• J A Chakera

Articles written in Pramana – Journal of Physics

• Study of $2\omega$ and $3/2\omega$ harmonics in ultrashort high-intensity laser plasma interaction

An experimental study is presented on measurements of optical spectrum of the laser light scattered from solid surface irradiated by Ti:sapphire laser pulses up to an intensity of $1.2 \times 10^{18}$ W cm-2. The spectrum has well-defined peaks at wavelengths corresponding to $2\omega$ and $3/2\omega$ radiations. The spectral features vary with the laser intensity and show blue-shift with increasing laser intensity. At a constant laser fluence, the spectrum is red-shifted with increasing laser pulse duration. The observed results are explained in terms of the density scale length variation of the plasma and laser chirp.

• Spectral analysis of K-shell X-ray emission of magnesium plasma produced by ultrashort high-intensity laser pulse irradiation

Spectral analysis of K-shell X-ray emission of magnesium plasma, produced by laser pulses of 45 fs duration, focussed up to an intensity of ∼1018 W cm-2, is carried out. The plasma conditions prevalent during the emission of X-ray spectrum were identified by comparing the experimental spectra with the synthetic spectra generated using the spectroscopic code Prism-SPECT. It is observed that He-like resonance line emission occurs from the plasma region having sub-critical density, whereas K-𝛼 emission arises from the bulk solid heated to a temperature of 10 eV by the impact of hot electrons. K-𝛼 line from Be-like ions was used to estimate the hot electron temperature. A power law fit to the electron temperature showed a scaling of $I^{0.47}$ with laser intensity.

• # Pramana – Journal of Physics

Current Issue
Volume 92 | Issue 6
June 2019