Acceleration of Hydrogen Ions up to 30 MeV and Generation of 3x10$^{12}$ Neutrons in Megaampere Deuterium Gas-Puff Z-Pinch*

Fusion neutrons were produced with a deuterium gas-puff z-pinch on the GIT-12 generator at the Institute of High Current Electronics in Tomsk. The peak neutron yield from DD reactions reached $Y_{n}=(2.9\pm 0.3)\times 10^{12}$ at 100 $\mu$g/cm linear mass density of deuterium, 700 ns implosion time and 2.7 MA current. Such a neutron yield means that the scaling law of deuterium z-pinches $Y_{n}\propto I^{4}$ was extended to 3 MA currents. The further increase of neutron yields up to $(3.7\pm 0.4)\times 10^{12}$ was achieved by placing a deuterated polyethylene catcher onto the axis. Maximum neutron energies of 15 and 22 MeV were observed by radial and axial nToF detectors, respectively. A stack of CR-39 track detectors showed up to 40 MeV deuterons (or 30 MeV protons) on the z-pinch axis. Since the energy input into plasmas was 70 kJ, the number of DD neutrons per one joule of stored plasma energy exceeded the value of $5\times 10^7$. This value implies that deuterium gas-puff z-pinches belong to the most efficient plasma-based sources of DD neutrons.