Thrust 99 ChitID 99.001 David Hill 6/09/2009 15:48 Thrust 99 This is the place to post chits of a general nature related to broad issues for ReNeW or which apply to all provisional Themes or Thrusts ChitID 99.002 Rob Goldston 6/09/2009 15:59 Thrust 99 It seems to me that the DT machines we are discussing are designed in order to make ourselves happy. We want to make lots of tritiium. We want to show that the bootstrap current profile is consistent with alpha heating. But everyone outside of this room only wants electricity from us. It seems to me that we should consider extending the requirement for a CTF (whether an ST, AT or CS) to include net electricity production. This means that Q_eng needs to be somewhat greater than unity, say 1.3, so that 100 MWe would be put on the grid, perhaps with 30% duty factor. ChitID 99.003 richard nygren 6/09/2009 16:06 Thrust 99 RENygren to ReNeW ExecComm: Thanks for your leadership. We are a long way along, perhaps too far to look at radical changes to the thrusts. I hope there is still time to recast the excellent work on the thrusts to make the important messages clearer. While you are closing in on a deadline, there was also an implicit promise perhaps by default in the ReNeW process that resolutions of the type I suggest would be done when we all gathered, i.e., at the workshop. I believe there needs to be a process to combine some thrusts and reduce the overall number and that this effort will (a) produce a document in which our logic and thinking appears crisper and (b) some of the existing overlaps are reduced. (I regard these are independent criteria.) I think there need to be less than 10 thrusts. To this end I suggest one possibility (below) to help move the process along. (I believe others can do better and I certainly admit that I am not the one to be combining the physics thrusts. ChitID 99.004 Rob Goldston 6/09/2009 16:07 Thrust 99 The full set of upgradabilities that are listed under Thrust 8 are greater in every respect than those of the original ITER, which itself cost twice what the present ITER costs. While we are not discussing price in detail, we need to have a sense of what you are talking about here. The Thrust 8 advocates need to present at least a cartoon idea of what they are talking about to make this worthy of consideration. What magnet technology are they discussing? What HH factors are they assuming to achieve their goals? What are they assuming about insulator lifetime (FIRE was already beyond the known limits)? What kind of PFC technology are they considering that could support this mission? Making a fog of options is not adequate for consideration. They need to show the scale/scope of at least one compelling concept that could be upgraded to all of these other missions. ChitID 99.005 Richard Callis 6/09/2009 16:23 Thrust 99 It appears that several of the thrusts have high overlap and should be combind, There were several that covered integrated modeling; high performance steady state operation, material development, etc. Also I would recommend that the magnet thrust be expanded to include all other enabling technology (such as heating and CD technology), which is buried throughout the thrusts. ChitID 99.006 richard nygren 6/09/2009 16:36 Thrust 99 The 6 pagers are pretty dry and we have seen many excellent summary figures in the presentations. Consider a format for the report where each thrust uses a summary figure at the beginning as part of its introductory comment. An example is Mike Ulrickson's transition bridge with supporting pillars for the PFCs. This was for Theme 3 but conveys a simple and powerful message. ChitID 99.007 Richard Buttery 6/09/2009 17:08 Thrust 99 I think it is completely wrong to separate out the "alternates" to their own chapter - it implicitly characterises them as being mainly of relevance to their own paths. In fact they offer broad contributions to many elements of the fusion path. Therefore foci of work should be about goals towards fusion (ends), rather than picking out particular means. Suggestion (needs some work, so perhaps do this after this week): reconsider thrusts 16-18 to be goal rather than means oriented. Similarly draft chapter 5 in terms of contributions of the 'alternate facilities' towards main stream fusion goals, rather than simply perpetuating lines - talk about need to pursue these facilities. Then review other thrusts and make sure they flag the potential roles of conventional and alternate devices to each. ChitID 99.008 Richard Buttery 6/09/2009 17:25 Thrust 99 I feel that for each thrust we need a short (3 line) description of each new resource option (extra facilities, or facility developments) with an approximate order of magnitude price, and time when it is needed. May also be wise to highlight major resources needed from existing programmes. This gives a sense of scale and difficulty, though of course is separate from specific hardware proposals, which may sometimes meet needs of more than one thrust. ChitID 99.009 Clement Wong 6/10/2009 07:47 