||The mechanical development of the 3.9
GHz, 3rd Harmonic SRF System is summarized in this poster presentation
to include: the development of a full scale copper prototype cavity
structure; the design of the niobium 3 cell and niobium 9 cell
structures; the design of the helium vessel and cryostat; the HOM
coupler design; and a preliminary look at the main coupler design. The
manufacturing processes for forming, rolling, and e-beam welding the
HOM coupler, cavity cells, and end tubes are also described. Due to the
exotic materials and manufacturing processes used in this type of
device, a cost estimate for the material and fabrication is provided.
As outlined in this presentation, the third harmonic design is being
managed via a web-based data management approach. Throughout the entire
design and engineering process, our data is being organized to keep us
on track and to share our ideas with our collaborators.