Third-generation electron beams at the accelerator test facility for JLC

The purpose of the ATF is to develop beams with very small transverse and l ongitudinal emittances, A 1.37 nm horizontal emittance was confirmed by emi ttance measurements using wire scanners in the extraction line and ct measu rement of the horizontal spacial coherence using an SR interferometer. This paper reports on the transverse emittance ratio and gives a discussion on an extreme intra-beam scattering effect. It also describes some problems wh ich should be overcome. (C) 2000 Elsevier Science B.V. All rights reserved.