Characteristics of plasma stream evolution in a pulsed plasma accelerator

The time-integrated spectroscopic measurements of argon plasma are carried out to characterize the transient plasma stream produced in a coaxial pulsed plasma accelerator. Transient plasmas produced in these types of devices have a temporal change in density and temperature. The temporal evolution of the plasma stream and its characteristic variation are studied from a time of 50-300 mu s in steps of 50 mu s. Analysis of different spectral lines shows the existence of some metastable states of Ar+ having a long lifetime. The evolution of different Ar+ transitions to metastable and non-metastable lower levels is observed for different time frames. From the Stark broadening and Boltzmann plot method assuming the partial local thermodynamic equilibrium model, the plasma densities and excitation temperatures are estimated. The temporal evolution study shows a decrease in plasma densities from 1.96x10(21) m(-3) at 50 mu s to 1.23x10(20) m(-3) at 300 mu s after the initiation of plasma formation. A reduction in excitation temperature is observed from 0.86 to 0.77eV. Based on the density profile, the estimated energy density of the plasma stream shows a time-dependent decreasing trend from 0.06 to 0.004MJ/m(2) during the observed period. The results may be useful for optimization of the plasma stream in pulsed plasma accelerators concerning its different parameters.

Automated summary

Time-integrated spectroscopic measurements of argon plasma in a coaxial pulsed plasma accelerator revealed the temporal evolution of plasma stream characteristics, including changes in density, excitation temperature, and energy density over time. The study showed a decrease in plasma densities and excitation temperature, as well as a time-dependent decreasing trend in energy density, providing valuable insights for optimizing pulsed plasma accelerators.