Science.gov

Sample records for plasma diagnostic applications

  1. Hypervelocity Dust Injection for Plasma Diagnostic Applications

    NASA Astrophysics Data System (ADS)

    Ticos, Catalin

    2005-10-01

    Hypervelocity micron-size dust grain injection was proposed for high-temperature magnetized plasma diagnosis. Multiple dust grains are launched simultaneously into high temperature plasmas at several km/s or more. The hypervelocity dust grains are ablated by the electron and ion fluxes. Fast imaging of the resulting luminous plumes attached to each grain is expected to yield local magnetic field vectors. Combination of multiple local magnetic field vectors reproduces 2D or even 3D maps of the internal magnetic field topology. Key features of HDI are: (1) a high spatial resolution, due to a relatively small transverse size of the elongated tail, and (2) a small perturbation level, as the dust grains introduce negligible number of particles compared to the plasma particle inventory. The latter advantage, however, could be seriously compromised if the gas load from the accelerator has an unobstructed access to the diagnosed plasma. Construction of a HDI diagnostic for National Spherical Torus Experiment (NSTX), which includes a coaxial plasma gun for dust grain acceleration, is underway. Hydrogen and deuterium gas discharges inside accelerator are created by a ˜ 1 mF capacitor bank pre-charged up to 10 kV. The diagnostic apparatus also comprises a dust dispenser for pre-loading the accelerator with dust grains, and an imaging system that has a high spatial and temporal resolution.

  2. Diagnostics and biomedical applications of radiofrequency plasmas

    NASA Astrophysics Data System (ADS)

    Lazović, Saša

    2012-11-01

    In this paper we present spatial profiles of ion and atomic oxygen concentrations in a large scale cylindrical 13.56 MHz capacitively coupled plasma low pressure reactor suitable for indirect biomedical applications (like treatment of textile to increase antibacterial properties) and direct (treatment of seeds of rare and protected species). Such reactor can easily be used for the sterilization of medical instruments by removing bacteria, spores, prions and fungi as well. We also discuss electrical properties of the system based on the signals obtained by the derivative probes and show the light emission profiles close to the sample platform. In the case of seeds treatment, the desired effect is to plasma etch the outer shell of the seed which will lead to the easier nutrition and therefore increase of the germination. In the case of textile treatment the functionalization is done by bounding atomic oxygen to the surface. It appears that antibacterial properties of the textile are increased by incorporating nanoparticles to the fibres which can successfully be done after the plasma treatment. From these two examples it is obvious that the balance of ion and atomic oxygen concentrations as well as proper choice of ion energy and power delivered to the plasma direct the nature of the plasma treatment.

  3. Applications of digital processing for noise removal from plasma diagnostics

    SciTech Connect

    Kane, R.J.; Candy, J.V.; Casper, T.A.

    1985-11-11

    The use of digital signal techniques for removal of noise components present in plasma diagnostic signals is discussed, particularly with reference to diamagnetic loop signals. These signals contain noise due to power supply ripple in addition to plasma characteristics. The application of noise canceling techniques, such as adaptive noise canceling and model-based estimation, will be discussed. The use of computer codes such as SIG is described. 19 refs., 5 figs.

  4. Near Infrared Spectroscopy for Burning Plasma Diagnostic Applications

    SciTech Connect

    Soukhanovskii, V A

    2008-06-18

    Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ion fuel species (H, D, T, Li) and impurities (e.g. He, Be, C, W) is a key element of plasma control and diagnosis on ITER and future magnetically confined burning plasma experiments (BPX). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window and optical fiber transmission under intense neutron and {gamma}-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can address machine protection and plasma control diagnostic tasks, as well as plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma facing component temperatures.

  5. Applications of quantum cascade lasers in plasma diagnostics: a review

    NASA Astrophysics Data System (ADS)

    Röpcke, J.; Davies, P. B.; Lang, N.; Rousseau, A.; Welzel, S.

    2012-10-01

    Over the past few years mid-infrared absorption spectroscopy based on quantum cascade lasers operating over the region from 3 to 12 µm and called quantum cascade laser absorption spectroscopy or QCLAS has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, nitrogen oxides and organo-silicon compounds has led to further applications of QCLAS because most of these compounds and their decomposition products are infrared active. QCLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species at time resolutions below a microsecond, which is of particular importance for the investigation of reaction kinetics and dynamics. Information about gas temperature and population densities can also be derived from QCLAS measurements. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of QCLAS techniques to industrial requirements including the development of new diagnostic equipment. The recent availability of external cavity (EC) QCLs offers a further new option for multi-component detection. The aim of this paper is fourfold: (i) to briefly review spectroscopic issues arising from applying pulsed QCLs, (ii) to report on recent achievements in our understanding of molecular phenomena in plasmas and at surfaces, (iii) to describe the current status of industrial process monitoring in the mid-infrared and (iv) to discuss the potential of advanced instrumentation based on EC-QCLs for plasma diagnostics.

  6. Low Temperature Atmospheric Argon Plasma: Diagnostics and Medical Applications

    NASA Astrophysics Data System (ADS)

    Ermolaeva, Svetlana; Petrov, Oleg; Zigangirova, Nailya; Vasiliev, Mikhail; Sysolyatina, Elena; Antipov, Sergei; Alyapyshev, Maxim; Kolkova, Natalia; Mukhachev, Andrei; Naroditsky, Boris; Shimizu, Tetsuji; Grigoriev, Anatoly; Morfill, Gregor; Fortov, Vladimir; Gintsburg, Alexander

    This study was devoted to diagnostic of low temperature plasma produced by microwave generator and investigation of its bactericidal effect against bacteria in biofilms and within eukaryotic cells. The profile of gas temperature near the torch outlet was measured. The spectrum in a wide range of wavelengths was derived by the method of optical emission spec-troscopy. Probe measurements of the floating potential of plasma were car-ried out. The estimation and adaptation of parameters of plasma flow (tem-perature, velocity, ion number density) according to medico-technical requirements were produced. The model of immersed surface-associated biofilms formed by Gram-negative bacteria, Pseudomonas aeruginosa and Burkholderia cenocepacia, and Gram-positive bacteria, Staphylococcus aureus, was used to assess bactericidal effects of plasma treatment. Reduction in the concentration of live bacteria in biofilms treated with plasma for 5 min was demonstrated by measuring Live/Dead fluorescent labeling and using direct plating. The intracellular infection model with the pathogenic bacterium, Chlamydia trachomatis, was used to study the efficacy of microwave argon plasma against intracellular parasites. A 2 min plasma treatment of mouse cells infected with C. trachomatis reduced infectious bacteria by a factor of 2×106. Plasma treatment diminished the number of viable host cells by about 20%. When the samples were covered with MgF2 glass to obstruct active particles and UV alone was applied, the bactericidal effect was re-duced by 5×104 fold compared to the whole plasma.

  7. Development, diagnostic and applications of radio-frequency plasma reactor

    NASA Astrophysics Data System (ADS)

    Puac, N.

    2008-07-01

    In many areas of the industry, plasma processing of materials is a vital technology. Nonequilibrium plasmas proved to be able to produce chemically reactive species at a low gas temperature while maintaining highly uniform reaction rates over relatively large areas (Makabe and Petrovic 2006). At the same time nonequilibrium plasmas provide means for good and precise control of the properties of active particles that determine the surface modification. Plasma needle is one of the atmospheric pressure sources that can be used for treatment of the living matter which is highly sensitive when it comes to low pressure or high temperatures (above 40 C). Dependent on plasma conditions, several refined cell responses are induced in mammalian cells (Sladek et al. 2005). It appears that plasma treatment may find many biomedical applications. However, there are few data in the literature about plasma effects on plant cells and tissues. So far, only the effect of low pressure plasmas on seeds was investigated. It was shown that short duration pretreatments by non equilibrium low temperature air plasma were stimulative in light induced germination of Paulownia tomentosa seeds (Puac et al. 2005). As membranes of plants have different properties to those of animals and as they show a wide range of properties we have tried to survey some of the effects of typical plasma which is envisaged to be used in biotechnological applications on plant cells. In this paper we will make a comparison between two configurations of plasma needle that we have used in treatment of biological samples (Puac et al. 2006). Difference between these two configurations is in the additional copper ring that we have placed around glass tube at the tip of the needle. We will show some of the electrical characteristics of the plasma needle (with and without additional copper ring) and, also, plasma emission intensity obtained by using fast ICCD camera.

  8. Millimeter-Wave Imaging Technology Advancements for Plasma Diagnostics Applications

    NASA Astrophysics Data System (ADS)

    Kong, Xiangyu

    To realize fusion plant, the very first step is to understand the fundamental physics of materials under fusion conditions, i.e. to understand fusion plasmas. Our research group, Plasma Diagnostics Group, focuses on developing advanced tools for physicists to extract as much information as possible from fusion plasmas at millions degrees. The Electron Cyclotron Emission Imaging (ECEI) diagnostics is a very useful tool invented in this group to study fusion plasma electron temperature and it fluctuations. This dissertation presents millimeter wave imaging technology advances recently developed in this group to improve the ECEI system. New technologies made it more powerful to image and visualize magneto-hydrodynamics (MHD) activities and micro-turbulence in fusion plasmas. Topics of particular emphasis start from development of miniaturized elliptical substrate lens array. This novel substrate lens array replaces the previous generation substrate lens, hyper-hemispherical substrate lens, in terms of geometry. From the optical performance perspective, this substitution not only significantly simplifies the optical system with improved optical coupling, but also enhances the RF/LO coupling efficiency. By the benefit of the mini lens focusing properties, a wideband dual-dipole antenna array is carefully designed and developed. The new antenna array is optimized simultaneously for receiving both RF and LO, with sharp radiation patterns, low side-lobe levels, and less crosstalk between adjacent antennas. In addition, a high frequency antenna is also developed, which extends the frequency limit from 145 GHz to 220 GHz. This type of antenna will be used on high field operation tokamaks with toroidal fields in excess of 3 Tesla. Another important technology advance is so-called extended bandwidth double down-conversion electronics. This new electronics extends the instantaneous IF coverage from 2 to 9.2 GHz to 2 to 16.4 GHz. From the plasma point of view, it means that the

  9. THz Plasma Diagnostics: an evolution from FIR and Millimeter waves historical applications

    NASA Astrophysics Data System (ADS)

    Bombarda, F.; Doria, A.; Galatola Teka, G.; Giovenale, E.; Zerbini, M.

    2016-08-01

    Extremely broadband (100 GHz–30 THz) single cycle THz pulses are routinely generated with femtosecond laser for Time Domain Spectroscopy applications (TDS). The wide frequency range has an unquestionable diagnostic potential for Tokamak plasmas and not surprisingly THz TDS finds a natural field of application in this area, which is an evolution of the FIR and millimeter waves diagnostics, where ENEA Frascati holds historical expertise. By illuminating the plasma with a THz beam, phase, intensity and polarization of both reflected and transmitted beams can be detected, devising a single diagnostic instrument capable of measuring multiple plasma parameters. We will describe and discuss the laboratory work now in progress to realise a tailored THz-TDS spectrometer with design parameters optimised for the requirements of Tokamak plasmas and the tests of optical fibers and quasioptical couplers to optimise access to plasma. ENEA Frascati and the Photonics group of Physics Dept. of Oxford University are collaborating on this subject [1].

  10. Application of coherent lidar to ion measurements in plasma diagnostics

    SciTech Connect

    Hutchinson, D.P.; Richards, R.K.; Bennett, C.A.; Simpson, M.L.

    1997-03-01

    A coherent lidar system has been constructed for the measurement of alpha particles in a burning plasma. The lidar system consists of a pulsed CO{sub 2} laser transmitter and a heterodyne receiver. The receiver local oscillator is a cw, sequence-band CO{sub 2} laser operating with a 63.23 GHz offset from the transmitter.

  11. FAR-TECH's Nanoparticle Plasma Jet System and its Application to Disruptions, Deep Fueling, and Diagnostics

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.

    2012-10-01

    Hyper-velocity plasma jets have potential applications in tokamaks for disruption mitigation, deep fueling and diagnostics. Pulsed power based solid-state sources and plasma accelerators offer advantages of rapid response and mass delivery at high velocities. Fast response is critical for some disruption mitigation scenario needs, while high velocity is especially important for penetration into tokamak plasma and its confining magnetic field, as in the case of deep fueling. FAR-TECH is developing the capability of producing large-mass hyper-velocity plasma jets. The prototype solid-state source has produced: 1) >8.4 mg of H2 gas only, and 2) >25 mg of H2 and >180 mg of C60 in a H2/C60 gas mixture. Using a coaxial plasma gun coupled to the source, we have successfully demonstrated the acceleration of composite H/C60 plasma jets, with momentum as high as 0.6 g.km/s, and containing an estimated C60 mass of ˜75 mg. We present the status of FAR-TECH's nanoparticle plasma jet system and discuss its application to disruptions, deep fueling, and diagnostics. A new TiH2/C60 solid-state source capable of generating significantly higher quantities of H2 and C60 in <0.5 ms will be discussed.

  12. Dust dynamics and diagnostic applications in quasi-neutral plasmas and magnetic fusion

    NASA Astrophysics Data System (ADS)

    Wang, Zhehui; Ticos, Catalin M.; Si, Jiahe; Delzanno, Gian Luca; Lapenta, Gianni; Wurden, Glen

    2007-11-01

    Little is known about dust dynamics in highly ionized quasi-neutral plasmas with ca. 1.0 e+20 per cubic meter density and ion temperature at a few eV and above, including in magnetic fusion. For example, dust motion in fusion, better known as UFO's, has been observed since 1980's but not explained. Solid understanding of dust dynamics is also important to International Thermonuclear Experimental Reactor (ITER) because of concerns about safety and dust contamination of fusion core. Compared with well studied strongly-coupled dusty plasma regime, new physics may arise in the higher density quasi-neutral plasma regime because of at least four orders of magnitude higher density and two orders of magnitude hotter ion temperature. Our recent laboratory experiments showed that plasma-flow drag force dominates over other forces in a quasi-neutral flowing plasma. In contrast, delicate balance among different forces in dusty plasma has led to many unique phenomena, in particular, the formation of dust crystal. Based on our experiments, we argue that 1) dust crystal will not form in the highly ionized plasmas with flows; 2) the UFO's are moving dust dragged by plasma flows; 3) dust can be used to measure plasma flow. Two diagnostic applications using dust for laboratory quasi-neutral plasmas and magnetic fusion will also be presented.

  13. PREFACE: IX International Conference on Modern Techniques of Plasma Diagnostics and their Application

    NASA Astrophysics Data System (ADS)

    Savjolov, A. S.; Dodulad, E. I.

    2016-01-01

    The IX Conference on ''Modern Techniques of Plasma Diagnosis and their Application'' was held on 5 - 7 November, 2014 at National Research Nuclear University MEPhI (NRNU MEPhI). The goal of the conference was an exchange of information on both high-temperature and low-temperature plasma diagnostics as well as deliberation and analysis of various diagnostic techniques and their applicability in science, industry, ecology, medicine and other fields. The Conference also provided young scientists from scientific centres and universities engaged in plasma diagnostics with an opportunity to attend the lectures given by the leading specialists in this field as well as present their own results and findings. The first workshop titled ''Modern problems of plasma diagnostics and their application for control of chemicals and the environment'' took place at Moscow Engineering and Physics Institute (MEPhI) in June 1998 with the support of the Section on Diagnostics of the Council of Russian Academic of Science on Plasma Physics and since then these forums have been held at MEPhI every two years. In 2008 the workshop was assigned a conference status. More than 150 specialists on plasma diagnostics and students took part in the last conference. They represented leading Russian scientific centres (such as Troitsk Institute of Innovative and Thermonuclear Research, National Research Centre ''Kurchatov Institute'', Russian Federal Nuclear Centre - All-Russian Scientific Research Institute of Experimental Physics and others) and universities from Belarus, Ukraine, Germany, USA, Belgium and Sweden. About 30 reports were made by young researchers, students and post-graduate students. All presentations during the conference were broadcasted online over the internet with viewers in Moscow, Prague, St. Petersburgh and other cities. The Conference was held within the framework of the Centre of Plasma, Laser Research and Technology supported by MEPhI Academic Excellence Project (Russian

  14. Spectroscopic Challenges in the Modelling and Diagnostics of High Temperature Air Plasma Radiation for Aerospace Applications

    SciTech Connect

    Laux, Christophe O.

    2007-04-06

    State-of-the-art spectroscopic models of the radiative transitions of interest for Earth re-entry and ground-based diagnostic facilities for aerospace applications are reviewed. The spectral range considered extends from the vacuum ultraviolet to the mid-infrared range (80 nm to 5.5 {mu}m). The modeling results are compared with absolute intensity measurements of the ultraviolet-visible-infrared emission of a well-characterized high-temperature air plasma produced with a 50 kW inductively coupled radio-frequency plasma torch, and with high-resolution absorption spectra from the Center for Astrophysics in the vacuum ultraviolet. The Spectroscopic data required to better model the spectral features of interest for aerospace applications are discussed.

  15. Application of advanced millimeter/far-infrared sources to collective Thomson scattering plasma diagnostics

    SciTech Connect

    Woskoboinikow, P.; Cohn, D.R.; Temkin, R.J.

    1983-01-01

    The application of advanced millimeter/far infrared sources to substantially improve the effectiveness of collective Thomson scattering plasma diagnostics is discussed. Gyrotrons, CO/sub 2/ lasers and far infrared lasers which are optically pumped with CO/sub 2/ laser radiation can now provide important new capabilities in terms of combined high peak power and high average power, fine frequency tunability and a wide range of operating frequencies. Their capabilities can improve the signal to noise ratio and make possible time dependent scattering measurements. Both thermal level scattering used for determination of ion temperature and low level non-thermal measurements used for the investigation of plasma turbulence and wave phenomena are considered. Rapidly pulsed gyrotrons, CO/sub 2/, and optically pumped lasers can provide a range of combinations of high peak power and high energy during a given time interval. The use of this high peak power - high energy trade off capability to maximize signal to noise ratios is discussed. Dramatic reduction in stray light, using fine frequency source tunability and gas absorption cell technology, is also discussed.

  16. Helium Atmospheric Pressure Plasma Jet: Diagnostics and Application for Burned Wounds Healing

    NASA Astrophysics Data System (ADS)

    Topala, Ionut; Nastuta, Andrei

    A new field of plasma applications developed in the last years, entitled plasma medicine, has focused the attention of many peoples from plasma ­community on biology and medicine. Subjects that involve plasma physics and technology (e.g. living tissue treatment or wound healing, cancer cell apoptosis, blood coagulation, sterilization and decontamination) are nowadays in study in many laboratories. In this paper we present results on optical and electrical diagnosis of a helium ­atmospheric pressure plasma jet designed for medical use. This type of plasma jet was used for improvement of the wound healing process. We observed a more rapid macroscopic healing of the plasma treated wounds in comparison with the control group.

  17. Tomographic diagnostics of nonthermal plasmas

    NASA Astrophysics Data System (ADS)

    Denisova, Natalia

    2009-10-01

    In the previous work [1], we discussed a ``technology'' of tomographic method and relations between the tomographic diagnostics in thermal (equilibrium) and nonthermal (nonequilibrium) plasma sources. The conclusion has been made that tomographic reconstruction in thermal plasma sources is the standard procedure at present, which can provide much useful information on the plasma structure and its evolution in time, while the tomographic reconstruction of nonthermal plasma has a great potential at making a contribution to understanding the fundamental problem of substance behavior in strongly nonequilibrium conditions. Using medical terminology, one could say, that tomographic diagnostics of the equilibrium plasma sources studies their ``anatomic'' structure, while reconstruction of the nonequilibrium plasma is similar to the ``physiological'' examination: it is directed to study the physical mechanisms and processes. The present work is focused on nonthermal plasma research. The tomographic diagnostics is directed to study spatial structures formed in the gas discharge plasmas under the influence of electrical and gravitational fields. The ways of plasma ``self-organization'' in changing and extreme conditions are analyzed. The analysis has been made using some examples from our practical tomographic diagnostics of nonthermal plasma sources, such as low-pressure capacitive and inductive discharges. [0pt] [1] Denisova N. Plasma diagnostics using computed tomography method // IEEE Trans. Plasma Sci. 2009 37 4 502.

  18. Application of Gaseous Laser Targets and Optical Diagnostics to Study High Mach Number Unstable Plasma Flows

    SciTech Connect

    Edwards, J; MacKinnon, A; Robey, H

    2001-04-01

    The information that can be obtained from current laser driven high Mach number (compressible) hydrodynamics experiments using solid targets and foams is limited by the need to use X-ray diagnostics. These do well at providing the shape of gross 2D structures which we model well, but are a long way from being able to reveal detailed information at the smaller spatial scales, or in 3D turbulent flows, where most of the modeling uncertainties exist. Remedying this is, and will continue to be, an ongoing research effort. An alternative approach that is not being considered is to use gaseous targets coupled with optical diagnostics. The lower density of gases compared to solids or foams means we can use much larger targets for a given laser energy. This should significantly improve spatial resolution, and the dynamic range of scales that are resolvable. In addition, it may be possible to adapt powerful techniques, such as LIF, used by the low Mach number (incompressible) fluid/gas community so that they work in the high Mach number plasma regime. This would provide much more detailed information on turbulent flows than could be achieved with current X-ray diagnostics. We propose a small research effort to use established techniques such as optical interferometry (absolute electron density), and Schlieren photography (electron density gradient), to study compressible hydrodynamic instabilities. We also propose to explore whether techniques such as LIF may be adapted to the plasma regime, thus providing detailed information, particularly about turbulent flows, that is not currently obtainable in plasmas using X-ray diagnostics. The setting will be radiating blast waves, which avoids costly target fabrication, while promising a high physics payoff to the astrophysics community just from using the established diagnostics alone. We propose to conduct the work in collaboration with Dr Todd Ditmire at the University of Texas at Austin, principally on the Janus laser, and

  19. Testing and Calibration of Novel Detectors for Nuclear and Plasma Physics Diagnostic Applications

    NASA Astrophysics Data System (ADS)

    Ali, Zaheer; Haugh, Mike; Tellinghuisen, Jim; Glebov, Vladimir; Roberts, Sam; Stoeckl, Christian; Sangster, Craig

    2008-10-01

    Calibrated chemical vapor deposition (CVD) diamond diodes, X-ray diodes (XRDs), and PIN diodes are used in nuclear and plasma physics diagnostic experiments, such as those conducted at the National Ignition Facility at Lawrence Livermore National Laboratory (LLNL). Calibrations of these diodes are conducted at the OMEGA Laser at the Lab for Laser Energetics of the University of Rochester, as well as at the Titan Laser in the Jupiter Laser Facility at LLNL. The OMEGA Laser is a 30-kilojoule one-nanosecond system designed for inertial confinement fusion and nuclear physics research. The Titan Laser is a picosecond system designed for plasma and X-ray studies. In addition, National Security Technologies, LLC, (NSTec) has built a new hard X-ray calibration facility (the ``HEX Laboratory''), where X-ray detector systems are also calibrated. In this paper we will present our methods of absolute and relative calibration, results of calibration, and the capabilities of the HEX Laboratory.

  20. ON THE ACCURACY OF THE DIFFERENTIAL EMISSION MEASURE DIAGNOSTICS OF SOLAR PLASMAS. APPLICATION TO SDO/AIA. II. MULTITHERMAL PLASMAS

    SciTech Connect

    Guennou, C.; Auchere, F.; Soubrie, E.; Bocchialini, K.; Barbey, N.

    2012-12-15

    Differential emission measure (DEM) analysis is one of the most used diagnostic tools for solar and stellar coronae. Being an inverse problem, it has limitations due to the presence of random and systematic errors. We present in this series of papers an analysis of the robustness of the inversion in the case of SDO/AIA observations. We completely characterize the DEM inversion and its statistical properties, providing all the solutions consistent with the data along with their associated probabilities, and a test of the suitability of the assumed DEM model. While Paper I focused on isothermal conditions, we now consider multithermal plasmas and investigate both isothermal and multithermal solutions. We demonstrate how the ambiguity between noises and multithermality fundamentally limits the temperature resolution of the inversion. We show that if the observed plasma is multithermal, isothermal solutions tend to cluster on a constant temperature whatever the number of passbands or spectral lines. The multithermal solutions are also found to be biased toward near-isothermal solutions around 1 MK. This is true even if the residuals support the chosen DEM model, possibly leading to erroneous conclusions on the observed plasma. We propose tools for identifying and quantifying the possible degeneracy of solutions, thus helping the interpretation of DEM inversion.

  1. Diagnostic techniques for thermal plasmas

    SciTech Connect

    Fincke, J.R.; Snyder, S.C.; Swank, W.D.; Haggard, D.C.; Reynolds, L.D.

    1994-12-31

    The plasma diagnostic techniques discussed are Rayleigh and coherent Thomson scattering, Coherent-Anti-Stokes-Raman Spectroscopy (CARS) and enthalpy probes. The quantities measured are heavy species and electron temperature, ionized fraction, plasma composition, and velocity. Examples of results from both subsonic and supersonic jets are presented and limitations discussed.

  2. Microwave diagnostics of atmospheric plasmas

    NASA Astrophysics Data System (ADS)

    Scott, David

    Plasma treatment of biological tissues has tremendous potential due to the wide range of applications. Most plasmas have gas temperatures which greatly exceed room temperature. These are often utilized in electro-surgery for cutting and coagulating tissue. Another type of plasma, referred to as cold atmospheric plasma, or CAP, is characterized by heavy particle temperatures which are at or near room temperature. Due to this lack of thermal effect, CAP may provide less invasive medical procedures. Additionally, CAP have been demonstrated to be effective at targeting cancer cells while minimizing damage to the surrounding tissue. A recently fabricated Microwave Electron Density Device (MEDD) utilizes microwave scattering on small atmospheric plasmas to determine the electron plasma density. The MEDD can be utilized on plasmas which range from a fraction of a millimeter to several centimeters at atmospheric pressure when traditional methods cannot be applied. Microwave interferometry fails due to the small size of the plasma relative to the microwave wavelength which leads to diffraction and negligible phase change; electrostatic probes introduce very strong perturbation and are associated with difficulties of application in strongly-collisional atmospheric conditions; and laser Thomson scattering is not sensitive enough to measure plasma densities less than 1012 cm-3. The first part of this dissertation provides an overview of two types of small atmospheric plasma objects namely CAPs and plasmas utilized in the electro-surgery. It then goes on to describe the fabrication, testing and calibration of the MEDD facility. The second part of this dissertation is focused on the application of the MEDD and other diagnostic techniques to both plasma objects. A series of plasma images that illustrate the temporal evolution of a discharge created by an argon electrosurgical device operating in the coagulation mode and its behavior was analyzed. The discharge of the argon

  3. Spectroscopy Diagnostics for Helicon Plasmas

    NASA Astrophysics Data System (ADS)

    Boivin, R. F.; Balkey, M. M.; Blackburn, M. A.; Keiter, P. A.; Kline, J. L.; Scime, E. E.; Spangler, R. S.

    1999-11-01

    Measuring plasma parameters via non-intrusive diagnostics is a matter of necessity in steady-state helicon sources. Contrary to probes, spectroscopy measurements are only weakly affected by RF fields and do not contaminate the plasma. We discuss spectroscopic diagnostics designed to evaluate the different plasma parameters of the HELIX helicon source. The wide range in density that can generated by HELIX (for He, 10^10 to 10^13 cm-3) makes it an ideal source to develop and validate diagnostics that can be used in RF plasmas. For He discharges, a spectroscopy technique based on the relative intensities of He I lines is used to measure Te in the plasma. This diagnostic is based on the fact that the dependence on the electron energy of the excitation rate differs between singlet and triplet lines of the He atom. In addition, using an absolute calibration, the study of specific neutral and ion transitions can predict the population of the different excited levels and the ion density. For Ar plasmas, the possibility of using a line ratio technique to evaluate the electron temperature is investigated. An alternative technique using the ratio of bound-bound radiation versus continuous radiation is also presented. Finally, absolute intensity measurements of specific Ar I and Ar II transitions are used to predict the excited levels populations and the ion density in the plasma, respectively.

  4. Nonequilibrium diagnostics of plasma thrusters

    SciTech Connect

    Eddy, T.L.; Grandy, J.D.

    1990-01-01

    This paper describes possible techniques by which the state of plasma thruster operation for space propulsion can be determined from a minimum set of experimental data in the laboratory. The kinetic properties of the nonequilibrium plasma plume usually can not be directly related to the observed radiation; hence, appropriate nonequilibrium diagnostic techniques must be employed. A newly developed multithermal, multichemical equilibrium method is discussed that uses measured line emission intensities and N equations to solve for N unknowns. The effect of arbitrarily changing the number of selected N unknowns and how one determines the optimum (minimum) number to be used for a given composition is also presented. The chemical nonequilibrium aspects and the application to molecular species have not yet been published. The important conclusions are that (1) complete thermodynamic systems in nonequilibrium can be described by relatively few variables if appropriate choices and filtering methods are used, (2) a few radiation measurements can yield valid kinetic properties, and (3) the major question in the relations to be used is in the form of the law of mass action. The results are substantiated in the laboratory by additional alternative methods of measurement of some of the kinetic properties. 13 refs., 1 fig.

  5. ON THE ACCURACY OF THE DIFFERENTIAL EMISSION MEASURE DIAGNOSTICS OF SOLAR PLASMAS. APPLICATION TO SDO/AIA. I. ISOTHERMAL PLASMAS

    SciTech Connect

    Guennou, C.; Auchere, F.; Soubrie, E.; Bocchialini, K.; Barbey, N.

    2012-12-15

    Differential emission measure (DEM) analysis is a major diagnostic tool for stellar atmospheres. However, both its derivation and its interpretation are notably difficult because of random and systematic errors, and the inverse nature of the problem. We use simulations with simple thermal distributions to investigate the inversion properties of SDO/AIA observations of the solar corona. This allows a systematic exploration of the parameter space, and using a statistical approach the respective probabilities of all the DEMs compatible with the uncertainties can be computed. Following this methodology, several important properties of the DEM inversion, including new limitations, can be derived and presented in a very synthetic fashion. In this first paper, we describe the formalism and we focus on isothermal plasmas as building blocks to understand the more complex DEMs studied in the second paper. The behavior of the inversion of AIA data being thus quantified, and we provide new tools to properly interpret the DEM. We quantify the improvement of the isothermal inversion with six AIA bands compared to previous EUV imagers. The maximum temperature resolution of AIA is found to be 0.03 log T{sub e} , and we derive a rigorous test to quantify the compatibility of observations with the isothermal hypothesis. However, we demonstrate limitations in the ability of AIA alone to distinguish different physical conditions.

  6. diagnostic in a recombining plasma

    NASA Astrophysics Data System (ADS)

    Wenzel, U.; Goto, M.

    2016-05-01

    In fusion devices the hydrogen Balmer lines are used to measure the neutral flux from the walls into the plasma using the atomic physics factor S/XB. This is a standard diagnostic which can be applied in ionizing plasma using {{H}α} , {{H}β} or {{H}γ} without knowledge of the electron density. We will extend this method to a recombining plasma in front of a surface. {{H}α} can be used in an analogous way to measure the plasma flow to this surface which can be e.g. a divertor target. The other Balmer lines are not suitable because the corresponding atomic physics factor R/YB depends on density due to three-body recombination. An application of this diagnostic method is provided.

  7. Far infrared fusion plasma diagnostics

    SciTech Connect

    Luhmann, N.C. Jr.; Peebles, W.A.

    1990-01-01

    Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several researchers, have theoretically investigated these questions. However, prior to the UCLA laboratory investigation, no group has experimentally investigated these questions. Because of the reflectometer's importance to the world effort in understanding plasma turbulence and transport, UCLA has, over the last year, made its primary Task IIIA effort the resolution of these questions. UCLA has taken the lead in a quantitative experimental understanding of reflectometer data as applied to the measurement of density fluctuations. In addition to this, work has proceeded on the design, construction, and installation of a reflectometer system on UCLA's CCT tokamak. This effort will allow a comparison between the improved confinement regimes (H-mode) observed on both the DIII-D and CCT machines with the goal of achieving a physics understanding of the phenomena. Preliminary investigation of a new diagnostic technique to measure density profiles as a function of time has been initiated at UCLA. The technique promises to be a valuable addition to the range of available plasma diagnostics. Work on advanced holographic reflectometry technique as applied to fluctuation diagnostics has awaited a better understanding of the reflectometer signal itself as discussed above. Efforts to ensure the transfer of the diagnostic developments have continued with particular attention devoted to the preliminary design of a multichannel FIR interferometer for MST.

  8. Advanced plasma diagnostics for plasma processing

    NASA Astrophysics Data System (ADS)

    Malyshev, Mikhail Victorovich

    1999-10-01

    A new, non-intrusive, non-perturbing diagnostic method was developed that can be broadly applied to low pressure, weakly ionized plasmas and glow discharges-trace rare gases optical emission spectroscopy (TRG-OES). The method is based on a comparison of intensities of atomic emission from trace amounts of inert gases (He, Ne, Ar, Kr, and Xe) that are added to the discharge to intensities calculated from the theoretical model. The model assumes a Maxwellian electron energy distribution function (EEDF), computes the population of emitting levels both from the ground state and the metastable states of rare gases, and from the best fit between theory and experiment determines electron temperature (Te). Subject to conditions, TRG-OES can also yield electron density or its upper or lower limit. From the comparison of the emission from levels excited predominantly by high energy electrons to that excited by low energy electrons, information about the EEDF can be obtained. The use of TRG-OES also allows a traditionally qualitative actinometry technique (determination of concentration of radical species in plasma through optical emission) to become a precise quantitative method by including Te and rare gases metastables effects. A combination of TRG-OES, advanced actinometry, and Langmuir probe measurements was applied to several different plasma reactors and regimes of operation. Te measurements and experiments to correct excitation cross section were conducted in a laboratory helical resonator. Two chamber configuration of a commercial (Lam Research) metal etcher were studied to determine the effects of plasma parameters on plasma-induced damage. Two different methods (RF inductive coupling and ultra-high frequency coupling) for generating a plasma in a prototype reactor were also studied. Pulsed plasmas, a potential candidate to eliminate the plasma-induced damage to microelectronics devices that occurs in manufacturing due to differential charging of the wafer, have

  9. Application and Continued Development of Thin Faraday Collectors as a Lost Ion Diagnostic for Tokamak Fusion Plasmas

    SciTech Connect

    F. Ed Cecil

    2011-06-30

    This report summarizes the accomplishment of sixteen years of work toward the development of thin foil Faraday collectors as a lost energetic ion diagnostic for high temperature magnetic confinement fusion plasmas. Following initial, proof of principle accelerator based studies, devices have been tested on TFTR, NSTX, ALCATOR, DIII-D, and JET (KA-1 and KA-2). The reference numbers refer to the attached list of publications. The JET diagnostic KA-2 continues in operation and hopefully will provide valuable diagnostic information during a possible d-t campaign on JET in the coming years. A thin Faraday foil spectrometer, by virtue of its radiation hardness, may likewise provide a solution to the very challenging problem of lost alpha particle measurements on ITER and other future burning plasma machines.

  10. On the application of cw external cavity quantum cascade infrared lasers for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Lopatik, D.; Lang, N.; Macherius, U.; Zimmermann, H.; Röpcke, J.

    2012-11-01

    Three continuous wave external cavity quantum cascade lasers (EC-QCLs) operating between 1305 and 2260 cm-1 (4.42-7.66 µm) have been tested as radiation sources for an absorption spectrometer focused on the analysis of physical and chemical phenomena in molecular plasmas. Based on the wide spectral tunability of EC-QCLs, multiple species detection has become feasible and is demonstrated in a study of low-pressure Ar/N2 microwave plasmas containing methane as a hydrocarbon precursor. Using the direct absorption technique, the evolution of the concentrations of CH4, C2H2, HCN and H2O has been monitored depending on the discharge conditions at a pressure of p = 0.5 mbar and at a frequency of f = 2.45 GHz in a planar microwave plasma reactor. The concentrations were found to be in the range of 1011-1014 molecules cm-3. In addition, based on the analysis of the line profile of selected absorption lines, the gas temperature Tg has been calculated in dependence on the discharge power. Tg increased with the power values and was in the range between 400 and 700 K. Further, in a pure He/Ar microwave plasma, the wavelength modulation spectroscopy technique has been applied for the sensitive detection of transient plasma species with absorbencies down to 10-5. The typical spectral line width of an EC-QCL under the study was found to be in the range 24 to 38 MHz depending (i) on the chopping technique used and (ii) on a single or averaged measurement approach. Further, different methods for the modulation and tuning of the laser radiation have been tested. Varying the power values of an EC-QCL between 0.1 and 154 mW for direct absorption measurements under low pressure conditions, no saturation effects in determining the concentrations of methane, acetylene and carbon monoxide could be found under the experimental conditions used, i.e. for lines with line strengths between 10-19 and 10-22 cm molecule-1.

  11. Optical emission spectroscopic diagnostics of a non-thermal atmospheric pressure helium-oxygen plasma jet for biomedical applications

    SciTech Connect

    Thiyagarajan, Magesh; Sarani, Abdollah; Nicula, Cosmina

    2013-06-21

    In this work, we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet, that are critical for biomedical applications, have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18 W. The effect of addition of small fractions of oxygen at 0.1%-0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity property of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=0) at 308 nm and A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=1) at 287 nm, O I transitions 3p{sup 5}P{yields}3s{sup 5}S{sup 0} at 777.41 nm, and 3p{sup 3}P{yields}3s{sup 3}S{sup 0} at 844.6 nm, N{sub 2}(C-B) second positive system with electronic transition C{sup 3}{Pi}{sub u}{sup {yields}}B{sup 3}{Pi}{sub g}'' in the range of 300-450 nm and N{sub 2}{sup +}(B-X) first negative system with electronic transition B{sup 2}{Sigma}{sub u}{sup +}{yields}X{sup 2}{Sigma}{sub g}{sup +}({Delta}{nu}=0) at 391.4 nm have been studied. The atomic emission lines of helium were identified, including the He I transitions 3p{sup 3}P{sup 0}{yields}2s{sup 3}S at 388.8 nm, 3p{sup 1}P{sup 0}{yields} 2s{sup 1}S at 501.6 nm, 3d{sup 3}D{yields}2p{sup 3}P{sup 0} at 587.6 nm, 3d{sup 1}D{yields}2p{sup 1}P{sup 0} at 667.8 nm, 3s{sup 3}S{sup 1}{yields}2p{sup 3}P{sup 0} at 706.5 nm, 3s{sup 1}S{sup 0}{yields}2p{sup 1}P{sup 0} at 728.1 nm, and H{sub {alpha}} transition 2p-3d at 656.3 nm. Using a spectral fitting method, the OH radicals at 306-312 nm, the rotational and vibrational temperatures

  12. Advanced diagnostics for plasma chemistry

    SciTech Connect

    Kruger, C.H.

    1994-03-01

    Since July 15, 1992, the High Temperature Gasdynamics Laboratory in the Department of Mechanical Engineering at Stanford University has been engaged in a four-year research program on Advanced Diagnostics for Plasma Chemistry. The goal of this program is to develop state-of-the-art laser-based diagnostics of molecular species in harsh chemical environments, particularly those encountered in plasma synthesis of new materials. Emphasis has been placed on exploiting a new nonlinear spectroscopy, degenerate four wave mixing, as well as linear laser induced fluorescence to accomplish these goals. The present submittal is a proposal for the continuation funding for the third year of this program, from July 15, 1994, until July 14, 1995. Section 2 summarizes the research accomplished during the first eighteen months of the program. Section 3 discusses the plans for continuing research activities. Publications and presentations to date resulting from this program are listed in Section 4. The proposed budget for the third year is given in Section 5.

  13. Multifunctional laser facility with photoelectric recording for plasma diagnostics

    SciTech Connect

    Pyatnitsky, L.N.; Yakushev, G.G.; Oberman, F.M. )

    1989-01-01

    A laser facility with photoelectric recording is described. It can be used in performing plasma diagnostics by four different measuring techniques. The application of photoelectric recording considerably simplifies the automation of measurements.

  14. Plasma diagnostics of non-equilibrium atmospheric plasma jets

    NASA Astrophysics Data System (ADS)

    Shashurin, Alexey; Scott, David; Keidar, Michael; Shneider, Mikhail

    2014-10-01

    Intensive development and biomedical application of non-equilibrium atmospheric plasma jet (NEAPJ) facilitates rapid growth of the plasma medicine field. The NEAPJ facility utilized at the George Washington University (GWU) demonstrated efficacy for treatment of various cancer types (lung, bladder, breast, head, neck, brain and skin). In this work we review recent advances of the research conducted at GWU concerned with the development of NEAPJ diagnostics including Rayleigh Microwave Scattering setup, method of streamer scattering on DC potential, Rogowski coils, ICCD camera and optical emission spectroscopy. These tools allow conducting temporally-resolved measurements of plasma density, electrical potential, charge and size of the streamer head, electrical currents flowing though the jet, ionization front propagation speed etc. Transient dynamics of plasma and discharge parameters will be considered and physical processes involved in the discharge will be analyzed including streamer breakdown, electrical coupling of the streamer tip with discharge electrodes, factors determining NEAPJ length, cross-sectional shape and propagation path etc.

  15. Optical diagnostics of dusty plasmas

    NASA Astrophysics Data System (ADS)

    Remy, Jerome Alphonse Robert

    The central topic of this thesis is dusty plasmas, in which particles are generated or injected. Such plasmas, when ignited in silane-based gas mixtures, are widely used in the semiconductor industry for depositing silicon layers (amorphous, micro-crystalline or polymorphous). These layers have applications in flat panel displays, sensors, and solar cells for instance. The inclusion of nano-crystallites in the amorphous silicon layer produces cells with enhanced properties but calls at the same time for a better comprehension and control of the particles' formation and growth. The role played by silicon-based radical species in these processes more particularly prompts detailed studies. Dusty plasmas are also a field of enduring interest to the astrophysics community. The interstellar medium can be simulated in a laboratory plasma to identify the carbon-based molecular complexes (Polycyclic Aromatic Hydrocarbons or PAHs) whose ions are thought to be responsible for unidentified emission and absorption bands seen in the spectra of starlight. This thesis covers some aspects of both industry-oriented and astrophysical dusty plasmas. The experimental study on silane-based plasmas includes optical measurements performed in emission, absorption, and by analyzing the light scattered by particles grown in-situ. The negative charge acquired by the particles while immersed in the plasma disturbs their dynamics but also the electrical properties of the discharge. Based on the monitoring of the plasma impedance, it is shown that the plasma is affected by the particles' presence, independently from the nature of the silane carrier gas. Optical emission spectroscopy performed on SiH, H a and H 2 excited states indicates that the silane dissociation occurs in the vicinity of the RF-powered electrode. A Fourier Transform Infrared (FTIR) time-dependent analysis of the silane consumption after plasma ignition demonstrates that the silane dissociation is actually a slow but

  16. Comparative analyses of plasma probe diagnostics techniques

    SciTech Connect

    Godyak, V. A.; Alexandrovich, B. M.

    2015-12-21

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range.

  17. Diagnostics of transient non-equilibrium atmospheric pressure plasmas

    NASA Astrophysics Data System (ADS)

    Bruggeman, Peter

    2015-09-01

    Atmospheric pressure plasmas have received a renewed interest in last decades for a variety of applications ranging from environmental remediation, material processing and synthesis to envisioned medical applications such as wound healing. While most low pressure plasmas are diffuse, atmospheric pressure plasmas are often filamentary in nature. The existence of these filaments is correlated with strong gradients in plasma properties both in space and time that can significantly affect the plasma chemistry. As these filaments are often randomly appearing in space and time, it poses great challenges for diagnostics often requiring the stabilization of the filament to study the in situ plasma kinetics. In this contribution, diagnostics of a stabilized nanosecond pulsed plasma filament in a pin-pin geometry and a filament in a nanosecond pulsed atmospheric pressure plasma jet will be presented. We will focus on electron kinetics and OH and H radical production in water containing plasmas. The extension of these diagnostics to plasmas in liquids will also be discussed. The author acknowledges support from NSF PHYS1500135, Department of Energy Plasma Science Center through the U.S. Department of Energy, Office of Fusion Energy Sciences (Contract No. DE-SC0001939), University of Minnesota and STW (Netherlands).

  18. Laser diagnostics of plasma assisted combustion

    NASA Astrophysics Data System (ADS)

    Rao, Xing

    In this study, a microwave re-entrant cavity discharge system and a direct current (DC) plasmatron are used to investigate flame enhancement and nitric oxide (NO) formation using laser and optical diagnostics. The uniqueness of this study lies in the direct coupling concept, a novel highly efficient strategy used here for the first time. To investigate combustion dynamics of direct microwave coupled combustion, an atmospheric high-Q re-entrant cavity applicator is used to couple microwave (2.45 GHz) electromagnetic energy directly into the reaction zone of a premixed laminar methane-oxygen flame using a compact torch. When microwave energy increases, a transition from electric field enhancement to microwave plasma discharge is observed. At 6 to 10 Watts, ionization and eventually break-down occurs. 2-D laser induced fluorescence (LIF) imaging of hydroxyl radicals (OH) and carbon monoxide (CO) is conducted in the reaction zone over this transition, as well as spectrally resolved flame emission measurements. These measurements serve to monitor excited state species and derive rotational temperatures using OH chemiluminescence for a range of equivalence ratios (both rich and lean) and total flow rates. Combustion dynamics is also investigated for plasma enhanced methane-air flames in premixed and nonpremixed configurations using a transient arc DC plasmatron. Results for OH and CO PLIF also indicate the differences in stability mechanism, and energy consumption for premixed and nonpremixed modes. It is shown that both configurations are significantly influenced by in-situ fuel reforming at higher plasma powers. Parametric studies are conducted in a plasma assisted methane/air premixed flame for quantitative NO production using a DC plasmatron with PLIF imaging. Quantitative measurements of NO are reported as a function of gas flow rate (20 to 50 SCFH), plasma power (100 to 900 mA, 150 to 750 W) and equivalence ratio (0.7 to 1.3). NO PLIF images and single point NO

  19. Diagnostics for characterisation of plasma actuators

    NASA Astrophysics Data System (ADS)

    Kotsonis, Marios

    2015-09-01

    The popularity of plasma actuators as flow control devices has sparked a flurry of diagnostic efforts towards their characterisation. This review article presents an overview of experimental investigations employing diagnostic techniques specifically aimed at AC dielectric barrier discharge, DC corona and nanosecond pulse plasma actuators. Mechanical, thermal and electrical characterisation techniques are treated. Various techniques for the measurement of induced velocity, body force, heating effects, voltage, current, power and discharge morphology are presented and common issues and challenges are described. The final part of this report addresses the effect of ambient conditions on the performance of plasma actuators.

  20. Tomography as a promising diagnostic tool for plasma turbulence

    NASA Astrophysics Data System (ADS)

    Fujisawa, A.; Nagashima, Y.; Inagaki, S.; Onchi, T.; Ohshima, S.; Shimizu, A.

    2016-02-01

    A system for plasma turbulence tomography has been developed in a linear cylindrical plasma as a prototype with aiming at future application on toroidal plasma of higher temperature. This paper describes the diagnostic system in both aspects of the soft- and hardware, and reports the first results of tomographic reconstruction that can successfully produce local emission and its fluctuations. In the reconstruction process, two dimensional view of plasma is obtained for approximately 0.6 ms in every sampling time of 1 μs using parallel processing of 120 cores with 10 personal computers. The results include the steady state analysis of local fluctuation power spectra using fast Fourier transform, analysis of temporal behavior of fluctuation power spectra with wavelet transform, and analyses of the structural deformation or pattern of local plasma emission, demonstrating that the success of tomography as a promising diagnostic tool for plasma turbulence.

  1. Diagnostics of thermal spraying plasma jets

    SciTech Connect

    Fauchais, P.; Coudert, J.F.; Vardelle, M.; Vardelle, A.; Denoirjean, A. )

    1992-06-01

    The development of diagnostic techniques for dc plasma spraying is reviewed with attention given to the need for thick highly reproducible coatings of good quality for aeronautic and other uses. Among the techniques examined are fast cameras, laser-Doppler anemometry (LDA), coherent anti-Stokes Raman spectroscopy (CARS), enthalpy probes, and emission spectroscopy. Particular emphasis is given to the effect of arc fluctuations on the spectroscopic measurements, and a method is introduced for obtaining temperature and species density of vapor clouds traveling with each particle in flight. Coating properties can be deduced from data on single particles, and statistical approaches are often unreliable without added data on surface temperature and particle velocity. Also presented is a method for deriving the temperature evolution of a cooled splat and successive layers and passes. These methods are of interest to the control of adhesion and cohesion in coatings for critical aerospace applications. 70 refs.

  2. Diagnostics of thermal spraying plasma jets

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Coudert, J. F.; Vardelle, M.; Vardelle, A.; Denoirjean, A.

    1992-06-01

    The development of diagnostic techniques for dc plasma spraying is reviewed with attention given to the need for thick highly reproducible coatings of good quality for aeronautic and other uses. Among the techniques examined are fast cameras, laser-Doppler anemometry (LDA), coherent anti-Stokes Raman spectroscopy (CARS), enthalpy probes, and emission spectroscopy. Particular emphasis is given to the effect of arc fluctuations on the spectroscopic measurements, and a method is introduced for obtaining temperature and species density of vapor clouds traveling with each particle in flight. Coating properties can be deduced from data on single particles, and statistical approaches are often unreliable without added data on surface temperature and particle velocity. Also presented is a method for deriving the temperature evolution of a cooled splat and successive layers and passes. These methods are of interest to the control of adhesion and cohesion in coatings for critical aerospace applications.

  3. Microwave imaging diagnostics for plasma fluctuation studies

    NASA Astrophysics Data System (ADS)

    Wang, Jian

    Electron Cyclotron Emission Imaging (ECEI) and Microwave Imaging Reflectometry (MIR) combined systems are being investigated by the UC Davis Plasma Diagnostic Group (PDG), in collaboration with Princeton Plasma Physics Laboratory (PPPL) researchers, Drs. E. Mazzucato, H.K. Park and T. Munsat, as well as researchers from the FOM-Instituut voor Plasmafysica Rijnhuizen,the Netherlands. The goal is to develop the plasma diagnostic systems based on the imaging technology developed in the UC Davis PDG group, for the study of plasma micro-turbulence, which is extremely important for the understanding of anomalous transport behavior of magnetically confined plasmas such as in tokamaks. This dissertation work provides the design of the optical systems, the design of the electronics, the testing of the antenna array and the data analysis of TEXTOR ECEI/MIR combined systems.

  4. THz time-domain spectroscopy for tokamak plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Causa, F.; Zerbini, M.; Johnston, M.; Buratti, P.; Doria, A.; Gabellieri, L.; Gallerano, G. P.; Giovenale, E.; Pacella, D.; Romano, A.; Tuccillo, A. A.; Tudisco, O.

    2014-08-01

    The technology is now becoming mature for diagnostics using large portions of the electromagnetic spectrum simultaneously, in the form of THz pulses. THz radiation-based techniques have become feasible for a variety of applications, e.g., spectroscopy, imaging for security, medicine and pharmaceutical industry. In particular, time-domain spectroscopy (TDS) is now being used also for plasma diagnostics in various fields of application. This technique is promising also for plasmas for fusion applications, where plasma characteristics are non-uniform and/or evolve during the discharge This is because THz pulses produced with femtosecond mode-locked lasers conveniently span the spectrum above and below the plasma frequency and, thus, can be used as very sensitive and versatile probes of widely varying plasma parameters. The short pulse duration permits time resolving plasma characteristics while the large frequency span permits a large dynamic range. The focus of this work is to present preliminary experimental and simulation results demonstrating that THz TDS can be realistically adapted as a versatile tokamak plasma diagnostic technique.

  5. THz time-domain spectroscopy for tokamak plasma diagnostics

    SciTech Connect

    Causa, F.; Zerbini, M.; Buratti, P.; Gabellieri, L.; Pacella, D.; Romano, A.; Tuccillo, A. A.; Tudisco, O.; Johnston, M.; Doria, A.; Gallerano, G. P.; Giovenale, E.

    2014-08-21

    The technology is now becoming mature for diagnostics using large portions of the electromagnetic spectrum simultaneously, in the form of THz pulses. THz radiation-based techniques have become feasible for a variety of applications, e.g., spectroscopy, imaging for security, medicine and pharmaceutical industry. In particular, time-domain spectroscopy (TDS) is now being used also for plasma diagnostics in various fields of application. This technique is promising also for plasmas for fusion applications, where plasma characteristics are non-uniform and/or evolve during the discharge This is because THz pulses produced with femtosecond mode-locked lasers conveniently span the spectrum above and below the plasma frequency and, thus, can be used as very sensitive and versatile probes of widely varying plasma parameters. The short pulse duration permits time resolving plasma characteristics while the large frequency span permits a large dynamic range. The focus of this work is to present preliminary experimental and simulation results demonstrating that THz TDS can be realistically adapted as a versatile tokamak plasma diagnostic technique.

  6. Diagnostics of nonlocal plasmas: advanced techniques

    NASA Astrophysics Data System (ADS)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  7. Spectroscopic diagnostics of high temperature plasmas

    SciTech Connect

    Moos, W.

    1990-01-01

    A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.

  8. Laser Diagnostics for Plasma Processes

    NASA Astrophysics Data System (ADS)

    Filimonov, Serguei Victor

    The time transients of vibrational/rotational excitation up to v = 7 vibrational level of the ground electronic state of nitrogen were measured in a positive column during the 1-10 mus pulsed electric discharges, and in the afterglow. Current densities were up to 25 A/cm^2, and pressures up to 6 Torr. It is shown that initially energy is being transferred, primarily into vibrational levels above v = 1, resulting in a highly non Boltzmann distribution. The redistribution between vibrational levels takes place within 100 mus after the discharge pulse. Beyond 100 mus the vibrational populations resemble closely Boltzmann distribution. Significant rotational heating was observed in the afterglow and is attributed to energy transfer from vibration to rotation via collisions with electrons. The rotational temperature was as high as 3500 K and reached maximum values between 80 and 100 mus after the discharge pulse. Standard, Coherent Anti-Stokes Raman Spectroscopy (CARS) was employed in all measurements. A novel laser interferometric system has been developed for real time in situ monitoring of the etch rate during the plasma etching. The two-beam-two-path optical set-up provides continuous etch rate measurements while plasma parameters are changing.

  9. Plasma Diagnostics by Antenna Impedance Measurements

    NASA Technical Reports Server (NTRS)

    Swenson, C. M.; Baker, K. D.; Pound, E.; Jensen, M. D.

    1993-01-01

    The impedance of an electrically short antenna immersed in a plasma provides an excellent in situ diagnostic tool for electron density and other plasma parameters. By electrically short we mean that the wavelength of the free-space electromagnetic wave that would be excited at the driving frequency is much longer than the physical size of the antenna. Probes using this impedance technique have had a long history with sounding rockets and satellites, stretching back to the early 1960s. This active technique could provide information on composition and temperature of plasmas for comet or planetary missions. Advantages of the impedance probe technique are discussed and two classes of instruments built and flown by SDL-USU for determining electron density (the capacitance and plasma frequency probes) are described.

  10. Diagnostics for the plasma liner experiment.

    PubMed

    Lynn, A G; Merritt, E; Gilmore, M; Hsu, S C; Witherspoon, F D; Cassibry, J T

    2010-10-01

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical "plasma liners" via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n(i)∼10(16) cm(-3), T(e)≈T(i)∼1 eV at the plasma gun mouth to n(i)>10(19) cm(-3), T(e)≈T(i)∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed. PMID:21033980

  11. Diagnostics for the Plasma Liner Experiment

    SciTech Connect

    Lynn, A. G.; Merritt, E.; Gilmore, M.; Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.

    2010-10-15

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical ''plasma liners'' via merging high Mach number plasma jets to reach peak liner pressures of {approx}0.1 Mbar using {approx}1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n{sub i}{approx}10{sup 16} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}1 eV at the plasma gun mouth to n{sub i}>10{sup 19} cm{sup -3}, T{sub e}{approx_equal}T{sub i}{approx}0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  12. SPDE: Solar Plasma Diagnostic Experiment

    NASA Technical Reports Server (NTRS)

    Bruner, Marilyn E.

    1995-01-01

    The physics of the Solar corona is studied through the use of high resolution soft x-ray spectroscopy and high resolution ultraviolet imagery. The investigation includes the development and application of a flight instrument, first flown in May, 1992 on NASA sounding rocket 36.048. A second flight, NASA founding rocket 36.123, took place on 25 April 1994. Both flights were successful in recording new observations relevant to the investigation. The effort in this contract covers completion of the modifications to the existing rocket payload, its reflight, and the preliminary day reduction and analysis. Experience gained from flight 36.048 led us to plan several payload design modifications. These were made to improve the sensitivity balance between the UV and EUV spectrographs, to improve the scattered light rejection in the spectrographs, to protect the visible light rejection filter for the Normal Incidence X-ray Imager instrument (NIXI), and to prepare one new multilayer mirror coating to the NIXI. We also investigated the addition of a brassboard CCD camera to the payload to test it as a possible replacement for the Eastman type 101-07 film used by the SPDE instruments. This camera was included in the experimeter's data package for the Project Initiation Conference for the flight of NASA Mission 36.123, held in January, 1994, but for programmatic reasons was deleted from the final payload configuration. The payload was shipped to the White Sands Missile Range on schedule in early April. The launch and successful recovery took place on 25 April, in coordination with the Yohkoh satellite and a supporting ground-based observing campaign.

  13. Plasma diagnostics for the compact ignition tokamak

    SciTech Connect

    Medley, S.S.; Young, K.M.

    1988-06-01

    The primary mission of the Compact Ignition Tokamak (CIT) is to study the physics of alpha-particle heating in an ignited D-T plasma. A burn time of about 10 /tau//sub E/ is projected in a divertor configuration with baseline machine design parameters of R=2.10 m, 1=0.65 m, b=1.30 m, I/sub p/=11 MA, B/sub T/=10 T and 10-20 MW of auxiliary rf heating. Plasma temperatures and density are expected to reach T/sub e/(O) /approximately/20 keV, T/sub i/(O) /approximately/30 keV, and n/sub e/(O) /approximately/ 1 /times/ 10/sup 21/m/sup /minus/3/. The combined effects of restricted port access to the plasma, the presence of severe neutron and gamma radiation backgrounds, and the necessity for remote of in-cell components create challenging design problems for all of the conventional diagnostic associated with tokamak operations. In addition, new techniques must be developed to diagnose the evolution in space, time, and energy of the confined alpha distribution as well as potential plasma instabilities driven by collective alpha-particle effects. The design effort for CIT diagnostics is presently in the conceptual phase with activity being focused on the selection of a viable diagnostic set and the identification of essential research and development projects to support this process. A review of these design issues and other aspects impacting the selection of diagnostic techniques for the CIT experiment will be presented. 28 refs., 10 figs., 2 tabs.

  14. Reflectometric measurement of plasma imaging and applications

    NASA Astrophysics Data System (ADS)

    Mase, A.; Ito, N.; Oda, M.; Komada, Y.; Nagae, D.; Zhang, D.; Kogi, Y.; Tobimatsu, S.; Maruyama, T.; Shimazu, H.; Sakata, E.; Sakai, F.; Kuwahara, D.; Yoshinaga, T.; Tokuzawa, T.; Nagayama, Y.; Kawahata, K.; Yamaguchi, S.; Tsuji-Iio, S.; Domier, C. W.; Luhmann, N. C., Jr.; Park, H. K.; Yun, G.; Lee, W.; Padhi, S.; Kim, K. W.

    2012-01-01

    Progress in microwave and millimeter-wave technologies has made possible advanced diagnostics for application to various fields, such as, plasma diagnostics, radio astronomy, alien substance detection, airborne and spaceborne imaging radars called as synthetic aperture radars, living body measurements. Transmission, reflection, scattering, and radiation processes of electromagnetic waves are utilized as diagnostic tools. In this report we focus on the reflectometric measurements and applications to biological signals (vital signal detection and breast cancer detection) as well as plasma diagnostics, specifically by use of imaging technique and ultra-wideband radar technique.

  15. NSTX Diagnostics for Fusion Plasma Science Studies

    SciTech Connect

    R. Kaita; D. Johnson; L. Roquemore; M. Bitter; F. Levinton; F. Paoletti; D. Stutman; and the NSTX Team

    2001-07-05

    This paper will discuss how plasma science issues are addressed by the diagnostics for the National Spherical Torus Experiment (NSTX), the newest large-scale machine in the magnetic confinement fusion (MCF) program. The development of new schemes for plasma confinement involves the interplay of experimental results and theoretical interpretations. A fundamental requirement, for example, is a determination of the equilibria for these configurations. For MCF, this is well established in the solutions of the Grad-Shafranov equation. While it is simple to state its basis in the balance between the kinetic and magnetic pressures, what they are as functions of space and time are often not easy to obtain. Quantities like the plasma pressure and current density are not directly measurable. They are derived from data that are themselves complex products of more basic parameters. The same difficulties apply to the understanding of plasma instabilities. Not only are the needs for spatial and temporal resolution more stringent, but the wave parameters which characterize the instabilities are difficult to resolve. We will show how solutions to the problems of diagnostic design on NSTX, and the physics insight the data analysis provides, benefits both NSTX and the broader scientific community.

  16. Adaptive Embedded Digital System for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    González, Angel; Rodríguez, Othoniel; Mangual, Osvaldo; Ponce, Eduardo; Vélez, Xavier

    2014-05-01

    An Adaptive Embedded Digital System to perform plasma diagnostics using electrostatic probes was developed at the Plasma Engineering Laboratory at Polytechnic University of Puerto Rico. The system will replace the existing instrumentation at the Laboratory, using reconfigurable hardware to minimize the equipment and software needed to perform diagnostics. The adaptability of the design resides on the possibility of replacing the computational algorithm on the fly, allowing to use the same hardware for different probes. The system was prototyped using Very High Speed Integrated Circuits Hardware Description Language (VHDL) into an Field Programmable Gate Array (FPGA) board. The design of the Embedded Digital System includes a Zero Phase Digital Filter, a Derivative Unit, and a Computational Unit designed using the VHDL-2008 Support Library. The prototype is able to compute the Plasma Electron Temperature and Density from a Single Langmuir probe. The system was tested using real data previously acquired from a single Langmuir probe. The plasma parameters obtained from the embedded system were compared with results computed using matlab yielding excellent matching. The new embedded system operates on 4096 samples versus 500 on the previous system, and completes its computations in 26 milliseconds compared with about 15 seconds on the previous system.

  17. Method of azimuthally stable Mueller-matrix diagnostics of blood plasma polycrystalline films in cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Ushenko, Yu. A.; Prysyazhnyuk, V. P.; Gavrylyak, M. S.; Gorsky, M. P.; Bachinskiy, V. T.; Vanchuliak, O. Ya.