Thrust 99 Due to the focus of Thrust 10 (surface materials) and 11 (innovation), together they have missed to emphasize the significant gap on the need for the development of robust high performance and disruption tolerant (both thermal and structural) PFC components. ChitID 99.010 Clement Wong 6/10/2009 07:53 Thrust 99 VG # 2 The presentation and therefore corresponding writing needs to identify deficiencies in PFC development including necessary helium test loops, test stands, fabrication with RAFM steel, CCGT and robust and disruption tolerant (both thermal and structural effects) PFC designs. We also need to include design margins. ChitID 99.011 Clement Wong 6/10/2009 07:53 Thrust 99 VG # 6 Under innovation should add “twisted tapes” and “2-D and 3-D surface roughening”. Actually there could be other new and combination of options. ChitID 99.012 Clement Wong 6/10/2009 07:54 Thrust 99 VG # 7 For a major cooling option for fusion power development, VG # 7 actually indicates the inadequacy of helium cooled development and limited development participants in the last 16 years, mostly from SBIR, which naturally focused on break through innovations like ChitID 99.013 Clement Wong 6/10/2009 07:55 Thrust 99 VG # 7 For a major cooling option for fusion power development, VG # 7 actually indicates the inadequacy of helium cooled development and limited development participants in the last 16 years, mostly from SBIR, which naturally focused on break through innovations like refractory alloys and porous media. A much broader base and fundamental support, like from universities and industries will be needed. ChitID 99.014 Clement Wong 6/10/2009 07:56 Thrust 99 VG # 8 All refractory metal heat sink…is not the correct indicator of necessary development. We will need a refractory metal surface and even the indicated examples shown later have transitional piece to RAFM steel or ODFS. A more straightforward option of planar refractory metal surface e.g. W, joining to ODFS and then RAFM steel and then to coolant channels should be considered for both FW and divertor designs. For lower temperature helium coolant at ~350-400 C, the ODFS is to bring the surface temperature up to 700 C such that the W surface could be maintained to >700 C, which is necessary to maintain the toughness of the W-alloy under neutron irradiation. ChitID 99.015 Clement Wong 6/10/2009 07:57 Thrust 99 VG # 20 Recommendations should add the need for broader base support and to enhance the training of a new generation of heat removal engineers and scientists. ChitID 99.016 Jerry Navratil 6/10/2009 09:03 Thrust 99 The ReNeW structure which separates the ST research line from the work on tokamak physics does not serve us well. Thrust 16 should be restructured as focusing agressively on CTF critical path issues for the ST approach and and the remainder of ST research should be folded into the broader AT research program. ChitID 99.017 Tony Peebles 6/10/2009 10:18 Thrust 99 I don't feel the diagnostic community needs to state in the opening paragraph that "the development of diagnostics is a legitimate branch of plasma science" This seems uneccessarily apologetic. After all science, in general, is BASED on testing hypotheses/theories through experimental measurement - surely the importance and inherent need for the continued development of new measurement techniques is obvious to all! Perhaps a more positive opening sentence along the lines of Measurement of plasma parameters has been critical to progress in fusion science. In addition, they are essential to plasma control and maintainence of machine infrastructure. As we approach the burning plasma era, existing measurement techniques will be severely challenged through the harsh nuclear environment and required measurement reliability ------ ChitID 99.018 Brad Patton 6/10/2009 10:19 Thrust 99 Safety and RAMI(Theme 4)to are not adequately addressed in any of the existing 18 Thrust areas. Discussion of these two overarching issues, essential to the success of the program, should be added to the appropiate existing Thrusts or a new Thrust needs to be added. Addition of a new Thrust area is recommended. ChitID 99.019 anonymous 6/10/2009 10:22 Thrust 99 ChitID 99.020 Richard Buttery 6/10/2009 10:24 Thrust 99 There are too many thrusts with narrow, subtle, expert-only differences between the thrusts. Some thrust divisions are present to indicate a time ordering, Should aim to get things down to a dozen thrusts. But structure already seems far to entrenched to consider this, and one get the feelings people are defending this high quanity to make sure they maximise focus on their respective fields. But is this the best structure to sell the programme outside the fusion expert community? Logical combinations: 3 into 8; 10 into 14; 17 into 18; 12 into 11 and 8; 13 into 15; (and if I'm tough with thiongs close to my heart) 2 into 5. ChitID 99.021 anonymous 6/10/2009 16:01 Thrust 99 ChitID 99.022 anonymous 6/10/2009 16:01 Thrust 99 ChitID 99.023 anonymous 6/10/2009 17:38 Thrust 99 