ARIES Documents -- Meetings ArchiveARIES Conference Call, 1 December 2004
Documented by L. Waganer
Les Waganer reminded the team the next meeting would be held at General Atomics, San Diego, on 24 February and half a day on 25 February. It was agreed the next conference call would be held on Wednesday, 19 January 2005.
Compact Stellarator Integrated Systems Assessment
Systems Code Analysis – Jim Lyon said that he worked little in November and December on the code as he was concentrating on other activities. In January 2005, he would start again on the code. He asked Leslie which superconductor to use and Leslie told him to use the HiTc option contained in their combined TOFE paper. Jim noted he is planning to evaluate seven blanket options.
Compact Stellarator Reactor Engineering Assessment
Gas-Cooled Divertor Studies - Said Abdel-Khalik said that GT is working on experiments to validate the analytical results he had provided to the team. He is also working on a gas-cooled divertor to satisfy the divertor requirements being coordinated with Rene Raffray. Said is defining performance evaluation tools applicable to gas-cooled divertors. He intends to provide a progress report at the February meeting.
Power Core Engineering – Rene Raffray noted that Siegfried Malang has returned to Germany, but he is continuing to participate in the design development of the dual-cooled blankets. The present work is defining the coolant manifolds for the modular approach. The main challenge is to simplify the flow passages. The thermal conversion system will be the Brayton cycle. Xueren Wang is working on the CAD design details on maintenance and power core elements.
Safety Assessment – Brad Merrill is continuing to work on the LiPb blanket and power core safety assessment in conjunction with Carl Martin, UW-Mad. Carl has added contact conductances between the blanket and shield elements. This lowered the LOFA maximum temperature 14°C. He also ran a case with the first wall heat load increased by a factor of 1.5 and the first wall temperature exceeded the recommended structure temperature of 740°C. This higher temperature level would not represent a safety issue, but would require the replacement of the blanket module as the material design properties would be compromised.
Magnet Analysis – Recently, Leslie met with PPPL NCSX personnel on the design loads and stresses/deflections anticipated for the NCSX. That design used discrete coil structures with bolted joints to limit stresses and deflections. The ARIES team noted that the ARIES-CS baseline coil structure is a continuous torus coil structure with breaks at the field period locations. The coil structure is increased locally at the coil to help locally reduce the deflections. Leslie was concerned about his ability to use a FEM model to analyze the loads and deflections. Carl Martin suggested UW could provide some assistance and UCSD also said they could help with the modeling as the CAD model already exists.
Compact Stellarator Reactor Physics Basis
Assessment of Prompt Alpha Loss – TK Mau mentioned PPPL has been working with a gyro orbit code for their beam ion calculations on NSTX. This code and analysis may be beneficial for TK to use on the CS configuration. He mentioned that Art Grossman may assist in these calculations. TK has been coordinating with Lang Lao on using the VMEC code.
Assessment of New QAS and QH configurations – Long-Poe Ku said he has developed two additional configurations generally based on the NCSX configuration that have shown some promise of lower alpha particle loss. He has provided the data results to Arthur Grossman. He also continues to refine and develop the configurations shown at the November 2004 meeting. They seem to have good QAS properties, high quality flux surfaces and reasonable MHD conditions. He is also working with Paul Garabedian on the MHH2 configurations.
Analysis to the 2-Field Period Configuration – Paul Garabedian said that he had been working with Long Poe Ku on the 2 field period cases. He expressed a concern that we needed to apply more engineering knowledge to the coil and coil structures. He continues to seek configurations with low alpha losses.