A5002900344- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Cold Fusion and Nuclear Reactions
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- Fusion materials and technologies
- Laser Design and Applications
- High-pressure geophysics and materials
- Radiation Detection and Scintillator Technologies
- Mass Spectrometry Techniques and Applications
- Particle accelerators and beam dynamics
- Laser-Matter Interactions and Applications
- Pulsed Power Technology Applications
- Quantum, superfluid, helium dynamics
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Astro and Planetary Science
- X-ray Spectroscopy and Fluorescence Analysis
- Vacuum and Plasma Arcs
- Fusion and Plasma Physics Studies
Czech Technical University in Prague
2016-2025
University of California, San Diego
2023
Manufacturing Advocacy & Growth Network (United States)
2023
Institute of Plasma Physics and Laser Microfusion
2010-2022
Czech Academy of Sciences, Institute of Plasma Physics
2010-2019
Czech Academy of Sciences, Institute of Physics
2010-2018
Czech Academy of Sciences
2015
École Polytechnique
2010
Centre National de la Recherche Scientifique
2010
Warsaw University of Technology
2010
Measurements of the return-current flowing through a solid target irradiated with sub-nanosecond kJ-class Prague Asterix Laser System is reported. A new inductive probe was developed which allows us measuring current derivative in kA/ns range. The dependences on laser pulse energy for cooper, graphite, and polyethylene targets are experiment shows that proportional to deposited strongly affected by shot-to-shot fluctuations. corresponding maximum charge exceeded value 10 μC. dependence...
This paper deals with time-of-flight diagnostics of relatively short neutron pulses from tens to hundreds nanoseconds. The aim is determine the time evolution energy spectra. diagnostic setup consists several detectors placed in one direction at different distances. approach improved by placing additional opposite direction. How reconstruction method works two directions explained this paper. Improvement limited deuterium fusion reaction D(d,n)3He. However, principles described here could be...
The current balancing the target charging and emission of transient electromagnetic pulses (EMP) driven by interaction a focused 1.315 μm iodine 300 ps PALS laser with metallic plastic targets were measured use inductive probes. It is experimentally proven that duration return currents EMPs much longer than laser-target interaction. laser-produced plasma active after During this phase, acts as virtual cathode plasma-target interface expands. A double exponential function used in order to...
In this paper, the possible evolution of a pinched plasma column is presented from results temporally resolved measurements using magnetic probe, interferometry and neutron diagnostics performed on focus PF-1000 device with deuterium as filling gas. Together discharge axial current about 1.5 MA toroidal component order 100 kA was estimated in toroidal, helical plasmoidal structures formed within dense column. The mass inside these increases due to injection neighborhood regions higher...
Acceleration of high energy ions was observed in z-pinches and dense plasma foci as early the 1950s. Even though many theories have been suggested, ion acceleration mechanism remains a source controversy. Recently, experiments on GIT-12 generator demonstrated up to 30 MeV from deuterium gas-puff z-pinch. High deuteron energies enable us obtain unique information about spatial, spectral temporal properties accelerated ions. In particular, off-axis emission concentric circles ∼1 cm diameter...
The paper presents a comparison of shots with high and low neutron yield at deuterium filling. Shots are characterized by higher energy produced hard x rays neutrons, larger volume plasmoid-like compact structure, lower plasma density in the pinched column. discrepancy was interpreted different magnetic energies stored model distribution plasmoid assumes existence poloidal component field plasma, formation structures closed toroidal current components, filamentary current, development MHD...
A novel configuration of a deuterium z pinch has been used to generate fusion neutrons. Injecting an outer hollow cylindrical plasma shell around inner gas puff, neutron yields from DD reactions reached Y(n)=(2.9 ± 0.3) × 10(12) at 700 ns implosion time and 2.7 MA current. Such yield means tenfold increase in comparison with previous puff experiments the same current generator. The beam-target was obtained by larger amount assembled on z-pinch axis, subsequently higher induced voltage...
