RF power generation for future linear colliders

The TeV collider RF source development effort at SLAC is being concentrated on both the high-power conventional klystron followed by some form of RF pulse compression (not necessarily three-stage binary described here) and the CFA. The relativistic klystron provided an excellent experimental source for initial high-gradient accelerator experiments. The induction linac required to make high current relativistic beams for these klystrons appears at present to be too expensive for use in a high pulse rate mode. The 100 MW conventional klystron is promising but requires stable operation at 800 ns with pulse compression to 100 ns. This has yet to be demonstrated. Problems with RF voltage breakdown in cavity gaps, ceramic windows and pulse compression waveguide components must be solved. The CFA development is not as far along as the klystron and will be a serious collider RF source candidate only if stable operation can be achieved above 200 MW. If one of these two approaches emerges as the more feasible, the focus of further effort will be toward producing that source at low cost.