Effects of the dynamic cathode sheath on electron transport at the initial period of HiPIMS pulse studied by Langmuir probe measurements and 2D PIC-MCC simulation

Plasma flux and energy enhancement in BP-HiPIMS discharge via auxiliary anode and solenoidal coil

“…The probe was made by tungsten wire with 0.2 mm in diameter, which was wrapped in an insulated double-layer ceramic tube, and only 5 mm tip was exposed in the plasma and parallel to the target surface. This tip size is applicable to the plasma with density of ∼10 16 -10 17 m −3 and electron temperature of 0.4-10 eV in this work, as estimated in [34]. In addition, the electron collection by probe is not affected by the coil magnetic field because the probe tip radius of 0.1 mm always remains smaller than the electron Larmor radius for the coil field ranging from 0-9 mT in this experiment.…”

“…The water-cooled titanium target (Ti, 99.99% in purity) was 50 mm in diameter (or ∼2 inch) and 5 mm in thickness, which was installed in a stainless-steel vacuum chamber with 600 mm in diameter and 800 mm in height. The detailed description of our vacuum system has been shown elsewhere [34,44]. The vacuum chamber was evacuated by the molecular pump to 10 −3 Pa base pressure before introducing the inert working gas argon (Ar, 99.99% in purity).…”

“…To obtain the plasma density and electron temperature, the home-built Langmuir probe was placed at z = 65 mm above the target center. The detailed description of our probe system has been shown elsewhere [34], and only a brief introduction is drawn as follows. The probe was made by tungsten wire with 0.2 mm in diameter, which was wrapped in an insulated double-layer ceramic tube, and only 5 mm tip was exposed in the plasma and parallel to the target surface.…”

“…Another approach by adjusting the magnetic field B to control charged-particle diffusion has been employed to increase deposition particle flux. For magnetized plasma, the mobility of electrons in the direction perpendicular to the magnetic field is quite low [4,33,34], thereby reducing the diffusion of ions towards downstream due to the requirement of the quasi-neutrality [35]. Therefore, weakening the magnetic field in HiPIMS has been confirmed to be an effective mean to enhance the charged particles transport and increase the deposition rate.…”

Methane–Air Plasma-Assisted Ignition Excited by Nanosecond Repetitively Pulsed Discharge: Numerical Modeling and Effect of Inert Gas

“…20 Because the experimental implementation of PAI and PAC in special environments still has certain limitations, numerical simulation has become a preferred approach to deeply explore the temporal and spatial evolution characteristics and the chemical dynamics of PAI and PAC. Models such as one-dimensional fluid models, 18 one-dimensional particle-in-cell Monte Carlo collision models, 21 and global models 22 are the extensively used methods to investigate PAI and PAC. Casey et al have explored the effect of the nanosecond pulsed applied voltage on ignition utilizing a twofluid solver, discovering that the recombination of the fuel and the oxidant fragments increases the content of OH in the front of the outwardly propagating flame and accelerates the consumption of fuel.…”