Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sensitive Phase Gratings for X-ray Phase Contrast - a Simulation-based
  Comparison   Medical differential phase contrast x-ray imaging (DPCI) promises improved
soft-tissue contrast at lower x-ray dose. The dose strongly depends on both the
angular sensitivity and on the visibility of a grating-based Talbot-Lau
interferometer. Using a conventional x-ray tube, a high sensitivity and a high
visibility are somewhat contradicting goals: To increase sensitivity, the
grating period has to be reduced and/or the grating distance increased.
Technically, this means using a higher Talbot order (3rd or 5th one instead of
first one). This however reduces the visibility somewhat, because only a
smaller part of the tube spectrum will get used. This work proposes to relax
this problem by changing the phase grating geometry. This allows to double
sensitivity (i.e., double the Talbot order) without reducing the visibility.
One proposed grating geometry is an older binary one (75% of a period
$\pi$-shifting), but applied in a novel way. The second proposed geometry is a
novel one, requiring three height levels for polychromatic correction. The
advantage is quantified by a simulation of the resulting interference patterns.
Visibilities for the common $\pi$-shifting gratings are compared with the
proposed alternative geometries. This is done depending on photon energy and
opening ratio of the coherence grating G0. It shows that despite of doubled
sensitivity of the proposed gratings, the overall visibility might even improve
a little.

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The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph