Alcator C-Mod inner divertor upgrade design and analysis

In 1993 there were indications that the C-Mod inner divertor was being over-loaded. As a result, an inner divertor modification is being installed in C-Mod. The new design is intended to allow a change in profile of the divertor to accommodate a higher plasma triangularity, strengthen the inner vessel wall to survive 9.0 Tesla, 2.5 MA disruptions and, eliminate tile rotation. The thermal differentials between tiles and vessel wall, necessitated the introduction of compliance in the reinforcement hardware. Practical assembly within the vessel required manageable part size,and bolted interfaces which further reduced the strength and stiffness. A modest improvement of 22% was achieved while meeting the many design constraints.