Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Linear Fringe Field Effects of Quadrupoles   Fringe field becomes important when one requires more accurate modeling of a
ring lattice to study the long-term beam dynamics in storage rings and deal
with large aperture magnets in high-intensity proton synchrotrons or
accumulator rings. In this paper, a simple expression to calculate the tune
shifts due to quadrupole fringe fields is derived by using Lie algebra
technique. With higher-order terms included, this method is more accurate
compared with the linear fringe field model used in SAD code. The method is
also applied to a BEPCII lattice. Also based on the Lie algebra technique and
an inverse series technique, an equivalent hard-edge model for quadrupoles is
proposed, in which the model parameters are derived analytically. The model has
the advantages of the direct calculation of the equivalent length and strength
of a quadrupole and the easy adaptation when the strength changes. The validity
of the model and its simplified version has been checked with a numerical
method, and they show very good agreements.

17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg