Limitation on prepulse level for cone-guided fast-ignition inertial confinement fusion.

The viability of fast-ignition (FI) inertial confinement fusion hinges on the efficient transfer of laser energy to the compressed fuel via multi-MeV electrons. Preformed plasma due to the laser prepulse strongly influences ultraintense laser plasma interactions and hot electron generation in the hollow cone of an FI target. We induced a prepulse and consequent preplasma in copper cone targets and measured the energy deposition zone of the main pulse by imaging the emitted K_{alpha} radiation.

Diagnostics for fast ignition science (invited).

The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an approximately 20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer.

Electron heated target temperature measurements in petawatt laser experiments based on extreme ultraviolet imaging and spectroscopy.

Three independent methods (extreme ultraviolet spectroscopy, imaging at 68 and 256 eV) have been used to measure planar target rear surface plasma temperature due to heating by hot electrons. The hot electrons are produced by ultraintense laser-plasma interactions using the 150 J, 0.5 ps Titan laser.

A Bremsstrahlung spectrometer using k-edge and differential filters with image plate dosimeters.

A Bremsstrahlung spectrometer using k-edge and differential filtering has been used with image plate dosimeters to measure the x-ray fluence from short-pulse laser/target interactions. An electron spectrometer in front of the Bremsstrahlung spectrometer deflects electrons from the x-ray line of sight and simultaneously measures the electron spectrum. The response functions were modeled with the Monte Carlo code INTEGRATED TIGER SERIES 3.

Determination of electron-heated temperatures of petawatt laser-irradiated foil targets with 256 and 68 eV extreme ultraviolet imaging.

Measurements of plasma temperature at the rear surface of foil targets due to heating by hot electrons, which were produced in short pulse high intensity laser matter interactions using the 150 J, 0.5 ps Titan laser, are reported. Extreme ultraviolet (XUV) imaging at 256 and 68 eV energies is used to determine spatially resolved target rear surface temperature patterns by comparing absolute intensities to radiation hydrodynamic modeling.

Laser heating of solid matter by light-pressure-driven shocks at ultrarelativistic intensities.

The heating of solid targets irradiated by 5 x 10(20) W cm(-2), 0.8 ps, 1.05 microm wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo, and V.

Use of GafChromic film to diagnose laser generated proton beams.

A calibration of three types of GafChromic radiochromic film (HS, MD-55, and HD-810) was carried out on the Crocker Nuclear Laboratory's 76 in. cyclotron at UC Davis over doses ranging from 0.001 to 15 kGy.

High-precision intensity-selective observation of multiphoton ionization: a new method of photoelectron spectroscopy.

We have developed a novel method of time-of-f light (TOF) photoelectron spectroscopy that permits observation of multiphoton ionizations with extremely high precision, especially for low-probability events. By scanning the laser-produced ionization region across a pinhole we can select specific laser peak intensities. The volumes occupied by low intensities rise rapidly compared with traditional straight TOF spectroscopy, resulting in high signal gains.