Effect of ion Bombardment in Polymer Surface Modification: Comparison of Pulsed High Frequency Plasma and ion Beam

1998 ◽  
Vol 544 ◽  
Author(s):  
O. Zabeida ◽  
J. E. Klemberg-Sapieha ◽  
L. Martinu ◽  
D. Morton
Keyword(s):  
Microwave Plasma ◽  
Ion Beam ◽  
Plasma Reactor ◽  
Polymer Surface ◽  
Ion Bombardment ◽  
Ion Source ◽  
Distribution Functions ◽  
Surface Restructuring ◽  
Microstructure Density ◽  
Energy Distribution Functions

AbstractThe energy and the flux of impinging ions are important factors which determine the properties of deposited films and of exposed surfaces (microstructure, density, hardness, roughness, stress, chemical structure, adhesion etc.). In the present work, we use a multigrid retarding field analyzer to study ion bombardment characteristics in two different systems: a pulsed microwave plasma reactor, and a cold cathode ion source. We have found that the ion energy distribution functions (IEDF) possess specific features for each mode of operation: we evaluate the shape and the maximum and the mean ion energies of the IEDF for different gases such as Ar and N2. These ion characteristics are correlated with surface restructuring of differently treated polymers (polycarbonate and polyethylene terephthalate), analyzed by XPS.

Die kinetische Energie ionisierter Molekülfragmente I. Methodik

1964 ◽  
Vol 19 (4) ◽  
pp. 484-493 ◽  
Author(s):  
Rolf Taubert
Keyword(s):  
Probability Function ◽  
Solid Angle ◽  
Initial Energy ◽  
Ion Source ◽  
Distribution Functions ◽  
Velocity Space ◽  
Ion Current ◽  
Molecular Fragments ◽  
Fragment Ions ◽  
Energy Distribution Functions

Methods of measuring initial energies of ionized molecular fragments are discussed in terms of the velocity space. An ion source together with the collector arrangement define a certain part of the velocity space from where ions are collected. If this part is not equivalent to a fixed solid angle in velocity space, discrimination due to initial energy takes place. Well defined discrimination effects can be used to measure the initial energy probability function WE of an ion ensemble. Emphasis is laid especially upon the deflection method. Using this method one obtaines the probability function WE simply by differentiating the primarily measured ion current distribution. The necessary working conditions which have to be fulfilled are discussed in some detail and an experimental arrangement is described, which has been used to measure the initial energy distribution functions of fragment ions from the lower paraffins.

A New Design and Computer Simulation of a 5-Electrode Ion Extraction/Focusing System

2005 ◽  
Vol 107 ◽  
pp. 21-24 ◽  
Author(s):  
M. Medhisuwakul ◽  
Thiraphat Vilaithong ◽  
Jürgen Engemann
Keyword(s):  
Microwave Plasma ◽  
Ion Beam ◽  
Plasma Source ◽  
Ion Source ◽  
Simulation Software ◽  
Ion Current ◽  
Extraction System ◽  
Beam Shape ◽  
Ion Extraction ◽  
Argon Ion

A 13.56 MHz radio-frequency (rf) driven multicusp ion source has been constructed [1] to produce a high argon ion current density. Milliampere-range argon ion current can be extracted from the source. An in-waveguide microwave plasma source has been utilized as the ion beam neutralizer [2]. The neutralization source was placed 20 cm downstream from the extraction system. With the former extraction system, comprised of extraction electrodes and an Einzel lens, the electrons from the neutralizer were attracted to the high positive potential of the lens. Consequently, the potential of the lens drops and the beam is diverged. To suppress electrons from being accelerated to the Einzel lens a negatively biased electrode was placed before the last electrode, which is grounded, to produce a retarding electric field for electrons. The hole of the electrode was made small to make sure that the potential at the center is negative enough to suppress electrons. All simulations have been performed with the KOBRA3-INP simulation software. The results of the beam shape from the simulation will be presented.

scholarly journals Taming microwave plasma to beat thermodynamics in CO2 dissociation

2015 ◽  
Vol 183 ◽  
pp. 233-248 ◽  
Author(s):  
G. J. van Rooij ◽  
D. C. M. van den Bekerom ◽  
N. den Harder ◽  
T. Minea ◽  
G. Berden ◽  
...  
Keyword(s):  
Rayleigh Scattering ◽  
Microwave Plasma ◽  
Vibrational Excitation ◽  
Distribution Functions ◽  
Dissociative Excitation ◽  
Plasma Dynamics ◽  
Novel Approach ◽  
Process Energy ◽  
Energy Distribution Functions ◽  
Non Equilibrium

