Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Secondary electrons and positrons in near earth orbit   The secondary e+ and e- populations in near earth's orbit have been
calculated by simulation. The results are in very good agreement with the
recent AMS measurements. The e$^+$ over e$^-$ flux ratio for particles below
the geomagnetic cutoff appears to be due to the geomagnetic East-West effect.

17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg