Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Single-Particle Dynamics in a Nonlinear Accelerator Lattice: Attaining a
  Large Tune Spread with Octupoles in IOTA   Fermilab is constructing the Integrable Optics Test Accelerator (IOTA) as the
centerpiece of the Accelerator R&D Program towards high-intensity circular
machines. One of the factors limiting the beam intensity in present circular
accelerators is collective instabilities, which can be suppressed by a spread
of betatron frequencies (tunes) through the Landau damping mechanism or by an
external damper, if the instability is slow enough. The spread is usually
created by octupole magnets, which introduce the tune dependence on the
amplitude and, in some cases, by a chromatic spread (tune dependence on
particle's momentum). The introduction of octupoles usually has both the
beneficial (improved Landau damping) and harmful properties, such as a resonant
behavior and a reduction of the dynamic aperture. One of the research goals at
the IOTA ring is to achieve a large betatron tune spread, while retaining a
large dynamic aperture, using conventional octupole magnets in a special but
realistic accelerator configuration. In this paper, we present results of
computer simulations of an electron beam in the IOTA by particle tracking and
the Frequency Map Analysis. The results show that the ring's octupole magnets
can be configured to provide a betatron tune shift of 0.08 (for particles at
large amplitudes) with the dynamical aperture of over 20 beam sigma for a
150-MeV electron beam. The influence of the synchrotron motion, lattice errors,
and magnet imperfections is insignificant for the parameters and levels of
tolerances set by the design of the ring. The described octupole insert could
be beneficial for enhancing Landau damping in high intensity machines.

34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
2
The categories of this paper are: math