Collimation of laser-induced high energy density electrons in imploded cylinder plasmas

We have studied propagation of high energy density electrons in long dense plasmas interacted with ultra-intense laser light. The experiments have been carried out with implosion of a cone attached hollow cylinder target. Ultra-intense laser light with an energy of 120J and a pulse duration of 1ps has been injected into the cone target to heat the imploded cylindrical imploded dense plasmas with the energetic electrons generated at the cone tip. Heating of the imploded plasma has been proved with measurements of thermal neutrons to be $2\times 10^5$ indicating efficient coupling of 15-20{\%} of the laser energy. The results imply that collimation of the high energy density electrons in the cylindrical imploded plasma with a length of 300$\mu $m. PIC simulations also predict the collimation of the electrons in the long dense plasmas with a magnetic field induced by spatial gradient of resistivity due to the temperature gradient.