Energetic Proton Generation in Ultra-Intense Laser-Solid Interactions

Energetic Proton Generation in Ultra-Intense Laser-Solid Interactions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
An explanation for the energetic ions observed in the PetaWatt experiments is presented. In solid target experiments with focused intensities exceeding 102° W/cm2, high-energy electron generation, hard bremsstrahlung, and energetic protons have been observed on the backside of the target. In this report, we attempt to explain the physical process present that will explain the presence of these energetic protons, as well as explain the number, energy, and angular spread of the protons observed in experiment. In particular, we hypothesize that hot electrons produced on the front of the target are sent through to the back off the target, where they ionize the hydrogen layer there. These ions are then accelerated by the hot electron cloud, to tens of MeV energies in distances of order tens of microns, whereupon they end up being detected in the radiographic and spectrographic detectors.

Energetic Proton Generation in Ultra-Intense Laser-Solid Interactions

Energetic Proton Generation in Ultra-Intense Laser-Solid Interactions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
An explanation for the energetic ions observed in the PetaWatt experiments is presented. In solid target experiments with focused intensities exceeding 102° W/cm2, high-energy electron generation, hard bremsstrahlung, and energetic protons have been observed on the backside of the target. In this report, we attempt to explain the physical process present that will explain the presence of these energetic protons, as well as explain the number, energy, and angular spread of the protons observed in experiment. In particular, we hypothesize that hot electrons produced on the front of the target are sent through to the back off the target, where they ionize the hydrogen layer there. These ions are then accelerated by the hot electron cloud, to tens of MeV energies in distances of order tens of microns, whereupon they end up being detected in the radiographic and spectrographic detectors.

Low-emittance Monoenergetic Electron and Ion Beams from Ultra-intense Laser-solid Interactions

Low-emittance Monoenergetic Electron and Ion Beams from Ultra-intense Laser-solid Interactions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Recent experiments at the LLNL Petawatt Laser have demonstrated the generation of intense, high energy beams of electrons and ions from the interaction of ultra-intense laser light with solid targets. Focused laser intensities as high as 6 x 102° W/cm2 are achieved, at which point the quiver energies of the target electrons extend to (almost equal to)10 MeV. In this new, fully relativistic regime of laser-plasma interactions, nuclear processes become important and nuclear techniques are required to diagnose the high-energy particle production. In recent experiments we have observed electrons accelerated to 100 MeV, up to 60 MeV brehmsstrahlung generation, photo-nuclear fission and positron-electron pair creation. We also have observed monoenergetic jets of electrons having sufficiently small emittance to be interesting as a laser-accelerated beam, if the production mechanism could be understood and controlled. The huge flux of multi-MeV ponderomotively accelerated electrons produced in the laser-solid interaction is also observed to accelerate contaminant ions from the rear surface of the solid target up to 50 MeV. We describe spectroscopic measurements which reveal intense monoenergetic beam features in the proton energy spectrum. The total spectrum contains>1013 protons, while the monoenergetic beam pulses contain (almost equal to)1 nC of protons, and exhibits a longitudinal and transverse emittance smaller than conventional RF proton accelerator beams.

Relativistically Intense Laser–Microplasma Interactions

Relativistically Intense Laser–Microplasma Interactions PDF Author: Tobias Ostermayr
Publisher: Springer
ISBN: 303022208X
Category : Science
Languages : en
Pages : 166

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Book Description
This dissertation covers several important aspects of relativistically intense laser–microplasma interactions and some potential applications. A Paul-trap based target system was developed to provide fully isolated, well defined and well positioned micro-sphere-targets for experiments with focused peta-watt laser pulses. The laser interaction turned such targets into microplasmas, emitting proton beams with kinetic energies exceeding 10 MeV. The proton beam kinetic energy spectrum and spatial distribution were tuned by variation of the acceleration mechanism, reaching from broadly distributed spectra in relatively cold plasma expansions to spectra with relative energy spread as small as 20% in spherical multi-species Coulomb explosions and in directed acceleration processes. Numerical simulations and analytical calculations support these experimental findings and show how microplasmas may be used to engineer laser-driven proton sources. In a second effort, tungsten micro-needle-targets were used at a peta-watt laser to produce few-keV x-rays and 10-MeV-level proton beams simultaneously, both measured to have only few-μm effective source-size. This source was used to demonstrate single-shot simultaneous radiographic imaging with x-rays and protons of biological and technological samples. Finally, the dissertation discusses future perspectives and directions for laser–microplasma interactions including non-spherical target shapes, as well as thoughts on experimental techniques and advanced quantitative image evaluation for the laser driven radiography.

