SIMULATION OF THE DEBUNCHING PROCESS AND ADIABATIC RF CAPTURE OF INTENSE BEAMS

The high intensity beam of an inertial confinement fusion storage ring will be affected by strong space charge fields. We have studied the e mittance growth during debunching of an intense linac beam and adiabat ic r.f. capture in the storage ring under the influence of the self-co nsistent space charge force. The particle motion is simulated with the particle-in-cell code SCOP-RZ neglecting particle collisions. The res ults show that rebunching can dramatically reduce the growth of the mo mentum spread during the debunching process. A funnelling injection sc enario is proposed, which avoids the final emittance growth following the rebuncher. We estimated the total r.f. ramping time needed for adi abatic r.f. capture. This ramping time is short enough to prevent part icle losses due to intrabeam charge exchange.