Accession Number : AD0427895


Title :   RESEARCH ON MICROWAVE WINDOW MULTIPACTOR AND ITS INHIBITION.


Descriptive Note : Quarterly progress rept. no. 5, 1 Jul-30 Sep 63,


Corporate Author : EITEL-MCCULLOUGH INC SAN CARLOS CA


Personal Author(s) : Hayes, Raymond


Report Date : 30 Sep 1963


Pagination or Media Count : 28


Abstract : Research concerns a study of multipactor effects at waveguide windows used with high power microwave tubes which will lead to practical methods for preventing or eliminating multipactor. Methods of reducing multipactor include evaporated titanium coatings, sputtered titanium monoxide coatings and grooves on fused silica windows without coatings. Multipactor discharges at beryllia and alumina windows operating at 2700 mc/s were suppressed by evaporated coatings of titanium. Coatings with resistivities in the range 10 to the 7th power to 10 to the 10th power ohms per square were tested satisfactorily. A weak discharge may occur during the initial operation of coated windows but this disappears after a period of operation. Arcing at the ceramic-metal seal limited the peak power dissipated in the window test units; this occurred at about 25 mw equivalent transmitted power. Coated windows tested under high average power showed no multipactor. A coated alumina window cracked due to thermal stresses at an equivalent transmitted power of 103 kw average and 10.3 mw peak. A beryllia-coated window operated satisfactorily up to 260 kw average and 13 mw peak equivalent transmitted power without failure. (Author)


Descriptors :   WAVEGUIDE WINDOWS , RADIOFREQUENCY POWER , TITANIUM , TITANIUM COMPOUNDS , SILICON COMPOUNDS , OXIDES , DISKS , ELECTRICAL RESISTANCE , THERMAL STRESSES , SURFACE PROPERTIES , AROMATIC HYDROCARBONS


Distribution Statement : APPROVED FOR PUBLIC RELEASE