N. A. Ratakhin

Experimental investigation of dd reaction in range of ultralow energies using Z -pinch

Experimental results on measurement of dd-reaction cross sections in the energy range of 0.1-1.5 keV using the Z-pinch technique are presented. The experiment was fulfilled at the high current generator of the High-Current Electronics Institute, city of Tomsk, Russia. The dd-fusion neutrons were registered by time-of-flight scintillator detectors and BF 3 detectors of thermal neutrons. The estimates were obtained at 90% of the confidence level for the upper limits of the neutron-producing dd-reaction cross sections for average deuteron collision energies of 0.11, 0.34, 0.37, and 1.46 keV. These results substantiate feasibility to get a cross section magnitude for dd-reaction in the range of the collision energy of 0.8-3 keV using similar technology at the pulse current level of 2-3 MA.

Measurement of the astrophysical S factor for dd interaction at ultralow deuteron-collision energies using the inverse Z pinch

This paper is devoted to measurement of the astrophysical S factor and cross sections of the d + d → 3He + n reaction at ultralow deuteron-collision energies. Formation of the flow of the accelerated deuterons incident on the CD2 solid-state target was made within the scheme of the inverse Z pinch. The liner in the initial state was a hollow supersonic deuterium jet of radius of 15 mm and length of 20 mm. The experiment was carried out at the pulsed high-current accelerator (I=950 kA, τ=80 ns) of the Institute of High-Current Electronics (Tomsk, Russia). Measurement of the deuteron energy distribution was performed through an analysis of the time distributions of the intensity of the liner radiation (Hα and Hβ lines) generated during the liner radial movement from the axis. Recording of this radiation was carried out by optical detectors placed along the direction of the liner moving from its axis. The measured value of the astrophysical S factor for the dd reaction at the average deuteron collision energy Ecoll=3.69 keV was equal to S(Ecoll=3.69 keV)=58.2±18.1 keV b. The dd-reaction cross section calculated using the found value of the S factor and known representation of the reaction cross section as the product of the barrier factor and the astrophysical S factor was σddn(Ecoll=3.69 keV)=(1.33±0.41)×10−30 cm2.

Astrophysical S factor for dd interaction at ultralow energies

Experimental results are presented that were obtained by measuring the astrophysical S factor for dd interaction at very low deuteron collision energies by using the liner-plasma technique. The experiment was performed at the high-current generator of the High-Current Electronics Institute (Tomsk, Russia). The values found for the S factor at the deuteron collision energies of 1.80, 2.06, and 2.27 keV are Sdd=114±68, 64±30, and 53±16 keV b, respectively. The corresponding dd cross sections obtained as the product of the barrier factor and the measured astrophysical S factor are σddn(Ecol=1.80 keV)=(4.3±2.6)×10−33cm2, σddn(Ecol=2.06 keV)=(9.8±4.6)×10−33cm2, and σddn(Ecol=2.27 keV)=(2.1±0.6)×10−32cm2.

Study of the pd reaction at ultralow energies using hydrogen liner plasma

AbstractThe pd reaction (pd → He + γ (5.5 MeV)) is studied in the astrophysical energy collision range of protons with deuterons using the hydrogen liner in the inverse Z-pinch configuration at the pulsed power generator MIG (HCEI, Tomsk). Fundamental characteristics of this and other light-nucleus reactions at ultralow energies are important for problems of basic physics and astrophysics. The knowledge of the energy distribution of the nuclei participating in these reactions is important due to their exponential type of dependence on the collision energy. Two experimental techniques were designed and tested for recovering the energy distribution of liner protons incident on the CD2 target by using optical detectors and ion collectors. It is shown that the combined use of these two techniques could provide relevant information on the energy distribution of the accelerated protons in the liner. The estimates of the upper limits for the astrophysical S factor and effective cross section of the pd reaction in the proton-deuteron collision energy range of 2.7–16.7 keV are obtained:

Measurement of the deuterium liner characteristics in the inverse Z-pinch configuration

\bar S_{pd} (E_{pd} = 10.2 keV) \leqslant 2.5 \times 10^{ - 7} MeV b;\overline \sigma _{pd} (2.7 \leqslant E_{pd} \leqslant 16.7 keV) \leqslant 4 \times 10^{ - 33} cm^2

The astrophysical S-factor for dd-reactions at keV-energy range

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Application of inverse Z-pinch for study of the pd reaction at keV energy range

A method and results of measurements are presented of the ion energy distribution in a deuterium liner accelerated in the inverse Z-pinch, in which the plasma is accelerated electrodynamically from the liner axis. Knowledge of the deuteron energy distribution is of primary importance for the correct interpretation of the experimental results from the study of the dd-reaction in the range of infralow energies with the use of a liner plasma. Experiments were carried out in a high-current pulsed accelerator (I=950 kA, τ=80 ns) at the Institute of High-Current Electronics of the Siberian Division of the Russian Academy of Sciences (Tomsk, Russia). In the initial state, the liner is a supersonic hollow deuterium jet 32 mm in diameter and 20 mm in length. The liner parameters were measured with the help of optical detectors of Hα and Hβ deuterium lines and magnetic probes arranged in a radial direction (along the direction the liner expansion). In addition, scintillation spectrometers and BF3 counters were used to measure the intensity of the neutron flux produced in the d + d → 3He + n reaction. The results obtained by simultaneously analyzing the data from magnetic probes, optical detectors, and neutron detectors point to the possibility of using a rather simple method for measuring the parameters of the liner accelerated up to energies of 3–6 keV.

Investigation of strong interactions between light nuclei at superlow energies using Z-pinch plasma flow

This work is a part of a continuing research on measuring dd- reaction cross sections in keV energy range using accelerated ion flow in the liner of the Z-pinch generator. The knowledge of the ions energy distribution in the accelerated liner is crucially important for calculation of cross section. Diagnostics and the first results on the measurement of the energy distribution of the liner ions in the inverse Z-pinch geometry are described. Experiments were fulfilled in HCEI (Tomsk, Russia) at the nanosecond pulsed generator of 1 MA, 80 ns pulse. The spatially and time resolved liner dynamics and its radiation were measured with a set of light detectors (LDs), placed at various radii registering H/sub /spl alpha// and H/sub /spl beta// deuterium lines, and with B-dot probes, measuring the dynamics of the current carrying plasma liner. Processing of the LDs signal waveforms based on assumption of ordered ion flow between the LDs provided compatible information on the ion energy distribution. The neutron TOF measurements provided data on the high energy deuterons flows, responsible for the main neutron output. These experiments substantiate potential of using optical plasma diagnostic, which in combination with conventional electro-physical and neutron diagnostics could significantly improve reliability of dd-reaction cross-section measurement.