Field Emission Dark Current of Technical Metallic Electrodes

In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration a -500 kV, 250 ns FWHM, pulse will be applied in between two electrodes. Those electrodes should sustain the pulsed field without arcing, must not outgass and must not emit electrons. Ion back bombardment, and dark current will be damageable to the electron source as well as for the low emittance beam. Electrodes of commercially available OFE copper, aluminium, stainless steel, titanium and molybdenum were tested following different procedures including plasma glow discharge cleaning.Comment: 22 pages, 6 tables, 10 figures Vs 2 : graphics more readable, enhanced content Vs 3 : typo correcte

Pulsed direct current magnetron sputtered nanocrystalline tin oxide films

The nanocrystalline tin oxide (SnO2) films were deposited on glass substrates by pulsed magnetron sputtering technique and subsequently annealed from 200 to 500 °C. The structural, microstructural, electrical, and optical properties of as deposited and annealed SnO2 films were studied. The crystallinity degree of the films increased with annealing temperature. Photoluminescence (PL) measurements showed that the emission peaks have low intensity and are positioned at 535 nm (2.31 eV) and 605 nm (2.05 eV) in as deposited SnO2 films. The intensity of PL peak increases sharply with the increasing of annealing temperature. The as deposited films exhibited high electrical resistivity and low optical transmittance. After annealing at 500 °C, the electrical resistivity of the films decreased to the lowest value of 0.015 Ω cm, being the optical transmittance 90%

Optimization of gas injection conditions during deposition of AlN layers by novel reactive GIMS method

In 2011, we proposed a novel magnetron sputtering method. It involved the use of pulsed injection of working gas for the initiation and control of gas discharge during reactive sputtering of an AlN layer (Gas Injection Magnetron Sputtering – GIMS). Unfortunately, the presence of Al–Al bonds was found in XPS spectra of the AlN layers deposited by GIMS onto Si substrate. Our studies reported in this paper proved that the synchronization of time duration of the pulses of both gas injection and applied voltage, resulted in the elimination of Al–Al bonds in the AlN layer material, which was confirmed by the XPS studies. In our opinion the most probable reason of Al–Al bonds in the AlN layers deposited by the GIMS was the self-sputtering of the Al target in the final stage of the pulsed discharge