Selective Deuteron Acceleration using Target Normal Sheath Acceleration

It has been known for more than a decade that surface contaminants from a thin foil will be accelerated to multi-MeV energies after irradiation with an ultra-intense laser. The versatility of an ion beam for the generation of neutrons can be improved by tailoring which ions are accelerated. Nominally, the dominant species accelerated is the lightest present on a target surface typically contaminated with hydrocarbons and water: protons. This work elucidates a method of in-situ cryogenic coating of heavy ice on ultra-intense laser targets and experimental confirmation of the dominant acceleration of ∼ MeV deuterons. 1D pseudo-Lagrangian calculations investigating the initial stages of ion acceleration with various levels of surface contamination are also presented.;The first successful demonstration of selective deuteron acceleration by target normal sheath acceleration (TNSA), in which the normally dominant contaminant proton and carbon ion signals are suppressed by orders of magnitude relative to the deuteron signals is reported. Using a laser pulse with 0.5 J, 120 fs duration, and ∼5 1018 W/cm2 mean intensity, the deuterons originating from a surface layer of heavy ice with energies up to 3.5 MeV comprised > 99% of the recorded ion signal.;The design, calibration, and implementation of a Thomson parabola spectrometer (TPS) to measure the target normal ion spectra is presented. In addition to estimations of the target coating and contamination rates, the effect of contamination thickness is modeled presented. Analytic calculations predicting characteristics of various neutron sources utilizing this deuteron source are presented.