    2015-02-01

    A new information optical technique of diagnostics of the structure of polycrystalline films of blood plasma is proposed. The model of Mueller-matrix description of mechanisms of optical anisotropy of such objects as optical activity, birefringence, as well as linear and circular dichroism is suggested. The ensemble of informationally topical azimuthally stable Mueller-matrix invariants is determined. Within the statistical analysis of such parameters distributions the objective criteria of differentiation of films of blood plasma taken from healthy and patients with liver cirrhosis were determined. From the point of view of probative medicine the operational characteristics (sensitivity, specificity and accuracy) of the information-optical method of Mueller-matrix mapping of polycrystalline films of blood plasma were found and its efficiency in diagnostics of liver cirrhosis was demonstrated. Prospects of application of the method in experimental medicine to differentiate postmortem changes of the myocardial tissue was examined.

  18. Mobile CARS instrument for combustion and plasma diagnostics

    SciTech Connect

    Anderson, T.J.; Dobbs, G.M.; Eckbreth, A.C.

    1986-11-15

    A compact and easily transportable coherent anti-Stokes Raman spectroscopy system for combustion and plasma diagnostics is described. The instrument is readily adaptable to a wide variety, test environments and experiments. The system is capable of withstanding high noise and vibration levels and is remotely operable to protect the operator and delicate components from high noise levels or hazardous environments. It is intended for single-pulse temperature and concentration measurements in practical combustion systems, such as gas turbines, diesel engines, and plasma process applications. The system is operational, and initial measurement demonstrations in a supersonic combusting flow are described.

  19. Charge Diagnostics for Laser Plasma Accelerators

    SciTech Connect

    Nakamura, K.; Gonsalves, A. J.; Lin, C.; Sokollik, T.; Smith, A.; Rodgers, D.; Donahue, R.; Bryne, W.; Leemans, W. P.

    2010-06-01

    The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1percent per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm2 and 0.4 pC/ps/mm2, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within +/-10 percent.

  20. Charge Diagnostics for Laser Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Gonsalves, A. J.; Lin, C.; Sokollik, T.; Smith, A.; Rodgers, D.; Donahue, R.; Bryne, W.; Leemans, W. P.

    2010-11-01

    The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1% per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm2 and 0.4 pC/ps/mm2, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within ±10%.

  1. Charge Diagnostics for Laser Plasma Accelerators

    SciTech Connect

    Nakamura, K.; Gonsalves, A. J.; Lin, C.; Sokollik, T.; Smith, A.; Rodgers, D.; Donahue, R.; Bryne, W.; Leemans, W. P.

    2010-11-04

    The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1% per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/ps/mm{sup 2}, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within {+-}10%.

  2. Diagnostic Development for ST Plasmas on NSTX

    SciTech Connect

    D. Johnson; NSTX Team

    2003-06-16

    Spherical tokamaks (STs) have much lower aspect ratio (a/R) and lower toroidal magnetic field, relative to tokamaks and stellarators. This paper will highlight some of the challenges and opportunities these features pose in the diagnosis of ST plasmas on the National Spherical Torus Experiment (NSTX), and discuss some of the corresponding diagnostic development that is underway. The low aspect ratio necessitates a small center stack, with tight space constraints and large thermal excursions, complicating the design of magnetic sensors in this region. The toroidal magnetic field on NSTX is less than or equal to 0.6 T, making it impossible to use ECE as a good monitor of electron temperature. A promising new development for diagnosing electron temperature is electron Bernstein wave (EBW) radiometry, which is currently being pursued on NSTX. A new high-resolution charge exchange recombination spectroscopy system is being installed. Since non-inductive current initiation and sustainment ar e top-level NSTX research goals, measurements of the current profile J(R) are essential to many planned experiments. On NSTX several modifications are planned to adapt the MSE technique to lower field, and two novel MSE systems are being prototyped. Several high speed 2-D imaging techniques are being developed, for viewing both visible and x-ray emission. The toroidal field is comparable to the poloidal field at the outside plasma edge, producing a large field pitch (>50{sup o}) at the outer mid-plane. The large shear in pitch angle makes some fluctuation diagnostics like beam emission spectroscopy very difficult, while providing a means of achieving spatial localization for microwave scattering investigations of high-k turbulence, which are predicted to be virulent for NSTX plasmas. A brief description of several of these techniques will be given in the context of the current NSTX diagnostic set.

  3. Coronal plasma diagnostics from eclipse observations

    NASA Astrophysics Data System (ADS)

    Landi, E.; Habbal, S. R.; Tomczyk, S.

    2015-12-01

    In this talk we will discuss the diagnostic potential of observationsof visible spectral lines formed in the extended solar corona that canbe obtained during eclipses. We will discuss the possible diagnosticapplications of visible eclipse observations to measure the physicalparameters of the extended corona, to understand solar wind origin andacceleration, and to determine the evolution of Coronal Mass Ejectionsduring onset.We will first review the mechanisms of formation of spectral lineintensities, we will then illustrate their diagnostic applications,and show some results from recent eclipse observations. We will alsoreview the spectral lines that are most likely to be observed inthe extended solar corona during the upcoming 2017 eclipse in thecontinental United States.

  4. Diagnostics of expanding mesoplasmas originated from a miniaturized inductively coupled plasma and their application to Si etching

    NASA Astrophysics Data System (ADS)

    Chen, Qiang; Tsuchiya, Shoichi; Ichiki, Takanori

    2014-01-01

    A miniaturized inductively coupled plasma (m-ICP) was generated at atmospheric pressure and introduced into an expansion chamber at a reduced pressure ranging from 10 to 1000 Pa to produce expanded mesoplasmas. The fundamental parameters of the m-ICP and the downstream mesoplasma were investigated by optical emission spectroscopy and Langmuir probe measurement. When the m-ICP entered the expansion chamber, it diffused into the surrounding area and the electron density decreased from 1013 to 109-1010 cm-3. Furthermore, Si etching in mesoplasmas was performed by adding SF6 to Ar plasmas. By changing the gas pressure, anisotropic etching with a vertical-to-horizontal etch rate ratio of 2.5 was achieved at 60 Pa with a vertical etch rate of 2.7 µm/min. In addition, the anisotropy was improved to 8 by introducing 10 sccm H2 into the Ar/SF6, which is ascribed to the reduction of sidewall undercutting resulting from the scavenging effect of fluorine atoms by atomic H.

  5. Some diagnostic interpretations from railgun plasma profile experiments

    SciTech Connect

    Stainsby, D.F.; Bedford, A.J.

    1984-03-01

    Some aspects of a railgun experimental series to investigate plasma profiles are reviewed. Certain diagnostic records clearly show plasma leakage past the projectile, and correspondence between various in-bore events and muzzle voltage. A muzzle flash detector is shown to have a useful role as a plasma diagnostic tool.

  6. Plasma diagnostic techniques using particle beam probes

    SciTech Connect

    Jennings, W C

    1980-07-01

    A brief overview is given of particle beam probing. The fundamental concepts common to all techniques are discussed as well as the design considerations for choosing a particular diagnostic technique. The capabilities of existing and proposed techniques, and the present status of the techniques in major magnetic confinement geometries is also presented. Techniques which involve the injection of a beam of neutral particles into the plasma are then considered. The techniques of beam attenuation, beam scattering, and active charge exchange using a beam of light particles such as hydrogen or helium are first presented. Optical measurements of the Zeeman splitting of the radiation from a neutral lithium beam is then discussed, including a new proposal for significantly improving this technique through the addition of a dye laser. Two techniques involving the injection of heavy neutral particles are then presented, and the section concludes with two proposed techniques for measuring the properties of the alpha particles produced from actual fusion reactions. The diagnostic techniques which are based upon the injection of a beam of charged particles into the plasma are next described. The advantages and limitations of these techniques in comparison with the neutral techniques are discussed, followed by a description of specific techniques.

  7. Diagnostics for first plasma and development plan on KSTAR.

    PubMed

    Lee, J H; Na, H K; Lee, S G; Bak, J G; Seo, D C; Seo, S H; Oh, S T; Ko, W H; Chung, J; Nam, Y U; Lee, K D; Ka, E M; Oh, Y K; Kwon, M; Jeong, S H

    2010-06-01

    The first plasma with target values of the plasma current and the pulse duration was finally achieved on June 13, 2008 in the Korea Superconducting Tokamak Advanced Research (KSTAR). The diagnostic systems played an important role in achieving successful first plasma operation for the KSTAR tokamak. The employed plasma diagnostic systems for the KSTAR first plasma including the magnetic diagnostics, millimeter-wave interferometer, inspection illuminator, H(alpha), visible spectrometer, filterscope, and electron cyclotron emission (ECE) radiometer have provided the main plasma parameters, which are essential for the plasma generation, control, and physics understanding. Improvements to the first diagnostic systems and additional diagnostics including an x-ray imaging crystal spectrometer, reflectometer, ECE radiometer, resistive bolometer, and soft x-ray array are scheduled to be added for the next KSTAR experimental campaign in 2009. PMID:20590236

  8. Diagnostics for first plasma and development plan on KSTAR

    SciTech Connect

    Lee, J. H.; Na, H. K.; Lee, S. G.; Bak, J. G.; Seo, D. C.; Seo, S. H.; Oh, S. T.; Ko, W. H.; Chung, J.; Nam, Y. U.; Lee, K. D.; Ka, E. M.; Oh, Y. K.; Kwon, M.; Jeong, S. H.

    2010-06-15

    The first plasma with target values of the plasma current and the pulse duration was finally achieved on June 13, 2008 in the Korea Superconducting Tokamak Advanced Research (KSTAR). The diagnostic systems played an important role in achieving successful first plasma operation for the KSTAR tokamak. The employed plasma diagnostic systems for the KSTAR first plasma including the magnetic diagnostics, millimeter-wave interferometer, inspection illuminator, H{sub {alpha}}, visible spectrometer, filterscope, and electron cyclotron emission (ECE) radiometer have provided the main plasma parameters, which are essential for the plasma generation, control, and physics understanding. Improvements to the first diagnostic systems and additional diagnostics including an x-ray imaging crystal spectrometer, reflectometer, ECE radiometer, resistive bolometer, and soft x-ray array are scheduled to be added for the next KSTAR experimental campaign in 2009.

  9. Diagnostics of N2 Ar plasma mixture excited in a 13.56 MHz hollow cathode discharge system: application to remote plasma treatment of polyamide surface

    NASA Astrophysics Data System (ADS)

    Saloum, S.; Naddaf, M.; Alkhaled, B.

    2008-02-01

    N2-x% Ar plasma gas mixture, generated in a hollow cathode RF discharge system, has been characterized by both optical emission spectroscopy (OES) and double Langmuir probe, as a function of experimental parameters: total pressure (5-33 Pa), and different fractions of argon (7 <= x <= 80), at a constant applied RF power of 300 W. N2 dissociation degree has been investigated qualitatively by both the actinometry method and the ratio I_N/I_{N_2} of the atomic nitrogen line emission intensity at 672.3 nm to the vibrational band (0-0) of the N2 second positive system at 337.1 nm. Both methods showed that the increase in argon fraction enhances the dissociation of N2, with a maximum at x = 50 for the pressure of 5 Pa, although the two methods give two opposite trends as a function of total pressure. Spectroscopic measurements showed that the vibrational temperature of the N2 second positive system increases with both argon fraction and total pressure increase, it lies between 4900 and 12 300 K. Langmuir probe measurements showed that, in the remote zone, the electron temperature falls in the range 1.57-1.75 eV, the N_{2}^{+} density varies between 5 × 109 and 1.4 × 1010 cm-3 and that both the plasma ionization degree and electron temperature increase towards the source. In addition, the process of plasma-polyamide (PA) surface interaction, in the remote plasma zone, has been studied through OES analysis during plasma treatment of PA to monitor the possible emissions due to the polymer etching. An increase in atomic nitrogen line (672.3 nm) intensity is obtained, atomic carbon line (833.52 nm) and the band emission (0-0) from the CN (B 2Σ+-X 2Σ+) violet system were observed. The PA surface modification has been confirmed through the improvement of its hydrophilic character as the water contact angle measured after the plasma treatment significantly decreased.

  10. Study of the SEE decay processes in application to mechanisms of dissipation of the HF plasma turbulence and diagnostics of the ionospheric plasma parameters

    NASA Astrophysics Data System (ADS)

    Sergeev, Evgeny

    Results of the investigations of the decay process for different stimulated electromagnetic emission (SEE) features at the SURA heating facility (Russia) are presented. The data of the measurements are used to analyze the nonlinear energy transformation through the spectra of the Langmuir and upper hybrid plasma turbulence as well as to determine a relationship between the electron collision frequency and the collisionless decay rate of the plasma waves under different ionospheric conditions. In particular, due to the SEE decay time measurements at the upper hybrid turbulence development stage it is found an increase of the decay rate γ of the emission from the collision values γ = τ -1 = 300 - 400 s-1 to the collisionless values γ = 2000 - 10000 s-1 in a wide frequency band (up to 600 kHz) near the 4th - 7th cyclotron electron gyroharmonics. On the other hand, the SEE decay times didn't found any dependence on the pump power but they slightly increase under change from day to night condition. The results of the daily SEE decay rate monitoring in dependence on the pumping frequency (re- flection altitude) are presented. The work was supported by RFBR grants 07-02-00464 and 06-02-17334.

  11. Signal processing methods for MFE plasma diagnostics

    SciTech Connect

    Candy, J.V.; Casper, T.; Kane, R.

    1985-02-01

    The application of various signal processing methods to extract energy storage information from plasma diamagnetism sensors occurring during physics experiments on the Tandom Mirror Experiment-Upgrade (TMX-U) is discussed. We show how these processing techniques can be used to decrease the uncertainty in the corresponding sensor measurements. The algorithms suggested are implemented using SIG, an interactive signal processing package developed at LLNL.

  12. Plasma Diagnostics Development for Advanced Rocket Engines

    NASA Astrophysics Data System (ADS)

    Glover, Timothy; Kittrell, Carter; Chan, Anthony; Chang-Diaz, Franklin

    2000-10-01

    The VASIMR (Variable Specific Impulse Magnetoplasma Rocket) engine is a next-generation rocket engine under development at the Johnson Space Center's Advanced Space Propulsion Laboratory. With an exhaust velocity up to 50 times that of chemical rocket engines such as the Space Shuttle Main Engine, the VASIMR concept promises fast, efficient interplanetary flight. Rice University has participated in VASIMR research since 1996 and at present is developing two new diagnostic probes: a retarding potential analyzer to measure the velocity of ions in the rocket's exhaust, and a moveable optical probe to examine the spectrum of the rocket's helicon plasma source. In support of the probe development, a test facility is under construction at Rice, consisting of a small electric rocket engine firing into a 2-m vacuum chamber. This engine, the MPD (magnetoplasmadynamic) thruster, dates from the 1960's and provides a well-characterized source plasma for testing of the probes under development. We present details of the ion energy analyzer and the facility under construction at Rice.

  13. X-ray lasers for plasma diagnostics

    SciTech Connect

    Da Silva, L.B.; Barbee, T.W. Jr.; Cauble, R.; Celliers, P.; Kalantar, D.H.; Snavely, R.; Trebes, J.E.; Wan, A.S.; Weber, F.

    1997-12-31

    Soft x-ray lasers have evolved from the early demonstration phase to becoming reliable xuv sources. They operate over a wide wavelength range extending from 35 to 400 {angstrom} and have output energies as high as 10 mJ in 150 ns pulses. The beam divergence of these lasers is less than 15 mrad and they have a typical linewidth of {Delta}{lambda}/{lambda} {approximately} 10{sup {minus}4} making them the brightest xuv sources available. In this talk the authors describe their use of x-ray lasers to probe high density plasmas using a variety of diagnostic techniques. Taking advantage of recently developed multilayer beam splitters they have constructed and sued a Mach-Zehnder interferometer operating at 155 {angstrom} to probe 1--3 mm size laser produced plasmas. They have also used x-ray lasers and a multilayer mirror imaging system to study hydrodynamic imprinting of laser speckle pattern on directly driven thin foils with 1--2 {micro}m spatial resolution. They are now planning a moire deflectometry to measure the electron density profile in ICF hohlraums. The results of these experiments and the limitations of these techniques will be presented. The prospects for short wavelength (10 {angstrom}) x-ray lasers which are better suited to higher density probing will also be discussed.

  14. Compact collimated fiber optic array diagnostic for railgun plasmas

    NASA Astrophysics Data System (ADS)

    Tang, V.; Solberg, J. M.; Ferriera, T. J.; Tully, L. K.; Stephan, P. L.

    2009-01-01

    We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  15. Compact collimated fiber optic array diagnostic for railgun plasmas.

    PubMed

    Tang, V; Solberg, J M; Ferriera, T J; Tully, L K; Stephan, P L

    2009-01-01

    We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments. PMID:19191464

  16. Compact collimated fiber optic array diagnostic for railgun plasmas

    SciTech Connect

    Tang, V.; Solberg, J. M.; Ferriera, T. J.; Tully, L. K.; Stephan, P. L.

    2009-01-15

    We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  17. Compact collimated fiber optic array diagnostic for railgun plasma experiments

    SciTech Connect

    Tang, V; Solberg, J; Ferriera, T; Tully, L; Stephan, P

    2008-10-02

    We have developed and tested a compact collimated sixteen channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with {approx}mm spatial and sub-{micro}s temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore Fixed Hybrid Armature experiment are presented and compared with 1-D simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  18. The ion acoustic decay instability, and anomalous laser light absorption for the OMEGA upgrade, large scale hot plasma application to a critical surface diagnostic, and instability at the quarter critical density. Final report

    SciTech Connect

    Mizuno, K.; DeGroot, J.S.; Seka, W.

    1996-11-01

    It is shown that laser light can be anomalously absorbed with a moderate intensity laster (I{lambda}{sup 2}{approx}10{sup 14} W/cm{sup 2}-{mu}m{sup 2}) in a large scale, laser produced plasma. The heating regime, which is characterized by a relatively weak instability in a large region, is different from the regime studied previously, which is characterized by a strong instability in a narrow region. The two dimensional geometrical effect (lateral heating) has an important consequence on the anomalous electron heating. The characteristics of the IADI, and the anomalous absorption of the laser light were studied in a large scale, hot plasma applicable to OMEGA upgrade plasma. These results are important for the diagnostic application of the IADI.

  19. Plasma-driven ultrashort bunch diagnostics

    NASA Astrophysics Data System (ADS)

    Dornmair, I.; Schroeder, C. B.; Floettmann, K.; Marchetti, B.; Maier, A. R.

    2016-06-01

    Ultrashort electron bunches are crucial for an increasing number of applications, however, diagnosing their longitudinal phase space remains a challenge. We propose a new method that harnesses the strong electric fields present in a laser driven plasma wakefield. By transversely displacing driver laser and witness bunch, a streaking field is applied to the bunch. This field maps the time information to a transverse momentum change and, consequently, to a change of transverse position. We illustrate our method with simulations where we achieve a time resolution in the attosecond range.

  20. Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

    SciTech Connect

    Stratton, B. C.; Biter, M.; Hill, K. W.; Hillis, D. L.; Hogan, J. T.

    2007-07-18

    Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

  1. Efficient EUV transmission gratings for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Braig, Christoph; Kley, Ernst-Bernhard

    2010-07-01

    We report on a theoretical study of binary phase transmission gratings for high-resolution EUV and soft X-ray spectroscopy and investigate their optical properties. Designed for wavelengths between about 2 and 40 nm, the devices may provide a first order diffraction efficiency beyond 30%. We use RCWA methods in order to optimize the grating design parameters and discuss special features of segmented grating arrays. Several elemental as well as compound materials like Be, Mo, LiF and PMMA are considered with respect to their potential and practical limitations in terms of feasibility and sensitivity to radiation damage. Simulations are performed for several samples on the radiation produced by a table-top EUV plasma source and applications to astrophysical problems are considered.

  2. Recent Advancements in Microwave Imaging Plasma Diagnostics

    SciTech Connect

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  3. Thomson Scattering Lineshape Fitting for Plasma Diagnostics

    Energy Science and Technology Software Center (ESTSC)

    1994-02-04

    HFIT30 is used for interpreting lineshape (intensity versus frequency) data from Thomson and Rayleigh light scattering from a plasma, to obtain temperatures and number densities of the component species in the plasma.

  4. Fusion gamma diagnostics for D-T and D-/sup 3/He plasmas

    SciTech Connect

    Medley, S.S.; Hendel, H.

    1982-11-01

    Nuclear reactions of interest in controlled thermonuclear fusion research often possess a branch yielding prompt emission of gamma radiation. In principle, the gamma emission can be exploited to provide a new fusion diagnostic offering measurements comparable to those obtained by the well established neutron diagnostics methods. The conceptual aspects for a fusion gamma diagnostic are discussed in this paper and the feasibility for application to the Tokamak Fusion Test Reactor during deuterium neutral beam heating of a D-T plasma and minority ion cyclotron resonance heating of a D-/sup 3/He plasma is examined.

  5. Laser scattering for temporal and spatial diagnostic of low temperature plasmas

    NASA Astrophysics Data System (ADS)

    Palomares Linares, Jose Maria

    2012-10-01

    Many recent industrial and technological applications like surface etching, inorganic films deposition, polymerization of surfaces or sterilization are developed within the field of low temperature plasmas. To study, monitor and model plasma processes is of great importance to have diagnostic tools that can provide reliable information on different plasma parameters. In general, laser scattering techniques provide a direct and accurate method for plasma diagnostic with spatial and temporal resolution. Laser Thomson scattering is used for the diagnostic of electron density and temperature, two of the most important parameters in low temperature discharges. With a similar setup Rayleigh and Raman scattering techniques are used for the diagnostic of gas density and temperature. In this contribution we deal with the different technical and theoretical aspects that are required for the application of these laser scattering techniques. Of special importance are the detection limit, laser stray light rejection and laser perturbations of the plasma. The present study is performed on different low temperature microwave discharges, both at low and atmospheric pressure. The laser scattering techniques provide information on the spatial distribution of the mentioned plasma parameters over different discharge conditions, including small micro-plasmas. Similarly, the temporal evolution of pulsed plasmas is studied, unraveling the features of the switching on and off phases of the discharges.

  6. The ion acoustic decay instability in a large scale, hot plasma relevant to direct drive laser fusion -- Application to a critical surface diagnostic. Final report

    SciTech Connect

    Mizuno, K.; DeGroot, J.S.; Drake, R.P.; Seka, W.; Craxton, R.S.; Estabrook, K.G.

    1996-08-01

    The authors have studied the ion acoustic decay instability in a large ({approximately} 1 mm) scale, hot ({approximately} 1 keV) plasma, which is relevant to a laser fusion reactor target. They have shown that the instability threshold is low. They have developed a novel collective Thomson scattering diagnostic at a 90{degree} scattering angle. The scattering is nonetheless coherent, because of the modest ratio of the frequency of the probe laser to that of the pump laser, such that even for such a large angle, (k{lambda}{sub De}){sup 2} is much less than one. With this system they have measured the electron plasma wave excited by the ion acoustic decay instability near the critical density (n{sub e} {approximately} 0.86 n{sub c}). This allows them to use the frequency of the detected wave to measure the electron temperature in the interaction region, obtaining a result reasonably close to that predicted by the SAGE computer code.

  7. Mechanical considerations for MFTF-B plasma-diagnostic system

    SciTech Connect

    Thomas, S.R. Jr.; Wells, C.W.

    1981-10-19

    The reconfiguration of MFTF to a tandem mirror machine with thermal barriers has caused a significant expansion in the physical scope of plasma diagnostics. From a mechanical perspective, it complicates the plasma access, system interfaces, growth and environmental considerations. Conceptual designs characterize the general scope of the design and fabrication which remains to be done.

  8. Challenges for Plasma Diagnostics in a Next Step Device (FIRE)

    SciTech Connect

    Kenneth M. Young

    2002-01-28

    The physics program of any next-step tokamak such as FIRE [Fusion Ignition Research Experiment] sets demands for plasma measurement which are at least as comprehensive as on present tokamaks, with the additional capabilities needed for control of the plasma and for understanding the effects of the alpha-particles. The diagnostic instrumentation must be able to provide the fine spatial and temporal resolution required for the advanced tokamak plasma scenarios. It must also be able to overcome the effects of neutron- and gamma-induced electrical noise in ceramic components or detectors, and fluorescence and absorption in optical components. There are practical engineering issues of minimizing radiation streaming while providing essential diagnostic access to the plasma. Many diagnostics will require components at or close to the first wall, e.g., ceramics and MI cable for magnetic diagnostics and mirrors for optical diagnostics; these components must be mounted to operate, and survive, i n fluxes which require special material selection. A better set of diagnostics of alpha-particles than that available for the TFTR [Tokamak Fusion Test Reactor] is essential; it must be qualified well before moving into D-T [deuterim-tritium] experiments. A start has been made to assessing the potential implementation of key diagnostics for the FIRE device. The present status is described.

  9. Magnetic Diagnostics for Plasma Control on ET.

    NASA Astrophysics Data System (ADS)

    Gauvreau, J.-L.; Carter, T. A.; Gourdain, P. A.; Grossman, A.; Lafonteese, D. J.; Pace, D. C.; Schmitz, L. W.; Taylor, R. J.; Yates, T. F.

    2003-10-01

    In order to operate ET successfully in high beta regimes, the present Langmuir probe based feedback system on plasma position needs to be upgraded with a system based on magnetic measurements. The vertical and horizontal field coil currents as well as the elongation coil current will be controlled in real-time, based on the evaluation of the average plasma radius, plasma height and elongation factor respectively. For that effect, the poloidal fluxes and poloidal fields of ET are measured outside the vessel to define the shape and position of the last flux surface of the plasma. The present system has one array distributed in 6 poloidal locations. After calibration, this information will be compared with the outputs from our different MHD codes and also used for magnetic reconstruction. In addition, a compensated toroidal flux loop around the vessel is used to measure the plasma poloidal beta. Finally, magnetic fluctuations are monitored in several poloidal and toroidal locations in order to identify the n and m modes responsible for loss of confinement during the giant saw-teeth crashes. Results from these measurements will be presented.

  10. New Electron Temperature Diagnostic for Low Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Boivin, Robert; Loch, Stuart

    2004-11-01

    A new line ratio diagnostic design to measure electron temperature in plasma is presented. Unlike previous diagnostics, this new technique features emission lines originating from levels with different principal quantum numbers. A significant advantage of this approach is that the line ratio varies considerably with temperature in the 1 to 20 eV range. Another advantage is that both transitions are optically thin even for plasma density up to 1 E 14 cm-3. The drawbacks are: a large difference in the line intensities and the significant difference in wavelength. The event of high sensitivity CCD camera combine with precise calibration can to a large extent minimize these latest two issues. The diagnostic is tested on the ASTRAL (Auburn Steady sTate Research fAciLity) helicon plasma source. ASTRAL is a 2.3 m long helicon source designed to investigate basic plasma and space plasma processes. The device produces plasmas with the following typical parameters ne = 1 E9 to 1 E13 cm-3, Te = 2 to 20 eV and Ti = 0.03 to 0.3 eV. A series of 8 large coils produce an axial magnetic field up to 1.2 kGauss. Operating pressure varies from 0.1 to 100 mTorr. A water cooled fractional helix antenna is used to introduce RF power up to 2 kwatt through a standard matching circuit. The line ratio temperatures are measured by means of a 0.33 m McPherson Criss-Cross Scanning monochromator instrumented with a SPH5 Apogee CCD camera. The line ratio temperatures are compared to electron temperatures measured by a rf compensated Langmuir Probe. To validate the diagnostic, a new collisional radiative model that makes use of the latest excitation cross-section values is presented. The model is also used to predict the potential range of this new diagnostic both in terms of electron temperature and plasma density.

  11. Spectroscopic diagnostics of high temperature plasmas. [Annual report

    SciTech Connect

    Moos, W.

    1990-12-31

    A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.

  12. Radio stimulation and diagnostics of space plasmas

    NASA Technical Reports Server (NTRS)

    Lee, Min-Chang

    1993-01-01

    We have investigated the small-scale topside ionospheric plasma structures first observed at Millstone Hill, Massachusetts with the 440 MHz incoherent scatter radar. These small-scale obliquely propagating plasma modes occurring in the vicinity of the midlatitude ionospheric trough, have large radar cross-sections and narrow spectral widths. They have, until recently, been dismissed solely as hard target contamination of the incoherent scatter radar. The geophysical conditions associated with the ionospheric trough, such as the field-aligned current activity and steep plasma density gradients, suggest that these recently discovered small-scale topside ionospheric plasmas may also appear in the auroral and polar ionosphere. In fact, this speculation has been corroborated by the preliminary experiments and data analyses at Tromso, Norway and Sondrestromfjord, Greenland. The primary research results are highlighted. Described in Section 3 are the experiments conducted at Arecibo, Puerto Rico in the past summer for simulating the geophysical conditions of generating these topside ionospheric plasma structures. Recommendation for the future research is finally given. Attached as the appendix of this report are several chapters which present the detailed results of research in the concerned topside ionospheric clutter. Highlights of the research results include: (1) causes of the enhanced radar backscatter (ERB) phenomenon; (2) occurrence of the ERB phenomenon; (3) altitudes of the ERB phenomenon; (4) strength of the ERB returns; (5) range of altitudes of the ERB returns; (6) occurrence frequency of the ERB phenomenon; (7) Doppler effect of the ERB phenomenon; (8) persistency of the ERB; and (9) distinction between ERB phenomenon and space object signatures.

  13. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    SciTech Connect

    Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G. R.; Schroeder, C. B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W. P.

    2010-06-01

    We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable electron bunches from LPAs.

  14. High-frequency Probing Diagnostic for Hall Current Plasma Thrusters

    SciTech Connect

    A.A. Litvak; Y. Raitses; N.J. Fisch

    2001-10-25

    High-frequency oscillations (1-100 MHz) in Hall thrusters have apparently eluded significant experimental scrutiny. A diagnostic setup, consisting of a single Langmuir probe, a special shielded probe connector-positioner, and an electronic impedance-matching circuit, was successfully built and calibrated. Through simultaneous high-frequency probing of the Hall thruster plasma at multiple locations, high-frequency plasma waves have been identified and characterized for various thruster operating conditions.

  15. Flush-mounted probe diagnostics for argon glow discharge plasma

    SciTech Connect

    Xu, Liang Cao, Jinxiang; Liu, Yu; Wang, Jian; Du, Yinchang; Zheng, Zhe; Zhang, Xiao; Wang, Pi; Zhang, Jin; Li, Xiao; Qin, Yongqiang; Zhao, Liang

    2014-09-15

    A comparison is made between plasma parameters measured by a flush-mounted probe (FP) and a cylindrical probe (CP) in argon glow discharge plasma. Parameters compared include the space potential, the plasma density, and the effective electron temperature. It is found that the ion density determined by the FP agrees well with the electron density determined by the CP in the quasi-neutral plasma to better than 10%. Moreover, the space potential and effective electron temperature calculated from electron energy distribution function measured by the FP is consistent with that measured by the CP over the operated discharge current and pressure ranges. These results present the FP can be used as a reliable diagnostic tool in the stable laboratory plasma and also be anticipated to be applied in other complicated plasmas, such as tokamaks, the region of boundary-layer, and so on.

  16. Fast frequency-step-tunable gyrotrons for plasma heating and fusion diagnostics

    SciTech Connect

    Dumbrajs, O.; Heikkinen, J.

    1994-11-01

    Usefulness of frequency tunable sources for plasma heating and fusion diagnostics is studied. Applicability of fast frequency-step-tunable gyrotrons for these purposes is examined. A gyrotron based on a coaxial cavity with impedance rod is considered as an example.

  17. Note: Refined possibilities for plasma probe diagnostics

    NASA Astrophysics Data System (ADS)

    Masherov, P. E.; Riaby, V. A.; Abgaryan, V. K.

    2016-08-01

    In an earlier publication, the ion mass determination technique was proposed using the Langmuir probe measurement results for low-pressure Maxwellian plasmas and their analysis, based on the Bohm effect and the Child-Boguslavsky-Langmuir (CBL) probe sheath model, allowing for probe sheath thickness and ion mass evaluations after the Bohm coefficient CBCyl ≈ 1.13 for cylindrical probes had been determined. In the present study, the step-front sheath model, being physically closer to the reality of gas discharge plasmas, was considered in order to correct the CBL sheath model results. At this stage, more real Bohm coefficient (CBCyl ≈ 1.23) for cylindrical probes was found to provide a more reliable method of probe sheath thickness and ion mass determination.

  18. Note: Refined possibilities for plasma probe diagnostics.

    PubMed

    Masherov, P E; Riaby, V A; Abgaryan, V K

    2016-08-01

    In an earlier publication, the ion mass determination technique was proposed using the Langmuir probe measurement results for low-pressure Maxwellian plasmas and their analysis, based on the Bohm effect and the Child-Boguslavsky-Langmuir (CBL) probe sheath model, allowing for probe sheath thickness and ion mass evaluations after the Bohm coefficient CBCyl ≈ 1.13 for cylindrical probes had been determined. In the present study, the step-front sheath model, being physically closer to the reality of gas discharge plasmas, was considered in order to correct the CBL sheath model results. At this stage, more real Bohm coefficient (CBCyl ≈ 1.23) for cylindrical probes was found to provide a more reliable method of probe sheath thickness and ion mass determination. PMID:27587177

  19. Hydrogen alpha laser ablation plasma diagnostics.

    PubMed

    Parigger, C G; Surmick, D M; Gautam, G; El Sherbini, A M

    2015-08-01

    Spectral measurements of the H(α) Balmer series line and the continuum radiation are applied to draw inferences of electron density, temperature, and the level of self-absorption in laser ablation of a solid ice target in ambient air. Electron densities of 17 to 3.2×10(24) m(-3) are determined from absolute calibrated emission coefficients for time delays of 100-650 ns after generation of laser plasma using Q-switched Nd:YAG radiation. The corresponding temperatures of 4.5-0.95 eV were evaluated from the absolute spectral radiance of the continuum at the longer wavelengths. The redshifted, Stark-broadened hydrogen alpha line emerges from the continuum radiation after a time delay of 300 ns. The electron densities inferred from power law formulas agree with the values obtained from the plasma emission coefficients. PMID:26258326

  20. A transmission grating spectrometer for plasma diagnostics

    SciTech Connect

    Bartlett, R.J.; Hockaday, R.G.; Gallegos, C.H.; Gonzales, J.M.; Mitton, V.

    1995-09-01

    Radiation temperature is an important parameter in characterizing the properties of hot plasmas. In most cases this temperature is time varying caused by the short lived and/or time dependent nature of the plasma. Thus, a measurement of the radiation flux as a function of time is quite valuable. To this end the authors have developed a spectrometer that can acquire spectra with a time resolution of less than 1 ns and covers the spectral energy range from {approximately} 60 to 1,000 eV. The spectrometer consists of an entrance slit placed relatively near the plasma, a thin gold film transmission grating with aperture, a micro channel plate (MCP) detector with a gold cathode placed at the dispersion plane and an electron lens to focus the electrons from the MCP onto a phosphor coated fiber optic plug. The phosphor (In:CdS) has a response time of {approximately} 500 ps. This detector system, including the fast phosphor is similar to one that has been previously described. The spectrometer is in a vacuum chamber that is turbo pumped to a base pressure of {approximately} 5 x 10{sup 7} torr. The light from the phosphor is coupled to two streak cameras through 100 m long fiber optic cables. The streak cameras with their CCD readouts provide the time resolution of the spectrum. The spectrometer has a built in alignment system that uses an alignment telescope and retractable prism.

  1. A transmission grating spectrometer for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Bartlett, Roger J.; Hockaday, Robert G.; Gallegos, Cenobio H.; Gonzales, Joseph M.; Mitton, Vance

    Radiation temperature is an important parameter in characterizing the properties of hot plasmas. In most cases this temperature is time varying caused by the short lived and/or time dependent nature of the plasma. Thus, a measurement of the radiation flux as a function of time is quite valuable. To this end the authors have developed a spectrometer that can acquire spectra with a time resolution of less than 1 ns and covers the spectral energy range from approximately 60 to 1,000 eV. The spectrometer consists of an entrance slit placed relatively near the plasma, a thin gold film transmission grating with aperture, a micro channel plate (MCP) detector with a gold cathode placed at the dispersion plane and an electron lens to focus the electrons from the MCP onto a phosphor coated fiber optic plug. The phosphor (In:CdS) has a response time of (approximately) 500 ps. This detector system, including the fast phosphor is similar to one that has been previously described. The spectrometer is in a vacuum chamber that is turbo pumped to a base pressure of approximately 5 x 10(exp 7) torr. The light from the phosphor is coupled to two streak cameras through 100 m long fiber optic cables. The streak cameras with their CCD readouts provide the time resolution of the spectrum. The spectrometer has a built in alignment system that uses an alignment telescope and retractable prism.

  2. Positron plasma diagnostics and temperature control for antihydrogen production.

    PubMed

    Amoretti, M; Amsler, C; Bonomi, G; Bouchta, A; Bowe, P D; Carraro, C; Cesar, C L; Charlton, M; Doser, M; Filippini, V; Fontana, A; Fujiwara, M C; Funakoshi, R; Genova, P; Hangst, J S; Hayano, R S; Jørgensen, L V; Lagomarsino, V; Landua, R; Lindelöf, D; Rizzini, E Lodi; Macrí, M; Madsen, N; Manuzio, G; Montagna, P; Pruys, H; Regenfus, C; Rotondi, A; Testera, G; Variola, A; van der Werf, D P

    2003-08-01

    Production of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss nondestructive measurements, based on a novel, real-time analysis of excited, low-order plasma modes, that provide comprehensive characterization of the positron plasma in the ATHENA antihydrogen apparatus. The plasma length, radius, density, and total particle number are obtained. Measurement and control of plasma temperature variations, and the application to antihydrogen production experiments are discussed. PMID:12906600

  3. The Diagnostics of the External Plasma for the Plasma Rocket

    NASA Technical Reports Server (NTRS)

    Karr, Gerald R.

    1997-01-01

    Three regions of plasma temperature/energy are being investigated to understand fully the behavior of the plasma created by the propulsion device and the operation of the RPA. Each type of plasma has a RPA associated with it; i.e. a thermal RPA, a collimated RPA, and a high temperature RPA. Through the process of developing the thermal and collimated RPAs, the proper knowledge and experience has been gained to not only design a high temperature RPA for the plasma rocket, but to understand its operation, results, and uncertainty. After completing a literature search for, reading published papers on, and discussing the operation of the RPA with electric propulsion researchers, I applied the knowledge gained to the development of a RPA for thermal plasma. A design of a thermal RPA was made which compensates for a large Debye length and low ionized plasma. From this design a thermal RPA was constructed. It consists of an outer stainless steel casing, a phenolic insulator (outgases slightly), and stainless steel mesh for the voltage screens. From the experience and knowledge gained in the development of the thermal RPA, a RPA for collimated plasma was developed. A collimated RPA has been designed and constructed. It compensate for a smaller Debye length and much higher ionization than that existing in the thermal plasma. It is 17% of the size of the thermal RPA. A stainless steel casing shields the detector from impinging electrons and ions. An insulating material, epoxy resin, was utilized which has a negligible outgassing. This material can be molded in styrofoam and machined quite nicely. It is capable of withstanding moderately high temperatures. Attached to this resin insulator are inconel screens attached by silver plated copper wire to a voltage supply. All the work on the RPAs and thermal ion source, I performed in the University of Alabama in Huntsville's (UAH) engineering machine shop.

  4. The Diagnostics of the External Plasma for the Plasma Rocket

    NASA Technical Reports Server (NTRS)

    Karr, Gerald R.

    1997-01-01

    The plasma rocket is located at NASA Johnson Space Center. To produce a thrust in space. an inert gas is ionized into a plasma and heated in the linear section of a tokamak fusion device to 1 x 10(exp 4) - 1.16 x 10(exp 6)K(p= 10(exp 10) - 10(exp 14)/cu cm ). The magnetic field used to contain the plasma has a magnitude of 2 - 10k Gauss. The plasma plume has a variable thrust and specific impulse. A high temperature retarding potential analyzer (RPA) is being developed to characterize the plasma in the plume and at the edge of the magnetically contained plasma. The RPA measures the energy and density of ions or electrons entering into its solid angle of collection. An oscilloscope displays the ion flux versus the collected current. All measurements are made relative to the facility ground. A RPA is being developed in a process which involves the investigation of several prototypes. The first prototype has been tested on a thermal plasma. The knowledge gained from its development and testing were applied to the development of a RPA for collimated plasma. The prototypes consist of four equally spaced grids and an ion collector. The outermost grid is a ground. The second grid acts as a bias to repel electrons. The third is a variable v voltage ion suppressor. Grid four (inner grid) acts to repel secondary electrons, being biased equal to the first. Knowledge gained during these two stages are being applied to the development of a high temperature RPA Testing of this device involves the determination of its output parameters. sensitivity, and responses to a wide range of energies and densities. Each grid will be tested individually by changing only its voltage and observing the output from the RPA. To verify that the RPA is providing proper output. it is compared to the output from a Langmuir or Faraday probe.

  5. A Recoverable Plasma Diagnostics Package (RPDP) for Spacelab

    NASA Technical Reports Server (NTRS)

    Shawhan, S. D.; Ackerson, K. L.; Anderson, R. R.; Craven, J. D.; Dangelo, N.; Frank, L. A.; Gurnett, D. A.; Shaw, R. R.; Block, L. P.; Falthammar, C. G.

    1980-01-01

    The RPDP is a fully instrumented, ejectable and recoverable unit with flight and ground support systems so that it can be utilized attached to the orbiter remote manipulator system, tethered from the orbiter, or as an orbiter subsatellite. Core instruments on the RPDP are flight proven hardware which provide diagnostics measurements of energetic particles, AC electromagnetic and electrostatic waves, vector magnetic field signatures of current systems, vector electric field signatures associated with plasma flow and particle acceleration, thermal plasma ion composition and density, thermal plasma electron density and temperature, and images of optical emissions regions in UV or visible wavelengths.

  6. Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas

    SciTech Connect

    Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.

    2008-09-07

    Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.

  7. A comparative study of electrical probe techniques for plasma diagnostics

    NASA Technical Reports Server (NTRS)

    Szuszczewicz, E. P.

    1972-01-01

    Techniques for using electrical probes for plasma diagnostics are reviewed. Specific consideration is given to the simple Langmuir probe, the symmetric double probe of Johnson and Malter, the variable-area probe of Fetz and Oeschsner, and a floating probe technique. The advantages and disadvantages of each technique are discussed.

  8. Plasma erosion rate diagnostics using laser-induced fluorescence

    NASA Technical Reports Server (NTRS)

    Gaeta, C. J.; Turley, R. S.; Matossian, J. N.; Beattie, J. R.; Williamson, W. S.

    1992-01-01

    An optical technique for measuring the sputtering rate of a molybdenum surface immersed in a xenon plasma has been developed and demonstrated. This approach, which may be useful in real-time wear diagnostics for ion thrusters, relies on laser-induced fluorescence to determine the density of sputtered molybdenum atoms.

  9. Heat flow diagnostics for helicon plasmas

    SciTech Connect

    Berisford, Daniel F.; Bengtson, Roger D.; Raja, Laxminarayan L.; Cassady, Leonard D.; Chancery, William J.

    2008-10-15

    We present experimental studies of power balance in an argon helicon discharge. An infrared camera measures the heating of the dielectric tube containing a helicon discharge based on measurement of temperature profiles of the tube surface before and after a rf pulse. Using this diagnostic, we have measured surface heating trends at a variety of operating conditions on two helicon systems: the 10 kW VASIMR VX-50 experiment and the University of Texas at Austin 1 kW helicon experiment. Power losses downstream from the antenna are measured using thermocouples and probes. The heating of the dielectric tube increases with decreasing magnetic fields, higher gas flow rates, and higher molecular mass of the gas. These preliminary results suggest that cross-field particle diffusion contributes a significant proportion of the energy flux to the wall.

  10. Micro-Particles as Electrostatic Probes for Plasma Sheath Diagnostic

    SciTech Connect

    Wolter, Matthias; Haass, Moritz; Ockenga, Taalke; Kersten, Holger; Blazec, Joseph; Basner, Ralf

    2008-09-07

    An interesting aspect in the research of complex (dusty) plasmas is the experimental study of the interaction of micro-particles of different sizes with the surrounding plasma for diagnostic purpose. In the plasma micro-disperse particles are negatively charged and confined in the sheath. The particles are trapped by an equilibrium of gravity, electric field force and ion drag force. From the behavior, local electric fields can be determined, e.g. particles are used as electrostatic probes. In combination with additional measurements of the plasma parameters with Langmuir probes and thermal probes as well as by comparison with an analytical sheath model, the structure of the sheath can be described. In the present work we focus on the behavior of micro-particles of different sizes and several plasma parameters e.g. the gas pressure and the rf-power.

  11. Arrayed Diagnostic Development on the HyperV Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Messer, Sarah; Bomgardner, Richard; Witherspoon, F. D.

    2008-11-01

    The sparkgap injected plasma accelerator is one of several coaxial railguns constructed at HyperV to accelerate dense plasmas to high velocities. A circumferential array of 112 high voltage tungsten electrodes ablates polyethylene to form and inject a toroidally shaped plasma into the annular breech at the rear of the accelerator. A pulse forming network then applies several hundred kiloamps to the coaxial electrodes to accelerate the plasma. A 4-chord laser deflectometer and a 32-sensor fast photodiode array are being developed to help resolve the structure, density, and velocity of the accelerated plasma jet for different accelerator parameters. We present details of the diagnostic designs and initial data. Work supported by the U.S. DOE Office of Fusion Energy Sciences.

  12. ICTP-IAEA Workshop on Dense Magnetized Plasma and Plasma Diagnostics: an executive summary

    NASA Astrophysics Data System (ADS)

    Gribkov, V. A.; Mank, G.; Markowicz, A.; Miklaszewski, R.; Tuniz, C.; Crespo, M. L.

    2011-12-01

    The Workshop on Dense Magnetized Plasma and Plasma Diagnostics was held from 15 to 26 November 2010 at the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy. It was attended by 60 participants, including 15 lecturers, 2 tutors and 37 trainees, representing 25 countries.

  13. Sequential quadrature measurements for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Martin-Hidalgo, Julio

    The study of the ionosphere has been very important due to its effects on terrestrial and satellite communications. This thesis presents an introduction of the ionosphere effects, its modeling and measurement methods that have been used along the history. The Sweeping Impedance Probe (SIP) has proven over the years to be a reliable method based on the radio frequency (RF) behavior of the plasma. A new SIP architecture is presented based on the latest techniques available, using a Vector Network Analyzer (VNA) detection and employing dynamic correction of errors with Correlated Double Sampling (CDS) and a reference channel. The design will be detailed showing the component selection based on their performance parameters. In this sense, several analyses have been made to ensure that the sweep rate and accuracy requirements can be met. The testing and calibration methodology is developed to further increase the final accuracy of the instrument. Lastly, the main conclusions of the project are summarized and new and exciting lines of work are presented for what is expected to be the next generation of SIP instruments.

  14. Neutral Beam Injection for Plasma and Magnetic FieldDiagnostics

    SciTech Connect

    Vainionpaa, Jaakko Hannes; Leung, Ka Ngo; Kwan, Joe W.; Levinton,Fred

    2007-08-01

    At the Lawrence Berkeley National Laboratory (LBNL) adiagnostic neutral beam injection system for measuring plasma parameters,flow velocity, and local magnetic field is being developed. High protonfraction and small divergence is essential for diagnostic neutral beams.In our design, a neutral hydrogen beam with an 8 cm x 11 cm (or smaller)elliptical beam spot at 2.5 m from the end of the extraction column isproduced. The beam will deliver up to 5 A of hydrogen beam to the targetwith a pulse width of ~;1 s, once every 1 - 2 min. The H1+ ion species ofthe hydrogen beamwill be over 90 percent. For this application, we havecompared two types of RF driven multicusp ion sources operating at 13.56MHz. The first one is an ion source with an external spiral antennabehind a dielectric RF-window. The second one uses an internal antenna insimilar ion source geometry. The source needs to generate uniform plasmaover a large (8 cm x 5 cm) extraction area. We expect that the ion sourcewith internal antenna will be more efficient at producing the desiredplasma density but might have the issue of limited antenna lifetime,depending on the duty factor. For both approaches there is a need forextra shielding to protect the dielectric materials from the backstreaming electrons. The source walls will be made of insulator materialsuch as quartz that has been observed to generate plasma with higheratomic fraction than sources with metal walls. The ion beam will beextracted and accelerated by a set of grids with slits, thus forming anarray of 6 sheet-shaped beamlets. The multiple grid extraction will beoptimized using computer simulation programs. Neutralization of the beamwill be done in neutralization chamber, which has over 70 percentneutralization efficiency.

  15. A limited-view-tomography for plasma diagnostics.

    NASA Astrophysics Data System (ADS)

    Denisova, Natalja

    2001-10-01

    In recent years progress in plasma diagnostics has led to the wide use of techniques and algorithms of computerized tomography. An important problem in the diagnostics of a plasma as a spectroscopic source is the determination of spatial distributions of the coefficients of emission (or absorption), which are directly related to the temperature and particle density. There are several methods for the reconstruction of the spatial distributions of the emission (absorption) coefficients from the integrated intensities. This paper describes a Maximum Entropy (ME) algorithm which seems especially attractive in the experimental situations when the number of views is strongly limited.The researcher should have enough justifications for reconstruction from a few views. This problem is discussed with reference to the reconstruction from two views of soft x-ray emissivity profiles in W7-AS stellarator.On the other hand, in experiments of this type there is usually some additional information which can be incorporated into the ME reconstruction algorithm. The crucial role of prior information is illustrated in reconstruction of a spatial distribution of electron density in a laser-produced plasma in a strong transverse magnetic field. References 1.Denisova N.V.Maximum-entropy-based tomography for gas and plasma diagnostics J.Phys.D:Appl.Phys. 31 (1998) 1888-1895. 1.Denisova N.V.Two-view tomography J.Phys.D.:Appl.Phys. 33 (2000) 313-319.

  16. Quantitative diagnostics of reactive, multicomponent low-temperature plasmas

    NASA Astrophysics Data System (ADS)

    Schwarz-Selinger, Thomas

    2013-09-01

    The special emphasis in this work is put on the quantitative determination of the plasma composition of an inductively coupled low temperature plasma (ICP). Several standard plasma diagnostic techniques were applied. As a test case for a multi-component low-temperature plasma argon-hydrogen as well as argon-hydrogen-nitrogen mixed plasmas were investigated. For steady-state plasma operation the ion density and electron temperature were determined with a single tip Langmuir probe. A multi-grid miniature retarding-field analyzer was used to measure the mass integrated ion flux. An energy-dispersive mass spectrometer - a so-called plasma monitor (PM) - was applied to sample ions from the plasma to derive the ion composition. The degree of dissociation of hydrogen and the gas temperature were derived from optical emission spectroscopy. The gas temperature was estimated by the rotational distribution of the Q-branch lines of the hydrogen Fulcher- α diagonal band for the argon-hydrogen mixed plasmas and from the second positive system of N2 in argon-hydrogen-nitrogen mixed plasmas. The degree of dissociation of hydrogen was measured by actinometry. The influence of the substrate material of the counter electrode (stainless steel, copper, tungsten, Macor, and aluminium) on the atomic hydrogen concentration was investigated by OES. In addition, ionization-threshold mass spectrometry (ITMS) was used to determine the densities of atomic nitrogen (N) and atomic hydrogen (H and D). Pulsed plasma operation was applied to directly measure the loss rate of H, D and N in the afterglow from the temporal decay of the ITMS signal. From these data the wall loss probability of atomic hydrogen was determined. Furthermore, a zero-dimensional rate equation model was devised to explain the ion composition in these mixed plasmas with different admixture ratios. In addition to the experimental data on electron density, gas temperature, total pressure, atomic hydrogen density, and Ar, H2

  17. A two photon absorption laser induced fluorescence diagnostic for fusion plasmas

    SciTech Connect

    Magee, R. M.; Galante, M. E.; McCarren, D.; Scime, E. E.; Boivin, R. L.; Brooks, N. H.; Groebner, R. J.; Hill, D. N.; Porter, G. D.

    2012-10-15

    The quality of plasma produced in a magnetic confinement fusion device is influenced to a large extent by the neutral gas surrounding the plasma. The plasma is fueled by the ionization of neutrals, and charge exchange interactions between edge neutrals and plasma ions are a sink of energy and momentum. Here we describe a diagnostic capable of measuring the spatial distribution of neutral gas in a magnetically confined fusion plasma. A high intensity (5 MW/cm{sup 2}), narrow bandwidth (0.1 cm{sup -1}) laser is injected into a hydrogen plasma to excite the Lyman {beta} transition via the simultaneous absorption of two 205 nm photons. The absorption rate, determined by measurement of subsequent Balmer {alpha} emission, is proportional to the number of particles with a given velocity. Calibration is performed in situ by filling the chamber to a known pressure of neutral krypton and exciting a transition close in wavelength to that used in hydrogen. We present details of the calibration procedure, including a technique for identifying saturation broadening, measurements of the neutral density profile in a hydrogen helicon plasma, and discuss the application of the diagnostic to plasmas in the DIII-D tokamak.

  18. Spectroscopic Analysis and Thomson Scattering Diagnostics of Wire Produced Plasma

    NASA Astrophysics Data System (ADS)

    Plechaty, Christopher; Sotnikov, Vladimir; Main, Daniel; Caplinger, James; Wallerstein, Austin; Kim, Tony

    2014-10-01

    The Lower Hybrid Drift Instability (LHDI) in plasma is driven by the presence of inhomogeneities in density, temperature, or magnetic field (Krall 1971, Davidson 1977), and occurs in systems where the electrons are magnetized and the ions are effectively unmagnetized. The LHDI is thought to occur in magnetic reconnection (Huba 1977), and has also been investigated as a mitigation technique which can allow for communications to take place through the plasma formed around hypersonic aircraft (Sotnikov 2010). To further understand the phenomenology of the LHDI, we plan to carry out experiments at the Air Force Research Laboratory, in the newly formed Plasma Physics Sensors Laboratory. In experiment, a pulsed power generator is employed to produce plasma by passing current through single, or dual-wire configurations. To characterize the plasma, a Thomson scattering diagnostic is employed, along with a visible spectroscopy diagnostic. This work was performed under the auspices of the U.S. Department of Defense by Riverside Research under Contract BAA-FA8650-13-C-1539.

  19. Evaluation of two-beam spectroscopy as a plasma diagnostic

    SciTech Connect

    Billard, B.D.

    1980-04-01

    A two-beam spectroscopy (TBS) system is evaluated theoretically and experimentally. This new spectroscopic technique uses correlations between components of emitted light separated by a small difference in angle of propagation. It is thus a non-perturbing plasma diagnostic which is shown to provide local (as opposed to line-of-sight averaged) information about fluctuations in the density of light sources within a plasma - information not obtainable by the usual spectroscopic methods. The present design is an improvement on earlier systems proposed in a thesis by Rostler.

  20. Transverse laser cooled Lithium atomic beam for plasma edge diagnostics

    NASA Astrophysics Data System (ADS)

    Barthwal, S.; Ajmathulla; Mahender, N.; Vudayagiri, A.; Kumar, A.

    2016-05-01

    We have built a set up to achieve a collimated atomic Lithium beam to be used for plasma edge diagnostics. The collimation is achieved by two-dimensional laser cooling, and such a beam could be very useful to obtain electron density at the edge of a plasma with very high spatial resolution. We present in this manuscript the details of this setup, including details of the oven we designed for the Lithium source. We present the metrics of the beam, including the transverse velocity profile of the atomic beam.

  1. SXR-XUV Diagnostics for Edge and Core of Magnetically Confined Plasmas

    SciTech Connect

    Stutman, Dan

    2014-09-10

    The present report summarizes the results obtained during a one-year extension of DoE grant “SXR-XUV Diagnostics for Edge and Core of Magnetically Confined Plasmas”, at Johns Hopkins University, aimed at completing the development of a new type of magnetic fusion plasma diagnostic, the XUV Transmission Grating Imaging Radiometer (TGIR). The TGIR enables simultaneous spatially and spectrally resolved measurements of the XUV/VUV radiated power from impurities in fusion plasmas, with high speed. The instrument was successfully developed and qualified in the laboratory and in experiments on a tokamak. Its future applications will be diagnostic of the impurity content and transport in the divertor and edge of advanced magnetic fusion experiments, such as NSTX Upgrade.

  2. Edge plasma and current profile diagnostic development. Final report

    SciTech Connect

    McChesney, J.M.

    1997-05-01

    This is the final report covering the research conducted under DOE Grant No. DE-FG03-92ER54150 entitled ``Edge Plasma and Current Profile Diagnostic Development.`` It is intended to summarize the investigation and will go into somewhat more detail regarding the aims, techniques, and results of the project research than the standard technical progress reports submitted previously. During the course of this work the authors developed and implemented an atomic beam-based diagnostic technique for investigating edge plasma density behavior on the TEXT Tokamak. The project required the modification of the existing 100 keV TEXT lithium beam to operate at 20--30 keV and the addition of a new 20 detector chain to collect the fluorescence emissions. The modifications were completed and experimental density profiles were unfolded using a new inversion technique.

  3. Molecular Diagnostic Applications in Colorectal Cancer

    PubMed Central

    Huth, Laura; Jäkel, Jörg; Dahl, Edgar

    2014-01-01

    Colorectal cancer, a clinically diverse disease, is a leading cause of cancer-related death worldwide. Application of novel molecular diagnostic tests, which are summarized in this article, may lead to an improved survival of colorectal cancer patients. Distinction of these applications is based on the different molecular principles found in colorectal cancer (CRC). Strategies for molecular analysis of single genes (as KRAS or TP53) as well as microarray based techniques are discussed. Moreover, in addition to the fecal occult blood testing (FOBT) and colonoscopy some novel assays offer approaches for early detection of colorectal cancer like the multitarget stool DNA test or the blood-based Septin 9 DNA methylation test. Liquid biopsy analysis may also exhibit great diagnostic potential in CRC for monitoring developing resistance to treatment. These new diagnostic tools and the definition of molecular biomarkers in CRC will improve early detection and targeted therapy of colorectal cancer.

  4. Charge resolved electrostatic diagnostic of colliding copper laser plasma plumes

    SciTech Connect

    Yeates, P.; Fallon, C.; Kennedy, E. T.; Costello, J. T.

    2011-10-15

    The collision of two laser generated plasma plumes can result, under appropriate conditions, in the formation of a ''stagnation layer.'' The processes underlying this phenomenon are complex and time dependent. The majority of experiments over the last few decades have focused upon spectroscopic diagnostic of colliding plasmas. We have performed electrostatic diagnosis of multiply charged copper ions (Cu{sup +} to Cu{sup 5+}) generated via Q-switched pulsed laser ({lambda} = 1.06 {mu}m, {tau} = 6 ns, and E{sub L} = 52-525 mJ) generation of copper plasma plumes from a planar target. Time dependent current traces, charge yields, and kinetic energy (K{sub e}) distributions are obtained for single plasma plumes (S{sub p}) and colliding plasma plumes (C{sub p}). The charge yield from a C{sub p} relative to twice that from a S{sub p} is characterized by a charge yield ratio (CYR) parameter. Superior ion yields for all charge states occur for a discrete range of fluences (F) from colliding plasma plumes leading to a CYR parameter exceeding unity. The kinetic energy distributions from colliding plasma plumes display well defined energy compression via narrowing of the distributions for all fluences and charge states. The extent of this energy compression is charge dependent. Space charge forces within the stagnation layer and the resulting charge dependent acceleration of ions are proposed to account for the transfer of ion kinetic energy in favour of collisional ionization mechanisms.

  5. Laser Induced Fluorescence Diagnostic for the ASTRAL Plasma Source.

    NASA Astrophysics Data System (ADS)

    Boivin, Robert; Kamar, Ola; Munoz, Jorge

    2006-10-01

    A Laser Induced Fluorescence (LIF) diagnostic is presented in this poster. The ion temperature measurements are made in the ASTRAL (Auburn Steady sTate Research fAciLity) helicon plasma source using a diode laser based LIF diagnostic. ASTRAL produces Ar plasmas with the following parameters: ne = 10^10 to 10^13 cm-3, Te = 2 to 10 eV and Ti = 0.03 to 0.5 eV. A series of 7 large coils produce an axial magnetic field up to 1.3 kGauss. Operating pressure varies from 0.1 to 100 mTorr and any gas can be used for the discharge. A fractional helix antenna is used to introduce rf power up to 2 kWatt. A number of diagnostics are presently installed on the plasma device (Langmuir Probe, Spectrometer, LIF system). The LIF diagnostic makes use of a diode laser with the following characteristics: 1.5 MHz bandwidth, Littrow external cavity, mode-hop free tuning range up to 16 GHz, total power output of about 15 mW. The wavelength is measured by a precision wavemeter and frequent monitoring prevents wavelength drift. For Ar plasma, a new LIF scheme has been developed. The laser tuned at 686.354 nm, is used to pump the 3d^4F5/2 Ar II metastable level to the 4p^4D5/2 state. The fluorescence radiation between the 4p^4D5/2 and the 4s^4P3/2 terms (442.6 nm) is monitored by a PMT.

  6. Nonintrusive microwave diagnostics of collisional plasmas in Hall thrusters and dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Stults, Joshua

    This research presents a numerical framework for diagnosing electron properties in collisional plasmas. Microwave diagnostics achieved a significant level of development during the middle part of the last century due to work in nuclear weapons and fusion plasma research. With the growing use of plasma-based devices in fields as diverse as space propulsion, materials processing and fluid flow control, there is a need for improved, flexible diagnostic techniques suitable for use under the practical constraints imposed by plasma fields generated in a wide variety of aerospace devices. Much of the current diagnostic methodology in the engineering literature is based on analytical diagnostic, or forward, models. The Appleton-Hartree formula is an oft-used analytical relation for the refractive index of a cold, collisional plasma. Most of the assumptions underlying the model are applicable to diagnostics for plasma fields such as those found in Hall Thrusters and dielectric barrier discharge (DBD) plasma actuators. Among the assumptions is uniform material properties, this assumption is relaxed in the present research by introducing a flexible, numerical model of diagnostic wave propagation that can capture the effects of spatial gradients in the plasma state. The numerical approach is chosen for its flexibility in handling future extensions such as multiple spatial dimensions to account for scattering effects when the spatial extent of the plasma is small relative to the probing beam's width, and velocity dependent collision frequency for situations where the constant collision frequency assumption is not justified. The numerical wave propagation model (forward model) is incorporated into a general tomographic reconstruction framework that enables the combination of multiple interferometry measurements. The combined measurements provide a quantitative picture of the spatial variation in the plasma properties. The benefit of combining multiple measurements in a coherent

  7. Low pressure plasma diagnostics by cars and other techniques

    SciTech Connect

    Hata, N. )

    1989-01-01

    Within the past several years, intensive research activities relating amorphous-silicon technology have stimulated plasma-chemical-vapor-deposition (plasma-CVD) diagnostics by laser-spectroscopic techniques. Among them, coherent anti-Stokes Raman spectroscopy (CARS) has attracted much attention because of its great success in combustion diagnostics, and has been employed for low-pressure-plasma studies. Gas-phase species such as SiH{sub 4}, H{sub 2}, Si{sub 2}H{sub 6}, SiH{sub 2}, and GeH{sub 4} have been detected, time dependences of their concentration and spatial profiles of their concentration and rotational temperature have been determined, and the gas-phase mechanisms have been discussed. This talk will employ those results as examples, and discuss (1) the potential of CARS for gas-phase analysis in CVD (including (i) what species are monitored, (ii) what information is obtained, and (iii) what are the advantages and limitations), and (2) some other diagnostic techniques that provide additional information for better understandings of CVD mechanisms.

