NCSX Memorandum

To: T. Brown, A. Brooks, H-M. Fan, B. Nelson, D. Williamson, M. Cole, P. Goranson, R. Hatcher, C. Neumeyer, L. Dudek, P. Heitzenroeder

CC: J. Schmidt, H. Neilson, J. Lyon, S. Hirshman, M. Zarnstorff, A. Reiman. L. Berry, D. Strickler, R. Simmons, H. Kugel

From: W. Reiersen

Date: 1/5/2001

Re: Minutes of 1/3 Engineering telecon

An engineering telecon was held on January 3. Brown presented a modified structural design that appeared to be easier to fabricate. It was based on having an L-shaped section that a rectangular conductor could be wound in rather than an I-beam section. Concerns were raised about preserving stellarator symmetry in the structure for the modular coils located on the symmetry plane. It was suggested that these coils could have a T-shaped section that would preserve stellarator symmetry while preserving the appearent machining advantages of an open channel and fewer machined surfaces. Concerns were also raised about the structural integrity of this approach. As drawn, the structural shell connecting adjacent coils was aligned with the centroid of the winding pack. It was suggested that aligning the shell with the side of the winding pack might be beneficial. Another concern was that the loads had to pass through the bolted/welded connection in the coil case. Brown suggested that the difficulty in machining the surfaces might be considerably relieved if the surfaces were constrained to be vertical and horizontal. (For reference, the radial plane of the module or a neutral plane through the coil could be defined as horizontal for machining.) Another advantage of this approach is that it might skirt some of the difficulties encountered in the present approach in coming up with a merged part in Pro/E. After much discussion, there was a consensus that an open channel (an L-shaped or T-shaped section) appeared to offer substantial benefits relative to an I-beam section. However, it was not clear what to do next. Brown should continue to develop this alternative approach. Nelson should assess the features of Brown’s concept and provide a recommendation on if and how some of these ideas might be incorporated in the reference design.

Williamson discussed some of the problems in constructing a finite element model for the structural analysis. Overlapping surfaces are preventing the formation of a merged part that could be fully meshed. Williamson and Fan should continue to seek solutions for this problem.

Cole reported on progress in the area of access. He showed the view angle along the CL of each of the ports. Cole also showed a layout of NCSX in the PBX/PLT test cell with PBX still in place. There appears to be ample space for locating NCSX in the combined test cell without removing PBX. Chrzanowski should provide a recommendation on whether this option is worth pursuing or not.

The next Engineering telecon will be held next Wednesday, January 10, at 1:30pm.