WorldWideScience

Sample records for plasma wiggler generation

  1. γ -Ray Generation from Plasma Wakefield Resonant Wiggler

    Science.gov (United States)

    Lei, Bifeng; Wang, Jingwei; Kharin, Vasily; Zepf, Matt; Rykovanov, Sergey

    2018-03-01

    A flexible gamma-ray radiation source based on the resonant laser-plasma wakefield wiggler is proposed. The wiggler is achieved by inducing centroid oscillations of a short laser pulse in a plasma channel. Electrons (self-)injected in such a wakefield experience both oscillations due to the transverse electric fields and energy gain due to the longitudinal electric field. The oscillations are significantly enhanced when the laser pulse centroid oscillations are in resonance with the electron betatron oscillations, extending the radiation spectrum to the gamma-ray range. The polarization of the radiation can be easily controlled by adjusting the injection of the laser pulse into the plasma channel.

  2. Enhanced THz radiation generation by photo-mixing of tophat lasers in rippled density plasma with a planar magnetostatic wiggler and s-parameter

    Science.gov (United States)

    Abedi-Varaki, M.

    2018-02-01

    In this paper, the effects of planar magnetostatic wiggler and s-parameter on the terahertz (THz) radiation generation through rippled plasma have been investigated. Efficient THz radiation generation by photo-mixing of tophat lasers for rippled density plasma in the presence of the wiggler field has been presented. Fundamental equations for the analysis of the non-linear current density and THz radiation generation by wiggler magnetostatic field have been derived. It is shown that for the higher order of the tophat lasers, the values of THz amplitude are greater. In fact, the higher order of the tophat lasers has a sharp gradient in the intensity of lasers, which leads to a stronger nonlinear ponderomotive force and, consequently, a stronger current density. In addition, it is seen that by increasing s-parameter, the normalized transverse profile becomes more focused near the axis of y. Furthermore, it is observed that the normalized laser efficiency has a decreasing trend with increasing normalized THz frequency for different values of the wiggler field. Also, it is shown that by employing a greater order of the tophat lasers and a stronger wiggler field, the efficiency of order of 30% can be achieved. Moreover, it is found that we can control focus and intensity of THz radiation emitted in rippled plasma by choosing the appropriate order of the tophat lasers and tuning of the wiggler field.

  3. Wiggler magnetic field assisted third harmonic generation in expanding clusters

    Science.gov (United States)

    Vij, Shivani

    2018-04-01

    A simple theoretical model is constructed to study the wiggler magnetic field assisted third harmonic generation of intense short pulse laser in a cluster in its expanding phase. The ponderomotive force of laser causes density perturbations in cluster electron density which couples with wiggler magnetic field to produce a nonlinear current that generates transverse third harmonic. An intense short pulse laser propagating through a gas embedded with atomic clusters, converts it into hot plasma balls via tunnel ionization. Initially, the electron plasma frequency inside the clusters ω pe > \\sqrt{3}{ω }1 (with ω 1 being the frequency of the laser). As the cluster expands under Coulomb force and hydrodynamic pressure, ω pe decreases to \\sqrt{3}{ω }1. At this time, there is resonant enhancement in the efficiency of the third harmonic generation. The efficiency of third harmonic generation is enhanced due to cluster plasmon resonance and by phase matching due to wiggler magnetic field. The effect of cluster size on the expansion rate is studied to observe that the clusters of different radii would expand differently. The impact of laser intensity and wiggler magnetic field on the efficiency of third harmonic generation is also explored.

  4. Harmonic generation with multiple wiggler schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, R.; De Salvo, L.; Pierini, P. [Universita degli Studi, Milano (Italy)

    1995-02-01

    In this paper the authors give a simple theoretical description of the basic physics of the single pass high gain free electron laser (FEL), describing in some detail the FEL bunching properties and the harmonic generation technique with a multiple-wiggler scheme or a high gain optical klystron configuration.

  5. Free-electron laser with a plasma wave wiggler propagating through a magnetized plasma channel

    International Nuclear Information System (INIS)

    Jafari, S; Jafarinia, F; Mehdian, H

    2013-01-01

    A plasma eigenmode has been employed as a wiggler in a magnetized plasma channel for the generation of laser radiation in a free-electron laser. The short wavelength of the plasma wave allows a higher radiation frequency to be obtained than from conventional wiggler free-electron lasers. The plasma can significantly slow down the radiation mode, thereby relaxing the beam energy requirement considerably. In addition, it allows a beam current in excess of the vacuum current limit via charge neutralization. This configuration has a higher tunability by controlling the plasma density in addition to the γ-tunability of the standard FEL. The laser gain has been calculated and numerical computations of the electron trajectories and gain are presented. Four groups (I–IV) of electron orbits have been found. It has been shown that by increasing the cyclotron frequency, the gain for orbits of group I and group III increases, while a decrease in gain has been obtained for orbits of group II and group IV. Similarly, the effect of plasma density on gain has been exhibited. The results indicate that with increasing plasma density, the orbits of all groups shift to higher cyclotron frequencies. The effects of beam self-fields on gain have also been demonstrated. It has been found that in the presence of beam self-fields the sensitivity of the gain increases substantially in the vicinity of gyroresonance. Here, the gain enhancement and reduction are due to the paramagnetic and diamagnetic effects of the self-magnetic field, respectively. (paper)

  6. X-ray Synchrotron Radiation in a Plasma Wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuoquin; /UCLA /SLAC, SSRL

    2005-09-27

    A relativistic electron beam can radiate due to its betatron motion inside an ion channel. The ion channel is induced by the electron bunch as it propagates through an underdense plasma. In the theory section of this thesis the formation of the ion channel, the trajectories of beam electrons inside the ion channel, the radiation power and the radiation spectrum of the spontaneous emission are studied. The comparison between different plasma wiggler schemes is made. The difficulties in realizing stimulated emission as the beam traverses the ion channel are investigated, with particular emphasis on the bunching mechanism, which is important for the ion channel free electron laser. This thesis reports an experiment conducted at the Stanford Linear Accelerator Center (SLAC) to measure the betatron X-ray radiations for the first time. They first describe the construction and characterization of the lithium plasma source. In the experiment, the transverse oscillations of the SLAC 28.5 GeV electron beam traversing through a 1.4 meter long lithium plasma source are clearly seen. These oscillations lead to a quadratic density dependence of the spontaneously emitted betatron X-ray radiation. The divergence angle of the X-ray radiation is measured. The absolute photon yield and the spectral brightness at 14.2 KeV photon energy are estimated and seen to be in reasonable agreement with theory.

  7. Analysis of the superconducting wiggler magnets for the ATF Harmonic Generation FEL experiment

    International Nuclear Information System (INIS)

    Zhang, X.; Ben-Zvi, I.; Ingold, G.; Krinsky, S.; Yu, L.H.

    1992-01-01

    In this paper, we consider the superconducting wiggler magnet under construction for the High Gain Harmonic Generation experiment (HGHG) at the Accelerator Test Facility (ATF) at BNL. This wiggler consists of an energy modulation section, a dispersion magnet and a radiator section. We present an analysis of the dispersion magnet and the end effects in the other wiggler sections. The purpose of the dispersion magnet is to convert energy modulation of the electron beam into spatial bunching. For the dispersion magnet, we discuss the physical requirements, analyze the magnetic design, determine the focusing properties, and consider the effect of departures from ideal behavior on the FEL gain. In the modulator and radiator wigglers we analyze the effects due to the ends of the wiggler and discuss their correction. In addition, the localized field produced by a trim coil for horizontal beam steering is investigated

  8. The ETA-II linear induction accelerator and IMP wiggler: A high-average-power millimeter-wave free-electron laser for plasma heating

    International Nuclear Information System (INIS)

    Allen, S.L.; Scharlemann, E.T.

    1993-01-01

    The authors have constructed a 140-GHz free-electron laser to generate high-average-power microwaves for heating the MTX tokamak plasma. A 5.5-m steady-state wiggler (Intense Microwave, Prototype-IMP) has been installed at the end of the upgraded 60-cell ETA-II accelerator, and is configured as an FEL amplifier for the output of a 140-GHz long-pulse gyrotron. Improvements in the ETA-II accelerator include a multicable-feed power distribution network, better magnetic alignment using a stretched-wire alignment technique (SWAT), and a computerized tuning algorithm that directly minimizes the transverse sweep (corkscrew motion) of the electron beam. The upgrades were first tested on the 20-cell, 3-MeV front end of ETA-II and resulted in greatly improved energy flatness and reduced corkscrew motion. The upgrades were then incorporated into the full 60-cell configuration of ETA-II, along with modifications to allow operation in 50-pulse bursts at pulse repetition frequencies up to 5 kHz. The pulse power modifications were developed and tested on the High Average Power Test Stand (HAPTS), and have significantly reduced the voltage and timing jitter of the MAG 1D magnetic pulse compressors. The 2-3 kA, 6-7 MeV beam from ETA-II is transported to the IMP wiggler, which has been reconfigured as a laced wiggler, with both permanent magnets and electromagnets, for high magnetic field operation. Tapering of the wiggler magnetic field is completely computer controlled and can be optimized based on the output power. The microwaves from the FEL are transmitted to the MTX tokamak by a windowless quasi-optical microwave transmission system. Experiments at MTX are focused on studies of electron-cyclotron-resonance heating (ECRH) of the plasma. The authors summarize here the accelerator and pulse power modifications, and describe the status of ETA-II, IMP, and MTX operations

  9. The ETA-II linear induction accelerator and IMP wiggler: A high-average-power millimeter-wave free-electron-laser for plasma heating

    International Nuclear Information System (INIS)

    Allen, S.L.; Scharlemann, E.T.

    1992-05-01

    We have constructed a 140-GHz free-electron laser to generate high-average-power microwaves for heating the MTX tokamak plasma. A 5.5-m steady-state wiggler (intense Microwave Prototype-IMP) has been installed at the end of the upgraded 60-cell ETA-II accelerator, and is configured as an FEL amplifier for the output of a 140-GHz long-pulse gyrotron. Improvements in the ETA-II accelerator include a multicable-feed power distribution network, better magnetic alignment using a stretched-wire alignment technique (SWAT). and a computerized tuning algorithm that directly minimizes the transverse sweep (corkscrew motion) of the electron beam. The upgrades were first tested on the 20-cell, 3-MeV front end of ETA-II and resulted in greatly improved energy flatness and reduced corkscrew motion. The upgrades were then incorporated into the full 60-cell configuration of ETA-II, along with modifications to allow operation in 50-pulse bursts at pulse repetition frequencies up to 5 kHz. The pulse power modifications were developed and tested on the High Average Power Test Stand (HAPTS), and have significantly reduced the voltage and timing jitter of the MAG 1D magnetic pulse compressors. The 2-3 kA. 6-7 MeV beam from ETA-II is transported to the IMP wiggler, which has been reconfigured as a laced wiggler, with both permanent magnets and electromagnets, for high magnetic field operation. Tapering of the wiggler magnetic field is completely computer controlled and can be optimized based on the output power. The microwaves from the FEL are transmitted to the MTX tokamak by a windowless quasi-optical microwave transmission system. Experiments at MTX are focused on studies of electron-cyclotron-resonance heating (ECRH) of the plasma. We summarize here the accelerator and pulse power modifications, and describe the status of ETA-II, IMP, and MTX operations

  10. Theory of nonlinear harmonic generation in free-electron lasers with helical wigglers

    International Nuclear Information System (INIS)

    Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2007-05-01

    CoherentHarmonicGeneration (CHG), and in particularNonlinearHarmonicGeneration (NHG), is of importance for both short wavelength Free-Electron Lasers (FELs), in relation with the achievement of shorter wavelengths with a fixed electron-beam energy, and high-average power FEL resonators, in relation with destructive effects of higher harmonics radiation on mirrors. In this paper we present a treatment of NHG from helical wigglers with particular emphasis on the second harmonic. Our study is based on an exact analytical solution of Maxwell's equations, derived with the help of a Green's function method. In particular, we demonstrate that nonlinear harmonic generation (NHG) fromhelicalwigglers vanishes on axis. Our conclusion is in open contrast with results in literature, that include a kinematical mistake in the description of the electron motion. (orig.)

  11. Plasma generator

    International Nuclear Information System (INIS)

    Omichi, Takeo; Yamanaka, Toshiyuki.

    1976-01-01

    Object: To recycle a coolant in a sealed hollow portion formed interiorly of a plasma limiter itself to thereby to cause direct contact between the coolant and the plasma limiter and increase of contact area therebetween to cool the plasma limiter. Structure: The heat resulting from plasma generated during operation and applied to the body of the plasma limiter is transmitted to the coolant, which recycles through an inlet and outlet pipe, an inlet and outlet nozzle and a hollow portion to hold the plasma limiter at a level less than a predetermined temperature. On the other hand, the heater wire is, at the time of emergency operation, energized to heat the plasma limiter, but this heat is transmitted to the limiter body to increase the temperature thereof. However, the coolant recycling the hollow portion comes into direct contact with the limiter body, and since the plasma limiter surround the hollow portion, the heat amount transmitted from the limiter body to the coolant increases to sufficiently cool the plasma limiter. (Yoshihara, H.)

  12. A CHI wiggler ubitron amplifier experiment: Wiggler characterization

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J.M.; Jackson, R.H.; Freund, H.P. [Naval Research Lab., Washington, DC (United States)] [and others

    1995-12-31

    A 35 GHz CHI (Coaxial Hybrid Iron) wiggler ubitron amplifier experiment is under construction at the Naval Research Laboratory. The CHI wiggler configuration has the potential of generating high wiggler magnetic fields at short periods with excellent beam focusing and transport properties. This makes it a desirable configuration for the generation of high power coherent radiation in relatively compact systems. The CHI wiggler consists of alternating rings of magnetic and non-magnetic materials concentric with a central rod of similar alternating design but shifted along the axis by half a period. Once inserted in a solenoidal magnetic field, the CHI structure deforms the axial field to create a radial field oscillating with the same periodicity as the rings. An annular electron beam is propagated through the coaxial gap where the oscillating radial field imparts an azimuthal wiggle motion. The principal goals of the experiment are to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Calculations have shown an intrinsic (untapered) efficiency of {approximately} 7% when operating at 6.3 kG axial field (wiggler field, B{sub w}{approximately}1270 G). The calculated gain was 36 dB, saturating at a distance of 46 cm. These parameters yield an instantaneous amplifier bandwidth of {approximately} 25%. There appears to be room for further improvement in efficiency, a matter which will be scrutinized more closely in the final design. A prototype CHI wiggler is presently being fabricated for use in conjunction with an existing 30 kG superconducting solenoid. The performance properties of the prototype will be characterized and compared with linear and non-linear calculations.

  13. Resonant third-harmonic generation of a short-pulse laser from electron-hole plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kant, Niti [Department of Physics, Lovely Professional University, Phagwara, Punjab 144 402 (India); Nandan Gupta, Devki [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)

    2012-01-15

    In semiconductors, free carriers are created in pairs in inter-band transitions and consist of an electron and its corresponding hole. At very high carrier densities, carrier-carrier collisions dominate over carrier-lattice collisions and carriers begin to behave collectively to form plasma. Here, we apply a short-pulse laser to generate third-harmonic radiation from a semiconductor plasma (electron-hole plasma) in the presence of a transverse wiggler magnetic-field. The process of third-harmonic generation of an intense short-pulse laser is resonantly enhanced by the magnetic wiggler, i.e., wiggler magnetic field provides the necessary momentum to third-harmonic photons. In addition, a high-power laser radiation, propagating through a semiconductor imparts an oscillatory velocity to the electrons and exerts a ponderomotive force on electrons at the third-harmonic frequency of the laser. This oscillatory velocity produces a third-harmonic longitudinal current. And due to the beating of the longitudinal electron velocity and the wiggler magnetic field, a transverse third-harmonic current is produced that drives third-harmonic electromagnetic radiation. It is finally observed that for a specific wiggler wave number value, the phase-matching conditions for the process are satisfied, leading to resonant enhancement in the energy conversion efficiency.

  14. Resonant third-harmonic generation of a short-pulse laser from electron-hole plasmas

    International Nuclear Information System (INIS)

    Kant, Niti; Nandan Gupta, Devki; Suk, Hyyong

    2012-01-01

    In semiconductors, free carriers are created in pairs in inter-band transitions and consist of an electron and its corresponding hole. At very high carrier densities, carrier-carrier collisions dominate over carrier-lattice collisions and carriers begin to behave collectively to form plasma. Here, we apply a short-pulse laser to generate third-harmonic radiation from a semiconductor plasma (electron-hole plasma) in the presence of a transverse wiggler magnetic-field. The process of third-harmonic generation of an intense short-pulse laser is resonantly enhanced by the magnetic wiggler, i.e., wiggler magnetic field provides the necessary momentum to third-harmonic photons. In addition, a high-power laser radiation, propagating through a semiconductor imparts an oscillatory velocity to the electrons and exerts a ponderomotive force on electrons at the third-harmonic frequency of the laser. This oscillatory velocity produces a third-harmonic longitudinal current. And due to the beating of the longitudinal electron velocity and the wiggler magnetic field, a transverse third-harmonic current is produced that drives third-harmonic electromagnetic radiation. It is finally observed that for a specific wiggler wave number value, the phase-matching conditions for the process are satisfied, leading to resonant enhancement in the energy conversion efficiency.

  15. Polarized wiggler for NSLS X-ray ring

    International Nuclear Information System (INIS)

    Friedman, A.; Zhang, X.; Krinsky, S.; Blum, E.B.

    1993-01-01

    We examine the properties of an elliptically polarized wiggler that will generate circularly polarized photons with energy spectrum of 3--12 KeV. The vertical wiggler magnetic field is produced by permanent magnets while the horizontal wiggler field is generated by electric coils capable of AC excitation. The radiation parameters of the wiggler is discussed. We consider AC excitation of the wiggler to produce the time modulation of the elliptic polarization. The power is dissipated in the vacuum chamber due to the eddy current

  16. Positron Source from Betatron X-rays Emitted in a Plasma Wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.K.; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Barnes, C.D.; Decker, F.J.; Hogan, M.J.; Iverson, R.H.; Krejcik, P.; O' Connell, C.L.; Siemann, R.; Walz, D.R.; /SLAC; Deng, S.; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

    2006-04-21

    In the E-167 plasma wakefield accelerator (PWFA) experiments in the Final Focus Test Beam (FFTB) at the Stanford Linear Accelerator Center (SLAC), an ultra-short, 28.5 GeV electron beam field ionizes a neutral column of Lithium vapor. In the underdense regime, all plasma electrons are expelled creating an ion column. The beam electrons undergo multiple betatron oscillations leading to a large flux of broadband synchrotron radiation. With a plasma density of 3 x 10{sup 17}cm{sup -3}, the effective focusing gradient is near 9 MT/m with critical photon energies exceeding 50 MeV for on-axis radiation. A positron source is the initial application being explored for these X-rays, as photo-production of positrons eliminates many of the thermal stress and shock wave issues associated with traditional Bremsstrahlung sources. Photo-production of positrons has been well-studied; however, the brightness of plasma X-ray sources provides certain advantages. In this paper, we present results of the simulated radiation spectra for the E-167 experiments, and compute the expected positron yield.

  17. Conceptual Design of ILC Damping Ring Wiggler Straight Vacuum System

    International Nuclear Information System (INIS)

    Marks, S.; Kennedy, K.; Plate, D.; Schlueter, R.D.; Zisman, M.

    2007-01-01

    The positron and electron damping rings for the International Linear Collider will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR superconducting design. There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC Reference Design Report. Particular emphasis will be placed on photon power load calculations and the absorber design

  18. Polarized wiggler for NSLS x-ray ring design considerations

    International Nuclear Information System (INIS)

    Friedman, A.; Krinsky, S.; Blum, E.

    1992-03-01

    We examine the properties of an elliptically polarized wiggler that will generate circularly polarized photons with energy spectrum of 3--12 KeV. The vertical wiggler magnetic field is produced by permanent magnets while the horizontal wiggler field is generated by electric coils capable of AC excitation. The radiation parameters of the wiggler are presented, including photon flux, circular and linear polarization and spectrum. These parameters are compared to the synchrotron radiation from a bending magnet. Numerical values are calculated for radiation from the wiggler and bending magnet for the NSLS X-ray ring parameters. A conceptual design for such a wiggler is discussed and several different alternatives are analyzed. We consider AC excitation of the wiggler to produce the time modulation of the elliptic polarization, and also to produce time modulated linearly polarized radiation

  19. Standard Wiggler magnets

    International Nuclear Information System (INIS)

    Winick, H.; Helm, R.H.

    1977-09-01

    Interest in Wiggler magnets (a close sequence of transverse fields with alternating polarity) to extend and enhance the spectrum of synchrotron radiation from electron storage rings has increased significantly during the past few years. Standard wigglers, i.e., wigglers in which interference effects on the spectrum of synchrotron radiation are not important, are considered. In standard wigglers the spectrum of synchrotron radiation has the same general shape as the spectrum from ring bending magnets. However, the critical energy of the wiggler spectrum may be different. The critical energy of the wiggler spectrum is given by epsilon/sub CW/ = epsilon/sub CB/(B/sub W//B/sub B/) where epsilon/sub CB/ is the critical energy from the bending magnets and B/sub W/ and B/sub B/ are the magnetic field strengths of the wiggler magnet and bending magnets respectively. Since most electron storage rings operate with relatively low bending magnet fields (B/sub B/ less than or equal to 12 kG), even a modest wiggler magnet field (less than or equal to 18 kG) can significantly increase the critical energy. Such magnets are planned for ADONE and SPEAR. Higher field (30 to 50 kG) superconducting magnets are planned at Brookhaven, Daresbury, and Novosibirsk to produce even larger increase in the critical energy. For some standard wigglers a further enhancement of the spectrum is produced due tothe superposition of the radiation from the individual poles. Wiggler designs are discussed as well as the effect of wigglers on the synchrotron radiation spectrum and on the operation of storage rings

  20. Generation of radiation by intense plasma and electromagnetic undulators

    International Nuclear Information System (INIS)

    Joshi, C.

    1989-01-01

    This is a second year progress report which details the work on the generation of radiation by intense plasma and electromagnetic undulators being carried out at UCLA. The status of the experimental work is described and the future directions are outlined. We have completed the first phase of experiments on the plasma wiggler generation and characterization. Suitability of a null-pinch as a plasma source was investigated in great detail. It is found that a w of a few percent can be excited but there are trapped magnetic fields within null-pinch plasma which hinder the injection of the electrons. A new more uniform and field-free plasma source is now being characterized

  1. Generation of radiation by intense plasma and electromagnetic undulators

    International Nuclear Information System (INIS)

    Joshi, C.

    1989-01-01

    This is a second year progress report which details the work on the generation of radiation by intense plasma and electromagnetic undulators being carried out at UCLA. The status of the experimental work is described and the future directions are outlined. We have completed the first phase of experiments on the plasma wiggler generation and characterization. Suitability of a θ-pinch as a plasma source was investigated in great detail. It is found that a w of a few percent can be excited but there are trapped magnetic fields within θ-pinch plasma which hinder the injection of the electrons. A few more uniform and field-free plasma source is now being characterized. 8 refs., 5 figs

  2. The new CHESS wiggler

    International Nuclear Information System (INIS)

    Finkelstein, K.D.

    1992-01-01

    A 25-pole permanent magnet hybrid wiggler has been built at CHESS and installed on the CESR (Cornell Electron Storage Ring). This device has a magnetic period of 19.6 cm, a peak on-axis field of 1.2 T at the nominal operating gap of 4.0 cm, and a K parameter of 22. The wiggler has been designed to provide radiation for two new experimental stations with approximately four times the flux available from the present CHESS six-pole electromagnet wiggler. Under normal running conditions at 100 mA currents, the total power radiated should exceed 6 kW making this one of the highest flux x-ray sources below 1 A critical wavelength. In this paper an overview of the development of the wiggler is given, including the unique features in its design and construction as well as results of measurements obtained on its magnetic and spectral properties

  3. Current driven wiggler

    Science.gov (United States)

    Tournes, C.; Aucouturier, J.; Arnaud, B.; Brasile, J. P.; Convert, G.; Simon, M.

    1992-07-01

    A current-driven wiggler is the cornerstone of an innovative, compact, high-efficiency, transportable tunable free-electron laser (FEL), the feasibility of which is currently being evaluated by Thomson-CSF. The salient advantages are: compactness of the FEL, along with the possibility to accelerate the beam through several successive passes through the accelerating section (the number of passes being defined by the final wavelength of the radiation; i.e. visible, MWIR, LWIR); the wiggler can be turned off and be transparent to the beam until the last pass. Wiggler periodicities as small as 5 mm can be achieved, hence contributing to FEL compactness. To achieve overall efficiencies in the range of 10% at visible wavelengths, not only the wiggler periodicity must be variable, but the strength of the magnetic field of each period can be adjusted separately and fine-tuned versus time during the macropulse, so as to take into account the growing contribution of the wave energy in the cavity to the total ponderomotive force. The salient theoretical point of this design is the optimization of the parameters defining each period of the wiggler for each micropacket of the macropulse. The salient technology point is the mechanical and thermal design of the wiggler which allows the required high currents to achieve magnetic fields up to 2T.

  4. A novel micro wiggler

    International Nuclear Information System (INIS)

    Liu Qingxiang; Xu Yong

    1995-01-01

    A novel structure of the micro-wiggler is presented. The authors developed a simplified theoretical model of the micro-wiggler. According to the model, an analytic formula of the magnetic field in two dimensions is got. A calculated program (PWMW-I) is developed from the formula. PWMW-I can calculate the field on the axis and the off-axis for the number of periods N, and the entrance or the exit of the micro-wiggler. Three model with different period (10 mm, 5 mm and 3 mm) is designed on the program. The 5T peak field for the period of 3 mm at the gap of 1 mm is got

  5. Wiggler magnets at SSRL

    International Nuclear Information System (INIS)

    Winick, H.

    1980-01-01

    A wiggler magnet has been installed in SPEAR and has been routinely used as a radiation source for Beam Line IV at SSRL since March, 1979. The magnets is 1.22 m long. It has five full central poles and two end half-poles producing a total of three complete small amplitude (<= 1 mm) oscillations of the electron beam in traversing the magnet. The magnet has been operated with the peak field in the central full poles at 17.2 kG and produces an intense beam of synchrotron radiation extending to 12 keV and beyond even at the lowest operating energies of SPEAR (1.5 GeV). It is compatible with all phases of colliding-beam operation of SPEAR and has improved the colliding-beam luminosity. The results of measurements on the spectrum and intensity of the radiation produced by the Wiggler will be presented. The measured effects of the wiggler on the stored beam tunes, energy spread and emittance will also be presented. Plans will also be described for installing additional high field wiggler magnets in SPEAR and also weak-field, many-period undulator magnets in both SPEAR and PEP. (orig.)

  6. Wigglers: the newest profession

    International Nuclear Information System (INIS)

    Spencer, J.E.

    1981-01-01

    Wiggler systems have been used in storage rings within the last year to increase the intensity of synchrotron radiation available for experiments as well as to increase the reaction rates in high energy physics experiments. Multiperiod wigglers or undulators have also been used recently to make quasi-monochromatic photon beams as well as amplify existing photon beams such as in the free electron laser. If one defines a wiggler to be any system of transverse, periodic electromagnetic fields, then recent results on photon production via charged particle channeling in crystals also fall within this sphere. Of course, any periodic modulation of a charge or magnetic moment (e.g., by a laser) could produce coherent radiation or, conversely, passage through a periodic aperture (e.g., a metal bellows). This discussion is limited to a typical, active, macroscopic device and how it provides some unique advantages which are practical to achieve in storage rings. As implied, the subject divides into two basic parts - one related to the radiation from the wiggler and the other related to machine physics applications, e.g., tailoring the phase space of the particle beam, modifying its damping rates or possibly optimizing a ring for production of radiation. Neither area is exhausted nor hopefully the reader, since our goal is only to present enough information to allow one to make reasonable estimates of some important effects

  7. Symplectic integration for complex wigglers

    International Nuclear Information System (INIS)

    Forest, E.; Ohmi, K.

    1992-01-01

    Using the example of the helical wiggler proposed for the KEK photon factory, we show how to integrate the equation of motion through the wiggler. The integration is performed in cartesian coordinates. For the usual expanded Hamiltonian (without square root), we derive a first order symplectic integrator for the purpose of tracking through a wiggler in a ring. We also show how to include classical radiation for the computation of the damping decrement

  8. Experimental and numerical studies of sheet electron beam propagation through a planar wiggler magnet

    International Nuclear Information System (INIS)

    Zhang, Ze Xiang; Granatstein, V.L.; Destler, W.W.; Rodgers, J.; Cheng, S.; Antonsen, T.M. Jr.; Levush, B.; Bidwell, S.W.

    1993-01-01

    Detailed experimental studies on sheet relativistic electron beam propagation through a long planar wiggler are reported and compared with numerical simulations. The planar wiggler has 56 periods with a period of 9.6 mm. Typically, the wiggler field peak amplitude is 5 kG. The experimental efforts have been focused on control of the deviation of the beam toward the side edge of the planar wiggler along the wide transverse direction. It is found that a suitably tapered magnetic field configuration at the wiggler entrance can considerably reduce the rate of the deviation. The effects of the following techniques on beam transport efficiency are also discussed: side focusing, beam transverse velocity tuning at the wiggler entrance, and beam spread limiting. High beam transport efficiency (almost 100%) of a 15 A beam has been obtained in some cases. The results are relevant to development of a free electron laser amplifier for application to stabilizing and heating of plasma in magnetic fusion research

  9. Design of a vertical wiggler with superconducting coils

    International Nuclear Information System (INIS)

    Huke, K.; Yamakawa, T.

    1980-01-01

    A vertical wiggler has been designed, which will be installed in the 2.5 GeV electron storage ring under construction at KEK-PF. The wiggler magnet with superconducting coils produces magnetic fields of 6 T and wiggles electron beams in a vertical plane. Synchrotron radiation generated by the wiggler has a critical wavelength of 0.5 Angstroem and has an electric field-vector in the vertical direction, which is very important for precise experiments in various fields of the material sciences. The wiggler consists of three pairs of superconducting coils, an iron magnetic shield, a beam pipe and a liquid helium cryogenic system and is contained in a vacuum vessel which can move up and down together with the wiggler. During the injection time, the vessel is pushed up, so that electron beams with a large spatial spread go through the lower part of the beam pipe, where the aperture of the beam pipe is large enough. After the beam size becomes small due to radiation damping, the vessel is pushed down so that the electron beams go through the narrow gap of the wiggler magnet. Using the iron magnetic shield with iron pole pieces, the ratio between the magnetic field in the gap and the maximum field on the superconductor coils is reduced to 1.1. (orig.)

  10. Electron dynamics with radiation and nonlinear wigglers

    International Nuclear Information System (INIS)

    Jowett, J.M.

    1986-06-01

    The physics of electron motion in storage rings is described by supplementing the Hamiltonian equations of motion with fluctuating radiation reaction forces to describe the effects of synchrotron radiation. This leads to a description of radiation damping and quantum diffusion in single-particle phase-space by means of Fokker-Planck equations. For practical purposes, most storage rings remain in the regime of linear damping and diffusion; this is discussed in some detail with examples, concentrating on longitudinal phase space. However special devices such as nonlinear wigglers may permit the new generation of very large rings to go beyond this into regimes of nonlinear damping. It is shown how a special combined-function wiggler can be used to modify the energy distribution and current profile of electron bunches

  11. Helical magnetized wiggler for synchrotron radiation laser

    International Nuclear Information System (INIS)

    Wang Mei; Park, S.Y.; Hirshfield, J.L.

    1999-01-01

    A helical magnetized iron wiggler has been built for a novel infrared synchrotron radiation laser (SRL) experiment. The wiggler consists of four periods of helical iron structure immersed in a solenoid field. This wiggler is to impart transverse velocity to a prebunched 6 MeV electron beam, and thus to obtain a desired high orbit pitch ratio for the SRL. Field tapering at beam entrance is considered and tested on a similar wiggler. Analytic and simulated characteristics of wigglers of this type are discussed and the performance of the fabricated wigglers is demonstrated experimentally. A 4.7 kG peak field was measured for a 6.4 mm air gap and a 5.4 cm wiggler period at a 20 kG solenoid field. The measured helical fields compare favorably with the analytical solution. This type of helical iron wigglers has the potential to be scaled to small periods with strong field amplitude

  12. Helical magnetized wiggler for synchrotron radiation laser

    CERN Document Server

    Wang Mei; Hirshfield, J L

    1999-01-01

    A helical magnetized iron wiggler has been built for a novel infrared synchrotron radiation laser (SRL) experiment. The wiggler consists of four periods of helical iron structure immersed in a solenoid field. This wiggler is to impart transverse velocity to a prebunched 6 MeV electron beam, and thus to obtain a desired high orbit pitch ratio for the SRL. Field tapering at beam entrance is considered and tested on a similar wiggler. Analytic and simulated characteristics of wigglers of this type are discussed and the performance of the fabricated wigglers is demonstrated experimentally. A 4.7 kG peak field was measured for a 6.4 mm air gap and a 5.4 cm wiggler period at a 20 kG solenoid field. The measured helical fields compare favorably with the analytical solution. This type of helical iron wigglers has the potential to be scaled to small periods with strong field amplitude.

  13. Effect of pulse slippage on resonant second harmonic generation of a short pulse laser in a plasma

    International Nuclear Information System (INIS)

    Nitikant; Sharma, A K

    2004-01-01

    The process of second harmonic generation of an intense short pulse laser in a plasma is resonantly enhanced by the application of a magnetic wiggler. The wiggler of suitable wave number k-vector 0 provides necessary momentum to second harmonic photons to make harmonic generation a resonant process. The laser imparts an oscillatory velocity to electrons and exerts a longitudinal ponderomotive force on them at (2ω 1 ,2k-vector 1 ), where ω 1 and k-vector 1 are the frequency and the wave number of the laser, respectively. As the electrons acquire oscillatory velocity at the second harmonic, the wiggler magnetic field beats with it to produce a transverse second harmonic current at (2ω 1 ,2k-vector 1 +k-vector 0 ), driving the second harmonic electromagnetic radiation. However, the group velocity of the second harmonic wave is greater than that of the fundamental wave, hence, the generated pulse slips out of the main laser pulse and its amplitude saturates

  14. An ECR table plasma generator

    International Nuclear Information System (INIS)

    Racz, R.; Palinkas, J.; Bin, S.

    2012-01-01

    A compact ECR plasma device was built in our lab using the 'spare parts' of the ATOMKI ECR ion source. We call it 'ECR Table Plasma Generator'. It consists of a relatively big plasma chamber (ID=10 cm, L=40 cm) in a thin NdFeB hexapole magnet with independent vacuum and gas dosing systems. For microwave coupling two low power TWTAs (Travelling Wave tube amplifier) can be applied individually or simultaneously, operating in the 6-18 GHz range. There is no axial magnetic trap and there is no extraction. The technical details of the plasma generator and preliminary plasma photo study results are shown. This paper is followed by the associated poster. (authors)

  15. Electron cloud dynamics in the Cornell Electron Storage Ring Test Accelerator wiggler

    Directory of Open Access Journals (Sweden)

    C. M. Celata

    2011-04-01

    Full Text Available The interference of stray electrons (also called “electron clouds” with accelerator beams is important in modern intense-beam accelerators, especially those with beams of positive charge. In magnetic wigglers, used, for instance, for transverse emittance damping, the intense synchrotron radiation produced by the beam can generate an electron cloud of relatively high density. In this paper the complicated dynamics of electron clouds in wigglers is examined using the example of a wiggler in the Cornell Electron Storage Ring Test Accelerator experiment at the Cornell Electron Storage Ring. Three-dimensional particle-in-cell simulations with the WARP-POSINST computer code show different density and dynamics for the electron cloud at locations near the maxima of the vertical wiggler field when compared to locations near the minima. Dynamics in these regions, the electron cloud distribution vs longitudinal position, and the beam coherent tune shift caused by the wiggler electron cloud will be discussed.

  16. Hollow core plasma channel generation

    International Nuclear Information System (INIS)

    Quast, Heinrich Martin

    2018-03-01

    The use of a hollow plasma channel in plasma-based acceleration has beneficial properties for the acceleration of electron and positron bunches. In the scope of the FLASHForward facility at DESY, the generation of such a plasma structure is examined. Therefore, the generation of a ring-shaped laser intensity profile with different techniques is analyzed. From the obtained intensity profiles the electron density of a hollow plasma channel is simulated in the focal region. Different parameters are scanned to understand their influence on the electron density distribution - an important parameter being, for example, the radius of the central region of the channel. In addition to the simulations, experiments are presented, during which a laser pulse is transformed into a hollow beam with a spiral phase plate. Subsequently, it forms a plasma during the interaction with hydrogen, where the plasma is imaged with interferometry. For energies above 0.9 mJ a hollow plasma structure can be observed at the location of first plasma formation.

  17. Plasma Generator Using Spiral Conductors

    Science.gov (United States)

    Szatkowski, George N. (Inventor); Dudley, Kenneth L. (Inventor); Ticatch, Larry A. (Inventor); Smith, Laura J. (Inventor); Koppen, Sandra V. (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor)

    2016-01-01

    A plasma generator includes a pair of identical spiraled electrical conductors separated by dielectric material. Both spiraled conductors have inductance and capacitance wherein, in the presence of a time-varying electromagnetic field, the spiraled conductors resonate to generate a harmonic electromagnetic field response. The spiraled conductors lie in parallel planes and partially overlap one another in a direction perpendicular to the parallel planes. The geometric centers of the spiraled conductors define endpoints of a line that is non-perpendicular with respect to the parallel planes. A voltage source coupled across the spiraled conductors applies a voltage sufficient to generate a plasma in at least a portion of the dielectric material.

  18. New system for wiggler fabrication and testing

    International Nuclear Information System (INIS)

    Warren, R.W.; Elliott, C.J.

    1988-01-01

    A system approach is taken for fabrication and testing of wigglers for free-electron lasers. Emphasis is placed on convenient, practical, assembly procedures that produce wigglers with high fields, two-plane focusing, and facilities for in-place adjustments. Equal emphasis is placed on rapid and precise techniques for measuring field errors, both before final assembly and afterward, during wiggler operation. (author). 10 refs, 12 figs

  19. Development of a strong electromagnet wiggler

    International Nuclear Information System (INIS)

    Burns, M.J.; Deis, G.A.; Holmes, R.H.; Van Maren, R.D.; Halbach, K.

    1987-01-01

    The Strong Electromagnet (SEM) wiggler is a permanent magnet-assisted electromagnet under development at the Lawrence Livermore National Laboratory (LLNL) as part of the Induction Linac Free-Electron-Laser (IFEL) program. This concept uses permanent magnets within the wiggler to provide a reverse bias flux in the iron and thus delay the onset of magnetic saturation. The electromagnet coils determine the wiggler field and operate at low current densities by virtue of their placement away from the midplane. We describe here the design approach used and test data from a 7-period wiggler prototype that includes curved pole tips to provide wiggle-plane focusing. 7 refs

  20. Wakefield generation in magnetized plasmas

    International Nuclear Information System (INIS)

    Holkundkar, Amol; Brodin, Gert; Marklund, Mattias

    2011-01-01

    We consider wakefield generation in plasmas by electromagnetic pulses propagating perpendicular to a strong magnetic field, in the regime where the electron cyclotron frequency is equal to or larger than the plasma frequency. Particle-in-cell simulations reveal that for moderate magnetic field strengths previous results are reproduced, and the wakefield wave number spectrum has a clear peak at the inverse skin depth. However, when the cyclotron frequency is significantly larger than the plasma frequency, the wakefield spectrum becomes broadband, and simultaneously the loss rate of the driving pulse is much enhanced. A set of equations for the scalar and vector potentials reproducing these results are derived, using only the assumption of a weakly nonlinear interaction.

  1. Magnetic field simulation of wiggler on LUCX accelerator facility using Radia

    Science.gov (United States)

    Sutygina, Y. N.; Harisova, A. E.; Shkitov, D. A.

    2016-11-01

    A flat wiggler consisting of NdFeB permanent magnets was installed on a compact linear electron accelerator LUCX (KEK) in Japan. After installing the wiggler on LUCX, the experiments on the generation of undulator radiation (UR) in the terahertz wavelength range is planned. To perform the detailed calculations and optimization of UR characteristics, it is necessary to know the parameters of the magnetic field generated in the wiggler. In this paper extended simulation results of wiggler magnetic field over the entire volume between the poles are presented. The obtained in the Radia simulation magnetic field is compared with the field calculated by another code, which is based on the finite element method.

  2. First operation of a wiggler-focused, sheet beam free electron laser amplifier

    International Nuclear Information System (INIS)

    Destler, W.W.; Cheng, S.; Zhang, Z.X.; Antonsen, T.M. Jr.; Granatstein, V.L.; Levush, B.; Rodgers, J.

    1994-01-01

    A wiggler-focused, sheet beam free electron laser (FEL) amplifier utilizing a short-period wiggler magnet has been proposed as a millimeter-wave source for current profile modification and/or electron cyclotron resonance heating of tokamak plasmas. As proposed, such an amplifier would operate at a frequency of approximately 100--200 GHz with an output power of 1--10 MW CW. Electron beam energy would be in the range 500--1000 keV. To test important aspects of this concept, an initial sheet beam FEL amplifier experiment has been performed using a 1 mmx2 cm sheet beam produced by a pulse line accelerator with a pulse duration of 100 ns. The 500--570 keV, 4--18 A sheet beam is propagated through a 56 period uniform wiggler (λ w =9.6 mm) with a peak wiggler amplitude of 2--5 kG. Linear amplification of a 5--10 W, 94 GHz signal injected in the TE 01 rectangular mode is observed. All features of the amplified signal, including pulse shape and duration, are in accordance with the predictions of numerical simulation. Amplified signal gain has been measured as a function of injected beam energy, current, and wiggler field amplitude and is also in good agreement with simulation results. Continuation of this experiment will involve studying nonlinear amplifier operation and adding a section of tapered wiggler

  3. New wiggler beam line for SSRL

    International Nuclear Information System (INIS)

    Hoyer, E.

    1982-08-01

    A new high-intensity-beam line with a wiggler magnet source is described. This project, in final stages of design, is a joint effort between Lawrence Berkeley Laboratory (LBL), the Exxon Research and Engineering Company (EXXON), and the Stanford Synchrotron Radiation Laboratory (SSRL). Installation at SSRL will begin in the summer of 1982. The goal of this project is to provide extremely high-brightness synchrotron radiation beams over a broad spectral range from 50 eV to 40 keV. The radiation source is a 27 period (i.e., 55 pole) permanent magnet wiggler of a new design. The wiggler utilizes rare-earth cobalt (REC) material in the steel hybrid configuration to achieve high magnetic fields with short periods. An analysis has been made of the polarization, angular distribution and power density of the radiation produced by the wiggler. Details of the wiggler design are presented. The magnet is outside a thin walled (1mm) variable gap stainless steel vacuum chamber. The chamber gap will be opened to 1.8 cm for beam injection into SPEAR and then closed to 1.0 cm (or less) for operation. Five remotely controlled drives are provided; to change the wiggler gap, to change the vacuum chamber aperture and to position the wiggler. Details of the beam line optics and end stations are presented. Thermal loading on beam line components is severe. The peak power density at 7.5 m is 5 kW/cm 2 for the nominal wiggler field and present SPEAR beam currents and will approach 20 kW/cm 2 with the maximum wiggler field and projected SPEAR beam currents

  4. Generators of nonequilibrium low-temperature plasma

    International Nuclear Information System (INIS)

    Dautov, G.Yu.

    1988-01-01

    Results are described of a study and of the characteristics of sources of a non-equilibrium gas-discharge plasma. The plasma generators considered include glow, high frequency, and arc discharge generators. Thermodynamic, ionic, and electronic processes occurring in the plasmas are evaluated

  5. Arc generators of low-temperature plasma

    International Nuclear Information System (INIS)

    Krolikowski, Cz.; Niewiedzial, R.; Siwiec, J.

    1979-01-01

    This paper is a review of works concerning investigation and use of low-temperature plasma in arc plasma generators made in Electric Power Institute of PP. There are discussed: analytical approach to a problem of volt-current and operational characteristics of DC arc plasma generators, determination of limits of their stable work and possibilities of their use to technological aims. (author)

  6. Calculated and measured fields in superferric wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Blum, E.B.; Solomon, L. [Brookhaven National Lab., Upton, NY (United States)

    1995-02-01

    Although Klaus Halbach is widely known and appreciated as the originator of the computer program POISSON for electromagnetic field calculation, Klaus has always believed that analytical methods can give much more insight into the performance of a magnet than numerical simulation. Analytical approximations readily show how the different aspects of a magnet`s design such as pole dimensions, current, and coil configuration contribute to the performance. These methods yield accuracies of better than 10%. Analytical methods should therefore be used when conceptualizing a magnet design. Computer analysis can then be used for refinement. A simple model is presented for the peak on-axis field of an electro-magnetic wiggler with iron poles and superconducting coils. The model is applied to the radiator section of the superconducting wiggler for the BNL Harmonic Generation Free Electron Laser. The predictions of the model are compared to the measured field and the results from POISSON.

  7. Nonlinear Dynamics in Spear Wigglers

    International Nuclear Information System (INIS)

    2002-01-01

    BL11, the most recently installed wiggler in the SPEAR storage ring at SSRL, produces a large nonlinear perturbation of the electron beam dynamics, which was not directly evident in the integrated magnetic field measurements. Measurements of tune shifts with betatron oscillation amplitude and with closed orbit shifts were used to characterize the nonlinear fields of the SPEAR insertion devices (IDs). Because of the narrow pole width in BL11, the nonlinear fields seen along the wiggling electron trajectory are dramatically different than the flip coil measurements made along a straight line. This difference explains the tune shift measurements and the observed degradation in dynamic aperture. Corrector magnets to cancel the BL11 nonlinear fields are presently under construction

  8. Particle motion in the ELF wiggler

    International Nuclear Information System (INIS)

    Wurtele, J.S.; Sessler, A.M.

    1982-06-01

    Particle motion in the ELF wiggler was investigated numerically and analytically. A transport system was designed using continuous quadrupole focusing in the wiggle plane and natural wiggle focusing in the non-wiggle plane

  9. Development of a laced electromagnetic wiggler

    International Nuclear Information System (INIS)

    Christensen, T.C.; Burns, M.J.; Deis, G.A.; Parkison, C.D.; Prosnitz, D.; Halbach, K.

    1987-01-01

    The laced electromagnetic wiggler is a new concept being developed to attain higher magnetic fields, shorter wavelengths, and larger gaps for the induction-linear accelerator, free-electron-laser (FEL) program. In the laced wiggler design, permanent magnets are located (''laced'') between the electromagnetic coils to increase the reverse-bias flux in the iron pole beyond that possible with only pole-edge (''side'') permanent magnets. This increase in reverse-bias flux allows wiggler operation at midplane magnetic field intensities comparable to those of a hybrid permanent magnet/steel wiggler, but with field adjustability over a specified range. The maximum field intensity and tuning range are selected, within limits, for specific design requirements. We have designed and tested a one-period prototype of this concept with promising results

  10. Single wavelength standard wiggler for PEP

    International Nuclear Information System (INIS)

    Brunk, W.; Fischer, G.; Spencer, J.

    1979-03-01

    A 1lambda planar wiggler has been designed that will be used for the initial operation of the 4 to 18 GeV storage ring PEP. Three of these wigglers will be installed symmetrically around the ring at 120 0 intervals in three of six available 5 m straight sections with the purpose of providing: (1) beam size control to obtain better luminosities below 15 GeV, and (2) decreased damping times to obtain better injection rates at lower energies. Design goals are discussed and a description of the final system including cost estimates is given. Expected results and usage in PEP are discussed. Some possibilities for production of synchrotron radiation and beam monitoring with shorter wavelength, multiple-period wigglers at PEP energies are also discussed. Comparison to a wiggler now operating in SPEAR is given

  11. Design of a superconducting wiggler system

    International Nuclear Information System (INIS)

    Shen, S.S.; Miller, J.R.; Heim, J.R.; Slack, D.S.

    1988-01-01

    We present a wiggler system based on currently available superconducting technology. The system is designed to provide maximum central field of 4.4 tesla with a specified period length of 160 mm and a gap of 40 mm, while meeting the field quality requirements along all axes. Also included are preliminary cost estimates and a survey of world-wide RandD efforts on superconducting wiggler systems. 12 refs., 6 figs., 3 tabs

  12. Superconducting wiggler magnets for beam-emittance damping rings

    CERN Document Server

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  13. Water-stabilized plasma generators

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    1998-01-01

    Roč. 70, č. 6 (1998), s. 1157-1162 ISSN 0033-4545 R&D Projects: GA ČR GA102/95/0592; GA ČR GV106/96/K245 Institutional research plan: CEZ:AV0Z2043910 Keywords : thermal plasma, plasma torch, water-stabilized plasma Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.677, year: 1998

  14. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  15. Modelling of new generation plasma optical devices

    Directory of Open Access Journals (Sweden)

    Litovko Irina V.

    2016-06-01

    Full Text Available The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

  16. Brightness of synchrotron radiation from wigglers

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2014-12-01

    According to literature, while calculating the brightness of synchrotron radiation from wigglers, one needs to account for the so called 'depth-of-field' effects. In fact, the particle beam cross section varies along the wiggler. It is usually stated that the effective photon source size increases accordingly, while the brightness is reduced. Here we claim that this is a misconception originating from an analysis of the wiggler source based on geometrical arguments, regarded as almost self-evident. According to electrodynamics, depth-of-field effects do not exist: we demonstrate this statement both theoretically and numerically, using a well-known first-principle computer code. This fact shows that under the usually accepted approximations, the description of the wiggler brightness turns out to be inconsistent even qualitatively. Therefore, there is a need for a well-defined procedure for computing the brightness from a wiggler source. We accomplish this task based on the use of a Wigner function formalism. In the geometrical optics limit computations can be performed analytically. Within this limit, we restrict ourselves to the case of the beam size-dominated regime, which is typical for synchrotron radiation facilities in the X-ray wavelength range. We give a direct demonstration of the fact that the apparent horizontal source size is broadened in proportion to the beamline opening angle and to the length of the wiggler. While this effect is well-understood, a direct proof appears not to have been given elsewhere. We consider the problem of the calculation of the wiggler source size by means of numerical simulations alone, which play the same role of an experiment. We report a significant numerical disagreement between exact calculations and approximations currently used in literature.

  17. Beam-generated plasmas for processing applications

    Science.gov (United States)

    Meger, R. A.; Blackwell, D. D.; Fernsler, R. F.; Lampe, M.; Leonhardt, D.; Manheimer, W. M.; Murphy, D. P.; Walton, S. G.

    2001-05-01

    The use of moderate energy electron beams (e-beams) to generate plasma can provide greater control and larger area than existing techniques for processing applications. Kilovolt energy electrons have the ability to efficiently ionize low pressure neutral gas nearly independent of composition. This results in a low-temperature, high-density plasma of nearly controllable composition generated in the beam channel. By confining the electron beam magnetically the plasma generation region can be designated independent of surrounding structures. Particle fluxes to surfaces can then be controlled by the beam and gas parameters, system geometry, and the externally applied rf bias. The Large Area Plasma Processing System (LAPPS) utilizes a 1-5 kV, 2-10 mA/cm2 sheet beam of electrons to generate a 1011-1012cm-3 density, 1 eV electron temperature plasma. Plasma sheets of up to 60×60 cm2 area have been generated in a variety of molecular and atomic gases using both pulsed and cw e-beam sources. The theoretical basis for the plasma production and decay is presented along with experiments measuring the plasma density, temperature, and potential. Particle fluxes to nearby surfaces are measured along with the effects of radio frequency biasing. The LAPPS source is found to generate large-area plasmas suitable for materials processing.

  18. Plasma wave and second harmonic generation

    International Nuclear Information System (INIS)

    Sodha, M.S.; Sharma, J.K.; Tewari, D.P.; Sharma, R.P.; Kaushik, S.C.

    1978-01-01

    An investigation is made of a plasma wave at pump wave frequency and second harmonic generation caused by a self induced transverse inhomogeneity introduced by a Gaussian electromagnetic beam in a hot collisionless plasma. In the presence of a Gaussian beam the carriers get redistributed from the high field region to the low field region by ponderomative force and a transverse density gradient is established in the plasma. When the electric vector of the main beam is parallel to this density gradient, a plasma wave at the pump wave frequency is generated. In addition to this the transverse intensity gradient of the electromagnetic wave also contributes significantly to the plasma wave generation. The power of the plasma wave exhibits a maximum and minimum with the power of the pump wave (at z = 0). The generated plasma wave interacts with the electromagnetic wave and leads to the generation of a second harmonic. Furthermore, if the initial power of the pump wave is more than the critical power for self-focusing, the beam gets self-focused and hence the generated plasma wave and second harmonic which depend upon the background electron concentration and power of the main beam also get accordingly modified. (author)

  19. Streaming metal plasma generation by vacuum arc plasma guns

    International Nuclear Information System (INIS)

    MacGill, R.A.; Dickinson, M.R.; Anders, A.; Monteiro, O.R.; Brown, I.G.

    1998-01-01

    We have developed several different embodiments of repetitively pulsed vacuum arc metal plasma gun, including miniature versions, multicathode versions that can produce up to 18 different metal plasma species between which one can switch, and a compact high-duty cycle well-cooled version, as well as a larger dc gun. Plasma guns of this kind can be incorporated into a vacuum arc ion source for the production of high-energy metal ion beams, or used as a plasma source for thin film formation and for metal plasma immersion ion implantation and deposition. The source can also be viewed as a low-energy metal ion source with ion drift velocity in the range 20 - 200 eV depending on the metal species used. Here we describe the plasma sources that we have developed, the properties of the plasma generated, and summarize their performance and limitations. copyright 1998 American Institute of Physics

  20. Field distribution in a coaxial electrostatic wiggler

    Directory of Open Access Journals (Sweden)

    Shi-Chang Zhang

    2010-09-01

    Full Text Available The field distribution in a coaxial electrostatic wiggler corresponds to the special solution of a Laplace equation in a cylindrical coordinate system with a boundary value problem of sinusoidal ripples. This paper is devoted to the physical and mathematical treatment for an analytical solution of the field distribution in the coaxial electrostatic wiggler. The explicit expression of the solution indicates that the field distribution in the coaxial electrostatic wiggler varies according to a periodic function in the longitudinal direction, and is related to the first and second kinds of modified Bessel functions in the radial direction, respectively. Comparison shows excellent agreement between the analytical formula and the computer simulation technology (CST results. The physical application of the considered system and its analytical solution are discussed.

  1. Plasma generation induced by triboelectrification

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Michelsen, Poul

    2009-01-01

    A gas discharge plasma can be induced by triboelectrification around a sliding contact. The detailed physical mechanism of triboelectrification is unknown, but an empirical classification scheme can be referred to in practice. It is reported that intense ultra-violet emission from a plasma...... is observed adjacent to the sliding contact, of which the location has a gap ranging from approximately 1 μm to 11 μm. When the gap is short enough, a theory predicts that the breakdown voltage can monotonically decrease with a decrease in the gap. However, when the gap is comparable to electron’s mean free...

  2. A plasma needle generates nitric oxide

    International Nuclear Information System (INIS)

    Stoffels, E; Gonzalvo, Y Aranda; Whitmore, T D; Seymour, D L; Rees, J A

    2006-01-01

    Generation of nitric oxide (NO) by a plasma needle is studied by means of mass spectrometry. The plasma needle is an atmospheric glow generated by a radio-frequency excitation in a mixture of helium and air. This source is used for the treatment of living tissues, and nitric oxide may be one of the most important active agents in plasma therapy. Efficient NO generation is of particular importance in the treatment of cardiovascular diseases. Mass spectrometric measurements have been performed under various plasma conditions; gas composition in the plasma and conversion of feed gases (nitrogen and oxygen) into other species has been studied. Up to 30% of the N 2 and O 2 input is consumed in the discharge, and NO has been identified as the main conversion product

  3. Design and analysis of a wiggler magnet system for the PEP-II B-Factory LER

    International Nuclear Information System (INIS)

    Heim, J.; Kendall, M.; Bertolini, L.; Fackler, O.; O'Connor, T.; Swan, T.; Zholents, A.

