Study of production of thermonuclear neutrons during laser irradiation of conical targets

In studies on the initiation of thermonuclear reaction in a conical target under the action of a laser beam, the variation of the total neutron yield was measured as a function of deuterium pressure, shell thickness, target geometry, and laser pulse energy. The velocity of the target shell was measured from the Doppler shift of the reflected radiation. The conical targets were extruded in zinc with apex angles of 30 and 60 degrees. For 30-deg target with shell thickness of 3 microns and deuterium pressure of 0.5 atm, a maximum of 50,000 neutrons per pulse was obtained for an 80-J pulse. Numerical calculations give a value of about 10% for the efficiency of transfer of laser energy to the deuterium plasma.