Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transmission of High-Power Electron Beams Through Small Apertures   Tests were performed to pass a 100 MeV, 430 kWatt c.w. electron beam from the
energy-recovery linac at the Jefferson Laboratory's FEL facility through a set
of small apertures in a 127 mm long aluminum block. Beam transmission losses of
3 p.p.m. through a 2 mm diameter aperture were maintained during a 7 hour
continuous run.

24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
19
The categories of this paper are: eess