Emittance growth during bunch compression of intense particle beams

Summary form only given. In high-energy ion accelerator, bunch compression using a longitudinal beam modulation is essential to increase the beam power. However, the bunching process is inevitably accompanied by emittance growth, because of a space charge effect, inaccurate bunching voltage, fluctuation in the beam transport line and others. To simulate the bunching process in high power ion accelerator, we constructed a small accelerator composed of an electron beam injector, induction voltage modulators and a beam transport line with 2 m in length, in which an electron beam is accelerated, longitudinally modulated, and trasported for bunching. Evolutions of the beam emittance are estimated by pepper-pot images of the bunched beam. We discuss the compressive effect including the correlation between transverse and longitudinal emittance, as a function of the beam current, the transport length, and the bunching factor.