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Sample records for energy plasma focus

  1. Energy coupling in the plasma focus

    International Nuclear Information System (INIS)

    Wainwright, T.E.; Pickles, W.L.; Sahlin, H.L.; Price, D.F.

    1979-01-01

    Experiments have been performed with a 125-kJ plasma focus to investigate mechanisms for rapid coupling of inductively-stored energy into plasmas. The coupling can take place through the formation of an electron or ion beam that deposits its energy in a target or directly by the penetration of the magnetic field into a resistive plasma. Some preliminary results from experiments of both types are described. The experiments use a replaceable conical anode tip that is intended to guide the focus to within a few millimeters of the axis, where it can suddenly deliver energy either to a small target or to particles that are accelerated. X-ray and fast-ion diagnostics have been used to study the effects

  2. Plasma focusing and diagnosis of high energy particle beams

    International Nuclear Information System (INIS)

    Chen, Pisin.

    1990-09-01

    Various novel concepts of focusing and diagnosis of high energy charged particle beams, based on the interaction between the relativistic particle beam and the plasma, are reviewed. This includes overdense thin plasma lenses, and (underdense) adiabatic plasma lens, and two beam size monitor concepts. In addition, we introduce another mechanism for measuring flat beams based on the impulse received by heavy ions in an underdense plasma. Theoretical investigations show promise of focusing and diagnosing beams down to sizes where conventional methods are not possible to provide. 21 refs

  3. Sausage instability threshold in a low energy plasma focus

    International Nuclear Information System (INIS)

    Zakaullah, M.; Nasir, M.; Khattak, F.Y.; Murtaza, G.

    1993-01-01

    Development of sausage instability (m = 0 mode) is studied in a small low energy Mather-type plasma focus. A shadow graphic study of the current sheath has shown that the focused plasma necks off during the radial phase before the maximum compression. This may indicate the lowering of the instability threshold. Three hook-type structures are observed which may not be due to the multifoci formation. The bubble shape structure is observed to be developed in the expansion phase. (author)

  4. Delayed hot spots in a low energy plasma focus

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1991-01-01

    In a low energy Mather-type plasma focus device, hot spots having temperature in the range of few keV have been observed even 1 μs after the pinch disintegration and in regions away from the pinch area. These hot spots are perhaps created by the thermal runaway due to temperature fluctuations in the background gas. (author). 12 refs., 6 figs

  5. Temporal evolution of ion energy in a plasma focus

    International Nuclear Information System (INIS)

    Rhee, M.J.; Weidman, D.J.

    1988-01-01

    For the first time, the temporal structure of ion energy in a plasma focus is revealed using a time-resolving Thomson spectrometer. The velocities and arrival times of ions are determined from the spectrogram. The resulting distribution of ions in velocity--time space at the source is found to be a line distribution, as if the ions were accelerated in a diode by a pulsed voltage

  6. Plasma focus breeder

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1981-09-01

    Instead of using linear accelerators, it is possible to breed fissile fuels with the help of high current plasma focus device. A mechanism of accelerating proton beam in plasma focus device to high energy would be a change of inductance in plasma column because of rapid growth of plasma instability. A possible scheme of plasma focus breeder is also proposed. (author)

  7. Energy analysis of the ion beam from plasma focus

    International Nuclear Information System (INIS)

    Kilic, H.; Nardi, V.; Prior, W.

    1984-01-01

    The authors have experimentally determined the energy spectrum of a deuteron beam in the energy interval 100 KeV ≤ E ≤ 10 MeV, with typical beam current I ≥ 1-2 A. A 5 kJ (15 kV, 49 μF) plasma focus machine is used to generate the ion beam at relatively low pressure 3-4 Torr D/sub 2/ (beam anode) and at higher pressure 6-8 Torr D/sub 2/ (high-neutron-yield mode). The spectrum is obtained from two different methods, i.e. from ion time of flight - by using time delays of Faraday cup signals with respect to hard x-ray signals - and from ion filtering, (mylar filter with different thickness from 2.5 μm up to 500 μm are used to cover the Faraday cup). The Faraday cup is located in a differentially pumed chamber (10/sup -4/ - 10/sup -5/ Torr) which is separated from the plasma focus chamber (8-3 Torr) by a 150 μm diam. pinhole (12.5 μm thick tungsten foil). The pinhole and Faraday cup are positioned on the gun axis at a distance of 15 cm and 25 cm from the end of the anode respectively

  8. Plasma Focus

    International Nuclear Information System (INIS)

    Bernard, Alain; Jolas, Alain; Garconnet, J.-P.; Mascureau, J. de; Nazet, Christian; Coudeville, Alain; Bekiarian, Andre.

    1977-01-01

    The present report is the edition of the lectures given in a conference on the Focus experiment held at the Centre d'etudes de Limeil, on Oct. 1975. After a survey of the early laboratories one will find the main results obtained in Limeil concerning interferometry, laser scattering, electric and magnetic-measurements, X-ray and neutron emission and also the possible use of explosive current generators instead of capacitor banks at high energy levels. The principal lines of future research are given in the conclusion [fr

  9. Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

    Science.gov (United States)

    Rawat, R. S.

    2015-03-01

    The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 1010 J/m3. The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

  10. Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

    International Nuclear Information System (INIS)

    Rawat, R S

    2015-01-01

    The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 10 10 J/m 3 . The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I 4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

  11. Energy conversion and concentration in a high-current gaseous discharge: Dense plasma spheromak in plasma focus experiments

    International Nuclear Information System (INIS)

    Kukushkin, A.B.; Rantsev-Kartinov, V.A.; Terentiev, A.R.

    1995-01-01

    Experimental results are presented which verify the possibility of the self-generated transformation of the magnetic field in plasma focus discharges to give a closed, spheromak-like magnetic configuration (SLMC). The energy conversion mechanism suggests a possibility of further concentrating the plasma power density by means of natural compressing the SLMC-trapped plasma by the residual magnetic field of the plasma focus discharge

  12. The dense plasma focus and nuclear energy. A possible path towards fuel-selfsufficiency

    International Nuclear Information System (INIS)

    Heindler, M.; Harms, A.A.

    1983-01-01

    This chapter examines the concept of incorporating a dense plasma focus device which supplies neutrons to breed fissile fuel for fission reactions in a nuclear energy system. Discusses the dense plasma focus in a fusion-fission symbiont concept; a parametric description of a DPF-based nuclear energy system; fissile fuel and energy balance in a DPF based symbiont; a fusion-fission symbiont with a DPF device of current design; and DPF facility requirements for a self-sufficient fusion-fission symbiont. The primary objective of this study was to establish a systems concept which is essentially self-sufficient with respect to nuclear fuel. Concludes that while existing dense plasma focus devices are insufficient and inadequate for such purpose, the improvement of some critical performance parameters (e.g., the pulse repetition rate and the neutron yield per pulse) could render a self-sufficient nuclear energy concept a nearterm technological objective

  13. Characterization of a Very Small Plasma Focus in the Limit of Low Energy (50 J)

    International Nuclear Information System (INIS)

    Silva, P.; Sotol, L.; Moreno, J.; Sylvester, G.; Zambra, M.; Altamirano, L.; Bruzzone, H.; Clausse, A.; Moreno, C.

    2001-01-01

    A very small plasma focus device has been designed and constructed. The plasma focus operates in the limit of low energy (160 nF capacitor bank, 65 nH, 250-40 kV, ∼32-128 J). The design of the electrode was assisted by a simple model of a Mather plasma focus. The calculations indicate that yields of 10 4 -10 5 neutrons per shot are expected when the discharge is operated with deuterium. A single frame image converter camera (5 ns exposure) was used to obtain plasma images in the visible range. The umbrella-like current sheath running over the end of the coaxial electrodes and the pinch after the radial collapse can be clearly observed in the photographs. The observations are similar to the results obtained with devices operating at energies several order of magnitude higher. (author)

  14. Plasma focus matching conditions

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.; Elkhalafawy, T.A.

    1988-01-01

    A snow-plough and slug models have been used to obtain the optimum matching conditions of the plasma in the focus. The dimensions of the plasma focus device are, inner electrode radius = 2 cm, outer electrode radius = 5.5 cm, and its length = 8 cm. It was found that the maximum magnetic energy of 12.26 kJ has to be delivered to plasma focus whose density is 10 19 /cm 3 at focusing time of 2.55 μs and with total external inductance of 24.2 n H. The same method is used to evaluate the optimum matching conditions for the previous coaxial discharge system which had inner electrode radius = 1.6 cm, outer electrode radius = 3.3 cm and its length = 31.5 cm. These conditions are charging voltage = 12 kV, capacity of the condenser bank = 430 μf, plasma focus density = 10 19 /cm 3 focusing time = 8 μs and total external inductance = 60.32 n H.3 fig., 2 tab

  15. High energy ions and energetic plasma irradiation effects on aluminum in a Filippov-type plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Roshan, M.V. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)], E-mail: mroshan20@yahoo.com; Rawat, R.S. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); Babazadeh, A.R.; Emami, M.; Sadat Kiai, S.M. [Plasma Physics Research Center, AEOI, 14155-1339 Tehran (Iran, Islamic Republic of); Verma, R.; Lin, J.J.; Talebitaher, A.R.; Lee, P.; Springham, S.V. [National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)

    2008-12-30

    High energy ions and energetic plasma irradiation of aluminum cathode inserts have been accomplished in nitrogen and argon filled plasma focus device. The Filippov-type plasma focus facility, Dena, with 288 {mu}F capacitor bank and charging voltage of 25 kV (90 kJ maximum storage energy) was first optimized for strong ion beam generation for nitrogen and argon gases by maximizing hard X-ray emission efficiency. X-ray diffraction analysis as well as scanning electron microscopy along with energy dispersive X-ray spectroscopy carried out to study the structural, morphological and compositional profile of the treated samples. Change in preferred orientation, emergence of meta-stable phases, generation of copper micro-droplets, and production of cracks across the sample are demonstrated and discussed. The micro-hardness measurements in Vickers scale reveal that after ion irradiation, the surface hardness of samples is reduced.

  16. Dense Plasma Focus Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Shengtai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jungman, Gerard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hayes-Sterbenz, Anna Catherine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    The mechanisms for pinch formation in Dense Plasma Focus (DPF) devices, with the generation of high-energy ions beams and subsequent neutron production over a relatively short distance, are not fully understood. Here we report on high-fidelity 2D and 3D numerical magnetohydrodynamic (MHD) simulations using the LA-COMPASS code to study the pinch formation dynamics and its associated instabilities and neutron production.

  17. Plasma focus project

    International Nuclear Information System (INIS)

    Sahlin, H.L.

    1975-12-01

    The primary objective of this project is to provide a relatively simple pulsed power source for high density pulsed fusion studies with a variety of DT and other fusion microexplosion targets. The plasma focus operated on DT at 1 MJ should produce greater than or equal to 10 15 DT neutrons per pulse corresponding to 2800 J of nuclear energy release and for low pressure operation and appropriately configured high Z anode center should yield an x-ray burst of about 1000 J with a substantial fraction of this x-ray energy concentrated in the 5-100 kV range. Because of its x-ray and neutron production potential, the operation of the focus as an x-ray source is also under study and an initial design study for a repetitively pulsed 1 MJ plasma focus as a pulsed neutron materials testing source has been completed. The plasma focus seems particularly appropriate for application as a materials testing source for pulsed fusion reactors, for example, based on laser driven fusion microexplosions. The construction status of the device is described

  18. Developing a plasma focus research training system for the fusion energy age

    International Nuclear Information System (INIS)

    Lee, S.

    2014-01-01

    The 3 kJ UNU/ICTP Plasma Focus Facility is the most significant device associated with the AAAPT (Asian African Association for Plasma Training). In original and modified/upgraded form it has trained generations of plasma focus (PF) researchers internationally, producing many PhD theses and peer-reviewed papers. The Lee Model code was developed for the design of this PF. This code has evolved to cover all PF machines for design, interpretation and optimization, for derivation of radiation scaling laws; and to provide insights into yield scaling limitations, radiative collapse, speed-enhanced and current-stepped PF variants. As example of fresh perspectives derivable from this code, this paper presents new results on energy transfers of the axial and radial phases of generalized PF devices. As the world moves inexorably towards the Fusion Energy Age it becomes ever more important to train plasma fusion researchers. A recent workshop in Nepal shows that demand for such training continues. Even commercial project development consultants are showing interest. We propose that the AAAPT-proven research package be upgraded, by modernizing the small PF for extreme modes of operation, switchable from the typical strong-focus mode to a slow-mode which barely pinches, thus producing a larger, more uniform plasma stream with superior deposition properties. Such a small device would be cost-effective and easily duplicated, and have the versatility of a range of experiments from intense multi-radiation generation and target damage studies to superior advanced-materials deposition. The complementary code is used to reference experiments up to the largest existing machine. This is ideal for studying machine limitations and scaling laws and to suggest new experiments. Such a modernized versatile PF machine complemented by the universally versatile code would extend the utility of the PF experience; so that AAAPT continues to provide leadership in pulsed plasma research training in

  19. Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus

    International Nuclear Information System (INIS)

    Mohammadnejad, M.; Pestehe, S. J.; Mohammadi, M. A.

    2013-01-01

    The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy

  20. Time resolved energy spectrum of the axial ion beam generated in plasma focus discharges

    International Nuclear Information System (INIS)

    Bostick, W.H.; Kilic, H.; Nardi, V.; Powell, C.W.

    1993-01-01

    The energy spectrum of the deuteron beam along the electrode axis (0 (degree) ) in a plasma focus discharge has been determined with a time of flight (TOF) method and with a differential filter method in the ion energy interval E = 0.3-9 MeV. The ion TOF method is applied to single-ion pulse events with an ion emission time t(E) that is only weakly dependent on the ion energy E for E > 0.3 MeV. The correlation of the ion beam intensity with the filling pressure, the neutron yield and the hard X-ray intensity is also reported. (author). 11 refs, 10 figs

  1. Pulsed neutron generators based on plasma focus devices of low energy

    International Nuclear Information System (INIS)

    Silva, Patricio; Moreno, Jose; Soto, Leopoldo

    2003-01-01

    The plasma focus is a pulsed neutron source especially suited for applications because it reduces the danger of contamination of conventional isotopic radioactive sources. As first stage of a program to design a repetitive pulsed neutron generator for industrial applications we constructed two very small plasma focus operating at an energy level of the order of a) tens of joules (PF-50J, 160nF capacitor bank, 20-35 kV, 32-100J, ∼150ns first quarter of period) and b) hundred of joules (PF-400J, 880nF, 20-35kV, 176-539J, ∼300ns first quarter of period). In this article we present results related to design and construction of these small plasma foci (PF-50J and PF-400J). Neutron yield vs. deuterium. pressure has been obtained, a maximum emission of the order of 7x10 4 and 10 6 neutrons per shot has been measured in the PF-50J and PF-400J respectively (author)

  2. Observation of helical structure in a low energy plasma focus pinch

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1989-01-01

    Helical structure and hot spots were observed in a Mather-type plasma focus operated at 3 KJ of bank energy. The experiments were carried out with the help of a fast optical framing camera and two X-ray pin-hole cameras with different filters. It was observed that initially a conical pinch (with base diameter of 6 mm and length of 14 mm) with temperature of ≅ 10 2 eV was formed. This pinch disintegrated after ≅ 50 ns by a single lobe sausage instability into a central high temperature (≅ 10 3 eV) filament of 1 mm diameter and 8 mm length containing a high emissivity helical structure. This helix is probably responsible for generation of axial magnetic field and relaxation of the focus pinch. Hot spots of high X-ray intensity and temperature (≅ 10 3 eV) were also observed much beyond the filament region. (author)

  3. Neutron and X-ray emission studies in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Murtaza, G. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Qamar, S. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Ahmad, I. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Beg, M.M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics

    1996-03-01

    In a low energy Mather-type plasma focus energized by a single 32 {mu}F capacitor, the X-ray and neutron emission is investigated using time-integrated and time-resolved detectors. The X-ray emission profile has a width (FWHM) of 40-50 ns. The neutron emission profile is broader compared to the X-ray emission profile and also delayed by 30-40 ns. To identify different regimes of X-ray emission, an X-ray pin-hole camera along with different absorption filters is employed. While the X-ray emission is high within a narrow pressure range of 2.0-2.5 mbar, the neutron emission is intense for a wider range of 1.0-4.5 mbar. The intense X-ray emission seems to originate from the axially moving shock wave. These results also indicate rather different production mechanisms for X-ray and neutron emission. Also on comparing the X-ray images with Al(2 {mu}m), Al(5 {mu}m), Al(9 {mu}m) filters, we find that the bulk of X-rays from the focus filament have energies less than 2 keV. (orig.).

  4. Effect of gas filling pressure and operation energy on ion and neutron emission in a medium energy plasma focus device

    Science.gov (United States)

    Niranjan, Ram; Rout, R. K.; Srivastava, Rohit; Kaushik, T. C.

    2018-03-01

    The effects of gas filling pressure and operation energy on deuterium ions and neutrons have been studied in a medium energy plasma focus device, MEPF-12. The deuterium gas filling pressure was varied from 1 to 10 mbar at an operation energy of 9.7 kJ. Also, the operation energy was varied from 3.9 to 9.7 kJ at a deuterium gas filling pressure of 4 mbar. Time resolved emission of deuterium ions was measured using a Faraday cup. Simultaneously, time integrated and time resolved emissions of neutrons were measured using a silver activation detector and plastic scintillator detector, respectively. Various characteristics (fluence, peak density, and most probable energy) of deuterium ions were estimated using the Faraday cup signal. The fluence was found to be nearly independent of the gas filling pressure and operation energy, but the peak density and most probable energy of deuterium ions were found to be varying. The neutron yield was observed to be varying with the gas filling pressure and operation energy. The effect of ions on neutrons emission was observed at each operation condition.

  5. Plasma focus as an x-ray source for tailoring of radiation in different energy windows

    International Nuclear Information System (INIS)

    Zakaullah, M.; Alamgir, K.; Shafiq, M.; Sharif, M.

    2001-01-01

    A low energy (2.3 kj) plasma focus energized by a single 32 micro f capacitor charged at 12 kv with filling gases hydrogen, neon and argon is investigated as an X-ray source. Experiments are conducted with a copper and an aluminum anode. Specifically, attention in given to tailoring the radiation in different windows, e. g. 1.2-1.3 keV, 1.3-1.5 keV, 2.5-5 keV and Cu-Ka line radiation. The highest X-ray emission is observed with neon filling and the copper anode in the 1.2-1.3 keV window, which speculated to be generated due to recombination of hydrogen like neon ions with a few eV to a few 10s of eV electrons. The wall-plug efficiency of the device is found to be 4%. The other significant emission occurs with Hydrogen filling, which exhibits wall plug efficiency of 1.7% for over all x-ray emission and 0.35% for Cu- Ka line radiation. The emission is dominated by the interaction of electrons in the current sheath with the anode tip. The emission with the aluminum anode and hydrogen filling is up to 10 j, which corresponds to wall-plug efficiency of 0.4%. The X-ray emission with argon filling is less significant. (author)

  6. Fusion reaction yield in focused discharges with variable energy and plasma fine structure

    International Nuclear Information System (INIS)

    Bortolotti, A.; Brzosko, J.S.; Chiara, P. De; Kilic, H.; Mezzetti, F.; Nardi, V.; Powell, C.; Wang, J.

    1992-01-01

    The same linear correlation between the distribution parameters (ΔT and Max ΔV) of the radial current density J between electrodes and the fusion reaction yield per pulse, Y, in the plasma focus (PF) pinch was quantitatively determined from different PF machines. Contact prints of current-sheath fragments (CSF) ejected from the pinch are obtained from 2.5-MeV-D + ions. CSF's show the same submillimetric fine structure of the pinch. (author) 3 refs., 2 tabs

  7. Proton acceleration: new developments for focusing and energy selection, and applications in plasma physics

    Science.gov (United States)

    Audebert, P.

    2007-11-01

    In the last few years, intense research has been conducted on laser-accelerated ion sources and their applications. These sources have exceptional properties, i.e. high brightness and high spectral cut-off, high directionality and laminarity, short burst duration. We have shown that for proton energies >10 MeV, the transverse and longitudinal emittance are respectively example point-projection radiography with unprecedented resolution. We will show example of such time and space-resolved radiography of fast evolving fields, either of associated with the expansion of a plasma in vacuum [*] or with the propagation of a ICF-relevant laser beam in an underdense plasma. These proton sources also open new opportunities for ion beam generation and control, and could stimulate development of compact ion accelerators for many applications.

  8. Energy transformation in Z-pinch and plasma focus discharges with wire and wire-in-liner loads

    International Nuclear Information System (INIS)

    Kubes, Pavel; Kravarik, Jozef; Klir, Daniel; Scholz, Marek; Paduch, Marian; Tomaszewski, Krzysztof; Karpinski, Leslaw; Bakshaev, Yury L.; Blinov, Peter I.; Chernenko, Andrey S.; Dan'ko, Sergey A.; Korolev, Valery D.; Shashkov, Andrey Y.; Tumanov, Victor I.

    2002-01-01

    The results of the study of the Z-pinch and plasma-focus plasmas at presence of the axial C, Al, or Cu wires of sufficient high diameter are discussed in this paper. The wire was positioned on the top of the inner electrode of the PF 1000 plasma focus (1.8 MA, IPPLM Warsaw), or at the axis with or without the tungsten or alumine wire array load at the S-300 facility (3 MA, RRC Kurchatov Institute, Moscow), and at the axis of the small Z-pinch Z-150 (50 kA, CTU Prague). The plasma corona around the wire was generated both by the current going through the wires and by the implosion of the wire array or of the current sheath. The experiments showed interesting results often observed in some shots of Z-pinch type discharges - existence of helical structures, two relatively long and stable pinch phases, oscillation of pinch diameter, and back return of the plasma exploding from the pinch. All these observed phenomena can be evolved by spontaneous self-generation and transformation of the axial magnetic field in the pinch during the plasma implosion and explosion. A configuration of axial and azimuthal magnetic field confines the plasma and later transforms or dissipates during a few tens or hundreds ns. A fast transformation of internal magnetic fields can induce a sufficiently high electric field for generation of keV particles and radiation. Study and usage of Z-pinch discharges is connected with solving of two principal problems, limitation of instability development and a way of generation of high energy particles and radiation. The first problem is partially solved by the faster increase of the current, by better cylindrical symmetry of the load and plasma, by higher density of the plasma or by the presence of a stronger magnetized plasma

  9. Effects of fusion relevant transient energetic radiation, plasma and thermal load on PLANSEE double forged tungsten samples in a low-energy plasma focus device

    Science.gov (United States)

    Javadi, S.; Ouyang, B.; Zhang, Z.; Ghoranneviss, M.; Salar Elahi, A.; Rawat, R. S.

    2018-06-01

    Tungsten is the leading candidate for plasma facing component (PFC) material for thermonuclear fusion reactors and various efforts are ongoing to evaluate its performance or response to intense fusion relevant radiation, plasma and thermal loads. This paper investigates the effects of hot dense decaying pinch plasma, highly energetic deuterium ions and fusion neutrons generated in a low-energy (3.0 kJ) plasma focus device on the structure, morphology and hardness of the PLANSEE double forged tungsten (W) samples surfaces. The tungsten samples were provided by Forschungszentrum Juelich (FZJ), Germany via International Atomic Energy Agency, Vienna, Austria. Tungsten samples were irradiated using different number of plasma focus (PF) shots (1, 5 and 10) at a fixed axial distance of 5 cm from the anode top and also at various distances from the top of the anode (5, 7, 9 and 11 cm) using fixed number (5) of plasma focus shots. The virgin tungsten sample had bcc structure (α-W phase). After PF irradiation, the XRD analysis showed (i) the presence of low intensity new diffraction peak corresponding to β-W phase at (211) crystalline plane indicating the partial structural phase transition in some of the samples, (ii) partial amorphization, and (iii) vacancy defects formation and compressive stress in irradiated tungsten samples. Field emission scanning electron microscopy showed the distinctive changes to non-uniform surface with nanometer sized particles and particle agglomerates along with large surface cracks at higher number of irradiation shots. X-ray photoelectron spectroscopy analysis demonstrated the reduction in relative tungsten oxide content and the increase in metallic tungsten after irradiation. Hardness of irradiated samples initially increased for one shot exposure due to reduction in tungsten oxide phase, but then decreased with increasing number of shots due to increasing concentration of defects. It is demonstrated that the plasma focus device provides

  10. Hard TiCx/SiC/a-C:H nanocomposite thin films using pulsed high energy density plasma focus device

    International Nuclear Information System (INIS)

    Umar, Z.A.; Rawat, R.S.; Tan, K.S.; Kumar, A.K.; Ahmad, R.; Hussain, T.; Kloc, C.; Chen, Z.; Shen, L.; Zhang, Z.

    2013-01-01

    Highlights: •The energetic ions and electron beams are used to synthesize TiC x /SiC/a-C:H films. •As-deposited crystalline and hard nanocomposite TiC x /SiC/a-C:H films are synthesized. •Very high average deposition rates of 68 nm/shot are achieved using dense plasma focus. •The maximum hardness of 22 GPa is achieved at the surface of the film. -- Abstract: Thin films of TiC x /SiC/a-C:H were synthesized on Si substrates using a complex mix of high energy density plasmas and instability accelerated energetic ions of filling gas species, emanated from hot and dense pinched plasma column, in dense plasma focus device. The conventional hollow copper anode of Mather type plasma focus device was replaced by solid titanium anode for synthesis of TiC x /SiC/a-C:H nanocomposite thin films using CH 4 :Ar admixture of (1:9, 3:7 and 5:5) for fixed 20 focus shots as well as with different number of focus shots with fixed CH 4 :Ar admixture ratio 3:7. XRD results showed the formation of crystalline TiC x /SiC phases for thin film synthesized using different number of focus shots with CH 4 :Ar admixture ratio fixed at 3:7. SEM results showed that the synthesized thin films consist of nanoparticle agglomerates and the size of agglomerates depended on the CH 4 :Ar admixture ratio as well as on the number of focus shots. Raman analysis showed the formation of polycrystalline/amorphous Si, SiC and a-C for different CH 4 :Ar ratio as well as for different number of focus shots. The XPS analysis confirmed the formation of TiC x /SiC/a-C:H composite thin film. Nanoindentation results showed that the hardness and elastic modulus values of composite thin films increased with increasing number of focus shots. Maximum values of hardness and elastic modulus at the surface of the composite thin film were found to be about 22 and 305 GPa, respectively for 30 focus shots confirming the successful synthesis of hard composite TiC x /SiC/a-C:H coatings

  11. Measurement of fluences and energies of D+ emitted from the plasma focus in capacitor bank energy interval of 1-20 kJ

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Sevic, D.; Zaric, A.; Lakicevic, I.; Popovic, S.; Vukovic, J.; Konjevic, Dj.; Puric, J.; Cuk, M.

    1993-01-01

    Diagnostics of D + ions emitted from the D-plasma focus (PF) have been performed with CR-39 and CA 80-15 detectors. Fluences and energies of D + ions were measured for the capacitor bank energy range of 1-20 kJ. Angular distribution of D + was measured usign a pin hole camera placed at different positions in PF chamber. Energy of D + ions was estimated by diameters measurement of D + -tracks. Incident angle was 90 o . (Author)

  12. Measurement of electron- and ion beam energies and currents in a plasma focus discharge

    International Nuclear Information System (INIS)

    Yamamoto, Toshikazu; Kondoh, Yoshiomi; Shimoda, Katsuji; Hirano, Katsumi

    1982-01-01

    Measurements of energetic particle beams in a plsma focus with a Mather type device are presented. Rogowski coils are used for time-resolved measurement, and solid-state nuclear track detectors for time-integrated measurement of the beams. In the upstream direction with respect to the discharge current, only the electron beam with the maximum current of several kA was detected, which was approximately one percent of the discharge current. The electron energies of the beam were spread from 0.1 to 1 MeV. In the downstream direction, two successive emissions of ions were observed. The first emission had an extremely high energy of the order of some MeV and a low beam current of less than 10 A. The second emission, the main part of the ion beam, with energies of 100 - 800 keV, followed the first one with a time lag of several tens of nanoseconds, and the beam current reached several tens of amperes. (author)

  13. Magnetic tearing in plasma focus

    International Nuclear Information System (INIS)

    Sharkawy, W.

    1994-01-01

    A plasma focus device used is Mather type filled with hydrogen gas at pressure between 0.1 and 1 torr. When connected to a large capacitor ≤10 KV a discharge is started with peak current 100 KA. Under the influence of the radial electric field E r , due to the potential between electrodes, and B φ the plasma will drift in the axial direction with velocity cE r /B φ . An induced axial magnetic field B z has been detected which due to sheath velocity. A propagation of magnetosonic wave has been observed with velocity ≅10 3 m sec -1 . Such a wave might be excited when the magnetic pressure is much greater than the plasma kinetic pressure B 2 /8π>nKT. Assuming (MHD) to be stable, Tearing model was driven which generally has smaller growth rates than (MHD) modes. Using the designed theoretical model and the plasma parameters the electron energy dΦ/dt=Ba 2 /τ R was calculated to be 2.22 KeV, which is comparable with that detected from X-ray measurements. (author)

  14. Measurement of the time dependent neutron energy spectrum in the 'DENA' plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Abdollahzadeh, M [Department of Physics, Imam Husein University, PO Box 16575-347, Tehran (Iran, Islamic Republic of); Sadat kiai, S M [Nuclear Science and Technology Research Institute (NSTRI), Nuclear Science Research School, A.E.O.I., PO Box 14155-1339, Tehran (Iran, Islamic Republic of); Babazadeh, A R [Physics Department, Qom University, PO Box 37165, Qom (Iran, Islamic Republic of)

    2008-10-15

    An extended time of flight method is used to determine the time dependent neutron energy spectrum in the Filippove type 'Dena' plasma focus (90 kJ, 25 kV, 288 {mu}F), filled with deuterium gas. An array of 5 detectors containing NE-102 plastic scintillators+photomultipliers is used. The number and position of the detectors are determined by a Monte Carlo program and the MCNP code. This paper briefly describes the simulation method and presents the experimental measurements and their results. The mechanisms of neutron production (thermonuclear and non-thermonuclear) and their time variations are discussed.

  15. Plasma focus as a pulsed power source

    International Nuclear Information System (INIS)

    Sahlin, H.; McFarland, G.; Barlett, R.; Gullickson, R.

    1975-01-01

    The plasma focus is a remarkable natural phenomena that achieves significant space-time compression of both particle and field energy. Depending on the mode of operation, about 20 percent of the bank energy can be concentrated into the kinetic energy of a thin, dense, cylindrically convergent gas shell, or into a small-diameter, high-ν/γ relativistic electron burst and oppositely directed ion burst. The kinetic energy of the fast ions and electrons can exceed the applied voltage by a factor of greater than 100. The different modes of energy concentration by the plasma focus are presented and discussed both in terms of their role in the direct yield of the focus and for the case of a plasma focus supplemented by various fusionable targets

  16. Correlation of the neutron yield from the plasma focus upon variations in the magnetic field energy of the discharge circuit

    Science.gov (United States)

    Ablesimov, V. E.; Dolin, Yu. N.; Kalinychev, A. E.; Tsibikov, Z. S.

    2017-10-01

    The relation between neutron yield Y and magnetic field energy variations Δ W in the discharge circuit has been studied for a Mather-type plasma-focus camera. The activation technique (activation of silver isotopes) has been used to measure the integral yield of DD neutrons from the source. The time dependence of the neutron yield has been recorded by scintillation detectors. For the device used in the investigations, the neutron yield exhibits a linear dependence on variations in the magnetic field energy Δ W in the discharge circuit at the instant of neutron generation. It is also found that this dependence is related to the initial deuteron pressure in the discharge chamber.

  17. Measurement of fluences and energies of D{sup +} emitted from the plasma focus in capacitor bank energy interval of 1-20 kJ

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Sevic, D.; Zaric, A.; Lakicevic, I.; Popovic, S.; Vukovic, J.; Konjevic, Dj. [Belgrade Univ. (Yugoslavia). Inst. za Fiziku; Puric, J.; Cuk, M. [Belgrade Univ. (Yugoslavia). Faculty of Physics

    1993-12-31

    Diagnostics of D{sup +} ions emitted from the D-plasma focus (PF) have been performed with CR-39 and CA 80-15 detectors. Fluences and energies of D{sup +} ions were measured for the capacitor bank energy range of 1-20 kJ. Angular distribution of D{sup +} was measured usign a pin hole camera placed at different positions in PF chamber. Energy of D{sup +} ions was estimated by diameters measurement of D{sup +} -tracks. Incident angle was 90{sup o}. (Author).

  18. Detection of x-rays emitted from a plasma focus device with energy of 2.8 KJ, and its applications in plasma diagnostic and radiography

    International Nuclear Information System (INIS)

    AL-Hawat, Sh.; Akel, M.

    2011-06-01

    The local plasma focus device was modified by replacing the old capacitors (25μF,20 kV ,1.43μH ) and the open spark gap by new capacitors with (25μF,20 kV ,200 nH ) and a new closed spark gap, so instead of a current of 50 kA as a maximum value we obtained a maximum current about 120 kA. The modified device is capable now to generate x-rays, which was confirmed by taking some radiographies for metallic pieces, electronic elements and others . In addition to that some diagnostics were carried out on the device using Ohm voltage divider to record voltage curves, Rogovskii coil for measuring the current, and five channel diodes to evaluate the temporal evolution of x-rays generated in the device working on argon vs. pressure and voltage. The generation of the soft x-ray emission in a low energy 2.8 kJ plasma focus device operated with argon using a detector of five PIN-Si BPX-65 diodes filtered with different foils of Mylar, Al and Cu. Spectral analysis using the recorded x-ray signals ratio method shows that there are two components in the x-ray emissions: one arising from the focused argon plasma with temperature of 2.5 keV and the other arising from the electron beam activity on copper anode, where the second component is predominant in most of investigated experiments due to the used of solid anode. Numerical experiments were carried out using five phases radiative Lee model RADPF5.15d-dd with N 2 , O 2 , Ar, Ne gases on plasma focus device AECS PF1-2 (or PF SY1-2) for its characterization and soft x-ray optimization. (author)

  19. Instabilities in the plasma focus

    International Nuclear Information System (INIS)

    Kaeppeler, H.J.

    1975-03-01

    The plasma focus was studied by many research teams in view of a possible approach to controlled thermonuclear fusion. Though it is questionable whether the plasma focus will ever lead to a fusion reactor, it nevertheless constitutes a strong source of neutron, X- and gamma radiation for simulating fusion reactor conditions. Furthermore, the plasma focus yields very high temperatures (10 7 K) and densities (> 10 19 cm -3 ) and thus provides interesting conditions for the study of high density plasmas. This review paper starts with a description of the compression stage of the focussing plasma, using a snow-plough model. It is shown that sophisticated MHD calculations substantiate the snowplough theory, but are not suited to describe the phenomena in the final compressed stage. For this purpose, a particle-in-cell calculation is employed, yielding a beam-beam collision model for the neutron production. Experimental evidence indicates that neutron production is associated with the appearence of m = O instabilities and is the direct result of collisions between anomalously accelerated ions. One of the mechanisms of ion acceleration are strong local electric fields. Another possible mechanism can bee seen in beam-plasma instabilities caused by runaway electrons. The analytical derivation of the dispersion relation for plasma focus conditions including runaway effect is discussed (orig.) [de

  20. Technology of a small plasma focus

    International Nuclear Information System (INIS)

    Lee, S.

    1990-01-01

    This paper reviews plasma focus technology, including the underlying dynamic and energy balance theory, scaling of the neutron yield, cost effectiveness of the design, as well as the main subsystems, e.g., capacitor bank, spark-gap switch and triggering electronics, the plasma focus tube, some simple diagnostics, and a high-voltage charger. It discusses the range of densities and temperatures available with a small plasma focus, and the type of experiments and applications that can be carried out with it. 61 refs, 21 figs

  1. Stability of expanded plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.

    1994-01-01

    In this study, the stabilization of the expanded plasma focus formed by 4.5 kJ plasma focus device of Mather type by magnetic field is presented. The experimental results of the induced axial magnetic field and electric probe measurements of the expanded plasma focus show that, the plasma consists of three plasmoids, electron temperature measurements off the plasmoids at a point close to the muzzle are 26 eV, 30 eV and 27 eV respectively and the electron densities are 6.6 x 10 14 , 6.1 x 10 14 / cm 3 respectively. The presence of external axial magnetic field (B 2 = 1.6 kg) at the mid distance between the breech and the muzzle has a less effect on the stability of expanded focus and it causes a restriction for the plasma motion. the electron temperature of the three plasmoids are found to increase in that case by 23%, 18.5% respectively. When this axial magnetic field is applied at the muzzle end, it leads to a more stable expanded plasma focus which consists mainly of one plasmoid with electron temperature of 39 eV and density of 3.4 x 10 14 / cm 3 . 5 figs

  2. Plasma focusing in coaxial gun

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.; El-Khalafawy, T.

    1986-01-01

    A capacitor bank has been discharged between two coaxial electrodes of 6.6 cm outer diameter, 3.2 cm inner diameter and length of 31.5 cm. filled with hydrogen gas at pressure of 310 μHg. Results show that, the axial and radial plasma current reach a maximum value at a position adjacent to the gun muzzle, at which the plasma focus occurs. The measurement of the electron temperature and density and azimuthal electric field along the axis of the expansion chamber, gives a maximum value at z∼18 cm from the gun muzzle, while the axial plasma current and velocity has a minimum value at that position. These results indicate that a second point of a plasma focus has been formed at z∼18 cm from the gun muzzle, along the axis of the expansion chamber

  3. Catastrophe in plasma focus evolution

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1984-07-01

    A theory of generating strong electric field in a dense plasma column in plasma focus is established by applying the formula for the electron thermal conductivity in destroyed magnetic surfaces like those in tokamaks. The origin of the electric field may be from abrupt rise of plasma resistivity when the irregularity of magnetic field is weak. However, the electric field can be from the inductive origin in case the irregularity attains a certain level. Both origin should be mixed up depending on the magnitude of the irregularity. (author)

  4. Beam acceleration in plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Banjanac, R.; Dragic, A.; Maric, Z.; Stanojevic, J.; Udovicic, V. E-mail: udovicic@atom.phy.bg.ac.yu; Vukovic, J

    2001-06-01

    The proton beam emission from the small 8 kJ plasma focus device operated with the H{sub 2} filling was analyzed. Maximum energy and yield were obtained using NTD. The fast protons were registered with the energy up to 500 keV using the polycarbonate absorbers with the different thickness.

  5. Beam acceleration in plasma focus device

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Banjanac, R.; Dragic, A.; Maric, Z.; Stanojevic, J.; Udovicic, V.; Vukovic, J.

    2001-01-01

    The proton beam emission from the small 8 kJ plasma focus device operated with the H 2 filling was analyzed. Maximum energy and yield were obtained using NTD. The fast protons were registered with the energy up to 500 keV using the polycarbonate absorbers with the different thickness

  6. Plasma-focused cyclic accelerators

    International Nuclear Information System (INIS)

    Mondelli, A.A.; Chernin, D.P.

    1985-01-01

    The use of ambient plasma to neutralize the transverse forces of an intense particle beam has been known for many years. Most recently, the so-called ion-focused regime (IFR) for beam propagation has been used as a means of focusing intense electron beams in linear accelerators and suggested for injecting an electron beam across magnetic field lines into a high-current cyclic accelerator. One technique for generating the required background plasma for IFR propagation is to use a laser to ionize ambient gas in the accelerator chamber. This paper discusses an alternative means of plasma production for IFR, viz. by using RF breakdown. For this approach the accelerator chamber acts as a waveguide. This technique is not limited to toroidal accelerators. It may be applied to any accelerator or recirculator geometry as well as for beam steering and for injection or extraction of beams in closed accelerator configurations

  7. A study of plasma focus

    International Nuclear Information System (INIS)

    Hirano, Katsumi; Majima, Kazuo

    1976-01-01

    The behavior of the plasma acceleration between electrodes, the phenomena due to the pinch effect at the top of the electrodes and the neutron emission mechanism were experimentally studied. The plasma focus device was a Mather type coaxial discharge device, and the instruments used for the present purpose were a Rogoski coil, an image converter camera, a scintillation detector and a silver foil activation counter. The results of the present experiment were as follows. Plasma focus was not definitely made under the same condition. When the focus was seen, a dip was observed in the discharge wave form, and the emissions of X-ray and neutrons were detected. The angular anisotropy of neutron emission was observed, and corresponds to a beam target model. The phenomena showing the occurrence of focus were seen, when the current sheet was produced at a delayed time after discharge, and arrived at the muzzle with large velocity. The relation between the number of emitted neutrons and the velocity of the current sheet was obtained, whereas no systematic relation exists between the number of emitted neutrons and the velocity of pinch. When the focus was not observed, no dip was seen in current wave form, and the emissions of X-ray and neutrons were not detected. The reason of no focus was considered. (Kato, T.)

  8. Axial sheath dynamics in a plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; El-Khalafawy, T.A.; Masoud, M.M.

    1990-01-01

    This paper presents the result of investigation with a 10 kJ Mather type plasma focus. It is operated in hydrogen gas at ambient pressure of 0.15--1 torr and charging voltage of 8--11 kV. Radial distribution of the current sheath density with axial distance has been estimated. Plasma rotation in the expansion chamber in the absence of external magnetic field has been detected. A plasma flare from the plasma focus region propagating in the radial direction has been observed. Streak photography shows two plasma streams flowing simultaneously out of the muzzle. The mean energy of the electron beam ejected from the pinch region of the focused plasma, was measured by retarding field analyzer to be 0.32 keV. The electron temperature of the plasma focus at peak compression was determined by measuring the X-ray intensity as a function of absorber thickness at a distance of 62 cm from the focus. The electron temperature has been found to 3 keV

  9. The Upgraded Plasma Focus Installation > - The Installation >

    International Nuclear Information System (INIS)

    Krokhin, O.N.; Nikulin, V.Ya.; Babenko, B.A.; Gorbunov, D.N.; Gurei, A.E.; Kalachev, N.V.; Kozlova, T.A.; Malafeev, Yu.S.; Polukhin, S.N.; Sychev, A.A.; Tikhomirov, A.A.; Tsybenko, S.P.; Volobuev, I.V.

    1999-01-01

    The paper presents the upgraded plasma focus installation > - the installation > and some preliminary experimental results. The total energy stored in capacity bank is now 400 kJ, current - 5 MA with the rise time 3.5 μs. The investigation is targeted on the study of near electrode processes and its influence on plasma dynamics in a special operating regime of Filippov type PF - Hard X-ray regime. (author)

  10. Plasma-focused cyclic accelerators

    International Nuclear Information System (INIS)

    Mondelli, A.A.; Chernin, D.P.

    1985-01-01

    The use of ambient plasma to neutralize the transverse forces of an intense particle beam has been known for many years. Most recently, the so-called ion-focused regime (IFR) for beam propagation has been used as a means of focusing intense electron beams in linear accelerators and suggested for injecting an electron beam across magnetic field lines into a high-current cyclic accelerator. One technique for generating the required background plasma for IFR propagation is to use a laser to ionize ambient gas in the accelerator chamber. For cyclic accelerators a technique is required for carrying the plasma channel and the beam around a bend. Multiple laser-generated channels with dipole magnetic fields to switch the beam from one channel to the next have been tested at Sandia. This paper discusses an alternative means of plasma production for IFR, viz. by using rf breakdown. For this approach the accelerator chamber acts as a waveguide. With a suitable driving frequency, a waveguide mode can be driven which has its peak field intensity on the axis with negligible fields at the chamber walls. The plasma production and hence the beam propagation is thereby isolated from the walls. This technique is not limited to toroidal accelerators. It may be applied to any accelerator or recirculator geometry as well as for beam steering and for injection or extraction of beams in closed accelerator configurations

  11. EDITORIAL: Focus on Plasma Medicine

    Science.gov (United States)

    Morfill, G. E.; Kong, M. G.; Zimmermann, J. L.

    2009-11-01

    'Plasma Healthcare' is an emerging interdisciplinary research topic of rapidly growing importance, exploring considerable opportunities at the interface of plasma physics, chemistry and engineering with life sciences. Some of the scientific discoveries reported so far have already demonstrated clear benefits for healthcare in areas of medicine, food safety, environmental hygiene, and cosmetics. Examples include ongoing studies of prion inactivation, chronic wound treatment and plasma-mediated cancer therapy. Current research ranges from basic physical processes, plasma chemical design, to the interaction of plasmas with (i) eukaryotic (mammalian) cells; (ii) prokaryotic (bacteria) cells, viruses, spores and fungi; (iii) DNA, lipids, proteins and cell membranes; and (iv) living human, animal and plant tissues in the presence of biofluids. Of diverse interests in this new field is the need for hospital disinfection, in particular with respect to the alarming increase in bacterial resistance to antibiotics, the concomitant needs in private practices, nursing homes etc, the applications in personal hygiene—and the enticing possibility to 'design' plasmas as possible pharmaceutical products, employing ionic as well as molecular agents for medical treatment. The 'delivery' of the reactive plasma agents occurs at the gaseous level, which means that there is no need for a carrier medium and access to the treatment surface is optimal. This focus issue provides a close look at the current state of the art in Plasma Medicine with a number of forefront research articles as well as an introductory review. Focus on Plasma Medicine Contents Application of epifluorescence scanning for monitoring the efficacy of protein removal by RF gas-plasma decontamination Helen C Baxter, Patricia R Richardson, Gaynor A Campbell, Valeri I Kovalev, Robert Maier, James S Barton, Anita C Jones, Greg DeLarge, Mark Casey and Robert L Baxter Inactivation factors of spore-forming bacteria using low

  12. Optimum Design of Plasma Focus

    International Nuclear Information System (INIS)

    Ramos, Ruben; Gonzalez, Jose; Clausse, Alejandro

    2000-01-01

    The optimum design of Plasma Focus devices is presented based in a lumped parameter model of the MHD equations.Maps in the design parameters space are obtained, which determine the length and deuterium pressure required to produce a given neutron yield.Sensitivity analyses of the main effective numbers (sweeping efficiencies) was performed, and lately the optimum values were determined in order to set a basis for the conceptual design

  13. Application of a Bonner sphere spectrometer for determination of the energy spectra of neutrons generated by ≈1 MJ plasma focus

    Czech Academy of Sciences Publication Activity Database

    Králík, M.; Krása, Josef; Velyhan, Andriy; Scholz, M.; Ivanova-Stanik, I.M.; Bienkowska, B.; Miklaszewski, R.; Schmidt, H.; Řezáč, K.; Klír, D.; Kravárik, J.; Kubeš, P.

    2010-01-01

    Roč. 81, č. 11 (2010), 113503/1-113503/5 ISSN 0034-6748 R&D Projects: GA MŠk LA08024 Grant - others:FP-6 EU(XE) RITA-CT2006-26095 Institutional research plan: CEZ:AV0Z10100523 Keywords : plasma focus * fusion DD neutrons * Bonner sphere spectrometer * energy spectra of scattered neutrons * unfolded and calculated spectra Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.598, year: 2010

  14. Dense plasma focus - a literature review

    International Nuclear Information System (INIS)

    Tendys, J.

    1976-01-01

    The dense plasma focus (DPF) is a convenient source of short, intense neutron pulses, and dense, high temperature plasma. This review of the literature on the DPF indicates that its operation is still not understood, and attempts to show where the present data is either inadequate or inconsistent. Because the plasma conditions and neutron and x-ray fluxes vary from shot to shot, it is maintained that, to resolve inconsistencies in the present data, spectra need to be measured with energy and time resolution simultaneously, and cannot be built up from a large number of shots. Time resolutions of the order of 1 nsec for pulse lengths of about 100 nsec make these requirements especially difficult. Some theoretical models are presented for the neutron output and its spectrum, but no self-consistent description of the plasma in the focus region is likely for some time. (author)

  15. Invited paper: Plasma focus in China

    International Nuclear Information System (INIS)

    Jinji, Y.

    1983-01-01

    Plasma focus research in China began in the seventies. There are now 3 devices in two institutions, Tsinghua University in Beijing and the Institute of Mining and Metallurgy in Changsha. The research works can be divided into two groups: the engineering problems related to plasma focus devices and the plasma phenomena and process of the focus. Under the first subject, insulation and plasma spark gaps are studied. By casting silicon rubber onto the ends of the transmission cable, the length of insulation can be appreciably reduced. With the method of simulating charges, the electric field distribution of a field distortion type spark gap was calculated. Comparison of the field distribution before and after triggering was represented. It shows that the electric field strength of the gap after triggering may reach 14-80 times as high as that before triggering. Thus the characteristic of the gap may be improved remarkably. In respect of the phenomena of the plasma focus, neutron emission and X-ray emission were measured. It was shown that the proportion of X-ray with higher energy depends upon the material of the inner electrode. Two kinds of stud materials, tungsten and molybendum, were adopted. Measured results of the distribution of X-ray energy were represented respectively for the two materials used. Evidently, the distribution changed with the inserted materials

  16. Characteristics of ion spectrum in a low energy nitrogen operated plasma focus: application to the metallic substrates thermal treatment

    International Nuclear Information System (INIS)

    Kelly, H.; Lepone, A.; Marquez, A.

    1998-01-01

    Full text: This work presents the nitrogen ion spectrum characteristics in a Plasma Focus device, determined using a Thomson spectrometer and a Faraday cup, operated in the secondary electron collective mode. It is also discussed the thermal treatment and the re coating induce by ions incident on a metallic surface (AISI 304 steel) placed in front of the coaxial gun, when the device is operated with a Ti implant at the end of the central electrode

  17. Investigation of Plasma Facing Components in Plasma Focus Operation

    Science.gov (United States)

    Roshan, M. V.; Babazadeh, A. R.; Kiai, S. M. Sadat; Habibi, H.; Mamarzadeh, M.

    2007-09-01

    Both aspects of the plasma-wall interactions, counter effect of plasma and materials, have been considered in our experiments. The AEOI plasma focus, Dena, has Filippov-type electrodes. The experimental results verify that neutron production increases using tungsten as an anode insert material, compared to the copper one. The experiments show decrement of the hardness of Aluminum targets outward the sides, from 135 to 78 in Vickers scale. The sputtering yield is about 0.0065 for deuteron energy of 50 keV.

  18. Application of plasma focus device to compression of toroidal plasma

    International Nuclear Information System (INIS)

    Ikuta, Kazunari

    1980-01-01

    A new concept of compressing a toroidal plasma using a plasma focus device is considered. Maximum compression ratio of toroidal plasma is determined merely by the initial density ratio of the toroidal plasma to a sheet plasma in a focus device because of the Rayleigh-Taylor instability. An initiation senario of plasma-linear is also proposed with a possible application of this concepts to the creation of a burning plasma in reversed field configurations, i.e., burning plasma vortex. (author)

  19. The plasma focus - numerical experiments leading technology

    International Nuclear Information System (INIS)

    Saw, S.H.; Lee, S.

    2013-01-01

    Numerical experiments on the plasma focus are now used routinely to assist design and provide reference points for diagnostics. More importantly guidance has been given regarding the implementation of technology for new generations of plasma focus devices. For example intensive series of experiments have shown that it is of no use to reduce static bank inductance L0 below certain values because of the consistent loading effects of the plasma focus dynamics on the capacitor bank. Thus whilst it was thought that the PF1000 could receive major benefits by reducing its bank inductance L 0 , numerical experiments have shown to the contrary that its present L 0 of 30 nH is already optimum and that reducing L 0 would be a very expensive fruitless exercise. This knowledge gained from numerical experiments now acts as a general valuable guideline to all high performance (ie low inductance) plasma focus devices not to unnecessarily attempt to further lower the static inductance L 0 . The numerical experiments also show that the deterioration of the yield scaling law (e.g. the fusion neutron yield scaling with storage energy) is inevitable again due to the consistent loading effect of the plasma focus, which becomes more and more dominant as capacitor bank impedance reduces with increasing capacitance C 0 as storage energy is increased. This line of thinking has led to the suggestion of using higher voltages (as an alternative to increasing C 0 ) and to seeding of Deuterium with noble gases in order to enhance compression through thermodynamic mechanisms and through radiation cooling effects of strong line radiation. Circuit manipulation e.g. to enhance focus pinch compression by current-stepping is also being numerically experimented upon. Ultimately however systems have to be built, guided by numerical experiments, so that the predicted technology may be proven and realized. (author)

  20. The heating of plasma focus electrodes

    International Nuclear Information System (INIS)

    Angeli, E; Frignani, M; Mannucci, S; Rocchi, F; Sumini, M; Tartari, A

    2006-01-01

    Plasma focus (PF) technology development today is strictly related to the possibility of a high frequency repetitive working regime. One of the more relevant obstacles to this goal is the heating of structural components due to direct interaction with plasma. In this paper, temperature decay measurements of the inner electrode of a 7 kJ Mather type PF are presented. Data from several series of shots at different bank energies are analysed and compared with theoretical and numerical models. Two possible scale laws are derived from the experimental data to correlate thermal deposition with bank energy. It is found that a fraction of about 10% of total energy is released to the inner electrode. Finally, after some considerations about the cooling and heating mechanisms, an analysis on maximum temperature sustained by materials is presented

  1. High energy plasma accelerators

    International Nuclear Information System (INIS)

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ω 0 , kappa 0 and ω 1 , kappa 1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 10 18 cm -3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  2. Bursting of filaments in the plasma focus

    International Nuclear Information System (INIS)

    Gratton, F.T.L.

    1976-01-01

    Photographs of the current sheath of (low energy) plasma focus show a disruption of the filaments. This phenomenon is interpreted as a vortex breakdown. Physical parameters which support this hypothesis are obtained from measurements, from the theoretical thickness of the current sheath given by Nardi and from some models of the plasma flow. The widening of a vortex due to axial velocity increase is analyzed by means of magnetohydrodynamic collinear models. The main results are: (1) the existence of a limit separating supercritical from subcritical regimes (their character changes with the ratio between kinetic and magnetic energy); (2) the existence of flow regimes where the vortex radius remains approximately constant for moderate increments of the external velocity; (3) the structure of the vortex may change substantially for a sufficiently large increment of the external velocity, even in subcritical states; (4) the possibility that a burst of the vortex may occur when the external velocity suffers a slowdown

  3. Properties of the Dense Plasma Produced in Plasma Focus

    International Nuclear Information System (INIS)

    Peacock, N.J.; Wilcock, P.D.; Speer, R.J.; Morgan, P.D.

    1969-01-01

    The plasma produced by the focus or quasi-cylindrical magnetic compression which occurs at the open end of a metal-walled, coaxial plasma gun has been studied, using the electrical waveforms and the electromagnetic and reaction particle, emission. The electromagnetic radiation in the XUV region of the spectrum has previously been briefly reported, and the present paper describes further more detailed analyses of the line emission at wavelengths shorter than 10 Å when impurities are added to the gas filling. The emission is characteristic of a plasma with a temperature of a few keV and a density greater than 10 19 cm -3 , while the appearance of optical transitions in highly stripped ions, e. g. A XVIII, gives a measure of the thermalization in the plasma. The stored electrical energy has been doubled and the scaling of the neutron emission with the applied voltage and the initial particle density is presented. The duration of the neutron and X-ray emission is considerably longer than the observed instability growth time in the plasma filament. Calculations of the mode of heating and the confinement of the plasma are compared with experimental observations. (author)

  4. Z-Pinch at extreme energies: Nanofocus of less than 1J. Plasma Focus of 400 J. Gas embedded Z-pinch operating at MA

    International Nuclear Information System (INIS)

    Pavez Morales, Cristian A

    2007-01-01

    The work presented in this thesis is in relation with an experimental study developed in three different pulsed plasma generators. Two of them were already operating in the plasma laboratory of the Chilean Nuclear Energy Commission (CCHEN ) at the beginning of this thesis and they are: a) plasma focus PF-40OJ ((880nF, 30kV, 120kA, 400J, 300ns maximum current, dl/dt4x10 11 A/s) which is one of the first plasma focus devices at low energy that produces neutron pulses of fusion and b) the pulsed power generator SPEED-2 (4.1μF equivalent capacity, 300 kV, 4 MA in short circuit, 187 kJ, 400 ns at maximum current, dl/dt∼10 13 A/s) designed to operate in a plasma focus configuration. The third experiment corresponds to a plasma focus device at energy lower than 1J (Nanofocus), which was designed, constructed and characterized during the development of this thesis. The performed work can be summarized in two general aspects: the experimental study of the scaling in plasma focus devices at low energy and the development of a linear Z-pinch configuration using the SPEED-2 generator. In this last situation, a mechanism of preionization was developed in order to create a gas embedded Z-pinch discharge (Deuterium in the case of our experiment) that was conveniently coupled to the electrical characteristics of the generator. In every experiment, the plasma properties were studied (density, dynamics, size, radiation emission) and they reported the state of it. In the plasma focus device PF-40OJ, the electronic density was characterized for discharges in H 2 by using optical refractive techniques, measuring density values in the pinch ∼10 25 m -3 , similar to those reported in plasma focus devices at higher energies. The anisotropy was measured in the distribution of the intensity in the neutron emission for discharges in D 2 using track detector techniques CR-39. A distribution for the neutron flux characterized by an isotropic contribution of 57.5% and also by other

  5. Energy in focus

    International Nuclear Information System (INIS)

    Albrecht, G.; Stegelmann, H.U.

    1985-01-01

    Part one of the publication abstracted contains some introductory information about different aspects of energy supply. The publication summarizes a number of papers held in connection with a project dealing with the 'social compatibility of energy systems'. The papers were presented to different groups interested in the subject by technico-scientific experts from university or research institutes. In a popular way the papers discuss the properties of different energy sources and deal with different conversion techniques applied on the electric power and heat market. They point out environmental effects, health and safety risks of energy systems and economic aspects of different energy systems. Part two deals with competing long-term energy systems in the Federal Republic of Germany, that is with the four 'energy paths' of the Enquete Commission. The paths are covering a large variety of feasible developments and trends and therefore reflect all aspects of the energy debate to their full extent. (orig./HP) [de

  6. Plasma lenses for focusing relativistic electron beams

    International Nuclear Information System (INIS)

    Govil, R.; Wheeler, S.; Leemans, W.

    1997-01-01

    The next generation of colliders require tightly focused beams with high luminosity. To focus charged particle beams for such applications, a plasma focusing scheme has been proposed. Plasma lenses can be overdense (plasma density, n p much greater than electron beam density, n b ) or underdense (n p less than 2 n b ). In overdense lenses the space-charge force of the electron beam is canceled by the plasma and the remaining magnetic force causes the electron beam to self-pinch. The focusing gradient is nonlinear, resulting in spherical aberrations. In underdense lenses, the self-forces of the electron beam cancel, allowing the plasma ions to focus the beam. Although for a given beam density, a uniform underdense lens produces smaller focusing gradients than an overdense lens, it produces better beam quality since the focusing is done by plasma ions. The underdense lens can be improved by tapering the density of the plasma for optimal focusing. The underdense lens performance can be enhanced further by producing adiabatic plasma lenses to avoid the Oide limit on spot size due to synchrotron radiation by the electron beam. The plasma lens experiment at the Beam Test Facility (BTF) is designed to study the properties of plasma lenses in both overdense and underdense regimes. In particular, important issues such as electron beam matching, time response of the lens, lens aberrations and shot-to-shot reproducibility are being investigated

  7. Anode plasma and focusing reb diodes

    International Nuclear Information System (INIS)

    Goldstein, S.A.; Swain, D.W.; Hadley, G.R.; Mix, L.P.

    1975-01-01

    The use of electrical, optical, x-ray, and particle diagnostics to characterize the production of anode plasma and to monitor its influence on beam generation and focusing is reviewed. Studies using the Nereus accelerator show that after cathode turn-on, deposition of several kJ/gm on the anode is necessary before ions from hydrocarbons, adsorbed gases, and heavier metallic species are detected. The actual time at which ions are liberated depends on several factors, one of which is the specific heat of the anode substrate. Once formed, anode ions cross the A-K gap (with an energy equal to the diode voltage) and interact with the cathode to produce an axially peaked beam profile, a ''pinch'' which does not follow the critical current criterion. Experiments with externally generated anode plasma show that this type of pinch can be attracted to localized areas on the anode. Preliminary observations on Hydra indicate the anode plasma composition is similar to that on Nereus. The effect of this plasma on pinch dynamics currently is under investigation

  8. Plasma devices for focusing extreme light pulses

    International Nuclear Information System (INIS)

    Fuchs, J.; Gonoskov, A.A.; Nakatsutsumi, M.; Nazarov, W.; Quere, F.; Sergeev, A.M.; Yan, X.Q.

    2014-01-01

    Since the inception of the laser, there has been a constant push toward increasing the laser peak intensity, as this has lead to opening the exploration of new territories, and the production of compact sources of particles and radiation with unprecedented characteristics. However, increasing the peak laser intensity is usually performed by enhancing the produced laser properties, either by lowering its duration or increasing its energy, which involves a great level of complexity for the laser chain, or comes at great cost. Focusing tightly is another possibility to increase the laser intensity, but this comes at the risk of damaging the optics with target debris, as it requires their placement in close proximity to the interaction region. Plasma devices are an attractive, compact alternative to tightly focus extreme light pulses and further increase the final laser intensity. (authors)

  9. Self-organisation phenomena in the plasma focus

    International Nuclear Information System (INIS)

    Deutsch, R.; Grauf, W.; Herold, H.; Schmidt, H.

    1982-06-01

    The structure of the final minimum-energy state of the focus plasma was studied, using Taylor's relaxation theory. A superposition of the reversed pinch field and the field of eddies was obtained. Similar structures could be observed experimentally. (orig.)

  10. Some optical diagnostics for the plasma focus

    International Nuclear Information System (INIS)

    Korzhavin, V.M.

    1980-01-01

    Some aspects of studying plasma focus dynamics are reported. Particular efforts were made to develop an infrared (IR) diagnostics. The plasma focus is formed in a discharge chamber, when shock waves and plasma sheath cumulate on the axis as a result of the break-down of filling gas by the application of high voltage. The current J was measured with a Rogovsky coil, and the voltage U was measured with a capacitor divider. The current derivative was measured with magnetic probes, and X-ray and neutron emission intensities were measured with a plastic scintillator. The total neutron yield were measured by the activation method. The time-integrated soft X-ray pictures of plasma focus were taken with a pin-hole camera. The formation and disruption of plasma focus were studied by multi-picture speed photography. Laser interferometry was used to study the time-space distribution of plasma density. For the study of turbulence phenomena in plasma focus, a new type IR detector was employed. The results of measurements suggest that there exists some superthermal radiation during the second compression of plasma focus, but it is not so strong. (Kato, T.)

  11. Structural Analysis of Extended Plasma Focus Chamber

    International Nuclear Information System (INIS)

    Mohd Azhar Ahmad; Abdul Halim Baijan; Siti Aiasah Hashim

    2016-01-01

    Accelerator Development Centre (ADC) of Nuclear Malaysia intends to upgrade the plasma focus device. It involves the extension part placed on top of the existing plasma focus vacuum chamber. This extended vacuum chamber purposely to give an extra space in conducting experiments on the existing plasma focus chamber. The aim of upgrading the plasma focus device is to solve the limitation in research and analysis of sample due to its done in an open system that cause analysis of samples is limited and less optimal. This extended chamber was design in considering the ease of fabrication as well as durability of its structural. Thus, this paper discusses the structural analysis in term of pressure loading effect in extended chamber. (author)

  12. Experimental investigation of the operating characteristic of a plasma focus

    International Nuclear Information System (INIS)

    Rapp, H.

    The design of a 60 kJ plasma focus installation of the Mather type for generating a deuterium plasma with fusion conditions is described. The advantages of a plasma focus layout in comparison with the linear z-pinch are explained, and questions which arise from the interaction of energy storage and plasma accelerator are discussed. The conclusions are used as a basis for planning the entire installation and dimensioning the individual components. This is followed by a description of some typical difficulties which can have a negative effect on the operation of the plasma focus and how these problems were overcome. Photographic observation of the acceleration and compression process has provided important information concerning the configuration, structure and velocity of the plasma, which is supplemented by magnetic probe measurements of the variations in current. Additional observations involve measurements of neutron yield, neutron flux anisotropy and the neutron spectrum. A theoretical analysis is also presented

  13. Matching of dense plasma focus devices with fission reactors

    International Nuclear Information System (INIS)

    Harms, A.A.; Heindler, M.

    1978-01-01

    The potential role of dense plasma focus devices as compact neutron sources for fissile fuel breeding in conjunction with existing fission reactors is considered. It is found that advanced plasma focus devices can be used effectively in conjunction with neutronically efficient fission reactors to constitute ''self-sufficient'' breeders. Correlations among the various parameters such as the power output and conversion ratio of the fission reactor with the neutron yield and capacitor bank energy of the dense plasma focus device are presented and discussed

  14. Preliminary results obtained from a dense plasma focus

    International Nuclear Information System (INIS)

    Sinman, S.; Sinman, A.

    1982-01-01

    In this study, for the data processing in our Dense Plasma Focus (DPF) system, a multiparameters numerical hierarchy obtained from the fundamental equations based on the snowplows model and its conclusions have been developed. Evaluating the data along the transients of the total plasma current, the anode current and the focus voltage recorded by an oscilloscope, they have been possible to determine the time domain plasma parameters such as the shock thickness, the sheath temperature, velocity and electron density, the pressure at the focus phase and the plasma temperature. Besides, the dissipated energy through the focus notch or in other words, the plasma temperature has also been calculated by means of the numerical integration. In the text, a performance chart together with some other correlation curves for the optimization of the DPF systems are submitted and discussed. (author)

  15. Kinetic Simulations of Dense Plasma Focus Breakdown

    Science.gov (United States)

    Schmidt, A.; Higginson, D. P.; Jiang, S.; Link, A.; Povilus, A.; Sears, J.; Bennett, N.; Rose, D. V.; Welch, D. R.

    2015-11-01

    A dense plasma focus (DPF) device is a type of plasma gun that drives current through a set of coaxial electrodes to assemble gas inside the device and then implode that gas on axis to form a Z-pinch. This implosion drives hydrodynamic and kinetic instabilities that generate strong electric fields, which produces a short intense pulse of x-rays, high-energy (>100 keV) electrons and ions, and (in deuterium gas) neutrons. A strong factor in pinch performance is the initial breakdown and ionization of the gas along the insulator surface separating the two electrodes. The smoothness and isotropy of this ionized sheath are imprinted on the current sheath that travels along the electrodes, thus making it an important portion of the DPF to both understand and optimize. Here we use kinetic simulations in the Particle-in-cell code LSP to model the breakdown. Simulations are initiated with neutral gas and the breakdown modeled self-consistently as driven by a charged capacitor system. We also investigate novel geometries for the insulator and electrodes to attempt to control the electric field profile. The initial ionization fraction of gas is explored computationally to gauge possible advantages of pre-ionization which could be created experimentally via lasers or a glow-discharge. Prepared by LLNL under Contract DE-AC52-07NA27344.

  16. Electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    Smith, J.R.; Luo, C.M.; Schneider, R.F.; Rhee, M.J.

    1984-01-01

    Operation of a plasma focus as a Compact Pulsed Accelerator (CPA) for ions has been previously reported. The CPA consists of: (1) a 15 μF, 3 kJ capacitor, (2) a triggered spark gap, (3) a coaxial transmission line, and (4) a Mather geometry plasma gun. Recently the authors have investigated application of the CPA as an accelerator for electrons. In the previously reported work using the standard Mather plasma gun geometry, ions were accelerated away from the plasma gun and were therefore conveniently extracted for analysis, but electrons were directed into the hollow anode where extraction is blocked by the coaxial transmission line. For investigation of accelerated electrons a new plasma gun design which allows extraction of electrons has been developed. Details of the new plasma gun design and further results of beam diagnostics are discussed

  17. Conceptual Design and Simulation of a Miniature Plasma Focus

    International Nuclear Information System (INIS)

    Jafari, H.; Habibi, M.; Amrollahi, R.

    2012-01-01

    Design and construction of a miniature plasma focus device with 3.6 J of energy bank is reported. In design the device, some of very important parameters of designing such as plasma energy density and derive parameter was used. Regarding to the electrical and geometrical parameters of the device, a simulation is carried out by MATLAB software. Simulation results showed that the formation of the pinch have occurred at the moment of the peak discharge current.

  18. Non-hydrodynamic model of plasma focus structure

    International Nuclear Information System (INIS)

    Imshennik, V.S.; Zueva, N.M.; Lokutsievskij, O.V.; Mikhajlova, M.S.

    1985-01-01

    Experimental and theoretical plasma focus study has resulted in the necessity of creating a non-hydrodynamic plasma focus structure model (MKHD model). This model describes the final stage of plasma focus, which starts immediately after maximum plasma compression. It is related to a very limited space near the neck of the sausage instability. The MKHD model is two-dimensional, axially symmetric and collisionless with respect to the ions and magnetohydrodynamic with respect to the electrons; it accounts for the pinch instability of the sausage type (m=0 mode). The MKHD model, first of all, explains the long time of the plasma focus existence and non-thermonuclear peculiarities in the neutron yield. The initial and boundary conditions are formulated in accordance with the experiments and the results of computations in the 2D MHD model. A non-stationary process of plasma focus dynamics is studied numerically for a relatively long time - about 20 ns; this time is, in principle, not restricted. The computations show that the external edge of the neck expands rather slowly (at a speed that is lower than the thermal ion velocity, by an order of magnitude), and the magnetic field energy is converted to the kinetic energy of the chaotic ion motion (which is doubled for the time of computation). A 'supra-thermal' tail (with the deuterium ion energy higher than 10 keV) forms slowly at the ion distribution function; this tail determines a substantial part of the total neutron yield. The formation of stable vortices, which actually determine the structure of the plasma flow during the developed non-hydrodynamic stage of the plasma focus, is also found in the computations. These properties of the development of the sausage instability, as found in the numerical experiment with the MKHD plasma focus model, are in qualitative agreement with the behaviour of an instability of the same type in the MHD models of the Z-pinch

  19. Physics and technology of large plasma focus devices

    International Nuclear Information System (INIS)

    Herold, H.

    1990-01-01

    This paper reports on the plasma focus (PF) which produces a high temperature (0,5 to 1 keV), high density (5 · 10 18 cm -3 ), short living (up to 500 ns) fusion plasma in a very simple and cheap device. In the focus plasma, fusion processes take place with an energy efficiency which is not surpassed even by large Tokamak or Inertial Confinement Fusion devices. But this fusion efficiency and the high fusion neutron yield are not the only impetus to PF research. Due to the high energy density in the focus plasma (j ≥ 10 6 A/cm 2 exclamation point), many very interesting, mostly nonlinear phenomena take place which led to high intensity electron, ion and radiation emission. Micro- and macro instabilities, turbulence and selforganization processes develop. Most of these phenomena are not or only poorly understood

  20. Computational numerical modelling of plasma focus

    International Nuclear Information System (INIS)

    Brollo, Fabricio

    2005-01-01

    Several models for calculation of the dynamics of Plasma Focus have been developed. All of them begin from the same physic principle: the current sheet run down the anode length, ionizing and collecting the gas that finds in its way.This is known as snow-plow model.Concerning pinch's compression, a MHD model is proposed.The plasma is treated as a fluid , particularly as a high ionized gas.However, there are not many models that, taking into account thermal equilibrium inside the plasma, make approximated calculations of the maximum temperatures reached in the pinch.Besides, there are no models which use those temperatures to estimate the termofusion neutron yield for the Deuterium or Deuterium-Tritium gas filled cases.In the PLADEMA network (Dense Magnetized Plasmas) a code was developed with the objective of describe the plasma focus dynamics, in a conceptual engineering stage.The codes calculates the principal variables (currents, time to focus, etc) and estimates the neutron yield in Deuterium-filled plasma focus devices.It can be affirmed that the code's experimental validation, in its axial and radial stages, was very successfully. However, it was accepted that the compression stage should be formulated again, to find a solution for a large variation of a parameter related with velocity profiles for the particles trapped inside the pinch.The objectives of this work can be stated in the next way : - Check the compression's model hypothesis. Develop a new model .- Implement the new model in the code. Compare results against experimental data of Plasma Focus devices from all around the world [es

  1. Reflectors to Focus Wave Energy

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    2005-01-01

    Wave Energy Converters (WEC’s) extract wave energy from a limited area, often a single point or line even though the wave energy is generally spread out along the wave crest. By the use of wave reflectors (reflecting walls) the wave energy is effectively focused and increased by approximately 30......-50%. Clearly longer wave reflectors will focus more wave energy than shorter wave reflectors. Thus the draw back is the increased wave forces for the longer wave reflectors. In the paper a procedure for calculating the energy efficiency and the wave forces on the reflectors are described, this by use of a 3D...... boundary element method. The calculations are verified by laboratory experiments and a very good agreement is found. The paper gives estimates of possible power benefit for different wave reflector geometries and optimal geometrical design parameters are specified. On this basis inventors of WEC’s can...

  2. Neutron emission from deuterium plasma focus

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Banjanac, R.; Dragic, A.; Djordjevic, D.; Joksimovic, D.; Maric, Z.; Udovicic, V.; Vukovic, J.

    1998-01-01

    The anisotropy of emitted neutrons is investigated on a small 'Mather-type' plasma focus device (PF). This problem is of importance for determining the nature of the fusion reaction mechanisms. Mica detectors together with thick uranium foils were used for both detection and angular distribution measurements of the neutrons. Previously, the annealing of the detectors was done and measured after the irradiation with neutrons from Am-Be source. Also, annealing ability of H-plasma focus has been tested. Geometry of detectors in both experiments was the same. (authors)

  3. Magnetized whirls in plasma focus discharges

    International Nuclear Information System (INIS)

    Witalis, E.

    1979-05-01

    The plasma focus is briefly described with emphasis on its capabilities as a neutron source. The filamentary whirl structures observed in the discharge plasma are described. Starting with a simple, early and particularly well established case of vorticity imparted by a rotational electric field to the plasma in MHD generators, a general derivation is then outlined proving that such magnetically induced rotation is a general feature for the normally Hall-conducting magnetized plasma. Physical interpretations of the effect are given and objections to it are critically reviewed as is also a theory proposing radiation cooling as the cause of plasma filamentation. A more detailed derivation based essentially on the consistent description of the motion and the field generation of the charged plasma particles yields a theoretical model where the specific features of magnetically compressed plasmas are found. In particular, the ion collisionless skin depth is obtained as the key length parameter. This length is identified as roughly the whirl radius. In conjunction with a generalized Bennett relation theoretical whirl properties are predicted and found to agree with observations. Mechanisms that relate the whirls to nuclear fusion reaction conditions are tentatively indicated. (author)

  4. Compression Models for Plasma Focus Devices

    International Nuclear Information System (INIS)

    Gonzalez, Jose; Calusse, Alejandro; Ramos, Ruben; Rodriguez Palomino, Luis

    2003-01-01

    Using a numerical model that calculates the dynamics of Plasma Focus devices, we compared the results of three different compression models of the plasma pinch.One of the main objectives in this area is to develop a simplified model to calculate the neutron production of Plasma Focus devices, to study the influence of the main parameters in this neutron yield.The dynamics is thoroughly studied, and the model predicts fairly well values such as maximum currents and times for pinch collapse.Therefore, we evaluate here different models of pinch compression, to try to predict the neutron production with good agreement with the rest of the variables involved.To fulfill this requirement, we have experimental results of neutron production as a function of deuterium filling pressure in the chamber, and typical values of other main variables in the dynamics of the current sheet

  5. Study of opening switch characteristics of a plasma focus

    International Nuclear Information System (INIS)

    Rhee, M.J.; Schneider, R.F.

    1985-01-01

    It is shown that a current charged transmission line and an opening switch can be used as an inductive energy storage system to produce a high power pulse. A plasma focus device, in which a transmission line is inserted in series with the capacitor bank and a coaxial gun, is considered as an inductive energy storage system. The m = 0 instability in the plasma focus is utilized as an opening switch and the disrupted plasma column is considered as bipolar diode. The system is described preferably by the transmission line theory rather than the lumped circuit theory. The relationship between the output voltage and the current drop is given by V = ΔIZ, where Z is the characteristic impedance of the transmission line. The current drop ΔI depends on the mismatched load impedance of the plasma diode which is governed by nature of the m = 0 instability

  6. A model for plasma evolution in Filipov type plasma focus facilities

    International Nuclear Information System (INIS)

    Siahpoush, V.; Sobhanian, S.; Tafreshi, M. A.; Lamehi, M.

    2003-01-01

    A model is presented in this paper for the evolution of plasma in Filipov type plasma focus facilities. With the help of this model, one can predict some of the main parameters of the produced plasma and obtain the optimized geometrical an physical properties (anode radius and length, gas pressure, capacitance, bank energy etc) for the primary design purposes. The results obtained by this model will be compared with the experimental data obtained from the 90 kJ plasma focus facility D ena

  7. Plasma focus system: Design, construction and experiments

    International Nuclear Information System (INIS)

    Alacakir, A.; Akguen, Y.; Boeluekdemir, A. S.

    2007-01-01

    The aim of this work is to construct a compact experimental system for fusion research. The design, construction and experiments of the 3 kJ Mather type plasma focus machine is described. This machine is established for neutron yield and fast neutron radiography by D-D reaction which is given by D + D→ 3 He (0.82 MeV) + n (2.45 MeV) . Investigation of the geometry of plasma focus machine in the presence of high voltage drive and vacuum system setup is shown. 108 neutron per pulse and 200 kA peak current is obtained for many shots. Scintillator screen for fast neutron imaging, sensitive to 2.45 MeV neutrons, is also manufactured in our labs. Structural neutron shielding computations for safety is also completed

  8. A Plasma Focus operated at a very low pressure range

    International Nuclear Information System (INIS)

    Bruzzone, H.; Grondona, D.; Kelly, H.; Marquez, A.

    1990-01-01

    Several characteristics of the neutron production and the hard X-ray emission from a Plasma Focus device operating at 30 kV (6 kV of stored energy) and at an unusually low pressure range are presented. (Author)

  9. A lumped parameter model of plasma focus

    International Nuclear Information System (INIS)

    Gonzalez, Jose H.; Florido, Pablo C.; Bruzzone, H.; Clausse, Alejandro

    1999-01-01

    A lumped parameter model to estimate neutron emission of a plasma focus (PF) device is developed. The dynamic of the current sheet is calculated using a snowplow model, and the neutron production with the thermal fusion cross section for a deuterium filling gas. The results were contrasted as a function of the filling pressure with experimental measurements of a 3.68 KJ Mather-type PF. (author)

  10. Ion Distribution Measurement In Plasma Focus

    International Nuclear Information System (INIS)

    Suryadi; Sunardi; Usada, Widdi; Purwadi, Agus; Zaenuri, Akhmad

    1996-01-01

    Measurement of the Argon ion distribution in plasma focus by using Faraday cup has been done. The intensity of ion beam followed the I Rn rule, n=1,02. In the operation condition of 0,8 mbar and 12,5 kV the current sheath spen 2.2 to 2.4 μsecond in the rundown phase. Cu ion was also been observed in the Faraday cup

  11. Parametric studies in a small plasma focus device

    International Nuclear Information System (INIS)

    Chuaqui, H.; Favre, M.; Silva, P.; Wyndham, E.

    1996-01-01

    Very high temperature and density plasmas can be produced in modest size plasma focus devices at the kJ level. Much of the scaling parameters on the plasma focus have been evaluated, though many questions still remain. The modest cost and simple construction allows easy modification to the device and the discharge parameters. In this paper the authors report on a small plasma focus device, which is set-up to investigate the effect of some of those modifications on the plasma, with detailed experimental diagnostics. Experiments have been carried out in various gases and with mixtures of different ratios. Extended operating range from below 0.5 torr upwards has been achieved with the implementation of the auxiliary discharge circuit. Despite the low voltage and low energy operation, energetic beam formation has been observed at the time of the final compression, prior to disruption. Current sheath formation and evolution has been characterized using the magnetic probes array, in correlation with beam formation and plasma emission. The relationship of the current sheath structure and that of the pinched plasma, as shown by the filtered X-ray pinhole camera, has been investigated

  12. Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

    Directory of Open Access Journals (Sweden)

    Sing Lee

    2010-04-01

    Full Text Available Recent extensive and systematic numerical experiments have uncovered new insights into plasma focus fusion devices including the following: (1 a plasma current limitation effect, as device static inductance is reduced towards very small values; (2 scaling laws of neutron yield and soft x-ray yield as functions of storage energies and currents; (3 a global scaling law for neutron yield as a function of storage energy combining experimental and numerical data showing that scaling deterioration has probably been interpreted as neutron ‘saturation’; and (4 a fundamental cause of neutron ‘saturation’. The ground-breaking insights thus gained may completely change the directions of plasma focus fusion research.

  13. Plasma focus as an heavy ion source in the problem of heavy ion fusion

    International Nuclear Information System (INIS)

    Gribkov, V.A.; Dubrovskij, A.V.; Kalachev, N.V.; Krokhin, O.N.; Silin, P.V.; Nikulin, V.Ya.; Cheblukov, Yu.N.

    1984-01-01

    Results of experiments on the ion flux formation in a plasma focus (PF) to develop a multicharged ion source for thermonuclear facility driver are presented. In plasma focus accelerating section copper ions were injected. Advantages of the suggested method of ion beam formation are demonstrated. Beam emittance equalling < 0.1 cmxmrad is obtained. Plasma focus ion energy exceeds 1 MeV. Plasma focus in combination with a neodymium laser is thought to be a perspective ion source for heavy ion fusion

  14. Electron density measurements on the plasma focus

    International Nuclear Information System (INIS)

    Rueckle, B.

    1976-01-01

    The paper presents a determination of the maximum electron density in a plasma focus, produced with the NESSI experimental setup, by the method of laser beam deflection. For each discharge a time-resolved measurement was performed at four different places. Neutron efficiency as well as the time of the initial X-ray emission was registrated. The principle and the economic aspects of the beam deflection method are presented in detail. The experimental findings and the resulting knowledge of the neutron efficiency are discussed. (GG) [de

  15. Light ion beams generation in dense plasma focus

    International Nuclear Information System (INIS)

    Yokoyama, M.; Kitagawa, Y.; Yamada, Y.; Okada, M.; Yamamoto, Y.

    1982-01-01

    The high energy deuterons and protons in a Mather type plasma focus device were measured by nuclear activation techniques. The radioactivity induced in graphite, aluminum and copper targets provided the deuteron intensity, energy spectra and angular dependence. High energy protons were measured by cellulose nitrate particle track detectors. The plasma focus device was operated at 30 kV for a stored energy of 18 kJ at 1.5 Torr D 2 (low pressure mode), and 5 Torr D 2 (high pressure mode). The yield ratio of N-13 and Al-28 showed the mean deuteron energy of 1.55 MeV under low pressure mode and of 1.44 MeV under high pressure mode. The deuteron energy spectra were measured by the stacks of 10 aluminum foils, and consisted of two components as well as the proton energy spectra measured by CN film technique. The angular spread of deuteron beam was within 30 degree under low pressure mode. Under high pressure mode, the distribution showed multi-structure, and two peaks were observed at the angle smaller than 20 degree and at 60 degree. The protons with energy more than 770 keV were directed in the angle of 10 degree. The high energy electron beam was also observed. A three-channel ruby laser holographic interferometry was used to see the spatial and temporal location of the generation of high energy ions. The ion temperature in plasma focus was estimated from D + He 3 mixture gas experiment. (Kato, T.)

  16. Pinches and micropinches in the SPEED 2 plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Roewekamp, P; Decker, G; Kies, W; Lucas, B; Schmitz, F; Ziethen, G [Heinrich-Heine-Univ., Duesseldorf (Germany). Institut fuer Experimentalphysik; Simanovskij, D M; Bobashev, S V [Russian Academy of Sciences, St. Petersburg (Russian Federation). A.F. Ioffe Physico-Technical Inst.

    1997-12-31

    The discharges in the SPEED 2 Plasma Focus as well as other pinch plasmas generated in a plasma focus configuration exhibit two different modes. The micropinch mode is experimentally investigated in detail and well theoretically modelled. Therefore its characteristics e.g. temperature, density, life time and energy output are well known. Nevertheless the micropinches appear very erratic in space and time and their optimization and application is rather difficult. In contrast to this the column mode is not equally well understood yet. Its remarkable features are the unexpectedly high stability (also if the critical current for radiative collapse is exceeded) and its reproducibility, which are important for applications in soft x-ray microscopy or lithography. (J.U.). 6 figs., 9 refs.

  17. Repetitively pulsed capacitor bank for the dense-plasma focus

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

    1975-12-01

    This report describes a 1 pulse per second capacitor bank designed to energize a dense-plasma focus (DPF). The DPF is a neutron source capable (with moderate scaling) of delivering a minimum of 10 15 neutrons per pulse or neutron flux of 2 x 10 13 N/cm 2 .s. The average power consumption, which has become a major issue due to the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. This small source size high flux neutron source could be extemely useful to qualify fission reactor material irradiation results for fusion reactor design

  18. Design of a repetitively pulsed megajoule dense-plasma focus

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

    1975-01-01

    This report describes a 1 pulse per second, dense-plasma-focus (DPF) materials-testing device capable of delivering a minimum of 10 15 neutrons per pulse. Moderate scaling up from existing designs is shown to be sufficient to provide 2 x 10 13 neutrons/ cm 2 . s to a suitable target. The average power consumption, which has become a major issue due to the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. Also discussed is a novel approach to capacitor-bank and switch design with respect to repetitive-pulse operation. (auth)

  19. Repetitively pulsed capacitor bank for the dense-plasma focus

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

    1976-01-01

    This report describes a 1 pulse per second capacitor bank designed to energize a dense-plasma focus (DPF). The DPF is a neutron source capable (with moderate scaling) of delivering a minimum of 10 15 neutrons per pulse or neutron flux of 2 x 10 13 N/cm 2 . s. The average power consumption, which has become a major issue due to the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. This small source size high flux neutron source could be extremely useful to qualify fission reactor material irradiation results for fusion reactor design

  20. Design and preliminary results of the IMA plasma focus experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, H M; Masoud, M M [Arab Republic of Egypt, Atomic Energy Authority Plasma physics and Nuclear Fusion department, Cairo (Egypt)

    1994-12-31

    The present paper describes the design, operation and characteristics of aton 1MA plasma focus device, which built in egypt at the plasma physics department, N.R.C., atomic energy authority. The main parts of the system are: the coaxial electrodes of mather type, the expansion chamber, the condenser bank of 75 kJ stored energy, the pressurized spark gap switches and Blumlein trigger system. Measurement of the breakdown voltage between plasma focus electrodes and discharge current, using half of the condenser bank, showed that, for U{sub c} h = 32 kV, the discharge current was 0.5 Ma. In the discharge current and voltage traces a sharp drop in discharge current correspondingly to a sudden rise in voltage have been observed, which characterize the focus regime. Time structure of the x-ray emission measurements have been performed by means of scintillation detectors. by using a hydrogen gas the results showed that, the x-ray intensity is increased with increasing the hydrogen gas pressure. plasma sheath current density, J-Z distribution in axial direction during the acceleration phase of the discharge is studied, using a miniature Rogovsky coil. The results cleared that J{sub z} is increased with the axial distance from breech to muzzle at different hydrogen gas pressures. 12 figs.

  1. Design and preliminary results of the IMA plasma focus experiment

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.

    1993-01-01

    The present paper describes the design, operation and characteristics of aton 1MA plasma focus device, which built in egypt at the plasma physics department, N.R.C., atomic energy authority. The main parts of the system are: the coaxial electrodes of mather type, the expansion chamber, the condenser bank of 75 kJ stored energy, the pressurized spark gap switches and Blumlein trigger system. Measurement of the breakdown voltage between plasma focus electrodes and discharge current, using half of the condenser bank, showed that, for U c h = 32 kV, the discharge current was 0.5 Ma. In the discharge current and voltage traces a sharp drop in discharge current correspondingly to a sudden rise in voltage have been observed, which characterize the focus regime. Time structure of the x-ray emission measurements have been performed by means of scintillation detectors. by using a hydrogen gas the results showed that, the x-ray intensity is increased with increasing the hydrogen gas pressure. plasma sheath current density, J-Z distribution in axial direction during the acceleration phase of the discharge is studied, using a miniature Rogovsky coil. The results cleared that J z is increased with the axial distance from breech to muzzle at different hydrogen gas pressures. 12 figs

  2. Application of an impedance matching transformer to a plasma focus.

    Science.gov (United States)

    Bures, B L; James, C; Krishnan, M; Adler, R

    2011-10-01

    A plasma focus was constructed using an impedance matching transformer to improve power transfer between the pulse power and the dynamic plasma load. The system relied on two switches and twelve transformer cores to produce a 100 kA pulse in short circuit on the secondary at 27 kV on the primary with 110 J stored. With the two transformer systems in parallel, the Thevenin equivalent circuit parameters on the secondary side of the driver are: C = 10.9 μF, V(0) = 4.5 kV, L = 17 nH, and R = 5 mΩ. An equivalent direct drive circuit would require a large number of switches in parallel, to achieve the same Thevenin equivalent. The benefits of this approach are replacement of consumable switches with non-consumable transformer cores, reduction of the driver inductance and resistance as viewed by the dynamic load, and reduction of the stored energy to produce a given peak current. The system is designed to operate at 100 Hz, so minimizing the stored energy results in less load on the thermal management system. When operated at 1 Hz, the neutron yield from the transformer matched plasma focus was similar to the neutron yield from a conventional (directly driven) plasma focus at the same peak current.

  3. Plasma focus - a pulsed radiation source

    International Nuclear Information System (INIS)

    Blagoev, Alexandar; Zapryanov, Stanislav; Gol'tsev, Vasilii; Gemishev, Orlin

    2014-01-01

    The article is devoted to the applications of plasma focus (PF) in radiobiology. Briefly describes the principle of operation of the device and the parameters of the PF type 'Mader' at the Physics Department of the University. Phase pinch discharge zones appear hot and dense plasma, which is a source of X-ray and neutron pulse when the working gas is deuterium. These radiations are essential for biological applications. Besides these bundles are obtained from accelerated charged particles and shock wave of ionized gas. Described are some of the contributions of other authors using PF in radiobiology. Given the results in the exposure of living organisms with soft X-ray emission of PF. We examined the viability of the cells of the two types of yeasts, after irradiation with X-rays at a dose of 65 mSv, where no change was found on the performance. It is shown that soft X-ray radiation doses on the order of tens of mSv, cause a significant change in the productivity of the electronic transport in the photosynthetic apparatus of Chlamydomonas reinhardtii. Trichoderma reesei M7 shows remarkable vitality irradiation with substantial doses of hard X-ray radiation (tens Sv). Appear endoglyukonazata changes in the protein component and the residual mass

  4. Current scaling of plasma focus devices

    International Nuclear Information System (INIS)

    Schiuma, C.; Herold, H.; Kaeppeler, H.J.; Shakhatre, M.; Auluck, S.K.H.

    1990-03-01

    In continuation of the work by G. Decker et al. on current and neutron yield scaling of plasma focus devices an analytical solution for the circuit equation (with resistance R = 0) in the compression phase was derived. Together with the solution for the rundown phase from G. Decker et al, which was extended for finite resistance (R ≠ 0), there follows an analytical scaling theory for maximum and pinch currents. At the same time there exists the possibility to discuss the influence of finite resistance on current variation and scaling parameters. The model solutions were checked out by numerical integrations of the current equation. While at the beginning of the rundown phase the ohmic resistance cannot be neglected (the magnitude R/L plays an important role), its influence at the end of the rundown phase and in the compression phase is negligible. The theoretically determined values are compared with the results of numerous probe measurements. (orig.)

  5. Ion acceleration in the plasma focus

    International Nuclear Information System (INIS)

    Deutsch, R.

    1982-09-01

    Experimental informations are used to estimate the time dependence of the current density in the plasma focus and the electromagnetic field is determined from the Maxwell equations. The acceleration of the ions in these fields is studied. A detailed analysis of the acceleration in the compression phase, in the expansion phase and during the evolution of the m=O instability is made. It is shown, that the appearance of fast selffocused quasineutral electron beams, as a result of the betatron acceleration, has a decisive importance in the ion acceleration during the m=O constriction. Models for electromagnetic ion acceleration are described for each phase. A concordance with many experimental results can be observed. (orig.)

  6. Deterministic dynamics of plasma focus discharges

    International Nuclear Information System (INIS)

    Gratton, J.; Alabraba, M.A.; Warmate, A.G.; Giudice, G.

    1992-04-01

    The performance (neutron yield, X-ray production, etc.) of plasma focus discharges fluctuates strongly in series performed with fixed experimental conditions. Previous work suggests that these fluctuations are due to a deterministic ''internal'' dynamics involving degrees of freedom not controlled by the operator, possibly related to adsorption and desorption of impurities from the electrodes. According to these dynamics the yield of a discharge depends on the outcome of the previous ones. We study 8 series of discharges in three different facilities, with various electrode materials and operating conditions. More evidence of a deterministic internal dynamics is found. The fluctuation pattern depends on the electrode materials and other characteristics of the experiment. A heuristic mathematical model that describes adsorption and desorption of impurities from the electrodes and their consequences on the yield is presented. The model predicts steady yield or periodic and chaotic fluctuations, depending on parameters related to the experimental conditions. (author). 27 refs, 7 figs, 4 tabs

  7. Potential medical applications of the plasma focus in the radioisotope production for PET imaging

    International Nuclear Information System (INIS)

    Roshan, M.V.; Razaghi, S.; Asghari, F.; Rawat, R.S.; Springham, S.V.; Lee, P.; Lee, S.; Tan, T.L.

    2014-01-01

    Devices other than the accelerators are desired to be investigated for generating high energy particles to induce nuclear reaction and positron emission tomography (PET) producing radioisotopes. The experimental data of plasma focus devices (PF) are studied and the activity scaling law for External Solid Target (EST) activation is established. Based on the scaling law and the techniques to enhance the radioisotopes production, the feasibility of generating the required activity for PET imaging is studied. - Highlights: • Short lived radioisotopes for PET imaging are produced in plasma focus device. • The scaling law of the activity induced with plasma focus energy is established. • The potential medical applications of plasma focus are studied

  8. Development of TPF-1 plasma focus for education

    Science.gov (United States)

    Picha, R.; Promping, J.; Channuie, J.; Poolyarat, N.; Sangaroon, S.; Traikool, T.

    2017-09-01

    The plasma focus is a device that uses high voltage and electromagnetic force to induce plasma generation and acceleration, in order to cause nuclear reactions. Radiation of various types (X-ray, gamma ray, electrons, ions, neutrons) can be generated using this method during the pinch phase, thus making the plasma focus able to serve as a radiation source. Material testing, modification, and identification are among the current applications of the plasma focus. Other than being an alternative option to isotopic sources, the plasma focus, which requires multidisciplinary team of personnel to design, operate, and troubleshoot, can also serve as an excellent learning device for physics and engineering students in the fields including, but not limited to, plasma physics, nuclear physics, electronics engineering, and mechanical engineering. This work describes the parameters and current status of Thai Plasma Focus 1 (TPF-1) and the characteristics of the plasma being produced in the machine using a Rogowski coil.

  9. Plasma focus - dense Z pinch and their applications

    International Nuclear Information System (INIS)

    Ishii, Shozo

    1986-02-01

    ''Workshop on the possibility of Z-pinch as a intense pulse light source'' in 1983 and ''Research meeting on plasma focus and Z-pinch'' in 1984 were held at Institute of Plasma Physics, Nagoya University under a collaborating research program. Research activities reported at the meetings on plasma focus, dense Z-pinch, and related phenomena are summerized. (author)

  10. Investigation of a staged plasma-focus apparatus

    International Nuclear Information System (INIS)

    Lee, J.H.; McFarland, D.R.; Harries, W.L.

    1978-01-01

    A new staged plasma-focus geometry combining two Mather-type plasma-focus guns has been constructed, and the current-sheet dynamics investigated. The production of simultaneous pairs of plasma foci has been achieved. The intensities of X-ray and fusion-neutron emission were measured and found to agree with the scaling law for a plasma focus. Advantages of this new geometry include the possibility of using plasma-focus type pinches in multiple arrays at power levels beyond the validity regime of the current scaling law for a single gun. (author)

  11. Experimental investigations of plasma lens focusing and plasma channel transport of heavy ion beams

    International Nuclear Information System (INIS)

    Tauschwitz, T.; Yu, S.S.; Eylon, S.; Reginato, L.; Leemans, W.; Rasmussen, J.O.; Bangerter, R.O.

    1995-04-01

    Final focusing of ion beams and propagation in a reactor chamber are crucial questions for heavy ion beam driven Fusion. An alternative solution to ballistic quadrupole focusing, as it is proposed in most reactor studies today, is the utilization of the magnetic field produced by a high current plasma discharge. This plasma lens focusing concept relaxes the requirements for low emittance and energy spread of the driver beam significantly and allows to separate the issues of focusing, which can be accomplished outside the reactor chamber, and of beam transport inside the reactor. For focusing a tapered wall-stabilized discharge is proposed, a concept successfully demonstrated at GSI, Germany. For beam transport a laser pre-ionized channel can be used

  12. Recent results on medium-size plasma-focus device

    International Nuclear Information System (INIS)

    Miklaszewski, R.; Kasperczuk, A.; Paduch, M.; Tomaszewaski, K.; Wereszczynski, Z.

    1992-01-01

    A brief history of investigation carried out on the PF-150 plasma-focus device is presented. Essential results concerning the dynamics of plasma sheath are summarized. The present state of investigation and main areas of interest are shown. (author)

  13. Laser plasma focus produced in a ring target

    International Nuclear Information System (INIS)

    Saint-Hilaire, G.; Szili, Z.

    1976-01-01

    A new geometry for generating a laser-produced plasma is presented. A toroidal mirror is used to focus a CO 2 laser beam on the inside wall of a copper ring target. The plasma produced converges at the center of the ring where an axial plasma focus is formed. High-speed photography shows details of a plasma generated at a distance from the target surface. This new geometry could have important applications in the field of x-ray lasers

  14. Preliminary studies of the plasma focus as an opening switch

    International Nuclear Information System (INIS)

    Venneri, F.; Gerdin, G.

    1983-01-01

    Sharp current interruption at pinch time suggests the possible application of the plasma focus as an opening switch. Switch impedances on the order of 0.5 ohms or greater would be of interest to pulsed power applications if the rise time for the impedance is sufficiently short. The experimental determination of the magnitude of the plasma focus impedance at pinch time and its nature (R or L) are obviously important in assessing the feasibility of this application. An experimental estimate of the Spitzer resistance of the plasma focus based on soft-X-ray measurements indicates a Spitzer resistance of 9 mΩ. Estimates of resistance based on the maximum particle energy observed 4 (V about E /sub MAX/ /e) and the current at pinch time (R about E /sub MAX/ /eI /sub p/ ) would indicate an effective resistance of about one ohm. Estimates of resistance based on circuit parameters (L, I, q/C) yield about one third of an ohm. To resolve these discrepancies a exclamationBexclamation probe 5 is being developed to get a better estimate of L(t), L(t) and I(t) through spatially resolved measurements. Preliminary results are reported

  15. Self-focusing of laser beam crossing a laser plasma

    International Nuclear Information System (INIS)

    Bakos, J.S.; Foeldes, I.B.; Ignacz, P.N.; Soerlei, Zs.

    1983-03-01

    A crossed-beam experiment was performed to clarify the mechanism of self-focusing in a laser produced spark. The plasma was created by one beam and self-focusing was observed in the weak probe beam which crossed the plasma. Experimental results show that the cause of self-focusing is the nonuniform heating mechanism. (author)

  16. The plasma focus as a large fluence neutron source

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Long, J.; Luce, J.; Sahlin, H.

    1977-01-01

    A continuously operated, 1 pps, dense-plasma-focus device capable of delivering a minimum of 10 15 neutrons per pulse for material testing purposes is described. With I 5 scaling, predicted from analysis of existing machines, yields of 10 16 -10 17 neutrons per pulse are postulated. The average power consumption, which has become a major issue as a result of the energy crisis is shown to be highly favorable. A novel approach to the capacitor bank and switch design allowing repetitive operation is discussed. (Auth.)

  17. Coupling of laser energy into plasma channels

    International Nuclear Information System (INIS)

    Dimitrov, D. A.; Giacone, R. E.; Bruhwiler, D. L.; Busby, R.; Cary, J. R.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

    2007-01-01

    Diffractive spreading of a laser pulse imposes severe limitations on the acceleration length and maximum electron energy in the laser wake field accelerator (LWFA). Optical guiding of a laser pulse via plasma channels can extend the laser-plasma interaction distance over many Rayleigh lengths. Energy efficient coupling of laser pulses into and through plasma channels is very important for optimal LWFA performance. Results from simulation parameter studies on channel guiding using the particle-in-cell (PIC) code VORPAL [C. Nieter and J. R. Cary, J. Comput. Phys. 196, 448 (2004)] are presented and discussed. The effects that density ramp length and the position of the laser pulse focus have on coupling into channels are considered. Moreover, the effect of laser energy leakage out of the channel domain and the effects of tunneling ionization of a neutral gas on the guided laser pulse are also investigated. Power spectral diagnostics were developed and used to separate pump depletion from energy leakage. The results of these simulations show that increasing the density ramp length decreases the efficiency of coupling a laser pulse to a channel and increases the energy loss when the pulse is vacuum focused at the channel entrance. Then, large spot size oscillations result in increased energy leakage. To further analyze the coupling, a differential equation is derived for the laser spot size evolution in the plasma density ramp and channel profiles are simulated. From the numerical solution of this equation, the optimal spot size and location for coupling into a plasma channel with a density ramp are determined. This result is confirmed by the PIC simulations. They show that specifying a vacuum focus location of the pulse in front of the top of the density ramp leads to an actual focus at the top of the ramp due to plasma focusing, resulting in reduced spot size oscillations. In this case, the leakage is significantly reduced and is negligibly affected by ramp length

  18. Fortum is focusing on energy

    International Nuclear Information System (INIS)

    Ropponen, V.M.

    1999-01-01

    At the end of January 1998, the Finnish government took the decision to found a new energy company, IVO-Neste Group Ltd, which would combine the businesses of the IVO Group and the Neste Group. In June the company was renamed Fortum Corporation. Fortum Group's new business structure was officially instituted on 1 January 1999. Most of the Neste Group has been joined to the Oil and Gas Division, which is divided into the Oil Business. Unit and the E and P Gas Business Unit. Neste's Oil Division has become part of the Oil Business Unit, while Neste's Exploration and Production Division and the gas business that used to be part of the Energy Division are now a part of the E and P and Gas Business Unit. Neste Laempoe and NAPS were transferred to the Power and Heat Division. Neste Chemicals has become Fortum's Chemicals Division, and Neste Engineering is part of the Engineering Division. Fortum controls approximately 80 % of the Finnish wholesale market for refined petroleum products. During 1998, wholesale deliveries amounted to some 8.3 million tonnes (8.4 million tonnes in 1997). Wholesale customers include all the major oil companies operating in Finland

  19. Needs of Non Energy-Focused Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Liaukus, C.

    2012-12-01

    To better understand the informational needs of non energy-focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

  20. Needs of Non-Energy Focused Contractors

    Energy Technology Data Exchange (ETDEWEB)

    Liakus, C. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States)

    2012-12-01

    To better understand the informational needs of non-energy focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

  1. Plasma lenses for SLAC Final Focus Test facility

    International Nuclear Information System (INIS)

    Betz, D.; Cline, D.; Joshi, C.; Rajagopalan, S.; Rosenzweig, J.; Su, J.J.; Williams, R.; Chen, P.; Gundersen, M.; Katsouleas, T.; Norem, J.

    1991-01-01

    A collaborative group of accelerator and plasma physicists and engineers has formed with an interest in exploring the use of plasma lenses to meet the needs of future colliders. Analytic and computational models of plasma lenses are briefly reviewed and several design examples for the SLAC Final Focus Test Beam are presented. The examples include discrete, thick, and adiabatic lenses. A potential plasma source with desirable lens characteristics is presented

  2. Preliminary Results Of A 600 Joules Small Plasma Focus Device

    International Nuclear Information System (INIS)

    Lee, S. H.; Yap, S. L.; Wong, C. S.

    2009-01-01

    Preliminary results of a 600 J (3.7 μF, 18 kV) Mather type plasma focus device operated at low pressure will be presented. The discharge is formed between a solid anode with length of 6 cm and six symmetrically and coaxially arranged cathode rods of same lengths. The cathode base is profiled in a knife-edge design and a set of coaxial plasma gun are attached to it in order to initiate the breakdown and enhance the current sheath formation. The experiments have been performed in argon gas under a low pressure condition of several microbars. The discharge current and the voltage across the electrodes during the discharge are measured with high voltage probe and current coil. The current and voltage characteristics are used to determine the possible range of operating pressure that gives good focusing action. At a narrow pressure regime of 9.0±0.5 μbar, focusing action is observed with good reproducibility. Preliminary result of ion beam energy is presented. More work will be carried out to investigate the radiation output.

  3. Fully kinetic simulations of megajoule-scale dense plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, A.; Link, A.; Tang, V.; Halvorson, C.; May, M. [Lawrence Livermore National Laboratory, Livermore California 94550 (United States); Welch, D. [Voss Scientific, LLC, Albuquerque, New Mexico 87108 (United States); Meehan, B. T.; Hagen, E. C. [National Security Technologies, LLC, Las Vegas, Nevada 89030 (United States)

    2014-10-15

    Dense plasma focus (DPF) Z-pinch devices are sources of copious high energy electrons and ions, x-rays, and neutrons. Megajoule-scale DPFs can generate 10{sup 12} neutrons per pulse in deuterium gas through a combination of thermonuclear and beam-target fusion. However, the details of the neutron production are not fully understood and past optimization efforts of these devices have been largely empirical. Previously, we reported on the first fully kinetic simulations of a kilojoule-scale DPF and demonstrated that both kinetic ions and kinetic electrons are needed to reproduce experimentally observed features, such as charged-particle beam formation and anomalous resistivity. Here, we present the first fully kinetic simulation of a MegaJoule DPF, with predicted ion and neutron spectra, neutron anisotropy, neutron spot size, and time history of neutron production. The total yield predicted by the simulation is in agreement with measured values, validating the kinetic model in a second energy regime.

  4. Charged particles beams measurements in plasma focus discharges

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M.; Zebrowski, J.

    2001-01-01

    Experimental studies performed with many Plasma-Focus (PF) facilities have shown that simultaneously with the emission of X-ray pulses and intense relativistic electron beams (REBs) there also appears the emission of pulsed ion streams of a relatively high energy (up to several MeV). Such ions are emitted mainly along the z-axis of the PF discharge, although the ion angular distribution is relatively wide. From PF discharges with deuterium filling fast neutrons produced by nuclear fusion reactions are also emitted. The paper concerns studies of the energetic ion beams and their correlation with the pulsed REBs. Time-integrated measurements were performed with an ion pinhole camera equipped with solid-state nuclear track detectors (SSNTDs), and time-resolved studies were carried out with a scintillation detector, enabling the determination of an ion energy spectrum on the basis of the time-of-flight (TOF) technique. (author)

  5. Three-fluid magnetohydrodynamical simulation of plasma focus discharges

    International Nuclear Information System (INIS)

    Behler, K.; Bruhns, H.

    1987-01-01

    A two-dimensional, three-fluid code based on the two-fluid Potter code [Methods in Computational Physics (Academic, New York, 1970), Vol. 9, p. 340] was developed for simulating the plasma focus discharge. With this code it is possible to treat the neutral gas in addition to the plasma components and to model the ionization and recombination phenomena. Thus the sheet dynamics in a plasma focus can be studied and effects investigated such as the occurrence of residual gas (or plasma) density behind the current sheet in the run-down phase. This is a prerequisite to the occurrence of leak currents, which are one of the causes limiting the performance of large plasma focus devices. It is shown that fast operating foci with small dimensions behave favorably compared with the ''classical'' Mather focus [Methods of Experimental Physics (Academic, New York, 1971), Vol. 9B, p. 187] with long coaxial electrodes

  6. Self-focusing of electron bunches in a nonlinear plasma

    International Nuclear Information System (INIS)

    Krasovitskii, V.B.; Osmolovsky, S.I.

    1994-01-01

    The phenomena of self-focusing of previously bunched electron beam in hot nonlinear plasma with the frequency which less than the plasma one is studied. It is established that influence of the Miller's force nonlinearity of the plasma don't leads to self-focusing breaking. However in the case of a dense beam, the appearance strong resonant electric field is followed by the change of the sign of the plasma dielectric constant to positive at the beam axis. But the dielectric constant remain negative at the outer of the beam

  7. Revitalize Electrical Program with Renewable Energy Focus

    Science.gov (United States)

    Karns, Robert J.

    2012-01-01

    Starting a renewable energy technology (RET) program can be as simple as shifting the teaching and learning focus of a traditional electricity program toward energy production and energy control systems. Redirecting curriculum content and delivery to address photovoltaic solar (PV solar) technology and small wind generation systems is a natural…

  8. Numerical experimentation on focusing time and neutron yield in GN1 plasma focus machine

    International Nuclear Information System (INIS)

    Singh, Arwinder; Lee, Sing; Saw, S.H.

    2014-01-01

    In this paper, we have shown how we have fitted Lee's six phase model code to analyze the current waveform of the GN1 plasma focus machine working in deuterium gas. The Lee's 6-phase model codes was later configured to work between 0.5 to 6 Torr and the results of both focusing time and neutron yield was then compared with the published experimental results. The final results indicate that Lee's code, gives realistic plasma dynamics and focus properties together with a realistic neutron yield for GN1 plasma focus, without the need of any adjustable parameters, needing only to fit the computed current trace to a measured current trace. (author)

  9. Instabilities in the 'on' phase of the plasma focus

    International Nuclear Information System (INIS)

    Kaeppeler, H.J.

    1990-07-01

    In the operation of large plasma focus devices, e.g. POSEIDON, there appear saturation phenomena in the neutron production when the charging energy of the condensor bank approaches its nominal value. This saturation is attributed to the action of impurities. It is assumed that there appear instabilities which are in part caused by impurities. In order to be able to answer this question, the linear dispersion relation was derived from a three-fluid theory (electrons, ions and neutrals) with the aid of the computer algebra (CA) code MACSYMA. The inversion of the 17x17 matrix (it is assumed that v a =v i and T a =T i ) and solution of the determinant was carried out on a CONVEX C 120 computer using the CA code MAPLE. The calculation of the zeros was done with a modified CPZERO program from the SLATEC library. There appear four instabilities in the rundown phase of the plasma focus, two of them gradient driven. The first two are unstable electrostatic waves with very high phase velocities, thus they do not contribute to anomalous dissipation. The third is identified as a gradient driven space charge instability which may possibly lead to current chopping. The electron acoustic wave instability, here gradient driven, is the fourth. It was found in a previous study of MPD thruster instabilities. (orig.)

  10. Compact and tunable focusing device for plasma wakefield acceleration

    Science.gov (United States)

    Pompili, R.; Anania, M. P.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Lollo, V.; Notargiacomo, A.; Picardi, L.; Ronsivalle, C.; Rosenzweig, J. B.; Shpakov, V.; Vannozzi, A.

    2018-03-01

    Plasma wakefield acceleration, either driven by ultra-short laser pulses or electron bunches, represents one of the most promising techniques able to overcome the limits of conventional RF technology and allows the development of compact accelerators. In the particle beam-driven scenario, ultra-short bunches with tiny spot sizes are required to enhance the accelerating gradient and preserve the emittance and energy spread of the accelerated bunch. To achieve such tight transverse beam sizes, a focusing system with short focal length is mandatory. Here we discuss the development of a compact and tunable system consisting of three small-bore permanent-magnet quadrupoles with 520 T/m field gradient. The device has been designed in view of the plasma acceleration experiments planned at the SPARC_LAB test-facility. Being the field gradient fixed, the focusing is adjusted by tuning the relative position of the three magnets with nanometer resolution. Details about its magnetic design, beam-dynamics simulations, and preliminary results are examined in the paper.

  11. Laser light scatter experiments on plasma focus plant

    International Nuclear Information System (INIS)

    Wenzel, N.

    1985-01-01

    The plasma focus plant is an experiment on nuclear fusion, which is distinguished by a high neutron yield. Constituting an important method of diagnosis in plasma focussing, the laser light scatter method makes it possible, apart from finding the electron temperature and density, to determine the ion temperature resolved according to time and place and further, to study the occurrence of micro-turbulent effects. Starting from the theoretical basis, this dissertation describes light scatter measurements with ruby lasers on the POSEIDON plasma focus. They are given, together with earlier measurements on the Frascati 1 MJ plant and the Heidelberg 12 KJ plant. The development of the plasma parameters and the occurrence of superthermal light scatter events are discussed in connection with the dynamics of the plasma and the neutron emission characteristics of the individual plants. The results support the view that the thermo-nuclear neutron production at the plasma focus is negligible. Although the importance of micro-turbulent mechanisms in producing neutrons cannot be finally judged, important guidelines are given for the spatial and time relationships with plasma dynamics, plasma parameters and neutron emission. The work concludes with a comparison of all light scatter measurements at the plasma focus described in the literature. (orig.) [de

  12. Preliminary studies on a plasma focus opening switch

    Energy Technology Data Exchange (ETDEWEB)

    Wong, C S; Moo, S P; Singh, J P [Univ. of Malaya, Kuala Lumpur (Malaysia). Physics Dept., Plasma Research Laboratory; Choi, P [Ecole Polytechnique, Palaiseau (France). Laboratoire de Physique des Milieux Ionises

    1997-12-31

    The small plasma focus device UNU/ICTP PFF has been modified to assess the operation of a plasma focus based long conduction (> 2 {mu}s) opening switch, with a plasma filled diode as the load. The UNU/ICTP PFF is a Mather type plasma focus device powered by a single 15 kV, 30 {mu}F capacitor delivering a peak current of 150 kA when discharged at 15 kV. The device has been optimized for reproducible focusing in various gases including deuterium, argon, carbon dioxide, helium as well as in air. In particular, the optimum operating pressure for air is between 0.5 to 1.1 mbar, whereas for argon it is between 0.3 to 3 mbar. For the operation of the UNU/ICTP PFF as an opening switch, the electrode geometry is modified to redirect the plasma motion at the end of the axial rundown phase to avoid the normal plasma focus action, and the operating regime is shifted to low pressure to favour plasma opening switch action. With air as the working gas, pressure as low as 10{sup -3} mbar was tested. At such a low pressure, a set of 12 plasma injection cable guns is used to initiate breakdown of the discharge. The design and operating principle is presented and some preliminary results obtained on the operational characteristics of this device are discussed. (author). 5 figs., 4 refs.

  13. Electrical characteristics of a small plasma focus device

    International Nuclear Information System (INIS)

    Choi, P.; Favre, M.; Silva, P.; Chuaqui, H.; Wyndham, E.

    1996-01-01

    Efficient plasma focus operation relies on uniform initial breakdown across the insulator surface. The basic plasma focus electric circuit is discussed in order to highlight circuit modifications that produce high voltage oscillation at the initial breakdown time. Superimposed on the main discharge voltage, such oscillating voltage has been found in real systems to enhance the initial gas breakdown by localizing the initial current path across the insulator surface. PSPICE circuit simulations are compared with electric signals from different operational plasma focus devices. (author). 3 figs., 7 refs

  14. Focusing of relativistic electron bunch, moving in cylindrical plasma waveguide

    International Nuclear Information System (INIS)

    Amatuni, A.Ts.; Ehlbakyan, S.S.; Sekhpossyan, E.V.

    1994-01-01

    The problem on the focusing of electron bunches moving with the relativistic velocity along the axis of cylindrical overdense plasma waveguide with the conducting internal surface is considered. The existence of periodic and nonperiodic components of the fields, generated in the plasma is shown. The conditions of electron bunch self-focusing by transverse electrical field and azimuthal magnetic field are derived. The possibility of the acceleration and focusing of electron or positron bunches by driving electron bunch wake field is discussed. The conditions, when the bunch in plasma waveguide moves without wake fields generating are obtained, which could be of the interest for the transport of relativistic electron (positron) bunches. 5 refs

  15. Architecture and Energy. Towards a broader Focus

    DEFF Research Database (Denmark)

    Lauring, Michael; Marsh, Rob

     Architecture and Energy. Towards a broader focus. By Michael Lauring and Rob Marsh   In typical new Danish dwellings build according to the standards of the Building Regulations 2008 approximately 35% of the primary energy use is related to heat consumption divided into 23% room heating and 12% ...... & Hacker (2008): Bygninger, Energi, Klima. Mod et nyt paradigme.  Statens Byggeforskningsinstitut (Danish Building Research Institute). [2] Marsh, Larsen, Lauring & Christensen (2006): Arkitektur og energi. Statens Byggeforskningsinstitut (Danish Building Research Instititute)....

  16. Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

    Science.gov (United States)

    Joshi, Chan; Malka, Victor

    2010-04-01

    The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage approach R M G M Trines, R Bingham, Z Najmudin

  17. Pinch modes in the SPEED2 plasma focus

    International Nuclear Information System (INIS)

    Kies, W.; Decker, G.; Berntien, U.; Glushkov, D.A.; Sidelnikov, Yu.V.; Koshelev, K.N.; Simanovskij, D.M.; Bobashev, S.V.

    2001-01-01

    Deuterium discharges in the SPEED2 plasma focus (80 kJ, 200 kV, 2 MA, 400 ns) have been found unexpectedly stable within the operational regime as a neutron source. Only at higher filling pressures (above 6 mbar) sometimes m=0 instabilities appeared in the pinch column, especially in discharges of lower efficiency (moderate dynamics and neutron yield). Enhancing the electromagnetic radiation by doping these discharges with heavy gases (e.g. neon, argon) distinctly two pinch modes are produced, the micropinch mode (MPM) or the stable column mode (SCM), with a transition regime where the initial SCM is followed by the MPM. Micropinches are local radiative collapses initiated by m=0 instabilities of low-energy-density pinch plasmas. These instabilities and the successive micropinches can be suppressed by kinetic deuterons produced during dynamical compression of high-energy-density deuterium plasma sheaths. Depending on the relaxation of this fast deuteron component the pinch column can be stabilized for several tens of nanoseconds. While the short-lived (appr.1 ns) micropinches erratically appear as point-like successive flashes along the pinch axis with temperatures about 1 keV and about solid density the reproducible SCM, optimized with respect to the compression ratio, forms a powerful linear radiation source of temperatures and densities similar to the MPM. The SCM needs powerful (fast) drivers in order to use the kinetic ion stabilization, but not necessarily MA currents as available from the SPEED2 driver. This opens the possibility to establish the SCM also in compact experiments like SPEED3 (8 kJ, 80 kV, 0.8 MA, 300 ns) or even SPEED4 (2 kJ, 40 kV 250 kA, 300 ns). (author)

  18. Characterization of bismuth nanospheres deposited by plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, M., E-mail: cscientific2@aec.org.sy [IBA Laboratory, Chemistry Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Al-Hawat, Sh.; Akel, M. [Physics Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Mrad, O. [Chemistry Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2015-02-14

    A new method for producing thin layer of bismuth nanospheres based on the use of low energy plasma focus device is demonstrated. Various techniques such as scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to characterize the morphology and the composition of the nanospheres. Experimental parameters may be adjusted to favour the formation of bismuth nanospheres instead of microspheres. Therefore, the formation of large surface of homogeneous layer of bismuth nanospheres with sizes of below 100 nm can be obtained. The natural snowball phenomenon is observed to be reproduced in nanoscale where spheres roll over the small nanospheres and grow up to bigger sizes that can reach micro dimensions. The comet-like structure, a reverse phenomenon to snowball is also observed.

  19. Characterization of bismuth nanospheres deposited by plasma focus device

    International Nuclear Information System (INIS)

    Ahmad, M.; Al-Hawat, Sh.; Akel, M.; Mrad, O.

    2015-01-01

    A new method for producing thin layer of bismuth nanospheres based on the use of low energy plasma focus device is demonstrated. Various techniques such as scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to characterize the morphology and the composition of the nanospheres. Experimental parameters may be adjusted to favour the formation of bismuth nanospheres instead of microspheres. Therefore, the formation of large surface of homogeneous layer of bismuth nanospheres with sizes of below 100 nm can be obtained. The natural snowball phenomenon is observed to be reproduced in nanoscale where spheres roll over the small nanospheres and grow up to bigger sizes that can reach micro dimensions. The comet-like structure, a reverse phenomenon to snowball is also observed

  20. Geometrical optimization of the dense plasma focus

    International Nuclear Information System (INIS)

    Lee, S.; Chen, Y.H.

    1982-01-01

    A 12 kJ DPF device with a periodic time of 12μsec, UMDPF1 has been optimized geometrically to produce a higher neutron yield of 1.5x10 9 at 10 torr filling pressure than from the same device before optimization. With the same optimization procedure a faster DPF device with a periodic time of 3.7μsec, UMDPF2, of the same energy has also been optimized to give a peak neutron yield of 6.3x10 9 at 16 torr filling pressure. Experimental evidence shows that over and above the increase in neutron production due to an increase in current according to the Isup(3.3) scaling law, a faster current rise time may have an additional effect of enhancement in neutron production. The outcome of this project is that a new high pressure regime of 16 torr with an enhanced neutron yield of 6.3x10 9 and improved yield reproducibility for an input energy of 12 kJ has thus been established. There is every reason to believe that this optimization procedure can be extended to other DPF devices. (author)

  1. Numerical Study of Radiation Emissions from the Plasma Focus

    International Nuclear Information System (INIS)

    Akel, M.; Salo, S.

    2013-12-01

    Ion populations of studied plasma have been calculated versus electron temperatures. The expected emission spectra (full, Bremsstrahlung, recombination, and line) of plasma focus operated with different gases (nitrogen, oxygen, neon, argon, krypton and xenon) have been studied for different conditions using POPULATE, SPECTRA, XRAYFIL and FLYCHK codes for non-local thermodynamic equilibrium model (NLTE). The suitable electron temperatures ranges for soft X-ray and extreme ultraviolet (EUV) emissions from plasma focus have been investigated. The Ratio- BPX65.F code has been written in FORTRAN 77 for studying the soft X-ray emission of plasma focus using BPX65 PIN Diode X-ray Spectrometer technique. The X-ray ratio curves for various electron temperatures with probable electron and ion densities of the studied plasma produced have been computed with the assumption of non-LTE model for the distribution of the ionic species. The calculated X-ray ratio curves have been compared with experimental results for the argon plasma focus. These ratio curves could be used for electron temperatures deduction of plasma focus (author).

  2. What is the Plasma Focus Thermonuclear Pulsors Technology?

    International Nuclear Information System (INIS)

    Ramos, R.; Gonzalez, J.; Moreno, C.; Clausse, A.

    2003-01-01

    In this paper we describe a type of neutron generators, called Plasma Focus, which is suitable to several applications, where traditional generators are non-applicable.The main characteristics are its transportability and to be non-contaminating, which would allow in-situ tests.The Plasma Focus, produces neutron pulses by thermonuclear fusion reactions, satisfy these requirements and it is comparatively non expensive.This last feature would assure competitivity in the neutron sources market

  3. Technical and experimental investigations of a plasma focus neutron source

    International Nuclear Information System (INIS)

    Rapp, H.K.

    The results obtained from two plasma-focus devices of different size allow to report on the technical and physical properties of such neutron flash sources. The results of some diagnostic methods used for the control of the gas discharge and for the measurement of the neutron production are included. The planning of plasma focus devices is illustrated with the aid of snow-plow calculations

  4. Method for the determination of the spectral composition of power-full energy-rich deuteron bundles generated in the plasma focus

    International Nuclear Information System (INIS)

    Philippow, N.W.; Philippowa, T.I.

    1977-01-01

    A method is presented which allows a quantitative determination of the spectral composition of a high power deuterium bunch produced in noncylindrical Z-pinch type systems when the plasma shell is increased. The bunch moves in the normal direction, i.e. from the anode to the region behind the cathodes. The method is based on the principle of a time-of-flight spectrometer, where the neutron scintillation detector signal is processed appropriately and displayed on a scope. The neutrons are produced by the 12 C(d,n) 13 N-reaction in the carbon target when hit by a deuterium bunch. These investigations have been performed in parallel with the method based on a comparison of carbon- and aluminium target activities. This method has been used in the past by R. Gallickson and G. Salin in the Livermore Laboratory for the same purpose but has now untergone some improvements. (orig.) [de

  5. On the excess energy of nonequilibrium plasma

    International Nuclear Information System (INIS)

    Timofeev, A. V.

    2012-01-01

    The energy that can be released in plasma due to the onset of instability (the excess plasma energy) is estimated. Three potentially unstable plasma states are considered, namely, plasma with an anisotropic Maxwellian velocity distribution of plasma particles, plasma with a two-beam velocity distribution, and an inhomogeneous plasma in a magnetic field with a local Maxwellian velocity distribution. The excess energy can serve as a measure of the degree to which plasma is nonequilibrium. In particular, this quantity can be used to compare plasmas in different nonequilibrium states.

  6. Self-focusing relativistic electron streams in plasmas

    International Nuclear Information System (INIS)

    Cox, J.L. Jr.

    1975-01-01

    A relativistic electron stream propagating through a dense plasma induces current and charge densities which determine how the stream can self-focus. Magnetic self-focusing is possible because stream-current neutralization, although extensive, is not complete. Electric self-focusing can occur because the stream charge becomes overneutralized when the net current is smaller than a critical value. Under some circumstances, the latter process can cause the stream to focus into a series of electron bunches

  7. Electrostatic plasma lens for focusing negatively charged particle beams.

    Science.gov (United States)

    Goncharov, A A; Dobrovolskiy, A M; Dunets, S M; Litovko, I V; Gushenets, V I; Oks, E M

    2012-02-01

    We describe the current status of ongoing research and development of the electrostatic plasma lens for focusing and manipulating intense negatively charged particle beams, electrons, and negative ions. The physical principle of this kind of plasma lens is based on magnetic isolation electrons providing creation of a dynamical positive space charge cloud in shortly restricted volume propagating beam. Here, the new results of experimental investigations and computer simulations of wide-aperture, intense electron beam focusing by plasma lens with positive space charge cloud produced due to the cylindrical anode layer accelerator creating a positive ion stream towards an axis system is presented.

  8. Experimental validation of models for Plasma Focus devices

    International Nuclear Information System (INIS)

    Rodriguez Palomino, Luis; Gonzalez, Jose; Clausse, Alejandro

    2003-01-01

    Plasma Focus(PF) Devices are thermonuclear pulsators that produce short pulsed radiation (X-ray, charged particles and neutrons). Since Filippov and Mather, investigations have been used to study plasma properties. Nowadays the interest about PF is focused in technology applications, related to the use of these devices as pulsed neutron sources. In the numerical calculus the Inter institutional PLADEMA (PLAsmas DEnsos MAgnetizados) network is developing three models. Each one is useful in different engineering stages of the Plasma Focus design. One of the main objectives in this work is a comparative study on the influence of the different parameters involved in each models. To validate these results, several experimental measurements under different geometry and initial conditions were performed. (author)

  9. Pulsed x-ray generation from a plasma focus device

    International Nuclear Information System (INIS)

    Zambra, M; Bruzzone, H; Sidelnikov, Y; Kies, W; Moreno, C; Sylvester, G; Silva, P; Moreno, J; Soto, L

    2003-01-01

    Dynamical pinches coupled to electrodes like the dense Z-pinch or the dense plasma focus have been intensively studied in the last four decades for their high fusion efficiency and their application potential. Though the expectations of the eighties of the last century, scaling these pinches up to fusion reactors, did not come true, the development of fast and powerful experiments resulted in new insights in pinch physics and paved the way for developing compact dynamical pinches as pulsed neutron and X-radiation sources for many applications. There is a permanent and growing interest in the research community for understanding and determining the generation properties of X-rays, neutrons and charged particles emitted from a high-temperature high-density plasmas, especially in the plasma focus configuration. The Plasma Physics and Plasma Technology Group of the CCHEN has developed the SPEED4 fast-plasma focus device, in collaboration with the Plasma Physics Group of the Dusseldorf University, in order to perform experimental studies such as X-ray and neutron emission, and electron and ion beam characterization (author)

  10. effect of the plasma ion channel on self-focusing of a Gaussian laser pulse in underdense plasma

    Directory of Open Access Journals (Sweden)

    Sh Irani

    2013-09-01

    Full Text Available  We have considered the self-focusing of a Gaussian laser pulse in unmagnetized plasma. High-intensity electromagnetic fields cause the variation of electron density in plasma. These changes in the special conditions cause the acceleration of electrons to the higher energy and velocities. Thus the equation of plasma density evolution was obtained considering the electrons ponderomotive force. Then, an equation for the width of laser pulse with a relativistic mass correction term and the effect of ion channel were derived and the propagation of high-intensity laser pulse in an underdense plasma with weak relativistic approximation was investigated. It is shown that the ratio of ion channel radius to spot size could result in different forms of self focusing for the laser pulse in plasma.

  11. Laser induced focusing for over-dense plasma beams

    International Nuclear Information System (INIS)

    Schmidt, Peter; Boine-Frankenheim, Oliver; Mulser, Peter

    2015-01-01

    The capability of ion acceleration with high power, pulsed lasers has become an active field of research in the past years. In this context, the radiation pressure acceleration (RPA) mechanism has been the topic of numerous theoretical and experimental publications. Within that mechanism, a high power, pulsed laser beam hits a thin film target. In contrast to the target normal sheath acceleration, the entire film target is accelerated as a bulk by the radiation pressure of the laser. Simulations predict heavy ion beams with kinetic energy up to GeV, as well as solid body densities. However, there are several effects which limit the efficiency of the RPA: On the one hand, the Rayleigh-Taylor-instability limits the predicted density. On the other hand, conventional accelerator elements, such as magnetic focusing devices are too bulky to be installed right after the target. Therefore, we present a new beam transport method, suitable for RPA-like/over-dense plasma beams: laser induced focusing

  12. Reduced energy conservation law for magnetized plasma

    International Nuclear Information System (INIS)

    Sosenko, P.P.; Decyk, V.K.

    1994-01-01

    A global energy conservation law for a magnetized plasma is studied within the context of a quasiparticle description. A reduced energy conservation law is derived for low-frequency, as compared to the gyromagnetic frequency, plasma motions with regard to both non-uniform mean flows and fluctuations in the plasma. The mean value of plasma energy is calculated and sufficient stability conditions for non-equilibrium plasmas are derived. (orig.)

  13. Paul Ion Trap as a Diagnostic for Plasma Focus

    Science.gov (United States)

    Sadat Kiai, S. M.; Adlparvar, S.; Zirak, A.; Alhooie, Samira; Elahi, M.; Sheibani, S.; Safarien, A.; Farhangi, S.; Dabirzadeh, A. A.; Khalaj, M. M.; Mahlooji, M. S.; KaKaei, S.; Talaei, A.; Kashani, A.; Tajik Ahmadi, H.; Zahedi, F.

    2010-02-01

    The plasma discharge contamination by high and low Z Impurities affect the rate of nuclear fusion reaction products, specially when light particles have to be confined. These impurities should be analyzed and can be fairly controlled. This paper reports on the development of a Paul ion trap with ion sources by impact electron ionization as a diagnostic for the 10 kJ Iranian sunshine plasma focus device. Preliminary results of the residual gas are analyzed and presented.

  14. Workshop on extremely high energy density plasmas and their diagnostics

    International Nuclear Information System (INIS)

    Ishii, Shozo

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  15. Workshop on extremely high energy density plasmas and their diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Shozo (ed.)

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  16. Focus on energy conservation: a project list

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    The Urban Land Institute (ULI) has prepared the following list of outstanding energy conserving projects for the US Department of Energy. As requested by the Department, the list includes descriptions of land developments and individual buildings suggested by members of ULI and by other sources. The projects have been selected to exemplify the major energy saving techniques in use today, with emphasis on those strategies most significant for people engaged in the business of land development. To make the list a useful reference for developers and public officials, ULI has attempted to cover energy conservation in the broadest sense from overall site planning to the functioning of individual building components. Focusing too closely on the myriad types of hardware available has been avoided and examples of the basic considerations important to energy-conscious planning and design are provided. Details on some heating, ventilation and air conditioning systems are provided in order to acquaint readers with major innovations in the field.

  17. Observation of intense beam in low pressure from IPR Plasma Focus facility

    International Nuclear Information System (INIS)

    Kumar, R.; Shyam, A.; Chaturvedi, S.; Lathi, D.; Sarkar, Partha; Chaudhari, V.; Verma, R.; Shukla, R.; Debnath, K.; Sonara, J.; Shah, K.; Adhikary, B.

    2004-01-01

    Full text: Plasma focus (PF) is a powerful source of various ionizing radiation such as charged particles beam (ions and electrons), X-ray, neutrons etc. This device can operate from energy level of 50J to 1MJ. Plasma Focus is relatively small, simple and cheap in comparison with other radiation sources based on isotopes, accelerators and fusion reactors. Radiation pulse from PF is strong and very short. Now with the new pulsed power technology this device can be operated repeatedly with enhanced lifetime. All these features make plasma focus a versatile device for academic as well as industrial interest such as hot plasma physics and plasma collective processes, equation of state of matter under extreme conditions, material science including material characterization, dynamic equation control, and surface modification and destruction test. Intense burst of neutrons have been observed from a low energy (3.6 kJ) Mather type plasma focus device operated in 0.4 Torr pressure of deuterium medium at IPR. The emitted neutrons (10 9 /shot), that are accompanied by a strong hard X-ray pulse, were found to be having energy up to 3.26 MeV in the axial direction of the device

  18. Experimental studies of plasma wake-field acceleration and focusing

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Cole, B.; Ho, C.; Argonne National Lab., IL

    1989-01-01

    More than four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These large amplitude plasma wake-fields are of interest in the laboratory, both for the wealth of basic nonlinear plasma wave phenomena which can be studied, as well as for the applications of acceleration of focusing of electrons and positrons in future linear colliders. Plasma wake-field waves are also of importance in nature, due to their possible role in direct cosmic ray acceleration. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory, in which many interesting beam and plasma phenomena have been observed. Emphasis is given to discussion of the nonlinear aspects of the PWFA beam-plasma interaction. 29 refs., 13 figs

  19. Deposition of aluminium nanoparticles using dense plasma focus device

    International Nuclear Information System (INIS)

    Devi, Naorem Bilasini; Srivastava, M P; Roy, Savita

    2010-01-01

    Plasma route to nanofabrication has drawn much attention recently. The dense plasma focus (DPF) device is used for depositing aluminium nanoparticles on n-type Si (111) wafer. The plasma chamber is filled with argon gas and evacuated at a pressure of 80 Pa. The substrate is placed at distances 4.0 cm, 5.0 cm and 6.0 cm from the top of the central anode. The aluminium is deposited on Si wafer at room temperature with two focused DPF shots. The deposits on the substrate are examined for their morphological properties using atomic force microscopy (AFM). The AFM images have shown the formation of aluminium nanoparticles. From the AFM images, it is found that the size of aluminium nanoparticles increases with increase in distance between the top of anode and the substrate for same number of DPF shots.

  20. Study of electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    Smith, J.R.; Luo, C.M.; Rhee, M.J.; Schneider, R.F.

    1983-01-01

    A preliminary investigation of the electron beam produced by a plasma focus device using a current charged transmission line is described. Electron beam currents as high as 10 kA were measured. Interaction of the extracted beam and the filling gas was studied using open shutter photography

  1. Multi-scaling of the dense plasma focus

    Science.gov (United States)

    Saw, S. H.; Lee, S.

    2015-03-01

    The dense plasma focus is a copious source of multi-radiations with many potential new applications of special interest such as in advanced SXR lithography, materials synthesizing and testing, medical isotopes and imaging. This paper reviews the series of numerical experiments conducted using the Lee model code to obtain the scaling laws of the multi-radiations.

  2. Preliminary results of neutron production in Sahand plasma focus device

    International Nuclear Information System (INIS)

    Siahpoush, V.; Mohammadi, M.A.; Khorram, S.; Shabani, I.; Borhanian, J.; Ashrafi, S.; Naghshara, H.; Moslehi-Fard, M.; Sobhanian, S.

    2004-01-01

    We report in this paper the preliminary results of neutron generation during fusion reaction in deuterium in the Sahand Filipov type plasma focus, recently installed and put in operation at Tabriz University. The special calibration procedure for neutron detection system, using activation method is described

  3. Electromagnetic field theory. Solely theories with plasma in focus

    International Nuclear Information System (INIS)

    Stenstrom, L.

    1979-01-01

    The Institute of Electromagnetic Field Theory at Chalmers Technical University is concerned with purely theoretical work on plasma physics for nuclear fusion. The team concerned is looking at nonlinear effects in the plasma energy exchange mechanism. Both inertia restricted and magnetically enclosed plasma are considered. Analytic and computer methods are used upon the model equations of the plasma. The Institute has associations with Euratom and with work in Maryland and in Grenoble. Work on particle paths is of interst. It also is associated with the construction at Sundsvik of an accelerator to give zero keV negative ions. A problem is to find staff of a sufficiently high quality for such complex work. The difficulties are not economic, but mainly that the desired practical results appear to be so far into the future. (G.P.)

  4. Computer simulation of a plasma focus device driven by a magnetic pulser

    Energy Technology Data Exchange (ETDEWEB)

    Georgescu, N; Zoita, V [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania); Larour, J [Ecole Polytechnique, Palaiseau (France). Lab. de Physique des Milieux Ionises

    1997-12-31

    A plasma focus device, driven by a magnetic pulse compression circuit, is simulated by using a PSPICE proffam. The elaborated program is much simpler than the other existing ones, which analyse the circuit by directly solving a system of integral-differential equations. The pre-pulse voltage and the high-voltage rise-times are obtained for a set of values of the bypass impedance (R or L). The optimum bypass impedance turns out to be an inductance. During the discharge period, the plasma load is considered as an LR impedance, each component being time dependent. A method is presented for giving us the possibility to introduce the time varying impedances in a PSPICE program. Finally, a set of simulation results (plasma current and voltage, plasma magnetic energy, plasma sheath mechanical energy, pinch voltage) is shown. The results are in good agreement with the classical experimental data. (author). 2 figs., 4 refs.

  5. Strong self-focusing of a cosh-Gaussian laser beam in collisionless magneto-plasma under plasma density ramp

    International Nuclear Information System (INIS)

    Nanda, Vikas; Kant, Niti

    2014-01-01

    The effect of plasma density ramp on self-focusing of cosh-Gaussian laser beam considering ponderomotive nonlinearity is analyzed using WKB and paraxial approximation. It is noticed that cosh-Gaussian laser beam focused earlier than Gaussian beam. The focusing and de-focusing nature of the cosh-Gaussian laser beam with decentered parameter, intensity parameter, magnetic field, and relative density parameter has been studied and strong self-focusing is reported. It is investigated that decentered parameter “b” plays a significant role for the self-focusing of the laser beam as for b=2.12, strong self-focusing is seen. Further, it is observed that extraordinary mode is more prominent toward self-focusing rather than ordinary mode of propagation. For b=2.12, with the increase in the value of magnetic field self-focusing effect, in case of extraordinary mode, becomes very strong under plasma density ramp. Present study may be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, and x-ray lasers. Moreover, plasma density ramp plays a vital role to enhance the self-focusing effect

  6. Strong self-focusing of a cosh-Gaussian laser beam in collisionless magneto-plasma under plasma density ramp

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, Vikas; Kant, Niti, E-mail: nitikant@yahoo.com [Department of Physics, Lovely Professional University, G. T. Road, Phagwara, Punjab 144411 (India)

    2014-07-15

    The effect of plasma density ramp on self-focusing of cosh-Gaussian laser beam considering ponderomotive nonlinearity is analyzed using WKB and paraxial approximation. It is noticed that cosh-Gaussian laser beam focused earlier than Gaussian beam. The focusing and de-focusing nature of the cosh-Gaussian laser beam with decentered parameter, intensity parameter, magnetic field, and relative density parameter has been studied and strong self-focusing is reported. It is investigated that decentered parameter “b” plays a significant role for the self-focusing of the laser beam as for b=2.12, strong self-focusing is seen. Further, it is observed that extraordinary mode is more prominent toward self-focusing rather than ordinary mode of propagation. For b=2.12, with the increase in the value of magnetic field self-focusing effect, in case of extraordinary mode, becomes very strong under plasma density ramp. Present study may be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, and x-ray lasers. Moreover, plasma density ramp plays a vital role to enhance the self-focusing effect.

  7. Norwegian focus on new energy technology

    International Nuclear Information System (INIS)

    Bull-Hansen, Eivind

    2001-01-01

    Norsk Hydro Technology Ventures, a venture capital fund recently set up by Norsk Hydro, will raise equity capital to companies that are developing promising new projects on new energy technology or to investment funds promoting such projects. Norsk Hydro will withdraw from the investments when the projects have reached commercialization or are listed on the stock exchange. There is a well-developed market for venture capital in the energy sector and a strong international competition for investments in good projects. The sharp environmental focus on fossil fuels and climate gases has boosted the research on new energy technologies. Another and more important factor is the fact that modern society with its heavy dependence on the computer is vulnerable to power failure

  8. Production of radioisotopes within a plasma focus device

    International Nuclear Information System (INIS)

    Angeli, E.; Tartari, A.; Frignani, M.; Molinari, V.; Mostacci, D.; Rocchi, F.; Sumini, M. . E-mail address of corresponding author: domiziano.mostacci@mail.ing.unibo.it

    2005-01-01

    In recent years, research conducted in the US and in Italy has demonstrated production of radioisotopes in Plasma Focus (PF) devices, and particularly, on what could be termed 'endogenous' production, to wit, production within the plasma itself, as opposed to irradiation of targets. This technique relies on the formation of localized small plasma zones characterized by very high densities and fairly high temperatures. The conditions prevailing in these zones lead to high nuclear reaction rates, as pointed out in previous work by several authors. Further investigation of the cross sections involved has proven necessary to model the phenomena involved. In this paper, the present status of research in this field is reviewed, both with regards to cross section models and to experimental production of radioisotopes. Possible outcomes and further development are discussed. (author)

  9. Time correlation between plasma behaviour and soft x-ray emission in a plasma focus

    International Nuclear Information System (INIS)

    Hirano, Katsumi; Tagaya, Yutaka; Shimoda, Katsuji; Okabe, Yushiro; Yamamoto, Toshikazu

    1986-01-01

    Soft X-rays emitted from a plasma focus are investigated experimentally. In contrast to single-pulsive burst of neutron, hard X-rays, ion- and electron beams, the soft X-rays are observed from the collapse phase to the decay phase of the plasma column, and have typically three successive peaks in its signal. Each peak corresponds to the maximum compression, the disruption and the decay phase of plasma column. It is revealed that the first and the second peaks are radiated by plasma itself, whereas the third peak is caused by emission from the inner electrode face. (author)

  10. Factors which affect operation of a plasma focus in various gases

    International Nuclear Information System (INIS)

    Smith, A.J.

    1987-06-01

    It is shown that the axial transit time t a and γ, the ratio of specific heats, are the main factors which affect the operation of a plasma focus in various gases. An energy balance theory is used to explore this dependence. The results are consistent with previous calculations and with experiment. (author). 12 refs

  11. Plasma focus sources: Supplement to the neutron resonance radiography workshop proceedings

    International Nuclear Information System (INIS)

    Nardi, V.; Brzosko, J.

    1989-01-01

    Since their discovery, plasma focus discharges have been recognized as very intense pulsed sources of deuterium-deuterium (D-D) or deuterium-tritium (D-T) fusion-reaction neutrons, with outstanding capabilities. Specifically, the total neutron emission/shot, YN, and the rate of neutron emission, Y/sub n/, of an optimized plasma focus (PF) are higher than the corresponding quantities observed in any other type of pinched discharge at the same level of powering energy W 0 . Recent developments have led to the concept and experimental demonstration of an Advanced Plasma Focus System (APF) that consists of a Mather-geometry plasma focus in which field distortion elements (FDEs) are inserted in the inter-electrode gap for increasing the neutron yield/shot, Y/sub n/. The FDE-induced redistribution of the plasma current increases Y/sub n/ by a factor ≅5-10 above the value obtained without FDEs under otherwise identical conditions of operation of the plasma focus. For example, an APF that is fed by a fast capacitor bank with an energy, W 0 = 6kJ, and voltage, V 0 = 16.5 kV provides Y/sub n/ /congruent/ 4 /times/ 10 9 D-D neutrons/shot (pure D 2 filling) and Y/sub n/ = 4 /times/ 10 11 D-T neutrons/shot (filling is 50% deuterium and 50% tritium). The FDE-induced increase of Y/sub n/ for fixed values of (W 0 , V 0 ), the observed scaling law Y/sub n/ /proportional to/ W 0 2 for optimized plasma focus systems, and our experience with neutron scattering in bulk objects lead us to the conclusion that we can use an APF as a source of high-intensity neutron pulses (10 14 n/pulse) in the field off neutron radiography (surface and bulk) with a nanosecond or millisecond time resolution

  12. Plasma Channel Lenses and Plasma Tornadoes for Optical Beam Focusing and Transport

    Science.gov (United States)

    Hubbard, R. F.; Kaganovich, D.; Johnson, L. A.; Gordon, D. F.; Penano, J. R.; Hafizi, B.; Helle, M. H.; Mamonau, A. A.

    2017-10-01

    Shaped plasmas offer the possibility of manipulating laser pulses at intensities far above the damage limits for conventional optics. An example is the plasma channel, which is a cylindrical plasma column with an on-axis density minimum. Long plasma channels have been widely used to guide intense laser pulses, particularly in laser wakefield accelerators. A new concept, the ``plasma tornado'', offers the possibility of creating long plasma channels with no nearby structures and at densities lower than can be achieved by capillary discharges. A short plasma channel can focus a laser pulse in much the same manner as a conventional lens or off-axis parabola. When placed in front of the focal point of an intense laser pulse, a plasma channel lens (PCL) can reduce the effective f-number of conventional focusing optics. When placed beyond the focal point, it can act as a collimator. We will present experimental and modeling results for a new plasma tornado design, review experimental methods for generating short PCLs, and discuss potential applications. Supported by the Naval Research Laboratory Base Program.

  13. Preionization Techniques in a kJ-Scale Dense Plasma Focus

    Science.gov (United States)

    Povilus, Alexander; Shaw, Brian; Chapman, Steve; Podpaly, Yuri; Cooper, Christopher; Falabella, Steve; Prasad, Rahul; Schmidt, Andrea

    2016-10-01

    A dense plasma focus (DPF) is a type of z-pinch device that uses a high current, coaxial plasma gun with an implosion phase to generate dense plasmas. These devices can accelerate a beam of ions to MeV-scale energies through strong electric fields generated by instabilities during the implosion of the plasma sheath. The formation of these instabilities, however, relies strongly on the history of the plasma sheath in the device, including the evolution of the gas breakdown in the device. In an effort to reduce variability in the performance of the device, we attempt to control the initial gas breakdown in the device by seeding the system with free charges before the main power pulse arrives. We report on the effectiveness of two techniques developed for a kJ-scale DPF at LLNL, a miniature primer spark gap and pulsed, 255nm LED illumination. Prepared by LLNL under Contract DE-AC52-07NA27344.

  14. Detection of light charged particles from plasma focus by CR-39

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Vukovic, J.; Popovic, S.; Popovic, M. (Belgrade Univ. (Yugoslavia). Inst. za Fiziku); Puric, J.; Cuk, M. (Faculty of Physical Science, Belgrade (Yugoslavia))

    1991-01-01

    An analysis of a deuteron (D{sup +}) beam, emitted from a plasma focus has been carried out, using a CR-39 plastic nuclear track detector. The CR-39 was pretreated using different processes to destroy the existing background before exposing it to the particles produced in the plasma focus. From measurements of the diameters of the tracks, the estimated energy of the D{sup +} ions is about 0.5 MeV. The total number of emitted D{sup +} ions was 10 particles/pulse. Some preliminary results on imaging etched CR-39 with an Atomic Force Microscope (NanoScope AFM) are also presented. (author).

  15. Detection of light charged particles from plasma focus by CR-39

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Vukovic, J.; Popovic, S.; Popovic, M.

    1991-01-01

    An analysis of a deuteron (D + ) beam, emitted from a plasma focus has been carried out, using a CR-39 plastic nuclear track detector. The CR-39 was pretreated using different processes to destroy the existing background before exposing it to the particles produced in the plasma focus. From measurements of the diameters of the tracks, the estimated energy of the D + ions is about 0.5 MeV. The total number of emitted D + ions was 10 particles/pulse. Some preliminary results on imaging etched CR-39 with an Atomic Force Microscope (NanoScope AFM) are also presented. (author)

  16. Electron beam effects on the spectroscopy of multiply charged ions in plasma focus experiments

    International Nuclear Information System (INIS)

    Abdallah, J.; Clark, R.E.H.; Faenov, A.Y.; Karpinski, L.; Pikuz, S.A.; Romanova, V.M.; Sadowski, M.; Scholz, M.; Szydlowski, A.

    1999-01-01

    Argon-hydrogen mixture plasma focus experiments performed at the Warsaw Institute of Plasma Physics and Laser Microfusion show detailed space resolved spectra for Ar K-shell satellite lines up to F-like Ar and K-alpha of Ar. These transitions originating from autoionizing levels are caused by collisions of ions with the energetic electron beams which are created by the constrictions of the plasma column due to the development of magnetohydrodynamic instabilities. A collisional-radiative model was constructed using a non-Maxwellian electron energy distribution consisting of a thermal Maxwellian part plus a Gaussian part to represent the high-energy electron beam. The shapes of the observed satellite structures are consistent with the calculated spectrum for electron temperatures between 20 and 230 eV, and beam densities of about 10 -3 times the plasma electron density. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Electron beam effects on the spectroscopy of multiply charged ions in plasma focus experiments

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, J. [UCLA Plasma Physics Laboratory, Los Angeles, CA (United States); Clark, R.E.H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Faenov, A.Y. [MISDC, NPO ' VNIIFTRI' , Mendeleevo, Moscow region, 141570 (Russian Federation); Karpinski, L. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Pikuz, S.A.; Romanova, V.M. [P. N. Lebedev Physical Institute, Moscow (Russian Federation); Sadowski, M. [Soltan Institute for Nuclear Studies, Swierk (Poland); Scholz, M.; Szydlowski, A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland)

    1999-05-01

    Argon-hydrogen mixture plasma focus experiments performed at the Warsaw Institute of Plasma Physics and Laser Microfusion show detailed space resolved spectra for Ar K-shell satellite lines up to F-like Ar and K-alpha of Ar. These transitions originating from autoionizing levels are caused by collisions of ions with the energetic electron beams which are created by the constrictions of the plasma column due to the development of magnetohydrodynamic instabilities. A collisional-radiative model wasconstructed using a non-Maxwellian electron energy distribution consisting of a thermal Maxwellian part plus a Gaussian part to represent the high-energy electron beam. The shapes of the observed satellite structures are consistent with the calculated spectrum for electron temperatures between 20 and 230 eV, and beam densities of about 10{sup -3} times the plasma electron density. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

    International Nuclear Information System (INIS)

    Horioka, Kazuhiko

    2002-06-01

    The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

  19. Current and Perspective Applications of Dense Plasma Focus Devices

    Science.gov (United States)

    Gribkov, V. A.

    2008-04-01

    Dense Plasma Focus (DPF) devices' applications, which are intended to support the main-stream large-scale nuclear fusion programs (NFP) from one side (both in fundamental problems of Dense Magnetized Plasma physics and in its engineering issues) as well as elaborated for an immediate use in a number of fields from the other one, are described. In the first direction such problems as self-generated magnetic fields, implosion stability of plasma shells having a high aspect ratio, etc. are important for the Inertial Confinement Fusion (ICF) programs (e.g. as NIF), whereas different problems of current disruption phenomenon, plasma turbulence, mechanisms of generation of fast particles and neutrons in magnetized plasmas are of great interest for the large devices of the Magnetic Plasma Confinement—MPC (e.g. as ITER). In a sphere of the engineering problems of NFP it is shown that in particular the radiation material sciences have DPF as a very efficient tool for radiation tests of prospect materials and for improvement of their characteristics. In the field of broad-band current applications some results obtained in the fields of radiation material sciences, radiobiology, nuclear medicine, express Neutron Activation Analysis (including a single-shot interrogation of hidden illegal objects), dynamic non-destructive quality control, X-Ray microlithography and micromachining, and micro-radiography are presented. As the examples of the potential future applications it is proposed to use DPF as a powerful high-flux neutron source to generate very powerful pulses of neutrons in the nanosecond (ns) range of its duration for innovative experiments in nuclear physics, for the goals of radiation treatment of malignant tumors, for neutron tests of materials of the first wall, blankets and NFP device's constructions (with fluences up to 1 dpa per a year term), and ns pulses of fast electrons, neutrons and hard X-Rays for brachytherapy.

  20. Current and Perspective Applications of Dense Plasma Focus Devices

    International Nuclear Information System (INIS)

    Gribkov, V. A.

    2008-01-01

    Dense Plasma Focus (DPF) devices' applications, which are intended to support the main-stream large-scale nuclear fusion programs (NFP) from one side (both in fundamental problems of Dense Magnetized Plasma physics and in its engineering issues) as well as elaborated for an immediate use in a number of fields from the other one, are described. In the first direction such problems as self-generated magnetic fields, implosion stability of plasma shells having a high aspect ratio, etc. are important for the Inertial Confinement Fusion (ICF) programs (e.g. as NIF), whereas different problems of current disruption phenomenon, plasma turbulence, mechanisms of generation of fast particles and neutrons in magnetized plasmas are of great interest for the large devices of the Magnetic Plasma Confinement--MPC (e.g. as ITER). In a sphere of the engineering problems of NFP it is shown that in particular the radiation material sciences have DPF as a very efficient tool for radiation tests of prospect materials and for improvement of their characteristics. In the field of broad-band current applications some results obtained in the fields of radiation material sciences, radiobiology, nuclear medicine, express Neutron Activation Analysis (including a single-shot interrogation of hidden illegal objects), dynamic non-destructive quality control, X-Ray microlithography and micromachining, and micro-radiography are presented. As the examples of the potential future applications it is proposed to use DPF as a powerful high-flux neutron source to generate very powerful pulses of neutrons in the nanosecond (ns) range of its duration for innovative experiments in nuclear physics, for the goals of radiation treatment of malignant tumors, for neutron tests of materials of the first wall, blankets and NFP device's constructions (with fluences up to 1 dpa per a year term), and ns pulses of fast electrons, neutrons and hard X-Rays for brachytherapy

  1. Study the Output Characteristics of a 90 kJ Filippove-Type Plasma Focus

    Science.gov (United States)

    Sadat Kiai, S. M.; Talaei, A.; Adlparvar, S.; Zirak, A.; Elahi, M.; Safarian, A.; Farhangi, S.; Alhooie, S.; Dabirzadeh, A. A.; Khalaj, M. M.; Mahlooji, M. S.; Talaei, M.; KaKaei, S.; Sheibani, S.; Kashani, A.; Zahedi, F.

    2010-08-01

    The output characteristics of a Filippove-Type plasma focus "Dena" (288 μF, 25 kV, 90 kJ) is numerically investigated by considering the voltage, current, current derivative, and maximum current as a function of capacitor bank energy in the constant Argon gas pressure and compared to the experiment. It is shown that increase on the bank energy leads to the increment on the maximum current and decrement on the pinch time.

  2. Self-focusing and self-defocusing of elliptically shaped Gaussian laser beams in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nayyar, V P; Soni, V S [Punjabi Univ., Patiala (India). Dept. of Physics

    1979-02-14

    This paper presents a study of the self-focusing and self-defocusing of elliptically shaped Gaussian laser beams in collisional and collisionless plasmas. The non-linear dependence of the dielectric constant inside a collisional plasma is due to inhomogeneous heating of energy carriers and in a collisionless plasma it is due to the ponderomotive force. It is found that the beam gets focused at different points in different planes, exhibiting the effect of astigmatism. In certain power regions considered, the beam either converges or defocuses in both the directions, while in some other regions of the power spectrum one dimension of the beam focuses while the other defocuses. The beam also propagates in an oscillatory waveguide.

  3. Dose Measurements in a 20-J Repetitive Plasma Focus

    Science.gov (United States)

    Goudarzi, S.; Babaee, H.; Esmaeli, A.; Nasiri, A.; Mazandarani, A.

    2018-02-01

    In this article, the results of X-ray dose measurements executed using thermoluminescent dosimeters in experiments with a very small (20 J) repetitive plasma focus device named SORENA-1 are presented and analyzed. The working gas in these experiments was Argon. Also, pinch formation in experiments with this device has been observed. This device has been designed and constructed in Plasma and Nuclear Fusion Research School of Nuclear Science and Technology Research Institute of Iran. From these results, it is concluded that we can do experiments with this device using Ar as working gas all over the working days of year, and a good symmetry for measured dose around the device has been seen.

  4. Low energy plasma observations at synchronous orbit

    International Nuclear Information System (INIS)

    Reasoner, D.L.; Lennartsson, W.

    1977-08-01

    The University of California at San Diego Auroral Particles Experiment on the ATS-6 Satellite in synchronous orbit has detected a low-energy plasma population which is separate and distinct from both the ring current and plasma sheet populations. These observations suggest that this plasma is the outer zone of the plasmasphere. During magnetically active periods, this low energy plasma is often observed flowing sunward. In the dusk sector, enhanced plasma flow is often observed for 1-2 hours prior to the onset of a substorm-associated particle injection. (author)

  5. Study of microwave emission from a dense plasma focus

    International Nuclear Information System (INIS)

    Gerdin, G.; Venneri, F.; Tanisi, M.

    1985-01-01

    Microwave emission was detected in a 12.5 kJ dense plasma focus, using microwave horns and detectors placed in various locations outside the device. The results show that the parallel plates connecting the focus to its capacitor banks act as antennas and transmission lines, rather than wave guides. Subsequent measurements were performed with a microwave detector (R-band) attached to the focus anode, directly looking into the coaxial gun region, allowing to restrict the microwave emitting region to the muzzle end of the focus. The microwave frequency spectrum, determined with a time of flight detection system, strongly suggests the lower hybrid instability as the driving mechanism of the emissions. Comparing the time sequence of the emissions with those of other observable phenomena in the focus, a model was developed, to explain the possible relationship between the generation of microwave radiation and turbulence induced resistivity in the focus pinch. According to the model, microwaves and enhanced resistivity are caused by current driven instabilities occurring in the current sheath produced at the outer boundary of the pinch during the initial compression phase. Comparisons of the model predictions with observed experimental results are presented, including time resolved measurements of the pinch resistivity

  6. Interaction of powerful hot plasma and fast ion streams with materials in dense plasma focus devices

    Czech Academy of Sciences Publication Activity Database

    Chernyshova, M.; Gribkov, V. A.; Kowalska-Strzeciwilk, E.; Kubkowska, M.; Miklaszewski, R.; Paduch, M.; Pisarczyk, T.; Zielinska, E.; Demina, E.V.; Pimenov, V. N.; Maslyaev, S. A.; Bondarenko, G.G.; Vilémová, Monika; Matějíček, Jiří

    2016-01-01

    Roč. 113, December (2016), s. 109-118 ISSN 0920-3796 R&D Projects: GA ČR(CZ) GA14-12837S Institutional support: RVO:61389021 Keywords : Radiation damageability * Materials tests * Plasma focus * Plasma streams * Ion beams * Laser interferometrya Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.319, year: 2016 http://www.sciencedirect.com/science/article/pii/S0920379616306858

  7. Dynamics of the plasma current sheath in plasma focus discharges in different gases

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, V. P.; Krauz, V. I., E-mail: krauz-vi@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation); Mokeev, A. N. [Project Center ITER (Russian Federation); Myalton, V. V.; Kharrasov, A. M. [National Research Center Kurchatov Institute (Russian Federation)

    2016-12-15

    The shape of the plasma current sheath (PCS) in the final stage of its radial compression, the dynamics of pinching, and the subsequent pinch decay in plasma focus (PF) discharges in different gases are studied using an improved multichannel system of electron-optical plasma photography and a newly elaborated synchronization system. The PCS structure in discharges in heavy gases (Ne, Ar) is found to differ significantly from that in discharges in hydrogen and deuterium. The influence of a heavy gas (Xe) additive to hydrogen and deuterium on the structure and compression dynamics of the PCS is investigated.

  8. Spectral study of the electron beam emitted from a 3 kJ plasma focus

    International Nuclear Information System (INIS)

    Patran, A; Tan, L C; Stoenescu, D; Rafique, M S; Rawat, R S; Springham, S V; Tan, T L; Lee, P; Zakaullah, M; Lee, S

    2005-01-01

    In a 3 kJ Mather-type plasma focus device operated in neon, the electron beam emission is investigated using both a magnetic electron energy analyser (in the 30-660 keV range) and a Rogowski coil (coupled with an appropriate RC passive integrator). Several electron emission features are identified and correlated with the x-ray emission in different energy ranges. The electron beam output shows very strong correlation with the general plasma dynamics (breakdown, axial and radial acceleration, pinch and post-pinch phases). The electrons' energy spectra showed most of the electron emission concentrating below 200 keV and negligible emission with energy above 350 keV. At 4 mbar neon, the electron emission, as well as the beam energy, is the highest and has a good shot-to-shot reproducibility

  9. Similitude observations and scaling laws for the plasma focus

    International Nuclear Information System (INIS)

    Kaeppeler, H.J.

    It has been attempted to give a coherent explanation of the most important physical processes concerning a model theory of the plasma focus of the Mather type. For this purpose the compression process, the stable dense phase and the subsequent neutron-producing instable phase were described. With the assumption that I 0 2 /rho 0 R 0 2 = const and t 0 /t/sub c/ = const a theoretical explanation is given for the already experimentally determined dependence of the neutron production on the fourth power of the maximum current. A few other conclusions based on these scaling laws are being discussed

  10. Time-resolved characteristics of deuteron-beam generated by plasma focus discharge

    Science.gov (United States)

    Bradley, D. A.

    2018-01-01

    The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1–3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic. PMID:29309425

  11. New aspects of high energy density plasma

    International Nuclear Information System (INIS)

    Hotta, Eiki

    2005-10-01

    The papers presented at the symposium on 'New aspects of high energy density plasma' held at National Institute for Fusion Science are collected in this proceedings. The papers reflect the present status and recent progress in the experiments and theoretical works on high energy density plasma produced by pulsed power technology. The 13 of the presented papers are indexed individually. (J.P.N.)

  12. ''Flicker'' in laser-plasma self-focusing

    International Nuclear Information System (INIS)

    Coggeshall, S.V.; Mead, W.C.; Jones, R.D.

    1988-01-01

    Under certain conditions, a new mode of laser-plasma self-focusing can occur which is characterized by a self-sustaining, continual shifting of filament-produced focal spots and a somewhat chaotic redistribution of light at the critical surface. Associated with this phenomenon is the possibility of significant intensity multiplication due to self-focusing. This flickering of laser light is caused by small amplitude, short wavelength ion acoustic waves which are produced near the foci of the filaments and subsequently propagate and convect toward the laser. As these ion fluctuations move toward the laser, they cause further light ray trajectory changes which shift the locations of the foci. New sound waves are launched and the process is self-perpetuated. 7 refs., 5 figs

  13. Geometrical optimization of an ellipsoidal plasma mirror toward tight focusing of ultra-intense laser pulse

    International Nuclear Information System (INIS)

    Kon, A; Nakatsutsumi, M; Chen, Z L; Kodama, R; Buffechoux, S; Fuchs, J; Jin, Z

    2010-01-01

    We developed for the first time, very compact ( 3 ) extremely low f-number (f/number = 0.4) confocal ellipsoid focusing systems. Direct measurement of the laser focal spot using a low-energy laser beam indicates 1/5 reduction of the spot size compared to standard focusing (using a f/2.7 optics). Such mirror is thus able to achieve significant enhancement of the focused laser intensity without modifying the laser system itself. The mirror is then used under plasma mirror regime which enables us to compactify the size, to liberate us from the anxiety of protecting the optics from target debris after shots, and to enhance the temporal contrast. In this paper, we focus our attention to designing and optimizing the geometry of such innovative plasma optics.

  14. Oscillation of the current sheet velocity in plasma focus discharges

    International Nuclear Information System (INIS)

    Melzacki, K.; Nardi, V.

    1994-01-01

    The oscillation of the propagation speed of the plasma focus current sheet has been recorded with schlieren photography. The sheet stuttering in the propagation during the implosion phase has a frequency of about 60 MHz. The effect could be recorded due to application of long exposure time (60 ns) technique. It is not detectable in the subnanosecond pictures. The pictures are taken in black schlieren. The probing range of the electron density gradient, with integration along the path of the 1 J, Q-switched ruby laser beam, has been selected by the size of the stop and aperture within 3 x 10 18 cm -3 and 3 x 10 20 cm -3 . Raising the sensitivity threshold to 2 x 10 19 cm -3 (refraction angle of 4 mrad) has helped to clear the pictures by limiting their image to high gradients of density only. With this technique (and other diagnostic methods) the dynamics of 6 kJ, 16 kV plasma focus discharges in deuterium at 5 torr, with a 10% decrease of the magnetic insulation at the breech has been investigated. The average implosion velocity of the current sheath obtained with this effect, 5 x 10 6 cm/s, is consistent with those measured by the smear effect, and the electric probe. The electron density gradient has been determined at several instants; at the pinch time it is (3 ± 1.5) x 10 20 cm -4 . The data are discussed on the basis of several pictures

  15. Soft X-ray spectroscopic investigation of a plasma focus operated in pure neon

    International Nuclear Information System (INIS)

    Presura, R.; Zoita, V.; Paraschiv, I.

    1996-01-01

    The soft X-ray emission of the medium-energy plasma focus device IPF-2/20 operated in pure neon was studied with spectral resolution. The spectra of H- and He-like Ne ions were recorded by means of a de Broglie spectrograph for initial filling pressures in the range 1.3 to 7 torr. Both the soft X-ray emission characteristics and the plasma parameters are strongly dependent on the working gas pressure. The intensity of the He-like neon ions lines increases when the working gas pressure is raised, while for the H-like ions it has a maximum for about 5 torr filling. The electron density has values of the order of 10 20 cm -3 . The electron temperature ranges between 300 and 350 eV. Both the plasma density and the plasma temperature decrease when the initial gas pressure is increased. (author). 2 figs., 9 refs

  16. Soft X-ray spectroscopic investigation of a plasma focus operated in pure neon

    Energy Technology Data Exchange (ETDEWEB)

    Presura, R; Zoita, V; Paraschiv, I [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

    1997-12-31

    The soft X-ray emission of the medium-energy plasma focus device IPF-2/20 operated in pure neon was studied with spectral resolution. The spectra of H- and He-like Ne ions were recorded by means of a de Broglie spectrograph for initial filling pressures in the range 1.3 to 7 torr. Both the soft X-ray emission characteristics and the plasma parameters are strongly dependent on the working gas pressure. The intensity of the He-like neon ions lines increases when the working gas pressure is raised, while for the H-like ions it has a maximum for about 5 torr filling. The electron density has values of the order of 10{sup 20} cm{sup -3}. The electron temperature ranges between 300 and 350 eV. Both the plasma density and the plasma temperature decrease when the initial gas pressure is increased. (author). 2 figs., 9 refs.

  17. Characterization of the axial plasma shock in a table top plasma focus after the pinch and its possible application to testing materials for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Leopoldo, E-mail: lsoto@cchen.cl; Pavez, Cristian; Moreno, José [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P" 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile); Inestrosa-Izurieta, María José [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P" 4, Santiago-Talca (Chile); Veloso, Felipe [Instituto de Física, Pontificia Universidad Católica de Chile, Santiago (Chile); Gutiérrez, Gonzalo [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Vergara, Julio [Facultad de Ingeniería, Pontificia Universidad Católica de Chile, Santiago (Chile); Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina); Bruzzone, Horacio [CONICET and Universidad de Mar del Plata, Mar del Plata (Argentina); Castillo, Fermín [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos (Mexico); and others

    2014-12-15

    The characterization of plasma bursts produced after the pinch phase in a plasma focus of hundreds of joules, using pulsed optical refractive techniques, is presented. A pulsed Nd-YAG laser at 532 nm and 8 ns FWHM pulse duration was used to obtain Schlieren images at different times of the plasma dynamics. The energy, interaction time with a target, and power flux of the plasma burst were assessed, providing useful information for the application of plasma focus devices for studying the effects of fusion-relevant pulses on material targets. In particular, it was found that damage factors on targets of the order of 10{sup 4} (W/cm{sup 2})s{sup 1/2} can be obtained with a small plasma focus operating at hundred joules.

