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11.
Yu. L. Bakshaev P. I. Blinov V. V. Vikhrev E. M. Gordeev S. A. Dan’ko V. D. Korolev S. F. Medovshchikov S. L. Nedoseev E. A. Smirnova V. I. Tumanov A. S. Chernenko A. Yu. Shashkov 《Plasma Physics Reports》2001,27(12):1039-1047
The development of a preformed constriction in cylindrical agar-agar loads at currents of up to 3 MA is studied experimentally.
The loads 3–5 mm in diameter have a mass density of 0.1 g/cm3 and are filled with different materials. Due to the implosion of the constriction to a minimum size of 40–70 μm, a hot dense
plasma (with the electron density n
e=1022 cm−3, electron temperature T
e=0.8–1.5 keV, and ion temperature T
i=3–12 keV) is produced. It is found that the ion temperature substantially exceeds the electron temperature. The lifetime
of the high-temperature plasma determined from the FWHM of a soft X radiation (SXR) pulse is shorter than 5 ns, the radiation
power of photons with energies of ≥1 keV is higher than 0.5×1010 W, and their total energy attains 50 J. High-speed photography in the VUV, SXR, and optical spectral regions indicates the
protracted generation of the high-temperature plasma. Calculations by the two-dimensional ideal MHD model of the Z-pinch show
that the most important consequence of the protracted plasma generation in the constriction region is that the current is
intercepted by a freshly produced plasma. In the course of plasma generation, the current near the axis inside the region
of radius 50 μm is at most one-half of the total current. After the plasma generation comes to an end, almost the entire current
is concentrated in this region for several nanoseconds; this process is accompanied by a sharp increase in the plasma temperature.
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Translated from Fizika Plazmy, Vol. 27, No. 12, 2001, pp. 1101–1110.
Original Russian Text Copyright ? 2001 by Bakshaev, Blinov, Vikhrev, Gordeev, Dan’ko, Korolev, Medovshchikov, Nedoseev, Smirnova,
Tumanov, Chernenko, Shashkov. 相似文献
12.
Yu. L. Bakshaev P. I. Blinov V. V. Vikhrev S. A. Dan’ko V. D. Korolev B. R. Meshcherov S. L. Nedoseev E. A. Smirnova G. I. Ustroev A. S. Chernenko A. Yu. Shashkov 《Plasma Physics Reports》2006,32(7):531-538
Results are presented from measurements of neutron emission generated during discharges with current amplitudes of up to 3 MA and a current rise time of ~100 ns through profiled loads 10 mm in height and 4–5 mm in diameter. The experiments were performed with the S-300 eight-module high-power generator. To enhance the effect of energy accumulation, a≤1-mm-diameter neck was made in the central region of the load. An agar-agar foam of mass density 0.1 g/cm3 with an additive of deuterated polyethylene was used as a plasma-forming material. The formation of a hot plasma in the Z-pinch constriction was accompanied by the emission of soft X-ray (E = 1–10 keV), hard X-ray (E ≥ 30 keV), and neutron pulses with a minimum pulse duration of ≤10 ns. The neutron energy measured by the time-of-flight technique in three directions relative to the load axis (0°, 90°, and 180°) was found to be 2.5 ± 0.3 MeV, which corresponds to the dd reaction. The total neutral yield during the development of one constriction with a characteristic size of 100 μm attained 108 neutrons per pulse. 相似文献
13.
P. Kubeš V. D. Korolev Yu. L. Bakshaev P. I. Blinov M. I. Ivanov E. D. Kazakov J. Kravárik D. Klír L. V. Korel’skiĭ E. V. Kravchenko K. Řezáč G. I. Ustroev A. S. Chernenko A. Yu. Shashkov 《Plasma Physics Reports》2008,34(1):52-59
Results are presented from Z-pinch experiments performed in the S-300 facility (Kurchatov Institute) at a maximum current of 2 MA and current rise time of 100 ns. The Z-pinch load was a 1-cm-long 1-cmdiameter cylindrical array made of 40 tungsten wires with a total mass of 160 μg, at the axis of which a 100-μm-diameter (CD2) n deuterated fiber was installed. Hard X-ray and neutron signals were recorded using five scintillation detectors oriented in one radial and two axial directions. The maximum neutron yield from the DD reaction reached 3 × 109 neutrons per shot. The average neutron energy was determined from time-of-flight measurements and Monte Carlo simulations under the assumption that the neutron emission time was independent of the neutron energy. The average neutron energy in different experiments was found to vary within the range 2.5–2.7 MeV. The fact that the average neutron energy was higher than 2.45 MeV (the energy corresponding to the DD reaction) is attributed to the beam-target collisional mechanism for the acceleration of deuterons to 100–500 keV. 相似文献
14.
