Related papers: Alternative Model of Space-Charge Limited Thermion…
We show that ion trapping in virtual cathodes can raise the transmitted current of emitted electrons much closer to the full emission than is predicted by theories without trapped ions. The transmitted current is controlled by the well…
Space-charge-limited (SCL) current density for time-invariant injection (under long-pulse condition) via the diode cathode is the maximum transportable density, while it can be leveraged higher when the injection pulselength becomes shorter…
The space charge limit (SCL) of emission from photocathodes sets an upper limit on the performance of both high- and low-field electron guns. Generally, one is forced to strike a compromise between the space charge limit and the cathode's…
Conventionally, space-charge (SC) limited current density is defined as the maximal cur- rent density allowed to traverse a diode under a DC voltage when a time-invariant flow is injected from the cathode. In this work, we study the SC…
An approximate analytic theory is developed and implemented numerically for calculating the space charge limited current and electric field of a thin cylindrical beam or current sheet between two wide parallel electrodes. The flow is…
The maximum current that can be transported across a vacuum diode is limited by forces arising due to space charge. In a planar diode configuration, the space charge limited (SCL) current density from a planar emitting patch is given by the…
An independent control of the flux and energy of ions impacting on an object immersed in a plasma is often desirable for many industrial processes such as microelectronics manufacturing. We demonstrate that a simultaneous control of these…
Electron emission from the boundary is ubiquitous in capacitively coupled plasma (CCP) and precipitates nonnegligible influences on the discharge properties. Here we present the PIC-MCC simulation of an Ohmic-dominant heating mode of…
The electron sheath is a particular electron-rich sheath with negative net charges where plasma potential is lower than the biased electrode. Here an improved understanding of electron sheath theory is provided using both fluid and kinetic…
Contemporary models of bounded plasmas assume that the target plasma electron temperature far exceeds the temperature of the cold electrons emitted from the target, T_emit. We show that when the sheath facing a collisional plasma becomes…
We use computational simulations to study the electron emission and propagation in planar vacuum diodes. We show how space-charge affects thermionic emission from cathodes with two different values of work function that form a checkerboard…
A one-dimensional (1D) model has been constructed to study the transition of the time-dependent ultrafast laser photo-electron emission from a flat metallic surface to the space charge limited (SCL) current, including the effect of…
Leading edges of hypersonic vehicles can reach temperatures greater than 2000 {\deg}C, and radii of curvature smaller than 1 cm, at which thermionic emission (also known as electron transpiration) can play a significant role in cooling the…
We study the quantum nature of current through plasma-probe junction from the viewpoint of the metal probe. The intrinsic material properties of the metal and their influence on the nature of the observed current are theoretically worked…
Electron transpiration cooling (ETC) can reduce aerothermal loads on sharp hypersonic leading edges, but its performance is governed by whether thermionically emitted electrons escape the hot surface or return as cathode-directed backflow.…
The traditional generalized Ohm's law in MHD do not explicitly present the relation of electric currents and electric fields in fully ionized plasma, and lead to some unexpected concepts, such as "the magnetic frozen-in plasma", magnetic…
This paper proposes a model that expands Godyak's collisional sheath model to the case of hot electrodes (anode or cathode) with thermionic electron emission. In the model, the electrodes are assumed to be made from refractory metals and,…
Drift space is a region free from externally applied fields. It is an important part of many devices involving charged particle beams. The space charge effect imposes a limit on the current that can be transported through a drift space. A…
We consider the steady state limiting current that can be carried by an infinite periodic array of thin electron sheets spaced by period p in a planar diode of gap voltage V and gap separation d. Our primary assumptions are (1) electron…
Space Charge Limited Current (SCLC) based conduction has been identified for PCMO-based RRAM devices based on the observation that $I \propto V^{\alpha}$ where $\alpha \approx 2$. A critical feature of the IV characteristics is a sharp rise…