  18. Characterization of the axial plasma shock in a table top plasma focus after the pinch and its possible application to testing materials for fusion reactors

    International Nuclear Information System (INIS)

    4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Soto, Leopoldo; 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Pavez, Cristian; 4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile); Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile))" >Moreno, José; 4, Santiago-Talca (Chile))" data-affiliation=" (Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Centro de Investigación y Aplicaciones en Física de Plasmas y Potencia Pulsada, P4, Santiago-Talca (Chile))" >Inestrosa-Izurieta, María José; Veloso, Felipe; Gutiérrez, Gonzalo; Vergara, Julio; Clausse, Alejandro; Bruzzone, Horacio; Castillo, Fermín

    2014-01-01

    The characterization of plasma bursts produced after the pinch phase in a plasma focus of hundreds of joules, using pulsed optical refractive techniques, is presented. A pulsed Nd-YAG laser at 532 nm and 8 ns FWHM pulse duration was used to obtain Schlieren images at different times of the plasma dynamics. The energy, interaction time with a target, and power flux of the plasma burst were assessed, providing useful information for the application of plasma focus devices for studying the effects of fusion-relevant pulses on material targets. In particular, it was found that damage factors on targets of the order of 10 4 (W/cm 2 )s 1/2 can be obtained with a small plasma focus operating at hundred joules

  19. Focus on energy autonomy in overseas districts

    International Nuclear Information System (INIS)

    Billerey, Jerome

    2016-01-01

    As French overseas territories have also had a role of leader in the development of renewable energies, and as the French law on energy transition states that energy autonomy is an objective by 2030 for these territories, with 50 per cent of renewable energies by 2020, this publication proposes an overview of the situation in these territories which still strongly depend on imported energies, notably for transports. The publication outlines the specificities of these islands with respect to the metropolitan territory in terms of electric power system: small territories, high production costs, strong consumption increase. It describes how the new energy policy plans evolutions to reach this autonomy: development of renewable energies and of smart grids, development of vehicles fuelled with electricity, biofuels or hydrogen, management of energy consumption in housing and through the use of renewable energies

  20. Plasma-current structures of plasma focus during the current disruption

    International Nuclear Information System (INIS)

    Krokhin, O.N.; Kalachev, N.V.; Malafeev, Yu.S.; Nikulin, V.Ya; Polukhin, S.N.; Tsybenko, S.P.

    2000-01-01

    The results are presented of an investigation of the plasma structures arising during the current disruption in the Dense Plasma Focus (DPF). The study was performed using the laser-shadow and interferometry methods together with measurements of current and X-ray radiation. An analysis of the experimental results shows that for the construction of a multi mega-amperes current disruption device, the Filippov type of DPF (in comparison with the Mather type) is to be preferred since the processes occurring in the X-ray regime are much faster than in the pinch regime, and this type of plasma focus is geometrically more suitable for the assembly of such a current disrupter.This disrupter is now under construction, based on the 'Tulip' DPF installation

  1. Adaptation of Sing Lee's model to the Filippov type plasma focus geometry

    International Nuclear Information System (INIS)

    Siahpoush, V; Tafreshi, M A; Sobhanian, S; Khorram, S

    2005-01-01

    A new model for plasma behaviour in Filippov type plasma focus (PF) systems has been described and used. This model is based on the so-called slug model and Sing Lee's model for Mather type PF devices. Using the model, the discharge current and its derivative as a function of time, and the pinch time and the maximum discharge current as a function of pressure, have been predicted. At the end, the predicted data are compared with the experimental data obtained through a Filippov type PF facility with a nominal maximum energy of 90 kJ

  2. Hard X-ray sources from miniature plasma focus devices

    International Nuclear Information System (INIS)

    Raspa, V.; Silva, P.; Moreno, J.; Zambra, M.; Soto, L.

    2004-01-01

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, ∼ 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, ∼ 300 ns time to peak current). Hard X-rays are being studied in these devices operating with hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400 J. An effective energy of the order of 90 keV was measured under those conditions. X ray images of different metallic objects also have been obtained. (authors)

  3. Hard X-ray sources from miniature plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Raspa, V. [Buenos Aires Univ., PLADEMA, CONICET and INFIP (Argentina); Silva, P.; Moreno, J.; Zambra, M.; Soto, L. [Comision Chilena de Energia Nuclear, Santiago (Chile)

    2004-07-01

    As first stage of a program to design a repetitive pulsed radiation generator for industrial applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, {approx} 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, {approx} 300 ns time to peak current). Hard X-rays are being studied in these devices operating with hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400 J. An effective energy of the order of 90 keV was measured under those conditions. X ray images of different metallic objects also have been obtained. (authors)

  4. Four-fluid description of turbulent plasma focus dynamics

    International Nuclear Information System (INIS)

    Hayd, A.; Maurer, M.; Meinke, P.; Kaeppeler, H.J.

    1984-06-01

    The dynamic phenomena in the compression, pinch and late phases of the plasma focus experiment POSEIDON in its operational mode at 60 kV, 280 kJ, were previously calculated from a two-fluid theory using the new hybrid code REDUCE/FORTRAN. Two important results were found: the neutron production already in the pinch phase for currents larger than 500 kA and filamentary structures on and around the pinch axis. In a continuation of this work, a four-fluid system of dynamical equations was formulated and programmed with the REDUCE/FORTRAN code. Besides macro-turbulence, the new four-fluid theory includes micro-instabilities and anomalous transport properties, as well as the runaway effect for electrons and ions. First results from calculations with this new theory are presented and are compared with previous calculations and with recent experimental observations. (orig.)

  5. Simulation of a dense plasma focus x-ray source

    International Nuclear Information System (INIS)

    Stark, R.A.

    1994-01-01

    The authors are performing simulations of the magnetohydrodynamics of a Dense Plasma Focus (DPF) x-ray source located at Science Research Laboratory (SRL), Alameda, CA, in order to optimize its performance. The SRL DPF, which was developed as a compact source for x-ray lithography, operates at 20 Hz, giving x-ray power (9--14 Angstroms) of 500 W using neon gas. The simulations are performed with the two dimensional MHD code MACH2, developed by Mission Research Corporation, with a steady state corona model as the equation of state. The results of studies of the sensitivity of x-ray output to charging voltage and current, and to initial gas density will be presented. These studies should indicate ways to optimize x-ray production efficiency. Simulations of various inner electrode configurations will also be presented

  6. Construction and characterization of a plasma focus device and diagnostic test ion

    International Nuclear Information System (INIS)

    Morales Arango, Diana Marsela

    2013-01-01

    In this work we designed and built a Plasma Focus device 2kJ power in order to extend the energy range of devices designed in DPTN CCHEN and study the scaling laws type Plasma Focus Device. The operating parameters of this device are: T/ 4 =907ns, C = 8000nF, L = 42nH, E = 2kJ, lo = 276kA. In such a way to optimize the device tests were performed with various electrode configurations, insulator length, to determine the conditions under which it operates in Plasma Focus mode. Subsequent to the construction tests were performed on devices PF-400J (T /4 = 300ns, C = 880nF, L = 38nH, E = 400J, lo = 168kA) y PF-2kJ (device between the hundreds of joules and kilojoules of energy) diagnostic charged particle emission used the Faraday Cup consisting of a biased graphite collector. For a series of shots on the PF-400J and PF-2kJ operated at 27kV and 20kV respectively kinetic energy distribution of proton between 60keV-150keV were found, deuterons between 60KeV-300KeV. With the idea of optimizing the results in future diagnostic type spectrometer Thompson, spectroscopy and diffraction networks in gas mixture will be implemented

  7. Tailored ion energy distributions on plasma electrodes

    International Nuclear Information System (INIS)

    Economou, Demetre J.

    2013-01-01

    As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas

  8. An investigation of the plasma behaviour in a Filippov type plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Mahabadi, T D [Plasma Physics Research Center, I.A.U, PO Box 14665-678, Tehran (Iran, Islamic Republic of); Tafreshi, M A [School of Plasma Physics and Nuclear Fusion, Institute of Nuclear Science and Technology, AEOI, PO Box 14155-1339, Tehran (Iran, Islamic Republic of)

    2007-09-15

    Plasma behaviour in the 90 kJ Filippov type plasma focus (PF) device Dena, is studied both experimentally and theoretically. The latest experimental data obtained by the use of the Dena facility are presented. Then the experimental data are compared with the simulated data obtained through the ML model. This study shows that the ML model, to a good extent, is capable of predicting the plasma behaviour in the Filippov type PF. The experimental and the theoretical results show that the increment of the discharge voltage leads to an almost linear decrement of the pinch time. It is also shown that the increment of the pressure leads to a decrement of the current sheath expansion velocity. Finally, a semiempirical method for determination of the permitted values of the current efficiency factor and the mass shedding factor is presented.

  9. Equilibrium fluctuation energy of gyrokinetic plasma

    International Nuclear Information System (INIS)

    Krommes, J.A.; Lee, W.W.; Oberman, C.

    1985-11-01

    The thermal equilibrium electric field fluctuation energy of the gyrokinetic model of magnetized plasma is computed, and found to be smaller than the well-known result (k)/8π = 1/2T/[1 + (klambda/sub D/) 2 ] valid for arbitrarily magnetized plasmas. It is shown that, in a certain sense, the equilibrium electric field energy is minimum in the gyrokinetic regime. 13 refs., 2 figs

  10. The application of selected radionuclides for monitoring of the D-D reactions produced by dense plasma-focus device.

    Science.gov (United States)

    Jednorog, S; Szydlowski, A; Bienkowska, B; Prokopowicz, R

    The dense plasma focus (DPF) device-DPF-1000U which is operated at the Institute of Plasma Physics and Laser Microfusion is the largest that type plasma experiment in the world. The plasma that is formed in large plasma experiments is characterized by vast numbers of parameters. All of them need to be monitored. A neutron activation method occupies a high position among others plasma diagnostic methods. The above method is off-line, remote, and an integrated one. The plasma which has enough temperature to bring about nuclear fusion reactions is always a strong source of neutrons that leave the reactions area and take along energy and important information on plasma parameters and properties as well. Silver as activated material is used as an effective way of neutrons measurement, especially when they are emitted in the form of short pulses like as it happens from the plasma produced in Dense Plasma-Focus devices. Other elements such as beryllium and yttrium are newly introduced and currently tested at the Institute of Plasma Physics and Laser Microfusion to use them in suitable activation neutron detectors. Some specially designed massive indium samples have been recently adopted for angular neutrons distribution measurements (vertical and horizontal) and have been used in the recent plasma experiment conducted on the DPF-1000U device. This choice was substantiated by relatively long half-lives of the neutron induced isotopes and the threshold character of the 115 In(n,n') 115m In nuclear reaction.

  11. Energy scaling of focused discharges with enhanced reactivity

    International Nuclear Information System (INIS)

    Bortolotti, A.; Broglio, L.; Brzosko, J.S.; Dechiara, P.; Kilic, H.; Mezzetti, F.; Montanari, T.; Nardi, V.; Powell, C.; Woo, H.

    1993-01-01

    The neutron yield per pulse (Y n ) from D + D reactions, the thickness (δ) and speed (v s ) of the leading plasma current sheath in the electrode gap and the multiplicity (υ) of current sheaths in one discharge are monitored in two plasma focus machines operating at different levels of the capacitor bank energy 5 kJ ≤ W ≤ 10 kJ and 12 kJ ≤ W ≤ 30 kJ, respectively .The time spacing (Δt) between leading (CS 1 ) and trailing (CS 2 ) current sheath is also recorded up to a CS distance r = 1.7 cm from the center electrode (anode) axis. The scaling of Y n ∼ A W 2 is tested for PF-Mather-geometry machines with a field distortion element (FDE) inserted at the breech side of the electrode gap which increases Y n (i.e. the constant A) by a factor ≥ 5, above the Y n value of the same machines, operating under identical conditions, but without FDE, Similar scaling tests on Y n = Y n (W, δ, V s , υ, Δt) confirm that Δt is one of the controlling parameters with strong effects on Y n . Spectra and intensities of ion and ion cluster emission from the pinch are also routinely observed in each discharge, in order to determine the relative weight of each controlling parameter for a variety of PF applications

  12. Energy transport in laser produced plasmas

    International Nuclear Information System (INIS)

    Key, M.H.

    1989-06-01

    The study of energy transport in laser produced plasmas is of great interest both because it tests and develops understanding of several aspects of basic plasma physics and also because it is of central importance in major applications of laser produced plasmas including laser fusion, the production of intense X-ray sources, and X-ray lasers. The three sections cover thermal electrons (energy transport in one dimension, plane targets and lateral transport from a focal spot, thermal smoothing, thermal instabilities), hot electrons (preheating in one dimension, lateral transport from a focal spot) and radiation (preheating in one dimension, lateral transport and smoothing, instabilities). (author)

  13. Neutron localization measurements from a two-gun plasma focus device

    International Nuclear Information System (INIS)

    Yeh, T.R.; Wen, M.; Tzeng, C.C.; Shang, D.J.; Yeh, C.K.; Wu, K.S.; Kuo, Y.Y.; Hou, W.S.

    1989-01-01

    The simultaneous formation of the two deuterium plasma foci has been reported recently by Hou, W.S., et al, in Procs I.E.E.E. Int. Conf. on Plasma Science, 1986, 87, in a Mather type two-gun plasma focus assembly with maximum bank energy of ∼700 kJ. In addition, these plasmas will evolve and then produce a disk-shaped plasma in the middle of the two plasma foci. Soft X-ray filter techniques which allow measurements of the electron temperature at both pinch points and the middle point yielded a few hundred eV for these three regions. Neutron localization measurements which were carried out with a collimator and a scintillator-fiber-photomultiplier assembly indicate that an enhancement of ∼80% in neutron yield is observed in the middle region as the separation between two electrodes is 9.1 cm. Further experimental evidence shows that the neutron production in the middle region is the result of the beam-beam interaction in nature. (author)

  14. The ADEME focuses on renewable energies

    International Nuclear Information System (INIS)

    Signoret, Stephane

    2015-01-01

    After a comment on the fact that the ADEME study on the future of electricity production based on renewable energies in France has been disclosed before being published, this article comments and discusses the principles adopted for the predictions (an optimisation of investment and production costs of the electric fleet while respecting some technical constraints, and a capacity of international exchanges of electricity). It also indicates the adopted scenarios: low demand, and lesser management of consumption. It discusses the assessed costs for the different scenarios, and for different energy mixes (with a 100 per cent renewable production). It outlines that, according to the study, 40 or 100 per cent of renewable energies result in the same cost

  15. Interaction of dense nitrogen plasma with SS304 surface using APF plasma focus device

    Science.gov (United States)

    Afrashteh, M.; Habibi, M.; Heydari, E.

    2012-04-01

    The nitridation of SS304 surfaces is obtained by irradiating nitrogen ions from Amirkabir plasma focus device, which use multiple focus deposition shots at optimum distance 10 cm from the anode. The Vickers Micro-Hardness values are improved more than twice for the nitrided samples comparing to the nonnitrided ones. The X-ray diffraction (XRD) analysis is carried out in order to explore the phase changes in the near surface structure of the metals. The results of Scanning Electron Microscopy (SEM) indicate changes in surface morphology which are the emergence of smooth and uniform film on the surface of the nitrided metals.

  16. Operational characteristics of a high voltage plasma focus device working with deuterium and heavy gas mixture

    International Nuclear Information System (INIS)

    Zoita, V.; Presura, R.; Gherendi, F.; Dumitrescu-Zoita, C.; Aliaga, R.

    1992-01-01

    The addition of a few neon percents to the deuterium gas filling of a medium energy plasma focus device (PFD) changes dramatically the radiation characteristics of the discharge as well as the pinch configuration. One exceptional result is the generation of high aspect ratio pinches shown clearly and reproducibly on X-ray pinhole camera images and on schlieren pictures. Another remarkable result is that these pinches which show no macroscopic instabilities copiously produce neutrons and hard X-rays. This confirms an experimental fact previously identified on a lower voltage PFD: the macroscopic instabilities do not play the decisive role in the neutronic performance of medium energy PFD's. (Author)

  17. The Z-pinch as plasma lens for the focusing of heavy ion beams

    International Nuclear Information System (INIS)

    Elfers, M.

    1992-04-01

    In the present thesis the influence of a Z-pinch plasma on the shape of heavy-ion beams and the for the understanding of this interaction most important plasma parameters were studied. For this the Z-pinch at the heavy-ion accelerator UNILAC was operated. The magnet field gradients of up to (25 ± 3) T/m occuring in the Z-pinch lead to the plasma-lens effect - the focusing of a charged-particle beam traversing axially the Z-pinch. In this thesis for the first time the focusing of a heavy-ion beam by the azimutal magnetic field of a Z-pinch is described. Different beams with an original diameter of 10 mm were focused. The smallest measured beam diameter amounts to 1 mm half-width. The beam energy amounts to 11.4 MeV/u, which leads at gold as projectile matter to a beam energy of 2.25 GeV. (orig./HSI) [de

  18. Nitriding of Ti substrate using energetic ions from plasma focus device

    International Nuclear Information System (INIS)

    Henriquez, A; Bhuyan, H; Favre, M; Bora, B; Wyndham, E; Chuaqui, H; Mändl, S; Gerlach, J W; Manova, D

    2012-01-01

    Plasma Focus (PF) discharge is a pulsed plasma producing discharge that generates high temperature and high density plasma for a short duration. PF devices are known to emit intense ion beams pulses of characteristic energy in the keV to a few MeV range, in a time scale of tens of nanoseconds. We have previously investigated the ion flux and energy spectrum of ion beams emitted from a low energy PF, operating at 20 kV, with 1.8 kJ stored energy. It was observed that the ion beams have wide range of energy and intensity spectra with a clear angular anisotropy. Due to the wide range of ion energy and intensity spectra PF has become a subject of current interest for its applications in material sciences including surface modification and thin film deposition. The purpose of this study is the formation of titanium nitride (TiN) thin film and to investigate the structural properties of the TiN thin films in terms of PF angular positions. Substrates like Ti and Ti/Si were nitrided in a 1.8 kJ PF device at different angular positions with respect to the PF axis in order to correlate their surface properties with ion beam parameters. Preliminary characterizations of the ion implanted substrates have been conducted, using SEM, EDX and XRD. Our results indicate the formation of nanocrystalline TiN thin film only in certain angular positions. Angular dependency of the surface morphology was observed, which shows that the surface features strongly depends on ion beam energy and flux. With increasing angular positions, a reduction in the deposition rate and the sputter rate is observed. A pronounced nanostructured surface is only observed at the axis of the pinched plasma column, indicating the dominant role of sputtering and perhaps melting and fast re-crystallization of the surface in creating the nanostructures.

  19. Simulation of electrical discharge in a 3.6 Joule miniature plasma focus device using SIMULINK

    International Nuclear Information System (INIS)

    Jafari, H.; Habibi, M.

    2014-01-01

    A novel technique has been developed and studied in this paper to simulate the electrical discharge circuit of a 3.6 J miniature plasma focus device (PFD) and investigate the effect of inductance variation on voltage spike and current dip. The technique is based on a correlation between the electrical discharge circuit and plasma dynamics in a very small PFD that operates at the energy of 3.6 J. The simulation inputs include the charging voltage, capacitor bank capacitance, current limiter resistance, bypass resistance as well as the time-dependent inductance and resistance of the plasma sheath which are calculated by assuming the plasma dynamics as transit times in going from one phase to the next. The variations of the most important elements in the circuit (i.e. the constant and breakdown inductances) and their effects on the current dip are studied in PFDs with low and high constant inductance. The model demonstrated for achieving a good pinch in the PFD, although the total inductance of the system should be low; however there is always an optimum inductance which causes an appropriate pinch. Furthermore, the electrical power produced by the pulsed power supply, the mechanical energy as well as the magnetic energy which are transferred into the plasma tube were obtained from simulation. The graph of electrical power demonstrated a high instantaneous increment in the power transferred into the plasma as one of the greatest advantages of the pulsed power supply. The simulation was performed using software tools within the MATLAB/SIMULINK simulation environment. The PFD, generating neutrons in the range of 10 6 to 10 10 neutrons per pulse will have substantial use in the physics and engineering applications. (authors)

  20. Energy Considerations for Plasma-Assisted N-Fixation Reactions

    Directory of Open Access Journals (Sweden)

    Aikaterini Anastasopoulou

    2014-09-01

    Full Text Available In a time of increasing concerns about the immense energy consumption and poor environmental performance of contemporary processes in the chemical industry, there is great need to develop novel sustainable technologies that enhance energy efficiency. There is abundant chemical literature on process innovations (laboratory-scale around the plasma reactor itself, which, naturally, is the essential part to be intensified to achieve a satisfactory process. In essence, a plasma process needs attention beyond reaction engineering towards the process integration side and also with strong electrical engineering focus. In this mini-review, we have detailed our future focus on the process and energy intensification of plasma-based N-fixation. Three focal points are mainly stressed throughout the review: (I the integration of renewable energy; (II the power supply system of plasma reactors and (III process design of industrial plasma-assisted nitrogen fixation. These different enabling strategies will be set in a holistic and synergetic picture so as to improve process performance.

  1. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    Energy Technology Data Exchange (ETDEWEB)

    Kiuttu, G F; Degnan, J H [Phillips Lab., Kirtland AFB, NM (United States). High Energy Sources Div.; Graham, J D [Maxwell Labs., Albuquerque, NM (United States); and others

    1997-12-31

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 {mu}s, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10{sup 8} neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs.

  2. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    International Nuclear Information System (INIS)

    Kiuttu, G.F.; Degnan, J.H.

    1996-01-01

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 μs, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10 8 neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs

  3. Plasma lens focusing and plasma channel transport for heavy ion fusion

    International Nuclear Information System (INIS)

    Tauschwitz, A.; Yu, S.S.; Bangerter, R.O.

    1996-01-01

    The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs

  4. Plasma lens focusing and plasma channel transport for heavy ion fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tauschwitz, A; Yu, S S; Bangerter, R O [Lawrence Berkeley Lab., CA (United States); and others

    1997-12-31

    The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs.

  5. Burning plasmas in ITER for energy source

    International Nuclear Information System (INIS)

    Inoue, Nobuyuki

    2002-01-01

    Fusion research and development has two aspects. One is an academic research on science and technology, i.e., discovery and understanding of unexpected phenomena and, development of innovative technology, respectively. The other is energy source development to realize fusion as a viable energy future. Fusion research has been made remarkable progress in the past several decades, and ITER will soon realize burning plasma that is essential for both academic research and energy development. With ITER, scientific research on unknown phenomena such as self-organization of the plasma in burning state will become possible and it contributes to create a variety of academic outcome. Fusion researchers will have a responsibility to generate actual energy, and electricity generation immediately after the success of burning plasma control experiment in ITER is the next important step that has to be discussed seriously. (author)

  6. Burning plasmas in ITER for energy source

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Nobuyuki [Atomic Energy Commission, Tokyo (Japan)

    2002-10-01

    Fusion research and development has two aspects. One is an academic research on science and technology, i.e., discovery and understanding of unexpected phenomena and, development of innovative technology, respectively. The other is energy source development to realize fusion as a viable energy future. Fusion research has been made remarkable progress in the past several decades, and ITER will soon realize burning plasma that is essential for both academic research and energy development. With ITER, scientific research on unknown phenomena such as self-organization of the plasma in burning state will become possible and it contributes to create a variety of academic outcome. Fusion researchers will have a responsibility to generate actual energy, and electricity generation immediately after the success of burning plasma control experiment in ITER is the next important step that has to be discussed seriously. (author)

  7. Investigation of plasma dynamics and x-ray emission in'ATON'plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.

    1995-01-01

    The experimental studies on 20 kJ 'Aton' plasma focus device are presented in this paper. The plasma sheath structure has been investigated by means of the measurements of the axial and azimuthal magnetic fields along the coaxial electrodes. The operating gas was hydrogen with pressures in the range of 0.62 torr to 6 torr. The intensity of visible radiation emitted by the plasma sheath was measured as a function of axial distances along the coaxial electrodes. The results showed that the visible radiation intensity is increased with axial distances until a position near the muzzle, then it decreased and has a minimum value at the coaxial electrode muzzle. The main parameters contributing to the behavior of the distribution are the plasma sheath density and the impurities from the eroded materials of the discharge electrodes. An x-ray pulse has been detected along the coaxial electrodes and extended up to the expansion chamber. At a distance near the muzzle two x-ray pulses have been detected, the second one has intensity relative to the first one with time lag of 11μs. 8 fig

  8. Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

    Energy Technology Data Exchange (ETDEWEB)

    Horioka, Kazuhiko (ed.)

    2002-06-01

    The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

  9. Kinetic Simulations of the Self-Focusing and Dissipation of Finite-Width Electron Plasma Waves

    Energy Technology Data Exchange (ETDEWEB)

    Winjum, B. J. [Univ. of California, Los Angeles, CA (United States); Berger, R. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chapman, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Banks, J. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brunner, S. [Federal Inst. of Technology, Lausanne (Switzerland)

    2013-09-01

    Two-dimensional simulations, both Vlasov and particle-in-cell, are presented that show the evolution of the field and electron distribution of finite-width, nonlinear electron plasma waves. The intrinsically intertwined effects of self-focusing and dissipation of field energy caused by electron trapping are studied in simulated systems that are hundreds of wavelengths long in the transverse direction but only one wavelength long and periodic in the propagation direction. From various initial wave states, both the width at focus Δm relative to the initial width Δ0 and the maximum field amplitude at focus are shown to be a function of the growth rate of the transverse modulational instability γTPMI divided by the loss rate of field energy νE to electrons escaping the trapping region. With dissipation included, an amplitude threshold for self-focusing γTPMIE~1 is found that supports the analysis of Rose [Phys. Plasmas 12, 012318 (2005)].

  10. Plasma waves generated by rippled magnetically focused electron beams surrounded by tenuous plasmas

    International Nuclear Information System (INIS)

    Cuperman, S.; Petran, F.

    1982-01-01

    This chapter investigates the electrostatic instability and the corresponding unstable wave spectrum of magnetically focused neutralized rippled electron beams under spacelike conditions. Topics considered include general equations and equilibrium, the derivation of the dispersion relation, and the solution of the dispersion relation (long wavelength perturbations, short wavelength perturbations, the rippled beam). The results indicate that in the long wavelength limit two types of instability (extending over different frequency ranges) exist. An instability of the beam-plasma type occurs due to the interaction between the beam electrons and the surrounding plasm electrons at the beam-plasma interface. A parametric type instability is produced by the coupling of a fast forward wave and a fast backward wave due to the rippling (modulation) of the beam. It is demonstrated that in the short wavelength limit, surface waves which are stable for the laminar beam may become unstable in the rippled beam case

  11. Interaction of powerful hot plasma and fast ion streams with materials in dense plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Gribkov, V.A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Kowalska-Strzeciwilk, E.; Kubkowska, M.; Miklaszewski, R.; Paduch, M.; Pisarczyk, T.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Demina, E.V.; Pimenov, V.N.; Maslyaev, S.A. [Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Bondarenko, G.G. [National Research University Higher School of Economics (HSE), Moscow (Russian Federation); Vilemova, M.; Matejicek, J. [Institute of Plasma Physics of the CAS, Prague (Czech Republic)

    2016-12-15

    Highlights: • Materials perspective for use in mainstream nuclear fusion facilities were studied. • Powerful streams of hot plasma and fast ions were used to induce irradiation. • High temporal, spatial, angular and spectral resolution available in experiments. • Results of irradiation were investigated by number of analysis techniques. - Abstract: A process of irradiating and ablating solid-state targets with hot plasma and fast ion streams in two Dense Plasma Focus (DPF) devices – PF-6 and PF-1000 was examined by applying a number of diagnostics of nanosecond time resolution. Materials perspective for use in chambers of the mainstream nuclear fusion facilities (mainly with inertial plasma confinement like NIF and Z-machine), intended both for the first wall and for constructions, have been irradiated in these simulators. Optical microscopy, SEM, Atomic Emission Spectroscopy, images in secondary electrons and in characteristic X-ray luminescence of different elements, and X-ray elemental analysis, gave results on damageability for a number of materials including low-activated ferritic and austenitic stainless steels, β-alloy of Ti, as well as two types of W and a composite on its base. With an increase of the number of shots irradiating the surface, its morphology changes from weakly pronounced wave-like structures or ridges to strongly developed ones. At later stages, due to the action of the secondary plasma produced near the target materials they melted, yielding both blisters and a fracturing pattern: first along the grain and then “in-between” the grains creating an intergranular net of microcracks. At the highest values of power flux densities multiple bubbles appeared. Furthermore, in this last case the cracks were developed because of microstresses at the solidification of melt. Presence of deuterium within the irradiated ferritic steel surface nanolayers is explained by capture of deuterons in lattice defects of the types of impurity atoms

  12. Experimental studies of fast deuterons, impurity- and admixture-ions emitted from a plasma focus

    International Nuclear Information System (INIS)

    Mozer, A.; Sadowski, M.; Herold, H.; Schmidt, H.

    1982-01-01

    The energy and mass analysis of ions emitted from a 50-kJ, 18-kV, plasma focus machine was performed with a Thomson analyzer. Energy distribution functions of fast deuterons (E> or =350 keV) and those of impurity ions have been determined. The energy distributions of the O, N, and C impurity ions in different ionization states have similar character. They usually increase exponentially and after reaching the maximum at E/Zroughly-equal1.0 MeV they decrease exponentially to E/Zroughly-equal1.8 MeV. For deuterons at lower operating pressures (p 0 + -Ar 7+ ions of energy from 0.5 to 14 MeV are produced

  13. Filamentary structures in dense plasma focus: Current filaments or vortex filaments?

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Leopoldo, E-mail: lsoto@cchen.cl; Pavez, Cristian; Moreno, José [Comisión Chilena de Energía Nuclear, CCHEN, Casilla 188-D, Santiago (Chile); Center for Research and Applications in Plasma Physics and Pulsed Power, P4, Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, República 220, Santiago (Chile); Castillo, Fermin [Universidad Nacional Autónoma de México, Cuernavaca, México (Mexico); Veloso, Felipe [Instituto de Física, Pontificia Universidad Católica de Chile, 7820436 Santiago (Chile); Auluck, S. K. H. [Bhabha Atomic Research Center, Mumbai 400 085 (India)

    2014-07-15

    Recent observations of an azimuthally distributed array of sub-millimeter size sources of fusion protons and correlation between extreme ultraviolet (XUV) images of filaments with neutron yield in PF-1000 plasma focus have re-kindled interest in their significance. These filaments have been described variously in literature as current filaments and vortex filaments, with very little experimental evidence in support of either nomenclature. This paper provides, for the first time, experimental observations of filaments on a table-top plasma focus device using three techniques: framing photography of visible self-luminosity from the plasma, schlieren photography, and interferometry. Quantitative evaluation of density profile of filaments from interferometry reveals that their radius closely agrees with the collision-less ion skin depth. This is a signature of relaxed state of a Hall fluid, which has significant mass flow with equipartition between kinetic and magnetic energy, supporting the “vortex filament” description. This interpretation is consistent with empirical evidence of an efficient energy concentration mechanism inferred from nuclear reaction yields.

  14. External circuit integration with electromagnetic particle in cell modeling of plasma focus devices

    International Nuclear Information System (INIS)

    Seng, Y. S.; Lee, P.; Rawat, R. S.

    2015-01-01

    The pinch performance of a plasma focus (PF) device is sensitive to the physical conditions of the breakdown phase. It is therefore essential to model and study the initial phase in order to optimize device performance. An external circuit is self consistently coupled to the electromagnetic particle in cell code to model the breakdown and initial lift phase of the United Nations University/International Centre for Theoretical Physics (UNU-ICTP) plasma focus device. Gas breakdown during the breakdown phase is simulated successfully, following a drop in the applied voltage across the device and a concurrent substantial rise in the circuit current. As a result, the plasma becomes magnetized, with the growing value of the magnetic field over time leading to the gradual lift off of the well formed current sheath into the axial acceleration phase. This lifting off, with simultaneous outward sheath motion along the anode and vertical cathode, and the strong magnetic fields in the current sheath region, was demonstrated in this work, and hence validates our method of coupling the external circuit to PF devices. Our method produces voltage waveforms that are qualitatively similar to the observed experimental voltage profiles of the UNU-ICTP device. Values of the mean electron energy before and after voltage breakdown turned out to be different, with the values after breakdown being much lower. In both cases, the electron energy density function turned out to be non-Maxwellian

  15. Characterization of light ion beams generated by a plasma focus device

    International Nuclear Information System (INIS)

    Koo, Bon Cheul

    1999-02-01

    Plasma focus device has been studied as neutron and X-ray sources generated from the high pressure fusion reaction during Z-pinch. Recently, the scope of the device is focused on efficient neutron generation, X-ray lithography, preliminary fusion experiment, and ion/electron beam generation devices. A Hexagonal Beam Generator with six parallel capacitors has been developed and generated ion beams from 30kJ(C=6 μ F, V= 100kV) maximum energy. To find the optimum condition of ion beam generation, the correlation among charging voltage(20∼30kV), operation pressure of chamber(0.1∼5 torr), and length of electrode has been studied. To measure ion beam, a Faraday Cup and 3 Rogowski coils were installed. Energy of ion beam was obtained by adopting time-of -flight method between Rogowski coils

  16. Palm top plasma focus device as a portable pulsed neutron source

    International Nuclear Information System (INIS)

    Rout, R. K.; Niranjan, Ram; Srivastava, R.; Rawool, A. M.; Kaushik, T. C.; Gupta, Satish C.; Mishra, P.

    2013-01-01

    Development of a palm top plasma focus device generating (5.2 ± 0.8) × 10 4 neutrons/pulse into 4π steradians with a pulse width of 15 ± 3 ns is reported for the first time. The weight of the system is less than 1.5 kg. The system comprises a compact capacitor bank, a triggered open air spark gap switch, and a sealed type miniature plasma focus tube. The setup is around 14 cm in diameter and 12.5 cm in length. The energy driver for the unit is a capacitor bank of four cylindrical commercially available electrolytic capacitors. Each capacitor is of 2 μF capacity, 4.5 cm in diameter, and 9.8 cm in length. The cost of each capacitor is less than US$ 10. The internal diameter and the effective length of the plasma focus unit are 2.9 cm and 5 cm, respectively. A DC to DC converter power supply powered by two rechargeable batteries charges the capacitor bank to the desired voltage and also provides a trigger pulse of −15 kV to the spark gap. The maximum energy of operation of the device is 100 J (8 μF, 5 kV, 59 kA) with deuterium gas filling pressure of 3 mbar. The neutrons have also been produced at energy as low as 36 J (3 kV) of operation. The neutron diagnostics are carried out with a bank of 3 He detectors and with a plastic scintillator detector. The device is portable, reusable, and can be operated for multiple shots with a single gas filling.

  17. Focusing Optics for High-Energy X-ray Diffraction

    DEFF Research Database (Denmark)

    Leinert, U.; Schulze, C.; Honkimäki, V.

    1998-01-01

    Novel focusing optical devices have been developed for synchrotron radiation in the energy range 40-100 keV. Firstly, a narrow-band-pass focusing energy-tuneable fixed-exit monochromator was constructed by combining meridionally bent Laue and Bragg crystals. Dispersion compensation was applied...

  18. Two-dimensional magnetohydrodynamic calculations for a 5 MJ plasma focus

    International Nuclear Information System (INIS)

    Maxon, S.

    1983-01-01

    This article describes the calculation of the performance of a 5 MJ plasma focus using a two-dimensional magnetohydrodynamic (2-D MHD) code. Discusses two configurations, a solid and a hollow anode. Finds an instability in the current sheath of the hollow anode which has the characteristics of the short wave length sausage instability. As the current sheath reaches the axis, the numerical solution is seen to break down. When the numerical solution breaks down, the code shows a splitting of the current sheath (from the axis to the anode) and the loss of a large amount of magnetic energy. Current-sheath stagnation is observed in the hollow anode configuration

  19. Time and space resolved observation of hot spots in a plasma focus

    International Nuclear Information System (INIS)

    Choi, P.; Aliaga, R.; Herold, H.

    1990-01-01

    The authors report some recent results on the time and space evolution of hot spots on the DPF-78 plasma focus at the University of Stuttgart. The experiments were carried out in mixtures of deuterium and krypton at a bank voltage of 60 kV and a stored energy of 28 kJ. A modification of the ADRRM streak technique carried out in the soft x-ray region allowed us to directly examine some characteristics of the hot spots. Simultaneous measurements were carried out on the hard x-ray radiation (80 keV), the spatially resolved optical emissions, the neutron yield rate with TOF information and the plasma and bank currents

  20. Studies of the Hard X-ray Emission from the Filippov Type Plasma Focus Device, Dena

    Science.gov (United States)

    Tafreshi, M. A.; Saeedzadeh, E.

    2006-12-01

    This article is about the characteristics of the hard X-ray (HXR) emission from the Filippov type plasma focus (PF) device, Dena. The article begins with a brief presentation of Dena, and the mechanism of the HXR production in PF devices. Then using the differential absorption spectrometry, the energy resolved spectrum of the HXR emission from a 37 kJ discharge in Dena, is estimated. The energy flux density and the energy fluence of this emission have also been calculated to be 1.9 kJ cm-2 s-1 and 9.4 × 10-5 J cm-2. In the end, after presentation of radiography of sheep bones and calf ribs, the medical application of the PF devices has been discussed.

  1. Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

    Science.gov (United States)

    Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

    2006-06-01

    Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET.

  2. Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

    International Nuclear Information System (INIS)

    Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

    2006-01-01

    Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET

  3. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    International Nuclear Information System (INIS)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-01-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm. - Highlights: • We investigated a small plasma focus as pulsed x-ray source for radiography applications. • The image quality was studied by several parameters such as image contrast, LSF and MTF. • The x-ray source focal spot was obtained to be ∼0.6 mm using the penumbra imaging method. • The x-ray dose measurement showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. • The profiles of LSF and MTF showed that the cut-off frequency is about 1.5 cycles/mm

  4. An electrodynamical model for the ion behaviour in the final plasma focus stages

    International Nuclear Information System (INIS)

    Zambreanu, V.; Doloc, C.M.

    1992-01-01

    Plasma focus devices (PFDs) are strong sources of fusion neutrons but the problem of which interactions are responsible for the fusion reactions is still open since neither of the proposed theoretical models has been confirmed experimentally. A model for the trajectories of the deuteron ions in a configuration of selfconsistent electromagnetic fields is proposed starting from an empirical plasma model which describes the plasma focus collapse and column phases. The proposed model is only electrodynamical under the assumption of a uniform current density and an infinite length of the plasma column, not taking into account the fluid characteristics of the plasma. (author)

  5. Quantum Phenomena in High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, Margaret [Univ. of Colorado, Boulder, CO (United States); Kapteyn, Henry [Univ. of Colorado, Boulder, CO (United States)

    2017-05-10

    The possibility of implementing efficient (phase matched) HHG upconversion of deep- UV lasers in multiply-ionized plasmas, with potentially unprecedented conversion efficiency is a fascinating prospect. HHG results from the extreme nonlinear response of matter to intense laser light:high harmonics are radiated as a result of a quantum coherent electron recollision process that occurs during laser field ionization of an atom. Under current support from this grant in work published in Science in 2015, we discovered a new regime of bright HHG in highly-ionized plasmas driven by intense UV lasers, that generates bright harmonics to photon energies >280eV

  6. Vacuum arc plasma thrusters with inductive energy storage driver

    Science.gov (United States)

    Krishnan, Mahadevan (Inventor)

    2009-01-01

    A plasma thruster with a cylindrical inner and cylindrical outer electrode generates plasma particles from the application of energy stored in an inductor to a surface suitable for the formation of a plasma and expansion of plasma particles. The plasma production results in the generation of charged particles suitable for generating a reaction force, and the charged particles are guided by a magnetic field produced by the same inductor used to store the energy used to form the plasma.

  7. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    Science.gov (United States)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-08-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

  8. Deposition of titanium nitride on Si(1 0 0) wafers using plasma focus

    International Nuclear Information System (INIS)

    Hussain, Tousif; Ahmad, R.; Khan, I.A.; Siddiqui, Jamil; Khalid, Nida; Bhatti, Arshad Saleem; Naseem, Shahzad

    2009-01-01

    Titanium nitride thin films were deposited on Si(1 0 0) substrates by using a low energy (2.3 KJ) Mather-type plasma focus device. The composition of the deposited films was characterized by X-ray diffraction (XRD). The crystallite size has strong dependence on the numbers of focus shots. The crystallinity of TiN thin films is found to increase with increasing the number of focus shots. The effect of different number of focus shots on micro structural changes of thin films was characterized by Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). SEM results showed net-like structure for film deposited for 15 numbers of shots, which are elongated grains of Si 3 N 4 in amorphous form embedded into TiN crystals. The average surface roughness was calculated from AFM images of the thin films. These results indicated that the average surface roughness increased for films deposited with increased number of focus shots. The least crystallite size and roughness are observed for film deposited with 25 focus shots.

  9. Investigation of focusing of relativistic electron and positron bunches moving in cold plasma. Final report

    International Nuclear Information System (INIS)

    Amatuni, A.Ts.; Elbakian, S.S.; Khachatryan, A.G.; Sekhpossian, E.V.

    1995-03-01

    This document is the final report on a project to study focusing effects of relativistic beams of electrons and positrons interacting with a cold plasma. The authors consider three different models for the overdense cold plasma - electron bunch interaction. They look at coulomb effects, wakefield effects, bunch parameters, and the effects of trains of pulses on focusing properties

  10. Research on pinches driven by Speed-2 generator: Hard X-ray and neutron emission in plasma focus configuration

    Energy Technology Data Exchange (ETDEWEB)

    Soto, L.; Moreno, J.; Silva, P.; Sylvester, G.; Zambra, M.; Pavez, C. [Comision Chilena de Energia Nuclear, Santiago (Chile); Pavez, C. [Universidad de Concepcion (Chile); Raspa, V. [Buenos Aires Univ., PLADEMA, CONICET and INFIP (Argentina); Castillo, F. [Insitituto de Ciencias Nucleares, UNAM (Mexico); Kies, W. [Heinrich-Heine-Univ., Dusseldorf (Germany)

    2004-07-01

    Speed-2 is a generator based on Marx technology and was designed in the University of Dusseldorf. Speed-2 consists on 40 +/- Marx modules connected in parallel (4.1 {mu}F equivalent Marx generator capacity, 300 kV, 4 MA in short circuit, 187 kJ, 400 ns rise time, dI/dt {approx} 10{sup 13} A/s). Currently Speed-2 is operating at CCHEN (Chilean nuclear energy commission), being the most powerful and energetic device for dense transient plasma in the Southern Hemisphere. Most of the previous works developed in Speed-2 at Dusseldorf were done in a plasma focus configuration for soft X-ray emission and the neutron emission from Speed-2 was not completely studied. The research program at CCHEN considers experiments in different pinch configurations (plasma focus, gas puffed plasma focus, gas embedded Z-pinch, wire arrays) at current of hundred of kilo- to mega-amperes, using the Speed-2 generator. The Chilean operation has begun implementing and developing diagnostics in a conventional plasma focus configuration operating in deuterium in order to characterize the neutron emission and the hard X-ray production. Silver activation counters, plastics CR39 and scintillator-photomultiplier detectors are used to characterize the neutron emission. Images of metallic plates with different thickness are obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize an effective energy of the hard X-ray outside of the discharge. (authors)

  11. Limits of deuterium pressure range with neutron production in plasma focus devices

    International Nuclear Information System (INIS)

    Pouzo, J.; Milanese, M.; Piriz, R.; Cortazar, D.; Moroso, R.

    1988-01-01

    In this work we present the experimental curves of neutron yield (Y) respect to the deuterium filling pressure (p) obtained in our plasma focuses device PACO. Y increases with the focus current (I f ) according with the scaling law Y ∼I 4-5 f , but it presents a limited range of p beyond which Y drastically decreases. The higher pressure limit is coincident with recently reported limit due to the energy available to maintain the ionization rate of the neutral gas during the roll-off stage. The lower pressure limit is here explained, through experimental evidences, in terms of a phenomenon connected with the dynamics of the current sheath (cs) during the roll-off stage. (author). 8 refs, 11 figs

  12. Plasma-focus neutron diagnostics by means of high-sensitivity bubble detectors

    International Nuclear Information System (INIS)

    Zoita, V.; Pantea, A.; Patran, A.; Lee, P.; Springham, S.V.; Koh, M.; Rawat, R.S.; Zhang, T.; Hassan, M.

    2005-01-01

    A new type of bubble detector (a superheated fluid detector), the DEFENDER TM , was tested as a neutron diagnostics device on the NX2 plasma focus (PF) device at the NIE/NTU, Singapore. The DEFENDER TM detector was recently developed and commercialised by BTI, Canada, and it is characterised by a very high sensitivity (a factor of about 30 higher than the standard detectors) to fast neutrons (energy above 100 keV). Together with its particular energy response this high sensitivity allows for the development of improved neutron diagnostics for the PF devices. The NX2 plasma focus device has the following typical operating parameters: condenser bank charging voltage: 15 kV; stored energy: 2.3 kJ; peak current: 420 kA; current rise-time: 1.35 μs; deuterium pressure: 20 mbar. During most of the experiments reported here the NX2 device was operated at 14 kV charging voltage and 20 mbar deuterium pressure. A few shots were done at voltages of 14.5 and 15 kV and the same gas pressure. The bubble detector neutron diagnostics experiments carried out on the NX2 machine involved the following measurements: 1. Relative calibration of the four detectors. The detectors were irradiated simultaneously, in identical conditions, by plasma focus neutron pulses and their neutron responses were compared.; 2. angular distribution of the neutron fluence (single shot). The distribution of the neutron fluence was measured at four angles with respect to the PF electrode axis: 0, 30, 60 and 90 deg; 3. Reproducibility of the neutron yield at high repetition rate operation. The NX2 device was operated at 1 Hz repetition rate.; 4. Bubble detector response time. The response time of the DEFENDER TM detector was tested by using the short PF neutron pulses and a high-speed video camera. The paper will present the results of these experiments and their implications for the development of neutron plasma diagnostics techniques based on the bubble detectors and their broader class of superheated

  13. Working gas effects on the X-ray emission of a plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Cengher, M; Presura, R; Zoita, V [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

    1997-12-31

    Experiments on the plasma focus device IPF-2/20 operating with argon, neon and mixtures of argon with deuterium were performed and some X-ray emission parameters measured. The time evolution of the X-ray emission and dependence of the X-ray yield on the working gas composition was analyzed. The softer X radiation was measured with time resolution in the energy bands from 4 to 40 keV, and the hard X-rays for energies above 200 keV. In deuterium-argon mixtures the soft X-ray yield increases both with pressure (for the same ratio of argon) and with the quantity of argon added to deuterium at the same total pressure. For argon or neon the hard X-ray yield is lower than for deuterium-heavy gas mixtures. The softer X-ray yield decreases with pressure both for neon and for argon. (author). 4 figs., 5 refs.

  14. Characteristics of x-rays from a plasma focus operated with neon gas

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Alamgir, K [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Shafiq, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Hassan, S M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Sharif, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Hussain, S [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Waheed, A [PINSTECH, PO Box 2151, 44000 Islamabad (Pakistan)

    2002-11-01

    The x-ray emission from a low-energy (2.3 kJ) plasma focus is investigated with neon as the filling gas. Two anode configurations are used in the experiment: the conventional cylindrical anode, and tapered anode slightly toward the open end. The latter geometry enhances soft x-ray emission by an order of magnitude. The emission is pressure dependent and, in both cases, the highest emission is observed at 3-3.5 mbar. For the cylindrical anode, the soft x-ray emission is up to 7 J per shot, which is from a pinched plasma column, 5-6 mm long. For the tapered anode, up to 80 J per shot soft x-ray yield in 4{pi} geometry is recorded, which corresponds to 4% wall plug efficiency. The diameter of the x-ray emission filament is much larger compared with the cylindrical anode. The bulk of emitted radiation is of energy 1.2-1.3 keV, which is thought to arise from recombination of hydrogen-like (Ne x) ions with the low-energy electrons.

  15. Characteristics of x-rays from a plasma focus operated with neon gas

    International Nuclear Information System (INIS)

    Zakaullah, M; Alamgir, K; Shafiq, M; Hassan, S M; Sharif, M; Hussain, S; Waheed, A

    2002-01-01

    The x-ray emission from a low-energy (2.3 kJ) plasma focus is investigated with neon as the filling gas. Two anode configurations are used in the experiment: the conventional cylindrical anode, and tapered anode slightly toward the open end. The latter geometry enhances soft x-ray emission by an order of magnitude. The emission is pressure dependent and, in both cases, the highest emission is observed at 3-3.5 mbar. For the cylindrical anode, the soft x-ray emission is up to 7 J per shot, which is from a pinched plasma column, 5-6 mm long. For the tapered anode, up to 80 J per shot soft x-ray yield in 4π geometry is recorded, which corresponds to 4% wall plug efficiency. The diameter of the x-ray emission filament is much larger compared with the cylindrical anode. The bulk of emitted radiation is of energy 1.2-1.3 keV, which is thought to arise from recombination of hydrogen-like (Ne x) ions with the low-energy electrons

  16. Laser focusing of high-energy charged-particle beams

    International Nuclear Information System (INIS)

    Channell, P.J.

    1986-01-01

    It is shown that laser focusing of high-energy charged-particle beams using the inverse Cherenkov effect is well suited for applications with large linear colliders. Very high gradient (>0.5 MG/cm) lenses result that can be added sequentially without AG cancellation. These lenses are swell understood, have small geometric aberrations, and offer the possibility of correlating phase and energy aberrations to produce an achromatic final focus

  17. Stationary self-focusing of Gaussian laser beam in relativistic thermal quantum plasma

    International Nuclear Information System (INIS)

    Patil, S. D.; Takale, M. V.

    2013-01-01

    In the present paper, we have employed the quantum dielectric response in thermal quantum plasma to model relativistic self-focusing of Gaussian laser beam in a plasma. We have presented an extensive parametric investigation of the dependence of beam-width parameter on distance of propagation in relativistic thermal quantum plasma. We have studied the role of Fermi temperature in the phenomenon of self-focusing. It is found that the quantum effects cause much higher oscillations of beam-width parameter and better relativistic focusing of laser beam in thermal quantum plasma in comparison with that in the relativistic cold quantum plasma and classical relativistic plasma. Our computations show more reliable results in comparison to the previous works

  18. Stopping of magnetic collapse due to residual plasma effect in a plasma focus

    International Nuclear Information System (INIS)

    Sasorov, P.V.

    1990-01-01

    The effect of the external plasma of a divergent current shell of a plasma pinch is discussed. Even a small amount of plasma is shown to be sufficiently enough for principal change in dynamics of late stages of sausage-type instability development in a Z-pinch

  19. World Energy Outlook 2007 Special Report: Focus on Energy Poverty

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Energy poverty affects many Indians and is an important issue for the Indian government. The number of households with access to electricity has risen over the past couple of decades, but access is still far from universal and the availability of modern cooking fuels and technologies is still limited, especially in rural areas. We use an energy development index, based on access to electricity and cleaner cooking fuels and on overall electricity generation per capita, to emphasise the disparity in energy poverty across India and relative to other developing countries. There are still some 412 million people without access to electricity in India. In all three WEO scenarios, the number of people without access declines, but it falls much faster in the High Growth Scenario. In that scenario, all households in India have access to electricity in 2030. In the Reference Scenario, the electrification rate in 2030 in India is 96% but nearly 60 million people in rural areas will still lack access. At an investment cost of $41 per person, it would cost some $17 billion to connect all those without electricity today to the central grid. But gridbased electrification is often not available to remote villages and households, because of the high cost of expanding the network. Diesel generators, mini-hydro, wind turbines, biomass gasifiers and photovoltaics, or a combination of these, could be more economic. The number of people relying on fuelwood and dung for cooking and heating declines from 668 million in 2005 to 395 million in 2030 in the High Growth Scenario, 77 million fewer people than in the Reference Scenario. About 22% of the population would still rely on these fuels in India in 2030, even with higher growth. According to the World Health Organization, the use of fuelwood and dung for cooking and heating causes over 400 000 premature deaths in India annually, mostly women and children. The concentration of particulate matter in the air in Indian households using

  20. Numerical experiments on plasma focus for soft x-ray yield scaling laws derivation using Lee model

    International Nuclear Information System (INIS)

    Akel, M.

    2015-01-01

    The required plasma parameters of krypton and xenon at different temperatures were calculated, the x-ray emission properties of plasmas were studied, and based on the corona model the suitable temperature range for generating H-like and He-like ions (therefore soft x-ray emissions) of different gases plasma were found. The code is applied to characterize the plasma focus in different plasma focus devices, and for optimizing the nitrogen, oxygen, neon, argon, krypton and xenon soft x-ray yields based on bank, tubes and operating parameters. It is found that t he soft x-ray yield increases with changing pressure until it reaches the maximum value for each plasma focus device. Keeping the bank parameters, operational voltage unchanged but systematically changing other parameters, numerical experiments were performed finding the optimum combination of Po, z0 and 'a' for the maximum soft x-ray yield. Thus we expect to increase the soft x-ray yield of plasma focus device several-fold from its present typical operation; without changing the capacitor bank, merely by changing the electrode configuration and the operating pressure. The Lee model code was also used to run numerical experiments on plasma focus devices for optimizing soft x-ray yield with reducing Lo, varying z0 and 'a' to get engineering designs with maximum soft x-ray yield for these devices at different experimental conditions and gases. Numerical experiments showed the influence of the gas used in plasma focus and its propor ties on soft x-ray emission and its propor ties and then on its applications. Scaling laws for soft x-ray of nitrogen, oxygen, neon, argon, krypton and xenon plasma focus in terms of energy, peak discharge current and focus pinch current were found. Radiative cooling effects are studied indicating that radiative collapse may be observed for heavy noble gases (Ar, Kr, Xe) for pinch currents even below 100 k A. The results show that the line radiation emission and

  1. Numerical experiments on plasma focus for soft x-ray yield scaling laws derivation using Lee model

    International Nuclear Information System (INIS)

    Akel, M.

    2012-09-01

    The required plasma parameters of krypton and xenon at different temperatures were calculated, the x-ray emission properties of plasmas were studied, and based on the corona model the suitable temperature range for generating H-like and He-like ions (therefore soft x-ray emissions) of different gases plasma were found. The code is applied to characterize the plasma focus in different plasma focus devices, and for optimizing the nitrogen, oxygen, neon, argon, krypton and xenon soft x-ray yields based on bank, tubes and operating parameters. It is found that the soft x-ray yield increases with changing pressure until it reaches the maximum value for each plasma focus device. Keeping the bank parameters, operational voltage unchanged but systematically changing other parameters, numerical experiments were performed finding the optimum combination of P o , Z o and 'a' for the maximum soft x-ray yield. Thus we expect to increase the soft x-ray yield of plasma focus device several-fold from its present typical operation; without changing the capacitor bank, merely by changing the electrode configuration and the operating pressure. The Lee model code was also used to run numerical experiments on plasma focus devices for optimizing soft x-ray yield with reducing L o , varying L o and 'a' to get engineering designs with maximum soft x-ray yield for these devices at different experimental conditions and gases. Numerical experiments showed the influence of the gas used in plasma focus and its properties on soft x-ray emission and its properties and then on its applications. Scaling laws for soft x-ray of nitrogen, oxygen, neon, argon, krypton and xenon plasma focus, in terms of energy, peak discharge current and focus pinch current were found. Radiative cooling effects are studied indicating that radiative collapse may be observed for heavy noble gases (Ar, Kr, Xe) for pinch currents even below 100 kA. The results show that the line radiation emission and tube voltages have

  2. Beam deviation method as a diagnostic tool for the plasma focus

    International Nuclear Information System (INIS)

    Schmidt, H.; Rueckle, B.

    1978-01-01

    The application of an optical method for density measurements in cylindrical plasmas is described. The angular deviation of a probing light beam sent through the plasma is proportional to the maximum of the density in the plasma column. The deviation does not depend on the plasma dimensions, however, it is influenced to a certain degree by the density profile. The method is successfully applied to the investigation of a dense plasma focus with a time resolution of 2 ns and a spatial resolution (in axial direction) of 2 mm. (orig.) [de

  3. Re-appraisal and extension of the Gratton-Vargas two-dimensional analytical snowplow model of plasma focus evolution in the context of contemporary research

    International Nuclear Information System (INIS)

    Auluck, S. K. H.

    2013-01-01

    Recent resurgence of interest in applications of dense plasma focus and doubts about the conventional view of dense plasma focus as a purely irrotational compressive flow have re-opened questions concerning device optimization. In this context, this paper re-appraises and extends the analytical snowplow model of plasma focus sheath evolution developed by F. Gratton and J. M. Vargas [Energy Storage, Compression and Switching, edited by V. Nardi, H. Sahlin, and W. H. Bostick (Plenum, New York, 1983), Vol. 2, p. 353)] and shows its relevance to contemporary research. The Gratton-Vargas (GV) model enables construction of a special orthogonal coordinate system in which the plasma flow problem can be simplified and a model of sheath structure can be formulated. The Lawrenceville Plasma Physics (LPP) plasma focus facility, which reports neutron yield better than global scaling law, is shown to be operating closer to an optimum operating point of the GV model as compared with PF-1000

  4. Varying Radii of On-Axis Anode Hollows For kJ-Class Dense Plasma Focus

    Science.gov (United States)

    Shaw, Brian; Chapman, Steven; Falabella, Steven; Pankin, Alexei; Liu, Jason; Link, Anthony; Schmidt, Andréa

    2017-10-01

    A dense plasma focus (DPF) is a compact plasma gun that produces high energy ion beams, up to several MeV, through strong potential gradients. Motivated by particle-in-cell simulations, we have tried a series of hollow anodes on our kJ-class DPF. Each anode has varying hollow sizes, and has been studied to optimize ion beam production in Helium, reduce anode sputter, and increase neutron yields in deuterium. We diagnose the rate at which electrode material is ablated and deposited onto nearby surfaces. This is of interest in the case of solid targets, which perform poorly in the presence of sputter. We have found that the larger the hollow radius produces more energetic ion beams, higher neutron yield, and sputter less than a flat top anode. A complete comparison is presented. This work was prepared by LLNL under Contract DE-AC52-07NA27344 and supported by Office of Defense Nuclear Nonproliferation Research and Development within U.S. Department of Energy's National Nuclear Security Administration.

  5. Hot spots and filaments in the pinch of a plasma focus: a unified approach

    International Nuclear Information System (INIS)

    Di Vita, A.

    2009-01-01

    To date, no MHD-based complete description of the tiny, relatively stable, well-ordered structures (hot spots, filaments) observed in the pinch of a plasma focus seems to be feasible. Indeed, the large value of electron density suggests that a classification of such structures which is based on the approximation of local thermodynamical equilibrium (LTE) is possible. Starting from an often overlooked, far-reaching result of LTE, we derive a purely analytical description of both hot spots and filaments. In spite of their quite different topology, both configurations are extrema of the same variational principle. Well-known results of conventional MHD are retrieved as benchmark cases. It turns out that hot spots satisfy Taylor's principle of constrained minimum of magnetic energy, the constraint being given by fixed magnetic helicity. Filaments are similar to the filaments of a superconductor and form a plasma with β equals 0.11 and energy diffusion coefficient equals 0.88*D(Bohm). Any process - like e.g. radiative collapse - which raises particle density while reducing radial size may transform filaments into hot spots. A well-known scaling law is retrieved - the collisional Vlasov high beta scaling. A link between dissipation and topology is highlighted. Accordingly, a large-current pinch may give birth to tiny hot spots with large electron density and magnetic field. (author)

  6. The Energy Balance of Plasma in a Coaxial Plasma Opening Switch

    International Nuclear Information System (INIS)

    Xu Xiang; Wang Younian

    2006-01-01

    The two-dimensional energy balance in a coaxial plasma opening switch (POS) is studied based on the single-fluid magnetohydrodynamic (MHD) equations coupled with the generalized Ohm's law. The energy transfers between the plasma and the magnetic field are considered during the penetration of the magnetic field as the Ohmic heating is included in the energy-balance equation. The focus is on the energy partition between the magnetic-field energy and the dissipated magnetic-field energy in a high-density POS with different rise-in-time electric currents at the generator boundary. The simulation code is tested in two cases: the constant-in-time current case and the linear rise-in-time current case. For the sinusoidally rise-in-time current similar to that of the experiments, it is shown that at the end of the conduction phase the dissipated magnetic-field energy is 36.5% of the input electromagnetic energy, which is consistent with the experimental results

  7. Ion implantation on nickel targets by means of repetitive plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Vitulli, S.; Rapezzi, L. [ENEA Brasimone, Camugnano, Bologna (Italy); Apicella, M.L.; Samuelli, M. [ENEA Frascati, Frascati, Roma (Italy)

    2004-07-01

    Some test has been done in order to assess the possible use of a plasma focus as an implanter. The device utilized is the repetitive Plasma Focus operating in the ENEA Brasimone Center. The implanted sample is a sheet of Nickel with a surface of 17 cm{sup 2} inserted in a rigid sample at a variable distance from the top of the anode. After irradiation the sample is analyzed with Auger spectroscopy that provides the surface concentration of the various elements on the sample at different implantation depths. The result of the analysis shows that the Plasma Focus is an effective implantation source, even for metallurgical applications. (orig.)

  8. Survey of energy resources: focus on shale gas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    The energy sector around the world is undergoing major changes resulting from increasing competitive pressures and concerns about costs, security of supply and the environment. At the same time, 1.6 billion people, almost a quarter of the world population, do not have access to commercial energy and the need for energy infrastructure investment is huge. The energy challenges are not the same in all regions. While rapidly burgeoning economies in the developing world are focusing on expanding energy access to support their economic growth and provide basic energy services to their citizens, industrialised countries are focusing on securing energy supplies in a competitive environment and in a publicly and environmentally acceptable way. In recent years, shale gas has been making headlines as a potential solution for many of the energy-related challenges, in particular in the United States. A number of studies on shale gas have been conducted, the majority focusing on the assessment of the resource base and the role of emerging technologies, which can significantly increase the current reserve estimates.

  9. Lifetime and shelf life of sealed tritium-filled plasma focus chambers with gas generator

    Directory of Open Access Journals (Sweden)

    B.D. Lemeshko

    2017-11-01

    Full Text Available The paper describes the operation features of plasma focus chambers using deuterium–tritium mixture. Handling tritium requires the use of sealed, vacuum-tight plasma focus chambers. In these chambers, there is an accumulation of the impurity gases released from the inside surfaces of the electrodes and the insulator while moving plasma current sheath inside chambers interacting with β-electrons generated due to the decay of tritium. Decay of tritium is also accompanied by the accumulation of helium. Impurities lead to a decreased yield of neutron emission from plasma focus chambers, especially for long term operation. The paper presents an option of absorption type gas generator in the chamber based on porous titanium, which allows to significantly increase the lifetime and shelf life of tritium chambers. It also shows the results of experiments on the comparison of the operation of sealed plasma focus chambers with and without the gas generator. Keywords: Plasma focus, Neutron yield, Tritium-filled plasma focus chambers, PACS Codes: 29.25.-v, 52.58.Lq

  10. Focus on strongly correlated quantum fluids: from ultracold quantum gases to QCD plasmas Focus on strongly correlated quantum fluids: from ultracold quantum gases to QCD plasmas

    Science.gov (United States)

    Adams, Allan; Carr, Lincoln D.; Schaefer, Thomas; Steinberg, Peter; Thomas, John E.

    2013-04-01

    The last few years have witnessed a dramatic convergence of three distinct lines of research concerned with different kinds of extreme quantum matter. Two of these involve new quantum fluids that can be studied in the laboratory, ultracold quantum gases and quantum chromodynamics (QCD) plasmas. Even though these systems involve vastly different energy scales, the physical properties of the two quantum fluids are remarkably similar. The third line of research is based on the discovery of a new theoretical tool for investigating the properties of extreme quantum matter, holographic dualties. The main goal of this focus issue is to foster communication and understanding between these three fields. We proceed to describe each in more detail. Ultracold quantum gases offer a new paradigm for the study of nonperturbative quantum many-body physics. With widely tunable interaction strength, spin composition, and temperature, using different hyperfine states one can model spin-1/2 fermions, spin-3/2 fermions, and many other spin structures of bosons, fermions, and mixtures thereof. Such systems have produced a revolution in the study of strongly interacting Fermi systems, for example in the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover region, where a close collaboration between experimentalists and theorists—typical in this field—enabled ground-breaking studies in an area spanning several decades. Half-way through this crossover, when the scattering length characterizing low-energy collisions diverges, one obtains a unitary quantum gas, which is universal and scale invariant. The unitary gas has close parallels in the hydrodynamics of QCD plasmas, where the ratio of viscosity to entropy density is extremely low and comparable to the minimum viscosity conjecture, an important prediction of AdS/CFT (see below). Exciting developments in the thermodynamic and transport properties of strongly interacting Fermi gases are of broad

  11. A study of x-ray emission from the anode region in a plasma focus device

    International Nuclear Information System (INIS)

    Jia Wang; Tsinchi Yang

    1988-01-01

    The physical process of x-ray emission from the anode region in a plasma focus device due to the interaction of a powerful electron beam with the metal anode and with ionised metallic vapour from the anode is investigated. The influence of the magnetic field of the beam is taken into consideration. A MC-PIC model (Monte Carlo-particle in cell) is proposed for the process, in which an electron-photon collision cascade is simulated by the MC approach and the time-dependent state of metallic vapour is determined by PIC computation. The time-resolved energy spectra and angular distributions of x-ray emission from the extending anode region are calculated. The time-integrated characteristics of the x-ray emission can be compared with the results of experiments as far as they are available. (author)

  12. Evaluation of the effect of anode groove pitch to ion beam focusibility on spherical plasma focus diode

    Energy Technology Data Exchange (ETDEWEB)

    Imanari, K [Oyama National College of Technology (Japan). Department of Electrical Engineering; Jiang, W; Masugata, K; Yatsui, K [Nagaoka Univ. of Technology (Japan). Laboratory of Beam Technology

    1997-12-31

    A new PIC simulation code was developed to evaluate the effect of anode plasma nonuniformity on LIB focusibility. The plasma nonuniformity was modelled by inducing anode grooves in the code. In the experimental conditions, groove pitch about 2.2 mm and groove width of 1.0 mm, the simulation results are in a good agreement with the observed data. At a groove pitch of 2.4 mm, the local divergence was very small, although the focal length was very long. It was inferred that the focusibility of SPFD will be determined by the z-deflection angle rather than the local divergence angle. Modification of the anode curvature may be advantageous to get a higher power density on the focal point. (author). 6 figs., 3 refs.

  13. Scaling Laws of Nitrogen Soft X-Ray Yields from 1 to 200 kJ Plasma Focus

    International Nuclear Information System (INIS)

    Akel, M.; Lee, S.

    2013-01-01

    Numerical experiments are carried out systematically to determine the nitrogen soft x-ray yield for optimized nitrogen plasma focus with storage energy E 0 from 1 kJ to 200 kJ. Scaling laws on nitrogen soft x-ray yield, in terms of storage energies E 0 , peak discharge current I p eak and focus pinch current I p inch were found. It was found that the nitrogen x-ray yields scales on average with y s xr, N= 1.93xE o 1 .21 J (E 0 in kJ) with the scaling showing gradual deterioration as E 0 rises over the range. A more robust scaling is y s xr = 8x10 - 8I 0 3.38 p inch . The optimum nitrogen soft x-ray yield emitted from plasma focus is found to be about 1 kJ for storage energy of 200 kJ. This indicates that nitrogen plasma focus is a good water-window soft x-ray source when properly designed. (author)

  14. Basic physical phenomena, neutron production and scaling of the dense plasma focus

    International Nuclear Information System (INIS)

    Kaeppeler, H.J.

    This paper presents an attempt at establishing a model theory for the dense plasma focus in order to present a consistent interpretation of the basic physical phenomena leading to neutron production from both acceleration and thermal processes. To achieve this, the temporal history of the focus is divided into the compression of the plasma sheath, a qiescent and very dense phase with ensuing expansion, and an instable phase where the focus plasma is disrupted by instabilities. Finally, the decay of density, velocity and thermal fields is considered. Under the assumption that Io 2 /sigmaoRo 2 = const and to/Tc = const, scaling laws for plasma focus devices are derived. It is shown that while generally the neutron yield scales with the fourth power of maximum current, neutron production from thermal processes becomes increasingly important for large devices, while in the small devices neutron production from acceleration processes is by far predominant. (orig.) [de

  15. Surface modification study of zirconium on exposure to fusion grade plasma in an 11.5 kJ plasma focus device

    International Nuclear Information System (INIS)

    Srivastava, Rohit; Niranjan, Ram; Rout, R.K.; Kaushik, T.C.; Chakravarthy, Y.; Mishra, P.

    2017-01-01

    In continuation of our investigation on effect of fusion grade plasma produced in an existing MEPF-12 (11.5 kJ, 40 μF, 24 kV) plasma focus (PF) facility on different materials, likely to be used in future fusion reactors, we have reported here the study on Zirconium (Zr) metal. In the present work, the Zr sample in disc (2 mm thick, 10 mm diameter) form was exposed to twenty shots of plasma focus operated at 4 mbar deuterium gas filling pressure and 11.5 kJ bank energy. The samples were placed at a distance of 6 cm from the tip of the anode in the MEPF-12 PF device. The emissions from the device comprise of deuterium ions in wide energy range (a few keV to several hundreds of keV), high temperature plasma (in general a few keV) and neutrons of 2.45 MeV energy produced due to D(D, 3 He)n fusion reactions

  16. Neutron production and ion beam generation in plasma focus devices

    International Nuclear Information System (INIS)

    Steinmetz, K.

    1980-01-01

    Concerning the physical processes leading to neutron emission, a clearer situation has been achieved compared to the state at the start of this work. The general discussion will realize that the whole experimental data cannot be described consistently by the predictions of either the beam-target model or the quasi-thermonuclear fusion model, although many questions about the neutron production properties have been solved. In particular the neutron fluence anisotropy is found to be a property basically related to the existence of fast ions escaping axially out of the pinch region. The requirements to explain broad radial neutron energy spectra, long emission times, and energetic but not spatial emission anisotropies suggest a kind of particle trapping in the main source region. (orig./HT)

  17. Nuclear Malaysia Plasma Focus Device as a X-ray Source For Radiography Applications

    International Nuclear Information System (INIS)

    Rokiah Mohd Sabri; Abdul Halim Baijan; Siti Aiasah Hashim; Mohd Rizal Mohd Chulan; Wah, L.K.; Mukhlis Mokhtar; Azaman Ahmad; Rosli Che Ros

    2013-01-01

    A 3.375 kJ plasma focus is designed to operate at 13.5 kV for the purpose of studying x-ray source for radiography in Argon discharge. X-rays is detected by using x-ray film from the mammography radiographic plate. The feasibility of the plasma focus as a high intensity flash x-ray source for good contrast in radiography image is presented. (author)

  18. Transport of long-pulse relativistic electron beams in preformed plasma channels in the ion focus regime

    International Nuclear Information System (INIS)

    Miller, J.D.

    1989-01-01

    Experiments have been performed demonstrating efficient transport of long-pulse (380 ns), high-current (200 A), relativistic electron beams (REBs) in preformed plasma channels in the ion focus regime (IFR). Plasma channels were created by low-energy ( e , and channel ion mass, in agreement with theoretical values predicted for the ion hose instability. Microwave emission has also been observed indicative of REB-plasma electron two-stream instability. Plasma channel density measurements indicate that the two-stream instability can become dominant for measured f e values slightly above unity. The author has introduced a theoretical analysis for high-current REB transport and modulation in axially periodic IFR plasma channels. Analytic expression for the electric field are found for the case of a cosine modulation of the channel ion density. Two different types of channels are considered: (i) periodic beam-induced ionization channels, and (ii) periodic plasma slab channels created by an external source. Analytical conditions are derived for the matched radius of the electron beam and for approximate beam envelope motion using a 'smooth' approximation. Numerical solutions to the envelope equation show that by changing the wavelength or the amplitude of the space-charge neutralization fraction of the ion channel density modulation, the beam can be made to focus and diverge, or to undergo stable, modulated transport

  19. Energy management technologies: special focus on textile industry

    International Nuclear Information System (INIS)

    Dayo, F.B.O.

    2000-08-01

    requirement in international competitiveness. The focus of this paper is the review of energy management technologies that can be used to achieve energy efficiency improvement objectives in textile manufacturing. The paper is arranged as follows: in section 2, the characteristics of energy consumption in textile manufacturing are presented; energy efficiency improvement technology options for the textile industry are discussed in section 3, section 4 covers a discussion of process specific technologies for improving energy use efficiency in textile manufacturing; the paper is concluded in section 5 with salient recommendation for promoting rational use of energy in the Nigerian Textile Industrial Sector

  20. Characterization of plasma-induced cell membrane permeabilization: focus on OH radical distribution

    International Nuclear Information System (INIS)

    Sasaki, Shota; Honda, Ryosuke; Hokari, Yutaro; Takashima, Keisuke; Kaneko, Toshiro; Kanzaki, Makoto

    2016-01-01

    Non-equilibrium atmospheric-pressure plasma (APP) is used medically for plasma-induced cell permeabilization. However, how plasma irradiation specifically triggers permeabilization remains unclear. In an attempt to identify the dominant factor( s ), the distribution of plasma-produced reactive species was investigated, primarily focusing on OH radicals. A stronger plasma discharge, which produced more OH radicals in the gas phase, also produced more OH radicals in the liquid phase (OH aq ), enhancing the cell membrane permeability. In addition, plasma irradiation-induced enhancement of cell membrane permeability decreased markedly with increased solution thickness (<1 mm), and the plasma-produced OH aq decayed in solution (diffusion length on the order of several hundred micrometers). Furthermore, the horizontally center-localized distribution of OH aq corresponded with the distribution of the permeabilized cells by plasma irradiation, while the overall plasma-produced oxidizing species in solution (detected by iodine-starch reaction) exhibited a doughnut-shaped horizontal distribution. These results suggest that OH aq, among the plasma-produced oxidizing species, represents the dominant factor in plasma-induced cell permeabilization. These results enhance the current understanding of the mechanism of APP as a cell-permeabilization tool. (paper)

  1. Compact activation detectors for measuring of neutron emission on plasma focus installations

    International Nuclear Information System (INIS)

    Krokhin, O.N.; Nikulin, V.Ya.; Peregudova, E.V.; Volobuev, I.V.

    2005-01-01

    The paper presents the two compact simple systems for the measurement of the absolute neutron yield in the range 10 6 - 10 12 neutrons/pulse and higher and spatial anisotropy of neutron radiation. The systems are destined for the registration of the short duration neutron radiation of the pulsed plasma installations, such as Plasma Focus (PF), z-pinches and others plasma installations. This paper also includes the results of the neutron emission measurements on different PF installations: 'Tulip' (P.N. Lebedev Physical Institute, Moscow Russia), the PF-1000 and PF-150 installations (Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland)

  2. Structuring of silicon with low energy focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Nebiker, P.W.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muehle, R. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    The defect production in silicon induced by focused ion beam irradiation as a function of energy and projectile mass has been investigated and compared to the measured sputter yield. The aim was to find optimal beam parameters for the structuring of semiconductors with a minimum amount of defects produced per removed atom. (author) 2 figs., 2 refs.

  3. Measurement of angular distribution of neutrons emitted from plasma focus using NTD

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Maric, Z.; Banjanac, R.; Dragic, A.; Stanojevic, J.; Dordevic, D.; Joksimovic, D.; Udovicic, V.; Vukovic, J.

    1999-01-01

    Mica detectors together with thick uranium foils were used for detection and angular distribution measurement of the neutrons emitted from the d-plasma focus (DPF). The distance between detectors and plasma pinch was 4 cm. For reason of detector protection from the thermal shock, they were covered with the mica layer of 1 mm thickness. Annealing of the detectors were measured after the irradiation with neutrons from an Am-Be source and treated with thermal shock H-plasma focus (HPF). Geometry of detectors in both experiments was the same

  4. Measurement of angular distribution of neutrons emitted from plasma focus using NTD

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Maric, Z.; Banjanac, R.; Dragic, A.; Stanojevic, J.; Dordevic, D.; Joksimovic, D.; Udovicic, V.; Vukovic, J

    1999-06-01

    Mica detectors together with thick uranium foils were used for detection and angular distribution measurement of the neutrons emitted from the d-plasma focus (DPF). The distance between detectors and plasma pinch was 4 cm. For reason of detector protection from the thermal shock, they were covered with the mica layer of 1 mm thickness. Annealing of the detectors were measured after the irradiation with neutrons from an Am-Be source and treated with thermal shock H-plasma focus (HPF). Geometry of detectors in both experiments was the same.

  5. Measurement of angular distribution of neutrons emitted from plasma focus using NTD

    CERN Document Server

    Antanasijevic, R; Banjanac, R; Dragic, A; Stanojevic, J; Dordevic, D; Joksimovic, D; Udovicic, V; Vukovic, J

    1999-01-01

    Mica detectors together with thick uranium foils were used for detection and angular distribution measurement of the neutrons emitted from the d-plasma focus (DPF). The distance between detectors and plasma pinch was 4 cm. For reason of detector protection from the thermal shock, they were covered with the mica layer of 1 mm thickness. Annealing of the detectors were measured after the irradiation with neutrons from an Am-Be source and treated with thermal shock H-plasma focus (HPF). Geometry of detectors in both experiments was the same.

  6. Ti film deposition process of a plasma focus: Study by an experimental design

    Directory of Open Access Journals (Sweden)

    M. J. Inestrosa-Izurieta

    2017-10-01

    Full Text Available The plasma generated by plasma focus (PF devices have substantially different physical characteristics from another plasma, energetic ions and electrons, compared with conventional plasma devices used for plasma nanofabrication, offering new and unique opportunities in the processing and synthesis of Nanomaterials. This article presents the use of a plasma focus of tens of joules, PF-50J, for the deposition of materials sprayed from the anode by the plasma dynamics in the axial direction. This work focuses on the determination of the most significant effects of the technological parameters of the system on the obtained depositions through the use of a statistical experimental design. The results allow us to give a qualitative understanding of the Ti film deposition process in our PF device depending on four different events provoked by the plasma dynamics: i an electric erosion of the outer material of the anode; ii substrate ablation generating an interlayer; iii electron beam deposition of material from the center of the anode; iv heat load provoking clustering or even melting of the deposition surface.

  7. Neutron angular distribution in a plasma focus obtained using nuclear track detectors.

    Science.gov (United States)

    Castillo-Mejía, F; Herrera, J J E; Rangel, J; Golzarri, J I; Espinosa, G

    2002-01-01

    The dense plasma focus (DPF) is a coaxial plasma gun in which a high-density, high-temperature plasma is obtained in a focused column for a few nanoseconds. When the filling gas is deuterium, neutrons can be obtained from fusion reactions. These are partially due to a beam of deuterons which are accelerated against the background hot plasma by large electric fields originating from plasma instabilities. Due to a beam-target effect, the angular distribution of the neutron emission is anisotropic, peaked in the forward direction along the axis of the gun. The purpose of this work is to illustrate the use of CR-39 nuclear track detectors as a diagnostic tool in the determination of the time-integrated neutron angular distribution. For the case studied in this work, neutron emission is found to have a 70% contribution from isotropic radiation and a 30% contribution from anisotropic radiation.

  8. Effects of admixture gas on the production of {sup 18}F radioisotope in plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Talaei, Ahmad [Nuclear Science and Technology Research Institute (NSTR), Nuclear Science Research School, A.E.O.I., 14155-1339 Tehran (Iran, Islamic Republic of); Sadat Kiai, S.M., E-mail: sadatkiai@yahoo.co [Nuclear Science and Technology Research Institute (NSTR), Nuclear Science Research School, A.E.O.I., 14155-1339 Tehran (Iran, Islamic Republic of); Zaeem, A.A. [Department of Physics, Khaje Nasir University of Technology (K.N. Toosi), 1541846911 Tehran (Iran, Islamic Republic of)

    2010-12-15

    In this article, the effect of admixture gas on the heating and cooling of pinched plasma directly related to the enhancement or reduction of {sup 18}F production through the {sup 16}O({sup 3}He, p){sup 18}F is considered in the plasma focus devices. It is shown that by controlling the velocity of added Oxygen particles mixed with the working helium gas into the plasma focus chamber, one can increase the current and decrease the confinement time (plasma heating) or vice verse (plasma cooling). The highest level of nuclear activities of {sup 18}F was found around 16% of the Oxygen admixture participation and was about 0.35 MBq in the conditions of 20 kJ, 0.1 Hz and after 2 min operating of Dena PF. However, in the same condition, but for the frequency of 1 Hz, the level of activity increased up to 3.4 MBq.

  9. Development of X-ray and ion diagnostic methods for plasma focus research

    International Nuclear Information System (INIS)

    Sadowski, M.

    1986-12-01

    A review of experimental methods used for investigation of X-rays and ion-beams emmited from plasma focus facilities is presented. The research program has been realized at the Institute for Nuclear Studies in Swierk and at the Institut fuer Plasmaforschung in Stuttgart, within the frames of an international co-operation. The studies on ion emission from different PF facilities are reviewed. The application of CN-films with Al-filters and of different ion-pinhole cameras is described. The use of a Thomson mass-spectrometer adopted for plasma studies is presented. The time-resolved measurements combined with a simultaneous mass- and energy-analysis of the ion beams are also described. The most important results of these studies are summarized. Particular attention is also paid to the studies of the X-ray emission. The use of stereoscopic sets of vacuum pinhole cameras with thin Be-filters is described. The application of X-ray pinhole cameras equipped with miniature scintillators for time-resolved measurements is also presented. The most important results of the X-ray emission studies are summarized. 35 refs., 12 figs. (author)

  10. Two-dimensional magnetohydrodynamic calculations for a 5 MJ plasma focus

    International Nuclear Information System (INIS)

    Maxon, S.

    1979-01-01

    The performance of a 5 MJ plasma focus is calculated using our two-dimensional magnetohydrodynamic (2-D MHD) code. Two configurations are discussed, a solid and a hollow anode. In the case of the hollow anode, we find an instability in the current sheath which has the characteristics of the short wave length sausage instability. As the current sheath reaches the axis, the numerical solution is seen to break down. Just before this time, plasma parameters take on the characteristic values rho/rho 0 = 143, kT/sup i/ = 7.4 keV, B/sub theta/ = 4.7 MG, and V/sub z/ = 60 cm/μs for a zone with r = 0.2 mm. When the numerical solution breaks down, the code shows a splitting of the current sheath (from the axis to the anode) and the loss of a large amount of magnetic energy. Current-sheath stagnation is observed in the hollow anode configuration, also

  11. The calculation of turbulence phenomena in plasma focus dynamics using REDUCE

    International Nuclear Information System (INIS)

    Hayd, A.; Maurer, M.; Meinke, P.; Kaeppeler, H.J.

    1982-05-01

    Based on previous calculations of the development of highly turbulent plasma states resulting from m=0 instabilities and the application to the turbulent development in the late stage of a plasma focus experiment, using REDUE, the treatment of plasma focus dynamics is extended to the compression stage and 'intermediate' stage between maximum density and m = o onset. For this, a two-fluid model of the magneto-fluid dynamic equations is employed. The non-linear development is again treated in ω, k-space and transformed back into r, t-space to obtain local dynamic variables as functions of time. The calculation is applied to the Stuttgart plasma focus experiment POSEIDON. It is shown that for relatively high pinch currents, neutron production also appears in the 'intermediate' phase, the life-time of which increases with increasing pinch current. (orig.)

  12. Concrete shielding of neutron radiations of plasma focus and dose examination by FLUKA

    Science.gov (United States)

    Nemati, M. J.; Amrollahi, R.; Habibi, M.

    2013-07-01

    Plasma Focus (PF) is among those devices which are used in plasma investigations, but this device produces some dangerous radiations after each shot, which generate a hazardous area for the operators of this device; therefore, it is better for the operators to stay away as much as possible from the area, where plasma focus has been placed. In this paper FLUKA Monte Carlo simulation has been used to calculate radiations produced by a 4 kJ Amirkabir plasma focus device through different concrete shielding concepts with various thicknesses (square, labyrinth and cave concepts). The neutron yield of Amirkabir plasma focus at varying deuterium pressure (3-9 torr) and two charging voltages (11.5 and 13.5 kV) is (2.25 ± 0.2) × 108 neutrons/shot and (2.88 ± 0.29) × 108 neutrons/shot of 2.45 MeV, respectively. The most influential shield for the plasma focus device among these geometries is the labyrinth concept on four sides and the top with 20 cm concrete.

  13. Energy expenditures of plasma method of isotope separation

    International Nuclear Information System (INIS)

    Karchevskij, A.I.; Potanin, E.P.

    1986-01-01

    The estimations are performed of specific energy expenditares in isotope separation of binary mixtures in different plasma systems with weak medium ionization (plasma centrifuge, gas discharge system with travelling magnetic field, direct current discharge). Potential advantages of plasma centrifuge over other gas discharge facilities are pointed out. The comparison of specific energy expenditure values in case of using plasma and conventional methods of isotope separation is carried out

  14. Space-time structure of neutron and X-ray sources in a plasma focus

    International Nuclear Information System (INIS)

    Bostick, W.H.; Nardi, V.; Prior, W.

    1977-01-01

    Systematic measurements with paraffin collimators of the neutron emission intensity have been completed on a plasma focus with a 15-20 kV capacitor bank (hollow centre electrode; discharge period T approximately 8 μs; D 2 filling at 4-8 torr). The space resolution was 1 cm or better. These data indicate that at least 70% of the total neutron yield originates within hot-plasma regions where electron beams and high-energy D beams (approximately > 0.1-1 MeV) are produced. The neutron source is composed of several (approximately > 1-10) space-localized sources of different intensity, each with a duration approximately less than 5 ns (FWHM). Localized neutron sources and hard (approximately > 100 keV) X-ray sources have the same time multiplicity and are usually distributed in two groups over a time interval 40-400 ns long. By the mode of operation used by the authors one group of localized sources (Burst II) is observed 200-400 ns after the other group (Burst I) and its space distribution is broader than for Burst I. The maximum intensity of a localized source of neutrons in Burst I is much higher than the maximum intensity in Burst II. Secondary reactions T(D,n) 4 He (from the tritium produced only by primary reactions in the same discharge; no tritium was used in filling the discharge chamber) are observed in a time coincidence with the strongest D-D neutron pulse of Burst I. The neutron signal from a localized source with high intensity has a relatively long tail of small amplitude (area tail approximately less than 0.2 X area peak). This tail can be generated by the D-D reactions of the unconfined part of an ion beam in the cold plasma. Complete elimination of scattered neutrons on the detector was achieved in these measurements. (author)

  15. Application of Plasma Waveguides to High Energy Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Milchberg, Howard M

    2013-03-30

    The eventual success of laser-plasma based acceleration schemes for high-energy particle physics will require the focusing and stable guiding of short intense laser pulses in reproducible plasma channels. For this goal to be realized, many scientific issues need to be addressed. These issues include an understanding of the basic physics of, and an exploration of various schemes for, plasma channel formation. In addition, the coupling of intense laser pulses to these channels and the stable propagation of pulses in the channels require study. Finally, new theoretical and computational tools need to be developed to aid in the design and analysis of experiments and future accelerators. Here we propose a 3-year renewal of our combined theoretical and experimental program on the applications of plasma waveguides to high-energy accelerators. During the past grant period we have made a number of significant advances in the science of laser-plasma based acceleration. We pioneered the development of clustered gases as a new highly efficient medium for plasma channel formation. Our contributions here include theoretical and experimental studies of the physics of cluster ionization, heating, explosion, and channel formation. We have demonstrated for the first time the generation of and guiding in a corrugated plasma waveguide. The fine structure demonstrated in these guides is only possible with cluster jet heating by lasers. The corrugated guide is a slow wave structure operable at arbitrarily high laser intensities, allowing direct laser acceleration, a process we have explored in detail with simulations. The development of these guides opens the possibility of direct laser acceleration, a true miniature analogue of the SLAC RF-based accelerator. Our theoretical studies during this period have also contributed to the further development of the simulation codes, Wake and QuickPIC, which can be used for both laser driven and beam driven plasma based acceleration schemes. We

  16. Energy poverty: A special focus on energy poverty in India and renewable energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Bhide, Anjali; Monroy, Carlos Rodriguez [Department of Business Administration, School of Industrial Engineering, Technical University of Madrid, Jose Gutierrez Abascal, 2, 28006 Madrid (Spain)

    2011-02-15

    As a large percentage of the world's poor come from India, development in India is a key issue. After the establishment of how access to energy enhances development and the achievement of the millennium development goals, energy poverty has become a major issue. In India there is a great interest in addressing the subject of energy poverty, in order to reach development goals set by the Government. This will imply an increase in India's energy needs. In a climate of change and environmental consciousness, sustainable alternatives must be considered to address these issues. Renewable energy technologies could provide a solution to this problem. The Government of India has been focussing in implementing electricity policies as well as on promoting renewable energy technologies. The focus of this article is to bring to light the problems faced in India in terms of energy consumption as well as the hindrances faced by renewable-based electrification networks. Government policies aimed at addressing these issues, as well as the current state of renewable energy technologies in India are discussed, so as to analyse the possibility of a solution to the problems of finding a sustainable method to eradicate energy poverty in India. The research reveals that the Government of India has been unable to meet some of its unrealistic development goals, and in order to achieve the remaining goals it will have to take drastic steps. The Government will have to be more aggressive in the promotion of renewable energy technologies in order to achieve sustainable development in India. (author)

  17. Measurements of fast electron beams and soft X-ray emission from plasma-focus experiments

    Directory of Open Access Journals (Sweden)

    Surała Władysław

    2016-06-01

    Full Text Available The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8 measuring channels. For discharges performed with the pure deuterium filling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the first hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds and appearing in different instants after the current peculiarity (so-called current dip were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and recorded with nuclear track detectors, were also investigated. Those measurements confirmed a multibeam character of the ion emission. The time-integrated soft X-ray images, which were taken side-on by means of a pinhole camera and sensitive X-ray films, showed the appearance of some filamentary structures and so-called hot spots. The application of small amounts of admixtures of different heavy noble gases, i.e. of argon (4.8% volumetric, krypton (1.6% volumetric, or xenon (0.8% volumetric, decreased intensity of the recorded electron beams, but increased intensity of the soft X-ray emission and showed more distinct and numerous hot spots. The recorded electron spikes have been explained as signals produced by quasi-mono-energetic microbeams emitted from tiny sources (probably plasma diodes, which can be formed near the observed hot spots.

  18. Reorganization at Oryx Energy focuses on teamwork, technology

    International Nuclear Information System (INIS)

    Box, J.W.

    1993-01-01

    As one of the largest independent oil and gas companies in the world, Oryx Energy Co. has become a strong international player, In an increasingly global business, they are competing with some very tough international companies. This competition calls for their continued focus on technology and innovative ways of conducting business, not only on the international scene but also in the U.S. Here the author focuses on ways his company is approaching U.S. activities, both onshore and in the Gulf of Mexico

  19. Dynamics of ponderomotive self-focusing and periodic bursts of stimulated Brillouin backscattering in plasmas

    International Nuclear Information System (INIS)

    Andreev, N.E.; Gorbunov, L.M.; Tarakanov, S.V.; Zykov, A.I.

    1993-01-01

    The space--time evolution of ponderomotive self-focusing of electromagnetic beams in a plasma is investigated. The quasineutral, hydrodynamic plasma response to the ponderomotive force is considered. The set of coupled quasioptic and acoustic equations is solved both analytically and numerically for slab and cylindrical beams. It is shown that the transient process of self-focusing has the form of a nonlinear wave propagating along the beam axis from boundary into the interior of a plasma with velocity considerably higher than the ion-sound velocity. Mutual dynamics of self-focusing and stimulated Brillouin backscattering (SBBS) is computed. It is shown that self-focusing results in the high intensity periodical bursts of SBBS. However, the time average level of scattered radiation is quite low

  20. Diagnostic systems for the nuclear fusion and plasma research in the PF-24 plasma focus laboratory at the IFJ PAN

    Directory of Open Access Journals (Sweden)

    Marciniak Łukasz

    2016-12-01

    Full Text Available This paper presents a set of diagnostics dedicated to PF-24 - new medium size - plasma focus (PF device built and operated at the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN. The PF-24 can operate at energy level up to 93 kJ and charging voltage up to 40 kV. Each condenser is connected with a specially designed spark gap with a very small jitter, which ensures a high effi ciency and a low current rise time. The working parameters of PF-24 generator make it a suitable tool for testing new detection systems to be used in fusion research. Four types of such detection systems are presented in this article: three diagnostic systems used to measure electric quantities (Rogowski coil, magnetic probe, capacitance probe, neutron counter based on beryllium activation, fast neutron pinhole camera based on small-area BCF-12 plastic scintillation detectors and high-speed four-frame soft X-ray camera with microchannel plate.

  1. Plasma generator utilizing dielectric member for carrying microwave energy

    International Nuclear Information System (INIS)

    Aklufi, M.E.; Brock, D.W.

    1991-01-01

    This patent describes a system in which electromagnetic energy is used to generate a plasma from a gas. It comprises a reaction chamber which is evacuated to less than ambient pressure and into which the gas is introduced; and a nonconductive member for carrying the electromagnetic energy and for emitting the electromagnetic energy so that a plasma is formed from the gas

  2. Formation of plasma channels in air under filamentation of focused ultrashort laser pulses

    International Nuclear Information System (INIS)

    Ionin, A A; Seleznev, L V; Sunchugasheva, E S

    2015-01-01

    The formation of plasma channels in air under filamentation of focused ultrashort laser pulses was experimentally and theoretically studied together with theoreticians of the Moscow State University and the Institute of Atmospheric Optics. The influence of various characteristics of ultrashort laser pulses on these plasma channels is discussed. Plasma channels formed under filamentation of focused laser beams with a wavefront distorted by spherical aberration (introduced by adaptive optics) and by astigmatism, with cross-section spatially formed by various diaphragms and with different UV and IR wavelengths, were experimentally and numerically studied. The influence of plasma channels created by a filament of a focused UV or IR femtosecond laser pulse (λ = 248 nm or 740 nm) on characteristics of other plasma channels formed by a femtosecond pulse at the same wavelength following the first one with varied nanosecond time delay was also experimentally studied. An application of plasma channels formed due to the filamentation of focused UV ultrashort laser pulses including a train of such pulses and a combination of ultrashort and long (∼100 ns) laser pulses for triggering and guiding long (∼1 m) electric discharges is discussed. (topical review)

  3. Enhanced relativistic self-focusing of Hermite-cosh-Gaussian laser beam in plasma under density transition

    International Nuclear Information System (INIS)

    Nanda, Vikas; Kant, Niti

    2014-01-01

    Enhanced and early relativistic self-focusing of Hermite-cosh-Gaussian (HChG) beam in the plasmas under density transition has been investigated theoretically using Wentzel-Kramers-Brillouin and paraxial ray approximation for mode indices m=0, 1, and 2. The variation of beam width parameter with normalized propagation distance for m=0, 1, and 2 is reported, and it is observed that strong self-focusing occurs as the HChG beam propagates deeper inside the nonlinear medium as spot size shrinks due to highly dense plasmas and the results are presented graphically. A comparative study between self-focusing of HChG beam in the presence and absence of plasmas density transition is reported. The dependency of beam width parameter on the normalized propagation distance for different values of decentered parameter “b” has also been presented graphically. For m=0 and 1, strong self-focusing is reported for b=1.8, and for m=2 and b=1.8, beam gets diffracted. The results obtained indicate the dependency of the self-focusing of the HChG beam on the selected values of decentered parameter. Moreover, proper selection of decentered parameter results strong self-focusing of HChG beam. Stronger self-focusing of laser beam is observed due to the presence of plasma density transition which might be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, etc

  4. Enhanced relativistic self-focusing of Hermite-cosh-Gaussian laser beam in plasma under density transition

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, Vikas; Kant, Niti, E-mail: nitikant@yahoo.com [Department of Physics, Lovely Professional University, Phagwara 144411, Punjab (India)

    2014-04-15

    Enhanced and early relativistic self-focusing of Hermite-cosh-Gaussian (HChG) beam in the plasmas under density transition has been investigated theoretically using Wentzel-Kramers-Brillouin and paraxial ray approximation for mode indices m=0, 1, and 2. The variation of beam width parameter with normalized propagation distance for m=0, 1, and 2 is reported, and it is observed that strong self-focusing occurs as the HChG beam propagates deeper inside the nonlinear medium as spot size shrinks due to highly dense plasmas and the results are presented graphically. A comparative study between self-focusing of HChG beam in the presence and absence of plasmas density transition is reported. The dependency of beam width parameter on the normalized propagation distance for different values of decentered parameter “b” has also been presented graphically. For m=0 and 1, strong self-focusing is reported for b=1.8, and for m=2 and b=1.8, beam gets diffracted. The results obtained indicate the dependency of the self-focusing of the HChG beam on the selected values of decentered parameter. Moreover, proper selection of decentered parameter results strong self-focusing of HChG beam. Stronger self-focusing of laser beam is observed due to the presence of plasma density transition which might be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, etc.

  5. Implosive Thermal Plasma Source for Energy Conversion

    Czech Academy of Sciences Publication Activity Database

    Šonský, Jiří; Tesař, Václav; Gruber, Jan; Mašláni, Alan

    2017-01-01

    Roč. 4, č. 1 (2017), s. 87-90 ISSN 2336-2626 Institutional support: RVO:61388998 ; RVO:61389021 Keywords : implosion * thermal plasma * detonation wave Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (UFP-V) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (UFP-V) https://ppt.fel.cvut.cz/ppt2017.html#number1

  6. Nanoscale control of energy and matter in plasma-surface interactions: towards energy-efficient nanotech

    Science.gov (United States)

    Ostrikov, Kostya

    2010-11-01

    This presentation focuses on the plasma issues related to the solution of the grand challenge of directing energy and matter at nanoscales. This ability is critical for the renewable energy and energy-efficient technologies for sustainable future development. It will be discussed how to use environmentally and human health benign non-equilibrium plasma-solid systems and control the elementary processes of plasma-surface interactions to direct the fluxes of energy and matter at multiple temporal and spatial scales. In turn, this makes it possible to achieve the deterministic synthesis of self- organised arrays of metastable nanostructures in the size range beyond the reach of the present-day nanofabrication. Such structures have tantalising prospects to enhance performance of nanomaterials in virtually any area of human activity yet remain almost inaccessible because the Nature's energy minimisation rules allow only a small number of stable equilibrium states. By using precisely controlled and kinetically fast nanoscale transfer of energy and matter under non-equilibrium conditions and harnessing numerous plasma- specific controls of species creation, delivery to the surface, nucleation and large-scale self-organisation of nuclei and nanostructures, the arrays of metastable nanostructures can be created, arranged, stabilised, and further processed to meet the specific requirements of the envisaged applications. These approaches will eventually lead to faster, unprecedentedly- clean, human-health-friendly, and energy-efficient nanoscale synthesis and processing technologies for the next-generation renewable energy and light sources, biomedical devices, information and communication systems, as well as advanced functional materials for applications ranging from basic food, water, health and clean environment needs to national security and space missions.

  7. Self-focusing and guiding of short laser pulses in ionizing gases and plasmas

    International Nuclear Information System (INIS)

    Esarey, E.; Sprangle, P.; Krall, J.; Ting, A.

    1997-01-01

    The propagation of intense laser pulses in gases and plasmas is relevant to a wide range of applications, including laser-driven accelerators, laser-plasma channeling, harmonic generation, supercontinuum generation, X-ray lasers, and laser-fusion schemes. Here, several features of intense, short-pulse (≤1 ps) laser propagation in gases undergoing ionization and in plasmas are reviewed, discussed, and analyzed. The wave equations for laser pulse propagation in a gas undergoing ionization and in a plasma are derived. The source-dependent expansion method is discussed, which is a general method for solving the paraxial wave equation with nonlinear source terms. In gases, the propagation of high-power (near the critical power) laser pulses is considered including the effects of diffraction, nonlinear self-focusing, ionization, and plasma generation. Self-guided solutions and the stability of these solutions are discussed. In plasmas, optical guiding by relativistic effects, ponderomotive effects, and preformed density channels is considered. The self-consistent plasma response is discussed, including plasma wave effects and instabilities such as self-modulation. Recent experiments on the guiding of laser pulses in gases and in plasmas are briefly summarized

  8. Self-focusing and Raman scattering of laser pulses in tenuous plasmas

    International Nuclear Information System (INIS)

    Antonsen, T.M. Jr.; Mora, P.

    1993-01-01

    The propagation and self-focusing of short, intense laser pulses in a tenuous plasma is studied both analytically and numerically. Specifically, pulses of length of the order of a few plasma wavelengths and of intensity, which is large enough for relativistic self-focusing to occur, are considered. Such pulses are of interest in various laser plasma acceleration schemes. It is found that these pulses are likely to be strongly affected by Raman instabilities. Two different regimes of instability, corresponding to large and small scattering angles, are found to be important. Small-angle scattering is perhaps the most severe since it couples strongly with relativistic self-focusing, leading the pulses to acquire significant axial and transverse structure in a time of the order of the self-focusing time. Thus it will be difficult to propagate smooth self-focused pulses through tenuous plasmas for distances longer than the Rayleigh length, except for pulse duration of the order of the plasma period

  9. Current sheath curvature correlation with the neon soft x-ray emission from plasma focus device

    International Nuclear Information System (INIS)

    Zhang, T; Lin, X; Chandra, K A; Tan, T L; Springham, S V; Patran, A; Lee, P; Lee, S; Rawat, R S

    2005-01-01

    The insulator sleeve length is one of the major parameters that can severely affect the neon soft x-ray yield from a plasma focus. The effect of the insulation sleeve length on various characteristic timings of plasma focus discharges and hence the soft x-ray emission characteristics has been investigated using a resistive divider. The pinhole images and laser shadowgraphy are used to explain the observed variation in the average soft x-ray yield (measured using a diode x-ray spectrometer) with variation of the insulator sleeve length. We have found that for a neon filled plasma focus device the change in insulator sleeve length changes the current sheath curvature angle and thus the length of the focused plasma column. The optimized current sheath curvature angle is found to be between 39 0 and 41 0 , at the specific axial position of 6.2-9.3 cm from the cathode support plate, for our 3.3 kJ plasma focus device. A strong dependence of the neon soft x-ray yield on the current sheath curvature angle has thus been reported

  10. Neutron production with mixture of deuterium and krypton in Sahand Filippov type plasma focus facility

    International Nuclear Information System (INIS)

    Mohammadi, M.A.; Sobhanian, S.; Rawat, R.S.

    2011-01-01

    This Letter reports the order of magnitude enhancement in neutron yield from Sahand plasma focus device with krypton seeded deuterium operation. The highest average neutron yield of 2.2x10 9 neutrons per shot was achieved at 1.00 Torr deuterium with 3% krypton which is higher than the best average neutron yield of 3.18x10 8 neutrons per shot for pure deuterium operation. Estimation of average neutron energy showed that the maximum and minimum average energies are 2.98±0.6 MeV at 16 kV in 0.25 Torr deuterium with 3% Kr and 2.07±0.2 MeV at 18 kV operation in 0.5 Torr deuterium with 3% Kr, respectively. The anisotropy of neutron emission from Sahand DPF showed that the neutrons are produced mainly by beam-target mechanisms. -- Highlights: → The highest average neutron yield of 2.2x10 9 neutrons per shot was achieved at mixture of deuterium and krypton. → In the krypton seeding of deuterium also anisotropy of neutron emission deuterium is found. → The krypton seeding of deuterium made the neutron emission more reliable over wider operating pressure ranges.

  11. Development and experimental study of oil-free capacitor module for plasma focus device

    Science.gov (United States)

    Sharma, Ravindra Kumar; Sharma, Archana

    2017-03-01

    This development is concerned with the compact capacitor module for a plasma focus device. Oil-free, non-standard geometry capacitors are designed and developed for high current delivery in sub-microseconds time. Metalized dielectric film based pulse capacitor becomes progressively less viable at currents above 10 kA. It is due to reliability and energy scaling difficulties, based on effects such as vaporization, high resistivity, and end connection. Bipolar electrolytic capacitors are also not preferred due to their limited life and comparatively low peak current delivery. Bi-axially oriented polypropylene (BOPP) film with extended aluminum foil is a combination to deliver moderately high power. But, electrically weak points, relative permittivity, and the edge gap margins have made its adoption difficult. A concept has been developed in lab for implementing the above combination in a less complex and costly manner. This paper concerns the development and testing process techniques for quite different hollow cylindrical, oil-free capacitors (4 μ F , 10 kV, 20 nH). Shot life of 1000 has been experimentally performed on the test bed at its rated energy density level. The technological methods and engineering techniques are now available and utilized for manufacturing and testing of BOPP film based oil-free capacitors.

  12. Soft x-ray measurements in the FN-II dense plasma focus device for different anode configurations

    International Nuclear Information System (INIS)

    Rojo-Blanco, C; Castillo-Mejía, F; Rangel-Gutiérrez, J; Herrera-Velázquez, J J E

    2012-01-01

    A study of the soft x-ray emission is presented, for a low energy (4.8 kJ) dense plasma focus device. Three Quantrad Si PIN-diodes with differential filter combinations of Be, Al, Ti, Ni, and Mo are employed as time-resolved x-ray detectors. The x-ray flux in different energy windows is measured as function of the deuterium filling pressure. A comparison is made for three anode configurations: (a) hollow, (b) flat, and (c) 2mm diameter W needle.

  13. Axial focusing of energy from a hypervelocity impact on earth

    International Nuclear Information System (INIS)

    Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.

    1994-01-01

    We have performed computational simulations to determine how energy from a large hypervelocity impact on the Earth's surface would couple to its interior. Because of the first-order axial symmetry of both the impact energy source and the stress-wave velocity structure of the Earth, a disproportionate amount of energy is dissipated along the axis defined by the impact point and its antipode (point opposite the impact). For a symmetric and homogeneous Earth model, all the impact energy that is radiated as seismic waves into the Earth at a given takeoff angle (ray parameter), independent of azimuthal direction, is refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Material on or near the axis of symmetry experiences more strain cycles with much greater amplitude than elsewhere, and therefore experiences more irreversible heating. The focusing is most intense in the upper mantle, within the asthenosphere, where seismic energy is most effectively converted to heat. For a sufficiently energetic impact, this mechanism might generate enough local heating to create an isostatic instability leading to uplift, possibly resulting in rifting, volcanism, or other rearrangement of the interior dynamics of the planet. These simulations demonstrate how hypervelocity impact energy can be transported to the Earth's interior, supporting the possibility of a causal link between large impacts on Earth and major internally-driven geophysical processes

  14. Axial focusing of energy from a hypervelocity impact on earth

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.

    1994-12-01

    We have performed computational simulations to determine how energy from a large hypervelocity impact on the Earth`s surface would couple to its interior. Because of the first-order axial symmetry of both the impact energy source and the stress-wave velocity structure of the Earth, a disproportionate amount of energy is dissipated along the axis defined by the impact point and its antipode (point opposite the impact). For a symmetric and homogeneous Earth model, all the impact energy that is radiated as seismic waves into the Earth at a given takeoff angle (ray parameter), independent of azimuthal direction, is refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Material on or near the axis of symmetry experiences more strain cycles with much greater amplitude than elsewhere, and therefore experiences more irreversible heating. The focusing is most intense in the upper mantle, within the asthenosphere, where seismic energy is most effectively converted to heat. For a sufficiently energetic impact, this mechanism might generate enough local heating to create an isostatic instability leading to uplift, possibly resulting in rifting, volcanism, or other rearrangement of the interior dynamics of the planet. These simulations demonstrate how hypervelocity impact energy can be transported to the Earth`s interior, supporting the possibility of a causal link between large impacts on Earth and major internally-driven geophysical processes.

  15. Brussels' new energy package. Focus on the internal market proposals

    International Nuclear Information System (INIS)

    Graeper, F.W.J.H.N.

    2007-01-01

    January 10, 2007, the European Commission presented its proposals for an integrated climate change and energy package. The proposals set out in the 'Energy Policy for Europe' document follow the Green Paper on a European Strategy for Sustainable, Competitive and Secure Energy, a consultation document launched in March 2006 by the Commission. The ideas put forward in the Green Paper have been developed and translated into a proposal for an action plan with respect to the three main objectives of a European Energy Policy: security of supply, combating climate change and the completion of the internal market for electricity and gas. This ardcle will briefly discuss the main elements of the Energy Policy for Europe proposals. The article will then focus on some aspects of the proposals for the internal energy market. In doing so it will concentrate on matters related to the natural gas market. Special attention will be given to the proposals with respect to unbundling and improved regulation of network access and the possible trade-off between the degree of unbundling and the level of regulatory involvement

  16. Plasma accelerators at the energy frontier and on tabletops

    CERN Document Server

    Joshi, Chandrashekhar

    2003-01-01

    New approaches to charged-particle acceleration by collective fields in plasma were discussed. These approaches show considerable promise for realizing plasma accelerators at the energy frontier as well as table-top electron and ion accelerators. Charged particles surfing on electron density waves in plasmas can experience enormous accelerating gradients. (Edited abstract) 45 Refs.

  17. Density profile measurements from a two-gun plasma focus device

    International Nuclear Information System (INIS)

    Tzeng, C.C.; Yen, C.K.; Yeh, T.R.; Kuo, Y.Y.; Shang, D.J.; Yu, Y.Z.; Hou, W.S.

    1990-01-01

    The dynamics of the plasma evolution in a two-gun plasma focus device has been studied using the laser shadowgraphy as well as the laser interferometry. The experiments were carried out from a 700 kJ two-gun plasma focus device reported earlier, which consisted of a pair of Mather type coaxial electrodes connected muzzle to muzzle. Previous results indicated that the simultaneous formation of the two deuterium plasma foci occurred earlier and then after ∼ 100 ns a disk-shaped plasma of ∼ 1.5 cm in diameter appeared in the middle region between the anodes. It is, therefore, the authors' goal to study the density profiles in the plasma foci and the middle region in order to understand further the formation of the plasma foci and their time evolution. The laser shadowgraphy was done with a XeCl excimer pumped dye laser system which operated at 550 nm with pulse width of ∼ 10 ns. The laser interferometry, on the other hand, was carried out using a TEA-TEA oscillator-amplifier N 2 -laser system with 337.1 nm and subnano-second pulse width. Both results show that the maximum electron density is ≥2 x 10 19 cm -3 and, in addition, the growth of the hydrodynamic instabilities are observed. These results together with the detailed density profiles are presented and discussed

  18. On the course of fusion processes occurring in the plasma focus - an investigation by using time-resolved neutron spectroscopy

    International Nuclear Information System (INIS)

    Schmidt, R.

    1987-01-01

    The plasma focus POSEIDON emits up to 2x10 11 neutrons during some 100 ns, if it is operated with deuterium. This very high neutron production cannot be explained by a thermal neutron production mechanism starting out from the measured values of temperature (about 1 KeV) and deuteron density (10 18 cm -3 ). There is no doubt, that there exist strong ''beam-target''-processes of the deuterons, which cause such a high suprathermal neutron production. The neutron emission of the plasma focus POSEIDON appears in two pulses, which are associated to the two main phases of the hot and dense plasma. The first is the pinch or quiescent phase, in which a stable plasma column over 100 or 150 ns exists. The second phase is characterized by turbulence processes and starts with the end of the stable phase with the on-set of the m=0-instabilities and ends with the decay of the plasma. Both phases of neutron production are studied by time-resolved analysis of the neutron anisotropy factor and by time and spatial-resolved measurements of the neutron emission. Hence it follows, that there exist during both phases different non thermal neutron production processes, which are caused by different deuteron acceleration mechanisms. To get information on these deuteron acceleration mechanisms it is appropriate to analyse the neutron spectra of the plasma focus, because the half-width and the shape of the measured spectra are related to the energy and the angular distribution of the accelerated deuterons. (orig./GG) [de

  19. Energy confinement in JT-60 lower hybrid current driven plasmas

    International Nuclear Information System (INIS)

    Ushigusa, K.; Imai, T.; Naito, O.; Ikeda, Y.; Tsuji, S.; Uehara, K.

    1990-01-01

    The energy confinement in high power lower hybrid current driven (LHCD) plasmas has been studied in the JT-60 tokamak. At a plasma current of 1 MA, the diamagnetically estimated energy confinement time in LHCD plasmas has almost the same value as the confinement time in ohmically heated plasmas at n-bar e ∼ 1.0x10 19 m -3 . The confinement time of high power LHCD plasmas (P LH E varies as to P LH α n e β I p 0 with α + β ∼ -0.3. (author). Letter-to-the-editor. 12 refs, 5 figs

  20. Bounds imposed on the sheath velocity of a dense plasma focus by conservation laws and ionization stability condition

    International Nuclear Information System (INIS)

    Auluck, S. K. H.

    2014-01-01

    Experimental data compiled over five decades of dense plasma focus research are consistent with the snowplow model of sheath propagation, based on the hypothetical balance between magnetic pressure driving the plasma into neutral gas ahead and “wind pressure” resisting its motion. The resulting sheath velocity, or the numerically proportional “drive parameter,” is known to be approximately constant for devices optimized for neutron production over 8 decades of capacitor bank energy. This paper shows that the validity of the snowplow hypothesis, with some correction, as well as the non-dependence of sheath velocity on device parameters, have their roots in local conservation laws for mass, momentum, and energy coupled with the ionization stability condition. Both upper and lower bounds on sheath velocity are shown to be related to material constants of the working gas and independent of the device geometry and capacitor bank impedance

  1. Bounds imposed on the sheath velocity of a dense plasma focus by conservation laws and ionization stability condition

    Energy Technology Data Exchange (ETDEWEB)

    Auluck, S. K. H., E-mail: skhauluck@gmail.com, E-mail: skauluck@barc.gov.in [Physics Group, Bhabha Atomic Research Center, Mumbai (India)

    2014-09-15

    Experimental data compiled over five decades of dense plasma focus research are consistent with the snowplow model of sheath propagation, based on the hypothetical balance between magnetic pressure driving the plasma into neutral gas ahead and “wind pressure” resisting its motion. The resulting sheath velocity, or the numerically proportional “drive parameter,” is known to be approximately constant for devices optimized for neutron production over 8 decades of capacitor bank energy. This paper shows that the validity of the snowplow hypothesis, with some correction, as well as the non-dependence of sheath velocity on device parameters, have their roots in local conservation laws for mass, momentum, and energy coupled with the ionization stability condition. Both upper and lower bounds on sheath velocity are shown to be related to material constants of the working gas and independent of the device geometry and capacitor bank impedance.