  8. Dense Hypervelocity Plasma Jets for Fusion Applications

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. Douglas; Thio, Y. C. Francis

    2005-10-01

    High velocity dense plasma jets are being developed for a variety of fusion applications, including refueling, disruption mitigation, High Energy Density Plasmas, magnetized target/magneto-inertial fusion, injection of angular momentum into centrifugally confined mirrors, and others. The technical goal is to accelerate plasma blobs of density >10^17 cm-3 and total mass >100 micrograms to velocities >200 km/s. The approach utilizes symmetrical injection of very high density plasma into a coaxial EM accelerator having a tailored cross-section that prevents formation of the blow-by instability. AFRL MACH2 modeling identified 2 electrode configurations that produce the desired plasma jet parameters. The injected plasma is generated by up to 64 radially oriented capillary discharges arranged uniformly around the circumference of an angled annular injection section. Initial experimental results are presented in which 8 capillaries are fired in parallel with jitter of ˜100 ns. Current focus is on higher voltage operation to reduce jitter to a few 10's of ns, and development of a suite of optical and spectroscopic plasma diagnostics.

  9. Magnetic Diagnostics at the Wisconsin Plasma Astrophysics Laboratory

    NASA Astrophysics Data System (ADS)

    Peterson, Ethan; Clark, Michael; Egedal, Jan; Wallace, John; Weisberg, David; Forest, Cary

    2015-11-01

    A flexible suite of magnetic diagnostics is being developed to measure low and high frequency magnetic fields, the 3-D magnetic field structure throughout the plasma volume, and the 2-D structure (polar and azimuthal fields) on the surface of the sphere. The internal 3-D structure is ascertained by scanning insertion probes with high sensitivity, high bandwidth, 3-axis hall effect sensors. Careful engineering of these insertion probes is required to effectively remove the heat load while simultaneously maintaining high performance (hot, dense, steady state) plasmas. A surface array of 3-axis hall-effect sensors and 2-axis flux loops will provide 3-D, low frequency magnetic field measurements as well as high frequency fluctuations in the polar and azimuthal directions due to plasma waves. This surface array can be used to observe the spatial structure of global modes such as spherical ion acoustic waves and can provide insight into the structure and magnitude of internal plasma flows. The engineering and capabilities of these diagnostics is the focus of this poster.

  10. Wavelet analysis as a nonstationary plasma fluctuation diagnostic tool

    SciTech Connect

    Santoso, S.; Powers, E.J.; Ouroua, A.; Heard, J.W.; Bengtson, R.D.

    1996-12-31

    Analysis of nonstationary plasma fluctuation data has been a long-time challenge for the plasma diagnostic community. For this reason, in this paper the authors present and apply wavelet transforms as a new diagnostic tool to analyze nonstationary plasma fluctuation data. Unlike the Fourier transform, which represents a given signal globally without temporal resolution, the wavelet transform provides a local representation of the given signal in the time-scale domain. The fundamental concepts and multiresolution properties of wavelet transforms, along with a brief comparison with the short-time Fourier transform, are presented in this paper. The selection of a prototype wavelet or a mother wavelet is also discussed. Digital implementation of wavelet spectral analysis, which include time-scale power spectra and scale power spectra are described. The efficacy of the wavelet approach is demonstrated by analyzing transient broadband electrostatic potential fluctuations inside the inversion radius of sawtoothing TEXT-U plasmas during electron cyclotron resonance heating. The potential signals are collected using a 2 MeV heavy ion beam probe.

  11. Filterscope edge plasma diagnostic for the W7-X stellarator

    NASA Astrophysics Data System (ADS)

    Harris, Jeffrey; Unterberg, Ezekial; Lore, Jeremy; Stephey, Laurie; Schmitz, Oliver; Wurden, Glen; Biedermann, Christoph; Krychowiak, Maciej; Koenig, Ralf

    2015-11-01

    W7-X is a large (R = 5.5m, a = 0.5m, B <3T, P>10 MW) superconducting stellarator at the Max-Planck Institut für Plasmaphysik in Greifswald, Germany, which will begin plasma operations in the last quarter of 2015. We describe here the first measurements with a 24-channel filterscope diagnostic [E. A. Unterberg et al., Rev. Sci. Instrum. 83, 10D722, (2012)] of edge plasma characteristics and spectral emission from impurities near the test limiters installed for initial plasma experiments. These measurements, together with high resolution IR thermography imaging of the limiter, will be used as inputs for edge transport modeling using the EMC3 code [J. D. Lore et al., Nucl. Fusion 52, 0540 (2012)]. This work is sponsored by DOE Contract No. DE-AC05- 00OR22725 with UT-Battelle.

  12. Diagnostic techniques in thermal plasma processing (Part II). Volume 2

    SciTech Connect

    Boulos, M.; Fauchais, P.; Pfender, E.

    1986-02-01

    Techniques for diagnostics for thermal plasmas are discussed. These include both optical techniques and in-flight measurements of particulate matter. In the core of the plasma, collisional excitation of the various chemical species is so strong that the population of the corresponding quantum levels becomes high enough for net emission from the plasma. In that case, the classical methods of emission spectroscopy may be applied. But in the regions where the temperatures are below 4000/sup 0/K (these regions are of primary importance for plasma processing), the emission from the plasma is no longer sufficient for emission spectroscopy. In this situation, the population of excited levels must be increased by the absorption of the light from an external source. Such sources, as for example pulsed tunable dye lasers, are now commercially available. The use of such new devices leads to various techniques such as laser induced fluorescence (LIF) or Coherent Anti Stockes Raman Spectroscopy (CARS) that can be used for analyzing plasmas. Particle velocity measurements can be achieved by photography and laser Doppler anemometry. Particle flux measurements are typically achieved by collecting particles on a substrate. Particle size measurements are based on intensity of scattered light. (WRF)

  13. Laser Thomson Scattering Diagnostics in the Low-Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Woo, Hyun-Jong; Chung, Kyu-Sun

    2008-10-01

    Laser Thomson Scattering (LTS) is the non-invasive method for measuring the electron temperature and its density, which can be used for the calibrations of electric probes within collisional and magnetized plasmas. For LTS diagnostics in the low-temperature plasmas, one need to special optics for detection of the scattered light with restricting the Rayleigh and Stray lights. For this, one uses the Triple Grating Spectrometer (TGS), which is composed of Rayleigh block (notch filter for Rayleigh light) and double grating filter (DGF). All focusing lenses are used with achromatic doublet configuration for reducing the non-linear optical effects such as spherical aberration, coma, etc. The specifications of the grating and achromatic doublet lens are 1800 gr/mm with the dimensions of 84 mm x 84 mm and 400 mm of focal length with the diameter of 100 mm, respectively. In this configurations, the linear dispersion is given as 1.006 nm/mm. Considering the dimension of Charged Coupled Device (CCD) with the linear dispersion, the LTS system can be measure the electron temperatures of less than 10 eV (in most laboratory plasmas). The initial measurement of LTS measurement and comparative study with single probe are done in Divertor Plasma Simulator (DiPS) with the following plasma parameters; plasma density of 10^11-10^13 cm-3, electron temperature of 1-4 eV, and the magnetic field of 0.2-1 kG, respectively.

  14. Plasma synthesis of silicon nanocrystals: Development and diagnostics

    NASA Astrophysics Data System (ADS)

    Bapat, Ameya

    Single-crystal semiconductor nanoparticles are suitable for single nanoparticle electronic devices. Low-pressure silane-argon plasmas are interesting due to their ability to synthesize silicon nanoparticles. The plasma described here is a capacitively-coupled, rotating filamentary plasma instability, composed of a number of plasma globules each ˜3mm in diameter. The 13.56 MHz, 200W RF plasma is operated at ˜2Torr in 5% silane diluted in helium and argon. This discharge can reproducibly synthesize monodisperse, single-crystal, cube-shaped silicon nanoparticles ˜35nm in size. These particles are used to fabricate a single nanoparticle transistor device. Process diagnostics are reported which help understand particle nucleation and growth in this unique plasma. Particle extraction studies are done along the length of the reactor. It is shown that particles nucleate and quickly form ˜300nm, amorphous, cauliflower-shape particles 50mm upstream of the RF electrode. These undergo crystallization in the plasma to form ˜90nm single crystalline spheres which undergo further reduction in size to 35nm cubes collected downstream. The plasma instability is characterized by plasma density and electron temperature measurements. Measurements are reported inside and outside the globules of the filamentary plasma. Density measurements are done using an electrostatic capacitance probe. Electron temperature measurements are done using optical emission spectroscopy. Experimentally measured emission line intensities are compared to those calculated using a model that accounts for ground-state excitation as well as excitation from metastable states. Using measured density and temperature it is found that particles get close to the melting point but do not melt. Low-temperature hydrogen-mediated crystallization as observed in a:Si-H thin films is proposed as a likely mechanism for particle crystallization. Polarization-sensitive light scattering diagnostics are reported. Scattering

  15. Diagnostic application of magnetic islands rotation in JET

    NASA Astrophysics Data System (ADS)

    Buratti, P.; Alessi, E.; Baruzzo, M.; Casolari, A.; Giovannozzi, E.; Giroud, C.; Hawkes, N.; Menmuir, S.; Pucella, G.; Contributors, JET

    2016-07-01

    Measurements of the propagation frequency of magnetic islands in JET are compared with diamagnetic drift frequencies, in view of a possible diagnostic application to the determination of markers for the safety factor profile. Statistical analysis is performed for a database including many well-diagnosed plasma discharges. Propagation in the plasma frame, i.e. with subtracted E  ×  B Doppler shift, results to be in the ion diamagnetic drift direction, with values ranging from 0.8 (for islands at the q  =  2 resonant surface) to 1.8 (for more internal islands) times the ion diamagnetic drift frequency. The diagnostic potential of the assumption of island propagation at exactly the ion diamagnetic frequency is scrutinised. Rational-q locations obtained on the basis of this assumption are compared with the ones measured by equilibrium reconstruction including motional Stark effect measurements as constraints. Systematic shifts and standard deviations are determined for islands with (poloidal, toroidal) periodicity indexes of (2, 1), (3, 2), (4, 3) and (5, 3) and possible diagnostic applications are indicated.

  16. High density plasmas and new diagnostics: An overview (invited).

    PubMed

    Celona, L; Gammino, S; Mascali, D

    2016-02-01

    One of the limiting factors for the full understanding of Electron Cyclotron Resonance Ion Sources (ECRISs) fundamental mechanisms consists of few types of diagnostic tools so far available for such compact machines. Microwave-to-plasma coupling optimisation, new methods of density overboost provided by plasma wave generation, and magnetostatic field tailoring for generating a proper electron energy distribution function, suitable for optimal ion beams formation, require diagnostic tools spanning across the entire electromagnetic spectrum from microwave interferometry to X-ray spectroscopy; these methods are going to be implemented including high resolution and spatially resolved X-ray spectroscopy made by quasi-optical methods (pin-hole cameras). The ion confinement optimisation also requires a complete control of cold electrons displacement, which can be performed by optical emission spectroscopy. Several diagnostic tools have been recently developed at INFN-LNS, including "volume-integrated" X-ray spectroscopy in low energy domain (2-30 keV, by using silicon drift detectors) or high energy regime (>30 keV, by using high purity germanium detectors). For the direct detection of the spatially resolved spectral distribution of X-rays produced by the electronic motion, a "pin-hole camera" has been developed also taking profit from previous experiences in the ECRIS field. The paper will give an overview of INFN-LNS strategy in terms of new microwave-to-plasma coupling schemes and advanced diagnostics supporting the design of new ion sources and for optimizing the performances of the existing ones, with the goal of a microwave-absorption oriented design of future machines. PMID:26931960

  17. High density plasmas and new diagnostics: An overview (invited)

    NASA Astrophysics Data System (ADS)

    Celona, L.; Gammino, S.; Mascali, D.

    2016-02-01

    One of the limiting factors for the full understanding of Electron Cyclotron Resonance Ion Sources (ECRISs) fundamental mechanisms consists of few types of diagnostic tools so far available for such compact machines. Microwave-to-plasma coupling optimisation, new methods of density overboost provided by plasma wave generation, and magnetostatic field tailoring for generating a proper electron energy distribution function, suitable for optimal ion beams formation, require diagnostic tools spanning across the entire electromagnetic spectrum from microwave interferometry to X-ray spectroscopy; these methods are going to be implemented including high resolution and spatially resolved X-ray spectroscopy made by quasi-optical methods (pin-hole cameras). The ion confinement optimisation also requires a complete control of cold electrons displacement, which can be performed by optical emission spectroscopy. Several diagnostic tools have been recently developed at INFN-LNS, including "volume-integrated" X-ray spectroscopy in low energy domain (2-30 keV, by using silicon drift detectors) or high energy regime (>30 keV, by using high purity germanium detectors). For the direct detection of the spatially resolved spectral distribution of X-rays produced by the electronic motion, a "pin-hole camera" has been developed also taking profit from previous experiences in the ECRIS field. The paper will give an overview of INFN-LNS strategy in terms of new microwave-to-plasma coupling schemes and advanced diagnostics supporting the design of new ion sources and for optimizing the performances of the existing ones, with the goal of a microwave-absorption oriented design of future machines.

  18. Diagnostic for Plasma Enhanced Chemical Vapor Deposition and Etch Systems

    NASA Technical Reports Server (NTRS)

    Cappelli, Mark A.

    1999-01-01

    concentration, temperature, ion energy distribution, and electron number density. A wide variety of diagnostic techniques are under development through this consortium grant to measure these parameters. including molecular beam mass spectrometry (MBMS). Fourier transform infrared (FTIR) spectroscopy, broadband ultraviolet (UV) absorption spectroscopy, a compensated Langmuir probe. Additional diagnostics. Such as microwave interferometry and microwave absorption for measurements of plasma density and radical concentrations are also planned.

  19. Laser assisted works for pulsed ion sources: Plasma productions, diagnostics and related computations

    SciTech Connect

    Kasuya, K.; Watanabe, M.; Matsuno, S.; Kamiya, T.; Suzuki, T.; Hushiki, T.; Horioka, K.; Kawakita, Y.; Kuwahara, T.; Shioda, K.; Kanazawa, H.; Okuda, H. )

    1994-10-05

    Recent laser assisted works for pulsed ion beam drivers are described in this paper. The first one is a plasma production by a KrF laser light which may be applicable to an ion source. The second item is a transverse-mode-diagnostic of a discharge-pumped laser. The third one is a one-dimensional computation of the latter laser. [copyright][ital American] [ital Institute] [ital of] [ital Physics] 1994

  20. PROMINENCE PLASMA DIAGNOSTICS THROUGH EXTREME-ULTRAVIOLET ABSORPTION

    SciTech Connect

    Landi, E.; Reale, F.

    2013-07-20

    In this paper, we introduce a new diagnostic technique that uses EUV and UV absorption to determine the electron temperature and column emission measure, as well as the He/H relative abundance of the absorbing plasma. If a realistic assumption on the geometry of the latter can be made and a spectral code such as CHIANTI is used, then this technique can also yield the absorbing plasma hydrogen and electron density. This technique capitalizes on the absorption properties of hydrogen and helium at different wavelength ranges and temperature regimes. Several cases where this technique can be successfully applied are described. This technique works best when the absorbing plasma is hotter than 15,000 K. We demonstrate this technique on AIA observations of plasma absorption during a coronal mass ejection eruption. This technique can be easily applied to existing observations of prominences and cold plasmas in the Sun from almost all space missions devoted to the study of the solar atmosphere, which we list.

  1. Quantum Cascade Laser Absorption Spectroscopy as a Plasma Diagnostic Tool: An Overview

    PubMed Central

    Welzel, Stefan; Hempel, Frank; Hübner, Marko; Lang, Norbert; Davies, Paul B.; Röpcke, Jürgen

    2010-01-01

    The recent availability of thermoelectrically cooled pulsed and continuous wave quantum and inter-band cascade lasers in the mid-infrared spectral region has led to significant improvements and new developments in chemical sensing techniques using in-situ laser absorption spectroscopy for plasma diagnostic purposes. The aim of this article is therefore two-fold: (i) to summarize the challenges which arise in the application of quantum cascade lasers in such environments, and, (ii) to provide an overview of recent spectroscopic results (encompassing cavity enhanced methods) obtained in different kinds of plasma used in both research and industry. PMID:22163581

  2. Predictive Gyrokinetic Transport Simulations and Application of Synthetic Diagnostics

    NASA Astrophysics Data System (ADS)

    Candy, J.

    2009-11-01

    In this work we make use of the gyrokinetic transport solver TGYRO [1] to predict kinetic plasma profiles consistent with energy and particle fluxes in the DIII-D tokamak. TGYRO uses direct nonlinear and neoclassical fluxes calculated by the GYRO and NEO codes, respectively, to solve for global, self-consistent temperature and density profiles via Newton iteration. Previous work has shown that gyrokinetic simulation results for DIII-D discharge 128913 match experimental data rather well in the plasma core, but with a discrepancy in both fluxes and fluctuation levels emerging closer to the edge (r/a > 0.8). The present work will expand on previous results by generating model predictions across the entire plasma core, rather than at isolated test radii. We show that TGYRO predicts temperature and density profiles in good agreement with experimental observations which simultaneously yield near-exact (to within experimental uncertainties) agreement with power balance calculations of the particle and energy fluxes for r/a <=0.8. Moreover, we use recently developed synthetic diagnostic algorithms [2] to show that TGYRO also predicts density and electron temperature fluctuation levels in close agreement with experimental measurements across the simulated plasma volume. 8pt [1] J. Candy, C. Holland, R.E. Waltz, M.R. Fahey, and E. Belli, ``Tokamak profile prediction using direct gyrokinetic and neoclassical simulation," Phys. Plasmas 16, 060704 (2009). [2] C. Holland, A.E. White, G.R. McKee, M.W. Shafer, J. Candy, R.E. Waltz, L. Schmitz, and G.R. Tynan, ``Implementation and application of two synthetic diagnostics for validating simulations of core tokamak turbulence," Phys. Plasmas 16, 052301 (2009).

  3. Diagnostics for real-time plasma control in PBX-M

    NASA Astrophysics Data System (ADS)

    Kaita, R.; Batha, S.; Bell, R. E.; Bernabei, S.; Hatcher, R.; Kozub, T.; Kugel, H.; Levinton, F.; Okabayashi, M.; Sesnic, S.; von Goeler, S.; Zolfaghari, A.; PBX-M Group

    1995-01-01

    An important issue for future tokamaks is real-time plasma control for the avoidance of magnetohydrodynamic instabilities and other applications that require detailed plasma profile and fluctuation data. Although measurements from diagnostics providing this information require significantly more processing than magnetic flux data, recent advancements could make them practical for adjusting operational settings for plasma heating and current drive systems as well as field coil currents. On the Princeton Beta Experiment-Modification (PBX-M), the lower hybrid current drive phasing can be varied during a plasma shot using digitally programmable ferrite phase shifters, and neural beam functions can be fully computer controlled. PBX-M diagnostics that may be used for control purposes include motional Stark-effect polarimetry for magnetic field pitch angle profiles, soft x-ray arrays for plasma position control and the separation of βp from li, hard x-ray detectors for energetic electron distributions, a multichannel electron cyclotron emission radiometer for ballooning mode identification, and passive plate eddy current monitors for kink stabilization. We will describe the present status of these systems on PBX-M, and discuss their suitability for feedback applications.

  4. Electron beam charge diagnostics for laser plasma accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Gonsalves, A. J.; Lin, C.; Smith, A.; Rodgers, D.; Donahue, R.; Byrne, W.; Leemans, W. P.

    2011-06-01

    A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160pC/mm2 and 0.4pC/(psmm2), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within ±8%, showing that they all can provide accurate charge measurements for LPAs.

  5. Aerospace applications of pulsed plasmas

    NASA Astrophysics Data System (ADS)

    Starikovskiy, Andrey

    2012-10-01

    The use of a thermal equilibrium plasma for combustion control dates back more than a hundred years to the advent of internal combustion (IC) engines and spark ignition systems. The same principles are still applied today to achieve high efficiency in various applications. Recently, the potential use of nonequilibrium plasma for ignition and combustion control has garnered increasing interest due to the possibility of plasma-assisted approaches for ignition and flame stabilization. During the past decade, significant progress has been made toward understanding the mechanisms of plasma chemistry interactions, energy redistribution and the nonequilibrium initiation of combustion. In addition, a wide variety of fuels have been examined using various types of discharge plasmas. Plasma application has been shown to provide additional combustion control, which is necessary for ultra-lean flames, high-speed flows, cold low-pressure conditions of high-altitude gas turbine engine (GTE) relight, detonation initiation in pulsed detonation engines (PDE) and distributed ignition control in homogeneous charge-compression ignition (HCCI) engines, among others. The present paper describes the current understanding of the nonequilibrium excitation of combustible mixtures by electrical discharges and plasma-assisted ignition and combustion. Nonequilibrium plasma demonstrates an ability to control ultra-lean, ultra-fast, low-temperature flames and appears to be an extremely promising technology for a wide range of applications, including aviation GTEs, piston engines, ramjets, scramjets and detonation initiation for pulsed detonation engines. To use nonequilibrium plasma for ignition and combustion in real energetic systems, one must understand the mechanisms of plasma-assisted ignition and combustion and be able to numerically simulate the discharge and combustion processes under various conditions.

  6. Thomson scattering diagnostics of atmospheric pressure plasmas - Pulsed filament discharges and plasma jets

    NASA Astrophysics Data System (ADS)

    Tomita, Kentaro

    2015-09-01

    Recently, non-thermal atmospheric-pressure plasmas have received much attention. Because the characteristics of the plasmas are governed by free electrons, measurements of the electron density (ne) and electron temperature (Te) are a prerequisite for understanding plasma behavior. To contribute to the understanding of non-thermal atmospheric-pressure plasmas, we have been developing a laser Thomson scattering (LTS) technique as a diagnostic method for measuring ne and Te of two types of plasmas; a pulsed-filament discharge and He flow plasma jet. The pulsed filament discharge has a short current width (a few tens of ns) and a small size. In order to apply LTS to such plasmas, reproducibility of time and space of the plasmas were improved using a high-speed semiconductor switch. Spatiotemporal evolutions of ne and Te of a main discharge have been obtained. Now we try to apply LTS at a time of primary streamer. Regarding to the He flow plasma jet, the discharge was generated with He gas flow with N2/O2(20%) or N2 shielding gas. It was confirmed that the ne at the center of the plasma with N2/O2 shielding gas was around 50% higher than that with the N2 shielding gas. In collaboration with Keiichiro Urabe, The University of Tokyo; Naoki Shirai, Tokyo Metropolitan University; Safwat Hassaballa, Al-Azhar University; Nima Bolouki, Munehiro Yoneda, Takahiro Shimizu, Yuta Sato, and Kiichiro Uchino, Kyushu University.

  7. Development of laser-aided plasma diagnostics and related technology

    SciTech Connect

    Kawahata, K.; Akiyama, T.; Pavlichenko, R.; Tanaka, K.; Nakayama, K.; Okajima, S.

    2008-03-12

    Laser-aided plasma diagnostics, aiming for establishment of reliable density measurement in next step magnetically confined fusion devices, are under development at the National Institute for Fusion Science. A new type of two color laser (57.2/47.6-{mu}m CH{sub 3}OD) interferometer has been developed and its original function, vibration subtraction, was confirmed in a test stand. The line integrated density measurements by the polarimeter were demonstrated at Compact Helical System by the Cotton-Mouton polarimeter and at the LHD by the Faraday rotation polarimeter.

  8. Polarizer design for millimeter-wave plasma diagnostics.

    PubMed

    Leipold, F; Salewski, M; Jacobsen, A S; Jessen, M; Korsholm, S B; Michelsen, P K; Nielsen, S K; Stejner, M

    2013-08-01

    Radiation from magnetized plasmas is in general elliptically polarized. In order to convert the elliptical polarization to linear polarization, mirrors with grooved surfaces are currently employed in our collective Thomson scattering diagnostic at ASDEX Upgrade. If these mirrors can be substituted by birefringent windows, the microwave receivers can be designed to be more compact at lower cost. Sapphire windows (a-cut) as well as grooved high density polyethylene windows can serve this purpose. The sapphire window can be designed such that the calculated transmission of the wave energy is better than 99%, and that of the high density polyethylene can be better than 97%. PMID:24007082

  9. Polarizer design for millimeter-wave plasma diagnostics

    SciTech Connect

    Leipold, F.; Salewski, M.; Jacobsen, A. S.; Jessen, M.; Korsholm, S. B.; Michelsen, P. K.; Nielsen, S. K.; Stejner, M.

    2013-08-15

    Radiation from magnetized plasmas is in general elliptically polarized. In order to convert the elliptical polarization to linear polarization, mirrors with grooved surfaces are currently employed in our collective Thomson scattering diagnostic at ASDEX Upgrade. If these mirrors can be substituted by birefringent windows, the microwave receivers can be designed to be more compact at lower cost. Sapphire windows (a-cut) as well as grooved high density polyethylene windows can serve this purpose. The sapphire window can be designed such that the calculated transmission of the wave energy is better than 99%, and that of the high density polyethylene can be better than 97%.

  10. Short recovery time, multianode, microchannel plate photomultiplier for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Bassan, M.; Sardella, A.; Perdon, E.

    1989-12-01

    Laser scattering-based plasma diagnostics are presently undertaken by means of a multianode microchannel plate (MCP) photomultiplier (PM) whose recovery time is two orders of magnitude shorter than that typical of conventional MCP devices. This PM is suitable for detection of fast light-pulse bursts whose repetition rate is sufficiently low for heat dissipation between successive bursts. Attention is given to the device's thermal behavior, measuring the temperature increase of the Z-plate due to a single, high-voltage square pulse as a function of pulse energy. The Z-plate recovers from the maximum linear pulse in about 50 microsec.

  11. Development of neutron spectrometer toward deuterium plasma diagnostics in LHD

    SciTech Connect

    Tomita, H.; Iwai, H.; Iguchi, T.; Kawarabayashi, J.; Isobe, M.; Konno, C.

    2010-10-15

    Neutron spectrometer based on coincident counting of associated particles has been developed for deuterium plasma diagnostics on Large Helical Device (LHD) at the National Institute for Fusion Science. Efficient detection of 2.5 MeV neutron with high energy resolution would be achievable by coincident detection of a scattered neutron and a recoiled proton associated with an elastic scattering of incident neutron in a plastic scintillator as a radiator. The calculated neutron spectra from deuterium plasma heated by neutral beam injection indicate that the energy resolution of better than 7% is required for the spectrometer to evaluate energetic deuterium confinement. By using a prototype of the proposed spectrometer, the energy resolution of 6.3% and the detection efficiency of 3.3x10{sup -7} count/neutron were experimentally demonstrated for 2.5 MeV monoenergetic neutron, respectively.

  12. Development of neutron spectrometer toward deuterium plasma diagnostics in LHD.

    PubMed

    Tomita, H; Iwai, H; Iguchi, T; Isobe, M; Kawarabayashi, J; Konno, C

    2010-10-01

    Neutron spectrometer based on coincident counting of associated particles has been developed for deuterium plasma diagnostics on Large Helical Device (LHD) at the National Institute for Fusion Science. Efficient detection of 2.5 MeV neutron with high energy resolution would be achievable by coincident detection of a scattered neutron and a recoiled proton associated with an elastic scattering of incident neutron in a plastic scintillator as a radiator. The calculated neutron spectra from deuterium plasma heated by neutral beam injection indicate that the energy resolution of better than 7% is required for the spectrometer to evaluate energetic deuterium confinement. By using a prototype of the proposed spectrometer, the energy resolution of 6.3% and the detection efficiency of 3.3×10(-7) count/neutron were experimentally demonstrated for 2.5 MeV monoenergetic neutron, respectively. PMID:21033835

  13. Spectroscopic investigations of tungsten EUV spectra for fusion plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Clementson, Joel; Lennartsson, Thomas; Beiersdorfer, Peter; Safronova, Ulyana; Brage, Tomas; Grumer, Jon

    2011-10-01

    The Livermore WOLFRAM spectroscopy project consists of experimental and theoretical investigations of tungsten ions of relevance to the diagnostics of magnetically confined fusion plasmas. A recent effort has focused on the complex extreme ultraviolet spectra of few-times ionized tungsten atoms that are expected to be abundant in ITER divertor plasmas. The tungsten ions were produced and excited in the Livermore EBIT-I electron beam ion trap by scanning the electron-beam energy between 30 and 300 eV. The emission was studied using a broad-band grazing-incidence spectrometer covering 150 - 300 Å and a high-resolution spectrometer covering the 180 - 220 Å region. Experimental spectra are presented together with analysis based on calculations using the FAC, GRASP, Cowan, HULLAC, and RMBPT codes. Part of this work was performed under the auspices of the US DOE by LLNL under Contract No. DE-AC52-07NA-27344.

  14. Measurements by the plasma diagnostics package on STS-3

    NASA Technical Reports Server (NTRS)

    Shawhan, S. D.; Murphy, G. B.

    1982-01-01

    A comprehensive set of measurements about the orbiter environment are provided by the plasma diagnostics package (PDP). Ion and electron particle densities, energies, and spatial distribution functions; ion mass for identification of particular molecular ion species; and magnetic fields, electric fields and electromagnetic waves over a broad frequency range are studied. Shuttle environmental measurements will be made both on the pallet and, by use of the remote manipulator system (RMS), the PDP will be maneuvered in and external to the bay area to continue environmental measurements and to carry on a joint plasma experiment with the Utah State University fast-pulsed electron generator. Results of orbiter environment EMI measurements and S-band field strengths as well as preliminary results from wake search operations indicating wake boundary identifiers are reported.

  15. Atomic Processes and Diagnostics of Low Pressure Krypton Plasma

    NASA Astrophysics Data System (ADS)

    Srivastava, Rajesh; Goyal, Dipti; Gangwar, Reetesh; Stafford, Luc

    2015-03-01

    Optical emission spectroscopy along with suitable collisional-radiative (CR) model is used in plasma diagnostics. Importance of reliable cross-sections for various atomic processes is shown for low pressure argon plasma. In the present work, radially-averaged Kr emission lines from the 2pi --> 1sj were recorded as a function of pressure from 1 to 50mTorr. We have developed a CR model using our fine-structure relativistic-distorted wave cross sections. The various processes considered are electron-impact excitation, ionization and their reverse processes. The required rate coefficients have been calculated from these cross-sections assuming Maxwellian energy distribution. Electron temperature obtained from the CR model is found to be in good agreement with the probe measurements. Work is supported by IAEA Vienna, DAE-BRNS Mumbai and CSIR, New Delhi.

  16. Investigation of plasma diagnostics using a dual frequency harmonic technique

    SciTech Connect

    Kim, Dong-Hwan; Kim, Young-Do; Cho, Sung-Won; Kim, Yu-Sin; Chung, Chin-Wook

    2014-09-07

    Plasma diagnostic methods using harmonic currents analysis of electrostatic probes were experimentally investigated to understand the differences in their measurement of the plasma parameters. When dual frequency voltage (ω{sub 1},ω{sub 2}) was applied to a probe, various harmonic currents (ω{sub 1}, 2ω{sub 1},ω{sub 2}, 2ω{sub 2},ω{sub 2}±ω{sub 1},ω{sub 2}±2ω{sub 1}) were generated due to the non-linearity of the probe sheath. The electron temperature can be obtained from the ratio of the two harmonics of the probe currents. According to the combinations of the two harmonics, the sensitivities in the measurement of the electron temperature differed, and this results in a difference of the electron temperature. From experiments and simulation, it is shown that this difference is caused by the systematic and random noise.

  17. Electromagnetic Analysis of ITER Diagnostic Equatorial Port Plugs During Plasma Disruptions

    SciTech Connect

    Y. Zhai, R. Feder, A. Brooks, M. Ulrickson, C.S. Pitcher and G.D. Loesser

    2012-08-27

    ITER diagnostic port plugs perform many functionsincluding structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to the plasma. The design of diagnostic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate responses of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs), Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration due to electrical contact among various EPP structural components are discussed.

  18. Laser erosion diagnostics of plasma facing materials with displacement sensors and their application to safeguard monitors to protect nuclear fusion chambers

    NASA Astrophysics Data System (ADS)

    Kasuya, Koichi; Motokoshi, Shinji; Taniguchi, Seiji; Nakai, Mitsuo; Tokunaga, Kazutoshi; Mroz, Waldemar; Budner, Boguslaw; Korczyc, Barbara

    2015-02-01

    Tungsten and SiC are candidates for the structural materials of the nuclear fusion reactor walls, while CVD poly-crystal diamond is candidate for the window material under the hazardous fusion stresses. We measured the surface endurance strength of such materials with commercial displacement sensors and our recent evaluation method. The pulsed high thermal input was put into the material surfaces by UV lasers, and the surface erosions were diagnosed. With the increase of the total number of the laser shots per position, the crater depth increased gradually. The 3D and 2D pictures of the craters were gathered and compared under various experimental conditions. For example, the maximum crater depths were plotted as a function of shot accumulated numbers, from which we evaluated the threshold thermal input for the surface erosions to be induced. The simple comparison-result showed that tungsten was stronger roughly two times than SiC. Then we proposed how to monitor the surface conditions of combined samples with such diamonds coated with thin tungsten layers, when we use such samples as parts of divertor inner walls, fusion chamber first walls, and various diagnostic windows. We investigated how we might be able to measure the inner surface erosions with the same kinds of displacement sensors. We found out the measurable maximum thickness of such diamond which is useful to monitor the erosion. Additionally we showed a new scheme of fusion reactor systems with injectors for anisotropic pellets and heating lasers under the probable use of W and/or SiC.

  19. Application and Analysis of the Isoelectronic Line Ratio Temperature Diagnostic in a Planar Ablating-Plasma Experiment at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Epstein, R.; Rosenberg, M. J.; Solodov, A. A.; Myatt, J. F.; Regan, S. P.; Seka, W.; Hohenberger, M.; Barrios, M. A.; Moody, J. D.

    2015-11-01

    The Mn/Co isoelectronic emission-line ratio from a microdot source in planar CH foil targets was measured to infer the electron temperature (Te) in the ablating plasma during two-plasmon-decay experiments at the National Ignition Facility (NIF). We examine the systematic uncertainty in the Te estimate based on the temperature and density sensitivities of the line ratio in conjunction with plausible density constraints, and its contribution to the total Te estimate uncertainty. The potential advantages of alternative microdot elements (e.g., Ti/Cr and Sc/V) are considered. The microdot mass was selected to provide ample line strength while minimizing the effect of self-absorption on the line emission, which is of particular concern, given the narrow linewidths of mid- Z emitters at subcritical electron densities. Atomic line-formation theory and detailed atomic-radiative simulations show that the straight forward interpretation of the isoelectronic ratio solely in terms of its temperature independence remains valid with lines of moderate optical thickness (up to ~ 10) at line center. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  20. Laser diagnostics of welding plasma by polarization spectroscopy.

    PubMed

    Lucas, Owen; Alwahabi, Zeyad T; Linton, Valerie; Meeuwissen, Karel

    2007-05-01

    The application of polarization spectroscopy (PS) to detect atomic species in an atmospheric pressure welding plasma has been demonstrated. PS spectra of Na atoms, seeded in the shielding gas flow of a gas tungsten arc welding (GTAW) plasma, are presented at different pump beam energies. The nature of the PS technique was found to be very efficient in suppressing the high background emission associated with the welding plasma. The PS spectral profiles appear to be Lorentzian and Lorentzian cubed for high and low pump beam energy, respectively. The effect of beam steering, due to the thermal gradient in the interaction plasma zone, was addressed. It was found that there is 2% unavoidable error in the detectable PS signal. PMID:17555627

  1. Diagnostics of Nano-Particle Formation in Process Plasmas

    NASA Astrophysics Data System (ADS)

    Kersten, Holger

    2015-09-01

    The main sources of particle generation during plasma surface processing and the formation of nano-composite materials are (i) the formation of large molecules, mesoscopic clusters and particles in the plasma bulk by chemically reactive gases, and (ii) the formation and incorporation of particles at surfaces (target, substrate) by means of plasma-wall interaction. The plasma process promotes the particle formation by excitation, dissociation and reaction of the involved species in the gas phase. The different stages of the particle growth in the gas phase can be observed by various plasma diagnostics as mass spectrometry, laser induced evaporation, photo-detachment, IR absorption, microwave cavity measurements, Mie scattering and self-excited electron resonance spectroscopy (SEERS). Common diagnostics of particle formation also use the observation and analysis of harmonics and other discharge characteristics. Especially the early stages of the particle growth are not well investigated since they are experimentally inaccessible by standard methods as mentioned above. A novel collection method based on neutral drag was tested in order to get a better insight into the early stages of particle growth. The experiments were performed in an asymmetric, capacitively coupled rf-discharge, where multiple growth cycles can be obtained. Making use of the correlation between the particle growth cycles and the bias voltage as well as the phase angle between discharge current and voltage it was possible to monitor each growth process in-situ. This allowed to collect particles at any desired stage of the growth cycle via the neutral drag method. Size distributions of the nanoparticles at the different stages of the growth cycle were determined ex-situ by transmission electron microscopy. The observed correlations of particle size and bias voltage, which can be used for prediction of the particle growth, are qualitatively explained. Furthermore, the change of the electron density

  2. X-ray diodes for laser fusion plasma diagnostics

    SciTech Connect

    Day, R.H.; Lee, P.; Saloman, E.B.; Nagel, D.J.

    1981-02-01

    Photodiodes with x-ray sensitive photocathodes are commonly used as broadband x-ray detectors in fusion plasma diagnostics. We have measured the risetime of the detector system and have measured the quantum efficiency between 1 to 500 A of numerous photocathode materials of practical interest. The materials studied include aluminum, copper, nickel, gold, three forms of carbon, chromium, and cesium iodide. The results of the measurements are compared with Henke's semiempirical model of photoyield. We have studied the effects of long-term cathode aging and use as a plasma diagnostic on cathode quantum efficiency. In addition, we have measured the x-ray mass-absorption coefficient of several ultrasoft x-ray windows in energy regions where data were unavailable. Windows studied were made of aluminum, Formvar, polypropylene, and Kimfoil. Measurements between 1 to 50 A were performed with the Los Alamos Scientific Laboratory's low-energy x-ray calibration facility, and the measurements between 50 to 550 A were performed at the National Bureau of Standard's synchrotron ultraviolet radiation facility.

  3. Plasma diagnostics in a PVD triode ion plating installation

    NASA Astrophysics Data System (ADS)

    Wouters, Stan Lambert Maria

    1998-12-01

    In this thesis, two diagnostics tools are combined to relate the plasma process parameters in the triode ion plating system (BAI 640) to the film microstructure of wear resistant coatings. As diagnostics tools, the energy-resolved mass analyzer of Balzers (PPM 421) and self-constructed Langmuir probes are used. The PPM 421 detects ion fluxes from the whole plasma volume, with its highest sensitivity along the axis of the ion optics while the probe measures electron and ion fluxes in the proximity of the probe. It is important to know which ions and which neutrals, with how much energy or speed, impinge on the surface of the substrates. An ion mass scan and a neutral mass scan, performed by the PPM 421 inserted next to the substrate table, can give information on the most important species, while the energy scan gives information on the energy distribution of these species. These so called energy spectra of neutrals and ions are a convolution of different energy distributions. This indicates that there are potential hills in the plasma were the ions can accelerate. The fast neutrals mostly originate from a charge exchange collision with the ions. The Langmuir probe can help to locate the potential hills in the plasma. Moreover, a simple current-voltage measurement, performed by this type of collecting probe, can give the value of the plasma parameters with some reasonable accuracy. In combination with the results of the film microstructure, performed by X-ray diffraction, the process parameters of a deposition can be optimized to obtain films with controlled adhesion properties, friction protection and microhardness. The configuration of the triode ion plating installation is given in its different modes used in this thesis, e.g. heating, etching and ion plating/evaporation mode. Finally, film properties, such as the macroscopic residual stress, the stress free lattice parameter, the preferred orientation, the Vickers microhardness and film thickness is discussed

  4. Interpretation of STS-3/plasma diagnostics package results in terms of large space structure plasma interactions

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.

    1984-01-01

    The Plasma Diagnostics Package, which was flown aboard STS-3 recorded various chemical releases from the Orbiter. Changes in the plasma environment were observed to occur during Flash Evaporator System (FES) releases, water dumps and maneuvering thruster operations. During flash evaporator operations, broadband Orbiter-generated electro-static noise is enhanced and plasma density irregularity (delta n/N) is observed to increase by as much as 4 times and is strongly peaked below 6 Hz. In the case of water dumps, background electrostatic noise is enhanced or suppressed depending on frequency and Delta N/N is also seen to increase by as much as 4 times. Various changes in the plasma environment are effected by primary and vernier thruster operations. In addition, thruster activity stimulates electrostatic noise with a spectrum which is most intense at frequencies below 10 kHz.

  5. Diagnostics for transport phenomena in strongly coupled dusty plasmas

    NASA Astrophysics Data System (ADS)

    Goree, J.; Liu, Bin; Feng, Yan

    2013-12-01

    Experimental methods are described for determining transport coefficients in a strongly coupled dusty plasma. A dusty plasma is a mixture of electrons, ions and highly charged microspheres. Due to their large charges, the microspheres are a strongly coupled plasma, and they arrange themselves like atoms in a crystal or liquid. Using a video microscopy diagnostic, with laser illumination and a high speed video camera, the microspheres are imaged. Moment-method image analysis then yields the microspheres' positions and velocities. In one approach, these data in the particle paradigm are converted into the continuum paradigm by binning, yielding hydrodynamic quantities like number density, flow velocity and temperature that are recorded on a grid. To analyze continuum data for two-dimensional laboratory experiments, they are fit to the hydrodynamic equations, yielding the transport coefficients for shear viscosity and thermal conductivity. In another approach, the original particle data can be used to obtain the diffusion and viscosity coefficients, as is discussed in the context of future three-dimensional microgravity experiments.

  6. Diagnostic techniques for measuring suprathermal electron dynamics in plasmas (invited)

    SciTech Connect

    Coda, S.

    2008-10-15

    Plasmas, both in the laboratory and in space, are often not in thermodynamic equilibrium, and the plasma electron distribution function is accordingly non-Maxwellian. Suprathermal electron tails can be generated by external drives, such as rf waves and electric fields, or internal ones, such as instabilities and magnetic reconnection. The variety and importance of the phenomena in which suprathermal electrons play a significant role explains an enduring interest in diagnostic techniques to investigate their properties and dynamics. X-ray bremsstrahlung emission has been studied in hot magnetized plasmas for well over two decades, flanked progressively by electron-cyclotron emission in geometries favoring the high-energy end of the distribution function (high-field-side, vertical, oblique emission), by electron-cyclotron absorption, by spectroscopic techniques, and at lower temperatures, by Langmuir probes and electrostatic analyzers. Continuous progress in detector technology and in measurement and analysis techniques, increasingly sophisticated layouts (multichannel and tomographic systems, imaging geometries), and highly controlled suprathermal generation methods (e.g., perturbative rf modulation) have all been brought to bear in recent years on an increasingly detailed, although far from complete, understanding of suprathermal electron dynamics.

  7. Electromagnetic Analysis For The Design Of ITER Diagnostic Port Plugs During Plasma Disruptions

    SciTech Connect

    Zhai, Y

    2014-03-03

    ITER diagnostic port plugs perform many functions including structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to plasma. The design of diagnotic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate response of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs). Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration due to electrical contact among various EPP structural components are discussed.

  8. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    SciTech Connect

    Pollack, B.R.

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  9. Papers presented at the Tenth Topical Conference on High-Temperature Plasma Diagnostics

    SciTech Connect

    Not Available

    1994-08-01

    This report contains papers on the following topics: Effects of limited spatial resolution on fluctuation measurements; vertical viewing of electron-cyclotron radiation in Text-U; measurement of temperature fluctuations from electron-cyclotron emission; a varying cross section magnetic coil diagnostic used in digital feedback control of plasma position in Text-Upgrade; high-sensitivity, high resolution measurements of radiated power on Text-U; wave launching as a diagnostic tool to investigate plasma turbulence; edge parameters from an energy analyzer and particle transport on Text-U; initial results from a charge exchange q-Diagnostic on Text-U; a method for neutral spectra analysis taking ripple-trapped particle losses into account; application of a three sample volume{sup S(k,{omega}}) estimate to optical measurements of turbulence on Text; initial operation of the 2D Firsis on Text-Upgrade; horizontal-view interferometer on Text-Upgrade; plasma potential measurements on Text-Upgrade with A 2 MeV heavy ion beam; fluctuation measurements using the 2 MeV heavy ion beam probe on Text-U; the time domain triple probe method; a phase contrast imaging system for Text-U; and development of rugged corner cube detectors for the Text-U-Fir interferometer. These papers have been placed on the database elsewhere.

  10. Development of High-Resolution UV-VIS Diagnostics for Space Plasma Simulation

    NASA Astrophysics Data System (ADS)

    Taylor, Andrew; Batishchev, Oleg

    2012-10-01

    Non-invasive far-UV-VIS plasma emission allows remote diagnostics of plasma, which is particularly important for space application. Accurate vacuum tank space plasma simulations require monochromators with high spectral resolution (better than 0.01A) to capture important details of atomic and ionic lines, such as Ly-alpha, etc. We are building a new system based on the previous work [1], and will discuss the development of a spectrometry system that combines a single-pass vacuum far-UV-NIR spectrometer and a tunable Fabry-Perot etalon. [4pt] [1] O. Batishchev and J.L. Cambier, Experimental Study of the Mini-Helicon Thruster, Air Force Research Laboratory Report, AFRL-RZ-ED-TR-2009-0020, 2009.

  11. Application of modern diagnostic methods to environmental improvement. Annual progress report, October 1994--September 1995

    SciTech Connect

    Shepard, W.S.

    1995-12-01

    The Diagnostic Instrumentation and Analysis Laboratory (DIAL), an interdisciplinary research department in the College of Engineering at Mississippi State University (MSU), is under contract with the US Department of Energy (DOE) to develop and apply advanced diagnostic instrumentation and analysis techniques to aid in solving DOE`s nuclear waste problem. The program is a comprehensive effort which includes five focus areas: advanced diagnostic systems; development/application; torch operation and test facilities; process development; on-site field measurement and analysis; technology transfer/commercialization. As part of this program, diagnostic methods will be developed and evaluated for characterization, monitoring and process control. Also, the measured parameters, will be employed to improve, optimize and control the operation of the plasma torch and the overall plasma treatment process. Moreover, on-site field measurements at various DOE facilities are carried out to aid in the rapid demonstration and implementation of modern fieldable diagnostic methods. Such efforts also provide a basis for technology transfer.

  12. Doppler spectroscopy and D-alpha emission diagnostics for the C-2 FRC plasma

    SciTech Connect

    Gupta, Deepak K.; Paganini, E.; Bonelli, L.; Deng, B. H.; Gornostaeva, O.; Hayashi, R.; Knapp, K.; McKenzie, M.; Pousa-Hijos, R.; Primavera, S.; Schroeder, J.; Tuszewski, M.; Balvis, A.; Giammanco, F.; Marsili, P.

    2010-10-15

    Two Doppler spectroscopy diagnostics with complementary capabilities are developed to measure the ion temperatures and velocities of FRC plasmas in the C-2 device. First, the multichord ion doppler diagnostic can simultaneously measure 15 chords of the plasma using an image intensified camera. Second, a single-chord fast-response ion Doppler diagnostic provides much higher faster time response by using a 16-channel photo-multiplier tube array. To study the neutral density of deuterium under different wall and plasma conditions, a highly sensitive eight-channel D-alpha diagnostic has been developed and calibrated for absolute radiance measurements. These spectroscopic diagnostics capabilities, combined with other plasma diagnostics, are helping to understand and improve the field reversed configuration plasmas in the C-2 device.

  13. Capabilities of Imaging Interferometry for Plasma Diagnostics in Open Systems

    SciTech Connect

    Vyacheslavov, L.N.; Sanin, A.L.; Tanaka, K.; Kawahata, K.

    2005-01-15

    Two modifications of imaging interferometry: heterodyne (HI) and phase contrast interferometers (PCI) are designed for observation of plasma density profiles and density fluctuations respectively. Besides, spatial distributions of plasma velocities, velocities fluctuations and related electrical fields can be obtained from the analysis of HI and PCI data. New sensitive phase counters, developed at Budker Institute of Nuclear Physics, enable HI to include some capabilities of the PCI. In addition to well recognized transversal spatial resolution of imaging technique, progress in deconvolution of line-of-sight-integrated data was recently made. Computer simulation, bench-test experiments and recent experimental results from the Large Helical Device illustrate the potentials of the imaging interferometry for investigation of plasma. Application of the imaging interferometry with spatial resolution along the viewing line to mirror machines is finally considered.

  14. Plasma Sterilization Technology for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Fraser, S. J.; Olson, R. L.; Leavens, W. M.

    1975-01-01

    The application of plasma gas technology to sterilization and decontamination of spacecraft components is considered. Areas investigated include: effective sterilizing ranges of four separate gases; lethal constituents of a plasma environment; effectiveness of plasma against a diverse group of microorganisms; penetrating efficiency of plasmas for sterilization; and compatibility of spacecraft materials with plasma environments. Results demonstrated that plasma gas, specifically helium plasma, is a highly effective sterilant and is compatible with spacecraft materials.

  15. Z-pinch diagnostics, plasma and liner instabilities and new x-ray techniques

    SciTech Connect

    Oona, H.; Anderson, B.; Benage, J.

    1996-09-01

    Pulse power experiments of the last several decades have contributed greatly to the understanding of high temperature and high density plasmas and, more recently, to the study of hydrodynamic effects in thick imploding cylinders. Common to all these experiments is the application of a large current pulse to a cylindrically symmetric load, with the resulting Lorenz force compressing the load to produce hydrodynamic motion and/or high temperature, high density plasma. In Los Alamos, Pulsed power experiments are carried out at two facilities. Experiments at low current (from several million to ten million Amperes) are conducted on the Pegasus II capacitor bank. Experiments with higher currents (10`s to 100`s MA range) are performed in Ancho Canyon with the explosively driven Procyon and MAGO magnetic flux compression generator systems. In this paper, the authors present a survey of diagnostic capabilities and results from several sets of experiments. First, they discuss the initiation and growth of instabilities in plasmas generated from the implosion of hollow z-pinches in the pegasus and Procyon experiments. Next they discuss spectroscopic data from the plasmas produced by the MAGO system. They also show time resolved imaging data from thick ({approximately} .4 mm) liner implosions. Finally, the authors discuss improvements to x-ray and visible light imaging and spectrographic diagnostic techniques. The emphasis of this paper is not so much a detailed discussion of the experiments, but a presentation of imaging and spectroscopic results and the implications of these observations to the experiments.

  16. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    SciTech Connect

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich; Byrne, Warren; Leemans, Wim

    2011-06-27

    A comprehensive study of charge diagnostics is conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond electron beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the electron energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/(ps mm{sup 2}), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using electron beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within {+-}8%, showing that they all can provide accurate charge measurements for LPAs.

  17. Plasma diagnostics package. Volume 1: OSS-1 section

    NASA Technical Reports Server (NTRS)

    Pickett, Jolene S. (Compiler); Frank, L. A. (Compiler); Kurth, W. S. (Compiler)

    1988-01-01

    This volume (1) of the Plasma Diagnostics Package (PDP) final science report contains a summary of all of the data reduction and scientific analyses which were performed using PDP data obtained on STS-3 as a part of the Office of Space Science first payload (OSS-1). This work was performed during the period of launch, March 22, l982, through June 30, l983. During this period the primary data reduction effort consisted of processing summary plots of the data received by the 14 instruments located on the PDP and submitting these data to the National Space Science Data Center (NSSDC). The scientific analyses during the performance period consisted of general studies which incorporated the results of several of the PDP's instruments, detailed studies which concentrated on data from only one or two of the instruments, and joint studies of beam-plasma interactions with the OSS-1 Fast Pulse Electron Generator (FPEG) of the Vehicle Charging and Potential Investigation (VCAP). Internal reports, published papers and oral presentations which involve PDP/OSS-1 data are listed in Sections 3 and 4. A PDP/OSS-1 scientific results meeting was held at the University of Iowa on April 19-20, 1983. This meeting was attended by most of the PDP and VCAP investigators and provided a forum for discussing and comparing the various results, particularly with regard to the shuttle orbiter environment. One of the most important functional objectives of the PDP on OSS-1 was to characterize the orbiter environment.

  18. Interpretation of plasma diagnostics package results in terms of large space structure plasma interactions

    NASA Technical Reports Server (NTRS)

    Kurth, William S.

    1991-01-01

    The Plasma Diagnostics Package (PDP) is a spacecraft which was designed and built at The University of Iowa and which contained several scientific instruments. These instruments were used for measuring Space Shuttle Orbiter environmental parameters and plasma parameters. The PDP flew on two Space Shuttle flights. The first flight of the PDP was on Space Shuttle Mission STS-3 and was a part of the NASA/Office of Space Science payload (OSS-1). The second flight of the PDP was on Space Shuttle Mission STS/51F and was a part of Spacelab 2. The interpretation of both the OSS-1 and Spacelab 2 PDP results in terms of large space structure plasma interactions is emphasized.

  19. Suprathermal plasma observed on STS-3 Mission by plasma diagnostics package

    NASA Technical Reports Server (NTRS)

    Paterson, W.; Frank, L. A.; Owens, H.; Pickett, J. S.; Murphy, G. B.; Shawhan, S. D.

    1985-01-01

    Artificially produced electron beams were used extensively during the past decade as a means of probing the magnetosphere, and more recently as a means of actively controlling spacecraft potential. Experimentation in these areas has proven valuable, yet at times confusing, due to the interaction of the electron beam with the ambient plasma. The OSS-1/STS-3 Mission in March 1982 provided a unique opportunity to study beam-plasma interactions at an altitude of 240 km. On board for this mission was a Fast Pulse Electron Generator (FPEG). Measurements made by the Plasma Diagnostics Package (PDP) while extended on the Orbiter RMS show modifications of the ion and electron energy distributions during electron beam injection. Observations made by charged particle detectors are discussed and related to measurements of Orbiter potential. Several of the PDP instruments, the joint PDP/FPEG experiment, and observations made during electron beam injection are described.

  20. Diagnostic applications of nucleic acid circuits.

    PubMed

    Jung, Cheulhee; Ellington, Andrew D

    2014-06-17

    CONSPECTUS: While the field of DNA computing and molecular programming was engendered in large measure as a curiosity-driven exercise, it has taken on increasing importance for analytical applications. This is in large measure because of the modularity of DNA circuitry, which can serve as a programmable intermediate between inputs and outputs. These qualities may make nucleic acid circuits useful for making decisions relevant to diagnostic applications. This is especially true given that nucleic acid circuits can potentially directly interact with and be triggered by diagnostic nucleic acids and other analytes. Chemists are, by and large, unaware of many of these advances, and this Account provides a means of touching on what might seem to be an arcane field. We begin by explaining nucleic acid amplification reactions that can lead to signal amplification, such as catalytic hairpin assembly (CHA) and the hybridization chain reaction (HCR). In these circuits, a single-stranded input acts on kinetically trapped substrates via exposed toeholds and strand exchange reactions, refolding the substrates and allowing them to interact with one another. As multiple duplexes (CHA) or concatemers of increasing length (HCR) are generated, there are opportunities to couple these outputs to different analytical modalities, including transduction to fluorescent, electrochemical, and colorimetric signals. Because both amplification and transduction are at their root dependent on the programmability of Waston-Crick base pairing, nucleic acid circuits can be much more readily tuned and adapted to new applications than can many other biomolecular amplifiers. As an example, robust methods for real-time monitoring of isothermal amplification reactions have been developed recently. Beyond amplification, nucleic acid circuits can include logic gates and thresholding components that allow them to be used for analysis and decision making. Scalable and complex DNA circuits (seesaw gates

  1. A solar tornado observed by EIS. Plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Levens, P. J.; Labrosse, N.; Fletcher, L.; Schmieder, B.

    2015-10-01

    Context. The term "solar tornadoes" has been used to describe apparently rotating magnetic structures above the solar limb, as seen in high resolution images and movies from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). These often form part of the larger magnetic structure of a prominence, however the links between them remain unclear. Here we present plasma diagnostics on a tornado-like structure and its surroundings, seen above the limb by the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard the Hinode satellite. Aims: We aim to extend our view of the velocity patterns seen in tornado-like structures with EIS to a wider range of temperatures and to use density diagnostics, non-thermal line widths, and differential emission measures to provide insight into the physical characteristics of the plasma. Methods: Using Gaussian fitting to fit and de-blend the spectral lines seen by EIS, we calculated line-of-sight velocities and non-thermal line widths. Along with information from the CHIANTI database, we used line intensity ratios to calculate electron densities at each pixel. Using a regularised inversion code we also calculated the differential emission measure (DEM) at different locations in the prominence. Results: The split Doppler-shift pattern is found to be visible down to a temperature of around log T = 6.0. At temperatures lower than this, the pattern is unclear in this data set. We obtain an electron density of log ne = 8.5 when looking towards the centre of the tornado structure at a plasma temperature of log T = 6.2, as compared to the surroundings of the tornado structure where we find log ne to be nearer 9. Non-thermal line widths show broader profiles at the tornado location when compared to the surrounding corona. We discuss the differential emission measure in both the tornado and the prominence body, which suggests that there is more contribution in the tornado at temperatures below log T = 6.0 than in the

  2. Plasma diagnostics package. Volume 2: Spacelab 2 section, part A

    NASA Technical Reports Server (NTRS)

    Pickett, Jolene S. (Compiler); Frank, L. A. (Compiler); Kurth, W. S. (Compiler)

    1988-01-01

    This volume (2), which consists of two parts (A and B), of the Plasma Diagnostics Package (PDP) Final Science Report contains a summary of all of the data reduction and scientific analyses which were performed using PDP data obtained on STS-51F as a part of the Spacelab 2 (SL-2) payload. This work was performed during the period of launch, July 29, l985, through June 30, l988. During this period the primary data reduction effort consisted of processing summary plots of the data received by 12 of the 14 instruments located on the PDP and submitting these data to the National Space Science Data Center (NSSDC). The scientific analyses during the performance period consisted of follow-up studies of shuttle orbiter environment and orbiter/ionosphere interactions and various plasma particle and wave studies which dealt with data taken when the PDP was on the Remote Manipulator System (RMS) arm and when the PDP was in free flight. Of particular interest during the RMS operations and free flight were the orbiter wake studies and joint studies of beam/plasma interactions with the SL-2 Fast Pulse Electron Generator (FPEG) of the Vehicle Charging and Potential Investigation (VCAP). Internal reports, published papers and presentations which involve PDP/SL-2 data are listed in Sections 3 and 4. A PDP/SL-2 scientific results meeting was held at the University of Iowa on June 10, l986. This meeting was attended by most of the PDP and VCAP investigators and provided a forum for discussing and comparing the various results, particularly with regard to the PDP free flight.

  3. Atherosclerosis and Nanotechnology: Diagnostic and Therapeutic Applications.

    PubMed

    Kratz, Jeremy D; Chaddha, Ashish; Bhattacharjee, Somnath; Goonewardena, Sascha N

    2016-02-01

    Over the past several decades, tremendous advances have been made in the understanding, diagnosis, and treatment of coronary artery disease (CAD). However, with shifting demographics and evolving risk factors we now face new challenges that must be met in order to further advance are management of patients with CAD. In parallel with advances in our mechanistic appreciation of CAD and atherosclerosis, nanotechnology approaches have greatly expanded, offering the potential for significant improvements in our diagnostic and therapeutic management of CAD. To realize this potential we must go beyond to recognize new frontiers including knowledge gaps between understanding atherosclerosis to the translation of targeted molecular tools. This review highlights nanotechnology applications for imaging and therapeutic advancements in CAD. PMID:26809711

  4. Plasma propulsion for space applications

    NASA Astrophysics Data System (ADS)

    Fruchtman, Amnon

    2000-04-01

    The various mechanisms for plasma acceleration employed in electric propulsion of space vehicles will be described. Special attention will be given to the Hall thruster. Electric propulsion utilizes electric and magnetic fields to accelerate a propellant to a much higher velocity than chemical propulsion does, and, as a result, the required propellant mass is reduced. Because of limitations on electric power density, electric thrusters will be low thrust engines compared with chemical rockets. The large jet velocity and small thrust of electric thrusters make them most suitable for space applications such as station keeping of GEO communication satellites, low orbit drag compensation, orbit raising and interplanetary missions. The acceleration in the thruster is either thermal, electrostatic or electromagnetic. The arcjet is an electrothermal device in which the propellant is heated by an electric arc and accelerated while passing through a supersonic nozzle to a relatively low velocity. In the Pulsed Plasma Thruster a solid propellant is accelerated by a magnetic field pressure in a way that is similar in principle to pulsed acceleration of plasmas in other, very different devices, such as the railgun or the plasma opening switch. Magnetoplasmadynamic thrusters also employ magnetic field pressure for the acceleration but with a reasonable efficiency at high power only. In an ion thruster ions are extracted from a plasma through a double grid structure. Ion thrusters provide a high jet velocity but the thrust density is low due to space-charge limitations. The Hall thruster, which in recent years has enjoyed impressive progress, employs a quasi-neutral plasma, and therefore is not subject to a space-charge limit on the current. An applied radial magnetic field impedes the mobility of the electrons so that the applied potential drops across a large region inside the plasma. Methods for separately controlling the profiles of the electric and the magnetic fields will

  5. TPX diagnostics for tokamak operation, plasma control and machine protection

    SciTech Connect

    Edmonds, P.H.; Medley, S.S.; Young, K.M.

    1995-08-01

    The diagnostics for TPX are at an early design phase, with emphasis on the diagnostic access interface with the major tokamak components. Account has to be taken of the very severe environment for diagnostic components located inside the vacuum vessel. The placement of subcontracts for the design and fabrication of the diagnostic systems is in process.

  6. Diagnostic characteristics and application of alcohol biomarkers.

    PubMed

    Topic, Aleksandra; Djukic, Mirjana

    2013-01-01

    Alcohol biomarkers play a significant role in the early diagnosis of alcohol intoxication/abuse, alcohol-related organ damages, assessment of alcoholism therapy outcomes, and in forensic medicine. Laboratory detection of excessive alcohol consumption can be carried out by direct measuring of the ethanol and/or metabolites in biological samples which is of particular importance in the cases of acute ethanol intoxication/controlling and/or monitoring of alcohol consumption, or indirectly, by using biomarkers. Preferred diagnostic characteristics of alcohol biomarkers, specificity and sensitivity dependent on the particular demands such as: prevention and treatment of alcoholism in primary and social care, criminal justice, workplace health and safety screening, trafficking control, etc. Alcohol biomarkers traditionally used in clinical practice [blood alcohol concentration (BAC), gamma-glutamyl transferase (GGT), carbohydrate-deficient transferrin (CDT), the ratio GGT/CDT, alanine aminotransferase (ALT), aspartate aminotransferase (AST), the rati. AST/ALT, mean cbrpuscular volume (MCV), phosphatidylethanol (PEth)] are well validated. They are used as screening/monitoring markers of acute/chronic excessive alcohol intake, alcoholism in pregnancy, and other disorders/conditions related to alcohol abuse. Numerous potential alcohol biomarkers have been discovered, but few are validated. Potential alcohol biomarkers (ethanol and serotonin metabolites, sialic acids, etc.) have good diagnostic characteristics, but their application in clinical practice is limited due to the costly equipment necessary for their measurement. Significant progress has been made in the development of sensitive and practical alcohol transdermal devices that can instantly/continuously measure BAC through human skin. Transdermal sensing of alcohol may become a valuable method for monitoring abstinence. A special aspect of alcoholism is genetic predisposition to alcohol abuse and alcoholism, or

  7. Diagnostics of silane and germane radio frequency plasmas by coherent anti-Stokes Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Perry, Joseph W.; Shing, Y. H.; Allevato, C. E.

    1988-06-01

    In situ plasma diagnostics using coherent anti-Stokes Raman spectroscopy have shown different dissociation characteristics for GeH4 and SiH4 in radio frequency (rf) plasma-enhanced chemical vapor deposition of amorphous silicon germanium alloy (a-SiGe:H) thin films. The GeH4 dissociation rate in rf plasmas is a factor of about 3 larger than that of SiH4. Plasma diagnostics have revealed that the hydrogen dilution of the SiH4 and GeH4 mixed plasma plays a critical role in suppressing the gas phase polymerization and enhancing the GeH4 dissociation.

  8. Diagnostics of silane and germane radio frequency plasmas by coherent anti-Stokes Raman spectroscopy

    NASA Technical Reports Server (NTRS)

    Perry, Joseph W.; Shing, Y. H.; Allevato, C. E.

    1988-01-01

    In situ plasma diagnostics using coherent anti-Stokes Raman spectroscopy have shown different dissociation characteristics for GeH4 and SiH4 in radio frequency (rf) plasma-enhanced chemical vapor deposition of amorphous silicon germanium alloy (a-SiGe:H) thin films. The GeH4 dissociation rate in rf plasmas is a factor of about 3 larger than that of SiH4. Plasma diagnostics have revealed that the hydrogen dilution of the SiH4 and GeH4 mixed plasma plays a critical role in suppressing the gas phase polymerization and enhancing the GeH4 dissociation.

  9. Ion source for neutral beam injection meant for plasma and magnetic field diagnostics

    SciTech Connect

    Vainionpaa, Jaakko Hannes; Leung, Ka Ngo; Gough, Richard A.; Kwan, Joe W.; Levinton, Fred

    2008-02-15

    At the Lawrence Berkeley National Laboratory a diagnostic neutral beam injection system for measuring plasma parameters, flow velocity, and local magnetic field is being developed. The system is designed to have a 90% proton fraction and small divergence with beam current at 5-6 A and a pulse length of {approx}1 s occurring once every 1-2 min. The ion source needs to generate uniform plasma over a large (8x5 cm{sup 2}) extraction area. For this application, we have compared rf driven multicusp ion sources operating with either an external or an internal antenna in similar ion source geometry. The ion beam will be made of an array of six sheet-shaped beamlets. The design is optimized using computer simulation programs.

  10. Ion Source for Neutral beam injection meant for plasma and magnetic field diagnostics

    SciTech Connect

    Vainionpaa, Jaakko Hannes; Leung, Ka Ngo; Gough, Richard A.; Kwan, Joe W.; Levinton, Fred

    2007-06-01

    At the Lawrence Berkeley National Laboratory (LBNL) a diagnostic neutral beam injection system for measuring plasma parameters, flow velocity, and local magnetic field is being developed. The systems is designed to have a 90 % proton fraction and small divergence with beam current at 5-6 A and a pulse length of {approx}1 s occurring once every 1-2 min. The ion source needs to generate uniform plasma over a large (8 cm x 5 cm) extraction area. For this application, we have compared RF driven multicusp ion sources operating with either an external or an internal antenna in similar ion source geometry. The ion beam will be made of an array of six sheet-shaped beamlets. The design is optimized using computer simulation programs.

  11. Process diagnostics and monitoring using the multipole resonance probe in an inhomogeneous plasma for ion-assisted deposition of optical coatings

    NASA Astrophysics Data System (ADS)

    Styrnoll, T.; Harhausen, J.; Lapke, M.; Storch, R.; Brinkmann, R. P.; Foest, R.; Ohl, A.; Awakowicz, P.

    2013-08-01

    The application of a multipole resonance probe (MRP) for diagnostic and monitoring purposes in a plasma ion-assisted deposition (PIAD) process is reported. Recently, the MRP was proposed as an economical and industry compatible plasma diagnostic device (Lapke et al 2011 Plasma Sources Sci. Technol. 20 042001). The major advantages of the MRP are its robustness against dielectric coating and its high sensitivity to measure the electron density. The PIAD process investigated is driven by the advanced plasma source (APS), which generates an ion beam in the deposition chamber for the production of high performance optical coatings. With a background neutral pressure of p0 ˜ 20 mPa the plasma expands from the source region into the recipient, leading to an inhomogeneous spatial distribution. Electron density and electron temperature vary over the distance from substrate (ne ˜ 109 cm-3 and Te,eff ˜ 2 eV) to the APS (ne ≳ 1012 cm-3 and Te,eff ˜ 20 eV) (Harhausen et al 2012 Plasma Sources Sci. Technol. 21 035012). This huge variation of the plasma parameters represents a big challenge for plasma diagnostics to operate precisely for all plasma conditions. The results obtained by the MRP are compared to those from a Langmuir probe chosen as reference diagnostics. It is demonstrated that the MRP is suited for the characterization of the PIAD plasma as well as for electron density monitoring. The latter aspect offers the possibility to develop new control schemes for complex industrial plasma environments.

  12. Meningioma Genomics: Diagnostic, Prognostic, and Therapeutic Applications

    PubMed Central

    Bi, Wenya Linda; Zhang, Michael; Wu, Winona W.; Mei, Yu; Dunn, Ian F.

    2016-01-01

    There has been a recent revolution in our understanding of the genetic factors that drive meningioma, punctuating an equilibrium that has existed since Cushing’s germinal studies nearly a century ago. A growing appreciation that meningiomas share similar biologic features with other malignancies has allowed extrapolation of management strategies and lessons from intra-axial central nervous system neoplasms and systemic cancers to meningiomas. These features include a natural proclivity for invasion, frequent intratumoral heterogeneity, and correlation between biologic profile and clinical behavior. Next-generation sequencing has characterized recurrent somatic mutations in NF2, TRAF7, KLF4, AKT1, SMO, and PIK3CA, which are collectively present in ~80% of sporadic meningiomas. Genomic features of meningioma further associate with tumor location, histologic subtype, and possibly clinical behavior. Such genomic decryption, along with advances in targeted pharmacotherapy, provides a maturing integrated view of meningiomas. We review recent advances in meningioma genomics and probe their potential applications in diagnostic, therapeutic, and prognostic frontiers. PMID:27458586

  13. Neural network application to comprehensive engine diagnostics

    NASA Technical Reports Server (NTRS)

    Marko, Kenneth A.

    1994-01-01

    We have previously reported on the use of neural networks for detection and identification of faults in complex microprocessor controlled powertrain systems. The data analyzed in those studies consisted of the full spectrum of signals passing between the engine and the real-time microprocessor controller. The specific task of the classification system was to classify system operation as nominal or abnormal and to identify the fault present. The primary concern in earlier work was the identification of faults, in sensors or actuators in the powertrain system as it was exercised over its full operating range. The use of data from a variety of sources, each contributing some potentially useful information to the classification task, is commonly referred to as sensor fusion and typifies the type of problems successfully addressed using neural networks. In this work we explore the application of neural networks to a different diagnostic problem, the diagnosis of faults in newly manufactured engines and the utility of neural networks for process control.

  14. Serial data acquisition for the X-ray plasma diagnostics with selected GEM detector structures

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Zabolotny, W.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zienkiewicz, P.

    2015-10-01

    The measurement system based on GEM—Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement tokamak plasmas. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. The required data processing have two steps: 1—processing in the time domain, i.e. events selections for bunches of coinciding clusters, 2—processing in the planar space domain, i.e. cluster identification for the given detector structure. So, it is the software part of the project between the electronic hardware and physics applications. The whole project is original and it was developed by the paper authors. The previous version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures for the new data acquisition system. The fast and accurate mode of data acquisition implemented in the hardware in real time can be applied for the dynamic plasma diagnostics. Several detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Final data processing is presented by histograms for selected range of position, time interval and cluster charge values. Exemplary radiation source properties are measured by the basic cumulative characteristics: the cluster position distribution and cluster charge value distribution corresponding to the energy spectra. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  15. Laser ablation plasmas for diagnostics of structured electronic and optical materials during or after laser processing

    NASA Astrophysics Data System (ADS)

    Russo, Richard E.; Bol'shakov, Alexander A.; Yoo, Jong H.; González, Jhanis J.

    2012-03-01

    Laser induced plasma can be used for rapid optical diagnostics of electronic, optical, electro-optical, electromechanical and other structures. Plasma monitoring and diagnostics can be realized during laser processing in real time by means of measuring optical emission that originates from the pulsed laser-material interaction. In post-process applications, e.g., quality assurance and quality control, surface raster scanning and depth profiling can be realized with high spatial resolution (~10 nm in depth and ~3 μm lateral). Commercial instruments based on laser induced breakdown spectrometry (LIBS) are available for these purposes. Since only a laser beam comes in direct contact with the sample, such diagnostics are sterile and non-disruptive, and can be performed at a distance, e.g. through a window. The technique enables rapid micro-localized chemical analysis without a need for sample preparation, dissolution or evacuation of samples, thus it is particularly beneficial in fabrication of thin films and structures, such as electronic, photovoltaic and electro-optical devices or circuits of devices. Spectrum acquisition from a single laser shot provides detection limits for metal traces of ~10 μg/g, which can be further improved by accumulating signal from multiple laser pulses. LIBS detection limit for Br in polyethylene is 90 μg/g using 50-shot spectral accumulation (halogen detection is a requirement for semiconductor package materials). Three to four orders of magnitude lower detection limits can be obtained with a femtosecond laser ablation - inductively coupled plasma mass spectrometer (LA-ICP-MS), which is also provided on commercial basis. Laser repetition rate is currently up to 20 Hz in LIBS instruments and up to 100 kHz in LA-ICP-MS.

  16. Diagnostics for a waste processing plasma arc furnace (invited) (abstract)a)

    NASA Astrophysics Data System (ADS)

    Woskov, P. P.

    1995-01-01

    Maintaining the quality of our environment has become an important goal of society. As part of this goal new technologies are being sought to clean up hazardous waste sites and to treat ongoing waste streams. A 1 MW pilot scale dc graphite electrode plasma arc furnace (Mark II) has been constructed at MIT under a joint program among Pacific Northwest Laboratory (PNL), MIT, and Electro-Pyrolysis, Inc. (EPI)c) for the remediation of buried wastes in the DOE complex. A key part of this program is the development of new and improved diagnostics to study, monitor, and control the entire waste remediation process for the optimization of this technology and to safeguard the environment. Continuous, real time diagnostics are needed for a variety of the waste process parameters. These parameters include internal furnace temperatures, slag fill levels, trace metals content in the off-gas stream, off-gas molecular content, feed and slag characterization, and off-gas particulate size, density, and velocity distributions. Diagnostics are currently being tested at MIT for the first three parameters. An active millimeter-wave radiometer with a novel, rotatable graphite waveguide/mirror antenna system has been implemented on Mark II for the measurement of surface emission and emissivity which can be used to determine internal furnace temperatures and fill levels. A microwave torch plasma is being evaluated for use as a excitation source in the furnace off-gas stream for continuous atomic emission spectroscopy of trace metals. These diagnostics should find applicability not only to waste remediation, but also to other high temperature processes such as incinerators, power plants, and steel plants.

  17. Spectroscopy of Z-pinch plasmas: how atomic and plasma physics merge and unfold new applications

    NASA Astrophysics Data System (ADS)

    Safronova, Alla

    2012-06-01

    Recent advances in theoretical and experimental work on plasma spectroscopy of Z-pinches are presented. We have shown that the University-scale Z-pinch generators are able to produce plasmas within a broad range of temperatures, densities, opacity, and radiative properties depending on the type, geometry, size, and mass of wire array loads and wire material. The full x-ray and EUV diagnostic set for detailed spatial and temporal monitoring of such a plasma together with relativistic atomic and non-LTE kinetic codes create a very useful and productive environment for the study of atomic and plasma spectroscopy features and development of their applications. A variety of examples of K-shell low-Z (such as Mg and Al), L-shell mid-Z (such as Ni, Cu, and Ag), and M- and L-shell high-Z (W) will be considered and their specific features and applications to fusion and astrophysics will be highlighted.

  18. Dust accelerators and their applications in high-temperature plasmas

    SciTech Connect

    Wang, Zhehui; Ticos, Catakin M

    2010-01-01

    The perennial presence of dust in high-temperature plasma and fusion devices has been firmly established. Dust inventory must be controlled, in particular in the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and potentially interfere with fusion energy production. Much effort has been devoted to gening rid of the dust nuisance. We have recognized a number of dust-accelerators applications in magnetic fusion, including in plasma diagnostics, in studying dust-plasma interactions, and more recently in edge localized mode (ELM)'s pacing. With the applications in mind, we will compare various acceleration methods, including electrostatic, gas-drag, and plasma-drag acceleration. We will also describe laboratory experiments and results on dust acceleration.

  19. Dust Accelerators And Their Applications In High-Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Ticoş, Cǎtǎlin M.; Wang, Zhehui

    2011-06-01

    The perennial presence of dust in high-temperature plasma and fusion devices has been firmly established. Dust inventory must be controlled, in particular in the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and potentially interfere with fusion energy production. Although much effort has been devoted to getting rid of the dust nuisance, there are instances where a controlled use of dust can be beneficial. We have recognized a number of dust-accelerators applications in magnetic fusion, including in plasma diagnostics, in studying dust-plasma interactions, and more recently in edge localized mode (ELM)'s pacing. With the applications in mind, we will compare various acceleration methods, including electrostatic, gas-drag, and plasma-drag acceleration. We will also describe laboratory experiments and results on dust acceleration.

  20. Analysis of plasma wave interference patterns in the Spacelab 2 PDP data. [PDP (Plasma Diagnostics Package)

    SciTech Connect

    Feng, Wei.

    1992-01-01

    During the Spacelab 2 mission the University of Iowa's Plasma Diagnostics Package (PDP) explored the plasma environment around the shuttle. Wideband spectrograms of plasma waves were obtained from the PDP at frequencies from 0 to 30 kHz up to 400 m from the shuttle. These spectrograms frequently showed interference patterns caused by waves with wavelengths short compared to the antenna length (3.89 meters). Two types of interference patterns were observed in the wideband data: associated with the ejection of an electron beam from the space shuttle; associated with lower hybrid waves generated by an interaction between the neutral gas cloud around shuttle and the ambient ionospheric plasma. Analysis of these antenna interference patterns permits a determination of the wavelength, the plasma rest frame frequency, the direction of propagation, the power spectrum and in some cases the location of the source. The electric field noise associated with the electron beam was observed in the wideband data for two periods during which an electron frequency range at low frequencies (below 10 kHz) and shows clear evidence of interference patterns. The broadband low frequency noise was the dominant type of noise produced by the electron beam. The waves have a linear dispersion relation very similar to ion acoustic waves. The returning to the shuttle in response to the ejected electron beam. The waves associated with the lower hybrid resonance have rest frame frequencies near the lower hybrid frequency and propagate perpendicular to the magnetic field. The occurrence of these waves depends strongly on the PDP's position relative to the shuttle and the magnetic field direction. The authors results confirm previous identifications of these waves as lower hybrid waves and suggest they are driven by pick-up ions (H[sub 2]O[sup +]) produced by a charge exchange interaction between a water cloud around the shuttle and the ambient ionosphere.

  1. Multiple diagnostics in a high-pressure hydrogen microwave plasma torch

    SciTech Connect

    Torres, J.; Mullen, J. J. A. M. van der; Gamero, A.; Sola, A.

    2010-02-01

    We present an experimental study of a hydrogen plasma produced by a microwave axial injection torch, launching the plasma in a helium-filled chamber. Three different diagnostic methods have been used to obtain the electron density and temperature as follows: The Stark intersection method of Balmer spectral lines (already tested in argon and helium plasmas); the modified Boltzmann-plot showing that the plasma is far from the local thermodynamic equilibrium but ruled by the excitation-saturation balance; and a study by the disturbed bilateral relations theory. All of these diagnostic techniques show a good agreement.

  2. Efficient extreme ultraviolet transmission gratings for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Braig, Christoph; Predehl, Peter; Kley, Ernst-Bernhard

    2011-06-01

    We report on a theoretical study of free-standing phase transmission gratings for high-resolution extreme ultraviolet (EUV) and soft x-ray spectroscopy and investigate their properties. Designed for wavelengths between about 2 and 40 nm, the devices may provide a first order diffraction efficiency beyond 30%. We use rigorous coupled wave analysis methods in order to optimize the grating design parameters and discuss features of segmented grating arrays. Elemental, as well as compound, materials such as Be, Mo, LiF, and poly-(methylmethacrylate) are considered with respect to their potential and practical limitations in terms of feasibility and sensitivity to radiation damage. Simulations are performed for several samples on the radiation produced by a table-top EUV plasma source and applications to astrophysical problems are considered.

  3. Development of diffractive XUV-VUV light extractors for fusion plasma diagnostic

    NASA Astrophysics Data System (ADS)

    Stutman, D.; Caravelli, G.; Delgado-Aparicio, L.; Finkenthal, M.; Tritz, K.; Kaita, R.; Roquemore, L.

    2009-11-01

    The diagnostic and control of next generation MFE and ICF fusion experiments will require optical light extractors capable of withstanding intense plasma and radiation exposure. A solution applicable from the XUV to the infrared is to use free-standing diffractive optics such as transmission gratings or zone plates. Here we present results on XUV-VUV diffractive extractors for the diagnostic of boundary MFE plasmas. For the VUV range we developed Si transmission gratings having 1 μm period, 5 μm thickness, 40% open fraction, 1x2 mm active area, and coated with Ni, while for the XUV range we use SiN gratings having 0.2 μm period, 0.3 μm thickness, 1x1 mm area, and coated with Ta. The grating extractors are spectrally and spatially calibrated in the laboratory using a newly developed extended XUV-VUV source and will be employed for imaging spectrometry on the NSTX experiment. The operational characteristics of the extended source and first space resolved XUV-VUV spectra will be presented. Work supported by DoE Grant DE-FG02-99ER54523 at JHU and Contract DE-AC02-09CH11466 at PU.

  4. A fluctuation-induced plasma transport diagnostic based upon fast-Fourier transform spectral analysis

    NASA Technical Reports Server (NTRS)

    Powers, E. J.; Kim, Y. C.; Hong, J. Y.; Roth, J. R.; Krawczonek, W. M.

    1978-01-01

    A diagnostic, based on fast Fourier-transform spectral analysis techniques, that provides experimental insight into the relationship between the experimentally observable spectral characteristics of the fluctuations and the fluctuation-induced plasma transport is described. The model upon which the diagnostic technique is based and its experimental implementation is discussed. Some characteristic results obtained during the course of an experimental study of fluctuation-induced transport in the electric field dominated NASA Lewis bumpy torus plasma are presented.

  5. STS-3/OSS-1 Plasma Diagnostics Package (PDP) measurements of the temperature pressure and plasma

    NASA Technical Reports Server (NTRS)

    Shawhan, S. D.; Murphy, G.

    1983-01-01

    Designed to withstand the thermal extremes of the STS-3 mission through the use of heaters and thermal blankets, the plasma diagnostics package sat on the release/engagement mechanism on the OSS-1 payload pallet without a coldplate and was attached to the RMS for two extended periods. Plots show temperature versus mission elapsed time for two temperature sensors. Pressure in the range of 10 to the -3 power torr and 10 to the -7 power torr, measured 3 inches from the skin of the package is plotted against GMT during the mission. The most distinctive feature of the pressure profile is the modulation at the obit period. It was found that pressure peaks when the atmospheric gas is rammed into the cargo bay. Electric and magnetic noise spectra and time variability due to orbiter systems, UHF and S-band transmitter field strengths, and measurements of the ion spectra obtained both in the cargo bay and during experiments are plotted.

  6. Physics and medical applications of cold atmospheric plasma

    NASA Astrophysics Data System (ADS)

    Keidar, Michael

    2013-09-01

    Recent progress in atmospheric plasmas led to the creation of cold plasmas with ion temperature close to room temperature. Varieties of novel plasma diagnostic techniques were applied in a quest to understand physics of cold plasmas. In particular it was established that the streamer head charge is about 108 electrons, the electrical field in the head vicinity is about 107 V/m, and the electron density of the streamer column is about 1019 m3. We have demonstrated the efficacy of cold plasma in a pre-clinical model of various cancer types (lung, bladder, breast, head, neck, brain and skin). Both in-vitro andin-vivo studies revealed that cold plasmas selectively kill cancer cells. We showed that: (a) cold plasma application selectively eradicates cancer cells in vitro without damaging normal cells. (b) Significantly reduced tumor size in vivo. Cold plasma treatment led to tumor ablation with neighbouring tumors unaffected. These experiments were performed on more than 10 mice with the same outcome. We found that tumors of about 5mm in diameter were ablated after 2 min of single time plasma treatment. The two best known cold plasma effects, plasma-induced apoptosis and the decrease of cell migration velocity can have important implications in cancer treatment by localizing the affected area of the tissue and by decreasing metastasic development. In addition, cold plasma treatment has affected the cell cycle of cancer cells. In particular, cold plasmainduces a 2-fold increase in cells at the G2/M-checkpoint in both papilloma and carcinoma cells at ~24 hours after treatment, while normal epithelial cells (WTK) did not show significant differences. It was shown that reactive oxygen species metabolism and oxidative stress responsive genes are deregulated. We investigated the production of reactive oxygen species (ROS) with cold plasma treatment as a potential mechanism for the tumor ablation observed.

  7. Practical applications of plasma surface modification

    SciTech Connect

    Smith, M.D.

    1993-12-01

    Radio frequency activated gas plasma is an environmentally conscious manufacturing process which provides surface treatments for improved product quality. Plasma processing offers significant potential for reducing the use of solvents and other wet processing chemicals now used in surface treatments such as cleaning, activation for bonding, and moisture removal. Plasma treatments are generally accomplished without creating hazardous waste streams to dispose of. Plasma process development and application is ongoing at Allied Signal Inc., Kansas City Division.

  8. Langmuir probe diagnostics of plasma in high current electron cyclotron resonance proton ion source

    SciTech Connect

    Roychowdhury, P.; Kewlani, H.; Mishra, L.; Mittal, K. C.; Patil, D. S.

    2013-07-15

    A high current Electron Cyclotron Resonance (ECR) proton ion source has been developed for low energy high intensity proton accelerator at Bhabha Atomic Research Centre. Langmuir probe diagnostics of the plasma generated in this proton ion source is performed using Langmuir probe. The diagnostics of plasma in the ion source is important as it determines beam parameters of the ion source, i.e., beam current, emittance, and available species. The plasma parameter measurement in the ion source is performed in continuously working and pulsed mode using hydrogen as plasma generation gas. The measurement is performed in the ECR zone for operating pressure and microwave power range of 10{sup −4}–10{sup −3} mbar and 400–1000 W. An automated Langmuir probe diagnostics unit with data acquisition system is developed to measure these parameters. The diagnostics studies indicate that the plasma density and plasma electron temperature measured are in the range 5.6 × 10{sup 10} cm{sup −3} to 3.8 × 10{sup 11} cm{sup −3} and 4–14 eV, respectively. Using this plasma, ion beam current of tens of mA is extracted. The variations of plasma parameters with microwave power, gas pressure, and radial location of the probe have been studied.

  9. Plasma diagnostics approach to welding heat source/molten pool interaction

    SciTech Connect

    Key, J.F.; McIlwain, M.E.; Isaacson, L.

    1980-01-01

    Plasma diagnostic techniques show that weld fusion zone profile and loss of metal vapors from the molten pool are strongly dependent on both the intensity and distribution of the heat source. These plasma properties, are functions of cathode vertex angle and thermal conductivity of the shielding gas, especially near the anode.

  10. Magnetic Diagnostics For Equilibrium Reconstruction And Realtime Plasma Control In NSTX-Upgrade

    SciTech Connect

    Gerhardt, Stefan P.; Erickson, Keith; Kaita, Robert; Lawson, John; Mozulay, Robert; Mueller, Dennis; Que, Weiguo; Rahman, Nabidur; Schneider, Hans; Smalley, Gustav; Tresemer, Kelsey

    2014-06-01

    This paper describes aspects of magnetic diagnostics for realtime control in NSTX-U. The sensor arrangement on the upgraded center column is described. New analog and digital circuitry for processing the plasma current rogowski data are presented. An improved algorithm for estimating the plasma vertical velocity for feedback control is presented.

  11. Influence of electron injection into 27 cm audio plasma cell on the plasma diagnostics

    SciTech Connect

    Haleem, N. A.; Ragheb, M. S.; Zakhary, S. G.; El Fiki, S. A.; Nouh, S. A.; El Disoki, T. M.

    2013-08-15

    emigration to a preferred electrode direction. Regardless of plasma electrodes positions and plasma shape, ions can be departed from one electrode to deposit on the other one. In consequence, as an application the AF plasma type can enhance the metal deposition from one electrode to the other.

  12. Design of the plasma current sensor diagnostic for MFTF-B

    SciTech Connect

    Goerz, D.A.; House, P.A.; Wells, C.W.

    1983-11-23

    The Plasma Current Sensor (PCS) diagnostic includes large diamagnetic loops (DL) that fully encircle the plasma as well as small multi-turn pickup coils (PCs) located between the plasma and the superconducting magnets. Both types of sensors respond to changing magnetic flux linkages caused by plasma currents and are used to measure plasma diamagnetism, from which estimates of temperature and density can be made. The DLs are used in the central cell and Axicell regions, while the PCs are used in the Yin-yang regions where DLs are impractical. Other PCs are used in the central cell to detect axial plasma currents, to help tune trim coils in the transition cell and confirm theoretical estimates of radial diffusion limits. This paper describes the PCS diagnostic and presents the detailed mechanical and electrical designs.

  13. Modeling of imaging diagnostics for laser plasma interaction experiments with the code PARAX

    NASA Astrophysics Data System (ADS)

    Lewis, K.; Riazuelo, G.; Labaune, C.

    2005-09-01

    We have developed a diagnostic simulation tool for the code PARAX to interpret recent measurements of far-field images of the laser light transmitted through a preformed plasma. This includes the complete treatment of the propagation of the light coming from a well-defined region of plasma through the rest of the plasma and all the optics of the imaging system. We have modeled the whole light path, as well as the spatio-temporal integration of the instruments, and the limited collecting aperture for the light emerging out of the plasma. The convolution of computed magnitudes with the plasma and diagnostics transfer functions is indispensable to enable the comparison between experiments and simulations. This tool is essential in the study of the propagation of intense laser beams in plasma media.

  14. Diagnostics of reactive pulsed plasmas by UV and VUV absorption spectroscopy and by modulated beam Mass spectrometry

    NASA Astrophysics Data System (ADS)

    Cunge, Gilles

    2011-10-01

    Pulsed plasmas are promising for etching applications in the microelectronic industry. However, many new phenomena are involved when a high density discharge is pulsed. To better understand these processes it is necessary to probe the radicals' kinetics with a microsecond resolution. We have developed several diagnostics to reach this goal including broad band absorption spectroscopy with UV LEDs to detect small polyatomic radicals and with a deuterium VUV source to detect larger closed shell molecules and the modulated mass spectrometry to monitor atomic species. We will discuss the impact of the plasma pulsing frequency and duty cycle on the radical densities in Cl2 based plasmas, and the consequences on plasma processes. Work done in collaboration with Paul Bodart, Melisa Brihoum, Maxime Darnon, Erwin Pargon, Olivier Joubert, and Nader Sadeghi, CNRS/LTM.

  15. Hilbert-Huang Transform in MHD Plasma Diagnostics

    SciTech Connect

    Kakurin, A.M.; Orlovsky, I.I.

    2005-12-15

    A new method for processing experimental data from MHD diagnostics is discussed that provides a more detailed study of the dynamics of large-scale MHD instabilities. The method is based on the Hilbert-Huang transform method and includes an empirical mode decomposition algorithm, which is used to decompose the experimental MHD diagnostic signals into a set of frequency- and amplitude-modulated harmonics in order to construct the time evolutions of the amplitudes and frequencies of these harmonics with the help of the Hilbert transform. The method can also be applied to analyze data from other diagnostics that measure unsteady oscillating signals.

  16. Optical diagnostics for plasma physics and accelerator science: commonalities and differences

    NASA Astrophysics Data System (ADS)

    Meshkov, Oleg

    2016-04-01

    Optical diagnostics are widely used both for experiments of plasma physics and for measurements of parameters of electron/positron beams in accelerators. The approaches applied for these often have the same methodological basis explained by the similarity of the properties of the studied phenomena. Nevertheless, these branches of physics are very specific and require special diagnostics. The possibility of closed contacts and cooperation between scientists solving similar problems in different areas of physics helps to overcome these problems. It is especially typical for BINP SB RAS known by pioneering works on electron-positron colliders and nuclear fusion. This paper describes the diagnostics that are used in plasma physics experiments, especially for plasma heating by a high-current electron beam, and contains a comparison with optical diagnostics which are recognized tools in colliders and storage rings.

  17. Industrial Applications of Low Temperature Plasmas

    SciTech Connect

    Bardsley, J N

    2001-03-15

    The use of low temperature plasmas in industry is illustrated by the discussion of four applications, to lighting, displays, semiconductor manufacturing and pollution control. The type of plasma required for each application is described and typical materials are identified. The need to understand radical formation, ionization and metastable excitation within the discharge and the importance of surface reactions are stressed.

  18. Applications of laser diagnostics in energy conservation research

    SciTech Connect

    Hutchinson, R.A.

    1985-02-01

    During the past decade, intensive research and development has demonstrated the feasibility, checked the accuracy, and extended the sensitivity of laser diagnostics for combustion systems. Combinations of diagnostics can now provide in-situ, time-, and space-resolved measurements of temperature, velocity, and species concentration. Although these tools are powerful, they also can be exceedingly difficult to use, and their application remains largely in the hands of specialized instrument developers rather than problem-oriented researchers. This report outlines a variety of applications for existing diagnostics that may interest both instrument developers and researchers in particular fields.

  19. Plasma chemistry and its applications

    NASA Technical Reports Server (NTRS)

    Hozumi, K.

    1980-01-01

    The relationship between discharge phenomena and plasma chemistry, as well as the equipment and mechanisms of plasma chemical reactions are described. Various areas in which plasma chemistry is applied are surveyed, such as: manufacturing of semiconductor integrated circuits; synthetic fibers; high polymer materials for medical uses; optical lenses; and membrane filters (reverse penetration films).

  20. Simulated plasma facing component measurements for an in situ surface diagnostic on Alcator C-Mod

    SciTech Connect

    Hartwig, Z. S.; Whyte, D. G.

    2010-10-15

    The ideal in situ plasma facing component (PFC) diagnostic for magnetic fusion devices would perform surface element and isotope composition measurements on a shot-to-shot ({approx}10 min) time scale with {approx}1 {mu}m depth and {approx}1 cm spatial resolution over large areas of PFCs. To this end, the experimental adaptation of the customary laboratory surface diagnostic - nuclear scattering of MeV ions - to the Alcator C-Mod tokamak is being guided by ACRONYM, a Geant4 synthetic diagnostic. The diagnostic technique and ACRONYM are described, and synthetic measurements of film thickness for boron-coated PFCs are presented.

  1. Atmospheric Pressure Plasma Process And Applications

    SciTech Connect

    Peter C. Kong; Myrtle

    2006-09-01

    This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmosphericpressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included.

  2. Application of Statistics in Establishing Diagnostic Certainty

    PubMed Central

    Denegar, Craig R.; Cordova, Mitchell L.

    2012-01-01

    The examination and assessment of injured and ill patients leads to the establishment of a diagnosis. However, the tests and procedures used in health care, including procedures performed by certified athletic trainers, are individually and collectively imperfect in confirming or ruling out a condition of concern. Thus, research into the utility of diagnostic tests is needed to identify the procedures that are most helpful and to indicate the confidence one should place in the results of the test. The purpose of this report is to provide an overview of selected statistical procedures and the interpretation of data appropriate for assessing the utility of diagnostic tests with dichotomous (positive or negative) outcomes, with particular attention to the interpretation of sensitivity and specificity estimates and the reporting of confidence intervals around likelihood ratio estimates. PMID:22488292

  3. Optical Spectroscopic Diagnostics Of Dusty Plasma In RF Discharge

    SciTech Connect

    Orazbayev, S. A.; Jumagulov, M. N.; Dosbolayev, M. K.; Silamiya, M.; Ramazanov, T. S.; Boufendi, L.

    2011-11-29

    The parameters of the buffer plasma containing dust particles were measured by means of spectroscopic methods. The change in the emission spectrum of the buffer plasma with addition of dust was observed. It seems to relate to changing in temperature and number density of electrons due to the influence of dusts.

  4. Diagnostic Applications of Saliva in Dentistry

    PubMed Central

    AR, Prabhakar; Gulati, Akanksha; Mehta, Deepak; Sugandhan, S

    2009-01-01

    Background: The use of saliva to identify individuals with disease and to follow the progress of the affected individual has attracted the attention of numerous investigators. Its noninvasive method of collection, simplicity, and cost effectiveness make it a useful tool not only to the general practitioner but also to the pediatric dentist. Aim: The aim of this paper is to provide the clinician with a comprehensive review of the diagnostic uses of saliva in dentistry. PMID:25206116

  5. Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Mahler, L.; Tredicucci, A.; Vitiello, M. S.

    2012-02-01

    Quantum cascade lasers (QCL) are unipolar injection lasers based on intersubband transitions in a modular semiconductor heterostructure. The first THz QCL, operating at 67 μm (4.3 THz), was demonstrated in 2002; the wavelength range now extends beyond 250 μm (1.2 THz) and is entering the sub-terahertz frequency range for devices operated in external magnetic field. Although a number of different quantum designs have been demonstrated, increasing the operating temperature remains a major challenge: the maximum temperature is still ~ 195 K, and recently approached 225 K in high magnetic fields. Nevertheless, compact continuous wave systems operating within Sterling coolers already ensure ample portability and turn-key operation and QCLs represent then the THz solid-state radiation source that actually shows the best performance in terms of optical output power, which can reach more than 100 mW average, and linewidth, typically in the tens of kHz for single mode devices. THz QCLs have then a realistic chance to deeply impact technological applications such as process monitoring, security controls, and bio-medical diagnostics. They are ideally suited though for plasma polarimetry and interferometry, thanks to their high polarization selectivity, excellent stability and ruggedness, and ease of high-speed modulation. Their compact size and monolithic cavity arrangement allows placement in the very proximity of the plasma to be monitored, easing requirements of stability against vibrations etc. Furthermore, the long coherence lengths should be easily compatible with interferometric arms of even very different lengths, a geometry ideal for coupling to a plasma reactor. The possibility of direct current modulation at MHz if not GHz frequencies ensures then an excellent temporal resolution of the meaurements, and a large low-frequency noise rejection. New analysis schemes also become feasible, for instance employing two-color lasers, operating at the same time at two

  6. Optical diagnostic instrument for monitoring etch uniformity during plasma etching of polysilicon in a chlorine-helium plasma

    SciTech Connect

    Hareland, W.A.; Buss, R.J.

    1993-06-01

    Nonuniform etching is a serious problem in plasma processing of semiconductor materials and has important consequences in the quality and yield of microelectronic components. In many plasmas, etching occurs at a faster rate near the periphery of the wafer, resulting in nonuniform removal of specific materials over the wafer surface. This research was to investigate in situ optical diagnostic techniques for monitoring etch uniformity during plasma processing of microelectronic components. We measured 2-D images of atomic chlorine at 726 nm in a chlorine-helium plasma during plasma etching of polysilicon in a parallel-plate plasma etching reactor. The 3-D distribution of atomic chlorine was determined by Abel inversion of the plasma image. The experimental results showed that the chlorine atomic emission intensity is at a maximum near the outer radius of the plasma and decreases toward the center. Likewise, the actual etch rate, as determined by profilometry on the processed wafer, was approximately 20% greater near the edge of the wafer than at its center. There was a direct correlation between the atomic chlorine emission intensity and the etch rate of polysilicon over the wafer surface. Based on these analyses, 3-D imaging would be a useful diagnostic technique for in situ monitoring of etch uniformity on wafers.

  7. The diverse applications of plasma

    NASA Astrophysics Data System (ADS)

    Sharma, Mukul; Dubey, Shivani; Darwhekar, Gajanan; Jain, Sudhir Kumar

    2015-07-01

    Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteria and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.

  8. The diverse applications of plasma

    SciTech Connect

    Sharma, Mukul Darwhekar, Gajanan; Dubey, Shivani; Jain, Sudhir Kumar

    2015-07-31

    Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteria and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.

  9. A transmission line bridge for the diagnostics of plasma channels

    NASA Astrophysics Data System (ADS)

    Pechacek, R. E.; Raleigh, M.; Greig, J. R.; Dwyer, T.; Ehrlich, J.

    1984-03-01

    This paper describes a device for measuring the average electrical conductivity of a long, narrow, cylindrical plasma. Interest in plasmas of this shape originates from two areas of study: the study of electron beam propagation through neutral gas, and the study of long straight electrical discharges for use as a communication antenna. Propagation of an electron beam through a neutral gas produces an ionized channel whose properties and evolution are very important to the propagation of the beam itself. Long straight electrical discharges are created in a channel that is ionized by a pulsed laser beam focused with a long focal length lens, and the properties of the plasma in this channel are important to the propagation of the electrical discharge along with channel. The properties of these plasmas are inferred from changes in the transmission properties of a transmission line placed close to and parallel to the plasma. In this paper an analysis is made of the relation between the bridge output voltage and the conductivity of the perturbing plasma for the case in which the conductivity is very low. In this case all perturbations on the bridge parameters are small, and linear approximations are appropriate. The usefulness of the bridge, however, extends to plasma well above this low conductivity range, although a different set of approximations may be necessary to make the analysis of the experiment tractable. A transmission line bridge is a device for measuring very small changes in the properties of transmission lines.

  10. Dark-ground illumination: a quantitative diagnostic for plasma density

    SciTech Connect

    Paul, S.F.

    1981-01-01

    Radial electron density profiles of a toroidal belt pinch plasma have been obtained by a single measurement. Collimated ruby laser light, incident on the plasma, is focused to a diffraction limited spot (100 ..mu..m). The technique, a variation of the dark-ground microscope, involves masking the center of the plasma diffraction pattern with a thin wire. Undiffracted light is blocked by a thin wire, whereas light diffracted by the plasma passes around the wire and onto a photoplate. The resulting interference generates a high contrast fringe pattern whose intensity varies as 1-cos..delta.. phi, where ..delta.. phi is the phase shift induced by the plasma. The fringes are recorded on Polaroid type 46L transparency film. Using this technique, radial density profiles of the plasma produced in the Columbia Torus I belt pinch have been measured. The plasma minor cross section is elliptical with a approx. 2 cm, b approx. 30 cm and approx. 3 x 10/sup 16//cm/sup 3/. Average densities as low as 2 x 10/sup 15//cm/sup 3/ have been measured.

  11. Laser-induced breakdown spectroscopy (LIBS), part I: review of basic diagnostics and plasma-particle interactions: still-challenging issues within the analytical plasma community.

    PubMed

    Hahn, David W; Omenetto, Nicoló

    2010-12-01

    Laser-induced breakdown spectroscopy (LIBS) has become a very popular analytical method in the last decade in view of some of its unique features such as applicability to any type of sample, practically no sample preparation, remote sensing capability, and speed of analysis. The technique has a remarkably wide applicability in many fields, and the number of applications is still growing. From an analytical point of view, the quantitative aspects of LIBS may be considered its Achilles' heel, first due to the complex nature of the laser-sample interaction processes, which depend upon both the laser characteristics and the sample material properties, and second due to the plasma-particle interaction processes, which are space and time dependent. Together, these may cause undesirable matrix effects. Ways of alleviating these problems rely upon the description of the plasma excitation-ionization processes through the use of classical equilibrium relations and therefore on the assumption that the laser-induced plasma is in local thermodynamic equilibrium (LTE). Even in this case, the transient nature of the plasma and its spatial inhomogeneity need to be considered and overcome in order to justify the theoretical assumptions made. This first article focuses on the basic diagnostics aspects and presents a review of the past and recent LIBS literature pertinent to this topic. Previous research on non-laser-based plasma literature, and the resulting knowledge, is also emphasized. The aim is, on one hand, to make the readers aware of such knowledge and on the other hand to trigger the interest of the LIBS community, as well as the larger analytical plasma community, in attempting some diagnostic approaches that have not yet been fully exploited in LIBS. PMID:21144145

  12. Recent Progress and Future Plans for Fusion Plasma Synthetic Diagnostics Platform

    NASA Astrophysics Data System (ADS)

    Shi, Lei; Kramer, Gerrit; Tang, William; Tobias, Benjamin; Valeo, Ernest; Churchill, Randy; Hausammann, Loic

    2015-11-01

    The Fusion Plasma Synthetic Diagnostics Platform (FPSDP) is a Python package developed at the Princeton Plasma Physics Laboratory. It is dedicated to providing an integrated programmable environment for applying a modern ensemble of synthetic diagnostics to the experimental validation of fusion plasma simulation codes. The FPSDP will allow physicists to directly compare key laboratory measurements to simulation results. This enables deeper understanding of experimental data, more realistic validation of simulation codes, quantitative assessment of existing diagnostics, and new capabilities for the design and optimization of future diagnostics. The Fusion Plasma Synthetic Diagnostics Platform now has data interfaces for the GTS and XGC-1 global particle-in-cell simulation codes with synthetic diagnostic modules including: (i) 2D and 3D Reflectometry; (ii) Beam Emission Spectroscopy; and (iii) 1D Electron Cyclotron Emission. Results will be reported on the delivery of interfaces for the global electromagnetic PIC code GTC, the extended MHD M3D-C1 code, and the electromagnetic hybrid NOVAK eigenmode code. Progress toward development of a more comprehensive 2D Electron Cyclotron Emission module will also be discussed. This work is supported by DOE contract #DEAC02-09CH11466.

  13. Laser-induced incandescence diagnostic for in situ monitoring of nanoparticle synthesis in an atmospheric plasma

    NASA Astrophysics Data System (ADS)

    Mitrani, James; Patel, Shane; Shneider, Mikhail; Stratton, Brent; Raitses, Yevgeny

    2014-10-01

    A DC arc discharge with a consumed graphite electrode is commonly used for synthesis of carbon nanoaparticles in a low temperature (0.1-1 eV), atmospheric pressure plasma. The formation of nanoparticles in this plasma is poorly understood; it is not clear where nanoparticles nucleate and grow in the arc discharge. Therefore, a laser-induced incandescence (LII) diagnostic for in situ monitoring of the nanoparticles' spatial distribution in the plasma is currently being constructed. The LII diagnostic involves heating the particles with a short-pulsed laser, and measuring the induced spatiotemporal incandescence profiles on longer timescales. By appropriately modeling the induced spatiotemporal incandescence profiles, one can measure particle diameters and volume fraction. LII diagnostics have been extensively used to study soot particles in flames. However, they have never been applied in a strongly coupled plasma background. Even though the spatial dimensions for soot and nanoparticles are similar, great care is needed in developing an LII diagnostic for monitoring nanoparticles in a plasma background. Therefore, we will calibrate our LII diagnostic by measuring spatiotemporal incandescence profiles of known, research grade soot and nanoparticles. This work was supported by DOE Contract DE-AC02-09CH11466.

  14. Development of laser-based diagnostics for 1-MA z-pinch plasmas

    NASA Astrophysics Data System (ADS)

    Ivanov, V. V.; Hakel, P.; Mancini, R. C.; Wiewior, P.; Presura, R.; Kindel, J. M.; Shevelko, A. P.; Chalyy, O.; Astanovitskiy, A.; Haboub, A.; Altemara, S. D.; Papp, D.; Durmaz, T.

    2009-11-01

    The 50 TW Leopard laser coupled with the 1-MA Zebra generator was used for development of new diagnostics of z-pinch plasmas. Two plasma diagnostics are presented: an x-ray broadband backlighting for z-pinch absorption spectroscopy and parametric two-plasmon decay of the laser beam in dense z-pinch plasma. Implementation of new diagnostics on the Zebra generator and the first results are discussed. The absorption spectroscopy is based on backlighting of z-pinch plasma with a broadband x-ray radiation from a Sm laser plasma. Detailed analysis of the absorption spectra yields the electron temperature and density of z-pinch plasma at the non-radiative stage. The parametric two-plasmon decay of intensive laser radiation generates 3/2φ and 1/2φ harmonics. These harmonics can be used to derive a temperature of z-pinch plasma with the electron density near the quarter of critical plasma density.

  15. Application of Raman diagnostics to combustion

    NASA Technical Reports Server (NTRS)

    Lederman, S.; Posillico, C.; Celentano, A.

    1980-01-01

    The use of laser Raman diagnostic techniques to measure the specie concentrations and their temperatures in combustion flow fields is discussed. The system designed to measure the specie concentrations, which included a ruby laser and a photodiode to trip the laser at the maximum light and heat output of the combustion process, is described and problems encountered in developing the system are reported. Photographs of the combustion process are presented and analyzed detailing the evolution of the combustion in terms of the photodiode and the lack of a noticeable Raman-Stokes signal. The absence of the Raman-Stokes signal is discussed.

  16. Cesium control and diagnostics in surface plasma negative ion sources

    SciTech Connect

    Dudnikov, Vadim; Chapovsky, Pavel; Dudnikov, Andrei

    2010-02-15

    For efficient and reliable negative ion generation it is very important to improve a cesium control and diagnostics. Laser beam attenuation and resonance fluorescence can be used for measurement of cesium distribution and cesium control. Resonant laser excitation and two-photon excitation can be used for improved cesium ionization and cesium trapping in the discharge chamber. Simple and inexpensive diode lasers can be used for cesium diagnostics and control. Cesium migration along the surface is an important mechanism of cesium escaping. It is important to develop a suppression of cesium migration and cesium accumulation on the extraction system.

  17. ECE diagnostic of high temperature ECRH heated plasmas on FTU

    SciTech Connect

    Zerbini, M; Buratti, P; Tudisco, O; Giruzzi, G; Bruschi, A; Cirant, S; Granucci, G; Simonetto, A; Sozzi, C; Gandini, F; Pacella, D; Fournier, K B; Finkenthal, M

    2000-01-31

    The Electron Cyclotron Emission (ECE) diagnostic on FTU tokamak is routinely performed with a Michelson interferometer with spectral range extending up to 1300 GHz. The diagnostic allowed accurate electron temperature measurements during the recent 140 Ghz Electron Cyclotron Resonance Heating (ECRH) experiments on FTU. Very accurate measurements have been performed on a wide range of electron temperatures and profile peaking. The ECE measurements have been compared with Thomson Scattering and with observations of X-ray spectra from highly stripped molybdenum ions. The suprathermal emission in these conditions has been studied.

  18. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    SciTech Connect

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2010-09-09

    A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity (<10{sup 14}Wcm{sup -2}) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

  19. Diagnostics of DC plasma jets generated with Laval anodes

    SciTech Connect

    Rahmane, M.; Soucy, G.; Boulos, M.I.; Henne, R.

    1995-12-31

    Plasma jets originating from d.c. torches equipped with Laval nozzles are considered to be more efficient for both vacuum and atmospheric plasma spraying than those generated with the standard cylindrical anodes. The present study is devoted to the measurement of the temperature and velocity fields in plasma jets resulting from three different nozzles: a cylindrical and two Laval anodes with nominal Mach numbers of 2.5 and 3. The enthalpy probe and emission spectroscopy techniques are used for this purpose. Attention is given to the effect of the chamber pressure on the distribution of the temperature and velocity fields. The results show that when Laval nozzles are used at reduced chamber pressure (200 torr), the jets are wider, with higher temperature and velocity values in the central regions, compared to those obtained using cylindrical anodes. These characteristics are expected to improve the results of plasma spraying processes with respect to the layer quality and deposition efficiency.

  20. Submillimeter laser interferometer for high density plasma diagnostic

    NASA Astrophysics Data System (ADS)

    Kamenev, Yu. E.; Kiselyev, V. K.; Kuleshov, E. M.; Knyaz'kov, B. N.; Kononenko, V. K.; Nesterov, P. K.; Yanovsky, M. S.

    1995-06-01

    There are presented the results of investigation of the one-channel homodyne laser interferometer λ=119 µm made on the basis of the hollow dielectric beamguide and quasioptical functional devices. The interferometer is designed for determination of the plasma electron density of the TOKAMAK-7. The density response threshold is 0.7% from the expected plasma density and the phase difference measurement total error is 5°

  1. Application of modern diagnostic methods to environmental improvement. Annual progress report, January--October 1994

    SciTech Connect

    Shepard, W.S.

    1994-12-01

    The Diagnostic Instrumentation and Analysis Laboratory (DIAL), a research department in the College of Engineering at Mississippi State University (MSU), is under contract with the US Department of Energy (DOE) to develop and apply advanced diagnostic instrumentation and analysis techniques to real world processes; measurements are made in hot, highly corrosive atmospheres in which conventional measurement devices are ineffective. Task 1 of this agreement is concerned with the development and application of various diagnostic methods to characterize the plasma properties, the melt properties and the downstream emissions from a plasma torch facility designed to vitrify mixed waste. Correlation of the measured properties with the operating parameters of the torch will be sought to improve, optimize and control the overall operation of the plasma treatment process. As part of this program, diagnostic methods will be developed and evaluated for characterization, monitoring and control purposes of treatment processes in general. Task 2 of this agreement is concerned with the development of a system to monitor and control the combustion stoichiometry in real time in order to minimize environmental impact and maximize process efficiency. Staged fuel injection is also being studied to minimize NO{sub x} formation.

  2. Overview of C-2 field-reversed configuration experiment plasma diagnostics.

    PubMed

    Gota, H; Thompson, M C; Tuszewski, M; Binderbauer, M W

    2014-11-01

    A comprehensive diagnostic suite for field-reversed configuration (FRC) plasmas has been developed and installed on the C-2 device at Tri Alpha Energy to investigate the dynamics of FRC formation as well as to understand key FRC physics properties, e.g., confinement and stability, throughout a discharge. C-2 is a unique, large compact-toroid merging device that produces FRC plasmas partially sustained for up to ∼5 ms by neutral-beam (NB) injection and end-on plasma-guns for stability control. Fundamental C-2 FRC properties are diagnosed by magnetics, interferometry, Thomson scattering, spectroscopy, bolometry, reflectometry, and NB-related fast-ion/neutral diagnostics. These diagnostics (totaling >50 systems) are essential to support the primary goal of developing a deep understanding of NB-driven FRCs. PMID:25430249

  3. Overview of C-2 field-reversed configuration experiment plasma diagnostics

    SciTech Connect

    Gota, H. Thompson, M. C.; Tuszewski, M.; Binderbauer, M. W.

    2014-11-15

    A comprehensive diagnostic suite for field-reversed configuration (FRC) plasmas has been developed and installed on the C-2 device at Tri Alpha Energy to investigate the dynamics of FRC formation as well as to understand key FRC physics properties, e.g., confinement and stability, throughout a discharge. C-2 is a unique, large compact-toroid merging device that produces FRC plasmas partially sustained for up to ∼5 ms by neutral-beam (NB) injection and end-on plasma-guns for stability control. Fundamental C-2 FRC properties are diagnosed by magnetics, interferometry, Thomson scattering, spectroscopy, bolometry, reflectometry, and NB-related fast-ion/neutral diagnostics. These diagnostics (totaling >50 systems) are essential to support the primary goal of developing a deep understanding of NB-driven FRCs.

  4. Diagnostics and required R&D for control of DEMO grade plasmas

    NASA Astrophysics Data System (ADS)

    Park, Hyeon K.

    2014-08-01

    Even if the diagnostics of ITER performs as expected, installation and operation of the diagnostic systems in Demo device will be much harsher than those of the present ITER device. In order to operate the Demo grade plasmas, which may have a higher beta limit, safely with very limited number of simple diagnostic system, it requires a well defined predictable plasma modelling in conjunction with the reliable control system for burn control and potential harmful instabilities. Development of such modelling in ITER is too risky and the logical choice would be utilization of the present day steady state capable devices such as KSTAR and EAST. In order to fulfill this mission, sophisticated diagnostic systems such as 2D/3D imaging systems can validate the physics in the theoretical modeling and challenge the predictable capability.

  5. Diagnostics and required R and D for control of DEMO grade plasmas

    SciTech Connect

    Park, Hyeon K.

    2014-08-21

    Even if the diagnostics of ITER performs as expected, installation and operation of the diagnostic systems in Demo device will be much harsher than those of the present ITER device. In order to operate the Demo grade plasmas, which may have a higher beta limit, safely with very limited number of simple diagnostic system, it requires a well defined predictable plasma modelling in conjunction with the reliable control system for burn control and potential harmful instabilities. Development of such modelling in ITER is too risky and the logical choice would be utilization of the present day steady state capable devices such as KSTAR and EAST. In order to fulfill this mission, sophisticated diagnostic systems such as 2D/3D imaging systems can validate the physics in the theoretical modeling and challenge the predictable capability.

  6. Optical Diagnostics of Electron Energy Distributions in Low Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Wendt, Amy

    2011-05-01

    Passive, non-invasive optical emission measurements provide a means of probing important plasma parameters without introducing contaminants into plasma systems. We investigate the electron energy distribution function (EEDF) in argon containing inductively-coupled plasmas due to dominant role in rates of gas-phase reactions for processing plasmas. EEDFs are determined using measurements of 3p5 4 p --> 3p5 4 s emissions in the 650-1150 nm wavelength range and measured metastable and resonant level concentrations, in conjunction with a radiation model that includes contributions from often neglected but critical processes such as radiation trapping and electron-impact excitation from metastable and resonant levels. Measurements over a wide range of operating conditions (pressure, RF power, Ar/Ne/N2 gas mixtures) show a depletion of the EEDF relative to the Maxwell- Boltzmann form at higher electron energy, in good agreement with measurements made with Langmuir probes and predictions of a global discharge model. This result is consistent with predictions of electron kinetics and can be explained in terms of reduced life times for energetic electrons due to wall losses and inelastic collisions. This example highlights the potential utility of this method as a tool for probing kinetics of many types of low-temperature plasma systems, which are typically characterized by non-Maxwellian EEDFs. This work was supported by the Wisconsin Alumni Research Foundation (WARF) and by NSF Grant CBET 0714600.

  7. EDITORIAL: The 9th Workshop on Frontiers in Low Temperature Plasma Diagnostics The 9th Workshop on Frontiers in Low Temperature Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    SAME ADDRESS--> Nader Sadeghi,

  1. Electron density and temperature profile diagnostics for C-2 field reversed configuration plasmas

    SciTech Connect

    Deng, B. H.; Kinley, J. S.; Schroeder, J.

    2012-10-15

    The 9-point Thomson scattering diagnostic system for the C-2 field reversed configuration plasmas is improved and the measured electron temperature profiles are consistent with theoretical expectations. Rayleigh scattering revealed a finite line width of the ruby laser emission, which complicates density calibration. Taking advantage of the plasma wobble motion, density profile reconstruction accuracy from the 6-chord two-color CO{sub 2}/HeNe interferometer data is improved.

  2. X-linked adrenoleukodystrophy with non-diagnostic plasma very long chain fatty acids.

    PubMed Central

    Kennedy, C R; Allen, J T; Fensom, A H; Steinberg, S J; Wilson, R

    1994-01-01

    Measurement of plasma very long chain fatty acids is widely recognised as a sensitive screening test for X-linked adrenoleukodystrophy (X-ALD). This test has particular importance because of the highly variable clinical expression of X-ALD. In this affected family the progressive childhood form of X-ALD was accompanied by "non-diagnostic" concentrations of plasma very long chain fatty acids. The implications for diagnosis of X-ALD are discussed. PMID:8006665

  3. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    SciTech Connect

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-08-29

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented.

  4. Modeling atmospheric pressure plasmas for biomedical applications

    NASA Astrophysics Data System (ADS)

    Graves, David

    2007-10-01

    The use of cold, atmospheric pressure plasmas for biomedical treatments is an exciting new application in gaseous electronics. Investigations to date include various tissue treatments and surgery, bacterial destruction, and the promotion of wound healing, among others. In this talk, I will present results from modeling the `plasma needle,' an atmospheric pressure plasma configuration that has been explored by several groups around the world. The biomedical efficacy of the plasma needle has been demonstrated but the mechanisms of cell and tissue modification or bacterial destruction are only just being established. One motivation for developing models is to help interpret experiments and evaluate postulated mechanisms. The model reveals important elements of the plasma needle sustaining mechanisms and operating modes. However, the extraordinary complexity of plasma-tissue interactions represents a long-term challenge for this burgeoning field.

  5. Antimicrobial Applications of Ambient--Air Plasmas

    NASA Astrophysics Data System (ADS)

    Pavlovich, Matthew John

    The emerging field of plasma biotechology studies the applications of the plasma phase of matter to biological systems. "Ambient-condition" plasmas created at or near room temperature and atmospheric pressure are especially promising for biomedical applications because of their convenience, safety to patients, and compatibility with existing medical technology. Plasmas can be created from many different gases; plasma made from air contains a number of reactive oxygen and nitrogen species, or RONS, involved in various biological processes, including immune activity, signaling, and gene expression. Therefore, ambient-condition air plasma is of particular interest for biological applications. To understand and predict the effects of treating biological systems with ambient-air plasma, it is necessary to characterize and measure the chemical species that these plasmas produce. Understanding both gaseous chemistry and the chemistry in plasma-treated aqueous solution is important because many biological systems exist in aqueous media. Existing literature about ambient-air plasma hypothesizes the critical role of reactive oxygen and nitrogen species; a major aim of this dissertation is to better quantify RONS by produced ambient-air plasma and understand how RONS chemistry changes in response to different plasma processing conditions. Measurements imply that both gaseous and aqueous chemistry are highly sensitive to operating conditions. In particular, chemical species in air treated by plasma exist in either a low-power ozone-dominated mode or a high-power nitrogen oxide-dominated mode, with an unstable transition region at intermediate discharge power and treatment time. Ozone (O3) and nitrogen oxides (NO and NO2, or NOx) are mutually exclusive in this system and that the transition region corresponds to the transition from ozone- to nitrogen oxides-mode. Aqueous chemistry agrees well with to air plasma chemistry, and a similar transition in liquid-phase composition

  6. Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Shevchenko, Vladimir F.; Freethy, Simon J.; Huang, Billy K.; Vann, Roddy G. L.

    2014-08-01

    A Synthetic Aperture Microwave Imaging (SAMI) system has been designed and built to obtain 2-D images at several frequencies from fusion plasmas. SAMI uses a phased array of linearly polarised antennas. The array configuration has been optimised to achieve maximum synthetic aperture beam efficiency. The signals received by antennas are down-converted to the intermediate frequency range and then recorded in a full vector form. Full vector signals allow beam focusing and image reconstruction in both real time and a post-processing mode. SAMI can scan over 16 pre-programmed frequencies in the range of 10-35GHz with a switching time of 300ns. The system operates in 2 different modes simultaneously: both a 'passive' imaging of plasma emission and also an 'active' imaging of the back-scattered signal of the radiation launched by one of the antennas from the same array. This second mode is similar to so-called Doppler backscattering (DBS) reflectometry with 2-D resolution of the propagation velocity of turbulent structures. Both modes of operation show good performance in fusion plasma experiments on Mega Amp Spherical Tokamak (MAST). We have obtained the first ever 2-D images of BXO mode conversion windows. With active probing, first ever turbulence velocity maps have been obtained. We present an overview of the diagnostic and discuss recent results. In contrast to quasi-optical microwave imaging systems SAMI requires neither big aperture viewing ports nor large 2-D detector arrays to achieve the desired imaging resolution. The number of effective 'pixels' of the synthesized image is proportional to the number of receiving antennas squared. Thus only a small number of optimised antennas is sufficient for the majority of applications. Possible implementation of SAMI on ITERand DEMO is discussed.

  7. Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics

    SciTech Connect

    Shevchenko, Vladimir F.; Freethy, Simon J.; Huang, Billy K.

    2014-08-21

    A Synthetic Aperture Microwave Imaging (SAMI) system has been designed and built to obtain 2-D images at several frequencies from fusion plasmas. SAMI uses a phased array of linearly polarised antennas. The array configuration has been optimised to achieve maximum synthetic aperture beam efficiency. The signals received by antennas are down-converted to the intermediate frequency range and then recorded in a full vector form. Full vector signals allow beam focusing and image reconstruction in both real time and a post-processing mode. SAMI can scan over 16 pre-programmed frequencies in the range of 10-35GHz with a switching time of 300ns. The system operates in 2 different modes simultaneously: both a 'passive' imaging of plasma emission and also an 'active' imaging of the back-scattered signal of the radiation launched by one of the antennas from the same array. This second mode is similar to so-called Doppler backscattering (DBS) reflectometry with 2-D resolution of the propagation velocity of turbulent structures. Both modes of operation show good performance in fusion plasma experiments on Mega Amp Spherical Tokamak (MAST). We have obtained the first ever 2-D images of BXO mode conversion windows. With active probing, first ever turbulence velocity maps have been obtained. We present an overview of the diagnostic and discuss recent results. In contrast to quasi-optical microwave imaging systems SAMI requires neither big aperture viewing ports nor large 2-D detector arrays to achieve the desired imaging resolution. The number of effective 'pixels' of the synthesized image is proportional to the number of receiving antennas squared. Thus only a small number of optimised antennas is sufficient for the majority of applications. Possible implementation of SAMI on ITERand DEMO is discussed.

