Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

Particle-in-cell (PIC) methods have a long history in the study of laser-plasma interactions. Early electromagnetic codes used the Yee staggered grid for field variables combined with a leapfrog EM-field update and the Boris algorithm for particle pushing. The general properties of such schemes are well documented. Modern PIC codes tend to add to these high-order shape functions for particles, Poisson preserving field updates, collisions, ionisation, a hybrid scheme for solid density and high-field QED effects. In addition to these physics packages, the increase in computing power now allows simulations with real mass ratios, full 3D dynamics and multi-speckle interaction. This paper presents a review of the core algorithms used in current laser-plasma specific PIC codes. Also reported are estimates of self-heating rates, convergence of collisional routines and test of ionisation models which are not readily available elsewhere. Having reviewed the status of PIC algorithms we present a summary of recent applications of such codes in laser-plasma physics, concentrating on SRS, short-pulse laser-solid interactions, fast-electron transport, and QED effects.

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Contemporary particle-in-cell approach to laser-plasma modelling

Fault interpretation enhances our understanding of complex geologic structures and stratigraphy apparent in 3D seismic images. Common steps in this interpretation include image processing to highlight faults, the construction of fault surfaces, and estimation of fault throws. Although all three of these steps have been automated to some extent by others, fault interpretation today typically requires significant manual effort, suggesting that further improvements in automatic methods are feasible and worthwhile. I first used an efficient algorithm to compute images of fault likelihoods, strikes, and dips from a 3D seismic image. From these three fault images, I then automatically extracted fault surfaces as meshes of quadrilaterals that coincide with ridges of fault likelihood. A quadrilateral mesh is a simple data structure alongside which one can easily gather samples of the 3D seismic image. I automatically estimated fault throws by minimizing differences in values of samples gathered from oppos...

Methods to compute fault images, extract fault surfaces, and estimate fault throws from 3D seismic images

When high-intensity laser interaction with matter enters the regime of dominated radiation reaction, the radiation losses open the way for producing short pulse high-power $\ensuremath{\gamma}$-ray flashes. The $\ensuremath{\gamma}$-ray pulse duration and divergence are determined by the laser pulse amplitude and by the plasma target density scale length. On the basis of theoretical analysis and particle-in-cell simulations with the radiation friction force incorporated, optimal conditions for generating a $\ensuremath{\gamma}$-ray flash with a tailored overcritical density target are found.

High-power γ-ray flash generation in ultraintense laser-plasma interactions.

This review is concerned with the results of studies into the behavior of substances at ultimately high pressures and temperatures obtainable by way of kinetic or electromagnetic energy cumulation in laboratory conditions. Also considered are the diversified states of matter and the processes occurring under gravitational forces and thermonuclear energy release.

https://iopscience.iop.org/article/10.3367/UFNe.0179.200906h.0653/pdf

Extreme states of matter on Earth and in space

In the last decade an evolution of experimental relativistic laser-plasma physics has led to highly sophisticated lasers, which are now able to generate ultra short pulses and can be focused to intensities in excess of 1021 W cm−2, with more than 500 J on target In the intense electric field of the laser focus, plasma with temperatures greater than 10 billion degrees can be generated The laser interactions with solid or gas targets can generate collimated beams of highly energetic electrons and ions Experiments utilizing high-intensity laser systems turn out to be an interesting and versatile source for radiation, high-energy particles and nuclear reactions, without recourse to large-scale facilities such as nuclear reactors or particle accelerators The possibility of accelerating electrons to energies over 200 MeV in such early experiments led to the utilization of high-energy bremsstrahlung radiation in order to investigate laser-induced gamma reactions Many experiments of this type have been reported in several laboratories worldwide However, to our knowledge, no dedicated investigations have been reported with respect to the characterization of the generated bremsstrahlung in such experiments As it is not experimentally feasible to measure directly a bremsstrahlung spectrum, we report in the present paper on a dedicated series of calculations on the generated bremsstrahlung distributions from two experimental electron spectra measured using the giant pulse VULCAN laser and a gas jet target Potential applications are also investigated

https://iopscience.iop.org/article/10.1088/1367-2630/9/2/023/pdf

Bremsstrahlung production with high-intensity laser matter interactions and applications

Systems and methods for modeling a three-dimensional (3D) geological structure to improve maximum continuity interpolation. An integration method describes local anisotropic effects and introduces interpolation techniques to perform the interpolation between two points of interest along a direction of maximum continuity and across fault surfaces.

Systems and Methods for Modeling 3D Geological Structures

Systems and methods for updating posterior geological models by integrating various reservoir data to support dynamic-quantitative data-inversion, stochastic-uncertainty-management and smart reservoir-management.

Systems and Methods for the Quantitative Estimate of Production-Forecast Uncertainty

The effects of sediment water content and bulk density on measurements of in-situ environmental gamma-radiation were investigated using Monte-Carlo simulations. The simulations consider a large bismuth-germanate detector in a semi-infinite geometry. The volume contributing radiation to the detector decreases with increasing sediment bulk density, as the detector sees' a constant sediment mass. The effect of variations in porosity on gamma-ray spectra is negligible. Variations in water content affect the shape of the spectra only in the region below 0.1 MeV and, more importantly, strongly affect spectral intensity. Separate measurements of sediment water content, when expressed as mass fraction of water, can be used to correct spectra collected on sediments with varying water content. (C) 2008 Elsevier B.V. All rights reserved.

Marko Maucec

Papers

Bremsstrahlung production with high-intensity laser matter interactions and applications

Systems and Methods for Modeling 3D Geological Structures

Systems and Methods for the Quantitative Estimate of Production-Forecast Uncertainty

Sensitivity of in-situ γ-ray spectra to soil density and water content

MCNP modelling of scintillation-detector γ-ray spectra from natural radionuclides