    1996-01-01

    The Low Energy Ring (LER) of the PEP-II B-Factory will use a wiggler magnet system for emittance control and additional damping. The wiggler magnet system is a set of 11 individual iron core, water cooled, dipole magnets designed to operate at 1.6 T and generate 400 kW of synchrotron radiation. Space has been provided to add a second wiggler with an additional 400 kW of synchrotron radiation if more damping is needed in the future. A copper vacuum chamber is used with continuous antechambers connected to both sides of the beam chamber via slots. Synchrotron radiation dump surfaces and distributed vacuum pumping are located in both antechambers. The authors describe the design and analysis of the wiggler magnets and the salient features of the vacuum chamber and dumps

  4. An amplitude modulated radio frequency plasma generator

    Science.gov (United States)

    Lei, Fan; Li, Xiaoping; Liu, Yanming; Liu, Donglin; Yang, Min; Xie, Kai; Yao, Bo

    2017-04-01

    A glow discharge plasma generator and diagnostic system has been developed to study the effects of rapidly variable plasmas on electromagnetic wave propagation, mimicking the plasma sheath conditions encountered in space vehicle reentry. The plasma chamber is 400 mm in diameter and 240 mm in length, with a 300-mm-diameter unobstructed clear aperture. Electron densities produced are in the mid 1010 electrons/cm3. An 800 W radio frequency (RF) generator is capacitively coupled through an RF matcher to an internally cooled stainless steel electrode to form the plasma. The RF power is amplitude modulated by a waveform generator that operates at different frequencies. The resulting plasma contains electron density modulations caused by the varying power levels. A 10 GHz microwave horn antenna pair situated on opposite sides of the chamber serves as the source and detector of probe radiation. The microwave power feed to the source horn is split and one portion is sent directly to a high-speed recording oscilloscope. On mixing this with the signal from the pickup horn antenna, the plasma-induced phase shift between the two signals gives the path-integrated electron density with its complete time dependent variation. Care is taken to avoid microwave reflections and extensive shielding is in place to minimize electronic pickup. Data clearly show the low frequency modulation of the electron density as well as higher harmonics and plasma fluctuations.

  5. Calibrated kallikrein generation in human plasma

    DEFF Research Database (Denmark)

    Biltoft, D; Sidelmann, J J; Olsen, L F

    2016-01-01

    generation method as a template. RESULTS: A suitable kallikrein specific fluorogenic substrate was identified (KM=0.91mM, kcat=19s(-1)), and kallikrein generation could be measured in undiluted plasma when silica was added as activator. Disturbing effects, including substrate depletion and the inner......-filter effect, however, affected the signal. These problems were corrected for by external calibration with α2-macroglobulin-kallikrein complexes. Selectivity studies of the substrate, experiments with FXII and PK depleted plasmas, and plasma with high or low complement C1-esterase inhibitor activity indicated...

  6. Investigation and applications of a plasma generator

    International Nuclear Information System (INIS)

    Frere, Isabelle

    1992-01-01

    This work describes the experimental study of a plasma generator: a cylindrical or parallelepipedic rectangle cathode. A permanent magnet creates an axial magnetic field of a few hundred Gauss. A cold and abnormal glow discharge plasma is obtained. The experimental research on the correlation between the discharge parameters (electrode geometry, gas pressure, discharge voltage and current, magnetic field) of the discharge is presented. Another part of the text mentions some generator applications to surface treatment: evaporation, sputtering, surface modification of polymers by exposure to plasma. (author) [fr

  7. Atmospheric plasma generation for LCD panel cleaning

    Science.gov (United States)

    Kim, Gyu-Sik; Won, Chung-Yuen; Choi, Ju-Yeop; Yim, C. H.

    2007-12-01

    UV lamp systems have been used for cleaning of display panels of TFT LCD or Plasma Display Panel (PDP). However, the needs for high efficient cleaning and low cost made high voltage plasma cleaning techniques to be developed and to be improved. Dielectric-barrier discharges (DBDs), also referred to as barrier discharges or silent discharges have for a long time been exclusively related to ozone generation. In this paper, a 6kW high voltage plasma power supply system was developed for LCD cleaning. The -phase input voltage is rectified and then inverter system is used to make a high frequency pulse train, which is rectified after passing through a high-power transformer. Finally, bi-directional high voltage pulse switching circuits are used to generate the high voltage plasma. Some experimental results showed the usefulness of atmospheric plasma for LCD panel cleaning.

  8. Characterization of a microwave generated plasma

    International Nuclear Information System (INIS)

    Root, D.J.; Mahoney, L.; Asmussen, J.

    1986-01-01

    Recent experiments have demonstrated a microwave ion beam source without and with static magnetic fields in inert gases and in oxygen gases. This plasma generation configuration also has uses in the areas of plasma processing such as plasma etching, plasma assisted thin flim deposition and plasma assisted oxide growth. These ion beam and plasma processing applications have provided motivation to investigate microwave discharge properties, such as electron density, electron temperature, gas temperature, degree of ionization, etc., of the microwave generated plasma over a wide range of experimental operating conditions. This paper presents the results of experimental measurements which attempt to characterize the experimental microwave discharge in the absence of a static magnetic field. Measurements from a double probe, which is located in the plasma in a zero microwave field region, are presented in argon, xenon and oxygen gases. Variations of plasma density and electron temperature versus absorbed microwave power, gas pressure (0.2 m Torr to 200 m Torr) and discharge diffusion length are presented and compared to dc positive column discharge theory

  9. 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.

  10. 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.

  11. A high-voltage pulse generator for corona plasma generation

    NARCIS (Netherlands)

    Yan, K.; Heesch, van E.J.M.; Pemen, A.J.M.; Huijbrechts, P.A.H.J.; Gompel, van F.M.; Leuken, van H.E.M.; Matyas, Z.

    2002-01-01

    This paper discusses a high-voltage pulse generator for producing corona plasma. The generator consists of three resonant charging circuits, a transmission line transformer, and a triggered spark-gap switch. Voltage pulses in the order of 30-100 kV with a rise time of 10-20 ns, a pulse duration of

  12. Power supply controlled for plasma torch generation

    International Nuclear Information System (INIS)

    Diaz Z, S.

    1996-01-01

    The high density of energy furnished by thermal plasma is profited in a wide range of applications, such as those related with welding fusion, spray coating and at the present in waste destruction. The waste destruction by plasma is a very attractive process because the remaining products are formed by inert glassy grains and non-toxic gases. The main characteristics of thermal plasmas are presented in this work. Techniques based on power electronics are utilized to achieve a good performance in thermal plasma generation. This work shown the design and construction of three phase control system for electric supply of thermal plasma torch, with 250 kw of capacity, as a part of the project named 'Destruction of hazard wastes by thermal plasma' actually working in the Instituto Nacional de Investigaciones Nucleares (ININ). The characteristics of thermal plasma and its generation are treated in the first chapter. The A C controllers by thyristors applied in three phase arrays are described in the chapter II, talking into account the power transformer, rectifiers bank and aliasing coil. The chapter III is dedicated in the design of the trigger module which controls the plasma current by varying the trigger angle of the SCR's; the protection and isolating unit are also presented in this chapter. The results and conclusions are discussed in chapter IV. (Author)

  13. Cascade generation in Al laser induced plasma

    Science.gov (United States)

    Nagli, Lev; Gaft, Michael; Raichlin, Yosef; Gornushkin, Igor

    2018-05-01

    We found cascade IR generation in Al laser induced plasma. This generation includes doublet transitions 3s 25s 2S1/2 → 3s24p 2P1/2,3/2 → 3s24s 2S1/2; corresponding to strong lines at 2110 and 2117 nm, and much weaker lines at 1312-1315 nm. The 3s25s2S 1/2 starting IR generation level is directly pumped from the 3s23p 2P3/2 ground level. The starting level for UV generation at 396.2 nm (transitions 3s24s 2S1/2 → 4p 2P3/2) is populated due to the fast collisional processes in the plasma plume. These differences led to different time and special dependences on the lasing in the IR and UV spectral range within the aluminum laser induced plasma.

  14. Surface plasma source with saddle antenna radio frequency plasma generator.

    Science.gov (United States)

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  15. Cold plasma brush generated at atmospheric pressure

    International Nuclear Information System (INIS)

    Duan Yixiang; Huang, C.; Yu, Q. S.

    2007-01-01

    A cold plasma brush is generated at atmospheric pressure with low power consumption in the level of several watts (as low as 4 W) up to tens of watts (up to 45 W). The plasma can be ignited and sustained in both continuous and pulsed modes with different plasma gases such as argon or helium, but argon was selected as a primary gas for use in this work. The brush-shaped plasma is formed and extended outside of the discharge chamber with typical dimension of 10-15 mm in width and less than 1.0 mm in thickness, which are adjustable by changing the discharge chamber design and operating conditions. The brush-shaped plasma provides some unique features and distinct nonequilibrium plasma characteristics. Temperature measurements using a thermocouple thermometer showed that the gas phase temperatures of the plasma brush are close to room temperature (as low as 42 deg. C) when running with a relatively high gas flow rate of about 3500 ml/min. For an argon plasma brush, the operating voltage from less than 500 V to about 2500 V was tested, with an argon gas flow rate varied from less than 1000 to 3500 ml/min. The cold plasma brush can most efficiently use the discharge power as well as the plasma gas for material and surface treatment. The very low power consumption of such an atmospheric argon plasma brush provides many unique advantages in practical applications including battery-powered operation and use in large-scale applications. Several polymer film samples were tested for surface treatment with the newly developed device, and successful changes of the wettability property from hydrophobic to hydrophilic were achieved within a few seconds

  16. Extreme hydrogen plasma densities achieved in a linear plasma generator

    NARCIS (Netherlands)

    Rooij, van G.J.; Veremiyenko, V.P.; Goedheer, W.J.; Groot, de B.; Kleyn, A.W.; Smeets, P.H.M.; Versloot, T.W.; Whyte, D.G.; Engeln, R.A.H.; Schram, D.C.; Lopes Cardozo, N.J.

    2007-01-01

    A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5×1020 m-3 electron density, ~2 eV electron and ion

  17. Initial operation of SSRL wiggler in spear

    International Nuclear Information System (INIS)

    Berndt, M.; Brunk, W.; Cronin, R.; Jensen, D.; Johnson, R.; King, A.; Spencer, J.; Taylor, T.; Winick, H.

    1979-03-01

    A 3 lambda planar, magnetic wiggler has been designed, built, installed and operated in the SPEAR storage ring. Its primary purpose is to provide tunable synchrotron radiation (SR) with a higher energy and intensity than previously available for a new SR beam line just commissioned at the Stanford Synchrotron Radiation Laboratory. Because the magnet operates from 0-18 kG, it should also produce undulator radiation (UR). Since the wiggler influences storage ring operation in both single beam and colliding beam modes, measurements were made of tune changes, emittance changes and energy spreads which are compared to predictions. Significant improvements in luminosity for high energy physics experiments were observed. The ability to do x-ray experiments easily that were not previously feasible at low electron beam energies and currents has also been demonstrated. The basic design, some interesting characteristics of the magnetic measurements and initial operating experience and results are discussed

  18. Wiggler as spin rotators for RHIC

    International Nuclear Information System (INIS)

    Luccio, A.; Conte, M.

    1993-01-01

    The spin of a polarized particle in a circular accelerator can be rotated with an arrangement of dipoles with field mutually perpendicular and perpendicular to the orbit. To achieve spin rotation, a given field integral value is required. The device must be designed in a way that the particle orbit is distorted as little as possible. It is shown that wigglers with many periods are suitable to achieve spin rotation with minimum orbit distortions. Wigglers are also more compact than more established structures and will use less electric power. Additional advantages include their use for non distructive beam diagnostics. Results are given for the Relativistic Heavy Ion Collider (RHIC) in the polarized proton mode

  19. Damping Wiggler Study at KEK-ATF

    CERN Document Server

    Naito, Takashi; Honda, Yosuke; Korostelev, Maxim S; Kubo, Kiyoshi; Kuriki, Masao; Kuroda, Shigeru; Muto, Toshiya; Nakamura, Norio; Ross, Marc; Sakai, Hiroshi; Terunuma, Nobuhiro; Urakawa, Junji; Zimmermann, Frank

    2005-01-01

    The effects by damping wiggler magnets have been studied at KEK-ATF. The damping ring of the KEK-ATF is a 1.3 GeV storage ring capable of producing ultra-low emittance electron beams. It is significant issue to realize fast damping in the damping ring. The tuning method with 4 sets of wiggler was investigated for the ultra-low emittance beam. The performance on the beam quality, which is related to the transverse (x and y) and the longitudinal (z and dp/p), has been measured by the SR monitor, the laser wire, the streak camera and the energy spread monitor at the extraction line. We report on the operation condition and the measurement results.

  20. Synchrotron radiation from a Helical Wiggler

    International Nuclear Information System (INIS)

    Irani, A.A.

    1979-01-01

    The use of Wiggler magnets as an improved source of synchrotron radiation from high energy electron storage rings was proposed a few years ago. Since then it has also been suggested that synchrotron radiation from Wiggler magnets placed in proton machines can be used to monitor energy, dimensions and position of the beam and that this effect is even more interesting in proton storage rings where the need to see the beam is greater. Most of the calculations carried out so far consider radiation from a single particle in a Wiggler which is appropriate when the beam is radiating incoherently. In this paper a general formalism is developed for the case when the beam radiates coherently. These results are then applied to both electron and proton storage rings. For the electron case, an expression is derived for the length of the bunch to be used as a more intense coherent radiation source. For proton machines the radiation can be used to measure energy, current, transverse dimensions and longitudinal density variations in the beam

  1. Synchrotron radiation from a helical wiggler

    International Nuclear Information System (INIS)

    Irani, A.A.

    1979-01-01

    The use of wiggler magnets as an improved source of synchrotron radiation from high energy electron storage rings was proposed a few years age. Since then it has also been suggested that synchrotron radiation from wiggler magnets placed in proton machines can be used to monitor energy, dimensions and position of the beam and that this effect is even more interesting in proton storage rings where the need to see the beam is greater. Most of the calculations carried out so far consider radiation from a single particle in a wiggler which is appropriate when the beam is radiating incoherently. A general formalism is presented for the case when the beam radiates coherently. These results are applied to both electron and proton storage rings. For the electron case, an expression is derived for the length of the bunch to use it as a more intense coherent radiation source. For proton machines the radiation can be used to measure energy, current, transverse dimensions and longitudinal density variations in the beam

  2. Modeling a horizontal wiggler in an electron storage ring

    International Nuclear Information System (INIS)

    Helm, R.H.

    1979-02-01

    The effects of a wiggler on the beam parameters depend on several integrals involving the machine functions and the field distribution in the wiggler. It is shown that these integrals are separable into sums of products of terms containing only the initial values of the machine functions, and terms containing integrals over the wiggler fields. The field-dependent integrals may be determined by numerical integrations based on measured field distribution. In typical wiggler designs, the energy and excitation dependencies of the integrals may be modeled mathematically by simple power series

  3. Plasma driven neutron/gamma generator

    Science.gov (United States)

    Leung, Ka-Ngo; Antolak, Arlyn

    2015-03-03

    An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.

  4. High order harmonic generation from plasma mirror

    International Nuclear Information System (INIS)

    Thaury, C.

    2008-09-01

    When an intense laser beam is focused on a solid target, its surface is rapidly ionized and forms a dense plasma that reflects the incident field. For laser intensities above few 10 15 W/cm 2 , high order harmonics of the laser frequency, associated in the time domain to a train of atto-second pulses (1 as = 10 18 s), can be generated upon this reflection. Because such a plasma mirror can be used with arbitrarily high laser intensities, this process should eventually lead to the production of very intense pulses in the X-ray domain. In this thesis, we demonstrate that for laser intensities about 10 19 W/cm 2 , two mechanisms can contribute to the generation of high order harmonics: the coherent wake emission and the relativistic emission. These two mechanisms are studied both theoretically and experimentally. In particular, we show that, thanks to very different properties, the harmonics generated by these two processes can be unambiguously distinguished experimentally. We then investigate the phase properties of the harmonic, in the spectral and in the spatial domain. Finally, we illustrate how to exploit the coherence of the generation mechanisms to get information on the dynamics of the plasma electrons. (author)

  5. Installation of a second superconducting wiggler at SAGA-LS

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, T., E-mail: kaneyasu@saga-ls.jp; Takabayashi, Y.; Iwasaki, Y.; Koda, S. [SAGA Light Source, 8-7 Yayoigaoka, Tosu 841-0005 (Japan)

    2016-07-27

    The SAGA Light Source is a synchrotron radiation facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring with a circumference of 75.6 m. A superconducting wiggler (SCW) with a peak magnetic field of 4 T has been routinely operating for generating hard X-rays since its installation in 2010. In light of this success, it was decided to install a second SCW as a part of the beamline construction by Sumitomo Electric Industries. To achieve this, machine modifications including installation of a new magnet power supply, improvement of the magnet control system, and replacement of the vacuum chambers in the storage ring were carried out. Along with beamline construction, installation and commissioning of the second SCW are scheduled to take place in 2015.

  6. Permanent magnets including undulators and wigglers

    CERN Document Server

    Bahrdt, J

    2010-01-01

    After a few historic remarks on magnetic materials we introduce the basic definitions related to permanent magnets. The magnetic properties of the most common materials are reviewed and the production processes are described. Measurement techniques for the characterization of macroscopic and microscopic properties of permanent magnets are presented. Field simulation techniques for permanent magnet devices are discussed. Today, permanent magnets are used in many fields. This article concentrates on the applications of permanent magnets in accelerators starting from dipoles and quadrupoles on to wigglers and undulators.

  7. Dispersion relation and growth rate of a relativistic electron beam propagating through a Langmuir wave wiggler

    Science.gov (United States)

    Zirak, H.; Jafari, S.

    2015-06-01

    In this study, a theory of free-electron laser (FEL) with a Langmuir wave wiggler in the presence of an axial magnetic field has been presented. The small wavelength of the plasma wave (in the sub-mm range) allows obtaining higher frequency than conventional wiggler FELs. Electron trajectories have been obtained by solving the equations of motion for a single electron. In addition, a fourth-order Runge-Kutta method has been used to simulate the electron trajectories. Employing a perturbation analysis, the dispersion relation for an electromagnetic and space-charge waves has been derived by solving the momentum transfer, continuity, and wave equations. Numerical calculations show that the growth rate increases with increasing the e-beam energy and e-beam density, while it decreases with increasing the strength of the axial guide magnetic field.

  8. Electron energy and electron trajectories in an inverse free-electron laser accelerator based on a novel electrostatic wiggler

    Science.gov (United States)

    Nikrah, M.; Jafari, S.

    2016-06-01

    We expand here a theory of a high-gradient laser-excited electron accelerator based on an inverse free-electron laser (inverse-FEL), but with innovations in the structure and design. The electrostatic wiggler used in our scheme, namely termed the Paul wiggler, is generated by segmented cylindrical electrodes with applied oscillatory voltages {{V}\\text{osc}}(t) over {{90}\\circ} segments. The inverse-FEL interaction can be described by the equations that govern the electron motion in the combined fields of both the laser pulse and Paul wiggler field. A numerical study of electron energy and electron trajectories has been made using the fourth-order Runge-Kutta method. The results indicate that the electron attains a considerable energy at short distances in this device. It is found that if the electron has got sufficient suitable wiggler amplitude intensities, it can not only gain higher energy in longer distances, but also can retain it even after the passing of the laser pulse. In addition, the results reveal that the electron energy gains different peaks for different initial axial velocities, so that a suitable small initial axial velocity of e-beam produces substantially high energy gain. With regard to the transverse confinement of the electron beam in a Paul wiggler, there is no applied axial guide magnetic field in this device.

  9. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap seimconductors (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas

  10. Beat-wave generation of plasmons in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap semiconductor (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas. (author). 7 refs

  11. High order harmonic generation from plasma mirrors

    International Nuclear Information System (INIS)

    George, H.

    2010-01-01

    When an intense laser beam is focused on a solid target, the target's surface is rapidly ionized and forms dense plasma that reflects the incident field. For laser intensities above few 10 to the power of 15 Wcm -2 , high order harmonics of the laser frequency, associated in the time domain to a train of atto-second pulses (1 as 10 -18 s), can be generated upon this reflection. In this thesis, we developed numerical tools to reveal original aspects of harmonic generation mechanisms in three different interaction regime: the coherent wake emission, the relativistic emission and the resonant absorption. In particular, we established the role of these mechanisms when the target is a very thin foil (thickness of the order of 100 nm). Then we study experimentally the spectral, spatial and coherence properties of the emitted light. We illustrate how to exploit these measurements to get information on the plasma mirror dynamics on the femtosecond and atto-second time scales. Last, we propose a technique for the single-shot complete characterization of the temporal structure of the harmonic light emission from the laser-plasma mirror interaction. (author)

  12. Competition of electron-cyclotron maser and free-electron laser modes with combined solenoidal and longitudinal wiggler fields

    International Nuclear Information System (INIS)

    Lin, A.T.; Lin, C.

    1986-01-01

    A relativistic electron beam with a finite transverse dc momentum (β/sub perpendicular/ = 1/γ 0 ) passing through a region of combined uniform solenoidal and longitudinal wiggler magnetic fields is observed to convert 25% of its kinetic energy into coherent radiation at frequency ω = γ 2 0 (k/sub w/V 0 +Ω/sub c//γ 0 ) if the phase velocity of the generated wave is slightly above the speed of light. In this situation, the bunchings of the slow electron-cyclotron mode and free-electron laser modes with combined solenoidal and longitudinal wiggler fields (lowbitron) are observed to compensate each other, which gives rise to a finite threshold for lowbitron operation. In order to attain high efficiency, the wiggler strength of a lowbitron must substantially exceed the threshold

  13. Modeling thrombin generation: plasma composition based approach.

    Science.gov (United States)

    Brummel-Ziedins, Kathleen E; Everse, Stephen J; Mann, Kenneth G; Orfeo, Thomas

    2014-01-01

    Thrombin has multiple functions in blood coagulation and its regulation is central to maintaining the balance between hemorrhage and thrombosis. Empirical and computational methods that capture thrombin generation can provide advancements to current clinical screening of the hemostatic balance at the level of the individual. In any individual, procoagulant and anticoagulant factor levels together act to generate a unique coagulation phenotype (net balance) that is reflective of the sum of its developmental, environmental, genetic, nutritional and pharmacological influences. Defining such thrombin phenotypes may provide a means to track disease progression pre-crisis. In this review we briefly describe thrombin function, methods for assessing thrombin dynamics as a phenotypic marker, computationally derived thrombin phenotypes versus determined clinical phenotypes, the boundaries of normal range thrombin generation using plasma composition based approaches and the feasibility of these approaches for predicting risk.

  14. D.C.-arc plasma generator for nonequilibrium plasmachemical processes

    International Nuclear Information System (INIS)

    Kvaltin, J.

    1990-06-01

    The analysis is made of the conditions for generation of nonequilibrium plasma in a plasmachemical reactor, and the design is described of a d.c. arc plasma generator based on the integral criterion. Results of measuring potentials on the plasma column of this generator are presented. (author)

  15. Beryllium dust generation resulting from plasma bombardment

    International Nuclear Information System (INIS)

    Doerner, R.; Mays, C.

    1997-01-01

    The beryllium dust resulting from erosion of beryllium samples subjected to plasma bombardment has been measured in PISCES-B. Loose surface dust was found to be uniformly distributed throughout the device and accounts for 3% of the eroded material. A size distribution measurement of the loose surface dust shows an increasing number of particles with decreasing diameter. Beryllium coatings on surfaces with a line of sight view of the target interaction region account for an additional 33% of the eroded beryllium material. Flaking of these surface layers is observed and is thought to play a significant role in dust generation inside the vacuum vessel. (orig.)

  16. Electromagnetic wiggler technology development at the Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Deis, G.A.; Burns, M.J.; Christensen, T.C.; Coffield, F.E.; Kulke, B.; Prosnitz, D.; Scharlemann, E.T.; Halbach, K.

    1987-01-01

    As a part of the program at the Lawrence Livermore National Laboratory (LLNL) in induction-linac free-electron laser (IFEL) research, we are conducting a variety of activities addressing the unique requirements imposed on IFEL wiggler systems. We are actively developing improved dc iron-core electromagnetic wiggler designs to attain higher peak fields, greater tunability, and lower random error levels. We are pursuing specialized control systems, such as magnetic-field and beam-position controllers, which can relax requirements on the wiggler itself. We are also pursuing basic studies to establish the effect of radiation on permanent magnets

  17. Calculation of the Coherent Synchrotron Radiation Impedance from a Wiggler

    International Nuclear Information System (INIS)

    Wu, Juhao

    2003-01-01

    Most studies of Coherent Synchrotron Radiation (CSR) have only considered the radiation from independent dipole magnets. However, in the damping rings of future linear colliders, a large fraction of the radiation power will be emitted in damping wigglers. In this paper, the longitudinal wakefield and impedance due to CSR in a wiggler are derived in the limit of a large wiggler parameter K. After an appropriate scaling, the results can be expressed in terms of universal functions, which are independent of K. Analytical asymptotic results are obtained for the wakefield in the limit of large and small distances, and for the impedance in the limit of small and high frequencies

  18. Novel methods of ozone generation by micro-plasma concept

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, A.; Chiper, A.; Chen, W.; Stamate, E.

    2008-02-15

    The project objective was to study the possibilities for new and cheaper methods of generating ozone by means of different types of micro-plasma generators: DBD (Dielectric Barrier Discharge), MHCD (Micro-Hollow Cathode Discharge) and CPED (Capillary Plasma Electrode Discharge). This project supplements another current project where plasma-based DeNOx is being studied and optimised. The results show potentials for reducing ozone generation costs by means of micro-plasmas but that further development is needed. (ln)

  19. Power consumption analysis DBD plasma ozone generator

    International Nuclear Information System (INIS)

    Nur, M.; Restiwijaya, M.; Muchlisin, Z.; Arianto, F.; Susan, I. A.; Widyanto, S. A.

    2016-01-01

    Studies on the consumption of energy by an ozone generator with various constructions electrodes of dielectric barrier discharge plasma (DBDP) reactor has been carried out. This research was done to get the configuration of the reactor, that is capable to produce high ozone concentrations with low energy consumption. BDBP reactors were constructed by spiral- cylindrical configuration, plasma ozone was generated by high voltage AC voltage up to 25 kV and maximum frequency of 23 kHz. The reactor consists of an active electrode in the form of a spiral-shaped with variation diameter Dc, and it was made by using copper wire with diameter Dw. In this research, we variated number of loops coil windings N as well as Dc and Dw. Ozone concentrations greater when the wire's diameter Dw and the diameter of the coil windings applied was greater. We found that impedance greater will minimize the concentration of ozone, in contrary to the greater capacitance will increase the concentration of ozone. The ozone concentrations increase with augmenting of power. Maximum power is effective at DBD reactor spiral-cylinder is on the Dc = 20 mm, Dw = 1.2 mm, and the number of coil windings N = 10 loops with the resulting concentration is greater than 20 ppm and it consumes energy of 177.60 watts (paper)

  20. Proton emission from laser-generated plasmas at different intensities

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Giuffrida, L.; Margarone, Daniele

    2012-01-01

    Roč. 57, č. 2 (2012), s. 237-240 ISSN 0029-5922. [International Conference on Research and Applications of Plasmas (PLASMA). Warsaw, 12.09.2011-16.09.2011] Institutional support: RVO:68378271 Keywords : laser-generated plasma * hydrogenated targets * proton acceleration Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.507, year: 2012

  1. Effects of wigglers and undulators on beam dynamics

    International Nuclear Information System (INIS)

    Smith, L.

    1986-08-01

    Synchrotron light facilities are making ever increasing use of wigglers and undulators, to the extent that these devices are becoming a significant part of the beam optical system of the storage ring itself. This paper presents a theoretical formulation for investigating the effect of wigglers and undulators on beam dynamics in the approximation that the wiggler parameter, K, divided by γ is a small number and that the number of wiggler periods in one device is large. In addition to the linear forces which must be taken into account when tuning and matching the ring, nonlinear stop bends are created, with even orders more serious than odd orders. Some numerical examples are given for devices similar to those proposed for the 1-2 GeV Synchrotron Radiation Source at Lawrence Berkeley Laboratory

  2. Plasma flow driven by fusion-generated alpha particles

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1978-05-01

    The confinement of fusion-generated alpha particles will affect the transports of the background plasma particles by the momentum transfer from the energetic alphas. The ions tend to migrate towards the center of plasma (i.e. fuel injection) and electrons towards the plasma periphery. This means the existence of a mechanism which enable to pump out the ashes in the fuel plasma because of the momentum conservation of whole plasma particles. (author)

  3. Magnetic measurements of the 10 T superconducting wiggler for the SPring-8 storage ring

    CERN Document Server

    Batrakov, A; Bekhtenev, E A; Fedurin, M; Hara, M; Karpov, G; Kuzin, M; Mezentsev, N A; Miahara, Y; Shimada, T; Shkaruba, V A; Soutome, K; Tzumaki, K

    2001-01-01

    In 1999, in the frame of the project ISTC No. 767 'Budker INP/RIKEN Slow Positron Source', the Budker Institute of Nuclear Physics had made a 10 T Three-pole Superconducting Wiggler. The wiggler will be the keystone of this project by its installation on the SPring-8 storage ring for powerful gamma ray generation (lambda sub c =450 keV), that will be used for slow positron production (N subgamma(epsilon>1 MeV)approx 10 sup 1 sup 5 , gamma/s I sub e =0.1 A). A. Ando et al., Proposal of the high magnetic field super conducting WLS for slow positron source at SPring-8, presented at SR1 '97 Conference. In January, 2000, the wiggler was transported to SPring-8, where the last test and measurements were carried out in collaboration with Japan. In this article, the results of measurements of the magnetic field, finding the magnetic field amplitude by an NMR probe, the definition of feed current relations by stretch current wire method, the calibration of a Hall probe in the high magnetic field, and the measurement o...

  4. Nonlinear analysis of wiggler-imperfections in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Freund, H.P. [Naval Research Lab., Washington, DC (United States); Yu, L.H. [Brookhaven National Lab., Upton, NY (United States)

    1995-12-31

    We present an analysis of the effect of wiggler imperfections in FELs using a variety of techniques. Our basic intention is to compare wiggler averaged nonlinear simulations to determine the effect of various approximations on the estimates of gain degradation due to wiggler imperfections. The fundamental assumption in the wiggler-averaged formulations is that the electrons are described by a random walk model, and an analytic representation of the orbits is made. This is fundamentally different from the approach taken for the non-wiggler-averaged formulation in which the wiggler imperfections are specified at the outset, and the orbits are integrated using a field model that is consistent with the Maxwell equations. It has been conjectured on the basis of prior studies using the non-wiggler-averaged formalism that electrons follow a {open_quotes}meander line{close_quotes} through the wiggler governed by the specific imperfections; hence, the electrons behave more as a ball-in-groove than as a random walk. This conjecture is tested by comparison of the wiggler-averaged and non-wiggler-averaged simulations. In addition, two different wiggler models are employed in the non-wiggler-averaged simulation: one based upon a parabolic pole face wiggler which is not curl and divergence free in the presence of wiggler imperfections, and a second model in which the divergence and z-component of the curl vanish identically. This will gauge the effect of inconsistencies in the wiggler model on the estimation of the effect of the imperfections. Preliminary results indicate that the inconsistency introduced by the non-vanishing curl and divergence result in an overestimation of the effect of wiggler imperfections on the orbit. The wiggler-averaged simulation is based upon the TDA code, and the non-wiggler-averaged simulation is a variant of the ARACHNE and WIGGLIN codes called MEDUSA developed to treat short-wavelength Gauss-Hermite modes.

  5. Kinetic description of a wiggler pumped ion-channel free electron laser

    International Nuclear Information System (INIS)

    Mehdian, H; Raghavi, A

    2006-01-01

    The wiggler pumped ion-channel free electron laser (WPIC-FEL) is treated and the classes of possible single-particle electron trajectories in this configuration are discussed in the paper. A new region of orbital stability is seen in the negative mass regime. A kinetic description of WPIC-FEL is given. Vlasov-Maxwell equations are solved to get the linear gain in a tenuous-beam limit, where the beam plasma frequency is much less than the radiation frequency and the self-field effects can be ignored

  6. Thermal Plasma Generators with Water Stabilized Arc

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    2009-01-01

    Roč. 2, č. 1 (2009), s. 99-104 ISSN 1876-5343 R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * plasma torch * Gerdien arc Subject RIV: BL - Plasma and Gas Discharge Physics http://www.bentham.org/open/toppj/openaccess2.htm

  7. The use of cold plasma generators in medicine

    Directory of Open Access Journals (Sweden)

    Kolomiiets R.O.

    2017-04-01

    Full Text Available Cold plasma treatment of wounds is a modern area of therapeutic medicine. We describe the physical mechanisms of cold plasma, the principles of therapeutic effects and design of two common types of cold plasma generators for medical use. This work aims at disclosing the basic principles of construction of cold atmospheric plasma generators in medicine and prospects for their further improvement. The purpose of this work is to improve the existing cold atmospheric plasma generators for use in medical applications. Novelty of this work consists in the application of new principles of construction of cold atmospheric plasmas medical apparatus, namely the combination of the gas discharge chamber, electrodes complex shape forming device and plasma flow in a single package. This helps to achieve a significant reduction in the size of the device, and a discharge chamber design change increases the therapeutic effect. The design of cold atmospheric plasma generator type «pin-to-hole», which is able to control parameters using the plasma current (modulation fluctuations in the primary winding and mechanically (using optional rotary electrode. It is also possible to combine some similar generators in the set, which will increase the surface area of the plasma treatment. We consider the basic principles of generating low atmospheric plasma flow, especially the formation of the plasma jet, changing its shape and modulation stream. The features of cold plasma generator design and information about prospects for further application, and opportunities for further improvement are revealed. The recommendations for further use of cold atmospheric plasma generators in medicine are formulated.

  8. Quantum SASE FEL with a Laser Wiggler

    CERN Document Server

    Bonifacio, R

    2005-01-01

    Quantum effects in high-gain FELs become relevant when ρ'=ρ(mcγ/ ћ k)<1. The quantum FEL parameter ρ' rules the maximum number of photons emitted per electrons. It has been shown that when ρ'<1 a "quantum purification" of the SASE regime occurs: in fact, the spectrum of the emitted radiation (randomly spiky in the usual classical SASE regime) shrinks to a very narrow single line, leading to a high degree of temporal coherence. From the definition of ρ it appears that in order to achieve the quantum regime, small values of ρ, beam energy and radiation wavelength are necessary. These requirements can be met only using a laser wiggler. In this work we state the scaling laws necessary to operate a SASE FEL in the Angstrom region. All physical quantities are expressed in terms of the normalized emittance and of two parameters: the ratio between laser and electron beam spot sizes and the ratio between Rayleigh range and electron ...

  9. Plasma generation using the hollow cathod

    International Nuclear Information System (INIS)

    Moon, K.J.

    1983-01-01

    A hollow cathode of tungsten was adapted to an University of California, Berkely, LBL bucket ion source to investigate ion density fluctuations at the extractior grid. Fluctuations in plasma ion density are observed to range between 100kHz to 2 MHz. The observed fluctuation frequencies of plasma ion density are found to be inversely proportional to the square root of ion masses. It is guessed that the plasma fluctuation are also correlated with the hollow cathode length. (Author)

  10. Performance of the SRRC storage ring and wiggler commissioning

    International Nuclear Information System (INIS)

    Kuo, C.C.; Hsu, K.T.; Luo, G.H.

    1995-01-01

    A 1.3 GeV synchrotron radiation storage ring at SRRC has been operated for more than a year since October 1993. Starting from April 1994, the machine has been open to the user community. In February 1995, the authors installed a wiggler magnet of 1.8 tesla 25-pole in the ring and successfully commissioned. The machine was scheduled for the users' runs from the middle of April this year. The authors describe the performance of the machine without wiggler magnet system and then report the wiggler effects on the beam dynamics of the storage ring, e.g., tune shift, beta-beating, orbit change, nonlinear dynamics effect, etc. Some measurements are compared with the model prediction and agreement between them was fairly good. Possible actions to minimize wiggler effects have been taken, such as orbit correction as a function wiggler gap change. The machine improvement projects, such as longitudinal and transverse damping systems as well as orbit stability feedback system are under construction and will be in use soon

  11. A wiggler magnet for FEL low voltage operation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shamma`a, A.; Stuart, R.A.; Lucas, J.

    1995-12-31

    In low voltage FELs (ie, 200kV), operation is necessarily in the microwave frequency range for wiggler periods of the order of cms., so that a waveguide system is mandatory. Also, because of the relatively low velocity of the electron beam, the wiggle amplitude of the electron beam can be much larger than is normal for highly relativistic FELs. Both these factors mean that the electron trajectory must be carefully controlled to avoid beam collision with the waveguide walls. A wiggler system with half poles at entrance and exit is not an acceptable solution because of the offset is gives rise to the electron trajectory. Consequently, we have designed and constructed a wiggler magnet with exponential entrance and exit tapers for a minimal deflection and displacement of the electron beam. Simulations and experimental measurements showed that an on axis trajectory is easily obtainable.

  12. Commissioning of the LNLS 2 T Hybrid Wiggler

    CERN Document Server

    Farias, Ruy H A; Aparecida-Gouveia, Ana F; Cabral-Jahnel, Lucia; Citadini, James F; Ferreira, Marcelo J; Franco, J G; Liu, Lin; Neuenschwander, Regis; Resende, Ximenes R; Tavares, Pedro; Tosin, Giancarlo

    2005-01-01

    We present the results of the commissioning of a 28-pole 2 T Hybrid Wiggler at the 1.37 GeV electron storage ring of the Brazilian Synchrotron Light Source. The wiggler will be used mainly for protein crystallography and was optimized for the production of 12 keV photons. The very high field and relatively large gap (22 mm) of this insertion device led to a magnetic design that includes large main and side magnets and heavily saturated poles. We present the results of the commissioning with beam, with special attention to the correction of the large linear tune-shift perturbations produced by the wiggler as well as on the reduction of beam lifetime at full energy. Since the injection at the LNLS storage ring is performed at 500 MeV we also focus on the effects of non-linearities and their impact on injection efficiency.

  13. Preliminary design for a pierce wiggler beamstick and addendum

    International Nuclear Information System (INIS)

    Pirkle, D.

    1988-05-01

    Lawrence Livermore National Laboratory is developing a fast tunable microwave source for operation at 250 GHz and 10kW peak output power. This report presents the preliminary design of a Pierce gun and solenoid magnet that will be compatible with a Pierce-wiggler electron beam formation system (beamstick). The beamstick will be an appropriate power source for a tunable gyro-BWO at 250 GHz. Figure 1 presents the major components of the Pierce-wiggler beamstick: the electron gun, solenoid, beam tunnel, wiggler, and vacuum valve. Figure 2 shows an artistic conception of how the beamstick will interface with the interaction magnet, modulator and gyro-BWO circuit at MIT. 15 figs

  14. Construction of compact FEM using solenoid-induced helical wiggler

    International Nuclear Information System (INIS)

    Ohigashi, N.; Tsunawaki, Y.; Fujita, M.; Imasaki, K.; Mima, K.; Nakai, S.

    2003-01-01

    A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7x2.9 m 2

  15. CALCULATION OF THE COHERENT RADIATION IMPDENACE FROM A WIGGLER

    International Nuclear Information System (INIS)

    Wu, J

    2004-01-01

    Most studies of coherent synchrotron radiation (CSR) have considered only the radiation from independent dipole magnets. However, in the damping rings of future linear colliders and many high luminosity factories, a large fraction of the radiation power will be emitted in damping wigglers. In this paper, the longitudinal wakefield and impedance due to CSR in a wiggler are derived in the limit of a large wiggler parameter K. After an appropriate scaling, the results can be expressed in terms of universal functions, which are independent of K. Analytical asymptotic results are obtained for the wakefield in the limit of large and small distances, and for the impedance in the limit of small and high frequencies

  16. Generation conditions of CW Diode Laser Sustained Plasma

    Science.gov (United States)

    Nishimoto, Koji; Matsui, Makoto; Ono, Takahiro

    2016-09-01

    Laser sustained plasma was generated using 1 kW class continuous wave diode laser. The laser beam was focused on the seed plasma generated by arc discharge in 1 MPa xenon lamp. The diode laser has advantages of high energy conversion efficiency of 80%, ease of maintenance, compact size and availability of conventional quartz based optics. Therefore, it has a prospect of further development compared with conventional CO2 laser. In this study, variation of the plasma shape caused by laser power is observed and also temperature distribution in the direction of plasma radius is measured by optical emission spectroscopy.

  17. Measurement of performance parameters of plasma source for plasma opening switch on Qiangguang-Ⅰ generator

    International Nuclear Information System (INIS)

    Luo Weixi; Zeng Zhengzhong; Lei Tianshi; Wang Liangping; Hu Yixiang; Sun Tieping; Huang Tao

    2012-01-01

    The plasma source (cable guns) of the plasma opening switch (POS) on Qiangguang Ⅰ generator was chosen as the study object. The plasma source performance was investigated by using charge collectors. Experimental results show that the plasma ejection density is positively correlated with the structural parameter, the distance between gun core tip and muzzle plane, and the plasma ejection velocity is negatively correlated with the parameter. The increasing rate of plasma ejection density is less than that of drive current. As far as a plasma source with tens of cable plasma guns is concerned, the influence of single cable gun's discharge dispersancy on plasma uniformity is little. Analysis of uncertainty shows that the uncertainty of measurement can be reduced by increasing the number of experiments and averaging the results. The combined standard uncertainty of plasma ejection density is less than 10%. (authors)

  18. Superconducting 63-Pole 2 Tesla Wiggler for Canadian Light Source

    International Nuclear Information System (INIS)

    Khruschev, S.V.; Kuper, E.A.; Lev, V.H.; Mezentsev, N.A.; Miginsky, E.G.; Repkov, V.V.; Shkaruba, B.A.; Syrovatin, V.M.; Tsukanov, V.M.

    2006-01-01

    A superconducting 63-pole wiggler with the average period 34 mm designed and fabricated at the Institute of Nuclear Physics in Novosibirsk for Synchrotron Radiation Center (CLS) in Canada is described. The maximum field 2.2 Tesla in the median plane has been achieved. The liquid helium consumption less than 0.03 liters per hour in operating mode has been reached. In January 2005, the wiggler was installed in the storage ring in CLS and now experiments are already underway. The main parameters of the magnet and the cryogenic systems as well as test results are presented

  19. Superconducting 63-pole 2 T wiggler for Canadian Light Source

    International Nuclear Information System (INIS)

    Khruschev, S.V.; Kuper, E.A.; Lev, V.H.; Mezentsev, N.A.; Miginsky, E.G.; Repkov, V.V.; Shkaruba, V.A.; Syrovatin, V.M.; Tsukanov, V.M.

    2007-01-01

    A superconducting 63-pole wiggler with the average period 34 mm designed and fabricated in the Institute of Nuclear Physics in Novosibirsk for Synchrotron Radiation Center Canadian Light Source (CLS) in Canada is described. The maximum field 2.2 T in the median plane has been achieved. The liquid helium consumption less than 0.03 L h in operating mode has been reached. It allows refilling liquid helium once a year. In January 2005, the wiggler was installed in the storage ring in CLS and now experiments are carried out. The main parameters of the magnet and the cryogenic systems as well as test results are presented

  20. The influence of plasma motion on disruption generated runaway electrons

    International Nuclear Information System (INIS)

    Russo, A.J.

    1991-01-01

    One of the possible consequences of disruptions is the generation of runaway electrons which can impact plasma facing components and cause damage due to high local energy deposition. This problem becomes more serious as the machine size and plasma current increases. Since large size and high currents are characteristics of proposed future machines, control of runaway generation is an important design consideration. A lumped circuit model for disruption runaway electron generation indicates that control circuitry on strongly influence runaway behavior. A comparison of disruption data from several shots on JET and D3-D with model results, demonstrate the effects of plasma motion on runaway number density and energy. 6 refs., 12 figs

  1. Theory and experiments on the generation of spontaneous emission using a plasma wave undulator

    International Nuclear Information System (INIS)

    Williams, R.L.; Clayton, C.E.; Joshi, C.; Katsouleas, T.; Mori, W.B.; Slater, J.

    1990-01-01

    This paper reports that, the authors are studying the feasibility of using relativistically moving plasma waves as short wavelength undulators for possible FEL and Compton scattering applications at UCLA. The remarkable property of such waves is that the wiggler parameter a w = eA/mc 2 can be on the order 0.1 while their wavelength λ w can be submillimeter. Such waves can be excited by either an intense electron bunch going through a plasma (plasma wake field) or a short but intense laser pulse going through the plasma (laser wake field). A variation of the laser wake field scheme is the plasm beat wave excitation. Here a moderately intense laser pulse containing two frequencies excites the plasm wave resonantly. Using a laser pulse containing 10.27 μm and 9.6 μm lines of the Co 2 laser that is approximately 400 ps (FWHM) and 200 GW of power, we were able to measure a w times the length product of 0.013 cm in our experiments. If a length of 0.75 cm i assumed, this implies an a w of 0.17 for a λ w ∼156 μm. Injection of an electron beam across such a plasma wave proved not to be feasible in these experiments, because the θ-pinch plasma source contained significant trapped magnetic fields. We are currently developing a field free plasma source which will permit transverse electron injection

  2. Development of solenoid-induced helical wiggler with four poles per period

    International Nuclear Information System (INIS)

    Ohigashi, N.; Tsunawaki, Y.; Kiyochi, M.; Nakao, N.; Fujita, M.; Imasaki, K.; Nakai, S.; Mima, K.

    1999-01-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field

  3. Development of solenoid-induced helical wiggler with four poles per period

    CERN Document Server

    Ohigashi, N; Kiyochi, M; Nakao, N; Fujita, M; Imasaki, K; Nakai, S; Mima, K

    1999-01-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field.

  4. Flux compression generators as plasma compression power sources

    International Nuclear Information System (INIS)

    Fowler, C.M.; Caird, R.S.; Erickson, D.J.; Freeman, B.L.; Thomson, D.B.; Garn, W.B.

    1979-01-01

    A survey is made of applications where explosive-driven magnetic flux compression generators have been or can be used to directly power devices that produce dense plasmas. Representative examples are discussed that are specific to the theta pinch, the plasma gun, the dense plasma focus and the Z pinch. These examples are used to illustrate the high energy and power capabilities of explosive generators. An application employing a rocket-borne, generator-powered plasma gun emphasizes the size and weight potential of flux compression power supplies. Recent results from a local effort to drive a dense plasma focus are provided. Imploding liners ae discussed in the context of both the theta and Z pinches

  5. Resonant and hollow beam generation of plasma channels

    International Nuclear Information System (INIS)

    Alexeev, I.; Kim, K.Y.; Fan, J.; Parra, E.; Milchberg, H.M.; Margolin, L.Ya.; Pyatnitskii, L.N.

    2001-01-01

    We report two variations on plasma channel generation using the propagation of intense Bessel beams. In the first experiment, the propagation of a high intensity Bessel beam in neutral gas is observed to give rise to resonantly enhanced plasma channel generation, resulting from resonant self-trapping of the beam and enhanced laser-plasma heating. In the second experiment, a high power, hollow Bessel beam (J 5 ) is produced and the optical breakdown of a gas target and the generation of a tubular plasma channel with such a beam is realized for the first time. Hydrodynamic simulations of the laser-plasma interaction of are in good agreement with the results of both experiments

  6. Generation mechanism and properties of plasma double layers

    International Nuclear Information System (INIS)

    Sanduloviciu, M.; Lozneanu, E.

    1985-01-01

    The generation mechanism of plasma double layers is studied surveying the results of some experiments. The main mechanism is the same in the cases of collisional and collisionless plasmas. Inelastic quantum collision processes taking place between plasma electrons, accelerated in a local field up to near the same oriented velocity and the neutral particles of the background gases create the necessary conditions for double layer formation. (D.Gy.)

  7. Novel modulator topology for corona plasma generation

    NARCIS (Netherlands)

    Ariaans, T.H.P.; Pemen, A.J.M.; Winands, G.J.J.; Liu, Z.; Heesch, van E.J.M.

    2009-01-01

    Gas cleaning using plasma technology is slowly introduced into industry nowadays. Several challenges still have to be overcome: increasing the scale, safety, life time and reducing costs. In 2006 we demonstrated a 20 kW nanosecond pulsed corona system. The electrical efficiency was > 90%. O-radical

  8. The linear plasma generator Magnum-PSI

    NARCIS (Netherlands)

    Eck, van H.J.N.

    2013-01-01

    The Dutch Institute for Fundamental Energy Research (DIFFER) has built the new experimental research facility Magnum-PSI. In Magnum-PSI, Plasma Surface Interaction (PSI) research for the nuclear fusion reactor ITER and reactors beyond ITER will be carried out. As such, it is essential that the

  9. 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

  10. Spiking mode operation for a uniform-period wiggler

    International Nuclear Information System (INIS)

    Warren, R.W.; Goldstein, J.C.; Newnam, B.E.

    1985-01-01

    The onset of saturation in a uniform-period wiggler has been examined experimentally and through numerical simulations. Models have been constructed that explain the observations in simple and consistent ways. The models are based upon the development of strong frequency and amplitude modulation of the optical wave as a way to increase extraction efficiency and optical power

  11. Design of High Field Multipole Wiggler at PLS

    International Nuclear Information System (INIS)

    Kim, D. E.; Park, K. H.; Lee, H. G.; Suh, H. S.; Han, H. S.; Jung, Y. G.; Chung, C. W.

    2007-01-01

    Pohang Accelerator Laboratory (PAL) is developing a high field multipole wiggler for new EXAFS beamline. The beamline is planning to utilize very high photon energy (∼40keV) synchrotron radiation at Pohang Light Source (PLS). To achieve higher critical photon energy, the wiggler field need to be maximized. A magnetic structure with wedged pole and blocks with additional side blocks which are similar to asymmetric wiggler of ESRF are designed to achieve higher flux density. The end structures were designed to be asymmetric along the beam direction to ensure systematic zero 1st field integral. The thickness of the last magnets were adjusted to minimize the transition sequence to the fully developed periodic field. This approach is more convenient to control than adjusting the strength of the end magnets. The final design features 140mm period, 2.5 Tesla peak flux density at 12mm pole gap, 1205mm magnetic structure length with 16 full field poles. In this article, all the design, engineering efforts for the HFMSII wiggler will be described

  12. Generation of zonal flows in rotating fluids and magnetized plasmas

    DEFF Research Database (Denmark)

    Juul Rasmussen, J.; Garcia, O.E.; Naulin, V.

    2006-01-01

    The spontaneous generation of large-scale flows by the rectification of small-scale turbulent fluctuations is of great importance both in geophysical flows and in magnetically confined plasmas. These flows regulate the turbulence and may set up effective transport barriers. In the present....... The analogy to large-scale flow generation in drift-wave turbulence dynamics in magnetized plasma is briefly discussed....

  13. Plasma X-ray sources powered by megajoule magnetocumulative generators

    Energy Technology Data Exchange (ETDEWEB)

    Popkov, N F; Averchenkov, V Ya; Pikar` , A S; Ryaslov, E A; Kargin, V I; Lazarev, S A; Borodkov, V V; Nazarenko, S T; Makartsev, G F [All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation). Russian Federal Nuclear Center

    1997-12-31

    Experiments using magnetocumulative generators (MCGs) were performed to power three different types of high-energy-density plasma discharges suitable for intense x-ray generation. These included the H-pressed discharge, the capillary z-pinch, and the {theta}-pinch. The MCGs were operated both with and without plasma opening switches. The characteristic currents were approximately 10 MA and characteristic time scales approximately 1 {mu}s. (author). 7 figs., 3 refs.

  14. Generation of toroidal pre-heat plasma

    International Nuclear Information System (INIS)

    Ikeda, Nagayasu; Tamaru, Ken; Nagata, Akiyoshi.

    1979-01-01

    The characteristics of toroidal plasma in the initial stage of electric discharge were investigated. A small toroidal-pinch system was used for the present work. A magnetic probe was used to measure the magnetic field. The time of beginning of discharge was determined by observing the variation of the magnetic field. The initial gas pressure dependence of the induced electric field regions, in which electric discharge can be caused, was studied. It is necessary to increase the initial induced electric field for starting discharge. The delay time of large current discharge was measured, and it was about 2 microsecond. Dependences of the electric fields at the beginning of discharge on the charging voltage of capacitors, on the initial gas pressure, and on the discharge frequency were studied. The formation mechanism of plasma column was analyzed. (Kato, T.)

  15. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical “plasma torch” distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  16. Generation of plasma rotation by ICRH in tokamaks

    International Nuclear Information System (INIS)

    Chang, C.; Phillips, C.K.; White, R.B.; Zweben, S.; Bonoli, P.T.; Rice, J.; Greenwald, M.; Grassie, J.S. de

    2001-01-01

    A physical mechanism to generate plasma rotation by ICRH is presented in a tokamak geometry. By breaking the omnigenity of resonant ion orbits, ICRH can induce a non-ambipolar minor-radial flow of resonant ions. This induces a return current j p r in the plasma, which then drives plasma rotation through the j p r xB force. It is estimated that the fast-wave power in the present-day tokamak experiments can be strong enough to give a significant modification to plasma rotation. (author)

  17. Spectral characteristics of a relativistic plasma microwave generator

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Loza, O.T.; Ponomarev, A.V.; Rukhadze, A.A.; Strelkov, P.S.; Ul'yanov, D.K.; Shkvarunets, A.G.

    1996-01-01

    The radiation spectrum of a broad-band relativistic plasma microwave generator, in which a hollow relativistic electron beam is injected into a plasma waveguide consisting of a hollow plasma within a round metallic waveguide is measured experimentally. The radiation spectrum is measured using a wide-aperture calorimetric spectrometer in the frequency range 3-32 GHz. The influence of the plasma density and the beam-plasma gap on the radiation spectrum is investigated. The amplification of the noise electromagnetic radiation when a relativistic electron beam is injected into the plasma waveguide is calculated on the basis of the nonlinear theory. The theory predicts passage from a one-particle generation regime to a collective regime and narrowing of the radiation spectrum as the plasma density and the gap between the hollow beam and the plasma increases. A comparison of the measurement results with the nonlinear theory accounts for several features of the measured spectrum. However, the predicted change in the generation regimes is not observed experimentally. Qualitative arguments are advanced, which explain the observed phenomena and call for further theoretical and experimental research, are advanced

  18. The low-current low-temperature plasma generators

    International Nuclear Information System (INIS)

    Dautov, G.Yu.

    2000-01-01

    In this article, the results of low-current gas-discharge plasma generator investigations carried out by a group of scientists from the Kazan' Aviation Institute are presented. When considered necessary, the results are compared with the data obtained by other authors. The basic configurations and theoretical calculation peculiarities of plasma generators are described. The electrical, thermal and energy characteristics of discharges in gas flows, as well as summarised empirical formulae and experimental data necessary for calculations and design of plasma devices are presented. (author)

  19. Waves generated in the plasma plume of helicon magnetic nozzle

    International Nuclear Information System (INIS)

    Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen

    2013-01-01

    Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of the plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.

  20. Waves generated in the plasma plume of helicon magnetic nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen [Department of Electrical and Computer Engineering, University of Alabama, Huntsville, Alabama 35899 (United States)

    2013-03-15

    Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of the plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.

  1. Analytic Electron Trajectories in an Extremely Relativistic Helical Wiggler an Application to the Proposed SLAC E166 Experiment.

    CERN Document Server

    ThomasDonohue, John

    2004-01-01

    The proposed experiment SLAC E166 intends to generate circularly polarized gamma rays of energy 10 MeV by passing a 15 GeV electron beam through a meter long wiggler with approximately 400 periods. Using an analytic model formulated by Rullier and me, I present calculations of electron trajectories. At this extremely high energy the trajectories are described quite well by the model, and an extremely simple picture emerges, even for trajectories that that fail to encircle the axis of the wiggler. Our calculations are successfully compared with standard numerical integration of the Lorentz force equations of motion. In addition, the calculation of the spectrum and angular distribution of the radiated photons is easily carried out.

