Possible pathways for pursuing burning plasma physics and fusion energy development

This report has been prepared in response to a request from the U.S. Depart ment of Energy's (DOE) Office of Fusion Energy Sciences to consider possibl e alternatives on reduced cost options for "next-step" devices. A central f ocus of next-step devices is the study of "burning" plasmas, which explore the impact of substantial fusion energy production via the deuterium-tritiu m reaction. An important part of the U.S. Fusion Energy Sciences Program is its partici pation in the International Thermonuclear Experimental Reactor (ITER) progr am. Taking into account the international situation and U.S. domestic issue s, the ITER process is exploring reduced-cost options to the present ITER d evice. A Special Working Group, reporting to the ITER Council, has been for med to explore these issues on behalf of the ITER Parties, i.e., the Europe an Union, Russian Federation, Japan, and the United States. This report and its related activities will aid the United States in the international pro cess. This report is the result of a broad-based U.S. community effort to discuss , debate, and work together on the crucial issues involved in considering n ext-step options. The main content of this report is based on three potenti al pathways identified at a broadly attended community Forum for Next-Step Fusion Experiments (University of Wisconsin, Madison, April 1998) organized principally by the University Fusion Association and by the work of the IT ER Steering Committee-US (ISCUS) on reduced cost ITER options. The Madison Workshop was followed by a smaller Workshop on Next-Step Options (Universit y of California, San Diego, June 1998) to focus on preparing this report. A broadly-announced Website was established to facilitate access to document s related to this process.