Optical photon transport and geometry contributions to time response of scintillation detectors

2018 ◽  
Vol 29 (09) ◽  
pp. 1850091
Author(s):  
N. Ghal-Eh ◽  
M. Aliannezhadi ◽  
S. V. Bedenko
Keyword(s):  
General Purpose ◽  
Optical Parameters ◽  
Scintillation Detectors ◽  
Light Wavelength ◽  
Scintillation Light ◽  
Simulation Code ◽  
Photon Transport ◽  
Optical Photon ◽  
Small Change ◽  
Time And Energy

The sensitivities of both time and energy resolutions of a typical scintillation detector to major optical parameters (i.e. paint reflectivity, quantum efficiency of photomultiplier tube and attenuation coefficient) have been estimated using a dedicated Monte Carlo (MC) optical photon transport (OPT) simulation code, PHOTRACK, and the OPT capabilities of general-purpose code, FLUKA. Both cylindrical and parallelepiped geometries have been considered for the scintillator cell and lightguide. The results determine the scintillation light wavelength regions that the energy and time resolution represent enhanced sensitivities to small change/uncertainty in optical parameters.

Experimental validation of the ANTS2 code for modelling optical photon transport in monolithic LYSO crystals

2021 ◽  
Vol 81 ◽  
pp. 215-226
Author(s):  
Víctor Manuel Lara-Camacho ◽  
Edgar Marcial Hernández-Acevedo ◽  
Héctor Alva-Sánchez ◽  
Tirso Murrieta-Rodríguez ◽  
Arnulfo Martínez-Dávalos ◽  
...  
Keyword(s):  
Experimental Validation ◽  
Photon Transport ◽  
Optical Photon

Analysis of the Operating Mode Influence Onto Energy Consumption of a Natural Gas Storage Plant

2012 ◽  
Author(s):  
Gianmario L. Arnulfi ◽  
Carlo Cravero ◽  
Martino Marini
Keyword(s):  
Natural Gas ◽  
Operating Mode ◽  
Ideal Gas ◽  
Gas Dynamics Equations ◽  
Simulation Code ◽  
Lumped Parameter ◽  
Wide Range ◽  
Set Up ◽  
Operation Pressure ◽  
Time And Energy

Natural gas carrying from production sites to users’ facilities is made by marine shipping in liquid phase or by terrestrial pumping in gaseous phase through long pipelines. In the latter case several storage stations are distributed along the pipeline nets to move the natural gas from its deposits to users’ terminals. Storage stations are set up to compensate seasonal fluctuations of the consumer demand versus methane supply, storing the gas in various kinds of reservoirs. In most of such plants centrifugal compressors are used, where the energy and the time that a complete charge takes are affected by the operation scheduling of the compressor from the minimum to the maximum storage levels. While the pressure in the reservoir enforces the instant operation pressure, the flow rate is limited within a quite wide range. Here an in-house code, based on the lumped parameter approach and a quasi-steady dynamics, is applied to a complete charge. The natural gas behavior is modeled by the pseudo-ideal gas in order to get a fair accuracy keeping the usual gas dynamics equations. The compression path has been parameterized and a multi objective optimization, embedding the simulation code, has been implemented to find the most suitable management of the compression station for the minimization of time and energy. The most significant paths are analyzed to pick out the effects of the compression strategy.

scholarly journals A general-purpose time-step criterion for simulations with gravity

2020 ◽  
Vol 495 (4) ◽  
pp. 4306-4313 ◽  
Author(s):  
Michael Y Grudić ◽  
Philip F Hopkins
Keyword(s):  
Time Scale ◽  
General Purpose ◽  
Gravitational Acceleration ◽  
Time Step ◽  
Simulation Code ◽  
Time Stepping ◽  
Dynamical Time ◽  
Adaptive Time Step ◽  
Order Of Magnitude ◽  
True Time

