Experimental research of neutron yield and spectrum from deuterium gas-puff z-pinch on the GIT-12 generator at current above 2 MA

The Z-pinch experiments with deuterium gas-puff surrounded by an outer plasma shell were carried out on the GIT-12 generator (Tomsk, Russia) at currents of 2 MA. The plasma shell consisting of hydrogen and carbon ions was formed by 48 plasma guns. The deuterium gas-puff was created by a fast electromagnetic valve. This configuration provides an efficient mode of the neutron production in DD reaction, and the neutron yield reaches a value above 1012 neutrons per shot. Neutron diagnostics included scintillation TOF detectors for determination of the neutron energy spectrum, bubble detectors BD-PND, a silver activation detector, and several activation samples for determination of the neutron yield analysed by a Sodium Iodide (NaI) and a high-purity Germanium (HPGe) detectors. Using this neutron diagnostic complex, we measured the total neutron yield and amount of high-energy neutrons

Processing of the Signals From Plasma Focus Discharge

Abstract. Recent experiments of D-D reactions at the PF-1000 device in IPPLM Warsaw made possible to determine more exactly the time and energy distribution of produced neutrons due to ten scintillation detectors placed at distances between 7 and 85 m from the neutron source in both axial directions. In this article the de-noising of neutron signal via wavelet transformation is described. The signals were filtered with using the discrete wavelet transformation. The Mallat multiresolution algorithm was used, which divides the signal using decomposition coefficients and a hard. This method was used for filtration of the neutron signals acquired from D-D fusion reaction at the device PF 1000 in IPPLM Warsaw. We present comparison of detected and reconstructed signals and a temporal evolution of neutron energy distribution for shot No. 6573

Evolution of the small ball-like structures in the plasma focus discharge

The experiments were carried out in the PF-1000 plasma-focus device at the maximum current reaching about 2 MA, at the deuterium or neon filling and with deuterium injected from a gas-puff nozzle placed on the axis of the anode face. Ball-like structures of diameters of 1–12 mm were identifi ed in interferometric and XUV pinhole camera frames. We made the statistical description of their parameters. A lifetime of the ball- -like structures was in the range from 30 to 210 ns, and in some cases even more. These structures appeared mostly at the surface of the imploding plasma shell and they did not change their position in relation to the anode end. During the evolution of these structures, interferometric fringes were observed near the surfaces of the structures only, and their internal parts were initially chaotic (without noticeable) fringes. Subsequently the number of interferometric fringes increased (the internal ‘chaotic’ area was fi lled with fringes too) and later on it decreased. The radii of the ball-like structures were mostly increasing during their existence. The maximum electron density reached the value of 1024 to 1025 m–3. The ball-like structures decayed by absorption inside the expanded pinch column and/or gradually expired in rare plasma outside of the dense plasma column

Evolution of the small ball-like structures in the plasma focus discharge

The experiments were carried out in the PF-1000 plasma-focus device at the maximum current reaching about 2 MA, at the deuterium or neon filling and with deuterium injected from a gas-puff nozzle placed on the axis of the anode face. Ball-like structures of diameters of 1–12 mm were identifi ed in interferometric and XUV pinhole camera frames. We made the statistical description of their parameters. A lifetime of the ball- -like structures was in the range from 30 to 210 ns, and in some cases even more. These structures appeared mostly at the surface of the imploding plasma shell and they did not change their position in relation to the anode end. During the evolution of these structures, interferometric fringes were observed near the surfaces of the structures only, and their internal parts were initially chaotic (without noticeable) fringes. Subsequently the number of interferometric fringes increased (the internal ‘chaotic’ area was fi lled with fringes too) and later on it decreased. The radii of the ball-like structures were mostly increasing during their existence. The maximum electron density reached the value of 1024 to 1025 m–3. The ball-like structures decayed by absorption inside the expanded pinch column and/or gradually expired in rare plasma outside of the dense plasma column

Non-thermal pumping of the H-like ions by Z-pinch discharge

The paper describes experimental studies of x-ray pulses generated by implosions of current-sheaths onto sufficiently thick carbon fibers with the focus on a possibility of pumping the inverse population of hydrogen like ions levels. The stabilizing role of carbon fibers on the pinched-phase plasma is suggested and documented by the pinhole and streak camera pictures, PIN diode signals, and detected non-equilibrium spectrum of the Lyman lines of hydrogen-like carbon ion

Evolution of the current channel of the high energy discharge at atmospheric pressure

The processes in the magnetized plasma are influenced by spontaneous generated internal magnetic fields and induced currents. In the plasma with high density of particles convenient for ICF we can observe very fast energy transformation in range of ps or ns. In that plasma the high energy electrons and ions occur. Problem of their acceleration is under discussion. One possible mechanism is based on the transformation and dissipation of internal magnetic field. In this case the reconnection of magnetic lines can play an important role. This problem is studied for example in solar flares as well. In this paper we present results of the development of the discharge with distance of electrodes 40 cm, current of 300 A and duration in order of 100 ms. Its behavior is directed by magnetohydrodynamic phenomenon – pinching, development of helical instabilities, connection of two channels with opposite orientation of the electric current, forming of the loops, squirm of the loops and forming and disintegration of spherical forms of the squirmed loops

Some characteristics of fusion neutrons produced by deuterium in loads of Z-pinch devices

The fusion neutrons from Z-pinch devices are observed and studied for last fifty years. Many experimental and theoretical papers were published in this field. Some problems are still under discussion for example, a thermal or beam-target origin of neutrons, mechanism of acceleration of high-energy electrons and ions, correlation of hard x-rays with neutrons, a reason for asymmetry of emitted particles and radiation, development of diagnostic methods and interpretation of results. This paper presents an experimental results of neutrons produced at the. implosion of an Al liner onto a CD2 fiber at the 3 MA fast Z-pinch S-300 in RRC Kurchatov Institute in Moscow. The velocity and energy of neutrons in the axial direction were estimated from the temporal position of the maximum of neutron signals at two different distances from the neutron source and the relationship between hard x-rays and neutrons is discussed