  2. Water plasma generation under atmospheric pressure for HFC destruction

    International Nuclear Information System (INIS)

    Watanabe, Takayuki; Tsuru, Taira

    2008-01-01

    The purpose of this paper is to investigate the decomposition process of hydrofluoroethylene (HFC-134a) by water plasmas. The water plasma was generated by DC arc discharge with a cathode of hafnium embedded into a copper rod and a nozzle-type copper anode. The advantage of the water plasma torch is the generation of 100%-water plasma by DC discharge. The distinctive steam generation leads to the portable light-weight plasma generation system that does not require the gas supply unit, as well as the high energy efficiency owing to the nonnecessity of the additional water-cooling. HFC-134a was injected into the water plasma jet to decompose it in the reaction tube. Neutralization vessel was combined to the reaction tube to absorb F 2 and HF generated from the HFC-134a decomposition. The decomposition was performed with changing the feed rate of HFC-134a up to 185 mmol/min. The decomposition efficiency of 99.9% can be obtained up to 0.43 mmol/kJ of the ratio of HFC-134a feed rate to the arc power, hence the maximum feed rate was estimated to be 160 g/h at 1 kW of the arc power

  3. A large volume uniform plasma generator for the experiments of electromagnetic wave propagation in plasma

    International Nuclear Information System (INIS)

    Yang Min; Li Xiaoping; Xie Kai; Liu Donglin; Liu Yanming

    2013-01-01

    A large volume uniform plasma generator is proposed for the experiments of electromagnetic (EM) wave propagation in plasma, to reproduce a “black out” phenomenon with long duration in an environment of the ordinary laboratory. The plasma generator achieves a controllable approximate uniform plasma in volume of 260 mm× 260 mm× 180 mm without the magnetic confinement. The plasma is produced by the glow discharge, and the special discharge structure is built to bring a steady approximate uniform plasma environment in the electromagnetic wave propagation path without any other barriers. In addition, the electron density and luminosity distributions of plasma under different discharge conditions were diagnosed and experimentally investigated. Both the electron density and the plasma uniformity are directly proportional to the input power and in roughly reverse proportion to the gas pressure in the chamber. Furthermore, the experiments of electromagnetic wave propagation in plasma are conducted in this plasma generator. Blackout phenomena at GPS signal are observed under this system and the measured attenuation curve is of reasonable agreement with the theoretical one, which suggests the effectiveness of the proposed method.

  4. Hologaphy of a CO2 laser generated plasma

    International Nuclear Information System (INIS)

    Elkerbout, A.C.H.; Van Dijk, J.W.; Donaldson, T.P.

    1976-01-01

    An expermental technique for generating holographic interferograms is discussed and illustrated with results obtained on a plasma generated by a 75 J CO 2 laser pulse incident at intensities of approximately 9 x 10 12 W/cm 2 on a plane carbon target. (author)

  5. Characterization of pulsed atmospheric-pressure plasma streams (PAPS) generated by a plasma gun

    Science.gov (United States)

    Robert, E.; Sarron, V.; Riès, D.; Dozias, S.; Vandamme, M.; Pouvesle, J.-M.

    2012-06-01

    An experimental study of atmospheric-pressure rare gas plasma propagation in a high-aspect-ratio capillary is reported. The plasma is generated with a plasma gun device based on a dielectric barrier discharge (DBD) reactor powered by either nanosecond or microsecond rise-time high-voltage pulses at single-shot to multi-kHz frequencies. The influence of the voltage waveform, pulse polarity, pulse repetition rate and capillary material have been studied using nanosecond intensified charge-coupled device imaging and plasma-front velocity measurements. The evolution of the plasma appearance during its propagation and the study of the role of the different experimental parameters lead us to suggest a new denomination of pulsed atmospheric-pressure plasma streams to describe all the plasma features, including the previously so-called plasma bullet. The unique properties of such non-thermal plasma launching in capillaries, far from the primary DBD plasma, are associated with a fast ionization wave travelling with velocity in the 107-108 cm s-1 range. Voltage pulse tailoring is shown to allow for a significant improvement of such plasma delivery. Thus, the plasma gun device affords unique opportunities in biomedical endoscopic applications.

  6. Characterization of pulsed atmospheric-pressure plasma streams (PAPS) generated by a plasma gun

    International Nuclear Information System (INIS)

    Robert, E; Sarron, V; Riès, D; Dozias, S; Vandamme, M; Pouvesle, J-M

    2012-01-01

    An experimental study of atmospheric-pressure rare gas plasma propagation in a high-aspect-ratio capillary is reported. The plasma is generated with a plasma gun device based on a dielectric barrier discharge (DBD) reactor powered by either nanosecond or microsecond rise-time high-voltage pulses at single-shot to multi-kHz frequencies. The influence of the voltage waveform, pulse polarity, pulse repetition rate and capillary material have been studied using nanosecond intensified charge-coupled device imaging and plasma-front velocity measurements. The evolution of the plasma appearance during its propagation and the study of the role of the different experimental parameters lead us to suggest a new denomination of pulsed atmospheric-pressure plasma streams to describe all the plasma features, including the previously so-called plasma bullet. The unique properties of such non-thermal plasma launching in capillaries, far from the primary DBD plasma, are associated with a fast ionization wave travelling with velocity in the 10 7 –10 8 cm s −1 range. Voltage pulse tailoring is shown to allow for a significant improvement of such plasma delivery. Thus, the plasma gun device affords unique opportunities in biomedical endoscopic applications. (paper)

  7. Transport of high fluxes of hydrogen plasma in a linear plasma generator

    NARCIS (Netherlands)

    Vijvers, W.A.J.; Al, R.S.; Lopes Cardozo, N.J.; Goedheer, W.J.; Groot, de B.; Kleyn, A.W.; Meiden, van der H.J.; Peppel, van de R.J.E.; Schram, D.C.; Shumack, A.E.; Westerhout, J.; Rooij, van G.J.; Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.

    2007-01-01

    A study was made to quantify the losses during the convective hydrogen plasma transport in the linear plasma generator Pilot-PSI due to volume recombination. A transport efficiency of 35% was achieved at neutral background pressures below ~7 Pa in a magnetic field of 1.2 T. This efficiency decreased

  8. Characterization of X-ray emission from laser generated plasma

    Science.gov (United States)

    Cannavò, Antonino; Torrisi, Lorenzo; Ceccio, Giovanni; Cutroneo, Mariapompea; Calcagno, Lucia; Sciuto, Antonella; Mazzillo, Massimo

    2018-01-01

    X-ray emission from laser generated plasma was studied at low (1010 W/cm2) and high (1018 W/cm2) intensity using ns and fs laser, respectively. Plasma characteristics were controlled trough the laser parameters, the irradiation conditions and the target properties. The X-ray spectra were acquired using fast detection technique based on SiC diodes with different active regions. The X-ray yield increases with the atomic number of the target, both at low and high intensity, and a similar empirical law has been obtained. The X-ray emission mechanisms from plasma are correlated to the plasma temperature and density and to the Coulomb charge particle acceleration, due to the charge separation effects produced in the non-equilibrium plasma. Functional dependences, theoretical approaches and interpretation of possible mechanism will be presented and discussed.

  9. Characterization of X-ray emission from laser generated plasma

    Directory of Open Access Journals (Sweden)

    Cannavò Antonino

    2018-01-01

    Full Text Available X-ray emission from laser generated plasma was studied at low (1010 W/cm2 and high (1018 W/cm2 intensity using ns and fs laser, respectively. Plasma characteristics were controlled trough the laser parameters, the irradiation conditions and the target properties. The X-ray spectra were acquired using fast detection technique based on SiC diodes with different active regions. The X-ray yield increases with the atomic number of the target, both at low and high intensity, and a similar empirical law has been obtained. The X-ray emission mechanisms from plasma are correlated to the plasma temperature and density and to the Coulomb charge particle acceleration, due to the charge separation effects produced in the non-equilibrium plasma. Functional dependences, theoretical approaches and interpretation of possible mechanism will be presented and discussed.

  10. Generator of the low-temperature heterogeneous plasma flow

    Science.gov (United States)

    Yusupov, D. I.; Gadzhiev, M. Kh; Tyuftyaev, A. S.; Chinnov, V. F.; Sargsyan, M. A.

    2018-01-01

    A generator of low-temperature dc plasma with an expanding channel of an output electrode for gas-thermal spraying was designed and constructed. The delivery of the sprayed powder into the cathode and anode arc-binding zones or into the plasma jet below the anode binding was realized. The electrophysical characteristics of both the plasma torch and the heterogeneous plasma flow with Al2O3 powder are studied. It is shown that the current-voltage characteristic (CVC) of a plasma torch depends on the gas flow rate. If the flow rate varies from 1 to 3 g/s, the falling CVC becomes gradually increasing. The speed and temperature of the sprayed powder are determined.

  11. Electrode assemblies, plasma apparatuses and systems including electrode assemblies, and methods for generating plasma

    Science.gov (United States)

    Kong, Peter C; Grandy, Jon D; Detering, Brent A; Zuck, Larry D

    2013-09-17

    Electrode assemblies for plasma reactors include a structure or device for constraining an arc endpoint to a selected area or region on an electrode. In some embodiments, the structure or device may comprise one or more insulating members covering a portion of an electrode. In additional embodiments, the structure or device may provide a magnetic field configured to control a location of an arc endpoint on the electrode. Plasma generating modules, apparatus, and systems include such electrode assemblies. Methods for generating a plasma include covering at least a portion of a surface of an electrode with an electrically insulating member to constrain a location of an arc endpoint on the electrode. Additional methods for generating a plasma include generating a magnetic field to constrain a location of an arc endpoint on an electrode.

  12. 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

  13. Plasma blob generation due to cooperative elliptic instability.

    Science.gov (United States)

    Manz, P; Xu, M; Müller, S H; Fedorczak, N; Thakur, S C; Yu, J H; Tynan, G R

    2011-11-04

    Using fast-camera measurements the generation mechanism of plasma blobs is investigated in the linear device CSDX. During the ejection of plasma blobs the plasma is dominated by an m=1 mode, which is a counterrotating vortex pair. These flows are known to be subject to the cooperative elliptic instability, which is characterized by a cooperative disturbance of the vortex cores and results in a three-dimensional breakdown of two-dimensional flows. The first experimental evidence of a cooperative elliptic instability preceding the blob-ejection is provided in terms of the qualitative evolution of the vortex geometries and internal wave patterns.

  14. Edge Plasma Boundary Layer Generated By Kink Modes in Tokamaks

    International Nuclear Information System (INIS)

    Zakharov, L.E.

    2010-01-01

    This paper describes the structure of the electric current generated by external kink modes at the plasma edge using the ideally conducting plasma model. It is found that the edge current layer is created by both wall touching and free boundary kink modes. Near marginal stability, the total edge current has a universal expression as a result of partial compensation of the (delta)-functional surface current by the bulk current at the edge. The resolution of an apparent paradox with the pressure balance across the plasma boundary in the presence of the surface currents is provided.

  15. Hollow laser plasma self-confined microjet generation

    Science.gov (United States)

    Sizyuk, Valeryi; Hassanein, Ahmed; CenterMaterials under Extreme Environment Team

    2017-10-01

    Hollow laser beam produced plasma (LPP) devices are being used for the generation of the self-confined cumulative microjet. Most important place by this LPP device construction is achieving of an annular distribution of the laser beam intensity by spot. An integrated model is being developed to detailed simulation of the plasma generation and evolution inside the laser beam channel. The model describes in two temperature approximation hydrodynamic processes in plasma, laser absorption processes, heat conduction, and radiation energy transport. The total variation diminishing scheme in the Lax-Friedrich formulation for the description of plasma hydrodynamic is used. Laser absorption and radiation transport models on the base of Monte Carlo method are being developed. Heat conduction part on the implicit scheme with sparse matrixes using is realized. The developed models are being integrated into HEIGHTS-LPP computer simulation package. The integrated modeling of the hollow beam laser plasma generation showed the self-confinement and acceleration of the plasma microjet inside the laser channel. It was found dependence of the microjet parameters including radiation emission on the hole and beam radiuses ratio. This work is supported by the National Science Foundation, PIRE project.

  16. A study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    Science.gov (United States)

    Wright, Kenneth Herbert, Jr.

    1988-01-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory.

  17. Study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    International Nuclear Information System (INIS)

    Wright, K.H. Jr.

    1988-02-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory

  18. Generation of low-temperature air plasma for food processing

    Science.gov (United States)

    Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

    2015-11-01

    The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

  19. ELECTRON TRAPPING IN WIGGLER AND QUADRUPOLE MAGNETS OF CESRTA

    International Nuclear Information System (INIS)

    Wang, Lanfa

    2010-01-01

    The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in the wiggler and quadrupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with long lifetime in a quadrupole magnet due to the mirror field trapping mechanism and photoelectrons produced in the wiggler zero field zone have long lifetime due to their complicated trajectory.

  20. Beam Line VI REC-steel hybrid wiggler for SSRL

    International Nuclear Information System (INIS)

    Hoyer, E.; Chan, T.; Chin, J.W.G.; Halbach, K.; Kim, K.J.; Winick, H.; Yang, J.

    1983-03-01

    A wiggler magnet with 27 periods, each 7 cm long which reaches 1.21 T at a 1.2 cm gap and 1.64 T at 0.8 cm gap has been designed and is in fabrication. Installation in SPEAR is scheduled for mid 1983. This new wiggler will be the radiation source for a new high intensity synchrotron radiation beam line at SSRL. The magnet utilizes rare-earth cobalt (REC) material and steel in a hybrid configuration to achieve simultaneously a high magnetic field with a short period. The magnet is external to a thin walled variable gap stainless steel vacuum chamber which is opened to provide beam aperture of 1.8 cm gap at injection and then closed to a smaller aperture (< 1.0 cm). Five independent drive systems are provided to adjust the magnet and chamber gaps and alignment. Magnetic design, construction details and magnetic measurements are presented

  1. Advanced optimization of permanent magnet wigglers using a genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Hajima, Ryoichi [Univ. of Tokyo (Japan)

    1995-12-31

    In permanent magnet wigglers, magnetic imperfection of each magnet piece causes field error. This field error can be reduced or compensated by sorting magnet pieces in proper order. We showed a genetic algorithm has good property for this sorting scheme. In this paper, this optimization scheme is applied to the case of permanent magnets which have errors in the direction of field. The result shows the genetic algorithm is superior to other algorithms.

  2. SRS Behaviour with a superconducting 5-Tesla wiggler insertion

    International Nuclear Information System (INIS)

    Suller, V.P.; Marks, N.; Poole, M.W.; Walker, R.P.

    1983-01-01

    A 5 Tesla superconducting wavelength shifting wiggler magnet has been inserted into the SRS lattice. Observations have been made of the behaviour of the stored electron beam with the magnet powered. Betatron tune shifts and modulation of the betatron function have been measured and good agreement obtained with theory. Closed orbit changes have been examined and the stored beam lifetime optimised. The magnet is fully operational and is producing intense x-ray beams for users

  3. Advanced optimization of permanent magnet wigglers using a genetic algorithm

    International Nuclear Information System (INIS)

    Hajima, Ryoichi

    1995-01-01

    In permanent magnet wigglers, magnetic imperfection of each magnet piece causes field error. This field error can be reduced or compensated by sorting magnet pieces in proper order. We showed a genetic algorithm has good property for this sorting scheme. In this paper, this optimization scheme is applied to the case of permanent magnets which have errors in the direction of field. The result shows the genetic algorithm is superior to other algorithms

  4. Pulse propagation in tapered wiggler free electron lasers

    International Nuclear Information System (INIS)

    Goldstein, J.C.; Colson, W.B.

    1981-01-01

    The one-dimensional theory of short pulse propagation in free electron lasers is extended to tapered wiggler devices and is used to study the behavior of an oscillator with parameter values close to those expected in forthcoming experiments. It is found that stable laser output is possible only over a small range of optical cavity lengths. Optical pulse characteristcs are presented and are found to change considerably over this range

  5. Foil-less plasma-filled diode for HPM generator

    International Nuclear Information System (INIS)

    Eltchaninov, A A; Kovalchuk, B M; Kurkan, I K; Zherlitsyn, A A

    2014-01-01

    Plasma-filled diode regarded as perspective source of electron beam feeding HPM generator of GW power level, comparing to conventional explosive emission vacuum diode. Electron beam generation occurs in plasma double layer, where plasma boundary plays as an anode. It allows cancelling the usage of anode foils or grids in HPM generators with the virtual cathode, which could limit its life time to few shots. The presence of ions in the e-beam drift space could raise the limiting current for a drift space, but it could affect to microwave generation also. Sectioned plasma-filled diode with beam current of about 100 kA, electron beam energy of about 0.5 MV and beam current density of 1-10 kA/cm 2 was realized. Cylindrical transport channel with the diameter of 200 mm and the length of about 30 cm was attached to the diode. Beam current measurements in a drift space were performed. Computer simulations of electron beam transport with the presence of ions were carried out with the 2.5D axisymmetric version of PiC-code KARAT. Obtained results would help optimizing electrodynamic system of HPM generator subjected to the presence of ions

  6. On the electric and magnetic field generation in expanding plasmas

    International Nuclear Information System (INIS)

    Gielen, H.J.G.

    1989-01-01

    This thesis deals with the generation of electric and magnetic fields in expanding plasmas. The theoretical model used to calculate the different field quantities in such plasmas is discussed in part 1 and is in fact an analysis of Ohm's law. A general method is given that decomposes each of the forces terms in Ohm's law in a component that induces a charge separation in the plasma and in a component that can drive current. This decomposition is unambiguous and depends upon the boundary conditions for the electric potential. It is shown that in calculating the electromagnetic field quantities in a plasma that is located in the vicinity of a boundary that imposes constraints on the electric potential, Ohm's law should be analyzed instead of the so-called induction equation. Three applications of the model are presented. A description is given of the unipolar arc discharge where both plasma and sheath effects have been taken into account. Secondly a description is presented of the plasma effects of a cathode spot. The third application of the model deals with the generation of magnetic fields in laser-produced plasmas. The second part of this thesis describes the experiments on a magnetized argon plasma expanding from a cascaded arc. With the use of spectroscopic techniques the electron density, ion temperature and the rotation velocity profiles of the ion gas have been determined. The magnetic field generated by the plasma has been measured with the use of the Zeeman effect. Depending on the channel diameter of the nozzle of the cascaded arc, self-generated magnetic fields with axial components of the order of 1% of the externally applied mangetic field have been observed. From the measured ion rotation it has been concluded that this magnetic field is mainly generated by azimuthal electron currents. The corresponding azimuthal current density is of the order of 15% of the axial current density. The observed ion rotation is caused by electron-ion friction. (author

  7. Generation of radiation by intense plasma and electromagnetic undulators

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, C.

    1991-10-01

    We examine the characteristics of the classical radiation emission resulting from the interaction of a relativistic electron beam that propagates perpendicularly through a large amplitude relativistic plasma wave. Such a study is useful for evaluating the feasibility of using relativistic plasma waves as extremely short wavelength undulators for generating short wavelength radiation. The electron trajectories in a plasma wave undulator and in an ac FEL undulator are obtained using perturbation techniques. The spontaneous radiation frequency spectrum and angular distribution emitted by a single electron oscillating in these two undulators are then calculated. The radiation gain of a copropagating electromagnetic wave is calculated. The approximate analytic results for the trajectories, spontaneous radiation and gain are compared with 3-D simulation results. The characteristics of the plasma wave undulator are compared with the ac FEL undulator and linearly polarized magnetic undulator. 50 refs., 26 figs., 3 tabs.

  8. Generation of radiation by intense plasma and electromagnetic undulators

    International Nuclear Information System (INIS)

    Joshi, C.

    1991-10-01

    We examine the characteristics of the classical radiation emission resulting from the interaction of a relativistic electron beam that propagates perpendicularly through a large amplitude relativistic plasma wave. Such a study is useful for evaluating the feasibility of using relativistic plasma waves as extremely short wavelength undulators for generating short wavelength radiation. The electron trajectories in a plasma wave undulator and in an ac FEL undulator are obtained using perturbation techniques. The spontaneous radiation frequency spectrum and angular distribution emitted by a single electron oscillating in these two undulators are then calculated. The radiation gain of a copropagating electromagnetic wave is calculated. The approximate analytic results for the trajectories, spontaneous radiation and gain are compared with 3-D simulation results. The characteristics of the plasma wave undulator are compared with the ac FEL undulator and linearly polarized magnetic undulator. 50 refs., 26 figs., 3 tabs

  9. Sum frequency generation for studying plasma-wall interactions

    International Nuclear Information System (INIS)

    Roke, Sylvie

    2010-01-01

    Interaction of a plasma with a surface results in chemical and physical restructuring of the surface as well as the plasma in the vicinity of the surface. Studying such a reorganization of the atoms and molecules in the surface layer requires optical tools that can penetrate the plasma environment. At the same time, surface specificity is required. Sum Frequency Generation (SFG) is an optical method that fulfills these requirements. SFG has been developed into a surface specific probe during the eighties and nineties. Nowadays SFG is routinely applied in the research of complex interfaces. In such experiments, liquid/gas, solid/gas, solid/liquid, or liquid/liquid interfaces are probed, and the chemical surface composition, orientational distribution, order and chirality can be retrieved. An application to investigate plasma-wall interactions is feasible too.

  10. Opacity measurements in shock-generated argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    Dense plasmas having uniform and constant density and temperature are generated by passage of a planar shock wave through gas. The opacity of the plasma is accurately measured versus wavelength by recording the risetime of emitted light. This technique is applicable to a wide variety of species and plasma conditions. Initial experiments in argon have produced plasmas with 2 eV temperatures, 0.004--0.04 g/cm{sup 3} densities, and coupling parameters {Gamma} {approximately}0.3--0.7. Measurements in visible light are compared with calculations using the HOPE code. An interesting peak in the capacity at 400 nm is observed for the first time and is identified with the 4s-5p transition in excited neutral argon atoms.

  11. Rf probe technology for the next generation of technological plasmas

    International Nuclear Information System (INIS)

    Law, V.J.; Kenyon, A.J.; Thornhill, N.F.; Seeds, A.J.; Batty, I.

    2001-01-01

    We describe radio frequency (rf) analysis of technological plasmas at the 13.56 MHz fundamental drive frequency and integer narrow-band harmonics up to n = 9. In particular, we demonstrate the use of harmonic amplitude information as a process end-point diagnostic. Using very high frequency (vhf) techniques, we construct non-invasive ex situ remote-coupled probes: a diplexer, an equal-ratio-arm bridge, and a dual directional coupler used as a single directional device. These probes bolt into the plasma-tool 50 Ω transmission-line between the rf generator and matching network, and hence do not require modification of the plasma tool. The 50 Ω probe environment produces repeatable measurements of the chamber capacitance and narrow-band harmonic amplitude with an end-point detection sensitivity corresponding to a 2 dB change in the harmonic amplitude with the removal of 1 cm 2 of photoresist. The methodology and design of an instrument for the measurement of the plasma-tool frequency response, and the plasma harmonic amplitude and phase response are examined. The instrument allows the monitoring of the plasma phase delay, plasma-tool short- and long-term ageing, and process end-point prediction. (author)

  12. 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)

  13. 27.12 MHz plasma generation in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Kawashima, Ayato; Toyota, Hiromichi; Nomura, Shinfuku; Takemori, Toshihiko; Mukasa, Shinobu; Maehara, Tsunehiro; Yamashita, Hiroshi

    2007-01-01

    An experiment was conducted for generating high-frequency plasma in supercritical carbon dioxide; it is expected to have the potential for applications in various types of practical processes. It was successfully generated at 6-20 MPa using electrodes mounted in a supercritical cell with a gap of 1 mm. Emission spectra were then measured to investigate the physical properties of supercritical carbon dioxide plasma. The results indicated that while the emission spectra for carbon dioxide and carbon monoxide could be mainly obtained at a low pressure, the emission spectra for atomic oxygen could be obtained in the supercritical state, which increased with the pressure. The temperature of the plasma in supercritical state was estimated to be approximately 6000-7000 K on the assumption of local thermodynamic equilibrium and the calculation results of thermal equilibrium composition in this state showed the increase of atomic oxygen by the decomposition of CO 2

  14. Pre-Excitation Studies for Rubidium-Plasma Generation

    CERN Document Server

    Aladi, M; Barna, I.F.; Czitrovszky, Aladar; Djotyan, Gagik; Dombi, Peter; Dzsotjan, David; FöLdes, Istvan; Hamar, Gergo; Ignacz, Peter; Kedves, Miklos; Kerekes, Attila; Levai, Peter; Marton, Istvan; Nagy, Attila; Oszetzky, Daniel; Pocsai, Mihaly; Racz, Peter; Raczkevi, Bela; Szigeti, Janos; Sörlei, Zsuzsa; Szipöcs, Robert; Varga, Dezso; Varga-Umbrich, Karoly; Varro, Sandor; Vamos, Lenard; Vesztergombi, György

    2014-01-01

    The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE) project is the generation of highly uniform plasma from Rubidium vapor. The standard way to achieve full ionization is to use high power laser which can assure the over-barrier-ionization (OBI) along the 10 meters long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi Photon Ionization (REMPI) scheme probably can be realized by much less laser power. In the following the resonant pre-excitations of the Rb atoms are investigated, theoretically and the status report about the preparatory work on the experiment are presented.

  15. Generation of nano roughness on fibrous materials by atmospheric plasma

    International Nuclear Information System (INIS)

    Kulyk, I; Scapinello, M; Stefan, M

    2012-01-01

    Atmospheric plasma technology finds novel applications in textile industry. It eliminates the usage of water and of hazard liquid chemicals, making production much more eco-friendly and economically convenient. Due to chemical effects of atmospheric plasma, it permits to optimize dyeing and laminating affinity of fabrics, as well as anti-microbial treatments. Other important applications such as increase of mechanical resistance of fiber sleeves and of yarns, anti-pilling properties of fabrics and anti-shrinking property of wool fabrics were studied in this work. These results could be attributed to the generation of nano roughness on fibers surface by atmospheric plasma. Nano roughness generation is extensively studied at different conditions. Alternative explanations for the important practical results on textile materials and discussed.

  16. Air spark-like plasma source for antimicrobial NOx generation

    International Nuclear Information System (INIS)

    Pavlovich, M J; Galleher, C; Curtis, B; Clark, D S; Graves, D B; Ono, T; Machala, Z

    2014-01-01

    We demonstrate and analyse the generation of nitrogen oxides and their antimicrobial efficacy using atmospheric air spark-like plasmas. Spark-like discharges in air in a 1 L confined volume are shown to generate NO x at an initial rate of about 1.5  ×  10 16 NO x molecules/J dissipated in the plasma. Such a discharge operating in this confined volume generates on the order of 6000 ppm NO x in 10 min. Around 90% of the NO x is in the form of NO 2 after several minutes of operation in the confined volume, suggesting that NO 2 is the dominant antimicrobial component. The strong antimicrobial action of the NO x mixture after several minutes of plasma operation is demonstrated by measuring rates of E. coli disinfection on surfaces and in water exposed to the NO x mixture. Some possible applications of plasma generation of NO x (perhaps followed by dissolution in water) include disinfection of surfaces, skin or wound antisepsis, and sterilization of medical instruments at or near room temperature. (paper)

  17. Electron-beam generated plasmas for processing applications

    Science.gov (United States)

    Meger, Robert; Leonhardt, Darrin; Murphy, Donald; Walton, Scott; Blackwell, David; Fernsler, Richard; Lampe, Martin; Manheimer, Wallace

    2001-10-01

    NRL's Large Area Plasma Processing System (LAPPS) utilizes a 5-10 mA/cm^2, 2-4 kV, 1 cm x 30-60 cm cross section beam of electrons guided by a magnetic field to ionize a low density (10-100 mTorr) gas.[1] Beam ionization allows large area, high density, low temperature plasmas to be generated in an arbitrary gas mixture at a well defined location. Energy and composition of particle fluxes to surfaces on both sides of the plasma can be controlled by gas mixture, location, rf bias, and other factors. Experiments have been performed using both pulsed and cw beams. Extensive diagnostics (Langmuir probes, mass and ion energy analyzers, optical emissions, microwave interferometry, etc.) have been fielded to measure the plasma properties and neutral particle fluxes (ions, neutrals, free radicals) with and without rf bias on nearby surfaces both with the beam on and off. Uniform, cold (Te < 1eV), dense (ne 10^13 cm-3) plasmas in molecular and atomic gases and mixtures thereof have been produced in agreement with theoretical expectations. Initial tests of LAPPS application such as ashing, etching, sputtering, and diamond growth have been performed. Program status will be presented. [1]R.A. Meger, et al, Phys. of Plasmas 8(5), p. 2558 (2001)

  18. Enhancement of plasma generation in catalyst pores with different shapes

    Science.gov (United States)

    Zhang, Yu-Ru; Neyts, Erik C.; Bogaerts, Annemie

    2018-05-01

    Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties.

  19. Generation of atto-second pulses on relativistic mirror plasma

    International Nuclear Information System (INIS)

    Vincenti, H.

    2012-12-01

    When an ultra intense femtosecond laser (I > 10 16 W.cm -2 ) with high contrast is focused on a solid target, the laser field at focus is high enough to completely ionize the target surface during the rising edge of the laser pulse and form a plasma. This plasma is so dense (the electron density is of the order of hundred times the critical density) that it completely reflects the incident laser beam in the specular direction: this is the so-called 'plasma mirror'. When laser intensity becomes very high, the non-linear response of the plasma mirror to the laser field periodically deforms the incident electric field leading to high harmonic generation in the reflected beam. In the temporal domain this harmonic spectrum is associated to a train of atto-second pulses. The goals of my work were to get a better comprehension of the properties of harmonic beams produced on plasma mirrors and design new methods to control theses properties, notably in order to produce isolated atto-second pulses instead of trains. Initially, we imagined and modeled the first realistic technique to generate isolated atto-second on plasma mirrors. This brand new approach is based on a totally new physical effect: 'the atto-second lighthouse effect'. Its principle consists in sending the atto-second pulses of the train in different directions and selects one of these pulses by putting a slit in the far field. Despite its simplicity, this technique is very general and applies to any high harmonic generation mechanism. Moreover, the atto-second lighthouse effect has many other applications (e.g in metrology). In particular, it paves the way to atto-second pump-probe experiments. Then, we studied the spatial properties of these harmonics, whose control and characterization are crucial if one wants to use this source in future application experiments. For instance, we need to control very precisely the harmonic beam divergence in order to achieve the atto-second lighthouse effect and get

  20. Control and metrology of high harmonic generation on plasma mirrors

    International Nuclear Information System (INIS)

    Monchoce, Sylvain

    2014-01-01

    When an ultra intense femtosecond laser with high contrast is focused on a solid target, the laser field at focus is sufficient enough to completely ionize the target surface during the rising edge of the laser pulse and form a plasma. This dense plasma entirely reflects the incident beam in the specular direction: this is a so-called plasma mirror. As the interaction between the laser and the plasma mirror is highly non-linear, it thus leads to the high harmonic generation (HHG) in the reflected beam. In the temporal domain, this harmonic spectrum is associated to a train of atto-second pulses. The aim of my PhD were to experimentally control this HHG and to measure the properties of the harmonics. We first studied the optimization of the harmonic signal, and then the spatial characterization of the harmonic beam in the far-field (harmonic divergence). These characterizations are not only important to develop an intense XUV/atto-second light source, but also to get a better understanding of the laser-matter interaction at very high intensity. We have thus been able to get crucial information of the electrons and ions dynamics of the plasma, showing that the harmonics can also be used as a diagnostic of the laser-plasma interaction. We then developed a new general approach for optically-controlled spatial structuring of overdense plasmas generated at the surface of initially plain solid targets. We demonstrate it experimentally by creating sinusoidal plasma gratings of adjustable spatial periodicity and depth, and study the interaction of these transient structures with an ultra-intense laser pulse to establish their usability at relativistically high intensities. We then show how these gratings can be used as a 'spatial ruler' to determine the source size of the high-order harmonic beams produced at the surface of an overdense plasma. These results open new directions both for the metrology of laser-plasma interactions and the emerging field of ultrahigh

  1. Second crystal cooling on cryogenically cooled undulator and wiggler double crystal monochromators

    International Nuclear Information System (INIS)

    Knapp, G. S.

    1998-01-01

    Simple methods for the cooling of the second crystals of cryogenically cooled undulator and wiggler double crystal monochromators are described. Copper braids between the first and second crystals are used to cool the second crystals of the double crystal monochromators. The method has proved successful for an undulator monochromator and we describe a design for a wiggler monochromator

  2. Design Concept of Superconducting Multipole Wiggler with Variably Polarized X-Ray

    International Nuclear Information System (INIS)

    Hwang, C.S.; Chang, C.H.; Li, W.P.; Lin, F.Y.

    2004-01-01

    In response to the growing demand for X-ray research, and to satisfy future needs for generating circularly polarized synchrotron radiation in the X-ray region, a 3.5 T superconducting multipole with a periodic length of 6 cm was designed to produce horizontal linearly polarized, and circularly polarized light on a 1.5 GeV electron storage ring. Differently arranged excitation current loop for the same coil design switched between the operation of symmetric and asymmetric modes to creat the linearly and circularly polarized light, respectively. This study elucidates the design concepts of the superconducting multipole wiggler with symmetric and asymmetric operation modes. The design of the magnetic circuit and the field calculation are also discussed. Meanwhile, the spectra characteristics of the symmetric and asymmetric modes are calculated and presented in this article

  3. High average power CW FELs [Free Electron Laser] for application to plasma heating: Designs and experiments

    International Nuclear Information System (INIS)

    Booske, J.H.; Granatstein, V.L.; Radack, D.J.; Antonsen, T.M. Jr.; Bidwell, S.; Carmel, Y.; Destler, W.W.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Zhang, Z.X.

    1989-01-01

    A short period wiggler (period ∼ 1 cm), sheet beam FEL has been proposed as a low-cost source of high average power (1 MW) millimeter-wave radiation for plasma heating and space-based radar applications. Recent calculation and experiments have confirmed the feasibility of this concept in such critical areas as rf wall heating, intercepted beam (''body'') current, and high voltage (0.5 - 1 MV) sheet beam generation and propagation. Results of preliminary low-gain sheet beam FEL oscillator experiments using a field emission diode and pulse line accelerator have verified that lasing occurs at the predicted FEL frequency. Measured start oscillation currents also appear consistent with theoretical estimates. Finally, we consider the possibilities of using a short-period, superconducting planar wiggler for improved beam confinement, as well as access to the high gain, strong pump Compton regime with its potential for highly efficient FEL operation

  4. Electromagnetic radiation generated by arcing in low density plasma

    Science.gov (United States)

    Vayner, Boris V.; Ferguson, Dale C.; Snyder, David B.; Doreswamy, C. V.

    1996-01-01

    An unavoidable step in the process of space exploration is to use high-power, very large spacecraft launched into Earth orbit. Obviously, the spacecraft will need powerful energy sources. Previous experience has shown that electrical discharges occur on the surfaces of a high-voltage array, and these discharges (arcs) are undesirable in many respects. Moreover, any high voltage conductor will interact with the surrounding plasma, and that interaction may result in electrical discharges between the conductor and plasma (or between two conductors with different potentials, for example, during docking and extravehicular activity). One very important aspect is the generation of electromagnetic radiation by arcing. To prevent the negative influence of electromagnetic noise on the operation of spacecraft systems, it seems necessary to determine the spectra and absolute levels of the radiation, and to determine limitations on the solar array bias voltage that depend on the parameters of LEO plasma and the technical requirements of the spacecraft equipment. This report describes the results of an experimental study and computer simulation of the electromagnetic radiation generated by arcing on spacecraft surfaces. A large set of high quality data was obtained during the Solar Array Module Plasma Interaction Experiment (SAMPIE, flight STS-62) and ground test. These data include the amplitudes of current, pulse forms, duration of each arc, and spectra of plasma waves. A theoretical explanation of the observed features is presented in this report too. The elaborated model allows us to determine the parameters of the electromagnetic noise for different frequency ranges, distances from the arcing site, and distinct kinds of plasma waves.

  5. High-order harmonics generation from overdense plasmas

    International Nuclear Information System (INIS)

    Quere, F.; Thaury, C.; Monot, P.; Martin, Ph.; Geindre, J.P.; Audebert, P.; Marjoribanks, R.

    2006-01-01

    Complete test of publication follows. When an intense laser beam reflects on an overdense plasma generated on a solid target, high-order harmonics of the incident laser frequency are observed in the reflected beam. This process provides a way to produce XUV femtosecond and attosecond pulses in the μJ range from ultrafast ultraintense lasers. Studying the mechanisms responsible for this harmonic emission is also of strong fundamental interest: just as HHG in gases has been instrumental in providing a comprehensive understanding of basic intense laser-atom interactions, HHG from solid-density plasmas is likely to become a unique tool to investigate many key features of laser-plasma interactions at high intensities. We will present both experimental and theoretical evidence that two mechanisms contribute to this harmonic emission: - Coherent Wake Emission: in this process, harmonics are emitted by plasma oscillations in te overdense plasma, triggered in the wake of jets of Brunel electrons generated by the laser field. - The relativistic oscillating mirror: in this process, the intense laser field drives a relativistic oscillation of the plasma surface, which in turn gives rise to a periodic phase modulation of the reflected beam, and hence to the generation of harmonics of the incident frequency. Left graph: experimental harmonic spectrum from a polypropylene target, obtained with 60 fs laser pulses at 10 19 W/cm 2 , with a very high temporal contrast (10 10 ). The plasma frequency of this target corresponds to harmonics 15-16, thus excluding the CWE mechanism for the generation of harmonics of higher orders. Images on the right: harmonic spectra from orders 13 et 18, for different distances z between the target and the best focus. At the highest intensity (z=0), harmonics emitted by the ROM mechanism are observed above the 15th order. These harmonics have a much smaller spectral width then those due to CWE (below the 15th order). These ROM harmonics vanish as soon

  6. Plasma effects in attosecond pulse generation from ultra-relativistic laser-plasma interactions

    International Nuclear Information System (INIS)

    Boyd, T.J.M.

    2010-01-01

    Complete text of publication follows. Particle-in-cell simulations were performed to examine the influence of plasma effects on high harmonic spectra from the interaction of ultra-intense p-polarized laser pulses with overdense plasma targets. Furthermore, a theoretical model is proposed to explain the radiation mechanism that leads to attosecond pulse generation in the reflected field. It is shown that plasma harmonic emission affects the spectral characteristics, causing deviations in the harmonic power decay as compared with the so-called universal 8/3-decay. These deviations may occur, in a varying degree, as a consequence of the extent to which the plasma line and its harmonics affect the emission. It is also found a strong correlation of the emitted attosecond pulses with electron density structures within the plasma, responsible to generate intense localised electrostatic fields. A theoretical model based on the excitation of Langmuir waves by the re-entrant Brunel electron beams in the plasma and their electromagnetic interaction with the laser field is proposed to explain the flatter power spectral emission - described by a weaker 5/3 index and observed in numerical simulations - than that of the universal decay.

  7. Study of the stacked plasma generator of Maecker type

    International Nuclear Information System (INIS)

    Shirai, Hiroyuki; Tabei, Katsuine; Machida, Ichiro; Ishihara, Kimio.

    1981-01-01

    An experimental investigation of a stacked plasma generator of Maecker type has been performed at low pressures (25 - 760 Torr) and low electric currents (10 - 60 A) for argon gas. Radial distributions of electron density and electron temperature were obtained by measuring the intensities of spectral lines and continuum from cylindrically confined plasmas. Based on such data of the macroscopic plasma parameters, the SAHA equilibrium relation, and the collisional and radiative theory of BATES et al., the spatial extent of equilibrium region and nonequilibrium effects of electronic excitation of the atom have been examined. In the plasmas generated in the apparatus, electron temperature ranged from 7,500 to 11,000 0 K and electron density 7 x 10 14 to 3 x 10 16 cm -3 . It was found that thermochemical equilibrium conditions existed only in the vicinity of the tube axis even at relatively high pressures and high currents, and the higher excited levels than the 5p level of argon atom were always in SAHA equilibrium with free electrons. (author)

  8. Modelling of diamond deposition microwave cavity generated plasmas

    International Nuclear Information System (INIS)

    Hassouni, K; Silva, F; Gicquel, A

    2010-01-01

    Some aspects of the numerical modelling of diamond deposition plasmas generated using microwave cavity systems are discussed. The paper mainly focuses on those models that allow (i) designing microwave cavities in order to optimize the power deposition in the discharge and (ii) estimating the detailed plasma composition in the vicinity of the substrate surface. The development of hydrogen plasma models that may be used for the self-consistent simulation of microwave cavity discharge is first discussed. The use of these models for determining the plasma configuration, composition and temperature is illustrated. Examples showing how to use these models in order to optimize the cavity structure and to obtain stable process operations are also given. A transport model for the highly reactive H 2 /CH 4 moderate pressure discharges is then presented. This model makes possible the determination of the time variation of plasma composition and temperature on a one-dimensional domain located on the plasma axis. The use of this model to analyse the transport phenomena and the chemical process in diamond deposition plasmas is illustrated. The model is also utilized to analyse pulsed mode discharges and the benefit they can bring as far as diamond growth rate and quality enhancement are concerned. We, in particular, show how the model can be employed to optimize the pulse waveform in order to improve the deposition process. Illustrations on how the model can give estimates of the species density at the growing substrate surface over a wide domain of deposition conditions are also given. This brings us to discuss the implication of the model prediction in terms of diamond growth rate and quality. (topical review)

  9. Simulation of current generation in a 3-D plasma model

    International Nuclear Information System (INIS)

    Tsung, F.S.; Dawson, J.M.

    1996-01-01

    Two wires carrying current in the same direction will attract each other, and two wires carrying current in the opposite direction will repel each other. Now, consider a test charge in a plasma. If the test charge carries current parallel to the plasma, then it will be pulled toward the plasma core, and if the test charge carries current anti-parallel to the plasma, then it will be pushed to the edge. The electromagnetic coupling between the plasma and a test charge (i.e., the A parallel circ v parallel term in the test charge's Hamiltonian) breaks the symmetry in the parallel direction, and gives rise to a diffusion coefficient which is dependent on the particle's parallel velocity. This is the basis for the open-quotes preferential lossclose quotes mechanism described in the work by Nunan et al. In our previous 2+1/2 D work, in both cylindrical and toroidal geometries, showed that if the plasma column is centrally fueled, then an initial current increases steadily. The results in straight, cylindrical plasmas showed that self generated parallel current arises without trapped particle or neoclassical diffusion, as assumed by the bootstrap theory. It suggests that the fundamental mechanism seems to be the conservation of particles canonical momenta in the direction of the ignorable coordinate. We have extended the simulation to 3D to verify the model put forth. A scalable 3D EM-PIC code, with a localized field-solver, has been implemented to run on a large class of parallel computers. On the 512-node SP2 at Cornell Theory Center, we have benchmarked the 2+1/2 D calculations using 32 grids in the previously ignored direction, and a 100-fold increase in the number of particles. Our preliminary results show good agreements between the 2+1/2 D and the 3D calculations. We will present our 3D results at the meeting

  10. Conceptual designs for NLC ubitrons with permanent-magnet wigglers

    International Nuclear Information System (INIS)

    Phillips, R.

    1994-09-01

    This paper describes three embodiments of the ubitron (FEL) amplifier that will be analyzed for possible use on the NLC. The design frequency and power are 11.424 GHz and 200 MW peak rf output power. The baseline against which these conceptual designs are to be evaluated is the PPM-focused 50-MW SIAC klystron, which in simulation shows 65% efficiency. In order to remain competitive in cost and power consumption, only ubitron beam-wave configurations that can use permanent-magnet wigglers are considered

  11. Dynamic apeerture in damping rings with realistic wigglers

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yunhai; /SLAC

    2005-05-04

    The International Linear Collider based on superconducting RF cavities requires the damping rings to have extremely small equilibrium emittance, huge circumference, fast damping time, and large acceptance. To achieve all of these requirements is a very challenging task. In this paper, we will present a systematic approach to designing the damping rings using simple cells and non-interlaced sextupoles. The designs of the damping rings with various circumferences and shapes, including dogbone, are presented. To model realistic wigglers, we have developed a new hybrid symplectic integrator for faster and accurate evaluation of dynamic aperture of the lattices.

  12. Chicane and wiggler based bunch compressors for future linear colliders

    International Nuclear Information System (INIS)

    Raubenheimer, T.O.; Emma, P.; Kheifets, S.

    1993-05-01

    In this paper, we discuss bunch compressors for future linear colliders. In the past, the bunch compression optics has been based upon achromatic cells using strong sextupoles to correct the dispersive and betatron chromaticity. To preserve the very small emittances required in most future collider designs, these schemes tend to have very tight alignment tolerances. Here, we describe bunch compressors based upon magnetic chicanes or wigglers which do need sextupoles to correct the chromatic emittance dilution. The dispersive chromaticity cancels naturally and the betatron chromaticity is not a significant source of emittance dilution. Thus, these schemes allow for substantially reduced alignment tolerances. Finally, we present a detailed design for the NLC linear collider

  13. Velocity shear generated Alfven waves in electron-positron plasmas

    International Nuclear Information System (INIS)

    Rogava, A.D.; Berezhiani, V.I.; Mahajan, S.M.

    1996-01-01

    Linear MHD modes in cold, nonrelativistic electron-positron plasma shear flow are considered. The general set of differential equations, describing the evolution of perturbations in the framework of the nonmodal approach is derived. It is found, that under certain circumstances, the compressional and shear Alfven perturbations may exhibit large transient growth fuelled by the mean kinetic energy of the shear flow. The velocity shear also induces mode coupling allowing the exchange of energy as well as the possibility of a strong mutual transformation of these modes into each other. The compressional Alfven mode may extract the energy of the mean flow and transfer it to the shear Alfven mode via this coupling. The relevance of these new physical effects to provide a better understanding of the laboratory e + e - plasma is emphasized. It is speculated that the shear-induced effects in the electron-positron plasmas could also help solve some astrophysical puzzles (e.g., the generation of pulsar radio emission). Since most astrophysical plasma are relativistic, it is shown that the major results of the study remain valid for weakly sheared relativistic plasmas. (author). 21 refs, 4 figs

  14. Determination of Plasma Screening Effects for Thermonuclear Reactions in Laser-generated Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuanbin; Pálffy, Adriana, E-mail: yuanbin.wu@mpi-hd.mpg.de, E-mail: Palffy@mpi-hd.mpg.de [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2017-03-20

    Due to screening effects, nuclear reactions in astrophysical plasmas may behave differently than in the laboratory. The possibility to determine the magnitude of these screening effects in colliding laser-generated plasmas is investigated theoretically, having as a starting point a proposed experimental setup with two laser beams at the Extreme Light Infrastructure facility. A laser pulse interacting with a solid target produces a plasma through the Target Normal Sheath Acceleration scheme, and this rapidly streaming plasma (ion flow) impacts a secondary plasma created by the interaction of a second laser pulse on a gas jet target. We model this scenario here and calculate the reaction events for the astrophysically relevant reaction {sup 13}C({sup 4}He, n ){sup 16}O. We find that it should be experimentally possible to determine the plasma screening enhancement factor for fusion reactions by detecting the difference in reaction events between two scenarios of ion flow interacting with the plasma target and a simple gas target. This provides a way to evaluate nuclear reaction cross-sections in stellar environments and can significantly advance the field of nuclear astrophysics.

  15. Laser-generated plasmas by graphene nanoplatelets embedded into polyethylene

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Ceccio, G.; Restuccia, N.; Messina, E.; Gucciardi, P. G.; Cutroneo, Mariapompea

    2017-01-01

    Roč. 35, č. 2 (2017), s. 294-303 ISSN 0263-0346 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : advanced targets * Au NP * graphene * laser-generated plasma * time-of-flight measurements Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 1.420, year: 2016

  16. Laser-generated plasma by carbon nanoparticles embedded into polyethylene

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Ceccio, G.; Cutroneo, Mariapompea

    2016-01-01

    Roč. 375, MAY (2016), s. 93-99 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : carbon nanoparticles * laser-generated plasma * Time-of-flight measurements * advanced targets Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.109, year: 2016

  17. Phase-matched third harmonic generation in a plasma

    International Nuclear Information System (INIS)

    Rax, J.M.; Fisch, N.J.

    1993-01-01

    Relativistic third harmonic generation in a plasma is investigated. The growth of a third harmonic wave is limited by the difference between the phase velocity of the pump and driven waves. This phase velocity mismatch results in a third harmonic amplitude saturation and oscillation. In order to overcome this saturation, the authors describe a phase-matching scheme based on a resonant density modulation. The limitations of this scheme are analyzed

  18. Flowing dusty plasma experiments: generation of flow and measurement techniques

    Science.gov (United States)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2016-12-01

    A variety of experimental techniques for the generation of subsonic/supersonic dust fluid flows and means of measuring such flow velocities are presented. The experiments have been carried out in a \\Pi -shaped dusty plasma experimental device with micron size kaolin/melamine formaldehyde particles embedded in a background of argon plasma created by a direct current glow discharge. A stationary dust cloud is formed over the cathode region by precisely balancing the pumping speed and gas flow rate. A flow of dust particles/fluid is generated by additional gas injection from a single or dual locations or by altering the dust confining potential. The flow velocity is then estimated by three different techniques, namely, by super particle identification code, particle image velocimetry analysis and the excitation of dust acoustic waves. The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral drag force responsible for the generation as well as the attenuation of the dust fluid flow is made. These techniques can be usefully employed in laboratory devices to investigate linear and non-linear collective excitations in a flowing dusty plasma.

  19. Study of non inductive current generation in a plasma

    International Nuclear Information System (INIS)

    Rax, J.M.

    1987-01-01

    The problem of non-thermal bremsstrahlung during lower hybrid current drive is considered. The proposed method shows the role of the Compton effects at low frequencies and allows us to establish the link between the emitted power and the absorbed power at high frequency. The non-thermal emission is considered as a kinematical mode conversion between the absorbed radio-frequency mode and the emitted X ray photons. The fast electrons diagnostics and the ways to reach the wave structure are shown. Kinetic and electromagnetic problems concerning current generation are described. The plasma properties and diagnostics in the case of a non inductive current generation are discussed [fr

  20. Laser plasma simulations of the generation processes of Alfven and collisionless shock waves in space plasma

    International Nuclear Information System (INIS)

    Prokopov, P A; Zakharov, Yu P; Tishchenko, V N; Shaikhislamov, I F; Boyarintsev, E L; Melekhov, A V; Ponomarenko, A G; Posukh, V G; Terekhin, V A

    2016-01-01

    Generation of Alfven waves propagating along external magnetic field B 0 and Collisionless Shock Waves propagating across B 0 are studied in experiments with laser- produced plasma and magnetized background plasma. The collisionless interaction of interpenetrating plasma flows takes place through a so-called Magnetic Laminar Mechanism (MLM) or Larmor Coupling. At the edge of diamagnetic cavity LP-ions produce induction electric field E φ which accelerates BP-ions while LP-ions rotate in opposite direction. The ions movement generates sheared azimuthal magnetic field B φ which could launches torsional Alfven wave. In previous experiments at KI-1 large scale facility a generation of strong perturbations propagating across B 0 with magnetosonic speed has been studied at a moderate value of interaction parameter δ∼0.3. In the present work we report on experiments at conditions of 5∼R2 and large Alfven-Mach number M A ∼10 in which strong transverse perturbations traveling at a scale of ∼1 m in background plasma at a density of ∼3*10 13 cm -3 is observed. At the same conditions but smaller M A ∼ 2 a generation, the structure and dynamic of Alfven wave with wavelength ∼0.5 m propagating along fields B 0 ∼100÷500 G for a distance of ∼2.5 m is studied. (paper)

  1. High-order harmonic generation in laser plasma plumes

    CERN Document Server

    Ganeev, Rashid A

    2013-01-01

    This book represents the first comprehensive treatment of high-order harmonic generation in laser-produced plumes, covering the principles, past and present experimental status and important applications. It shows how this method of frequency conversion of laser radiation towards the extreme ultraviolet range matured over the course of multiple studies and demonstrated new approaches in the generation of strong coherent short-wavelength radiation for various applications. Significant discoveries and pioneering contributions of researchers in this field carried out in various laser scientific centers worldwide are included in this first attempt to describe the important findings in this area of nonlinear spectroscopy. "High-Order Harmonic Generation in Laser Plasma Plumes" is a self-contained and unified review of the most recent achievements in the field, such as the application of clusters (fullerenes, nanoparticles, nanotubes) for efficient harmonic generation of ultrashort laser pulses in cluster-containin...

  2. Theoretical study of H- stripping with a wiggler magnet

    International Nuclear Information System (INIS)

    Hutson, R.L.

    1991-01-01

    The first step for injecting protons into the LAMPF Proton Storage Ring (PSR) at LANL is to strip a beam of 800-MeV H - ions to H 0 with a 1.8-T dipole magnet. Because of the finite lifetime of energetic H - ions in the magnetic field, their trajectories bend before stripping causing the angular spread of the beam, and therefore its emittance, to grow during the stripping process. In the case of the PSR, the horizontal beam emittance grows by a factor of roughly three during injection. As a consequence, beam losses in the ring are significantly greater than they would be if there were not emittance growth. A speculative technique is proposed in which the beam divergence growth and resulting emittance growth is reduced by stripping the H - in a wiggler magnet whose transverse field alternates in direction as a function of position along the beam axis. The wiggler field configuration is adjusted so that the angular beam spread introduced during passage through one unidirectional-field increment of path is relatively small and so that 99.99% of the beam is stripped after passing through the whole magnet. With careful field design the net added angular beam spread is reduced because the incremental angular spreads are painted back and forth over the same small range. In the hypothetical case described, the calculated emittance growth and beam loss increase are significantly smaller than those calculated for a conventional stripper magnet. 3 refs., 3 figs

  3. Inductive thermal plasma generation applied for the materials coating

    International Nuclear Information System (INIS)

    Pacheco, J.; Pena, R.; Cota, G.; Segovia, A.; Cruz, A.

    1996-01-01

    The coatings by thermal plasma are carried out introducing particles into a plasma system where they are accelerated and melted (total or partially) before striking the substrate to which they adhere and are suddenly cooled down. The nature of consolidation and solidification of the particles allows to have control upon the microstructure of the deposit. This technique is able to deposit any kind of material that is suitable to be merged (metal, alloy, ceramic, glass) upon any type of substrate (metal, graphite, ceramic, wood) with an adjustable thickness ranging from a few microns up to several millimeters. The applications are particularly focused to the coating of materials in order to improve their properties of resistance to corrosion, thermal and mechanical efforts as well as to preserve the properties of the so formed compound. In this work the electromagnetic induction phenomenon in an ionized medium by means of electric conductivity, is described. Emphasis is made on the devices and control systems employed in order to generate the thermal plasma and in carrying out the coatings of surfaces by the projection of particles based on plasma

  4. Laser propagation and soliton generation in strongly magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Feng, W.; Li, J. Q.; Kishimoto, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2016-03-15

    The propagation characteristics of various laser modes with different polarization, as well as the soliton generation in strongly magnetized plasmas are studied numerically through one-dimensional (1D) particle-in-cell (PIC) simulations and analytically by solving the laser wave equation. PIC simulations show that the laser heating efficiency substantially depends on the magnetic field strength, the propagation modes of the laser pulse and their intensities. Generally, large amplitude laser can efficiently heat the plasma with strong magnetic field. Theoretical analyses on the linear propagation of the laser pulse in both under-dense and over-dense magnetized plasmas are well confirmed by the numerical observations. Most interestingly, it is found that a standing or moving soliton with frequency lower than the laser frequency is generated in certain magnetic field strength and laser intensity range, which can greatly enhance the laser heating efficiency. The range of magnetic field strength for the right-hand circularly polarized (RCP) soliton formation with high and low frequencies is identified by solving the soliton equations including the contribution of ion's motion and the finite temperature effects under the quasi-neutral approximation. In the limit of immobile ions, the RCP soliton tends to be peaked and stronger as the magnetic field increases, while the enhanced soliton becomes broader as the temperature increases. These findings in 1D model are well validated by 2D simulations.

