First Observation of Laser Satellites from Plasma created by High Intensity Laser Pulses
Abstract
When an ion is placed in a strong laser field, new discrete emission lines are predicted to appear. For laser intensities above 10^16 W/cm^2, anti-Stokes scattering and induced two-photon emission produce two lines with nearly equal intensities separated by hbar ω_las from the position of each forbidden transition. In the present work, the 100 ps Janus laser facility was used to irradiate titanium targets at laser intensities near 10^17 W/cm^2. A high resolution (λ/Δ λ > 10000), high luminosity spectrograph with a spherically bent mica crystal was used to observe the emitted K-shell radiation of Ti XII with spatial resolution of 18 μm. Spectra of the He-α and He-β lines with satellites were observed and wavelengths of the various lines were measured with an accuracy of 0.00012 ÅWe observed for the first time laser satellites induced from the 1s2s ^1S_0, 1s3s ^1S0 and 1s3d ^1D2 levels. We also measured the energy of these metastable levels. This process should be taken into account in the interpretation of emission spectra produced in high-intensity pico- and subpicosecond laser-target interactions. *Work conducted in part under the auspices of the US DOE by Lawrence Livermore Laboratory under Contract No. W-7405-Eng-48.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1996
- Bibcode:
- 1996APS..DPP..4R28S