Acceleration of heavy ions to MeV/nucleon energies by ultrahigh-intensity lasers

The primary aim of this thesis was the acceleration of ions with a nuclear charge Z > 1 to multi-MeV energies by means of a laser pulse. While laser-induced proton acceleration in the MeV-range has recently been achieved by a number of groups, the laser acceleration of high quality, high energy beams of heavier particles has been demonstrated for the first time within the framework of this thesis. Furthermore, the obtained data could then subsequently be used to understand the dynamics of the acceleration physics, which was not accessible by the means of the previously performed experiments. (orig.)Available from TIB Hannover: RN 5339(281) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Spectroscopic diagnostics for multi-TW laser-produced plasmas

Data from a pinhole camera and a transmission grating spectrograph are used in multi-TW laser irradiance of thin metal films to assess the maximum laser spot size and to show tenths of a percent conversion of laser light to K-, L-, and M-band x rays. The distribution of target debris, an operational issue for the survivability of an unshielded parabola in a large laser system, is revealed by x-ray fluorescence measurements of witness samples. At the 25-J, 30-TW level, we find little evidence of damage to the f/3 parabola with an angle of incidence on target greater than 22$^{\circ}$

Theory and modeling of ion acceleration from the interaction of ultra-intense lasers with solid density targets

The interaction of a high intensity, short-pulse laser with a thin target can lead to the generation of a highly collimated beam of fast ions off the rear target surface. These ion beams have the potential to impact inertial confinement fusion applications, including their use in diagnostics and fast-ignition. Recent work by the authors in the modeling of ion acceleration, using both full particle-in-cell and hybrid (particle ions, reduced electron physics) models, is leading to improved understanding of the physics governing ion acceleration

Ultrashort-laser-produced heavy ion generation via target laser-ablation cleaning

It has become apparent in the last few years that the surface contamination on laser-acceleration targets is a major impediment to the acceleration of the actual target ions. To this end we have performed experiments at the Los Alamos Trident Laser facility using one arm of the Trident laser at 150 ps to ablatively clean targets that are subsequently irradiated by the Trident TW Short-pulse arm to accelerate the bulk target ions to high energies. The 150 ps ablation pulse rids the rear of the target of its omnipresent surface contamination layer allowing the short-pulse to illuminate the target and accelerate ions via the Target Normal Sheath Acceleration (TNSA) mechanism. Our experimental results are compared to the LASNEX code to validate and improve our predictive capabilities for future acceleration experiments

Improved large-energy-range magnetic electron-positron spectrometer for experiments with the Texas Petawatt Laser

© 2019 IOP Publishing Ltd and Sissa Medialab. We present the design, construction, and first use of a magnetic electron-positron spectrometer at the Texas Petawatt Laser facility. The Global Spectrometer for Positron and Electron Characterization (GSPEC) is capable of detecting electrons and positrons over a large energy range from 3-150 MeV and has been designed to diagnose the electrons and positrons accelerated by high-intensity laser interactions with over-critical target