Accelerator drift-tube braze-joint failures in the PIGMI APF cavity [report]

L.D. Hansborough, L.S. Levinson, R.D. Reiswig, L.C. Wilkerson
1981 unpublished
During tne assembly of the Alternating Phase Focusing cavity for the PIGMI Prototype proton accelerator, recurring failures of drift-tube braze joints occurred. In the fabrication technique, a torch craze was used to attach the stems to both the drift-tube body and the stem termination; all materials used were stainless steel. The assemblies were copper plated, using brignt-acid-leveling copper plating. Some braze joints, althouqh satisfactorily tension-tested before plating, later failed at a
more » ... later failed at a relatively low loading. A detailed investigation of one drift tube inoicated that residual copper-plating solution in the cooling passages acted to dissolve the braze solution over a period of weeks, leading to an eventual joint failure. I.
doi:10.2172/6682549 fatcat:ku6hik6n5bblfl7xcpqghm2rae