Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Application of a Portable $^3$He-Based Polarization Insert at a
  Time-of-Flight Neutron Reflectometer   The suitability of a transportable 3He-spin filter as temporary broadband
polarizer for a Time-of-Flight neutron reflectometer is demonstrated. A simple
two-wavelength method for characterisation of a 3He-spin filter is proposed,
which can be applied even if the absolute transmittance of the 3He-spin filter
cannot be accurately determined. We demonstrate the data treatment procedure
for extracting the spin-up and spin-down neutron reflectivity from measurements
obtained with a time dependent 3He polarization. The extraction of a very weak
magnetic signal from reflectivity data, measured on the in-situ grown magnetic
heterostructure Fe1 nm/Cu20 nm/Sisubstrate in an externally applied magnetic
field of 30mT is presented and compared to similar measurements on the growth
stage Cu20 nm/Sisubstrate of the very same sample, which does not yet contain
any magnetic material.

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The categories of this paper are: hep-ph
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys