Magnetized plasma accelerator

The investigation of the dynamics of coaxial plasma acceleratorsystem for its use as a source of microwave radiation in gyrotron mode isof interest. A simulation model of microwave emissions of gyrotron typehas been designed and was in agreement with experimental results. Thefindings of this study showed that the emission of microwave has astarting condition, which is markedly depends on sheath velocity ofrotation around the axis of discharge. i.e. it depends on gas density anddriving Lorentz force.The introduction of a. magnetization coil provides a strong axialmagnetic field driving a radial force, which in turn acts upon the coaxialaccelerator current sheath and forces it to rotate around the axis ofdischarge electrodes. As a result of the current sheath fast rotation insidethe magnetic field, wave emission in the range of microwave frequenciesis produced. This hypothesis is investigated experimentally on twoaccelerator discharge chambers having contrast aspect ratios. Theoreticalmodeling describing this wave emission as a result of current sheathrotation around the axis is analyzed and comparison of the model resultswith experimental results is illustrated.The validity of the Lee simulation model for coaxial dischargegeometries IS investigated: experimentally on the two electrodeconfigurations (apparatus A and apparatus B). The results ofphotomultiplier tubes detection of the time of arrival of luminous area ofthe current sheath are compared with the simulated results. The simulatedsheath dynamics model results are used in theoretical representation ofthe wave emission described in the derived analytical model. Results ofthe model showed a time-band of wave emission for case of 3-cm 10-GHz waves in the microwave region occurring at ranges of chargingvoltage and gas p.essure.Experimental results of 3-cm 1 O-GHz wave emission for inspectedranges of charging voltage and gas pressure are compared with theoreticalresults, showing that experimental results of time of occurrence of waveemission are In agreement with results calculated from the derivedanalytical model.