Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cascade emission in electron beam ion trap plasma of W$^{25+}$ ion   Spectra of the W$^{25+}$ ion are studied using the collisional-radiative
model (CRM) with an ensuing cascade emission. It is determined that the cascade
emission boosts intensities only of a few lines in the $10 - 3$ nm range. The
cascade emission is responsible for the disappearance of structure of lines at
about 6 nm in the electron beam ion trap plasma. Emission band at 4.5 to 5.3 nm
is also affected by the cascade emission. The strongest lines in the CRM
spectrum correspond to $4d^{9} 4f^{4} \rightarrow 4f^{3}$ transitions, while
$4f^{2} 5d \rightarrow 4f^{3}$ transitions arise after the cascade emission is
taken into account.

5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom