Monte-Carlo-Rechnungen zur Rückstreuung von schweren, hochenergetischen Ionen an Metalloberflächen

1971 ◽  
Vol 26 (8) ◽  
pp. 1290-1296
Author(s):  
Klaus Güttner
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Heavy Ions ◽  
Metal Surfaces ◽  
High Energy ◽  
Energy Losses ◽  
Energy Distributions ◽  
Metal Foils ◽  
Penetration Depths ◽  
Good Agreement

A Monte-Carlo-Method is applied to describe the backscattering of high energy heavy ions from metal surfaces taking into account the energy losses. The calculations yield the angular and energy distributions of the reflected particles together with the percentage distributions of the complete particle histories. Furthermore it is possible to get informations concerning penetration depths and the number of collisions during the interaction of these particles with the metal foils. The calculated distributions are in good agreement with known experiments

Monte-Carlo-Rechnungen und Messungen zur Vielfachstreuung von schweren Ionen in dünnen Folien / Monte Carlo Calculations and Measurements Concerning the Multiple Scattering of Heavy Ions in Thin Films

1976 ◽  
Vol 31 (8) ◽  
pp. 949-955 ◽  
Author(s):  
J. Zienert ◽  
K. Güttner ◽  
G. Münzenberg
Keyword(s):  
Thin Films ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Energy Loss ◽  
Heavy Ions ◽  
Energy Distributions ◽  
Monte Carlo Calculations ◽  
Screening Parameter ◽  
Screened Coulomb Potential ◽  
Good Agreement

Abstract The behaviour of energetic heavy ions in thin films is simulated by means of a Monte Carlo method taking especially into account the energy loss of the scattered particles. Based on a variably matched screened Coulomb potential the calculations yield the angular and energy distributions of the transmitted ions. The results show a good agreement with the theory of Meyer. Furthermore for keV He ions scattering distributions have been measured in C, Al and Ag, which agree fairly well with the computations, if a suitable fit of the screening parameter is used in the Monte Carlo simulations.

Handling of Collimated Irradiation on a Plane-Parallel Participating Medium

2000 ◽  
Author(s):  
Christian Proulx ◽  
Daniel R. Rousse ◽  
Rodolphe Vaillon ◽  
Jean-François Sacadura
Keyword(s):  
Heat Flux ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiative Heat ◽  
Radiative Heat Flux ◽  
Scattering Media ◽  
One Dimensional ◽  
Plane Parallel ◽  
Collimated Beam ◽  
Good Agreement

Abstract This article presents selected results of a study comparing two procedures for the treatment of collimated irradiation impinging on one boundary of a participating one-dimensional plane-parallel medium. These procedures are implemented in a CVFEM used to calculate the radiative heat flux and source. Both isotropically and anisotropically scattering media are considered. The results presented show that both procedures provide results in good agreement with those obtained using a Monte Carlo method, when the collimated beam impinges normally.

Monte Carlo studies on electromagnetic cascades in extensive air showers

1968 ◽  
Vol 46 (10) ◽  
pp. S189-S196 ◽  
Author(s):  
K. O. Thielheim ◽  
E. K. Schlegel ◽  
R. Beiersdorf
Keyword(s):  
Monte Carlo ◽  
Electron Density ◽  
Three Dimensional ◽  
High Energy ◽  
Extensive Air Showers ◽  
Air Showers ◽  
Energy Distributions ◽  
The Core ◽  
Fragmentation Mechanisms ◽  
Monte Carlo Studies

Three-dimensional Monte Carlo calculations have been performed on the trajectories of high-energy hadrons in extensive air showers. The central electron density and gradient of distribution are obtained for individual electromagnetic cascades together with coordinates at the level of observation. Various assumptions concerning primary mass number and energy, distributions of strong interaction parameters, and fragmentation mechanisms are discussed with respect to the production of steep maxima of electron density by single electromagnetic cascades in the core region of extensive air showers.

scholarly journals Alignment of Dust Grains by Magnetic Relaxation: A Comparison Between Results Obtained by Two Different Methods

