The University of Southampton
University of Southampton Institutional Repository

A model for hollow cathode surface work function evolution

A model for hollow cathode surface work function evolution
A model for hollow cathode surface work function evolution
In this paper a model to predict the evolution with time of the surface work function of an hollow cathode insert will be presented. The processes involved in BaO deposition and desorption on the surface is described and quantified using chemical data present in the literature. The model is compared with test results from the ELT NSTAR cathode. Predictions obtained from the model have been found to be qualitatively in agreement with the expectations and conservative, model predictions always overestimating the increases in work function with time. An explanation of this has been given noting that all the assumption made in the model tend to overestimate the desorption rates hence producing conservative estimate of the cathode lifetime. Possible ways to improve the model accuracy will be the development of an ignition model and the coupling of the model presented in this paper with a plasma model to take into account the effect that a change in the emission characteristics of the insert surface will produce on the cathode plasma.
hollow cathode, work function, hollow cathode lifetime, barium oxide depletion
1973-7459
Coletti, Michele
f99567c2-8fab-42dd-9e25-c3f69495667f
Gabriel, S.B.
ac76976d-74fd-40a0-808d-c9f68a38f259
Coletti, Michele
f99567c2-8fab-42dd-9e25-c3f69495667f
Gabriel, S.B.
ac76976d-74fd-40a0-808d-c9f68a38f259

Coletti, Michele and Gabriel, S.B. (2008) A model for hollow cathode surface work function evolution. International Review of Aerospace Engineering, 1 (6).

Record type: Article

Abstract

In this paper a model to predict the evolution with time of the surface work function of an hollow cathode insert will be presented. The processes involved in BaO deposition and desorption on the surface is described and quantified using chemical data present in the literature. The model is compared with test results from the ELT NSTAR cathode. Predictions obtained from the model have been found to be qualitatively in agreement with the expectations and conservative, model predictions always overestimating the increases in work function with time. An explanation of this has been given noting that all the assumption made in the model tend to overestimate the desorption rates hence producing conservative estimate of the cathode lifetime. Possible ways to improve the model accuracy will be the development of an ignition model and the coupling of the model presented in this paper with a plasma model to take into account the effect that a change in the emission characteristics of the insert surface will produce on the cathode plasma.

Text
IREASEdeposition.docx - Author's Original
Restricted to Repository staff only
Request a copy

More information

Published date: December 2008
Keywords: hollow cathode, work function, hollow cathode lifetime, barium oxide depletion
Organisations: Astronautics Group

Identifiers

Local EPrints ID: 156153
URI: http://eprints.soton.ac.uk/id/eprint/156153
ISSN: 1973-7459
PURE UUID: 6f8e792c-7fbc-497f-8411-722a97991f4e

Catalogue record

Date deposited: 01 Jun 2010 14:44
Last modified: 16 Sep 2020 16:39

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×