Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orbit Feedback using X-ray Beam Position Monitoring at the Advanced
  Photon Source   The Advanced Photon Source (APS) was commissioned in 1995 as a
third-generation x-ray user facility. At that time orbit control was performed
exclusively with broadband rf beam position monitors (BPMs). Since then,
emphasis has been placed on incorporating x-ray beam position monitors into the
orbit control algorithms. This has resulted in an order of magnitude
improvement in long-term beam stability vertically, using x-ray BPMs (X-BPMs)
on bending magnet beamlines. Additional processing will allow similar
improvements horizontally, once systematic effects associated with variable
insertion device (ID) x-ray beams are properly compensated. Progress to date
and upgrade plans will be presented, with an emphasis on the details of the
required digital signal processing.

27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an