1973 ◽  
Vol 52 ◽  
pp. 187-189
Author(s):  
P. Cugnon
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Magnetic Relaxation ◽  
Planck Equation ◽  
Dust Grains ◽  
Fokker Planck Equation ◽  
The Monte Carlo Method ◽  
Good Agreement ◽  
Fokker Planck

This paper is devoted to a comparison between results obtained by Purcell and Spitzer (1971) using a Monte-Carlo method and by the author (1971) using a Fokker-Planck equation. It is shown that there is a good agreement between the results within the dispersion expected from the Monte-Carlo method.

scholarly journals Cosmic ray e± at high energy

2019 ◽  
Vol 208 ◽  
pp. 04001 ◽  
Author(s):  
Kfir Blum ◽  
Annika Reinert
Keyword(s):  
Secondary Production ◽  
Primary Source ◽  
Cosmic Ray ◽  
High Energy ◽  
Radiative Energy ◽  
Energy Losses ◽  
Propagation Time ◽  
Interstellar Matter ◽  
Independent Evidence ◽  
Good Agreement

There is a commonly expressed opinion in the literature, that cosmic-ray (CR) e+ come from a primary source, which could be dark matter or pulsars. In these proceedings we review some evidence to the contrary: namely, that e+ come from secondary production due to CR nuclei scattering on interstellar matter. We show that recent measurements of the total e± flux at E ≲ 3 TeV are in good agreement with the predicted flux of secondary e±, that would be obtained if radiative energy losses during CR propagation do not play an important role. If the agreement between data and secondary prediction is not accidental, then the requirement of negligible radiative energy losses implies a very short propagation time for high energy CRs: tesc ≲. 105 yr at rigidities R ≳ 3 TV. Such short propagation history may imply that a recent, near-by source dominates the CRs at these energies. We review independent evidence for a transition in CR propagation, based on the spectral hardening of primary and secondary nuclei around R ~ 100 GV. The transition rigidity of the nuclei matches the rigidity at which the e+ flux saturates its secondary upper bound.

scholarly journals Ground state calculations of the confined molecular ions H2+ and HeH++ using variational Monte Carlo method

2016 ◽  
Vol 94 (5) ◽  
pp. 501-506 ◽  
Author(s):  
Salah B. Doma ◽  
Fatma N. El-Gammal ◽  
Asmaa A. Amer
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Ground State ◽  
State Energy ◽  
Molecular Ions ◽  
Variational Monte Carlo ◽  
Molecular Ion ◽  
Spheroidal Cavity ◽  
Variational Monte Carlo Method ◽  
Good Agreement

The ground state energy of hydrogen molecular ion [Formula: see text] confined by a hard prolate spheroidal cavity is calculated. The case in which the nuclear positions are clamped at the foci is considered. Our calculations are based on using the variational Monte Carlo method with an accurate trial wave function depending on many variational parameters. The results were extended to also include the HeH++ molecular ion. The obtained results are in good agreement with the most recent results.

scholarly journals Evaluation of Average Directional Effective Emissivities of Isothermal Cylindrical-inner-cone Cavitties Using Monte-Carlo Method

2017 ◽  
Vol 27 (4) ◽  
pp. 357 ◽  
Author(s):  
Minh Nguyen Quang ◽  
Binh Nguyen Van
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Geometrical Parameters ◽  
Time Saving ◽  
Infrared Spectral Range ◽  
Reflection Model ◽  
The Monte Carlo Method ◽  
Infrared Spectral ◽  
Cavity Design ◽  
Good Agreement

We have used the Monte Carlo method based on theory of successive reflections and ray tracing to calculate the average normal directional effective emissivities of isothermal cylindrical-inner-cone cavities for various geometrical parameters. A simplified specular-directional diffuse reflection model was applied in our calculations for cavities working in the infrared spectral range. Our results are in good agreement comparing with what obtained by other authors. The algorithm developed by us has an advantage in simplicity and time saving of calculations. It can be used in blackbody cavity design considerations, especially in the cylindrical-inner-cone cases.

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