Various collector options for MW 170 GHz gyrotrons with electron beam scanning frequencies 100–1000 Hz are analyzed. The distribution of scanning magnetic fields has been calculated for the scanning system being inside the copper collector. The scanning field attenuation due to the skin effect is shown to be the least in current loop systems. Beam tracing of these systems has confirmed the possibility of obtaining an effective length of the beam trace of about 400-500 mm while keeping the specific power density of the falling MW beam within 0.5–0.6 kW/cm2. The power density distribution is shown to vary little under the action of the perturbing external scattered field from controlled thermonuclear fusion (CTF) where it is planned to use these gyrotrons.
|
