Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimization of a laser ion source for $^{163}$Ho isotope separation   To measure the mass of the electron neutrino, the "Electron Capture in
Holmium-163" (ECHo) collaboration aims at calorimetrically measuring the
spectrum following electron capture in $^{163}$Ho. The success of the ECHo
experiment depends critically on the radiochemical purity of the $^{163}$Ho
sample, which is ion-implanted into the calorimeters. For this, a $30 \,
\textrm{kV}$ high transmission magnetic mass separator equipped with a
resonance ionization laser ion source is used. To meet the ECHo requirements,
the ion source unit was optimized with respect to its thermal characteristics
and material composition by means of finite element method (FEM)
thermal-electric calculations and chemical equilibrium simulation using the
Gibbs energy minimization method. The new setup provides a much improved
selectivity in laser ionization versus interfering surface ionization of
$2700(500)$ and a superior overall efficiency of $41(5) \, \textrm{%}$ for the
ion-implantation process.

8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat