||The performance of the twelve
split-loop resonators (SLRs) of the ANU LINAC has been substantially
improved by re-plated with 96%Pb-4%Sn. The re-plating with Pb-Sn
Schlotter MSA solution was initially plagued by the appearance of
dendrites on the surface plated. Reverse-pulse-plating at modest
currents eliminated the dendrites. In addition, a new technique
has been demonstrated of mechanically polishing the unsatisfactory PbSn
surface and then re-plating, rather than laboriously chemically
stripping the old PbSn and hand polishing the Cu substrate. It is
enormously easier, faster and does not put at risk the thin cosmetic
electron-beam-welds or the solder-repaired welds. An average
acceleration field of 3.5 MV/m has been achieved in off-line tests.
Twelve SLRs are currently installed and operated in the ANU LINAC.