Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mapping the material distribution of a complex structure in an electron
  beam   The simulation and analysis of High Energy Physics experiments require a
realistic simulation of the detector material and its distribution. The
challenge is to describe all active and passive parts of large scale detectors
like ATLAS in terms of their size, position and material composition. The
common method for estimating the radiation length by weighing individual
components, adding up their contributions and averaging the resulting material
distribution over extended structures provides a good general estimate, but can
deviate significantly from the material actually present. A method has been
developed to assess its material distribution with high spatial resolution
using the reconstructed scattering angles and hit positions of high energy
electron tracks traversing an object under investigation. The study presented
here shows measurements for an extended structure with a highly inhomogeneous
material distribution. The structure under investigation is an
End-of-Substructure-card prototype designed for the ATLAS Inner Tracker strip
tracker -- a PCB populated with components of a large range of material budgets
and sizes. The measurements presented here summarise requirements for data
samples and reconstructed electron tracks for reliable image reconstruction of
large scale, inhomogeneous samples, choices of pixel sizes compared to the size
of features under investigation as well as a bremsstrahlung correction for high
material densities and thicknesses.

12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org