Description
posters session.
additional opportunity to discuss posters and more.
When an individual post-like field emitter (modelled as standing on one of a pair of parallel planes) is sufficiently resistive, and current through it sufficiently large, then voltage loss occurs along it. This Poster shows this voltage loss is directly and inextricably linked to a reduction in the field enhancement factor (FEF) at the post apex. A formula relating apex-FEF reduction to this...
In a Vacuum Arc with a Black Body Assembly (VABBA), cathode material is
emitted into a closed chamber formed by the end surface of a water-cooled cylindrical
cathode and a cup shaped refractory anode that is heated by the arc. Material is eroded from
the cathode spots as plasma and MPs. They impinge on the hot anode and are re-evaporated
from it, forming a dense high-pressure...
Many optical elements such as mirror, window, amplifier, and wavelength conversion elements are made from oxide materials. The elucidation of damage threshold and mechanism is indispensable to the development of high-power system. Especially, in high-repetition-rate system, the accumulation of defects such as color center causes the damage.
In this work, we propose a kinetic model including...
Certain adaptations of metal vapor vacuum arcs can be a promising approach as high charge state ion sources for various applications including relativistic heavy ion colliders, heavy ion inertial confinement fusion and with modifications to boron phosphorous as well as for As, and Sb ions for ion implantation for semiconductor manufacturing as well. Two approaches have shown good promise:...
This note suggests improvements in presenting field electron emission (FE) theory. It relates to the so-called principal Schottky-Nordheim (SN) barrier function "v" used in Murphy-Good-type FE theory. I argue that: (1) we should separate the mathematics of v from its applications in tunnelling theory; (2) we need to change the independent variable used; and (3) we can improve the notation.
It...
For the development of high gradient accelerating structures of CLIC and other similar machines it is vital to understand the mechanism of vacuum breakdown. Previous investigations into the phenomena were performed through lengthy and costly RF conditioning of accelerating structures and cells. In an attempt to more efficiently investigate the effects of different materials and conditioning...
Surface defects are thought to play an important role in vacuum breakdowns. Possible nanoprotrusions can significantly enhance the electric field, leading to increased field emission, atom evaporation, and eventually arcing. Atomic scale simulations are very useful in studying dislocation behaviour and surface defects. However, the main material of interest, copper, is in practice covered by...
In order to investigate the evolution of species type during a vacuum breakdown, a spectroscope with a ICCD was adopted to detect the spectrum during the breakdown, and the state of species can be deduced from the spectra. A tip-to-tip gap was installed in a vacuum chamber; the gap distance varied from 0.5 mm to 3 mm; and copper and tungsten were chosen as the cathode and anode material,...
Fowler-Nordheim (FN) theory uses "smooth-surface" conceptual emitter models. It is not accurate theory because it disregards the existence of atoms, and takes the emitter surface charge as confined to an infinitesimally thin classical layer. Developing fully self-consistent field emission theory will be intensively difficult, and has received limited attention. It could take 50-100 years....
