Abstract
We report the first interferometric observations of the dynamics of electron-ion cavitation of relativistically self-focused intense 4 TW, 400 fs laser pulse in a He gas jet. The electron density in a channel 1 mm long and 30 μm in diameter drops by a factor of approximately 10 from the maximum value of ∼8×1019 cm-3. A high radial velocity of the plasma expansion, ∼3.8×108 cm/s, corresponding to an ion energy of about 300 keV, is observed. The total energy of fast ions is estimated to be 6% of the laser pulse energy. The high-velocity radial plasma expulsion is explained by a charge separation due to the strong ponderomotive force. This experiment demonstrates a new possibility for direct transmission of a significant portion of the energy of a laser pulse to ions.
| Original language | English |
|---|---|
| Pages (from-to) | 828-834 |
| Number of pages | 7 |
| Journal | JETP Letters |
| Volume | 66 |
| Issue number | 12 |
| DOIs | |
| State | Published - 1997 |
| Externally published | Yes |
Funding
The authors would like to acknowledge Dr. S. Pikuz for useful discussion. This work was supported by NSF PHY 972661, NSF STC PHY 8920108, DOE/LLNL subcontract B307953, and the Russian Fund for Fundamental Research (Grants 96-02-16707-a and 96-02-16165-a).