30 August 1995
G. Hofer said he was finishing the tritium report and reconciling review comments. It will soon be at the printers and be completed within a week.
Physics - S. Jardin reviewed that Reverse Shear (RS) data had been obtained for the aspect ratios of 3.0 and 4.5. However, results from the systems code had indicated that the optimal aspect ratio may at an intermediate value. Since the last meeting, data had been generated reflecting stable equilibrium conditions at A=3.5 and 4.0 at 90% of beta limit. The next step is to determine the current drive requirements. The difficulty is that D. Ehst and T.K. Mau are obtaining different results for the current drive requirements. D. Ehst and T.K. Mau believe they know the cause of the difference and will verify within two weeks.
Engineering - D-K Sze has organized an engineering subgroup meeting to be held at ANL on 6 Sept for the purpose of developing the rationale and selection of the maintenance and structural aspects of the reactor core. Specific attention will be given to the vacuum vessel, the core structural support, the access clearances around the coils and the general maintenance scenario. Dennis Lee has been added at MDA to help integrate the mechanical design of the power core.
C. Wong summarized the PFC/divertor design in that it would be generally based upon the ITER design philosophy of a radiatively cooled divertor system. A gas would be employed to enhance the radiation capability. C. Wong postulated that the life of the divertor should be assumed to be similar to that of the First Wall.
L. Bromberg had just come back from vacation and had no new work to report. D. Lee said they should discuss the magnet design approach for the basic structure.
T.K. Mau suggested, for the on-axis current drive, the use of ICRH Fast Wave would be best. A folded-loop antenna could be used with a first wall area around 10m2 located somewhat above the mid-plane. The loop antenna would be around 10-20 cm thick and approximately 20-30% dense. These data would suggest a blanket could be used behind the antenna. It was suggested that firm numbers be provided in lieu of rough estimates. For the off axis current drive system, there is no system having a clear advantage.
The Engineering Group asked about the technical details of the RS stabilizing shells. L. El-Guebaly has some information kink stabilizing shell. The blanket vanadium structure may provide this shell effect. Inputs are needed for the vertical stabilizing shell from C. Kessel who will not return until late September.
C. Bathke stated that if it is desired to have a RS strawman somewhat in advance of the next meeting (circa 16 Oct), he needs BOTH Physics and Engineering inputs by 9 October.
R. Miller mentioned that the costing basis for both capital and O&M costs would be a part of his IEEE paper. Any updates would be incorporated in the upcoming strawman.