Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Studies of the beam-ion instability and its mitigation with feedback
  system   The beam-ion interaction is a potential limitation of beam performance in
electron accelerators, especially where the beam emittance is of a great
concern in future ultra-low emittance light source. "Conventionally", the beam
instability due to beam-ion interaction is attributed to two types of effects:
ion trapping effect and fast ion effect, which emphasize the beam-ion dynamics
in different time scales. Whereas, in accelerators, the beam suffers from a
mixture of ion trapping effect and fast ion effect, leading to a more
complicated process and requiring a self-consistent treatment. To evaluate the
beam characteristics, as emittance growth under the influence from beam-ion
effect, a new numerical simulation code based on the "quasi-strong-strong"
model has been developed, including modules of ionization, beam-ion
interaction, synchrotron radiation damping, quantum excitation, bunch-by-bunch
feedback, etc. In the study, we do not regularly distinguish the ion trapping
effect and the fast ion effect, but treat beam-ion interaction more generally
and consistently. The lattice of High Energy Photon Source, a diffraction limit
ring under construction in Beijing, is used as an example to show the beam-ion
effect. It is found that in this low emittance ring, the beam-ion instability
is not a dominant mechanism in operation mode with a high beam current, but
seriously occurs in a lower beam current region. When the beam-ion instability
were significantly driven and can not be damped by the synchrotron radiation
damping, the simulations show the bunch-by-bunch feedback system based on the
Finite Impulse Response filter technique can be adopted to mitigate it
effectively.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom