Inertial Fusion Energy Workshop Summarized

June 8, 2022

A Summary Report of the February 22-24 Inertial Fusion Energy (IFE) Science & Technology Strategic Planning Workshop has been issued.

The community-driven effort assessed near- and long-term research opportunities in inertial fusion energy and outlined and developed a strategy for the High Energy Density Physics (HEDP), Inertial Confinement Fusion (ICF), and Inertial Fusion Energy (IFE) communities to work together. The workshop focused on the science and technology needed to make IFE an attractive energy source and how the needed R&D might evolve from current HEDP/ICF/IFE activities and facilities.

Copies of the report can be requested from Alex Zylstra: zylstra1@llnl.gov or from Fusion Power Associates: fusionpwrassoc@aol.com and will also be posted on the workshop website: https://lasers.llnl.gov/nif-workshops/ife-workshop-2022

The final section of the over 50-page report reads as follows:

Based on the content of the workshop we have summarized several recurring themes of the white papers and discussion into a short list of observations and recommendations. Since the charge of this workshop was intentionally not oriented towards assessing the relative merits of any specific approach or technology, such work is left to future reports.

1. Guide research by systems-level assessments
It is apparent that the community strongly supports guiding our efforts with system-level assessments that will guide the work and investments towards areas of particular importance for IFE systems. Several forms in which this could be formed were suggested, for example a working group on systems studies, composed of experts; creating a multi-institution consortium (or consortia), similar to the HAPL project, which have clear goals; or organizing the community around a yearly workshop or other process. In terms of technical work, this could include identifying and tackling any subsystem integration studies with high impact to the overall systems maturity.

2. Leverage the modularity of IFE
Significant interest in driver "module" type capabilities, considered an important precursor to larger-scale concept tests, was expressed during the meeting, although without strong consensus on a particular scheme or approach. Such subscale capabilities can also support a parallel program on physics topics that need to be addressed for credible scaling to robust high gain, while developing technology. That such work can be conducted at a variety of scales and in parallel embraces the modular aspect of IFE.

3. Timeline and process for focusing the program
The community is hesitant to identify a specific timeline for attempting to focus a program on a subset of IFE approaches. Simultaneously, we have a sense of urgency that dictates that the IFE program should aim for reasonable timelines for IFE to become a reality - for example a similar timeline to the 2040 goal adopted by the MFE community. A strategy for this challenging aspect of the program definition is beyond the scope of this workshop, including the fact that no specific budget scenarios were considered in detail. For future processes, this community-led workshop did have substantial discussion on the potential limitations of a strict application of standard (e.g. NASA-type) 'TRL' ratings to fusion approaches, which are not uniformly accepted. This potentially motivates a new methodology which is rigorous and applicable for assessing the relative readiness of disparate approaches and/or system components (e.g. wherever we use the term TRL in this report). If and when the program becomes more focused, maintaining a base level of broad research supported by the government was considered important, which leaves open the possibilities of leapfrog technologies or surprising R&D developments.

4. Building the research community
A productive and collaborative research community is critical to the success of this endeavor. IFE has some unique opportunities and challenges in this, which were discussed in the workshop. First, it is clear that a productive engagement with the science programs under NNSA are absolutely essential - including both technical areas of common interest, plus coordinating on facility use and workforce development. Given the growing investment by the private sector in fusion, it is clearly important that we have productive mechanisms for collaboration with private industry and that current mechanisms, such as CRADAs, are cumbersome or difficult to execute in a timely fashion. There is no substitute for tackling topics unique to IFE directly and systematically. Also, another recurring theme was that we strongly support and encourage productive collaboration with the MFE community on technologies and topics of common interest. Last but not least, the community recognizes that a healthy and growing workforce will be key for execution of the IFE program and we clearly support efforts to incorporate diversity, equity, and inclusion efforts in the development of our future workforce.