Progress in relativistic klystron research

Experimental work by collaborators at SLAC, LLNL and LBL is continuing towards the development of a relativistic Klystron capable of supplying RF power to a next generation high gradient Linear Collider. With the latest modifications to the Relativistic Klystron, the authors have been able to obtain over 300 MW pulsed RF power (In pulse widths of 30-40 ns.) at 11.4 GHz. This power has been used to accelerate electrons in a short length of high gradient accelerator section. Efforts are now underway to investigate RF breakdown limitations in multiple high gradient accelerator section using this power. A description of progress with these programs presented. A discussion of some of the obstacles which has been overcome is also described