Recent developments in the field of electrostatically focused CW-klystrons

Two new types of electrostatically focused klystrons (ESFK´s) with improved performance have been developed. Refinements in the electron-optical design have resulting in a beam current transmission under full RF conditions between 80% and 90%, compared to typically 50%-60% with ESFK´s of older design. Because of the reduced beam current interception, higher level of CW power can now be achieved. In addition, the thermal stability of the tubes is greatly increased.