  5. Nonthermal Argon Plasma Generator and Some Potential Applications

    Directory of Open Access Journals (Sweden)

    Bunoiu M.

    2015-12-01

    Full Text Available A laboratory - made nonthermal plasma generator is presented. It has a diameter of 0.020 m and length of 0.155 m and contains two electrodes. The first electrode is a 2% Th-W alloy, 0.002 m in diameter bar, centred inside the generator’s body by means of a four channel teflon piece; the other three channels, 0.003 m in diameter, are used for Ar supply. The second electrode is a nozzle of 0.002 m - 0.008 m diameter and 0.005m length. A ~500 kV/m electric field is generated between the two electrodes by a high frequency source (13.56 MHz ±5%, equipped with a OT-1000 (Tungsram power triode. For Ar flows ranging from 0.00008 m3/s to 0.00056 m3/s, a plasma jet of length not exceeding 0.015 m and temperature below 315 K is obtained. Anthurium andraeanumis sample , blood matrix, human hair and textile fibers may be introduced in the plasma jet. For time periods of 30 s and 60 s, various effects like, cell detexturization, fast blood coagulation or textile fiber or hair cleaning and smoothing are obtained. These effects are presented and discussed in the paper.

  6. Material for electrodes of low temperature plasma generators

    Science.gov (United States)

    Caplan, Malcolm; Vinogradov, Sergel Evge'evich; Ribin, Valeri Vasil'evich; Shekalov, Valentin Ivanovich; Rutberg, Philip Grigor'evich; Safronov, Alexi Anatol'evich

    2008-12-09

    Material for electrodes of low temperature plasma generators. The material contains a porous metal matrix impregnated with a material emitting electrons. The material uses a mixture of copper and iron powders as a porous metal matrix and a Group IIIB metal component such as Y.sub.2O.sub.3 is used as a material emitting electrons at, for example, the proportion of the components, mass %: iron: 3-30; Y.sub.2O.sub.3:0.05-1; copper: the remainder. Copper provides a high level of heat conduction and electric conductance, iron decreases intensity of copper evaporation in the process of plasma creation providing increased strength and lifetime, Y.sub.2O.sub.3 provides decreasing of electronic work function and stability of arc burning. The material can be used for producing the electrodes of low temperature AC plasma generators used for destruction of liquid organic wastes, medical wastes, and municipal wastes as well as for decontamination of low level radioactive waste, the destruction of chemical weapons, warfare toxic agents, etc.

  7. Schlieren Technique Applied to Magnetohydrodynamic Generator Plasma Torch

    Science.gov (United States)

    Chopra, Nirbhav; Pearcy, Jacob; Jaworski, Michael

    2017-10-01

    Magnetohydrodynamic (MHD) generators are a promising augmentation to current hydrocarbon based combustion schemes for creating electrical power. In recent years, interest in MHD generators has been revitalized due to advances in a number of technologies such as superconducting magnets, solid-state power electronics and materials science as well as changing economics associated with carbon capture, utilization, and sequestration. We use a multi-wavelength schlieren imaging system to evaluate electron density independently of gas density in a plasma torch under conditions relevant to MHD generators. The sensitivity and resolution of the optical system are evaluated alongside the development of an automated analysis and calibration program in Python. Preliminary analysis shows spatial resolutions less than 1mm and measures an electron density of ne = 1 ×1016 cm-3 in an atmospheric microwave torch. Work supported by DOE contract DE-AC02-09CH11466.

  8. Morphology of magnetic fields generated in laser-produced plasmas

    International Nuclear Information System (INIS)

    Boyd, T.J.M.; Cooke, D.

    1988-01-01

    Magnetic fields in the megagauss range have been measured in experiments on plasmas generated by irradiating targets with high power lasers. A study of the morphology of these self-generated fields is important not only for its intrinsic interest but for possible implications in laser--target physics. In this paper work on the numerical modeling of large magnetic fields generated in target experiments is reported. The results show generally satisfactory agreement with the fields measured experimentally both in terms of the magnitude of the peak fields and their morphology. In the numerical model the contribution from the Hall term in describing the evolution of the magnetic field is shown to be important especially in short pulse (≅100 psec) experiments

  9. Nonlinear generation of the fundamental radiation in plasmas

    International Nuclear Information System (INIS)

    Chian, A.C.L.; Rizzato, F.B.

    1993-01-01

    Nonlinear generation of coherent electromagnetic radiation by intense Langmuir waves in the vicinity of the fundamental plasma frequency f p is of current interest in space and laboratory plasmas. In a pioneer work, Lashmore-Davies demonstrated that an efficient process for converting intense Langmuir waves into f p electromagnetic radiation can be achieved by two counterstreaming Langmuir pump waves through an electromagnetic oscillating two-stream instability. Recently Chian and Alves, Akimoto and Rizzato and Chian extended the formalism of Lashmore-Davies in order to include mixed processes with induced modes which are purely electrostatic or electromagnetic. In this paper we extend our previous analysis, in order to study the nonlinear interaction involving travelling electromagnetic pumps, low-frequency density fluctuations and high-frequency f p modes which can be electrostatic-electromagnetic hybrids. (author) 5 refs., 2 figs

  10. SOLAR WIND STRAHL BROADENING BY SELF-GENERATED PLASMA WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Pavan, J.; Gaelzer, R. [UFPEL, Pelotas (Brazil); Vinas, A. F. [NASA GSFC, Greenbelt, MD 20771 (United States); Yoon, P. H. [IPST, UMD, College Park, MD (United States); Ziebell, L. F., E-mail: joel.pavan@ufpel.edu.br, E-mail: rudi@ufpel.edu.br, E-mail: adolfo.vinas@nasa.gov, E-mail: yoonp@umd.edu, E-mail: luiz.ziebell@ufrgs.br [UFRGS, Porto Alegre (Brazil)

    2013-06-01

    This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave-particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.

  11. Runaway electron generation during plasma shutdown by killer pellet injection

    International Nuclear Information System (INIS)

    Gal, K; Feher, T; Smith, H; Fueloep, T; Helander, P

    2008-01-01

    Tokamak discharges are sometimes terminated by disruptions that may cause large mechanical and thermal loads on the vessel. To mitigate disruption-induced problems it has been proposed that 'killer' pellets could be injected into the plasma in order to safely terminate the discharge. Killer pellets enhance radiative energy loss and thereby lead to rapid cooling and shutdown of the discharge. But pellets may also cause runaway electron generation, as has been observed in experiments in several tokamaks. In this work, runaway dynamics in connection with deuterium or carbon pellet-induced fast plasma shutdown is considered. A pellet code, which calculates the material deposition and initial cooling caused by the pellet is coupled to a runaway code, which determines the subsequent temperature evolution and runaway generation. In this way, a tool has been created to test the suitability of different pellet injection scenarios for disruption mitigation. If runaway generation is avoided, the resulting current quench times are too long to safely avoid large forces on the vessel due to halo currents

  12. Next Generation Driver for Attosecond and Laser-plasma Physics.

    Science.gov (United States)

    Rivas, D E; Borot, A; Cardenas, D E; Marcus, G; Gu, X; Herrmann, D; Xu, J; Tan, J; Kormin, D; Ma, G; Dallari, W; Tsakiris, G D; Földes, I B; Chou, S-W; Weidman, M; Bergues, B; Wittmann, T; Schröder, H; Tzallas, P; Charalambidis, D; Razskazovskaya, O; Pervak, V; Krausz, F; Veisz, L

    2017-07-12

    The observation and manipulation of electron dynamics in matter call for attosecond light pulses, routinely available from high-order harmonic generation driven by few-femtosecond lasers. However, the energy limitation of these lasers supports only weak sources and correspondingly linear attosecond studies. Here we report on an optical parametric synthesizer designed for nonlinear attosecond optics and relativistic laser-plasma physics. This synthesizer uniquely combines ultra-relativistic focused intensities of about 10 20  W/cm 2 with a pulse duration of sub-two carrier-wave cycles. The coherent combination of two sequentially amplified and complementary spectral ranges yields sub-5-fs pulses with multi-TW peak power. The application of this source allows the generation of a broad spectral continuum at 100-eV photon energy in gases as well as high-order harmonics in relativistic plasmas. Unprecedented spatio-temporal confinement of light now permits the investigation of electric-field-driven electron phenomena in the relativistic regime and ultimately the rise of next-generation intense isolated attosecond sources.

  13. Low energy proton beams from laser-generated plasma

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Giuffrida, L.; Margarone, Daniele; Caridi, F.; Di Bartolo, F.

    2011-01-01

    Roč. 653, č. 1 (2011), s. 140-144 ISSN 0168-9002 R&D Projects: GA ČR(CZ) GAP205/11/1165; GA MŠk(CZ) 7E09092; GA MŠk ED1.1.00/02.0061 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-generated plasma * proton acceleration * hydrogenated targets * proton yield * doped polymers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.207, year: 2011

  14. Magnetic field generation during intense laser channelling in underdense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, A. G.; Sarri, G.; Doria, D.; Kar, S.; Borghesi, M. [School of Mathematics and Physics, The Queen' s University of Belfast, University Road, Belfast BT7 1NN (United Kingdom); Vranic, M.; Guillaume, E.; Silva, L. O.; Vieira, J. [GoLP/IPFN, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon (Portugal); Amano, Y.; Habara, H.; Tanaka, K. A. [Graduate School of Engineering Osaka University. Suita, Osaka 5650871 (Japan); Heathcote, R.; Norreys, P. A. [STFC Rutherford Appleton Laboratory, Didcot, Oxon OX1 0Qx (United Kingdom); Hicks, G.; Najmudin, Z.; Nakamura, H. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)

    2016-06-15

    Channel formation during the propagation of a high-energy (120 J) and long duration (30 ps) laser pulse through an underdense deuterium plasma has been spatially and temporally resolved via means of a proton imaging technique, with intrinsic resolutions of a few μm and a few ps, respectively. Conclusive proof is provided that strong azimuthally symmetric magnetic fields with a strength of around 0.5 MG are created inside the channel, consistent with the generation of a collimated beam of relativistic electrons. The inferred electron beam characteristics may have implications for the cone-free fast-ignition scheme of inertial confinement fusion.

  15. Aerospace propulsion using laser-driven plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Daozhi (Beijing Univ. of Aeronautics and Astronautics (People' s Republic of China))

    1989-04-01

    The use of a remote pulsed laser beam for aerospace vehicle propulsion is suggested. The engine will be of variable cycle type using a plasma generator, and the vehicle will be of rotary plate type. It will be launched using an external radiated-heated VTOL thruster, lifted by an MHD fanjet, and accelerated by a rotary rocket pulsejet. It is speculated that, sending the same payload into low earth orbit, the vehicle mass at liftoff will be 1/20th that of the Space Shuttle, and the propellant mass carried by the new vehicle will be only 1/40th that of the Shuttle. 40 refs.

  16. Initial experiment of focusing wiggler of MM wave Free Electron Laser on LAX-1

    International Nuclear Information System (INIS)

    Sakamoto, Keishi; Maebara, Sunao; Watanabe, Akihiko; Kishimoto, Yasuaki; Nagashima, Takashi; Maeda, Hikosuke; Shiho, Makoto; Oda, Hisako; Kawasaki, Sunao.

    1991-03-01

    Initial results of Free Electron laser (FEL) Experiment in the mm wave region are presented. The experiment is carried out using a induction linac system (LAX-1: Large current Accelerator Experiment) of E b = 1 MeV, Ib = 1 ∼ 3 kA. The wiggler of FEL is composed of the curved surface magnets arrays (focusing wiggler), which is found to be effective for a transport of low energy and high current beam through the wiggler. The superradiance of the mm wave region (30 GHz ∼ 40 GHz) is observed. The growth rate of this radiation is 0.42 dB/cm. (author)

  17. Generation of two-dimensional binary mixtures in complex plasmas

    Science.gov (United States)

    Wieben, Frank; Block, Dietmar

    2016-10-01

    Complex plasmas are an excellent model system for strong coupling phenomena. Under certain conditions the dust particles immersed into the plasma form crystals which can be analyzed in terms of structure and dynamics. Previous experiments focussed mostly on monodisperse particle systems whereas dusty plasmas in nature and technology are polydisperse. Thus, a first and important step towards experiments in polydisperse systems are binary mixtures. Recent experiments on binary mixtures under microgravity conditions observed a phase separation of particle species with different radii even for small size disparities. This contradicts several numerical studies of 2D binary mixtures. Therefore, dedicated experiments are required to gain more insight into the physics of polydisperse systems. In this contribution first ground based experiments on two-dimensional binary mixtures are presented. Particular attention is paid to the requirements for the generation of such systems which involve the consideration of the temporal evolution of the particle properties. Furthermore, the structure of these two-component crystals is analyzed and compared to simulations. This work was supported by the Deutsche Forschungsgemeinschaft DFG in the framework of the SFB TR24 Greifswald Kiel, Project A3b.

  18. Influence of Ar addition on ozone generation in nonthermal plasmas

    International Nuclear Information System (INIS)

    Chen, Hsin Liang; Lee, How Ming; Chen, Shiaw Huei; Wei, Ta Chin; Chang, Moo Been

    2010-01-01

    Inconsistency regarding the influence of Ar addition on ozone generation in a corona discharge has been found in relevant studies. Unlike in the literature to date, a dielectric barrier discharge (DBD) reactor is adopted in this study. In addition to clarifying whether using Ar as an additive would lead to different types of behavior in a DBD and a corona discharge, this study is also motivated to explore the possible causes leading to the inconsistency. The experimental results show that adding Ar into the O 2 plasma would lead to the same influence on ozone generation in the DBD and corona discharge. Moreover, all types of controversial behavior caused by Ar addition reported in the relevant literature are observed in this study as well, indicating that the results of this study are comprehensive enough to interpret the inconsistency. By examining the experimental results in detail, it is found that the controversial influences of Ar addition on ozone generation were found using different assumptions. At a fixed applied voltage, the ozone generation might increase as the Ar concentration is increased, which results from a higher discharge power. Nevertheless, for a certain specific input energy (the ratio of discharge power to gas flow rate), the ozone concentration is lower as the Ar concentration is increased. Therefore, adding Ar is not a good way to enhance ozone generation from an economic point of view.

  19. Generation and Sustainment of Plasma Rotation by ICRF Heating

    Science.gov (United States)

    Perkins, F. W.

    2000-10-01

    When tokamak plasmas are heated by the fundamental minority ion-cyclotron process, they are observed to rotate toroidally, even though this heating process introduces negligable angular momentum. This work proposes and evaluates a physics mechanism which resolves this apparent conflict. The argument has two elements. First, it is assumed that angular momentum transport is governed by a diffusion equation with a v_tor = 0 boundary condition at the plasma surface and a torque-density source. When the source consists of separated regions of positive and negative torque density, a finite central rotation velocity results, even though the volume integrated torque density - the angular momentum input - vanishes. Secondly, ions energized by the ICRF process can generate separated regions of positive and negative torque density. Heating increases their banana widths which leads to radial energetic-particle transport that must be balanced by neutralizing radial currents and a j_rB_pR torque density in the bulk plasma. Additional, comparable torque density results from collisional transfer of mechanical angular momentum from energetic particles to the bulk plasma and particle loss through banana particles impacting the wall. Monte-Carlo calculations utilizing the ORBIT code evaluate all sources of torque density and rigorously assure that no net angular momentum is introduced. Two models of ICRF heating, diffusive and instantaneous, give similar results. When the resonance location is on the LFS, the calculated rotation has the magnitude, profile, and co-current sense of Alcator C-Mod observations. For HFS resonance locations, the model predicts counter-current rotation. Scans of rotational profiles vs. resonance location, initial energy, particle loss, pitch, and qm will be presented as will the location of the velocity shear layer its scaling to a reactor.

  20. A new type of permanent magnet ondulator and wiggler

    International Nuclear Information System (INIS)

    Jianming, X.; Maosan, L.; Qing, X.

    1987-01-01

    A new type of permanent magnet ondulator and wiggler is discussed. In this new design the magnet is composed of permanent magnet segments with modulated thickness. The magnetization directions of the segments are all perpendicular to the symmetrical plane of the magnet gap. By modulating the thicknesses of the segments, the field distribution is a pure sinusoidal curve in the ideal 2-dimensional case. The spatial expressions of the magnet field in the ideal case and in the real case are given. The methods for reducing the undesirable harmonics in the magnet field in the real case are discussed. Because of the arrangement of the magnetization directions of the magnet segments, soft iron shield can be used to strenghten the magnet field. In some cases, the stregnthening factor is more than two. The strenghtening effect of the soft iron shield is analysed also

  1. CSEM-steel hybrid wiggler/undulator magnetic field studies

    International Nuclear Information System (INIS)

    Halbach, K.; Hoyer, E.; Marks, S.; Plate, D.; Shuman, D.

    1985-05-01

    Current design of permanent magnet wiggler/undulators use either pure charge sheet equivalent material (CSEM) or the CSEM-Steel hybrid configuration. Hybrid configurations offer higher field strength at small gaps, field distributions dominated by the pole surfaces and pole tuning. Nominal performance of the hybrid is generally predicted using a 2-D magnetic design code neglecting transverse geometry. Magnetic measurements are presented showing transverse configuration influence on performance, from a combination of models using CSEMs, REC (H/sub c/ = 9.2 kOe) and NdFe (H/sub c/ = 10.7 kOe), different pole widths and end configurations. Results show peak field improvement using NdFe in place of REC in identical models, gap peak field decrease with pole width decrease (all results less than computed 2-D fields), transverse gap field distributions, and importance of CSEM material overhanging the poles in the transverse direction for highest gap fields

  2. Low-frequency quadrupole impedance of undulators and wigglers

    Directory of Open Access Journals (Sweden)

    A. Blednykh

    2016-10-01

    Full Text Available An analytical expression of the low-frequency quadrupole impedance for undulators and wigglers is derived and benchmarked against beam-based impedance measurements done at the 3 GeV NSLS-II storage ring. The adopted theoretical model, valid for an arbitrary number of electromagnetic layers with parallel geometry, allows to calculate the quadrupole impedance for arbitrary values of the magnetic permeability μ_{r}. In the comparison of the analytical results with the measurements for variable magnet gaps, two limit cases of the permeability have been studied: the case of perfect magnets (μ_{r}→∞, and the case in which the magnets are fully saturated (μ_{r}=1.

  3. Magnetic X-ray measurements using the elliptical multipole wiggler

    International Nuclear Information System (INIS)

    Montano, P. A.; Li, Y.; Beno, M. A.; Jennings, G.; Kimball, C. W.

    1999-01-01

    The EMW at the BESSRC beam lines at the APS provides high photon flux at high energies with the capability of producing circular polarization on axis. The authors observe a high degree of circularly polarized x-rays at such energies. The polarization and frequency tunability of the elliptical multipole wiggler (EMW) is an ideal source for many magnetic measurements from X-ray Magnetic Circular Dichroism (XMCD) to Compton scattering experiments. They performed Compton scattering measurements to determine the polarization and photon flux at the sample as a function of the deflection parameters K y and K x . They used for their measurements a Si (220) Laue monochromator providing simultaneous photon energies at 50 keV, 100 keV and 150 keV. Magnetic Compton Profiles were determined by either switching the magnet polarity or the photon helicity. The results obtained using Fe(110) single crystals were very similar

  4. Nuclear Fusion Effects Induced in Intense Laser-Generated Plasmas

    Directory of Open Access Journals (Sweden)

    Lorenzo Torrisi

    2013-01-01

    Full Text Available Deutered polyethylene (CD2n thin and thick targets were irradiated in high vacuum by infrared laser pulses at 1015W/cm2 intensity. The high laser energy transferred to the polymer generates plasma, expanding in vacuum at supersonic velocity, accelerating hydrogen and carbon ions. Deuterium ions at kinetic energies above 4 MeV have been measured by using ion collectors and SiC detectors in time-of-flight configuration. At these energies the deuterium–deuterium collisions may induce over threshold fusion effects, in agreement with the high D-D cross-section valuesaround 3 MeV energy. At the first instants of the plasma generation, during which high temperature, density and ionacceleration occur, the D-D fusions occur as confirmed by the detection of mono-energetic protonsand neutrons with a kinetic energy of 3.0 MeV and 2.5 MeV, respectively, produced by the nuclear reaction. The number of fusion events depends strongly on the experimental set-up, i.e. on the laser parameters (intensity, wavelength, focal spot dimension, target conditions (thickness, chemical composition, absorption coefficient, presence of secondary targets and used geometry (incidence angle, laser spot, secondary target positions.A number of D-D fusion events of the order of 106÷7 per laser shot has been measured.

  5. PREFACE: Acceleration and radiation generation in space and laboratory plasmas

    Science.gov (United States)

    Bingham, R.; Katsouleas, T.; Dawson, J. M.; Stenflo, L.

    1994-01-01

    Sixty-six leading researchers from ten nations gathered in the Homeric village of Kardamyli, on the southern coast of mainland Greece, from August 29-September 4, 1993 for the International Workshop on Acceleration and Radiation Generation in Space and Laboratory Plasmas. This Special Issue represents a cross-section of the presentations made at and the research stimulated by that meeting. According to the Iliad, King Agamemnon used Kardamyli as a dowry offering in order to draw a sulking Achilles into the Trojan War. 3000 years later, Kardamyli is no less seductive. Its remoteness and tranquility made it an ideal venue for promoting the free exchange of ideas between various disciplines that do not normally interact. Through invited presen tations, informal poster discussions and working group sessions, the Workshop brought together leaders from the laboratory and space/astrophysics communities working on common problems of acceleration and radiation generation in plasmas. It was clear from the presentation and discussion sessions that there is a great deal of common ground between these disciplines which is not at first obvious due to the differing terminologies and types of observations available to each community. All of the papers in this Special Issue highlight the role collective plasma processes play in accelerating particles or generating radiation. Some are state-of-the-art presentations of the latest research in a single discipline, while others investi gate the applicability of known laboratory mechanisms to explain observations in natural plasmas. Notable among the latter are the papers by Marshall et al. on kHz radiation in the magnetosphere ; Barletta et al. on collective acceleration in solar flares; and by Dendy et al. on ion cyclotron emission. The papers in this Issue are organized as follows: In Section 1 are four general papers by Dawson, Galeev, Bingham et al. and Mon which serves as an introduction to the physical mechanisms of acceleration

  6. High duty factor plasma generator for CERN's Superconducting Proton Linac.

    Science.gov (United States)

    Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-02-01

    CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

  7. Promoting Plasma Physics as a Career: A Generational Approach

    Science.gov (United States)

    Morgan, James

    2005-10-01

    A paradigm shift is occurring in education physics programs. Educators are shifting from the traditional teaching focus to concentrate on student learning. Students are unaware of physics as a career, plasma physics or the job opportunities afforded to them with a physics degree. The physics profession needs to promote itself to the younger generations, or specifically the millennial generation (Born in the 1980's-2000's). Learning styles preferred by ``Millennials'' include a technological environment that promotes learning through active task performance rather than passive attendance at lectures. Millennials respond well to anything experiential and will be motivated by opportunities for creativity and challenging learning environments. The open-ended access to information, the ability to tailor learning paths, and continuous and instantaneous performance assessment offer flexibility in the design of curricula as well as in the method of delivery. Educators need to understand the millennial generation, appeal to their motivations and offer a learning environment designed for their learning style. This poster suggests promoting a physics career by focusing on generational learning styles and preferences.

  8. Adjustment of Adiabatic Transition Magnetic Field of Solenoid-Induced Helicla Wiggler

    CERN Document Server

    Tsunawaki, Y

    2005-01-01

    We have been constructed a solenoid-induced helical wiggler for a compact free electron maser operated in a usual small laboratory which does not have electric source capacity available enough. It consists of two staggered-iron arrays inserted perpendicularly to each other in a solenoid electromagnet. In order to lead/extract an electron beam into/from the wiggler, adiabatic transition (AT) field is necessary at both ends of the wiggler. In this work the AT field was produced by setting staggered-nickel plates with different thickness in the five periods. The thickness of each nickel plate was decided by the field analysis using the MAGTZ computational code based on a magnetic moment method. Exact thickness was, however, found by the precise measurement of the field distribution with the greatest circumspection to obtain a homogeneous increment of the AT field. The change of AT field distribution was studied by referring to an equivalent electric circuit of the wiggler.

  9. Study on the plasma generation characteristics of an induction-triggered coaxial pulsed plasma thruster

    Science.gov (United States)

    Weisheng, CUI; Wenzheng, LIU; Jia, TIAN; Xiuyang, CHEN

    2018-02-01

    At present, spark plugs are used to trigger discharge in pulsed plasma thrusters (PPT), which are known to be life-limiting components due to plasma corrosion and carbon deposition. A strong electric field could be formed in a cathode triple junction (CTJ) to achieve a trigger function under vacuum conditions. We propose an induction-triggered electrode structure on the basis of the CTJ trigger principle. The induction-triggered electrode structure could increase the electric field strength of the CTJ without changing the voltage between electrodes, contributing to a reduction in the electrode breakdown voltage. Additionally, it can maintain the plasma generation effect when the breakdown voltage is reduced in the discharge experiments. The induction-triggered electrode structure could ensure an effective trigger when the ablation distance of Teflon increases, and the magnetic field produced by the discharge current could further improve the plasma density and propagation velocity. The induction-triggered coaxial PPT we propose has a simplified trigger structure, and it is an effective attempt to optimize the micro-satellite thruster.

  10. Operational characteristics of the high flux plasma generator magnum-PSI

    NARCIS (Netherlands)

    Van Eck, H.J.N.; Abrams, T.; Van Den Berg, M.A.; Brons, S.D.N.; Van Eden, G.G.; Jaworski, M.A.; Kaita, R.; Van Der Meiden, H.J.; Morgan, T.W.; van de Pol, Marc J.; Scholten, J.; Smeets, P.H.M.; De Temmerman, G.; De Vries, P.C.; Zeijlmans Van Emmichoven, P.A.

    2014-01-01

    In Magnum-PSI (MAgnetized plasma Generator and NUMerical modeling for Plasma Surface Interactions), the high density, low temperature plasma of a wall stabilized dc cascaded arc is confined to a magnetized plasma beam by a quasi-steady state axial magnetic field up to 1.3 T. It aims at conditions

  11. A novel small-period wiggler for free-electron lasers

    International Nuclear Information System (INIS)

    Feng Bibo; Wang Mingchang; Wang Zhijiang

    1992-01-01

    A novel small-period wiggler configuration constructed by sheet of bifilar-helix with ferro-core for free-electron lasers is proposed. The performance characteristics of the wiggler prototype with 10 mm period are measured. The field as high as 500 G to 1 kG have been obtained. The amplifier designs for operation at 190 GHz using modest electron beam energies in the range of 400-500 keV are presented

  12. The first steps towards a 7.5 T superconducting wiggler

    International Nuclear Information System (INIS)

    Werin, S.

    1988-01-01

    A 7.5 T superconducting wiggler is currently beeing constructed in cooperation between MAX-lab and the Institute of Technology in Tammerfors, Finland. The wiggler will be places at MAX-lab, either at the existing 550 MeV storage ring or at a future 1.2 GeV ring. In this paper some basic designs and calculations are described and discussed. (author)

  13. 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.)

  14. Arc generation from sputtering plasma-dielectric inclusion interactions

    International Nuclear Information System (INIS)

    Wickersham, C.E. Jr.; Poole, J.E.; Fan, J.S.

    2002-01-01

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al 2 O 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect density, and the intensity of the optical emission from the arcing plasma indicates that the critical aluminum oxide inclusion area for arcing is 0.22±0.1 mm2 when the sputtering plasma sheath dark-space λ d , is 0.51 mm. Inclusions with areas greater than this critical value readily induce arcing and macroparticle ejection during sputtering. Inclusions below this critical size do not cause arcing or macroparticle ejection. When the inclusion major axis is longer than 2λ d and lies perpendicular to the sputter erosion track tangent, the arcing activity increases significantly over the case where the inclusion major axis lies parallel to the erosion track tangent

  15. Characterization of a deuterium-deuterium plasma fusion neutron generator

    Science.gov (United States)

    Lang, R. F.; Pienaar, J.; Hogenbirk, E.; Masson, D.; Nolte, R.; Zimbal, A.; Röttger, S.; Benabderrahmane, M. L.; Bruno, G.

    2018-01-01

    We characterize the neutron output of a deuterium-deuterium plasma fusion neutron generator, model 35-DD-W-S, manufactured by NSD/Gradel-Fusion. The measured energy spectrum is found to be dominated by neutron peaks at 2.2 MeV and 2.7 MeV. A detailed GEANT4 simulation accurately reproduces the measured energy spectrum and confirms our understanding of the fusion process in this generator. Additionally, a contribution of 14 . 1 MeV neutrons from deuterium-tritium fusion is found at a level of 3 . 5%, from tritium produced in previous deuterium-deuterium reactions. We have measured both the absolute neutron flux as well as its relative variation on the operational parameters of the generator. We find the flux to be proportional to voltage V 3 . 32 ± 0 . 14 and current I 0 . 97 ± 0 . 01. Further, we have measured the angular dependence of the neutron emission with respect to the polar angle. We conclude that it is well described by isotropic production of neutrons within the cathode field cage.

  16. Evaluations of electric field in laser-generated pulsed plasma

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Gammino, S.; Láska, Leoš; Krása, Josef; Rohlena, Karel; Wolowski, J.

    2006-01-01

    Roč. 56, Suppl. B (2006), B580-B585 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /22./. Prague, 26.06.2006-29.06.2006] Institutional research plan: CEZ:AV0Z10100523 Keywords : electric field in plasma * debye length * plasma temperature * plasma density Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.568, year: 2006

  17. Electron-positron plasma generation in a pulsar magnetosphere

    International Nuclear Information System (INIS)

    Gurevich, A.V.; Istomin, Ya.N.

    1985-01-01

    The generation of an electron-positron plasma in vacuum (vacuum ''breakdown'') in the presence of an inhomogeneous electric field and strong curvilinear magnetic field is considered. A situation of this type may occur in the magnetosphere of a rotating neutron star. A general set of kinetic equations for electrons, positrons and γ quanta in a curvilinear magnetic field is derived by taking into account electron-positron pair production and emission of curvicur and synchrotron photons. The conditions for appearance of ''breakdown'' are determined and the threshold value of the elec tric field discontinuity at the surface of the star is found. Multiplication of particles in the magnetosphere is investigated and the electron, positron and γ quantum distribution functions are found. The extinction limit of pulsars is determined. The theory is shown to be in accordance with the observation results

  18. Mechanisms of polymer degradation using an oxygen plasma generator

    Science.gov (United States)

    Colony, Joe A.; Sanford, Edward L.

    1987-01-01

    An RF oxygen plasma generator was used to produce polymer degradation which appears to be similar to that which has been observed in low Earth orbit. Mechanisms of this type of degradation were studied by collecting the reaction products in a cryogenic trap and identifying the molecular species using infrared, mass spectral, and X-ray diffraction techniques. No structurally dependent species were found from Kapton, Teflon, or Saran polymers. However, very reactive free radical entities are produced during the polymer degradation, as well as carbon dioxide and water. Reactions of the free radicals with the glass reaction vessel, with copper metal in the cold trap, and with a triphenyl phosphate scavenger in the cold trap, demonstrated the reactivity of the primary products.

  19. Nonlinear mode conversion with chaotic soliton generation at plasma resonance

    International Nuclear Information System (INIS)

    Pietsch, H.; Laedke, E.W.; Spatschek, K.H.

    1993-01-01

    The resonant absorption of electromagnetic waves near the critical density in inhomogeneous plasmas is studied. A driven nonlinear Schroedinger equation for the mode-converted oscillations is derived by multiple-scaling techniques. The model is simulated numerically. The generic transition from a stationary to a time-dependent solution is investigated. Depending on the parameters, a time-chaotic behavior is found. By a nonlinear analysis, based on the inverse scattering transform, solitons of a corresponding integrable equation are identified as the dominant coherent structures of the chaotic dynamics. Finally, a map is presented which predicts chaotic soliton generation and emission at the critical density. Its qualitative behavior, concerning the bifurcation points, is in excellent agreement with the numerical simulations

  20. Finite element thermal study of the Linac4 plasma generator

    International Nuclear Information System (INIS)

    Faircloth, D.; Kronberger, M.; Kuechler, D.; Lettry, J.; Scrivens, R.

    2010-01-01

    The temperature distribution and heat flow at equilibrium of the plasma generator of the rf-powered noncesiated Linac4 H - ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW rf power, 2 Hz repetition rate, and 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of the Superconducting Proton Linac (SPL), an extrapolation of the heat load toward 100 kW rf power, 50 Hz repetition rate, and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in the high-power mode of SPL.

  1. Finite element thermal study of the Linac4 plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Faircloth, D. [STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Kronberger, M.; Kuechler, D.; Lettry, J.; Scrivens, R. [BE-ABP, Hadron Sources and Linacs, CERN, CH-1211 Geneva (Switzerland)

    2010-02-15

    The temperature distribution and heat flow at equilibrium of the plasma generator of the rf-powered noncesiated Linac4 H{sup -} ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW rf power, 2 Hz repetition rate, and 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of the Superconducting Proton Linac (SPL), an extrapolation of the heat load toward 100 kW rf power, 50 Hz repetition rate, and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in the high-power mode of SPL.

  2. Magnum-psi, a plasma generator for plasma-surface interaction research in ITER-like conditions

    International Nuclear Information System (INIS)

    Groot, B. de; Rooij, G.J. van; Veremiyenko, V.; Hellermann, M.G. von; Eck, H.J.N. van; Barth, C.J.; Kruijtzer, G.L.; Wolff, J.C.; Goedheer, W.J.; Lopes Cardozo, N.J.; Kleyn, A.W.; Smeets, P.H.M.; Brezinsek, S.; Pospieszczyk, A.; Engeln, R.A.H.; Dahiya, R.P.

    2005-01-01

    The FOM Institute for Plasma Physics is preparing the construction of the linear plasma generator, Magnum-psi. A pilot experiment (Pilot-psi) has been constructed, which we have used to optimize the cascaded arc plasma source and to explore the effect of high magnetic fields on the source operation as well as the expanding plasma beam and the effectiveness of Ohmic heating for manipulating the electron temperature and plasma density after the plasma expansion. Results are presented that demonstrate increasing source efficiency for increasing magnetic fields (up to 1.6 T). Thomson scattering measurements demonstrate that ITER relevant plasma fluxes are presently achieved in Pilot-psi: ∼10 24 m -2 s -1 and that additional heating could elevate the plasma temperature from 1.0 to 1.7 eV

  3. Numerical studies of third-harmonic generation in laser filament in air perturbed by plasma spot

    International Nuclear Information System (INIS)

    Feng Liubin; Lu Xin; Liu Xiaolong; Li Yutong; Chen Liming; Ma Jinglong; Dong Quanli; Wang Weimin; Xi Tingting; Sheng Zhengming; Zhang Jie; He Duanwei

    2012-01-01

    Third-harmonic emission from laser filament intercepted by plasma spot is studied by numerical simulations. Significant enhancement of the third-harmonic generation is obtained due to the disturbance of the additional plasma. The contribution of the pure plasma effect and the possible plasma-enhanced third-order susceptibility on the third-harmonic generation enhancement are compared. It is shown that the plasma induced cancellation of destructive interference [Y. Liu et al., Opt. Commun. 284, 4706 (2011)] of two-colored filament is the dominant mechanism of the enhancement of third-harmonic generation.

  4. Characteristics of semiconductor bridge (SCB) plasma generated in a micro-electro-mechanical system (MEMS)

    International Nuclear Information System (INIS)

    Kim, Jong-Uk; Park, Chong-Ook; Park, Myung-Il; Kim, Sun-Hwan; Lee, Jung-Bok

    2002-01-01

    Plasma ignition method has been applied in various fields particularly to the rocket propulsion, pyrotechnics, explosives, and to the automotive air-bag system. Ignition method for those applications should be safe and also operate reliably in hostile environments such as; electromagnetic noise, drift voltage, electrostatic background and so on. In the present Letter, a semiconductor bridge (SCB) plasma ignition device was fabricated and its plasma characteristics including the propagation speed of the plasma, plasma size, and plasma temperature were investigated with the aid of the visualization of micro scale plasma (i.e., ≤350 μm), which generated from a micro-electro-mechanical poly-silicon semiconductor bridge (SCB)

  5. Plasma generation using high-power millimeter-wave beam and its application for thrust generation

    International Nuclear Information System (INIS)

    Oda, Yasuhisa; Komurasaki, Kimiya; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi

    2006-01-01

    Propagation of an ionization front in the beam channel was observed after plasma was generated using a 170 GHz millimeter-wave beam in the atmosphere. The propagation velocity of the ionization front was found to be supersonic when the millimeter-wave power density was greater than 75 kW cm -2 . The momentum coupling coefficient C m , a ratio of the propulsive impulse to the input energy, was measured using conical and cylindrical thruster models. A C m value greater than 350 N MW -1 was recorded when the ionization front propagated with supersonic velocity

  6. Microwave plasmas generated in bubbles immersed in liquids for hydrocarbons reforming

    International Nuclear Information System (INIS)

    Levko, Dmitry; Sharma, Ashish; Raja, Laxminarayan L

    2016-01-01

    We present a computational modeling study of microwave plasma generated in cluster of atmospheric-pressure argon bubbles immersed in a liquid. We demonstrate that the use of microwaves allows the generation of a dense chemically active non-equilibrium plasma along the gas–liquid interface. Also, microwaves allow generation of overdense plasma in all the bubbles considered in the cluster which is possible because the collisional skin depth of the wave exceeds the bubble dimension. These features of microwave plasma generation in bubbles immersed in liquids are highly desirable for the large-scale liquid hydrocarbon reforming technologies. (letter)

  7. On-site SiH4 generator using hydrogen plasma generated in slit-type narrow gap

    Science.gov (United States)

    Takei, Norihisa; Shinoda, Fumiya; Kakiuchi, Hiroaki; Yasutake, Kiyoshi; Ohmi, Hiromasa

    2018-06-01

    We have been developing an on-site silane (SiH4) generator based on use of the chemical etching reaction between solid silicon (Si) and the high-density H atoms that are generated in high-pressure H2 plasma. In this study, we have developed a slit-type plasma source for high-efficiency SiH4 generation. High-density H2 plasma was generated in a narrow slit-type discharge gap using a 2.45 GHz microwave power supply. The plasma’s optical emission intensity distribution along the slit was measured and the resulting distribution was reflected by both the electric power distribution and the hydrogen gas flow. Because the Si etching rate strongly affects the SiH4 generation rate, the Si etching behavior was investigated with respect to variations in the experimental parameters. The weight etch rate increased monotonically with increasing input microwave power. However, the weight etch rate decreased with increasing H2 pressure and an increasing plasma gap. This reduction in the etch rate appears to be related to shrinkage of the plasma generation area because increased input power is required to maintain a constant plasma area with increasing H2 pressure and the increasing plasma gap. Additionally, the weight etch rate also increases with increasing H2 flow rate. The SiH4 generation rate of the slit-type plasma source was also evaluated using gas-phase Fourier transform infrared absorption spectroscopy and the material utilization efficiencies of both Si and the H2 gas for SiH4 gas formation were discussed. The main etch product was determined to be SiH4 and the developed plasma source achieved a SiH4 generation rate of 10 sccm (standard cubic centimeters per minute) at an input power of 900 W. In addition, the Si utilization efficiency exceeded 60%.

  8. Design of a High-Throughput Biological Crystallography Beamline for Superconducting Wiggler

    International Nuclear Information System (INIS)

    Tseng, P.C.; Chang, C.H.; Fung, H.S.; Ma, C.I.; Huang, L.J.; Jean, Y.C.; Song, Y.F.; Huang, Y.S.; Tsang, K.L.; Chen, C.T.

    2004-01-01

    We are constructing a high-throughput biological crystallography beamline BL13B, which utilizes the radiation generated from a 3.2 Tesla, 32-pole superconducting multipole wiggler, for multi-wavelength anomalous diffraction (MAD), single-wavelength anomalous diffraction (SAD), and other related experiments. This beamline is a standard double crystal monochromator (DCM) x-ray beamline equipped with a collimating mirror (CM) and a focusing mirror (FM). Both the CM and FM are one meter long and made of Si substrate, and the CM is side-cooled by water. Based on detailed thermal analysis, liquid nitrogen (LN2) cooling for both crystals of the DCM has been adopted to optimize the energy resolution and photon beam throughput. This beamline will deliver, through a 100 μm diameter pinhole, photon flux of greater than 1011 photons/sec in the energy range from 6.5 keV to 19 keV, which is comparable to existing protein crystallography beamlines from bending magnet source at high energy storage rings

  9. Plasma generation and processing of interstellar carbonaceous dust analogs

    Science.gov (United States)

    Peláez, R. J.; Maté, B.; Tanarro, I.; Molpeceres, G.; Jiménez-Redondo, M.; Timón, V.; Escribano, R.; Herrero, V. J.

    2018-03-01

    Interstellar (IS) dust analogs, based on amorphous hydrogenated carbon (a-C:H) were generated by plasma deposition in radio frequency discharges of CH4 + He mixtures. The a-C:H samples were characterized by means of secondary electron microscopy, infrared (IR) spectroscopy and UV-visible reflectivity. DFT calculations of structure and IR spectra were also carried out. From the experimental data, atomic compositions were estimated. Both IR and reflectivity measurements led to similar high proportions (≈50%) of H atoms, but there was a significant discrepancy in the sp2/sp3 hybridization ratios of C atoms (sp2/sp3 = 1.5 from IR and 0.25 from reflectivity). Energetic processing of the samples with 5 keV electrons led to a decay of IR aliphatic bands and to a growth of aromatic bands, which is consistent with a dehydrogenation and graphitization of the samples. The decay of the CH aliphatic stretching band at 3.4 μm upon electron irradiation is relatively slow. Estimates based on the absorbed energy and on models of cosmic ray (CR) flux indicate that CR bombardment is not enough to justify the observed disappearance of this band in dense IS clouds.

  10. Arc generation from sputtering plasma-dielectric inclusion interactions

    CERN Document Server

    Wickersham, C E J; Fan, J S

    2002-01-01

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al sub 2 O sub 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect...

  11. The 8 cm Period Electromagnetic Wiggler Magnet with Coils Made from Sheet Copper

    CERN Document Server

    Biallas, George H; Hiatt, Tommy; Neil, George R; Snyder, Michael D

    2005-01-01

    An electromagnetic wiggler, now lasing at the Jefferson Lab FEL, has 29 eight cm periods with K variable from 0.6 to1.1 and gap of 2.6 cm. The wiggler was made inexpensively in 11 weeks by an industrial machine shop. The conduction cooled coil design uses copper sheet material cut to forms using water jet cutting. The conductor is cut to serpentine shapes and the cooling plates are cut to ladder shape. The sheets are assembled in stacks insulated with polymer film, also cut with water jet. The coil design extends the serpentine conductor design of the Duke OK4 to more and smaller conductors. The wiggler features graded fields in the two poles at each end and trim coils on these poles to eliminate field errors caused by saturation. An added critical feature is mirror plates at the ends with integral trim coils to eliminate three dimensional end field effects and align the entrance and exit orbit with the axis of the wiggler. Details of construction, measurement methods and excellent wiggler performance are pre...

  12. CESR-c Performance of a Wiggler-Dominated Storage Ring

    CERN Document Server

    Temnykh, Alexander

    2005-01-01

    CESR-c operates now as a Wiggler-Dominated Storage Ring extending the lowest operating energy to 1.5GeV/beam. To improve beam stability at low energy, 12 super-ferric wiggler magnets with total length of 15m and 2.1T maximum field were installed in the ring. They cause ~90% of total beam radiation lost and increase radiation damping rate by factor 10 from ~3 to 40 Hz. However, the field of the wiggler magnets not only initiates the radiation, but potentially affects beam dynamics. The latter was an issue of a great concern from the planning the CESR-c project. In this paper we describe general performance of CESR-c and report the results of an experimental study on some aspects of beam dynamics. Comparisons are made between the experimental data and the model prediction. We find that all parameters, which are critically dependent on wigglers, such as beam properties and ring nonlinearity, are in good agreement with those calculated from the model. This validates the ring and wiggler models and justifies our d...

  13. Development of plasma properties along thermal plasma jet generated by hybrid water-argon torch

    Czech Academy of Sciences Publication Activity Database

    Kavka, Tetyana; Hrabovský, Milan

    2002-01-01

    Roč. 52, supplement D (2002), s. 637-642 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : thermal plasma, plasma jet, enthalpy probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  14. Plasma generated in culture medium induces damages of HeLa cells due to flow phenomena

    Science.gov (United States)

    Sato, Yusuke; Sato, Takehiko; Yoshino, Daisuke

    2018-03-01

    Plasma in a liquid has been anticipated as an effective tool for medical applications, however, few reports have described cellular responses to plasma generated in a liquid similar to biological fluids. Herein we report the effects of plasma generated in a culture medium on HeLa cells. The plasma in the culture medium produced not only heat, shock waves, and reactive chemical species but also a jet flow with sub millimeter-sized bubbles. Cells exposed to the plasma exhibited detachment, morphological changes, and changes in the actin cytoskeletal structure. The experimental results suggest that wall shear stress over 160 Pa was generated on the surface of the cells by the plasma. It is one of the main factors that cause those cellular responses. We believe that our findings would provide valuable insight into advancements in medical applications of plasma in a liquid.

  15. Engineering design of plasma generation devices using Elmer finite element simulation methods

    Directory of Open Access Journals (Sweden)

    Daniel Bondarenko

    2017-02-01

    Full Text Available Plasma generation devices are important technology for many engineering disciplines. The process for acquiring experience for designing plasma devices requires practice, time, and the right tools. The practice and time depend on the individual and the access to the right tools can be a limiting factor to achieve experience and to get an idea on the possible risks. The use of Elmer finite element method (FEM software for verifying plasma engineering design is presented as an accessible tool that can help modeling multi-physics and verifying plasma generation devices. Furthermore, Elmer FEM will be suitable for experienced engineer and can be used for determining the risks in a design or a process that use plasma. A physical experiment was conducted to demonstrate new features of plasma generation technology where results are compared with plasma simulation using Elmer FEM.

  16. Spectroscopic determination of temperatures in plasmas generated by arc torches

    Czech Academy of Sciences Publication Activity Database

    Mašláni, Alan; Sember, Viktor; Hrabovský, Milan

    2017-01-01

    Roč. 133, July (2017), s. 14-20 ISSN 0584-8547 R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : Arc plasma torch * Optical emission spectroscopy * Temperature * Boltzmann plot Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.241, year: 2016

  17. Plasma waveguides: Addition of end funnels and generation in clustered gases

    International Nuclear Information System (INIS)

    Kim, K.Y.; Alexeev, I.; Fan, J.; Parra, E.; Milchberg, H.M.

    2002-01-01

    We present results from some recent experiments: the generation of a plasma funnel for improved pump pulse input coupling to plasma waveguides, and the development of a single shot transient phase diagnostic with 15 fs temporal resolution. The phase diagnostic is used in two experiments. We first demonstrate that short pulse heated clustered gases can act as an optical guiding medium and are highly absorbing. We show that this leads to a method for plasma waveguide generation at densities substantially lower than current typical values. Second, we measure transient phase shifts generated by intense pump pulses injected into plasma waveguides

  18. Power supply for plasma generator of HL-1M neutral beam injector

    International Nuclear Information System (INIS)

    Wang Detai; Qian Jiamei; Lei Guangjiu; Shun Mengda; Jiang Shaofeng; Wang Enyao; Lu Xuejun; Yang Tiehai; Wang Xuehua; Zhao Zhimin; Hao Ming; Huang Jianrong; Yu Yanqiu; Cheng Baoqiang; Wu Zhige; Sheng Ning; Hu Qingtao

    1999-01-01

    The diagram of the HL-1M Neutral Beam Injector (NBI) and the power supply (PS) system is shown. The NBI consists of ion source, beam line and power supply system etc. The ion source includes plasma generator and three-electrode extraction system. The power supply for plasma generator consists of a filament PS, an arc PS and gas valve PS. Testing has shown that the PS for plasma generator of the HL-1M NBI has excellent stability and obtain good plasma heating effect

  19. Experimental observation of current generation by asymmetrical heating of ions in a tokamak plasma

    International Nuclear Information System (INIS)

    Gahl, J.; Ishihara, O.; Wong, K.L.; Kristiansen, M.; Hagler, M.

    1986-01-01

    The first experimental observation of current generation by asymmetrical heating of ions is reported. Ions were asymmetrically heated by a unidirectional fast Alfven wave launched by a slow wave antenna inside a tokamak. Current generation was detected by measuring the asymmetry of the toroidal plasma current with probes at the top and bottom of the toroidal plasma column

  20. The comparative analysis of the compressible plasma streams generated in QSPA from the various gases

    International Nuclear Information System (INIS)

    Kozlov, A.N.; Drukarenko, S.P.; Seytkhalilova, E.I.; Velichkin, M.A.; Solyakov, D.G.

    2012-01-01

    The numerical research of streams dynamics in the channel and the compressible flows at the QSPA output is carried out for the plasma generated from hydrogen, helium, argon and xenon. The MHD equations in the one-fluid approach taking into account the final conductivity of medium, the heat conductivity and the effective losses of radiation energy underlie the numerical model of the two-dimensional axisymmetric plasma flows. Features of the compressible plasma streams generated from various gases are revealed.

  1. Power excitation by the use of a rf wiggler

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1992-01-01

    It is well-known that there are difficulties to obtain rf power sources of significant amount for frequencies larger than 3 GHz. Yet, rf sources in the centimeter/millimeter wavelength range would be very useful to drive, for example, high-gradient accelerating linacs for electron-positron linear colliders. We would like to propose an alternative method to produce such radiation. It makes use of a short electron bunch traveling along the axis of a waveguide which is at the same time excited by a TM propagating electromagnetic wave. It is well known that radiation can be obtained by wiggling the motion of the electrons in a direction perpendicular to the main one. The wiggling action can be included by electromagnetic fields in a fashion similar to the one caused by wiggler magnets. We found that an interesting mode of operation is to drive the waveguide with an excitation frequency very close to the cut off. For such excitation, the corresponding e.m. wave travels with a very large phase velocity which in turn has the effect to increase the wiggling action on the electron bunch. Our method, to be effective, relies also on the coherence of the radiation; that is the bunch length is taken to be considerably shorter than the radiated wavelength. In this case, the total power radiated should be proportional to the square of the total number of electrons in the bunch. The paper concludes with possible modes of operation, a list of performance parameters and a proposed experimental set-up

  2. Near-ideal lasing with a uniform wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.W.; Sollid, J.E.; Feldman, D.W.; Stein, W.E.; Johnson, W.J.; Lumpkin, A.H.; Goldstein, J.C.

    1988-01-01

    Over the years the Los Alamos FEL team has reduced or eliminated many of the experimental problems that resulted in non-ideal lasing. The major problems were accelerator instabilities that cause noise and fluctuations in current, energy, and timing; wakefield effects in the wiggler and beamline that introduce fluctuations in the beam's energy; and mirror nonlinearities caused by free carriers produced in the mirror by the high light levels, which caused extra light losses and interfered with the diagnostics. Lasing is not thought to be ideal in that it lacks major disturbing effects and is limited only by emittance, energy spread, and peak current. In this paper we describe the features of lasing that we have observed over a range of optical power of 1000, from the onset of lasing, to the threshold of the sideband instability, to the organization of regular optical spikes, to the region of chaotic spikes. Cavity-length detuning is presented as an ideal technique, in most circumstances, to completely suppress sidebands. With detuning one can easily switch operating modes from that giving the highest efficiency (chaotic spiking) to that giving the narrowest spectral line (no sidebands). Alternative techniques for sideband suppression normally use some kind of wavelength selective device (e.g., a grating) inserted in the cavity. With detuning, there is no need for such a device, and, therefore, no conflict between the wavelength control exerted by this extra optical component and that exerted by the energy of the electron beam. Lasing, therefore, starts easily, a shift in wavelength, i.e., chirp, is easily accomplished, and the consequences of inadequate control of the electron beam energy are not severe. 35 refs., 16 figs.

  3. Making an Inexpensive Electromagnetic Wiggler Using Sheet Materials for the Coils

    CERN Document Server

    Herman-Biallas, George; Hiatt, Thomas; Neil, George; Snyder, Michael

    2004-01-01

    An inexpensive electromagnetic wiggler, made with twenty-eight, 4 cm periods with a K of 1 and gap of 2.6 cm was made within 10 weeks after receipt of order by an industrial machine shop. The coil design used sheet and plate materials cut to shapes using water jet cutting and was assembled in a simple stack design. The coil design extends the serpentine conductor design of the Duke OK4 to more and smaller conductors. The coils are conduction cooled to imbedded cooling plates. The wiggler features graded end pole fields, trim coil compensation for end field errors and mirror plates on the ends to avoid three dimensional end field effects. Details of the methods used in construction and the wiggler performance are presented.

  4. A long electromagnetic wiggler for the paladin free-electron laser experiments

    International Nuclear Information System (INIS)

    Deis, G.A.; Harvey, A.R.; Parkison, C.D.; Prosnitz, D.; Rego, J.; Scharlemann, E.T.; Halbach, K.

    1987-01-01

    We have designed, built, and tested a 25.6-m-long wiggler for a free-electron-laser (FEL) experiment. It is a DC iron-core electromagnetic wiggler that incorporates a number of important and unique features. Permanent magnets are used to suppress saturation in the iron and extend the linear operating range. Steering-free excitation allows real-time adjustment of the field taper without causing beam steering. Wiggle-plane focusing is produced by curved pole tips. The magnitude of random pole-to-pole field errors is minimized by a mechanical design concept that reduces tolerance stackup in critical locations. To date, we have tested 15 m of this wiggler, and our measurements have shown exceptionally low levels of random errors. 8 refs

  5. Field correction for a one meter long permanent-magnet wiggler

    International Nuclear Information System (INIS)

    Fortgang, C.M.

    1992-01-01

    Field errors in wigglers are usually measured and corrected on-axis only, thus ignoring field error gradients. We find that gradient scale lengths are of the same order as electron beam size and therefore can be important. We report measurements of wiggler field errors in three dimensions and expansion of these errors out to first order (including two dipole and two quadrupole components). Conventional techniques for correcting on-axis errors (order zero) create new off-axis (first order) errors. We present a new approach to correcting wiggler fields out to first order. By correcting quadrupole errors in addition to the usual dipole correction, we minimize growth in electron beam size. Correction to first order yields better overlap between the electron and optical beams and should improve laser gain. (Author) 2 refs., 5 figs

  6. Design and manufacture of a 6-T wiggler magnet for the Daresbury SRS

    International Nuclear Information System (INIS)

    Ross, J.; Smith, K.

