2,359 research outputs found
Validation of fluorescence transition probability calculations
A systematic and quantitative validation of the K and L shell X-ray
transition probability calculations according to different theoretical methods
has been performed against experimental data. This study is relevant to the
optimization of data libraries used by software systems, namely Monte Carlo
codes, dealing with X-ray fluorescence. The results support the adoption of
transition probabilities calculated according to the Hartree-Fock approach,
which manifest better agreement with experimental measurements than
calculations based on the Hartree-Slater method.Comment: 8 pages, 21 figures and images, 3 tables, to appear in proceedings of
the Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
Re-engineering a nanodosimetry Monte Carlo code into Geant4: software design and first results
A set of physics models for nanodosimetry simulation is being re-engineered
for use in Geant4-based simulations. This extension of Geant4 capabilities is
part of a larger scale R&D project for multi-scale simulation involving
adaptable, co-working condensed and discrete transport schemes. The project in
progress reengineers the physics modeling capabilities associated with an
existing FORTRAN track-structure code for nanodosimetry into a software design
suitable to collaborate with an object oriented simulation kernel. The first
experience and results of the ongoing re-engineering process are presented.Comment: 4 pages, 2 figures and images, to appear in proceedings of the
Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
The GEANT4 Object Oriented Simulation Tookit
Geant4 is a toolkit for the simulation of the passage of particles through matter, developed with advanced software engineering techniques. Its application areas include high energy and nuclear physics experiments, space physics, $9 medical physics and radiation background studies
A new development cycle of the Statistical Toolkit
The Statistical Toolkit is an open source system specialized in the
statistical comparison of distributions. It addresses requirements common to
different experimental domains, such as simulation validation (e.g. comparison
of experimental and simulated distributions), regression testing in the course
of the software development process, and detector performance monitoring.
Various sets of statistical tests have been added to the existing collection to
deal with the one sample problem (i.e. the comparison of a data distribution to
a function, including tests for normality, categorical analysis and the
estimate of randomness). Improved algorithms and software design contribute to
the robustness of the results. A simple user layer dealing with primitive data
types facilitates the use of the toolkit both in standalone analyses and in
large scale experiments.Comment: To be published in the Proc. of CHEP (Computing in High Energy
Physics) 201
R&D on co-working transport schemes in Geant4
A research and development (R&D) project related to the extension of the
Geant4 toolkit has been recently launched to address fundamental methods in
radiation transport simulation. The project focuses on simulation at different
scales in the same experimental environment; this problem requires new methods
across the current boundaries of condensed-random-walk and discrete transport
schemes. The new developments have been motivated by experimental requirements
in various domains, including nanodosimetry, astronomy and detector
developments for high energy physics applications.Comment: To be published in the Proceedings of the CHEP (Computing in High
Energy Physics) 2009 conferenc
A Role for Sunspots in Explaining Endogenous Fluctutations in Illegal Immigration
In this paper we provide an alternative explanation for why illegal immigration can exhibit substantial fluctuations despite a constant wage gap. We develop a model economy in which migrants make decisions in the face of uncertain border enforcement and lump-sum transfers from the host country. The uncertainty is extrinsic in nature, a sunspot, and arises as a result of ambiguity regarding the commodity price of money. Migrants are restricted from participating in state-contingent insurance markets in the host country, whereas host country natives are not. We establish the existence of sunspot equilibria that are not mere randomizations over certainty equilibria. Volatility in migration flows stems from two distinct sources: the tension between transfers inducing migration and enforcement discouraging it and secondly the existence of a sunspot. Finally, we examine the impact of a change in tax/transfer policies by the government on migration.Sunspots, Immigration, International Migration
New models for PIXE simulation with Geant4
Particle induced X-ray emission (PIXE) is a physical effect that is not yet
adequately modelled in Geant4. The current status as in Geant4 9.2 release is
reviewed and new developments are described. The capabilities of the software
prototype are illustrated in application to the shielding of the X-ray
detectors of the eROSITA telescope on the upcoming Spectrum-X-Gamma space
mission.Comment: To be published in the Proceedings of the CHEP (Computing in High
Energy Physics) 2009 conferenc
Publication patterns in HEP computing
An overview of the evolution of computing-oriented publications in high
energy physics following the start of operation of LHC. Quantitative analyses
are illustrated, which document the production of scholarly papers on
computing-related topics by high energy physics experiments and core tools
projects, and the citations they receive. Several scientometric indicators are
analyzed to characterize the role of computing in high energy physics
literature. Distinctive features of software-oriented and hardware-oriented
scholarly publications are highlighted. Current patterns and trends are
compared to the situation in previous generations' experiments.Comment: To be published in the Proc. of CHEP (Computing in High Energy
Physics) 201
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