Formation of stationary and transient spots on thermionic cathodes and its prevention

Detalhes bibliográficos
Autor(a) principal: Almeida, Pedro G. C.
Data de Publicação: 2008
Outros Autores: Benilov, M. S., Cunha, M. D.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10400.13/4527
Resumo: Spots on cathodes of high-pressure arc discharges induced by a rapid increase in the arc current are studied numerically and experimentally. Appearance of stationary and transient spots is analysed in the context of the general pattern of steady-state modes of current transfer to thermionic cathodes and their stability. Transient spots are studied in experiments with COST-529 standard lamps. Modelling and experimental results are in reasonable agreement. A method to prevent formation of transient spots on cathodes of high-pressure arc discharges by means of short negative rectangular current pulses is proposed and validated both numerically and experimentally. Experimental indications are found that the main mechanism of blackening of burners of HID lamps that accompanies appearance of transient cathode spots is evaporation of the cathode material and not sputtering.
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spelling Formation of stationary and transient spots on thermionic cathodes and its preventionArc dischargesStationary and transient spotsThermionic cathodes.Faculdade de Ciências Exatas e da EngenhariaSpots on cathodes of high-pressure arc discharges induced by a rapid increase in the arc current are studied numerically and experimentally. Appearance of stationary and transient spots is analysed in the context of the general pattern of steady-state modes of current transfer to thermionic cathodes and their stability. Transient spots are studied in experiments with COST-529 standard lamps. Modelling and experimental results are in reasonable agreement. A method to prevent formation of transient spots on cathodes of high-pressure arc discharges by means of short negative rectangular current pulses is proposed and validated both numerically and experimentally. Experimental indications are found that the main mechanism of blackening of burners of HID lamps that accompanies appearance of transient cathode spots is evaporation of the cathode material and not sputtering.IOP PublishingDigitUMaAlmeida, Pedro G. C.Benilov, M. S.Cunha, M. D.2022-08-30T14:47:01Z2008-01-01T00:00:00Z2008-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.13/4527engAlmeida, P. G. C., Benilov, M. S., & Cunha, M. D. (2008). Formation of stationary and transient spots on thermionic cathodes and its prevention. Journal of Physics D: Applied Physics, 41(14), 144004. DOI: 10.1088/0022-3727/41/14/14400410.1088/0022-3727/41/14/144004info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-09-05T12:57:51Zoai:digituma.uma.pt:10400.13/4527Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:08:39.370353Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Formation of stationary and transient spots on thermionic cathodes and its prevention
title Formation of stationary and transient spots on thermionic cathodes and its prevention
spellingShingle Formation of stationary and transient spots on thermionic cathodes and its prevention
Almeida, Pedro G. C.
Arc discharges
Stationary and transient spots
Thermionic cathodes
.
Faculdade de Ciências Exatas e da Engenharia
title_short Formation of stationary and transient spots on thermionic cathodes and its prevention
title_full Formation of stationary and transient spots on thermionic cathodes and its prevention
title_fullStr Formation of stationary and transient spots on thermionic cathodes and its prevention
title_full_unstemmed Formation of stationary and transient spots on thermionic cathodes and its prevention
title_sort Formation of stationary and transient spots on thermionic cathodes and its prevention
author Almeida, Pedro G. C.
author_facet Almeida, Pedro G. C.
Benilov, M. S.
Cunha, M. D.
author_role author
author2 Benilov, M. S.
Cunha, M. D.
author2_role author
author
dc.contributor.none.fl_str_mv DigitUMa
dc.contributor.author.fl_str_mv Almeida, Pedro G. C.
Benilov, M. S.
Cunha, M. D.
dc.subject.por.fl_str_mv Arc discharges
Stationary and transient spots
Thermionic cathodes
.
Faculdade de Ciências Exatas e da Engenharia
topic Arc discharges
Stationary and transient spots
Thermionic cathodes
.
Faculdade de Ciências Exatas e da Engenharia
description Spots on cathodes of high-pressure arc discharges induced by a rapid increase in the arc current are studied numerically and experimentally. Appearance of stationary and transient spots is analysed in the context of the general pattern of steady-state modes of current transfer to thermionic cathodes and their stability. Transient spots are studied in experiments with COST-529 standard lamps. Modelling and experimental results are in reasonable agreement. A method to prevent formation of transient spots on cathodes of high-pressure arc discharges by means of short negative rectangular current pulses is proposed and validated both numerically and experimentally. Experimental indications are found that the main mechanism of blackening of burners of HID lamps that accompanies appearance of transient cathode spots is evaporation of the cathode material and not sputtering.
publishDate 2008
dc.date.none.fl_str_mv 2008-01-01T00:00:00Z
2008-01-01T00:00:00Z
2022-08-30T14:47:01Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10400.13/4527
url http://hdl.handle.net/10400.13/4527
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Almeida, P. G. C., Benilov, M. S., & Cunha, M. D. (2008). Formation of stationary and transient spots on thermionic cathodes and its prevention. Journal of Physics D: Applied Physics, 41(14), 144004. DOI: 10.1088/0022-3727/41/14/144004
10.1088/0022-3727/41/14/144004
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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