Testing of the ITER CS Module #4

The ITER Central Solenoid is under fabrication by the US ITER organization and its subcontractors. US ITER will supply seven modules to ITER IO, six of which will be assembled in a stack that forms the ITER Central Solenoid (CS). All CS modules were or will be tested at 40 kA in the Final Test facility at General Atomics, Poway, CA. Testing included high voltage, as well as Paschen testing in the vacuum and global leak tests before and after the cooldown to 4.5 K and EM cycling to 40 kA. In the paper we present the results of the CS Module 4 performance, after modifications to the test facility to improve reliability and instrumentation. We measured critical temperatures in several pancakes, AC losses before and after 10 cycles to 40 kA, joints resistance and hydraulic characteristics of the coils. We also measured displacements of the coil height and vertical strain of the CSM (central solenoid module) to verify structural mechanical characteristics of the coil along with cooldown shrinkage of the coil. We studied performance of the cowound quench detectors, confirmed their effectiveness in suppression of the inductive noise, but also developed a plan to improve sensitivity of the quench detection in ITER CS. This information is necessary for verification of the stack behavior of CS in ITER operation. The test results, preliminary analyses, comparisons to the other tested modules are presented and discussed.