The DIII-D Research Opportunities Forum (ROF) for proposing experiments for 2008 is scheduled for October 16-18, 2007 at General Atomics. We anticipate receiving a large number of proposals spanning a range of exciting and timely research topics at the Opportunities Forum. As in the past, remote participation will be possible and we anticipate hearing ideas from both the national and international fusion community.

The 2008 DIII-D Research Council met three times in September to begin the planning process and prepare for the upcoming ROF. As a result of these meetings, eight high priority research topics have been identified for DIII-D experiments in 2008. These topics support the three high level mission elements for the DIII-D program: support of ITER, development of a scientific basis for steady-state operation, and fusion science. These topics also capitalize on the increased EC heating power.

While broad, these eight highest priority topics are not all-inclusive. We encourage proposals addressing other research issues (e.g., NTM, hybrid discharges, disruptions, SOL flows, hydrogen operation, RWM, etc.); such research will be organized as additional Working Groups within the structure of the Experimental Science Division. The eight highest priority research topics for 2008 are:

• ITER Demonstration Discharges: The primary activity here will be to develop and evaluate the baseline H-mode, advanced inductive, hybrid, and steady-state scenarios envisioned for ITER. The goal of this research is to reproduce as many of the ITER core-plasma discharge characteristics (e.g., q₉₅, β_N, shape) to extent possible, and to exploit these discharges as research platforms for development of a detailed physics basis for ITER (e.g., <math>T_e=T_i</math>, low rotation, detachment, ELM suppression, etc.). The research in this area will be organized as a Task Force under the Director of Experimental Science.

• Rotation Physics: It is now recognized that plasma rotation affects a broad range of fundamental tokamak physics. This is a critical near-term issue since ITER performance projections and system requirements are sensitive to the assumed plasma rotation. A proposed FY2008 DOE OFES joint C-Mod/DIII-D/NSTX JOULE Milestone highlights the urgent need for rotation physics research. The full capabilities of the DIII-D heating and feedback control systems, along with its extensive diagnostic set, provide opportunities to plan a broad range of experiments to address this urgent research topic (e.g., experiments on intrinsic rotation, effect of rotation on RWM and NTM stability, non-resonant braking, error field screening, etc.). This effort will be organized as a Task Force under the Director of Experimental Science.

• ELM Control and Pedestal Physics: Research here should aim to develop a more complete understanding of the processes that control the ELM behavior and pedestal structure both with and without 3-D field effects. Topics of interest include comparison of pedestal structure with available models and detailed studies of the physics of both active ELM control and operation in ELM-free or small-ELM regimes. Experiments will be organized as a Task Force under the Director of Experimental Science.

• Steady-state high-beta operation: The primary focus of these experiments will be the demonstration of fully non-inductive operation utilizing the increased EC power available in 2008. This research will be organized as a Working Group within Steady-State Integration.

• Transport Model Validation: New diagnostics, simulation tools, and tokamak capabilities enable focused experiments aimed at the validation of theory-based transport and turbulence models, including but not limited to GYRO and TGLF. Close coordination with theoreticians at GA and in the broader international community should lead to determination of key tests (both detailed and higher level integrated comparisons) that can and should be made using the profile and fluctuation diagnostics presently available on DIII-D. These experiments will be coordinated as a Working Group within Fusion Science.

• Thermal Transport in the Plasma Boundary: Divertor heat and particle flux have long been recognized as an important design driver for tokamak reactors, though the physics of 2D and 3D thermal transport in the scrape-off layer is not well established. DIII-D has extensive diagnostic and edge-plasma control capability which enables experiments to develop an improved H-mode edge and divertor database suitable for comparison with physics models and edge data from other tokamaks. Activities here will be organized as a Working Group within Fusion Science.

• Hydrogenic Retention: Tritium retention is a major driver for the choice of Plasma Facing Components in ITER, and DIII-D is uniquely positioned to evaluate plasma-wall interactions with all-carbon PFCs. Topics of interest include quantifying carbon migration pathways, developing methods for mitigating carbon co-deposits, and testing techniques for removal of hydrogen species from co-deposits. Activity here will prepare us for addressing a proposed FY09 JOULE milestone and will be organized as a Working Group within ITER Physics.

• ITER Startup, Shutdown, and Vertical Stability: This group will develop a detailed database of proposed startup and shutdown scenarios for ITER through simulations on DIII-D as well as develop information required for assessing vertical stability issues for ITER. Research here will be organized as a Working Group in Plasma Control & Operations.

Instructions on accessing the ROF web page (fusion.gat.com/global/rof2008) to submit your proposal, along with the organization of topics and the topical leaders, will be sent in a subsequent e-mail. We look forward to receiving your proposals in preparation for an exciting year of research on DIII-D.