  8. Large area cold plasma applicator for decontamination

    NASA Astrophysics Data System (ADS)

    Konesky, G. A.

    2008-04-01

    Cold plasma applicators have been used in the Medical community for several years for uses ranging from hemostasis ("stop bleeding") to tumor removal. An added benefit of this technology is enhanced wound healing by the destruction of infectious microbial agents without damaging healthy tissue. The beam is typically one millimeter to less than a centimeter in diameter. This technology has been adapted and expanded to large area applicators of potentially a square meter or more. Decontamination applications include both biological and chemical agents, and assisting in the removal of radiological agents, with minimal or no damage to the contaminated substrate material. Linear and planar multiemitter array plasma applicator design and operation is discussed.

  9. Topics in high voltage pulsed power plasma devices and applications

    NASA Astrophysics Data System (ADS)

    Chen, Hao

    Pulsed power technology is one of the tools that is used by scientists and engineers nowadays to produce gas plasmas. The transient ultra high power is able to provide a huge pulse of energy which is sometimes greater than the ionization energy of the gas, and therefore separates the ions and electrons to form the plasma. Sometimes, the pulsed power components themselves are plasma devices. For example, the gas type switches can "turn on" the circuit by creating the plasma channel between the switch electrodes. Mini Back Lighted Thyratron, or as we call it, mini-BLT, is one of these gas type plasma switches. The development of the reduced size and weight "mini-BLT" is presented in this dissertation. Based on the operation characteristics testing of the mini-BLT, suggestions of optimizing the design of the switch are proposed. All the factors such as the geometry of the hollow electrodes and switch housing, the gas condition, the optical triggering source, etc. are necessary to consider when we design and operate the mini-BLT. By reducing the diameter of the cylindrical gas path between the electrodes in the BLT, a novel high density plasma source is developed, producing the plasma in the "squeezed" capillary. The pulsed power generator, of course, is inevitably used to provide the ionization energy for hydrogen gas sealed in the capillary. Plasma diagnostics are necessarily analyzed and presented in detail to properly complete and understand the capillary plasma. This high density plasma source (1019 cm-3) has the potential applications in the plasma wakefield accelerator. The resonant oscillation behavior of the particles in plasmas allows for dynamically generated accelerating electric fields that have orders of magnitude larger than those available in the conventional RF accelerators. Finally, the solid state switches are introduced as a comparison to the gas type switch. Pulsed power circuit topologies such as the Marx Bank, magnetic pulse compression and diode

  10. Absolute calibration of vacuum ultraviolet spectrograph system for plasma diagnostics

    SciTech Connect

    Yoshikawa, M.; Kubota, Y.; Kobayashi, T.; Saito, M.; Numada, N.; Nakashima, Y.; Cho, T.; Koguchi, H.; Yagi, Y.; Yamaguchi, N.

    2004-10-01

    A space- and time-resolving vacuum ultraviolet (VUV) spectrograph system has been applied to diagnose impurity ions behavior in plasmas produced in the tandem mirror GAMMA 10 and the reversed field pinch TPE-RX. We have carried out ray tracing calculations for obtaining the characteristics of the VUV spectrograph and calibration experiments to measure the absolute sensitivities of the VUV spectrograph system for the wavelength range from 100 to 1100 A. By changing the incident angle, 50.6 deg. -51.4 deg., to the spectrograph whose nominal incident angle is 51 deg., we can change the observing spectral range of the VUV spectrograph. In this article, we show the ray tracing calculation results and absolute sensitivities when the angle of incidence into the VUV spectrograph is changed, and the results of VUV spectroscopic measurement in both GAMMA 10 and TPE-RX plasmas.

  11. Infrared laser induced plasma diagnostics of silver target

    SciTech Connect

    Ahmat, L. Nadeem, Ali; Ahmed, I.

    2014-09-15

    In the present work, the optical emission spectra of silver (Ag) plasma have been recorded and analyzed using the laser induced breakdown spectroscopy technique. The emission line intensities and plasma parameters were investigated as a function of lens to sample distance, laser irradiance, and distance from the target surface. The electron number density (n{sub e}) and electron temperature (T{sub e}) were determined using the Stark broadened line profile and Boltzmann plot method, respectively. A gradual increase in the spectral line intensities and the plasma parameters, n{sub e} from 2.89 × 10{sup 17} to 3.92 × 10{sup 17 }cm{sup −3} and T{sub e} from 4662 to 8967 K, was observed as the laser irradiance was increased 2.29 × 10{sup 10}–1.06 × 10{sup 11} W cm{sup −2}. The spatial variations in n{sub e} and T{sub e} were investigated from 0 to 5.25 mm from the target surface, yielding the electron number density from 4.78 × 10{sup 17} to 1.72 × 10{sup 17 }cm{sup −3} and electron temperature as 9869–3789 K. In addition, the emission intensities and the plasma parameters of silver were investigated by varying the ambient pressure from 0.36 to 1000 mbars.

  12. Edge Plasma Studies and Related Diagnostics on CASTOR Tokamak

    SciTech Connect

    Hron, M.; Stockel, J.; Duran, I.; Panek, R.; Adamek, J.; Weinzettl, V.

    2006-12-04

    In this contribution, two sets of measurements using a full poloidal array of Langmuir probes in the scrape-off layer of the CASTOR tokamak are described. First, results obtained with edge plasma biasing show creation of convective cells that cause radial transport due to ExB drift. Next, the analysis of the turbulence behaviour in standard ohmic discharges shows the presence of a spatially periodical mode with mode number equal to the edge safety factor q.

  13. Spectral Diagnostics of Plasma Confined within a Field Reversed Configuration

    NASA Astrophysics Data System (ADS)

    Little, J. M.; Heidbrink, W. W.; Garate, E. P.; McWilliams, R.; Trask, E.; Harris, W. S.

    2006-10-01

    A field reversed configuration (FRC) consists of a toroidal plasma current confined by closed magnetic field lines within a cylindrical chamber. The FRC at the University of California Irvine is estimated to operate in a temperature range of 1eV-5eV at a density of approximately 5x10^13 cm-3. An impurity ion survey and temperature measurement are to be performed by analyzing the visible light emitted by the plasma. In order to determine the different species of ions confined within the field, a spectrometer with a resolution of one nanometer will be used. Light from the chamber will be collected using a collimating probe and transmitted to the spectrometer via fiber optic cable. Software will be used to analyze the data, which will then be compared to the NIST Atomic Spectra Database. Expected impurities include oxygen and carbon ions from the plasma injectors. Measurements of the ion temperature will be performed by an observation of the Doppler broadening of the H-alpha emission line. Assuming an ion temperature of 5eV, a resoultion of approximately one angstrom is needed to observe this effect. Due to limitations of the spectrometer, the light from the fiber optic cable will instead be sent through a high resolution spectrometer and imaged using a gated intensifier. By observing the H-alpha line shape the ion temperature can be determined.

  14. Thomson scattering as a method for laser plasma diagnostics

    SciTech Connect

    Alayi, Y.

    1983-12-01

    The Thomson scattering has been used to determine the density and temperature of an inhomogeneous nonstationary plasma. A common method to calibrate the Thomson scattering device consists in replacing the plasma by a gas and measuring the Rayleigh scattering cross section. The angular distribution of the scattered light in Argon is measured, the incident light is a ruby laser with ..delta..t = 30ns and lambda = 6943nm and vertically polarized. We have found that angular distribution is strongly favored in the forward direction (30/sup 0/, 45/sup 0/, 60/sup 0/) and defavored for backward direction (90/sup 0/, 120/sup 0/, 135/sup 0/, 150/sup 0/) in agreement with the results of George, et al, but in disagreement with the Rayleigh theory which assumes a uniform distribution. Our results may be related to the form of the scattered light spectrum which undergoes a dramatic change through the kinetic-hydrodynamic transition. The general form of the spectrum is determined by the parameter y = 1/Kl (where K = 4..pi.. sin (theta/2)/lambda, theta is the scattering angle and l is the free path path), which increases in the direction of the hydrodynamic regime (small angles). By analogy, the Thomson scattering presents the same aspects with ..cap alpha.. = 1/Klambda /SUB D/ (where lambda /SUB D/ is the Debye length). The deviation from the uniform distribution provides the possibility to determine the plasma turbulence spectrum from the scattered light.

  15. Plasma diagnostic approach for high rate nanocrystalline Si synthesis in RF/UHF hybrid plasmas using a PECVD process

    NASA Astrophysics Data System (ADS)

    Sahu, B. B.; Han, Jeon G.; Shin, Kyung S.; Ishikawa, K.; Hori, M.; Miyawaki, Yudai

    2015-04-01

    Hydrogenated nanocrystalline silicon (nc-Si : H) films intended for efficient nc-Si : H solar cells are usually made at the transition to the nanocrystalline regime using the plasma-enhanced chemical vapor deposition (PECVD) process. This change occurs within a sensitive process window and is affected by various deposition parameters. This paper reports a study of nc-Si : H films' fabrication by utilizing systematic plasma diagnostics. This work presents a novel approach for plasma processing using radio frequency (RF), ultra high frequency (UHF) and RF/UHF hybrid plasmas. Using careful analysis, efforts are made to investigate the radicals and plasma formation by changing the operating source power and silane (SiH4) concentration. The aim of this work is also to investigate the PECVD process and conditions favorable for the synthesis of nc-Si : H film. For the present study, we systematically use the optical emission spectroscopy (OES), normal, and RF-compensated Langmuir probe (LP) and vacuum ultraviolet absorption spectroscopy diagnostics. Measurements reveal that the OES diagnostic is consistent with the LP measurements. Investigation reveals that UHF power in addition to RF enables higher dissociation of H or SiH radicals and the production of higher plasma density. The combined effect of both RF and UHF sources is used as the hybrid plasma source. Measurements also reveal that inbetween SiH4 flow rates ˜20-30 sccm, there is significant change in the plasma characteristics that denotes the nc-Si : H-a-Si : H transition region. An atomic hydrogen density (nH) in the range ≈(8 - 10) × 1011 cm-3 and plasma density n0 ≈ (2 - 3) × 1011 cm-3 with a silane to hydrogen ratio of 1-2% with high crystallinity has been obtained. Along with the discussion on the effect of frequency on plasma chemistry, this explains the RF power coupling and the role of electrons and ions in plasmas with increasing frequency.

  16. Electron kinetic effects on optical diagnostics in fusion plasmas

    SciTech Connect

    Mirnov, V. V.; Den Hartog, D. J.; Duff, J.; Parke, E.; Brower, D. L. Ding, W. X.

    2014-08-21

    At anticipated high electron temperatures in ITER, the effects of electron thermal motion on Thomson scattering (TS), toroidal interferometer/polarimeter (TIP) and poloidal polarimeter (PoPola) diagnostics will be significant and must be accurately treated. We calculate electron thermal corrections to the interferometric phase and polarization state of an EM wave propagating along tangential and poloidal chords (Faraday and Cotton-Mouton polarimetry) and perform analysis of the degree of polarization for incoherent TS. The precision of the previous lowest order linear in τ = T{sub e}/m{sub e}c{sup 2} model may be insufficient; we present a more precise model with τ{sup 2}-order corrections to satisfy the high accuracy required for ITER TIP and PoPola diagnostics. The linear model is extended from Maxwellian to a more general class of anisotropic electron distributions that allows us to take into account distortions caused by equilibrium current, ECRH and RF current drive effects. The classical problem of degree of polarization of incoherent Thomson scattered radiation is solved analytically exactly without any approximations for the full range of incident polarizations, scattering angles, and electron thermal motion from non-relativistic to ultra-relativistic. The results are discussed in the context of the possible use of the polarization properties of Thomson scattered light as a method of T{sup e} measurement relevant to ITER operational scenarios.

  17. Micro-plasma Luminescence And Signal Noise Used To Solar Cells Defects Diagnostic

    NASA Astrophysics Data System (ADS)

    Jiri, Vanek; Pavel, Koktavy; Jan, Dolensky; Ales, Vesely; Zdenek, Chobola; Petr, Paracka

    2009-04-01

    This work deals with the usage of signal noise and micro-plasmas luminescence for solar cells diagnostic. When high electric field is applied to PN junction of solar cell with some technological imperfections it produces in tiny areas of enhanced impact ionization called micro-plasmas which could lead to deterioration in quality or destruction of PN junction. On this account it is possible to use methods which indicate presence of micro-plasma in junction and enable quality and quantitative description of tested cells.

  18. Tracer-encapsulated pellet injector for plasma diagnostics

    SciTech Connect

    Sudo, S.; Viniar, I.; Lukin, A.; Reznichenko, P.; Umov, A.

    2005-05-15

    An injector for making solid hydrogen pellets around impurity cores has been developed for plasma transport study in large helical device. A technique has been employed for automatic loading carbon or polystyrene cores of 0.2 mm diameter from a gun magazine to a light-gas gun barrel. The injector is equipped with a cryocooler and is able to form a 3.2 mm long and 3 mm diameter cylindrical solid hydrogen pellet at 7-8 K with an impurity core in its center within 6 min and to inject it in the light-gas gun up to 1 km/s.

  19. Spectral diagnostics of laser erosion plasma of mercury chalcogenide targets

    NASA Astrophysics Data System (ADS)

    Kotlyarchuk, B. K.; Popovych, D. I.; Savchuk, V. K.; Savitsky, V. G.

    1995-11-01

    The article sets out to investigate spatial-time and spectral characteristics of laser erosive vapor-plasma torch (EVT), formed at the vaporization of mercury chalcogenines targets. Its influence on the synthesis processes of HgTe and CdHgTe layers, condensed in mercury vapor, is described. It is shown that the laser radiation flux density and Hg vapor pressure in the reaction chamber are dominating factors which determine the character of gas-dynamic spread and EVT composition of mercury chalcogenides targets.

  20. MFTF-B plasma-diagnostics-system instrumentation and data-acquisition system

    SciTech Connect

    Goerz, D.A.; Lau, N.H.C.; Mead, J.E.; Throop, A.L.

    1981-10-21

    The change of scope for MFTF from a simple mirror to a tandem mirror configuration utilizing thermal barriers has expanded the range of plasma parameters and increased the requirements of the plasma diagnostics system. The instrument set that is needed for start-up operation has been identified and conceptual design work is proceeding. This paper describes the diagnostic instrumentation as presently envisioned for start-up operation, with a summary of the detectors and data channels. Also presented is an overview of the current conceptual design for the Local Control and Data Acquisition System and the Data Processing and Display system. As more detailed design is done, the exact number and nature of instruments may change, but overall, the system described here is one expected to satisfy the requirements for start-up and be expandable to the basic set of diagnostics.

  1. Temperature diagnostics of ECR plasma by measurement of electron bremsstrahlung

    SciTech Connect

    Kasthurirangan, S.; Agnihotri, A. N.; Desai, C. A.; Tribedi, L. C.

    2012-07-15

    The x-ray bremsstrahlung spectrum emitted by the electron population in a 14.5 GHz ECR plasma source has been measured using a NaI(Tl) detector, and hence the electron temperature of the higher energy electron population in the plasma has been determined. The x-ray spectra for Ne and Ar gases have been systematically studied as a function of inlet gas pressure from 7 Multiplication-Sign 10{sup -7} mbar to 7 Multiplication-Sign 10{sup -5} mbar and for input microwave power {approx}1 W to {approx}300 W. At the highest input power and optimum pressure conditions, the end point bremsstrahlung energies are seen to reach {approx}700 keV. The estimated electron temperatures (T{sub e}) were found to be in the range 20 keV-80 keV. The T{sub e} is found to be peaking at a pressure of 1 Multiplication-Sign 10{sup -5} mbar for both gases. The T{sub e} is seen to increase with increasing input power in the intermediate power region, i.e., between 100 and 200 W, but shows different behaviour for different gases in the low and high power regions. Both gases show very weak dependence of electron temperature on inlet gas pressure, but the trends in each gas are different.

  2. Optical and electrical diagnostics of fluorocarbon plasma etching processes

    NASA Astrophysics Data System (ADS)

    Booth, Jean-Paul

    1999-05-01

    This article reviews recent work concerning the role of CF and CF2 radicals in etching and polymerization processes occurring in capacitively coupled radio-frequency plasmas in fluorocarbon gases used for the selective etching of SiO2 layers in microelectronic device fabrication. Laser-induced fluorescence (LIF) was used to determine time-resolved axial concentration profiles of these species in continuous and pulse-modulated CF4 and C2F6 plasmas. Calibration techniques, including broad-band UV absorption spectroscopy, were developed to put the LIF measurements on an absolute scale. A novel technique was used to determine the ion flux to the reactor walls in these polymerizing environments. The mass distribution of the ions arriving at the reactor walls was determined using a quadrupole mass spectrometer. It was found that CFx radicals are produced predominantly by the reflection of neutralized and dissociated CFx+ ions at the powered electrode surface. When the fluorine atom concentration is high, the CFx radicals are destroyed effectively by recombination catalysed by the reactor walls. When the fluorine atom concentration is lowered, the CF2 concentration rises markedly, and it participates in gas-phase oligomerization processes, forming large CxFy molecules and, after ionization, large CxFy+ ions. These species appear to be the true polymer precursors. This mechanism explains the well known correlation between high CF2 concentrations, polymer deposition and SiO2 over Si etch selectivity.

  3. Plasma Sources for Medical Applications - A Comparison of Spot Like Plasmas and Large Area Plasmas

    NASA Astrophysics Data System (ADS)

    Weltmann, Klaus-Dieter

    2015-09-01

    Plasma applications in life science are currently emerging worldwide. Whereas today's commercially available plasma surgical technologies such as argon plasma coagulation (APC) or ablation are mainly based on lethal plasma effects on living systems, the newly emerging therapeutic applications will be based on selective, at least partially non-lethal, possibly stimulating plasma effects on living cells and tissue. Promising results could be obtained by different research groups worldwide revealing a huge potential for the application of low temperature atmospheric pressure plasma in fields such as tissue engineering, healing of chronic wounds, treatment of skin diseases, tumor treatment based on specific induction of apoptotic processes, inhibition of biofilm formation and direct action on biofilms or treatment of dental diseases. The development of suitable and reliable plasma sources for the different therapies requires an in-depth knowledge of their physics, chemistry and parameters. Therefore much basic research still needs to be conducted to minimize risk and to provide a scientific fundament for new plasma-based medical therapies. It is essential to perform a comprehensive assessment of physical and biological experiments to clarify minimum standards for plasma sources for applications in life science and for comparison of different sources. One result is the DIN-SPEC 91315, which is now open for further improvements. This contribution intends to give an overview on the status of commercial cold plasma sources as well as cold plasma sources still under development for medical use. It will discuss needs, prospects and approaches for the characterization of plasmas from different points of view. Regarding the manageability in everyday medical life, atmospheric pressure plasma jets (APPJ) and dielectric barrier discharges (DBD) are of special interest. A comprehensive risk-benefit assessment including the state of the art of commercial sources for medical use

  4. Diffusing Wave Spectroscopy: Application for Blood Diagnostics

    NASA Astrophysics Data System (ADS)

    Meglinski, Igor; Tuchin, Valery V.

    This chapter describes the application of diffusing wave spectroscopy (DWS) for noninvasive characterization of skin blood flow and skin blood microcirculation in vivo. The DWS is a simple but ingenious approach, utilizing the loss of correlation of scattered laser light to observe the structural changes and displacement of scattering particles, such as red blood cells (RBC) within the biological tissues. This approach has the potential to be so specific that it can revolutionize the currently developed techniques for blood flow monitoring. Developments in DWS are likely to lead it to be used for characterization of skin blood microcirculation, to assess burn depth, to diagnose atherosclerotic disease, and investigate mechanisms of photodynamic therapy for cancer treatment, as well as to monitor pharmacological intervention for failing surgical skin flaps or replants.

  5. Analysis of measurement errors for Thomson diagnostics of non-Maxwellian plasmas in tokamak reactors

    NASA Astrophysics Data System (ADS)

    Sdvizhenskii, P. A.; Kukushkin, A. B.; Kurskiev, G. S.; Mukhin, E. E.; Bassan, M.

    2016-01-01

    The study is stimulated by the expected noticeable deviation of the electron velocity distribution function (eVDF) from a Maxwellian under condition of a strong auxiliary heating of electron plasmas in tokamak-reactors. The key principles of accuracy estimation of the Thomson scattering diagnostic of non-Maxwellian plasmas in tokamak-reactors are presented. The algorithm extends the conventional approach to the assessment of non-Maxwellian plasmas measurements errors for a broad class of deviations of the eVDF from a Maxwellian. The algorithm is based on solving the inverse problem many times to determine main parameters of the eVDF with allowance for all possible sources of error and statistical variation of the input parameters of the problem. The method is applied to a preliminary analysis of the advantages of the formerly suggested use of various wavelengths of probing laser radiation in the Thomson diagnostics of non-Maxwellian plasma on the example of the core plasma Thomson scattering diagnostic system which is under design for ITER tokamak. The results obtained confirm the relevance of the diversification of the probing laser radiation wavelength.

  6. Development of the Zebra load region for increased capability plasma diagnostics and improved Leopard laser access

    NASA Astrophysics Data System (ADS)

    Astanovitskiy, Alexey; Presura, R.; Ivanov, V. V.; Haboub, A.; Plachaty, C.; Kindel, J. M.

    2008-11-01

    A new geometry for the load area in the Zebra (1MA pulse generator) is developed. It will form the basis for future experiments requiring Leopard (1057nm, 50TW laser) to Zebra coupling and give extended capability to z-pinch diagnostics. This required the development of a new current return, which allows laser access and installation of the OD 4'' parabolic mirror for the x-ray radiography, isochoric heating and magnetized plasma experiments, and accommodates wire-array z-pinch loads, to which the laser may then be coupled. In addition, this configuration allows diagnostics access close to the plasma, leading to a significant increase of the spatial resolution for imaging of z-pinches, as well as the photon flux in imaging and spectroscopy of laser produced plasmas. These diagnostics will allow coupling of the Leopard beam for x-ray laser probing of the pinch plasma and we will test point-projection x-ray backlighting of the pinch plasma.

  7. Operation of a multiple cell array detector in plasma experiments with a heavy ion beam diagnostic

    SciTech Connect

    Goncalves, B.; Malaquias, A.; Nedzelskiy, I. S.; Pereira, L.; Silva, C.; Varandas, C.A.F.; Cabral, J.A.C.; Khrebtov, S.M.; Dreval, N.B.; Krupnik, L.I.; Hidalgo, C.; Depablos, J.

    2004-10-01

    A multiple cell array detector (MCAD) has been developed to investigate the spatial structure of plasma turbulence in fusion plasmas. This system is expected to provide simultaneous measurements of edge and core density fluctuations with both temporal and spatial resolution, extending the range and number of the sample volumes simultaneously recorded by a heavy ion beam diagnostic (HIBD). Since the detector (usually located close to the vessel wall of a plasma device) operates in a strong plasma radiation environment, the effective shielding of the detector presents a special problem. This article describes and compares the MCAD operation conditions on ISTTOK tokamak and TJ-II stellarator. Experimental results of the detector performance are presented together with the first measurements of n{sub e}{sigma}{sub eff} in the TJ-II plasmas.

  8. Microfluidic blood plasma separation for medical diagnostics: is it worth it?

    PubMed

    Mielczarek, W S; Obaje, E A; Bachmann, T T; Kersaudy-Kerhoas, M

    2016-09-21

    Circulating biomarkers are on the verge of becoming powerful diagnostic tools for various human diseases. However, the complex sample composition makes it difficult to detect biomarkers directly from blood at the bench or at the point-of-care. Blood cells are often a source of variability of the biomarker signal. While the interference of hemoglobin is a long known source of variability, the release of nucleic acids and other cellular components from hemocytes is a new concern for measurement and detection of circulating extracellular markers. Research into miniaturised blood plasma separation has been thriving in the last 10 years (2006-2016). Most point-of-care systems need microscale blood plasma separation, but developed solutions differ in complexity and sample volume range. But could blood plasma separation be avoided completely? This focused review weights the advantages and limits of miniaturised blood plasma separation and highlights the most interesting advances in direct capture as well as smart blood plasma separation. PMID:27502438

  9. Electron density diagnostics using B-like and C-like iron ndarrow2p (n=3 to 6) transitions in fusion and astrophysical plasmas

    NASA Astrophysics Data System (ADS)

    Chen, H.; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.

    2001-10-01

    The idea of using L-shell iron spectroscopic information as electron density diagnostics is not only of interest for fusion plasmas, where the iron maybe indigenous to the plasma, it also has become very attractive for diagnosing astrophysical plasmas following the availability of high-resolution data measured by current x-ray observatories. Using the Livermore electron beam ion trap EBIT-II, we measured density dependent ndarrow2p line (n=3 to 6) intensities in Fe XXII and Fe XXI. We compared the experimental data with detailed atomic models using the HULLAC code. We present the analysis of these transitions and a discussion of their diagnostic applications to fusion and astrophysical plasmas. This work was performed under the auspices of DOE by UC-LLNL under contract W-7405-Eng-48 and supported by NASA SARA grants to LLNL, GSFC, and Columbia University.

  10. A Review of Diagnostic Techniques for ISHM Applications

    NASA Technical Reports Server (NTRS)

    Patterson-Hine, Ann; Biswas, Gautam; Aaseng, Gordon; Narasimhan, Sriam; Pattipati, Krishna

    2005-01-01

    System diagnosis is an integral part of any Integrated System Health Management application. Diagnostic applications make use of system information from the design phase, such as safety and mission assurance analysis, failure modes and effects analysis, hazards analysis, functional models, fault propagation models, and testability analysis. In modern process control and equipment monitoring systems, topological and analytic , models of the nominal system, derived from design documents, are also employed for fault isolation and identification. Depending on the complexity of the monitored signals from the physical system, diagnostic applications may involve straightforward trending and feature extraction techniques to retrieve the parameters of importance from the sensor streams. They also may involve very complex analysis routines, such as signal processing, learning or classification methods to derive the parameters of importance to diagnosis. The process that is used to diagnose anomalous conditions from monitored system signals varies widely across the different approaches to system diagnosis. Rule-based expert systems, case-based reasoning systems, model-based reasoning systems, learning systems, and probabilistic reasoning systems are examples of the many diverse approaches ta diagnostic reasoning. Many engineering disciplines have specific approaches to modeling, monitoring and diagnosing anomalous conditions. Therefore, there is no "one-size-fits-all" approach to building diagnostic and health monitoring capabilities for a system. For instance, the conventional approaches to diagnosing failures in rotorcraft applications are very different from those used in communications systems. Further, online and offline automated diagnostic applications are integrated into an operations framework with flight crews, flight controllers and maintenance teams. While the emphasis of this paper is automation of health management functions, striking the correct balance between

  11. EUV spectroscopic plasma diagnostics for the solar wind acceleration region

    NASA Technical Reports Server (NTRS)

    Kohl, J. L.; Withbroe, G. L.

    1982-01-01

    Possibilities are considered for probing physical conditions in the solar corona with strong EUV resonance lines from ions such as N V, O VI, Ne VIII, Mg X, and Si XII. Through measurements of the intensities and profiles of EUV spectral lines with coronagraphic instrumentation employing normal incidence reflecting optics, it is possible to acquire information on electron, proton, and ion temperatures and velocity distributions; electron, H I, and ion densities; mass flow and nonthermal velocities; and chemical abundances. This information will provide critical empirical constraints on physical processes responsible for plasma heating, solar wind acceleration, and transport of mass, momentum, and energy in the solar corona, as well as providing constraints on theoretical models for solar and stellar coronae and mass loss.

  12. Process control using new approaches in plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Reeves, Steve; Fullwood, Clayton; Turner, Terry R.

    1994-09-01

    As semiconductor processing requirements evolve to meet the demands of decreasing geometries, new approached in plasma metrology will be needed to monitor the performances of the equipment and its processes. This performance has traditionally been monitored via Statistical Process Control (SPC) on output parameters such as etch rate and uniformity. These measurements are typically taken on single film wafers which may not be an accurate representation of product. With emerging, nonintrusive, RF sensor technology, equipment and process engineers have access to signals which provide better resolution in determining the health of the equipment. This paper will discuss the relationships between machine settings, real-time RF sensor measurements and the etch rate and uniformity metrics typically used in machine/process qualifications. Run to run control algorithms using the RF sensor measurements will also be presented. Finally, the implications of using RF sensor measurements to provide real-time closed loop control of machine settings will be discussed.

  13. Basis set expansion for inverse problems in plasma diagnostic analysis.

    PubMed

    Jones, B; Ruiz, C L

    2013-07-01

    A basis set expansion method [V. Dribinski, A. Ossadtchi, V. A. Mandelshtam, and H. Reisler, Rev. Sci. Instrum. 73, 2634 (2002)] is applied to recover physical information about plasma radiation sources from instrument data, which has been forward transformed due to the nature of the measurement technique. This method provides a general approach for inverse problems, and we discuss two specific examples relevant to diagnosing fast z pinches on the 20-25 MA Z machine [M. E. Savage, L. F. Bennett, D. E. Bliss, W. T. Clark, R. S. Coats, J. M. Elizondo, K. R. LeChien, H. C. Harjes, J. M. Lehr, J. E. Maenchen, D. H. McDaniel, M. F. Pasik, T. D. Pointon, A. C. Owen, D. B. Seidel, D. L. Smith, B. S. Stoltzfus, K. W. Struve, W. A. Stygar, L. K. Warne, J. R. Woodworth, C. W. Mendel, K. R. Prestwich, R. W. Shoup, D. L. Johnson, J. P. Corley, K. C. Hodge, T. C. Wagoner, and P. E. Wakeland, in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, 2007), p. 979]. First, Abel inversion of time-gated, self-emission x-ray images from a wire array implosion is studied. Second, we present an approach for unfolding neutron time-of-flight measurements from a deuterium gas puff z pinch to recover information about emission time history and energy distribution. Through these examples, we discuss how noise in the measured data limits the practical resolution of the inversion, and how the method handles discontinuities in the source function and artifacts in the projected image. We add to the method a propagation of errors calculation for estimating uncertainties in the inverted solution. PMID:23902066

  14. Basis set expansion for inverse problems in plasma diagnostic analysis

    NASA Astrophysics Data System (ADS)

    Jones, B.; Ruiz, C. L.

    2013-07-01

    A basis set expansion method [V. Dribinski, A. Ossadtchi, V. A. Mandelshtam, and H. Reisler, Rev. Sci. Instrum. 73, 2634 (2002)], 10.1063/1.1482156 is applied to recover physical information about plasma radiation sources from instrument data, which has been forward transformed due to the nature of the measurement technique. This method provides a general approach for inverse problems, and we discuss two specific examples relevant to diagnosing fast z pinches on the 20-25 MA Z machine [M. E. Savage, L. F. Bennett, D. E. Bliss, W. T. Clark, R. S. Coats, J. M. Elizondo, K. R. LeChien, H. C. Harjes, J. M. Lehr, J. E. Maenchen, D. H. McDaniel, M. F. Pasik, T. D. Pointon, A. C. Owen, D. B. Seidel, D. L. Smith, B. S. Stoltzfus, K. W. Struve, W. A. Stygar, L. K. Warne, J. R. Woodworth, C. W. Mendel, K. R. Prestwich, R. W. Shoup, D. L. Johnson, J. P. Corley, K. C. Hodge, T. C. Wagoner, and P. E. Wakeland, in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, 2007), p. 979]. First, Abel inversion of time-gated, self-emission x-ray images from a wire array implosion is studied. Second, we present an approach for unfolding neutron time-of-flight measurements from a deuterium gas puff z pinch to recover information about emission time history and energy distribution. Through these examples, we discuss how noise in the measured data limits the practical resolution of the inversion, and how the method handles discontinuities in the source function and artifacts in the projected image. We add to the method a propagation of errors calculation for estimating uncertainties in the inverted solution.

  15. Basis set expansion for inverse problems in plasma diagnostic analysis

    SciTech Connect

    Jones, B.; Ruiz, C. L.

    2013-07-15

    A basis set expansion method [V. Dribinski, A. Ossadtchi, V. A. Mandelshtam, and H. Reisler, Rev. Sci. Instrum. 73, 2634 (2002)] is applied to recover physical information about plasma radiation sources from instrument data, which has been forward transformed due to the nature of the measurement technique. This method provides a general approach for inverse problems, and we discuss two specific examples relevant to diagnosing fast z pinches on the 20–25 MA Z machine [M. E. Savage, L. F. Bennett, D. E. Bliss, W. T. Clark, R. S. Coats, J. M. Elizondo, K. R. LeChien, H. C. Harjes, J. M. Lehr, J. E. Maenchen, D. H. McDaniel, M. F. Pasik, T. D. Pointon, A. C. Owen, D. B. Seidel, D. L. Smith, B. S. Stoltzfus, K. W. Struve, W. A. Stygar, L. K. Warne, J. R. Woodworth, C. W. Mendel, K. R. Prestwich, R. W. Shoup, D. L. Johnson, J. P. Corley, K. C. Hodge, T. C. Wagoner, and P. E. Wakeland, in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, 2007), p. 979]. First, Abel inversion of time-gated, self-emission x-ray images from a wire array implosion is studied. Second, we present an approach for unfolding neutron time-of-flight measurements from a deuterium gas puff z pinch to recover information about emission time history and energy distribution. Through these examples, we discuss how noise in the measured data limits the practical resolution of the inversion, and how the method handles discontinuities in the source function and artifacts in the projected image. We add to the method a propagation of errors calculation for estimating uncertainties in the inverted solution.

  16. Application of Dusty Plasmas for Space

    NASA Astrophysics Data System (ADS)

    Bhavasar, Hemang; Ahuja, Smariti

    plasmas, dust particles are actually grown in the discharge from the reactive gases used to form the plasmas. Perhaps the most intriguing aspect of dusty plasmas is that the particles can be directly imaged and their dynamic behavior recorded as digital images. This is accomplished by laser light scattering from the particles. Since the particle mass is relatively high, their dynamical timescales are much longer than that of the ions or electrons. Dusty plasmas has a broad range of applications including interplanetary space dust, comets, planetary rings, dusty surfaces in space, and aerosols in the atmosphere.

  17. Recent Progress in Nanomedicine: Therapeutic, Diagnostic and Theranostic Applications

    PubMed Central

    Rizzo, Larissa Y.; Theek, Benjamin; Storm, Gert; Kiessling, Fabian; Lammers, Twan

    2013-01-01

    In recent years, the use of nanomedicine formulations for therapeutic and diagnostic applications has increased exponentially. Many different systems and strategies have been developed for drug targeting to pathological sites, as well as for visualizing and quantifying important (patho-) physiological processes. In addition, ever more efforts have been undertaken to combine diagnostic and therapeutic properties within a single nanomedicine formulation. These so-called nanotheranostics are able to provide valuable information on drug delivery, drug release and drug efficacy, and they are considered to be highly useful for personalizing nanomedicine-based (chemo-) therapeutic interventions. PMID:23578464

  18. Study on re-sputtering during CNx film deposition through spectroscopic diagnostics of plasma

    NASA Astrophysics Data System (ADS)

    Liang, Peipei; Yang, Xu; Li, Hui; Cai, Hua; Sun, Jian; Xu, Ning; Wu, Jiada

    2015-10-01

    A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CNx) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CNx film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N2 gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CNx film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CNx film growth. The other one represents the CN radicals re-sputtered from the growing CNx film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features.

  19. The Buffer Diagnostic Prototype: A fault isolation application using CLIPS

    NASA Technical Reports Server (NTRS)

    Porter, Ken

    1994-01-01

    This paper describes problem domain characteristics and development experiences from using CLIPS 6.0 in a proof-of-concept troubleshooting application called the Buffer Diagnostic Prototype. The problem domain is a large digital communications subsystems called the real-time network (RTN), which was designed to upgrade the launch processing system used for shuttle support at KSC. The RTN enables up to 255 computers to share 50,000 data points with millisecond response times. The RTN's extensive built-in test capability but lack of any automatic fault isolation capability presents a unique opportunity for a diagnostic expert system application. The Buffer Diagnostic Prototype addresses RTN diagnosis with a multiple strategy approach. A novel technique called 'faulty causality' employs inexact qualitative models to process test results. Experimental knowledge provides a capability to recognize symptom-fault associations. The implementation utilizes rule-based and procedural programming techniques, including a goal-directed control structure and simple text-based generic user interface that may be reusable for other rapid prototyping applications. Although limited in scope, this project demonstrates a diagnostic approach that may be adapted to troubleshoot a broad range of equipment.

  20. Local area network for the plasma diagnostics system of MFTF-B

    SciTech Connect

    Lau, N.H.; Minor, E.G.

    1983-01-01

    The MFTF-B Plasma Diagnostics System will be implemented in stages, beginning with a start-up set of diagnostics and evolving toward a basic set. The start-up set contains 12 diagnostics which will acquire a total of about 800 Kbytes of data per machine pulse; the basic set contains 23 diagnostics which will acquire a total of about 8 Mbytes of data per pulse. Each diagnostic is controlled by a Foundation System consisting of a DEC LSI-11/23 microcomputer connected to CAMAC via a 5 Mbits/second serial fiber-optic link and connected to a supervisory computer (Perkin-Elmer 3250) via a 9600 baud RS232 link. The Foundation System is a building block used throughout MFTF-B for control and status monitoring. However, its 9600 baud link to the supervisor presents a bottleneck for the large data transfers required by diagnostics. To overcome this bottleneck the diagnostics Foundation Systems will be connected together with an additional LSI-11/23 called the master to form a Local Area Network (LAN) for data acquisition.

  1. The Multiple Resonance Probe: A Novel Device for Industry Compatible Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brinkmann, Ralf Peter; Storch, Robert; Lapke, Martin; Oberrath, Jens; Schulz, Christian; Styrnoll, Tim; Zietz, Christian; Awakowicz, Peter; Musch, Thomas; Mussenbrock, Thomas; Rolfes, Ilona

    2012-10-01

    To be useful for the supervision or control of technical plasmas, a diagnostic method must be i) robust and stable, ii) insensitive to perturbation by the process, iii) itself not perturbing the process, iv) clearly and easily interpretable without the need for calibration, v) compliant with the requirements of process integration, and, last but not least, vi) economical in terms of investment, footprint, and maintenance. Plasma resonance spectroscopy, exploiting the natural ability of plasmas to resonate on or near the electron plasma frequency, provides a good basis for such an ``industry compatible'' plasma diagnostics. The contribution will describe the general idea of active plasma resonance spectroscopy and introduce a mathematical formalism for its analysis. It will then focus on the novel multipole resonance probe (MRP), where the excited resonances can be classified explicitly and the connection between the probe response and the desired electron density can be cast as a simple formula. The current state of the MRP project will be described, including the experimental characterization of a prototype in comparison with Langmuir probes, and the development of a specialized measurement circuit.

  2. Matched dipole probe for magnetized low electron density laboratory plasma diagnostics

    SciTech Connect

    Rafalskyi, Dmytro; Aanesland, Ane

    2015-07-15

    In this paper, a diagnostic method for magnetized and unmagnetized laboratory plasma is proposed, based on impedance measurements of a short matched dipole. The range of the measured electron densities is limited to low density plasmas (10{sup 12}–10{sup 15 }m{sup −3}), where other diagnostic methods have strong limitations on the magnetic field strength and topology, plasma dimensions, and boundary conditions. The method is designed for use in both large- and small-dimension plasma (<10 cm) without or with strong non-homogeneous magnetic field, which can be undefined within the probe size. The design of a matched dipole probe allows to suppress the sheath resonance effects and to reach high sensitivity at relatively small probe dimensions. Validation experiments are conducted in both magnetized (B ∼ 170 G) and unmagnetized (B = 0) low density (7 × 10{sup 12 }m{sup −3}–7 × 10{sup 13 }m{sup −3}) low pressure (1 mTorr) 10 cm scale plasmas. The experimentally measured data show very good agreement with an analytical theory both for a non-magnetized and a magnetized case. The electron density measured by the matched dipole and Langmuir probes in the range of 7 × 10{sup 12 }m{sup −3}–7 × 10{sup 13 }m{sup −3} show less than 30% difference. An experimentally measured tolerance/uncertainty of the dipole probe method is estimated to ±1% for plasma densities above 2 × 10{sup 13 }m{sup −3}. A spatial resolution is estimated from the experiments to be about 3d, where d is the dipole diameter. The diagnostic method is also validated by comparing the measured plasma impedance curves with results of analytical modelling.

  3. Laser diagnostics on atmospheric-pressure low-temperature helium pulsed plasmas in room- and cryogenic-temperature environments

    NASA Astrophysics Data System (ADS)

    Sakakibara, Noritaka; Muneoka, Hitoshi; Urabe, Keiichiro; Yasui, Ryoma; Terashima, Kazuo

    2015-09-01

    In atmospheric-pressure low- temperature plasmas, the control of the plasma gas temperature (Tg) by a few kelvin is considered to be crucial for their applications to novel materials processing such as bio-materials. However, there have been only few studies that focused on the influence of Tg on the plasma characteristics. On the other hand, it was reported that helium metastables played a key role in the dependency of chemical reactions on Tg in helium-nitrogen plasmas. In this study, laser diagnostics were carried out in atmospheric-pressure helium pulsed plasmas near or below room temperature, at 340 -100 K. Parallel electrodes of copper rods (diameter: 2 mm) with a gap distance of 535 μm were used and pulsed discharges with a pulse width of a few hundred nanoseconds were generated inside a reactor. The density and lifetime of helium metastables were estimated by laser absorption spectroscopy measurements and Tg was evaluated by near-infrared laser heterodyne interferometry measurements. At 300 K, the helium metastable density was 1.5 × 1013 cm-3 while the lifetime was 3.1 μs, and increase in Tg was up to 70 K. Dependency of the density and lifetime of helium metastables on Tg was observed and also discussed.

  4. Laser Thomson Scattering Diagnostics of Pulsed Filamentary Discharge Plasmas

    NASA Astrophysics Data System (ADS)

    Bolouki, Nima

    2012-10-01

    Laser Thomson scattering (LTS) has been applied to measure spatiotemporal evolution of electron density and electron temperature in a pulsed filamentary discharge. The light source of LTS is the second harmonics Nd:YAG laser with a energy of 8 mJ. Also a triple grating spectrometer (TGS) having high rejection rate for stray light is used to measure LTS spectra. In our experimental conditions, non-thermal and non-equilibrium micro-plasmas are generated at round atmospheric pressure. Moreover, the electrode set in this experiment is consisted of a needle electrode and a hemispherical electrode with an inter-electrode gap of 0.5 mm. The total electric charge that flows through the discharge channel vary from 20 nC to 850 nC by changing capacitance in electrical circuit. We could show that the total charge variation leads to increase in electron density from 10^22 m-3 to 10^23 m-3. However, the electron temperature remains almost constant at the main discharge. In order to investigate the streamer phase, we changed the gap up to 16mm, and then performed the LTS method to measure the electron density and electron temperature.

  5. Magnetic Field and Plasma Diagnostics from Coordinated Prominence Observations

    NASA Astrophysics Data System (ADS)

    Schmieder, B.; Levens, P.; Dalmasse, K.; Mein, N.; Mein, P.; Lopez-Ariste, A.; Labrosse, N.; Heinzel, P.

    2016-04-01

    We study the magnetic field in prominences from a statistical point of view, by using THEMIS in the MTR mode, performing spectropolarimetry of the He I D3 line. Combining these measurements with spectroscopic data from IRIS, Hinode/EIS as well as ground-based telescopes, such as the Meudon Solar Tower, we infer the temperature, density, and flow velocities of the plasma. There are a number of open questions that we aim to answer: - What is the general direction of the magnetic field in prominences? Is the model using a single orientation of magnetic field always valid for atypical prominences? %- Does this depend on the location of the filament on the disk (visible in Hα, in He II 304 Å) over an inversion line between weak or strong network ? - Are prominences in a weak environment field dominated by gas pressure? - Measuring the Doppler shifts in Mg II lines (with IRIS) and in Hα can tell us if there are substantial velocities to maintain vertical rotating structures, as has been suggested for tornado-like prominences. We present here some results obtained with different ground-based and space-based instruments in this framework.

  6. Diagnostic Suite for HyperV Coaxial Plasma Gun Development for the PLX- α Project

    NASA Astrophysics Data System (ADS)

    Case, Andrew; Brockington, Sam; Witherspoon, F. Douglas

    2015-11-01

    We present the diagnostic suite to be used during development of the coaxial guns HyperV will deliver to LANL in support of the ARPA-E Accelerating Low-Cost Plasma Heating And Assembly (ALPHA) program. For plasma jet diagnostics this includes fast photodiodes for velocimetry, a ballistic pendulum for measuring total plasmoid momentum, interferometry for line integrated plasma density, deflectometry for line integrated perpendicular density gradient measurements, and spectroscopy, both time resolved high resolution spectroscopy using a novel detector developed by HyperV and time integrated survey spectroscopy, for measurements of velocity and temperature as well as impurities. In addition, we plan to use fast pressure probes for stagnation pressure, a Faraday cup for density, fast imaging for plume geometry and time integrated imaging for overall light emission. A novel low resolution long record length camera developed by HyperV will also be used for plume diagnostics. For diagnostics of gun operation, we will use Rogowski coils to measure current, voltage dividers for voltages, B-dot probes for magnetic field, and time resolved fast photodiodes to measure plasmoid velocity inside the accelerator. This work supported by the ARPA-E ALPHA program.

  7. Non-linear optical diagnostic studies of high pressure non-equilibrium plasmas

    NASA Astrophysics Data System (ADS)

    Lempert, Walter

    2012-10-01

    Picosecond Coherent Anti-Stokes Raman Spectroscopy (CARS) is used for study of vibrational energy loading and relaxation kinetics in high pressure nitrogen and air nsec pulsed non-equilibrium plasmas in a pin-to-pin geometry. It is found that ˜33% of total discharge energy in a single pulse in air at 100 torr couples directly to nitrogen vibration by electron impact, in good agreement with master equation modeling predictions. However in the afterglow the total quanta in vibrational levels 0 -- 9 is found to increase by a factor of approximately 2 and 4 in nitrogen and air, respectively, a result in direct contrast to modeling results which predict the total number of quanta to be essentially constant. More detailed comparison between experiment and model show that the VDF predicted by the model during, and directly after, the discharge pulse is in good agreement with that determined experimentally, however for time delays exceeding ˜10 μsec the experimental and predicted VDFs diverge rapidly, particularly for levels v = 2 and greater. Specifically modeling predicts a rapid drop in population of high levels due to net downward V-V energy transfer whereas the experiment shows an increase in population in levels 2 and 3 and approximately constant population for higher levels. It is concluded that a collisional process is feeding high vibrational levels at a rate which is comparable to the rate at which population of the high levels is lost due to net downward V-V. A likely candidate for the source of additional vibrational quanta is the quenching of metastable electronic states of nitrogen to highly excited vibrational levels of the ground electronic state. Recent progress in the development and application of psec coherent Raman electric field and spontaneous Thomson scattering diagnostics for study of high pressure nsec pulsed plasmas will also be presented.

  8. Formation of Imploding Plasma Liners for HEDP and MIF Application

    SciTech Connect

    Witherspoon, F. Douglas; Case, Andrew; Brockington, Samuel; Messer, Sarah; Bomgardner, Richard; Phillips, Mike; Wu, Linchun; Elton, Ray

    2014-11-11

    /s for the Plasma Liner Experiment (PLX) at Los Alamos National Laboratory (LANL). Initial work used existing computational and analytical tools to develop and refine a specific plasma gun concept having a novel tapered coaxial electromagnetic accelerator contour with an array of symmetric ablative plasma injectors. The profile is designed to suppress the main barrier to success in coaxial guns, namely the blow-by instability in which the arc slips past and outruns the bulk of the plasma mass. Efforts to begin developing a set of annular non-ablative plasma injectors for the coaxial gun, in order to accelerate pure gases, resulted in development of linear parallel-plate MiniRailguns that turned out to work well as plasma guns in their own right and we subsequently chose them for an initial plasma liner experiment on the PLX facility at LANL. This choice was mainly driven by cost and schedule for that particular experiment, while longer term goals still projected use of coaxial guns for reactor-relevant applications for reasons of better symmetry, lower impurities, more compact plasma jet formation, and higher gun efficiency. Our efforts have focused mainly on 1) developing various plasma injection systems for both coax and linear railguns and ensuring they work reliably with the accelerator section, 2) developing a suite of plasma and gun diagnostics, 3) performing computational modeling to design and refine the plasma guns, 4) establishing a research facility dedicated to plasma gun development, and finally, 5) developing plasma guns and associated pulse power systems capable of achieving these goals and installing and testing the first two gun sets on the PLX facility at LANL. During the second funding cycle for this program, HyperV joined in a collaborative effort with LANL, the University of Alabama at Huntsville, and the University of New Mexico to perform a plasma liner experiment (PLX) to investigate the physics and technology of forming spherically imploding

  9. Additive manufacture (3d printing) of plasma diagnostic components and assemblies for fusion experiments

    NASA Astrophysics Data System (ADS)

    Sieck, Paul; Woodruff, Simon; Stuber, James; Romero-Talamas, Carlos; Rivera, William; You, Setthivoine; Card, Alexander

    2015-11-01

    Additive manufacturing (or 3D printing) is now becoming sufficiently accurate with a large range of materials for use in printing sensors needed universally in fusion energy research. Decreasing production cost and significantly lowering design time of energy subsystems would realize significant cost reduction for standard diagnostics commonly obtained through research grants. There is now a well-established set of plasma diagnostics, but these expensive since they are often highly complex and require customization, sometimes pace the project. Additive manufacturing (3D printing) is developing rapidly, including open source designs. Basic components can be printed for (in some cases) less than 1/100th costs of conventional manufacturing. We have examined the impact that AM can have on plasma diagnostic cost by taking 15 separate diagnostics through an engineering design using Conventional Manufacturing (CM) techniques to determine costs of components and labor costs associated with getting the diagnostic to work as intended. With that information in hand, we set about optimizing the design to exploit the benefits of AM. Work performed under DOE Contract DE-SC0011858.

  10. Use of Plasma Metabolomics to Identify Diagnostic Biomarkers for Early Stage Epithelial Ovarian Cancer

    PubMed Central

    Fan, Lijun; Yin, Mingzhu; Ke, Chaofu; Ge, Tingting; Zhang, Guangming; Zhang, Wang; Zhou, Xiaohua; Lou, Ge; Li, Kang

    2016-01-01

    The early detection of ovarian carcinoma is difficult due to the absence of recognizable physical symptoms and a lack of sensitive screening methods. The currently available biomarkers (such as CA125 and HE4) are insufficiently reliable to distinguish early stage (I/II) epithelial ovarian cancer (EOC) patients from normal individuals because they possess a relatively poor sensitivity and specificity. To evaluate the application of metabolomics to biomarker discovery in the early stages of epithelial ovarian cancer (EOC), plasma samples from 21 early stage EOC patients and 31 healthy controls were analyzed with ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-Tof/MS) in conjunction with multivariate statistical analysis. Eighteen metabolites, including lysophospholipids, 2-piperidone and MG (18:2), were found to be disturbed in early stage EOC with satisfactory diagnostic accuracy (AUC=0.920). These biomarkers were specifically validated in the EOC nude mouse model, and five of the biomarkers (lysophospholipids, adrenoyl ethanolamide et al.) were highly suspected of being associated with EOC because they were differentially expressed with the same tendency in the EOC nude mice versus normal controls. In conclusion, the selected metabolic biomarkers have considerable utility and significant potential for diagnosing early ovarian cancer and investigating its underlying mechanisms. PMID:27390602

  11. A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas.

    PubMed

    Cazzaniga, C; Nocente, M; Rebai, M; Tardocchi, M; Calvani, P; Croci, G; Giacomelli, L; Girolami, M; Griesmayer, E; Grosso, G; Pillon, M; Trucchi, D M; Gorini, G

    2014-11-01

    Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the (12)C(n, α)(9)Be reaction occurring between neutrons and (12)C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas. PMID:25430280

  12. Novel diagnostics of metabolic dysfunction detected in breath and plasma by selective isotope-assisted labeling.

    PubMed

    Haviland, Julia A; Tonelli, Marco; Haughey, Dermot T; Porter, Warren P; Assadi-Porter, Fariba M

    2012-08-01

    Metabolomics is the study of a unique fingerprint of small molecules present in biological systems under healthy and disease conditions. One of the major challenges in metabolomics is validation of fingerprint molecules to identify specifically perturbed pathways in metabolic aberrations. This step is crucial to the understanding of budding metabolic pathologies and the ability to identify early indicators of common diseases such as obesity, type 2 diabetes mellitus, metabolic syndrome, polycystic ovary syndrome, and cancer. We present a novel approach to diagnosing aberrations in glucose utilization including metabolic pathway switching in a disease state. We used a well-defined prenatally exposed glucocorticoid mouse model that results in adult females with metabolic dysfunction. We applied the complementary technologies of nuclear magnetic resonance spectroscopy and cavity ring-down spectroscopy to analyze serial plasma samples and real-time breath measurements following selective (13)C-isotope-assisted labeling. These platforms allowed us to trace metabolic markers in whole animals and identify key metabolic pathway switching in prenatally glucocorticoid-treated animals. Total glucose flux is significantly proportionally increased through the major oxidative pathways of glycolysis and the pentose phosphate pathway in the prenatally glucocorticoid-treated animals relative to the control animals. This novel diagnostics approach is fast, noninvasive, and sensitive for determining specific pathway utilization, and provides a direct translational application in the health care field. PMID:22304834

  13. Novel diagnostics of metabolic dysfunction detected in breath and plasma by selective isotope assisted labeling (SIAL)

    PubMed Central

    Haviland, Julia A.; Tonelli, Marco; Haughey, Dermot T.; Porter, Warren P.; Assadi-Porter, Fariba M.

    2012-01-01

    OBJECTIVE Metabolomics is the study of a unique fingerprint of small molecules present in biological systems under healthy and disease conditions. One of the major challenges in metabolomics is validation of fingerprint molecules to identify specifically perturbed pathways in metabolic aberrations. This step is crucial to the understanding of budding metabolic pathologies and the ability to identify early indicators of common diseases such as obesity, diabetes mellitus type II, metabolic syndrome, polycystic ovary syndrome, and cancer. We present a novel approach to diagnosing aberrations in glucose utilization including metabolic pathway switching in a disease state. METHODS We used a well-defined prenatally exposed glucocorticoid mouse model that results in adult females with metabolic dysfunction. We applied the complementary technologies of nuclear magnetic resonance spectroscopy, and cavity ringdown spectroscopy to analyze serial plasma samples and real-time breath measurements following selective 13C-isotope assisted labeling (SIAL). These platforms allowed us to trace metabolic markers in whole animals and identify key metabolic pathway switching in prenatally glucocorticoid-treated animals. RESULTS Total glucose flux is significantly proportionally increased through the major oxidative pathways of glycolysis and the pentose phosphate pathway in the prenatally glucocorticoid-treated animals relative to the control animals. CONCLUSION This novel diagnostics approach is fast, non-invasive and sensitive for determining specific pathway utilization, and provides a direct translational application in the healthcare field. PMID:22304834

  14. A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas

    NASA Astrophysics Data System (ADS)

    Cazzaniga, C.; Nocente, M.; Rebai, M.; Tardocchi, M.; Calvani, P.; Croci, G.; Giacomelli, L.; Girolami, M.; Griesmayer, E.; Grosso, G.; Pillon, M.; Trucchi, D. M.; Gorini, G.

    2014-11-01

    Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the 12C(n, α)9Be reaction occurring between neutrons and 12C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas.

  15. A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas

    SciTech Connect

    Cazzaniga, C. Nocente, M.; Gorini, G.; Rebai, M.; Giacomelli, L.; Tardocchi, M.; Croci, G.; Grosso, G.; Calvani, P.; Girolami, M.; Trucchi, D. M.; Griesmayer, E.; Pillon, M.

    2014-11-15

    Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the {sup 12}C(n, α){sup 9}Be reaction occurring between neutrons and {sup 12}C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas.

  16. Some historic and current aspects of plasma diagnostics using atomic spectroscopy

    NASA Astrophysics Data System (ADS)

    Hutton, Roger; Zou, Yaming; Andersson, Martin; Brage, Tomas; Martinson, Indrek

    2010-07-01

    In this paper we give a short introduction to the use of atomic spectroscopy in plasma diagnostics. Both older works and exciting new branches of atomic physics, which have relevance to diagnostics, are discussed. In particular we focus on forbidden lines in Be-like ions, lines sensitive to magnetic fields and levels which have a lifetime dependence on the nuclear spin of the ion, i.e. f-dependent lifetimes. Finally we mention a few examples of where tokamaks, instead of needing atomic data, actually provide new data and lead to developments in atomic structure studies. This paper is dedicated to the memory of Nicol J Peacock (1931-2008), a distinguished plasma scientist who contributed much to the field of spectroscopy applied to plasma, and in particular, fusion plasma diagnostics. During the final stages of the preparation of this paper Professor Indrek Martinson passed away peacefully in his sleep on 14 November 2009. Indrek will be greatly missed by many people, both for his contributions to atomic spectroscopy and for his great kindness and friendliness, which many of us experienced.

  17. Influence of plasma diagnostics and constraints on the quality of equilibrium reconstructions on Joint European Torus.

    PubMed

    Gelfusa, M; Murari, A; Lupelli, I; Hawkes, N; Gaudio, P; Baruzzo, M; Brix, M; Craciunescu, T; Drozdov, V; Meigs, A; Peluso, E; Romanelli, M; Schmuck, S; Sieglin, B

    2013-10-01

    One of the main approaches to thermonuclear fusion relies on confining high temperature plasmas with properly shaped magnetic fields. The determination of the magnetic topology is, therefore, essential for controlling the experiments and for achieving the required performance. In Tokamaks, the reconstruction of the fields is typically formulated as a free boundary equilibrium problem, described by the Grad-Shafranov equation in toroidal geometry and axisymmetric configurations. Unfortunately, this results in mathematically very ill posed problems and, therefore, the quality of the equilibrium reconstructions depends sensitively on the measurements used as inputs and on the imposed constraints. In this paper, it is shown how the different diagnostics (Magnetics Measurements, Polarimetry and Motional Stark Effect), together with the edge current density and plasma pressure constraints, can have a significant impact on the quality of the equilibrium on JET. Results show that both the Polarimetry and Motional Stark Effect internal diagnostics are crucial in order to obtain reasonable safety factor profiles. The impact of the edge current density constraint is significant when the plasma is in the H-mode of confinement. In this plasma scenario the strike point positions and the plasma last closed flux surface can change even by centimetres, depending on the edge constraints, with a significant impact on the remapping of the equilibrium-dependent diagnostics and of pedestal physics studies. On the other hand and quite counter intuitively, the pressure constraint can severely affect the quality of the magnetic reconstructions in the core. These trends have been verified with several JET discharges and consistent results have been found. An interpretation of these results, as interplay between degrees of freedom and available measurements, is provided. The systematic analysis described in the paper emphasizes the importance of having sufficient diagnostic inputs and of

  18. Influence of plasma diagnostics and constraints on the quality of equilibrium reconstructions on Joint European Torus

    SciTech Connect

    Gelfusa, M.; Gaudio, P.; Peluso, E.; Murari, A.; Baruzzo, M.; Lupelli, I.; Hawkes, N.; Brix, M.; Drozdov, V.; Meigs, A.; Romanelli, M.; Schmuck, S.; Sieglin, B.; Collaboration: JET-EFDA Contributors

    2013-10-15

    One of the main approaches to thermonuclear fusion relies on confining high temperature plasmas with properly shaped magnetic fields. The determination of the magnetic topology is, therefore, essential for controlling the experiments and for achieving the required performance. In Tokamaks, the reconstruction of the fields is typically formulated as a free boundary equilibrium problem, described by the Grad-Shafranov equation in toroidal geometry and axisymmetric configurations. Unfortunately, this results in mathematically very ill posed problems and, therefore, the quality of the equilibrium reconstructions depends sensitively on the measurements used as inputs and on the imposed constraints. In this paper, it is shown how the different diagnostics (Magnetics Measurements, Polarimetry and Motional Stark Effect), together with the edge current density and plasma pressure constraints, can have a significant impact on the quality of the equilibrium on JET. Results show that both the Polarimetry and Motional Stark Effect internal diagnostics are crucial in order to obtain reasonable safety factor profiles. The impact of the edge current density constraint is significant when the plasma is in the H-mode of confinement. In this plasma scenario the strike point positions and the plasma last closed flux surface can change even by centimetres, depending on the edge constraints, with a significant impact on the remapping of the equilibrium-dependent diagnostics and of pedestal physics studies. On the other hand and quite counter intuitively, the pressure constraint can severely affect the quality of the magnetic reconstructions in the core. These trends have been verified with several JET discharges and consistent results have been found. An interpretation of these results, as interplay between degrees of freedom and available measurements, is provided. The systematic analysis described in the paper emphasizes the importance of having sufficient diagnostic inputs and of

  19. Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic.

    PubMed

    Cao, Norman M; Mier Valdivia, Andrés M; Rice, John E

    2016-01-01

    X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line intensity ratios. By using a Johann spectrometer viewing the plasma, it is possible to construct profiles of plasma parameters such as density, temperature, and velocity with good spatial and time resolution. However, benchmarking atomic code modeling of X-ray spectra obtained from well-diagnosed laboratory plasmas is important to justify use of such spectra to determine plasma parameters when other independent diagnostics are not available. This manuscript presents the operation of the High Resolution X-ray Crystal Imaging Spectrometer with Spatial Resolution (HIREXSR), a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma. In addition, this manuscript covers a laser blow-off system that can introduce such ions to the plasma with precise timing to allow for perturbative studies of transport in the plasma. PMID:27585305

  20. Spectroscopic diagnostics of plasma-chemical-vapor deposition from silane and germane

    NASA Astrophysics Data System (ADS)

    Hata, Nobuhiro; Matsuda, Akihisa; Tanaka, Kazunobu

    1987-04-01

    Coherent anti-Stokes Raman spectroscopy (CARS), laser-induced fluorescence (LIF), and emission spectroscopy are employed for the diagnostics of radio-frequency discharge plasmas of silane and germane; CARS signal of germane molecule; and LIF signal and ultraviolet emission signal of germanium atom in discharges, as well as signals from nongermanium-related neutral species are measured. The effect of hydrogen dilution on emission signal intensities in the steady-state discharge explains dynamic behaviors of the emission and CARS signal intensities in the closed discharge; these spectroscopic techniques are powerful diagnostic tools for gas-phase processes using mixed gas sources.

