Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 3-D Tracking of Nuclear Recoils in a Miniature Time Projection Chamber   The three-dimensional (3-D) reconstruction of nuclear recoils is of interest
for directional detection of fast neutrons and for direction-sensitive searches
for weakly interacting massive particles(WIMPs), which may constitute the Dark
Matter of the universe. We demonstrate this capability with a miniature gas
target Time Projection Chamber (TPC) where the drift charge is
avalanche-multiplied with Gas Electron Multipliers (GEMs) and detected with the
ATLAS FE-I3 Pixel Application Specific Integrated Circuit (ASIC). We report on
performance characterization of the detector, including measurements of gain,
gain resolution, point resolution, diffusion, angular resolution, and energy
resolution with low-energy x-rays, cosmic rays, and alpha particles, using the
gases Ar:CO$_2$ (70:30) and He:CO$_2$ (70:30) at atmospheric pressure. We
discuss the implications for future, larger directional neutron and Dark Matter
detectors. With an eye to designing and selecting components for these, we
generalize our results into analytical expressions for detector performance
whenever possible. We conclude by demonstrating the 3-D directional detection
of a fast neutron source.

16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga