Weibel instability by ultraintense laser pulses

Particle-in-cell (PIC) simulations show that an anisotropic electron veloci ty distribution is demonstrated by ultraintense laser pulses in underdense plasmas. Recently, it is reported that the anisotropy has been experimental ly demonstrated in laser-produced plasmas. It is also pointed out that giga gauss magnetic fields are generated by ultraintense laser pulses. We have a lready published that the Weibel-type electromagnetic instabilities can be theoretically excited by electrons in a velocity distribution with anisotro pic temperature. If these electromagnetic waves are excited, the target may have a possibility not only to give rise to a new type of energy loss mech anism but also to influence the implosion characteristics. In this work, we present PIC simulation of the interaction of ultraintense laser pulses wit h plasmas. Intense self-generated magnetic fields is produced by the mechan ism of Weibel instability in underdense plasmas.