    1992-01-01

    The 6-T wiggler is an iron-cored, warm bore, superconducting dipole magnet destined for the SERC Daresbury Laboratory's 2-GeV Synchrotron Radiation Source to enhance the available radiation spectrum. The new wiggler will be inserted in the ring in addition to an existing 5-T wiggler, both of which will use the existing, although upgraded, refrigerator. The magnet is designed to provide a peak field of 6 T on the beam line. The design and manufacturing contract for this magnet was started in September 1989 and was preceded by a feasibility study, presented by Oxford Instruments in mid 1988. The major features of the magnet, along with a discussion of the early stages of manufacture, are described in the article

  7. Theoretical model for plasma expansion generated by hypervelocity impact

    International Nuclear Information System (INIS)

    Ju, Yuanyuan; Zhang, Qingming; Zhang, Dongjiang; Long, Renrong; Chen, Li; Huang, Fenglei; Gong, Zizheng

    2014-01-01

    The hypervelocity impact experiments of spherical LY12 aluminum projectile diameter of 6.4 mm on LY12 aluminum target thickness of 23 mm have been conducted using a two-stage light gas gun. The impact velocity of the projectile is 5.2, 5.7, and 6.3 km/s, respectively. The experimental results show that the plasma phase transition appears under the current experiment conditions, and the plasma expansion consists of accumulation, equilibrium, and attenuation. The plasma characteristic parameters decrease as the plasma expands outward and are proportional with the third power of the impact velocity, i.e., (T e , n e ) ∝ v p 3 . Based on the experimental results, a theoretical model on the plasma expansion is developed and the theoretical results are consistent with the experimental data

  8. Theoretical model for plasma expansion generated by hypervelocity impact

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yuanyuan; Zhang, Qingming, E-mail: qmzhang@bit.edu.cn; Zhang, Dongjiang; Long, Renrong; Chen, Li; Huang, Fenglei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Gong, Zizheng [National Key Laboratory of Science and Technology on Reliability and Environment Engineering, Beijing Institute of Spacecraft Environment Engineering, Beijing 100094 (China)

    2014-09-15

    The hypervelocity impact experiments of spherical LY12 aluminum projectile diameter of 6.4 mm on LY12 aluminum target thickness of 23 mm have been conducted using a two-stage light gas gun. The impact velocity of the projectile is 5.2, 5.7, and 6.3 km/s, respectively. The experimental results show that the plasma phase transition appears under the current experiment conditions, and the plasma expansion consists of accumulation, equilibrium, and attenuation. The plasma characteristic parameters decrease as the plasma expands outward and are proportional with the third power of the impact velocity, i.e., (T{sub e}, n{sub e}) ∝ v{sub p}{sup 3}. Based on the experimental results, a theoretical model on the plasma expansion is developed and the theoretical results are consistent with the experimental data.

  9. Power supply controlled for plasma torch generation; Fuente de alimentacion controlada para la generacion de un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Z, S

    1997-12-31

    The high density of energy furnished by thermal plasma is profited in a wide range of applications, such as those related with welding fusion, spray coating and at the present in waste destruction. The waste destruction by plasma is a very attractive process because the remaining products are formed by inert glassy grains and non-toxic gases. The main characteristics of thermal plasmas are presented in this work. Techniques based on power electronics are utilized to achieve a good performance in thermal plasma generation. This work shown the design and construction of three phase control system for electric supply of thermal plasma torch, with 250 kw of capacity, as a part of the project named `Destruction of hazard wastes by thermal plasma` actually working in the Instituto Nacional de Investigaciones Nucleares (ININ). The characteristics of thermal plasma and its generation are treated in the first chapter. The A C controllers by thyristors applied in three phase arrays are described in the chapter II, talking into account the power transformer, rectifiers bank and aliasing coil. The chapter III is dedicated in the design of the trigger module which controls the plasma current by varying the trigger angle of the SCR`s; the protection and isolating unit are also presented in this chapter. The results and conclusions are discussed in chapter IV. (Author).

  10. Repetitive plasma opening switch for powerful high-voltage pulse generators

    International Nuclear Information System (INIS)

    Dolgachev, G.I.; Zakatov, L.P.; Nitishinskii, M.S.; Ushakov, A.G.

    1998-01-01

    Results are presented of experimental studies of plasma opening switches that serve to sharpen the pulses of inductive microsecond high-voltage pulse generators. It is demonstrated that repetitive plasma opening switches can be used to create super-powerful generators operating in a quasi-continuous regime. An erosion switching mechanism and the problem of magnetic insulation in repetitive switches are considered. Achieving super-high peak power in plasma switches makes it possible to develop new types of high-power generators of electron beams and X radiation. Possible implementations and the efficiency of these generators are discussed

  11. Dust generation at interaction of plasma jet with surfaces

    Science.gov (United States)

    Ticos, Catalin; Toader, Dorina; Banu, Nicoleta; Scurtu, Adrian; Oane, Mihai

    2013-10-01

    Coatings of W and C with widths of a few microns will be exposed to plasma jet for studying the erosion of the surface and detachment of micron size dust particles. A coaxial plasma gun has been built inside a vacuum chamber for producing supersonic plasma jets. Its design is based on a 50 kJ coaxial plasma gun which has been successfully used for accelerating hypervelocity dust. Initial shots were carried out for a capacitor bank with C = 12 μF and charged up to 2 kV. Currents of tens of amps were measured with a Rogowsky coil and plasma flow speeds of 4 km/s were inferred from high-speed images of jet propagation. An upgrade consisting in adding capacitors in parallel will be performed in order to increase the energy up to 2 kJ. A coil will be installed at the gun muzzle to compress the plasma flow and increase the energy density of the jet on the sample surface. A CCD camera with a maximum recording speed of 100 k fps and a maximum resolution of 1024 × 1024 pixels was set for image acquisition of the plasma and dust. A laser system used to illuminate the ejected dust from the surface includes a laser diode emitting at 650 nm with a beam power of 25 mW. The authors acknowledge support from EURATOM WP13-IPH-A03-P2-02-BS22.

  12. Control System of the Superconducting 63-Pole 2-Tesla Wiggler for Canadian Light Source

    International Nuclear Information System (INIS)

    Kuper, E.A.; Mezentsev, N.A.; Miginsky, E.G.; Repkov, V.V.; Tsukanov, V.M.

    2006-01-01

    A control system of the superconducting 63-pole wiggler fabricated at the Institute of Nuclear Physics in Novosibirsk (BINP) for Synchrotron Radiation Center in Canada (CLS) is described. Specific electronics and software which provide continuos monitoring of all the superconducting wiggler parameters as well as full control and monitoring of power suppliers and cryogenics machines, have been designed. The control system is VME-based. A client/server architecture of the software allowed us to integrate easily this system into the CLS distributed control system

  13. Design of a 6 Tesla wiggler for the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Hsieh, H.; Krinsky, S.; Luccio, A.; van Steenbergen, A.

    1981-01-01

    A 6-pole, 6 Tesla wiggler with Nb-Ti superconducting windings has been designed, to be installed in a straight section of the 2.5 GeV x-ray storage ring of the NSLS. The technical problems of this magnet are discussed, in particular the optimization of the two-layer magnetic windings and the mechanical structure designed to counteract the strong magnetic forces. The effects of the insertion of the wiggler in the storage ring lattice are also studied

  14. Wigglers and single-particle dynamics in the NLC damping rings

    International Nuclear Information System (INIS)

    Venturini, Marco; Wolski, Andrzej; Dragt, Alex

    2003-01-01

    Wiggler insertions are expected to occupy a significant portion of the lattice of the Next Linear Collider (NLC) Main Damping Rings (MDR) and have a noticeable impact on the single-particle beam dynamics. Starting from a realistic 3D representation of the magnetic fields we calculate the transfer maps for the wigglers, accounting for linear and nonlinear effects, and we study the beam dynamics with particular attention paid to the Dynamic Aperture(DA). A DA reduction is observed but appears to remain within acceptable limits

  15. Design of the 1.8 Tesla wiggler for the DAΦNE Main Rings

    International Nuclear Information System (INIS)

    Sanelli, C.; Hsieh, H.

    1992-01-01

    The electromagnetic and mechanical design of the eight wiggler magnets for DAΦNE Main Rings is described. The wigglers have a large 1.8 Tesla flat top magnetic field, 64 cm period and 4 cm gap. The magnetic 3-D calculations, the electromagnetic design and the adopted mechanical solutions, with particular attention to the vacuum chamber problems are described. A full scale prototype (5 full poles and two half pole) will be constructed in order to verify the accuracy of magnetic calculations, the end pole design and the multipole content. (author) 4 figs.; 1 tab

  16. Enhanced resonant second harmonic generation in plasma based on density transition

    Directory of Open Access Journals (Sweden)

    Kant Niti

    2015-06-01

    Full Text Available Resonant second harmonic generation of a relativistic self-focusing laser in plasma with density ramp profile has been investigated. A high intense Gaussian laser beam generates resonant second harmonic beam in plasma with density ramp profile. The second harmonic undergoes periodic focusing in the plasma channel created by the fundamental wave. The normalized second harmonic amplitude varies periodically with distance and attains maximum value in the focal region. Enhancement in the second harmonic amplitude on account of relativistic self-focusing of laser based on plasma density transition is seen. Plasma density ramp plays an important role to make self-focusing stronger which leads to enhance the second harmonic generation in plasma.

  17. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    International Nuclear Information System (INIS)

    Fisch, N.J.

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave rf energy is injected into said plasma to establish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected rf energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected rf energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range delta . The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width delta in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated in the plasma

  18. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    International Nuclear Information System (INIS)

    Bers, A.

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave rf energy is injected into said plasma to estalish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected rf energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected rf energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range delta . The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width delta in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated inthe plasma

  19. Ion Beam Analysis applied to laser-generated plasmas

    Czech Academy of Sciences Publication Activity Database

    Cutroneo, Mariapompea; Macková, Anna; Havránek, Vladimír; Malinský, Petr; Torrisi, L.; Kormunda, M.; Barchuk, M.; Ullschmied, Jiří; Dudžák, Roman

    2016-01-01

    Roč. 11, APR (2016), C04011 ISSN 1748-0221. [Conference on Plasma Physics by Laser and Applications (PPLA). Frascati, 05.10.2015-07.10.2015] R&D Projects: GA MŠk(CZ) LM2011019; GA ČR GA15-01602S; GA MŠk LM2015073 Institutional support: RVO:61389021 ; RVO:61389005 Keywords : accelerator applications * lasers * plasma diagnostics Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BL - Plasma and Gas Discharge Physics (UFP-V) Impact factor: 1.220, year: 2016

  20. High density plasma gun generates plasmas at 190 kilometers per second

    Science.gov (United States)

    Espy, P. N.

    1971-01-01

    Gun has thin metal foil disc which positions or localizes gas to be ionized during electrical discharge cycle, overcoming major limiting factor in obtaining such plasmas. Expanding plasma front travels at 190 km/sec, compared to plasmas of 50 to 60 km/sec previously achieved.

  1. Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X., E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Naidis, G.V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Laroussi, M. [Plasma Engineering & Medicine Institute, Old Dominion University, Norfolk, VA 23529 (United States); Reuter, S. [Leibniz Institute for Plasma Science and Technology, Felix-Hausdorff-Strasse 2, 17489 Greifswald (Germany); Graves, D.B. [Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720 (United States); Ostrikov, K. [Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000 (Australia); School of Physics, Chemistry, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000 (Australia); Commonwealth Scientific and Industrial Research Organization, P.O.Box 218, Lindfield, NSW 2070 (Australia); School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

    2016-05-04

    Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmospheric-pressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, time-resolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors’ vision for the emerging convergence trends across several disciplines and application domains is presented to

  2. Studies on EOS of shock-generated argon plasmas

    International Nuclear Information System (INIS)

    Wang Fanhou; Jing Fuqian

    2001-01-01

    The equation of state for argon plasma, covering the thermodynamic states of 10000-30000 K in temperature and 0.0133-0.166 GPa in pressure, is computed using the Saha model and Debye-Huckel correction. Comparisons of the measured EOS with the calculated ones demonstrate the Saha model and Debye-Huckel correction can be used to well describe the essential behavior of argon plasma under the thermodynamic condition above-mentioned

  3. Investigations of Pulsed Plasma Streams Generated by 'Prosvet' device Operated with Different Gases

    International Nuclear Information System (INIS)

    Byrka, O.V.; Bandura, A.N.; Chebotarev, V.V. and others

    2006-01-01

    The paper presents the investigations of plasma streams generated by pulsed plasma gun 'Prosvet' operated with different gases: krypton (m=84) and helium (m=4). Contour parameters of working gas spectral lines (full intensities and half-widths) are used for determination of spatial distributions of the electron density and temperature. Temporal distributions of the spectral lines intensities (both neutrals and ions of working gas), impurity spectral lines and continuum intensities are analyzed. Plasma stream velocity was estimated by time-of-flight method between two monochromators (MUM) connected with photo-multiplier. longitudinal distributions of the plasma pressure for different time moments and varied distances from the accelerator output have been used for investigation of the plasma stream dynamics and study the plasma compression in the focus region for different operational regimes of plasma accelerator. Experiments show that operation regime of the accelerator and plasma stream parameters strongly depend on the gas atomic mass

  4. Electron current generated in a toroidal plasma on injection of high-energy neutrals

    International Nuclear Information System (INIS)

    Kolesnichenko, Ya.I.; Reznik, S.N.

    1981-01-01

    Problem of generation of electron current in toroidal plasma with a high-energy ion beam produced during neutral injection has been considered. The analysis was performed on the assumption that plasma is in the regime of rare collisions (banana regime) and ion beam velocity is considerably lower than thermal velocity of plasma ions. Formulae establishing the relation between beam current and electron current have been derived. It follows from them that toroidal affect considerably plasma current generated with the beam and under certain conditions result in changing this current direction in an area remoted from magne-- tic axis [ru

  5. Transport and deposition of injected hydrocarbons in plasma generator PSI-2

    International Nuclear Information System (INIS)

    Bohmeyer, W.; Naujoks, D.; Markin, A.; Arkhipov, I.; Koch, B.; Schroeder, D.; Fussmann, G.

    2005-01-01

    The transport and deposition of hydrocarbons were studied in the stationary plasma of plasma generator PSI-2. CH 4 or C 2 H 4 were injected into the plasma at different positions in the target chamber. After an interaction between the plasma and the hydrocarbons, different species are produced, some of them having high sticking probabilities and forming a:CH films on a temperature controlled collector. The film growth is studied in situ for different plasma parameters. The 3D Monte Carlo code ERO including three different sets of atomic data is used to describe the formation of hydrocarbon films

  6. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    Energy Technology Data Exchange (ETDEWEB)

    Hamaguchi, Satoshi [Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-07-11

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed.

  7. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    International Nuclear Information System (INIS)

    Hamaguchi, Satoshi

    2013-01-01

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed

  8. High resolution X-ray spectroscopy of laser generated plasmas

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Skobelev, I.Yu.; Rosmej, F.B.

    1999-01-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.)

  9. High resolution X-ray spectroscopy of laser generated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo (Russian Federation); Rosmej, F.B. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

    1999-11-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.) 28 refs.

  10. In vacuum permanent magnet wiggler optimized for the production of hard x rays

    Directory of Open Access Journals (Sweden)

    O. Marcouille

    2013-05-01

    Full Text Available A new concept of wiggler has been designed and realized at SOLEIL to produce high energy photons in low/intermediate electron storage rings. Instead of using the superconducting technology which requires new equipment and instrumentation, heavy maintenance, and additional running costs, we have proposed to build a compact in-vacuum small gap short period wiggler that operates rather at moderate field than at high field. The wiggler composed of 38 periods of 50 mm produces 2.1 T at a gap of 5.5 mm. The moderate value of the magnetic field enables one to limit the effects on the beam dynamics and to avoid excessive power and magnetic forces. In this purpose, the narrow magnetic system has been equipped with a counterforce device made of nonmagnetic springs. The roll-off resulting from the small size of poles has been compensated in situ by permanent magnet magic fingers. This paper reports the phases of design, construction, magnetic measurements, and on-beam tests of the in-vacuum wiggler WSV50.

  11. Predesign Study of a 4-5 tesla Superconducting Wiggler Magnet for the ESRF

    NARCIS (Netherlands)

    ten Kate, Herman H.J.; ter Avest, D.; ter Avest, D.; Ravex, A.; Lagnier, M.; Elleaume, P.

    1994-01-01

    The ESRF is currently setting up a beam line for very hard photons well above 250 keV. This requires the installation of a high field three polewavelength shifter. The nominal and target fields of the wiggler magnet are 4 and 5 tesla respectively while the nominal field integral over the central

  12. Impact of the Wiggler Coherent Synchrotron Radiation Impedance on the Beam Instability

    International Nuclear Information System (INIS)

    Wu, Juhao

    2003-01-01

    Coherent Synchrotron Radiation (CSR) can play an important role by not only increasing the energy spread and emittance of a beam, but also leading to a potential instability. Previous studies of the CSR induced longitudinal instability were carried out for the CSR impedance due to dipole magnets. However, many storage rings include long wigglers where a large fraction of the synchrotron radiation is emitted. This includes high-luminosity factories such as DAPHNE, PEP-II, KEK-B, and CESR-C as well as the damping rings of future linear colliders. In this paper, the instability due to the CSR impedance from a wiggler is studied assuming a large wiggler parameter K. The primary consideration is a low frequency microwave-like instability, which arises near the pipe cut-off frequency. Detailed results are presented on the growth rate and threshold for the damping rings of several linear collider designs. Finally, the optimization of the relative fraction of damping due to the wiggler systems is discussed for the damping rings

  13. High-power free-electron laser amplifier using a scalloped electron beam and a two-stage wiggler

    Directory of Open Access Journals (Sweden)

    D. C. Nguyen

    2006-05-01

    Full Text Available High-power free-electron laser (FEL amplifiers present many practical design and construction problems. One such problem is possible damage to any optical beam control elements beyond the wiggler. The ability to increase the optical beam’s divergence angle after the wiggler, thereby reducing the intensity on the first optical element, is important to minimize such damage. One proposal to accomplish this optical beam spreading is to pinch the electron beam thereby focusing the radiation as well. In this paper, we analyze an approach that relies on the natural betatron motion to pinch the electron beam near the end of the wiggler. We also consider a step-tapered, two-stage wiggler to enhance the efficiency. The combination of a pinched electron beam and step-taper wiggler leads to additional optical guiding of the optical beam. This novel configuration is studied in simulation using the MEDUSA code. For a representative set of beam and wiggler parameters, we discuss (i the effect of the scalloped beam on the interaction in the FEL and on the focusing and propagation of the radiation, and (ii the efficiency enhancement in the two-stage wiggler.

  14. Dense strongly non-ideal plasma generation by laser isobaric heating

    International Nuclear Information System (INIS)

    Kulik, P.P.; Rozanov, E.K.; Riabii, V.A.; Titov, M.A.

    1975-01-01

    A method of generation of a dense strongly non-ideal plasma by slow isobaric heating of a small target in a high inert gas medium is discussed. The characteristic life-time of dense plasma is 10 -3 sec. Estimations show that such a plasma is homogeneous. Conditions are found for temperature uniformity. The experimental results of the isobaric heating of a thin potassium foil target by a ruby laser beam at 500 atm are described. (Auth.)

  15. Numerical simulation of the ion beam generated in the diode with anode plasma column

    International Nuclear Information System (INIS)

    Vrba, P.; Sunka, P.

    1991-02-01

    The ion beam generation in a high current diode with anode plasma slab was studied. The ions were extracted from the anode plasma by the strong electric field of a deep potential well (virtual cathode), arising after the propagation of relativistic electrons through the anode plasma slab. The movement of this potential well with the front part of the ion beam leads to collective ion acceleration up to the 10 MeV energy range. (author). 7 figs., 5 refs

  16. Generation of Suprathermal Electrons by Collective Processes in Collisional Plasma

    Science.gov (United States)

    Tigik, S. F.; Ziebell, L. F.; Yoon, P. H.

    2017-11-01

    The ubiquity of high-energy tails in the charged particle velocity distribution functions (VDFs) observed in space plasmas suggests the existence of an underlying process responsible for taking a fraction of the charged particle population out of thermal equilibrium and redistributing it to suprathermal velocity and energy ranges. The present Letter focuses on a new and fundamental physical explanation for the origin of suprathermal electron velocity distribution function (EVDF) in a collisional plasma. This process involves a newly discovered electrostatic bremsstrahlung (EB) emission that is effective in a plasma in which binary collisions are present. The steady-state EVDF dictated by such a process corresponds to a Maxwellian core plus a quasi-inverse power-law tail, which is a feature commonly observed in many space plasma environments. In order to demonstrate this, the system of self-consistent particle- and wave-kinetic equations are numerically solved with an initially Maxwellian EVDF and Langmuir wave spectral intensity, which is a state that does not reflect the presence of EB process, and hence not in force balance. The EB term subsequently drives the system to a new force-balanced steady state. After a long integration period it is demonstrated that the initial Langmuir fluctuation spectrum is modified, which in turn distorts the initial Maxwellian EVDF into a VDF that resembles the said core-suprathermal VDF. Such a mechanism may thus be operative at the coronal source region, which is characterized by high collisionality.

  17. Generation of uniform atmospheric pressure argon glow plasma by ...

    Indian Academy of Sciences (India)

    The electron temperature and electron density of the plasma are determined ... Dielectric barrier discharge (DBD) and APGD are the subjects of research for the last ... The gap between the electrodes can be varied from 0.5 mm to 2 mm and Ar ...

  18. A model for steady-state large-volume plasma generation

    International Nuclear Information System (INIS)

    Uhm, H.S.; Miller, J.D.; Schneider, R.F.

    1991-01-01

    In this paper, a simple, new scheme to generate a uniform, steady-state, large-volume plasma is presented. The weakly magnetized plasma is created by direct ionization of the background gas by low-energy electrons generated from thermionic filaments. An annular arrangement of the filaments ensures a uniform plasma density in the radial direction as predicted by theory. Experiments have been performed to characterize the plasma generated in such a configuration. In order to explain the experimental observation, we develop a bulk plasma theory based on plasma transport via cross-field diffusion. As assumed in the theoretical model, the experimental measurements indicate a uniform plasma density along the axis. Both the theory and experiment indicate that the plasma density is a function of the square of the external magnetic field. The theory also predicts the plasma density to be proportional to the neutral density to the two-thirds power in agreement with the experimental data. We also observe the experimental data to agree remarkably well with theoretical prediction for a broad range of system parameters

  19. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    NARCIS (Netherlands)

    Eck, van H.J.N.; Koppers, W.R.; Rooij, van G.J.; Goedheer, W.J.; Engeln, R.A.H.; Schram, D.C.; Lopes Cardozo, N.J.; Kleyn, A.W.

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial

  20. Advanced Thomson scattering system for high-flux linear plasma generator

    NARCIS (Netherlands)

    Meiden, van der H.J.; Lof, A.R.; Berg, van den M.A.; Brons, S.; Donné, A.J.H.; Eck, van H.J.N.; Koelman, Peter; Koppers, W.R.; Kruijt, O.G.; Naumenko, N.N.; Oyevaar, T.; Prins, P.R.; Rapp, J.; Scholten, J.; Schram, D.C.; Smeets, P.H.M.; Star, van der G.; Tugarinov, S.N.; Zeijlmans van Emmichoven, P.A.

    2012-01-01

    An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f /3) transmission grating

  1. Software architecture for control and data acquisition of linear plasma generator Magnum-PSI

    NARCIS (Netherlands)

    Groen, P. W. C.; van Beveren, V.; Broekema, A.; Busch, P. J.; Genuit, J. W.; Kaas, G.; Poelman, A. J.; Scholten, J.; van Emmichoven, P. A. Zeijlma

    2013-01-01

    The FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research has completed the construction phase of Magnum-PSI, a magnetized, steady-state, large area, high-flux linear plasma beam generator to study plasma surface interactions under ITER divertor conditions. Magnum-PSI consists of

  2. AC/DC/pulsed-power modulator for corona-plasma generation

    NARCIS (Netherlands)

    Ariaans, T.H.P.; Pemen, A.J.M.; Winands, G.J.J.; Heesch, van E.J.M.; Liu, Z.

    2009-01-01

    Gas-cleaning techniques using nonthermal plasma are slowly introduced into industry nowadays. In this paper, we present a novel power modulator for the efficient generation of large-volume corona plasma. No expensive high-voltage components are required. Switching is done at an intermediate voltage

  3. Generation of electromagnetic pulses from plasma channels induced by femtosecond light strings

    OpenAIRE

    Cheng, Chung-Chieh; Wright, E. M.; Moloney, J. V.

    2000-01-01

    We present a model that elucidates the physics underlying the generation of an electromagnetic pulse from a femtosecond laser induced plasma channel. The radiation pressure force from the laser pulse spatially separates the ionized electrons from the heavier ions and the induced dipole moment subsequently oscillates at the plasma frequency and radiates an electromagnetic pulse.

  4. Influence of the RF electrode cleanliness on plasma characteristics and dust-particle generation in methane dusty plasmas

    Science.gov (United States)

    Géraud-Grenier, I.; Desdions, W.; Faubert, F.; Mikikian, M.; Massereau-Guilbaud, V.

    2018-01-01

    The methane decomposition in a planar RF discharge (13.56 MHz) leads both to a dust-particle generation in the plasma bulk and to a coating growth on the electrodes. Growing dust-particles fall onto the grounded electrode when they are too heavy. Thus, at the end of the experiment, the grounded electrode is covered by a coating and by fallen dust-particles. During the dust-particle growth, the negative DC self-bias voltage (VDC) increases because fewer electrons reach the RF electrode, leading to a more resistive plasma and to changes in the plasma chemical composition. In this paper, the cleanliness influence of the RF electrode on the dust-particle growth, on the plasma characteristics and composition is investigated. A cleanliness electrode is an electrode without coating and dust-particles on its surface at the beginning of the experiment.

  5. Beam-plasma generators of stochastic microwave oscillations using for plasma heating in fusion and plasma-chemistry devices and ionospheric investigations

    Energy Technology Data Exchange (ETDEWEB)

    Mitin, L A; Perevodchikov, V I; Shapiro, A L; Zavyalov, M A [All-Russian Electrotechnical Inst., Moscow (Russian Federation); Bliokh, Yu P; Fajnberg, Ya B [Kharkov Inst. of Physics and Technology (Russian Federation)

    1997-12-31

    The results of theoretical and experimental investigations of a generator of stochastic microwave power based on a beam-plasma inertial feedback amplifier is discussed with a view to using stochastic oscillations for plasma heating. The plasma heating efficiency in the region of low-frequency resonance in the geometry of the Tokamak is considered theoretically. It is shown that the temperature of heating is proportional to the power multiplied by the spectra width of the noiselike signal. The creation and heating of plasma by stochastic microwave power in an oversized waveguide without external magnetic field is discussed with a view to plasma-chemistry applications. It is shown that the efficiency of heating are defined by the time of phase instability of the stochastic power. (author). 3 figs., 13 refs.

  6. PLASMA-WAVE GENERATION IN A DYNAMIC SPACETIME

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huan [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L2Y5 (Canada); Zhang, Fan [Gravitational Wave and Cosmology Laboratory, Department of Astronomy, Beijing Normal University, Beijing 100875 (China)

    2016-02-01

    We propose a new electromagnetic (EM)-emission mechanism in magnetized, force-free plasma, which is driven by the evolution of the underlying dynamic spacetime. In particular, the emission power and angular distribution of the emitted fast-magnetosonic and Alfvén waves are separately determined. Previous numerical simulations of binary black hole mergers occurring within magnetized plasma have recorded copious amounts of EM radiation that, in addition to collimated jets, include an unexplained, isotropic component that becomes dominant close to the merger. This raises the possibility of multimessenger gravitational-wave and EM observations on binary black hole systems. The mechanism proposed here provides a candidate analytical characterization of the numerical results, and when combined with previously understood mechanisms such as the Blandford–Znajek process and kinetic-motion-driven radiation, it allows us to construct a classification of different EM radiation components seen in the inspiral stage of compact-binary coalescences.

  7. Thomson parabola spectrometry for gold laser generated plasmas

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Cutroneo, M.; Andó, L.; Ullschmied, Jiří

    2013-01-01

    Roč. 20, č. 2 (2013), 023106-023106 ISSN 1070-664X R&D Projects: GA MŠk LM2010014 Institutional research plan: CEZ:AV0Z20430508 Keywords : acceleration * ions * Thomson parabola spectrometry * PALS laser * laser targets * gold ions Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.249, year: 2013 http://pop.aip.org/resource/1/phpaen/v20/i2/p023106_s1

  8. High magnetic field generation for laser-plasma experiments

    International Nuclear Information System (INIS)

    Pollock, B. B.; Froula, D. H.; Davis, P. F.; Ross, J. S.; Fulkerson, S.; Bower, J.; Satariano, J.; Price, D.; Krushelnick, K.; Glenzer, S. H.

    2006-01-01

    An electromagnetic solenoid was developed to study the effect of magnetic fields on electron thermal transport in laser plasmas. The solenoid, which is driven by a pulsed power system supplying 30 kJ, achieves magnetic fields of 13 T. The field strength was measured on the solenoid axis with a magnetic probe and optical Zeeman splitting. The measurements agree well with analytical estimates. A method for optimizing the solenoid design to achieve magnetic fields exceeding 20 T is presented

  9. Plasma jet generation by flyer disk collision with massive target

    Czech Academy of Sciences Publication Activity Database

    Kasperczuk, A.; Pisarczyk, T.; Borodziuk, S.; Gus'kov, S. Yu.; Ullschmied, Jiří; Krouský, Eduard; Mašek, Karel; Pfeifer, Miroslav; Rohlena, Karel; Skála, Jiří; Kálal, M.; Pisarczyk, P.

    2007-01-01

    Roč. 37, č. 1 (2007), s. 1-10 ISSN 0078-5466 R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508; CEZ:AV0Z10100523 Keywords : Plasma jets * flyer targets * laser targets * laser ablation * shock waves * craters * PALS facility Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.284, year: 2007

  10. Magnetic filter apparatus and method for generating cold plasma in semicoductor processing

    Science.gov (United States)

    Vella, Michael C.

    1996-01-01

    Disclosed herein is a system and method for providing a plasma flood having a low electron temperature to a semiconductor target region during an ion implantation process. The plasma generator providing the plasma is coupled to a magnetic filter which allows ions and low energy electrons to pass therethrough while retaining captive the primary or high energy electrons. The ions and low energy electrons form a "cold plasma" which is diffused in the region of the process surface while the ion implantation process takes place.

  11. Magnetic filter apparatus and method for generating cold plasma in semiconductor processing

    Science.gov (United States)

    Vella, M.C.

    1996-08-13

    Disclosed herein is a system and method for providing a plasma flood having a low electron temperature to a semiconductor target region during an ion implantation process. The plasma generator providing the plasma is coupled to a magnetic filter which allows ions and low energy electrons to pass therethrough while retaining captive the primary or high energy electrons. The ions and low energy electrons form a ``cold plasma`` which is diffused in the region of the process surface while the ion implantation process takes place. 15 figs.

  12. Mapping return currents in laser-generated Z-pinch plasmas using proton deflectometry

    International Nuclear Information System (INIS)

    Manuel, M. J.-E.; Sinenian, N.; Seguin, F. H.; Li, C. K.; Frenje, J. A.; Rinderknecht, H. G.; Casey, D. T.; Zylstra, A. B.; Petrasso, R. D.; Beg, F. N.

    2012-01-01

    Dynamic return currents and electromagnetic field structure in laser-generated Z-pinch plasmas have been measured using proton deflectometry. Experiments were modeled to accurately interpret deflections observed in proton radiographs. Current flow is shown to begin on axis and migrate outwards with the expanding coronal plasma. Magnetic field strengths of ∼1 T are generated by currents that increase from ∼2 kA to ∼7 kA over the course of the laser pulse. Proton deflectometry has been demonstrated to be a practical alternative to other magnetic field diagnostics for these types of plasmas.

  13. Method and apparatus for generating and utilizing a compound plasma configuration

    International Nuclear Information System (INIS)

    Koloc, P.M.

    1977-01-01

    A method and apparatus for generating and utilizing a compound plasma configuration is disclosed. The plasma configuration includes a central toroidal plasma with electrical currents surrounded by a generally ellipsoidal mantle of ionized particles or electrically conducting matter. The preferred methods of forming this compound plasma configuration include the steps of forming a helical ionized path in a gaseous medium and simultaneously discharging a high potential through the ionized path to produce a helical or heliform current which collapses on itself to produce a toroidal current, or generating a toroidal plasmoid, supplying magnetic energy to the plasmoid, and applying fluid pressure external to the plasmoid. The apparatus of the present invention includes a pressure chamber wherein the compound plasma configuration can be isolated or compressed by fluid or other forms of mechanical or magnetic pressure. 47 claims, 10 figures

  14. Quantitative detection of plasma-generated radicals in liquids by electron paramagnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Tresp, H; Hammer, M U; Winter, J; Reuter, S; Weltmann, K-D

    2013-01-01

    In this paper the qualitative and quantitative detection of oxygen radicals in liquids after plasma treatment with an atmospheric pressure argon plasma jet by electron paramagnetic resonance spectroscopy is investigated. Absolute values for · OH and O 2 ·- radical concentration and their net production rate in plasma-treated liquids are determined without the use of additional scavenging chemicals such as superoxide dismutase (SOD) or mannitol (D-MAN). The main oxygen-centred radical generation in PBS was found to originate from the superoxide radical. It is shown that hidden parameters such as the manufacturer of chemical components could have a big influence on the comparability and reproducibility of the results. Finally, the effect of a shielding gas device for the investigated plasma jet with a shielding gas composition of varying oxygen-to-nitrogen ratio on radical generation after plasma treatment of phosphate-buffered saline solution was investigated. (paper)

  15. Method of generating magnetoactive plasma for forming thin surface layers on solid substrates and equipment therefor

    International Nuclear Information System (INIS)

    Bardos, L.; Loncar, G.; Musil, J.; Zacek, F.

    1979-01-01

    The invention essentially consists in the use of the axially symmetrical high-frequency magnetized plasma column for thin layer formation. The plasma is generated using a cylindrical microwave slow-down structure in the outer magnetic field. Plasma particles density and temperature and their radial distribution are adjusted by changing the intensity of the magnetic field and of high-frequency power. The plasma may be generated from any gases in a pressure range of 10 -3 to 10 2 Pa. In an oxygen plasma, e.g., it is thus possible to form layers of 200 nm in thickness in 60 mins at an input high-frequency power of 100 to 300 W. (J.U.)

  16. Short-range wakefields generated in the blowout regime of plasma-wakefield acceleration

    Science.gov (United States)

    Stupakov, G.

    2018-04-01

    In the past, calculation of wakefields generated by an electron bunch propagating in a plasma has been carried out in linear approximation, where the plasma perturbation can be assumed small and plasma equations of motion linearized. This approximation breaks down in the blowout regime where a high-density electron driver expels plasma electrons from its path and creates a cavity void of electrons in its wake. In this paper, we develop a technique that allows us to calculate short-range longitudinal and transverse wakes generated by a witness bunch being accelerated inside the cavity. Our results can be used for studies of the beam loading and the hosing instability of the witness bunch in plasma-wakefield and laser-wakefield acceleration.

  17. Operational characteristics of the high flux plasma generator Magnum-PSI

    Energy Technology Data Exchange (ETDEWEB)

    Eck, H.J.N. van, E-mail: h.j.n.vaneck@differ.nl [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Abrams, T. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Berg, M.A. van den; Brons, S.; Eden, G.G. van [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Jaworski, M.A.; Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Meiden, H.J. van der; Morgan, T.W.; Pol, M.J. van de; Scholten, J.; Smeets, P.H.M.; De Temmerman, G.; Vries, P.C. de; Zeijlmans van Emmichoven, P.A. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2014-10-15

    Highlights: •We have described the design and capabilities of the plasma experiment Magnum-PSI. •The plasma conditions are well suited for PSI studies in support of ITER. •Quasi steady state heat fluxes over 10 MW m{sup −2} have been achieved. •Transient heat and particle loads can be generated to simulate ELM instabilities. •Lithium coating can be applied to the surfaces of samples under vacuum. -- Abstract: In Magnum-PSI (MAgnetized plasma Generator and NUMerical modeling for Plasma Surface Interactions), the high density, low temperature plasma of a wall stabilized dc cascaded arc is confined to a magnetized plasma beam by a quasi-steady state axial magnetic field up to 1.3 T. It aims at conditions that enable fundamental studies of plasma–surface interactions in the regime relevant for fusion reactors such as ITER: 10{sup 23}–10{sup 25} m{sup −2} s{sup −1} hydrogen plasma flux densities at 1–5 eV. To study the effects of transient heat loads on a plasma-facing surface, a high power pulsed magnetized arc discharge has been developed. Additionally, the target surface can be transiently heated with a pulsed laser system during plasma exposure. In this contribution, the current status, capabilities and performance of Magnum-PSI are presented.

  18. MAGNUM-PSI, a plasma generator for plasma-surface interaction research in ITER-like conditions

    International Nuclear Information System (INIS)

    Goedheer, W.J.; Rooij, G.J. van; Veremiyenko, V.; Ahmad, Z.; Barth, C.J.; Eck, H.J.N. van; Groot, B. de; Hellermann, M.G. von; Kruijtzer, G.L.; Wolff, J.C.; Brezinsek, S.; Philipps, V.; Pospieszczyk, A.; Samm, U.; Schweer, B.; Dahiya, R.P.; Engeln, R.A.H.; Schram, D.C.; Fantz, U.; Kleyn, A.W.; Lopes Cardozo, N.J.

    2005-01-01

    The FOM-Institute for Plasma Physics - together with its TEC partners - is preparing the construction of Magnum-psi, a magnetized (3 T), steady-state, large area (100 cm 2 ), high-flux (up to 10 24 H + ions m -2 s -1 ) plasma generator. The research programme of Magnum-psi will address the questions for the ITER divertor: erosion, redeposition and hydrogen retention with carbon substrates, melting of metal surfaces, erosion and redeposition with mixed materials. In order to explore and develop the techniques to be applied in Magnum-psi, a pilot experiment (Pilot-psi), operating at a magnetic field up to 1.6 Tesla, has been constructed. Pilot-psi produces a hydrogen plasma beam with the required parameters (T e ≤ 1eV and flux ≥ 10 23 m -2 s -1 ) over an area of 1 cm 2 . In this paper the results of extensive diagnostic measurements on Pilot-psi (a.o., Thomson Scattering and high-resolution spectroscopy), combined with numerical studies of the source and the expansion of the plasma will be presented to demonstrate the feasibility of the large Magnum-psi plasma generator. (author)

  19. Multi-probe ionization chamber system for nuclear-generated plasma diagnostics

    International Nuclear Information System (INIS)

    Choi, W.Y.; Ellis, W.H.

    1990-01-01

    This paper reports on the pulsed ionization chamber (PIC) plasma diagnostic system used in studies of nuclear seeded plasma kinetics upgraded to increase the capabilities and extend the range of plasma parameter measurements to higher densities and temperatures. The PIC plasma diagnostic chamber has been provided with additional measurement features in the form of conductivity and Langmuir probes, while the overall experimental system has been fully automated, with computerized control, measurement, data acquisition and analysis by means of IEEE-488 (GPIB) bus control and data transfer protocols using a Macintosh series microcomputer. The design and use of a simple TTL switching system enables remote switching among the various GPIB instruments comprising the multi-probe plasma diagnostic system using software, without the need for a microprocessor. The new system will be used to extend the present study of nuclear generated plasma in He, Ar, Xe, fissionable UF 6 and other fluorine containing gases

  20. Helium generated cold plasma finely regulates activation of human fibroblast-like primary cells.

    Directory of Open Access Journals (Sweden)

    Paola Brun

    Full Text Available Non-thermal atmospheric pressure plasmas are being developed for a wide range of health care applications, including wound healing. However in order to exploit the potential of plasma for clinical applications, the understanding of the mechanisms involved in plasma-induced activation of fibroblasts, the cells active in the healing process, is mandatory. In this study, the role of helium generated plasma in the tissue repairing process was investigated in cultured human fibroblast-like primary cells, and specifically in hepatic stellate cells and intestinal subepithelial myofibroblasts. Five minutes after treatment, plasma induced formation of reactive oxygen species (ROS in cultured cells, as assessed by flow cytometric analysis of fluorescence-activated 2',7'-dichlorofluorescein diacetate probe. Plasma-induced intracellular ROS were characterized by lower concentrations and shorter half-lives with respect to hydrogen peroxide-induced ROS. Moreover ROS generated by plasma treatment increased the expression of peroxisome proliferator activated receptor (PPAR-γ, nuclear receptor that modulates the inflammatory responses. Plasma exposure promoted wound healing in an in vitro model and induced fibroblast migration and proliferation, as demonstrated, respectively, by trans-well assay and partitioning between daughter cells of carboxyfluorescein diacetate succinimidyl ester fluorescent dye. Plasma-induced fibroblast migration and proliferation were found to be ROS-dependent as cellular incubation with antioxidant agents (e.g. N-acetyl L-cysteine cancelled the biological effects. This study provides evidence that helium generated plasma promotes proliferation and migration in liver and intestinal fibroblast-like primary cells mainly by increasing intracellular ROS levels. Since plasma-evoked ROS are time-restricted and elicit the PPAR-γ anti-inflammatory molecular pathway, this strategy ensures precise regulation of human fibroblast activation and

  1. State-space modeling of the radio frequency inductively-coupled plasma generator

    International Nuclear Information System (INIS)

    Dewangan, Rakesh Kumar; Punjabi, Sangeeta B; Mangalvedekar, H A; Lande, B K; Joshi, N K; Barve, D N

    2010-01-01

    Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

  2. Neutron Generation by Laser-Driven Spherically Convergent Plasma Fusion

    Science.gov (United States)

    Ren, G.; Yan, J.; Liu, J.; Lan, K.; Chen, Y. H.; Huo, W. Y.; Fan, Z.; Zhang, X.; Zheng, J.; Chen, Z.; Jiang, W.; Chen, L.; Tang, Q.; Yuan, Z.; Wang, F.; Jiang, S.; Ding, Y.; Zhang, W.; He, X. T.

    2017-04-01

    We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 1 014- 1 015 W /cm2 intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Yn to be related to the laser energy EL, the hohlraum radius Rh, and the pulse duration τ through a scaling law of Yn∝(EL/Rh1.2τ0.2 )2.5. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.

  3. Collimated fast electron beam generation in critical density plasma

    Energy Technology Data Exchange (ETDEWEB)

    Iwawaki, T., E-mail: iwawaki-t@eie.eng.osaka-u.ac.jp; Habara, H.; Morita, K.; Tanaka, K. A. [Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871 (Japan); Baton, S.; Fuchs, J.; Chen, S. [LULI, CNRS-Ecole Polytechnique-Université Pierre et Marie Curie-CEA, 91128 Palaiseau (France); Nakatsutsumi, M. [LULI, CNRS-Ecole Polytechnique-Université Pierre et Marie Curie-CEA, 91128 Palaiseau (France); European X-Ray Free-Electron Laser Facility (XFEL) GmbH (Germany); Rousseaux, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Filippi, F. [La SAPIENZA, University of Rome, Dip. SBAI, 00161 Rome (Italy); Nazarov, W. [School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, Scotland (United Kingdom)

    2014-11-15

    Significantly collimated fast electron beam with a divergence angle 10° (FWHM) is observed when an ultra-intense laser pulse (I = 10{sup 14 }W/cm{sup 2}, 300 fs) irradiates a uniform critical density plasma. The uniform plasma is created through the ionization of an ultra-low density (5 mg/c.c.) plastic foam by X-ray burst from the interaction of intense laser (I = 10{sup 14 }W/cm{sup 2}, 600 ps) with a thin Cu foil. 2D Particle-In-Cell (PIC) simulation well reproduces the collimated electron beam with a strong magnetic field in the region of the laser pulse propagation. To understand the physical mechanism of the collimation, we calculate energetic electron motion in the magnetic field obtained from the 2D PIC simulation. As the results, the strong magnetic field (300 MG) collimates electrons with energy over a few MeV. This collimation mechanism may attract attention in many applications such as electron acceleration, electron microscope and fast ignition of laser fusion.

  4. Megawatt low-temperature DC plasma generator with divergent channels of gas-discharge tract

    Science.gov (United States)

    Gadzhiev, M. Kh.; Isakaev, E. Kh.; Tyuftyaev, A. S.; Yusupov, D. I.; Sargsyan, M. A.

    2017-04-01

    We have developed and studied a new effective megawatt double-unit generator of low-temperature argon plasma, which belongs to the class of dc plasmatrons and comprises the cathode and anode units with divergent gas-discharge channels. The generator has an efficiency of about 80-85% and ensures a long working life at operating currents up to 4000 A.

  5. On the equivalence of convergent kinetic equations for hot dilute plasmas: Generating functions for collision brackets

    NARCIS (Netherlands)

    Cohen, J.S.; Suttorp, L.G.

    1982-01-01

    The generating functions for the collision brackets associated with two alternative convergent kinetic equations are derived for small values of the plasma parameter. It is shown that the first few terms in the asymptotic expansions of these generating functions are identical. Consequently, both

  6. Resistive wall tearing mode generated finite net electromagnetic torque in a static plasma

    International Nuclear Information System (INIS)

    Hao, G. Z.; Wang, A. K.; Xu, M.; Qu, H. P.; Peng, X. D.; Wang, Z. H.; Xu, J. Q.; Qiu, X. M.; Liu, Y. Q.

    2014-01-01

    The MARS-F code [Y. Q. Liu et al., Phys. Plasmas 7, 3681 (2000)] is applied to numerically investigate the effect of the plasma pressure on the tearing mode stability as well as the tearing mode-induced electromagnetic torque, in the presence of a resistive wall. The tearing mode with a complex eigenvalue, resulted from the favorable averaged curvature effect [A. H. Glasser et al., Phys. Fluids 18, 875 (1975)], leads to a re-distribution of the electromagnetic torque with multiple peaking in the immediate vicinity of the resistive layer. The multiple peaking is often caused by the sound wave resonances. In the presence of a resistive wall surrounding the plasma, a rotating tearing mode can generate a finite net electromagnetic torque acting on the static plasma column. Meanwhile, an equal but opposite torque is generated in the resistive wall, thus conserving the total momentum of the whole plasma-wall system. The direction of the net torque on the plasma is always opposite to the real frequency of the mode, agreeing with the analytic result by Pustovitov [Nucl. Fusion 47, 1583 (2007)]. When the wall time is close to the oscillating time of the tearing mode, the finite net torque reaches its maximum. Without wall or with an ideal wall, no net torque on the static plasma is generated by the tearing mode. However, re-distribution of the torque density in the resistive layer still occurs

  7. 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

  8. Fast camera studies at an electron cyclotron resonance table plasma generator

    International Nuclear Information System (INIS)

    Rácz, R.; Biri, S.; Hajdu, P.; Pálinkás, J.

    2014-01-01

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the “big” ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper

  9. Fast camera studies at an electron cyclotron resonance table plasma generator.

    Science.gov (United States)

    Rácz, R; Biri, S; Hajdu, P; Pálinkás, J

    2014-02-01

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the "big" ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

  10. Fast camera studies at an electron cyclotron resonance table plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Rácz, R., E-mail: rracz@atomki.hu [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen, Bem tér 18/c (Hungary); Department of Experimental Physics, University of Debrecen, H-4032 Debrecen, Egyetem tér 1 (Hungary); Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen, Bem tér 18/c (Hungary); Hajdu, P.; Pálinkás, J. [Department of Experimental Physics, University of Debrecen, H-4032 Debrecen, Egyetem tér 1 (Hungary)

    2014-02-15

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the “big” ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

  11. Self-consistent modeling of radio-frequency plasma generation in stellarators

    Energy Technology Data Exchange (ETDEWEB)

    Moiseenko, V. E., E-mail: moiseenk@ipp.kharkov.ua; Stadnik, Yu. S., E-mail: stadnikys@kipt.kharkov.ua [National Academy of Sciences of Ukraine, National Science Center Kharkov Institute of Physics and Technology (Ukraine); Lysoivan, A. I., E-mail: a.lyssoivan@fz-juelich.de [Royal Military Academy, EURATOM-Belgian State Association, Laboratory for Plasma Physics (Belgium); Korovin, V. B. [National Academy of Sciences of Ukraine, National Science Center Kharkov Institute of Physics and Technology (Ukraine)

    2013-11-15

    A self-consistent model of radio-frequency (RF) plasma generation in stellarators in the ion cyclotron frequency range is described. The model includes equations for the particle and energy balance and boundary conditions for Maxwell’s equations. The equation of charged particle balance takes into account the influx of particles due to ionization and their loss via diffusion and convection. The equation of electron energy balance takes into account the RF heating power source, as well as energy losses due to the excitation and electron-impact ionization of gas atoms, energy exchange via Coulomb collisions, and plasma heat conduction. The deposited RF power is calculated by solving the boundary problem for Maxwell’s equations. When describing the dissipation of the energy of the RF field, collisional absorption and Landau damping are taken into account. At each time step, Maxwell’s equations are solved for the current profiles of the plasma density and plasma temperature. The calculations are performed for a cylindrical plasma. The plasma is assumed to be axisymmetric and homogeneous along the plasma column. The system of balance equations is solved using the Crank-Nicholson scheme. Maxwell’s equations are solved in a one-dimensional approximation by using the Fourier transformation along the azimuthal and longitudinal coordinates. Results of simulations of RF plasma generation in the Uragan-2M stellarator by using a frame antenna operating at frequencies lower than the ion cyclotron frequency are presented. The calculations show that the slow wave generated by the antenna is efficiently absorbed at the periphery of the plasma column, due to which only a small fraction of the input power reaches the confinement region. As a result, the temperature on the axis of the plasma column remains low, whereas at the periphery it is substantially higher. This leads to strong absorption of the RF field at the periphery via the Landau mechanism.

  12. Stimulated Brillouin backscattering and magnetic field generation in laser-produced plasmas

    International Nuclear Information System (INIS)

    Bawa'aneh, M.S.

    1999-01-01

    This thesis is concerned with aspects of laser-plasma interactions related to fusion reactions; in particular thermoelectric magnetic field generation around a hole dug in plasma by intense laser beams, and stimulated Brillouin back scattering (SBBS) from plasmas containing hot spots. A hole, of the size of the laser focal spot, is dug in the plasma when illuminated by intense laser if the laser pressure exceeds the plasma thermal pressure. This hole is found to have steep, radial density gradients. My first concern arose from the prediction that magnetic fields might be generated around the hole-plasma interface in places where the steep density gradients overlap with the non-aligned temperature gradients. When a high-power laser beam is focused on a solid pellet, plasma is formed at the surface. In order to create conditions for thermonuclear reactions in the interior of the pellet, an effective deposition of the laser energy to thermal energy of the pellet via laser-plasma coupling is necessary. When light irradiates a plasma collective processes occur, which can either enhance or reduce the light absorption. For a better understanding of the fusion problem a knowledge of the nature of these collective processes and of the fraction of light reflected from the plasma modes is required. Local hot spots seen experimentally lead to higher gain levels of scattered light. These local temperature inhomogeneities could lead to non-equilibrium distributions, which result in a free energy leading to some interesting phenomena in plasma. In the second part of the thesis stimulated Brillouin back scattering from an ion acoustic mode in a hot spot is studied. Temperature inhomogeneities lead to an ion acoustic instability, and to higher levels of SBBS gain, which leads to lower thresholds for the same electron to ion temperature ratios. This could be the answer for the observed high levels of scattering from hot spots. (author)

  13. Conducting grids to stabilize MHD generator plasmas against ionization instabilities

    International Nuclear Information System (INIS)

    Veefkind, A.

    1972-09-01

    Ionization instabilities in MHD generators may be suppressed by the use of grids that short circuit the AC electric field component corresponding to the direction of maximum growth. An analysis of the influence of the corresponding boundary conditions has been performed in order to obtain more quantitative information about the stabilizing effect of this system

  14. Simulations of the effects of a superconducting damping wiggler on a short bunched electron beam at ANKA

    Energy Technology Data Exchange (ETDEWEB)

    Gethmann, Julian; Bernhard, Axel; Blomley, Edmund; Hillenbrand, Steffen; Mueller, Anke-Susanne; Smale, Nigel [Karlsruher Institut fuer Technologie (KIT) (Germany); Zolotarev, Konstantin [Budker Institute of Nuclear Physics (Russian Federation)

    2016-07-01

    (As a part of the CLIC collaboration) A CLIC damping wiggler prototype has been installed at the ANKA synchrotron light source in order to validate the technical design of the 3 T superconducting conduction cooled wiggler and its cryostat and to cary out studies on beam dynamical aspects including collective effects. The latter one will be the main focus in this talk. Collective effects that will occur in damping rings are an issue in ANKA's short bunch operation as well. To simulate these effects the accelerator's model including its insertion device has to be very accurate. Such a model of the ANKA storage ring in short bunch operation mode has been developed in elegant. Simulations with the damping wiggler switched on and off have been performed in order to investigate effects of the wiggler on different machine parameters. These new results will be discussed with regard to the question if on the one hand the wiggler could be used for diagnostic purposes and if on the other hand the wiggler's impact on the beam dynamics is changed by the collective effects.

  15. Effects of external magnetic field on harmonics generated in laser interaction with underdense plasma

    International Nuclear Information System (INIS)

    Faghihi-Nik, M.; Ghorbanalilu, M.; Shokri, B.

    2010-01-01

    Complete text of publication follows. Generation of harmonic radiation is an important subject of laser plasma interaction and attracts great attention due to a wide range of applications. It has been seen that intense electromagnetic and quasi-static transverse magnetic fields are generated in laser plasma interaction. An extremely intense magnetic field (up to hundreds of MG) has been observed by experimental measurements in interaction of short laser pulses with plasma. These self-generated or applied magnetic fields affect the propagation of the laser pulses. In most laser interactions with homogeneous plasma, odd harmonics of laser frequency are generated. In this paper, we point out the possibility of even harmonics generation when a linearly polarized laser beam propagates in homogeneous plasma in the presence of a transverse magnetic field. It is shown that applying external field induces a transverse current density oscillating twice of the laser field which leds to generation of second harmonic radiation. This current density is derived using the perturbation method, and the steady state amplitude of the second harmonic obtained by solution of the wave equation. By the same procedure the current density and then the steady state amplitude of higher order harmonics are calculated. The efficiency of harmonic generation (the ratio of harmonic power to incident power) is a drastically function of the strength of external magnetic field. It is found that the efficiency of even harmonics is zero in the absence of magnetic field and increases as the magnetic field is increased. For odd harmonics, applying the external magnetic field enhances the generated harmonics as well. The conversion efficiency also increases with increase in plasma density and intensity of the laser beam.

  16. High kinetic energy plasma jet generation and its injection into the Globus-M spherical tokamak

    International Nuclear Information System (INIS)

    Voronin, A.V.; Gusev, V.K.; Petrov, Yu.V.; Sakharov, N.V.; Abramova, K.B.; Sklyarova, E.M.; Tolstyakov, S.Yu.

    2005-01-01

    Progress in the theoretical and experimental development of the plasma jet source and injection of hydrogen plasma and neutral gas jets into the Globus-M spherical tokamak is discussed. An experimental test bed is described for investigation of intense plasma jets that are generated by a double-stage plasma gun consisting of an intense source for neutral gas production and a conventional pulsed coaxial accelerator. A procedure for optimizing the accelerator parameters so as to achieve the maximum possible flow velocity with a limited discharge current and a reasonable length of the coaxial electrodes is presented. The calculations are compared with experiment. Plasma jet parameters, among them pressure distribution across the jet, flow velocity, plasma density, etc, were measured. Plasma jets with densities of up to 10 22 m -3 , total numbers of accelerated particles (1-5) x 10 19 , and flow velocities of 50-100 km s -1 were successfully injected into the plasma column of the Globus-M tokamak. Interferometric and Thomson scattering measurements confirmed deep jet penetration and a fast density rise ( 19 to 1 x 10 19 ) did not result in plasma degradation

  17. A differentially pumped argon plasma in the linear plasma generator Magnum-PSI: gas flow and dynamics of the ionized fraction

    NARCIS (Netherlands)

    van Eck, H.J.N.; Hansen, T.A.R.; Kleyn, A.W.; van der Meiden, H.J.; Schram, D.C.; Zeijlmans van Emmichoven, P.A.

    2011-01-01

    Magnum-PSI is a linear plasma generator designed to reach the plasma-surface interaction (PSI) regime of ITER and nuclear fusion reactors beyond ITER. To reach this regime, the influx of cold neutrals from the source must be significantly lower than the plasma flux reaching the target. This is

  18. The Beam Line X NdFe-steel hybrid wiggler for SSRL

    International Nuclear Information System (INIS)

    Hoyer, E.; Halbach, K.; Humphries, D.; Marks, S.; Plate, D.; Shuman, D.; Karpenko, V.P.; Kulkarni, S.; Tirsell, K.G.

    1987-01-01

    A wiggler magnet with 15 periods, each 12.85 cm long, which achieves 1.40 T at a 2.1 cm gap (2.26T at 0.8 cm) has been designed and is now in fabrication at LBL. This wiggler will be the radiation source of the high intensity synchrotron radiation beam line for the Beam Line X PRT facility at SSRL. The magnet utilizes Neodymium-Iron (NdFe) material and Vanadium Permendur (steel) in the hybrid configuration to achieve simultaneously a high magnetic field and short period. Magnetic field adjustment is with a driven chain and ball screw drive system. The magnetic structure is external to an s.s. vacuum chamber which has thin walls, 0.76 mm thickness, at each pole tip for higher field operation. Magnetic design, construction details and magnetic measurements are presented

  19. Particle-in-Cell Calculations of the Electron Cloud in the ILC Positron Damping Ring Wigglers

    International Nuclear Information System (INIS)

    Celata, C.M.; Furman, M.A.; Vay, J.-L.; Grote, D.P.

    2007-01-01

    The self-consistent code suite WARP-POSINST is being used to study electron cloud effects in the ILC positron damping ring wiggler. WARP is a parallelized, 3D particle-in-cell code which is fully self-consistent for all species. The POSINST models for the production of photoelectrons and secondary electrons are used to calculate electron creation. Mesh refinement and a moving reference frame for the calculation will be used to reduce the computer time needed by several orders of magnitude. We present preliminary results for cloud buildup showing 3D electron effects at the nulls of the vertical wiggler field. First results from a benchmark of WARP-POSINST vs. POSINST are also discussed

  20. Experimental investigation of the hot point generation in the Z pinch plasma

    International Nuclear Information System (INIS)

    Afonin, V.I.; Podgornov, V.A.; Litvin, D.N.; Senik, A.V.

    1999-01-01

    Experiments to explode thin composite (W-Al-W, W-SiO 2 -W) wires in SIGNAL fast high-current generator diode under about 200 kA load current amplitude and about 50 ns rise duration were carried out to study the possibility to control generation of hot point in Z pinch plasma. The parameters of generated hot points were studied using X-ray techniques. Analysis of the experiment results shows the possibility to control this process [ru

  1. Generation and sustainment of plasma rotation by ICRF heating

    International Nuclear Information System (INIS)

    Perkins, F.W.; White, R.; Bonoli, P.T.; Chan, V.S.

    2001-01-01

    A mechanism is proposed and evaluated for driving rotation in tokamak plasmas by minority ion-cyclotron heating, even though this process introduces negligible angular momentum. The mechanism has two elements: First, angular momentum transport is governed by a diffusion equation with a non-slip boundary condition at the separatrix. Second, Monte-Carlo calculations show that energized particles will provide a torque density source which has a zero volume integral but separated positive and negative regions. With such a source, a solution of the diffusion equation predicts the on-axis rotation frequency Ω to be Ω=(4q max WJ*)eBR 3 a 2 n e (2π) 2 ) -1 (τ M /τ E ) where vertical bar J* vertical bar ∼ 5-10 is a non-dimensional rotation frequency calculated by the Monte-Carlo ORBIT code. Overall, agreement with experiment is good, when the resonance is on the low-field-side of the magnetic axis. The rotation becomes more counter-current and reverses sign on the high field side for a no-slip boundary. The velocity shear layer position is controllable and of sufficient magnitude to affect microinstabilities. (author)

  2. Exogenous nitric oxide (NO) generated by NO-plasma treatment modulates osteoprogenitor cells early differentiation

    International Nuclear Information System (INIS)

    Elsaadany, Mostafa; Subramanian, Gayathri; Ayan, Halim; Yildirim-Ayan, Eda

    2015-01-01

    In this study, we investigated whether nitric oxide (NO) generated using a non-thermal plasma system can mediate osteoblastic differentiation of osteoprogenitor cells without creating toxicity. Our objective was to create an NO delivery mechanism using NO-dielectric barrier discharge (DBD) plasma that can generate and transport NO with controlled concentration to the area of interest to regulate osteoprogenitor cell activity. We built a non-thermal atmospheric pressure DBD plasma nozzle system based on our previously published design and similar designs in the literature. The electrical and spectral analyses demonstrated that N 2 dissociated into NO under typical DBD voltage–current characteristics. We treated osteoprogenitor cells (MC3T3-E1) using NO-plasma treatment system. Our results demonstrated that we could control NO concentration within cell culture media and could introduce NO into the intracellular space using NO-plasma treatment with various treatment times. We confirmed that NO-plasma treatment maintained cell viability and did not create any toxicity even with prolonged treatment durations. Finally, we demonstrated that NO-plasma treatment induced early osteogenic differentiation in the absence of pro-osteogenic growth factors/proteins. These findings suggest that through the NO-plasma treatment system we are able to generate and transport tissue-specific amounts of NO to an area of interest to mediate osteoprogenitor cell activity without subsequent toxicity. This opens up the possibility to develop DBD plasma-assisted tissue-specific NO delivery strategies for therapeutic intervention in the prevention and treatment of bone diseases. (paper)

  3. Time domain phenomena of wave propagation in rapidly created plasma of periodic distribution

    International Nuclear Information System (INIS)

    Kuo, S P

    2007-01-01

    Theories, experiments and numerical simulations on the interaction of electromagnetic waves with rapidly created unmagnetized plasmas are presented. In the case that plasma is created uniformly, the frequency of a propagating electromagnetic wave is upshifted. An opposite propagation wave of the same frequency is also generated. In addition, a static current supporting a wiggler magnetic field is also produced in the plasma. When a spatially periodic structure is introduced to the rapidly created plasma, the theory and numerical simulation results show that both frequency-upshifted and downshifted waves are generated. If the plasma has a large but finite dimension in the incident wave propagation direction and is created rapidly rather than instantaneously, the frequency downshifted waves are found to be trapped by the plasma when the plasma frequency is larger than the wave frequency. The wave trapping results in accumulating the frequency-downshifted waves during the finite transient period of plasma creation. Indeed, in the experimental observations the frequency downshifted signals were detected repetitively with considerably enhanced spectral intensities, confirming the results of the numerical simulations. The missing of frequency upshifted signals in the experimental observations is explained by the modal field distributions in the periodic structure, indicating that the frequency upshifted modes experience heavier collisional damping of the plasma than the frequency downshifted modes

  4. Measurements of electron cloud growth and mitigation in dipole, quadrupole, and wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Calvey, J.R., E-mail: jrc97@cornell.edu; Hartung, W.; Li, Y.; Livezey, J.A.; Makita, J.; Palmer, M.A.; Rubin, D.

    2015-01-11

    Retarding field analyzers (RFAs), which provide a localized measurement of the electron cloud, have been installed throughout the Cornell Electron Storage Ring (CESR), in different magnetic field environments. This paper describes the RFA designs developed for dipole, quadrupole, and wiggler field regions, and provides an overview of measurements made in each environment. The effectiveness of electron cloud mitigations, including coatings, grooves, and clearing electrodes, are assessed with the RFA measurements.

  5. Dispersion relation of Raman FEL with helical Wiggler and ion channel

    International Nuclear Information System (INIS)

    Hosseinalinezhad, M.; Bahmani, M.; Hasanbeigi, A.; Salehkoutahi, M.

    2012-01-01

    In this paper the theory of free electron laser with helical wiggler and ion channel guiding has been presented. The equations of motion for an electron have been analyzed. A formula for the dispersion relation is then derived in the low-gain-per-pass limit. The results of a numerical study of the growth rate enhancement due to the ion channel are presented and discussed.

  6. Investigation of betatron instability in a wiggler pumped ion-channel free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Raghavi, A [Physics Department, Payame Noor University, 19395-4697 (Iran, Islamic Republic of); Mehdian, H, E-mail: Raghavi@tmu.ac.ir, E-mail: Mehdian@tmu.ac.ir [Department of Physics, Teacher Training University, Tehran (Iran, Islamic Republic of)

    2011-10-15

    Betatron emission from an ion-channel free electron laser in the presence of a helical wiggler pump and in the high gain regime is studied. The dispersion relation and the frequency of betatron emission are derived. Growth rate is illustrated and maximum growth rate as a function of ion-channel density is considered. Finally, the relation between beam energy, the density of ion channel and the region of betatron emission is discussed.

  7. Characterization studies of lithium vapour generated in heat pipe oven for the Plasma Wakefield Accelerator Experiment

    International Nuclear Information System (INIS)

    Mohandas, K.K.; Mahavar, Kanchan; Ajai Kumar; Kumar, Ravi A.V.

    2013-01-01

    Characterization and optimization studies of lithium vapor by white light as well as UV laser absorption were carried out as part of generation of photo ionized Li plasma for the Plasma Wake Field Acceleration Experiment. Temperature and buffer gas pressure dependency of the neutral density of lithium vapor was studied in detail. The line integrated neutral density of Li(n o L) was found to be of the order of 10 17 -10 18 cm -2 at heat pipe oven temperatures in the range from 600-800℃ which is sufficient to obtain the required 1013-1014 cm -3 plasma densities by photo ionization. (author)

  8. Probing plasma wakefields using electron bunches generated from a laser wakefield accelerator

    Science.gov (United States)

    Zhang, C. J.; Wan, Y.; Guo, B.; Hua, J. F.; Pai, C.-H.; Li, F.; Zhang, J.; Ma, Y.; Wu, Y. P.; Xu, X. L.; Mori, W. B.; Chu, H.-H.; Wang, J.; Lu, W.; Joshi, C.

    2018-04-01

    We show experimental results of probing the electric field structure of plasma wakes by using femtosecond relativistic electron bunches generated from a laser wakefield accelerator. Snapshots of laser-driven linear wakes in plasmas with different densities and density gradients are captured. The spatiotemporal evolution of the wake in a plasma density up-ramp is recorded. Two parallel wakes driven by a laser with a main spot and sidelobes are identified in the experiment and reproduced in simulations. The capability of this new method for capturing the electron- and positron-driven wakes is also shown via 3D particle-in-cell simulations.

  9. 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

  10. Dynamic processes in the generation of quasisteady magnetic fields in a laser plasma

    International Nuclear Information System (INIS)

    Aleksich, N.; Andreev, N.E.; Bychenko, V.Yu.

    1991-01-01

    Research on the generation of quasisteady magnetic fields (QSMF) in plasma under the action of strong electro-magnetic fields has long attracted attention in connection with its role when high-power laser radiation interacts with matter. In connection with the problem of laser thermonuclear fusion, a great deal of attention has been devoted to the generation of QSMF through resonant conversion of the heating radiation into electron plasma oscillations near the critical surface. Under conditions which are of interest for present-day experiments, this conversion is nonlinear due to the ponderomotive action of the radiation on the plasma plays an important role; when it is taken into account the picture of the nonlinear interaction between the radiation and the plasma changes fundamentally. Moreover, thus far QSMF generation under the action of the heating radiation has been studied mainly without including both (nonlinearity and plasma expansion) of these factors, although in the numerical simulation of the problem QSMF has been studied for a comparatively long time. The present work presents results of a theoretical study of QSMF excitation made using the LAST code, which treats the self-consistent dynamical nonlinear picture of the plasma electrodynamics and hydrodynamics

  11. X-ray lithography using wiggler and undulator synchrotron-radiation sources

    International Nuclear Information System (INIS)

    Neureuther, A.R.; Kim, K.J.; Thompson, A.C.; Hoyer, E.

    1983-08-01

    A systems design approach is used to identify feasible options for wiggler and undulator beam lines for x-ray lithography in the 0.5 to 0.2 μm linewidth region over 5 cm by 5 cm fields. Typical parameters from the Wiggler and Undulator in the Advanced Light Source designed at the Lawrence Berkeley Laboratory are used as examples. Moving from the conventional wavelengths of 4 to 9 A to very soft wavelengths around 15 A is shown to be very promising. The mask absorber thickness can be reduced a factor of three so that 0.2 μm features can be made with a 1:1 mask aspect ratio. The mask heating limited exposure time is also reduced a factor of three to 3 sec/cm 2 . However, extremely thin beam line windows (1/4 mil Be) and mask supports (1 μm Si) must be used. A wiggler beam line design using a small slit window at a scanning mirror appears feasible. A unconventional, windowless differentially pumped beam line with dual deflecting mirrors could be used with an undulator source

  12. Global beta-beating compensation of the ALS W16 wiggler

    International Nuclear Information System (INIS)

    Robin, D.; Decking, W.; Nishimura, H.

    1997-05-01

    The W16 wiggler is the first wiggler and highest field insertion device to be installed in the ALS storage ring. When the gaps of the W16 wiggler are closed, the vertical tune increases by 0.065 and the vertical beta function is distorted by up to ±37%. There are 48 quadrupoles in the ring whose fields can be adjusted individually to restore the tunes and partially compensate the beta-beating. In order to adjust the quadrupole field strengths to accurately compensate the focusing, it is necessary to have a method to precisely determine the beta-beating. In this paper we compare measurements of the induced beta-beating using two methods: measuring the tune dependence on quadrupole field strength and fitting a lattice model with measured response matrices. The fitted model also allows us to predict quadrupole field strengths that will best compensate the beta beating. These quadrupole field strengths are then applied and the resultant beta-beating is measured

  13. Conceptual design of a three-pole wiggler for the APS upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Abliz, M., E-mail: mabliz@aps.anl.gov; Grimmer, J., E-mail: grimmer@aps.anl.gov; Dejus, R.; Ramanathan, M., E-mail: mohan@aps.anl.gov [The Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2016-07-27

    The current design of the Advanced Photon Source Upgrade (APS-U) project is a multi-bend achromat (MBA) lattice, which incorporates three-pole wigglers as radiation sources for the bending magnet beamlines. They are located in the short section between the M4 dipole and Q8 quadrupole magnets. Due to space constraints, a hybrid permanent magnet design is necessary to provide the required magnetic field strength. A three-pole wiggler with a flat peak field profile along the beam axis was designed to enhance the photon flux and flatten the transverse flux density distributions. The magnetic peak field at the center pole reached 1.08 Tesla for a magnetic gap of 26 mm. The maximum power density, integrated over all vertical angles, is 3.1 W/mm{sup 2}, which is substantially higher than that of the existing bending magnets at the APS (0.86 W/mm{sup 2}). Detailed designs of the three-pole wiggler is presented, including calculated spectral-angular flux distributions.

  14. Decreasing the emittance using a multi-period Robinson wigglers in TPS

    Energy Technology Data Exchange (ETDEWEB)

    Huamg, C. W., E-mail: huang.zw@nsrrc.org.tw [Department of Physics, National Tsing Hua University Hsinchu 30043, Taiwan (China); Hwang, C. S., E-mail: cshwang@nsrrc.org.tw [NSRRC, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan (China); Lee, S. Y., E-mail: shylee@indiana.edu [Department of Physics, Indiana University (United States)

    2016-07-27

    The Taiwan Photon Source (TPS) has been successfully commissioned. However, the minimum emittance in the TPS lattice is 1.6 nm rad. In the existing TPS storage ring lattice, it is imperative to reduce the emittance to below 1 nm rad. Therefore, a feasibility study for reducing the effective emittance of the TPS storage ring by using a Robinson wiggler was launched; the reduction is necessary to enhance the photon brilliance. In this study, a permanent-magnet multiperiod Robinson wiggler (MRW) was developed for use instead of the single-period Robinson wiggler. In general, the quadruple field of a combined function magnet in the storage ring is approximately few tesla per meter. According to beam dynamic analysis, we found that it is necessary to adopt a high gradient (40 T/m) combined-function MRW magnet to reduce the emittance effectively. Therefore, a high gradient field strength is required in the combined function MRW magnet. In this study, the quadrupole field strength of the MRW magnet was allowed to be approximately 40 T/m at a magnet gap of 20 mm. The period length of the MRW magnet was 300 mm and the period number was 16. The of MRWs is discussed in regard to the possibility of increasing the photon brilliance from IU22.

  15. Decontamination possibilities of high-toxic wastes by means of dense plasma generators

    International Nuclear Information System (INIS)

    Rutberg, P.G.; Kolikov, V.A.; Bogomaz, A.A.; Budin, A.V.

    1997-01-01

    In present time the idea of plasma generators application for the high-toxic agents and wastes decontamination has become very urgent. It is known that chemical bonds energy of some molecules being part of these substances is so high that it is impossible to destroy them using traditional methods. Taking into account the fact that the temperature of plasma generator's arc column may be of tens eV, and its energy of hundreds kJ, one may state that any known chemical substances taken in quite large amount, may be dissociated to the atoms. In this paper simplified construction of plasma generator and technological scheme of plasmachemical installation are presented. (author)

  16. High speed and high functional inverter power supplies for plasma generation and control, and their performance

    International Nuclear Information System (INIS)

    Uesugi, Yoshihiko; Razzak, Mohammad A.; Kondo, Kenji; Kikuchi, Yusuke; Takamura, Shuichi; Imai, Takahiro; Toyoda, Mitsuhiro

    2003-01-01

    The Rapid development of high power and high speed semiconductor switching devices has led to their various applications in related plasma fields. Especially, a high speed inverter power supply can be used as an RF power source instead of conventional linear amplifiers and a power supply to control the magnetic field in a fusion plasma device. In this paper, RF thermal plasma production and plasma heating experiments are described emphasis placed on using a static induction transistor inverter at a frequency range between 200 kHz and 2.5 MHz as an RF power supply. Efficient thermal plasma production is achieved experimentally by using a flexible and easily operated high power semiconductor inverter power supply. Insulated gate bipolar transistor (IGBT) inverter power supplies driven by a high speed digital signal processor are applied as tokamak joule coil and vertical coil power supplies to control plasma current waveform and plasma equilibrium. Output characteristics, such as the arbitrary bipolar waveform generation of a pulse width modulation (PWM) inverter using digital signal processor (DSP) can be successfully applied to tokamak power supplies for flexible plasma current operation and fast position control of a small tokamak. (author)

  17. Plasma Modification of Poly Lactic Acid Solutions to Generate High Quality Electrospun PLA Nanofibers.

    Science.gov (United States)

    Rezaei, Fatemeh; Nikiforov, Anton; Morent, Rino; De Geyter, Nathalie

    2018-02-02

    Physical properties of pre-electrospinning polymer solutions play a key role in electrospinning as they strongly determine the morphology of the obtained electrospun nanofibers. In this work, an atmospheric-pressure argon plasma directly submerged in the liquid-phase was used to modify the physical properties of poly lactic acid (PLA) spinning solutions in an effort to improve their electrospinnability. The electrical characteristics of the plasma were investigated by two methods; V-I waveforms and Q-V Lissajous plots while the optical emission characteristics of the plasma were also determined using optical emission spectroscopy (OES). To perform a complete physical characterization of the plasma-modified polymer solutions, measurements of viscosity, surface tension, and electrical conductivity were performed for various PLA concentrations, plasma exposure times, gas flow rates, and applied voltages. Moreover, a fast intensified charge-couple device (ICCD) camera was used to image the bubble dynamics during the plasma treatments. In addition, morphological changes of PLA nanofibers generated from plasma-treated PLA solutions were observed by scanning electron microscopy (SEM). The performed plasma treatments were found to induce significant changes to the main physical properties of the PLA solutions, leading to an enhancement of electrospinnability and an improvement of PLA nanofiber formation.

  18. Study of noninductive current generation in a plasma

    International Nuclear Information System (INIS)

    Rax, J.M.

    1987-01-01

    Three aspects of noninductive current generation are treated: (1) The kinetic problem, i.e., coupling between current-carrying energetic electrons on the one hand, and the electromagnetic wave and thermal particles on the other. (2). The electromagnetic problem, i.e., calculation of the wave structure produced by the antennas. (3) The study of nonthermal radiation and electrical responses. Green's functions are used to solve the kinetic problem. The electron distribution function is calculated. For the electromagnetic problem of wave structure at different wave numbers, the Green's function of the Maxwell equations in an inhomogeneous, anisotropic medium which is spatially and temporally scattered was calculated. Perturbation of propagation by diffusion and conversion was studied. The calculation of nonthermal radiation and of transfer of electromagnetic wave energy into magnetic energy is derived from the two preceding problems. A method to produce fusion power quasi-continuously using two inductively and thermally coupled tokamaks is proposed [fr

  19. Generation of stable mixed-compact-toroid rings by inducing plasma currents in strong E rings

    International Nuclear Information System (INIS)

    Jayakumar, R.; Taggart, D.P.; Parker, M.R.; Fleischmann, H.H.

    1989-01-01

    In the RECE-Christa device, hybrid-type compact toroid rings are generated by inducing large toroidal plasma currents I rho in strong electron rings using a thin induction coil positioned along the ring axis. Starting from field-reversal values δ ο = 50 - 120 percent of the original pure fast-electron ring, the induced plasma current I rho raises δ to a maximum value of up to 240 percent with I rho contributing more than 50 percent of the total ring current. Quite interestingly, the generated hybrid compact toroid configurations appear gross-stable during the full I rho pulse length (half-amplitude width about 100 μs)

  20. Determination of self generated magnetic field and the plasma density using Cotton Mouton polarimetry with two color probes

    Directory of Open Access Journals (Sweden)

    Joshi A.S.

    2013-11-01

    Full Text Available Self generated magnetic fields (SGMF in laser produced plasmas are conventionally determined by measuring the Faraday rotation angle of a linearly polarized laser probe beam passing through the plasma along with the interferogram for obtaining plasma density. In this paper, we propose a new method to obtain the plasma density and the SGMF distribution from two simultaneous measurements of Cotton Mouton polarimetry of two linearly polarized probe beams of different colors that pass through plasma in a direction normal to the planar target. It is shown that this technique allows us to determine the distribution of SGMF and the plasma density without doing interferometry of laser produced plasmas.

  1. Explosive-driven hemispherical implosions for generating fusion plasmas

    International Nuclear Information System (INIS)

    Sagie, D.; Glass, I.I.

    1982-03-01

    The UTIAS explosive-driven-implosion facility was used to produce stable, centered and focussed hemispherical implosions to generate neutrons from D-D reactions. A high resolution scintillator-detection system measured the neutrons and γ-rays resulting from the fusion of deuterium. Several approaches were used to initiate fusion in deuterium. The simplest and most direct proved to be in a predetonated stoichiometric mixture of deuterium-oxygen. The other successful method was a miniature Voitenko-type compressor where a plane diaphragm was driven by the implosion wave into a secondary small spherical cavity that contained pure deuterium gas at one atmosphere. A great deal of work still remains in order to measure accurately the neutron flux and its velocity distribution as well as the precise interactions of the neturons with the steel chamber which produced the γ-rays. Nevertheless, this is the only known work where fusion neutrons were produced by chemical energy only in a direct and indirect manner

  2. Detailed study of the plasma-activated catalytic generation of ammonia in N2-H2 plasmas

    Science.gov (United States)

    van Helden, J. H.; Wagemans, W.; Yagci, G.; Zijlmans, R. A. B.; Schram, D. C.; Engeln, R.; Lombardi, G.; Stancu, G. D.; Röpcke, J.

    2007-02-01

    We investigated the efficiency and formation mechanism of ammonia generation in recombining plasmas generated from mixtures of N2 and H2 under various plasma conditions. In contrast to the Haber-Bosch process, in which the molecules are dissociated on a catalytic surface, under these plasma conditions the precursor molecules, N2 and H2, are already dissociated in the gas phase. Surfaces are thus exposed to large fluxes of atomic N and H radicals. The ammonia production turns out to be strongly dependent on the fluxes of atomic N and H radicals to the surface. By optimizing the atomic N and H fluxes to the surface using an atomic nitrogen and hydrogen source ammonia can be formed efficiently, i.e., more than 10% of the total background pressure is measured to be ammonia. The results obtained show a strong similarity with results reported in literature, which were explained by the production of ammonia at the surface by stepwise addition reactions between adsorbed nitrogen and hydrogen containing radicals at the surface and incoming N and H containing radicals. Furthermore, our results indicate that the ammonia production is independent of wall material. The high fluxes of N and H radicals in our experiments result in a passivated surface, and the actual chemistry, leading to the formation of ammonia, takes place in an additional layer on top of this passivated surface.

  3. Fast electron generation and transport in a turbulent, magnetized plasma

    International Nuclear Information System (INIS)

    Stoneking, W.R.

    1994-05-01

    The nature of fast electron generation and transport in the Madison Symmetric Torus (MST) reversed field pinch (RFP) is investigated using two electron energy analyzer (EEA) probes and a thermocouple calorimeter. The parallel velocity distribution of the fast electron population is well fit by a drifted Maxwellian distribution with temperature of about 100 eV and drift velocity of about 2 x 10 6 m/s. Cross-calibration of the EEA with the calorimeter provides a measurement of the fast electron perpendicular temperature of 30 eV, much lower than the parallel temperature, and is evidence that the kinetic dynamo mechanism (KDT) is not operative in MST. The fast electron current is found to match to the parallel current at the edge, and the fast electron density is about 4 x 10 11 cm -3 independent of the ratio of the applied toroidal electric field to the critical electric field for runaways. First time measurements of magnetic fluctuation induced particle transport are reported. By correlating electron current fluctuations with radial magnetic fluctuations the transported flux of electrons is found to be negligible outside r/a∼0.9, but rises the level of the expected total particle losses inside r/a∼0.85. A comparison of the measured diffusion coefficient is made with the ausilinear stochastic diffusion coefficient. Evidence exists that the reduction of the transport is due to the presence of a radial ambipolar electric field of magnitude 500 V/m, that acts to equilibrate the ion and electron transport rates. The convective energy transport associated with the measured particle transport is large enough to account for the observed magnetic fluctuation induced energy transport in MST

  4. Ion beam generation at the plasma sheet boundary layer by kinetic Alfven waves

    International Nuclear Information System (INIS)

    Moghaddam-Taaheri, E.; Goertz, C.K.; Smith, R.A.

    1989-01-01

    The kinetic Alfven wave, an Alfven wave with a perpendicular wavelength comparable to the ion gyroradius, can diffuse ions both in velocity and coordinate spaces with comparable transport rates. This may lead to the generation of ion beams in the plasma sheet boundary layer (PSBL). To investigate the ion beam generation process numerically, a two-dimensional quasi-linear code was constructed. Assuming that the plasma β (the ratio of plasma pressure to the magnetic pressure) varies from β = 1 to β << 1 across the magnetic field, the dynamics of the ion beam generation in the PSBL was studied. It was found that if your start with an ion distribution function which monotonically decreases with velocity along the magnetic field and a density gradient across the magnetic field, ions diffuse in velocity-coordinate space until nearly a plateau is established along the diffusion path. Depending on the topology of the magnetic field at the lobe side of the simulation system, i.e., open or closed field lines, the ion distribution function may or may not reach a steady state. If the field lines are open there, i.e., if the diffusion extends into the lobe, the double diffusion process may provide a mechanism for continuously transferring the ions from the central plasma sheet to the lobe. The authors comment on the effect of the particle loss on the establishment of the pressure balance in the plasma sheet

  5. Finite toroidal flow generated by unstable tearing mode in a toroidal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hao, G. Z., E-mail: haogz@swip.ac.cn; Wang, A. K.; Xu, Y. H.; He, H. D.; Xu, M.; Qu, H. P.; Peng, X. D.; Xu, J. Q.; Qiu, X. M. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Liu, Y. Q. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Sun, Y. [Institute of Plasma Physics, Chinese Academic of Sciences, P.O. Box 1126, Hefei 230031 (China); Cui, S. Y. [School of Mathematics and Statistics Science, Ludong University, Yantai 264025 (China)

    2014-12-15

    The neoclassical toroidal plasma viscosity torque and electromagnetic torque, generated by tearing mode (TM) in a toroidal plasma, are numerically investigated using the MARS-Q code [Liu et al., Phys. Plasmas 20, 042503 (2013)]. It is found that an initially unstable tearing mode can intrinsically drive a toroidal plasma flow resulting in a steady state solution, in the absence of the external momentum input and external magnetic field perturbation. The saturated flow is in the order of 0.5%ω{sub A} at the q=2 rational surface in the considered case, with q and ω{sub A} being the safety factor and the Alfven frequency at the magnetic axis, respectively. The generation of the toroidal flow is robust, being insensitive to the given amplitude of the perturbation at initial state. On the other hand, the flow amplitude increases with increasing the plasma resistivity. Furthermore, the initially unstable tearing mode is fully stabilized by non-linear interaction with the self-generated toroidal flow.

  6. Efficient second- and third-harmonic radiation generation from relativistic laser-plasma interactions

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mamta; Gupta, D. N., E-mail: dngupta@physics.du.ac.in [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Suk, H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 500 712 (Korea, Republic of)

    2015-06-15

    We propose an idea to enhance the efficiency of second- and third-harmonic generation by considering the amplitude-modulation of the fundamental laser pulse. A short-pulse laser of finite spot size is modeled as amplitude modulated in time. Amplitude-modulation of fundamental laser contributes in quiver velocity of the plasma electrons and produces the strong plasma-density perturbations, thereby increase in current density at second- and third-harmonic frequency. In a result, the conversion efficiency of harmonic generation increases significantly. Power conversion efficiency of harmonic generation process is the increasing function of the amplitude-modulation parameter of the fundamental laser beam. Harmonic power generated by an amplitude modulated laser is many folds higher than the power obtained in an ordinary case.

  7. Efficient second- and third-harmonic radiation generation from relativistic laser-plasma interactions

    International Nuclear Information System (INIS)

    Singh, Mamta; Gupta, D. N.; Suk, H.

    2015-01-01

    We propose an idea to enhance the efficiency of second- and third-harmonic generation by considering the amplitude-modulation of the fundamental laser pulse. A short-pulse laser of finite spot size is modeled as amplitude modulated in time. Amplitude-modulation of fundamental laser contributes in quiver velocity of the plasma electrons and produces the strong plasma-density perturbations, thereby increase in current density at second- and third-harmonic frequency. In a result, the conversion efficiency of harmonic generation increases significantly. Power conversion efficiency of harmonic generation process is the increasing function of the amplitude-modulation parameter of the fundamental laser beam. Harmonic power generated by an amplitude modulated laser is many folds higher than the power obtained in an ordinary case

  8. Generation of Low-Energy High-Current Electron Beams in Plasma-Anode Electron Guns

    Science.gov (United States)

    Ozur, G. E.; Proskurovsky, D. I.

    2018-01-01

    This paper is a review of studies on the generation of low-energy high-current electron beams in electron guns with a plasma anode and an explosive-emission cathode. The problems related to the initiation of explosive electron emission under plasma and the formation and transport of high-current electron beams in plasma-filled systems are discussed consecutively. Considerable attention is given to the nonstationary effects that occur in the space charge layers of plasma. Emphasis is also placed on the problem of providing a uniform energy density distribution over the beam cross section, which is of critical importance in using electron beams of this type for surface treatment of materials. Examples of facilities based on low-energy high-current electron beam sources are presented and their applications in materials science and practice are discussed.

  9. Surface treatment by the ion flow from electron beam generated plasma in the forevacuum pressure range

    Directory of Open Access Journals (Sweden)

    Klimov Aleksandr

    2018-01-01

    Full Text Available The paper presents research results of peculiarities of gas ion flows usage and their generation from large plasma formation (>50 sq.cm obtained by electron beam ionization of gas in the forevacuum pressure range. An upgraded source was used for electron beam generation, which allowed obtaining ribbon electron beam with no transmitting magnetic field. Absence of magnetic field in the area of ion flow formation enables to obtain directed ion flows without distorting their trajectories. In this case, independent control of current and ion energy is possible. The influence of electron beam parameters on the parameters of beam plasma and ion flow – current energy and density – was determined. The results of alumina ceramics treatment with a beam plasma ions flow are given.

  10. Using self-generated harmonics as a diagnostic of high intensity laser-produced plasmas

    International Nuclear Information System (INIS)

    Krushelnick, K; Watts, I; Tatarakis, M; Gopal, A; Wagner, U; Beg, F N; Clark, E L; Clarke, R J; Dangor, A E; Norreys, P A; Wei, M S; Zepf, M

    2002-01-01

    The interaction of high intensity laser pulses (up to I∼10 20 W cm -2 ) with plasmas can generate very high order harmonics of the laser frequency (up to the 75th order have been observed). Measurements of the properties of these harmonics can provide important insights into the plasma conditions which exist during such interactions. For example, observations of the spectrum of the harmonic emission can provide information of the dynamics of the critical surface as well as information on relativistic non-linear optical effects in the plasma. However, most importantly, observations of the polarization properties of the harmonics can provide a method to measure the ultra-strong magnetic fields (greater than 350 MG) which can be generated during these interactions. It is likely that such techniques can be scaled to provide a significant amount of information from experiments at even higher intensities

  11. Generation of various radicals in nitrogen plasma and their behavior in media

    International Nuclear Information System (INIS)

    Uhm, Han S.

    2015-01-01

    Research on the generation of radicals in nitrogen plasma shows that the most dominant radicals are excited nitrogen molecules in the metastable state of N 2 (A 3 ∑ u + ). Hydroxyl molecules are generated from the dissociation of water molecules upon contact with excited nitrogen molecules. The estimated densities of various radicals in nitrogen plasma with an electron temperature of 1 eV are presented in this study. The behavior of these radicals in media is also investigated. Excited nitrogen molecules in the N 2 (A 3 ∑ u + ) state from a plasma jet are injected into water, after which the molecules disappear instantaneously within a few tens of nm, producing hydroxyl molecules. Hydrogen peroxide, hydrogen dioxide, and nitrogen monoxide molecules can diffuse much deeper into water, implying the possibility that a chemical reaction between hydrogen dioxide and nitrogen monoxide molecules produces hydroxyl molecules in deep water, even though density in this case may not be very high

  12. Theory of coherent transition radiation generated at a plasma-vacuum interface

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Carl B.; Esarey, Eric; van Tilborg, Jeroen; Leemans, Wim P.

    2003-06-26

    Transition radiation generated by an electron beam, produced by a laser wakefield accelerator operating in the self-modulated regime, crossing the plasma-vacuum boundary is considered. The angular distributions and spectra are calculated for both the incoherent and coherent radiation. The effects of the longitudinal and transverse momentum distributions on the differential energy spectra are examined. Diffraction radiation from the finite transverse extent of the plasma is considered and shown to strongly modify the spectra and energy radiated for long wavelength radiation. This method of transition radiation generation has the capability of producing high peak power THz radiation, of order 100 (mu)J/pulse at the plasma-vacuum interface, which is several orders of magnitude beyond current state-of-the-art THz sources.

  13. Ultra-low emittance electron beam generation using ionization injection in a plasma beatwave accelerator

    Science.gov (United States)

    Schroeder, Carl; Benedetti, Carlo; Esarey, Eric; Leemans, Wim

    2017-10-01

    Ultra-low emittance beams can be generated using ionization injection of electrons into a wakefield excited by a plasma beatwave accelerator. This all-optical method of electron beam generation uses three laser pulses of different colors. Two long-wavelength laser pulses, with frequency difference equal to the plasma frequency, resonantly drive a plasma wave without fully ionizing a gas. A short-wavelength injection laser pulse (with a small ponderomotive force and large peak electric field), co-propagating and delayed with respect to the beating long-wavelength lasers, ionizes a fraction of the remaining bound electrons at a trapped wake phase, generating an electron beam that is accelerated in the wakefield. Using the beating of long-wavelength pulses to generate the wakefield enables atomically-bound electrons to remain at low ionization potentials, reducing the required amplitude of the ionization pulse, and, hence, the initial transverse momentum and emittance of the injected electrons. An example is presented using two lines of a CO2 laser to form a plasma beatwave accelerator to drive the wake and a frequency-doubled Ti:Al2O3 laser for ionization injection. Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  14. Coherent bremsstrahlung generation of harmonics in a laser-produced plasma

    International Nuclear Information System (INIS)

    Silin, Viktor P

    1999-01-01

    Foundations of a theory of generation of the harmonics of a laser pump in a fully ionised plasma are proposed. This theory makes it possible to describe the relationships governing harmonic generation in an analytical form. For an elliptically polarised pump field with a low degree of circular polarisation A, the range of plasma parameters is established in which the number of harmonics is found to be of the order of A -1 . Anomalous polarisation properties of the harmonics are predicted. In this case, their polarisation is seen to be nearly perpendicular to the pump polarisation and the degree of circular polarisation increases with the harmonic order number. The harmonic-order-dependent intensity of the pump field which results in circular polarisation of a harmonic is determined making allowance for thermal plasma motion. The conditions under which increasing the low degree of circular pump polarisation increases the efficiency of harmonic generation are established. The nonlinear dependence of the pump polarisation on its intensity under the conditions of collisional absorption in a plasma are identified and an instability of the circular polarisation is revealed. For a plane-polarised pump, it is shown how the maximum power of a harmonic and the pump power corresponding to this maximum scale up with the harmonic order number. The conditions under which the number of harmonics generated is limited owing to the relativistic nature of electron motion in the pump field are established. This effect appears for an unexpectedly weak relativity. (invited paper)

  15. High-order harmonic generation in a laser plasma: a review of recent achievements

    International Nuclear Information System (INIS)

    Ganeev, R A

    2007-01-01

    A review of studies of high-order harmonic generation in plasma plumes is presented. The generation of high-order harmonics (up to the 101st order, λ = 7.9 nm) of Ti:sapphire laser radiation during the propagation of short laser pulses through a low-excited, low-ionized plasma produced on the surfaces of different targets is analysed. The observation of considerable resonance-induced enhancement of a single harmonic (λ = 61.2 nm) at the plateau region with 10 -4 conversion efficiency in the case of an In plume can offer some expectations that analogous processes can be realized in other plasma samples in the shorter wavelength range. Recent achievements of single-harmonic enhancement at mid- and end-plateau regions are discussed. Various methods for the optimization of harmonic generation are analysed, such as the application of the second harmonic of driving radiation and the application of prepulses of different durations. The enhancement of harmonic generation efficiency during the propagation of femtosecond pulses through a nanoparticle-containing plasma is discussed. (topical review)

  16. Atmospheric plasma generates oxygen atoms as oxidizing species in aqueous solutions

    International Nuclear Information System (INIS)

    Hefny, Mohamed Mokhtar; Pattyn, Cedric; Benedikt, Jan; Lukes, Petr

    2016-01-01

    A remote microscale atmospheric pressure plasma jet ( µ APPJ) with He, He/H 2 O, He/O 2 , and He/O 2 /H 2 O gas mixtures was used to study the transport of reactive species from the gas phase into the liquid and the following aqueous phase chemistry. The effects induced by the µ APPJ in water were quantitatively studied using phenol as a chemical probe and by measuring H 2 O 2 concentration and pH values. These results were combined with the analysis of the absolute densities of the reactive species and the modeling of convective/diffusion transport and recombination reactions in the effluent of the plasma jet. Additionally, modified plasma jets were used to show that the role of emitted photons in aqueous chemistry is negligible for these plasma sources. The fastest phenol degradation was measured for the He/O 2 plasma, followed by He/H 2 O, He/O 2 /H 2 O, and He plasmas. The modeled quantitative flux of O atoms into the liquid in the He/O 2 plasma case was highly comparable with the phenol degradation rate and showed a very high transfer efficiency of reactive species from the plasma into the liquid, where more than half of the O atoms leaving the jet nozzle entered the liquid. The results indicate that the high oxidative effect of He/O 2 plasma was primarily due to solvated O atoms, whereas OH radicals dominated the oxidative effects induced in water by plasmas with other gas mixtures. These findings help to understand, in a quantitative way, the complex interaction of cold atmospheric plasmas with aqueous solutions and will allow a better understanding of the interaction of these plasmas with water or buffered solutions containing biological macromolecules, microorganisms, or even eukaryotic cells. Additionally, the µ APPJ He/O 2 plasma source seems to be an ideal tool for the generation of O atoms in aqueous solutions for any future studies of their reactivity. (paper)

  17. The Tethered Balloon Current Generator - A space shuttle-tethered subsatellite for plasma studies and power generation

    Science.gov (United States)

    Williamson, P. R.; Banks, P. M.

    1976-01-01

    The objectives of the Tethered Balloon Current Generator experiment are to: (1) generate relatively large regions of thermalized, field-aligned currents, (2) produce controlled-amplitude Alfven waves, (3) study current-driven electrostatic plasma instabilities, and (4) generate substantial amounts of power or propulsion through the MHD interaction. A large balloon (a diameter of about 30 m) will be deployed with a conducting surface above the space shuttle at a distance of about 10 km. For a generally eastward directed orbit at an altitude near 400 km, the balloon, connected to the shuttle by a conducting wire, will be positive with respect to the shuttle, enabling it to collect electrons. At the same time, the shuttle will collect positive ions and, upon command, emit an electron beam to vary current flow in the system.

  18. A plasma aerodynamic actuator supplied by a multilevel generator operating with different voltage waveforms

    International Nuclear Information System (INIS)

    Borghi, Carlo A; Cristofolini, Andrea; Grandi, Gabriele; Neretti, Gabriele; Seri, Paolo

    2015-01-01

    In this work a high voltage—high frequency generator for the power supply of a dielectric barrier discharge (DBD) plasma actuator for the aerodynamic control obtained by the electro-hydro-dynamic (EHD) interaction is described and tested. The generator can produce different voltage waveforms. The operating frequency is independent of the load characteristics and does not require impedance matching. The peak-to-peak voltage is 30 kV at a frequency up to 20 kHz and time variation rates up to 60 kV μs −1 . The performance of the actuator when supplied by several voltage waveforms is investigated. The tests have been performed in still air at atmospheric pressure. Voltage and current time behaviors have been measured. The evaluation of the energy delivered to the actuator allowed the estimation of the periods in which the plasma was ignited. Vibrational and rotational temperatures of the plasma have been estimated through spectroscopic acquisitions. The flow field induced in the region above the surface of the DBD actuator has been studied and the EHD conversion efficiency has been evaluated for the voltage waveforms investigated. The nearly sinusoidal multilevel voltage of the proposed generator and the sinusoidal voltage waveform of a conventional ac generator obtain comparable plasma features, EHD effects, and efficiencies. Inverse saw tooth waveform presents the highest effects and efficiency. The rectangular waveform generates suitable EHD effects but with the lowest efficiency. The voltage waveforms that induce plasmas with higher rotational temperatures are less efficient for the conversion of the electric into kinetic energy. (paper)

  19. Impact of plasma jet vacuum ultraviolet radiation on reactive oxygen species generation in bio-relevant liquids

    Energy Technology Data Exchange (ETDEWEB)

    Jablonowski, H.; Hammer, M. U.; Reuter, S. [Center for Innovation Competence plasmatis, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Leibniz Institute for Plasma Science and Technology, INP Greifswald e.V. Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Bussiahn, R.; Weltmann, K.-D.; Woedtke, Th. von [Leibniz Institute for Plasma Science and Technology, INP Greifswald e.V. Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2015-12-15

    Plasma medicine utilizes the combined interaction of plasma produced reactive components. These are reactive atoms, molecules, ions, metastable species, and radiation. Here, ultraviolet (UV, 100–400 nm) and, in particular, vacuum ultraviolet (VUV, 10–200 nm) radiation generated by an atmospheric pressure argon plasma jet were investigated regarding plasma emission, absorption in a humidified atmosphere and in solutions relevant for plasma medicine. The energy absorption was obtained for simple solutions like distilled water (dH{sub 2}O) or ultrapure water and sodium chloride (NaCl) solution as well as for more complex ones, for example, Rosewell Park Memorial Institute (RPMI 1640) cell culture media. As moderate stable reactive oxygen species, hydrogen peroxide (H{sub 2}O{sub 2}) was studied. Highly reactive oxygen radicals, namely, superoxide anion (O{sub 2}{sup •−}) and hydroxyl radicals ({sup •}OH), were investigated by the use of electron paramagnetic resonance spectroscopy. All species amounts were detected for three different treatment cases: Plasma jet generated VUV and UV radiation, plasma jet generated UV radiation without VUV part, and complete plasma jet including all reactive components additionally to VUV and UV radiation. It was found that a considerable amount of radicals are generated by the plasma generated photoemission. From the experiments, estimation on the low hazard potential of plasma generated VUV radiation is discussed.

  20. Modeling of the plasma generated in a rarefied hypersonic shock layer

    International Nuclear Information System (INIS)

    Farbar, Erin D.; Boyd, Iain D.

    2010-01-01

    In this study, a rigorous numerical model is developed to simulate the plasma generated in a rarefied, hypersonic shock layer. The model uses the direct simulation Monte Carlo (DSMC) method to treat the particle collisions and the particle-in-cell (PIC) method to simulate the plasma dynamics in a self-consistent manner. The model is applied to compute the flow along the stagnation streamline in front of a blunt body reentering the Earth's atmosphere at very high velocity. Results from the rigorous DSMC-PIC model are compared directly to the standard DSMC modeling approach that uses the ambipolar diffusion approximation to simulate the plasma dynamics. It is demonstrated that the self-consistent computation of the plasma dynamics using the rigorous DSMC-PIC model captures many physical phenomena not accurately predicted by the standard modeling approach. These computations represent the first assessment of the validity of the ambipolar diffusion approximation when predicting the rarefied plasma generated in a hypersonic shock layer.

  1. High-Intensity High-order Harmonics Generated from Low-Density Plasma

    International Nuclear Information System (INIS)

    Ozaki, T.; Bom, L. B. Elouga; Abdul-Hadi, J.; Ganeev, R. A.; Haessler, S.; Salieres, P.

    2009-01-01

    We study the generation of high-order harmonics from lowly ionized plasma, using the 10 TW, 10 Hz laser of the Advanced Laser Light Source (ALLS). We perform detailed studies on the enhancement of a single order of the high-order harmonic spectrum generated in plasma using the fundamental and second harmonic of the ALLS beam line. We observe quasi-monochromatic harmonics for various targets, including Mn, Cr, Sn, and In. We identify most of the ionic/neutral transitions responsible for the enhancement, which all have strong oscillator strengths. We demonstrate intensity enhancements of the 13th, 17th, 29th, and 33rd harmonics from these targets using the 800 nm pump laser and varying its chirp. We also characterized the attosecond nature of such plasma harmonics, measuring attosecond pulse trains with 360 as duration for chromium plasma, using the technique of ''Reconstruction of Attosecond Beating by Interference of Two-photon Transitions''(RABBIT). These results show that plasma harmonics are intense source of ultrashort coherent soft x-rays.

  2. 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

  3. Outline of the relativistic electron beam (REB) generator at Institute of Plasma Physics, Nagoya University

    International Nuclear Information System (INIS)

    Tsuzuki, Tetsuya

    1979-01-01

    The REB generators at the Institute of Plasma Physics are introduced. The generators Phoebus-2 and Phoebus-3 are main generators. The generators consist of a Marx generator (a condenser bank), a pulse forming line (PFL), a transmission line (TL) and a diode part. The rise time of current in the Marx generator must be short. The charge up time of the Phoebus-2 and the Phoebus-3 is less than 400 ns. The jitter is less than 10 ns. The dielectric material of the PFL is water, since the dielectric constant is large, and it makes self recovering. The inductance of gap at the edge of PFL should be small. The gap is useful for short rise time. The TL prevents the prepulse at the time of charging-up and works as an impedance transformer. The Phoebus-3 is connected to the torus system (SPAC-6) to make experiment on REB ring formation. (Kato, T.)

  4. Spatial properties of a terahertz beam generated from a two-color air plasma

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Wang, Tianwu; Buron, Jonas Christian Due

    2013-01-01

    We present a spatial characterization of terahertz (THz) beams generated from a two-color air plasma under different conditions by measuring full 3D beam profiles using a commercial THz camera. We compare two THz beam profiles emitted from plasmas generated by 35 fs and 100 fs laser pulses...... that this reduces the beam waist, and that the beam spot shape changes from Lorentzian to Gaussian. Finally, we observe a forward-propagating Gaussian THz beam by spatially filtering away the conical off-axis radiation with a 1 cm aperture......., and show that the spatial properties of the two THz beams do not change significantly. For the THz beam profile generated by the 35 fs pulse, the spatial effect of eliminating the lower frequencies is investigated by implementing two crossed polarizers working as a high-pass filter. We show...

  5. Arc Voltage Fluctuation in DC Laminar and Turbulent Plasma Jets Generation

    International Nuclear Information System (INIS)

    Pan Wenxia; Meng Xian; Wu Chengkang

    2006-01-01

    Arc voltage fluctuations in a direct current (DC) non-transferred arc plasma generator are experimentally studied, in generating a jet in the laminar, transitional and turbulent regimes. The study is with a view toward elucidating the mechanism of the fluctuations and their relationship with the generating parameters, arc root movement and flow regimes. Results indicate that the existence of a 300 Hz alternating current (AC) component in the power supply ripples does not cause the transition of the laminar plasma jet into a turbulent state. There exists a high frequency fluctuation at 4 kHz in the turbulent jet regime. It may be related to the rapid movement of the anode attachment point of the arc

  6. Generation and evolution of anisotropic turbulence and related energy transfer in drifting proton-alpha plasmas

    Science.gov (United States)

    Maneva, Y. G.; Poedts, S.

    2018-05-01

    The power spectra of magnetic field fluctuations in the solar wind typically follow a power-law dependence with respect to the observed frequencies and wave-numbers. The background magnetic field often influences the plasma properties, setting a preferential direction for plasma heating and acceleration. At the same time the evolution of the solar-wind turbulence at the ion and electron scales is influenced by the plasma properties through local micro-instabilities and wave-particle interactions. The solar-wind-plasma temperature and the solar-wind turbulence at sub- and sup-ion scales simultaneously show anisotropic features, with different components and fluctuation power in parallel with and perpendicular to the orientation of the background magnetic field. The ratio between the power of the magnetic field fluctuations in parallel and perpendicular direction at the ion scales may vary with the heliospheric distance and depends on various parameters, including the local wave properties and nonthermal plasma features, such as temperature anisotropies and relative drift speeds. In this work we have performed two-and-a-half-dimensional hybrid simulations to study the generation and evolution of anisotropic turbulence in a drifting multi-ion species plasma. We investigate the evolution of the turbulent spectral slopes along and across the background magnetic field for the cases of initially isotropic and anisotropic turbulence. Finally, we show the effect of the various turbulent spectra for the local ion heating in the solar wind.

  7. Temperature and Nitric Oxide Generation in a Pulsed Arc Discharge Plasma

    International Nuclear Information System (INIS)

    Namihira, T.; Sakai, S.; Matsuda, M.; Wang, D.; Kiyan, T.; Akiyama, H.; Okamoto, K.; Toda, K.

    2007-01-01

    Nitric oxide (NO) is increasingly being used in medical treatments of high blood pressure, acute respiratory distress syndrome and other illnesses related to the lungs. Currently a NO inhalation system consists of a gas cylinder of N 2 mixed with a high concentration of NO. This arrangement is potentially risky due to the possibility of an accidental leak of NO from the cylinder. The presence of NO in the air leads to the formation of nitric dioxide (NO 2 ), which is toxic to the lungs. Therefore, an on-site generator of NO would be highly desirable for medical doctors to use with patients with lung disease. To develop the NO inhalation system without a gas cylinder, which would include a high concentration of NO, NAMIHIRA et al have recently reported on the production of NO from room air using a pulsed arc discharge. In the present work, the temperature of the pulsed arc discharge plasma used to generate NO was measured to optimize the discharge condition. The results of the temperature measurements showed the temperature of the pulsed arc discharge plasma reached about 10,000 K immediately after discharge initiation and gradually decreased over tens of microseconds. In addition, it was found that NO was formed in a discharge plasma having temperatures higher than 9,000 K and a smaller input energy into the discharge plasma generates NO more efficiently than a larger one

  8. Kinetic description of self-field effects on laser and betatron emission in wiggler-pumped ion-channel free electron lasers

    International Nuclear Information System (INIS)

    Alimohamadi, M; Mehdian, H; Hasanbeigi, A

    2011-01-01

    The effects of self-fields on the free electron lasers (FELs) with a helical wiggler and ion-channel guiding are considered. The steady-state orbits for a single electron in this configuration are obtained. The rate of change of axial velocity with energy, the characteristic function Φ, is derived and studied numerically. A kinetic approach has been used to get the effects of self-field on the FEL and betatron gain formula in the low-gain-pre-pass limit. It is shown that betatron gain is smaller than FEL gain. We also found a gain decrement (enhancement), arising from diamagnetism (paramagnetism) generated by the self-magnetic field for group I (group II) orbits. It is interesting that the gain enhancement is found for the non-relativistic part of group II orbits. The FEL gain and betatron gain have also been investigated for different relativistic factors γ.

  9. Beam-plasma instability in ion beam systems used in neutral beam generation

    International Nuclear Information System (INIS)

    Hooper, E.B. Jr.

    1977-02-01

    The beam-plasma instability is analyzed for the ion beams used for neutral beam generation. Both positive and negative ion beams are considered. Stability is predicted when the beam velocity is less than the electron thermal velocity; the only exception occurs when the electron density accompanying a negative ion beam is less than the ion density by nearly the ratio of electron to ion masses. For cases in which the beam velocity is greater than the electron thermal velocity, instability is predicted near the electron plasma frequency

  10. Generation of static magnetic fields by a test charge in a plasma with anisotropic electron temperature

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Yu.M.; Bychenkov, V.Yu.; Frolov, A.A. (AN SSSR, Moscow. Fizicheskij Inst.)

    Structure of electomagnetic field generated with a charge in a plasma with anisotropic electron temperature has been studied. Unlike a hydrodynamical approach to study on the magnetic field qeneration with a test charge a kinetic theory describing spatial distribution of both magnetic and electrostatic components of charge field was constructed. Such theory results permit to investigate the charge field structure both at distances larger than length of free electron path and not exceeding it. The developed theory can serve as the basis for development of new methods for anisotropic plasma diagnostics.

  11. Generation of high-power-density atmospheric pressure plasma with liquid electrodes

    International Nuclear Information System (INIS)

    Dong Lifang; Mao Zhiguo; Yin Zengqian; Ran Junxia

    2004-01-01

    We present a method for generating atmospheric pressure plasma using a dielectric barrier discharge reactor with two liquid electrodes. Four distinct kinds of discharge, including stochastic filaments, regular square pattern, glow-like discharge, and Turing stripe pattern, are observed in argon with a flow rate of 9 slm. The electrical and optical characteristics of the device are investigated. Results show that high-power-density atmospheric pressure plasma with high duty ratio in space and time can be obtained. The influence of wall charges on discharge power and duty ratio has been discussed

  12. Diamond detectors for time-of-flight measurements in laser-generated plasmas

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Margarone, D.; Milani, E.; Verona-Rinati, G.; Prestopino, G.; Tuvè, C.; Potenza, R.; Láska, Leoš; Krása, Josef; Ullschmied, Jiří

    2009-01-01

    Roč. 164, 5-6 (2009), s. 369-375 ISSN 1042-0150. [Workshop on European Collaboration for Higher Education and Research in Nuclear Engineering and Radiological Protection /4./. Favignana, 26.05.2008-28.05.2008] R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : diamond detector * laser-generated plasma * x-ray detection Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.550, year: 2009

  13. Intense isolated attosecond pulse generation from relativistic laser plasmas using few-cycle laser pulses

    International Nuclear Information System (INIS)

    Ma, Guangjin; Dallari, William; Borot, Antonin; Tsakiris, George D.; Veisz, Laszlo; Krausz, Ferenc; Yu, Wei

    2015-01-01

    We have performed a systematic study through particle-in-cell simulations to investigate the generation of attosecond pulse from relativistic laser plasmas when laser pulse duration approaches the few-cycle regime. A significant enhancement of attosecond pulse energy has been found to depend on laser pulse duration, carrier envelope phase, and plasma scale length. Based on the results obtained in this work, the potential of attaining isolated attosecond pulses with ∼100 μJ energy for photons >16 eV using state-of-the-art laser technology appears to be within reach

  14. Influence of external-detonation-generated plasmas on the performance of semi-confined explosive charges

    Energy Technology Data Exchange (ETDEWEB)

    Udy, L.L.

    1979-02-01

    External-detonation-generated plasmas, highly ionized zones of reacting material ejected from the surface of detonating explosive charges, are shown to be the cause of channel desensitization, i.e., the self-quenching of a detonating explosive column loaded in a borehole with an air annulus between the explosive and the borehole wall. The effects of this phenomenon on several explosive compositions and types are demonstrated and discussed. The explosives tested include aluminum-sensitized and explosive-sensitized slurries, ANFO, liquid explosives and dynamites. Various techniques are described that can be used to reduce or eliminate the plasma effect.

  15. New developments on the generation of arbitrary polarized radiation from insertion devices

    International Nuclear Information System (INIS)

    Elleaume, P.