  1. Perspectives of Use of Diagnostic Mirrors with Transparent Protection Layer in Burning Plasma Experiments

    SciTech Connect

    Mukhin, Eugene E.; Razdobarin, Gennadiy T.; Semenov, Vladimir V.; Tolstyakov, Sergey Yu.; Kochergin, Mikhail M.; Kurskiev, Gleb S.; Podushnikova, Klara A.; Andreev, Alexandr N.; Davydov, Denis V.; Rastegaeva, Marina G.; Khimich, Yuriy P.; Gorshkov, Vladimir N.; Nikitin, Dmitriy B.; Litnovsky, Andrej M.

    2008-03-12

    We evaluate using of metal mirrors over-coated with transparent protection layer for the in-vessel diagnostic systems in reactor-grade fusion devices. Ideally, these should satisfy the contradictory demands of high reflectivity and small rate degradation when being bombarded by CX atoms. The serious threat to the performance of diagnostic mirrors is surface contamination with carbon-based material eroded from carbon tiles. Via coupling the protective layer to a bulk mirror we can mitigate the deposit infiuence on the reflectance spectra. The regards are given to survivability in plasma environment of protected coated metallic mirrors.

  2. Application of aptamers in diagnostics, drug-delivery and imaging.

    PubMed

    Chandola, Chetan; Kalme, Sheetal; Casteleijn, Marco G; Urtti, Arto; Neerathilingam, Muniasamy

    2016-09-01

    Aptamers are small, single-stranded oligonucleotides (DNA or RNA) that bind to their target with high specificity and affinity. Although aptamers are analogous to antibodies for a wide range of target recognition and variety of applications, they have significant advantages over antibodies. Since aptamers have recently emerged as a class of biomolecules with an application in a wide array of fields, we need to summarize the latest developments herein. In this review we will discuss about the latest developments in using aptamers in diagnostics, drug delivery and imaging. We begin with diagnostics, discussing the application of aptamers for the detection of infective agents itself, antigens/ toxins (bacteria), biomarkers (cancer), or a combination. The ease of conjugation and labelling of aptamers makes them a potential tool for diagnostics. Also, due to the reduced off-target effects of aptamers, their use as a potential drug delivery tool is emerging rapidly. Hence, we discuss their use in targeted delivery in conjugation with siRNAs, nanoparticles, liposomes, drugs and antibodies. Finally, we discuss about the conjugation strategies applicable for RNA and DNA aptamers for imaging. Their stability and self-assembly after heating makes them superior over protein-based binding molecules in terms of labelling and conjugation strategies. PMID:27581942

  3. Diagnostic and interventional musculoskeletal ultrasound: part 2. Clinical applications.

    PubMed

    Smith, Jay; Finnoff, Jonathan T

    2009-02-01

    Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Technological advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applications in the evaluation and treatment of patients with neurological and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared to other available imaging modalities; (2) describe how ultrasound machines produce images using sound waves; (3) discuss the steps necessary to acquire and optimize an ultrasound image; (4) understand the difference ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones; and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound. Part 2 of this 2-part article will focus on the clinical applications of musculoskeletal ultrasound in clinical practice, including the ultrasonographic appearance of normal and abnormal tissues as well as specific diagnostic and interventional applications in major body regions. PMID:19627890

  4. Diagnostic value of plasma morphology in patients with coronary heart disease

    NASA Astrophysics Data System (ADS)

    Malinova, Lidia I.; Sergeeva, Yuliya V.; Simonenko, Georgy V.; Tuchin, Valery V.; Denisova, Tatiana P.

    2006-08-01

    Blood plasma can be considered as a special water system with self-organization possibilities. Plasma slides as the results of wedge dehydration reflect its stereochemical interaction and their study can be used in diagnostic processes. 46 patients with coronary heart disease were studied. The main group was formed of men in age ranged from 54 to 72 years old with stable angina pectoris of II and III functional class (by Canadian classification) (n=25). The group of compare was of those who was hospitalized with diagnosis of acute coronary syndrome, men in age range 40-82. Clinical examination, basic biochemical tests and functional plasma morphology characteristics were studied. A number of qualitative and quantitative differences of blood plasma morphology of patients with chronic and acute coronary disease forms was revealed.

  5. Papers presented at the eleventh topical conference on high-temperature plasma diagnostics

    SciTech Connect

    1996-12-31

    This report contains the following eleven papers presented at the conference: Neutral Beam Diagnostics for Alcator C-Mod; A Study for the Installation of the TEXT HIBP on DIII-D; Time-domain Triple-probe Measurement of Edge Plasma Turbulence on TEXT-U; A Langmuir/Mach Probe Array for Edge Plasma Turbulence and Flow; Determination of Field Line Location and Safety Factor in TEXT-U; Hybrid ECE Imaging Array System for TEXT-U; First Results from the Phase Contrast Imaging System on TEXT-U; A Fast Tokamak Plasma Flux and Electron Density Reconstruction Technique; Time-series Analysis of Nonstationary Plasma Fluctuations Using Wavelet Transforms; Quantitative Modeling of 3-D Camera Views for Tokamak Divertors; and Variable-frequency Complex Demodulation Technique for Extracting Amplitude and Phase Information. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  6. Far infrared fusion plasma diagnostics. Task 3A, Progress report, FY 1990

    SciTech Connect

    Luhmann, N.C. Jr.; Peebles, W.A.

    1990-12-31

    Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several researchers, have theoretically investigated these questions. However, prior to the UCLA laboratory investigation, no group has experimentally investigated these questions. Because of the reflectometer`s importance to the world effort in understanding plasma turbulence and transport, UCLA has, over the last year, made its primary Task IIIA effort the resolution of these questions. UCLA has taken the lead in a quantitative experimental understanding of reflectometer data as applied to the measurement of density fluctuations. In addition to this, work has proceeded on the design, construction, and installation of a reflectometer system on UCLA`s CCT tokamak. This effort will allow a comparison between the improved confinement regimes (H-mode) observed on both the DIII-D and CCT machines with the goal of achieving a physics understanding of the phenomena. Preliminary investigation of a new diagnostic technique to measure density profiles as a function of time has been initiated at UCLA. The technique promises to be a valuable addition to the range of available plasma diagnostics. Work on advanced holographic reflectometry technique as applied to fluctuation diagnostics has awaited a better understanding of the reflectometer signal itself as discussed above. Efforts to ensure the transfer of the diagnostic developments have continued with particular attention devoted to the preliminary design of a multichannel FIR interferometer for MST.

  7. Development of plasma needle to be used for biomedical applications

    NASA Astrophysics Data System (ADS)

    Bora, B.; Jain, J.; Inestrosa-Izurieta, M. J.; Avaria, G.; Moreno, J.; Pavez, C.; Marcelain, K.; Armisen, R.; Soto, L.

    2016-05-01

    Plasma needle is a novel design of a plasma source at atmospheric pressure to achieve a non-thermal plasma jet. The advantage of the plasma needle is that it can be operated in open air, outside a vessel. The plasma that is generated with the plasma needle is small (about one millimetre) and non-thermal, the temperature of the neutral particles and ions is in about room temperature and suitably can interact with living biological cell without damaging the cell. In this work, we report the development of a plasma needle, which is operated by a dc power source and produced a stable plasma jet on water surface. Argon gas is used to operate the plasma needle. The preliminary electrical diagnostics of the plasma needle shows that the discharge is filamentary in nature. For diagnostic of the plasma jet produced by the developed plasma needle, the produced plasma jet is directed to water surface and characterization are carried out by means of electrical discharge characteristics and optical emission spectroscopy. In this work, preliminary results of the diagnostic will be presented.

  8. Infrared Imaging Tools for Diagnostic Applications in Dermatology

    PubMed Central

    Gurjarpadhye, Abhijit Achyut; Parekh, Mansi Bharat; Dubnika, Arita; Rajadas, Jayakumar; Inayathullah, Mohammed

    2015-01-01

    Infrared (IR) imaging is a collection of non-invasive imaging techniques that utilize the IR domain of the electromagnetic spectrum for tissue assessment. A subset of these techniques construct images using back-reflected light, while other techniques rely on detection of IR radiation emitted by the tissue as a result of its temperature. Modern IR detectors sense thermal emissions and produce a heat map of surface temperature distribution in tissues. Thus, the IR spectrum offers a variety of imaging applications particularly useful in clinical diagnostic area, ranging from high-resolution, depth-resolved visualization of tissue to temperature variation assessment. These techniques have been helpful in the diagnosis of many medical conditions including skin/breast cancer, arthritis, allergy, burns, and others. In this review, we discuss current roles of IR-imaging techniques for diagnostic applications in dermatology with an emphasis on skin cancer, allergies, blisters, burns and wounds. PMID:26691203

  9. Applications of Molecular Diagnostic Testing in Food Allergy.

    PubMed

    Hoffmann-Sommergruber, Karin; Pfeifer, Sabine; Bublin, Merima

    2015-09-01

    IgE-mediated food allergy is a relevant health problem inducing symptoms ranging from mild local reactions up to severe life-threatening situations. Currently, no immunotherapy is available and avoidance of the incriminating food is the method of choice. Therefore, reliable diagnostic tools to formulate dietary recommendations and to avoid unnecessary exclusion diets for the individual patient are urgently needed. This review provides an update on the current knowledge on food allergens and their application in various diagnostic approaches such as skin prick test, basophil activation test, and serum IgE testing. Furthermore, these new approaches are discussed and compared to conventional extract-based assays and correlated to the gold standard of food allergy diagnosis, the double-blind placebo-controlled food challenge. Finally, the application of food allergens for preventive measurements such as allergen detection assays and the determination of threshold levels for allergen levels are discussed. PMID:26233429

  10. Applications of Next-Generation Sequencing Technologies to Diagnostic Virology

    PubMed Central

    Barzon, Luisa; Lavezzo, Enrico; Militello, Valentina; Toppo, Stefano; Palù, Giorgio

    2011-01-01

    Novel DNA sequencing techniques, referred to as “next-generation” sequencing (NGS), provide high speed and throughput that can produce an enormous volume of sequences with many possible applications in research and diagnostic settings. In this article, we provide an overview of the many applications of NGS in diagnostic virology. NGS techniques have been used for high-throughput whole viral genome sequencing, such as sequencing of new influenza viruses, for detection of viral genome variability and evolution within the host, such as investigation of human immunodeficiency virus and human hepatitis C virus quasispecies, and monitoring of low-abundance antiviral drug-resistance mutations. NGS techniques have been applied to metagenomics-based strategies for the detection of unexpected disease-associated viruses and for the discovery of novel human viruses, including cancer-related viruses. Finally, the human virome in healthy and disease conditions has been described by NGS-based metagenomics. PMID:22174638

  11. Development of fast steering mirror control system for plasma heating and diagnostics.

    PubMed

    Okada, K; Nishiura, M; Kubo, S; Shimozuma, T; Yoshimura, Y; Igami, H; Takahashi, H; Tanaka, K; Kobayashi, S; Ito, S; Mizuno, Y; Ogasawara, S

    2014-11-01

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering. PMID:25430376

  12. Development of fast steering mirror control system for plasma heating and diagnostics

    SciTech Connect

    Okada, K. Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tanaka, K.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Ogasawara, S.; Nishiura, M.

    2014-11-15

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

  13. Statistical analysis of polarizing maps of blood plasma laser images for the diagnostics of malignant formations

    NASA Astrophysics Data System (ADS)

    Ungurian, V. P.; Ivashchuk, O. I.; Ushenko, V. O.

    2012-01-01

    This work is aimed at searching the interconnections between the statistic structure of blood plasma microscopic images and manifestations of optical anisotropy of liquid crystal protein network. The model of linear birefringence of albumin and globulin crystals underlies in the ground of this work. The results of investigating the interrelation between statistical moments of the 1st-4th order are presented that characterize the coordinate distributions of polarization ellipticity of laser images of blood plasma smears and pathological changes in human organism. The diagnostic criteria of breast cancer nascency and its severity degree differentiation are determined.

  14. Statistical analysis of polarizing maps of blood plasma laser images for the diagnostics of malignant formations

    NASA Astrophysics Data System (ADS)

    Ungurian, V. P.; Ivashchuk, O. I.; Ushenko, V. O.

    2011-09-01

    This work is aimed at searching the interconnections between the statistic structure of blood plasma microscopic images and manifestations of optical anisotropy of liquid crystal protein network. The model of linear birefringence of albumin and globulin crystals underlies in the ground of this work. The results of investigating the interrelation between statistical moments of the 1st-4th order are presented that characterize the coordinate distributions of polarization ellipticity of laser images of blood plasma smears and pathological changes in human organism. The diagnostic criteria of breast cancer nascency and its severity degree differentiation are determined.

  15. Current new applications of laser plasmas

    SciTech Connect

    Hauer, A.A.; Forslund, D.W.; McKinstrie, C.J.; Wark, J.S.; Hargis, P.J. Jr.; Hamil, R.A.; Kindel, J.M.

    1988-09-01

    This report describes several new applications of laser-produced plasmas that have arisen in the last few years. Most of the applications have been an outgrowth of the active research in laser/matter interaction inspired by the pursuit of laser fusion. Unusual characteristics of high-intensity laser/matter interaction, such as intense x-ray and particle emission, were noticed early in the field and are now being employed in a significant variety of applications outside the fusion filed. Applications range from biology to materials science to pulsed-power control and particle accelerators. 92 refs., 23 figs., 4 tabs.

  16. Diagnostic of charge balance in high-temperature tungsten plasmas using LLNL EBIT

    SciTech Connect

    Osborne, G. C.; Safronova, A. S.; Kantsyrev, V. L.; Safronova, U. I.; Yilmaz, M. F.; Williamson, K. M.; Shrestha, I.; Beiersdorfer, P.

    2008-10-15

    Diagnostic of high-temperature M-shell W plasmas is challenging because of contribution of numerous ionization stages in a relatively narrow x-ray spectral region. A method using LLNL EBIT data generated at different electron beam energies has been established for the identification of prominent spectral features and for the determination of charge balance in x-ray M-shell W spectra between 3.5 and 8.5 A . It extends previous work [A. S. Safronova et al., Can. J. Phys. 86, 267 (2008)] which used only Ni-like lines to include the neighboring ionization stages. This diagnostic procedure was tested with results from Z-pinch plasmas produced on the 1 MA pulse power generator Zebra at UNR. These results are of particular importance for fusion research.

  17. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    EPA Science Inventory

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  18. Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control

    SciTech Connect

    Bongers, W. A.; Beveren, V. van; Westerhof, E.; Goede, A. P. H.; Krijger, B.; Berg, M. A. van den; Graswinckel, M. F.; Schueller, F. C.; Thoen, D. J.; Nuij, P. J. W. M.; Baar, M. R. de; Donne, A. J. H.; Hennen, B. A.; Kantor, M.

    2011-06-15

    An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.

  19. Diagnostics of surface wave driven low pressure plasmas based on indium monoiodide-argon system

    NASA Astrophysics Data System (ADS)

    Ögün, C. M.; Kaiser, C.; Kling, R.; Heering, W.

    2015-06-01

    Indium monoiodide is proposed as a suitable alternative to hazardous mercury, i.e. the emitting component inside the compact fluorescent lamps (CFL), with comparable luminous efficacy. Indium monoiodide-argon low pressure lamps are electrodelessly driven with surface waves, which are launched and coupled into the lamp by the ‘surfatron’, a microwave coupler optimized for an efficient operation at a frequency of 2.45 GHz. A non intrusive diagnostic method based on spatially resolved optical emission spectroscopy is employed to characterize the plasma parameters. The line emission coefficients of the plasma are derived by means of Abel’s inversion from the measured spectral radiance data. The characteristic plasma parameters, e.g. electron temperature and density are determined by comparing the experimentally obtained line emission coefficients with simulated ones from a collisional-radiative model. Additionally, a method to determine the absolute plasma efficiency via irradiance measurements without any goniometric setup is presented. In this way, the relationship between the plasma efficiency and the plasma parameters can be investigated systematically for different operating configurations, e.g. electrical input power, buffer gas pressure and cold spot temperature. The performance of indium monoiodide-argon plasma is compared with that of conventional CFLs.

  20. Towards personalized diagnostics via longitudinal study of the human plasma N-glycome.

    PubMed

    Hennig, René; Cajic, Samanta; Borowiak, Matthias; Hoffmann, Marcus; Kottler, Robert; Reichl, Udo; Rapp, Erdmann

    2016-08-01

    Facilitated by substantial advances in analytical methods, plasma N-glycans have emerged as potential candidates for biomarkers. In the recent years, several investigations could link aberrant plasma N-glycosylation to numerous diseases. However, due to often limited specificity and sensitivity, only a very limited number of glycan biomarkers were approved by the authorities up to now. The inter-individual heterogeneity of the plasma N-glycomes might mask disease related changes in conventional large cross-sectional cohort studies, with a one-time sampling approach. But, a possible benefit of longitudinal sampling in biomarker discovery could be, that already small changes during disease progression are revealed, by monitoring the plasma N-glycome of individuals over time. To evaluate this, we collected blood plasma samples of five healthy donors over a time period of up to six years (min. 1.5years). The plasma N-glycome was analyzed by xCGE-LIF, to investigate the intra-individual N-glycome variability over time. It is shown, that the plasma N-glycome of an individual is remarkably stable over a period of several years, and that observed small longitudinal changes are independent from seasons, but significantly correlated with lifestyle and environmental factors. Thus, the potential of future longitudinal biomarker discovery studies could be demonstrated, which is a further step towards personalized diagnostics. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc. PMID:27038647

  1. Multi-Spectral Solar Telescope Array. V - Temperature diagnostic response to the optically thin solar plasma

    NASA Technical Reports Server (NTRS)

    Deforest, Craig E.; Kankelborg, Charles C.; Allen, Max J.; Paris, Elizabeth S.; Willis, Tom D.; Lindblom, Joakim F.; O'Neal, Ray H.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Hoover, Richard B.

    1991-01-01

    The compact soft X-ray/EUV/FUV multilayer coated telescopes developed for solar chromosphere, corona, and corona/solar-wind interface studies permit the use of conventional (Cassegrain, Herschelian, etc.) configurations. The multilayer coatings also allow a narrow-wavelength band to be selected for imaging. NASA's Multi-Spectral Solar Telescope Array is composed of 17 of these compact telescopes; attention is given to their ability to obtain temperature-diagnostic information concerning the solar plasma.

  2. Statistical uncertainties in temperature diagnostics for hot coronal plasma using the ASCA SIS

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.; O'Dell, S. L.; Sulkanen, M. E.; Tennant, A. F., Jr.

    1994-01-01

    Statistical uncertainties in determining the temperatures of hot (0.5-10 keV) coronal plasmas are investigated. The statistical presicion of various spectral temperature diagnostics is established by analyzing synthetic ASCA solid-state imaging spectrometer (SIS) CCD spectra. The diagnostics considered are the ratio of hydrogen-like to helium-like line complexes of Z greater than or = 14 elements, line-free portions of the continuum, and the entire spectrum. While fits to the entire spectrum yield the highest statistical precision, it is argued that fits to the line-free continuum are less susceptible to atomic data uncertainties but lead to a modest increase in statistical uncertainty over full spectral fits. Temperatures deduced from line ratios can have similar accuracy, but only over a narrow range of temperatures. Convenient estimates of statistical accuracies for the various temperature diagnostics are provided which may be used in planning ASCA SIS observations.

  3. Exploring diagnostic capabilities for application to new photovoltaic technologies.

    SciTech Connect

    Rolfe, Kevin D.; Quintana, Enrico Carlo; Thompson, Kyle Richard; Quintana, Michael A.; Hacke, Peter

    2009-06-01

    Explosive growth in photovoltaic markets has fueled new creative approaches that promise to cut costs and improve reliability of system components. However, market demands require rapid development of these new and innovative technologies in order to compete with more established products and capture market share. Often times diagnostics that assist in R&D do not exist or have not been applied due to the innovative nature of the proposed products. Some diagnostics such as IR imaging, electroluminescence, light IV, dark IV, x-rays, and ultrasound have been employed in the past and continue to serve in development of new products, however, innovative products with new materials, unique geometries, and previously unused manufacturing processes require additional or improved test capabilities. This fast-track product development cycle requires diagnostic capabilities to provide the information that confirms the integrity of manufacturing techniques and provides the feedback that can spawn confidence in process control, reliability and performance. This paper explores the use of digital radiography and computed tomography (CT) with other diagnostics to support photovoltaic R&D and manufacturing applications.

  4. Plasmas as Antennas - Theory, Experiment and Applications

    NASA Astrophysics Data System (ADS)

    Borg, Gerard

    1999-11-01

    A variety of antennas are employed in telecommunications and radar systems. Some applications pose special problems. Large structures are easily detected by hostile radar. The performance of multi-element HF-VHF arrays is complicated by mutual coupling between large radiating elements. High speed data communications and radar can be limited by signal decay and ringing. A novel solution is an antenna made of plasma that can be made to disappear on microsecond time scales. Recent experiments at the Australian National University (G.G. Borg et. al. App. Phys. Letts. Vol. 74, 3272-3274 [1999]), have shown that highly efficient (25 - 50radiating elements for the range 3 - 300 MHz can be formed using low power (10 - 50 W average) plasma surface waves launched at one end of a tube containing a suitable gas. Only a single capacitive coupler is needed to launch the waves - there is no electrical connection to the other end of the tube. The regimes of wave propagation correlate with expectations from plasma surface wave theory. Actual communications experiments have shown that these plasma antennas can have surprisingly low noise provided they are excited by the rf surface waves and not by a low frequency or DC ohmic current. Applications to HF-VHF communications and radar are being developed. These include both single ruggedised plasma elements and multi-element arrays.

  5. Laser-based diagnostics for characterizing materials exposed to a plasma environment

    NASA Astrophysics Data System (ADS)

    Shaw, G. C.; Biewer, T. M.; Caughman, J. B. O.; Goulding, R.; Leonard, K.; Lore, J.; Martin, M.; Martin, R.; Rapp, J.; Wirth, B.

    2013-10-01

    To address the needs of fusion reactors, diagnostic techniques for plasma-material interactions (PMI) are being developed at ORNL. Laser-based diagnostic techniques (LBDT) will be used to both characterize the plasma environment and probe the material surface during plasma exposure. A Nd:YAG laser is needed for LBDT. Initial setup and diagnostic testing of the beam will be performed before installing it onto the ORNL device, PHISX (Prototype High Intensity Source Experiment). Installation of the Nd:YAG laser on PHISX, will enable Thomson Scattering (TS) measurements as well as Laser Induced Ablation/Breakdown/Desorption Spectroscopy (LIAS/LIBS/LIDS) to be performed in-situ on material targets. The material targets can be further characterized ex-situ by surface techniques available at ORNL; ex-situ results will be compared to the in-situ characterizations. This poster will show the initial setup and plans for LBDT on PHISX at ORNL. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725.

  6. PREFACE: The 8th Workshop on Frontiers in Low Temperature Plasma Diagnostics The 8th Workshop on Frontiers in Low Temperature Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Sadeghi, Nader; Czarnetzki, Uwe

    2010-03-01

    The 8th Workshop on Frontiers in Low Temperature Plasma Diagnostics (FLTPD) was held in Blansko, near Brno, Czech Republic. FLTPD is a biennial European event in which scientists working on low temperature plasmas present their recent results, pointing out in particular the originality of the diagnostic techniques used. The idea of starting this series of workshops was born out of a discussion between Frieder Döbele, Bill Graham and one of us when travelling together from Bar Harbor, USA (after the 6th LAPD) to Montreal, Canada, in October 1993. It became evident that we had been lacking a European meeting that could bring together experts in the field of low temperature plasma diagnostics and facilitate sharing the knowledge of these diagnostics with a new generation of scientists. The first FLTPD was held in Les Houches, France, in February 1995. Since then it has been held in the spring of every other year in different European countries, as shown below. The next meeting will be held in Zinnowitz, near Greifswald, Germany, in May 2011. Year Location Chair of LOC 1995 Les Houches, France J Derouard 1997 Bad Honnef, Germany F Döbele 1999 Saillon, Switzerland Ch Hollenstein 2001 Rolduc, The Netherlands R van de Sanden 2003 Specchia, Italy S De Benedictis 2005 Les Houches, France N Sadeghi 2007 Cumbria, United Kingdom M Bowden 2009 Blansko, Czech Republic F Krčma To favour brainstorming and extended discussions between participants, FLTPD meetings have always been organized in isolated locations with the number of attendees limited to about 70. Workshops are held over three and a half days with about ten expert presentations by invited speakers (a few from overseas), as well as short oral or poster contributions. This special issue of Journal of Physics D: Applied Physics contains 20 articles representative of contributions to the last FLTPD in Blansko. All invited speakers and others who gave presentations, as selected by the Scientific Committee, were invited

  7. The importance of EBIT data for Z-pinch plasma diagnostics

    SciTech Connect

    Safronova, A S; Kantsyrev, V L; Neill, P; Safronova, U I; Fedin, D A; Ouart, N D; Yilmaz, M F; Osborne, G; Shrestha, I; Williamson, K; Hoppe, T; Harris, C; Beiersdorfer, P; Hansen, S

    2007-04-04

    The results from the last six years of x-ray spectroscopy and spectropolarimetry of high energy density Z-pinch plasmas complemented by experiments with the electron beam ion trap (EBIT) at the Lawrence Livermore National Laboratory (LLNL) are presented. The two topics discussed are the development of M-shell x-ray W spectroscopic diagnostics and K-shell Ti spectropolarimetry of Z-pinch plasmas. The main focus is on radiation from a specific load configuration called an 'X-pinch'. X-pinches are excellent sources for testing new spectral diagnostics and for atomic modelling because of the high density and temperature of the pinch plasmas, which scale from a few {micro}m to several mm in size. They offer a variety of load configurations, which differ in wire connections, number of wires, and wire materials. In this work the study of X-pinches with tungsten wires combined with wires from other, lower-Z materials is reported. Utilizing data produced with the LLNL EBIT at different energies of the electron beam the theoretical prediction of line positions and intensity of M-shell W spectra were tested and calibrated. Polarization-sensitive X-pinch experiments at the University of Nevada, Reno (UNR) provide experimental evidence for the existence of strong electron beams in Ti and Mo X-pinch plasmas and motivate the development of x-ray spectropolarimetry of Z-pinch plasmas. This diagnostic is based on the measurement of spectra recorded simultaneously by two spectrometers with different sensitivity to the linear polarization of the observed lines and compared with theoretical models of polarization-dependent spectra. Polarization-dependent K-shell spectra from Ti X-pinches are presented and compared with model calculations and with spectra generated by a quasi-Maxwellian electron beam at the LLNL EBIT-II electron beam ion trap.

  8. Novel applications of plasma actuators

    NASA Astrophysics Data System (ADS)

    Ozturk, Arzu Ceren

    The current study investigates the effectiveness of two different dielectric barrier discharge plasma actuator configurations, a 3-D annular geometry for use in micro thrusters and internal duct aerodynamics and a jet vectoring actuator that acts as a vortex generator and flow control device. The first configuration consists of a closed circumferential arrangement which yields a body force when a voltage difference is applied across the inner and outer electrodes separated by a dielectric. The primary flow is driven by this zero-net mass flux jet at the wall that then entrains fluid in the core of the duct. PIV experiments in both quiescent flow and freestream are conducted on tubes of different diameters while varying parameters such as the modulation frequency, duty cycle and tunnel speed. The values of the induced velocities increase with the forcing frequency and duty cycle although there is a peak value for the forcing frequency after which the velocity and thrust decrease for each thruster. The velocities and thrust increase as the inner diameter of the tubes are increased while the velocity profiles show a great difference with the (l/di) ratio; recirculation occurs after going below a critical value. Experiments in the wind tunnel illustrate that the jet exit characteristics significantly change upon actuation in freestream flow but the effect tends to diminish with increasing inner diameters and tunnel speeds. Using staged arrays of these thrusters result in higher velocities while operating at both in phase and out of phase. The jet vectoring configuration consists of a single embedded electrode separated from two exposed electrodes on either side by the dielectric. The embedded electrode is grounded while the exposed electrodes are driven with a high frequency high voltage input signal. PIV measurements of the actuator in a freestream show that vectoring the jet yields stronger vortices than a linear configuration and increasing the difference between

  9. A Langmuir Probe Diagnostic for Use in Inhomogeneous, Time-Varying Plasmas Produced by High-Energy Laser Ablation

    SciTech Connect

    Patterson, J R; Emig, J A; Fournier, K B; Jenkins, P P; Trautz, K M; Seiler, S W; Davis, J F

    2012-05-01

    Langmuir probes (LP) are used extensively to characterize plasma environments produced by radio frequency, pulsed plasma thrusters, and laser ablation. We discuss here the development of a LP diagnostic to examine high-density, high-temperature inhomogeneous plasmas such as those that can be created at the University of Rochester's Laboratory for Laser Energetics OMEGA facility. We have configured our diagnostic to examine the velocity of the plasma expanding from the target. We observe velocities of approximately 16-17 cm/{micro}s, with individual LP currents displaying complex structures, perhaps due to the multiple atomic species and ionization states that exist.

  10. Development of Simple Designs of Multitip Probe Diagnostic Systems for RF Plasma Characterization

    PubMed Central

    Naz, M. Y.; Shukrullah, S.; Ghaffar, A.; Rehman, N. U.

    2014-01-01

    Multitip probes are very useful diagnostics for analyzing and controlling the physical phenomena occurring in low temperature discharge plasmas. However, DC biased probes often fail to perform well in processing plasmas. The objective of the work was to deduce simple designs of DC biased multitip probes for parametric study of radio frequency plasmas. For this purpose, symmetric double probe, asymmetric double probe, and symmetric triple probe diagnostic systems and their driving circuits were designed and tested in an inductively coupled plasma (ICP) generated by a 13.56 MHz radio frequency (RF) source. Using I-V characteristics of these probes, electron temperature, electron number density, and ion saturation current was measured as a function of input power and filling gas pressure. An increasing trend was noticed in electron temperature and electron number density for increasing input RF power whilst a decreasing trend was evident in these parameters when measured against filling gas pressure. In addition, the electron energy probability function (EEPF) was also studied by using an asymmetric double probe. These studies confirmed the non-Maxwellian nature of the EEPF and the presence of two groups of the energetic electrons at low filling gas pressures. PMID:24683326

  11. Development of simple designs of multitip probe diagnostic systems for RF plasma characterization.

    PubMed

    Naz, M Y; Shukrullah, S; Ghaffar, A; Rehman, N U

    2014-01-01

    Multitip probes are very useful diagnostics for analyzing and controlling the physical phenomena occurring in low temperature discharge plasmas. However, DC biased probes often fail to perform well in processing plasmas. The objective of the work was to deduce simple designs of DC biased multitip probes for parametric study of radio frequency plasmas. For this purpose, symmetric double probe, asymmetric double probe, and symmetric triple probe diagnostic systems and their driving circuits were designed and tested in an inductively coupled plasma (ICP) generated by a 13.56 MHz radio frequency (RF) source. Using I-V characteristics of these probes, electron temperature, electron number density, and ion saturation current was measured as a function of input power and filling gas pressure. An increasing trend was noticed in electron temperature and electron number density for increasing input RF power whilst a decreasing trend was evident in these parameters when measured against filling gas pressure. In addition, the electron energy probability function (EEPF) was also studied by using an asymmetric double probe. These studies confirmed the non-Maxwellian nature of the EEPF and the presence of two groups of the energetic electrons at low filling gas pressures. PMID:24683326

  12. Diagnostics of plasma-biological surface interactions in low pressure and atmospheric pressure plasmas

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kenji; Hori, Masaru

    2014-08-01

    Mechanisms of plasma-surface interaction are required to understand in order to control the reactions precisely. Recent progress in atmospheric pressure plasma provides to apply as a tool of sterilization of contaminated foodstuffs. To use the plasma with safety and optimization, the real time in situ detection of free radicals - in particular dangling bonds by using the electron-spin-resonance (ESR) technique has been developed because the free radical plays important roles for dominantly biological reactions. First, the kinetic analysis of free radicals on biological specimens such as fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge. We have obtained information that the in situ real time ESR signal from the spores was observed and assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal was correlated with a link to the inactivation of the fungal spore. Second, we have studied to detect chemical modification of edible meat after the irradiation. Using matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF-MS) and ESR, signals give qualification results for chemical changes on edible liver meat. The in situ real-time measurements have proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens.

  13. The effects of a multidensity plasma on ultraviolet spectroscopic electron density diagnostics

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.

    1984-01-01

    Spectroscopic electron density diagnostics have been developed for interpretation of UV, EUV, and X-ray emission line spectra of solar and other astrophysical plasmas, and tokamak plasmas. In principle, accurate electron densities can be determined. However, in practice, a number of difficulties arise with respect to the determination of very accurate electron densities in the 1100-3000 A region. The present study has the objective to investigate one of these difficulties, taking into account the effect on line ratios produced by a source composed of several regions of substantially different densities, all at the same temperature. The study is in particular concerned with a source in which small high density knots are embedded in low-density plasma. Attention is given to line ratios involving the O IV multiplet near 1400 A, obtained from the spectrum of a surge observed outside the solar limb.

  14. Use of the Plasma Spectrum RMS Signal for Arc-Welding Diagnostics.

    PubMed

    Mirapeix, Jesus; Cobo, Adolfo; Fuentes, Jose; Davila, Marta; Etayo, Juan Maria; Lopez-Higuera, Jose-Miguel

    2009-01-01

    A new spectroscopic parameter is used in this paper for on-line arc-welding quality monitoring. Plasma spectroscopy applied to welding diagnostics has typically relied on the estimation of the plasma electronic temperature, as there is a known correlation between this parameter and the quality of the seams. However, the practical use of this parameter gives rise to some uncertainties that could provoke ambiguous results. For an efficient on-line welding monitoring system, it is essential to prevent the appearance of false alarms, as well as to detect all the possible defects. In this regard, we propose the use of the root mean square signal of the welding plasma spectra, as this parameter will be proven to exhibit a good correlation with the quality of the resulting seams. Results corresponding to several arc-welding field tests performed on Inconel and titanium specimens will be discussed and compared to non-destructive evaluation techniques. PMID:22346696

  15. Development of the Megahertz Planar Laser-induced Fluorescence Diagnostic for Plasma Turbulence Visualization

    SciTech Connect

    Aleksey Kuritsyn; Fred M. Levinton

    2004-04-27

    A megahertz LIF-based diagnostic system for measuring ion density fluctuations in two spatial dimensions is described. Well resolved spatial and temporal 2D images of turbulent structures will be useful in understanding ion turbulence in magnetically confined plasmas which is a key factor in the performance of fusion experimental devices. A sheet beam of a megahertz repetition rate tunable Alexandrite laser is used to excite ion emission from argon plasma. The fluorescence emitted from the plane of the laser beam is detected with a narrow band interference filter and intensified ultra-fast CCD camera providing 2D images of relative ion density fluctuations every microsecond. It is expected that the edge plasma on fusion devices will be accessible to this technique.

  16. Development of the megahertz planar laser-induced fluorescence diagnostic for plasma turbulence visualization

    SciTech Connect

    Kuritsyn, Aleksey; Levinton, Fred M.

    2004-10-01

    A megahertz laser-induced fluorescence-based diagnostic system for measuring ion density fluctuations in two spatial dimensions is described. Well resolved spatial and temporal two-dimensional (2D) images of turbulent structures will be useful in understanding ion turbulence in magnetically confined plasmas which is a key factor in the performance of fusion experimental devices. A sheet beam of a megahertz repetition rate tunable Alexandrite laser is used to excite ion emission from argon plasma. The fluorescence emitted from the plane of the laser beam is detected with a narrow band interference filter and intensified ultrafast charge coupled device camera providing 2D images of relative ion density fluctuations every microsecond. It is expected that the edge plasma on fusion devices will be accessible to this technique.

  17. TiN Deposition and Process Diagnostics using Remote Plasma Sputtering

    NASA Astrophysics Data System (ADS)

    Yang, Wonkyun; Kim, Gi-Taek; Lee, Seunghun; Kim, Do-Geun; Kim, Jong-Kuk

    2013-08-01

    The discharge voltage-current characteristics and the optical diagnostics of a remote plasma sputtering system called by high density plasma assisted sputtering source (HiPASS) were investigated. The remote plasma was generated by the hollow cathode discharge (HCD) gun and was transported to the target surface by external electromagnet coils. This showed a wide process window because the sputtering voltage and current could be individually controlled. The ion density and energy distribution could be also controlled unlike the conventional magnetron sputtering. Titanium nitride films were deposited under different sputtering voltage. The high voltage mode induced the high ionization ratio of the sputtered atoms and the high ion energy toward the substrate. That resulted in the enlarged grain size, and the preferred orientation toward (220). Eventually, this optimized condition of HiPASS obtained the best hardness of TiN films to be about 48 GPa at the sputtering voltage of -800 V.

  18. Use of the Plasma Spectrum RMS Signal for Arc-Welding Diagnostics

    PubMed Central

    Mirapeix, Jesus; Cobo, Adolfo; Fuentes, Jose; Davila, Marta; Etayo, Juan Maria; Lopez-Higuera, Jose-Miguel

    2009-01-01

    A new spectroscopic parameter is used in this paper for on-line arc-welding quality monitoring. Plasma spectroscopy applied to welding diagnostics has typically relied on the estimation of the plasma electronic temperature, as there is a known correlation between this parameter and the quality of the seams. However, the practical use of this parameter gives rise to some uncertainties that could provoke ambiguous results. For an efficient on-line welding monitoring system, it is essential to prevent the appearance of false alarms, as well as to detect all the possible defects. In this regard, we propose the use of the root mean square signal of the welding plasma spectra, as this parameter will be proven to exhibit a good correlation with the quality of the resulting seams. Results corresponding to several arc-welding field tests performed on Inconel and titanium specimens will be discussed and compared to non-destructive evaluation techniques. PMID:22346696

  19. Cross-diagnostic comparison of fluctuation measurements in a linear plasma column

    NASA Astrophysics Data System (ADS)

    Light, Adam D.; Archer, Nicholas A. A.; Bashyal, Atit; Chakraborty Thakur, Saikat; Tynan, George R.

    2015-11-01

    The advent of fast imaging diagnostics, which provide two-dimensional measurements on relevant plasma time scales, has proven invaluable for interpreting plasma dynamics in laboratory devices. Despite its success, imaging remains a qualitative aid for many studies, because intensity is difficult to map onto a single physical variable for use in a theoretical model. This work continues our exploration of the relationship between visible-light and electrostatic probe measurements in the Controlled Shear Decorrelation Experiment (CSDX). CSDX is a well-characterized linear machine producing dense plasmas relevant to the tokamak edge (Te ~ 3 eV, ne ~1013 /cc). Visible light from ArI and ArII line emission is collected at high frame rates using a fast digital camera. Floating potential and ion-saturation current are measured by an array of electrostatic probe tips. We present a detailed comparison between imaging and probe measurements of fluctuations, including temporal, spatial, and spectral properties in various operational regimes.

  20. Multi-diagnostic comparison of femtosecond and nanosecond pulsed laser plasmas

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; VanRompay, P. A.; Nees, J. A.; Pronko, P. P.

    2002-09-01

    Understanding and fully characterizing highly dynamic and rapidly streaming laser ablation plasmas requires multiple techniques for monitoring effects at different stages. By combining multiple diagnostic methods, it is possible to analyze the broad time window over which these ablation plasmas develop and to learn more about the related physical processes that occur. Two laser sources, an 80 fs Ti:Sapphire laser (780 nm) and a 6 ns Nd:YAG laser (1.06 mum), are used in this work in order to compare pulse duration effects at similar wavelengths. Characteristics of the plasma produced by these two lasers are compared under conditions of comparable ablation flux. Results are presented involving correlation of time-resolved Langmuir probe data and electrostatic energy analysis for aluminum plasmas as a representative investigation for metallic systems. In addition, continuous-wave refractive index laser beam deflection is used to characterize the plasma and hot gas generated from boron nitride targets in terms of their ion and neutral atom densities. A self-similarity plasma expansion model is used to analyze the plumes under various conditions. Fundamental data obtained in this way can be relevant to laser micro-machining, laser induced breakdown spectroscopy, and pulsed laser deposition.

  1. PIC Simulation of RF Plasma Sheath Formation and Initial Validation of Optical Diagnostics using HPC Resources

    NASA Astrophysics Data System (ADS)

    Icenhour, Casey; Exum, Ashe; Martin, Elijah; Green, David; Smithe, David; Shannon, Steven

    2014-10-01

    The coupling of experiment and simulation to elucidate near field physics above ICRF antennae presents challenges on both the experimental and computational side. In order to analyze this region, a new optical diagnostic utilizing active and passive spectroscopy is used to determine the structure of the electric fields within the sheath region. Parallel and perpendicular magnetic fields with respect to the sheath electric field have been presented. This work focuses on the validation of these measurements utilizing the Particle-in-Cell (PIC) simulation method in conjunction with High Performance Computing (HPC) resources on the Titan supercomputer at Oak Ridge National Laboratory (ORNL). Plasma parameters of interest include electron density, electron temperature, plasma potentials, and RF plasma sheath voltages and thicknesses. The plasma is modeled utilizing the VSim plasma simulation tool, developed by the Tech-X Corporation. The implementation used here is a two-dimensional electromagnetic model of the experimental setup. The overall goal of this study is to develop models for complex RF plasma systems and to help outline the physics of RF sheath formation and subsequent power loss on ICRF antennas in systems such as ITER. This work is carried out with the support of Oak Ridge National Laboratory and the Tech-X Corporation.

  2. Diagnostics of Argon Inductively Coupled Plasma and Dielectric Barrier Discharge Plasma by Optical Emission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Jia-liang; Yu, Shi-ji; Ma, Teng-cai; Deng, Xin-lu

    2001-08-01

    An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES from argon ICP and DBD plasmas in visible and near ultraviolet region were measured. For argon ICP, the higher RF power input (higher than 500 W for our machine), the higher degree of argon plasma ionization. But that doesn't mean a higher mean electron energy. With the increase in the power input, the mean electron energy increases slightly, whereas the density of electron increases apparently. Or, the contrary, argon DBD discharge behaves in the manner of a pulsed DC discharge on optical emission spectroscopy and V-I characteristics. DBD current is composed of a series of pulses equally spaced in temporal domain. The kinetics of DBD emission strength is mainly governed by the frequency of the current pulse.

  3. PLASMA DIAGNOSTICS OF AN EIT WAVE OBSERVED BY HINODE/EIS AND SDO/AIA

    SciTech Connect

    Veronig, A. M.; Kienreich, I. W.; Muhr, N.; Temmer, M.; Goemoery, P.; Vrsnak, B.; Warren, H. P.

    2011-12-10

    We present plasma diagnostics of an Extreme-Ultraviolet Imaging Telescope (EIT) wave observed with high cadence in Hinode/Extreme-Ultraviolet Imaging Spectrometer (EIS) sit-and-stare spectroscopy and Solar Dynamics Observatory/Atmospheric Imaging Assembly imagery obtained during the HOP-180 observing campaign on 2011 February 16. At the propagating EIT wave front, we observe downward plasma flows in the EIS Fe XII, Fe XIII, and Fe XVI spectral lines (log T Almost-Equal-To 6.1-6.4) with line-of-sight (LOS) velocities up to 20 km s{sup -1}. These redshifts are followed by blueshifts with upward velocities up to -5 km s{sup -1} indicating relaxation of the plasma behind the wave front. During the wave evolution, the downward velocity pulse steepens from a few km s{sup -1} up to 20 km s{sup -1} and subsequently decays, correlated with the relative changes of the line intensities. The expected increase of the plasma densities at the EIT wave front estimated from the observed intensity increase lies within the noise level of our density diagnostics from EIS Fe XIII 202/203 A line ratios. No significant LOS plasma motions are observed in the He II line, suggesting that the wave pulse was not strong enough to perturb the underlying chromosphere. This is consistent with the finding that no H{alpha} Moreton wave was associated with the event. The EIT wave propagating along the EIS slit reveals a strong deceleration of a Almost-Equal-To -540 m s{sup -2} and a start velocity of v{sub 0} Almost-Equal-To 590 km s{sup -1}. These findings are consistent with the passage of a coronal fast-mode MHD wave, pushing the plasma downward and compressing it at the coronal base.

  4. Thruster Plume Plasma Diagnostics: A Ground Chamber Experiment for a 2-Kilowatt Arcjet

    NASA Technical Reports Server (NTRS)

    Galofaro, Joel T.; Vayner, Boris V.; Hillard, G. Barry; Chornak, Michael T.

    2005-01-01

    Although detailed near field (0 to 3 cm) information regarding the exhaust plume of a two kilowatt arc jet is available (refs. 1 to 6), there is virtually little or no information (outside of theoretical extrapolations) available concerning the far field (2.6 to 6.1 m). Furthermore real information about the plasma at distances between (3 to 6 m) is of critical importance to high technology satellite companies in understanding the effect of arc jet plume exhausts on space based power systems. It is therefore of utmost importance that one understands the exact nature of the interaction between the arc jet plume, the spacecraft power system and the surrounding electrical plasma environment. A good first step in understanding the nature of the interactions lies in making the needed plume parameter measurements in the far field. All diagnostic measurements are performed inside a large vacuum system (12 m diameter by 18 m high) with a full scale arc jet and solar array panel in the required flight configuration geometry. Thus, necessary information regarding the plume plasma parameters in the far field is obtained. Measurements of the floating potential, the plasma potential, the electron temperature, number density, density distribution, debye length, and plasma frequency are obtained at various locations about the array (at vertical distances from the arc jet nozzle: 2.6, 2.7, 2.8, 3.2, 3.6, 4.0, 4.9, 5.0, 5.4, 5.75, and 6.14 m). Plasma diagnostic parameters are measured for both the floating and grounded configurations of the arc jet anode and array. Spectroscopic optical measurements are then acquired in close proximity to the nozzle, and contamination measurements are made in the vicinity of the array utilizing a mass spectrometer and two Quartz Crystal Microbalances (QCM's).

  5. Circulating MicroRNA-26a in Plasma and Its Potential Diagnostic Value in Gastric Cancer

    PubMed Central

    Liu, Sang; Kang, Meiyun; Chu, Haiyan; Wu, Dongmei; Tong, Na; Gong, Weida; Tao, Guoquan; Zhao, Qinghong; Qiang, Fulin; Zhu, Haixia; Wu, Qin; Wang, Meilin; Zhang, Zhengdong

    2016-01-01

    Background In the past decades, a good deal of studies has provided the possibility of the circulating microRNAs (miRNAs) as noninvasive biomarkers for cancer diagnosis. The aim of our study was to detect the levels of circulating miRNAs in tissues and plasmas of gastric cancer (GC) patients and evaluate their diagnostic value. Methods Tissue samples were collected from 85 GC patients. Plasma samples were collected from 285 GC patients and 285 matched controls. Differentially expressed miRNAs were filtered with by Agilent Human miRNA Microarray and TaqMan low density array (TLDA) with pooled samples, followed by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) validation. Receiver operating characteristic (ROC) curves were structured to evaluate the diagnostic accuracy of the miRNAs. The plasma level of miR-26a in GC patients of different clinical stages was compared. Results Four miRNAs (miR-26a, miR-142-3p, miR-148a, and miR-195) revealed coincidentally decreased levels in tissue and plasma of the GC patients compared with controls, and ROC curves were constructed to demonstrate that miR-26a had a highest area under the ROC curve (AUC) of 0.882. Furthermore, miR-26a was stably detected in the plasma of GC patients with different clinical characteristics. Conclusion Plasma miR-26a may provide a novel and stable marker of gastric cancer. PMID:27010210

  6. Furfuryl methacrylate plasma polymers for biomedical applications.

    PubMed

    Shirazi, Hanieh Safizadeh; Rogers, Nicholas; Michelmore, Andrew; Whittle, Jason D

    2016-01-01

    Furfuryl methacrylate (FMA) is a promising precursor for producing polymers for biomedical and cell therapy applications. Herein, FMA plasma polymer coatings were prepared with different powers, deposition times, and flow rates. The plasma polymer coatings were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results from AFM and SEM show the early growth of the coatings and the existence of particle aggregates on the surfaces. XPS results indicated no measureable chemical differences between the deposited films produced under different power and flow rate conditions. ToF-SIMS analysis demonstrated differing amounts of C5H5O (81 m/z) and C10H9O2 (161 m/z) species in the coatings which are related to the furan ring structure. Through judicious choice of plasma polymerization parameters, the quantity of the particle aggregates was reduced, and the fabricated plasma polymer coatings were chemically uniform and smooth. Primary human fibroblasts were cultured on FMA plasma polymer surfaces to determine the effect of surface chemical composition and the presence of particle aggregates on cell culture. Particle aggregates were shown to inhibit fibroblast attachment and proliferation. PMID:27609095

  7. Application of new simulation algorithms for modeling rf diagnostics of electron clouds

    NASA Astrophysics Data System (ADS)

    Veitzer, Seth A.; Smithe, David N.; Stoltz, Peter H.

    2012-12-01

    Traveling wave rf diagnostics of electron cloud build-up show promise as a non-destructive technique for measuring plasma density and the efficacy of mitigation techniques. However, it is very difficult to derive an absolute measure of plasma density from experimental measurements for a variety of technical reasons. Detailed numerical simulations are vital in order to understand experimental data, and have successfully modeled build-up. Such simulations are limited in their ability to reproduce experimental data due to the large separation of scales inherent to the problem. Namely, one must resolve both rf frequencies in the GHz range, as well as the plasma modulation frequency of tens of MHz, while running for very long simulations times, on the order of microseconds. The application of new numerical simulation techniques allow us to bridge the simulation scales in this problem and produce spectra that can be directly compared to experiments. The first method is to use a plasma dielectric model to measure plasma-induced phase shifts in the rf wave. The dielectric is modulated at a low frequency, simulating the effects of multiple bunch crossings. This allows simulations to be performed without kinetic particles representing the plasma, which both speeds up the simulations as well as reduces numerical noise from interpolation of particle charge and currents onto the computational grid. Secondly we utilize a port boundary condition model to simultaneously absorb rf at the simulation boundaries, and to launch the rf into the simulation. This method improves the accuracy of simulations by restricting rf frequencies better than adding an external (finite) current source to drive rf, and absorbing layers at the boundaries. We also explore the effects of non-uniform plasma densities on the simulated spectra.

  8. 13th TOPICAL CONFERENCE ON HIGH TEMPERATURE PLASMA DIAGNOSTICS SCIENTIFIC PROGRAM

    SciTech Connect

    C. BARNES

    2000-07-01

    Electron cyclotron emission (ECE) has been employed as a standard electron temperature profile diagnostic on many tokamaks and stellarators, but most magnetically confined plasma devices cannot take advantage of standard ECE diagnostics to measure temperature. They are either overdense, operating at high density relative to the magnetic field (e.g. {omega}{sub pe} >> {Omega}{sub ce} in a spherical torus) or they have insufficient density and temperature to reach the blackbody condition ({tau} > 2). Electron Bernstein waves (EBWs) are electrostatic waves which can propagate in overdense plasmas and have a high optical thickness at the electron cyclotron resonance layers, as a result of their large K{sub i}. This talk reports on measurements of EBW emission on the CDX-U spherical torus, where B{sub 0} {approx} 2 kG, {approx} 10{sup 13} cm{sup -3} and T{sub e} {approx} 10 - 200 eV. Results will be presented for both direct detection of EBWs and for mode-converted EBW emission. The EBW emission was absolutely calibrated and compared to the electron temperature profile measured by a multi-point Thomson scattering diagnostic. Depending on the plasma conditions, the mode-converted EBW radiation temperature was found to be {le} T{sub e} and the emission source was determined to be radially localized at the electron cyclotron resonance layer. A Langmuir triple probe was employed to measure changes in edge density profile in the vicinity of the upper hybrid resonance where the mode conversion of the EBWs is expected to occur. Changes in the mode conversion efficiency may explain the observation of mode-converted EBW radiation temperatures below T{sub e}. Initial results suggest EBW emission and EBW heating are viable concepts for plasmas where {omega}{sub pe} >> {Omega}{sub ce}.

  9. Plasma levels of miRNA-155 as a powerful diagnostic marker for dedifferentiated liposarcoma

    PubMed Central

    Boro, Aleksandar; Bauer, David; Born, Walter; Fuchs, Bruno

    2016-01-01

    Atypic lipomatous tumors (ALT) and dedifferentiated liposarcomas (DDLS) are closely related liposarcoma subtypes, often difficult to distinguish but they exhibit an entirely different clinical outcome. Recently discovered regulatory functions of miRNAs in liposarcoma progression prompted us to investigate miRNAs as potential diagnostic biomarkers in liposarcoma with a main focus on circulating miRNAs for fast and reliable differential diagnosis. Tumor and blood samples of 35 patients with lipomatous lesions collected between June 2011 and September 2014 were analyzed by qRT-PCR. They included 10 lipomas, 7 ALT, 5 DDLS and 13 myxoid liposarcomas (MLS). Ten samples of normal fat tissue and blood from 20 healthy volunteers were used as controls. A meta-analysis of public data on miRNA expression in liposarcoma revealed 9 miRNAs with potential diagnostic power. Out of these, miRNA-155 was found significantly elevated in the circulation of DDLS patients as compared to the plasma levels detected in all other liposarcoma subtypes and in healthy subjects. miRNA-155 levels in the plasma samples correlated significantly (r=0.41, p=0.02) with those in corresponding tumor extracts. This correlation was even more pronounced in an analysis of plasma and tumor extracts of malignant liposarcoma subtypes alone (r=0.51, p=0.02). Receiver operating characteristic analysis indicated that plasma miRNA-155 levels have a high diagnostic accuracy for distinguishing DDLS from healthy subjects (AUC=0.91, p=0.005) and from lipomas (AUC=0.86, p=0.02), MLS (AUC=0.92, p=0.006) and most importantly ALT (AUC=0.91, p=0.01) patients. In conclusion, this study identified miRNA-155 as a first blood biomarker for the differential diagnosis of DDLS. PMID:27186423

  10. Temperature diagnostics of a non-thermal plasma jet at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Schäfer, Jan

    2013-09-01

    The study reflects the concept of the temperature as a physical quantity resulting from the second thermodynamic law. The reliability of different approaches of the temperature diagnostics of open non-equilibrium systems is discussed using examples of low temperature atmospheric pressure discharges. The focus of this work is a miniaturized non-thermal atmospheric pressure plasma jet for local surface treatment at ambient atmosphere. The micro-discharge is driven with a capacitively coupled radio frequency electric field at 27.12 MHz and fed with argon at rates of about 1 slm through the capillary with an inner diameter of 4 mm. The discharge consists of several contracted filaments with diameter around 300 μm which are rotating azimuthally in the capillary in a self-organized manner. While the measured temperatures of the filament core exceed 700 K, the heat impact on a target below the plasma jet remains limited leading to target temperatures below 400 K. Different kinds of temperatures and energy transport processes are proposed and experimentally investigated. Nevertheless, a reliable and detailed temperature diagnostics is a challenge. We report on a novel diagnostics approach for the spatially and temporally resolved measurement of the gas temperature based on the optical properties of the plasma. Laser Schlieren Deflectometry is adapted to explore temperature profiles of filaments and their behaviour. In parallel, the method demonstrates a fundamental Fermat's principle of minimal energy. Information acquired with this method plays an important role for the optimization of local thin film deposition and surface functionalization by means of the atmospheric pressure plasma jet. The work was supported in part by the Deutsche Forschungsgemeinschaft within SFB-TR 24.

  11. Label-free surface-enhanced Raman spectroscopy of biofluids: fundamental aspects and diagnostic applications.

    PubMed

    Bonifacio, Alois; Cervo, Silvia; Sergo, Valter

    2015-11-01

    In clinical practice, one objective is to obtain diagnostic information while minimizing the invasiveness of the tests and the pain for the patients. To this end, tests based on the interaction of light with readily available biofluids including blood, urine, or saliva are highly desirable. In this review we examine the state of the art regarding the use of surface-enhanced Raman spectroscopy (SERS) to investigate biofluids, focusing on diagnostic applications. First, a critical evaluation of the experimental aspects involved in the collection of SERS spectra is presented; different substrate types are introduced, with a clear distinction between colloidal and non-colloidal metal nanostructures. Then the effect of the excitation wavelength is discussed, along with anomalous bands and artifacts which might affect SERS spectra of biofluids. The central part of the review examines the literature available on the SERS spectra of blood, plasma, serum, urine, saliva, tears, and semen. Finally, diagnostic applications are critically discussed in the context of the published evidence; this section clearly reveals that SERS of biofluids is most promising as a rapid, cheap, and non-invasive tool for mass screening for cancer. PMID:25935674

  12. Plasma Diagnostics For The Investigation of Silane Based Glow Discharge Deposition Processes

    NASA Astrophysics Data System (ADS)

    Mataras, Dimitrios

    2001-10-01

    In this work is presented the study of microcrystalline silicon PECVD process through highly diluted silane in hydrogen discharges. The investigation is performed by applying different non intrusive plasma diagnostics (electrical, optical, mass spectrometric and laser interferometric measurements). Each of these measurements is related to different plasma sub-processes (gas physics, plasma chemistry and plasma surface interaction) and compose a complete set, proper for the investigation of the effect of external discharge parameters on the deposition processes. In the specific case these plasma diagnostics are applied for prospecting the optimal experimental conditions from the ic-Si:H deposition rate point of view. Namely, the main characteristics of the effect of frequency, discharge geometry, power consumption and total gas pressure on the deposition process are presented successively. Special attention is given to the study of the frequency effect (13.56 MHz 50 MHz) indicating that the correct way to compare results of different driving frequency discharges is by maintaining constant the total power dissipation in the discharge. The important role of frequency in the achievement of high deposition rates and on the optimization of all other parameters is underlined. Finally, the proper combination of experimental conditions that result from the optimal choice of each of the above-mentioned discharge parameters and lead to high microcrystalline silicon deposition rates (7.5 Å/sec) is presented. The increase of silane dissociation rate towards neutral radicals (frequency effect), the contribution of highly sticking to the surface radicals (discharge geometry optimum) and the controlled production of higher radicals through secondary gas phase reactions (total gas pressure), are presented as prerequisites for the achievement of high deposition rates.

  13. Plasma Density Profile Measurement of Accelerated SCT Using Laser Deflection Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Hwang, David; Horton, Robert; Evans, Russ; Howard, Steven

    2002-11-01

    Laser interferometers, while providing accurate line-averaged density measurements, require highly complex apparatus, precision alignment, and high coherence length lasers. A simpler method of obtaining plasma line-averaged density profiles is through the detection of deflection of a laser beam from the changes in the local index of refraction as a result of the density profile. By combining plasma density gradient measurements made at multiple locations and different chords, a plasma density profile can be reconstructed. This method of density profile measurement places far less requirements on the laser quality and alignment procedure. We are investigating the use of arrays of short coherence length diode lasers and point detectors to obtain line-averaged plasma density profiles on the CTIX device. Various density reconstruction methods will be presented. The final goal of this diagnostic is to develop abilities for diagnosing plasma shock fronts created during the deceleration phase of the SCT injector. Work Supported by DOE grant DE-FG03-99ER54558

  14. Issues and Solutions for Implementation of a Nanoparticle Plasma Jet Diagnostic on DIII-D

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Bogatu, I. N.

    2014-10-01

    For ITER, runaway electron (RE) beams are considered a critical problem. Moreover, RE beam dynamics involves processes not yet fully understood or precisely diagnosed. FAR-TECH has proposed using a C60/C plasma jet as a novel diagnostic probe for RE beam-plasma interaction on DIII-D. The existing FAR-TECH prototype plasma jet system is expected to deliver up to ~75 mg C60, at ~4 km/s, and within ~1 ms of triggering, resulting in a free and bound electron density ~2.4 × 1021 m3, about 60 times larger than the typical DIII-D pre-disruption operation value. Implementation of a 100 kJ pulsed power plasma jet system is non-trivial, with electromagnetic interference (EMI) and safety being two major issues. Microsecond timescale, high current drivers generate significant EMI from which other DIII D systems need to be shielded. Safety issues associated with high voltage and potential capacitor failure must also be addressed. We will present the status of our investigation into the principle solutions for the critical issues involved in the implementation of FAR-TECH's prototype C60/C plasma jet system on DIII-D. Work supported by US DOE Grant DE-SC0011864.

  15. Plasma spectroscopy diagnostics in pulsed-power X-ray radiography diode research.

    SciTech Connect

    Maron, Yitzhak; Oliver, Bryan Velten; Portillo, Salvador; Johnston, Mark D.; Rose, David Vincent; Hahn, Kelly Denise; Schamiloglu, Edl; Welch, Dale R.; Droemer, Darryl W.; Rovang, Dean Curtis; Maenchen, John Eric

    2005-07-01

    Spectroscopic investigations in the visible and near UV are underway to study plasmas present in X-ray radiography diodes during the time of the electron beam propagation. These studies are being performed on the RITS-3 accelerator (5.25 MV and 120 kA) at Sandia National Laboratories using several diode configurations. The proper characterization of the plasmas occurring during the time of the X-ray pulse can lead to a greater understanding of diode behavior and X-ray spot size evolution. By studying these plasmas along with the use of selective dopants, insights into such phenomena as impedance collapse, thermal and non-thermal species behavior, charge and current neutralization, anode and cathode plasma formation and propagation, and beam/foil interactions, can be obtained. Information from line and continuum emission and absorption can give key plasma parameters such as temperatures, densities, charge states, and expansion velocities. This information is important for proper modeling and future predictive capabilities for the design and improvement of flash X-ray radiography diodes. Diagnostics include a gated, intensified multichannel plate camera combined with a 1 meter Czerny-Turner monochromator with a multi-fiber spectral input, allowing for both temporal and spatial resolution. Recent results are presented.

  16. Experimental investigations of plasma perturbation in Thomson scattering applied to thermal plasma diagnostics

    SciTech Connect

    Dzierzega, Krzysztof; Zawadzki, Witold; Pokrzywka, Bartlomiej; Pellerin, Stephane

    2006-08-15

    Time and space resolved measurements of Thomson scattering of 532 nm, 6 ns laser pulses were performed on argon thermal discharge plasma with electron temperature T{sub e}>10 000 K and electron density 8x10{sup 22} m{sup -3}plasma. The initial 'undisturbed' electron density was derived by studying the spatial variations of n{sub e} within the laser beam. On the other hand, the initial electron temperature was determined by studying the temporal evolution of T{sub e} during the laser pulse and then by extrapolating the results to the origin of the pulse. Despite strong and nonlinear plasma heating by the Thomson scattered laser light, our study yields temperatures close to those obtained by modeling and time-resolved spectroscopic measurements.

  17. SiC detector damage and characterization for high intensity laser-plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Cannavò, A.

