Title: Generation of Anomalous High Energy Picosecond X-Ray Pulse from Laser-Produced Plasma
Abstract: Dynamical behavior of X-ray emission from laser-produced plasma has been extensively studied up to the power density of 1016W/cm2. It has been observed that the intensities of emitted hard X-ray pulses with picosecond time duration are anomalously enhanced as if it has a threshold laser intensity. Strong anomalies in spatial distribution of emitted X-ray are found out in the direction perpendicular to the plane of laser polarization. Sometimes intense "spots" were created on the X-ray photographic films. These results are attributed to the relativistic effect caused by the electron streaming due to oscillating two stream instability at critical density surface of the plasma.