We have developed and tested sensitive neutron detectors for time-of-flight measurements in z-pinch plasma focus experiments with emission times tens of nanoseconds yields between 106 1012 per one shot. The are composed a BC-408 fast plastic scintillator Hamamatsu H1949-51 photomultiplier tube (PMT). During the calibration procedure, PMT delay was determined various operating voltages. temporal resolution detector measured most commonly used voltage 1.4 kV. At PF-1000 focus, novel method...
In this paper the results of temporally resolved measurements using calibrated azimuthal and axial magnetic probes are presented, together with interferometry neutron diagnostics performed on PF-1000 (IPPLM, Warsaw, 2 MA) device a deuterium filling 1011 yield. The located in anode front at three different radial positions allow determination dominant part discharge current flows behind imploding dense plasma layer. sheath is composed both components field. After reaching minimum diameter,...
The present experiments were performed on the PF-1000 plasma focus device at a current of 2 MA with deuterium injected from gas-puff placed in axis anode face. XUV frames showed, contrast interferograms, fine structure: filaments and spots up to 1 mm diameter. In filling, short are registered mainly region internal plasmoidal structures their number correlates intensity neutron production. longer filamentary structure was recorded close after constriction decay. long curve-like big bubble...
Z-pinch experiments with deuterium gas puffs have been carried out on the GIT-12 generator at 3 MA currents. Recently, a novel configuration of gas-puff z-pinch was used to accelerate deuterons and generate fast neutrons. In order form homogeneous, uniformly conducting layer large initial radius, an inner puff surrounded by outer hollow cylindrical plasma shell. The shell consisting hydrogen carbon ions formed diameter 350 mm 48 guns. A linear mass about 5 µg cm−1 whereas total in single or...
Z-pinch experiments with a hybrid configuration of deuterium gas puff have been carried out on the HAWK (NRL, Washington, DC) and GIT-12 (IHCE, Tomsk) pulsed power generators at 0.7 MA 3 currents, respectively. On GIT-12, neutron yields reached an average value 2 × 1012 neutrons, deuterons were accelerated up to energy 30 MeV. This was 50 times ion provided by generator driving voltage 0.6 MV highest observed in z-pinches dense plasma foci. To confirm these unique results independently...
The laser interferometry and X-ray diagnostic studies were performed within the PF-1000 facility operated with maximum current of 2 MA deuterium gas filling (ensuring neutron yield above ). At this current, plasmoidal, helical toroidal structures formed inside plasma column. Some them penetrated column surface later on dissolved dense period their life was from a few tens to hundreds nanoseconds density higher than in neighbor regions. It could be explained as result pinching by magnetic...
A plasma column generated in the PF-1000 device working deuterium gas at a current level of 1 MA was investigated with interferometric diagnostics and scintillation detectors. The beam diagnostic laser 527-nm wavelength optically split into 16 beams time delay range from 0 to 220 ns. This tool makes possible imaging evolution pinch geometry, axial radial distributions density stagnation phase, their comparison X-ray neutron production. dense structure is described respect its importance for...
A PF-1000 device working with a deuterium gas filling and current on the order of 1 MA was used for studies pinch-column structure by means laser interferometric system at period hard X-ray (HXR) neutron production. Three different phases plasma-column evolution, corresponding to intense HXR emission, were studied discharges yields equal about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> neutrons/shot. First, start stagnation...
Plasma focus experiments were carried out at a modified PF-1000 where the cathode disc was added in front of anode. Experimental results indicated fraction thermonuclear neutrons on mega-ampere current level. In order to prove mechanism, time neutron production and energy spectrum measured by time-of-flight (TOF) diagnostics. Neutron TOF signals showed that multiphase process more than one mechanism occurred simultaneously. The occurrence most evident during plasma stagnation low deuterium...
