Abstract: Correlated ion stopping arising from an intense cluster ion beam (CIB) interacting with an ultradense plasma target of relevance to inertial confinement fusion (ICF) is first investigated in a two-body approximation in an arbitrarily degenerate electron fluid target. The specific advantages of CIB-driven ICF are first demonstrated through 1D simulations, highlighting the very fine focusing of the ion beam on the target pellet. Then, the N-body configurations of ion debris resulting from the impact of heavy cluster ions are determined in terms of their specific topology. The validities of the usual assumptions of equal ion fragment charge and negligible coupling between stopping and Coulomb explosion are assessed.
Abstract: The interaction of micro-bubbles with ultra-intense laser pulses has been shown to generate ultra-high proton densities and correspondingly high electric fields. We investigate the possibility of using such a combination to study the fundamental physical phenomenon of vacuum polarization. With current or near-future laser systems, measurement of vacuum polarization via the bending of gamma rays that pass near imploded micro-bubbles may be possible. Since it is independent of photon energy to within the leading-order solution of the Heisenberg–Euler Lagrangian and the geometric optics approximation, the corresponding index of refraction can dominate the indices of refraction due to other effects at sufficiently high photon energies. We consider the possibility of its application to a transient gamma-ray lens.
Abstract: The Technological Laboratory of LMU Munich supplies various types of solid-state target for laser plasma experiments at the Centre for Advanced Laser Applications in Garching. Our main focus here is on the production of free-standing, thin foil targets, such as diamond-like-carbon foils, carbon nanotube foams (CNFs), plastic, and gold foils. The presented methods comprise cathodic arc deposition for DLC targets, chemical vapor deposition for CNFs, a droplet and spin-coating process for plastic foil production, as well as physical vapor deposition that has been optimized to provide ultrathin gold foils and tailored sacrifice layers. This paper reviews our current capabilities, which are a result of a close collaboration between target production processes and experiment, using high-power chirped pulse amplification laser systems over the past eight years.
Abstract: The dynamics of wire array Z pinches are greatly affected by the initial state of the wires, which can be preconditioned by a prepulse current. Recent advances in experimental research on preconditioned wire array Z pinches at Xi’an Jiaotong University are presented in this paper. Single-wire explosion experiments were carried out to check the state of the preconditioning and to obtain the current parameters needed for wire gasification. Double-wire explosion experiments were conducted to investigate the temporal evolution of the density distribution of the two gasified wires. Based on the results of these experiments, a double-pulse Z-pinch facility, Qin-1, in which a 10 kA prepulse current was coupled with the 0.8 MA main current was designed and constructed. Wire arrays of different wire materials, including silver and tungsten, can be preconditioned by the prepulse current to a gaseous state. Implosion of the two preconditioned aluminum wires exhibited no ablation and little trailing mass.
Abstract: The generation of runaway electrons (REs) is a significant problem in tokamak installations, causing energy loss, and melting and vaporization of the walls of the vacuum chamber. The wide deployment of Cherenkov-type detectors, in addition to other methods, is routinely used to detect high-energy electrons. This paper focuses on the cathodoluminescence and Cherenkov radiation excited in different crystals by REs. The spectral energy density of Cherenkov radiation in CaF2 (fluorite) and diamond at various initial electron energies is calculated, taking into account the ionization losses of electron energy, the dispersion of the refractive index of these substances, and the electron energy distribution of the beam.
Current Issue
Issue 6, November, 2022
ISSN2468-2047
eISSN2468-080X
CN51-1768/O4
Co Editors-in-Chief:Weiyan Zhang Michel Koenig Hokwang Mao
