Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or nonstationary with cold cathodes (cathodic arcs). A brief review on cathodic arc properties serves as the starting point to better understand arcing phenomena in sputtering. Although arcing occurs in both me...

In their rocksalt structure, rare-earth monosulfides offer a more stable alternative to alkali metals to attain low or negative electron affinity when deposited on various III-V and II-VI semiconductor surfaces. In this article, the authors first describe the successful deposition of lanthanum monosulfide via pulsed laser deposition on Si and MgO substrates. These thin films have been character...

A method is described for mapping the plasma parameters nearby a hollow cathode using a high speed positioning system and a segment-shielded electrostatic probe. Contour maps of plasma density, plasma potential, and electron temperature are presented for wide ranges of discharge current (2 20 A) and xenon flow rate (1.5 – 4.5 sccm). The contour maps are constructed from the analysis of 320 I-V ...

High-efficiency polymer light-emitting diodes were fabricated by inserting a layer of nonionic neutral surfactant between the electroluminescent (EL) layer and the high-work-function aluminum cathode via spin coating. It was found that both the poly(ethylene glycol)- and poly(propylene glycol)-based surfactants as well as their copolymers can all demonstrate similar performance enhancement. Dev...

The [O] [H] functionalization of carbon nanotube (CNT) was studied using oxygen–hydrogen (O2–H2) gas mixture direct current (DC) glow discharge plasma technique for cathode/CNT-anode separation of 0.10 ± 0.01 cm. O2 and H2 were fixed at flowrate of 10.0 ml/min in order to obtain gas mixture ratio of 1:1. During the (O2–H2) gas mixture DC glow discharge, current–voltage (I–V) characteristic of g...

Sequential two-step electron tunneling from nanoparticles has been studied from a transport point of view. A steady-state balance equation for the partial electron currents is derived and solved to obtain the stationary level occupancy, which leads to the overall tunneling current as a function of the applied field. Our model explains the steplike features observed in high field tunneling exper...

A comparison of electron beam parameters from a 1.6 cell S-band rf gun with Cu and Mg cathode at the SLAC Gun Test Facility are reported. The lower work function of Mg compared to Cu theoretically increases the quantum efficiency for a fixed laser wavelength and also increases the thermal emittance. Slice emittance measurements at low charge (15 pC) set an upper limit on the thermal emittance o...

From the prospect of the high average current electron injectors, the most important advantage of the fieldemission cathodes is their capability to generate very large current densities. Simulation of field-emission cathodes is complicated by the large range of spatial dimensions: from sub-micron scale, for a single field-emission tip, to millimeter scale, for a field-emitter array. To overcome...

The stability of the photo injector is a key issue for the successful operation of linac based free electron lasers. Several types of jitter can impact the stability of a laser driven RF gun. Fluctuations of the RF launch phase and the cathode laser energy have significant influence on the performance of a high brightness electron source. Bunch charge measurements are used to monitor the stabil...