAt n=3偶宇称I线圈电流产生的共振磁扰动场（含等离子体响应场）对同一逃逸电子束几乎不产生丢失。