Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-Ray Propulsor: Physical Principle for an Electromagnetic
  Propellantless Propulsion System   In this work we are going to develop a physical model that explains how
propulsion may be developed in a vacuum by the collision of electrons with an
anode. Instead of using principles related to the conservation of only the
mechanical momentum to achieve propulsion, like all the current propulsion
systems do, the present system achieves propulsion by using principles related
to the conservation of the canonical momentum. The complete physical model will
be provided and comparison with preliminary experimental results will be
performed. These results are important since they show that it is possible to
achieve a radical different propulsion system with many advantages.

37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat