Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Retrospective of the ARPA-E ALPHA fusion program   This paper provides a retrospective of the ALPHA (Accelerating Low-cost
Plasma Heating and Assembly) fusion program of the Advanced Research Projects
Agency-Energy (ARPA-E) of the U.S. Department of Energy. ALPHA's objective was
to catalyze research and development efforts to enable substantially lower-cost
pathways to economical fusion power. To do this in a targeted, focused program,
ALPHA focused on advancing the science and technology of pulsed,
intermediate-density fusion approaches, including magneto-inertial fusion and
Z-pinch variants, that have the potential to scale to commercially viable
fusion power plants. The paper includes a discussion of the origins and framing
of the ALPHA program, a summary of project status and outcomes, a description
of associated technology-transition activities, and thoughts on a potential
follow-on ARPA-E fusion program.

35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess