4 research outputs found
Neutron emission parameters from the collapse of the condensed Z-pinch
The parameters of neutron emission from the neck of the condensed Z-pinch, were measured at an S-300 installation (2 MA, 100 ns). Profiled loads with central parts made from microporous deuterated polyethylene (with a density of 100 mg/cm3) were used in the experiments. Neutron emission parameters were measured by the time-of-flight (TOF) method. Neutrons were registered using four flight bases with 10 scintillation detectors which were placed at two axial and two radial directions. It was found that the mean neutron energy, determined by the TOF method, turned out to be anisotropic. The average energy of neutrons emitted along the axis towards the cathode, was shifted to higher energy (2.6-2.8 MeV) and the average energy of neutrons emitted towards the anode, was shifted to lower energy (2.1-2.3 MeV) compared to the d-d reaction neutron energy 2.45 MeV. The average energy of neutrons, emitted in two opposite radial directions, was close to 2.45 MeV. The half-width of the energy distributions reconstructed for all directions was 400-500 keV. The analysis of the experimental results demonstrated that the found phenomena could be explained by a slowly decaying high energy tail in the energy distribution of colliding deuterons. The maximal neutron yield was of 6 x 109
Measuring of spatio-temporal characteristics Z-pinch from deuterated polyethylene
On the S-300 installation at currents up to 2 MA with rise time 100 ns, the investigation of the formation process of high-temperature plasma in fast Z-pinch was carried out. The central part of the loads was made from agar-agar and represented a deuterated polyethylene cylinder with small density 50 and 75 mg/sm3 and 1–2 mm diameter. On the ICT images, obtained in optical and soft X-ray range of a spectrum with 3–5 ns exposition, it is visible that on the axis of the polyethylene cylinder at the current`s rise time a cord is formed and it is separated into bright formations. They were observed on a background of a luminous area which occupied the initial neck volume. On time-integrated pinhole pictures obtained in SXR range (E > 1–4 keV), hot points with minimal size of 50 microns were registered. From the chronograms results, obtained by means of the optical high-speed-streak camera mount along the neck axis with time resolution 1 keV with short duration of 2–4 ns. Simultaneously with X-ray radiation neutrons with the maximal yield of 4.5×109 were registered. The average energy measured in 4 directions under angles with an axis of: 0○ (above the anode), 90○, 180○ (under the cathode) and 270○, were accordingly: 2.4±0.2, 2.5±0.1, 2.5±0.1, 2.5±0.1 MeV