Experimental Verification of Magnetron Operation with a Transparent Cathode

Magnetrons are considered to be one of the most efficient sources of high power microwaves. However, the rather slow start of oscillations makes them unattractive for short-pulse applications. At the University of New Mexico (UNM) we proposed a new cathode design, namely the transparent cathode that provides fast start of oscillations in magnetrons [1]. Furthermore, we have been able to demonstrate via 3-dimensional particle-in-cell simulations that the magnetron output characteristic is significantly improved using the transparent cathode [2]. We have successfully modified the short-pulse electron beam accelerator ``SINUS-6'' at UNM that will be used for experimental verification of our simulation results. SINUS-6 has a pulse duration of 16 ns and is now capable of delivering 320 kV and a total current of 13 kA to the magnetron load. Experimental results of magnetron operation with a transparent cathode and solid cathode will be presented. [1] M. Fuks et al, ``Rapid Start of Oscillations in a magnetron with a Transparent Cathode'', Phys. Rev. Lett., vol 95, pp. 205101-1-205101-4, 2005. [2] H. Bosman et al., ``Improvement of the Output Characteristics of Magnetrons Using the Transparent Cathode'', IEEE Trans. Plasma Sci, 34 (4), 606 (2006).