Short pulse radiation excited by the short laser pulse and magnetized plasma interaction

Abstract

Summary form only given, as follows. Theories and experiments have shown that plasma is a capable medium to convert different initial energies to coherent radiation. In this paper radiation from magnetized wakes, excited by the interaction of ultrashort and high intensity laser pulse and magnetized plasma, known as Cherenkov radiation, have been studied experimentally. Wakefields are excited by a mode locked Ti:sapphire laser beam operating at 800 nm wavelength with the pulse width of 100 fs (FWHM) and maximum energy of 100 mJ per pulse with 10 Hz repetition rate. External DC magnetic field of strength between 0 to 8 kG is applied at the interaction region normal to the direction of laser pulse propagation. The frequency of the emitted radiation with pulse width of 200 ps is in the millimeter wave range up to 0.2 THz., close to the plasma frequency. The effect of DC magnetic field strength in the intensity of the signal is observed. Also polarization and spatial distribution of the emitted radiation are measured. The radiation is polarized in the direction normal to the DC magnetic field and propagates mainly in the forward direction as is expected from the theory.