Use of imaging plates at near saturation for high energy density particles

Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 79(10), 10E910, 2008 and may be found at http://dx.doi.org/10.1063/1.298767

Measurements of high energy density electrons via observation of Cherenkov radiation

Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 17(5), 056306, 2010 and may be found at http://dx.doi.org/10.1063/1.334637

Direct, absolute, and in situ measurement of fast electron transport via cherenkov emission

We present direct measurements of the absolute energy distribution of relativistic electrons generated in intense, femtosecond laser interaction with a solid. Cherenkov emission radiated by these electrons in a novel prism target is spectrally dispersed to obtain yield and energy distribution of electrons simultaneously. A crucial advance is the observation of high density electron current as predicted by particle simulations and its transport as it happens inside the target. In addition, the strong sheath potential present at the rear side of the target is inferred from a comparison of the electron spectra derived from Cherenkov light observation with that from a magnet spectrometer

Pulse compression and beam focusing with segmented diffraction gratings in a high-power chirped-pulse amplification glass laser system

This paper was published in Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.35.001783 Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law

The Role of Optical Coherence Tomography in Coronary Intervention

Optical coherence tomography (OCT) is an optical analog of intravascular ultrasound (IVUS) that can be used to examine the coronary arteries and has 10-fold higher resolution than IVUS. Based on polarization properties, OCT can differentiate tissue characteristics (fibrous, calcified, or lipid-rich plaque) and identify thin-cap fibroatheroma. Because of the strong attenuation of light by blood, OCT systems required the removal of blood during OCT examinations. A recently developed frequency-domain OCT system has a faster frame rate and pullback speed, making the OCT procedure more user-friendly and not requiring proximal balloon occlusion. During percutaneous coronary intervention (PCI), OCT can provide detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition [ISA]). At follow-up examinations after stent implantation, stent strut coverage and ISA can be assessed. Several OCT studies have demonstrated delayed neointimal coverage following drug-eluting stent (DES) implantation vs. bare metal stent (BMS) placement. While newer DESs promote more favorable vascular healing, the clinical implications remain unknown. Recent OCT studies have provided insights into restenotic tissue characteristics; DES restenotic morphologies differ from those with BMSs. OCT is a novel, promising imaging modality; with more in-depth assessments of its use, it may impact clinical outcomes in patients with symptomatic coronary artery disease

In-Target Proton–Boron Nuclear Fusion Using a PW-Class Laser

Nuclear reactions between protons and boron-11 nuclei (p–B fusion) that were used to yield energetic α-particles were initiated in a plasma that was generated by the interaction between a PW-class laser operating at relativistic intensities (~3 × 10^19 W/cm2) and a 0.2-mm thick boron nitride (BN) target. A high p–B fusion reaction rate and hence, a large α-particle flux was generated and measured, thanks to a proton stream accelerated at the target’s front surface. This was the first proof of principle experiment to demonstrate the efficient generation of α-particles (~10^10/sr) through p–B fusion reactions using a PW-class laser in the “in-target” geometry

Generation of α-Particle Beams With a Multi-kJ, Peta-Watt Class Laser System

We present preliminary results on generation of energetic α-particles driven by lasers. The experiment was performed at the Institute of Laser Engineering in Osaka using the short-pulse, high-intensity, high-energy, PW-class laser. The laser pulse was focused onto a thin plastic foil (pitcher) to generate a proton beam by the well-known TNSA mechanism which, in turn, was impinging onto a boron-nitride (BN) target (catcher) to generated alpha-particles as a result of proton-boron nuclear fusion events. Our results demonstrate generation of α-particles with energies in the range 8–10 MeV and with a flux around 5 × 10^9 sr^−1