Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The roles of charge exchange and dissociation in spreading Saturn's
  neutral clouds   Neutrals sourced directly from Enceladus's plumes are initially confined to a
dense neutral torus in Enceladus's orbit around Saturn. This neutral torus is
redistributed by charge exchange, impact/photodissociation, and neutral-neutral
collisions to produce Saturn's neutral clouds. Here we consider the former
processes in greater detail than in previous studies. In the case of
dissociation, models have assumed that OH is produced with a single speed of 1
km/s, whereas laboratory measurements suggest a range of speeds between 1 and
1.6 km/s. We show that the high-speed case increases dissociation's range of
influence from 9 to 15 Rs. For charge exchange, we present a new modeling
approach, where the ions are followed within a neutral background, whereas
neutral cloud models are conventionally constructed from the neutrals' point of
view. This approach allows us to comment on the significance of the ions'
gyrophase at the moment charge exchange occurs. Accounting for gyrophase: (1)
has no consequence on the H2O cloud; (2) doubles the local density of OH at the
orbit of Enceladus; and (3) decreases the oxygen densities at Enceladus's orbit
by less than 10%. Finally, we consider velocity-dependent, as well as
species-dependent cross sections and find that the oxygen cloud produced from
charge exchange is spread out more than H2O, whereas the OH cloud is the most
confined.

13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin