TY - JOUR
T1 - Electron densities and energies of a guided argon streamer in argon and air environments
AU - Hübner, S.
AU - Hofmann, S.
AU - Van Veldhuizen, E. M.
AU - Bruggeman, P. J.
PY - 2013/12/1
Y1 - 2013/12/1
N2 - In this study we report the temporally and spatially resolved electron densities and mean energies of a guided argon streamer in ambient argon and air obtained by Thomson laser scattering. The plasma is driven by a positive monopolar 3.5 kV pulse, with a pulse width of 500 ns and a frequency of 5 kHz which is synchronized with the high repetition rate laser system. This configuration enables us to use the spatial and temporal stability of the guided streamer to accumulate a multitude of laser/plasma shots by a triple grating spectrometer equipped with an ICCD camera and to determine the electron parameters. We found a strong initial ne-overshoot with a maximum of 7 × 1019 m-3 and a mean electron energy of 4.5 eV. This maximum is followed by a fast decay toward the streamer channel. Moreover, a 2D distribution of the electron density is obtained which exhibits a peculiar mushroom-like shape of the streamer head with a diameter significantly larger than that of the emission profile. A correlation of the width of the streamer head with the expected pre-ionization channel is found.
AB - In this study we report the temporally and spatially resolved electron densities and mean energies of a guided argon streamer in ambient argon and air obtained by Thomson laser scattering. The plasma is driven by a positive monopolar 3.5 kV pulse, with a pulse width of 500 ns and a frequency of 5 kHz which is synchronized with the high repetition rate laser system. This configuration enables us to use the spatial and temporal stability of the guided streamer to accumulate a multitude of laser/plasma shots by a triple grating spectrometer equipped with an ICCD camera and to determine the electron parameters. We found a strong initial ne-overshoot with a maximum of 7 × 1019 m-3 and a mean electron energy of 4.5 eV. This maximum is followed by a fast decay toward the streamer channel. Moreover, a 2D distribution of the electron density is obtained which exhibits a peculiar mushroom-like shape of the streamer head with a diameter significantly larger than that of the emission profile. A correlation of the width of the streamer head with the expected pre-ionization channel is found.
UR - http://www.scopus.com/inward/record.url?scp=84892668233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892668233&partnerID=8YFLogxK
U2 - 10.1088/0963-0252/22/6/065011
DO - 10.1088/0963-0252/22/6/065011
M3 - Article
AN - SCOPUS:84892668233
SN - 0963-0252
VL - 22
JO - Plasma Sources Science and Technology
JF - Plasma Sources Science and Technology
IS - 6
M1 - 065011
ER -