Formation of stationary and transient spots on thermionic cathodes and its prevention
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , |
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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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 |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799129954747678720 |