The strong non-equilibrium conditions provided by the plasma phase offer the opportunity to beat traditional thermal process energy efficiencies via preferential excitation of molecular vibrations. Simple molecular physics considerations are presented to explain potential dissociation pathways in plasma and their effect on energy efficiency. A common microwave reactor approach is evaluated experimentally with Rayleigh scattering and Fourier transform infrared spectroscopy to assess gas temperatures (exceeding 104 K) and conversion degrees (up to 30%), respectively. The results are interpreted on a basis of estimates of the plasma dynamics obtained with electron energy distribution functions calculated with a Boltzmann solver. It indicates that the intrinsic electron energies are higher than is favorable for preferential vibrational excitation due to dissociative excitation, which causes thermodynamic equilibrium chemistry to dominate. The highest observed energy efficiencies of 45% indicate that non-equilibrium dynamics had been at play. A novel approach involving additives of low ionization potential to tailor the electron energies to the vibrational excitation regime is proposed.

scholarly journals RF and Microwave Ion Sources Study at Institute of Modern Physics

Plasma ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 332-344
Author(s):  
Qian Y. Jin ◽  
Yu G. Liu ◽  
Yang Zhou ◽  
Qi Wu ◽  
Yao J. Zhai ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Ion Beam ◽  
Ion Beams ◽  
Ion Source ◽  
Negative Ion ◽  
Power Coupling ◽  
Beam Production ◽  
Planar Coil ◽  
Coil Antenna ◽  
Ridged Waveguide

Intense ion beam production is of high importance for various versatile applications from accelerator injectors to secondary ion mass spectrometry (SIMS). For these purposes, different types of ion beams are needed and, accordingly, the optimum plasma to produce the desired ion beams. RF-type plasma features a simple structure, high plasma density and low plasma temperature, which is essential for negative ion beam production. A very compact RF-type ion source using a planar coil antenna has been developed at IMP for negative molecular oxygen ion beam production. In terms of high-intensity positive ion beam production, 2.45 GHz microwave power-excited plasma has been widely used. At IMP, we developed a 2.45 GHz plasma source with both ridged waveguide and coaxial antenna coupling schemes, tested successfully with intense beam production. Thanks to the plasma built with an external planar coil antenna, high O2− production efficiency has been achieved, i.e., up to 43%. With 2.45 GHz microwave plasma, the ridged waveguide can support a higher power coupling of high efficiency that leads to the production of intense hydrogen beams up to 90 emA, whereas the coaxial antenna is less efficient in power coupling to plasma but can lead to attractive ion source compactness, with a reasonable beam extraction of several emA.

scholarly journals Experiments on intense ion beam formation with inhomogeneous electric field

2021 ◽  
Author(s):  
Sergey Vybin ◽  
V. A. Skalyga ◽  
Ivan Izotov ◽  
Sergey Golubev ◽  
Sergey Razin ◽  
...  
Keyword(s):  
Electric Field ◽  
Current Density ◽  
Microwave Plasma ◽  
Ion Beam ◽  
Plasma Heating ◽  
Ion Source ◽  
Ecr Ion Source ◽  
Inhomogeneous Electric Field ◽  
Beam Formation ◽  
Current Densities

Abstract The high efficiency of a new ion beam extraction system with a strongly inhomogeneous electric field has been experimentally demonstrated. Previously, this approach was proposed and analysed numerically by the authors. The experiment was carried out using a pulsed high-current electron-cyclotron resonance (ECR) ion source SMIS 37 with high frequency (37.5 GHz) and high power (100 kW) microwave plasma heating. The accelerating field strength is increased (when compared to a flat or a quasi-pierced geometry) in the plasma meniscus region due to its inhomogeneity. It allows for the increase of the ion acceleration rate and for expansion of the available range of current densities with effective ion beam formation. The experiment demonstrated the main advantages of this approach, such as: a significant decrease in the optimal accelerating voltage for certain values of current density; a possibility of ion beam formation with previously inaccessible current densities; a significant decrease in the ion flux to the puller in non-optimal modes of ion beam formation. Proton beams with a current density of up to 1.1 A cm-2 were obtained for the first time with an ECR ion source.

Sign in / Sign up

Export Citation Format

Share Document