Target irradiation experiments

Target irradiation experiments have been carried out on the Hydra accelerator, operating at powers between 0.15 and 0.3 TW. As listed in Table I, four types of spherical shell targets have been studied: 3 mm diameter, 200 μm and 50 μm wall thickness Au targets; 3 mm diameter, 300 μm wall thickness plastic targets; and 0.85 mm diameter, 10 μm wall thickness Ni targets. When compared to a practical range for 700 keV electrons, the ratio of shell thickness to electron range varied between 0.03 for the Ni targets to 1.5 for the thick walled Au targets. Multiple exposure optical holography was utilized to determine ablator velocity, and a one-dimensional hydrodynamical materials code CHARTD was utilized to model target response and infer beam deposition. Energy deposition varied from 1 TW/gm for thick Au targets up to 8 TW/gm for thin Ni targets, and pusher velocities ranged between 0.5 and 3.5 cm/μsec. Neutron production from D2 and DT filled Ni exploding pusher targets was measured using Ag and Li activation counters and gated scintillator photomultiplier time of flight detectors