  2. Cross focusing of mixed mode operation in an extra dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Soni, V S; Nayyar, V P [Punjabi Univ., Patiala (India). Dept. of Physics

    1979-08-01

    This paper presents a study of the nonlinear propagation of a mixture of two degenerate modes (TEM/sub 00/ and TEM/sub 10/) of a high power laser beam in an extradense plasma. The high irradiance inhomogeneous laser beam creates an electron density gradient region in the overdense plasma (n > nsub(c)) through which the beam can propagate. The focusing effects have been studied for different power ratios of the two modes (TEM/sub 00/ mode is considered to be stronger than the TEM/sub 10/ mode). Self-focusing of the beam in x and y directions for critical power has been extensively studied.

  3. Dense Plasma Focus: A question in search of answers, a technology in search of applications

    International Nuclear Information System (INIS)

    Auluck, S.K.H.

    2014-01-01

    Diagnostic information accumulated over four decades of research suggests a directionality of toroidal motion for energetic ions responsible for fusion neutron production in the Dense Plasma Focus (DPF) and existence of an axial component of magnetic field even under conditions of azimuthal symmetry. This is at variance with the traditional view of Dense Plasma Focus as a purely irrotational compressive flow. The difficulty in understanding the experimental situation from a theoretical standpoint arises from polarity of the observed solenoidal state: three independent experiments confirm existence of a fixed polarity of the axial magnetic field or related azimuthal current. Since the equations governing plasma dynamics do not have a built-in direction, the fixed polarity must be related with initial conditions: the plasma dynamics must interact with an external physical vector in order to generate a solenoidal state of fixed polarity. Only four such external physical vectors can be identified: the earth's magnetic field, earth's angular momentum, direction of current flow and the direction of the plasma accelerator. How interaction of plasma dynamics with these fields can generate observed solenoidal state is a question still in search of answers; this paper outlines one possible answer. The importance of this question goes beyond scientific curiosity into technological uses of the energetic ions and the high-power-density plasma environment. However, commercial utilization of such technologies faces reliability concerns, which can be met only by first-principles integrated design of globally-optimized industrial-quality DPF hardware. Issues involved in the emergence of the Dense Plasma Focus as a technology platform for commercial applications in the not-too-distant future are discussed. (author)

  4. Energy Balance in DC Arc Plasma Melting Furnace

    International Nuclear Information System (INIS)

    Zhao Peng; Meng Yuedong; Yu Xinyao; Chen Longwei; Jiang Yiman; Nie Guohua; Chen Mingzhou

    2009-01-01

    In order to treat hazardous municipal solid waste incinerator's (MSWI) fly ash, a new DC arc plasma furnace was developed. Taking an arc of 100 V/1000 A DC as an example, the heat transfer characteristics of the DC arc plasma, ablation of electrodes, heat properties of the fly ash during melting, heat transfer characteristics of the flue gas, and heat loss of the furnace were analyzed based on the energy conservation law, so as to achieve the total heat information and energy balance during plasma processing, and to provide a theoretical basis for an optimized design of the structure and to improve energy efficiency. (plasma technology)

  5. Fine structure of modal focusing effect in a three dimensional plasma-sheath-lens formed by disk electrodes

    DEFF Research Database (Denmark)

    Stamate, Eugen; Yamaguchi, Masahito

    2015-01-01

    Modal and discrete focusing effects associated with three-dimensional plasma-sheath-lenses show promising potential for applications in ion beam extraction, mass spectrometry, plasma diagnostics and for basic studies of plasma sheath. The ion focusing properties can be adjusted by controlling the...

  6. A Comparative Review of a Dozen National Energy Plans. Focus on Renewable and Efficient Energy

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Jeffrey [National Renewable Energy Lab. (NREL), Golden, CO (United States); James, Ted L. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2009-03-01

    Dozens of groups have submitted energy, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, focusing especially on energy efficiency (EE) and renewable energy (RE) market and policy issues.

  7. Comparative Review of a Dozen National Energy Plans: Focus on Renewable and Efficient Energy

    Energy Technology Data Exchange (ETDEWEB)

    Logan, J.; James, T. L.

    2009-03-01

    Dozens of groups have submitted energy, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, focusing especially on energy efficiency (EE) and renewable energy (RE) market and policy issues.

  8. Research on high energy density plasmas and applications

    International Nuclear Information System (INIS)

    1999-01-01

    Recently, technologies on lasers, accelerators, and pulse power machines have been significantly advanced and input power density covers the intensity range from 10 10 W/cm 2 to higher than 10 20 W/cm 2 . As the results, high pressure gas and solid targets can be heated up to very high temperature to create hot dense plasmas which have never appeared on the earth. The high energy density plasmas opened up new research fields such as inertial confinement fusion, high brightness X-ray radiation sources, interiors of galactic nucleus,supernova, stars and planets, ultra high pressure condensed matter physics, plasma particle accelerator, X-ray laser, and so on. Furthermore, since these fields are intimately connected with various industrial sciences and technologies, the high energy density plasma is now studied in industries, government institutions, and so on. This special issue of the Journal of Plasma Physics and Nuclear Fusion Research reviews the high energy density plasma science for the comprehensive understanding of such new fields. In May, 1998, the review committee for investigating the present status and the future prospects of high energy density plasma science was established in the Japan Society of Plasma Science and Nuclear Fusion Research. We held three committee meetings to discuss present status and critical issues of research items related to high energy density plasmas. This special issue summarizes the understandings of the committee. This special issue consists of four chapters: They are Chapter 1: Physics important in the high energy density plasmas, Chapter 2: Technologies related to the plasma generation; drivers such as lasers, pulse power machines, particle beams and fabrication of various targets, Chapter 3: Plasma diagnostics important in high energy density plasma experiments, Chapter 4: A variety of applications of high energy density plasmas; X-ray radiation, particle acceleration, inertial confinement fusion, laboratory astrophysics

  9. An energy principle for two-dimensional collisionless relativistic plasmas

    International Nuclear Information System (INIS)

    Otto, A.; Schindler, K.

    1984-01-01

    Using relativistic Vlasov theory an energy principle for two-dimensional plasmas is derived, which provides a sufficient and necessary criterion for the stability of relativistic plasma equilibria. This energy principle includes charge separating effects since the exact Poisson equation was taken into consideration. Applying the variational principle to the case of the relativistic plane plasma sheet, the same marginal wave length is found as in the non-relativistic case. (author)

  10. Evaluations of the electron energy distribution in multidipole plasmas

    International Nuclear Information System (INIS)

    Taylor, G.R.; Kessel, M.A.; Sealock, J.W.

    1980-01-01

    In a previous paper a preliminary evaluation of the electron energy distribution in multidipole plasmas was presented. A polynominal regression technique for evaluating the distribution function from Langmuir probe current-voltage characteristics was described. This paper presents an extension of that analysis and the evaluations of the electron energy distributions in multidipole argon and hydrogen plasmas

  11. Nustar: Bringing the High-Energy Universe into Focus

    Science.gov (United States)

    Fineberg, Larry

    2016-01-01

    This is a presentation to students at the University of Florida in the Small Satellite Design Club. The subject matter is the NuSTAR mission and covers topics about the spacecraft itself and the launch campaign. NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing high-energy X-ray mission. Studies the hottest, densest, most energetic phenomena in the Universe. Purpose is to search for black holes, map the remnants of stellar explosions, and study the most extreme active galaxies.

  12. Electrostatic storage ring with focusing provided by the space charge of an electron plasma

    International Nuclear Information System (INIS)

    Pacheco, J. L.; Ordonez, C. A.; Weathers, D. L.

    2013-01-01

    Electrostatic storage rings are used for a variety of atomic physics studies. An advantage of electrostatic storage rings is that heavy ions can be confined. An electrostatic storage ring that employs the space charge of an electron plasma for focusing is described. An additional advantage of the present concept is that slow ions, or even a stationary ion plasma, can be confined. The concept employs an artificially structured boundary, which is defined at present as one that produces a spatially periodic static field such that the spatial period and range of the field are much smaller than the dimensions of a plasma or charged-particle beam that is confined by the field. An artificially structured boundary is used to confine a non-neutral electron plasma along the storage ring. The electron plasma would be effectively unmagnetized, except near an outer boundary where the confining electromagnetic field would reside. The electron plasma produces a radially inward electric field, which focuses the ion beam. Self-consistently computed radial beam profiles are reported.

  13. The use of convalescent plasma to treat emerging infectious diseases: focus on Ebola virus disease.

    Science.gov (United States)

    Winkler, Anne M; Koepsell, Scott A

    2015-11-01

    The purpose of this review is to discuss the use of convalescent plasma for the treatment of emerging infectious diseases, focusing on the recent use for the treatment of Ebola virus disease (EVD). Ebola convalescent plasma has been used as a therapy for treatment of EVD during the 2014 West Africa epidemic. Several cases from the United States and Europe have been recently published, in addition to multiple ongoing clinical trials in the United States and West Africa. Even more recently, convalescent plasma has been used for treatment of individuals with Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Although the first reports of successful treatment with passive immune therapy date back to the early 1900s, convalescent plasma has materialized as a possible therapy for patients who develop infection from one of the emerging infectious diseases such as EVD or MERS-CoV, although the efficacy of such therapy has yet to be proven in clinical trials.

  14. Time resolved x-ray photography of a dense plasma focus

    International Nuclear Information System (INIS)

    Burnett, J.C.; Meyer, J.; Rankin, G.

    1977-01-01

    The temporal development of the hot plasma in a dense plasma focus is studied by x-ray streak photography of approximately 2 ns resolution time. It is shown that initially a uniform x-ray emitting pinch plasma is formed which subsequently cools down until x-ray emission stops after approximately 50 ns. At a time of around 100 ns after initial x-ray emission coinciding with the break-up time of the pinch a second burst of x-rays is observed coming from small localized regions. The observations are compared with results obtained from time-resolved shadow and schlieren photography of a similar dense focus discharge. (author)

  15. On the Self-Focusing of Whistler Waves in a Radial Inhomogeneous Plasma

    DEFF Research Database (Denmark)

    Balmashnov, A. A.

    1980-01-01

    The process of whistler wave self-focusing is experimentally investigated. It was found that a whistler wave propagating along the plasma column with a density crest excites a longitudinal wave of the same frequency propagating across the external magnetic field. The amplitude modulation of the l......The process of whistler wave self-focusing is experimentally investigated. It was found that a whistler wave propagating along the plasma column with a density crest excites a longitudinal wave of the same frequency propagating across the external magnetic field. The amplitude modulation...... of the latter wave is accompanied by a density modification, which leads to trapping of the whistler wave in a density trough in the center of the plasma column....

  16. Properties of hotspots in plasma focus discharges operating in hydrogen-argon mixtures

    International Nuclear Information System (INIS)

    Silva, P; Favre, M

    2002-01-01

    We have investigated the properties of hotspots formed in low energy plasma focus (PF) discharges operating in hydrogen-argon mixtures, at 140 kA current level. A combination of filtered pinhole and slit-wire camera is used to measure the hotspot size and temperature. The results show that the best conditions for reproducible and localized hotspot formation are obtained by adjusting the base pressure in such a way that the mass load allows the time of first radial collapse to coincide with peak current. When the PF is operated with 20% argon content, rather uniform hotspots, of 115 μm characteristic size and 300 eV characteristic temperature, are produced with a better than 80% reproducibility in their axial localization. The electron density in the hotspots is estimated to be ∼10 20 cm -3 . Calculations performed with a CRE code indicate that a significant fraction of the radiation is emitted in the 3.2 to 3.88 keV region, corresponding to K α emission from highly ionized argon

  17. The thermal evolution of targets under plasma focus pulsed ion implantation

    International Nuclear Information System (INIS)

    Sanchez, G.; Feugeas, J.

    1997-01-01

    Pulsed ion beam implantation with plasma focus has proved to be an effective method of metal surface treatment for tribological purposes. Nevertheless, the pulsed nature and the continuous energy spectrum of the ion beams differ from those of the standard ion implantation processes. In this paper a model of the thermal evolution of the surface layers of stainless steel, titanium and copper, during and after nitrogen and argon ion beam incidence, is presented using the finite-difference method. In the calculations, the geometry and physical characteristics of the ion beams, the single-ion-solid interaction process and the thermal properties of the materials were used. The results showed a strong thermal effect consisting in the generation of transitory heating slopes and heating speeds as high as ∼3600 K μm -1 and ∼40 K ns -1 respectively, with maximum temperatures that can reach even the material evaporation point at the surface layers. The cooling down process, through the thermal conduction mechanism at the target bulk, turns out to be fast enough to produce the complete thermal relaxation of the target in only a few microseconds after the end of the ion beam incidence. The results presented are contrasted with experiments performed in similar conditions to those used in the numerical model. (Author)

  18. Response of inorganic materials to laser - plasma EUV radiation focused with a lobster eye collector

    Science.gov (United States)

    Bartnik, Andrzej; Fiedorowicz, Henryk; Jarocki, Roman; Kostecki, Jerzy; Szczurek, Miroslaw; Havlikova, Radka; Pína, Ladislav; Švéda, Libor; Inneman, Adolf

    2007-05-01

    A single photon of EUV radiation carries enough energy to break any chemical bond or excite electrons from inner atomic shells. It means that the radiation regardless of its intensity can modify chemical structure of molecules. It is the reason that the radiation even with low intensity can cause fragmentation of long chains of organic materials and desorption of small parts from their surface. In this work interaction of EUV radiation with inorganic materials was investigated. Different inorganic samples were irradiated with a 10 Hz laser - plasma EUV source based on a gas puff target. The radiation was focused on a sample surface using a lobster eye collector. Radiation fluence at the surface reached 30 mJ/cm2 within a wavelength range 7 - 20 nm. In most cases there was no surface damage even after several minutes of irradiation. In some cases there could be noticed discolouration of an irradiated surface or evidences of thermal effects. In most cases however luminescent and scattered radiation was observed. The luminescent radiation was emitted in different wavelength ranges. It was recorded in a visible range of radiation and also in a wide wavelength range including UV, VUV and EUV. The radiation was especially intense in a case of non-metallic chemical compounds.

  19. Hard X-ray dosimetry of a plasma focus suitable for industrial radiography

    Science.gov (United States)

    Knoblauch, P.; Raspa, V.; Di Lorenzo, F.; Clausse, A.; Moreno, C.

    2018-04-01

    Dosimetric measurements of the hard X-ray emission by a small-chamber 4.7 kJ Mather-type plasma focus device capable of producing neat radiographs of metallic objects, were carried out with a set of thermoluminescent detectors TLD 700 (LiF:Mg,Ti). Measurements of the hard X-ray dose dependence with the angular position relative to the electrodes axis, are presented. The source-detector distance was changed in the range from 50 to 100 cm, and the angular positions were explored between ± 70°, relative to the symmetry axis of the electrodes. On-axis measurements show that the X-ray intensity is uniform within a half aperture angle of 6°, in which the source delivers an average dose of (1.5 ± 0.1) mGy/sr per shot. Monte Carlo calculations suggest that the energy of the electron beam responsible for the X-ray emission ranges 100-600 keV.

  20. Noise Suppression and Enhanced Focusability in Plasma Raman Amplifier with Multi-frequency Pump

    International Nuclear Information System (INIS)

    Balakin, A.A.; Fraiman, G.M.; Fisch, N.J.; Malkin, V.M.

    2003-01-01

    Laser pulse compression/amplification through Raman backscattering in plasmas can be facilitated by using multi-frequency pump laser beams. The efficiency of amplification is increased by suppressing the Raman instability of thermal fluctuations and seed precursors. Also the focusability of the amplified radiation is enhanced due to the suppression of large-scale longitudinal speckles in the pump wave structure

  1. Analysis of the results obtained by optical measurements in plasma focus equipments

    International Nuclear Information System (INIS)

    Bilbao, L.; Bruzzone, H.

    1982-01-01

    The results obtained by shadow and Schlieren photographies and interferometry in a 1MJ plasma focus device of Frascati (CNEN-EURATOM, Italy) are compared with a great number of similar measurement results in several devices of the world. A critical analysis of the above results is presented. (L.C.) [pt

  2. Surface ionization wave in a plasma focus-like model device

    International Nuclear Information System (INIS)

    Yordanov, V; Blagoev, A; Ivanova-Stanik, I; Veldhuizen, E M van; Nijdam, S; Dijk, J van; Mullen, J J A M van der

    2008-01-01

    A numerical particle in cell-Monte Carlo model of the breakdown in the plasma focus device simulates the development of an ionization wave sliding along the insulator. In order to validate this model a planar model device is created. The pictures of the discharges taken by a fast optical camera show that we have qualitative agreement between the model and the experimental observations.

  3. Surface ionization wave in a plasma focus-like model device

    Energy Technology Data Exchange (ETDEWEB)

    Yordanov, V; Blagoev, A [Faculty of Physics, University of Sofia, 5 James Bourchier Blvd, BG-1164, Sofia (Bulgaria); Ivanova-Stanik, I [IPPLM, 23 Hery St, PO Box 49, PL-00-908 Warsaw (Poland); Veldhuizen, E M van; Nijdam, S; Dijk, J van; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)], E-mail: v.yordanov@phys.uni-sofia.bg

    2008-11-07

    A numerical particle in cell-Monte Carlo model of the breakdown in the plasma focus device simulates the development of an ionization wave sliding along the insulator. In order to validate this model a planar model device is created. The pictures of the discharges taken by a fast optical camera show that we have qualitative agreement between the model and the experimental observations.

  4. Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients

    International Nuclear Information System (INIS)

    Gray, R J; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Quinn, M N; Tresca, O; McKenna, P; Burza, M; Wahlström, C-G; Lancaster, K L; Neely, D; Lin, X X; Li, Y T

    2014-01-01

    Laser energy absorption to fast electrons during the interaction of an ultra-intense (10 20 W cm −2 ), picosecond laser pulse with a solid is investigated, experimentally and numerically, as a function of the plasma density scale length at the irradiated surface. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient. (paper)

  5. Abnormal energy deposition on the wall through plasma disruptions

    International Nuclear Information System (INIS)

    Yamazaki, K.; Schmidt, G.L.

    1984-01-01

    The dissipation of plasma kinetic and magnetic energy during sawtooth oscillations and disruptions in tokamak is analyzed using Kadomtsev's disruption model and the plasma-circuit equations. New simple scalings of several characteristic times are obtained for sawteeth and for thermal and magnetic energy quenches of disruptions. The abnormal energy deposition on the wall during major or minor disruptions, estimated from this analysis, is compared with bolometric measurements in the PDX tokamak. Especially, magnetic energy dissipation during the current termination period is shown to be reduced by the strong coupling of the plasma current with external circuits. These analyses are found to be useful to predict the phenomenological behavior of plasma disruptions in large future tokamaks, and to estimate abnormal heat deposition on the wall during plasma disruptions. (orig.)

  6. Abnormal energy deposition on the wall through plasma disruptions

    International Nuclear Information System (INIS)

    Yamazaki, K.; Schmidt, G.L.

    1984-07-01

    The dissipation of plasma kinetic and magnetic energy during sawtooth oscillstions and disruptions in tokamaks is analyzed using Kadomtsev's disruption model and the plasma-circuit equations. New simple scalings of several characteristic times are obtained for sawteeth and for thermal and magnetic energy quenches of disruptions. The abnormal energy deposition on the wall during major or minor disruptions, estimated from this analysis, is compared with bolometric measurements in the PDX tokamak. Especially, magnetic energy dissipation during current termination period is shown to be reduced by the strong coupling of the plasma current with external circuits. These analyses are found to be useful to predict the phenomenological behavior of plasma disruptions in large future tokamaks, and to estimate abnormal heat deposition on the wall during plasma disruptions. (author)

  7. Synthesis of nano-crystalline zirconium aluminium oxynitride (ZrAlON) composite films by dense plasma Focus device

    Energy Technology Data Exchange (ETDEWEB)

    Khan, I.A.; Hassan, M.; Hussain, T. [Department of Physics, GC University, 54000 Lahore (Pakistan); Ahmad, R., E-mail: ahriaz@gmail.com [Department of Physics, GC University, 54000 Lahore (Pakistan); Zakaullah, M. [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Rawat, R.S. [National Institute of Education, Nanyang Technological University, Singapore 637616 (Singapore)

    2009-04-01

    Zirconium aluminium oxynitride multiphase composite film is deposited on zirconium substrate using energetic nitrogen ions delivered from dense plasma Focus device. X-ray diffractometer (XRD) results show that five Focus shots are sufficient to initiate the nucleation of ZrN and Al{sub 2}O{sub 3} whereas 10 Focus shots are sufficient to initiate the nucleation of AlN. XRD results reveal that crystal growth of nitrides/oxides increases by increasing Focus shots (up to 30 Focus shots) and resputtering of the previously deposited film is taken place by further increase in Focus shots (40 Focus shots). Scanning electron microscopic (SEM) results indicate the uniform distribution of spherical grains ({approx}35 nm). A smoother surface is observed for 20 Focus shots at 0 deg. angular position. SEM results also show a net-type microstructure (thread like features) of the sample treated for 30 Focus shots whereas rough surface morphology is observed for 40 Focus shots. Energy dispersive spectroscopic profiles show the distribution of different elements present in the deposited composite films. A typical microhardness value of the deposited composite films is 5255 {+-} 10 MPa for 10 grams imposed load which is 3.3 times than the microhardness values of unexposed sample. The microhardness values of the exposed samples increases with increasing Focus shots (up to 30 Focus shots) and decreases for 40 Focus shots treatment due to resputtering of the previously deposited composite film. The microhardness values of the composite films decreases by increasing the sample's angular position.

  8. Effect of spin-polarized D-3He fuel on dense plasma focus for space propulsion

    Science.gov (United States)

    Mei-Yu Wang, Choi, Chan K.; Mead, Franklin B.

    1992-01-01

    Spin-polarized D-3He fusion fuel is analyzed to study its effect on the dense plasma focus (DPF) device for space propulsion. The Mather-type plasma focus device is adopted because of the ``axial'' acceleration of the current carrying plasma sheath, like a coaxial plasma gun. The D-3He fuel is chosen based on the neutron-lean fusion reactions with high charged-particle fusion products. Impulsive mode of operation is used with multi-thrusters in order to make higher thrust (F)-to-weight (W) ratio with relatively high value of specific impulse (Isp). Both current (I) scalings with I2 and I8/3 are considered for plasma pinch temperature and capacitor mass. For a 30-day Mars mission, with four thrusters, for example, the typical F/W values ranging from 0.5-0.6 to 0.1-0.2 for I2 and I8/3 scalings, respectively, and the Isp values of above 1600 s are obtained. Parametric studies indicate that the spin-polarized D-3He provides increased values of F/W and Isp over conventional D-3He fuel which was due to the increased fusion power and decreased radiation losses for the spin-polarized case.

  9. Self-focusing of nonlinear waves in a relativistic plasma with positive and negative ions

    International Nuclear Information System (INIS)

    Mukherjee, Joydeep; Chowdhury, A.R.

    1994-01-01

    The phenomenon of self-focusing of nonlinear waves was analysed in a relativistic plasma consisting of both positive and negative ions, which are assumed to be hot. The effect of the inertia of the relativistic electron is also considered by treating it dynamically. A modified form of reductive perturbation is used to deduce a nonlinear Schroedinger equation describing the purely spatial variation of the nonlinear wave. Self-focusing of the wave can be ascertained by analysing the transversal stability of the solitary wave. It is shown that the zones of stability of the wave may become wider due to the mutual influence of various factors present in the plasma, thus favouring the process of self-focusing. 10 refs., 2 figs

  10. Development of high energy pulsed plasma simulator for plasma-lithium trench experiment

    Science.gov (United States)

    Jung, Soonwook

    To simulate detrimental events in a tokamak and provide a test-stand for a liquid lithium infused trench (LiMIT) device, a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. An overall objective of the project is to develop a compact device that can produce 100 MW/m2 to 1 GW/m2 of plasma heat flux (a typical heat flux level in a major fusion device) in ~ 100 mus (≤ 0.1 MJ/m2) for a liquid lithium plasma facing component research. The existing theta pinch device, DEVeX, was built and operated for study on lithium vapor shielding effect. However, a typical plasma energy of 3 - 4 kJ/m2 is too low to study an interaction of plasma and plasma facing components in fusion devices. No or little preionized plasma, ringing of magnetic field, collisions of high energy particles with background gas have been reported as the main issues. Therefore, DEVeX is reconfigured to mitigate these issues. The new device is mainly composed of a plasma gun for a preionization source, a theta pinch for heating, and guiding magnets for a better plasma transportation. Each component will be driven by capacitor banks and controlled by high voltage / current switches. Several diagnostics including triple Langmuir probe, calorimeter, optical emission measurement, Rogowski coil, flux loop, and fast ionization gauge are used to characterize the new device. A coaxial plasma gun is manufactured and installed in the previous theta pinch chamber. The plasma gun is equipped with 500 uF capacitor and a gas puff valve. The increase of the plasma velocity with the plasma gun capacitor voltage is consistent with the theoretical predictions and the velocity is located between the snowplow model and the weak - coupling limit. Plasma energies measured with the calorimeter ranges from 0.02 - 0.065 MJ/m2 and increases with the voltage at the capacitor bank. A cross-check between the plasma energy measured with the calorimeter and the triple probe

  11. Effect of an Energy Reservoir on the Atmospheric Propagation of Laser-Plasma Filaments

    Science.gov (United States)

    Eisenmann, Shmuel; Peñano, Joseph; Sprangle, Phillip; Zigler, Arie

    2008-04-01

    The ability to select and stabilize a single filament during propagation of an ultrashort, high-intensity laser pulse in air makes it possible to examine the longitudinal structure of the plasma channel left in its wake. We present the first detailed measurements and numerical 3-D simulations of the longitudinal plasma density variation in a laser-plasma filament after it passes through an iris that blocks the surrounding energy reservoir. Since no compensation is available from the surrounding background energy, filament propagation is terminated after a few centimeters. For this experiment, simulations indicate that filament propagation is terminated by plasma defocusing and ionization loss, which reduces the pulse power below the effective self-focusing power. With no blockage, a plasma filament length of over a few meters was observed.

  12. Effect of an Energy Reservoir on the Atmospheric Propagation of Laser-Plasma Filaments

    International Nuclear Information System (INIS)

    Eisenmann, Shmuel; Penano, Joseph; Sprangle, Phillip; Zigler, Arie

    2008-01-01

    The ability to select and stabilize a single filament during propagation of an ultrashort, high-intensity laser pulse in air makes it possible to examine the longitudinal structure of the plasma channel left in its wake. We present the first detailed measurements and numerical 3-D simulations of the longitudinal plasma density variation in a laser-plasma filament after it passes through an iris that blocks the surrounding energy reservoir. Since no compensation is available from the surrounding background energy, filament propagation is terminated after a few centimeters. For this experiment, simulations indicate that filament propagation is terminated by plasma defocusing and ionization loss, which reduces the pulse power below the effective self-focusing power. With no blockage, a plasma filament length of over a few meters was observed

  13. Relativistic self-focusing of intense laser beam in thermal collisionless quantum plasma with ramped density profile

    Directory of Open Access Journals (Sweden)

    S. Zare

    2015-04-01

    Full Text Available Propagation of a Gaussian x-ray laser beam has been analyzed in collisionless thermal quantum plasma with considering a ramped density profile. In this density profile due to the increase in the plasma density, an earlier and stronger self-focusing effect is noticed where the beam width oscillates with higher frequency and less amplitude. Moreover, the effect of the density profile slope and the initial plasma density on the laser propagation has been studied. It is found that, by increasing the initial density and the ramp slope, the laser beam focuses faster with less oscillation amplitude, smaller laser spot size and more oscillations. Furthermore, a comparison is made among the laser self-focusing in thermal quantum plasma, cold quantum plasma and classical plasma. It is realized that the laser self-focusing in the quantum plasma becomes stronger in comparison with the classical regime.

  14. Mixed Waste Focus Area: Department of Energy complex needs report

    International Nuclear Information System (INIS)

    Roach, J.A.

    1995-01-01

    The Assistant Secretary for the Office of Environmental Management (EM) at the US Department of Energy (DOE) initiated a new approach in August of 1993 to environmental research and technology development. A key feature of this new approach included establishment of the Mixed Waste Characterization, Treatment, and Disposal Focus Area (MWFA). The mission of the MWFA is to identify, develop, and implement needed technologies such that the major environmental management problems related to meeting DOE's commitments for treatment of mixed wastes under the Federal Facility Compliance Act (FFCA), and in accordance with the Land Disposal Restrictions (LDR) of the Resource Conservation and Recovery Act (RCRA), can be addressed, while cost-effectively expending the funding resources. To define the deficiencies or needs of the EM customers, the MWFA analyzed Proposed Site Treatment Plans (PSTPs), as well as other applicable documents, and conducted site visits throughout the summer of 1995. Representatives from the Office of Waste Management (EM-30), the Office of Environmental Restoration (EM-40), and the Office of Facility Transition and Management (EM-60) at each site visited were requested to consult with the Focus Area to collaboratively define their technology needs. This report documents the needs, deficiencies, technology gaps, and opportunities for expedited treatment activities that were identified during the site visit process. The defined deficiencies and needs are categorized by waste type, namely Wastewaters, Combustible Organics, Sludges/Soils, Debris/Solids, and Unique Wastes, and will be prioritized based on the relative affect the deficiency has on the DOE Complex

  15. Local thermodynamic equilibrium in rapidly heated high energy density plasmas

    International Nuclear Information System (INIS)

    Aslanyan, V.; Tallents, G. J.

    2014-01-01

    Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance

  16. Global parameter optimization of a Mather-type plasma focus in the framework of the Gratton–Vargas two-dimensional snowplow model

    International Nuclear Information System (INIS)

    Auluck, S K H

    2014-01-01

    Dense plasma focus (DPF) is known to produce highly energetic ions, electrons and plasma environment which can be used for breeding short-lived isotopes, plasma nanotechnology and other material processing applications. Commercial utilization of DPF in such areas would need a design tool that can be deployed in an automatic search for the best possible device configuration for a given application. The recently revisited (Auluck 2013 Phys. Plasmas 20 112501) Gratton–Vargas (GV) two-dimensional analytical snowplow model of plasma focus provides a numerical formula for dynamic inductance of a Mather-type plasma focus fitted to thousands of automated computations, which enables the construction of such a design tool. This inductance formula is utilized in the present work to explore global optimization, based on first-principles optimality criteria, in a four-dimensional parameter-subspace of the zero-resistance GV model. The optimization process is shown to reproduce the empirically observed constancy of the drive parameter over eight decades in capacitor bank energy. The optimized geometry of plasma focus normalized to the anode radius is shown to be independent of voltage, while the optimized anode radius is shown to be related to capacitor bank inductance. (paper)

  17. World energy outlook in 2020 focusing on China's energy impacts on the world and Northeast Asia

    International Nuclear Information System (INIS)

    Komiyama, R.; Ito, K.; Li Zhidong

    2005-01-01

    This paper presents a consistent international energy projection developed by an integrated econometric model for the purpose of analysing China's energy impacts on the energy markets in the world and Northeast Asia to 2020. Vigorous economic growth, soaring electricity demand and progressive motorisation are going to expand the primary energy demand in China, which accounts for a large part of the world primary energy increase, eventually positioning China as an important player in the world energy market and in terms of CO 2 emissions. Focusing on Northeast Asia, considerable oil demand growth in China, which has only a limited oil production, would increase the regional reliance on Middle Eastern oil thereby underlining a serious energy security problem of oil importing countries in this region. It is becoming increasingly important for the energy issue to be addressed as one where all Northeast Asian countries have a common stake and can commit themselves. (author)

  18. Optimization of sources for focusing wave energy in targeted formations

    KAUST Repository

    Jeong, C

    2010-06-08

    We discuss a numerical approach for identifying the surface excitation that is necessary to maximize the response of a targeted subsurface formation. The motivation stems from observations in the aftermath of earthquakes, and from limited field experiments, whereby increased oil production rates were recorded and were solely attributable to the induced reservoir shaking. The observations suggest that focusing wave energy to the reservoir could serve as an effective low-cost enhanced oil recovery method. In this paper, we report on a general method that allows the determination of the source excitation, when provided with a desired maximization outcome at the targeted formation. We discuss, for example, how to construct the excitation that will maximize the kinetic energy in the target zone, while keeping silent the neighbouring zones. To this end, we cast the problem as an inverse-source problem, and use a partial-differential- equation-constrained optimization approach to arrive at an optimized source signal. We seek to satisfy stationarity of an augmented functional, which formally leads to a triplet of state, adjoint and control problems. We use finite elements to resolve the state and adjoint problems, and an iterative scheme to satisfy the control problem to converge to the sought source signal. We report on one-dimensional numerical experiments in the time domain involving a layered medium of semi-infinite extent. The numerical results show that the targeted formation\\'s kinetic energy resulting from an optimized wave source could be several times greater than the one resulting from a blind source choice, and could overcome the mobility threshold of entrapped reservoir oil. © 2010 Nanjing Geophysical Research Institute.

  19. Optimization of sources for focusing wave energy in targeted formations

    International Nuclear Information System (INIS)

    Jeong, C; Kallivokas, L F; Huh, C; Lake, L W

    2010-01-01

    We discuss a numerical approach for identifying the surface excitation that is necessary to maximize the response of a targeted subsurface formation. The motivation stems from observations in the aftermath of earthquakes, and from limited field experiments, whereby increased oil production rates were recorded and were solely attributable to the induced reservoir shaking. The observations suggest that focusing wave energy to the reservoir could serve as an effective low-cost enhanced oil recovery method. In this paper, we report on a general method that allows the determination of the source excitation, when provided with a desired maximization outcome at the targeted formation. We discuss, for example, how to construct the excitation that will maximize the kinetic energy in the target zone, while keeping silent the neighbouring zones. To this end, we cast the problem as an inverse-source problem, and use a partial-differential-equation-constrained optimization approach to arrive at an optimized source signal. We seek to satisfy stationarity of an augmented functional, which formally leads to a triplet of state, adjoint and control problems. We use finite elements to resolve the state and adjoint problems, and an iterative scheme to satisfy the control problem to converge to the sought source signal. We report on one-dimensional numerical experiments in the time domain involving a layered medium of semi-infinite extent. The numerical results show that the targeted formation's kinetic energy resulting from an optimized wave source could be several times greater than the one resulting from a blind source choice, and could overcome the mobility threshold of entrapped reservoir oil

  20. Plasma response to electron energy filter in large volume plasma device

    International Nuclear Information System (INIS)

    Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K.

    2013-01-01

    An electron energy filter (EEF) is embedded in the Large Volume Plasma Device plasma for carrying out studies on excitation of plasma turbulence by a gradient in electron temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the plasma to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in plasma regions with different characteristics, including a plasma region free from energetic electrons, suitable for the study of ETG turbulence. Specifically, we report that localized structures of plasma density, potential, electron temperature, and plasma turbulence are excited in the EEF plasma. It is shown that structures of electron temperature and potential are created due to energy dependence of the electron transport in the filter region. On the other hand, although structure of plasma density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF plasma

  1. Computational Simulation of High Energy Density Plasmas

    Science.gov (United States)

    2009-10-30

    the imploding liner. The PFS depends on a lithium barrier foil slowing the advance of deuterium up the coaxial gun to the corner. There the plasma ...the coaxial gun section, and Figure 4 shows the physical state of the plasma just prior to pinch. Figure 5 shows neutron yield reaching 1014 in this...details the channel geometry between the center cylinder and coaxial gas gun . The deuterium injection starts when the pressure of the deuterium gas in

  2. Plasma physics: innovation in energy and industrial technology

    International Nuclear Information System (INIS)

    Harris, J.H.

    2000-01-01

    Full text: Plasmas-ionised gases-are truly ubiquitous. More than 99% of the matter in the universe is in the plasma state. All of the matter that comprises the Earth, and all of the energy that powers it, has been processed through plasma fusion reactions in stars. Plasmas also play a crucial role in the Earth's atmosphere, which screens out harmful radiation, and make long distance radio propagation possible. While the study of plasma physics was originally motivated by astrophysics, the discipline has grown to address terrestrial concerns. These include lighting, welding, the switching of large electrical currents, the processing of materials such as semiconductors, and the quest to build fusion power reactors artificial stars for low-emissions generation of electricity from hydrogen isotopes. Plasma physics is fundamentally multi-disciplinary. It requires understanding not only of the complex collective behaviour of ionised gases in unusual conditions, but also knowledge of the atomic and nuclear physics that determines how plasmas are formed and maintained, and the specialised engineering and instrumentation of the mechanical and electromagnetic containers needed to confine plasmas on Earth. These characteristics make plasma physics a fertile breeding ground for imagination and innovation. This paper draws together examples of innovation stimulated by plasma physics research in the areas of energy, materials, communications, and computation

  3. Highly ionized copper contribution to the soft X-ray emission in a plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Zoita, V; Patran, A [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania); Larour, J [Ecole Polytechnique, Palaiseau (France). Lab. de Physique des Milieux Ionises

    1997-12-31

    In order to discriminate between the contributions of the gas plasma and of the anode (solid or plasma) to the soft X-ray emission in a plasma focus device, a series of experiments was carried out using the following combinations of experimental conditions: various gases, different absorption filters and viewing different regions in front of the centre electrode. The experiments were performed on the IPF-2/20 plasma focus device using the following working gases: helium, neon and helium-argon mixtures. The diagnostics used: magnetic probe for current derivative, PIN diode for the minimum pinch radius detection, PIN diodes for the soft X-ray emission, scintillator-photomultiplier detector for the hard X-ray emission. From the analysis of the various diagnostics data recorded with very good time correlation, it followed that the soft K-ray signals had a strong contribution from optical transitions of the highly ionised Cu (Cu XX to XXII) emitting in the range 0.8-1.3 nm. (author). 7 figs., 9 refs.

  4. Energy consumption and economic growth on the focus on nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Ozkan, Filiz [Sakarya Univ., Sakarya (Turkey). Dept. of Financial Econometric; Pektas, Ali Osman [Bahcesehir Univ., Istanbul (Turkey). Dept. of Civil Engineering; Ozkan, Omer [Istanbul Medeniyet Univ. (Turkey). Dept. of Civil Engineering

    2017-01-15

    Since the quest for global and personal prosperity, the drive to eradicate poverty and the motivation to ensure sustainability for the world are collectively dependent on a supply of safe, emissions-free power there are many studies in literature focuses on the relationship between economic growth and energy consumption. This study tries to enlarge the dimensions of these researches by using a large dataset. The second aim of this study is to focus on Nuclear energy consumption. According to the empirical results of the study, Energy consumption is found as co-integrated with the GDP in all 55 countries. There exist bidirectional causality between nuclear, renewable energy consumption and the GDP. Additionally, the unidirectional causality extends from economic growth to hydroelectric, petroleum, coal and total energy consumption.

  5. Energy consumption and economic growth on the focus on nuclear energy

    International Nuclear Information System (INIS)

    Ozkan, Filiz; Pektas, Ali Osman; Ozkan, Omer

    2017-01-01

    Since the quest for global and personal prosperity, the drive to eradicate poverty and the motivation to ensure sustainability for the world are collectively dependent on a supply of safe, emissions-free power there are many studies in literature focuses on the relationship between economic growth and energy consumption. This study tries to enlarge the dimensions of these researches by using a large dataset. The second aim of this study is to focus on Nuclear energy consumption. According to the empirical results of the study, Energy consumption is found as co-integrated with the GDP in all 55 countries. There exist bidirectional causality between nuclear, renewable energy consumption and the GDP. Additionally, the unidirectional causality extends from economic growth to hydroelectric, petroleum, coal and total energy consumption.

  6. Spectrum of reflected light by self-focusing of light in a laser plasma

    International Nuclear Information System (INIS)

    Gorbunov, L.M.

    1983-01-01

    The spectrum of the radiation reflected by a laser-produced plasma is considered. In this situation, self-focusing occurs and a region of low density (caviton) is formed. It is shown that the process leads to a considerable broadening of the spectrum on the ''red'' side, and to the appearance of a line structure in the spectrum. The results can explain data for the reflected light spectrum [L. M. Gorbunov et al., FIAN Preprint No. 126 (1979)] as being due to the nonstationary self-focusing of light in a laser-produced plasma that has recently been observed [V. L. Artsimovich et al., FIAN Preprint No. 252 (1981); Sov. Phys. Doklady 27, 618 (1982)

  7. Compressing and focusing a short laser pulse by a thin plasma lens

    International Nuclear Information System (INIS)

    Ren, C.; Duda, B. J.; Hemker, R. G.; Mori, W. B.; Katsouleas, T.; Antonsen, T. M.; Mora, P.

    2001-01-01

    We consider the possibility of using a thin plasma slab as an optical element to both focus and compress an intense laser pulse. By thin we mean that the focal length is larger than the lens thickness. We derive analytic formulas for the spot size and pulse length evolution of a short laser pulse propagating through a thin uniform plasma lens. The formulas are compared to simulation results from two types of particle-in-cell code. The simulations give a greater final spot size and a shorter focal length than the analytic formulas. The difference arises from spherical aberrations in the lens which lead to the generation of higher-order vacuum Gaussian modes. The simulations also show that Raman side scattering can develop. A thin lens experiment could provide unequivocal evidence of relativistic self-focusing

  8. Preliminary results on a 4 kJ, 140 k A plasma focus

    International Nuclear Information System (INIS)

    Silva, Patricio; Favre, Mario; Chuaqui, Hernan; Wyndham, Edmund

    1996-01-01

    Preliminary results on the operation of a 4 kJ, 140 kA Plasma Focus device are presented. The machine operates Hydrogen and Hydrogen-Argon mixtures at pressures between 400 m Torr to 10 Torr. Main diagnostics include electric and current measurements, time and space resolved X-ray observations, with limited spectral resolution, and B-dot sensors to monitor the evolution of de current sheet during the run up phase of the discharge. The results indicate that good focus is obtained in the above pressure range. This is inferred from I-dot traces and Pin diode and pin-hole camera X-ray observations. The B-dot loops suggest that a symmetric current sheet is produced. These results show that the machine exhibits a reliable performance, which allows further studies on dense transient plasmas to be developed. (author)

  9. System for deuterium-tritium mixture filling the working chamber of a dense plasma focus device

    International Nuclear Information System (INIS)

    Bondar', A.I.; Vyskubov, V.P.; Gerasimov, S.A.

    1981-01-01

    A gas-vacuum system designed for filling the gas-discharge chamber of a plasma focus device with equal-coaponent deuterium-tritium mixture is described. The system consists of a unit for gaseous mixture prepa ration and a unit for mixture absorption and device evacuation. The system provides the gaseous mixture purification of O 2 and N 2 impurities. Final tritium content in the gas-discharge chamber after tritium removal is not greater than 2x10 8 Bq/l. Tritium content in a sealed box in which the device is placed does not exceed 30 Bq/l that is less than limiting safe value. The conclusion is made that the described system design gives an opportunity to begin experimental studies at plasma focus devices with deuterium-tritium mixture [ru

  10. On the energy crisis in the Io plasma torus

    Science.gov (United States)

    Smith, Robert A.; Bagenal, Fran; Cheng, Andrew F.; Strobel, Darrell

    1988-01-01

    Recent calculations of the energy balance of the Io plasma torus show that the observed UV and EUV radiation cannot be maintained solely via energy input by the ion pickup mechanism. Current theoretical models of the torus must be modified to include non-local energy input. It is argued that the required energy may be supplied by inward diffusion of energetic heavy ions with energies less than about 20 keV.

  11. Energy Accommodation from Surface Catalyzed Reactions in Air Plasmas

    Data.gov (United States)

    National Aeronautics and Space Administration — Understanding energy transport at the gas-surface interface between catalytic/reacting surfaces exposed to highly dissociated plasmas remains a significant research...

  12. Numerical Analysis of Amirkabir Plasma Focus (APF) Device for Neon and Argon Gases

    Science.gov (United States)

    Niknam Sharak, M.; Goudarzi, S.; Raeisdana, A.; Jafarabadi, M.

    2013-04-01

    In this paper the experimental results in different working conditions in Amirkabir Plasma Focus (APF) Device have been compared with the numerical results of a two-dimensional simulation code based on Lee's model. The experiments were done with pure Neon and Argon as operating gases over a wide range of working conditions (gas pressures and discharge voltages). It is observed that by a proper choice for values of the efficiency factors, comparison between numerical and experimental results shows a good agreement.

  13. Better Policies Accelerate Clean Energy Transition. Policy brief - Focus on energy system flexibility

    DEFF Research Database (Denmark)

    Karimi, Farid; Lund, Peter; Skytte, Klaus

    2018-01-01

    The use of variable renewable energy sources will increase in the Nordic and Baltic countries in the future. This will call for increased flexibility in the electricity market to ensure both high energy security and efficient use of renewable power in all circumstances. The barriers and hence also...... policies to energy system flexibility are numerous. In this brief, we focus on policy recommendations for two important barriers to flexibility in the Nordic electricity market, namely insufficient market signals to some stakeholders, and uneven market frameworks for different renewable energy resources...

  14. Investigation of the neutron production phases of a large plasma focus device

    International Nuclear Information System (INIS)

    Hayd, A.; Maurer, M.; Meinke, P.; Herold, H.; Bertalot, L.; Deutsch, R.; Grauf, W.; Jaeger, U.; Kaeppeler, H.J.; Lepper, F.; Oppenlaender, T.; Schmidt, H.; Schmidt, R.; Schwarz, J.; Schwoerer, K.; Shakhatre, M.

    1982-09-01

    Plasma dynamic behavior and neutron production in large focus devices with pinch currents of approximately 1 MA have been studied with theoretical as well as experimental methods. For treating turbulent plasma motion, a hybrid code based on the analytical computer algorithm REDUCE was developed. Experimental diagnostics include schlieren photographs, reaction proton localization with pinhole cameras and neutron measurements with Ag-counters and scintillators. Calculated and measured data concern the 280 kJ, 60 kV operational mode of the POSEIDON plasma focus. It is shown that for large pinch currents ( > 500 kA), neutron emission also appears before m = 0 onset in the intermediate phase. This part of the neutron production becomes predominant for very large currents. The lifetime of this intermediate phase strongly increases with increasing current. According to theory, the late phase of the focus is governed by strong turbulence phenomena. The lifetime of the turbulence packets is approximately 150 ns and seems to explain the long lasting neutron emission in this phase. (orig.)

  15. Comparison of measured and computed radial trajectories of plasma focus devices UMDPF1 and UMDPF0

    Energy Technology Data Exchange (ETDEWEB)

    Lim, L. H.; Yap, S. L., E-mail: yapsl@um.edu.my; Lim, L. K.; Lee, M. C.; Poh, H. S.; Ma, J. [Plasma Technology Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yap, S. S. [UMPEDAC, University of Malaya, 50603 Kuala Lumpur (Malaysia); Faculty of Engineering, Multimedia University, Cyberjaya, 63100 Selangor (Malaysia); Lee, S. [Plasma Technology Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); INTI International University, 71800 Nilai (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone 3148 (Australia)

    2015-09-15

    In published literature, there has been scant data on radial trajectory of the plasma focus and no comparison of computed with measured radial trajectory. This paper provides the first such comparative study. We compute the trajectories of the inward-moving radial shock and magnetic piston of UMDPF1 plasma focus and compare these with measured data taken from a streak photograph. The comparison shows agreement with the measured radial trajectory in terms of average speeds and general shape of trajectory. This paper also presents the measured trajectory of the radially compressing piston in another machine, the UMDPF0 plasma focus, confirming that the computed radial trajectory also shows similar general agreement. Features of divergence between the computed and measured trajectories, towards the end of the radial compression, are discussed. From the measured radial trajectories, an inference is made that the neutron yield mechanism could not be thermonuclear. A second inference is made regarding the speeds of axial post-pinch shocks, which are recently considered as a useful tool for damage testing of fusion-related wall materials.

  16. The Dense Plasma Focus Group of IFAS at Argentina: A brief history and recent direction of the investigations

    International Nuclear Information System (INIS)

    Milanese, Maria Magdalena

    2006-01-01

    This is a short review of the research done by the Dense Plasma Focus Group (GPDM) presently working in Tandil, Argentina, from its origin, more than three decades ago, as part of the Plasma Physics Laboratory of Buenos Aires University (the first one in Latin-America where experiments in plasma focus have been made) up to the present. The interest has been mainly experimental studies on plasma focus and, in general, fast electrical discharges. The plasma focus has extensively been studied as neutron producer, including its possibility to play a role in nuclear fusion. It was also researched not only for basic plasma studies, but also for other important applications. Conception, design, construction and study of devices and diagnostics suitable for each application have been made on basis of developed criteria

  17. Active transfer of poloidal magnetic energy during plasma disruptions in J-TEXT

    International Nuclear Information System (INIS)

    Zhang, Ming; Zhang, Jun; Rao, Bo; Chen, Zhongyong; Li, Xiaolong; Xu, Wendi; Pan, Yuan; Yu, Kexun

    2016-01-01

    Highlights: • An alternative plasma disruption mitigation method by transferring partial poloidal magnetic energy out of the vacuum vessel has been presented in this paper. • This method can reduced the magnetic energy dissipated inside the vacuum vessel during disruption and mitigated the disruption damage. • This method has been experimentally verified in J-TEXT with an experiment system set up. • According to the experimental results, the magnetic energy dissipated inside the vacuum vessel during disruption can be reduced by 20% or more and the loop voltage can be reduced by 58%. - Abstract: The magnitude of the damaging effects of plasma disruptions on vacuum vessel (VV) components increases with the thermal energy and poloidal magnetic energy dissipated inside the VV. This study focuses on an alternative method, by which partial poloidal magnetic energy is transferred out of the VV. The quantity of the poloidal magnetic energy dissipated inside the VV (W_d_i_s) can be reduced with this method, and the damaging effects can be mitigated. Partial magnetic energy is transferred based on magnetic coupling by a group of energy transfer coils (ETCs) that are coupled with the plasma current. This method, which is called magnetic energy transfer (MET), has been experimentally verified in J-TEXT. W_d_i_s can be reduced by approximately 20%, and the loop voltage can be reduced by 58%. MET is established as a novel, promising, and effective plasma disruption mitigation method.

  18. Energy coupling to the plasma in repetitive nanosecond pulse discharges

    International Nuclear Information System (INIS)

    Adamovich, Igor V.; Nishihara, Munetake; Choi, Inchul; Uddi, Mruthunjaya; Lempert, Walter R.

    2009-01-01

    A new analytic quasi-one-dimensional model of energy coupling to nanosecond pulse discharge plasmas in plane-to-plane geometry has been developed. The use of a one-dimensional approach is based on images of repetitively pulsed nanosecond discharge plasmas in dry air demonstrating that the plasma remains diffuse and uniform on a nanosecond time scale over a wide range of pressures. The model provides analytic expressions for the time-dependent electric field and electron density in the plasma, electric field in the sheath, sheath boundary location, and coupled pulse energy. The analytic model predictions are in very good agreement with numerical calculations. The model demonstrates that (i) the energy coupled to the plasma during an individual nanosecond discharge pulse is controlled primarily by the capacitance of the dielectric layers and by the breakdown voltage and (ii) the pulse energy coupled to the plasma during a burst of nanosecond pulses decreases as a function of the pulse number in the burst. This occurs primarily because of plasma temperature rise and resultant reduction in breakdown voltage, such that the coupled pulse energy varies approximately proportionally to the number density. Analytic expression for coupled pulse energy scaling has been incorporated into the air plasma chemistry model, validated previously by comparing with atomic oxygen number density measurements in nanosecond pulse discharges. The results of kinetic modeling using the modified air plasma chemistry model are compared with time-resolved temperature measurements in a repetitively pulsed nanosecond discharge in air, by emission spectroscopy, and purely rotational coherent anti-Stokes Raman spectroscopy showing good agreement.

  19. Comments on experimental results of energy confinement of tokamak plasmas

    International Nuclear Information System (INIS)

    Chu, T.K.

    1989-04-01

    The results of energy-confinement experiments on steady-state tokamak plasmas are examined. For plasmas with auxiliary heating, an analysis based on the heat diffusion equation is used to define heat confinement time (the incremental energy confinement time). For ohmically sustained plasmas, experiments show that the onset of the saturation regime of energy confinement, marfeing, detachment, and disruption are marked by distinct values of the parameter /bar n//sub e///bar j/. The confinement results of the two types of experiments can be described by a single surface in 3-dimensional space spanned by the plasma energy, the heating power, and the plasma density: the incremental energy confinement time /tau//sub inc/ = ΔW/ΔP is the correct concept for describing results of heat confinement in a heating experiment; the commonly used energy confinement time defined by /tau//sub E/ = W/P is not. A further examination shows that the change of edge parameters, as characterized by the change of the effective collision frequency ν/sub e/*, governs the change of confinement properties. The totality of the results of tokamak experiments on energy confinement appears to support a hypothesis that energy transport is determined by the preservation of the pressure gradient scale length. 70 refs., 6 figs., 1 tab

  20. Obervations of low energy magnetospheric plasma outside the plasmasphere

    International Nuclear Information System (INIS)

    Hultqvist, B.

    1985-01-01

    After some introductory discussions about morphological concepts and limitations of various measurement techniques, existing low energy plasma data, orginating primarily from the GEOS, Dynamics Explorer, and Prognoz spacecraft, is described and discussed. The plasmasphere measurements are not included (but for some observations of plasmasphere refilling). It is finally concluded that we are very far from a complete picture of the low-energy plasma component in the magnetosphere and that this problem has to be given high priority in planning payloads of future space plasma physics missions. (Author)

  1. Dense plasma focus x-ray source for sub-micron lithography

    International Nuclear Information System (INIS)

    Prasad, R.R.; Krishnan, M.; Mangano, J.; Greene, P.; Qi, Niansheng

    1993-01-01

    A discharge driven, dense plasma focus in neon is under development at SRL for use as a point x-ray source for sub-micron lithography. This source is presently capable of delivering ∼ 13j/pulse of neon K-shell x-rays (8--14 angstrom) into 4π steradians with 2 kj of electrical energy stored in the capacitor bank charged to 9 kV at a pulse repetition rate of 2 Hz. The discharge is produced by a ≤4 kj, ≤12 kV, capacitor bank circuit, which has a fixed inductance of 12 nH and drives ≤450 kA currents into the DPF load, with ∼1.1 μs rise-times. X-rays are produced when a dense pinch of neon is formed along the axis of the DPF electrodes. A new rail-gap switched capacitor bank and DPF have been built, designed for continuous operation at 2 Hz and burst mode operation at 20 Hz. This paper will present measurements of the x-ray output at a repetition rate of 2 Hz using the new capacitor bank. It will also describe measurements of the spot size (0.3--0.8 mm) and the spectrum (8--14 angstrom) of the DPF source. The dependence of these parameters on the DPF head geometry, bank energy and operating pressure will be discussed. The x-ray output has been measured using filtered pin diodes, x-ray diodes, and absolutely calibrated x-ray crystal spectra. Results from the source operating at 2 Hz will be presented. A novel concept of a windowless beamline has also been developed. The results of preliminary experiments to test the concept will be discussed. At a pulse repetition rate of 20 Hz, this source should produce 200--400 W of x-ray power in the 8-14 angstrom wavelength band, with an input power of 40--60 kW

  2. Plasma sheath dynamics and parameters in focus and defocus conditions. Vol. 2

    International Nuclear Information System (INIS)

    Masoud, M.M.; Soliman, H.M.; El-Aragi, G.M.

