CNR - lstituto Matematica Applicata, Via L.E.Albertl, 16132 Geneva

Abstracz: This paper deals with the design of high 0 TE resonators for high efficiency RF pulse compression. This kind of resonator 1s used to double the energy gradient of linear accelerators. In order to study the influence of the geomet:-y of the resonator on the Q , a computer code nemed OSCAR2D was developed. By means of this code ar, optimum geometry for TE storage cavfties was found. The results of the computer simulation are shortly compared with the experimental measurements performed on a TE caiilty prototype. 1. - Introduction. 1 As proved elsewhere , it's possible to double the energy gradient of a linear accelerator, without modifications of acceleratcng sections and RF systems, by installing a pulse compressor after the klystron. The pulse compressor makes use of a high Q resonator to store the RF energy. A feasibility study of a similar system started at INFN Frascati Laboratories with the goal to double the energy of the 400 cZeV linac. The results of this investigations show that the storage ,cavities x5. must exi-lbit a quality factor of, at least, Such very high Jalues of Q can be achieved with TE mode resonators . Our report presents the various kinds of usable ca\iltles, taking into account the problems given by the degeneratioc of TE modes into low Q TM modes.