    1991-01-01

    The complete description of the polarization of a beam of radiation is described in terms of the total energy and three polarization rates. The polarization characteristics from conventional undulators and wigglers is recalled. A presentation is made of some new insertion devices that were proposed and/or built to generate circular polarization and more generally to improve the control of polarization. They are the asymmetric and elliptical wigglers and the helical and crossed undulators

  16. Impedance Mismatch study between the Microwave Generator and the PUPR Plasma Machine

    International Nuclear Information System (INIS)

    Gaudier, Jorge R.; Castellanos, Ligeia; Encarnacion, Kabir; Zavala, Natyaliz; Rivera, Ramon; Farahat, Nader; Leal, Edberto

    2006-01-01

    Impedance mismatch inside the connection from the microwave power generator to the plasma machine is studied. A magnetron power generator transmits microwaves of 2.45 GHz and variable power from 50W to 5000W, through a flexible rectangular waveguide to heat plasma inside a Mirror Cusp devise located at the Polytechnic University of Puerto Rico. Before the production of plasma, the residual gas of the devise must be extracted by a vacuum system (5Torr or better), then Argon gas is injected to the machine. The microwaves heat the Argon ions to initiate ionization and plasma is produced. A dielectric wall is used inside the rectangular waveguide to isolate the plasma machine and maintain vacuum. Even though the dielectric will not block the wave propagation, some absorption of microwaves will occur. This absorption will cause reflection, reducing the efficiency of the power transfer. Typically a thin layer of Teflon is used, but measurements using this dielectric show a significant reflection of power back to the generator. Due to the high-power nature of the generator (5KW), this mismatch is not desirable. An electromagnetic field solver based on the Finite Difference Time Domain Method(FDTD) is used to model the rectangular waveguide connection. The characteristic impedance of the simulation is compared with the analytical formula expression and a good agreement is obtain. Furthermore the Teflon-loaded guide is modeled using the above program and the input impedance is computed. The reflection coefficient is calculated based on the transmission line theory with the characteristic and input impedances. Based on the simulation results it is possible to optimize the thickness, shape and dielectric constant of the material, in order to seal the connection with a better match

  17. Harmonic generation by atomic and nanoparticle precursors in a ZnS laser ablation plasma

    International Nuclear Information System (INIS)

    Oujja, M.; Lopez-Quintas, I.; Benítez-Cañete, A.; Nalda, R. de; Castillejo, M.

    2017-01-01

    Highlights: • Plume species in infrared ns laser ablation of ZnS studied by low-order harmonic generation. • Different spatiotemporal properties of harmonics from atoms and nanoparticles. • Results compared with calculations of optical frequency up-conversion in perturbative regime. - Abstract: Harmonic generation of a driving laser propagating across a laser ablation plasma serves for the diagnosis of multicomponent plumes. Here we study the contribution of atomic and nanoparticle precursors to the generation of coherent ultraviolet and vacuum ultraviolet light as low-order harmonics of the fundamental emission (1064 nm) of a Q-switched Nd:YAG laser in a nanosecond infrared ZnS laser ablation plasma. Odd harmonics from the 3rd up to the 9th order (118.2 nm) have been observed with distinct temporal and spatial characteristics which were determined by varying the delay between the ablation and driving nanosecond pulses and by spatially scanning the plasma with the focused driving beam propagating parallel to the target. At short distances from the target surface (≤1 mm), the harmonic intensity displays two temporal components peaked at around 250 ns and 10 μs. While the early component dies off quickly with increasing harmonic order and vanishes for the 9th order, the late component is notably intense for the 7th harmonic and is still clearly visible for the 9th. Spectral analysis of spontaneous plume emissions help to assign the origin of the two components. While the early plasma component is mainly constituted by neutral Zn atoms, the late component is mostly due to nanoparticles, which upon interaction with the driving laser are subject to breakup and ionization. With the aid of calculations of the phase matching integrals within the perturbative model of optical harmonic generation, these results illustrate how atom and nanoparticle populations, with differing temporal and spatial distributions within the ablation plasma, contribute to the nonlinear

  18. An Influence of 7.5 T Superconducting Wiggler on Beam Parameters of Siberia-2 Storage Ring

    International Nuclear Information System (INIS)

    Korchuganov, Vladimir; Valentinov, Alexander; Mezentsev, Nikolai

    2007-01-01

    At present the dedicated synchrotron radiation source Siberia-2 in Kurchatov Institute operates with electron energy 2.5 GeV and current up to 200 mA. In order to expand spectral range of SR and to increase brightness an installation of 7.5 T 19-pole superconducting wiggler is planned at the end of 2006. Now the wiggler is under fabrication in BINP, Novosibirsk. Such high level of a magnetic field in the wiggler will have a great influence on electron beam parameters of Siberia-2. Changes of these parameters (betatron tunes, horizontal emittance of the electron beam, momentum compaction, energy spread etc.) are discussed in the report. Different methods of compensation (global and local) of betatron functions distortion are presented. Much attention is paid to dynamic aperture calculations using analytical approximation of magnetic field behavior in transverse horizontal direction

  19. EXPERIMENTAL CHARACTERIZATION OF A MAGNETOHYDRODYNAMIC POWER GENERATOR UNDER DC ARC PLASMA

    Directory of Open Access Journals (Sweden)

    Ayokunle Oluwaseun Ayeleso

    2018-02-01

    Full Text Available The generation of electric power through the conventional systems (thermal and hydroelectric is no longer sufficient to meet the increasing industrial and commercial usage. Therefore, an alternative energy conversion system is currently being sought. The aim of the presented study is to develop a direct energy conversion system (Magnetohydrodynamics, MHD generator to generate electric power using plasma. Additionally, the generator electric response is investigated based on the Faraday’s principle of electromagnetism and fluid dynamics. For this purpose, a rectangular MHD generator prototype with segmented electrodes was constructed and subjected to continuous plasma from a DC arc source at test facilities available in the Western Cape region (South Africa. Subsequently, the terminal voltages at the middle-electrodes were measured one after another across 1, 100 and 470 Ω load resistors. In all experiments, the absolute time-averages of the measured terminal voltage across each load resistor were similar, which indicates a generation of power. The maximum power of the order 0.203mW was obtained when 1 Ω resistor was connected to the middle-electrodes. Conclusively, these results validate the measurement approach of the MHD generator with segmented electrodes and could be used to design a large MHD unit that can be incorporated to the existing conventional thermal plant to improve their cyclic thermal efficiency.

  20. CesrTA Retarding Field Analyzer Measurements in Drifts, Dipoles, Quadrupoles and Wigglers

    International Nuclear Information System (INIS)

    Calvey, J.R.; Li, Y.; Livezey, J.A.; Makita, J.; Meller, R.E.; Palmer, M.A.; Schwartz, R.M.; Strohman, C.R.; Harkay, K.; Calatroni, S.; Rumolo, G.; Kanazawa, K.; Suetsugu, Y.; Pivi, M.; Wang, L.

    2010-01-01

    Over the course of the CesrTA program, the Cornell Electron Storage Ring (CESR) has been instrumented with several retarding field analyzers (RFAs), which measure the local density and energy distribution of the electron cloud. These RFAs have been installed in drifts, dipoles, quadrupoles, and wigglers; and data have been taken in a variety of beam conditions and bunch configurations. This paper will provide an overview of these results, and give a preliminary evaluation of the efficacy of cloud mitigation techniques implemented in the instrumented vacuum chambers.

  1. Design of end magnetic structures for the Advanced Light Source wigglers

    International Nuclear Information System (INIS)

    Humphries, D.; Akre, J.; Hoyer, E.; Marks, S.; Minamihara, Y.; Pipersky, P.; Plate, D.; Schlueter, R.

    1995-01-01

    The vertical magnetic structures for the Advanced Light planar wiggler and 20 cm period elliptical hybrid permanent magnet design. The ends of these structures are characterized by diminishing scalar potential distributions the poles which control beam trajectories. They incorporate electromagnetic correction coils to dynamically correct for variations in the first integral of the field as a function of gap. A permanent magnet trim mechanism is incorporated to minimize the transverse integrated error field distribution. The ends were designed using analytic and computer modeling techniques. The design and modeling results are presented

  2. Depth-of-field effects in wiggler radiation sources: Geometrical versus wave optics

    Directory of Open Access Journals (Sweden)

    Richard P. Walker

    2017-02-01

    Full Text Available A detailed analysis is carried out of the optical properties of synchrotron radiation emitted by multipole wigglers, concentrating on the effective source size and brightness and the so-called “depth of field” effects, concerning which there has been some controversy in the literature. By comparing calculations made with both geometrical optics and wave optics methods we demonstrate that the two approaches are not at variance, and that the wave optics results tend towards those of geometrical optics under well-defined conditions.

  3. A differentially pumped argon plasma in the linear plasma generator Magnum-PSI: gas flow and dynamics of the ionized fraction

    NARCIS (Netherlands)

    Eck, van H.J.N.; Hansen, T.A.R.; Kleyn, A.W.; Meiden, van der H.J.; Schram, D.C.; Zeijlmans van Emmichoven, P.A.

    2011-01-01

    Magnum-PSI is a linear plasma generator designed to reach the plasma–surface interaction (PSI) regime of ITER and nuclear fusion reactors beyond ITER. To reach this regime, the influx of cold neutrals from the source must be significantly lower than the plasma flux reaching the target. This is

  4. Megagauss field generation for high-energy-density plasma science experiments

    International Nuclear Information System (INIS)

    Rovang, Dean Curtis; Struve, Kenneth William; Porter, John Larry Jr.

    2008-01-01

    There is a need to generate magnetic fields both above and below 1 megagauss (100 T) with compact generators for laser-plasma experiments in the Beamlet and Petawatt test chambers for focused research on fundamental properties of high energy density magnetic plasmas. Some of the important topics that could be addressed with such a capability are magnetic field diffusion, particle confinement, plasma instabilities, spectroscopic diagnostic development, material properties, flux compression, and alternate confinement schemes, all of which could directly support experiments on Z. This report summarizes a two-month study to develop preliminary designs of magnetic field generators for three design regimes. These are, (1) a design for a relatively low-field (10 to 50 T), compact generator for modest volumes (1 to 10 cm3), (2) a high-field (50 to 200 T) design for smaller volumes (10 to 100 mm3), and (3) an extreme field (greater than 600 T) design that uses flux compression. These designs rely on existing Sandia pulsed-power expertise and equipment, and address issues of magnetic field scaling with capacitor bank design and field inductance, vacuum interface, and trade-offs between inductance and coil designs

  5. Simulation studies of plasma waves in the electron foreshock: The generation of downshifted oscillations

    International Nuclear Information System (INIS)

    Dum, C.T.

    1990-01-01

    The generation of waves with frequencies downshifted from the plasma frequency, as observed in the electron foreshock, is analyzed by particle simulation. Wave excitation differs fundamentally from the familiar excitation of the plasma eigenmodes by a gentle bump-on-tail electron distribution. Beam modes are destabilized by resonant interaction with bulk electrons, provided the beamvelocity spread is very small. These modes are stabilized, starting with the higher frequencies, as the beam is broadened and slowed down by the interaction with the wave spectrum. Initially, a very cold beam is also capable of exciting frequencies considerably above the plasma frequency, but such oscillations are quickly stabilized. Low-frequency modes persist for a long time, until the bump in the electron distribution is completely ironed out. This diffusion process also is quite different from the familiar case of well-separated beam and bulk electrons. A quantitative analysis of these processes is carried out

  6. Simulation studies of plasma waves in the electron foreshock - The generation of downshifted oscillations

    Science.gov (United States)

    Dum, C. T.

    1990-01-01

    The generation of waves with frequencies downshifted from the plasma frequency, as observed in the electron foreshock, is analyzed by particle simulation. Wave excitation differs fundamentally from the familiar excitation of the plasma eigenmodes by a gentle bump-on-tail electron distribution. Beam modes are destabilized by resonant interaction with bulk electrons, provided the beam velocity spread is very small. These modes are stabilized, starting with the higher frequencies, as the beam is broadened and slowed down by the interaction with the wave spectrum. Initially a very cold beam is also capable of exciting frequencies considerably above the plasma frequency, but such oscillations are quickly stabilized. Low-frequency modes persist for a long time, until the bump in the electron distribution is completely 'ironed' out. This diffusion process also is quite different from the familiar case of well-separated beam and bulk electrons. A quantitative analysis of these processes is carried out.

  7. Terahertz radiation generation by lasers with remarkable efficiency in electron–positron plasma

    International Nuclear Information System (INIS)

    Malik, Hitendra K.

    2015-01-01

    Photo-mixing of spatial-super-Gaussian lasers and electron–positron plasma are proposed for realizing a large amplitude nonlinear current in order to generate an efficient terahertz radiation. An external magnetic field together with a proper index of the lasers helps achieving controllable current and hence, the focused radiation of tunable frequency and power along with a remarkable efficiency of the scheme as ∼6%. - Highlights: • First proposal of photo-mixing of spatial-super-Gaussian (SSG) lasers in electron–positron (e–p) plasma. • Large amplitude nonlinear current due to the contribution of both the plasma species. • Magnetic field as an additional parameter for tunable THz radiation with a remarkable efficiency of ∼6%.

  8. Generation and confinement of microwave gas-plasma in photonic dielectric microstructure.

    Science.gov (United States)

    Debord, B; Jamier, R; Gérôme, F; Leroy, O; Boisse-Laporte, C; Leprince, P; Alves, L L; Benabid, F

    2013-10-21

    We report on a self-guided microwave surface-wave induced generation of ~60 μm diameter and 6 cm-long column of argon-plasma confined in the core of a hollow-core photonic crystal fiber. At gas pressure of 1 mbar, the micro-confined plasma exhibits a stable transverse profile with a maximum gas-temperature as high as 1300 ± 200 K, and a wall-temperature as low as 500 K, and an electron density level of 10¹⁴ cm⁻³. The fiber guided fluorescence emission presents strong Ar⁺ spectral lines in the visible and near UV. Theory shows that the observed combination of relatively low wall-temperature and high ionisation rate in this strongly confined configuration is due to an unprecedentedly wide electrostatic space-charge field and the subsequent ion acceleration dominance in the plasma-to-gas power transfer.

  9. Propagation of laser-generated plasma jet in an ambient medium

    International Nuclear Information System (INIS)

    Loupias, B; Falize, E; Vinci, T; Bouquet, S; Gregory, C D; Koenig, M; Ravasio, A; Pikuz, S; Waugh, J; Woolsey, N C; Nazarov, W; Michaut, C; Kuramitsu, Y; Seiichi, D; Sakawa, Y; Takabe, H; Schiavi, A; Atzeni, S

    2009-01-01

    In this work we present experimental research related to laboratory astrophysics using an intense laser. The goal of these experiments is to investigate some of the complex features of young stellar objects and astrophysical outflows, in particular the plasma jet interaction with the interstellar medium. The relevance of these experiments to astrophysics is measured through similarity criteria (scaling laws). These ensure the similarity between the astrophysical object and the laboratory provided that the dimensionless numbers are equivalent. Consequently, measurements of the plasma parameters are crucial to link laboratory research to astrophysics as they are needed for the determination of these dimensionless numbers. In this context, we designed experiments to generate plasma jets using an intense laser, and to study the evolution in vacuum and in an ambient medium.

  10. Ion energy loss at maximum stopping power in a laser-generated plasma

    International Nuclear Information System (INIS)

    Cayzac, W.

    2013-01-01

    In the frame of this thesis, a new experimental setup for the measurement of the energy loss of carbon ions at maximum stopping power in a hot laser-generated plasma has been developed and successfully tested. In this parameter range where the projectile velocity is of the same order of magnitude as the thermal velocity of the plasma free electrons, large uncertainties of up to 50% are present in the stopping-power description. To date, no experimental data are available to perform a theory benchmarking. Testing the different stopping theories is yet essential for inertial confinement fusion and in particular for the understanding of the alpha-particle heating of the thermonuclear fuel. Here, for the first time, precise measurements were carried out in a reproducible and entirely characterized beam-plasma configuration. It involved a nearly fully-stripped ion beam probing a homogeneous fully-ionized plasma. This plasma was generated by irradiating a thin carbon foil with two high-energy laser beams and features a maximum electron temperature of 200 eV. The plasma conditions were simulated with a two-dimensional radiative hydrodynamic code, while the ion-beam charge-state distribution was predicted by means of a Monte-Carlo code describing the charge-exchange processes of projectile ions in plasma. To probe at maximum stopping power, high-frequency pulsed ion bunches were decelerated to an energy of 0.5 MeV per nucleon. The ion energy loss was determined by a time-of-flight measurement using a specifically developed chemical-vapor-deposition diamond detector that was screened against any plasma radiation. A first experimental campaign was carried out using this newly developed platform, in which a precision better than 200 keV on the energy loss was reached. This allowed, via the knowledge of the plasma and of the beam parameters, to reliably test several stopping theories, either based on perturbation theory or on a nonlinear T-Matrix formalism. A preliminary

  11. DIII-D Integrated plasma control solutions for ITER and next-generation tokamaks

    International Nuclear Information System (INIS)

    Humphreys, D.A.; Ferron, J.R.; Hyatt, A.W.; La Haye, R.J.; Leuer, J.A.; Penaflor, B.G.; Walker, M.L.; Welander, A.S.; In, Y.

    2008-01-01

    Plasma control design approaches and solutions developed at DIII-D to address its control-intensive advanced tokamak (AT) mission are applicable to many problems facing ITER and other next-generation devices. A systematic approach to algorithm design, termed 'integrated plasma control,' enables new tokamak controllers to be applied operationally with minimal machine time required for tuning. Such high confidence plasma control algorithms are designed using relatively simple ('control-level') models validated against experimental response data and are verified in simulation prior to operational use. A key element of DIII-D integrated plasma control, also required in the ITER baseline control approach, is the ability to verify both controller performance and implementation by running simulations that connect directly to the actual plasma control system (PCS) that is used to operate the tokamak itself. The DIII-D PCS comprises a powerful and flexible C-based realtime code and programming infrastructure, as well as an arbitrarily scalable hardware and realtime network architecture. This software infrastructure provides a general platform for implementation and verification of realtime algorithms with arbitrary complexity, limited only by speed of execution requirements. We present a complete suite of tools (known collectively as TokSys) supporting the integrated plasma control design process, along with recent examples of control algorithms designed for the DIII-D PCS. The use of validated physics-based models and a systematic model-based design and verification process enables these control solutions to be directly applied to ITER and other next-generation tokamaks

  12. Magnetic field adjustment structure and method for a tapered wiggler

    Science.gov (United States)

    Halbach, Klaus

    1988-01-01

    An improved method and structure is disclosed for adjusting the magnetic field generated by a group of electromagnet poles spaced along the path of a charged particle beam to compensate for energy losses in the charged particles which comprises providing more than one winding on at least some of the electromagnet poles; connecting one respective winding on each of several consecutive adjacent electromagnet poles to a first power supply, and the other respective winding on the electromagnet pole to a different power supply in staggered order; and independently adjusting one power supply to independently vary the current in one winding on each electromagnet pole in a group whereby the magnetic field strength of each of a group of electromagnet poles may be changed in smaller increments.

  13. Iron plasma generation using a Nd:YAG laser pulse of several hundred picoseconds

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Jun, E-mail: jtamura@post.j-parc.jp [J-PARC Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Kumaki, Masafumi [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Kondo, Kotaro [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Kanesue, Takeshi; Okamura, Masahiro [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2016-02-15

    We investigated the high intensity plasma generated by using a Nd:YAG laser to apply a laser-produced plasma to the direct plasma injection scheme. The capability of the source to generate high charge state ions strongly depends on the power density of the laser irradiation. Therefore, we focused on using a higher power laser with several hundred picoseconds of pulse width. The iron target was irradiated with the pulsed laser, and the ion current of the laser-produced iron plasma was measured using a Faraday cup and the charge state distribution was investigated using an electrostatic ion analyzer. We found that higher charge state iron ions (up to Fe{sup 21+}) were obtained using a laser pulse of several hundred picoseconds in comparison to those obtained using a laser pulse of several nanoseconds (up to Fe{sup 19+}). We also found that when the laser irradiation area was relatively large, the laser power was absorbed mainly by the contamination on the target surface.

  14. An Explorative Study to Use DBD Plasma Generation for Aircraft Icing Mitigation

    Science.gov (United States)

    Hu, Hui; Zhou, Wenwu; Liu, Yang; Kolbakir, Cem

    2017-11-01

    An explorative investigation was performed to demonstrate the feasibility of utilizing thermal effect induced by Dielectric-Barrier-Discharge (DBD) plasma generation for aircraft icing mitigation. The experimental study was performed in an Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). A NACA0012 airfoil/wing model embedded with DBD plasma actuators was installed in ISU-IRT under typical glaze icing conditions pertinent to aircraft inflight icing phenomena. While a high-speed imaging system was used to record the dynamic ice accretion process over the airfoil surface for the test cases with and without switching on the DBD plasma actuators, an infrared (IR) thermal imaging system was utilized to map the corresponding temperature distributions to quantify the unsteady heat transfer and phase changing process over the airfoil surface. The thermal effect induced by DBD plasma generation was demonstrated to be able to keep the airfoil surface staying free of ice during the entire ice accretion experiment. The measured quantitative surface temperature distributions were correlated with the acquired images of the dynamic ice accretion and water runback processes to elucidate the underlying physics. National Science Foundation CBET-1064196 and CBET-1435590.

  15. Design of extraction system on grid of plasma generator electrode for pulsed electron irradiator

    International Nuclear Information System (INIS)

    Agus Purwadi; Bambang Siswanto; Lely Susita RM; Suprapto; Anjar Anggraini H; Ihwanul Azis

    2016-01-01

    It has been carried out design and study of electron extraction particularly for obtaining the electron extraction current via grid on the Plasma Generator Chamber (PGC) caused by the existence of extraction voltage U_a. Electrons of plasma surface emitted to acceleration region through emission window and then extracted acceleration by extraction voltage U_a through foil window to atmospheric region for being applied to any target. Applied extraction voltage U_a on PEI device influences the forming and energy value of electron extraction current I_e then the PGC dimension influences the product of thermal electron emission current I_e_0. It has been determinated the PGC geometry and dimension of producing electron extraction current based on arc discharge plasma current to desire on any plasma density. From the calculation yield for the value of plasma density n_e = 78 x 10"1"0 cm"-"3 and the arc discharge current Id = 80 A (pulse width τ = 100µs) used the PGC size of (80 x 20 x 40) cm"3. Emission window area of (65 x 15) cm"2 located on the low part surface of PGC is covered by a grid sheet made of stainless steel of rectangular shape and the distance of one grid hole to another is 0,25 mm each others. Current value of I_e beside depends on plasma parameters also depends on the size of grid holes. The optimum of geometry and size is rectangular with its side size of p ≈ 0,50 mm with the plasma parameters optimum (density value n_e = 10"1"6 m"-"3 and electron temperature T_e = 6 eV). From the initial experiment yields obtained that the electron extraction efficiency value α = 37,25 % on extraction voltage V = 3 kV. (author)

  16. Generation of longitudinal current by a transverse electromagnetic field in classical and quantum plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Latyshev, A. V., E-mail: avlatyshev@mail.ru; Yushkanov, A. A. [Moscow State Regional University (Russian Federation)

    2015-09-15

    A distribution function for collisionless plasma is derived from the Vlasov kinetic equation in the quadratic approximation with respect to the electromagnetic field. Formulas for calculation of the electric current at an arbitrary temperature (arbitrary degree of degeneration of the electron gas) are deduced. The case of small wavenumbers is considered. It is shown that nonlinearity leads to the generation of an electric current directed along the wave vector. This longitudinal current is orthogonal to the classical transverse current, well known in the linear theory. A distribution function for collisionless quantum plasma is derived from the kinetic equation with the Wigner integral in the quadratic approximation with respect to the vector potential. Formulas for calculation of the electric current at an arbitrary temperature are deduced. The case of small wavenumbers is considered. It is shown that, at small values of the wavenumber, the value of the longitudinal current for quantum plasma coincides with that for classical plasma. The dimensionless currents in quantum and classical plasmas are compared graphically.

  17. Electron emission and plasma generation in a modulator electron gun using ferroelectric cathode

    International Nuclear Information System (INIS)

    Chen Shutao; Zheng Shuxin; Zhu Ziqiu; Dong Xianlin; Tang Chuanxiang

    2006-01-01

    Strong electron emission and dense plasma generation have been observed in a modulator electron gun with a Ba 0.67 Sr 0.33 TiO 3 ferroelectric cathode. Parameter of the modulator electron gun and lifetime of the ferroelectric cathode were investigated. It was shown that electron emission from Ba 0.67 Sr 0.33 TiO 3 cathode with a positive triggering pulse is a sort of plasma emission. Electrons were emitted by the co-effect of surface plasma and non-compensated negative polarization charges at the surface of the ferroelectric. The element analyses of the graphite collector after emission process was performed to show the ingredient of the plasma consist of Ba, Ti and Cu heavy cations of the ceramic compound and electrode. It was demonstrated the validity of the Child-Langmuir law by introducing the decrease of vacuum gap and increase of emission area caused by the expansion of the surface plasma

  18. Study of magnetic field expansion using a plasma generator for space radiation active protection

    International Nuclear Information System (INIS)

    Jia Xianghong; Jia Shaoxia; Wan Jun; Wang Shouguo; Xu Feng; Bai Yanqiang; Liu Hongtao; Jiang Rui; Ma Hongbo

    2013-01-01

    There are many active protecting methods including Electrostatic Fields, Confined Magnetic Field, Unconfined Magnetic Field and Plasma Shielding etc. for defending the high-energy solar particle events (SPE) and Galactic Cosmic Rays (GCR) in deep space exploration. The concept of using cold plasma to expand a magnetic field is the best one of all possible methods so far. The magnetic field expansion caused by plasma can improve its protective efficiency of space particles. One kind of plasma generator has been developed and installed into the cylindrical permanent magnet in the eccentric. A plasma stream is produced using a helical-shaped antenna driven by a radio-frequency (RF) power supply of 13.56 MHz, which exits from both sides of the magnet and makes the magnetic field expand on one side. The discharging belts phenomenon is similar to the Earth's radiation belt, but the mechanism has yet to be understood. A magnetic probe is used to measure the magnetic field expansion distributions, and the results indicate that the magnetic field intensity increases under higher increments of the discharge power. (authors)

  19. Electrostatic wave heating and possible formation of self-generated high electric fields in a magnetized plasma

    Science.gov (United States)

    Mascali, D.; Celona, L.; Gammino, S.; Miracoli, R.; Castro, G.; Gambino, N.; Ciavola, G.

    2011-10-01

    A plasma reactor operates at the Laboratori Nazionali del Sud of INFN, Catania, and it has been used as a test-bench for the investigation of innovative mechanisms of plasma ignition based on electrostatic waves (ES-W), obtained via the inner plasma EM-to-ES wave conversion. Evidences of Bernstein wave (BW) generation will be shown. The Langmuir probe measurements have revealed a strong increase of the ion saturation current, where the BW are generated or absorbed, this being a signature of possible high energy ion flows. The results are interpreted through the Bernstein wave heating theory, which predicts the formation of high speed rotating layers of the plasma (a dense plasma ring is in fact observed). High intensity inner plasma self-generated electric fields (on the order of several tens of kV/cm) come out by our calculations.

  20. Characterization of the gas-puff imploding plasma on the NRL Gamble II generator

    International Nuclear Information System (INIS)

    Stephanakis, S.J.; Boller, J.R.; Cooperstein, G.

    1984-01-01

    Recently, an experimental and theoretical effort has been undertaken at NRL aimed at contributing to understanding the physics of the implosion dynamics and of the resulting highly localized plasma pinch in such experiments. Supersonic nozzles producing a cylindrical gas flow provide the load for the Gamble II generator operating at the 1.5 TW level. The gas jet is preionized and then imploded to the axis by the machine electrical pulse in a very short time scale. During the implosion process, the attained kinetic energy is efficiently converted to plasma thermal energy and produces the desired radiation. Preliminary experimental results are presented from the study of the conditions necessary in order to efficiently couple such loads to the Gamble II generator. These results are correlated to existing scaling laws and are compared with theoretical models

  1. Modeling Laser and e-Beam Generated Plasma-Plume Experiments Using LASNEX

    CERN Document Server

    Ho, D

    1999-01-01

    The hydrodynamics code LASNEX is used to model the laser and e-beam generated plasma-plume experiments. The laser used has a wavelength of 1 (micro)m and the FWHM spot size is 1 mm. The total laser energy is 160 mJ. The simulation shows that the plume expands at a velocity of about 6 cm/(micro)s. The e-beam generated from the Experimental Test Accelerator (ETA) has 5.5 MeV and FWHM spot size ranges from 2 to 3.3 mm. From the simulations, the plasma plume expansion velocity ranges from about 3 to 6 mm/(micro)s and the velocity increases with decreasing spot size. All the simulation results reported here are in close agreement with experimental data.

  2. Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Gregory Elijah [The Ohio State Univ., Columbus, OH (United States)

    2013-01-01

    Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic

  3. Study on THz wave generation from air plasma induced by quasi-square Airy beam

    Science.gov (United States)

    Zhang, Shijing; Zhang, Liangliang; Jiang, Guangtong; Zhang, Cunlin; Zhao, Yuejin

    2018-01-01

    Terahertz (THz) wave has attracted considerable attention in recent years because of its potential applications. The intense THz waves generated from air plasma induced by two-color femtosecond laser are widely used due to its high generation efficiency and broad frequency bandwidth. The parameters of the laser change the distribution of the air plasma, and then affect the generation of THz wave. In this research, we investigate the THz wave generation from air plasma induced by quasi-square Airy beam. Unlike the common Gauss beam, the quasi-square Airy beam has ability to autofocus and to increase the maximum intensity at the focus. By using the spatial light modulator (SLM), we can change the parameters of phase map to control the shape of the Airy beam. We obtain the two-color laser field by a 100-um-thick BBO crystal, then use a Golay detector to record THz wave energy. By comparing terahertz generation at different modulation depths, we find that terahertz energy produced by quasi-square Airy beam is up to 3.1 times stronger than that of Gauss beam with identical laser energy. In order to understand the influence of quasi-square Airy beam on the BBO crystal, we record THz wave energy by changing the azimuthal angle of BBO crystal with Gauss beam and Airy beam at different modulation depths. We find that the trend of terahertz energy with respect to the azimuthal angle of the BBO crystal keeps the same for different laser beams. We believe that the quasi-square Airy beam or other auto focusing beam can significantly improve the efficiency of terahertz wave generation and pave the way for its applications.

  4. RF generator interlock by plasma grid bias current - An alternate to Hα interlock

    Science.gov (United States)

    Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

    2017-08-01

    ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma

  5. Gyrofluid Simulations of Intrinsic Rotation Generation in Reversed Shear Plasmas with Internal Transport Barriers

    Science.gov (United States)

    Jhang, Hogun; Kim, S. S.; Kwon, J. M.; Terzolo, L.; Kim, J. Y.; Diamond, P. H.

    2010-11-01

    It is accepted that the intrinsic rotation is generated via the residual stress, which is non-diffusive components of the turbulent Reynolds stress, without external momentum input. The physics leading to the onset of intrinsic rotation in L- and H- mode plasmas have been elucidated elsewhere. However, the physics responsible for the generation and transport of the intrinsic rotation and its relationship to the formation of internal transport barriers (ITBs) in reversed shear (RS) plasmas have not been explored in detail, which is the main subject in the present work. The revised version of the global gyrofluid code TRB is used for this study. It is found that the large intrinsic rotation (˜10-30% of the ion sound speed depending on ITB characteristics) is generated near the ITB region and propagates into the core. The intrinsic rotation increases linearly as the temperature gradient at ITB position increases, albeit not indefinitely. Key parameters related to the symmetry breaking, such as turbulent intensity and its gradient, the flux surface averaged parallel wavenumber are evaluated dynamically during the ITB formation. In particular, the role of reversed shear and the q-profile curvature is presented in relation to the symmetry breaking in RS plasmas.

  6. Plasmas generated by ultra-violet light rather than electron impact

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, R. N. [Department of Astronomy and Physics, The Open University, Milton Keynes MK7 6AA (United Kingdom); Allen, J. E. [University College, University of Oxford, Oxford OX1 4BH, United Kingdom and OCIAM, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Thomas, D. M. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Benilov, M. S. [Departamento de Fisica, CCCEE, Universidade de Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2013-12-15

    We analyze, in both plane and cylindrical geometries, a collisionless plasma consisting of an inner region where generation occurs by UV illumination, and an un-illuminated outer region with no generation. Ions generated in the inner region flow outwards through the outer region and into a wall. We solve for this system's steady state, first in the quasi-neutral regime (where the Debye length λ{sub D} vanishes and analytic solutions exist) and then in the general case, which we solve numerically. In the general case, a double layer forms where the illuminated and un-illuminated regions meet, and an approximately quasi-neutral plasma connects the double layer to the wall sheath; in plane geometry, the ions coast through the quasi-neutral section at slightly more than the Bohm speed c{sub s}. The system, although simple, therefore has two novel features: a double layer that does not require counter-streaming ions and electrons, and a quasi-neutral plasma where ions travel in straight lines with at least the Bohm speed. We close with a précis of our asymptotic solutions of this system, and suggest how our theoretical conclusions might be extended and tested in the laboratory.

  7. Spontaneous generation of electromagnetic waves in plasmas with electron thermal flux

    International Nuclear Information System (INIS)

    Okada, Toshio

    1977-01-01

    Spontaneous generation of propagating electromagnetic fields due to a microinstability is investigated for plasmas which convey electron thermal fluxes. The following two cases are examined: 1) Electromagnetic fields spontaneously excited by electrons in a velocity distribution of skewed Maxwellian type. 2) Electromagnetic waves generated by electrons in a velocity distribution which consists of a main part and a high energy part. In this case, the electron thermal flux can be very high. In both cases, induced electromagnetic waves with relatively low frequencies propagate parallel to the direction of Thermal flux. (auth.)

  8. Modulation of terahertz generation in dual-color filaments by an external electric field and preformed plasma

    International Nuclear Information System (INIS)

    Li Min; Li An-Yuan; Yuan Shuai; Zeng He-Ping; He Bo-Qu

    2016-01-01

    Terahertz generation driven by dual-color filaments in air is demonstrated to be remarkably enhanced by applying an external electric field to the filaments. As terahertz generation is sensitive to the dual-color phase difference, a preformed plasma is verified efficiently in modulating terahertz radiation from linear to elliptical polarization. In the presence of preformed plasma, a dual-color filament generates terahertz pulses of elliptical polarization and the corresponding ellipse rotates regularly with the change of the preformed plasma density. The observed terahertz modulation with the external electric field and the preformed plasma provides a simple way to estimate the plasma density and evaluate the photocurrent dynamics of the dual-color filaments. It provides further experimental evidence of the photo-current model in governing the dual-color filament driven terahertz generation processes. (paper)

  9. Modeling the effects of a flat wiggler on a storage ring beam

    International Nuclear Information System (INIS)

    Helm, R.H.

    1978-06-01

    The purpose of the present note is to show how the various effects of the wiggler may be modeled in a simple way suitable for use in machine control. It will be seen that in general a total of about 17 functions are involved. However, in typical designs many of these functions vanish identically because of symmetries, and others are neglibly small. Furthermore, each of the functions may be modeled quite accurately by a single power law in (B/sub o//E)/sup n/ where B is a measure of the field excitation. E is the beam energy, and n is an integer which takes on values of either 0, 2, 3, 4, for 5 for the different functions. Magnet saturation may cause the field distribution to vary with excitation so that the series coefficients would vary slowly with B/sub o/. A computer program has been used to obtain numerical results for typical wiggler designs. In practice, the required functions could be determined either by computer analysis of the measured field data, or by experimental calibration using the stored beam in the ring. 9 refs., 3 figs., 11 tabs

  10. Ion tail formation and its effect on 14-MeV neutron generation in D-3He plasmas

    International Nuclear Information System (INIS)

    Matsuura, H.; Nakao, Y.; Kudo, K.

    1992-01-01

    This paper reports on the triton distribution function in D- 3 He plasmas which is distorted from a Maxwellian owing to the presence of a 1.01-MeV birth component. The deuteron-triton reaction rate (i.e., 14-MeV neutron generation rate) in the plasma should be smaller than the values evaluated by assuming a Maxwellian triton distribution. A local Fokker-Planck calculation shows that although the degree of the decrease in 14-MeV neutron generation strongly depends on the plasma conditions and also on the energy loss mechanism, it becomes appreciable in actual burning plasmas

  11. Occurrence and location of concentrated load and generator regions observed by Cluster in the plasma sheet

    Directory of Open Access Journals (Sweden)

    M. Hamrin

    2009-11-01

    Full Text Available Here, and in a companion paper by Hamrin et al. (2009 [Scale size and life time of energy conversion regions observed by Cluster in the plasma sheet], we investigate localized energy conversion regions (ECRs in the Earth's plasma sheet. In total we have studied 151 ECRs within 660 h of plasma sheet data from the summer and fall of 2001 when Cluster was close to apogee at an altitude of about 15–20 RE. Cluster offers appropriate conditions for the investigation of energy conversion by the evaluation of the power density, E·J, where E is the electric field and J the current density. From the sign of the power density, we have identified more than three times as many Concentrated Load Regions (CLRs as Concentrated Generator Regions (CGRs. We also note that the CLRs appear to be stronger. To our knowledge, these are the first in situ observations confirming the general notion of the plasma sheet, on the average, behaving as a load. At the same time the plasma sheet appears to be highly structured, with energy conversion occurring in both directions between the fields and the particles. From our data we also find that the CLRs appear to be located closer to the neutral sheet, while CGRs prefer locations towards the plasma sheet boundary layer (PSBL. For both CLRs and CGRs, E and J in the GSM y (cross-tail direction dominate the total power density, even though the z contribution occasionally can be significant. The prevalence of the y-direction seems to be weaker for the CGRs, possibly related to a higher fluctuation level near the PSBL.

  12. Roughness generation during Si etching in Cl{sub 2} pulsed plasma

    Energy Technology Data Exchange (ETDEWEB)

    Mourey, Odile; Petit-Etienne, Camille; Cunge, Gilles, E-mail: gilles.cunge@cea.fr; Darnon, Maxime; Despiau-Pujo, Emilie; Brichon, Paulin; Lattu-Romain, Eddy; Pons, Michel; Joubert, Olivier [Univ. Grenoble Alpes, CNRS, CEA-Leti Minatec, LTM, F-38054 Grenoble Cedex (France)

    2016-07-15

    Pulsed plasmas are promising candidates to go beyond limitations of continuous waves' plasma. However, their interaction with surfaces remains poorly understood. The authors investigated the silicon etching mechanism in inductively coupled plasma (ICP) Cl{sub 2} operated either in an ICP-pulsed mode or in a bias-pulsed mode (in which only the bias power is pulsed). The authors observed systematically the development of an important surface roughness at a low duty cycle. By using plasma diagnostics, they show that the roughness is correlated to an anomalously large (Cl atoms flux)/(energetic ion flux) ratio in the pulsed mode. The rational is that the Cl atom flux is not modulated on the timescale of the plasma pulses although the ion fluxes and energy are modulated. As a result, a very strong surface chlorination occurs during the OFF period when the surface is not exposed to energetic ions. Therefore, each energetic ion in the ON period will bombard a heavily chlorinated silicon surface, leading to anomalously high etching yield. In the ICP pulsed mode (in which the ion energy is high), the authors report yields as high as 40, which mean that each individual ion impacts will generate a “crater” of about 2 nm depth at the surface. Since the ion flux is very small in the pulsed ICP mode, this process is stochastic and is responsible for the roughness initiation. The roughness expansion can then be attributed partly to the ion channeling effect and is probably enhanced by the formation of a SiClx reactive layer with nonhomogeneous thickness over the topography of the surface. This phenomenon could be a serious limitation of pulsed plasma processes.

  13. Effects of laser-polarization and wiggler magnetic fields on electron acceleration in laser-cluster interaction

    Science.gov (United States)

    Singh Ghotra, Harjit; Kant, Niti

    2018-06-01

    We examine the electron dynamics during laser-cluster interaction. In addition to the electrostatic field of an individual cluster and laser field, we consider an external transverse wiggler magnetic field, which plays a pivotal role in enhancing the electron acceleration. Single-particle simulation has been presented with a short pulse linearly polarized as well as circularly polarized laser pulses for electron acceleration in a cluster. The persisting Coulomb field allows the electron to absorb energy from the laser field. The stochastically heated electron finds a weak electric field at the edge of the cluster from where it is ejected. The wiggler magnetic field connects the regions of the stochastically heated, ejected electron from the cluster and high energy gain by the electron from the laser field outside the cluster. This increases the field strength and hence supports the electron to meet the phase of the laser field for enhanced acceleration. A long duration resonance appears with an optimized magnetic wiggler field of about 3.4 kG. Hence, the relativistic energy gain by the electron is enhanced up to a few 100 MeV with an intense short pulse laser with an intensity of about 1019 W cm‑2 in the presence of a wiggler magnetic field.

  14. The dynamics of gas-puff imploding plasmas on the NRL Gamble II Generator

    International Nuclear Information System (INIS)

    Stephanakis, S.J.; Boller, J.R.; Hinshelwood, D.D.; McDonald, S.W.; Mehlman, C.G.; Ottinger, P.F.; Young, F.C.

    1985-01-01

    The experimental study of imploding plasma loads on the NRL Gamble II generator was initiated more than a year ago. Preliminary results including scaling laws for K-line radiation output from neon puffs and the effect of plasma erosion opening switches (PEOS's) on the x-ray yields and the pinch quality were reported upon during the past year. In order to better understand the implosion dynamics of such plasmas, time-resolved photographs have been taken of the implosion history. In contrast with time-integrated x-ray pinhole photographs, the time-resolved visible-light pictures indicate that the implosion phase is essentially instability-free, while pinching and flaring occur at late times during the blow-up phase. Furthermore, these visible-light framing photographs clearly show that the discharge is flared out toward the anode at early times and becomes cylindrical at implosion. This so-called ''zipper-effect'' has been seen in previous argon-puff experiments and is due to the non-uniform initial distribution of gas across the anode-cathode gap. The authors present comparisons of time-resolved photographs taken both in visible and x-ray light along with x-ray spectra taken with and without PEOS's. The implications of these data are discussed in view of the present theoretical understanding of the plasma implosion dynamics

  15. The dynamics of gas-puff imploding plasmas on the NRL Gamble II generator

    International Nuclear Information System (INIS)

    Stephanakis, S.J.; Boller, J.R.; Hinshelwood, D.D.; McDonald, S.W.; Mehlman, C.G.; Ottinger, P.F.; Young, F.C.

    1985-01-01

    The experimental study of imploding plasma loads on the NRL Gamble II generator was initiated more than a year ago. Preliminary results including scaling laws for K-line radiation output from neon puffs and the effect of plasma erosion opening switches (PEOS's) on the x-ray yields and the pinch quality were reported upon during the past year. In order to better understand the implosion dynamics of such plasmas, time-resolved photographs have been taken of the implosion history. In contrast with time-integrated x-ray pinhole photographs, the time-resolved visible-light pictures indicate that the implosion phase is essentially instability-free, while pinching and flaring occur at late times during the blow-up phase. Furthermore, these visible-light framing photographs clearly show that the discharge is flared out toward the anode at early times and becomes cylindrical at implosion. This so-called ''zipper-effect'' has been seen in previous argon-puff experiments and is due to the non-uniform initial distribution of gas across the anode-cathode gap. The authors present comparisons of time-resolved photographs taken both in visible and x-ray light along with x-ray spectra taken with and without PEOS's. The implications of these data are discussed in view of the present theoretical understanding of the plasma implosion dynamics

  16. Magnetic and electric deflector spectrometers for ion emission analysis from laser generated plasma

    Directory of Open Access Journals (Sweden)

    Torrisi Lorenzo

    2018-01-01

    Full Text Available The pulsed laser-generated plasma in vacuum and at low and high intensities can be characterized using different physical diagnostics. The charge particles emission can be characterized using magnetic, electric and magnet-electrical spectrometers. Such on-line techniques are often based on time-of-flight (TOF measurements. A 90° electric deflection system is employed as ion energy analyzer (IEA acting as a filter of the mass-to-charge ratio of emitted ions towards a secondary electron multiplier. It determines the ion energy and charge state distributions. The measure of the ion and electron currents as a function of the mass-to-charge ratio can be also determined by a magnetic deflector spectrometer, using a magnetic field of the order of 0.35 T, orthogonal to the ion incident direction, and an array of little ion collectors (IC at different angles. A Thomson parabola spectrometer, employing gaf-chromix as detector, permits to be employed for ion mass, energy and charge state recognition. Mass quadrupole spectrometry, based on radiofrequency electric field oscillations, can be employed to characterize the plasma ion emission. Measurements performed on plasma produced by different lasers, irradiation conditions and targets are presented and discussed. Complementary measurements, based on mass and optical spectroscopy, semiconductor detectors, fast CCD camera and Langmuir probes are also employed for the full plasma characterization. Simulation programs, such as SRIM, SREM, and COMSOL are employed for the charge particle recognition.

  17. Generation of plasma X-ray sources via high repetition rate femtosecond laser pulses

    Science.gov (United States)

    Baguckis, Artūras; Plukis, Artūras; Reklaitis, Jonas; Remeikis, Vidmantas; Giniūnas, Linas; Vengris, Mikas

    2017-12-01

    In this study, we present the development and characterization of Cu plasma X-ray source driven by 20 W average power high repetition rate femtosecond laser in ambient atmosphere environment. The peak Cu- Kα photon flux of 2.3 × 109 photons/s into full solid angle is demonstrated (with a process conversion efficiency of 10-7), using pulses with peak intensity of 4.65 × 1014 W/cm2. Such Cu- Kα flux is significantly larger than others found in comparable experiments, performed in air environment. The effects of resonance plasma absorption process, when optimized, are shown to increase measured flux by the factor of 2-3. The relationship between X-ray photon flux and plasma-driving pulse repetition rate is quasi-linear, suggesting that fluxes could further be increased to 1010 photons/s using even higher average powers of driving radiation. These results suggest that to fully utilize the potential of high repetition rate laser sources, novel target material delivery systems (for example, jet-based ones) are required. On the other hand, this study demonstrates that high energy lasers currently used for plasma X-ray sources can be conveniently and efficiently replaced by high average power and repetition rate laser radiation, as a way to increase the brightness of the generated X-rays.

  18. Generation of a subgigagauss magnetic field by pinching the plasma channel of exploded-wire

    International Nuclear Information System (INIS)

    Bogolyubsky, S.L.

    1990-01-01

    An interest in the dense pinches produced in the explosion of thin wires in the diodes of high current-nanosecond-REB-generators is provided by an opportunity to obtain high temperature-dense plasma configurations as an object of fusion studies and that in the spectroscopy of multi-charged ions. One needs to have a micrometer size of the Z-pinch neck to ignite the fusion reaction. The plasma channel pinching of the wires exploded by a megaampere current to a micrometer size of its neck can provide gigagauss magnetic fields. An important aspect of a given study is verification of an opportunity to obtain the radiation collapse of the plasma channel due to an exploded wire along its whole length up to the kA because of a line radiation cut-off due to the Braginsky-Pease current reduction to 150-200 from the plasma with left-angle Z right-angle much-gt 1. This paper presents experimental studies in this field, with the currents 0.2 MA, 0.5 MA, 1.2 MA

  19. Detecting subtle plasma membrane perturbation in living cells using second harmonic generation imaging.

    Science.gov (United States)

    Moen, Erick K; Ibey, Bennett L; Beier, Hope T

    2014-05-20

    The requirement of center asymmetry for the creation of second harmonic generation (SHG) signals makes it an attractive technique for visualizing changes in interfacial layers such as the plasma membrane of biological cells. In this article, we explore the use of lipophilic SHG probes to detect minute perturbations in the plasma membrane. Three candidate probes, Di-4-ANEPPDHQ (Di-4), FM4-64, and all-trans-retinol, were evaluated for SHG effectiveness in Jurkat cells. Di-4 proved superior with both strong SHG signal and limited bleaching artifacts. To test whether rapid changes in membrane symmetry could be detected using SHG, we exposed cells to nanosecond-pulsed electric fields, which are believed to cause formation of nanopores in the plasma membrane. Upon nanosecond-pulsed electric fields exposure, we observed an instantaneous drop of ~50% in SHG signal from the anodic pole of the cell. When compared to the simultaneously acquired fluorescence signals, it appears that the signal change was not due to the probe diffusing out of the membrane or changes in membrane potential or fluidity. We hypothesize that this loss in SHG signal is due to disruption in the interfacial nature of the membrane. The results show that SHG imaging has great potential as a tool for measuring rapid and subtle plasma membrane disturbance in living cells. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Magnetic and electric deflector spectrometers for ion emission analysis from laser generated plasma

    Science.gov (United States)

    Torrisi, Lorenzo; Costa, Giuseppe; Ceccio, Giovanni; Cannavò, Antonino; Restuccia, Nancy; Cutroneo, Mariapompea

    2018-01-01

    The pulsed laser-generated plasma in vacuum and at low and high intensities can be characterized using different physical diagnostics. The charge particles emission can be characterized using magnetic, electric and magnet-electrical spectrometers. Such on-line techniques are often based on time-of-flight (TOF) measurements. A 90° electric deflection system is employed as ion energy analyzer (IEA) acting as a filter of the mass-to-charge ratio of emitted ions towards a secondary electron multiplier. It determines the ion energy and charge state distributions. The measure of the ion and electron currents as a function of the mass-to-charge ratio can be also determined by a magnetic deflector spectrometer, using a magnetic field of the order of 0.35 T, orthogonal to the ion incident direction, and an array of little ion collectors (IC) at different angles. A Thomson parabola spectrometer, employing gaf-chromix as detector, permits to be employed for ion mass, energy and charge state recognition. Mass quadrupole spectrometry, based on radiofrequency electric field oscillations, can be employed to characterize the plasma ion emission. Measurements performed on plasma produced by different lasers, irradiation conditions and targets are presented and discussed. Complementary measurements, based on mass and optical spectroscopy, semiconductor detectors, fast CCD camera and Langmuir probes are also employed for the full plasma characterization. Simulation programs, such as SRIM, SREM, and COMSOL are employed for the charge particle recognition.

  1. Diagnostics of Particles emitted from a Laser generated Plasma: Experimental Data and Simulations

    Science.gov (United States)

    Costa, Giuseppe; Torrisi, Lorenzo

    2018-01-01

    The charge particle emission form laser-generated plasma was studied experimentally and theoretically using the COMSOL simulation code. The particle acceleration was investigated using two lasers at two different regimes. A Nd:YAG laser, with 3 ns pulse duration and 1010 W/cm2 intensity, when focused on solid target produces a non-equilibrium plasma with average temperature of about 30-50 eV. An Iodine laser with 300 ps pulse duration and 1016 W/cm2 intensity produces plasmas with average temperatures of the order of tens keV. In both cases charge separation occurs and ions and electrons are accelerated at energies of the order of 200 eV and 1 MeV per charge state in the two cases, respectively. The simulation program permits to plot the charge particle trajectories from plasma source in vacuum indicating how they can be deflected by magnetic and electrical fields. The simulation code can be employed to realize suitable permanent magnets and solenoids to deflect ions toward a secondary target or detectors, to focalize ions and electrons, to realize electron traps able to provide significant ion acceleration and to realize efficient spectrometers. In particular it was applied to the study two Thomson parabola spectrometers able to detect ions at low and at high laser intensities. The comparisons between measurements and simulation is presented and discussed.

  2. Fourth-generation plasma immersion ion implantation and deposition facility for hybrid surface modification layer fabrication

    International Nuclear Information System (INIS)

    Wang Langping; Huang Lei; Xie Zhiwen; Wang Xiaofeng; Tang Baoyin

    2008-01-01

    The fourth-generation plasma immersion ion implantation and deposition (PIIID) facility for hybrid and batch treatment was built in our laboratory recently. Comparing with our previous PIIID facilities, several novel designs are utilized. Two multicathode pulsed cathodic arc plasma sources are fixed on the chamber wall symmetrically, which can increase the steady working time from 6 h (the single cathode source in our previous facilities) to about 18 h. Meanwhile, the inner diameter of the pulsed cathodic arc plasma source is increased from the previous 80 to 209 mm, thus, large area metal plasma can be obtained by the source. Instead of the simple sample holder in our previous facility, a complex revolution-rotation sample holder composed of 24 shafts, which can rotate around its axis and adjust its position through revolving around the center axis of the vacuum chamber, is fixed in the center of the vacuum chamber. In addition, one magnetron sputtering source is set on the chamber wall instead of the top cover in the previous facility. Because of the above characteristic, the PIIID hybrid process involving ion implantation, vacuum arc, and magnetron sputtering deposition can be acquired without breaking vacuum. In addition, the PIIID batch treatment of cylinderlike components can be finished by installing these components on the rotating shafts on the sample holder

  3. Fourth-generation plasma immersion ion implantation and deposition facility for hybrid surface modification layer fabrication.

    Science.gov (United States)

    Wang, Langping; Huang, Lei; Xie, Zhiwen; Wang, Xiaofeng; Tang, Baoyin

    2008-02-01

    The fourth-generation plasma immersion ion implantation and deposition (PIIID) facility for hybrid and batch treatment was built in our laboratory recently. Comparing with our previous PIIID facilities, several novel designs are utilized. Two multicathode pulsed cathodic arc plasma sources are fixed on the chamber wall symmetrically, which can increase the steady working time from 6 h (the single cathode source in our previous facilities) to about 18 h. Meanwhile, the inner diameter of the pulsed cathodic arc plasma source is increased from the previous 80 to 209 mm, thus, large area metal plasma can be obtained by the source. Instead of the simple sample holder in our previous facility, a complex revolution-rotation sample holder composed of 24 shafts, which can rotate around its axis and adjust its position through revolving around the center axis of the vacuum chamber, is fixed in the center of the vacuum chamber. In addition, one magnetron sputtering source is set on the chamber wall instead of the top cover in the previous facility. Because of the above characteristic, the PIIID hybrid process involving ion implantation, vacuum arc, and magnetron sputtering deposition can be acquired without breaking vacuum. In addition, the PIIID batch treatment of cylinderlike components can be finished by installing these components on the rotating shafts on the sample holder.

  4. 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.

  5. Generation and confinement of hot ions and electrons in a reversed-field pinch plasma

    International Nuclear Information System (INIS)

    Chapman, B E; Almagri, A F; Anderson, J K; Caspary, K J; Clayton, D J; Den Hartog, D J; Ennis, D A; Fiksel, G; Gangadhara, S; Kumar, S; Magee, R M; O'Connell, R; Parke, E; Prager, S C; Reusch, J A; Sarff, J S; Stephens, H D; Brower, D L; Ding, W X; Craig, D

    2010-01-01

    By manipulating magnetic reconnection in Madison Symmetric Torus (MST) discharges, we have generated and confined for the first time a reversed-field pinch (RFP) plasma with an ion temperature >1 keV and an electron temperature of 2 keV. This is achieved at a toroidal plasma current of about 0.5 MA, approaching MST's present maximum. The manipulation begins with intensification of discrete magnetic reconnection events, causing the ion temperature to increase to several kiloelectronvolts. The reconnection is then quickly suppressed with inductive current profile control, leading to capture of a portion of the added ion heat with improved ion energy confinement. Electron energy confinement is simultaneously improved, leading to a rapid ohmically driven increase in the electron temperature. A steep electron temperature gradient emerges in the outer region of the plasma, with a local thermal diffusivity of about 2 m 2 s -1 . The global energy confinement time reaches 12 ms, the largest value yet achieved in the RFP and which is roughly comparable to the H-mode scaling prediction for a tokamak with the same plasma current, density, heating power, size and shape.

  6. Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams

    Science.gov (United States)

    Hershkowitz, Noah [Madison, WI; Longmier, Benjamin [Madison, WI; Baalrud, Scott [Madison, WI

    2009-03-03

    An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.

  7. Experimental platform for investigations of high-intensity laser plasma interactions in the magnetic field of a pulsed power generator

    Science.gov (United States)

    Ivanov, V. V.; Maximov, A. V.; Swanson, K. J.; Wong, N. L.; Sarkisov, G. S.; Wiewior, P. P.; Astanovitskiy, A. L.; Covington, A. M.

