Impedance Scaling for Small-angle Tapers and Collimators

Stupakov, G.

Stanford Linear Accelerator Center

关键词: 99 General And Miscellaneous//Mathematics, Computing, And Information Science;    Frequency Range Accelerators,Accphy, Xfel;    Scalars;    Collimators;    Accelerators,Accphy, Xfel;   

DOI  :  10.2172/972231
RP-ID  :  SLAC-TN-10-001
RP-ID  :  AC02-76SF00515
RP-ID  :  972231

美国|英语

来源: UNT Digital Library

【 摘 要 】

In this note I will prove that the impedance calculated for a small-angle collimator or taper, of arbitrary 3D profile, has a scaling property that can greatly simplify numerical calculations. This proof is based on the parabolic equation approach to solving Maxwell's equation developed in Refs. [1, 2]. We start from the parabolic equation formulated in [3]. As discussed in [1], in general case this equation is valid for frequencies {omega} >> c/a where a is a characteristic dimension of the obstacle. However, for small-angle tapers and collimators, the region of validity of this equation extends toward smaller frequencies and includes {omega} {approx} c/a.