Thrust 17 ChitID 17.001 Richard Callis 6/09/2009 16:51 Thrust 17 There was no mention if the technology needed for heating plasmas was in hand. If not what are the issues and challenges? ChitID 17.002 Ron Parker 6/09/2009 16:55 Thrust 17 Why have you not mentioned completing NCSX as the first step in your plan? NCSX was cancelled for political purposes, but maintained strong scientific support in the community. We have a new DOE administration, so why shy away from bringing up its completion as a way of jump starting a major US stellarator program? ChitID 17.003 Bruce Lipschultz 6/09/2009 17:00 Thrust 17 The thrust is well written, covering optimizing steallarators and ELM control. However, it seems to be missing a study of what is the minimal 3D winding one could add to a tokamak to slow down disruptions in tokamaks (as current ending transients occur in Stellarators) to a reasonable period which lowers heat loads. ChitID 17.004 Martin Peng 6/09/2009 17:04 Thrust 17 It appears scientifically necessary for thrust 17 to clarify the nature of compact quasi-symmetric stellarator configurations being "disruption-free", particularly for those that carry substantial toroidal bootstrap plasma current. If disruption free operation is already guarranteed based on existing data and understanding, the proposed research on intermediate new stellarator experiments will aim to carry out confinement research for a plasma free of disruption worries. If disruption free operation still needs to be tested and verified in intermediate new stellarator experiments, the proposed research should include the determination of the parameter regimes that are indeed free of disruptions. ChitID 17.005 tom intrator 6/09/2009 18:01 Thrust 17 I wanted to point out that there is at least one other potentially fusion relevant concept that is capable of steady state operation without disruptions. It is not toroidal, and fully axisymmetric, ie not 3D. This is the magnetic mirror, possibly of the Gas Dynamic Trap type (GDT). The GDT relies on being sufficiently collisional so that ions are scattered into the loss cone and make its ion velocity distribution isotropic. This eliminates the usual mirror velocity space (loss cone) instabilities.