The PF-1000 plasma focus was modified by adding the cathode disk 3 cm in front of anode. This modification facilitated evaluation neutron energy spectra. Two pulses were distinguishable. As regards first pulse, it lasted 40 ns during stagnation and demonstrated high isotropy emission. A peak detected upstream 2.46±0.02 MeV. full width spectra 90±20 keV enabled to calculate an ion temperature 1.2 keV. These parameters a yield 109 corresponded theoretical predictions for thermonuclear neutrons.
A novel configuration of a deuterium z-pinch has been used to generate nanosecond pulse fast ions and neutrons. At 3 MA current, the peak neutron yield (3.6 ± 0.5) × 1012 was emitted within 20 ns implying production rate 1020 neutrons/s. High yields resulted from magnetization MeV deuterons inside plasmas. Whereas were trapped in radial direction, lot escaped along z-axis. large number &gt;25 into 250 mrad cone. The cut-off energy broad spectra hydrogen approached 40 MeV. total &gt;1...
Fast neutrons from deuteron-deuteron fusion reactions were used for a study of fast deuterons in the PF-1000 plasma-focus device. The energy spectrum was determined by time-of-flight method using ten scintillation detectors positioned downstream, upstream, and side-on experimental facility. Neutron energy-distribution functions enabled determination axial radial components producing neutrons, as well rough evaluation total distribution all pinch. It found that deuteron function decreases...
Deuterium gas puff experiments were carried out on the S-300 Z-pinch at Kurchatov Institute in Moscow. Gas puffs imploded onto axis before a current peak about 100 ns. Fusion neutrons generated after implosion during global expansion of plasma column. Neutron emission lasted average 35 ± 5 ns (full width half maximum, FWHM). In downstream direction (on behind cathode), mean neutron energy was 2.6 0.1 MeV. Side-on spectra peaked 2.40 0.05 MeV with 600 150 keV FWHM. A broad side-on implied...
The implosion of a solid deuterium gas-puff <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> -pinch was studied on the S-300 pulsed power generator [A. S. Chernenko, , Proceedings 11th Int. Conf. High Power Particle Beams, 154 (1996)]. peak neutron yield above 10 <sup xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> achieved current level 2 MA. fusion neutrons were generated at about 150 ns after onset, i.e., during stagnation and...
Deuterium gas-puff experiments have been carried out on the GIT-12 generator at Institute of High Current Electronics in Tomsk. The emphasis was put study plasma dynamics and neutron production double shell gas puffs. A linear mass density deuterium (D2) varied between 50 85 μg/cm. Somewhat problematic a spread D2 large diameter central anode–cathode region. operated two regimes, with without opening switch (POS). When POS used, current reached peak 2.7 MA 200 ns rise time. Without POS, time...
Experiments with deuterium (D2) triple shell gas puffs were carried out on the GIT-12 generator at a 3 MA current level and microsecond implosion times. The outer, middle inner nozzle diameters 160 mm, 80 mm 30 respectively. influence of mass shells neutron emission times, yields energy spectra was studied. injected linear varied between 50 255 µg cm−1. Gas imploded onto axis before peak 700–1100 ns. Most neutrons emitted during second pulse after development instabilities. Despite higher...
The paper describes the filamentary structure observed in high-energy ultraviolet radiation for discharges performed at hydrogen- or deuterium-filling and puffing of hydrogen, deuterium helium, a mega-ampere dense plasma-focus facility. lifetime this overcomes 50 ns. These filaments connect surface pinched column with internal plasmoids formed different combinations filling gases they should transport some current plasma. During all investigated shots, fusion-produced neutrons were recorded....
Neutron-producing experiments have been carried out on the Prague Asterix Laser System. At fundamental wavelength of 1.315 μm, laser pulse a 600 J energy and 300 ps duration was focused thick deuterated-polyethylene target. Neutron yields reached (4.1 ± 0.8) × 108 at peak intensity ≈3 1016 W/cm2. A more detailed analysis neutron time-of-flight signals showed that significant fraction produced both by 2H(d,n)3He reaction other neutron-producing reactions. energies together with delayed gamma...