Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vortex Trapping in Hybrid Magnetometers   Hybrid magnetometers based on a normal conducting sensor and a
superconducting flux concentrator have been investigated. When this sensor is
operated in an unshielded environment flux vortices can be trapped in the
superconducting body when the sensor is cooled. Thermal hopping of the trapped
vortices gives rise to 1/f noise. The mechanism for vortex trapping has been
investigated. A new model for the critical field for vortex trapping and vortex
densities has been derived. Experimental verification on YBa2Cu3O7-delta (YBCO)
strips with a Scanning SQUID Microscope shows very good agreement between
measurements and the new theory. The results have been applied in a hybrid
magnetometer design based on a bismuth Hall sensor and an YBCO flux
concentrator. Measurements show a field gain up to G=7 with a large effective
range of 175uT.

31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex