Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Center-of-Mass Corrections in Associated Particle Imaging   Associated Particle Imaging utilizes the inelastic scattering of neutrons
produced in deuterium-tritium fusion reactions to obtain 3D isotopic
distributions within an object. The locations of the inelastic scattering
centers are calculated by measuring the arrival time and the position of the
associated particle, the alpha particle in the fusion reaction, and the arrival
time of the prompt gamma created in the scattering event. While the neutron and
its associated particle move in opposite directions in the center-of-mass (COM)
system, in the laboratory system the angle is slightly less than 180 degrees,
and the COM movement must be taken into account in the reconstruction of the
scattering location. Furthermore, due to energy loss of ions in the target, the
fusion reactions are produced by ions of different energies, and thus the COM
velocity varies, resulting in an uncertainty in the reconstructed positions. In
this paper, we analyze the COM corrections to this reconstruction by simulating
the energy loss of beam ions in the target material and identifying sources of
uncertainty in these corrections. We show that an average COM velocity can be
used in the reconstruction and discuss errors as a function of ion beam energy,
composition, and alpha detection location. When accounting for the COM effect,
the mean of the reconstructed locations can be considered a systematic error
leading to shift/tilt in the reconstruction. However, the distribution of
reconstructed locations also have a spread that will introduce an error in the
reconstruction that cannot be corrected. In this paper, we will use the known
stopping powers of ions in materials and reaction cross-sections to examine
this effect.

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The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th