L-band, annular beam klystron design

The International Linear Collider (ILC) requires a 1.3 GHz RF source with a minimum efficiency of 65% at 10 MW output power, and a cathode current density of less than 5 A/cm
²
. In addition, the source must be compatible with a pulse width of 1.5 milliseconds at a repetition rate of 15 Hz. Present source development is centered on multiple beam (MBK) and sheet beam (SBK) klystrons. These devices are more complex, both structurally and magnetically, than standard klystrons. Calabazas Creek Research (CCR) is investigating an alternative concept, the annular beam klystron (ABK), to meet the stringent ILC requirements.