A. E. Shikanov

Small-size plasma diode with a transparent internal cathode for neutron generation

A discharge plasma system for neutron generation based on the concept of inertial electrostatic confinement is considered. The system is made in the form of a gas-filled (1–60 Pa) diode with a composite hollow cathode placed at its center symmetrically to an embracing hollow cylindrical anode. Preionization of the discharge gap and an original design of the electrode system with a transparent central part make it possible to initiate a pulse high-voltage (100–150 kV) volume discharge in the ion oscillation mode. Estimates of the neutron emission in such a deuterium-filled diode show the feasibility of generating a pulse with a neutron yield on the order of 105 in the reaction D(d, n)3He, which is confirmed in experiments with an optimized geometry of the electrodes.

Applicability of a Conical Cavity as a Target for Generation of Neutrons in a Linear Accelerator

Results of the study are presented, which demonstrate the applicability of targets with a tapered surface of the reaction layer for generation of neutrons in linear accelerators of hydrogen nuclides in the nuclear reactions T(d, n)4He, T(p, n)3He, and D(d, n)3He. An algorithm is proposed for calculating the neutron yield, taking into account possible changes in the concentration of hydrogen isotopes in the target with depth. As a result of computer simulations, the dependence of the neutron yield on the cone angle has been established, and the possibility has been shown of increasing the neutron yield from a target with a conical surface of its reaction layer without changing its thickness.

Model for Generation of Neutrons in a Compact Diode with Laser-Plasma Anode and Suppression of Electron Conduction Using a Permanent Cylindrical Magnet

A model for acceleration of deuterons and generation of neutrons in a compact laser-plasma diode with electron isolation using magnetic field generated by a hollow cylindrical permanent magnet is presented. Experimental and computer-simulated neutron yields are compared for the diode structure under study. An accelerating neutron tube with a relatively high neutron generation efficiency can be constructed using suppression of electron conduction with the aid of a magnet placed in the vacuum volume.

Deuteron flux production in a small high-voltage high-current diode with pulsed magnetic insulation

The results of new studies on the production of accelerated deuteron fluxes in a small ion diode with pulsed magnetic insulation of electrons have been presented. A plasma anode of the diode has been formed under the action of a 1.06 μm laser radiation with a pulse duration of 10 ns, a pulse energy of up to 1 J, and a power density on the target of 5 × 1015 W m–2. An accelerating voltage of up to 300 kV has been created using an Arkad’ev–Marx pulsed voltage generator with a stored energy of 50 J and a repetition rate of 1 Hz. A magnetic field of higher than 0.6 T for insulating electrons has been formed by a current pulse of the first cascade of the generator in a spiral line before a conical cascade. Stable deuteron acceleration to 300 keV with a current of up to 1.5 kA and a pulse duration of 0.3 μs has been achieved.

Neutron Diagnostics for Deuteron Flows from Pulsed Plasma Formations in a Magnetic Field

A diagnostic procedure establishing a relation between the energy of a laser pulse W (0.1 ≤ W ≤ 0.8) and the number of deuterons Nd extracted from the laser plasma in a vacuum accelerating diode with magnetic isolation of electrons is presented. The diagnostics is based on the measurement of neutrons generated at a target, which is a part of the ion collector at the same time. The results of experimental research and numerical modeling for the accelerating voltage at a diode interval up to 400 kV are presented.

An accelerating voltage generator for compact pulsed neutron sources

A multistage generator of high-voltage pulses with a scroll geometry of spark switches, which is produced according to the Marx scheme, is presented. The device is designed for a small pulsed neutron source and makes it possible to obtain accelerating-voltage pulses with amplitudes of up to 450 kV at a stored energy of up to 50 J and a load current of up to 1.5 kA.

Study of Oil Wells With the Use of Accelerator Tubes, Time and Energy Spectrometers of Neutrons and Gamma Rays in a Single Geophysical Complex

The report discusses the finding of the coefficient of oil saturation of the reservoir by of nuclear methods. For this purpose, the data about pulse and the activation neutron logging and spectral logging of natural gamma activity are used in a single geophysical complex. As sources of neutron radiation can been applied accelerating tube (AT) based on different ion sources, such as plasma discharge with oscillating electrons (gas AT), vacuum arc and laserplasma (vacuum AT). For investigation of the oil reservoir, in particular with heavy oil, we discuss the prospects of using vacuum accelerating tube based on a laser-plasma source of deuterons with coaxial acceleration geometry and pulsed magnetic isolation of electrons.

Generator of High-Voltage Pulse for High-Current Accelerator of Deuteron With Laser Starts

The report deals with the source of pulsed high voltage, and simultaneously, source of the pulsed current for the magnetic insulation of electrons near the cathode that was developed for a high-current accelerator of deuterons with laser-plasma anode. The accelerating voltage up to 400 kV and ion current about 1 kA have been achieved. The current in the spiral inductor has reached 5 kA and it excludes breakdown between the cathode and anode for 0.5 μs. For synchronization of physical processes in accelerator of deuterons with pulsed power, the laser control is applied.

Acceleration of deuterons from laser plasma in direct pulsed electron fluxes for generation of neutrons

We report the results of experiments in which laser plasma deuterons are accelerated toward beryllium and deuterated polyethylene targets in a drift tube by means of a direct pulsed flux of electrons accelerated to maximum energy of 250 keV. Neutrons produced as a result of the interaction of deuterons with the targets are detected. The yield of neutrons in some of the experimental series reaches 106 n/pulse. Using a pulsed magnetic field synchronized with the generation of laser plasma is proposed for increasing the neutron yield as a result of electron flux compression. This magnetic field in the drift region of electrons is created by a spiral coil of conical shape.

Acceleration of deuterons with suppression of electronic conductance in a vacuum diode with a laser target on the anode

We report new experimental results on the acceleration of deuterons in a compact coaxial diode with the suppression of electronic conductance by a constant longitudinal magnetic field. Plasma containing deuterons is created on a laser TiD target located on the anode. The pulse of accelerating voltage is formed by means of the Arkad’ev−Marx generator. The cathode symmetrically surrounds the anode and comprises a hollow permanent ring magnet with an inner radius of no more than 0.02 m and an on-axis induction of up to 0.4 T, which provides the magnetic insulation of the accelerating gap. The experiments demonstrate the possibility of obtaining accelerated deuterons with energy of up to 300 keV and a current of up to 0.5 kA with a pulse duration of 0.2 μs.