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In the interaction of high power laser beams with solid density plasma, there are a number of magnetic field generating mechanisms that result in very strong fields that can inhibit energy transport. Here, we present 2D numerical modeling of near critical density plasma using a fully implicit Vlasov-Fokker-Planck code, IMPACTA, which includes self-consistent magnetic fields as well as anisotropic...
The physics of the transport of large currents of fast (relativistic) electrons in dense matter underpins many topics in high intensity laser-solid interactions, including warm dense matter, ion acceleration and the fast ignition approach to inertial confinement fusion. The propagation of fast electrons within the target is subject to transport instabilities (e.g. resistive instabilities) which give...
In a Fast Ignition approach to achieving inertial confinement fusion (ICF) the processes of thermonuclear fuel compression and ignition are separated. The fusion fuel is partially compressed with a primary series of long-pulse, high energy lasers and in one scheme a single high power, short-pulse laser is used to drive a stream of energetic electrons into the core of the plasma to heat and ignite...
Fast Ignition [1] holds the promise of improved efficiency and reduced laser energy requirements for Laser Fusion Energy systems. The main approach proposed to date is by coupling a beam of 1 to 2 MeV electrons from the laser interaction spot to a 40 micron spot in the compressed fuel core using a metal cone insert to get close to the compressed core [2]. However, multi-millijoule level laser prepulse...
The propagation of a large flux of laser generated mildly relativistic electrons in warm resistive plasma is one of the most important problems for the fast ignition scenario of laser inertial confinement fusion. At the initial stage of propagation, the beam induces a return current in the plasma so that the beam-plasma system is unstable to three well known instabilities[1], i.e., the two-stream...
A commonly used laser-based method of acceleration of dense plasma, particularly applied for compression and ignition of a fusion target in ICF research, is ablative acceleration (AA) employing the “rocket effect ”. However, the energetic efficiency of acceleration in the AA scheme is relatively small (≤10%), so significant efforts have been made to find more efficient schemes. Very recently, a novel...
A portable experiment platform is constructed, which can be used for both single wire z pinch and laser initiated z pinch. At the current level of several kiloampere, a series of experiments have been carried out, and the dynamic behavior of laser initiated z pinch is observed. Effects of the following conditions on z pinch motion are studied: gas pressure surrounding the plasma (0.33atm∼3atm), material...
The idea to use microscopic test particles as electrostatic and thermal probes in complex plasmas has been consequently developed during the last years1–3. Due to the force balance of the particles, however, it is very difficult to change their position in the plasma sheath without changing the external and internal plasma parameters. Recently, experiments have been performed where the confined particles...
Presenting initial results from an experimental investigation into the interaction of supersonic, radiatively cooled plasma jets with solid targets. The jet is produced with a converging conical plasma flow from a cylindrically symmetric array of inclined wires (a conical wire array) driven by 1.4MA, 250ns current pulse on the MAGPIE Z-pinch. The produced jet has scalable characteristics (Mach number...
Acceleration of particles driven by the interaction of a relativistic laser intensity, having femtosecond duration, with an under-dense plasma can produce plasma wave, in the form of bubble, delivering several hundred gigavolts per meter accelerating electric fields [1] and deliver high quality femtosecond-scale electron beams with relatively narrow energy spread [2] and low emittance [3]. We will...
Laser Induced Fluoresces (LIF) and laser cavity ring-down spectroscopy (CRDS) have been recently developed in our group for diagnosis of the active species (atoms, ions or radicals) in reactive plasmas. In the first experimental approach, time-resolved LIF technique was used to investigate the temporal evolutions of the number density of metastable state N2 (A) in the nanosecond pulsed post discharge...
The gas-filled capillary discharge waveguide (CDW) is a commonly applied accelerating structure for the laser wakefield accelerator (LWFA) because an intense femtosecond laser pulse can be successfully guided over several centimetres, leading to the generation of GeV-scale electron beams. Simulations have shown that tapering the longitudinal plasma density leads to significant enhancement of the final...
A Laser-Wakefiled acceleration (LWFA) experiment, aiming the production of high-quality electron relativistic beams, was performed at Astra-Gemini Laser Facility. The interaction was used sub-50 fs laser pulses with energies in the range 4 – 10 J and structured gas cells with lengths of 2 – 4 cm filled with hydrogen as target. Reliable and reproducible electron beams with energies close to 1 GeV were...
This paper discovered the results of series of theoretical and experimental researches of the ability to create the conductive channel with length of 50 – 100 m in normal atmosphere by directional flux of radiation. This channel is essential condition for creation nonlethal means for influence on bio object and electro-technical devise by pulse current. Currently existing electric shocks own range...
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