Experimental verification of the advantages of the transparent cathode in a short-pulse magnetron

Increased efficiency and faster turn-on in magnetrons using the transparent cathode

“…PIC simulations [5] of the well-known relativistic A6 magnetron [2] with applied voltage V = 350 kV and voltage rise time € τ V =10 ns show (Fig. 3) that using a transparent cathode significantly reduces the time of achievement of the maximum radiation power P and increases the power (and thus the efficiency) by over 16% at least, in comparison with using a solid cathode.…”

“…PIC simulations [5] with this magnetron (using UNM's SINUS-6 electron beam accelerator's voltage waveform with an applied voltage V = 260 kV in a 9 ns FWHM pulse as shown in Fig. 4, left) shows that this voltage pulse is too short for the development of oscillations when a solid cathode is used, resulting in only a small radiation power and a complicated spectrum (Fig.…”

“…Left: anode block of the A6 magnetron with anode radius Ra= 2.11 cm, cavity depth 2 cm, and axial length 7.2 cm; right: graphite solid and transparent cathodes used in experiments[5].…”

Hysteresis dependence of mode separation on time-varying applied voltage in a magnetron with diffraction output

“…Contribution of (3) in (2) depends on the sign of dU/ dt. Therefore, a shift of regions (6) and the boundary voltage U 0 is different for increasing and decreasing voltages. Naturally, the boundary regions will be different for different shapes of the voltage pulse as well.…”

“…1 left) with modified diffraction output [3] driven by a transparent cathode [4][5][6] it is found that this magnetron can operate with a high efficiency 'tJ e that is comparable to conventional magnetrons and, as a consequence, with long lifetime (since fewer electrons have unspent energy that is dumped on the magnetron electrodes, which lead to their overheating and erosion).…”