Direct observation of particles with energy >10 MeV/u from laser-induced fusion in ultra-dense deuterium

摘要

Nuclear fusion in ultra-dense deuterium D(-1) induced by 0.2 J pulses with 5ns pulse length ejects ions with energies in the MeV range. The ns-resolvedsignal to a collector can be observed directly on an oscilloscope, showing ionsarriving with energies in the range 2-14 MeV u-1 at flight times 12-100 ns,mainly protons from the fusion process and deuterons ejected by protoncollisions. Electrons and photons give almost no contribution to the fastsignal. The observed signal at several mA peak current corresponds to 1x10^13particles released per laser shot and to an energy release > 1 J assumingisotropic formation and average particle energy of 3 MeV as observed. A movableslit close to the laser target gives spatial resolution of the signalgeneration, showing almost only fast ions from the point of laser impact andpenetrating photons from the plasma outside the laser impact point. The initialphoton pulse from the fusion process is observed by a photomultiplier detectoron-line.