Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Finding matched rms envelopes in rf linacs: A Hamiltonian approach   We present a new method for obtaining matched solutions of the rms envelope
equations. In this approach, the envelope equations are first expressed in
Hamiltonian form. The Hamiltonian defines a nonlinear mapping, $\cal M$, and
for periodic transport systems the fixed points of the one-period map are the
matched envelopes. Expanding the Hamiltonian around a fiducial trajectory one
obtains a linear map, $M$, that describes trajectories (rms envelopes) near the
fiducial trajectory. Using $\cal M$ and $M$ we construct a contraction mapping
that can be used to obtain the matched envelopes. The algorithm is
quadratically convergent. Using the zero-current matched parameters as starting
values, the contraction mapping typically converges in a few to several
iterations. Since our approach uses numerical integration to obtain all the
mappings, it includes the effects of nonidealized, $z$-dependent transverse and
longitudinal focusing fields. We present numerical examples including finding a
matched beam in a quadrupole channel with rf bunchers.

31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph