Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lifetime of the Highly Efficient H- Ion Sources   Factors limiting the operating lifetime of Compact Surface Plasma Sources
(CSPS) are analyzed and possible treatments for lifetime enhancement are
considered. Noiseless discharges with lower gas and cesium densities are
produced in experiments with modified discharge cells. With these discharge
cells it is possible to increase the emission aperture and extract the same
beam with a lower discharge current and with correspondingly increased source
lifetime. A design of an advanced CSPS is presented.

24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg