Spectral/target activity of short lived radio isotope in pulsed plasma accelerator.
Accelerated deuteron spectra from magnetic spectrometry and graphite bombardment by such deuterons were used to produce short-lived radionuclides in NX2 plasma focus. The experiments show one order of magnitude difference between the activity generated by these techniques. The average activity of NX2 is 5.2 kBq and the highest activity for the best shot is about 40 kBq.
Neutron and high energy deuteron anisotropy investigations in plasma focus device
The anisotropies of neutron and high energy deuteron emissions from the NX2 plasma focus device [M. V. Roshan et al., Phys. Lett. A 373, 851 (2009)] are studied. The nuclear activation of graphite targets is used to measure the fluences of high energy deuterons in the axial and radial directions. Two bismuth germanate scintillation detectors connected to multichannel analyzer systems are used for the detection of 511 keV gamma rays resulting from positron annihilation in the two targets. In addition, fast neutron activation detectors are employed to measure the axial and radial fluences of fusion neutrons. These detection systems are calibrated using the simulation code MCNPX [L. S. Waters et al., AIP Conf. Proc. 896, 81 (2007)]. Two distinct regimes of neutron and deuteron anisotropies are observed for the NX2 device. For deuterium gas pressures below 10 mbar, the neutron anisotropy increases with increasing pressure, while the overall neutron yield remains low. For gas pressures of 10–14 mbar, the neutr...
Operation of a plasma‐focus device with D2 and He3
Two plasma‐focus devices at the Lawrence Livermore Laboratory, the B Division device (BDPF), with a stored energy of 73 kJ at 18 kV, and the Physics Department device (PDPF), with a stored energy of 67 kJ at 20 kV, were operated with various mixtures of D2 and He3. The purpose of the experiments was to evaluate the D‐D/D‐He3 yield ratio as a diagnostic tool for determining the plasma ion temperature. Measurements were made in the high‐pressure mode (total pressure of 4.0 Torr for the BDPF, 7.5 Torr for the PDPF), where previous measurements using carbon activation showed no significant ion acceleration to energies above the 330‐keV carbon (d,n) reaction threshold. The yield from the D(d,n)He3 reaction was determined from measurements of the total neutron yield using the standard silver‐activation technique. The yield from the He3(d,p) He4 reaction was determined by measuring the reaction‐product protons by copper activation. The Cu anode insert from the center electrode was analyzed for γ activity followi...