ChitID 99.024 Jim Callen 6/11/2009 08:36 Thrust 99 THRUST 99: Executive Summary --> Hazeltine, Hill, Neilson OVERARCHING NEEDS TO SUPPORT THE THRUSTS -- to facilitate developing predictive capability, as noted in details of most of the thrust descriptions: Diagnostics -- both new types and more extensive employment of present ones (we can only understand what we measure) Theory and modeling -- next generation of reduced models that capture key physics elements in computable, experimentally relevant models Much more capacity computing resources -- to facilitate in-depth validation of the invariably compute-intensive models More experimental run time -- beyond present ~ 15 weeks per year on major experiments toward 26 weeks (~ 50%), to facilitate more rapid progress on model validations MINOR OBSERVATION -- Thrust 6 "understanding/validation" coming after Thrust 5 Controlling, Sustaining Burning Plasmas is a bit awkward logically. ChitID 99.025 anonymous 6/11/2009 10:07 Thrust 99 ChitID 99.026 anonymous 6/11/2009 10:07 Thrust 99 ChitID 99.027 Hantao Ji 6/11/2009 11:00 Thrust 99 I suggest to provide high-level explanations of interrelations and logics of all 18 thrusts.(Even only 1 pagers from each thrust, we have 18 pages, and it is hard to get a global picture out of these 18 1-pagers). One practical way at this late stage of ReNeW is to provide these explanations is to use the classifications of 5 Themes in the Executive Summary drafted by Richard H. The idea is to use general words to explain why fusion research can be divided into 5 themes, and why each theme can general a few thrusts. If we take this approach, we will need to have a generally accessible introduction or summary for each theme in their Theme Chapter. ChitID 99.028 Larry Baylor 6/11/2009 11:10 Thrust 99 Fusion research is very much an international effort. ReNeW has not made this very clear except in the thrust to develop ITER burning plasmas. It may be useful to the intended ReNeW audience to note the international nature of fusion reearch and suggest more coherent ways beyond and outside of ITER to capitaize on this. ChitID 99.029 Jim Callen 6/11/2009 13:45 Thrust 99 Comments On Thursday morning discussion issue: 1) Martin Greenwald's suggestion that there should be fewer themes. How about putting single sentence descriptions at the first of each of the Themes beginning on page 5 of the Exec Summary -- indicating the generic aspects of the thrusts they include (e.g., for Theme I, activities to help ITER accomplish its mission). This could give the impression of "only" 5 theme areas rather than the very large number (18) of specific thrusts. 2) Rob Goldston's concern that the ReNeW document could be interpreted by (unfriendly) outsiders that fusion cannot deliver energy-related contributions over the next 20 years. Emphasize strongly (in 3rd and 4th paragraphs) what the ReNeW process was asked to do (quote charter?) -- and say (briefly) it does not lay out a "roadmap" with time, budget lines for developing fusion energy electricity production. Rather, the ReNeW objective is needed research to develop foundational basis for a fusion energy sy ChitID 99.030 Kofi Korsah 6/24/2009 09:41 Thrust 99 Although instrumentation needs are alluded to here and there in the Thrusts, I believe that it probably could have benefited from a stand-alone Thrust, owing to its cross cutting nature. There is a need for research into new and/or significantly improved instrumentation for real time measurements in the harsh fusion environment. Examples include, but not limited to, ONLINE tritium measurements, corrosion, improved measurement of plasma parameters for control and safety, etc. Since its too late to have a separate Thrust of its own, each Thrust that requires significantly improved instrumentation for any of its activities should have a section that BRIEFLY identifies the state of the art of instrumentation for that activitity, then briefly discuss areas that require significant improvement for DEMO. ChitID 99.031 Clement Wong 6/29/2009 13:47 Thrust 99 To an outsider, after reading our 18 one pagers, our gems, they could get the feeling that we are disoriented with the goal of continuation but without a clear mission. In the following, I will attempt to recommend a few activities and see how the 18 thrusts could be imbedded. 1. Support of ITER (T1, T2, T3, T4, T5, T6, T8, T9, T11, T13, T14, T15) 2. Assessment, selection, design and construction of the long pulse high fluence DT machine. (T1, T2, T3, T5, T6, T7+normal magnet, T8, T9, T10, T11, T12+DT*, T13, T14, T15, T16**) 3. Linear machines for PMI studies. (T1, T10, T14) 4. Demo design with iteration with activity #2. (T1, T2, T3, T5, T6, T7, T8, T9, T10, T11, T12+DT*, T13, T14, T15) This is a conceptual design effort. 5. Present and up-grade machines. (T1, T2, T4, T5, T6, T8, T9, T12, T15, T16**) 6. Alternatives. (T17 and T18) *T12 will become an extremely useful thrust if the non-DT limitation is lifted. ** ST should be treated as a low aspect ratio tokamak With the