Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Motionless Phase Stepping in X-Ray Phase Contrast Imaging with a Compact
  Source   X-ray phase contrast imaging offers a way to visualize the internal
structures of an object without the need to deposit any radiation, and thereby
alleviate the main concern in x-ray diagnostic imaging procedures today.
Grating-based differential phase contrast imaging techniques are compatible
with compact x-ray sources, which is a key requirement for the majority of
clinical x-ray modalities. However, these methods are substantially limited by
the need for mechanical phase stepping. We describe an electromagnetic phase
stepping method that eliminates mechanical motion, and thus removing the
constraints in speed, accuracy and flexibility. The method is broadly
applicable to both projection and tomography imaging modes. The transition from
mechanical to electromagnetic scanning should greatly facilitate the
translation of x-ray phase contrast techniques into mainstream applications.

16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org