15.
Plasma Physics Reports - Experiments on ion acceleration in the ambipolar field were carried out at the Kalmar relativistic electron beam generator with a pulsed voltage of ~250 kV, current of ~40... 相似文献
16.
S. S. Anan’ev Yu. L. Bakshaev P. I. Blinov V. A. Bryzgunov V. V. Vikhrev S. A. Dan’ko A. A. Zelenin E. D. Kazakov Yu. G. Kalinin A. S. Kingsep V. D. Korolev E. A. Smirnova G. I. Ustroev A. S. Chernenko V. A. Shchagin 《Plasma Physics Reports》2010,36(7):601-608
Results are presented from experimental studies of the parameters of an X-pinch-based neutron source made of 70- to 80-μm-diameter deuterated polyethylene fibers. At currents of up to 1.7 MA and a current rise time of ~150 ns, hot plasma spots were observed in the fiber crossing region. The formation of hot spots was accompanied by the generation of short soft X-ray pulses with a duration of 2–4 ns, as well as by neutron emission. The neutron energy was measured using the time-of-flight technique in four directions, at 0°, 90°, 180°, and 270° with respect to the load axis. The mean energy of the neutrons emitted along the axis towards the anode and cathode was found to be 2.0 ± 0.2 and 2.6 ± 0.1 MeV, respectively, and that of neutrons emitted in two opposite directions along the radius, 2.5 ± 0.1 and 2.4 ± 0.1 MeV. The maximum neutron yield at a current amplitude of 1.6 MA was of 1010 neutrons per shot. 相似文献
17.
S. S. Anan’ev Yu. L. Bakshaev A. V. Bartov P. I. Blinov S. A. Dan’ko A. I. Zhuzhunashvili E. D. Kazakov Yu. G. Kalinin A. S. Kingsep V. D. Korolev V. I. Mizhiritskii V. P. Smirnov S. I. Tkachenko A. S. Chernenko 《Plasma Physics Reports》2008,34(7):574-586
Results are presented from experimental studies of a section of a magnetically insulated transmission line (MITL) with a current density of up to 500 MA/cm2 and linear current density of up to 7 MA/cm (the parameters close to those in a fast-Z-pinch-driven fusion reactor projected at Sandia Laboratories). The experiments were performed in the S-300 facility (3 MA, 0.15 Ω, 100 ns). At high linear current densities, the surface of the ohmically heated MITL electrode can explode and a plasma layer can form near the electrode surface. As a result, the MITL can lose its transmission properties due to the shunting of the vacuum gap by the plasma produced. In this series of experiments, the dynamics of the electrode plasma and the dependence of the transmission properties of the MITL on the material and cleanness of the electrode surface were studied. It is shown experimentally that, when the current with a linear density of up to 7 MA/cm begins to flow along a model MITL, the input and output currents differ by less than 10% over a time interval of up to 230 ns for nickel electrodes and up to 350 ns for a line with a gold central electrode. No effect of the oil film present on the electrode surface on the loss of the transmission properties of the line was observed. It is also shown that electron losses insignificantly contribute to the total current balance. The experimental results are compared with calculations of the electrode explosion and the subsequent expansion of the plasma layer. A conclusion is made that the life-time of the model MITL satisfies the requirements imposed on the transmission lines intended for use in the projected thermonuclear reactor. 相似文献
18.
Ashmarina L. F. Lednev G. R. Tomilova O. G. Sadokhina T. A. Bakshaev D. Yu. Levchenko M. V. Volkova N. S. Tyurin M. V. Danilov V. P. Glupov V. V. 《Doklady. Biochemistry and biophysics》2021,499(1):260-265
Doklady Biochemistry and Biophysics - Several ascomycetous entomopathogenic fungi, including species in the genera Beauveria, are plant symbionts/endophytes and are termed as endophytic... 相似文献