A5062722475- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser Design and Applications
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Radioactive Decay and Measurement Techniques
- Geophysics and Sensor Technology
- Advanced Fiber Laser Technologies
- Embedded Systems Design Techniques
- Quantum Electrodynamics and Casimir Effect
- Photocathodes and Microchannel Plates
- Nuclear Physics and Applications
- Fusion materials and technologies
- Magnetic confinement fusion research
- Advanced X-ray Imaging Techniques
University of California, San Diego
2019-2025
Los Alamos National Laboratory
2020
Intense lasers enable generating high-energy particle beams in university-scale laboratories. With the direct laser acceleration (DLA) method, leading part of pulse ionizes target material and forms a positively charged ion plasma channel into which electrons are injected accelerated. The high energy conversion efficiency DLA makes it ideal for large numbers photonuclear reactions. In this work, we reveal that, efficient to prevail, sufficiently atomic number is required maintain injection...
Direct Laser Acceleration (DLA) of electrons during a high-energy, picosecond laser interaction with an underdense plasma has been demonstrated to be substantially enhanced by controlling the focusing geometry. Experiments using OMEGA EP facility measured accelerated maximum energies exceeding 120 times ponderomotive energy under certain focusing, pulse energy, and density conditions. Two-dimensional particle-in-cell simulations show that conditions alter field evolution, channel fields...
With the advent of high repetition rate laser facilities, novel diagnostic tools compatible with these advanced specifications are required. This paper presents design an active gamma-ray spectrometer intended for experiments, particular emphasis on functionality within a PW level laser-plasma interaction chamber’s extreme conditions. The uses stacked scintillators to accommodate broad range energies, demonstrating its adaptability various experimental setups. In addition, it has been...
Abstract We investigate the mechanisms responsible for single-lobed versus double-lobed angular distributions of emitted γ-rays in laser-irradiated plasmas, focusing on how direct laser acceleration (DLA) shapes emission profile. Using test-particle calculations, we show that efficiency DLA plays a central role. In inefficient regime, electrons rapidly gain and lose energy within single cycle, resulting profile heavily influenced by fields. contrast, efficient steadily accumulate over...
We discovered a simple regime where near-critical plasma irradiated by laser of experimentally available intensity can self-organize to produce positrons and accelerate them ultrarelativistic energies. The pulse piles up electrons at its leading edge, producing strong longitudinal electric field. field creates moving gamma-ray collider that generates via the linear Breit-Wheeler process-annihilation two gamma rays into an electron-positron pair. At same time, field, rather than laser, serves...
Direct laser acceleration of electrons is an important energy deposition mechanism for laser-irradiated plasmas that particularly effective at relativistic intensities in the presence quasi-static laser-driven plasma electric and magnetic fields. These radial azimuthal fields provide transverse electron confinement by inducing betatron oscillations forward-moving undergoing acceleration. Electrons are said to experience a resonance when frequency matches average field position. In this...
Abstract Using a test-particle model, we examine direct laser acceleration of electrons within magnetic filament that has been shown to form inside laser-irradiated plasma. We focus on ultra-high intensity interactions where the force radiation friction caused by electron emission electromagnetic must be taken into account. It is even relatively weak superluminosity wave fronts—the feature previously neglected—qualitatively changes dynamics, leading so-called attractor effect. As result this...
A relatively simple model problem where a single electron moves in two relativistically-strong obliquely intersecting plane wave-packets is studied using number of different numerical solvers. It shown that, general, even the most advanced solvers are unable to obtain converged solutions for more than about 100 fs contrast plane-wave problem, and that some basic metrics orbit show enormous sensitivity initial conditions. At bare minimum this indicates an unusual degree non-linearity, may...
Abstract Direct laser acceleration of electrons during a high-energy, picosecond interaction with an underdense plasma has been demonstrated to be substantially enhanced by controlling the focusing geometry. Experiments using OMEGA EP facility measured accelerated maximum energies exceeding 120 times ponderomotive energy under certain focusing, pulse energy, and density conditions. Two-dimensional particle-in-cell simulations show that conditions alter field evolution, channel fields...
Motivated by experiments employing ps-long, kilojoule laser pulses, we examined x-ray emission in a finite-length underdense plasma irradiated such pulse using two dimensional particle-in-cell simulations. We found that, addition to the expected forward emission, also efficiently emits backward direction. Our simulations reveal that occurs when exits plasma. The longitudinal electric field generated at density down-ramp turns around some of laser-accelerated electrons and re-accelerates them...
In this paper, we investigate the conditions under which direct laser acceleration (DLA) of electrons in a laser-irradiated plasma can produce distinct photon emission profiles, focusing on mechanisms responsible for single-lobed versus double-lobed angular distributions emitted \(\gamma\)-rays. Through combination particle-in-cell simulations, test-electron and theoretical analysis, demonstrate that efficiency DLA is key determinant resulting pattern. Our results show inefficient DLA,...
Motivated by experiments employing picosecond-long, kilojoule laser pulses, we examined x-ray emission in a finite-length underdense plasma irradiated such pulse using two-dimensional particle-in-cell simulations. We found that, addition to the expected forward emission, also efficiently emits backward direction. Our simulations reveal that occurs when exits plasma. The longitudinal electric field generated at density down-ramp turns around some of laser-accelerated electrons and...
We discovered a simple regime where near-critical plasma irradiated by laser of experimentally available intensity can self-organize to produce positrons and accelerate them ultra-relativistic energies. The pulse piles up electrons at its leading edge, producing strong longitudinal electric field. field creates moving gamma-ray collider that generates via the linear Breit-Wheeler process -- annihilation two gamma-rays into an electron-positron pair. At same time, field, rather than laser,...
With the advent of high repetition rate laser facilities, novel diagnostic tools compatible with these advanced specifications are in demand. This paper presents design an active gamma-ray spectrometer intended for experiments, particular emphasis on functionality within a PW level laser-plasma interaction chamber's extreme conditions. The uses stacked scintillators to accommodate broad range energies, demonstrating its adaptability various experimental setups. Additionally, it has been...
For the past two decades, intense lasers have supported new schemes for generating high-energy particle beams in university-scale laboratories. With direct laser acceleration (DLA) method, leading part of pulse ionizes target material and forms a positively charged ion plasma channel into which electrons are injected accelerated. DLA has been realized over wide range parameters, using low-atomic-number materials. In this presented work we reveal that at these higher intensities, edge...
Direct Laser Acceleration (DLA) of electrons is a mechanism for superponderomotive energy gain during relativistically intense laser-plasma interactions. The presence the plasma produces channel with transverse electric and azimuthal magnetic fields that enable exchange from laser to electrons. We investigate DLA using experiments performed at OMEGA EP facility particle-in-cell simulations. experimental variables include density profile, pulse focusing, duration. Matching focal spot size...