Plasma dynamics during relativistic S-band magnetron operation

Results of a time- and space-resolved spectroscopic research studies of an S-band relativistic magnetron generating 1.5 X 10(8) W microwave power at f=2950 MHz, powered by a linear induction accelerator (450 W, 4 kA, 150 ns), are presented. The cathode plasma electron density and temperature were obtained by analyzing H(alpha) and H(beta) hydrogen Ballmer series and carbon C II and C III ion spectral lines and the results of collision radiative modeling. It was shown that the microwave generation is accompanied by a significant increase in plasma density and ion temperature, up to similar to 5 X 10(16) cm(-3) and similar to 8 eV, respectively. The plasma electron temperature was found to be similar to 8 eV. It was shown that the plasma expansion velocity in the axial direction reaches similar to 10(7) cm/ s and does not exceed similar to 2 X 10(5) cm/s in the radial direction. In addition, it was shown that the plasma is not uniform and consists of separate plasma spots whose number increases during the accelerating pulse. Estimates of the plasma transport parameters and its interaction with microwave radiation are also discussed. (c) 2008 American Institute of Physics.