Coaxial cavity gyrotron with dual rf beam output

Piosczyk, B; Braz, O; Dammertz, G; Iatrou, CT; Illy, S; Kuntze, M; Michel, G; Mobius, A; Thumm, M; Flyagin, VA; Khishnyak, VI; Pavelyev, AB; Zapevalov, VE

dc.contributor.author	Piosczyk, B	en
dc.contributor.author	Braz, O	en
dc.contributor.author	Dammertz, G	en
dc.contributor.author	Iatrou, CT	en
dc.contributor.author	Illy, S	en
dc.contributor.author	Kuntze, M	en
dc.contributor.author	Michel, G	en
dc.contributor.author	Mobius, A	en
dc.contributor.author	Thumm, M	en
dc.contributor.author	Flyagin, VA	en
dc.contributor.author	Khishnyak, VI	en
dc.contributor.author	Pavelyev, AB	en
dc.contributor.author	Zapevalov, VE	en
dc.date.accessioned	2014-03-01T01:13:37Z
dc.date.available	2014-03-01T01:13:37Z
dc.date.issued	1998	en
dc.identifier.issn	0093-3813	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12621
dc.subject	coaxial gyrotron	en
dc.subject	dual rf beam	en
dc.subject.classification	Physics, Fluids & Plasmas	en
dc.subject.other	GHZ GYROTRON	en
dc.title	Coaxial cavity gyrotron with dual rf beam output	en
heal.type	journalArticle	en
heal.identifier.primary	10.1109/27.700770	en
heal.identifier.secondary	http://dx.doi.org/10.1109/27.700770	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	A 140-GHz, 1.5-MW, TE28,16-coaxial cavity gyrotron with a dual rf beam output has been designed, built, and tested. For the first time, the generated rf power has been split into two parts and coupled out through two rf output windows in order to reduce the power loading in the windows, The quasioptical output system is based on a two-step mode conversion scheme. First, the cavity mode TE-28,16 is converted into its degenerate whispering gallery mode TE+76,2 using a rippled-wall mode converter, Then, this mode is transformed into two TEM00 output wave beams. A maximum rf output power of about 950 kW with an output efficiency of 20% has been measured. According to numerical calculations, an rf power above 1.5 MW is expected to be generated in the cavity, Even if all losses are taken into account, a discrepancy between experiment and calculations remains, The power deficit seems to be partly caused by the influence of the stray radiation captured inside the tube, However, the two main reasons are probably an incomplete mode conversion from TE-28,16 to TE+76,2 and a large energy spread of the electron beam due to trapped electrons. An increased amount of captured stray radiation resulted in a reduced stability of operation. A single-stage depressed collector was used successfully, increasing the rf output efficiency from 20% to 29%.	en
heal.publisher	IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC	en
heal.journalName	IEEE TRANSACTIONS ON PLASMA SCIENCE	en
dc.identifier.doi	10.1109/27.700770	en
dc.identifier.isi	ISI:000074686400023	en
dc.identifier.volume	26	en
dc.identifier.issue	3	en
dc.identifier.spage	393	en
dc.identifier.epage	401	en