Related papers: Arc plasma ablation of quartz crystals
Phase-Field Crystal (PFC) models are able to resolve atomic length scale features of materials during temporal evolution over diffusive time scales. Traditional PFC models contain solid and liquid phases, however many important materials…
When an electron emitting tip is subjected to very high electric fields, plasma forms even under ultra high vacuum conditions. This phenomenon, known as vacuum arc, causes catastrophic surface modifications and constitutes a major limiting…
The results of an extensive operation of a Vacuum Spark plasma using Titanium electrodes in a 120 ns 150 kA discharge are presented. The hot spots are found to form with a regular spacing in a zippering Z-pinch plasma, which forms close to…
A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma, where the energy gain per distance of a test particle is Lorentz invariant. We show that there…
Seeking to establish whether active region upflow material contributes to the slow solar wind, we examine in detail the plasma upflows from Active Region (AR)10978, which crossed the Sun's disc in the interval 8 to 16 December, 2007 during…
Overdense plasmas have been attained with 2.45 GHz microwave heating in the low-field, low-aspect-ratio CNT stellarator. Densities higher than four times the ordinary (O) mode cutoff density were measured with 8 kW of power injected in the…
Radiation hydrodynamics simulations were used to study the effect of plastic ablators in laser-driven shock experiments. The sensitivity to composition and equation of state was found to be 5-10% in ablation pressure. As was found for…
Ultra-high energy cosmic rays interacting with the radiation fields in the universe cause electromagnetic cascades resulting in a flux of extragalactic gamma rays, detectable to some 100 GeV. Recent precise measurements of the extragalactic…
Superflares on the solar type stars observed by \textit{Kepler} demonstrate the contrast in the optical continuum of the order 0.1--1 per cent. The mechanism of formation of this radiation is not firmly established. We consider a model…
Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows which cannot cool through emission of radiation are presented. The calculations begin from an equilibrium configuration consisting of a thick torus…
High power single mode quantum cascade lasers with a narrow far field are important for several applications including surgery or military countermeasure. Existing technologies suffer from drawbacks such as operation temperature and…
In pursuit of diamond nanoparticles, a capacitively-coupled radio frequency (CCRF) flow-through plasma reactor was operated with methane argon gas mixtures. Signatures of the final product obtained microscopically and spectroscopically…
The slow advance of a crack in sodo-silicate glasses was studied at nanometer scale by in situ and real time atomic force microscopy (AFM) in a well controlled atmosphere. An enhanced diffusion of sodium ions in the stress gradient field at…
We address amorphization of montmorillonite crystal structure. Powdered montmorillonite samples with an effective particle diameter 630 micrometers were treated by a microwave field with frequency 2,45 GHz and power 750 W for ten minutes in…
Sapphire (single-crystal Al2O3) is a representative Earth material and is used as a window and/or anvil in shock experiments. Pressure, for example, at the core-mantle boundary is about 130 gigapascals (GPa). Defects induced by 100-GPa…
High density ($.3 < \bar{n}/10^{20}{\rm m^{-3}} < .8$), low $q_a$ ($1.9<q_a<3.4$), Ohmic discharges from the ASDEX experiment is analysed statistically. Bulk parameter scalings and parameterised temperature and density profile shapes are…
The measurement of the propulsion of metallic microdroplets exposed to nanosecond laser pulses provides an elegant method for probing the ablation pressure in dense laser-produced plasma. We present the measurements of the propulsion…
When a free-falling liquid droplet is hit by a laser it experiences a strong ablation driven pressure pulse. Here we study the resulting droplet deformation in the regime where the ablation pressure duration is short, i.e. comparable to the…
Pulsed plasmas in liquids exhibit complex interaction between three phases of matter (liquids, gas, plasmas) and are currently used in a wide range of applications across several fields, however significant knowledge gaps in our…
Direct laser electron acceleration in near-critical density plasma produces collimated electron beams with high charge $Q$ (up to $\mu$C). This regime could be of interest for high energy THz radiation generation, as many of the mechanisms…