    2016-05-01

    Silicon-Carbide (SiC) detectors are always more extensively employed as diagnostics in laser-generated plasma due to their remarkable properties such as their high band gap, high carrier velocity, high detection efficiency, high radiation resistance and low leakage current at room temperature. SiC detectors, in comparison with Si detectors, have the advantage of being insensitive to visible light, having low reverse current at high temperature and high radiation hardness. A similar energy resolution characterizes the two types of detectors, being 0.8% in Si and 1.0% in SiC, as measured detecting 5.8 MeV alpha particles. Generally, SiC detectors are employed as laser-plasma diagnostics in time-of-flight configuration, permitting the simultaneous detection of photons, electrons and ions based on discrimination of velocity. SiC detectors can be employed in the proportionality regime, because their response is proportional to the radiation energy deposited in the active layer. Using thin absorbers in front of the detectors makes it possible to have further information on the radiation nature, intensity and energy. Surface characterization of SiC before and after prolonged exposure to hot plasma laser generated shows the formation of bulk defects and thin film deposition on the detector surface limiting the device functionality.

  18. A simple, high performance Thomson scattering diagnostic for high temperature plasma research

    SciTech Connect

    Hartog, D.J.D.; Cekic, M.

    1994-02-01

    This Thomson scattering diagnostic is used to measure the electron temperature and density of the plasma in the MST reversed-field pinch, a magnetic confinement fusion research device. This diagnostic system is unique for its type in that it combines high performance with simple design and low cost components. In the design of this instrument, careful attention was given to the suppression of stray laser line light with simple and effective beam dumps, viewing dumps, aperatures, and a holographic edge filter. This allows the use of a single grating monochromator for dispersion of the Thomson scattered spectrum onto the microchannel plate detector. Alignment and calibration procedures for the laser beam delivery system, the scattered light collection system, and the spectrometer and detector are described. A sample Thomson scattered spectrum illustrates typical data.

  19. Materials analysis and particle probe: A compact diagnostic system for in situ analysis of plasma-facing components (invited)

    SciTech Connect

    Taylor, C. N.; Heim, B.; Gonderman, S.; Allain, J. P.; Yang, Z.; Kaita, R.; Roquemore, A. L.; Skinner, C. H.; Ellis, R. A.

    2012-10-15

    The objective of the materials analysis particle probe (MAPP) in NSTX is to enable prompt and direct analysis of plasma-facing components exposed to plasma discharges. MAPP allows multiple samples to be introduced to the level of the plasma-facing surface without breaking vacuum and analyzed using X-ray photoelectron spectroscopy (XPS), ion-scattering and direct recoil spectroscopy, and thermal desorption spectroscopy (TDS) immediately following the plasma discharge. MAPP is designed to operate as a diagnostic within the {approx}12 min NSTX minimum between-shot time window to reveal fundamental plasma-surface interactions. Initial calibration demonstrates MAPP's XPS and TDS capabilities.

  20. Materials analysis and particle probe: a compact diagnostic system for in situ analysis of plasma-facing components (invited).

    PubMed

    Taylor, C N; Heim, B; Gonderman, S; Allain, J P; Yang, Z; Kaita, R; Roquemore, A L; Skinner, C H; Ellis, R A

    2012-10-01

    The objective of the materials analysis particle probe (MAPP) in NSTX is to enable prompt and direct analysis of plasma-facing components exposed to plasma discharges. MAPP allows multiple samples to be introduced to the level of the plasma-facing surface without breaking vacuum and analyzed using X-ray photoelectron spectroscopy (XPS), ion-scattering and direct recoil spectroscopy, and thermal desorption spectroscopy (TDS) immediately following the plasma discharge. MAPP is designed to operate as a diagnostic within the ∼12 min NSTX minimum between-shot time window to reveal fundamental plasma-surface interactions. Initial calibration demonstrates MAPP's XPS and TDS capabilities. PMID:23126877

  1. Diagnostics of high-brightness short-pulse lasers and the plasmas they generate

    SciTech Connect

    Kyrala, G.A.; Fulton, R.D.; Cobble, J.A.; Schappert, G.T.; Taylor, A.J.

    1994-02-01

    The properties of a laser influence the interaction of the intense laser light with materials. The authors will describe some of the diagnostics that they have implemented at the Los Alamos Bright Source to correlate the changes in the x-ray spectrum and temporal history of a laser generated silicon plasmas with the changes of the incident XeCl laser light. One property is of special interest, the existence of a short prepulse. They find that the prepulse enhances the generation of the x-rays from a later pulse.

  2. Spectroscopic diagnostics of superthermal electrons with high-number harmonic EC radiation in tokamak reactor plasmas

    NASA Astrophysics Data System (ADS)

    Minashin, P. V.; Kukushkin, A. B.

    2015-03-01

    A method of spectroscopic diagnostics of the average perpendicular-to-magnetic-field momentum of the superthermal component of the electron velocity distribution (EVD), based on the high-number-harmonic electron cyclotron (EC) radiation, is suggested for nuclear fusion-reactor plasmas under condition of a strong auxiliary heating (e.g. in tokamak DEMO, a next step after tokamak ITER). The method is based on solving an inverse problem for reconstruction of the EVD in parallel and perpendicular-to-magnetic-field components of electron momentum at high and moderate energies responsible for the emission of the high-number-harmonic EC radiation.

  3. Soft x-ray pinhole imaging diagnostics for compact toroid plasmas

    NASA Astrophysics Data System (ADS)

    Crawford, E. A.; Taggart, D. P.; Bailey, A. D., III

    1990-10-01

    Soft x-ray pinhole imaging has recently become established as a valuable diagnostic for visualization of field reversed configuration (FRC) plasmas in the TRX-2, FRX-C/LSM devices. Gated MCP image converter devices with CsI cathodes and Be filters with a peak response around 11 nm wavelength are used for exposure durations ranging from a few tenths up to several microseconds. Results of experiments with single and Chevron channel plates are discussed along with estimates of linear exposure limitations with both film and CCD cameras as recording media. Plans for multiframe devices on the FRX-C/LSM and the LSX devices are also discussed.

  4. A novel ultra-thin 3D detector—For plasma diagnostics at JET and ITER tokamaks

    NASA Astrophysics Data System (ADS)

    García, Francisco; Pelligrini, G.; Balbuena, J.; Lozano, M.; Orava, R.; Ullan, M.

    2009-08-01

    A novel ultra-thin silicon detector called U3DTHIN has been designed and built for applications that range from Neutral Particle Analyzers (NPA) used in Corpuscular Diagnostics of High Temperature Plasma to very low X-ray spectroscopy. The main purpose of this detector is to provide a state-of-the-art solution to upgrade the current detector system of the NPAs at JET and also to pave the road for the future detection systems of the ITER experimental reactor. Currently the NPAs use a very thin scintillator-photomultiplier tube [F. García, S.S. Kozlovsky, D.V. Balin, Background Properties of CEM, MCP and PMT detectors at n-γ irradiation. Preprint PNPI-2392, Gatchina, 2000, p. 9 [1]; F. García, S.S. Kozlovsky, V.V. Ianovsky, Scintillation Detectors with Low Sensitivity to n-γ Background. Preprint PNPI-2391, Gatchina, 2000, p. 8 [2

  5. A real-time algorithm for the harmonic estimation and frequency tracking of dominant components in fusion plasma magnetic diagnostics

    SciTech Connect

    Alves, D.; Coelho, R. [Associação Euratom Collaboration: JET-EFDA Contributors

    2013-08-15

    The real-time tracking of instantaneous quantities such as frequency, amplitude, and phase of components immerse in noisy signals has been a common problem in many scientific and engineering fields such as power systems and delivery, telecommunications, and acoustics for the past decades. In magnetically confined fusion research, extracting this sort of information from magnetic signals can be of valuable assistance in, for instance, feedback control of detrimental magnetohydrodynamic modes and disruption avoidance mechanisms by monitoring instability growth or anticipating mode-locking events. This work is focused on nonlinear Kalman filter based methods for tackling this problem. Similar methods have already proven their merits and have been successfully employed in this scientific domain in applications such as amplitude demodulation for the motional Stark effect diagnostic. In the course of this work, three approaches are described, compared, and discussed using magnetic signals from the Joint European Torus tokamak plasma discharges for benchmarking purposes.

  6. Wave launching as a diagnostic tool to investigate plasma turbulence (abstract)

    NASA Astrophysics Data System (ADS)

    Tsui, H. Y. W.; Bengtson, R. D.; Li, G. X.; Richards, B.; Uckan, T.; Uglum, J.; Wootton, A. J.

    1995-01-01

    An experimental scheme to extend the investigation of plasma turbulence has been implemented. It involves driving waves into the plasma to modify the statistical properties of the fluctuations; the dynamical balance of the turbulence is perturbed via the injection of waves at selected spectral regions. New analysis techniques based on conditional sampling and high order correlation are developed for studying the wave launching and the wave-wave coupling processes. Experimental results from TEXT-U tokamak show that the launched waves interact with the intrinsic fluctuations both linearly and nonlinearly. The attainment of driven nonlinearity is necessary for this diagnostic scheme to work. It is also the key to an active modification and control of edge turbulence in tokamaks.

  7. Optical and electrical diagnostics for the investigation of edge turbulence in fusion plasmas

    SciTech Connect

    Cavazzana, R.; Scarin, P.; Serianni, G.; Agostini, M.; Degli Agostini, F.; Cervaro, V.; Lotto, L.; Yagi, Y.; Sakakita, H.; Koguchi, H.; Hirano, Y.

    2004-10-01

    A new, two dimensional and fast diagnostic system has been developed for studying the dynamic structure of plasma turbulence; it will be used in the edge of the reversed-field pinch devices TPE-RX and RFX. The system consists of a gas-puffing nozzle, 32 optical channels measuring H{sub {alpha}} emitted from the puffed gas (to study the optical emissivity of turbulent patterns and to analyze structures in two dimensions), and an array of Langmuir probes (to compare the turbulent pattern with the optical method and to measure the local plasma parameters). The signals can be acquired at 10 Msamples/s with 2 MHz band width. The design of the system, calibrations, and tests of the electronic circuitry and the optical sensors are presented.

  8. Diagnostics of ion beam generated from a Mather type plasma focus device

    SciTech Connect

    Lim, L. K. Ngoi, S. K. Wong, C. S. Yap, S. L.

    2014-03-05

    Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 10{sup 11} per shot. Solid state nuclear track detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.

  9. Computer-aided application of quantitative microscopy in diagnostic pathology.

    PubMed

    Baak, J P; Kurver, P H; Boon, M E

    1982-01-01

    The quantitative analysis of microscopic images gives objective, consistently reproducible results. The number of applications of such analysis in diagnostic pathology is increasing rapidly. In this chapter, two examples have been given of the development and application of a quantitative microscopic classification rule. Both examples involve admittedly difficult areas of diagnostic pathology, in which considerable disagreement may not only exist among pathologists, but may affect the same pathologist judging the same specimen at different times. These areas are: (1) the discrimination of endometrial hyperplasia from carcinoma, and the grading of endometrial carcinomas; and (2) the preoperative distinction of follicular adenoma from carcinoma of the thyroid in cytologic specimens. With routine use of the classification rule in 148 cases of endometrial hyperplasia or carcinoma received in our laboratory in 1980, with each case judged by one of eight pathologists, there was mild or absolute disagreement in 7.4 percent and 4.7 percent of the cases, respectively (total: 12.1 percent). However, with blind review of one of us (J.B.), there were no absolute and only 3.3 percent mild disagreement. In this series, the quantitative microscopically assigned grades of carcinomas correlated significantly with the depth of invasion in the myometrial wall, whereas the grade routinely indicated by eight pathologists did not. These two facts strongly support the quality and utility of the developed quantitative microscopic rule for classifying endometrial lesions in a diagnostic setting. The rule can also be used to objectively define such endometrial lesions in order to evaluate more accurately their clinical outcome in a prospective study. In the thyroid adenoma cases discussed in the chapter, material from follicular tumors was subjected to quantitative analysis in 1980, again using a classification rule developed in our laboratory. All 10 cases of adenoma were correctly

  10. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Rácz, R.; Biri, S.; Pálinkás, J.; Mascali, D.; Castro, G.; Caliri, C.; Romano, F. P.; Gammino, S.

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  11. An Optical Streak Diagnostic for Observing Anode-Cathode Plasmas for Radiographic Source Development

    SciTech Connect

    Droemer, Darryl W.; Crain, Marlon D.; Lare, Gregory A.; Bennett, Nichelle L.; Johnston, Mark D.

    2013-06-13

    National Security Technologies, LLC, and Sandia National Laboratories are collaborating in the development of pulsed power–driven flash x-ray radiographic sources that utilize high-intensity electron beam diodes. The RITS 6 (Radiographic Integrated Test Stand) accelerator at Sandia is used to drive a self magnetic pinch diode to produce a Bremsstrahlung x-ray source. The high electric fields and current densities associated with these short A-K gap pinch beam diodes present many challenges in diode development. Plasmas generated at both the anode and cathode affect the diode performance, which is manifested in varying spot (source) sizes, total dose output, and impedance profiles. Understanding the nature of these plasmas including closure rates and densities is important in modeling their behavior and providing insight into their mitigation. In this paper we describe a streak camera–based optical diagnostic that is capable of observing and measuring plasma evolution within the A-K gap. By imaging a region of interest onto the input slit of a streak camera, we are able to produce a time-resolved one-dimensional image of the evolving plasma. Typical data are presented.

  12. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics.

    PubMed

    Rácz, R; Biri, S; Pálinkás, J; Mascali, D; Castro, G; Caliri, C; Romano, F P; Gammino, S

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented. PMID:26931959

  13. The information-expert system for complex diagnostics and researches of technological plasma

    SciTech Connect

    Kresnin, Yu.A.; Stervoedov, S.N.

    1996-12-31

    The information-expert system for complex diagnostics and researches of technological plasma includes closely connected hardware and program part. The hardware consists of the set of intelligent sensors, possessing optical isolation on information channels, and functional modules, incorporated crate CAMAC. Crate is connected by serial interface with IBM-compatible computer. The intelligent sensors are realized on the basis of microcontroller Intel MCS51. They are used for multisensor and spectroscopical measurements of plasma parameters, laser measurement of plasma etched surfaces thickness, measurements of parameters of generators and power supplies of plasma sources. The information from the sensor sis sent on functional modules for preliminary processing and compression, and further, through controller crate--in computer. The program part provides the exchange by information of computer with crate, restores the amplitude-frequent and temporary characteristics of signals, compares them with chosen models of technological process, produces the recommendations on change of operating modes, optimizes technological process as a whole and carries out the documenting of researches.

  14. UV Laser Diagnostics of the 1-MA Z-pinch Plasmas

    SciTech Connect

    Altemara, S. D.; Ivanov, V. V.; Astanovitskiy, A. L.; Haboub, A.

    2009-01-21

    The 532 nm laser diagnostic set at the Zebra generator shows the details of the ablation and stagnation phases in cylindrical, planar, and star-like wire arrays but it cannot show the structure of the stagnated z-pinch and the implosion in small diameter loads, 1-3 mm in diameter. The absorption increment and the refraction angle of the 532 nm laser, when passing through the plasma, are too great to obtain quality images. An ultraviolet probing beam at the wavelength of 266 nm was developed to study small-diameter loads and to investigate the structure of the 1-MA z-pinch. The UV radiation has a much smaller absorption increment and refraction angles in plasmas than the 532 nm light and allows for better imaging of the z-pinch plasmas. Estimates showed that UV probing would be able to probe the high-density z-pinch plasma in experiments on the Zebra generator, and the early results of UV probing on the Zebra generator have shown promise.

  15. Novel scanner characterization method for color measurement and diagnostics applications

    NASA Astrophysics Data System (ADS)

    Lee, Bong-Sun; Bala, Raja; Sharma, Gaurav

    2006-02-01

    We propose a novel scanner characterization approach for applications requiring color measurement of hardcopy output in printer calibration, characterization, and diagnostic applications. It is assumed that a typical printed medium comprises the three basic colorants C, M, Y. The proposed method is particularly advantageous when additional colorants are used in the print (e.g. black (K)). A family of scanner characterization targets is constructed, each varying in C, M, Y and at a fixed level of K. A corresponding family of 3-D scanner characterizations is derived, one for each level of K. Each characterization maps scanner RGB to a colorimetric representation such as CIELAB, using standard characterization techniques. These are then combined into a single 4-D characterization mapping RGBK to CIELAB. A refinement of the technique improves performance significantly by using a function of the scanned values for K (e.g. the scanner's green channel response to printed K) instead of the digital K value directly. This makes this new approach more robust with respect to variations in printed K over time. Secondly it enables, with a single scanner characterization, accurate color measurement of prints from different printers within the same family. Results show that the 4-D characterization technique can significantly outperform standard 3-D approaches especially in cases where the image being scanned is a patch target made up of unconstrained CMYK combinations. Thus the algorithm finds particular use in printer characterization and diagnostic applications. The method readily generalizes to printed media containing other (e.g "hi-fi") colorants, and also to other image capture devices such as digital cameras.

  16. Nanomaterials for Photo-Based Diagnostic and Therapeutic Applications

    PubMed Central

    Menon, Jyothi U.; Jadeja, Parth; Tambe, Pranjali; Vu, Khanh; Yuan, Baohong; Nguyen, Kytai T.

    2013-01-01

    Photo-based diagnosis and treatment methods are gaining prominence due to increased spatial imaging resolution, minimally invasive modalities involved as well as localized treatment. Recently, nanoparticles (NPs) have been developed and used in photo-based therapeutic applications. While some nanomaterials have inherent photo-based imaging capabilities, others including polymeric NPs act as nanocarriers to deliver various fluorescent dyes or photosensitizers for photoimaging and therapeutic applications. These applications can vary from Magnetic Resonance Imaging (MRI) and optical imaging to photothermal therapy (PTT) and chemotherapy. Materials commonly used for development of photo-based NPs ranges from metal-based (gold, silver and silica) to polymer-based (chitosan, dextran, poly ethylene glycol (PEG) and poly lactic-co-glycolic acid (PLGA)). Recent research has paved the way for multi-modal 'theranostic' (a combination of therapy and diagnosis) nano-carriers capable of active targeting using cell-specific ligands and carrying multiple therapeutic and imaging agents for accurate diagnosis and controlled drug delivery. This review summarizes the different materials used today to synthesize photo-based NPs, their diagnostic and therapeutic applications as well as the current challenges faced in bringing these novel nano-carriers into clinical practices. PMID:23471164

  17. Continuum emission-based electron diagnostics for atmospheric pressure plasmas and characteristics of nanosecond-pulsed argon plasma jets

    NASA Astrophysics Data System (ADS)

    Park, Sanghoo; Choe, Wonho; Kim, Holak; Park, Joo Young

    2015-06-01

    Electron diagnostics based on electron-neutral atom (e-a) bremsstrahlung in the UV and visible range emitted from atmospheric pressure plasmas is presented. Since the spectral emissivity of the e-a bremsstrahlung is determined by electron density (ne) and mean electron temperature (Te) representing the Maxwellian electron energy distribution, their diagnostics is possible. As an example, emission spectra measured from capacitive discharges are presented, which show good agreement with the theoretically calculated emissivity of the e-a bremsstrahlung. For a single pin electrode nanosecond-pulsed plasma jet (n-PPJ) in argon, we investigate the electron properties and the temporal behavior of the positive streamers. Streamers with many branches are clearly observed inside the dielectric tube, while a few main streamers propagate outside the tube along the jet axis. A two-dimensional (2D) measurement of the time-averaged Te distribution was developed using a commercial digital camera and optical band pass filters based on the emissivity ratio of two wavelengths of the e-a bremsstrahlung. The viable measurement range of Te is 0.5-7 eV for the choice of two wavelengths of 300s and 900s nm and 0.5-4 eV for two wavelengths of 400s and 900s nm, which are uncontaminated by the atomic and/or molecular spectra. The 2D Te distribution obtained using 514.5 and 632.8 nm emissions helps to reveal the role of electrons in streamer characteristics in the argon n-PPJ. Time-averaged Te of 2.0 eV and 1.0 eV inside and outside the tube, respectively, were measured. The streamer dynamics of the n-PPJ is shown to be dependent on Te.

  18. Clinical applications of plasma based electrosurgical systems

    NASA Astrophysics Data System (ADS)

    Woloszko, Jean; Endler, Ashley; Ryan, Thomas P.; Stalder, Kenneth R.

    2013-02-01

    Over the past 18 years, several electrosurgical systems generating a low temperature plasma in an aqueous conductive solution have been commercialized for various clinical applications and have been used in over 10 million patients to date. The most popular utilizations are in arthroscopic surgery, otorhinolaryngology surgery, spine and neurosurgery, urology and wound care. These devices can be configured to bring saline to the tip and to have concomitant aspiration to remove by-products and excess fluid. By tuning the electrode geometry, waveform and fluid dynamic at the tip of the devices, tissue resection and thermal effects can be adjusted individually. This allows one to design products that can operate as precise tissue dissectors for treatment of articular cartilage or debridement of chronic wounds, as well as global tissue debulking devices providing sufficient concomitant hemostasis for applications like tonsillectomies. Effects of these plasma based electrosurgical devices on cellular biology, healing response and nociceptive receptors has also been studied in various models. This talk will include a review of the clinical applications, with product descriptions, results and introductory review of some of the research on the biological effects of these devices.

  19. ALCBEAM - Neutral beam formation and propagation code for beam-based plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Bespamyatnov, I. O.; Rowan, W. L.; Liao, K. T.

    2012-03-01

    ALCBEAM is a new three-dimensional neutral beam formation and propagation code. It was developed to support the beam-based diagnostics installed on the Alcator C-Mod tokamak. The purpose of the code is to provide reliable estimates of the local beam equilibrium parameters: such as beam energy fractions, density profiles and excitation populations. The code effectively unifies the ion beam formation, extraction and neutralization processes with beam attenuation and excitation in plasma and neutral gas and beam stopping by the beam apertures. This paper describes the physical processes interpreted and utilized by the code, along with exploited computational methods. The description is concluded by an example simulation of beam penetration into plasma of Alcator C-Mod. The code is successfully being used in Alcator C-Mod tokamak and expected to be valuable in the support of beam-based diagnostics in most other tokamak environments. Program summaryProgram title: ALCBEAM Catalogue identifier: AEKU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 66 459 No. of bytes in distributed program, including test data, etc.: 7 841 051 Distribution format: tar.gz Programming language: IDL Computer: Workstation, PC Operating system: Linux RAM: 1 GB Classification: 19.2 Nature of problem: Neutral beams are commonly used to heat and/or diagnose high-temperature magnetically-confined laboratory plasmas. An accurate neutral beam characterization is required for beam-based measurements of plasma properties. Beam parameters such as density distribution, energy composition, and atomic excited populations of the beam atoms need to be known. Solution method: A neutral beam is initially formed as an ion beam which is extracted from

  20. Coherent anti-Stokes Raman scattering and spontaneous Raman scattering diagnostics of nonequilibrium plasmas and flows

    NASA Astrophysics Data System (ADS)

    Lempert, Walter R.; Adamovich, Igor V.

    2014-10-01

    The paper provides an overview of the use of coherent anti-Stokes Raman scattering (CARS) and spontaneous Raman scattering for diagnostics of low-temperature nonequilibrium plasmas and nonequilibrium high-enthalpy flows. A brief review of the theoretical background of CARS, four-wave mixing and Raman scattering, as well as a discussion of experimental techniques and data reduction, are included. The experimental results reviewed include measurements of vibrational level populations, rotational/translational temperature, electric fields in a quasi-steady-state and transient molecular plasmas and afterglow, in nonequilibrium expansion flows, and behind strong shock waves. Insight into the kinetics of vibrational energy transfer, energy thermalization mechanisms and dynamics of the pulse discharge development, provided by these experiments, is discussed. Availability of short pulse duration, high peak power lasers, as well as broadband dye lasers, makes possible the use of these diagnostics at relatively low pressures, potentially with a sub-nanosecond time resolution, as well as obtaining single laser shot, high signal-to-noise spectra at higher pressures. Possibilities for the development of single-shot 2D CARS imaging and spectroscopy, using picosecond and femtosecond lasers, as well as novel phase matching and detection techniques, are discussed.

  1. Plasma magnetic field diagnostic using two-photon Doppler-free LIF

    NASA Astrophysics Data System (ADS)

    Yoon, Young Dae; Bellan, Paul

    2015-11-01

    A detailed description of a new plasma B field diagnostic using Doppler-free two-photon laser-induced fluorescence is presented. The diagnostic is based on a method previously developed in the context of rubidium vapor experiments. Two counter-propagating 393nm diode laser beams are directed into an argon plasma to excite Ar-II ions from 3s2 3p4 4 s4P1 / 2 ⟶ 3s2 3p4 4 p4S3 / 2 ⟶ 3s2 3p4 4 d4P3 / 2 . These levels involve two similar (392.86 and 393.25nm) transition wavelengths, so the two counter-propagating beams effectively cancel out the Doppler effect. The excited ions then decay to the 3s2 3p4 4 p4P1 / 2 level, emitting a 324.98nm line which is to be detected by a photomultiplier tube. The Zeeman splitting -- normally unobservable because of the large Doppler broadening -- of the resultant fluorescence is then to be analyzed, yielding the magnetic field of the particular location. This method is expected to provide a 3-D localized, non-perturbing measurement of magnetic fields. An experimental implementation is currently in progress.

  2. Superparamagnetic nanoparticles as targeted probes for diagnostic and therapeutic applications.

    PubMed

    Xu, Chenjie; Sun, Shouheng

    2009-08-01

    Superparamagnetic nanoparticles (NPs) have been attractive for medical diagnostics and therapeutics due to their unique magnetic properties and their ability to interact with various biomolecules of interest. The solution phase based chemical synthesis provides a near precise control on NP size, and monodisperse magnetic NPs with standard deviation in diameter of less than 10% are now routinely available. Upon controlled surface functionalization and coupling with fragments of DNA strands, proteins, peptides or antibodies, these NPs can be well-dispersed in biological solutions and used for drug delivery, magnetic separation, magnetic resonance imaging contrast enhancement and magnetic fluid hyperthermia. This Perspective reviews the common syntheses and controlled surface functionalization of monodisperse Fe(3)O(4)-based superparamagnetic NPs. It further outlines the exciting application potentials of these NPs in magnetic resonance imaging and drug delivery. PMID:20449070

  3. Statistics of biospeckles with application to diagnostics of periodontitis

    NASA Astrophysics Data System (ADS)

    Starukhin, Pavel Y.; Kharish, Natalia A.; Sedykh, Alexey V.; Ulyanov, Sergey S.; Lepilin, Alexander V.; Tuchin, Valery V.

    1999-04-01

    Results of Monte-Carlo simulations Doppler shift are presented for the model of random medium that contain moving particles. The single-layered and two-layered configurations of the medium are considered. Doppler shift of the frequency of laser light is investigated as a function of such parameters as absorption coefficient, scattering coefficient, and thickness of the medium. Possibility of application of speckle interferometry for diagnostics in dentistry has been analyzed. Problem of standardization of the measuring procedure has been studied. Deviation of output characteristics of Doppler system for blood microcirculation measurements has been investigated. Dependence of form of Doppler spectrum on the number of speckles, integration by aperture, has been studied in experiments in vivo.

  4. Diagnostic Applications of Cone-Beam CT for Periodontal Diseases

    PubMed Central

    AlJehani, Yousef A.

    2014-01-01

    Objectives. This paper aims to review the diagnostic application of cone beam computed tomography (CBCT) in the field of periodontology. Data. Original articles that reported on the use of CBCT for periodontal disease diagnosis were included. Sources. MEDLINE (1990 to January 2014), PubMed (using medical subject headings), and Google Scholar were searched using the following terms in different combinations: “CBCT,” “volumetric CT,” “periodontal disease ,” and “periodontitis.” This was supplemented by hand-searching in peer-reviewed journals and cross-referenced with the articles accessed. Conclusions. Bony defects, caters, and furcation involvements seem to be better depicted on CBCT, whereas bone quality and periodontal ligament space scored better on conventional intraoral radiography. CBCT does not offer a significant advantage over conventional radiography for assessing the periodontal bone levels. PMID:24803932

  5. Analyses of substantially different plasma current densities and safety factors reconstructed from magnetic diagnostics data

    NASA Astrophysics Data System (ADS)

    Zaitsev, F. S.; Kostomarov, D. P.; Suchkov, E. P.; Drozdov, V. V.; Solano, E. R.; Murari, A.; Matejcik, S.; Hawkes, N. C.; Contributors, JET-EFDA

    2011-10-01

    The problem of plasma current density and safety factor reconstruction using magnetic field measurements is considered. In the traditional formulation, the problem is strongly ill-posed. In particular, substantially different current densities and safety factors can be equally well attributed to the same set of measurements, given their experimental errors. In other words, the problem can be strongly unstable with respect to the input data. Different constraints are used in practice to make the problem more stable. This paper presents an accurate mathematical formulation of the inverse problem and its variants. A numerical algorithm is provided, which permits us to study the stability with respect to variations in the input data, to find all substantially different solutions, or to prove their absence, and to determine the confidence intervals of the reconstructions. The proposed method also allows establishing the maximum error for a given diagnostic (additional constraint), below which the diagnostic efficiently extracts one solution among several substantially different ones. Examples of very different current density and safety factor reconstructions for measurements with finite accuracy are presented for the original formulation of the inverse problem. Cases of MAST, JET and ITER-like plasmas are considered. It is shown that including the motional Stark effect (MSE) measurements as a constraint, provided the accuracy of MSE measurements is sufficient, allows identifying one solution among several very different ones, obtained without such a constraint. The maximum MSE diagnostics error for efficient identification of this solution is estimated for JET. The approach of this paper can be used for a wide range of ill-posed problems in physics and can help in selecting additional conditions, which can identify the most likely solution among several.

  6. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Kubo, S.; Tanaka, K.; Seki, R.; Ogasawara, S.; Shimozuma, T.; Okada, K.; Kobayashi, S.; Mutoh, T.; Kawahata, K.; Watari, T.; LHD Experiment Group; Saito, T.; Tatematsu, Y.; Korsholm, S. B.; Salewski, M.

    2014-02-01

    A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron cyclotron heating beam. To clarify the diagnostic applicability of the gyrotron in the 77 GHz frequency band, we investigated the dependence of the probe and receiver beam trajectories in plasmas with high electron densities of (4-5) × 1019 m-3 and low electron densities of (1-2) × 1019 m-3. At high density, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1-2 keV for electron densities of (1-2) × 1019 m-3 and electron temperatures of 2-4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v‖, v⊥) based on Monte Carlo simulation results. The analysis method of the CTS spectra is used to evaluate the ion temperature and fast-ion velocity distribution from the measured CTS data.

  7. Contact glow discharge electrolysis: its origin, plasma diagnostics and non-faradaic chemical effects

    NASA Astrophysics Data System (ADS)

    Gupta, Susanta K. Sen

    2015-12-01

    Contact glow discharge electrolysis (CGDE) also termed plasma electrolysis is a novel electrolysis where a stable sheath of light emitting plasma develops around an electrode immersed well inside a relatively high-conductivity liquid electrolyte during normal electrolysis (NE) at several hundred volts. The phenomenon may develop in dc-, pulsed dc-, ac- as well as RF-driven electrolyses. The chemical effects of CGDE are remarkably non-faradaic in respect to the nature of the products as well as their yields. The article traces comprehensively the progress made in studies of CGDE in aqueous and non-aqueous solutions since 1844 and reviews the developments in the understanding of its origin, light emission, plasma state and non-faradaic effects leading to the elucidation of detailed mechanism of the origin of CGDE on the basis of the onset of hydrodynamic instabilities in local vaporization of the solvent near the working electrode during NE, and that of highly non-faradaic effects of CGDE based on a model of two reaction zones located within the electrode plasma and at the plasma-liquid interface producing solvent derived radicals at high local concentrations. Keeping in view the recent surge of interest in varied applications of CGDE, the article is appended with highlights of these applications across synthetic chemistry, waste water treatment, electrosurgical devices, nanoparticle fabrications, surface engineering and micro-machining.

  8. Plasma diagnostics from self-absorbed doublet lines in laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    D'Angelo, C. A.; Garcimuño, M.; Díaz Pace, D. M.; Bertuccelli, G.

    2015-10-01

    In this paper, a generalized approach is developed and applied for plasma characterization and quantitative purposes in laser-induced breakdown spectroscopy (LIBS) experiences by employing a selected pair of spectral lines belonging to the same multiplet. It is based on the comparison between experimental ratios of line parameters and the theoretical calculus obtained under the framework of a homogeneous plasma in local thermodynamic equilibrium. The applicability of the method was illustrated by using the atomic resonance transitions 279.55-280.27 nm of Mg II, which are usually detected in laser-induced plasma (LIP) during laser ablation of many kinds of targets. The laser induced plasmas were produced using a Nd:YAG laser from a pressed pellet of powdered calcium hydroxide with a concentration of 300 ppm of Mg. The experimental ratios for peak intensities, total intensities and Stark widths were obtained for different time windows and matched to the theoretical calculus. The temperature and the electron density of the plasma, as well as the Mg columnar density (the atom/ion concentration times the length of the plasma along the line-of-sight), were determined. The results were interpreted under the employed approach.

  9. Multilayer vacuum window for wide-band microwave plasma diagnostic systems

    SciTech Connect

    Cavazzana, Roberto; Moresco, Maurizio

    2006-10-15

    Microwave diagnostics, e.g., reflectometry and electron cyclotron emission in plasma machines, often require large windows displaying low attenuation and reflection on a wide band, in addition to some basic features such as vacuum tightness and mechanical robustness. Wide-band matching is usually achieved by coating the window with dielectric layers of suitable permittivity and thickness. On the vacuum side the coating must also be vacuum compatible and resistant to the thermal radiation coming from plasma. On the RFX machine, to satisfy these requirements, a boron nitride disk properly machined on the surface facing the plasma has been clamped to the existing fused silica window. The addition of a Teflon layer on the air side allowed to attain power reflection coefficients as low as 0.025 in the frequency ranges of 26.5-40, 40-56, and 56-75 GHz and as low as 0.01 in the frequency ranges of 75-92 and 92-110 GHz.

  10. Localized measurement of short wavelength plasma fluctuations with the DIII-D phase contrast imaging diagnostic

    SciTech Connect

    Dorris, J. R.; Rost, J. C.; Porkolab, M.

    2009-02-15

    A novel rotating mask system has been designed and implemented on the DIII-D phase contrast imaging (PCI) diagnostic to produce the first spatially localized PCI measurements of a tokamak plasma. The localization technique makes use of the variation in the magnetic field component perpendicular to the viewing chord as a function of chord height. This new capability provides measurements in the range of 2plasma edge. This upgrade is part of a broader program to operate the DIII-D PCI at wave numbers up to 40 cm{sup -1} to probe electron scale turbulence in the plasma core.

  11. Optical Plasma Diagnostics for Magnetic Reconnection Studies in the Versatile Toroidal Facility

    NASA Astrophysics Data System (ADS)

    Tarkowski, David; Fasoli, Ambrogio; Egedal, Jan

    2000-10-01

    Magnetic reconnection studies in a collisionless regime are performed on the MIT Versatile Toroidal Facility (VTF) with emphasis on particle dynamics around the magnetic null point. Plasmas are produced in the VTF by electron cyclotron resonance heating and are confined in a magnetic cusp field. Magnetic reconnection is driven by the ExB drift generated by the combination of the cusp field and the toroidal electric field, which is created by electromagnetic induction using an ohmic transformer. The plasmas are composed primarily of singly ionized argon with typical densities and electron temperatures on the order of 10^17 m-3 and 10 eV. The number of available optical lines and the optical thinness of the plasma suggest that optical diagnostics can play a key role on VTF. Passive spectroscopic measurements yield ion temperature and density and electron temperature as a function of time both before and after the reconnection event. The active measurement is a three level laser induced fluorescence (LIF) scheme. A 10 ns pulsed dye laser is used to pump the 611 nm Argon II line. LIF yields the ion distribution function at a single point in time and can be used to study ion evolution during the reconnection event. Measurement techniques and an analysis of first results will be presented.

  12. Schlieren, Phase-Contrast, and Spectroscopy Diagnostics for the LBNL HIF Plasma Channel Experiment

    NASA Astrophysics Data System (ADS)

    Ponce, D. M.; Niemann, C.; Fessenden, T. J.; Leemans, W.; Vandersloot, K.; Dahlbacka, G.; Yu, S. S.; Sharp, W. M.; Tauschwitz, A.

    1999-11-01

    The LBNL Plasma Channel experiment has demonstrated stable 42-cm Z-pinch discharge plasma channels with peak currents in excess of 50 kA for a 7 torr nitrogen, 30 kV discharge. These channels offer the possibility of transporting heavy-ion beams for inertial fusion. We postulate that the stability of these channels resides in the existance of a neutral-gas density depresion created by a pre-pulse discharge before the main capacitor bank discharge is created. Here, we present the results and experimental diagnostics setup used for the study of the pre-pulse and main bank channels. Observation of both the plasma and neutral gas dynamics is achieved. Schlieren, Zernike's phase-contrast, and spectroscopic techniques are used. Preliminary Schlieren results show a gas shockwave moving radially at a rate of ≈ 10^6 mm/sec as a result of the fast and localized deposited energy during the evolution of the pre-pulse channel. This data will be used to validate simulation codes (BUCKY and CYCLOPS).

  13. Plasma DNA integrity index as a potential molecular diagnostic marker for breast cancer.

    PubMed

    Kamel, Azza M; Teama, Salwa; Fawzy, Amal; El Deftar, Mervat

    2016-06-01

    Plasma DNA integrity index is increased in various malignancies including breast cancer, the most common cancer in women worldwide; early detection is crucial for successful treatment. Current screening methods fail to detect many cases of breast cancer at an early stage. In this study, we evaluated the level of plasma DNA integrity index in 260 females (95 with breast cancer, 95 with benign breast lesions, and 70 healthy controls) to verify its potential value in discriminating malignant from benign breast lesions. The criteria of the American Joint Committee on Cancer were used for staging of breast cancer patients. DNA integrity index was measured by real-time PCR. DNA integrity index was significantly higher in breast cancer than in benign breast patients and healthy subjects (P = <0.001). DNA integrity index is correlated with TNM stage. Given 100 % specificity, the highest sensitivity achieved in detecting cancer group was 85.3 % at 0.55 DNA integrity index cutoff. In conclusion, the plasma DNA integrity index may be a promising molecular diagnostic marker of malignancy in breast lesions. PMID:26684805

  14. Localized measurement of short wavelength plasma fluctuations with the DIII-D phase contrast imaging diagnostic

    NASA Astrophysics Data System (ADS)

    Dorris, J. R.; Rost, J. C.; Porkolab, M.

    2009-02-01

    A novel rotating mask system has been designed and implemented on the DIII-D phase contrast imaging (PCI) diagnostic to produce the first spatially localized PCI measurements of a tokamak plasma. The localization technique makes use of the variation in the magnetic field component perpendicular to the viewing chord as a function of chord height. This new capability provides measurements in the range of 2plasma edge. This upgrade is part of a broader program to operate the DIII-D PCI at wave numbers up to 40 cm-1 to probe electron scale turbulence in the plasma core.

  15. Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition

    SciTech Connect

    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.

  16. Spectroscopy of middle charge state high-Z ions in the ultraviolet for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Utter, Steven Bryan

    The quest for the creation of an economically feasible thermonuclear fusion energy reactor is still active after many decades of research. Modern machines produce plasmas which are both hotter and more dense than those created 30 years ago and future devices promise to continue this trend. Paramount to this research is the capability to adequately measure certain parameters of the plasma such as temperature, density, impurity concentration and radiation loss. This dissertation reports three sets of spectroscopic measurements from intermediate charge state of high-Z ions, which have been performed at the Electron Beam Ion Rap (EBIT) facility of the Lawrence Livermore National Laboratory 1, relevant to the development of spectral plasma diagnostics and to the understanding of radiative energy loss from heavy impurity ions of today's and future fusion devices: measurements of W radiation from 40-85 Å, precision measurements along the Cu isoelectronic sequence, and UV spectroscopy of Ti-like W. The results are also compared to the best available theoretical calculations. 1This work was performed under the auspices of the United States Department of Energy by Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.

  17. Optical diagnostics with radiation trapping effect in low density and low temperature helium plasma

    NASA Astrophysics Data System (ADS)

    Lee, Wonwook; Park, Kyungdeuk; Kwon, Duck-Hee; Oh, Cha-Hwan

    2016-06-01

    Low density (ne < 1011 cm-3) and low temperature (Te < 10 eV) helium plasma was generated by hot filament discharge. Electron temperature and density of neutral helium plasma were measured by Langmuir probe and were determined by line intensity ratio method using optical emission spectroscopy with population modelings. Simple corona model and collisional-radiative (CR) model without consideration for radiation trapping effect are applied. In addition, CR model taking into account the radiation trapping effect (RTE) is adopted. The change of single line intensity ratio as a function of electron temperature and density were investigated when the RTE is included and excluded. The changes of multi line intensity ratios as a function of electron temperature were scanned for various radiative-excitation rate coefficients from the ground state and the helium gas pressures related with the RTE. Our CR modeling with RTE results in fairly better agreement of the spectroscopic diagnostics for the plasma temperature or density with the Langmuir probe measurements for various helium gas pressures than corona modeling and CR modeling without RTE.

  18. Robust regression with CUDA and its application to plasma reflectometry

    NASA Astrophysics Data System (ADS)

    Ferreira, Diogo R.; Carvalho, Pedro J.; Fernandes, Horácio

    2015-11-01

    In many applications, especially those involving scientific instrumentation data with a large experimental error, it is often necessary to carry out linear regression in the presence of severe outliers which may adversely affect the results. Robust regression methods do exist, but they are much more computationally intensive, making it difficult to apply them in real-time scenarios. In this work, we resort to graphics processing unit (GPU)-based computing to carry out robust regression in a time-sensitive application. We illustrate the results and the performance gains obtained by parallelizing one of the most common robust regression methods, namely, least median of squares. Although the method has a complexity of O(n3logn), with GPU computing, it is possible to accelerate it to the point that it becomes usable within the required time frame. In our experiments, the input data come from a plasma diagnostic system installed at Joint European Torus, the largest fusion experiment in Europe, but the approach can be easily transferred to other applications.

  19. Robust regression with CUDA and its application to plasma reflectometry.

    PubMed

    Ferreira, Diogo R; Carvalho, Pedro J; Fernandes, Horácio

    2015-11-01

    In many applications, especially those involving scientific instrumentation data with a large experimental error, it is often necessary to carry out linear regression in the presence of severe outliers which may adversely affect the results. Robust regression methods do exist, but they are much more computationally intensive, making it difficult to apply them in real-time scenarios. In this work, we resort to graphics processing unit (GPU)-based computing to carry out robust regression in a time-sensitive application. We illustrate the results and the performance gains obtained by parallelizing one of the most common robust regression methods, namely, least median of squares. Although the method has a complexity of O(n(3)logn), with GPU computing, it is possible to accelerate it to the point that it becomes usable within the required time frame. In our experiments, the input data come from a plasma diagnostic system installed at Joint European Torus, the largest fusion experiment in Europe, but the approach can be easily transferred to other applications. PMID:26628135

  20. Plasma beta-amyloid as potential biomarker of Alzheimer disease: possibility of diagnostic tool for Alzheimer disease.

    PubMed

    Takeda, Shuko; Sato, Naoyuki; Rakugi, Hiromi; Morishita, Ryuichi

    2010-10-01

    Alzheimer disease (AD), which is characterized by progressive cognitive and behavioral deficit, is the most common form of dementia. The incidence of AD is increasing at an alarming rate, and has become a major public health concern in many countries. It is well known that the onset of AD is preceded by a long preclinical period. It is thus critical to establish diagnostic biomarkers that can predict the risk of developing AD prior to clinical manifestation of dementia, for effective prevention and early intervention. With the emergence of potential promising approaches to treat AD targeting the beta-amyloid (Abeta) pathway, such as gamma-secretase inhibitors and vaccine therapy, there is an urgent need for such diagnostic markers. Although cerebrospinal fluid (CSF) Abeta and tau protein levels are candidate biomarkers for AD, the invasive sampling procedure with associated complications limits their use in routine clinical practice. Plasma Abeta has been suggested as an inexpensive and non-invasive biomarker for AD. Although most previous cross-sectional studies on plasma Abeta level in humans failed to show a significant difference between individuals with AD compared to healthy older adults, many strategies are under investigation to improve the diagnostic potential of plasma Abeta. One promising approach is to modify the plasma Abeta level using some potential modulators. It is possible that a difference in plasma Abeta level might be unmasked by evaluating the response to stimulation by a modulator. Anti-Abeta antibody and Abeta binding proteins have been reported to be such modulators of plasma Abeta. In addition, the glucometabolic or hormonal status appears to modulate the plasma Abeta level. Our recent study has shown the possibility that glucose loading could be a novel simple strategy to modulate the plasma Abeta level, making it better suited for early diagnosis. This review summarizes the utility and limitations of current biomarkers of AD and

  1. Development of laser-plasma diagnostics using ultrafast atomic-scale dynamics. 96-ERD-046 final report

    SciTech Connect

    Bolton, P.R.; Kulander, K.C.; Boreham, B.W.

    1997-03-01

    Ultrashort laser pulse systems allow examination of intense, ultrafast laser-plasma interactions. More specifically, intense laser irradiation can induce short xuv/x-ray bursts from the surface of condensed phase targets. Ultrafast xuv/x-ray detection is needed to understand laser-plasma interactions in this dynamic regime. Support of the Stockpile Stewardship and Management Program requires this critical understanding. Our effort here has been to extend understanding of atomic-scale dynamics in such environments with the goal of developing next generation ultrafast xuv/x-ray diagnostics where the sensors will be the atoms and ions themselves and the time resolution will approach that of the induced atomic transitions ({approx} a few femtoseconds). Pivotal contributions to the rapidly developing field of highly nonperturbative interactions of ultrashort pulse lasers with atoms/ions have been made at this laboratory. In the visible/infrared wavelength regions the temporal and spectral content of ultrashort laser pulses are now reliably monitored within a single pulse using frequency resolved optical gating (FROG) which is based on rapid nonlinear optical processes such as the Kerr effect. New applications of this basic concept are still being developed. Corresponding detection for the xuv/x-ray wavelengths does not exist and is urgently needed in many laboratory programs. The FROG technique cannot be applied in the xuv/x-ray region. Current x-ray streak camera technology is limited to {approx}0.5 picosecond resolution.

  2. High-resolution spectroscopic diagnostics of very high-temperature plasmas in the hard x-ray regime

    SciTech Connect

    Widmann, K

    1999-12-06

    Motivated by the need for establishing a reliable database useful for the application of x-ray spectroscopic tools for the diagnostic of very high temperature plasmas, high-resolution crystal spectrometer measurements have been performed investigating the characteristic K-shell radiation of highly charged krypton and xenon. The measurements, which have been performed at the Electron-Beam-Ion-Trap (EBIT) facility of the Lawrence Livermore National Laboratory, include the investigation of the n = 2 {yields} 1 transitions in heliumlike krypton (Kr{sup 34+}) and innershell excited lithiumlike krypton (Kr{sup 33+}) utilizing a conventional reflection-type crystal spectrometer of von Hamos geometry. The electron-excitation-energy selective measurements map the contribution of the dielectronic recombination lines providing the means of accurate interpretation of the line profiles of the characteristic K{alpha} x-ray emission of plasmas. The high-resolution measurements of the n = 2 {yields} 1 transitions in heliumlike xenon (Xe{sup 52+}) and hydrogenlike xenon (Xe{sup 53+}) were based on a new transmission-type crystal spectrometer of DuMond geometry. The resolving power of the developed spectrometer was sufficient for charge state specific observation allowing the determination of the electron-impact excitation cross section for the hydrogen- and heliumlike K{alpha} transitions. The disagreement with theoretically predicted values is a measure of the magnitude of the Breit interaction for the highly charged high-Z ions.

  3. Data processing for soft X-ray diagnostics based on GEM detector measurements for fusion plasma imaging

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Byszuk, A.; Juszczyk, B.; Wojenski, A.; Zabolotny, W.; Zienkiewicz, P.

    2015-12-01

    The measurement system based on GEM - Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement fusion plasmas. The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. So, it is the software part of the project between the electronic hardware and physics applications. The project is original and it was developed by the paper authors. Multi-channel measurement system and essential data processing for X-ray energy and position recognition are considered. Several modes of data acquisition determined by hardware and software processing are introduced. Typical measuring issues are deliberated for the enhancement of data quality. The primary version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures initially for the investigation purpose. Two detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Fundamental output characteristics are presented for one and two dimensional detector structure. Representative results for reference source and tokamak plasma are demonstrated.

  4. Cold plasma: overview of plasma technologies and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold plasma is a novel nonthermal food processing technology. It is based on energetic, reactive gases which inactivate contaminating microbes on meats, poultry and fruits and vegetables. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization pro...

  5. Modeling of low-temperature plasmas generated using laser-induced breakdown spectroscopy: the ChemCam diagnostic tool on the Mars Science Laboratory Rover

    NASA Astrophysics Data System (ADS)

    Colgan, James

    2016-05-01

    We report on efforts to model the low-temperature plasmas generated using laser-induced breakdown spectroscopy (LIBS). LIBS is a minimally invasive technique that can quickly and efficiently determine the elemental composition of a target and is employed in an extremely wide range of applications due to its ease of use and fast turnaround. In particular, LIBS is the diagnostic tool used by the ChemCam instrument on the Mars Science Laboratory rover Curiosity. In this talk, we report on the use of the Los Alamos plasma modeling code ATOMIC to simulate LIBS plasmas, which are typically at temperatures of order 1 eV and electron densities of order 10 16 - 17 cm-3. At such conditions, these plasmas are usually in local-thermodynamic equilibrium (LTE) and normally contain neutral and singly ionized species only, which then requires that modeling must use accurate atomic structure data for the element under investigation. Since LIBS devices are often employed in a very wide range of applications, it is therefore desirable to have accurate data for most of the elements in the periodic table, ideally including actinides. Here, we discuss some recent applications of our modeling using ATOMIC that have explored the plasma physics aspects of LIBS generated plasmas, and in particular discuss the modeling of a plasma formed from a basalt sample used as a ChemCam standard1. We also highlight some of the more general atomic physics challenges that are encountered when attempting to model low-temperature plasmas. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396. Work performed in conjunction with D. P. Kilcrease, H. M. Johns, E. J. Judge, J. E. Barefield, R. C. Wiens, S. M. Clegg.

  6. Advances in Langmuir probe diagnostics of the plasma potential and electron-energy distribution function in magnetized plasma

    NASA Astrophysics Data System (ADS)

    Popov, Tsv K.; Dimitrova, M.; Ivanova, P.; Kovačič, J.; Gyergyek, T.; Dejarnac, R.; Stöckel, J.; Pedrosa, M. A.; López-Bruna, D.; Hidalgo, C.

    2016-06-01

    Advanced Langmuir probe techniques for evaluating the plasma potential and electron-energy distribution function (EEDF) in magnetized plasma are reviewed. It is shown that when the magnetic field applied is very weak and the electrons reach the probe without collisions in the probe sheath the second-derivative Druyvesteyn formula can be used for EEDF evaluation. At low values of the magnetic field, an extended second-derivative Druyvesteyn formula yields reliable results, while at higher values of the magnetic field, the first-derivative probe technique is applicable for precise evaluation of the plasma potential and the EEDF. There is an interval of intermediate values of the magnetic field when both techniques—the extended second-derivative and the first-derivative one—can be used. Experimental results from probe measurements in different ranges of magnetic field are reviewed and discussed: low-pressure argon gas discharges in the presence of a magnetic field in the range from 0.01 to 0.08 T, probe measurements in circular hydrogen plasmas for high-temperature fusion (magnetic fields from 0.45 T to 1.3 T) in small ISTTOK and CASTOR tokamaks, D-shape COMPASS tokamak plasmas, as well as in the TJ-II stellarator. In the vicinity of the last closed flux surface (LCFS) in tokamaks and in the TJ-II stellarator, the EEDF obtained is found to be bi-Maxwellian, while close to the tokamak chamber wall it is Maxwellian. The mechanism of the appearance of a bi-Maxwellian EEDF in the vicinity of the LCFS is discussed. Comparison of the results from probe measurements with those obtained from calculations using the ASTRA and EIRENE codes shows that the main reason for the appearance of a bi-Maxwellian EEDF in the vicinity of the LCFS is the ionization of the neutral atoms.

  7. Wall current probe: A non-invasive in situ plasma diagnostic for space and time resolved current density distribution measurement

    SciTech Connect

    Baude, R.; Gaboriau, F.; Hagelaar, G. J. M.

    2013-08-15

    In the context of low temperature plasma research, we propose a wall current probe to determine the local charged particle fluxes flowing to the chamber walls. This non-intrusive planar probe consists of an array of electrode elements which can be individually biased and for which the current can be measured separately. We detail the probe properties and present the ability of the diagnostic to be used as a space and time resolved measurement of the ion and electron current density at the chamber walls. This diagnostic will be relevant to study the electron transport in magnetized low-pressure plasmas.

  8. Multiplex PCR: Optimization and Application in Diagnostic Virology

    PubMed Central

    Elnifro, Elfath M.; Ashshi, Ahmed M.; Cooper, Robert J.; Klapper, Paul E.

    2000-01-01

    PCR has revolutionized the field of infectious disease diagnosis. To overcome the inherent disadvantage of cost and to improve the diagnostic capacity of the test, multiplex PCR, a variant of the test in which more than one target sequence is amplified using more than one pair of primers, has been developed. Multiplex PCRs to detect viral, bacterial, and/or other infectious agents in one reaction tube have been described. Early studies highlighted the obstacles that can jeopardize the production of sensitive and specific multiplex assays, but more recent studies have provided systematic protocols and technical improvements for simple test design. The most useful of these are the empirical choice of oligonucleotide primers and the use of hot start-based PCR methodology. These advances along with others to enhance sensitivity and specificity and to facilitate automation have resulted in the appearance of numerous publications regarding the application of multiplex PCR in the diagnosis of infectious agents, especially those which target viral nucleic acids. This article reviews the principles, optimization, and application of multiplex PCR for the detection of viruses of clinical and epidemiological importance. PMID:11023957

  9. The photon-plasmon transitions and diagnostics of the space plasma turbulence

    NASA Astrophysics Data System (ADS)

    Glushkov, Alexander; Glushkov, Alexander; Khetselius, Olga

    We present a new approach to treating the space plasma turbulence, based on using to make diagnostic data regarding the photon-plasmon transitions. The theoretical definition of characteristics for these transitions is caried out within consistent theoretical approach, based on the Gell-Mann and Low formalism (energy approach in QED theory).We apply it to calculation of such transitions (Ps) with emission of photon and Langmuir quanta. It is well known that the hfs states of positronium Ps Ps differ in spin S, life time t and mode of annihilation. As a rule, probabilities of the cascade radiation transitions are more than the annihilation probability. The ortho-Ps atom has a metastable state 23s1 and probability of two-photon radiation transition from this state into 13s1 state (1.8•10(-3) 1/s) is significantly less than probability of the three-photon annihilation directly from 23s1level 8.9•10(5) s(-1), i.e. it is usually supposed that the ortho-Ps annihilates from 23s1state. Another situation may take place in plasma, where it is arisen the competition process of destruction of the metastable level - the photonplasmon transition 23s1-13s1with emission of photon and Langmuir quanta. In this paper we carried out the calculation of the probability of the Ps photon-plasmon transition and propose tu use it for diagnostics of the space plasma (dusty one etc.).Standard S-matrix calculation with using an expression for tensor of dielectric permeability of the isotropic space plasma and dispersion relationships for transverse and Langmuir waves [3] allows getting the corresponding probability P(ph-pl). Numerical value of P(ph-pl) is 5.2•10(6)•UL(s-1), where UL is density of the Langmuir waves energy. Our value is correlated with estimate, available in literature [3]: P(phpl)= 6•10(6)•UL (s-1). Comparison of the obtained probability with the life time t(3) allows getting the condition of predominance of the photon-plasmon transition over three

  10. Sports medicine applications of platelet rich plasma.

    PubMed

    Mishra, Allan; Harmon, Kimberly; Woodall, James; Vieira, Amy

    2012-06-01

    Platelet rich plasma (PRP) is a powerful new biologic tool in sports medicine. PRP is a fraction of autologous whole blood containing and increased number of platelets and a wide variety of cytokines such as platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and transforming growth factor beta-1 (TGF-B1), fibroblast growth factor (FGF), Insulin-like growth factor-1 (IGF-1) among many others. Worldwide interest in this biologic technology has recently risen sharply. Basic science and preclinical data support the use of PRP for a variety of sports related injuries and disorders. The published, peer reviewed, human data on PRP is limited. Although the scientific evaluation of clinical efficacy is in the early stages, elite and recreational athletes already use PRP in the treatment of sports related injuries. Many questions remain to be answered regarding the use of PRP including optimal formulation, including of leukocytes, dosage and rehabilitation protocols. In this review, a classification for platelet rich plasma is proposed and the in-vitro, preclinical and human investigations of PRP applications in sports medicine will be reviewed as well as a discussion of rehabilitation after a PRP procedure. The regulation of PRP by the World Anti-Doping Agency will also be discussed. PRP is a promising technology in sports medicine; however, it will require more vigorous study in order to better understand how to apply it most effectively. PMID:21740373

  11. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2014-10-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers of 100 to 1000 pixels can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a prototype 100 pixel array with an extremely deep record length (128 k points at 20 Msamples/s) and 10 bit pixel resolution has already been achieved. HyperV now seeks to extend these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 12 bit depth. Preliminary experimental results as well as Phase 2 plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  12. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2015-11-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a scalable solution for 100 to 1000 pixel systems with 14 bit resolution and record-lengths of 128k frames has been developed. HyperV is applying these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 14 bit depth. Preliminary experimental results as well as future plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  13. A 10MHz Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    NASA Astrophysics Data System (ADS)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2013-10-01

    HyperV Technologies has been developing an imaging diagnostic comprised of arrays of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers of 100 to 10,000 pixels can be constructed. By interfacing analog photodiode systems directly to commercial analog to digital convertors and modern memory chips, a prototype pixel with an extremely deep record length (128 k points at 40 Msamples/s) has been achieved for a 10 bit resolution system with signal bandwidths of at least 10 MHz. Progress on a prototype 100 Pixel streak camera employing this technique is discussed along with preliminary experimental results and plans for a 10,000 pixel imager. Work supported by USDOE Phase 1 SBIR Grant DE-SC0009492.

  14. The growth of microcrystalline silicon oxide thin films studied by in situ plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Kirner, S.; Gabriel, O.; Stannowski, B.; Rech, B.; Schlatmann, R.

    2013-02-01

    The crystallinity and refractive index of microcrystalline silicon oxide (μc-SiOx:H) n-layers and their dependence on the pressure and radio frequency power during the deposition process is correlated with plasma properties derived from in situ diagnostics. From process gas depletion measurements, the oxygen content of the layers was calculated. High crystallinities were observed for increased pressures and decreased powers, indicating clear differences to trends previously shown for microcrystalline silicon (μc-Si:H) material, which are explained by the varying oxygen incorporation. Amorphous/microcrystalline silicon (a-Si:H/μc-Si:H) tandem solar cells with μc-SiOx:H intermediate reflector layers deposited at optimized pressures showed greatly improved series resistances.

  15. Status of the GEC RF Reference Cell/laser diagnostics of plasma etching discharges

    SciTech Connect

    Hargis, P.J. Jr.; Greenerg, K.E.; Miller, P.A.

    1991-01-01

    The Gaseous Electronics Conference (GEC) RF Reference Cell was developed to enhance studies of radiofrequency (rf) discharge systems analogous to those used to fabricate microelectronic devices. The Reference Cell concept includes both a standard discharge-chamber design and a set of diagnostic tools that can be used to verify that different Cells behave similarly. Voltage and current measurements in Reference Cells in the United States show that, with proper care, plasmas that behave in a similar manner can be generated in different Cells. The versatility of the Reference Cell is illustrated by results on the use of planar laser-induced fluorescence imaging to obtain two-dimensional spatial profiles of SO{sub 2} in an SF{sub 6}/O{sub 2} rf discharge. 4 refs., 5 figs.

  16. Plasma diagnostics package. Volume 2: Spacelab 2 section. Part B: Thesis projects

    NASA Technical Reports Server (NTRS)

    Pickett, Jolene S. (Compiler); Frank, L. A. (Compiler); Kurth, W. S. (Compiler)

    1988-01-01

    This volume (2), which consists of two parts (A and B), of the Plasma Diagnostics Package (PDP) Final Science Report contains a summary of all of the data reduction and scientific analyses which were performed using PDP data obtained on STS-51F as a part of the Spacelab 2 (SL-2) payload. This work was performed during the period of launch, July 29, 1985, through June 30, 1988. During this period the primary data reduction effort consisted of processing summary plots of the data received by 12 of the 14 instruments located on the PDP and submitting these data to the National Space Science Data Center (NSSDC). Three Master's and three Ph.D. theses were written using PDP instrumentation data. These theses are listed in Volume 2, Part B.

  17. Spectral Catalogue of Kr Optical Lines for the Development of Diagnostics for Fusion Plasmas

    SciTech Connect

    Hui, C.; Beiersdorfer, P.; Harris, C.L.; Utter, S.B.; Wong, K.L.

    2000-06-14

    We made an inventory of krypton spectra over the wavelength range 3700-6000 {angstrom} for the development of fusion plasma diagnostics. The measurements were performed using a Steinheil prism spectrometer on the LLNL low energy electron beam ion trap (EBIT II). With the electron energy from 150 eV to 17000 eV, we recorded low ionization stages together with a number of magnetic dipole transitions from higher charge states. In total, we observed over 80 lines, of which about 70% of the lines have not been listed in the literature. This measurement established a baseline for future extension using spectrometers with very high resolution. As an example, we present the Kr spectra from 3770 {angstrom} to 3900 {angstrom} measured with a transmission grating spectrometer that has a resolving power of about 15000. Among the 41 lines observed, only 6 lines have been listed in the databases.

  18. STS-3/OSS-1 Plasma Diagnostics Package (PDP) measurements of Orbiter transmitter and subsystem electromagnetic interference

    NASA Technical Reports Server (NTRS)

    Shawhan, S. D.; Murphy, G.

    1983-01-01

    The plasma diagnostics package receiver system is described to identify the various antennas and to characterize the complement of receivers which cover the frequency range of 30 Hz to 800 Hz and S-band at 2200 + or - 300 MHz. Sample results are presented to show the variability of electromagnetic effects associated with the orbiter and the time variability of these effects. The electric field and magnetic field maximum and minimum field strength spectra observed during the mission at the pallet location are plotted. Values are also derived for the maximum UHF transmitter and S-band transmitter field strengths. Calibration data to convert from the survey plots to actual narrowband and broadband field strengths are listed.

