Study of the Compression Dynamics of a Fiber Liner with a Deuterated Target Mounted on the Axis

• Published in: Plasma physics reports 2020-10, Vol.46 (10), p.967-977
• Main Authors: Abramov, O. N., Aleksandrov, V. V., Volkov, G. S., Volobuev, I. V., Grabovsky, E. V., Gritsuk, A. N., Zhigalov, D. V., Kalinin, Yu. G., Korolev, V. D., Laukhin, Ya. N., Medovshchikov, S. F., Mitrofanov, K. N., Oleinik, G. M., Smirnova, E. A., Frolov, I. N.
• Format: Article
• Language: English
• Subjects: Arrays; Atomic; Deuteration; Diameters; Electron density; Emission; Fibers; Molecular; Neutron counters; Optical and Plasma Physics; Physics; Physics and Astronomy; Pinhole cameras; Pinholes; Plasma; Plasma compression; Plasma Dynamics; Polyethylenes; Polypropylene; Soft x rays
• ISSN: 1063-780X; 1562-6938
• DOI: 10.1134/S1063780X20100013

Compression of a fiber array with a deuterated target mounted on its axis is studied at the Angara-5-1 facility (3.5 MA, 100 ns). Cylindrical arrays with an initial diameter of 12 mm made from polypropylene fibers with a diameter of 13.4 µm are used. The number of fibers varied from 30 to 120. The target with the density of 0.08–0.2 g/cm 3 and the diameter of 1 mm was made on the basis of deuterated polyethylene. A 10‑frame ultra-high-speed X-ray camera, optical slit scans, an integral X-ray pinhole camera, vacuum X-ray diodes, a crystal spectrograph, and neutron detectors are used to measure the plasma parameters in the Z‑pinch. It is found that the dynamics of plasma compression and evolution of local plasma formations, which are sources of neutrons and soft X-ray emission in the energy range of E > 150 eV, depend on the load configuration: the number of fibers, diameter, and density of the deuterated target. Efficient compression of the liner plasma, high concentration and temperature of the compressed target state, as well as the highest neutron yield (8 × 10 9 neutron/pulse) are observed in experiments with arrays with the fiber number of 60, inside which the target with the diameter of 1 mm and density of 0.2 g/cm 3 was placed. The electron density and temperature of the hot plasma in local formations are estimated as n e ≈ 10 21 cm –3 , T e ≈ 1 keV, respectively. The average neutron energy was 2.6 ± 0.2 MeV. The intensity of the plasma formation [in µg/(cm 2 ns)] of polypropylene fibers under the action of the discharge current of the facility is determined in experiments with fiber arrays.