Computation of charged-particle transfer maps for general fields and geometries using electromagnetic boundary-value data.

Stasevich, T. J. ; Bodoh-Creed, A. ; Walstrom, P. ; Roberts, P. ; Dragt, A. J.

Technical Information Center Oak Ridge Tennessee

关键词: Charged particles;    Accelerators;    Electromagnetic fields;    Physics;    LANL;   

RP-ID  :  DE2000762078

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The passage of a charged particle through a region of nonvanishing electromagnetic fields (e.g., a bending magnet, multipole magnet, spectrometer, electrostatic lens, electromagnetic velocity separator, etc. ) can be described by a transfer map. In general, the map is a six-vector-valued function that relates the final six phase-space coordinates of a beam particle to its initial six phase-space coordinates. The map can be represented in either Taylor- or Lie-series form. The series-expansion variables for the map are deviations from a nominal or reference trajectory, which in general is curved and must be found by numerical integration of the equations of motion of a reference particle. The reference particle is represented by a particular point in the initial phase space and a corresponding point in the final phase space. Calculation of aberration terms (terms beyond lowest order) in the series form of the map requires knowledge of multiple derivatives of the electromagnetic fields along the reference trajectory.