ABSTRACT We describe a new adaptive time-step criterion for integrating gravitational motion, which uses the tidal tensor to estimate the local dynamical time-scale and scales the time-step proportionally. This provides a better candidate for a truly general-purpose gravitational time-step criterion than the usual prescription derived from the gravitational acceleration, which does not respect the equivalence principle, breaks down when $\boldsymbol {a}=0$, and does not obey the same dimensional scaling as the true time-scale of orbital motion. We implement the tidal time-step criterion in the simulation code gizmo, and examine controlled tests of collisionless galaxy and star cluster models, as well as galaxy merger simulations. The tidal criterion estimates the dynamical time faithfully, and generally provides a more efficient time-stepping scheme compared to an acceleration criterion. Specifically, the tidal criterion achieves order-of-magnitude smaller energy errors for the same number of force evaluations in potentials with inner profiles shallower than ρ ∝ r−1 (i.e. where $\boldsymbol {a}\rightarrow 0$), such as star clusters and cored galaxies. For a given problem these advantages must be weighed against the additional overhead of computing the tidal tensor on-the-fly, but in many cases this overhead is small.

A General Purpose Formulation for Nonsmooth Dynamics With Finite Rotations: Application to the Woodpecker Toy

2020 ◽  
Vol 16 (3) ◽  
Author(s):  
Alejandro Cosimo ◽  
Federico J. Cavalieri ◽  
Javier Galvez ◽  
Alberto Cardona ◽  
Olivier Brüls
Keyword(s):  
Finite Element ◽  
Multibody Dynamics ◽  
Equations Of Motion ◽  
Horizontal Displacement ◽  
General Purpose ◽  
Nonsmooth Dynamics ◽  
Unilateral Constraints ◽  
Simulation Code ◽  
Frictional Contacts ◽  
Large Rotations

Abstract The aim of this work is to extend the finite element multibody dynamics approach to problems involving frictional contacts and impacts. The nonsmooth generalized-α (NSGA) scheme is adopted, which imposes bilateral and unilateral constraints both at position and velocity levels avoiding drift phenomena. This scheme can be implemented in a general purpose simulation code with limited modifications of pre-existing elements. The study of the woodpecker toy dynamics sets up a good example to show the capabilities of the NSGA scheme within the context of a general finite element framework. This example has already been studied by many authors who generally adopted a model with a minimal set of coordinates and small rotations. It is shown that good results are obtained using a general purpose finite element code for multibody dynamics, in which the equations of motion are assembled automatically and large rotations are easily taken into account. In addition, comparing results between different models of the woodpecker toy, the importance of modeling large rotations and the horizontal displacement of the woodpecker's sleeve is emphasized.

scholarly journals Simulation of femtosecond laser absorption by metallic targets and their thermal evolution

2017 ◽  
Vol 35 (3) ◽  
pp. 415-428 ◽  
Author(s):  
A. Suslova ◽  
A. Hassanein
Keyword(s):  
Femtosecond Laser ◽  
Laser Intensity ◽  
Laser Energy ◽  
Absorption Efficiency ◽  
Optical Parameters ◽  
Temperature Dependent ◽  
Simulation Code ◽  
Laser Absorption ◽  
Plasma State ◽  
Wide Range

AbstractThe interaction of femtosecond laser with initially cold solid metallic targets (Al, Au, Cu, Mo, Ni) was investigated in a wide range of laser intensity with focus on the laser energy absorption efficiency. Our developed simulation code (FEMTO-2D) is based on two-temperature model in two-dimensional configuration, where the temperature-dependent optical and thermodynamic properties of the target material were considered. The role of the collisional processes in the ultrashort pulse laser–matter interaction has been carefully analyzed throughout the process of material transition from the cold solid state into the dense plasma state during the pulse. We have compared the simulation predictions of the laser pulse absorption with temperature-dependent reflectivity and optical penetration depth to the case of constant optical parameters. By considering the effect of the temporal and spatial (radial) distribution of the laser intensity on the light absorption efficiency, we obtained a good agreement between the simulated results and available experimental data. The appropriate model for temperature-dependent optical parameters defining the laser absorption efficiency will allow more accurate simulation of the target thermal response in the applications where it is critical, such as prediction of the material damage threshold, laser ablation threshold, and the ablation profile.

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