Continued Monitoring of the Conditioning of the Fermilab Linac 805 MHz   Cavities
  We have reported previously on the conditioning of the high-gradient accelerating cavities in the Fermilab Linac. Automated measurements of the sparking rate have been recorded since 1994 and are reported here. The sparking rate has declined since the beginning, but there are indications that this rate may have leveled off now. The X-rays emitted by the cavities are continuing to decrease. 
E. McCrory, T. Kroc, A. Moretti, M. Popovic