FRPI011  ビームダイナミクス  8月2日 国際科学イノベーション棟5階 ホワイエ 10:50-12:50
Space-Charge Effects in the Induction Microtron
○タウフィク(国立大学法人 総合研究大学院大学(総研大)),安達 利一,高山 健(高エネルギー加速器研究機構)
○Taufik Taufik (SOKENDAI), Toshikazu Adachi, Ken Takayama (KEK)
Space-charge effects resulting in beam loss or emittance degradation are known to determine the space-charge limit in any circular accelerators. Beam-core evolution equation approach that can describe a long term evolution of the beam core under the space-charge effects in a few seconds has been developed. The characteristic of the beam core evolution strongly affected by the space-charge effects is presented on a Poincare map of the beam core phase-space (σ,σ'). The beam core evolution equation approach was justified by macroparticle tracking simulation. The beam-core instability has been theoretically identified as the perio-doubling bifurcation of the elliptical point in the beam core phase-space (σ,σ'), which corresponds to the matched beam envelope. Set-on of this instability determines the beam current threshold. The threshold of C_60^(+10) beam current with emittance of 0.01 mrad in the induction microtron is obtained at 225 µA.