Low energy, ion-induced electron and ion emission from stainless steel: The effect of oxygen coverage and the implications for discharge modeling

Abstract

Multiply charged ion-induced secondary electron emission from metals relevant for laser ion source beam diagnostics Rev. Sci. Instrum. 73, 776 (2002); 10.1063/1.1431704Electron emission from ion bombarded stainless-steel surfaces coated and noncoated with TiN and its relevance to the design of high intensity storage rings Negative ion emission from a stainless steel surface due to positive ion collisions Absolute yields of electrons and negative ions resulting from positive ions impacting stainless steel have been determined as a function of impact energy for clean and oxygen-covered surfaces. Photoelectron emission has been used to monitor the effect of oxygen coverage on the surface work function. The emission of negative ions and electrons has been described with an excitation mechanism similar to that used in the Menzel-Gomer-Redhead model. We illustrate the implications of the present observations for discharge modeling and diagnostics by citing a parallel-plate, rf discharge in oxygen as an example.

Preferential antiferromagnetic coupling of vacancies in graphene onSiO2: Electron spin resonance and scanning tunneling spectroscopy

“…Within five minutes after bombardment, the sample is transferred to another UHV chamber separated from the preparation chamber by a UHV valve and exhibiting p = 10 −8 Pa. The ion flux is calibrated by measuring the current on a steel plate leading to a good estimate, since secondary electron emission has a rate of about 0.01 electrons/ion at 50 eV only and even possible O − sputtering has a rate of only 0.1/ion [63]. The STM measurements are performed with a modified Omicron STM operating at room temperature with the voltage V applied to the sample.…”

Recent advances in dual mode charge compensation for XPS analysis

“…Whilst Cu (II) can reduce under prolonged X‐ray exposure, typically believed to be due to secondary electron emission, the use of the optimised flood gun settings indicates we can mitigate reduction regardless of continued X‐ray exposure. Therefore, it is possible the observed reduction either results from ion‐induced secondary electron emission or via an Auger decay mechanism of the copper centre as proposed for the metal oxides.…”

Polyatomic Ion-Induced Electron Emission (IIEE) in Electrospray Thrusters

“…Measured primary and secondary currents determine the electron emission yield, γ, defined as the ratio between the emitted electron current density and the impinging ion current density. Secondary ion emission can also result from particle impacts and may not be negligible in thruster lifetime estimates, its yield depending greatly upon surface conditions [24,25]. However, given the already large scope and differing physics of IIEE as well as the high detection efficiency of secondary ions [25], secondary ion emission will not be treated in this study, and γ will refer exclusively to secondary electron yield.…”

“…Reliable IIEE measurements from controlled metallic surfaces have typically required both ion-etching and annealing in an ultra-high vacuum (UHV) environment [27][28][29][30] due to the substantial complexity of surfaces generally at the atomic scale. A "technical" stainless steel surface, or a surface not cleaned in UHV conditions [24], typical of electrospray electrodes instead possesses, for example, surface oxides, chemical deposits, and asperities, to name a few complications. Furthermore, as impingement continues a thin film of propellant can accumulate on the grid's surface, substantially altering the subsequent secondary emission.…”