1,514 research outputs found
Track reconstruction with MIMAC
Directional detection of Dark Matter is a promising search strategy. However,
to perform such kind of detection, the recoiling tracks have to be accurately
reconstructed: direction, sense and position in the detector volume. In order
to optimize the track reconstruction and to fully exploit the data from the
MIMAC detector, we developed a likelihood method dedicated to the track
reconstruction. This likelihood approach requires a full simulation of track
measurements with MIMAC in order to compare real tracks to simulated ones.
Finally, we found that the MIMAC detector should have the required performance
to perform a competitive directional detection of Dark Matter.Comment: 9 pages, 6 figures; Proceedings of the 3rd International conference
on Directional Detection of Dark Matter (CYGNUS 2011), Aussois, France, 8-10
June 201
Pressure effect in the X-ray intrinsic position resolution in noble gases and mixtures
A study of the gas pressure effect in the position resolution of an
interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic
position resolution for pure noble gases (Argon and Xenon) and their mixtures
with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for
photon energies between 5.4 and 60.0 keV, being possible to establish a linear
match between the intrinsic position resolution and the inverse of the gas
pressure in that energy range. In order to evaluate the quality of the method
here described, a comparison between the available experimental data and the
calculated one in this work, is done and discussed. In the majority of the
cases, a strong agreement is observed
Simulation benchmarks for low-pressure plasmas: capacitive discharges
Benchmarking is generally accepted as an important element in demonstrating the correctness of computer simulations. In the modern sense, a benchmark is a computer simulation result that has evidence of correctness, is accompanied by estimates of relevant errors, and which can thus be used as a basis for judging the accuracy and efficiency of other codes. In this paper, we present four benchmark cases related to capacitively coupled discharges. These benchmarks prescribe all relevant physical and numerical parameters. We have simulated the benchmark conditions using five independently developed particle-in-cell codes. We show that the results of these simulations are statistically indistinguishable, within bounds of uncertainty that we define. We therefore claim that the results of these simulations represent strong benchmarks, that can be used as a basis for evaluating the accuracy of other codes. These other codes could include other approaches than particle-in-cell simulations, where benchmarking could examine not just implementation accuracy and efficiency, but also the fidelity of different physical models, such as moment or hybrid models. We discuss an example of this kind in an appendix. Of course, the methodology that we have developed can also be readily extended to a suite of benchmarks with coverage of a wider range of physical and chemical phenomena
Electron Transport in Gaseous Detectors with a Python-based Monte Carlo Simulation Code
Understanding electron drift and diffusion in gases and gas mixtures is a
topic of central importance for the development of modern particle detection
instrumentation. The industry-standard MagBoltz code has become an invaluable
tool during its 20 years of development, providing capability to solve for
electron transport (`swarm') properties based on a growing encyclopedia of
built-in collision cross sections. We have made a refactorization of this code
from FORTRAN into Cython, and studied a range of gas mixtures of interest in
high energy and nuclear physics. The results from the new open source PyBoltz
package match the outputs from the original MagBoltz code, with comparable
simulation speed. An extension to the capabilities of the original code is
demonstrated, in implementation of a new Modified Effective Range Theory
interface. We hope that the versatility afforded by the new Python code-base
will encourage continued use and development of the MagBoltz tools by the
particle physics community.Comment: Preprint submitted to Computer Physics Communication
Characterization of microbulk detectors in argon- and neon-based mixtures
A recent Micromegas manufacturing technique, so called Microbulk, has been
developed, improving the uniformity and stability of this kind of detectors.
Excellent energy resolutions have been obtained, reaching values as low as 11%
FWHM at 5.9 keV in Ar+5%iC4H10. This detector has other advantages like its
flexible structure, low material budget and high radio-purity. Two microbulk
detectors with gaps of 50 and 25 um have been characterized in argon- and
neon-based mixtures with ethane, isobutane and cyclohexane. The results will be
presented and discussed. The gain curves have been fitted to the Rose-Korff
gain model and dependences of the electron mean free path and the threshold
energy for ionization have been obtained. The possible relation between these
two parameters and the energy resolution will be also discussed.Comment: Submitted to the Journal of Instrumentatio
A new experimental snow avalanche test site at Seehore peak in Aosta Valley (NW Italian Alps) - Part II: Engineering aspects
The estimate of the effects produced by the impact of a snow avalanche against an obstacle is of the utmost importance in designing safe mountain constructions. For this purpose, an ad-hoc instrumented obstacle was designed and built in order to measure impact forces of small and medium snow avalanches at Seehore peak (NW Italian Alps). The structural design had to consider several specific and unusual demands dictated by the difficult environment. In this article, the new test facility is described from the engineering point of view, discussing the most important aspects of the analyzed problems which were solved before and after the construction. The performance of the instrumented obstacle in the first two operating seasons, and some proposals for future upgrading are eventually illustrate
Short communication: Characterization of molasses chemical composition
Beet and cane molasses are produced worldwide as a
by-product of sugar extraction and are widely used in
animal nutrition. Due to their composition, they are fed
to ruminants as an energy source. However, molasses
has not been properly characterized in the literature;
its description has been limited to the type (sugarcane
or beet) or to the amount of dry matter (DM), total or
water-soluble sugars, crude protein, and ash. Our objective was to better characterize the composition of cane
and beet molasses, examine possible differences, and obtain a proper definition of such feeds. For this purpose,
16 cane and 16 beet molasses samples were sourced
worldwide and analyzed for chemical composition. The
chemical analysis used in this trial characterized 97.4
and 98.3% of the compounds in the DM of cane and
beet molasses, respectively. Cane molasses contained
less DM compared with beet molasses (76.8 ± 1.02 vs.
78.3 ± 1.61%) as well as crude protein content (6.7 ±
1.8 vs. 13.5 ± 1.4% of DM), with a minimum value of
2.2% of DM in cane molasses and a maximum of 15.6%
of DM in beet molasses. The amount of sucrose differed
between beet and cane molasses (60.9 ± 4.4 vs. 48.8 ±
6.4% of DM), but variability was high even within cane
molasses (39.2–67.3% of DM) and beet molasses. Glucose and fructose were detected in cane molasses (5.3 ±
2.7 and 8.1 ± 2.8% of DM, respectively), showing high
variability. Organic acid composition differed as well.
Lactic acid was more concentrated in cane molasses
than in beet molasses (6.1 ± 2.8 vs. 4.5 ± 1.8% of DM),
varying from 1.6 to 12.8% of DM in cane molasses. Dietary cation-anion difference showed numerical differences among cane and beet molasses (7 ± 53 vs. 66 ±
45 mEq/100 g of DM, on average). It varied from −76
to +155 mEq/100 g of DM in the cane group and from
+0 to +162 mEq/100 g of DM in the beet group. Data
obtained in this study detailed differences in composition between sources of molasses and suggested that a
more complete characterization could improve the use
of molasses in ration formulation
A {\mu}-TPC detector for the characterization of low energy neutron fields
The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20
MeV for metrological purposes. To be considered as a reference facility,
fluence and energy distributions of neutron fields have to be determined by
primary measurement standards. For this purpose, a micro Time Projection
Chamber is being developed to be dedicated to measure neutron fields with
energy ranging from 8 keV up to 1 MeV. In this work we present simulations
showing that such a detector, which allows the measurement of the ionization
energy and the 3D reconstruction of the recoil nucleus, provides the
determination of neutron energy and fluence of these neutron fields
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