Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reciprocating probe measurements in the test divertor operation phase of
  Wendelstein 7-X   Reciprocating probes are a classic and widespread tool for the investigation
of the edge and Scrape-Off Layer of magnetic fusion plasmas. In the Wendelstein
7-X (W7-X) stellarator, the Multi-Purpose Manipulator serves as a multi-user
platform for probe measurements of various kinds. This paper presents a review
on reciprocating probe operation during the first operation phase of W7-X with
a test divertor (2017-2018). It gives an overview of the diverse zoo of probe
heads and presents lessons learned about probe operation in complex magnetic
geometries, operation safety, and probe head design. A few examples of probe
measurements with a focus on unexpected observations are presented.

25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc