Dynamics of Argon Clusters in an Intense Laser Pulse: Bloch-Like Hydrodynamic Model
M. Rusek and A. Orłowski
Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
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Received: May 7, 2004
The dynamics of small (≤55 atoms) argon clusters ionized by an intense, infrared, femtosecond laser pulse is studied using a Bloch-like hydrodynamic model. Evolution of both free electrons and ions formed in the cluster explosion process is examined. Oscillations of the electron cloud in a rare-gas atomic cluster are described as a motion of a fluid obeying Bloch-like hydrodynamic equations. Our theoretical approach includes all possible ionization mechanisms: tunnel (or field) ionization both by an external laser field, and by an internal field due to the space-charge distribution inside the cluster, as well as electron-impact (or collisional) ionization. The results of our simulations are compared both with experimental findings and with predictions of other theoretical models.
DOI: 10.12693/APhysPolA.106.3
PACS numbers: 36.40.-c, 32.80.Rm, 42.50.Hz, 07.05.Tp