Measurements of beam breakup (BBU) instability performed on the Advanced Test Accelerator (ATA) up to the end of February 1984 are reported. The main objective was to produce a high current usable electron beam at the ATA output. A well-known instability is BBU which arises from the accelerator cavity modes interacting with the electron beam. The dominant mode is TM//1//3//0 at a frequency of approximately 785 MHz. It couples most strongly to the beam motion and has been observed to grow in the Experimental Test Accelerator (ETA), which has only eight accelerator cavities. ATA has 170 cavities and therefore the growth of BBU is expected to be more severe. BBU measurements are reported for ATA with beam currents of 4 to 7 kA. Analysis showed that the growth of the instability with propagation distance was as expected for the lower currents. However, the high current data showed an apparent higher growth rate than expected. An explanation for this anomaly is given in terms of a 'corkscrew' excitation.
|Original language||English (US)|
|Journal||IEEE Transactions on Nuclear Science|
|State||Published - Oct 1985|
ASJC Scopus subject areas
- Nuclear Energy and Engineering
- Electrical and Electronic Engineering