Atoms, Solids, and Plasmas in Super-Intense Laser Fields

Atoms, Solids, and Plasmas in Super-Intense Laser Fields PDF Author: Dimitri Batani
Publisher: Springer Science & Business Media
ISBN: 1461513510
Category : Science
Languages : en
Pages : 409

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Book Description
The recent developement of high power lasers, delivering femtosecond pulses of 20 2 intensities up to 10 W/cm , has led to the discovery of new phenomena in laser interactions with matter. At these enormous laser intensities, atoms, and molecules are exposed to extreme conditions and new phenomena occur, such as the very rapid multi photon ionization of atomic systems, the emission by these systems of very high order harmonics of the exciting laser light, the Coulomb explosion of molecules, and the acceleration of electrons close to the velocity of light. These phenomena generate new behaviour of bulk matter in intense laser fields, with great potential for wide ranging applications which include the study of ultra-fast processes, the development of high-frequency lasers, and the investigation of the properties of plasmas and condensed matter under extreme conditions of temperature and pressure. In particular, the concept of the "fast ignitor" approach to inertial confinement fusion (ICF) has been proposed, which is based on the separation of the compression and the ignition phases in laser-driven ICF. The aim of this course on "Atom, Solids and Plasmas in Super-Intense Laser fields" was to bring together senior researchers and students in atomic and molecular physics, laser physics, condensed matter and plasma physics, in order to review recent developments in high-intensity laser-matter interactions. The course was held at the Ettore Majorana International Centre for Scientific Culture in Erice from July 8 to July 14,2000.

Atoms, Solids, and Plasmas in Super-Intense Laser Fields

Atoms, Solids, and Plasmas in Super-Intense Laser Fields PDF Author: Dimitri Batani
Publisher: Springer Science & Business Media
ISBN: 9780306466151
Category : Science
Languages : en
Pages : 434

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Book Description
Proceedings of the 30th Course of the International School of Quantum Electronics on Atoms, Solids and Plasmas in Super-Intense Laser Fields, held 8-14 July, in Erice, Sicily

Radiation Generation and High-field Physics Phenomena in Ultra-intense Laser-solid Interactions

Radiation Generation and High-field Physics Phenomena in Ultra-intense Laser-solid Interactions PDF Author: Matthew James Duff
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
It is found that it is possible to produce a radially polarised mode, of high intensity (∼10exp18 Wcm−2). Such a mode has applications in the efficient acceleration of electrons and positrons, and in the generation of radiation sources which are optimised in terms of their average photon energy and beam divergence. It is highly difficult to generate these modes at high intensity, using conventional solid-state optics, given their damage thresholds.

Frontiers in High Energy Density Physics

Frontiers in High Energy Density Physics PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 030908637X
Category : Science
Languages : en
Pages : 177

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Book Description
Recent scientific and technical advances have made it possible to create matter in the laboratory under conditions relevant to astrophysical systems such as supernovae and black holes. These advances will also benefit inertial confinement fusion research and the nation's nuclear weapon's program. The report describes the major research facilities on which such high energy density conditions can be achieved and lists a number of key scientific questions about high energy density physics that can be addressed by this research. Several recommendations are presented that would facilitate the development of a comprehensive strategy for realizing these research opportunities.

Investigations of Field Dynamics in Laser Plasmas with Proton Imaging

Investigations of Field Dynamics in Laser Plasmas with Proton Imaging PDF Author: Thomas Sokollik
Publisher: Springer Science & Business Media
ISBN: 3642150403
Category : Science
Languages : en
Pages : 126

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Book Description
Laser-driven proton beams are still in their infancy but already have some outstanding attributes compared to those produced in conventional accelerators. One such attribute is the typically low beam emittance. This allows excellent resolution in imaging applications like proton radiography. This thesis describes a novel imaging technique - the proton streak camera - that the author developed and first used to measure both the spatial and temporal evolution of ultra-strong electrical fields in laser-driven plasmas. Such investigations are of paramount importance for the understanding of laser-plasma interactions and, thus, for optimization of laser-driven particle acceleration. In particular, the present work investigated micrometer-sized spherical targets after laser irradiation. The confined geometry of plasmas and fields was found to influence the kinetic energy and spatial distribution of accelerated ions. This could be shown both in experimental radiography images and and in numerical simulations, one of which was selected for the cover page of Physical Review Letters.

The 2nd International Conference on Ultra-Intense Laser Interaction Science

The 2nd International Conference on Ultra-Intense Laser Interaction Science PDF Author: Andrea Gamucci
Publisher: American Institute of Physics
ISBN:
Category : Science
Languages : en
Pages : 176

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Book Description
Conference Location and Date: Frascati (Rome), Italy, 24-29 May 2009

Advanced Diagnostics for Magnetic and Inertial Fusion

Advanced Diagnostics for Magnetic and Inertial Fusion PDF Author: Peter E. Stott
Publisher: Springer Science & Business Media
ISBN: 1441986960
Category : Science
Languages : en
Pages : 449

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Book Description
Proceedings of the International Conference on Advanced Diagnostics for Magnetic and Inertial Fusion, held September 3-7, 2001 at Villa Monastero, Varenna, Italy. This volume focuses on future diagnostic requirements for fusion energy research emphasizing advanced diagnostics, new techniques and areas where further progress is required.