Development of CW and short-pulse calorimetric loads for high power millimetre-wave beams

An increased power handling of rf-beam loads is required by the development of high power gyrotrons for fusion research, as well as the achievement of full capability to work under vacuum conditions, which is imposed by the use of evacuated transmission lines. New techniques were developed at IFP/CNR, leading to two prototypes. One is capable of 1 MW CW operation, while the second one is designed for precise measurements at short-pulses (0.1 s) at higher peak power (2 MW). Preliminary tests at 140 GHz, high power and long pulse (500 kW, 10 s) were performed. (c) 2005 Published by Elsevier B.V.