    1996-01-01

    The study deals with the effect of the inner electrode polarity on the dynamic behaviour and parameters of plasma sheath in a coaxial discharge. The experimental investigations presented here were carried out in a coaxial plasma focus discharge device of mather geometry. It consisted of coaxial stainless steel hollow cylindrical electrodes with inner electrode 18.2 cm length and outer-electrode 31.5 cm length. The diameter of the inner and outer electrodes are 3.2 cm and 6.6 cm, respectively. The two electrodes are separated by a teflon disc at the breech. The outer electrode muzzle is connected to stainless steel expansion chamber of 23 cm length and 17 cm diameter. The discharge takes place in hydrogen gas with a base pressure of 1 torr. The experiments were conducted with 10 kV bank voltage, which corresponds to 100 K A peak discharge current. By using a double electric probe, It was found that the plasma electron density was higher near the negative electrode. Investigations using a miniature rogovsky coil have shown that, the radial and azimuthal current density increased with radial distance from negative electrode to positive electrode. The shape and the axial velocity of plasma sheath were measured using a magnetic probe. The experimental results indicate that, the plasma is thick near the negative electrode, in both cases of the outer or the inner electrode. Also it has been found that the axial plasma sheath velocity reaches its maximum value at the muzzle for positive and negative inner electrode. The magnitude of maximum axial velocity reaches 1.7 x 10 60 cm/s for positive inner electrode and decreased by 25% for negative inner electrode further investigations revealed that on interchanging the polarity from normal operation (positive inner electrode), it was found that with negative inner electrode the soft x-ray emission intensity dropped by three orders of magnitude from that with positive inner electrode. 9 figs

  3. Plasma sheath dynamics and parameters in focus and defocus conditions. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Masoud, M M; Soliman, H M; El-Aragi, G M [Plasma Physics and Nuclear Fusion Department, Nuclear Research Centre, Atomic Energy Aurhority, Cairo (Egypt)

    1996-03-01

    The study deals with the effect of the inner electrode polarity on the dynamic behaviour and parameters of plasma sheath in a coaxial discharge. The experimental investigations presented here were carried out in a coaxial plasma focus discharge device of mather geometry. It consisted of coaxial stainless steel hollow cylindrical electrodes with inner electrode 18.2 cm length and outer-electrode 31.5 cm length. The diameter of the inner and outer electrodes are 3.2 cm and 6.6 cm, respectively. The two electrodes are separated by a teflon disc at the breech. The outer electrode muzzle is connected to stainless steel expansion chamber of 23 cm length and 17 cm diameter. The discharge takes place in hydrogen gas with a base pressure of 1 torr. The experiments were conducted with 10 kV bank voltage, which corresponds to 100 K A peak discharge current. By using a double electric probe, It was found that the plasma electron density was higher near the negative electrode. Investigations using a miniature rogovsky coil have shown that, the radial and azimuthal current density increased with radial distance from negative electrode to positive electrode. The shape and the axial velocity of plasma sheath were measured using a magnetic probe. The experimental results indicate that, the plasma is thick near the negative electrode, in both cases of the outer or the inner electrode. Also it has been found that the axial plasma sheath velocity reaches its maximum value at the muzzle for positive and negative inner electrode. The magnitude of maximum axial velocity reaches 1.7 x 10{sup 60} cm/s for positive inner electrode and decreased by 25% for negative inner electrode further investigations revealed that on interchanging the polarity from normal operation (positive inner electrode), it was found that with negative inner electrode the soft x-ray emission intensity dropped by three orders of magnitude from that with positive inner electrode. 9 figs.

  4. Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium–tritium fillings

    Energy Technology Data Exchange (ETDEWEB)

    Dulatov, A. K., E-mail: bogolubov@vniia.ru; Krapiva, P. S.; Lemeshko, B. D.; Mikhailov, Yu. V.; Moskalenko, I. N.; Prokuratov, I. A.; Selifanov, A. N. [All-Russia Research Institute of Automatics (Russian Federation)

    2016-01-15

    The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with deuterium and deuterium–tritium fillings are determined. In experiments with PF chambers filled with a deuterium–tritium mixture, in addition to the HXR pulse with photon energies of up to 200–300 keV, a γ-ray pulse with photon energies of up to 2.5–3.0 MeV is recorded, and a mechanism of its generation is proposed.

  5. Applications of plasma core reactors to terrestrial energy systems

    International Nuclear Information System (INIS)

    Lantham, T.S.; Biancardi, F.R.; Rodgers, R.J.

    1974-01-01

    Plasma core reactors offer several new options for future energy needs in addition to space power and propulsion applications. Power extraction from plasma core reactors with gaseous nuclear fuel allows operation at temperatures higher than conventional reactors. Highly efficient thermodynamic cycles and applications employing direct coupling of radiant energy are possible. Conceptual configurations of plasma core reactors for terrestrail applications are described. Closed-cycle gas turbines, MHD systems, photo- and thermo-chemical hydrogen production processes, and laser systems using plasma core reactors as prime energy sources are considered. Cycle efficiencies in the range of 50 to 65 percent are calculated for closed-cycle gas turbine and MHD electrical generators. Reactor advantages include continuous fuel reprocessing which limits inventory of radioactive by-products and thorium-U-233 breeder configurations with about 5-year doubling times

  6. Polarization of X-ray lines emitted from plasma-focus discharges; Problems of interpretation

    International Nuclear Information System (INIS)

    Jakubowski, L.

    2002-01-01

    In high current pulse discharges of the Plasma Focus (PF) type, inside the collapsing pinch column, there are formed local micro-regions of high-density and high-temperature plasma, so-called hot spots. Individual hot spots are separated in space and time. Each hot spot is characterized by its specific electron concentration and temperature, as well as by the emission of X-ray lines with different polarization. When numerous hot spots are produced it is impossible to determine local plasma parameters and to interpret the polarization effects. To eliminate this problem this study was devoted to the realization of PF-type discharges with single hot spot only. It has been achieved by a choice of the electrode configuration, which facilitated the formation of a single hot spot emitting intense X-ray lines. At the chosen experimental conditions it was possible to determine local plasma parameters and to demonstrate evident differences in the polarization of the observed X-ray lines. (author)

  7. X-ray polarization studies of plasma focus experiments with a single hot spots

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M.J.; Baronova, E.O.

    2004-01-01

    In high current pulse discharges of the plasma focus (PF) type, inside the collapsing pinch column, there are formed local micro-regions of high-density and high-temperature plasma, so-called hot spots. Individual hot spots are separated in space and time. Each hot spot is characterized by its specific electron concentration and temperature, as well as by the emission of x-ray lines with different polarization. When numerous hot spots are produced it is impossible to determine local plasma parameters and to interpret the polarization effects. To eliminate this problem this study was devoted to the realization of PF-type discharges with single hot spot only. It has been achieved by a choice of the electrode configuration, which facilitated the formation of a single hot spot emitting intense x-ray lines. At the chosen experimental conditions it was possible to determine local plasma parameters and to demonstrate evident differences in the polarization of the observed x-ray lines. (author)

  8. Polarization of x-ray lines emitted from plasma-focus discharges; Problems of interpretation

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M.J.; Baronova, E.O.

    2003-01-01

    In high current pulse discharges of the Plasma Focus (PF) type, inside the collapsing pinch column, there are formed local micro-regions of high-density and high-temperature plasma, so-called hot spots. Individual hot spots are separated in space and time. Each hot spot is characterized by its specific electron concentration and temperature, as well as by the emission of X-ray lines with different polarization. When numerous hot spots are produced it is impossible to determine local plasma parameters and to interpretate the polarization effects. To eliminate this problem this study was devoted to the realization of PF-type discharges with single hot spot only. It has been achieved by a choice of the electrode configuration, which facilitated the formation of a single hot spot emitting intense X-ray lines. At the chosen experimental conditions it was possible to determine local plasma parameters and to demonstrate evident differences in the polarization of the observed X-ray lines. (author)

  9. Simulations of a dense plasma focus on a high impedance generator

    Science.gov (United States)

    Beresnyak, Andrey; Giuliani, John; Jackson, Stuart; Richardson, Steve; Swanekamp, Steve; Schumer, Joe; Commisso, Robert; Mosher, Dave; Weber, Bruce; Velikovich, Alexander

    2017-10-01

    We study the connection between plasma instabilities and fast ion acceleration for neutron production on a Dense Plasma Focus (DPF). The experiments will be performed on the HAWK generator (665 kA), which has fast rise time, 1.2 μs, and a high inductance, 607 nH. It is hypothesized that high impedance may enhance the neutron yield because the current will not be reduced during the collapse resulting in higher magnetization. To prevent upstream breakdown, we will inject plasma far from the insulator stack. We simulated rundown and collapse dynamics with Athena - Eulerian 3D, unsplit finite volume MHD code that includes shock capturing with Riemann solvers, resistive diffusion and the Hall term. The simulations are coupled to an equivalent circuit model for HAWK. We will report the dynamics and implosion time as a function of the initial injected plasma distribution and the implications of non-ideal effects. We also traced test particles in MHD fields and confirmed the presence of stochastic acceleration, which was limited by the size of the system and the strength of the magnetic field. Supported by DOE/NNSA and the Naval Research Laboratory Base Program.

  10. Soft X-ray measurements for investigating the plasma focus dynamics

    International Nuclear Information System (INIS)

    Nahrath, B.

    In a Mather-type plasma focus short time soft x-ray pictures are taken by means of a double pinhole camera equipped with a pulsed channel plate and two different filters to study the local development of electron temperatures Tsub(e) with time resolution of 3 ns. Up to the maximum compression the measured Tsub(e) are roughly in accordance with the results of MHD-calculations. During a later phase, characterized by the occurence of m=O-instabilities, localized plasma regions with high densities and high electron temperatures Tsub(e) of about 600 eV (up to 1000 eV) are observed. Using the channel plate technique with increased sensivity a slowly decaying plasma with local Tsub(e)-values of about 300 eV and large diffuse structures is identified for several hundred nanoseconds. During this 'late phase' of the focus most of the neutron emission takes place. There is no correlation between the value of Tsub(e) and the rate of neutron emission. (orig.) [de

  11. Recent development in high energy plasma production techniques by the deflagration plasma gun

    International Nuclear Information System (INIS)

    Cheng, D.Y.; Chang, C.N.; Tripathi, P.P.

    1983-01-01

    This chapter reports experimental data and experience which establish the phenomenon of deflagration in plasma as unique and with quite different properties from the normal snowplow modes. Demonstrates that extremely high velocities and energies in plasma beams are possible with obvious applications in many field and, in particular, in fusion. Suggests that the potential of deflagration beams' scalability to very high energy quasi-neutral plasma beam is possible with present day technology. Discusses plasma deflagration in a T-tube; coaxial deflagration plasma guns; a typical deflagration gun and its operating procedures; electrical design considerations; kinetic theory point of view of the deflagration acceleration of particles; measurements and results; properties of the deflagration gun; applications; inertial confinement experiments; injection into magnetic confinement systems; interaction experiments; and highly energetic beams

  12. Designing Neutralized Drift Compression for Focusing of Intense Ion Beam Pulses in a Background Plasma

    International Nuclear Information System (INIS)

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.; Startsev, E.A.; Barnard, J.J.; Friedman, A.; Lee, E.P.; Lidia, S.M.; Logan, B.G.; Roy, P.K.; Seidl, P.A.; Welch, D.R.; Sefkow, A.B.

    2009-01-01

    Neutralized drift compression offers an effective method for particle beam focusing and current amplification. In neutralized drift compression, a linear radial and longitudinal velocity drift is applied to a beam pulse, so that the beam pulse compresses as it drifts in the drift-compression section. The beam intensity can increase more than a factor of 100 in both the radial and longitudinal directions, resulting in more than 10,000 times increase in the beam number density during this process. The self-electric and self-magnetic fields can prevent tight ballistic focusing and have to be neutralized by supplying neutralizing electrons. This paper presents a survey of the present theoretical understanding of the drift compression process and plasma neutralization of intense particle beams. The optimal configuration of focusing and neutralizing elements is discussed in this paper.

  13. Influence of damping on proton energy loss in plasmas of all degeneracies

    International Nuclear Information System (INIS)

    Barriga-Carrasco, Manuel D.

    2007-01-01

    The purpose of the present paper is to describe the effects of electron-electron collisions on the stopping power of plasmas of any degeneracy. Plasma targets are considered fully ionized so electronic stopping is only due to the free electrons. We focus our analysis on plasmas which electronic density is around solid values n e ≅10 23 cm -3 and which temperature is around T≅10 eV; these plasmas are in the limit of weakly coupled plasmas. This type of plasma has not been studied extensively though it is very important for inertial confinement fusion. The electronic stopping is obtained from an exact quantum mechanical evaluation, which takes into account the degeneracy of the target plasma, and later it is compared with common classical and degenerate approximations. Differences are around 30% in some cases which can produce bigger mistakes in further energy deposition and projectile range studies. Then we consider electron-electron collisions in the exact quantum mechanical electronic stopping calculation. Now the maximum stopping occurs at velocities smaller than for the calculations without considering collisions for all kinds of plasmas analyzed. The energy loss enhances for velocities smaller than the velocity at maximum while decreases for higher velocities. Latter effects are magnified with increasing collision frequency. Differences with the same results for the case of not taking into account collisions are around 20% in the analyzed cases

  14. Energy loss of a high charge bunched electron beam in plasma: Simulations, scaling, and accelerating wakefields

    Directory of Open Access Journals (Sweden)

    J. B. Rosenzweig

    2004-06-01

    Full Text Available The energy loss and gain of a beam in the nonlinear, “blowout” regime of the plasma wakefield accelerator, which features ultrahigh accelerating fields, linear transverse focusing forces, and nonlinear plasma motion, has been asserted, through previous observations in simulations, to scale linearly with beam charge. Additionally, from a recent analysis by Barov et al., it has been concluded that for an infinitesimally short beam, the energy loss is indeed predicted to scale linearly with beam charge for arbitrarily large beam charge. This scaling is predicted to hold despite the onset of a relativistic, nonlinear response by the plasma, when the number of beam particles occupying a cubic plasma skin depth exceeds that of plasma electrons within the same volume. This paper is intended to explore the deviations from linear energy loss using 2D particle-in-cell simulations that arise in the case of experimentally relevant finite length beams. The peak accelerating field in the plasma wave excited behind the finite-length beam is also examined, with the artifact of wave spiking adding to the apparent persistence of linear scaling of the peak field amplitude into the nonlinear regime. At large enough normalized charge, the linear scaling of both decelerating and accelerating fields collapses, with serious consequences for plasma wave excitation efficiency. Using the results of parametric particle-in-cell studies, the implications of these results for observing severe deviations from linear scaling in present and planned experiments are discussed.

  15. Fields of an ultrashort tightly focused radially polarized laser pulse in a linear response plasma

    Science.gov (United States)

    Salamin, Yousef I.

    2017-10-01

    Analytical expressions for the fields of a radially polarized, ultrashort, and tightly focused laser pulse propagating in a linear-response plasma are derived and discussed. The fields are obtained from solving the inhomogeneous wave equations for the vector and scalar potentials, linked by the Lorenz gauge, in a plasma background. First, the scalar potential is eliminated using the gauge condition, then the vector potential is synthesized from Fourier components of an initial uniform distribution of wavenumbers, and the inverse Fourier transformation is carried out term-by-term in a truncated series (finite sum). The zeroth-order term in, for example, the axial electric field component is shown to model a pulse much better than its widely used paraxial approximation counterpart. Some of the propagation characteristics of the fields are discussed and all fields are shown to have manifested the expected limits for propagation in a vacuum.

  16. Energy eigenvalues of helium-like atoms in dense plasmas

    International Nuclear Information System (INIS)

    Hashino, Tasuke; Nakazaki, Shinobu; Kato, Takako; Kashiwabara, Hiromichi.

    1987-04-01

    Calculations based on a variational method with wave functions including the correlation of electrons are carried out to obtain energy eigenvalues of Schroedinger's equation for helium-like atoms embedded in dense plasmas, taking the Debye-Hueckel approximation. Energy eigenvalues for the 1 1 S, 2 1 S, and 2 3 S states are obtained as a function of Debye screening length. (author)

  17. The energy density of a Landau damped plasma wave

    NARCIS (Netherlands)

    Best, R. W. B.

    1999-01-01

    In this paper some theories about the energy of a Landau damped plasma wave are discussed and new initial conditions are proposed. Analysis of a wave packet, rather than an infinite wave, gives a clear picture of the energy transport from field to particles. Initial conditions are found which excite

  18. Endogenous magnetic reconnection and associated high energy plasma processes

    Science.gov (United States)

    Coppi, B.; Basu, B.

    2018-02-01

    An endogenous reconnection process involves a driving factor that lays inside the layer where a drastic change of magnetic field topology occurs. A process of this kind is shown to take place when an electron temperature gradient is present in a magnetically confined plasma and the evolving electron temperature fluctuations are anisotropic. The width of the reconnecting layer remains significant even when large macroscopic distances are considered. In view of the fact that there are plasmas in the Universe with considerable electron thermal energy contents this feature can be relied upon in order to produce generation or conversion of magnetic energy, high energy particle populations and momentum and angular momentum transport.

  19. Relaxational dissipation of magnetic field energy in a rarefied plasma

    International Nuclear Information System (INIS)

    Vekshtejn, G.E.

    1987-01-01

    A mechanism of solar corona plasma heating connected with relaxation of a magnetic configuration in the corona to the state of the magnetic energy minimum at restrictions imposed by high conductivity of a medium is considered. Photospheric plasma pulsations leading to generation of longitudinal currents in the corona are in this case energy sources. The excess magnetic energy of these currents is dissipated as a result of reclosing of force lines of the magnetic field in narrow current layers. Plasmaturbulence related to the process of magnetic reclosing is phenomenologically described in this case by introducing certain characteristic time of relaxation. Such an approach permits to relate the plasma heating energy with parameters of photospheric motions in the framework of a simple model of the magnetic field

  20. DLC coating on stainless steel by pulsed methane discharge in repetitive plasma focus

    International Nuclear Information System (INIS)

    Hassan, M.; Qayyum, A.; Ahmad, S.; Mahmood, S.; Shafiq, M.; Zakaullah, M.; Lee, P.; Rawat, R.S.

    2014-01-01

    Amorphous hydrogenated carbon (a-C:H)/diamond-like carbon (DLC) coatings have been achieved on AISI 304 stainless steel (SS) substrates by employing energetic ions emitted from a repetitive plasma focus operated in CH 4 discharge. The Raman spectroscopy of the coatings exhibits the evolution of a-C:H/DLC coatings with clearly observed D and G peaks centered about 1320–1360 and 1560–1620 cm −1 respectively. The diamond character of the coatings is influenced by the ion flux and repetition rate of the focus device. The repetitive discharge mode of plasma focus has led to the formation of a-C:H/DLC coatings in short duration of time. The coatings transform from a-C to a-C:H depending upon substrate angular position. X-ray diffraction (XRD) analysis confirms the formation of DLC coating owing to stress-induced restructuring in SS. The estimated crystallite size is found to be ∼40–50 nm. Field emission scanning electron micrographs exhibit a layered granular surface morphology of the coatings. The Vickers surface hardness of the DLC coated SS samples has been significantly improved.

  1. DLC coating on stainless steel by pulsed methane discharge in repetitive plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, M., E-mail: hassanjh@gmail.com [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, BLK7, 1 Nanyang Walk, Singapore 637616 (Singapore); Qayyum, A.; Ahmad, S. [National Tokamak Fusion Program, 3329 Islamabad (Pakistan); Mahmood, S. [Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, BLK7, 1 Nanyang Walk, Singapore 637616 (Singapore); Department of Physics, University of Karachi, 75270 Karachi (Pakistan); Shafiq, M.; Zakaullah, M. [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Lee, P.; Rawat, R.S. [Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, BLK7, 1 Nanyang Walk, Singapore 637616 (Singapore)

    2014-06-01

    Amorphous hydrogenated carbon (a-C:H)/diamond-like carbon (DLC) coatings have been achieved on AISI 304 stainless steel (SS) substrates by employing energetic ions emitted from a repetitive plasma focus operated in CH{sub 4} discharge. The Raman spectroscopy of the coatings exhibits the evolution of a-C:H/DLC coatings with clearly observed D and G peaks centered about 1320–1360 and 1560–1620 cm{sup −1} respectively. The diamond character of the coatings is influenced by the ion flux and repetition rate of the focus device. The repetitive discharge mode of plasma focus has led to the formation of a-C:H/DLC coatings in short duration of time. The coatings transform from a-C to a-C:H depending upon substrate angular position. X-ray diffraction (XRD) analysis confirms the formation of DLC coating owing to stress-induced restructuring in SS. The estimated crystallite size is found to be ∼40–50 nm. Field emission scanning electron micrographs exhibit a layered granular surface morphology of the coatings. The Vickers surface hardness of the DLC coated SS samples has been significantly improved.

  2. World trends in wind energy. A focus per country. Analysis

    International Nuclear Information System (INIS)

    Kane, Mamadou

    2016-01-01

    A set of articles highlights and comments various trends related to the development of wind energy in 2015. More specifically, the articles outline that 2015 has been a record year for wind energy in the World (an increase of 63.900 MW in installed power), that wind energy covers 11.4 per cent of energy demand in Europe, that the wind energy sector is still in a very good health in the USA (more megawatts have been installed during the last quarter of 2015 than during the whole 2014 year and perspectives seem promising in terms of installed power, share of energy, costs and prices), that Denmark holds the world record of wind energy consumption in 2015 (42.1 per cent of its energy consumption in 2015), that Mauritania could be the engine of the wind energy sector in western Africa (a first important wind farm has been installed in 2012, followed by others with a higher production, and a 100 MW project), that Scotland awarded a 53 MW project to Siemens (using the Siemens G2 platform), and that Kenya signed a partnership with a Chinese company for a 102 MW project. The last article outlines that renewable energies appear to be resilient in front of the oil crisis

  3. Development of Diagnostics for Large-Scale Experiments with Dense Magnetized Plasmas - MJ Plasma-focus diagnostics systems

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, M.; Karpinski, L.; Paduch, M.; Pisarczyk, T.; Zielinska, E.; Chodukowski, T. [Institute of Plasma Physics and Laser Microfusion IPPLM, 01-497 Warsaw (Poland); Sadowski, M.J. [Institute of Plasma Physics and Laser Microfusion IPPLM, 01-497 Warsaw (Poland)] [The Andrzej Soltan Institute for Nuclear Studies IPJ, 05-400 Otwock-Swiert (Poland); Skladnik-Sadowska, E.; Czaus, K.; Kwiatkowski, R.; Malinowski, K. [The Andrzej Soltan Institute for Nuclear Studies IPJ, 05-400 Otwock-Swiert (Poland); Krauz, S. [RNC Kurchatov Institute, Moscow (Russian Federation); Mitrovanov, K. [FGUP GNC RF Triniti, Troick (Russian Federation)

    2011-07-01

    This document presents the diagnostics arrangements and interesting results of research on fusion pulsed plasma, which was generated within the large PF-1000 facility operated in the Institute of Plasma Physics and Laser Microfusion (Warsaw, Poland). Experimental studies were carried out with the following diagnostic techniques: 1) Rogovski coil for current measurements; 2) Four dI/dt probes in different places around the collector of PF-1000; 3) Voltage divider; 4) Mach-Zender interferometer (16 frames); 5) Fast scintillation probes for X-ray and neutron detection; 6) Silver activation counters; 7) Specially prepared current probes; 8) Thomson spectrometer for mass- and energy-analysis of deuterium beams; 9) Ion-pinhole cameras equipped with nuclear-track detectors, etc. The studies have been carried out with the pure deuterium filling, and particular attention was paid to correlations between the fast-neutron emission and an evolution of plasma parameters. The total fusion-neutron yield, as measured with four silver-activation counters, was found to be up to 7*10{sup 11} per shot, depending on the experimental conditions. Correlations of the neutron pulses with interferometric frame-pictures of the PF pinch column were studied. From time-of-flight (ToF) measurements of the fusion neutrons it was possible to estimate a CM velocity of deuterons involved in the D-D reactions. The fast fusion-produced protons have also been recorded and analyzed by means pinhole cameras and shielded track detectors. The document is composed of an abstract followed by the slides of the presentation. (authors)

  4. Electron energy distribution function control in gas discharge plasmas

    International Nuclear Information System (INIS)

    Godyak, V. A.

    2013-01-01

    The formation of the electron energy distribution function (EEDF) and electron temperature in low temperature gas discharge plasmas is analyzed in frames of local and non-local electron kinetics. It is shown, that contrary to the local case, typical for plasma in uniform electric field, there is the possibility for EEDF modification, at the condition of non-local electron kinetics in strongly non-uniform electric fields. Such conditions “naturally” occur in some self-organized steady state dc and rf discharge plasmas, and they suggest the variety of artificial methods for EEDF modification. EEDF modification and electron temperature control in non-equilibrium conditions occurring naturally and those stimulated by different kinds of plasma disturbances are illustrated with numerous experiments. The necessary conditions for EEDF modification in gas discharge plasmas are formulated

  5. Strict calculation of electron energy distribution functions in inhomogeneous plasmas

    International Nuclear Information System (INIS)

    Winkler, R.

    1996-01-01

    It is objective of the paper to report on strict calculations of the velocity or energy distribution function function and related macroscopic properties of the electrons from appropriate electron kinetic equations under various plasma conditions and to contribute to a better understanding of the electron behaviour in inhomogeneous plasma regions. In particular, the spatial relaxation of plasma electrons acted upon by uniform electric fields, the response of plasma electrons on spatial disturbances of the electric field, the electron kinetics under the impact of space charge field confinement in the dc column plasma and the electron velocity distribution is stronger field as occurring in the electrode regions of a dc glow discharge is considered. (author)

  6. X-ray and neutron emission studies in a new Filippov type plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Babazadeh, A.R.; Banoushi, A. [Technical University of Amirkabir, Tehran (Iran, Islamic Republic of). Dept. of Physics; Roshan, M.V.; Habibi, H.; Nasiry, A.; Memarzadeh, M.; Lamehi, M.; Kiai, S.M. Sadat [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of). Nuclear Fusion Research Center

    2002-03-01

    We have performed experimental comparative studies of the X-ray and neutron emission generated by the new Filippov-type plasma focus 'Dena', (90 kJ, 25 kV, 288{mu}F) in the pressure range of 0.6-1 torr. Time-integrated and time-resolved detectors, together with an X-ray pin-hole camera, along with a Be filter of 10{mu}m thickness have been used. For a working gas of neon and a at insert anode, the maximum soft and hard X-rays (SXR-HXR) yield obtained was 16 V and 1.5 V/shot over a 4{pi} solid angle, respectively, for a charging voltage range of 16-20 kV. As for the argon gas, the similar results such as 3.5 and 2 V/shot have been found, leading to a total conversion efficiency of X-ray emission of 0.09 % (for neon) and 0.03 % (for argon) of the stored energy. These efficiencies have been improved by the employment of a conic insert anode up to 0.4% and 0.1%. With deuterium puffing gas and a at insert anode, the maximum emission yield has been found to be 2.5 V for SXR and 1 V for HXR/shot which produce an ultimate emission profile width (FWHM) of 70-90 ns for X-rays and neutrons, giving rise to a maximum neutron yield of 1.2 x 10{sup 9}. Nevertheless, the maximum yield has been increased up to 5.5 times with the conic insert anode. In order to increase the neutron yield, we have introduced a krypton admixture to the deuterium filling gas and found that, for a krypton pressure of about 0.1 torr, the neutron yield increases by a factor of 3.5 for the flat insert and 1.5 for the conic insert anodes. (author)

  7. Drag Reduction by Laser-Plasma Energy Addition in Hypersonic Flow

    International Nuclear Information System (INIS)

    Oliveira, A. C.; Minucci, M. A. S.; Toro, P. G. P.; Chanes, J. B. Jr; Myrabo, L. N.

    2008-01-01

    An experimental study was conducted to investigate the drag reduction by laser-plasma energy addition in a low density Mach 7 hypersonic flow. The experiments were conducted in a shock tunnel and the optical beam of a high power pulsed CO 2 TEA laser operating with 7 J of energy and 30 MW peak power was focused to generate the plasma upstream of a hemispherical model installed in the tunnel test section. The non-intrusive schlieren optical technique was used to visualize the effects of the energy addition to hypersonic flow, from the plasma generation until the mitigation of the shock wave profile over the model surface. Aside the optical technique, a piezoelectric pressure transducer was used to measure the impact pressure at stagnation point of the hemispherical model and the pressure reduction could be observed

  8. Comparison the Results of Numerical Simulation And Experimental Results for Amirkabir Plasma Focus Facility

    Science.gov (United States)

    Goudarzi, Shervin; Amrollahi, R.; Niknam Sharak, M.

    2014-06-01

    In this paper the results of the numerical simulation for Amirkabir Mather-type Plasma Focus Facility (16 kV, 36μF and 115 nH) in several experiments with Argon as working gas at different working conditions (different discharge voltages and gas pressures) have been presented and compared with the experimental results. Two different models have been used for simulation: five-phase model of Lee and lumped parameter model of Gonzalez. It is seen that the results (optimum pressures and current signals) of the Lee model at different working conditions show better agreement than lumped parameter model with experimental values.

  9. Comparison the results of numerical simulation and experimental results for Amirkabir plasma focus facility

    International Nuclear Information System (INIS)

    Goudarzi, Shervin; Amrollahi, R; Sharak, M Niknam

    2014-01-01

    In this paper the results of the numerical simulation for Amirkabir Mather-type Plasma Focus Facility (16 kV, 36μF and 115 nH) in several experiments with Argon as working gas at different working conditions (different discharge voltages and gas pressures) have been presented and compared with the experimental results. Two different models have been used for simulation: five-phase model of Lee and lumped parameter model of Gonzalez. It is seen that the results (optimum pressures and current signals) of the Lee model at different working conditions show better agreement than lumped parameter model with experimental values.

  10. Energy distribution and transfer in flowing hydrogen microwave plasmas

    International Nuclear Information System (INIS)

    Chapman, R.A.

    1987-01-01

    This thesis is an experimental investigation of the physical and chemical properties of a hydrogen discharge in a flowing microwave plasma system. The plasma system is the mechanisms utilized in an electrothermal propulsion concept to convert electromagnetic energy into the kinetic energy of flowing hydrogen gas. The plasmas are generated inside a 20-cm ID resonant cavity at a driving frequency of 2.45 GHz. The flowing gas is contained in a coaxially positioned 22-mm ID quartz discharge tube. The physical and chemical properties are examined for absorbed powers of 20-100 W, pressures of 0.5-10 torr, and flow rates of 0-10,000 μ-moles/sec. A calorimetry system enclosing the plasma system to accurately measure the energy inputs and outputs has been developed. The rate of energy that is transferred to the hydrogen gas as it flows through the plasma system is determined as a function of absorbed power, pressure, and flow rate to +/-1.8 W from an energy balance around the system. The percentage of power that is transferred to the gas is found to increase with increasing flow rate, decrease with increasing pressure, and to be independent of absorbed power

  11. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    CERN Document Server

    Assmann, R.; Bohl, T.; Bracco, C.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Chattopadhyay, S.; Cipiccia, S.; Feldbaumer, E.; Fonseca, R.A.; Goddard, B.; Gross, M.; Grulke, O.; Gschwendtner, E.; Holloway, J.; Huang, C.; Jaroszynski, D.; Jolly, S.; Kempkes, P.; Lopes, N.; Lotov, K.; Machacek, J.; Mandry, S.R.; McKenzie, J.W.; Meddahi, M.; Militsyn, B.L.; Moschuering, N.; Muggli, P.; Najmudin, Z.; Noakes, T.C.Q.; Norreys, P.A.; Oz, E.; Pardons, A.; Petrenko, A.; Pukhov, A.; Rieger, K.; Reimann, O.; Ruhl, H.; Shaposhnikova, E.; Silva, L.O.; Sosedkin, A.; Tarkeshian, R.; Trines, R.M.G.N.; Tuckmantel, T.; Vieira, J.; Vincke, H.; Wing, M.; Xia, G.

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  12. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    International Nuclear Information System (INIS)

    Assmann, R; Gross, M; Bingham, R; Holloway, J; Bohl, T; Bracco, C; Butterworth, A; Feldbaumer, E; Goddard, B; Gschwendtner, E; Buttenschön, B; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Jaroszynski, D; Fonseca, R A; Grulke, O; Kempkes, P; Huang, C; Jolly, S

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN—the AWAKE experiment—has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator. (paper)

  13. Fly ash particles spheroidization using low temperature plasma energy

    OpenAIRE

    Shekhovtsov, V. V.; Volokitin, O. G.; Vitske, Rudolf Evaldovich; Kondratyuk, Alexey Alekseevich

    2016-01-01

    The paper presents the investigations on producing spherical particles 65-110 [mu]m in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition ...

  14. Energy balance in a coaxial plasma diode

    International Nuclear Information System (INIS)

    Ivanov, A.A. Jr.

    1999-01-01

    The energy fluxes in a coaxial system with a propagating convective magnetic-field wave are considered in an electron MHD model with inertia-free electrons. In contrast to the previous results obtained by other authors, it is shown that, with allowance for a finite electron pressure after the passage of the wave front, the energy flux at the boundary between the generator and coaxial system is continuous. The balance of energy fluxes in the system is studied. The angular anode point is shown to play an important role in this balance

  15. Solar energy converter using surface plasma waves

    Science.gov (United States)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

  16. Energy exchange in strongly coupled plasmas with electron drift

    International Nuclear Information System (INIS)

    Akbari-Moghanjoughi, M.; Ghorbanalilu, M.

    2015-01-01

    In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam

  17. Electromagnetic-implosion generation of pulsed high energy density plasma

    International Nuclear Information System (INIS)

    Baker, W.L.; Broderick, N.F.; Degnan, J.H.; Hussey, T.W.; Kiuttu, G.F.; Kloc, D.A.; Reinovsky, R.E.

    1983-01-01

    This chapter reports on the experimental and theoretical investigation of the generation of pulsed high-energy-density plasmas by electromagnetic implosion of cylindrical foils (i.e., imploding liners or hollow Z-pinches) at the Air Force Weapons Laboratory. Presents a comparison of experimental data with one-dimensional MHD and two-dimensional calculations. Points out that the study is distinct from other imploding liner efforts in that the approach is to produce a hot, dense plasma from the imploded liner itself, rather than to compress a magnetic-field-performed plasma mixture. The goal is to produce an intense laboratory pulsed X-ray source

  18. Self-focusing of a non-Gaussian laser mode in a dense plasma

    International Nuclear Information System (INIS)

    Nayyar, V.P.

    1978-01-01

    This paper presents a study of the self-focusing of a high-power non-Gaussian laser beam operating in TEM 01 mode in a strongly ionized plasma. The nonlinearity in the dielectric constant is caused by the nonuniform redistribution of carriers due to their inhomogeneous heating by the laser beam having transverse variation of intensity along its wave front. It is found that when the power of the beam exceeds the critical power, focusing effects are observed in the Y direction, whereas divergence of the beam takes place in the X direction. In the reverse case (when P 2 first increases in the Y direction, after penetrating a certain depth it reaches a broadened maxima and then starts decreasing with the distance of propagation inside the medium. The beam continues diverging in the X direction. It has also been found that absorption brings about a reduction in the extent of self-focusing. When the absorption length is less than the self-focusing length appreciable self-focusing does not take place

  19. Experimental study of a fast plasma focus discharge operated in the range of tens of joules emitting neutrons

    International Nuclear Information System (INIS)

    Tarifeno Saldivia, Eriel Esteban

    2011-01-01

    In this doctoral research, a small plasma focus discharge operated at tens of joules and kilo amperes has been experimentally studied. This device produces a coaxial discharge by an electrode arrange which consists of an inner electrode, a cylindrical insulator, and an outer electrode. The discharge is driven by a capacitive generator and it is operated at pressures of some millibars. Typical electrical parameters of the device are T/4∼150ns, 160 nF, 40 nH, 30-100J, 40-70kA. When Deuterium is used as filling gas, neutrons are produced by fusion reactions. The device, namely PF-50J, is one of the most extreme plasma focus reported in the literature to emit neutrons. The results of this work have demonstrated that the same dynamics found in larger machines (operated from kJ to MJ) is also found in this extremely low energy device which means that after the discharge is initiated, a plasma sheet is formed over the insulator. By the action of the Lorentz force, the plasma sheet moves axially. When the sheet reaches the top end of the inner electrode, it starts to implode radially to finally form a dense plasma column (pinch). Finally, the plasma column is disrupted 5-10ns after column formation. Shock piston velocities of the order of 10 4 -10 5 m/s were estimated from experiments for each discharge dynamical phase. Typical pinch densities of 10 24-25 m -3 were also observed in PF-50J. An interesting feature observed in this work is the formation of axial jet-like structures which appears at late times almost hundred nanoseconds after pinch disruption. These structures are composed by a metallic plasma which results from ablation of the inner electrode. The mechanism responsible for the formation of this kind of structure is still unknown, although evidence suggests that the phenomena is not related to the pinch formation process. One of the principal motivations of this thesis was to study the optimization for neutron emission in the PF-50J device. This plasma focus

  20. Plasma Photonic Devices for High Energy Density Science

    International Nuclear Information System (INIS)

    Kodama, R.

    2005-01-01

    High power laser technologies are opening a variety of attractive fields of science and technology using high energy density plasmas such as plasma physics, laboratory astrophysics, material science, nuclear science including medical applications and laser fusion. The critical issues in the applications are attributed to the control of intense light and enormous density of charged particles including efficient generation of the particles such as MeV electrons and protons with a current density of TA/cm2. Now these application possibilities are limited only by the laser technology. These applications have been limited in the control of the high power laser technologies and their optics. However, if we have another device consisted of the 4th material, i.e. plasma, we will obtain a higher energy density condition and explore the application possibilities, which could be called high energy plasma device. One of the most attractive devices has been demonstrated in the fast ignition scheme of the laser fusion, which is cone-guiding of ultra-intense laser light in to high density regions1. This is one of the applications of the plasma device to control the ultra-intense laser light. The other role of the devices consisted of transient plasmas is control of enormous energy-density particles in a fashion analogous to light control with a conventional optical device. A plasma fibre (5?m/1mm), as one example of the devices, has guided and deflected the high-density MeV electrons generated by ultra-intense laser light 2. The electrons have been well collimated with either a lens-like plasma device or a fibre-like plasma, resulting in isochoric heating and creation of ultra-high pressures such as Giga bar with an order of 100J. Plasmas would be uniquely a device to easily control the higher energy density particles like a conventional optical device as well as the ultra-intense laser light, which could be called plasma photonic device. (Author)

  1. The energy of perturbations for Vlasov plasmas

    International Nuclear Information System (INIS)

    Morrison, P.J.

    1994-02-01

    The energy content of electrostatic perturbations about homogeneous equilibria is discussed. The calculation leading to the well-known dielectric (or as it is sometimes called the wave) energy is revisited and interpreted in light of Vlasov theory. It is argued that this quantity is deficient because resonant particles are not correctly handled. A linear integral transform is presented that solves the linear Vlasov-Poisson equation. This solution together with the Kruskal-Oberman energy [Phys. Fluids 1, 275 (1958)] is used to obtain an energy expression in terms of the electric field [Phys. Fluids B 4, 3038 (1992)]. It is described how the integral transform amounts to a change to normal coordinates in an infinite dimensional Hamiltonian system

  2. Development of the dense plasma focus for short-pulse applications

    Science.gov (United States)

    Bennett, N.; Blasco, M.; Breeding, K.; Constantino, D.; DeYoung, A.; DiPuccio, V.; Friedman, J.; Gall, B.; Gardner, S.; Gatling, J.; Hagen, E. C.; Luttman, A.; Meehan, B. T.; Misch, M.; Molnar, S.; Morgan, G.; O'Brien, R.; Robbins, L.; Rundberg, R.; Sipe, N.; Welch, D. R.; Yuan, V.

    2017-01-01

    The dense plasma focus (DPF) has long been considered a compact source for pulsed neutrons and has traditionally been optimized for the total neutron yield. In this paper, we describe the efforts to optimize the DPF for short-pulse applications by introducing a reentrant cathode at the end of the coaxial plasma gun. The resulting neutron pulse widths are reduced by an average of 21 ±9 % from the traditional long-drift DPF design. Pulse widths and yields achieved from deuterium-tritium fusion at 2 MA are 61.8 ±30.7 ns FWHM and 1.84 ±0.49 ×1012 neutrons per shot. Simulations were conducted concurrently to elucidate the DPF operation and confirm the role of the reentrant cathode. A hybrid fluid-kinetic particle-in-cell modeling capability demonstrates correct sheath velocities, plasma instabilities, and fusion yield rates. Consistent with previous findings that the DPF is dominated by beam-target fusion from superthermal ions, we estimate that the thermonuclear contribution is at the 1% level.

  3. Dose-current discharge correlation analysis in a Mather type Plasma Focus device for medical applications

    Science.gov (United States)

    Sumini, M.; Mostacci, D.; Tartari, A.; Mazza, A.; Cucchi, G.; Isolan, L.; Buontempo, F.; Zironi, I.; Castellani, G.

    2017-11-01

    In a Plasma Focus device the plasma collapses into the pinch where it reaches thermonuclear conditions for a few tens of nanoseconds, becoming a multi-radiation source. The nature of the radiation generated depends on the gas filling the chamber and the device working parameters. The self-collimated electron beam generated in the backward direction with respect to the plasma motion is one of the main radiation sources of interest also for medical applications. The electron beam may be guided against a high Z material target to produce an X-ray beam. This technique offers an ultra-high dose rate source of X-rays, able to deliver during the pinch a massive dose (up to 1 Gy per discharge for the PFMA-3 test device), as measured with EBT3 GafchromicⒸfilm tissue equivalent dosimeters. Given the stochastic behavior of the discharge process, a reliable on-line estimate of the dose-delivered is a very challenging task, in some way preventing a systematic application as a potentially interesting therapy device. This work presents an approach to linking the dose registered by the EBT3 GafchromicⒸfilms with the information contained in the signal recorded during the current discharge process. Processing the signal with the Wigner-Ville distribution, a spectrogram was obtained, displaying the information on intensity at various frequency scales, identifying the band of frequencies representative of the pinch events and define some patterns correlated with the dose.

  4. Plasma focus neutron anisotropy measurements and influence of a deuteron beam obstacle

    Energy Technology Data Exchange (ETDEWEB)

    Talebitaher, A. [Physics Department, University of Regina, Saskatchewan, Canada S4S 0A2 (Canada); Springham, S.V., E-mail: stuart.springham@nie.edu.sg [Natural Sciences and Science Education, National Institute of Education, 637616 (Singapore); Rawat, R.S.; Lee, P. [Natural Sciences and Science Education, National Institute of Education, 637616 (Singapore)

    2017-03-11

    The deuterium-deuterium (DD) fusion neutron yield and anisotropy were measured on a shot-to-shot basis for the NX2 plasma focus (PF) device using two beryllium fast-neutron activation detectors at 0° and 90° to the PF axis. Measurements were performed for deuterium gas pressures in the range 6–16 mbar, and positive correlations between neutron yield and anisotropy were observed at all pressures. Subsequently, at one deuterium gas pressure (13 mbar), the contribution to the fusion yield produced by the forwardly-directed D{sup +} ion beam, emitted from the plasma pinch, was investigated by using a circular Pyrex plate to obstruct the beam and suppress its fusion contribution. Neutron measurements were performed with the obstacle positioned at two distances from the anode tip, and also without the obstacle. It was found that ~ 80% of the neutron yield originates in the plasma pinch column and just above that. In addition, proton pinhole imaging was performed from the 0° and 90° directions to the pinch. The obtained proton images are consistent with the conclusion that DD fusion is concentrated (~ 80%) in the pinch column region.

  5. Dense Plasma Focus-Based Nanofabrication of III-V Semiconductors: Unique Features and Recent Advances.

    Science.gov (United States)

    Mangla, Onkar; Roy, Savita; Ostrikov, Kostya Ken

    2015-12-29

    The hot and dense plasma formed in modified dense plasma focus (DPF) device has been used worldwide for the nanofabrication of several materials. In this paper, we summarize the fabrication of III-V semiconductor nanostructures using the high fluence material ions produced by hot, dense and extremely non-equilibrium plasma generated in a modified DPF device. In addition, we present the recent results on the fabrication of porous nano-gallium arsenide (GaAs). The details of morphological, structural and optical properties of the fabricated nano-GaAs are provided. The effect of rapid thermal annealing on the above properties of porous nano-GaAs is studied. The study reveals that it is possible to tailor the size of pores with annealing temperature. The optical properties of these porous nano-GaAs also confirm the possibility to tailor the pore sizes upon annealing. Possible applications of the fabricated and subsequently annealed porous nano-GaAs in transmission-type photo-cathodes and visible optoelectronic devices are discussed. These results suggest that the modified DPF is an effective tool for nanofabrication of continuous and porous III-V semiconductor nanomaterials. Further opportunities for using the modified DPF device for the fabrication of novel nanostructures are discussed as well.

  6. Hot electron spatial distribution under presence of laser light self-focusing in over-dense plasmas

    International Nuclear Information System (INIS)

    Tanimoto, T; Yabuuchi, T; Habara, H; Kondo, K; Kodama, R; Mima, K; Tanaka, K A; Lei, A L

    2008-01-01

    In fast ignition for laser thermonuclear fusion, an ultra intense laser (UIL) pulse irradiates an imploded plasma in order to fast-heat a high-density core with hot electrons generated in laser-plasma interactions. An UIL pulse needs to make plasma channel via laser self-focusing and to propagate through the corona plasma to reach close enough to the core. Hot electrons are used for heating the core. Therefore the propagation of laser light in the high-density plasma region and spatial distribution of hot electron are important in issues in order to study the feasibility of this scheme. We measure the spatial distribution of hot electron when the laser light propagates into the high-density plasma region by self-focusing

  7. Atomic Oxygen Energy in Low Frequency Hyperthermal Plasma Ashers

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K R.; Kneubel, Christian A.

    2014-01-01

    Experimental and analytical analysis of the atomic oxygen erosion of pyrolytic graphite as well as Monte Carlo computational modeling of the erosion of Kapton H (DuPont, Wilmington, DE) polyimide was performed to determine the hyperthermal energy of low frequency (30 to 35 kHz) plasma ashers operating on air. It was concluded that hyperthermal energies in the range of 0.3 to 0.9 eV are produced in the low frequency air plasmas which results in texturing similar to that in low Earth orbit (LEO). Monte Carlo computational modeling also indicated that such low energy directed ions are fully capable of producing the experimentally observed textured surfaces in low frequency plasmas.

  8. Staging laser plasma accelerators for increased beam energy

    International Nuclear Information System (INIS)

    Panasenko, Dmitriy; Shu, Anthony; Schroeder, Carl; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Cormier-Michel, Estelle; Plateau, Guillaume; Lin, Chen; Toth, Csaba; Geddes, Cameron; Esarey, Eric; Leemans, Wim

    2008-01-01

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  9. Locally Appropriate Energy Strategies for the Developing World: A focus on Clean Energy Opportunities in Borneo

    Science.gov (United States)

    Shirley, Rebekah Grace

    This dissertation focuses on an integration of energy modeling tools to explore energy transition pathways for emerging economies. The spate of growth in the global South has led to a global energy transition, evidenced in part by a surge in the development of large scale energy infrastructure projects for the provision of reliable electricity service. The rational of energy security and exigency often usher these large scale projects through to implementation with minimal analysis of costs: social and environmental impact, ecological risk, or opportunity costs of alternative energy transition pathways foregone. Furthermore, development of energy infrastructure is inherently characterized by the involvement of a number of state and non-state actors, with varying interests, objectives and access to authority. Being woven through and into social institutions necessarily impacts the design, control and functionality of infrastructure. In this dissertation I therefore conceptualize energy infrastructure as lying at the intersection, or nexus, of people, the environment and energy security. I argue that energy infrastructure plans and policy should, and can, be informed by each of these fields of influence in order to appropriately satisfy local development needs. This case study explores the socio-techno-environmental context of contemporary mega-dam development in northern Borneo. I describe the key actors of an ongoing mega-dam debate and the constellation of their interaction. This highlights the role that information may play in public discourse and lends insight into how inertia in the established system may stymie technological evolution. I then use a combination of power system simulation, ecological modeling and spatial analysis to analyze the potential for, and costs and tradeoffs of, future energy scenarios. In this way I demonstrate reproducible methods that can support energy infrastructure decision making by directly addressing data limitation barriers. I

  10. A review of ocean energy converters, with an Australian focus

    Directory of Open Access Journals (Sweden)

    Chris Knight

    2014-08-01

    Full Text Available The requirement to move away from carbon based fossil fuels has led to a renewed interest in unconventional energy sources. Of interest in this article are ocean waves and current and tidal flows. This paper reviews the numerous options for ocean energy conversion systems that are currently available. A basic nomenclature for the variety of systems is utilized to classify the devices. A variety of issues including competing use, boating, fishing, commercial shipping and tourism are discussed with respect to impacts on and from ocean renewable energy.

  11. Study of the thermal effect on silicon surface induced by ion beam from plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Z., E-mail: pscientific5@aec.org.sy [Scientific Service Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Ahmad, M. [IBA Laboratory, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Chemistry Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic); Al-Hawat, Sh.; Akel, M. [Physics Department, Atomic Energy Commission of Syria, P.O. Box: 6091, Damascus (Syrian Arab Republic)

    2017-04-01

    Structural modifications in form of ripples and cracks are induced by nitrogen ions from plasma focus on silicon surface. The investigation of such structures reveals correlation between ripples and cracks formation in peripheral region of the melt spot. The reason of such correlation and structure formation is explained as result of thermal effect. Melting and resolidification of the center of irradiated area occur within one micro second of time. This is supported by a numerical simulation used to investigate the thermal effect induced by the plasma focus ion beams on the silicon surface. This simulation provides information about the temperature profile as well as the dynamic of the thermal propagation in depth and lateral directions. In accordance with the experimental observations, that ripples are formed in latter stage after the arrival of last ion, the simulation shows that the thermal relaxation takes place in few microseconds after the end of the ion beam arrival. Additionally, the dependency of thermal propagation and relaxation on the distance of the silicon surface from the anode is presented.

  12. Synthesis of nanostructured multiphase Ti(C,N)/a-C films by a plasma focus device

    International Nuclear Information System (INIS)

    Ghareshabani, E.; Rawat, R.S.; Sobhanian, S.; Verma, R.; Karamat, S.; Pan, Z.Y.

    2010-01-01

    Nanostructured multiphase Ti(C,N)/a-C films were deposited using a 3.3 kJ pulsed plasma focus device onto silicon (1 0 0) substrates at room temperature. The plasma focus device, fitted with solid titanium anode instead of usual hollow copper anode, was operated with nitrogen and Ar/CH 4 as the filling gas. Films were deposited with different number of shots, at 80 mm from top of the anode and at zero angular position with respect to anode axis. X-ray diffraction results show the diffraction peaks related to different compounds such as TiC 2 , TiN, Ti 2 CN, Ti and TiC 0.62 confirming the deposition of multiphase titanium carbo-nitride composite films on silicon. X-ray photoelectron spectroscopy confirms the formation of Ti-C, C-N, Ti-N, Ti-O and C-C bonds in the films. Scanning electron microscopy reveals that the nanostructure grains are agglomerates of smaller nanoparticles about 10-20 nm in size. Raman studies verify the formation of multiphase Ti(C,N) and also of amorphous graphite in the films. The maximum microhardness value of the composite film is 14.8 ± 1.3 GPa for 30 shots.

  13. The pressure, internal energy, and conductivity of tantalum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Apfelbaum, E.M. [Russian Academy of Sciences, Joint Institute for High Temperatures, Department of Computational Physics, Moscow (Russian Federation)

    2017-11-15

    The pressure, internal energy, and conductivity of a tantalum plasma were calculated at the temperatures 10-100 kK and densities less than 3 g/cm{sup 3}. The plasma composition, pressure, and internal energy were obtained by means of the corresponding system of the coupled mass action law equations. We have considered atom ionization up to +3. The conductivity was calculated within the relaxation time approximation. Comparisons of our results with available measurements and calculation data show good agreement in the area of correct applicability of the present model. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Theory and application of maximum magnetic energy in toroidal plasmas

    International Nuclear Information System (INIS)

    Chu, T.K.

    1992-02-01

    The magnetic energy in an inductively driven steady-state toroidal plasma is a maximum for a given rate of dissipation of energy (Poynting flux). A purely resistive steady state of the piecewise force-free configuration, however, cannot exist, as the periodic removal of the excess poloidal flux and pressure, due to heating, ruptures the static equilibrium of the partitioning rational surfaces intermittently. The rupture necessitates a plasma with a negative q'/q (as in reverse field pinches and spheromaks) to have the same α in all its force-free regions and with a positive q'/q (as in tokamaks) to have centrally peaked α's

  15. Knowing the dense plasma focus - The coming of age (of the PF) with broad-ranging scaling laws

    Science.gov (United States)

    Saw, S. H.; Lee, S.

    2017-03-01

    The dense plasma focus is blessed not only with copious multi-radiations ranging from electron and ion beams, x-rays both soft and hard, fusion neutrons D-D and D-T but also with the property of enhanced compression from radiative collapse leading to HED (high energy density) states. The Lee code has been used in extensive systematic numerical experiments tied to reality through fitting with measured current waveforms and verified through comparison of measured and computed yields and measurements of multi-radiation. The studies have led to establishment of scaling laws with respect to storage energy, discharge current and pinch currents for fusion neutrons, characteristic soft x-rays, all-line radiation and ion beams. These are summarized here together with a first-time presentation of a scaling law of radiatively enhanced compression as a function of atomic number of operational gas. This paper emphasizes that such a broad range of scaling laws signals the coming of age of the DPF and presents a reference platform for planning the many potential applications such as in advanced SXR lithography, materials synthesizing and testing, medical isotopes, imaging and energy and high energy density (HED).

  16. Dynamics of 120 and 20 kV plasma focus devices with respect to density and current distribution, neutron and X-ray emission

    International Nuclear Information System (INIS)

    Decker, G.; Nahrath, B.; Oppenlaender, T.; Pross, G.; Rueckle, B.; Schmidt, H.; Shakhatre, M.; Trunk, M.

    1976-01-01

    Our experiments have aimed at two goals: 1) better understanding of the dynamics and neutron production of the focus phase and 2) improved scaling of the neutron yield by operating a high voltage focus. 1) For the first goal, experiments with a 30 kJ/ 16 kV plasma focus of the Mather type (NESSI) were performed. The simultaneously applied diagnostics include interferometry, X-ray photography with channel plates, magnetic probes and neutron emission. In the established chronology we can distinguish 5 phases in the development of the plasma focus: a compression phase is followed by a short (8 ns) very dense phase, where the density peaks at a minimum radius (t = 0 in our chronology). The plasma cylinder expands to a relatively long lasting (30 to 70 ns) quiescent phase before instabilities occur. This short unstable phase is followed by a decay phase during which the neutron emission peaks. Important correlations between the plasma parameters and the neutron emission are discussed. 2) Under the assumption that the neutron yield scales with a high power of the current, we concluded that a high voltage focus could result in higher neutron yield as compared with a lower voltage device of the same energy. The proper adjustments of the discharge parameters necessary due to the very short current risetime have been investigated. (orig.) [de

  17. Dynamics of 120 and 20 kV plasma focus devices with respect to density and current distribution, and neutron and X-ray emission

    International Nuclear Information System (INIS)

    Decker, G.; Nahrath, B.; Oppenlaender, T.; Pross, G.; Rueckle, B.; Schmidt, H.; Shakhatre, M.; Trunk, M.

    1977-01-01

    The experiments had two goals: (1) Better understanding of the dynamics and neutron production of the focus phase and (2) improved scaling of the neutron yield by operating a high-voltage focus. For the first goal, experiments with a 30-kJ/16-kV plasma focus of the Mather type (NESSI) were performed. The simultaneously applied diagnostics include interferometry, X-ray photography with channel plates, magnetic probes and scintillator/photomultiplier detectors for measuring hard X-ray and neutron emission. In the established chronology one can distinguish five phases in the development of the plasma focus: A compression phase is followed by a short (8 ns) very dense phase, where the density peaks at a minimum radius (t=0, authors' chronology). The plasma cylinder expands to a relatively long-lasting (30 to 70 ns) quiescent phase before instabilities occur. This short unstable phase is followed by a decay phase during which the neutron emission peaks. Important correlations between the plasma parameters and the neutron emission are discussed. Secondly, on the assumption that the neutron yield scales with a high power of the current, it was concluded that a high-voltage focus could result in higher neutron yield as compared with a lower voltage device of the same energy. The proper adjustments of the discharge parameters necessary due to the very short current risetime were investigated. (author)

  18. Coating of Titanium Nitride on Stainless Steel Targets by a 4 kJ Plasma Focus Device

    Science.gov (United States)

    Omrani, M.; Habibi, M.; Amrollahi, R.

    2012-08-01

    Titanium nitride thin films were deposited on stainless steel (SS316L) targets by using a 4 kJ plasma focus device. The corresponding energy flux delivered to SS316L surface is estimated to be 2.69 × 1013 kev cm-3 ns-1. X-ray diffraction analysis reveals the formation of a nanocrystalline titanium nitride coating on the surface of targets. Thickness of the elements found on the surface of treated samples which are obtained by Rutherford backscattering spectrometry analysis (RBS) were (×1015 at/cm2) .45% Ti, 50% N and 5% Fe. Scanning electron microscopy was used to indicate changes in surface morphology. Existence of grains in different size confirms the formation of TiN crystals on the surface of targets.

