HBT-EP External Kink Mode Control Research Program: Recent Progress and Future Plans

HBT-EP MHD mode control research is studying ITER relevant internal modular feedback control coil configurations and their impact on kink mode rigidity, advanced digital control algorithms, and the effects of plasma rotation on MHD mode stability. HBT-EP is installing a new segmented adjustable conducting wall with internal modular feedback control coils of varying toroidal angular coverage similar to that of the ITER `VAC02' internal coil design to test RWM interaction and multimode response to such highly localized control fields. In parallel with this hardware development, we have also extended our 3-D VALEN feedback modeling code to include the effects of multimode plasma response$. $This enhanced VALEN physics capability will allow detailed comparison and benchmarking of its new plasma model with our new wall, control and sensor coil geometry measurements. Multi-mode VALEN is now being tested and initial calculations of plasma stability for HBT-EP and NSTX will be presented along with details of the design and construction of our new wall-feedback coil system and future experimental plans.