An effective longitudinal space-charge impedance model for beamswith non-uniform and non-axissymmetric transverse density

Venturini, Marco

Lawrence Berkeley National Laboratory

关键词: Space Charge Space Charge Impedance;    Space Charge Impedance;    Impedance;    43;    Instability;   

DOI  :  10.2172/927331
RP-ID  :  LBNL--63111
RP-ID  :  DE-AC02-05CH11231
RP-ID  :  927331

美国|英语

来源: UNT Digital Library

【 摘 要 】

Use of a one-dimensional model of longitudinal space-charge(SC) impedance has been proposed for studying the microbunchinginstability in single-pass delivery systems relevant for the nextgeneration of FELs. For beams with uniform transverse density andcircular cross-section of radius r_b the SC impedance can be expressed ina handy analytical form, making this model particularly convenient. Inthis report we show how with an appropriate choice of r_b one can usethis as an effective-beam model to approximate beams with non-axissymmetric and non-uniform transverse densities.