Progress on High Power Tests of Dielectric-Loaded Accelerating Structures

To evaluate the Dielectric-Loaded Accelerating (DLA) structure as a potential alternative high-gradient accelerator, a series of high power RF experiments have been carried-out by a joint Argonne National Laboratory/Naval Research Laboratory program. We have tested DLA structures loaded with two different ceramic materials, alumina and MgxCa1-xTiO3. For the alumina tube, we concentrated on the study of the multipactor effect in the DLA structures under the high power rf field. In the MgxCa1-xTiO3tests, we mainly investigate the local field enhancement that caused dielectric joint breakdown of the DLA structures. In both cases, physical models have been set up, and the corresponding engineering solutions are being implemented.