Measured performance of magnetron injection guns for gyrotrons
Magnetron injection guns (MIGs) are a principle component in gyrotrons and gyroklystrons. The performance of the RF device critically depends on the performance of the MIG that provides the electron beam. Unfortunately, recent measurements indicate that MIGS often generate asymmetrical electron beams that can adversely impact the operation of the RF source. This presentation will describe the measurement facility and provide results from recent tests.
Experimental study of gyrotron efficiency enhancement by improvement of electron beam quality
The methods for suppressing parasitic low- frequency oscillations (LFOs) have been applied to improve electron beam quality in a 4-mm 100-kW gyrotron. In the conditions of suppressed LFOs and of high cathode emission uniformity, the stable operation of this gyrotron at pitch factor values high than 1.5 has been achieved. As a result, the efficiency of the gyrotron at the main TE12,3 mode has been increased from 32 % (corresponds to the designed regime with pitch factor of 1.28) up to 42 %.
Effects of Equipment Dimensions on Liquid Mixing Time of Bubble Column with Draft Tube
The liquid mixing time of a bubble column with a draft tube is experimentally studied. The diameter and height of the column, the diameter and length of the draft tube, and the mode of sparging gas were changed and the liquid mixing time was measured.The lengths of bottom and top clearances have significant effects on the liquid mixing time. The liquid mixing time increases with increasing column aspect ratio of height to diameter. The liquid mixing time of the bubble column with a draft tube is longer than that of a standard bubble column when the column aspect ratio is relatively high. The liquid mixing time has a minimum when the diameter ratio of draft tube to column is 0.5 to 0.6. These effects of equipment dimensions are expressed by an equation. In the experiment using different solutions, the liquid mixing time becomes shorter with increasing liquid surface tension, or with increasing liquid viscosity.