Title :
Dual anode electron gun & PPM focusing for Ka-Band TWT
Author :
Sharma, RK ; Choudhury, AR ; Sharma, SM ; Arya, S. ; Bera, A. ; Srivastava, V.
Author_Institution :
MWT Div., Council of Sci. & Ind. Res. (CSIR), Pilani, India
Abstract :
In this paper, a low perveance (0.14 mup) convergent electron gun with dual anodes has been designed using codes EGUN (2D), TRAK (2D), OPERA (3D) and OMNITRAK (3D) for Ka-band helix (TWT) for space applications. Pierce type electron gun with an electrically isolated beam forming electrode (BFE), control anode (A1) and an ion barrier anode (A2) has been opted. An M-type dispenser cathode with low cathode emission loading (~1.0 Amp/cm2), has been selected to ensure the desired long life of more than 10 years and high reliability. To further enhance the life and reliability, non-evaporating type SAES ST-175 getter, has been incorporated in the gun assembly. Application of BFE negative bias of the order of 10 to 20 volts with respect to the cathode is used to achieve the desired beam transmission in the CW tube.
Keywords :
anodes; cathodes; electron guns; getters; millimetre wave tubes; permanent magnets; reliability; travelling wave tubes; CW tube; EGUN code; Ka-band helix TWT; M-type dispenser cathode; OMNITRAK code; OPERA code; PPM focusing; Pierce type electron gun; TRAK code; beam transmission; cathode emission loading; control anode; dual anode electron gun; electrically isolated beam forming electrode; gun assembly; ion barrier anode; low perveance convergent electron gun; nonevaporating type SAES ST-175 getter; periodic permanent magnet; reliability; space applications; Anodes; Assembly; Cathodes; Electrodes; Electron beams; Geometry; Magnetic confinement; Magnetic flux; Shape control; Solid modeling;
Conference_Titel :
Vacuum Electronics Conference, 2009. IVEC '09. IEEE International
Conference_Location :
Rome
Print_ISBN :
978-1-4244-3500-5
Electronic_ISBN :
978-1-4244-3501-2
DOI :
10.1109/IVELEC.2009.5193514