    2018-03-01

    An experimental platform for the studying of high-intensity laser plasma interactions in strong magnetic fields has been developed based on the 1 MA Zebra pulsed power generator coupled with the 50-TW Leopard laser. The Zebra generator produces 100-300 T longitudinal and transverse magnetic fields with different types of loads. The Leopard laser creates plasma at an intensity of 1019 W/cm2 in the magnetic field of coil loads. Focusing and targeting systems are integrated in the vacuum chamber of the pulsed power generator and protected from the plasma debris and strong mechanical shock. The first experiments with plasma at laser intensity >2 × 1018 W/cm2 demonstrated collimation of the laser produced plasma in the axial magnetic field strength >100 T.

  8. Laser plasma as a source of intense attosecond pulses via high-order harmonic generation

    International Nuclear Information System (INIS)

    Ozaki, T.

    2013-01-01

    The incredible progress in ultrafast laser technology and Ti:sapphire lasers have lead to many important applications, one of them being high-order harmonic generation (HHG). HHG is a source of coherent extreme ultraviolet (XUV) radiation, which has opened new frontiers in science by extending nonlinear optics and time-resolved spectroscopy to the XUV region, and pushing ultrafast science to the attosecond domain. Progress in attosecond science has revealed many new phenomena that have not been seen with femtosecond pulses. Clearly, the next frontier is to study nonlinear effects at the attosecond timescale and in the XUV. However, a problem with present-day attosecond pulses is that they are just too weak to induce measurable nonlinearities, which severely limits the application of this source. While HHG from solid targets has shown promise for higher conversion efficiency, there is no experiment so far that demonstrates isolated attosecond pulse generation. The generation of isolated, several 100-as pulses with few-µJ energy will enable us to enter a completely new phase in attoscience. In past works, we have demonstrated that high-order harmonics from lowly ionized plasma is a highly efficient method to generate coherent XUV pulses. For example, indium plasma has been shown to generate intense 13th harmonic of the Ti:sapphire laser, with conversion efficiency of 10-4. However, the quasi-monochromatic nature of indium harmonics would make it difficult to generate attosecond pulses. We have also demonstrated that one could increase the harmonic yield by using nanoparticle targets. Specifically, we showed that by using indium oxide nanoparticles or C60 film, we could obtain intense harmonics between wavelengths of 50 to 90 nm. The energy in each of these harmonic orders was measured to be a few µJ, which is sufficient for many applications. However, the problem of using nanoparticle or film targets is the rapid decrease in the harmonic intensity, due to the rapid

  9. TVA - Thermionic Vacuum Arc - A new type of discharge generating pure metal vapor plasma

    International Nuclear Information System (INIS)

    Musa, G.; Popescu, A.; Mustata, I.; Borcoman, I.; Cretu, M.; Leu, G.F.; Salambas, A.; Ehrich, H.; Schumann, I.

    1996-01-01

    In this paper it is presented a new type of discharge in vacuum conditions generating pure metal vapor plasma with energetic metal ions content. The peculiarities of this heated cathode discharge are described and the dependence of the measured ion energy of the working parameters are established. The ion energy value can be easily and smoothly changed. A nearly linear dependence between energy of ions and arc voltage drop has been observed. The ion energy can be increased by the increase of the interelectrode distance, decrease of cathode temperature, change of the relative position of the electrodes and by the decrease of the arc discharge current. A special configuration with cylindrical geometry has been used to develop a small size and compact metal vapour plasma gun. Due to the mentioned peculiarities, this discharge offers new openings for important applications. (author)

  10. Energy loss of argon in a laser-generated carbon plasma.

    Science.gov (United States)

    Frank, A; Blazević, A; Grande, P L; Harres, K; Hessling, T; Hoffmann, D H H; Knobloch-Maas, R; Kuznetsov, P G; Nürnberg, F; Pelka, A; Schaumann, G; Schiwietz, G; Schökel, A; Schollmeier, M; Schumacher, D; Schütrumpf, J; Vatulin, V V; Vinokurov, O A; Roth, M

    2010-02-01

    The experimental data presented in this paper address the energy loss determination for argon at 4 MeV/u projectile energy in laser-generated carbon plasma covering a huge parameter range in density and temperature. Furthermore, a consistent theoretical description of the projectile charge state evolution via a Monte Carlo code is combined with an improved version of the CasP code that allows us to calculate the contributions to the stopping power of bound and free electrons for each projectile charge state. This approach gets rid of any effective charge description of the stopping power. Comparison of experimental data and theoretical results allows us to judge the influence of different plasma parameters.

  11. Laser-produced plasma-extreme ultraviolet light source for next generation lithography

    International Nuclear Information System (INIS)

    Nishihara, Katsunobu; Nishimura, Hiroaki; Gamada, Kouhei; Murakami, Masakatsu; Mochizuki, Takayasu; Sasaki, Akira; Sunahara, Atsushi

    2005-01-01

    Extreme ultraviolet (EUV) lithography is the most promising candidate for the next generation lithography for the 45 nm technology node and below. EUV light sources under consideration use 13.5 nm radiations from multicharged xenon, tin and lithium ions, because Mo/Si multiplayer mirrors have high reflectivity at this wavelength. A review of laser-produced plasma (LPP) EUV light sources is presented with a focus on theoretical and experimental studies under the auspices of the Leading Project promoted by MEXT. We discuss three theoretical topics: atomic processes in the LPP-EUV light source, conversion efficiency from laser light to EUV light at 13.5 nm wave-length with 2% bound width, and fast ion spectra. The properties of EUV emission from tin and xenon plasmas are also shown based on experimental results. (author)

  12. The third generation multi-purpose plasma immersion ion implanter for surface modification of materials

    CERN Document Server

    Tang Bao Yin; Wang Xiao Feng; Gan Kong Yin; Wang Song Yan; Chu, P K; Huang Nian Ning; Sun Hong

    2002-01-01

    The third generation multi-purpose plasma immersion ion implantation (PIII) equipment has been successfully used for research and development of surface modification of biomedical materials, metals and their alloys in the Southwest Jiaotong University. The implanter equipped with intense current, pulsed cathodic arc metal plasma sources which have both strong coating function and gas and metal ion implantation function. Its pulse high voltage power supply can provide big output current. It can acquire very good implantation dose uniformity. The equipment can both perform ion implantation and combine ion implantation with sputtering deposition and coating to form many kinds of synthetic surface modification techniques. The main design principles, features of important components and achievement of research works in recent time have been described

  13. Analysis of laser-generated plasma ionizing radiation by synthetic single crystal diamond detectors

    Czech Academy of Sciences Publication Activity Database

    Marinelli, M.; Milani, E.; Prestopino, G.; Verona, C.; Verona-Rinati, G.; Cutroneo, M.; Torrisi, L.; Margarone, Daniele; Velyhan, Andriy; Krása, Josef; Krouský, Eduard

    2013-01-01

    Roč. 272, May (2013), s. 104-108 ISSN 0169-4332 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279; GA MŠk EE.2.3.20.0087; GA MŠk(CZ) 7E09092; GA MŠk(CZ) LC528 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087; 7FP LASERLAB-EUROPE(XE) 228334 Program:EE; FP7 Institutional support: RVO:68378271 Keywords : single crystal diamond * diamond detector * laser-generated plasma * ionizing radiation * time-of-fight spectrometer Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.538, year: 2013

  14. Particle and energy balance in the SOL generated by a limiter in a RFP plasma

    International Nuclear Information System (INIS)

    Antoni, V.; Bagatin, M.; Desideri, D.; Serianni, G.

    1992-01-01

    The plasma outer region of the RFP experiment ETA BETA II has been extensively investigated. In particular by an insertable graphite limiter, instrumented with thermocouples and Langmuir probes, the energy and particle fluxes in the shadow of the limiter have been measured at different insertions. The results are compared with those obtained by small-sized calorimeter/Langmuir probes inserted to investigate, with fine space resolution, the outer region without limiter. Almost 80% of the power to the limiter is estimated to be carried by fast suprathermal electrons flowing along the magnetic field line direction. From an energy balance equation, applied in the SOL locally generated, the connection length of the limiter has been derived. Thus a particle balance has been applied to determine the particle diffusion coefficient at the plasma edge. (orig.)

  15. Anomalous electron heating and energy balance in an ion beam generated plasma

    Energy Technology Data Exchange (ETDEWEB)

    Guethlein, G.

    1987-04-01

    The plasma described in this report is generated by a 15 to 34 kV ion beam, consisting primarily of protons, passing through an H/sub 2/ gas cell neutralizer. Plasma ions (or ion-electron pairs) are produced by electron capture from (or ionization of) gas molecules by beam ions and atoms. An explanation is provided for the observed anomalous behavior of the electron temperature (T/sub e/): a step-lite, nearly two-fold jump in T/sub e/ as the beam current approaches that which minimizes beam angular divergence; insensitivity of T/sub e/ to gas pressure; and the linear relation of T/sub e/ to beam energy.

  16. Astrophysics of magnetically collimated jets generated from laser-produced plasmas.

    Science.gov (United States)

    Ciardi, A; Vinci, T; Fuchs, J; Albertazzi, B; Riconda, C; Pépin, H; Portugall, O

    2013-01-11

    The generation of astrophysically relevant jets, from magnetically collimated, laser-produced plasmas, is investigated through three-dimensional, magnetohydrodynamic simulations. We show that for laser intensities I∼10(12)-10(14) W cm(-2), a magnetic field in excess of ∼0.1  MG, can collimate the plasma plume into a prolate cavity bounded by a shock envelope with a standing conical shock at its tip, which recollimates the flow into a supermagnetosonic jet beam. This mechanism is equivalent to astrophysical models of hydrodynamic inertial collimation, where an isotropic wind is focused into a jet by a confining circumstellar toruslike envelope. The results suggest an alternative mechanism for a large-scale magnetic field to produce jets from wide-angle winds.

  17. En Route: next-generation laser-plasma-based electron accelerators; En Route: Elektronenbeschleuniger der naechsten Generation auf Laser-Plasma-Basis

    Energy Technology Data Exchange (ETDEWEB)

    Hidding, Bernhard

    2008-05-15

    Accelerating electrons to relativistic energies is of fundamental interest, especially in particle physics. Today's accelerator technology, however, is limited by the maximum electric fields which can be created. This thesis presents results on various mechanisms aiming at exploiting the fields in focussed laser pulses and plasma waves for electron acceleration, which can be orders of magnitude higher than with conventional accelerators. With relativistic, underdense laser-plasma-interaction, quasimonoenergetic electron bunches with energies up to {approx}50 MeV and normalized emittances of the order of 5mmmrad have been generated. This was achieved by focussing the {approx}80 fs, 1 J pulses of the JETI-laser at the FSU Jena to intensities of several 10{sup 19}W=cm{sup 2} into gas jets. The experimental observations could be explained via 'bubble acceleration', which is based on self-injection and acceleration of electrons in a highly nonlinear breaking plasma wave. For the rst time, this bubble acceleration was achieved explicitly in the self-modulated laser wakefield regime (SMLWFA). This quasimonoenergetic SMLWFA-regime stands out by relaxing dramatically the requirements on the driving laser pulse necessary to trigger bubble acceleration. This is due to self-modulation of the laser pulse in high-density gas jets, leading to ultrashort laser pulse fragments capable of initiating bubble acceleration. Electron bunches with durations

  18. Effect of Fluctuations of DC Current on Properties of Plasma Jet Generated in Plasma Spraying Torch with Gerdien Arc

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan; Kopecký, Vladimír; Chumak, Oleksiy; Kavka, Tetyana; Mašláni, Alan; Sember, Viktor; Ctibor, Pavel

    2009-01-01

    Roč. 13, č. 2 (2009), s. 229-240 ISSN 1093-3611 Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma torch * dc arc * plasma jet * fluctuations * plasma spraying Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.333, year: 2009 http://www.begellhouse.com/journals/57d172397126f956,4e2a92412d8c6bb5.html

  19. Generation of poloidal magnetic field in a hot collisional plasma by inverse Faraday effect

    International Nuclear Information System (INIS)

    Srivastava, M.K.; Lawande, S.V.; Dutta, D.; Sarkar, S.; Khan, M.; Chakraborty, B.

    1996-01-01

    Generation of poloidal magnetic field in a hot and collisional plasma by an inverse Faraday effect is discussed. This field can either be induced by a circularly polarized laser beam (CPLB) or a plane-polarized laser beam (PPLB). For the CPLB, an average field left-angle Re x right-angle ∼I 0 λ∼11.6 MG could be produced in a DT plasma for a high intensity (I 0 =10 22 W/m 2 ) and shorter wavelength (λ=0.35 μm) laser. This field is essentially induced by the field inhomogeneity effect and dominates over that induced by the plasma inhomogeneity effect (left-angle Re x right-angle ∼I 2/3 0 λ 7/3 ∼2.42 MG). The collisional and thermal contribution to left-angle Re x right-angle is just negligible for the CPLB. However, in the case of PPLB the poloidal field is generated only for a hot and collisional plasma and can be quite large for a longer wavelength laser (e.g., CO 2 laser, λ=10.6 μm). The collisional effect induces a field left-angle Re x right-angle ∼0.08 kG, which dominates near the turning point and is independent of the laser parameters. However, in the outer cronal region the thermal pressure effect dominates (e.g., left-angle Re x right-angle ∼I 5/3 0 λ 4/3 ∼3.0 MG). Further, left-angle Re x right-angle for the p-polarized beam is, in general, relatively smaller than that for the s-polarized beam. Practical implications of these results and their limitations are discussed. copyright 1996 American Institute of Physics

  20. Flow Cytometry Assessment of In Vitro Generated CD138+ Human Plasma Cells

    Directory of Open Access Journals (Sweden)

    Rayelle Itoua Maïga

    2014-01-01

    Full Text Available The in vitro CD40-CD154 interaction promotes human B lymphocytes differentiation into plasma cells. Currently, CD138 is the hallmark marker enabling the detection of human plasma cells, both in vitro and in vivo; its presence can be monitored by flow cytometry using a specific antibody. We have developed a culture system allowing for the differentiation of memory B lymphocytes. In order to detect the newly formed plasma cells, we have compared their staining using five anti-CD138 monoclonal antibodies (mAbs. As a reference, we also tested human cell lines, peripheral blood mononuclear cells, and bone marrow samples. The five anti-CD138 mAbs stained RPMI-8226 cells (>98% with variable stain index (SI. The highest SI was obtained with B-A38 mAb while the lowest SI was obtained with DL-101 and 1D4 mAbs. However, the anti-CD138 mAbs were not showing equivalent CD138+ cells frequencies within the generated plasma cells. B-A38, B-B4, and MI-15 were similar (15–25% while DL-101 mAb stained a higher proportion of CD138-positive cells (38–42%. DL-101 and B-A38 mAbs stained similar populations in bone marrow samples but differed in their capacity to bind to CD138high and CD138lo cell lines. In conclusion, such cellular fluctuations suggest heterogeneity in human plasma cell populations and/or in CD138 molecules.

  1. RF generated currents in a magnetized plasma using a slow wave structure

    International Nuclear Information System (INIS)

    Poole, B.R.; Cheo, B.R.; Kuo, S.P.; Tang, M.G.

    1983-01-01

    The generation of a dc current in a plasma by using RF waves is of importance for the operation of steadystate toroidal devices. An experimental investigation in the use of unidirectional, low frequency RF waves to drive currents has been made. Instead of using a natural plasma wave a slow wave guiding structure is used along the entire length of the plasma. When the RF wave is injected an increase in ionization and T/sub e/, and hence the background current is observed. However, the change depends on wave direction: The +k/sub z/ excitation yields a much larger electron current compared with the -k/sub z/ excitation indicating a net wave driven current. The measured modification in electron density and T/sub e/ is independent of wave direction. The current with a standing wave excitation generally falls at the average of the travelling wave (+ or - k/sub z/) driven currents. The net wave driven current is proportional to the feed power at approx. = 10 mA/kW. No saturation of the current is observed with feed powers up to 1 kW. Since the exciting structure is only 1 wavelength long, its k/sub z/ spectrum is relatively broad and hence no sharp resonances are observed as various plasma parameters and B/sub O/ are changed. There is no measurable difference between the power absorbed by the load resistors and the input power to the slow wave structure. Thus the current is driven by the wave field exclamation E exclamation 2 rather than the power absorbed in the plasma. The theoretical background and the physical mechanism is presented

  2. Ex vivo spontaneous generation of 19-norandrostenedione and nandrolone detected in equine plasma and urine.

    Science.gov (United States)

    Guan, Fuyu; Uboh, Cornelius E; Soma, Lawrence R; You, Youwen; Li, Xiaoqing; McDonnell, Sue

    2012-01-01

    19-Norandrostenedione (NAED) and nandrolone are anabolic-androgenic steroids (AASs). Nandrolone was regarded solely as a synthetic AAS until the 1980s when trace concentrations of apparently endogenous nandrolone were detected in urine samples obtained from intact male horses (stallions). Since then, its endogenous origin has been reported in boars and bulls; endogenous NAED and nandrolone have been identified in plasma and urine samples collected from stallions. More recently, however, it was suggested that NAED and nandrolone detected in urine samples from stallions are primarily artifacts due to the analytical procedure. The present study was undertaken to determine whether NAED and nandrolone detected in plasma and urine samples collected from stallions are truly endogenous or artifacts from sample processing. To answer this question, fresh plasma and urine samples from ≥8 stallions were analyzed for the two AASs, soon after collection, by liquid chromatography hyphenated to tandem mass spectrometry (LC-MS/MS). NAED and nandrolone were not detected in fresh plasma samples but detected in the same samples post storage. Concentrations of both AASs increased with storage time, and the increases were greater at a higher storage temperature (37°C versus 4°C, and ambient temperature versus 4°C). Although NAED was detected in some fresh stallion urine samples, its concentration (samples post storage (at ambient temperature for 15 days). Nandrolone was not detected in most of fresh urine samples but detected in the same samples post storage. Based on these results, it is concluded that all NAED and nandrolone detected in stored plasma samples of stallions and most of them in the stored urine samples are not from endogenous origins but spontaneously generated during sample storage, most likely from spontaneous decarboxylation of androstenedione-19-oic acid and testosterone-19-oic acid. To our knowledge, it is the first time that all NAED and nandrolone detected in

  3. Plasma loading and wave generation for ICRH in the ST Tokamak

    International Nuclear Information System (INIS)

    Adam, J.; Getty, W.D.; Hooke, W.M.; Hosea, J.C.; Sinclair, R.M.

    1974-01-01

    Plasma loading and wave generation for two half-turn loops operating at 25 MHz are being investigated on the ST Tokamak at power levels up to 1 MW. The equivalent series resistance R/sub s/ = P/sub rf//I 2 /sub rf/, measured as a function of Ω = ω/ω/sub ci/(r = 0) and plasma density, is found to be in good agreement with the predictions of the cylindrical theory. R/sub s/ values as high as several ohms are obtained at high densities giving wave generation efficiencies well above 90 percent. Loading near Ω = 1 and 2 is apparently independent of power level. Measurements of B/sub zrf/ at 20 locations about the torus reveal the predicted wave generation; m = 0, +1 slow waves in the vicinity of Ω = 1, m = -1 fast waves after the expected onset (usually Ω greater than or equal to 1), and m = 0, +1 fast waves for higher Ω. Toroidal eigenmodes accompanied by large loading are detected for the fast waves when the damping lengths are long

  4. Study of novel plasma devices generated by high power lasers coupled with a micro-pulse power technology

    International Nuclear Information System (INIS)

    Nishida, A; Chen, Z L; Jin, Z; Kondo, K; Nakagawa, M; Kodama, R; Arima, H; Yoneda, H

    2008-01-01

    The authors have proposed introducing a micro pulse power technology in high power laser plasma experiments to boost up the return current, resulting in efficiently guiding of energetic electrons. High current pulse power generators with a pulse laser trigger system generate high-density plasma that is well conductor. To efficiently guiding by using a micro pulse power, we estimated parameter of a micro pulse power system that is voltage of rise time, current, charging voltage and capacitance

  5. Non-thermal atmospheric pressure HF plasma source: generation of nitric oxide and ozone for bio-medical applications

    Science.gov (United States)

    Kühn, S.; Bibinov, N.; Gesche, R.; Awakowicz, P.

    2010-01-01

    A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical NO-detector at variable gas flows. Correlations between plasma parameters and concentrations of the particles in the effluent of the plasma source are discussed. By varying the gas flows, the HF plasma source can be optimized for nitric oxide or ozone production. Maximum concentrations of 2750 ppm and 400 ppm of NO and O3, correspondingly, are generated.

  6. Ion energy distributions from laser-generated plasmas at two different intensities

    Science.gov (United States)

    Ceccio, Giovanni; Torrisi, Lorenzo; Okamura, Masahiro; Kanesue, Takeshi; Ikeda, Shunsuke

    2018-01-01

    Laser-generated non-equilibrium plasmas were analyzed at Brookhaven National Laboratory (NY, USA) and MIFT Messina University (Italy). Two laser intensities of 1012 W/cm2 and 109 W/cm2, have been employed to irradiate Al and Al with Au coating targets in high vacuum conditions. Ion energy distributions were obtained using electrostatic analyzers coupled with ion collectors. Time of flight measurements were performed by changing the laser irradiation conditions. The study was carried out to provide optimum keV ions injection into post acceleration systems. Possible applications will be presented.

  7. Role of plasma-induced defects in the generation of 1/f noise in graphene

    Science.gov (United States)

    Cultrera, Alessandro; Callegaro, Luca; Marzano, Martina; Ortolano, Massimo; Amato, Giampiero

    2018-02-01

    It has already been reported that 1/f noise in graphene can be dominated by fluctuations of charge carrier mobility. We show here that the increasing damage induced by oxygen plasma on graphene samples result in two trends: at low doses, the magnitude of the 1/f noise increases with the dose; and at high doses, it decreases with the dose. This behaviour is interpreted in the framework of 1/f noise generated by carrier mobility fluctuations where the concentration of mobility fluctuation centers and the mean free path of the carriers are competing factors.

  8. Improved numerical grid generation techniques for the B2 edge plasma code

    International Nuclear Information System (INIS)

    Stotler, D.P.; Coster, D.P.

    1992-06-01

    Techniques used to generate grids for edge fluid codes such as B2 from numerically computed equilibria are discussed. Fully orthogonal, numerically derived grids closely resembling analytically prescribed meshes can be obtained. But, the details of the poloidal field can vary, yielding significantly different plasma parameters in the simulations. The magnitude of these differences is consistent with the predictions of an analytic model of the scrape-off layer. Both numerical and analytic grids are insensitive to changes in their defining parameters. Methods for implementing nonorthogonal boundaries in these meshes are also presented; they differ slightly from those required for fully orthogonal grids

  9. On the generation of steady currents in a plasma cylinder using RF waves

    International Nuclear Information System (INIS)

    Hugrass, W.N.

    1980-10-01

    The generation of a steady current in a resistive plasma cylinder by means of a travelling wave magnetic field has been studied using the resistive MHD equations. The nonlinear initial-boundary value problem has been solved using a semi-Lagrangian two dimensional algorithm. The numerical code has been used to simulate the Synchromak experiment of Nagoya University. Hollow d.c. current profiles, similar to the experimental data, have been obtained. A simple analytical argument, of a more general nature, shows that classical resistive diffusion cannot lead to a more uniform current distribution

  10. Femtosecond laser-plasma interaction with prepulse-generated liquid metal microjets

    Energy Technology Data Exchange (ETDEWEB)

    Uryupina, D. S.; Ivanov, K. A.; Savel' ev, A. B.; Volkov, R. V. [Faculty of Physics and International Laser Center of M.V. Lomonosov Moscow State University, 119991 Moscow, Leninskie Gory (Russian Federation); Brantov, A. V.; Bychenkov, V. Yu. [P. N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow (Russian Federation); Povarnitsyn, M. E. [Joint Institute for High Temperatures, Russian Academy of Sciences, 125412 Moscow (Russian Federation); Tikhonchuk, V. T. [CELIA, University of Bordeaux - CNRS - CEA, 33405 Talence (France)

    2012-01-15

    Ultrashort laser pulse interaction with a microstructured surface of a melted metal is a promising source of hard x-ray radiation. Microstructuring is achieved by a weak prepulse that produces narrow high-density microjets. As an x-ray source, the interaction of the main laser pulse with such jets is shown to be nearly two orders of magnitude more efficient than the interaction with ordinary metal targets. This paper presents the results of optical and x-ray studies of laser-plasma interaction physics under such conditions supported by numerical simulations of microjet formation and fast-electron generation.

  11. Femtosecond laser-plasma interaction with prepulse-generated liquid metal microjets

    International Nuclear Information System (INIS)

    Uryupina, D. S.; Ivanov, K. A.; Savel'ev, A. B.; Volkov, R. V.; Brantov, A. V.; Bychenkov, V. Yu.; Povarnitsyn, M. E.; Tikhonchuk, V. T.

    2012-01-01

    Ultrashort laser pulse interaction with a microstructured surface of a melted metal is a promising source of hard x-ray radiation. Microstructuring is achieved by a weak prepulse that produces narrow high-density microjets. As an x-ray source, the interaction of the main laser pulse with such jets is shown to be nearly two orders of magnitude more efficient than the interaction with ordinary metal targets. This paper presents the results of optical and x-ray studies of laser-plasma interaction physics under such conditions supported by numerical simulations of microjet formation and fast-electron generation.

  12. Temperature anisotropy in a cyclotron resonance heated tokamak plasma and the generation of poloidal electric field

    International Nuclear Information System (INIS)

    Choe, W.; Ono, M.; Chang, C.S.

    1994-11-01

    The temperature anisotropy generated by cyclotron resonance heating of tokamak plasmas is calculated and the poloidal equilibrium electric field due to the anisotropy is studied. For the calculation of anisotropic temperatures, bounce-averaged Fokker-Planck equation with a bi-Maxwellian distribution function of heated particles is solved, assuming a moderate wave power and a constant quasilinear cyclotron resonance diffusion coefficient. The poloidal electrostatic potential variation is found to be proportional to the particle density and the degree of temperature anisotropy of warm species created by cyclotron resonance heating

  13. Fast ion generation in femto- and picosecond laser plasma at low fluxes of heating radiation

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Pikuz, T.A.; Magunov, A.I.

    2006-01-01

    X-ray spectra from fluoroplastic targets irradiated by laser pulses with duration of 60 fs to 1 ps have been investigated experimentally. It is shown that, when the contrast of the laser pulse is sufficiently low, the effect of self-focusing of the main laser pulse in the plasma produced by the prepulse can significantly enhance the generation efficiency of fast particles. In this case, ions with energies as high as ∼1 MeV are observed at relatively low laser intensities [ru

  14. Pierce-Wiggler electron beam system for 250 GHz GYRO-BWO: Final report

    International Nuclear Information System (INIS)

    Pirkle, D.R.; Alford, C.W.; Anderson, M.H.; Garcia, R.F.; Legarra, J.R.; Nordquist, A.L.

    1989-01-01

    This final report summarizes the design and performance of the VUW-8028 Pierce-Wiggler electron beam systems, which can be used to power high frequency gyro-BWO's. The operator's manual for this gyro-BWO beamstick is included as appendix A. Researchers at Lawrence Livermore National Laboratory (LLNL) are developing a gyro-BWO with a center frequency of 250 GHz, 6% bandwidth, and 10 kV peak output power. The gyro-BWO will be used to drive a free electron laser amplifier at LLNL. The electron beam requirements of the gyro-BWO application are: Small beam size, .100 inch at 2500 gauss axial magnetic field; a large fraction of the electron energy in rotational velocity; ability to vary the electrons' axial velocity easily, for electronic tuning; and low velocity spread i.e. little variation in the axial velocities of the electrons in the interaction region. 1 ref., 13 figs

  15. Self-fields in free-electron lasers with planar wiggler and ion-channel guiding

    International Nuclear Information System (INIS)

    Farokhi, B; Jafary, F B; Maraghechi, B

    2006-01-01

    A theory of self-electric and self-magnetic fields of a relativistic electron beam passing through a one-dimensional planar wiggler and an ion-channel is presented. The equilibrium orbits and their stability, under the influence of self-electric and self-magnetic fields, are analysed. New unstable orbits, in the first part of the group I orbits, are found. It is shown that for a low energy and high density beam the self-fields can produce very large effects. Stabilities of quasi-steady-state orbits are investigated by analytical and numerical methods and perfect agreement was found. The theory of small signal gain is used to derive a formula for the gain with the self-field effects included. A numerical analysis is conducted to study the self-field effects on the quasi-steady-state orbits and the gain

  16. Traveling waves in a free-electron laser with an electromagnetic wiggler

    International Nuclear Information System (INIS)

    Olumi, Mohsen; Maraghechi, B; Rouhani, M H

    2011-01-01

    The propagation of electromagnetic traveling wave in a free-electron laser (FEL) with an electromagnetic wiggler is investigated using the relativistic fluid-Maxwell formulation. By adapting the traveling-wave ansatz, three coupled, nonlinear ordinary differential equations are obtained describing the nonlinear propagation of the coupled wave. These equations may be used to study saturation in FELs. By linearizing the nonlinear equations dispersion relations for the traveling wave are obtained. Numerical solution of the small-signal traveling dispersion relation reveals the coupling of radiation to both slow and fast space-charge waves. It is shown that the traveling wave, which is not a normal mode in a laboratory frame, becomes a normal mode in terms of a transformed variable.

  17. Prospects for searching axion-like particle dark matter with dipole, toroidal and wiggler magnets

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Oliver K. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Betz, Michael; Caspers, Fritz [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Institute for Particle Physics Phenomenology, Durham (United Kingdom); Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Semertzidis, Yannis [Brookhaven National Lab., Upton, NY (United States); Sikivie, Pierre [Florida Univ., Gainesville, FL (United States). Dept. of Physics; Zioutas, Konstantin [Patras Univ. (Greece)

    2011-10-15

    In this work we consider searches for dark matter made of axions or axion-like particles (ALPs) using resonant radio frequency cavities inserted into dipole magnets from particle accelerators, wiggler magnets developed for accelerator based advanced light sources, and toroidal magnets similar to those used in particle physics detectors. We investigate the expected sensitivity of such ALP dark matter detectors and discuss the engineering aspects of building and tuning them. Brief mention is also made of even stronger field magnets that are becoming available due to improvements in magnetic technology. It is concluded that new experiments utilizing already existing magnets could greatly enlarge the mass region in searches for axion-like dark matter particles. (orig.)

  18. Prospects for searching axion-like particle dark matter with dipole, toroidal and wiggler magnets

    International Nuclear Information System (INIS)

    Baker, Oliver K.; Jaeckel, Joerg; Lindner, Axel; Ringwald, Andreas; Semertzidis, Yannis; Sikivie, Pierre

    2011-10-01

    In this work we consider searches for dark matter made of axions or axion-like particles (ALPs) using resonant radio frequency cavities inserted into dipole magnets from particle accelerators, wiggler magnets developed for accelerator based advanced light sources, and toroidal magnets similar to those used in particle physics detectors. We investigate the expected sensitivity of such ALP dark matter detectors and discuss the engineering aspects of building and tuning them. Brief mention is also made of even stronger field magnets that are becoming available due to improvements in magnetic technology. It is concluded that new experiments utilizing already existing magnets could greatly enlarge the mass region in searches for axion-like dark matter particles. (orig.)

  19. Outlook for the use of microsecond plasma opening switches to generate high-power nanosecond current pulses

    International Nuclear Information System (INIS)

    Dolgachev, G.I.; Maslennikov, D.D.; Ushakov, A.G.

    2006-01-01

    Paper deals with a phenomenon of current breaking in a conducting plasma volume of plasma opening switchers with a nanosecond time of energy initiation and their application in high-power generators. One determined the conditions to ensure megavolt voltages under the erosion mode making use of external applied magnetic field to ensure magnetic insulation of gap of plasma opening switchers. One studied the peculiar features of application of plasma opening switchers under 5-6 MV voltages to ensure X-ray and gamma-radiation pulses [ru

  20. A linear-field plasma jet for generating a brush-shaped laminar plume at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuechen; Jia, Pengying, E-mail: plasmalab@126.com [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Key Laboratory of Photo-Electronics Information Materials of Hebei Province, Baoding 071002 (China); Li, Jiyuan; Chu, Jingdi; Zhang, Panpan [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

    2016-06-15

    A linear-field plasma jet composed of line-to-plate electrodes is used to generate a large-scale brush-shaped plasma plume with flowing argon used as working gas. Through electrical measurement and fast photography, it is found that the plasma plume bridges the two electrodes for the discharge in the positive voltage half-cycle, which behaves like fast moving plasma bullets directed from the anode to the cathode. Compared with the positive discharge, the negative discharge only develops inside the nozzle and propagates much slower. Results also indicate that the gas temperature of the plume is close to room temperature, which is promising for biomedical application.

  1. Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Geohegan, D.B.

    1994-09-01

    Characteristics of laser plasmas used for pulsed laser deposition (PLD) of thin films are examined with four in situ diagnostic techniques: Optical emission spectroscopy, optical absorption spectroscopy, ion probe studies, and gated ICCD (intensified charge-coupled-device array) fast photography. These four techniques are complementary and permit simultaneous views of the transport of ions, excited states, ground state neutrals and ions, and hot particulates following KrF laser ablation of YBCO, BN, graphite and Si in vacuum and background gases. The implementation and advantages of the four techniques are first described in order to introduce the key features of laser plasmas for pulsed laser deposition. Aspects of the interaction of the ablation plume with background gases (i.e., thermalization, attenuation, shock formation) and the collision of the plasma plume with the substrate heater are then summarized. The techniques of fast ICCD photography and gated photon counting are then applied to investigate the temperature, velocity, and spatial distribution of hot particles generated during KrF ablation of YBCO, BN, Si and graphite. Finally, key features of fast imaging of the laser ablation of graphite into high pressure rare gases are presented in order to elucidate internal reflected shocks within the plume, redeposition of material on a surface, and formation of hot nanoparticles within the plume.

  2. Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition

    International Nuclear Information System (INIS)

    Geohegan, D.B.

    1994-01-01

    Characteristics of laser plasmas used for pulsed laser deposition (PLD) of thin films are examined with four in situ diagnostic techniques: Optical emission spectroscopy, optical absorption spectroscopy, ion probe studies, and gated ICCD (intensified charge-coupled-device array) fast photography. These four techniques are complementary and permit simultaneous views of the transport of ions, excited states, ground state neutrals and ions, and hot particulates following KrF laser ablation of YBCO, BN, graphite and Si in vacuum and background gases. The implementation and advantages of the four techniques are first described in order to introduce the key features of laser plasmas for pulsed laser deposition. Aspects of the interaction of the ablation plume with background gases (i.e., thermalization, attenuation, shock formation) and the collision of the plasma plume with the substrate heater are then summarized. The techniques of fast ICCD photography and gated photon counting are then applied to investigate the temperature, velocity, and spatial distribution of hot particles generated during KrF ablation of YBCO, BN, Si and graphite. Finally, key features of fast imaging of the laser ablation of graphite into high pressure rare gases are presented in order to elucidate internal reflected shocks within the plume, redeposition of material on a surface, and formation of hot nanoparticles within the plume

  3. 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)

  4. X-Pinch Plasma Generation Testing for Neutron Source Development and Nuclear Fusion

    Directory of Open Access Journals (Sweden)

    Hossam A.Gabbar

    2018-04-01

    Full Text Available Nuclear fusion is a sought-out technology in which two light elements are fused together to create a heavier element and releases energy. Two primary nuclear fusion technologies are being researched today: magnetic and inertial confinement. However, a new type of nuclear fusion technology is currently being research: multi-pinch plasma beams. At the University of Ontario Institute of Technology, there is research on multi-pinch plasma beam technology as an alternative to nuclear fusion. The objective is to intersect two plasma arcs at the center of the chamber. This is a precursor of nuclear fusion using multi-pinch. The innovation portion of the students’ work is the miniaturization of this concept using high energy electrical DC pulses. The experiment achieved the temperature of 2300 K at the intersection. In comparison to the simulation data, the temperature from the simulation is 7000 K at the intersection. Additionally, energy harvesting devices, both photovoltaics and a thermoelectric generator, were placed in the chamber to observe the viable energy extraction.

  5. Vacuum arc plasma generation and thin film deposition from a TiB{sub 2} cathode

    Energy Technology Data Exchange (ETDEWEB)

    Zhirkov, Igor, E-mail: igozh@ifm.liu.se; Petruhins, Andrejs; Naslund, Lars-Ake; Rosen, Johanna [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Kolozsvári, Szilard; Polcik, Peter [PLANSEE Composite Materials GmbH, Siebenbürgerstraße 23, 86983 Lechbruck am See (Germany)

    2015-11-02

    We have studied the utilization of TiB{sub 2} cathodes for thin film deposition in a DC vacuum arc system. We present a route for attaining a stable, reproducible, and fully ionized plasma flux of Ti and B by removal of the external magnetic field, which leads to dissipation of the vacuum arc discharge and an increased active surface area of the cathode. Applying a magnetic field resulted in instability and cracking, consistent with the previous reports. Plasma analysis shows average energies of 115 and 26 eV, average ion charge states of 2.1 and 1.1 for Ti and B, respectively, and a plasma ion composition of approximately 50% Ti and 50% B. This is consistent with measured resulting film composition from X-ray photoelectron spectroscopy, suggesting a negligible contribution of neutrals and macroparticles to the film growth. Also, despite the observations of macroparticle generation, the film surface is very smooth. These results are of importance for the utilization of cathodic arc as a method for synthesis of metal borides.

  6. Physical phenomena in a low-temperature non-equilibrium plasma and in MHD generators with non-equilibrium conductivity

    International Nuclear Information System (INIS)

    Velikhov, E.P.; Golubev, V.S.; Dykhne, A.M.

    1976-01-01

    The paper assesses the position in 1975 of theoretical and experimental work on the physics of a magnetohydrodynamic generator with non-equilibrium plasma conductivity. This research started at the beginning of the 1960s; as work on the properties of thermally non-equilibrium plasma in magnetic fields and also in MHD generator ducts progressed, a number of phenomena were discovered and investigated that had either been unknown in plasma physics or had remained uninvestigated until that time: ionization instability and ionization turbulence of plasma in a magnetic field, acoustic instability of a plasma with anisotropic conductivity, the non-equilibrium ionization wave and the energy balance of a non-equilibrium plasma. At the same time, it was discovered what physical requirements an MHD generator with non-equilibrium conductivity must satisfy to achieve high efficiency in converting the thermal or kinetic energy of the gas flow into electric energy. The experiments on MHD power generation with thermally non-equilibrium plasma carried out up to 1975 indicated that it should be possible to achieve conversion efficiencies of up to 20-30%. (author)

  7. Measurements of magnetic fields generated in underdense plasmas by intense lasers

    International Nuclear Information System (INIS)

    Najmudin, Z.; Walton, B. R.; Mangles, S. P. D.; Dangor, A. E.; Krushelnick, K.; Fritzler, S.; Malka, V.; Faure, J.; Tatarakis, M.

    2006-01-01

    Measurements have been made of the magnetic field generated by the passage of high intensity short laser pulses through underdense plasmas. For a 30 fs, 1 J, 800 nm linearly-polarised laser pulse, an azimuthal magnetic field is observed at a radial extent of approximately 200 μm. The field is found to exceed 2.8 MG. For a 1 ps, 40 J, 1054 nm circularly-polarised laser pulse, a solenoidal field is observed that can exceed 7 MG. This solenoidal field is absent with linear polarised light, and hence can be considered as an Inverse Faraday effect. Both types of field are found to decay on the picosecond timescale. For both the azimuthal and solenoidal fields produced by such intense lasers, the production of energetic electrons by the interaction is thought to be vital for magnetic field generation

  8. Non-thermal plasma at atmospheric pressure for ozone generation and volatile organic compounds decomposition

    International Nuclear Information System (INIS)

    Pekarek, S.; Khun, J.

    2006-01-01

    The non-thermal plasma technologies based on electrical discharges play an important role in ecological applications. The classical corona discharge is however relatively low power discharge. With the aim to extend its current-voltage range we studied hollow needle-to-plate DC corona discharge enhanced by the flow of a gas through the needle electrode. With this type of the discharge we performed an extensive study of ozone generation and volatile organic compounds decomposition. We found that supply of air through the needle substantially increases current-voltage range of the discharge in comparison with classical pin-to-plate corona discharge. Consequently the ozone generation as well as toluene decomposition efficiency was increased (Authors)

  9. Second-generation nanofiltered plasma-derived mannan-binding lectin product

    DEFF Research Database (Denmark)

    Laursen, I.; Houen, G.; Højrup, P.

    2007-01-01

    infections. Substitution therapy with plasma-derived MBL is a promising treatment of diseases associated with MBL deficiency. A first-generation MBL product has been shown to be safe and well tolerated, and patients have benefited from MBL treatment. Following is a description of the development...... of a nanofiltered second-generation MBL product from Cohn fraction III, with the use of a new affinity matrix for MBL purification and the characteristics of this improved product. MATERIALS AND METHODS: Carbohydrate-based gels were comparatively screened as affinity matrices. MBL was extracted from fraction III......, and affinity purified on a Superdex 200 pg column. The eluted material underwent two virus reduction steps: filtration through Planova 20N and solvent/detergent treatment. It was further purified by anion-exchange and gel-filtration chromatography. The affinity eluate and the final MBL fraction were...

  10. Evaluation of Novel Integrated Dielectric Barrier Discharge Plasma as Ozone Generator

    Directory of Open Access Journals (Sweden)

    Muhammad Nur

    2017-04-01

    Full Text Available This paper presents a characterization of an integrated ozone generator constructed by seven of reactors of Dielectric Barrier Discharge Plasma (DBDP. DBDP a has spiral-cylindrical configuration. Silence plasma produced ozone inside the DBDP reactor was generated by AC-HV with voltage up to 25 kV and maximum frequency of 23 kHz. As a source of ozone, dry air was pumped into the generator and controlled by valves system and a flowmeter. We found ozone concentration increased with the applied voltage, but in contrary, the concentration decreased with the flow rate of dry air. It was also found that a maximum concentration was 20 mg/L and ozone capacity of 48 g/h with an input power of 1.4 kW. Moreover, in this generator, IP efficiency of 8.13 g/kWh was obtained at input power 0.45 kW and air flow rate of 9 L/min. Therefore, be the higher ozone capacity can be produced with higher input power; however, it provided lower IP efficiency. The effect of dry air flow rate and applied voltage on ozone concentrations have been studied. At last, spiral wire copper was very corrosive done to the interaction with ozone, and it is necessary to do a research for finding the best metals as an active electrode inside of the quartz dielectric. Copyright © 2017 BCREC GROUP. All rights reserved Received: 18th July 2016; Revised: 25th September 2016; Accepted: 5th October 2016 How to Cite: Nur, M., Susan, A.I., Muhlisin, Z., Arianto, F., Kinandana, A.W., Nurhasanah, I., Sumariyah, S., Wibawa, P.J., Gunawan, G., Usman, A. (2017. Evaluation of Novel Integrated Dielectric Barrier Discharge Plasma as Ozone Generator. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 24-31 (doi:10.9767/bcrec.12.1.605.24-31 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.605.24-31

  11. Novel high-frequency energy-efficient pulsed-dc generator for capacitively coupled plasma discharge

    Science.gov (United States)

    Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

    2018-03-01

    The circuit design, assembly, and operating tests of a high-frequency and high-voltage (HV) pulsed dc generator (PDG) for capacitively coupled plasma (CCP) discharge inside a vacuum chamber are reported. For capacitive loads, it is challenging to obtain sharp rectangular pulses with fast rising and falling edges, requiring intense current for quick charging and discharging. The requirement of intense current generally limits the pulse operation frequency. In this study, we present a new type of PDG consisting of a pair of half-resonant converters and a constant current-controller circuit connected with HV solid-state power switches that can deliver almost rectangular high voltage pulses with fast rising and falling edges for CCP discharge. A prototype of the PDG is assembled to modulate from a high-voltage direct current (HVdc) input into a pulsed HVdc output, while following an input pulse signal and a set current level. The pulse rise time and fall time are less than 500 ns and 800 ns, respectively, and the minimum pulse width is 1 µs. The maximum voltage for a negative pulse is 1000 V, and the maximum repetition frequency is 500 kHz. During the pulse on time, the plasma discharge current is controlled steadily at the set value. The half-resonant converters in the PDG perform recovery of the remaining energy from the capacitive load at every termination of pulse discharge. The PDG performed with a high energy efficiency of 85% from the HVdc input to the pulsed dc output at a repetition rate of 1 kHz and with stable plasma operation in various discharge conditions. The results suggest that the developed PDG can be considered to be more efficient for plasma processing by CCP.

  12. Novel high-frequency energy-efficient pulsed-dc generator for capacitively coupled plasma discharge.

    Science.gov (United States)

    Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

    2018-03-01

    The circuit design, assembly, and operating tests of a high-frequency and high-voltage (HV) pulsed dc generator (PDG) for capacitively coupled plasma (CCP) discharge inside a vacuum chamber are reported. For capacitive loads, it is challenging to obtain sharp rectangular pulses with fast rising and falling edges, requiring intense current for quick charging and discharging. The requirement of intense current generally limits the pulse operation frequency. In this study, we present a new type of PDG consisting of a pair of half-resonant converters and a constant current-controller circuit connected with HV solid-state power switches that can deliver almost rectangular high voltage pulses with fast rising and falling edges for CCP discharge. A prototype of the PDG is assembled to modulate from a high-voltage direct current (HVdc) input into a pulsed HVdc output, while following an input pulse signal and a set current level. The pulse rise time and fall time are less than 500 ns and 800 ns, respectively, and the minimum pulse width is 1 µs. The maximum voltage for a negative pulse is 1000 V, and the maximum repetition frequency is 500 kHz. During the pulse on time, the plasma discharge current is controlled steadily at the set value. The half-resonant converters in the PDG perform recovery of the remaining energy from the capacitive load at every termination of pulse discharge. The PDG performed with a high energy efficiency of 85% from the HVdc input to the pulsed dc output at a repetition rate of 1 kHz and with stable plasma operation in various discharge conditions. The results suggest that the developed PDG can be considered to be more efficient for plasma processing by CCP.

  13. Deactivation of Legionella Pneumophila in municipal wastewater by ozone generated in arrays of microchannel plasmas

    Science.gov (United States)

    Dong, Shengkun; Li, Jun; Kim, Min-Hwan; Cho, Jinhoon; Park, Sung-Jin; Nguyen, Thanh H.; Eden, J. Gary

    2018-06-01

    A greater than four log10 reduction in the concentration of Legionella pneumophila in municipal wastewater has been achieved in 1 min with ozone produced by a microchannel plasma reactor. Requiring less than 22 W of electrical power, and ambient air as the feedstock gas, the microplasma ozone generator is robust and a promising alternative to conventional corona and dielectric barrier discharge (DBD) technologies. Contrary to previous studies, the Ct model for pathogen deactivation (i.e. rate proportional to the product of the available disinfectant concentration and the exposure duration) is found to be valid for L. pneumophila. Accordingly, wastewater-specific Ct equations have been developed to predict the deactivation of L. pneumophila in the secondary wastewater environment. Inactivation of this pathogen was found to be dependent on temperature only in the absence of wastewater organic matter (WOM). In the presence of WOM, pathogen deactivation is controlled by the disinfection contact time, initial ozone concentration (varied between 15 and 281 µg l‑1), and initial WOM loading. The data reported here will assist in the implementation of plasma ozone generators for L. pneumophila deactivation in cooling towers, point-of-use systems, and wastewater reclamation facilities.

  14. High duty factor Plasma Generator for CERN’s Superconducting Proton Linac

    CERN Document Server

    Lettry, J; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, JM; Kuchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-01-01

    CERN’s Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN’s PS-Booster. Its ion source is a non-cesiated RF driven H- volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H- during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the LHC, it consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV Synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H- during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H- plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the...

  15. Cassie state robustness of plasma generated randomly nano-rough surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Di Mundo, Rosa, E-mail: rosa.dimundo@poliba.it; Bottiglione, Francesco; Carbone, Giuseppe

    2014-10-15

    Graphical abstract: - Highlights: • Superhydrophobic randomly rough surfaces are generated by plasma etching. • Statistical analysis of roughness allows calculation of theWenzel roughness factor, r{sub W.} • A r{sub W} threshold is theoretically determined, above which superhydrophobicity is “robust”. • Dynamic wetting, e.g. with high speed impacting drops, confirms this prediction. - Abstract: Superhydrophobic surfaces are effective in practical applications provided they are “robust superhydrophobic”, i.e. able to retain the Cassie state, i.e. with water suspended onto the surface protrusions, even under severe conditions (high pressure, vibrations, high speed impact, etc.). We show that for randomly rough surfaces, given the Young angle, Cassie states are robust when a threshold value of the Wenzel roughness factor, r{sub W}, is exceeded. In particular, superhydrophobic nano-textured surfaces have been generated by self-masked plasma etching. In view of their random roughness, topography features, acquired by Atomic Force Microscopy, have been statistically analyzed in order to gain information on statistical parameters such as power spectral density, fractal dimension and Wenzel roughness factor (r{sub W}), which has been used to assess Cassie state robustness. Results indicate that randomly rough surfaces produced by plasma at high power or long treatment duration, which are also fractal self-affine, have a r{sub W} higher than the theoretical threshold, thus for them a robust superhydrophobicity is predicted. In agreement with this, under dynamic wetting conditionson these surfaces the most pronounced superhydrophobic character has been appreciated: they show the lowest contact angle hysteresis and result in the sharpest bouncing when hit by drops at high impact velocity.

  16. Generation and analysis of plasmas with centrally reduced helicity in full-tungsten ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Alexander

    2016-03-01

    The most promising concepts for harnessing nuclear fusion are toroidal devices like tokamaks, where a plasma is confined by helically twisted magnetic field lines. To provide the twisting of the field lines, a tokamak relies on a toroidal current in the plasma, which is largely generated by a transformer. As such, conventional tokamaks are limited to pulsed operation. Moreover, this current makes tokamak plasmas prone to numerous confinement degrading magnetohydrodynamic (MHD) instabilities that can emerge at locations where the field line helicity q takes on rational values like 1/1, 3/2 or 2/1, i.e. sawteeth or neoclassical tearing modes (NTMs). This thesis presents studies of plasmas with centrally elevated q-profiles created by external electron-cyclotron and neutral beam current drive (ECCD/NBCD) under steady-state conditions in the full-tungsten tokamak ASDEX Upgrade. Without the usually monotonic q-profile, instabilities of low helicity disappear, thereby improving the plasma stability. Furthermore, elevating q increases the amount of so-called (toroidal) bootstrap current, which the plasma drives by itself in the presence of pressure gradients, thereby reducing the reliance on the transformer. In the best case, an advanced tokamak (AT) could thus run in steady state. Additionally, an elevated and thus flat/slightly reversed q-profile is thought to improve confinement by impeding turbulent transport. Reconstruction of the tailored q-profile is accomplished with the new integrated data equilibrium (IDE) code and information from a key diagnostic that is based on the Motional Stark Effect (MSE). During the course of this work it was discovered that the MSE diagnostic suffers from interference from polarised background light. A prototype mitigation system was successfully tested. Also, non-linearities in the diagnostic's optical relay system were found and a calibration scheme devised to take them into account. Both the conventional approach of AT

  17. Free electron laser with small period wiggler and sheet electron beam: A study of the feasibility of operation at 300 GHz with 1 MW CW output power

    International Nuclear Information System (INIS)

    Booske, J.H.; Granatstein, V.L.; Antonsen, T.M. Jr.

    1988-01-01

    The use of a small period wiggler (/ell//sub ω/ 2 ). Based on these encouraging results, a proof-of-principle experiment is being assembled, and is aimed at demonstrating FEL operating at 120 GHz with 300 kW output power in 1 μs pulses: electron energy would be 410 keV. Preliminary design of a 300 GHz 1 MW FEL with an untapered wiggler is also presented. 10 refs., 5 figs., 3 tabs

  18. Large amplitude waves and fields in plasmas

    International Nuclear Information System (INIS)

    Angelis, U. de; Naples Univ.

    1990-02-01

    In this review, based mostly on the results of the recent workshop on ''Large Amplitude Waves and Fields in Plasmas'' held at ICTP (Trieste, Italy) in May 1989 during the Spring College on Plasma Physics, I will mostly concentrate on underdense, cold, homogeneous plasmas, discussing some of the alternative (to fusion) uses of laser-plasma interaction. In Part I an outline of some basic non-linear processes is given, together with some recent experimental results. The processes are chosen because of their relevance to the applications or because new interesting developments have been reported at the ICTP workshop (or both). In Part II the excitation mechanisms and uses of large amplitude plasma waves are presented: these include phase-conjugation in plasmas, plasma based accelerators (beat-wave, plasma wake-field and laser wake-field), plasma lenses and plasma wigglers for Free Electron Lasers. (author)

  19. Comprehensive study on the pressure dependence of shock wave plasma generation under TEA CO2 laser bombardment on metal sample

    International Nuclear Information System (INIS)

    Marpaung, A.M.; Kurniawan, H.; Tjia, M.O.; Kagawa, K.

    2001-01-01

    An experimental study has been carried out on the dynamical process taking place in the plasma generated by a TEA CO 2 laser (400 mJ, 100 ns) on a zinc target when surrounded by helium gas of pressure ranging from 2 Torr to 1 atm. Plasma characteristics were examined in detail on the emission lines of Zn I 481.0 nm and He I 587.6 nm by means of an unique time-resolved spatial distribution technique in addition to an ordinary time-resolved emission measurement technique. The results reveal, for the first time, persistent shock wave characteristics in all cases throughout the entire pressure range considered. Further analysis of the data has clarified the distinct characteristics of laser plasmas generated in different ranges of gas pressure. It is concluded that three types of shock wave plasma can be identified; namely, a target shock wave plasma in the pressure range from 2 Torr to around 50 Torr; a coupling shock wave plasma in the pressure range from around 50 Torr to 200 Torr and a gas breakdown shock wave plasma in the pressure range from around 200 Torr to 1 atm. These distinct characteristics are found to be ascribable to the different extents of the gas breakdown process taking place at the different gas pressures. These results, obtained for a TEA CO 2 laser, will provide a useful basis for the analyses of plasmas induced by other lasers. (author)

  20. Super-Gaussian transport theory and the field-generating thermal instability in laser–plasmas

    International Nuclear Information System (INIS)

    Bissell, J J; Ridgers, C P; Kingham, R J

    2013-01-01

    Inverse bremsstrahlung (IB) heating is known to distort the electron distribution function in laser–plasmas from a Gaussian towards a super-Gaussian, thereby modifying the equations of classical transport theory (Ridgers et al 2008 Phys. Plasmas 15 092311). Here we explore these modified equations, demonstrating that super-Gaussian effects both suppress traditional transport processes, while simultaneously introducing new effects, such as isothermal (anomalous Nernst) magnetic field advection up gradients in the electron number density n e , which we associate with a novel heat-flow q n ∝∇n e . Suppression of classical phenomena is shown to be most pronounced in the limit of low Hall-parameter χ, in which case the Nernst effect is reduced by a factor of five, the ∇T e × ∇n e field generation mechanism by ∼30% (where T e is the electron temperature), and the diffusive and Righi–Leduc heat-flows by ∼80 and ∼90% respectively. The new isothermal field advection phenomenon and associated density-gradient driven heat-flux q n are checked against kinetic simulation using the Vlasov–Fokker–Planck code impact, and interpreted in relation to the underlying super-Gaussian distribution through simplified kinetic analysis. Given such strong inhibition of transport at low χ, we consider the impact of IB on the seeding and evolution of magnetic fields (in otherwise un-magnetized conditions) by examining the well-known field-generating thermal instability in the light of super-Gaussian transport theory (Tidman and Shanny 1974 Phys. Fluids 12 1207). Estimates based on conditions in an inertial confinement fusion (ICF) hohlraum suggest that super-Gaussian effects can reduce the growth-rate of the instability by ≳80%. This result may be important for ICF experiments, since by increasing the strength of IB heating it would appear possible to inhibit the spontaneous generation of large magnetic fields. (paper)