SOME STUDIES ON PICOSECOND LASER-PRODUCED PLASMA EXPANDING ACROSS A UNIFORM EXTERNAL MAGNETIC-FIELD

Some characteristics of the picosecond laser produced plasma expanding across an externally applied magnetic field (0.6 T) have been reporte d. Two to three times enhancement in X-ray emission from copper plasma has been observed for the laser intensity range similar to 5 X 10(11) to 5 X 10(12) W/cm(2). The X-ray yield has been found to increase wit h an increase in the magnetic field intensity. Enhancement in X-ray em ission is correlated with confinement of expanding plasma either in ex ternal magnetic field or in high ambient gas pressure. Generation of s ome high-frequency instability and fast ions was also observed in the plasma along with bouncing of plasma near the beta = 1 surface where k inetic pressure of plasma equals magnetic pressure.