  19. Theoretical Study of the Endogenous Production of N-13 in 115 kJ Plasma Focus Device Using Methane Gas

    Science.gov (United States)

    Faghih Haghani, Saeedeh; Sadighzadeh, A.; Talaei, A.; Zaeem, A. A.; Sadat Kiai, S. M.; Heydarnia, A.; Damideh, V.

    2013-08-01

    Mather type plasma focus device with the bank energy of 115 kJ (40 kV, 144μF) was studied for induced activity of N-13; a short-lived radioisotope β+ emitter with 511 keV of gamma rays and has a half-life of t1/2 = 9.93 min through 12C (d, n)13N nuclear reaction. N-13 radioisotope is used in Positron Emission Tomography (PET) for imaging and treatment. In this paper endogenous production of 13N is considered. It is shown by adding 3-4 % CH4 to the chamber, the induced activity of N-13 has increased about 4 %. Our study is representative of producing 106 - 109 Bq induced activity of this SLR in IR-MPF-100 device.

  20. Plasma thermal energy transport: theory and experiments

    International Nuclear Information System (INIS)

    Coppi, B.

    Experiments on the transport across the magnetic field of electron thermal energy are reviewed (Alcator, Frascati Torus). In order to explain the experimental results, a transport model is described that reconfirmed the need to have an expression for the local diffusion coefficient with a negative exponent of the electron temperature

  1. Ultrafast laser driven micro-lens to focus and energy select MeV protons

    International Nuclear Information System (INIS)

    Toncian, Toma

    2008-05-01

    A technique for simultaneous focusing and energy selection of high-current, MeV proton beams using radial, transient electric fields (10 7 -10 10 V/m) triggered on the inner wall of a hollow micro-cylinder by an intense, sub-picosecond laser-pulse is presented. Due to the transient nature of the radial focusing field, the proposed method allows selection of a desired range out of the spectrum of the poly-energetic proton beam. This technique addresses current drawbacks of laser-accelerated proton beams, i.e. their broad spectrum and divergence at the source. This thesis presents both experimental and computational studies that led to the understanding of the physical processes driving the micro-lens. After an one side irradiation of a hollow metallic cylinder a radial electric field develops inside the cylinder. Hot electrons generated by the interaction between laser pulse and cylinder wall spread inside the cylinder generating a plasma at the wall. This plasma expands into vacuum and sustains an electric field that acts as a collecting lens on a proton beam propagating axially through the cylinder. Both focusing and the reduction of the intrinsic beam divergence from 20 deg to.3 deg for a narrow spectral range was demonstrated. By sub-aperturing the beam a narrow spectral range (δε/ε < 3%) was selected from the poly-energetic beam. The micro-lens properties are tunable allowing for optimization towards applications. Optical probing techniques and proton imaging were employed to study the spacial and temporal evolution of the field and revealed a complex physical scenario of the rise and decay of the radial electric field. Each aspect studied experimentally is interpreted using 2D PIC and ray tracing simulations. A very good agreement between the experimental and computational data is found. The PIC simulations are used to upscale the demonstrated micro-lens capabilities to the focusing of a 270 MeV proton beam, an energy relevant for medical applications such

  2. Ultrafast laser driven micro-lens to focus and energy select MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Toncian, Toma

    2008-05-15

    A technique for simultaneous focusing and energy selection of high-current, MeV proton beams using radial, transient electric fields (10{sup 7}-10{sup 10} V/m) triggered on the inner wall of a hollow micro-cylinder by an intense, sub-picosecond laser-pulse is presented. Due to the transient nature of the radial focusing field, the proposed method allows selection of a desired range out of the spectrum of the poly-energetic proton beam. This technique addresses current drawbacks of laser-accelerated proton beams, i.e. their broad spectrum and divergence at the source. This thesis presents both experimental and computational studies that led to the understanding of the physical processes driving the micro-lens. After an one side irradiation of a hollow metallic cylinder a radial electric field develops inside the cylinder. Hot electrons generated by the interaction between laser pulse and cylinder wall spread inside the cylinder generating a plasma at the wall. This plasma expands into vacuum and sustains an electric field that acts as a collecting lens on a proton beam propagating axially through the cylinder. Both focusing and the reduction of the intrinsic beam divergence from 20 deg to.3 deg for a narrow spectral range was demonstrated. By sub-aperturing the beam a narrow spectral range ({delta}{epsilon}/{epsilon} < 3%) was selected from the poly-energetic beam. The micro-lens properties are tunable allowing for optimization towards applications. Optical probing techniques and proton imaging were employed to study the spacial and temporal evolution of the field and revealed a complex physical scenario of the rise and decay of the radial electric field. Each aspect studied experimentally is interpreted using 2D PIC and ray tracing simulations. A very good agreement between the experimental and computational data is found. The PIC simulations are used to upscale the demonstrated micro-lens capabilities to the focusing of a 270 MeV proton beam, an energy relevant

  3. Geomagnetic activity effects on plasma sheet energy conversion

    Directory of Open Access Journals (Sweden)

    M. Hamrin

    2010-10-01

    Full Text Available In this article we use three years (2001, 2002, and 2004 of Cluster plasma sheet data to investigate what happens to localized energy conversion regions (ECRs in the plasma sheet during times of high magnetospheric activity. By examining variations in the power density, E·J, where E is the electric field and J is the current density obtained by Cluster, we have studied the influence on Concentrated Load Regions (CLRs and Concentrated Generator Regions (CGRs from variations in the geomagnetic disturbance level as expressed by the Kp, the AE, and the Dst indices. We find that the ECR occurrence frequency increases during higher magnetospheric activities, and that the ECRs become stronger. This is true both for CLRs and for CGRs, and the localized energy conversion therefore concerns energy conversion in both directions between the particles and the fields in the plasma sheet. A higher geomagnetic activity hence increases the general level of energy conversion in the plasma sheet. Moreover, we have shown that CLRs live longer during magnetically disturbed times, hence converting more electromagnetic energy. The CGR lifetime, on the other hand, seems to be unaffected by the geomagnetic activity level. The evidence for increased energy conversion during geomagnetically disturbed times is most clear for Kp and for AE, but there are also some indications that energy conversion increases during large negative Dst. This is consistent with the plasma sheet magnetically mapping to the auroral zone, and therefore being more tightly coupled to auroral activities and variations in the AE and Kp indices, than to variations in the ring current region as described by the Dst index.

  4. Energy Conversion in Imploding Z-Pinch Plasma

    International Nuclear Information System (INIS)

    Fisher, V.I.; Gregorian, L.; Davara, G.; Kroupp, E.; Bernshtam, V.A.; Ralchenko, Yu. V.; Starobinets, A.; Maron, Y.

    2002-01-01

    Due to important applications, Z-pinches became a subject of extensive studies. In these studies, main attention is directed towards improvement in efficiency of electric energy conversion into high-power radiation burst. At present, knowledge available on physics of Z-pinch operation, plasma motion, atomic kinetics, and energy conversion is mainly knowledge of numerical simulation results. We believe further progress require (i) experimental determination of spatial distribution and time history of thermodynamic parameters and magnetic field, as well as (ii) utilization of this data for experiment-based calculation of r,t-distribution of driving forces, mass and energy fluxes, and local energy deposition rates due to each of contributing mechanisms, what provides an insight into a process of conversion of stored electric energy into radiation burst. Moreover, experimentally determined r, t-distribution of parameters may serve for verification of computer programs developed for simulation of Z-pinch operation and optimization of radiation output. Within this research program we performed detailed spectroscopic study of plasmas imploding in modest-size (25 kV, 5 kJ, 1.2 μs quaterperiod) gas-puff Z-pinch. This facility has reasonably high repetition rate and provides good reproducibility of results. Consistent with plasma ionization degree in the implosion period, measurements are performed in UV-visible spectral range. Observation of spectral lines emitted at various azimuthal angles f showed no dependence on f. Dependence on axial coordinate z is found to be weak in near-anode half of the anode-cathode gap. Based on these observations and restricting the measurements to near-anode half of the gap, an evolution of parameters is studied in time and radial coordinate r only. In present talk we report on determination of radial component of plasma hydrodynamic velocity u r (r,t), magnetic field B ζ (r,t), electron density n e (r,t), density of ions in various

  5. Energy loss of heavy ion beams in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Okada, T; Hotta, T [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology

    1997-12-31

    The energy loss of heavy-ion beams (HIB) is studied by means of Vlasov theory and Particle-in-Cell (PIC) simulations in a plasma. The interaction of HIB with a plasma is of central importance for inertial confinement fusion (ICF). A number of studies on the HIB interaction with target plasma have been published. It is important for heavy-ion stopping that the effects of the non-linear interaction of HIB within the Vlasov theory are included. Reported are results of a numerical study of nonlinear effects to the stopping power for HIB in plasma. It is shown that the PIC simulations of collective effects of the stopping power are in a good agreement with the Vlasov theory. (author). 2 tabs., 1 fig., 5 refs.

  6. High energy density Z-pinch plasmas using flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Shumlak, U., E-mail: shumlak@uw.edu; Golingo, R. P., E-mail: shumlak@uw.edu; Nelson, B. A., E-mail: shumlak@uw.edu; Bowers, C. A., E-mail: shumlak@uw.edu; Doty, S. A., E-mail: shumlak@uw.edu; Forbes, E. G., E-mail: shumlak@uw.edu; Hughes, M. C., E-mail: shumlak@uw.edu; Kim, B., E-mail: shumlak@uw.edu; Knecht, S. D., E-mail: shumlak@uw.edu; Lambert, K. K., E-mail: shumlak@uw.edu; Lowrie, W., E-mail: shumlak@uw.edu; Ross, M. P., E-mail: shumlak@uw.edu; Weed, J. R., E-mail: shumlak@uw.edu [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington, 98195-2250 (United States)

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  7. Optimization of sources for focusing wave energy in targeted formations

    KAUST Repository

    Jeong, C; Kallivokas, L F; Huh, C; Lake, L W

    2010-01-01

    that will maximize the kinetic energy in the target zone, while keeping silent the neighbouring zones. To this end, we cast the problem as an inverse-source problem, and use a partial-differential- equation-constrained optimization approach to arrive at an optimized

  8. Portable linear-focused solar thermal energy collecting system

    Science.gov (United States)

    Miller, C. G.; Pohl, J. G. (Inventor)

    1977-01-01

    A solar heat collection system is provided by utilizing a line-focusing device that is effectively a cylindrically curved concentrator within a protected environment formed by a transparent inflatable casing. A target, such as a fluid or gas carrying conduit is positioned within or near the casing containing the concentrator, at the line focus of the concentrator. The casing can be inflated at the site of use by a low pressure air supply to form a unitary light weight structure. The collector, including casing, concentrator and target, is readily transportable and can be used either at ground level or on rooftops. The inflatable concentrator can be replaced with a rigid metal or other concentrator while maintaining the novel advantages of the whole solar heat collection system.

  9. Energy distributions and radiation transport in uranium plasmas

    International Nuclear Information System (INIS)

    Miley, G.; Bathke, C.; Maceda, E.; Choi, C.

    1976-01-01

    Electron energy distribution functions have been calculated in a 235 U-plasma at 1 atmosphere for various plasma temperatures (5000 to 8000 0 K) and neutron fluxes (2 x 10 12 to 2 x 10 16 neutrons/(cm 2 -sec)). Two sources of energetic electrons are included; namely fission-fragment and electron-impact ionization, resulting in a high-energy tail superimposed on the thermalized electron distribution. Consequential derivations from equilibrium collision rates are of interest relative to direct pumping of lasers and radiation emission. Results suggest that non-equilibrium excitation can best be achieved with an additive gas such as helium or in lower temperature plasmas requiring UF 6 . An approximate analytic model, based on continuous electron slowing, has been used for survey calculations. Where more accuracy is required, a Monte Carlo technique is used which combines an analytic representation of Coulombic collisions with a random-walk treatment of inelastic collisions

  10. Design a 10 kJ IS Mather Type Plasma Focus for Solid Target Activation to Produce Short-Lived Radioisotopes 12C(d,n)13N

    Science.gov (United States)

    Sadat Kiai, S. M.; Adlparvar, S.; Sheibani, S.; Elahi, M.; Safarien, A.; Farhangi, S.; Zirak, A. R.; Alhooie, S.; Mortazavi, B. N.; Khalaj, M. M.; Khanchi, A. R.; Dabirzadeh, A. A.; Kashani, A.; Zahedi, F.

    2010-10-01

    A 10 kJ (15 kV, 88 μF) IS (Iranian Sun) Mather type plasma focus device has been studied to determine the activity of a compound exogenous carbon solid target through 12C(d,n)13N nuclear reaction. The produced 13N is a short-lived radioisotope with a half-life of 9.97 min and threshold energy of 0.28 MeV. The results indicate that energetic deuterons impinging on the solid target can produce yield of = 6.7 × 10-5 with an activity of A = 6.8 × 104 Bq for one plasma focus shut and A ν = 4 × 105 Bq for 6 shut per mint when the projectile maximum deuterons energy is E max = 3 MeV.

  11. Density Transition Based Self-Focusing of cosh-Gaussian Laser Beam in Plasma with Linear Absorption

    International Nuclear Information System (INIS)

    Kant, Niti; Wani, Manzoor Ahmad

    2015-01-01

    Density transition based self-focusing of cosh-Gaussian laser beam in plasma with linear absorption has been studied. The field distribution in the plasma is expressed in terms of beam width parameter, decentered parameter, and linear absorption coefficient. The differential equation for the beam width parameter is solved by following Wentzel–Kramers–Brillouin (WKB) and paraxial approximation through parabolic wave equation approach. The behaviour of beam width parameter with dimensionless distance of propagation is studied at optimum values of plasma density, decentered parameter and with different absorption levels in the medium. The results reveal that these parameters can affect the self-focusing significantly. (paper)

  12. Pinching evidences in a miniature plasma focus with fast pseudospark switch

    International Nuclear Information System (INIS)

    Hassan, S M; Zhang, T; Patran, A; Rawat, R S; Springham, S V; Tan, T L; Wong, D; Wang, W; Lee, S; Gribkov, V A; Mohanty, S R; Lee, P

    2006-01-01

    We report the observations of pinching in a miniature plasma focus (PF) (58-160 J) operated in repetitive mode using fast pseudospark switch (PSS). The size of the device, which includes the capacitor bank, PSS and the focus chamber, is of the order of 22 cm x 22 cm x 38 cm. Several diagnostic tools, the gated imager, streak camera, current and voltage probe, are employed simultaneously to confirm the occurrence of pinching in this fast miniature PF device. The device is optimized for operation in neon and hydrogen as the working gas. The best focus formation was obtained at pressures between 0.5 to 8.0 mbar for neon and between 7.0 to 15.0 mbar for hydrogen. When the system was operated at 100 J with hydrogen as the filling gas, the typical dip in the current derivative signal and the typical peak in the voltage signal associated with pinch compression, are observed to be most intense indicating efficient pinching in the miniature PF device

  13. Particle-in-cell simulations of high energy electron production by intense laser pulses in underdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Susumu, Kato; Eisuke, Miura; Kazuyoshi, Koyama [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Mitsumori, Tanimoto [Meisei Univ., Dept. of Electrical Engineering, Hino, Tokyo (Japan); Masahiro, Adachi [Hiroshima Univ., Graduate school of Advanced Science of Matter, Higashi-Hiroshima, Hiroshima (Japan)

    2004-07-01

    The propagation of intense laser pulses and the generation of high energy electrons from underdense plasmas are investigated using two dimensional particle-in-cell simulations. When the ratio of the laser power to the critical power of relativistic self-focusing gets the optimal value, the laser pulse propagates in a steady way and electrons have maximum energies. (author)

  14. Particle-in-cell simulations of high energy electron production by intense laser pulses in underdense plasmas

    International Nuclear Information System (INIS)

    Susumu, Kato; Eisuke, Miura; Kazuyoshi, Koyama; Mitsumori, Tanimoto; Masahiro, Adachi

    2004-01-01

    The propagation of intense laser pulses and the generation of high energy electrons from underdense plasmas are investigated using two dimensional particle-in-cell simulations. When the ratio of the laser power to the critical power of relativistic self-focusing gets the optimal value, the laser pulse propagates in a steady way and electrons have maximum energies. (author)

  15. Design, fabrication, and characterization of a 2.3 kJ plasma focus of negative inner electrode

    International Nuclear Information System (INIS)

    Mathuthu, M.; Zengeni, T.G.; Gholap, A.V.

    1997-01-01

    The design, fabrication, and characterization of a 2.3 kJ plasma focus device with negative inner electrode are discussed. The purpose of the design was to initiate research in and study of plasma dynamics, nuclear reactions, and neutron emission mechanisms at the university. Also the device will be used to teach and demonstrate plasma phenomena at the postgraduate level and to perform experiments with inverted polarity to examine different operating regimes with nonstandard gases. It is hoped that in the long run the research work will help find a solution to the polarity riddle of plasma focus devices. When the system was operated with spectrographic argon as the filling gas, the best focus was obtained at a pressure range of 0.1 endash 1.25 Torr. With nitrogen as the filling gas, the best focus was obtained at pressures between 0.1 and 1.25 Torr. Air gave the best focus at a pressure range of 0.5 endash 1.5 Torr. The observed good focus action is attributed to the small inner electrode length (this reduces the amount of anode material ablated into the current sheath) and tapering of the inner electrode. Positive z-directed electrons contribute to the temperature and further ionization of the plasma gas during focusing. The performance of the device compares quite well with other known devices. copyright 1997 American Institute of Physics

  16. Evidence of magnetic field in plasma focus by means of Faraday rotation measurements

    International Nuclear Information System (INIS)

    Fischfeld, G.

    1982-01-01

    Preliminary results of Faraday rotation measurements on a beam of laser light crossing the plasma column in the axial direction. are repacted. The presence of intense axial magnetic field Bsup(z) in the column both before and during the pinch phase is demonstrated. The experiments were performed on the Mather type Frascati 1 MJ plasma Focus, operated at 250 KJ 3 torr D 2 filling pressure. Is is used in the measurements a Quantel YG 49 YAG laser, frecuency doubled by means of KD*P crystal, which delivers about 60 mJ in 3 ns at = 530 nm. The beam polarization is analized by Wollaston prism. The electronic density is determined by Mach-Zender insterferometry. Two measurements are taken at time close to the end of the radial collapse phase, yielding Faraday rotation angles of 0.25 +- 0.05 rd and 0.56 +- o.05 rd which correspond to values, of axial magnetic fields of b(sup z) = 500 KG and B(sub z) = 400 KG. (Author) [pt

  17. Electromagnetic particle in cell modeling of the plasma focus: Current sheath formation and lift off

    International Nuclear Information System (INIS)

    Seng, Y. S.; Lee, P.; Rawat, R. S.

    2014-01-01

    The shaping and formation of the current sheath takes place in the breakdown phase of a plasma focus device and critically controls the device performance. Electrostatic particle in cell codes, with magnetic effects ignored, have been used to model the breakdown phase. This Letter reports the successful development and implementation of an electromagnetic particle in cell (EMPIC) code, including magnetic effects self-consistently, to simulate the breakdown phase; from the ionization, localization and gliding discharge along the insulator to the time instant of current sheath lift off. The magnetic field was found to be appreciable from the time the current sheath came into contact with the anode with increased local current, initiating the voltage breakdown of the device as a result

  18. Discrete focusing effect of positive ions by a plasma-sheath lens

    International Nuclear Information System (INIS)

    Stamate, E.; Sugai, H.

    2005-01-01

    We demonstrate that the sheath created adjacent to the surface of a negatively biased electrode that interfaces an insulator acts as a lens that focuses the positive ions to distinct regions on the surface. Thus, the positive ion flux is discrete, leading to the formation of a passive surface, of no ion impact, near the edge and an active surface at the center. Trajectories of positive ions within the sheath are obtained by solving in three dimensions the Poisson equation for electrodes of different geometry. Simulations are confirmed by developing the ion flux profile on the electrode surface as the sputtering pattern produced by ion impact. Measurements are performed in a dc plasma produced in Ar gas

  19. Efficacy of liver assisting in patients with hepatic encephalopathy with special focus on plasma exchange

    DEFF Research Database (Denmark)

    Stenbøg, Poul; Busk, Troels; Larsen, Fin Stolze

    2013-01-01

    Severe liver injury result in development of hepatic encephalopathy (HE) and often also in brain edema that is a potentially fatal complication. HE and brain edema are correlated to the level and persistence of hyperammonemia and the presence of systemic inflammation. Treatment of HE and brain...... edema is based on restoring and keeping normal physiological variables including tonicity, blood gasses, lactate, temperature and vascular resistance by a wide variety of interventions. In addition liver support devices improve the stage of HE, cerebral metabolic rate for oxygen and glucose......, and are used either as a bridge to liver transplantation or liver recovery in patients with fulminant hepatic failure and in patients with acute-on-chronic liver failure. This short review will mainly focus on the management and efficacy of doing plasma exchange on HE in patients with acute HE....

  20. Review of results from the FN-2 dense plasma focus machine

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, J.J.E.; Castillo, F.; Gamboa, I.; Rangel, J. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Golzarri, J.I.; Espinosa, G. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2004-07-01

    The FN-II is a small dense plasma focus (4.8 kJ at 36 kV), operating at the University of Mexico. Substantial effort has been dedicated to the study of the anisotropy in the neutron, proton and hard X-ray radiation. Concerning the neutron, it has been observed that there is an anisotropic distribution superposed on a far larger isotropic one. These clearly separated effects can be interpreted as the consequence of two different neutron emission mechanisms. The shape of the proton distribution is very similar to the neutron one. The angular distribution of hard X-rays and ions is also studied within the chamber with TLD and CR-39 detectors respectively. Two maxima are found around the axis of the device for X rays within the 20-200 keV range. (authors)

  1. Correlating neutron yield and reliability for selecting experimental parameters for a plasma focus machine

    International Nuclear Information System (INIS)

    Pross, G.

    Possibilities of optimizing focus machines with a given energy content in the sense of high neutron yield and high reliability of the discharges are investigated experimentally. For this purpose, a focus machine of the Mather type with an energy content of 12 kJ was constructed. The following experimental parameters were varied: the material of the insulator in the ignition zone, the structure of the outside electrode, the length of the inside electrode, the filling pressure and the amount and polarity of the battery voltage. An important part of the diagnostic program consists of measurements of the azimuthal and axial current distribution in the accelerator, correlated with short-term photographs of the luminous front as a function of time. The results are given. A functional schematic has been drafted for focus discharge as an aid in extensive optimization of focus machines, combining findings from theory and experiments. The schematic takes into account the multiparameter character of the discharge and clarifies relationships between the experimental parameters and the target variables neutron yield and reliability

  2. Simulation of high-energy particle production through sausage and kink instabilities in pinched plasma discharges

    International Nuclear Information System (INIS)

    Haruki, Takayuki; Yousefi, Hamid Reza; Masugata, Katsumi; Sakai, Jun-Ichi; Mizuguchi, Yusuke; Makino, Nao; Ito, Hiroaki

    2006-01-01

    In an experimental plasma, high-energy particles were observed by using a plasma focus device, to obtain energies of a few hundred keV for electrons, up to MeV for ions. In order to study the mechanism of high-energy particle production in pinched plasma discharges, a numerical simulation was introduced. By use of a three-dimensional relativistic and fully electromagnetic particle-in-cell code, the dynamics of a Z-pinch plasma, thought to be unstable against sausage and kink instabilities, are investigated. In this work, the development of sausage and kink instabilities and subsequent high-energy particle production are shown. In the model used here, cylindrically distributed electrons and ions are driven by an external electric field. The driven particles spontaneously produce a current, which begins to pinch by the Lorentz force. Initially the pinched current is unstable against a sausage instability, and then becomes unstable against a kink instability. As a result high-energy particles are observed

  3. Energy and environment market conditions in Mexico. Business focus series

    International Nuclear Information System (INIS)

    1992-03-01

    The report provides: (1) an overview of the Mexican economy and the energy and environmental sectors; (2) specific market assessments of the oil and gas sector, the electric power sector, the industrial air pollution control sector, and the municipal and industrial water pollution control sector; and (3) an analysis of the Mexican business climate and procedures. Each of the sectors is projected to show significant growth over the next several years. The Mexican government has taken many positive steps to improve the country's business climate, including trade and foreign exchange liberalization, foreign investment incentives, and strengthened intellectual property regulation. The North American Free Trade Agreement is expected to further improve the business climate in Mexico

  4. Main theorems of thermodynamics focused on future energy supply

    Energy Technology Data Exchange (ETDEWEB)

    Knizia, K

    1983-09-01

    Proceeding from the ethical aim to minimize sufferings, we have to develop rules of conduct which take into account the effects of our actions which in our complex world reach spatially as well as temporally further than in previous times. The basic laws of nature which govern our activities include the first and the second main theorems of thermodynamics. It is especially the second main theorem which also represent the creative principle of shaping and maintaining order and structures. In general, this is achieved by the use of the production factors: energy - information - matter. This also applies to the human creativity, including specific adjustment of these production factors related to man and his environment. It is only the correct use which can achieve an adequate supply of goods for a still growing world population, together with its peaceful and humane numerical stabilisation, satisfactory environment protection and careful consumption of raw material reserves.

  5. Generation of second-harmonic radiations of a self-focusing laser from a plasma with density-transition

    International Nuclear Information System (INIS)

    Kant, Niti; Gupta, Devki Nandan; Suk, Hyyong

    2011-01-01

    A Gaussian laser-beam resonantly generates a second-harmonic wave in a plasma in the presence of a wiggler magnetic-field of suitable period. The self-focusing of the fundamental pulse enhances the intensity of the second-harmonic pulse. An introduction of an upward plasma-density ramp strongly enhances the self-focusing of the fundamental laser pulse. The laser pulse attains a minimum spot size and propagates up to several Rayleigh lengths without divergence. Due to the strong self-focusing of the fundamental laser pulse, the second-harmonic intensity enhances significantly. A considerable enhancement of the intensity of the second-harmonic is observed from the proposed mechanism. -- Highlights: → An upward plasma-density ramp is very important for laser propagation in plasmas. → As the plasma density increases, effect of self-focusing becomes stronger. → We utilize this self-focused laser to generate second-harmonic radiations. → The self-focusing laser enhances the intensity of the second-harmonic pulse.

  6. Generation of second-harmonic radiations of a self-focusing laser from a plasma with density-transition

    Energy Technology Data Exchange (ETDEWEB)

    Kant, Niti [Department of Physics, Lovely Professional University, Phagwara 144 402, Punjab (India); Gupta, Devki Nandan, E-mail: dngupta@physics.du.ac.in [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Suk, Hyyong [Advanced Photonics Research Institute (APRI) and Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500 712 (Korea, Republic of)

    2011-08-15

    A Gaussian laser-beam resonantly generates a second-harmonic wave in a plasma in the presence of a wiggler magnetic-field of suitable period. The self-focusing of the fundamental pulse enhances the intensity of the second-harmonic pulse. An introduction of an upward plasma-density ramp strongly enhances the self-focusing of the fundamental laser pulse. The laser pulse attains a minimum spot size and propagates up to several Rayleigh lengths without divergence. Due to the strong self-focusing of the fundamental laser pulse, the second-harmonic intensity enhances significantly. A considerable enhancement of the intensity of the second-harmonic is observed from the proposed mechanism. -- Highlights: → An upward plasma-density ramp is very important for laser propagation in plasmas. → As the plasma density increases, effect of self-focusing becomes stronger. → We utilize this self-focused laser to generate second-harmonic radiations. → The self-focusing laser enhances the intensity of the second-harmonic pulse.

  7. Plasma screening effects on the energies of hydrogen atom

    International Nuclear Information System (INIS)

    Soylu, A.

    2012-01-01

    A more general exponential cosine screened Coulomb potential is used for the first time to investigate the screening effects on the hydrogen atom in plasmas. This potential is examined for four different cases that correspond to four different type potentials when the different parameters are used in the potential within the framework of the well-known asymptotic iteration method. By solving the corresponding the radial Schrödinger equation with the screened and exponential cosine screened Coulomb potentials and comparing the obtained energy eigenvalues with the results of other studies, the applicability of the method to this kind of plasma physics problem is shown. The energy values of more general exponential cosine screened Coulomb potential are presented for various parameters in the potential. One of the advantages of the present potential is that it exhibits stronger screening effect than that of the exponential cosine screened Coulomb potential and it is also reduced to screened Coulomb and exponential cosine screened Coulomb as well as Coulomb potentials for special values of parameters. The parameters in the potential would be useful to model screening effects which cause an increase or decrease in the energy values of hydrogen atom in both Debye and quantum plasmas and in this manner this potential would be useful for the investigations of the atomic structure and collisions in plasmas.

  8. Conservation of energy and momentum in nonrelativistic plasmas

    International Nuclear Information System (INIS)

    Sugama, H.; Watanabe, T.-H.; Nunami, M.

    2013-01-01

    Conservation laws of energy and momentum for nonrelativistic plasmas are derived from applying Noether's theorem to the action integral for the Vlasov-Poisson-Ampère system [Sugama, Phys. Plasmas 7, 466 (2000)]. The symmetric pressure tensor is obtained from modifying the asymmetric canonical pressure tensor with using the rotational symmetry of the action integral. Differences between the resultant conservation laws and those for the Vlasov-Maxwell system including the Maxwell displacement current are clarified. These results provide a useful basis for gyrokinetic conservation laws because gyrokinetic equations are derived as an approximation of the Vlasov-Poisson-Ampère system.

  9. Wave energy focusing to subsurface poroelastic formations to promote oil mobilization

    KAUST Repository

    Karve, P. M.; Kallivokas, L. F.

    2015-01-01

    We discuss an inverse source formulation aimed at focusing wave energy produced by ground surface sources to target subsurface poroelastic formations. The intent of the focusing is to facilitate or enhance the mobility of oil entrapped within

  10. FUSION ENERGY SCIENCES WORKSHOP ON PLASMA MATERIALS INTERACTIONS: Report on Science Challenges and Research Opportunities in Plasma Materials Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, Rajesh [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Zinkle, Steven J. [University of Tennessee – Knoxville; Foster, Mark S. [U.S. Department of Energy

    2015-05-01

    The realization of controlled thermonuclear fusion as an energy source would transform society, providing a nearly limitless energy source with renewable fuel. Under the auspices of the U.S. Department of Energy, the Fusion Energy Sciences (FES) program management recently launched a series of technical workshops to “seek community engagement and input for future program planning activities” in the targeted areas of (1) Integrated Simulation for Magnetic Fusion Energy Sciences, (2) Control of Transients, (3) Plasma Science Frontiers, and (4) Plasma-Materials Interactions aka Plasma-Materials Interface (PMI). Over the past decade, a number of strategic planning activities1-6 have highlighted PMI and plasma facing components as a major knowledge gap, which should be a priority for fusion research towards ITER and future demonstration fusion energy systems. There is a strong international consensus that new PMI solutions are required in order for fusion to advance beyond ITER. The goal of the 2015 PMI community workshop was to review recent innovations and improvements in understanding the challenging PMI issues, identify high-priority scientific challenges in PMI, and to discuss potential options to address those challenges. The community response to the PMI research assessment was enthusiastic, with over 80 participants involved in the open workshop held at Princeton Plasma Physics Laboratory on May 4-7, 2015. The workshop provided a useful forum for the scientific community to review progress in scientific understanding achieved during the past decade, and to openly discuss high-priority unresolved research questions. One of the key outcomes of the workshop was a focused set of community-initiated Priority Research Directions (PRDs) for PMI. Five PRDs were identified, labeled A-E, which represent community consensus on the most urgent near-term PMI scientific issues. For each PRD, an assessment was made of the scientific challenges, as well as a set of actions

  11. Modelling of the energy density deposition profiles of ultrashort laser pulses focused in optical media

    International Nuclear Information System (INIS)

    Vidal, F; Lavertu, P-L; Bigaouette, N; Moore, F; Brunette, I; Giguere, D; Kieffer, J-C; Olivie, G; Ozaki, T

    2007-01-01

    The propagation of ultrashort laser pulses in dense optical media is investigated theoretically by solving numerically the nonlinear Schroedinger equation. It is shown that the maximum energy density deposition as a function of the pulse energy presents a well-defined threshold that increases with the pulse duration. As a consequence of plasma defocusing, the maximum energy density deposition is generally smaller and the size of the energy deposition zone is generally larger for shorter pulses. Nevertheless, significant values of the energy density deposition can be obtained near threshold, i.e., at lower energy than for longer pulses

  12. Propulsion and Power Generation Capabilities of a Dense Plasma Focus (DPF) Fusion System for Future Military Aerospace Vehicles

    International Nuclear Information System (INIS)

    Knecht, Sean D.; Mead, Franklin B.; Thomas, Robert E.; Miley, George H.; Froning, David

    2006-01-01

    The objective of this study was to perform a parametric evaluation of the performance and interface characteristics of a dense plasma focus (DPF) fusion system in support of a USAF advanced military aerospace vehicle concept study. This vehicle is an aerospace plane that combines clean 'aneutronic' dense plasma focus (DPF) fusion power and propulsion technology, with advanced 'lifting body'-like airframe configurations utilizing air-breathing MHD propulsion and power technology within a reusable single-stage-to-orbit (SSTO) vehicle. The applied approach was to evaluate the fusion system details (geometry, power, T/W, system mass, etc.) of a baseline p-11B DPF propulsion device with Q = 3.0 and thruster efficiency, ηprop = 90% for a range of thrust, Isp and capacitor specific energy values. The baseline details were then kept constant and the values of Q and ηprop were varied to evaluate excess power generation for communication systems, pulsed-train plasmoid weapons, ultrahigh-power lasers, and gravity devices. Thrust values were varied between 100 kN and 1,000 kN with Isp of 1,500 s and 2,000 s, while capacitor specific energy was varied from 1 - 15 kJ/kg. Q was varied from 3.0 to 6.0, resulting in gigawatts of excess power. Thruster efficiency was varied from 0.9 to 1.0, resulting in hundreds of megawatts of excess power. Resulting system masses were on the order of 10's to 100's of metric tons with thrust-to-weight ratios ranging from 2.1 to 44.1, depending on capacitor specific energy. Such a high thrust/high Isp system with a high power generation capability would allow military versatility in sub-orbital space, as early as 2025, and beyond as early as 2050. This paper presents the results that coincide with a total system mass between 15 and 20 metric tons

  13. Energy absorption in cold inhomogeneous plasmas - The Herlofson paradox.

    Science.gov (United States)

    Crawford, F. W.; Harker, K. J.

    1972-01-01

    Confirmation of Barston's (1964) conclusions regarding the underlying mechanism of the Herlofson paradox by examining in detail several analytically tractable cases of delta-function and sinusoidal excitation. The effects of collisions and nonzero electron temperature in determining the steady state fields and dissipation are considered. Energy absorption without dissipation in plasmas is shown to be analogous to that occurring after application of a signal to a network of lossless resonant circuits. This analogy is pursued and is extended to cover Landau damping in a warm homogeneous plasma in which the resonating elements are the electron streams making up the velocity distribution. Some of the practical consequences of resonant absorption are discussed, together with a number of paradoxical plasma phenomena which can also be elucidated by considering a superposition of normal modes rather than a single Fourier component.

  14. Theoretical characterization of electron energy distribution function in RF plasmas

    International Nuclear Information System (INIS)

    Capitelli, M.; Capriati, G.; Dilonardo, M.; Gorse, C.; Longo, S.

    1993-01-01

    Different methods for the modeling of low-temperature plasmas of both technological and fundamental interest are discussed. The main concept of all these models is the electron energy distribution function (eedf) which is necessary to calculate the rate coefficients for any chemical reaction involving electrons. Results of eedf calculations in homogeneous SF 6 and SiH 4 plasmas are discussed based on solution of the time-dependent Boltzmann equation. The space-dependent eedf in an RF discharge in He is calculated taking into account the sheath oscillations by a Monte Carlo model assuming the plasma heating mechanism and the electric field determined by using a fluid model. The need to take into account the ambipolar diffusion of electrons in RF discharge modeling is stressed. A self-consistent model based on coupling the equations of the fluid model and the chemical kinetics ones is presented. (orig.)

  15. Utilizing the ratio and the summation of two spectral lines for estimation of optical depth: Focus on thick plasmas

    Science.gov (United States)

    Rezaei, Fatemeh; Tavassoli, Seyed Hassan

    2016-11-01

    In this paper, a study is performed on the spectral lines of plasma radiations created from focusing of the Nd:YAG laser on Al standard alloys at atmospheric air pressure. A new theoretical method is presented to investigate the evolution of the optical depth of the plasma based on the radiative transfer equation, in LTE condition. This work relies on the Boltzmann distribution, lines broadening equations, and as well as the self-absorption relation. Then, an experimental set-up is devised to extract some of plasma parameters such as temperature from modified line ratio analysis, electron density from Stark broadening mechanism, line intensities of two spectral lines in the same order of ionization from similar species, and the plasma length from the shadowgraphy section. In this method, the summation and the ratio of two spectral lines are considered for evaluation of the temporal variations of the plasma parameters in a LIBS homogeneous plasma. The main advantage of this method is that it comprises the both of thin and thick laser induced plasmas without straight calculation of self-absorption coefficient. Moreover, the presented model can also be utilized for evaluation the transition of plasma from the thin condition to the thick one. The results illustrated that by measuring the line intensities of two spectral lines at different evolution times, the plasma cooling and the growth of the optical depth can be followed.

  16. Axial and radial preliminary results of the neutron radiation from miniature plasma focus devices

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, J.; Silva, P.; Soto, L. [Comision Chilena de Energia Nuclear, Santiago (Chile)

    2004-07-01

    As first step of a program to design a repetitive pulsed neutron generator for applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, {approx} 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, {approx} 300 ns time to peak current). Neutron emission has been obtained in both devices operating in deuterium. A specific technique was necessary to develop in order to detect neutron pulsed of 10{sup 4} neutrons per shot. The maximum total neutron yield measured was of the order of 10{sup 6} and 10{sup 4} neutrons per shot in the PF-400 J and PF-50 J respectively. Axial and radial measurements of the neutron emission are presented and the anisotropy is evaluated in this work. The neutrons are measured by pairs of silver activation counters, {sup 3}He detectors and scintillator-photomultiplier detectors. (authors)

  17. Diagnosing collisionless energy transfer using field-particle correlations: Vlasov-Poisson plasmas

    Science.gov (United States)

    Howes, Gregory G.; Klein, Kristopher G.; Li, Tak Chu

    2017-02-01

    Turbulence plays a key role in the conversion of the energy of large-scale fields and flows to plasma heat, impacting the macroscopic evolution of the heliosphere and other astrophysical plasma systems. Although we have long been able to make direct spacecraft measurements of all aspects of the electromagnetic field and plasma fluctuations in near-Earth space, our understanding of the physical mechanisms responsible for the damping of the turbulent fluctuations in heliospheric plasmas remains incomplete. Here we propose an innovative field-particle correlation technique that can be used to measure directly the secular energy transfer from fields to particles associated with collisionless damping of the turbulent fluctuations. Furthermore, this novel procedure yields information about the collisionless energy transfer as a function of particle velocity, providing vital new information that can help to identify the dominant collisionless mechanism governing the damping of the turbulent fluctuations. Kinetic plasma theory is used to devise the appropriate correlation to diagnose Landau damping, and the field-particle correlation technique is thoroughly illustrated using the simplified case of the Landau damping of Langmuir waves in a 1D-1V (one dimension in physical space and one dimension in velocity space) Vlasov-Poisson plasma. Generalizations necessary to apply the field-particle correlation technique to diagnose the collisionless damping of turbulent fluctuations in the solar wind are discussed, highlighting several caveats. This novel field-particle correlation technique is intended to be used as a primary analysis tool for measurements from current, upcoming and proposed spacecraft missions that are focused on the kinetic microphysics of weakly collisional heliospheric plasmas, including the Magnetospheric Multiscale (MMS), Solar Probe Plus, Solar Orbiter and Turbulence Heating ObserveR (THOR) missions.

  18. Effect of exponential density transition on self-focusing of q-Gaussian laser beam in collisionless plasma

    Science.gov (United States)

    Valkunde, Amol T.; Vhanmore, Bandopant D.; Urunkar, Trupti U.; Gavade, Kusum M.; Patil, Sandip D.; Takale, Mansing V.

    2018-05-01

    In this work, nonlinear aspects of a high intensity q-Gaussian laser beam propagating in collisionless plasma having upward density ramp of exponential profiles is studied. We have employed the nonlinearity in dielectric function of plasma by considering ponderomotive nonlinearity. The differential equation governing the dimensionless beam width parameter is achieved by using Wentzel-Kramers-Brillouin (WKB) and paraxial approximations and solved it numerically by using Runge-Kutta fourth order method. Effect of exponential density ramp profile on self-focusing of q-Gaussian laser beam for various values of q is systematically carried out and compared with results Gaussian laser beam propagating in collisionless plasma having uniform density. It is found that exponential plasma density ramp causes the laser beam to become more focused and gives reasonably interesting results.

  19. Deposition of Al N and Ti N thin films on substrates of stainless steel SS304 using plasma focus device

    International Nuclear Information System (INIS)

    Al-Hawat, Sh.; Soukieh, M.; Abou Kharoub, M.; Al-Sadat, W.

    2006-06-01

    A 2.8 kJ plasma focus device was used to deposit thin films of aluminium nitride Al N and titanium nitride Ti N on a stainless steel 394 substrate, in order to improve its surface properties. The deposition process was carried out using various number of nitrogen plasma shots at pressures 0.5-0.75 mbar and at different sample's distances from the anode. The plasma diagnostics was achieved using the voltage and current signals recorded by a voltage divider and Rogovskii coil to determine the temperature and plasma density. The surface hardness of SS-304 was increased by about 50% after plasma coating and the thickness of the coated layers was about 1-2μm. This study shows that the hardness is increased with increasing the number of shots and decreased with the distance from the anode. The coated layers were characterized and a qualitative understanding of the deposition process was given. (author)

  20. Energy Transfer and Dual Cascade in Kinetic Magnetized Plasma Turbulence

    International Nuclear Information System (INIS)

    Plunk, G. G.; Tatsuno, T.

    2011-01-01

    The question of how nonlinear interactions redistribute the energy of fluctuations across available degrees of freedom is of fundamental importance in the study of turbulence and transport in magnetized weakly collisional plasmas, ranging from space settings to fusion devices. In this Letter, we present a theory for the dual cascade found in such plasmas, which predicts a range of new behavior that distinguishes this cascade from that of neutral fluid turbulence. These phenomena are explained in terms of the constrained nature of spectral transfer in nonlinear gyrokinetics. Accompanying this theory are the first observations of these phenomena, obtained via direct numerical simulations using the gyrokinetic code AstroGK. The basic mechanisms that are found provide a framework for understanding the turbulent energy transfer that couples scales both locally and nonlocally.

  1. Energy Transfer and Dual Cascade in Kinetic Magnetized Plasma Turbulence

    Science.gov (United States)

    Plunk, G. G.; Tatsuno, T.

    2011-04-01

    The question of how nonlinear interactions redistribute the energy of fluctuations across available degrees of freedom is of fundamental importance in the study of turbulence and transport in magnetized weakly collisional plasmas, ranging from space settings to fusion devices. In this Letter, we present a theory for the dual cascade found in such plasmas, which predicts a range of new behavior that distinguishes this cascade from that of neutral fluid turbulence. These phenomena are explained in terms of the constrained nature of spectral transfer in nonlinear gyrokinetics. Accompanying this theory are the first observations of these phenomena, obtained via direct numerical simulations using the gyrokinetic code AstroGK. The basic mechanisms that are found provide a framework for understanding the turbulent energy transfer that couples scales both locally and nonlocally.

  2. Study of the thermal and suprathermal electron density fluctuations of the plasma in the Focus experiment

    International Nuclear Information System (INIS)

    Jolas, A.

    1981-10-01

    An experiment on Thomson scattering of ruby laser light by the electrons of a plasma produced by an intense discharge between the electrodes of a coaxial gun in a gas at low pressure has been carried out. It is shown that the imploding plasma is made up of layers with different characteristics: a dense plasma layer where the density fluctuations are isotropic and have a thermal level, and a tenuous plasma layer where the fluctuations are anisotropic, and strongly suprathermal. The suprathermal fluctuations are attributed to microscopic instabilities generated by the electric current circulating in the transition zone where the magnetic field penetrates the plasma [fr

  3. Formation of vertically aligned carbon nanostructures in plasmas: numerical modelling of growth and energy exchange

    Energy Technology Data Exchange (ETDEWEB)

    Denysenko, I; Azarenkov, N A, E-mail: idenysenko@yahoo.com [School of Physics and Technology, V N Karazin Kharkiv National University, 4 Svobody sq., 61077 Kharkiv (Ukraine)

    2011-05-04

    Results on modelling of the plasma-assisted growth of vertically aligned carbon nanostructures and of the energy exchange between the plasma and the growing nanostructures are reviewed. Growth of carbon nanofibres and single-walled carbon nanotubes is considered. Focus is made on studies that use the models based on mass balance equations for species, which are adsorbed on catalyst nanoparticles or walls of the nanostructures. It is shown that the models can be effectively used for the study and optimization of nanostructure growth in plasma-enhanced chemical vapour deposition. The results from these models are in good agreement with the available experimental data on the growth of nanostructures. It is discussed how input parameters for the models may be obtained.

  4. Supplementary plasma heating studies in the Atomic Energy Commission France

    International Nuclear Information System (INIS)

    Consoli, T.

    1976-01-01

    The research on supplementary heating of toroidal plasma made in France at the Atomic Energy Commission and in the European Community are described (with special reference to the J.E.T. project) in the frame of the national programs. A non exhaustive description of the world effort in this topic is also presented: (neutral injection heating, TTMP (transit time magnetic pumping) heating, electron and ion cyclotron resonance, and lower hybrid resonance heating)

  5. Energy Confinement of both Ohmic and LHW Plasma on EAST

    International Nuclear Information System (INIS)

    Yang Yao; Gao Xiang

    2011-01-01

    Study on the characters of energy confinement in both Ohmic and lower hybrid wave (LHW) discharges on EAST is conducted and the linear Ohmic confinement (LOC), saturated ohmic confinement (SOC) and improved Ohmic confinement (IOC) regimes are investigated in this paper. It is observed that an improved confinement mode characterized by both a drop of D α line intensity and an increase in line average density can be triggered by a gas puffing pulse. (magnetically confined plasma)

  6. Energy balance in turbulent weakly ionized ionospheric plasma

    International Nuclear Information System (INIS)

    Dyatko, N.A.; Mishin, E.V.; Telegin, V.A.

    1994-01-01

    On the base of numerical solution of the Boltzmann equation are determined the electron distribution function and energy balance in the case if the longitudinal current exceeds the critical one and the resistance becames anomalously high one. In the equation are accounted for both electron scattering by plasma density fluctuations and electron elastic and inelastic collisions with atoms and molecules and electron-electron collisions

  7. The electromagnetic Ram action of the plasma focus as a paradigm for the generation of cosmic rays and the gigantic jets in active galaxies

    Science.gov (United States)

    Bostick, W. H.; Nardi, V.

    1985-08-01

    Recent measurements of the energy spectrum of the plasma-focus-generated deuteron beam yield as spectrum of the form N(E)=(approx.) E to the -2.7 for 1MeV E 13 MeV. Other measurements show that the beta 1 electron beam which is generated simultaneously with the deuteron beam is interrupted into segments of spacing 25ps and duration approximately 4ps. A stuttering-electro-magnetic-ram (ser) model of the plasma focus in proposed which is similar to Raudorf's electronic ram which produces a similar spectrum for an electron beam for 1Mev E 10MeV. It is proposed that the cosmic ray spectrum and the giganic galactic jets are both generated by ser action near the centers of active galaxies.

  8. Electromagnetic ram action of the plasma focus as a paradigm for the generation of cosmic rays and the gigantic jets in active galaxies

    International Nuclear Information System (INIS)

    Bostick, W.H.; Nardi, V.

    1985-01-01

    Recent measurements of the energy spectrum of the plasma-focus-generated deuteron beam yield a spectrum of the form N(E)=(approx.) E to the -2.7 for 1MeV E 13 MeV. Other measurements show that the beta 1 electron beam, which is generated simultaneously with the deuteron beam, is interrupted into segments of spacing 25ps and duration approximately 4ps. A stuttering-electro-magnetic-ram (ser) model of the plasma focus in proposed which is similar to Raudorf's electronic ram which produces a similar spectrum for an electron beam for 1Mev 10MeV. It is proposed that the cosmic ray spectrum and the giganic galactic jets are both generated by action near the centers of active galaxies

  9. Traveling-wave laser-produced-plasma energy source for photoionization laser pumping and lasers incorporating said

    Science.gov (United States)

    Sher, Mark H.; Macklin, John J.; Harris, Stephen E.

    1989-09-26

    A traveling-wave, laser-produced-plasma, energy source used to obtain single-pass gain saturation of a photoionization pumped laser. A cylindrical lens is used to focus a pump laser beam to a long line on a target. Grooves are cut in the target to present a surface near normal to the incident beam and to reduce the area, and hence increase the intensity and efficiency, of plasma formation.

  10. Low Energy Electrons in the Mars Plasma Environment

    Science.gov (United States)

    Link, Richard

    2001-01-01

    The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although electron fluxes were estimated from changes in the ion currents. Using these derived low-energy electron fluxes, Mantas and Hanson studied the photoelectron and the solar wind electron interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy electron fluxes in the vicinity of the Mars plasma boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/Electron Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to electron impact ionization of exospheric neutral species by solar wind electrons. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (internal (photoelectron) sources of ionization, and accounts for Auger electron production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining plasma densities in the region of the Mars plasma boundary.

  11. Energy balance and transient responses in wave driven plasmas

    International Nuclear Information System (INIS)

    Rax, J.M.

    1987-06-01

    In a current-drive experiment with a RF power source, a certain amount of power is absorbed by resonant electrons. From the electrons, energy can flow through four channels: it can be converted into magnetic work when the electron interacts with an electric field, or it can be converted into heat when the electron collides the thermal plasma. In addition, there exists also the conversion of the low frequency RF energy into high frequency non thermal free-free or cyclotron radiation. Efficiencies of these conversions are considered together with the turn-on times of the associated responses

  12. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    Energy Technology Data Exchange (ETDEWEB)

    Saw, S. H. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); Lee, S. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); National Institute of Education, Nanyang Technological University, Singapore 637616 (Singapore); Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A. [INTI University College, Nilai 71800 (Malaysia)

    2010-05-15

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L{sub 0}, and resistance r{sub 0} to be obtained using lightly damped sinusoid equations given the bank capacitance C{sub 0}. However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  13. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    International Nuclear Information System (INIS)

    Saw, S. H.; Lee, S.; Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A.

    2010-01-01

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L 0 , and resistance r 0 to be obtained using lightly damped sinusoid equations given the bank capacitance C 0 . However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  14. Saturation of backward stimulated scattering of laser in kinetic regime: Wavefront bowing, trapped particle modulational instability, and trapped particle self-focusing of plasma waves

    International Nuclear Information System (INIS)

    Yin, L.; Albright, B. J.; Bowers, K. J.; Daughton, W.; Rose, H. A.

    2008-01-01

    Backward stimulated Raman and Brillouin scattering (SRS and SBS) of laser are examined in the kinetic regime using particle-in-cell simulations. The SRS reflectivity measured as a function of the laser intensity in a single hot spot from two-dimensional (2D) simulations shows a sharp onset at a threshold laser intensity and a saturated level at higher intensities, as obtained previously in Trident experiments [D. S. Montgomery et al., Phys. Plasmas 9, 2311 (2002)]. In these simulations, wavefront bowing of electron plasma waves (ion acoustic waves) due to the trapped particle nonlinear frequency shift, which increases with laser intensity, is observed in the SRS (SBS) regime for the first time. Self-focusing from trapped particle modulational instability (TPMI) [H. A. Rose, Phys. Plasmas 12, 12318 (2005)] is shown to occur in both two- and three-dimensional SRS simulations. The key physics underlying nonlinear saturation of SRS is identified as a combination of wavefront bowing, TPMI, and self-focusing of electron plasma waves. The wavefront bowing marks the beginning of SRS saturation and self-focusing alone is sufficient to terminate the SRS reflectivity, both effects resulting from cancellation of the source term for SRS and from greatly increased dissipation rate of the electron plasm waves. Ion acoustic wave bowing also contributes to the SBS saturation. Velocity diffusion by transverse modes and rapid loss of hot electrons in regions of small transverse extent formed from self-focusing lead to dissipation of the wave energy and an increase in the Landau damping rate in spite of strong electron trapping that reduces Landau damping initially. The ranges of wavelength and growth rate associated with transverse breakup of the electron-plasma wave are also examined in 2D speckle simulations as well as in 2D periodic systems from Bernstein-Greene-Kruskal equilibrium and are compared with theory predictions

  15. Measurement of the energy loss of heavy ions in laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch-Maas, Renate

    2009-11-25

    The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10{sup 22} cm{sup -3}. With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a

  16. Measurement of the energy loss of heavy ions in laser-produced plasmas

    International Nuclear Information System (INIS)

    Knobloch-Maas, Renate

    2009-01-01

    The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10 22 cm -3 . With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a diameter of only

  17. Self-Similar Nonlinear Dynamical Solutions for One-Component Nonneutral Plasma in a Time-Dependent Linear Focusing Field

    International Nuclear Information System (INIS)

    Qin, Hong; Davidson, Ronald C.

    2011-01-01

    In a linear trap confining a one-component nonneutral plasma, the external focusing force is a linear function of the configuration coordinates and/or the velocity coordinates. Linear traps include the classical Paul trap and the Penning trap, as well as the newly proposed rotating-radio- frequency traps and the Mobius accelerator. This paper describes a class of self-similar nonlinear solutions of nonneutral plasma in general time-dependent linear focusing devices, with self-consistent electrostatic field. This class of nonlinear solutions includes many known solutions as special cases.

  18. Study of self-focusing of Non Gaussian laser beam in a plasma with density variation using moment theory approach

    Science.gov (United States)

    Pathak, Nidhi; Kaur, Sukhdeep; Singh, Sukhmander

    2018-05-01

    In this paper, self-focusing/defocusing effects have been studied by taking into account the combined effect of ponder-motive and relativistic non linearity during the laser plasma interaction with density variation. The formulation is based on the numerical analysis of second order nonlinear differential equation for appropriate set of laser and plasma parameters by employing moment theory approach. We found that self-focusing increases with increasing the laser intensity and density variation. The results obtained are valuable in high harmonic generation, inertial confinement fusion and charge particle acceleration.

  19. Effects of target electron collisions on energy loss straggling in plasmas of all degeneracies

    Energy Technology Data Exchange (ETDEWEB)

    Barriga Carrasco, Manuel D. [E.T.S.I. Industriales, Universisdad de Castilla La Mancha, Ciudad Real E13071 (Spain)]. E-mail: ManuelD.Barriga@uclm.es

    2007-07-01

    The purpose of the present paper is to describe the effects of target electron collisions on the energy loss straggling in plasmas of any degeneracy. We focus our analysis on targets that are in the limit of weakly coupled electron gases, where the random phase approximation can be applied. This type of plasmas targets has not been studied extensively, though they are very important for inertial confinement fusion. The energy loss straggling is obtained from an exact quantum mechanical evaluation, which takes into account the degeneracy of the target plasma, and later it is compared with common classical and degenerate approximations. Also we consider electron collisions in the exact quantum mechanical straggling calculation. Now the maximum straggling occurs at velocities smaller than for the calculations without considering collisions for all kinds of plasmas analyzed. The straggling remains equal or enhances for velocities less than or equal to the velocity at maximum while is slightly decreases for higher velocities. Differences are significant in all cases, that can let large errors creep on in further energy deposition and projectile range studies.

  20. Effects of target electron collisions on energy loss straggling in plasmas of all degeneracies

    International Nuclear Information System (INIS)

    Barriga Carrasco, Manuel D.

    2007-01-01

    The purpose of the present paper is to describe the effects of target electron collisions on the energy loss straggling in plasmas of any degeneracy. We focus our analysis on targets that are in the limit of weakly coupled electron gases, where the random phase approximation can be applied. This type of plasmas targets has not been studied extensively, though they are very important for inertial confinement fusion. The energy loss straggling is obtained from an exact quantum mechanical evaluation, which takes into account the degeneracy of the target plasma, and later it is compared with common classical and degenerate approximations. Also we consider electron collisions in the exact quantum mechanical straggling calculation. Now the maximum straggling occurs at velocities smaller than for the calculations without considering collisions for all kinds of plasmas analyzed. The straggling remains equal or enhances for velocities less than or equal to the velocity at maximum while is slightly decreases for higher velocities. Differences are significant in all cases, that can let large errors creep on in further energy deposition and projectile range studies