  19. Spectral catalog of Kr optical lines for the development of diagnostics for fusion plasmas

    NASA Astrophysics Data System (ADS)

    Chen, H.; Beiersdorfer, P.; Harris, C. L.; Utter, S. B.; Wong, K. L.

    2001-01-01

    We made an inventory of krypton spectra over the wavelength range 3700-6000 Å for the development of fusion plasma diagnostics. The measurements were performed using a prism spectrometer on the Lawrence Livermore National Laboratory low energy electron beam ion trap (EBIT II). With the electron energy from 150 to 17 000 eV, we recorded low ionization stages together with a number of magnetic dipole transitions from higher charge states. In total, we observed over 80 lines, of which about 70% of the lines have not been listed in the literature. This measurement established a baseline for future extension using spectrometers with very high resolution. As an example, we present the Kr spectra from 3770 to 3900 Å measured with a transmission grating spectrometer that has a resolving power of about 15 000. Among the 41 lines observed, only six lines have been listed in the databases.

  20. Pulse-discharge plasmas for plasma-accelerator applications

    SciTech Connect

    Clayton, C. E.; Joshi, C.; Lopes, N. C.

    2012-12-21

    For particle-beam-driven plasma wakefield accelerators, a long and fully-ionized plasma is desirable. We describe an experiment at UCLA to develop a prototype of such plasma using a pulsed-current discharge. Scaling of the plasma density with glass-tube diameter and with discharge-circuit parameters is currently underway. We have found that 4 Torr of Argon can be fully ionized to a density of about 1.3 Multiplication-Sign 10{sup 17} cm{sup -3} when the current density in the 1 inch diameter, 1.2 meter-long tube is around 2 kA/cm{sup 2}, at least at one point along the discharge. The homogeneity of the plasma density in the longitudinal direction is crucial to prevent slippage of the driven plasma structures with the particles. Equally important are the transverse gradients since any dipole asymmetry in the transverse direction can lead to 'steering' of the particle beam. The longitudinal and transverse gradients may be a function of time into the discharge, the shape of the electrodes, the tube size, and the fractional ionization for a given fill pressure. These issues are currently under investigation.

  1. Invitation to the World of the Plasma for Light Source 3.Light Source Measurement 3.1 Laser Diagnostics of Plasmas for Light Sources

    NASA Astrophysics Data System (ADS)

    Motomura, Hideki; Jinno, Masafumi

    Examples and basic theories of various methods of laser diagnostics of plasmas for light sources are introduced. Most introduced papers were presented at International Symposium on the Science and Technology of Light Sources (LS), which is the only international symposium on the science and technology of light sources.

  2. Urethral ultrasonography: A novel diagnostic tool for dysuria following bipolar transurethral plasma kinetic prostatectomy.

    PubMed

    Wang, Guang-Chun; Bian, Cui-Dong; Zhou, Ting-Ting; Liu, Min; Huang, Jian-Hua; Peng, Bo

    2016-04-29

    Urethral ultrasonography is non-invasive and able to indicate the urethral lumen clearly, as well as the surrounding tissues of the posterior urethra, without contrast agent or X-ray irradiation. In this paper, we evaluate the reliability of urethral ultrasonography in the diagnosis of dysuria following bipolar transurethral plasma kinetic prostatectomy (TUPKP). A total of 120 benign prostate hyperplasia (BPH) patients with dysuria undergoing TUPKP were enrolled in this study, with a mean age of 72.8 years. All the patients received urethral ultrasonography, urethroscopy and bladder neck urethra stenosis oulectomy. Among the 120 cases, there were 22 cases of bladder neck closure, 20 bladder orifice stricture, 60 urethral stricture, 10 prostate remnants, 2 calculi in prostatic urethra, 4 dysfunction of bladder detrusor muscle and 2 flap of internal urethral orifice. χ2-test was used for the comparison of ultrasonography and urethral cystoscopy in the diagnosis of dysuria following TRPKP, and no significant difference was found between two diagnostic tools (χ 2 = 0.94, P > 0.05). Urethral ultrasonography is a reliable and minimally invasive diagnostic tool for dysuria following TUPKP and is conducive to early treatment of dysuria following prostatectomy. PMID:27163308

  3. Data Acquisition and Automation for Plasma Rotation Diagnostic in the TCABR Tokamak

    NASA Astrophysics Data System (ADS)

    Ronchi, G.; Severo, J. H. F.; de Sá, W. P.; Galvão, R. M. O.

    2015-03-01

    In this work we describe the implementation of a full modular system of data acquisition and processing for the plasma rotation diagnostic in the TCABR tokamak. The experimental setup uses a single monochromator and six photomultipliers (PMT), in which pair of PMTs measures the light at slightly different wavelengths. Thus, it can measure the time evolution of the Doppler shift of the impurities emission lines coming from three spatial positions (one for toroidal rotation and two for poloidal rotation). The data acquisition and preanalysis program were written with LabVIEW software and is capable of controlling the spectrometer wavelength, PMTs power supplies, data acquisition, and storage. All data are recorded in MDSplus trees that easily allow data visualization and post-processing analysis (both locally and remotely) via MATLAB, Python, Java and others programming languages. This system can run independently from other diagnostics and machine systems and can be integrated with the main tokamak control system by means of TCP/IP messages.

  4. New diagnostic methods for laser plasma- and microwave-enhanced combustion.

    PubMed

    Miles, Richard B; Michael, James B; Limbach, Christopher M; McGuire, Sean D; Chng, Tat Loon; Edwards, Matthew R; DeLuca, Nicholas J; Shneider, Mikhail N; Dogariu, Arthur

    2015-08-13

    The study of pulsed laser- and microwave-induced plasma interactions with atmospheric and higher pressure combusting gases requires rapid diagnostic methods that are capable of determining the mechanisms by which these interactions are taking place. New rapid diagnostics are presented here extending the capabilities of Rayleigh and Thomson scattering and resonance-enhanced multi-photon ionization (REMPI) detection and introducing femtosecond laser-induced velocity and temperature profile imaging. Spectrally filtered Rayleigh scattering provides a method for the planar imaging of temperature fields for constant pressure interactions and line imaging of velocity, temperature and density profiles. Depolarization of Rayleigh scattering provides a measure of the dissociation fraction, and multi-wavelength line imaging enables the separation of Thomson scattering from Rayleigh scattering. Radar REMPI takes advantage of high-frequency microwave scattering from the region of laser-selected species ionization to extend REMPI to atmospheric pressures and implement it as a stand-off detection method for atomic and molecular species in combusting environments. Femtosecond laser electronic excitation tagging (FLEET) generates highly excited molecular species and dissociation through the focal zone of the laser. The prompt fluorescence from excited molecular species yields temperature profiles, and the delayed fluorescence from recombining atomic fragments yields velocity profiles. PMID:26170432

  5. New diagnostic methods for laser plasma- and microwave-enhanced combustion

    PubMed Central

    Miles, Richard B; Michael, James B; Limbach, Christopher M; McGuire, Sean D; Chng, Tat Loon; Edwards, Matthew R; DeLuca, Nicholas J; Shneider, Mikhail N; Dogariu, Arthur

    2015-01-01

    The study of pulsed laser- and microwave-induced plasma interactions with atmospheric and higher pressure combusting gases requires rapid diagnostic methods that are capable of determining the mechanisms by which these interactions are taking place. New rapid diagnostics are presented here extending the capabilities of Rayleigh and Thomson scattering and resonance-enhanced multi-photon ionization (REMPI) detection and introducing femtosecond laser-induced velocity and temperature profile imaging. Spectrally filtered Rayleigh scattering provides a method for the planar imaging of temperature fields for constant pressure interactions and line imaging of velocity, temperature and density profiles. Depolarization of Rayleigh scattering provides a measure of the dissociation fraction, and multi-wavelength line imaging enables the separation of Thomson scattering from Rayleigh scattering. Radar REMPI takes advantage of high-frequency microwave scattering from the region of laser-selected species ionization to extend REMPI to atmospheric pressures and implement it as a stand-off detection method for atomic and molecular species in combusting environments. Femtosecond laser electronic excitation tagging (FLEET) generates highly excited molecular species and dissociation through the focal zone of the laser. The prompt fluorescence from excited molecular species yields temperature profiles, and the delayed fluorescence from recombining atomic fragments yields velocity profiles. PMID:26170432

  6. Diagnostic and therapeutic applications of water-immersion colonoscopy

    PubMed Central

    Sugimoto, Shinya; Mizukami, Takeshi

    2015-01-01

    Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications. PMID:26074684

  7. Diagnostic and therapeutic applications of water-immersion colonoscopy.

    PubMed

    Sugimoto, Shinya; Mizukami, Takeshi

    2015-06-01

    Colonoscopy techniques combining or replacing air insufflation with water infusion are becoming increasingly popular. They were originally designed to reduce colonic spasms, facilitate cecal intubation, and lower patient discomfort and the need for sedation. These maneuvers straighten the rectosigmoid colon and enable the colonoscope to be inserted deeply without causing looping of the colon. Water-immersion colonoscopy minimizes colonic distension and improves visibility by introducing a small amount of water. In addition, since pain during colonoscopy indicates risk of bowel perforation and sedation masks this important warning, this method has the potential to be the favored insertion technique because it promotes patient safety without sedation. Recently, this water-immersion method has not only been used for colonoscope insertion, but has also been applied to therapy for sigmoid volvulus, removal of lesions, lower gastrointestinal bleeding, and therapeutic diagnosis of abnormal bowel morphology and irritable bowel syndrome. Although a larger sample size and prospective head-to-head-designed studies will be needed, this review focuses on the usefulness of water-immersion colonoscopy for diagnostic and therapeutic applications. PMID:26074684

  8. Magnetic Nanoparticles and microNMR for Diagnostic Applications

    PubMed Central

    Shao, Huilin; Min, Changwook; Issadore, David; Liong, Monty; Yoon, Tae-Jong; Weissleder, Ralph; Lee, Hakho

    2012-01-01

    Sensitive and quantitative measurements of clinically relevant protein biomarkers, pathogens and cells in biological samples would be invaluable for disease diagnosis, monitoring of malignancy, and for evaluating therapy efficacy. Biosensing strategies using magnetic nanoparticles (MNPs) have recently received considerable attention, since they offer unique advantages over traditional detection methods. Specifically, because biological samples have negligible magnetic background, MNPs can be used to obtain highly sensitive measurements in minimally processed samples. This review focuses on the use of MNPs for in vitro detection of cellular biomarkers based on nuclear magnetic resonance (NMR) effects. This detection platform, termed diagnostic magnetic resonance (DMR), exploits MNPs as proximity sensors to modulate the spin-spin relaxation time of water molecules surrounding the molecularly-targeted nanoparticles. With new developments such as more effective MNP biosensors, advanced conjugational strategies, and highly sensitive miniaturized NMR systems, the DMR detection capabilities have been considerably improved. These developments have also enabled parallel and rapid measurements from small sample volumes and on a wide range of targets, including whole cells, proteins, DNA/mRNA, metabolites, drugs, viruses and bacteria. The DMR platform thus makes a robust and easy-to-use sensor system with broad applications in biomedicine, as well as clinical utility in point-of-care settings. PMID:22272219

  9. Characterization of an atmospheric pressure plasma jet and its applications for disinfection and cancer treatment.

    PubMed

    Thiyagarajan, Magesh; Sarani, Abdollah; Gonzales, Xavier F

    2013-01-01

    In this work an atmospheric pressure non-thermal resistive barrier (RB) plasma jet was constructed, characterized and was applied for biomedical applications. The RB plasma source can operate in both DC (battery) as well as in standard 60/50 Hz low frequency AC excitation, and it functions effectively in both direct and indirect plasma exposure configurations. The characteristics of the RB plasma jet such as electrical properties, plasma gas temperature and nitric oxides concentration were determined using voltage-current characterization, optical emission spectroscopy and gas analyzer diagnostic techniques. Plasma discharge power of 26.33 W was calculated from voltage-current characterization. An optical emission spectroscopy was applied and the gas temperature which is equivalent to the nitrogen rotational (Trot) temperatures was measured. The concentrations of the reactive oxygen species at different spatial distances from the tip of the plasma jet were measured and the ppm concentration of NO is at the preferred level for a wide range of standard biomedical treatment applications. The ppm values of nitric oxides after the cooling unit are observed to be of the same order of magnitude as compared to plasma jet. The portable RB plasma source was tested to be very effective for decontamination and disinfection of a wide range of foodborne and opportunistic nosocomial pathogens such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus and the preliminary results are presented. The effects of indirect exposure of the portable RBP source on monocytic leukemia cancer cells (THP-1) were also tested and the results demonstrate that a preference for apoptosis in plasma treated THP-1 cells under particular plasma parameters and dosage levels. PMID:23400199

  10. In situ process diagnostics of silane plasma for device-quality a-Si:H deposition

    NASA Astrophysics Data System (ADS)

    Shing, Y. H.; Perry, J. W.; Hermann, A. M.

    Coherent anti-Stokes Raman spectroscopy (CARS) and mass spectrometry (MS) have been applied to in situ process diagnostics of a silane plasma for device-quality a-Si:H film deposition. Silane depletion was directly measured by CARS and is linearly dependent on RF power in the region of 4-12 W with a slope of 0.5 percent/mW-sq cm. The depletion is also dependent on SiH4 flow rate starting with a 50 percent depletion at a low flow rate of 5.6 sccm and asymptotically approaching an 8 percent depletion at a flow rate of 80 sccm. The mass spectral line signal intensity of disilane increases with RF power and shows an apparent transition at 6 W. Disilane formation in silane plasma, film deposition rate, and silane depletion ratio as a function of the RF power indicate that the film growth mechanism in the low-power region of 3.5-6.5 W is substantially different from that in the high-power region of 6.5-12 W.

  11. Diagnostic-management system and test pulse acquisition for WEST plasma measurement system

    NASA Astrophysics Data System (ADS)

    Wojenski, A.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Juszczyk, B.; Zabolotny, W.; Zienkiewicz, P.; Chernyshova, M.; Czarski, T.; Mazon, D.; Malard, P.

    2014-11-01

    This paper describes current status of electronics, firmware and software development for new plasma measurement system for use in WEST facility. The system allows to perform two dimensional plasma visualization (in time) with spectrum measurement. The analog front-end is connected to Gas Electron Multiplier detector (GEM detector). The system architecture have high data throughput due to use of PCI-Express interface, Gigabit Transceivers and sampling frequency of ADC integrated circuits. The hardware is based on several years of experience in building X-ray spectrometer system for Joint European Torus (JET) facility. Data streaming is done using Artix7 FPGA devices. The system in basic configuration can work with up to 256 channels, while the maximum number of measurement channels is 2048. Advanced firmware for the FPGA is required in order to perform high speed data streaming and analog signal sampling. Diagnostic system management has been developed in order to configure measurement system, perform necessary calibration and prepare hardware for data acquisition.

  12. THE IRON PROJECT: High-Energy-Density (HED) Plasma Opacities and Diagnostics

    NASA Astrophysics Data System (ADS)

    Gokce, Yasin; Bostelmann, T.; Nahar, S.; Pradhan, A.; Bailey, J.

    2014-05-01

    The composition of the Sun, the benchmark for astronomical objects, has been a longstanding problem for the last few decades. The abundances of common elements in the Sun, such as, carbon, nitrogen, oxygen, supported by helioseismology are at discrepant by up to 50% higher from those derived from state-of-the-art spectroscopy and elaborate 3-D radiative transfer models. The uncertainty is compounded by recent experiments at the Sandia National Laboratory on the Z-pinch inertial confinement fusion device which is able to re-create the HED plasma conditions existing at the solar radiative-convection zone boundary. Measured monochromatic iron opacities disagree with all known theoretical opacities models. The abundance problem and potential solution are related to radiative opacities. Uur continued investigation of the problem will be presented. We will also present collision strengths of carbon-like silicon which shows new resonances in the low energy region introduced by relativistic effects in the Breit-Pauli R-matrix method. Line intensity ratios of this ion, obtained for optically allowed transitions as seen in astronomical spectra, are the diagnostics for the density and termperature of the plasmas will be reported. Partial support of NSF, DOE.

  13. In situ process diagnostics of silane plasma for device-quality a-Si:H deposition

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Perry, J. W.; Hermann, A. M.

    1987-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) and mass spectrometry (MS) have been applied to in situ process diagnostics of a silane plasma for device-quality a-Si:H film deposition. Silane depletion was directly measured by CARS and is linearly dependent on RF power in the region of 4-12 W with a slope of 0.5 percent/mW-sq cm. The depletion is also dependent on SiH4 flow rate starting with a 50 percent depletion at a low flow rate of 5.6 sccm and asymptotically approaching an 8 percent depletion at a flow rate of 80 sccm. The mass spectral line signal intensity of disilane increases with RF power and shows an apparent transition at 6 W. Disilane formation in silane plasma, film deposition rate, and silane depletion ratio as a function of the RF power indicate that the film growth mechanism in the low-power region of 3.5-6.5 W is substantially different from that in the high-power region of 6.5-12 W.

  14. PLASMA-2013: International Conference on Research and Applications of Plasmas (Warsaw, Poland, 2-6 September 2013)

    NASA Astrophysics Data System (ADS)

    Sadowski, Marek J.

    2014-05-01

    The PLASMA-2013 International Conference on Research and Applications of Plasmas was held in Warsaw (Poland) from 2 to 6 September 2013. The conference was organized by the Institute of Plasma Physics and Laser Microfusion, under the auspices of the Polish Physical Society. The scope of the PLASMA conferences, which have been organized every two years since 1993, covers almost all issues of plasma physics and fusion research as well as selected problems of plasma technology. The PLASMA-2013 conference topics included: •Elementary processes and general plasma physics. •Plasmas in tokamaks and stellarators (magnetic confinement fusion). •Plasmas generated by laser beams and inertial confinement fusion. •Plasmas produced by Z-pinch and plasma-focus discharges. •Low-temperature plasma physics. •Space plasmas and laboratory astrophysics. •Plasma diagnostic methods and applications of plasmas. This conference was designed not only for plasma researchers and engineers, but also for students from all over the world, in particular for those from Central and Eastern Europe. Almost 140 participants had the opportunity to hear 9 general lectures, 11 topical talks and 26 oral presentations, as well as to see and discuss around 120 posters. From about 140 contributions, after the preparation of about 100 papers and the peer review process, only 74 papers have been accepted for publication in this topical issue. Acknowledgments Acting on behalf of the International Scientific Committee I would like to express our thanks to all the invited speakers and all the participants of the PLASMA-2013 conference for their numerous contributions. In particular, I wish to thank all of the authors of papers submitted for publication in this topical issue of Physica Scripta . Particular thanks are due to all of the reviewers for their valuable reports and comments, which helped to improve the quality of many of the papers. International Scientific Committee Marek J Sadowski, NCBJ

  15. Atmospheric pressure non-thermal plasma: Sources and applications

    NASA Astrophysics Data System (ADS)

    Napartovich, A. P.

    2008-07-01

    Non-thermal plasma at atmospheric pressure is an inherently unstable object. Nature of discharge plasma instabilities and conditions for observation of uniform non-thermal plasma at atmospheric pressure in different environments will be discussed. Various discharge techniques have been developed, which could support uniform non-thermal plasma with parameters varied in a wide range. Time limitation by plasma instabilities can be overcome by shortening pulse length or by restriction of plasma plug residence time with a fast gas flow. Discharge instabilities leading to formation of filaments or sparks are provoked by a positive feedback between the electric field and plasma density, while the counteracting process is plasma and thermal diffusion. With gas pressure growth the size of plasma fluctuation, which could be stabilized by diffusion, diminishes. As a result, to have long lived uniform plasma one should miniaturize discharge. There exist a number of active methods to organize negative feedback between the electric field and plasma density in order to suppress or, at least, delay the instability. Among them are ballast resistors in combination with electrode sectioning, reactive ballast, electronic feedback, and dielectric barrier across the electric current. The last methods are relevant for ac discharges. In the lecture an overview will be given of different discharge techniques scalable in pressure up to one atmosphere. The interest in this topic is dictated by a potential economic benefit from numerous non-thermal plasma technologies. The spectrum of non-thermal plasma applications is continuously broadening. An incomplete list of known applications includes: plasma-assisted chemical vapor deposition, etching, polymerization, gas-phase synthesis, protective coating deposition, toxic and harmful gas decomposition, destruction of warfare agents, electromagnetic wave shielding, polymer surface modifications, gas laser excitation, odor control, plasma assisted

  16. A Survey of Plasmas and Their Applications

    NASA Technical Reports Server (NTRS)

    Eastman, Timothy E.; Grabbe, C. (Editor)

    2006-01-01

    Plasmas are everywhere and relevant to everyone. We bath in a sea of photons, quanta of electromagnetic radiation, whose sources (natural and artificial) are dominantly plasma-based (stars, fluorescent lights, arc lamps.. .). Plasma surface modification and materials processing contribute increasingly to a wide array of modern artifacts; e.g., tiny plasma discharge elements constitute the pixel arrays of plasma televisions and plasma processing provides roughly one-third of the steps to produce semiconductors, essential elements of our networking and computing infrastructure. Finally, plasmas are central to many cutting edge technologies with high potential (compact high-energy particle accelerators; plasma-enhanced waste processors; high tolerance surface preparation and multifuel preprocessors for transportation systems; fusion for energy production).

  17. Multi-energy x-ray imaging and sensing for diagnostic and control of the burning plasma

    SciTech Connect

    Stutman, D.; Tritz, K.; Finkenthal, M.

    2012-10-15

    New diagnostic and sensor designs are needed for future burning plasma (BP) fusion experiments, having good space and time resolution and capable of prolonged operation in the harsh BP environment. We evaluate the potential of multi-energy x-ray imaging with filtered detector arrays for BP diagnostic and control. Experimental studies show that this simple and robust technique enables measuring with good accuracy, speed, and spatial resolution the T{sub e} profile, impurity content, and MHD activity in a tokamak. Applied to the BP this diagnostic could also serve for non-magnetic sensing of the plasma position, centroid, ELM, and RWM instability. BP compatible x-ray sensors are proposed using 'optical array' or 'bi-cell' detectors.

  18. Cross-calibrating Spatial Positions of Light-viewing Diagnostics using Plasma Edge Sweeps in DIII-D

    SciTech Connect

    W.M. Solomon; K.H. Burrell; P. Gohil; R. Groebner; D. Kaplan

    2003-07-07

    An experimental technique is presented that permits diagnostics viewing light from the plasma edge to be spatially calibrated relative to one another. By sweeping the plasma edge, each chord of each diagnostic sweeps out a portion of the light emission profile. A nonlinear least-squares fit to such data provides superior cross-calibration of diagnostics located at different toroidal locations compared with simple surveying. Another advantage of the technique is that it can be used to monitor the position of viewing chords during an experimental campaign to ensure that alignment does not change over time. Moreover, should such a change occur, the data can still be cross-calibrated and its usefulness retained.

  19. Supersonic Gas Injector for Fueling and Diagnostic Applications on the National Spherical Torus Experiment

    SciTech Connect

    Soukhanovskii, V; Kugel, H; Kaita, R; Majeski, R; Roquemore, A

    2004-06-04

    A prototype pulsed supersonic gas injector (SGI) has been developed for the National Spherical Torus Experiment (NSTX). Experiments in NSTX will explore the compatibility of the supersonic gas jet fueling with H-mode plasma edge, edge localized mode control, edge magnetohydrodynamic stability, radio frequency heating scenarios, and start-up scenarios with fast plasma density ramp-up. The diagnostic applications include localized impurity gas injections for transport and turbulence experiments and edge helium spectroscopy for edge T{sub e} and n{sub e} profile measurements. Nozzle and gas injector design considerations are presented and four types of supersonic nozzles are discussed. The prototype SGI operates at room temperature. It is comprised of a small graphite Laval nozzle coupled to a modified commercial piezoelectric valve and mounted on a movable vacuum feedthrough. The critical properties of the SGI jet - low divergence, high density, and sharp boundary gradient, achievable only at M > 1, have been demonstrated in a laboratory setup simulating the NSTX edge conditions. The Mach numbers of about 4, the injection rate up to 10{sup 22} particles/s, and the jet divergence half-angle of 6 have been inferred from pulsed pressure measurements.

  20. High-intensity laser for Ta and Ag implantation into different substrates for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Cutroneo, M.; Mackova, A.; Malinsky, P.; Matousek, J.; Torrisi, L.; Ullschmied, J.

    2015-07-01

    High-intensity lasers generating non-equilibrium plasma, can be employed to accelerate ions in the keV-MeV region, useful for many applications. In the present work, we performed study of ion implantation into different substrates by using a high-intensity laser at the PALS laboratory in Prague. Multi-energy ions generated by plasma from Ta and Ag targets were implanted into polyethylene and metallic substrates (Al, Ti) at energies of tens of keV per charge state. The ion emission was monitored online using time-of-flight detectors and electromagnetic deflection systems. Rutherford Backscattering Spectrometry (RBS) was used to characterise the elemental composition in the implanted substrates by ion plasma emission and to provide the implanted ion depth profiling. These last measurements enable offline plasma characterisation and provide information on the useful potentiality of multi-ion species and multi-energy ion implantation into different substrates. XPS analysis gives information on the chemical bonds and their modifications in the first superficial implanted layers. The depth distributions of implanted Ta and Ag ions were compared with the theoretical ones achieved by using the SRIM-2012 simulation code.

  1. Diagnostic signature of low-energy secondary electron emission at the boundary of a partially-ionized plasma

    NASA Astrophysics Data System (ADS)

    Demidov, V. I.; Adams, S. F.; Kaganovich, I. D.; Koepke, M. E.; Kurlyandskaya, I. P.

    2015-09-01

    Effects of secondary electron emission (SEE) from a solid surface in contact with plasma are important for conducting and interpreting plasma experiments and modeling. Those effects are especially strong for contaminated surfaces. Measurements of SEE reported here are conducted in a plasma having a nearly mono-energetic population of electrons that is energetically well resolved and separated from a broader-energy-range electron population. By performing the SEE measurement in an afterglow or afterglow-like plasma, we take advantage of the nearly mono-energetic electron population that arises in ionizing plasma-chemical reactions, such as binary like-particle collisions of metastable atoms. We demonstrate a diagnostic method for measuring the low-energy electron absorption coefficient across the broader energy range and the effects of contamination on the swept-bias probe characteristic trace. A part of this research was performed while VID held a National Research Council Research Associateship Award at AFRL.

  2. SOFT-X RAY DIAGNOSTICS AND TREATMENTS FOR FUTURE REAL TIME APPLICATIONS

    SciTech Connect

    Pacella, D.; Mazon, D.

    2008-03-12

    This paper offers a preliminary review of the present diagnostics and data analysis techniques in the domain of Soft X-ray (SXR) emissions of fusion magnetic plasmas, including a short description of the theoretical background as well. Particular attention is devoted to the wide use of SXR tomography and impurity transport simulation. In their actual form, these techniques are not adequate to future real time applications. For this goal a step forward in the diagnosing and analysis of SXR emissions is required. The following part of the paper is therefore dedicated to the discussion of these improvements. The first one is the SXR tomography optimized for real time applications, like that one developed at Tore Supra (Cadarache, France). Fast 2-D tomographic inversions using different techniques (regularisation of Minimum Fisher, Maximum entropy, Zernicke polynomial expansions), will be optimized to be performed in a few millisecond time scale, crucial for MHD analysis, mode detection and localisation. The other goal to be pursued is the energy resolved imaging, now possible with a gas Micro Pattern Gas Detector with pixel read-out, as recently demonstrated at FTU (Frascati, Italy) and at NSTX (Princeton NJ, US), together with an ad hoc modeling of SXR emissions, compatible with future real time applications.

  3. An in situ accelerator-based diagnostic for plasma-material interactions science on magnetic fusion devices

    SciTech Connect

    Hartwig, Zachary S.; Barnard, Harold S.; Lanza, Richard C.; Sorbom, Brandon N.; Stahle, Peter W.; Whyte, Dennis G.

    2013-12-15

    This paper presents a novel particle accelerator-based diagnostic that nondestructively measures the evolution of material surface compositions inside magnetic fusion devices. The diagnostic's purpose is to contribute to an integrated understanding of plasma-material interactions in magnetic fusion, which is severely hindered by a dearth of in situ material surface diagnosis. The diagnostic aims to remotely generate isotopic concentration maps on a plasma shot-to-shot timescale that cover a large fraction of the plasma-facing surface inside of a magnetic fusion device without the need for vacuum breaks or physical access to the material surfaces. Our instrument uses a compact (∼1 m), high-current (∼1 milliamp) radio-frequency quadrupole accelerator to inject 0.9 MeV deuterons into the Alcator C-Mod tokamak at MIT. We control the tokamak magnetic fields – in between plasma shots – to steer the deuterons to material surfaces where the deuterons cause high-Q nuclear reactions with low-Z isotopes ∼5 μm into the material. The induced neutrons and gamma rays are measured with scintillation detectors; energy spectra analysis provides quantitative reconstruction of surface compositions. An overview of the diagnostic technique, known as accelerator-based in situ materials surveillance (AIMS), and the first AIMS diagnostic on the Alcator C-Mod tokamak is given. Experimental validation is shown to demonstrate that an optimized deuteron beam is injected into the tokamak, that low-Z isotopes such as deuterium and boron can be quantified on the material surfaces, and that magnetic steering provides access to different measurement locations. The first AIMS analysis, which measures the relative change in deuterium at a single surface location at the end of the Alcator C-Mod FY2012 plasma campaign, is also presented.

  4. Applicability of moire deflection tomography for diagnosing arc plasmas

    SciTech Connect

    Chen Yunyun; Song Yang; He Anzhi; Li Zhenhua

    2009-01-20

    The argon arc plasma whose central temperature, 1.90x10{sup 4} K, is used as a practical example for an experiment to research the applicability of moire deflection tomography in arc plasma flow-field diagnosis. The experimental result indicates that moire deflection of the measured argon arc plasma is very small, even smaller than that of a common flame with the maximal temperature of nearly 1.80x10{sup 3} K. The refractive-index gradient in moire deflection tomography mainly contributes to the temperature gradient in essence when the probe wavelength and pressure are certain in plasma diagnosis. The applicable temperature ranges of moire deflection tomography in the argon arc plasma diagnosis are given with the probe wavelength 532 nm at 1 atm in certain measuring error requirements. In a word, the applicable temperature range of moire deflection tomography for arc plasma diagnosis is intimately related to the probe wavelength and the practical measuring requirements.

  5. Laser Diagnostics of Atomic Hydrogen and Oxygen Production in RF and Microwave Plasma Discharges

    NASA Astrophysics Data System (ADS)

    Preppernau, Bryan Lee

    1993-01-01

    The research for this thesis involved the application of two-photon allowed laser-induced fluorescence (TALIF) to the study of atomic hydrogen and oxygen production in industrial scale radio-frequency and microwave plasma discharge apparatus. Absolute atomic hydrogen concentration profiles were measured in a Gaseous Electronics Conference Reference Cell installed at Wright-Patterson AFB, Ohio operating with a simple H_2 discharge. Two -dimensional atomic hydrogen concentration profiles were also measured in an ASTEX HPMM microwave plasma diamond deposition reactor during actual diamond growth. In addition, absolute atomic oxygen concentrations were measured in the ASTEX system. Particular attention was paid to refining the concentration calibration technique and in determining a correction to account for the collisional quenching of excited state fluorescence in high pressure gases.

  6. High temperature UF6 RF plasma experiments applicable to uranium plasma core reactors

    NASA Technical Reports Server (NTRS)

    Roman, W. C.

    1979-01-01

    An investigation was conducted using a 1.2 MW RF induction heater facility to aid in developing the technology necessary for designing a self critical fissioning uranium plasma core reactor. Pure, high temperature uranium hexafluoride (UF6) was injected into an argon fluid mechanically confined, steady state, RF heated plasma while employing different exhaust systems and diagnostic techniques to simulate and investigate some potential characteristics of uranium plasma core nuclear reactors. The development of techniques and equipment for fluid mechanical confinement of RF heated uranium plasmas with a high density of uranium vapor within the plasma, while simultaneously minimizing deposition of uranium and uranium compounds on the test chamber peripheral wall, endwall surfaces, and primary exhaust ducts, is discussed. The material tests and handling techniques suitable for use with high temperature, high pressure, gaseous UF6 are described and the development of complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma, effluent exhaust gases, and residue deposited on the test chamber and exhaust system components is reported.

  7. Potential applications of an electron cyclotron resonance multicusp plasma source

    SciTech Connect

    Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Stirling, W.L.

    1989-01-01

    An electron cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produced large (about 25-cm-diam), uniform (to within {plus minus}10%), dense (>10{sup 11}-cm{sup -3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Results and potential applications of this new ECR plasma source for plasma processing of thin films are discussed. 21 refs., 10 figs.

  8. Surfatron Plasma Source Working at Frequency 2.45 GHz for Technological Applications

    SciTech Connect

    Stranak, V.; Tichy, M.; Blazek, J.; Adamek, P.; Navratil, Z.; Slavicek, P.; Spatenka, P.

    2006-01-15

    Plasma as an active medium is widely exploited in technological applications. We have developed a microwave plasma source which might be suitable for future technological application. Plasma is generated by commercial (Sairem) surfatron working at frequency 2.45 GHz. The surfatron is fed by microwave power in the range from several watts up to 300 watts. Plasma is created from working gas mixture; typical flow rate is kept constant at 600 sccm. Technical Ar is used as carrier gas, O2 or N2 as reactive gases. We present complex diagnostics of the plasma created by this plasma source: by means of Langmuir probe measurements and by optical emission spectroscopy. Single probe method was used for determination of basic plasma parameters (plasma potential Vpl, mean electron energy Em, electron density ne, electron temperature) at low pressures. For determination of electron temperature at higher pressures when ion-neutral collision processes in the probe sheath had to be taken into account the double probe method was used. The discharge plasma was investigated and the results are discussed in cw as well as in computer-controlled impulse regime (time-resolved measurements). The pulse regime of plasma source is one of the ways how to increase an instantaneous input power and at the same time prevent treated materials (especially thermal sensitive materials, e.g. plastics) against thermal damage. Rotational and vibrational temperatures as well as consistence of discharge and axial intensity development of particular spectral lines were revealed on base of optical emission spectroscopy in cw regime.

  9. PREFACE: Fourteenth International Symposium on Laser-Aided Plasma Diagnostics (LAPD14)

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Pasqualotto, R.

    2010-04-01

    The attached PDF contains, the full preface, a list of the scientific committee, former LAPD chairmen, local organizers, previous locations of LAPD meetings, participants email contacts and a list of the contributed papers. logo The Fourteenth International Symposium on Laser-Aided Plasma Diagnostics (LAPD14), was held from 21-24 September 2009 in Castelbrando, Treviso, Italy. The series of LAPD symposia was originally started at Kyushu University in 1983, and since then it has been organized every two years alternately in Japan, Europe and the United States, traveling around the world five times. Each LAPD Symposium brings together scientists working in different disciplines all related to the diagnostics of any type of plasma by laser or similar techniques. Researchers working on nuclear fusion, industrial process, low temperature plasma chemistry, laser development and material science, are invited to present prominent new diagnostic developments, with the aim of synergetic discussions. The broad spectrum of contributions represents one of the strengths of this symposium, which is an important, unique and fruitful source of cross-fertilization between these fields and a forum of discussions. The scope of LAPD14 was very broad, including many techniques related to laser probing of plasmas: incoherent and coherent Thomson scattering, polarimetry, interferometry, reflectometry, laser induced fluorescence, laser absorption spectroscopy, laser photodetachment spectroscopy, cavity ringdown spectroscopy, Raman scattering, reflectometry, microwave diagnostics and related laser and hardware developments. LAPD14 was attended by 66 researchers, from 15 different countries who presented a total of 57 papers (13 general, 12 topical, 10 short talks and 23 poster contributions). It is a tradition of LAPD that the first lecture of each meeting, which is more general and aims to review prominent new developments, is called 'the Akazaki lecture' in honor of Professor Masanori

  10. Low efficiency gratings for 3rd harmonic diagnostics applications

    SciTech Connect

    Britten, J.A.; Boyd, R.D.; Perry, M.D.; Shore, B.W.; Thomas, I.M.

    1995-08-09

    The baseline design of the National Ignition Facility (NIF) calls for sampling gratings to provide third-harmonic energy diagnostics in the highly constrained area of the target chamber. These 40 {times} 4O cm transmission gratings are to diffract at (order +1) nominally 0.3% of the incident 351 run light at a small angle on to a focusing mirror and into a calorimeter. The design calls for a plane grating of 500 lines/mm, and approximately 30 run deep, etched into a fused silica focusing lens and subsequently overcoated with a solgel anti reflective coating. Gratings of similar aperture and feature size have been produced for other applications by ion etching processes, but, in an effort to reduce substantially the cost of such optics, we are studying the feasibility of making these gratings by wet chemical etching techniques. Experimentation with high-quality fused silica substrates on 5 and 15 cm. scale has led to a wet etching process which can meet the design goals and which offers no significant scaleup barriers to full sized optics. The grating is produced by holographic exposure and a series of processing steps using only a photoresist mask and a final hydrofluoric acid etch. Gratings on 15 cm diameter test substrates exhibit absolute diffraction efficiencies from 0.2--0.4% with a standard deviation of about 15% of the mean over the full aperture. The efficiency variation is due to variation in linewidth caused by spatial nonuniformities in exposure energy. Uniformity improvements can be realized by using a smaller, more uniform portion of the exposure beam and exposing for longer times. The laser damage threshold for these gratings has been measured at LLNL and found to be identical to that of the fused silica substrate.

  11. DIAGNOSTIC TOOL DEVELOPMENT AND APPLICATION THROUGH REGIONAL CASE STUDIES

    EPA Science Inventory

    Case studies are a useful vehicle for developing and testing conceptual models, classification systems, diagnostic tools and models, and stressor-response relationships. Furthermore, case studies focused on specific places or issues of interest to the Agency provide an excellent ...

  12. Study on re-sputtering during CN{sub x} film deposition through spectroscopic diagnostics of plasma

    SciTech Connect

    Liang, Peipei; Yang, Xu; Li, Hui; Cai, Hua; Sun, Jian; Xu, Ning; Wu, Jiada

    2015-10-15

    A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CN{sub x}) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CN{sub x} film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N{sub 2} gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CN{sub x} film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CN{sub x} film growth. The other one represents the CN radicals re-sputtered from the growing CN{sub x} film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features.

  13. Plasma Science and Applications at the Intel

    NASA Astrophysics Data System (ADS)

    Berry, Lee

    2006-10-01

    The Coalition for Plasma Science (CPS) has established a plasma prize at the annual Intel International Science and Engineering Fair (ISEF). The 2006 prize was awarded for a project that investigated the correlation of GPS errors with various measures of near-earth plasma activity. The CPS is a broadly-based group of institutions and individuals whose goal is to increase the understanding of plasmas for non-technical audiences. In addition to the ISEF plasma award, CPS activities include maintaining a website, http://www.plasmacoalition.org; developing educational literature; organizing educational luncheon presentations for Members of Congress and their staffs; and responding to questions about plasmas. In addition, the CPS has begun as effort to examine the plasma content of state education standards with the goal of promoting the adoption of standards with appropriate plasma conten; e.g. are there three or four states of matter. The success of this and other activities depend on the voluntary labor of CPS members and associates. Please send an e-mail to the CPS at CPS@plasmacoalition.org for information if you would like to become involved in spreading the good word about plasmas.

  14. Note: Background Oriented Schlieren as a diagnostics for airflow control by plasma actuators.

    PubMed

    Biganzoli, I; Capone, C; Barni, R; Riccardi, C

    2015-02-01

    Background Oriented Schlieren (BOS) is an optical technique sensitive to the first spatial derivative of the refractive index inside a light-transmitting medium. Compared to other Schlieren-like techniques, BOS is more versatile and allows to capture bi-dimensional gradients rather than just one spatial component. We propose to adopt BOS for studying the capabilities of surface dielectric barrier discharges to work like plasma actuators in flow control applications. The characteristics of the BOS we implemented at this purpose are discussed, together with few results concerning the ionic wind produced by the discharge in absence of an external airflow. PMID:25725896

  15. Optical fiber imaging for high speed plasma motion diagnostics: applied to low voltage circuit breakers.

    PubMed

    McBride, J W; Balestrero, A; Ghezzi, L; Tribulato, G; Cross, K J

    2010-05-01

    An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1 x 10(6) images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker. PMID:20515174

  16. Admissible Crosstalk Limits in a Two Colour Interferometers for Plasma Density Diagnostics. A Reduction Algorithm.

    NASA Astrophysics Data System (ADS)

    Sánchez, M.; Esteban, L.; Kornejew, P.; Hirsch, M.

    2008-03-01

    Mid Infrared (10,6 μm CO2 laser lines) interferometers as a plasma density diagnostic must use two-colour systems with superposed interferometers beams at different wavelengths in order to cope with mechanical vibrations and drifts. They require a highly precise phase difference measurement where all sources of error must be reduced. One of these is the cross-talk between the signals which creates nonlinear spurious periodic mixing products. The reason may be either optical or electrical crosstalk both resulting in similar perturbations of the measurement. In the TJII interferometer a post-processing algorithm is used to reduce the crosstalk in the data. This post-processing procedure is not appropriate for very long pulses, as it is the case for in new tokamak (ITER) or stellarator (W7-X) projects. In both cases an on-line reduction process is required or—even better—the unwanted signal components must be reduced in the system itself CO2 laser interferometers which as the second wavelength use the CO laser line (5,3 μm), may apply a single common detector sensitive to both wavelengths and separate the corresponding IF signals by appropriate bandpass filters. This reduces complexity of the optical arrangement and avoids a possible source of vibration induced phase noise as both signals share the same beam path. To avoid cross talk in this arrangement filtering must be appropriate. In this paper we present calculations to define the limits of crosstalk for a desired plasma density precision. A crosstalk reduction algorithm has been developed and is applied to experimental results from TJ-II pulses. Results from a single detector arrangement as under investigation for the CO2/CO laser interferometer developed for W7-X are presented.

  17. Plasma Science and Applications at the Intel Science Fair: A Retrospective

    NASA Astrophysics Data System (ADS)

    Berry, Lee

    2009-11-01

    For the past five years, the Coalition for Plasma Science (CPS) has presented an award for a plasma project at the Intel International Science and Engineering Fair (ISEF). Eligible projects have ranged from grape-based plasma production in a microwave oven to observation of the effects of viscosity in a fluid model of quark-gluon plasma. Most projects have been aimed at applications, including fusion, thrusters, lighting, materials processing, and GPS improvements. However diagnostics (spectroscopy), technology (magnets), and theory (quark-gluon plasmas) have also been represented. All of the CPS award-winning projects so far have been based on experiments, with two awards going to women students and three to men. Since the award was initiated, both the number and quality of plasma projects has increased. The CPS expects this trend to continue, and looks forward to continuing its work with students who are excited about the possibilities of plasma. You too can share this excitement by judging at the 2010 fair in San Jose on May 11-12.

  18. [Clinical trial requests of indigenous diagnostic imaging ultrasound devices in first-time registration application].

    PubMed

    Guo, Zhaojun; Cao, Guofang; Tao, Kan

    2012-11-01

    This article introduces the clinical requests of indigenous diagnostic imaging ultrasound devices in first-time registration application and the clinical trial requests in Technical Review Guidance of Ultrasound Imaging Diagnostic Devices (category III) Registration and puts forward some questions of the guidance's implementation. It is hoped to help concerned people. PMID:23461122

  19. Atmospheric-pressure plasma sources for biomedical applications

    NASA Astrophysics Data System (ADS)

    Park, G. Y.; Park, S. J.; Choi, M. Y.; Koo, I. G.; Byun, J. H.; Hong, J. W.; Sim, J. Y.; Collins, G. J.; Lee, J. K.

    2012-08-01

    Atmospheric-pressure plasmas (APPs) have attracted great interest and have been widely applied in biomedical applications, as due to their non-thermal and reactive properties, they interact with living tissues, cells and bacteria. Various types of plasma sources generated at atmospheric pressure have been developed to achieve better performance in specific applications. This article presents an overview of the general characteristics of APPs and a brief summary of their biomedical applications, and reviews a wide range of these sources developed for biomedical applications. The plasma sources are classified according to their power sources and cover a wide frequency spectrum from dc to microwaves. The configurations and characteristics of plasma sources are outlined and their biomedical applications are presented.

  20. Preface to Special Topic: Plasmas for Medical Applications

    NASA Astrophysics Data System (ADS)

    Keidar, Michael; Robert, Eric

    2015-12-01

    Intense research effort over last few decades in low-temperature (or cold) atmospheric plasma application in bioengineering led to the foundation of a new scientific field, plasma medicine. Cold atmospheric plasmas (CAP) produce various chemically reactive species including reactive oxygen species (ROS) and reactive nitrogen species (RNS). It has been found that these reactive species play an important role in the interaction of CAP with prokaryotic and eukaryotic cells triggering various signaling pathways in cells.

  1. Preface to Special Topic: Plasmas for Medical Applications

    SciTech Connect

    Keidar, Michael; Robert, Eric

    2015-12-15

    Intense research effort over last few decades in low-temperature (or cold) atmospheric plasma application in bioengineering led to the foundation of a new scientific field, plasma medicine. Cold atmospheric plasmas (CAP) produce various chemically reactive species including reactive oxygen species (ROS) and reactive nitrogen species (RNS). It has been found that these reactive species play an important role in the interaction of CAP with prokaryotic and eukaryotic cells triggering various signaling pathways in cells.

  2. Laser techniques for arc jet plasma diagnostics; continuation of a feasibility and design study

    NASA Technical Reports Server (NTRS)

    Wierum, F. A.

    1986-01-01

    This study is concerned with the continuation of a feasibility and design study of laser-based diagnostic techniques for the non-instrusive measurement of species concentrations, temperatures, and velocity in the low density, high enthalpy flow through the arc-heated wind tunnel facility (ARMSEF) at NASA/JSC. Last summer several laser-induced radiation scattering methods were investigated and some preliminary measurements of the spectral distribution of radiation emitted by the arc-heated gas flow were made. Based upon those preliminary measurements and subsequent investigations, four laser-induced radiation scattering methods were selected for further detailed study, and preliminary design of a measurement system has been undertaken. Further measurements of the spectral distribution of radiation emitted from the arc-heated free stream and shock layer flows, using a redesigned measurement system, have been made for one axial position in the flow for a range of tunnel operating power levels. Further study of the literature for physical property data, theoretical models of processes, and applications of the diagnostic methods has been also carried out.

  3. Application of 5-ALA for differential diagnostics of stomach diseases

    NASA Astrophysics Data System (ADS)

    Okhotnikova, Natalja L.; Dadvany, Sergey A.; Kuszin, Michail I.; Kharnas, Sergey S.; Zavodnov, Victor Y.; Sklyanskaya, Olga A.; Loschenov, Victor B.; Volkova, Anna I.; Agafonov, Valery V.

    2001-01-01

    59 patients with stomach diseases including gastric cancer or polyp, gastritis, esofagus disease were investigated. Before gastroscopy all patients were given 5-ALA in doses 5mg, 10mg and 20mg per 1kg of body weight orally. Fluorescence diagnostics which estimates concentration of ALA-induced PPIX in regular and alternated tissues of gastric mucosa were carried out in 2-4 hours. Using of 5-ALA has shown high diagnostic effectiveness for differential diagnostics of stomach diseases. This technique has proved 10 diagnosis of cancer and revealed 15 malignant stomach diseases including 4 cancer in situ for patients with preliminary diagnosis of gastric ulcer. It also revealed 5 patients with enhanced fluorescence for which aimed biopsy has shown high degree of inflammation process. The latter were assigned as a risk group.

  4. Optical and laser spectroscopic diagnostics for energy applications

    NASA Astrophysics Data System (ADS)

    Tripathi, Markandey Mani

    The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the

  5. Optical and UV x-ray imaging diagnostics for imploding plasma experiments

    NASA Astrophysics Data System (ADS)

    Lee, P. H. Y.; Price, R. H.; Reay, J.; Pecos, J.; Seagrave, J.; McGurn, J.; Cochrane, B.; Anderson, B.

    1986-08-01

    The Trailmaster/Pioneer 1 series of imploding plasma experiments are aimed at using an inductive storage driver to implode an ultrathin aluminum foil with a multimegampere, submicrosecond electrical pulse. The power pulse is produced by an explosive flux compression generator and a fast plasma compression opening switch. The goal is to obtain an intense source of soft x rays from the thermalization of the plasma kinetic energy when pinch occurs on axis. An important target diagnostic is a fast camera which measures the dynamics of foil run-in and implosion symmetry. These measurements are made in the visible, UV, and x-ray portions of the electromagnetic spectrum. UV/x-ray images are first converted to visible light, then transmitted by visible light optics to a framing camera, which is located at a safe distance. For UV/soft x-ray imaging, we mount a disposable pinhole camera with a p-terphenyl-coated converter screen on the target chamber. For soft/hard x-ray imaging, a microchannel plate is used in front of the p-terphenyl-coated screen to boost quantum detection efficiency and signal gain. For faster temporal response the p-terphenyl can be replaced by NE-111 or other fast fluors. Image transmission is accomplished by means of two large mirrors (150-250 mm diam) and a large catadioptric telescope. The framing camera consists of four gated microchannel plates with adjustable gate and interframe times. The framing camera is a versatile and rugged instrument, it has performed satisfactorily for each and every Pioneer shot. Experimental data indicate that this camera, which uses individual gated microchannel plates, is far superior to commercial streak/framing cameras, because it has a dynamic range which is orders of magnitude larger than commercial cameras, each channel can be attenuated separately, further increasing the dynamic range of the imaging system. This makes our framing camera especially suitable for recording sequences of events where the brightness

  6. Rapid, absolute calibration of x-ray filters employed by laser-produced plasma diagnostics.

    PubMed

    Brown, G V; Beiersdorfer, P; Emig, J; Frankel, M; Gu, M F; Heeter, R F; Magee, E; Thorn, D B; Widmann, K; Kelley, R L; Kilbourne, C A; Porter, F S

    2008-10-01

    The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are detected using the high resolution EBIT Calorimeter Spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the x-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated x-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed. PMID:19044471

  7. Spectroscopic diagnostics and experimental planning for plasma-surface interaction studies in NSTX-U

    NASA Astrophysics Data System (ADS)

    Scotti, F.; Soukhanovskii, V. A.; Allain, J. P.; Bedoya, F.; Kaita, R.; Roquemore, A. L.; Skinner, C. H.

    2015-11-01

    In the mixed-material environment of the NSTX-U first wall, visible imaging diagnostics will be used to study the evolution of the plasma facing component (PFC) surface conditions and the distribution of impurity influxes. Characterizing the dynamic material environment originating from wall conditioning techniques (boronization, lithium evaporation) on graphite PFCs requires simultaneous monitoring of emission from different atomic species. Full poloidal/toroidal coverage of impurity emission is achieved via a combination of bandpass-filtered fast cameras viewing upper and lower PFCs and line-scan cameras. Two image-intensified radiation-hardened cameras expand these capabilities with the ability to image weaker visible lines and a custom-built two-color system for the simultaneous imaging of different wavelengths. Intensified camera views include the lower divertor and a close-up of the surface analysis sample system Material Analysis and Particle Probe (MAPP). Redundant views via multiple cameras and two-color setups will enable a more accurate determination of impurity influxes (via line ratio techniques) and the simultaneous characterization of carbon (chemical/physical), lithium and oxygen influx evolution following lithium and boron wall conditioning. The imaging of MAPP samples will allow comparing the evolution of surface composition determined via surface analysis techniques to visible spectroscopy. Supported by U.S. DOE Contracts: DE-AC02-09CH11466, DE-AC52-07NA27344, DE-SC0010717.

  8. Measurements of Short Wavelength Plasma Fluctuations Using the DIII-D Phase Contrast Imaging Diagnostic

    NASA Astrophysics Data System (ADS)

    Dorris, J. R.; Rost, J. C.; Porkolab, M.; Burrell, K. H.

    2010-11-01

    The DIII-D Phase Contrast Imaging (PCI) diagnostic has been upgraded and used to measure turbulence in the outer plasma region (0.7 < r/a < 1) covering an operational range of 10 kHz through 10 MHz and 2-30 cm-1. A novel rotating mask has been used to measure turbulence as a function of propagation angle about the PCI chord. This technique provides localized measurements along the PCI chord for turbulence with k˜0, and an estimate of the turbulence k value otherwise. Long wavelength (|k|<˜12 cm-1) turbulence is localized to within the instrumental width of the last closed flux surface (LCFS) (r/a>˜0.9). Modes with finite (and theoretically unexpected) parallel wavenumber have been seen to propagate at angles as large as k/k ˜0.1-0.4. Due to the finite k, these modes cannot be localized with the present techniques. A theoretical explanation for these modes is lacking at the present time.

  9. Rapid, absolute calibration of x-ray filters employed by laser-produced plasma diagnostics

    SciTech Connect

    Brown, G. V.; Beiersdorfer, P.; Emig, J.; Frankel, M.; Gu, M. F.; Heeter, R. F.; Magee, E.; Thorn, D. B.; Widmann, K.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.

    2008-10-15

    The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are detected using the high resolution EBIT Calorimeter Spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the x-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated x-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.

  10. Rapid, Absolute Calibration of X-ray Filters Employed By Laser-Produced Plasma Diagnostics

    SciTech Connect

    Brown, G V; Beiersdorfer, P; Emig, J; Frankel, M; Gu, M F; Heeter, R F; Magee, E; Thorn, D B; Widmann, K; . Kelley, R L; Kilbourne, C A; Porter, F S

    2008-05-11

    The electron beam ion trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of X-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen X-ray energies. X-rays are detected using the high-resolution EBIT calorimeter spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the X-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated X-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.

  11. Quantitative PCR for Plasma Epstein-Barr Virus Loads in Cancer Diagnostics.

    PubMed

    Loghavi, Sanam

    2016-01-01

    Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis and is associated with posttransplant lymphoproliferative disease (PTLD), Hodgkin's lymphoma, Burkitt's lymphoma, nasopharyngeal carcinoma, and HIV-related lymphomas. It infects nearly all humans and then persists for the life of the host in a small proportion of benign B lymphocytes. EBV reactivation, usually in the setting of immunosuppression, is the main risk factor for development of EBV-associated malignancies. EBV reactivation can be detected in tissue specimens using EBV-encoded RNA (EBER) in situ hybridization (ISH), which is routinely used for diagnosis of PTLD and nasopharyngeal carcinoma. However, EBER ISH cannot be routinely used for screening asymptomatic or monitoring posttreatment outcome due to difficulty in obtaining tissue specimens for testing and the nonquantitative nature of the assay. Recent studies have shown that EBV genomic DNA can be detected in blood of patients with EBV-associated diseases, and that monitoring of EBV viral load in blood could be an effective method of distinguishing disease-associated EBV reactivation from incidental EBV present in benign B lymphocytes, and could be used for diagnostic screening and monitoring of EBV-associated diseases. In this chapter we discuss a protocol for quantitative plasma EBV DNA analysis. PMID:26843046

  12. A collisional radiative model of hydrogen plasmas developed for diagnostic purposes of negative ion sources

    NASA Astrophysics Data System (ADS)

    Iordanova, Snejana; Paunska, Tsvetelina

    2016-02-01

    A collisional radiative model of low-pressure hydrogen plasmas is elaborated and applied in optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The model accounts for the main processes determining both the population densities of the first ten states of the hydrogen atom and the densities of the positive hydrogen ions H+, H2+, and H3+. In the calculations, the electron density and electron temperature are varied whereas the atomic and molecular temperatures are included as experimentally obtained external parameters. The ratio of the Hα to Hβ line intensities is calculated from the numerical results for the excited state population densities, obtained as a solution of the set of the steady-state rate balance equations. The comparison of measured and theoretically obtained ratios of line intensities yields the values of the electron density and temperature as well as of the degree of dissociation, i.e., of the parameters which have a crucial role for the volume production of the negative ions.

  13. Fast data transmission in dynamic data acquisition system for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Byszuk, Adrian; Poźniak, Krzysztof; Zabołotny, Wojciech M.; Kasprowicz, Grzegorz; Wojeński, Andrzej; Cieszewski, Radosław; Juszczyk, Bartłomiej; Kolasiński, Piotr; Zienkiewicz, Paweł; Chernyshova, Maryna; Czarski, Tomasz

    2014-11-01

    This paper describes architecture of a new data acquisition system (DAQ) targeted mainly at plasma diagnostic experiments. Modular architecture, in combination with selected hardware components, allows for straightforward reconfiguration of the whole system, both offline and online. Main emphasis will be put into the implementation of data transmission subsystem in said system. One of the biggest advantages of described system is modular architecture with well defined boundaries between main components: analog frontend (AFE), digital backplane and acquisition/control software. Usage of a FPGA chips allows for a high flexibility in design of analog frontends, including ADC <--> FPGA interface. Data transmission between backplane boards and user software was accomplished with the use of industry-standard PCI Express (PCIe) technology. PCIe implementation includes both FPGA firmware and Linux device driver. High flexibility of PCIe connections was accomplished due to use of configurable PCIe switch. Whenever it's possible, described DAQ system tries to make use of standard off-the-shelf (OTF) components, including typical x86 CPU & motherboard (acting as PCIe controller) and cabling.

  14. Advances in experimental spectroscopy of Z-pinch plasmas and applications

    NASA Astrophysics Data System (ADS)

    Kantsyrev, V. L.; Safronova, A. S.; Safronova, U. I.; Shrestha, I.; Weller, M. E.; Osborne, G. C.; Shlyaptseva, V. V.; Wilcox, P. G.; Stafford, A.

    2012-06-01

    Recent advances in experimental work on plasma spectroscopy of Z-pinches are presented. The results of experiments on the 1.7 MA Z-pinch Zebra generator at UNR with wire arrays of various configurations and X-pinches are overviewed. A full x-ray and EUV diagnostic set for detailed spatial and temporal monitoring of such plasmas together with theoretical support from relativistic atomic structure and non-LTE kinetic codes used in the analysis are discussed. The use of a variety of wire materials in a broad range from Al to W provided an excellent opportunity to observe and study specific atomic and plasma spectroscopy features. In addition, the applications of such features to fusion and astrophysics will be considered.

  15. Point-of-care diagnostics for niche applications.

    PubMed

    Cummins, Brian M; Ligler, Frances S; Walker, Glenn M

    2016-01-01

    Point-of-care or point-of-use diagnostics are analytical devices that provide clinically relevant information without the need for a core clinical laboratory. In this review we define point-of-care diagnostics as portable versions of assays performed in a traditional clinical chemistry laboratory. This review discusses five areas relevant to human and animal health where increased attention could produce significant impact: veterinary medicine, space travel, sports medicine, emergency medicine, and operating room efficiency. For each of these areas, clinical need, available commercial products, and ongoing research into new devices are highlighted. PMID:26837054

  16. Computational Imaging, Sensing and Diagnostics for Global Health Applications

    PubMed Central

    Coskun, Ahmet F.; Ozcan, Aydogan

    2013-01-01

    In this Review, we summarize some of the recent work in emerging computational imaging, sensing and diagnostics techniques, along with some of the complementary non-computational modalities that can potentially transform the delivery of health care globally. As computational resources are becoming more and more powerful, while also getting cheaper and more widely available, traditional imaging, sensing and diagnostic tools will continue to experience a revolution through simplification of their designs, making them compact, light-weight, cost-effective, and yet quite powerful in terms of their performance when compared to their bench-top counterparts. PMID:24484875

  17. Diagnostics of a nonlocal plasma of a short glow discharge with active boundaries

    NASA Astrophysics Data System (ADS)

    Demidov, Vladimir; Astafiev, Alexander; Gutsev, Sergie; Kudryavtsev, Anatoly; Zamchiy, Roman

    2013-10-01

    Short glow discharges have attracted interest of researchers. In such discharges, the gap is chosen such a way that the positive column with direct electron heating by electric field could not be formed. However, in contrast to the positive column, the properties of the plasmas of NG and FDS are poorly understood. In this work, experimental study of the short glow discharge in helium at different gas pressures and distances between the electrodes are performed. The short discharge has a positive differential characteristic. As a result the discharge is stable even without ballast resistance, which may be important for applications. Experiments confirm that the plasma of the short glow discharge is characterized by a low electron temperature and weak electric field. Since the dimensions of the NG are determined by energy of fast electrons produced in the cathode sheath, in atomic gases, the electron distribution function is nonlocal, i.e. different groups of electrons behave independently of each other (did not have time ``to mix due to collisions''). As the EDF is nonlocal, it allows measurement of the fast part of the EDF by application of measuring wall electrode. The results of measurements by Langmuir and wall probes are in good agreement. This work has been supported by SPbSU and FZP.

  18. Plasma Potential Measurements by the Heavy Ion Beam Probe Diagnostic in Fusion Plasmas: Biasing Experiments in the TJ-II Stellarator and T-10 Tokamak

    SciTech Connect

    Melnikov, A.V.; Hidalgo, C.; Eliseev, L.G.

    2004-09-15

    The effect of edge biasing on plasma potential was investigated in the TJ-II stellarator and the T-10 tokamak. The Heavy Ion Beam Probe (HIBP) diagnostic, a unique tool for studying the core potential directly, was used in both machines. Experiments in TJ-II show that it is possible to modify the global confinement and edge plasma parameters with limiter biasing, illustrating the direct impact of radial electric fields on TJ-II confinement properties. For the first time it was shown that the plasma column in a stellarator can be charged as a whole for a hot, near-reactor-relevant plasma. The plasma potential and electric fields evolve on two different characteristic time scales. Although the experimental conditions in the two machines have many important differences, the basic features of plasma potential behavior have some similarities: The potential response has the same polarity and scale as the biasing voltage, and the fluctuations are suppressed near the electrode/limiter region. However, whereas both edge and core plasma potential are affected by biasing in TJ-II, the potential changes mainly near the biased electrode in T-10.

  19. Compact Plasma Accelerator for Micropropulsion Applications

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2001-01-01

    There is a need for a low power, light-weight (compact), high specific impulse electric propulsion device to satisfy mission requirements for microsatellite (1 to 20 kg) class missions. Satisfying these requirements entails addressing the general problem of generating a sufficiently dense plasma within a relatively small volume and then accelerating it. In the work presented here, the feasibility of utilizing a magnetic cusp to generate a dense plasma over small length scales of order 1 mm is investigated. This approach could potentially mitigate scaling issues associated with conventional ion thruster plasma containment schemes. Plume and discharge characteristics were documented using a Faraday probe and a retarding potential analyzer.

  20. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC_LAB test facility

    NASA Astrophysics Data System (ADS)

    Shpakov, V.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Dabagov, S.; Ferrario, M.; Filippi, F.; Marocchino, A.; Paroli, B.; Pompili, R.; Rossi, A. R.; Zigler, A.

    2016-09-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC_LAB for such diagnostics tool, along with expected parameters of betatron radiation.