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Sample records for ac53 thompsonpaak2006 thomson

  1. Autographa californica multiple nucleopolyhedrovirus ac53 plays a role in nucleocapsid assembly

    SciTech Connect

    Liu Chao; Li Zhaofei Wu Wenbi; Li Lingling; Yuan Meijin; Pan Lijing; Yang Kai Pang Yi

    2008-12-05

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) orf53 (ac53) is a highly conserved gene existing in all sequenced Lepidoptera and Hymenoptera baculoviruses, but its function remains unknown. To investigate its role in the baculovirus life cycle, an ac53 deletion virus (vAc{sup ac53KO-PH-GFP}) was generated through homologous recombination in Escherichia coli. Fluorescence and light microscopy and titration analysis revealed that vAc{sup ac53KO-PH-GFP} could not produce infectious budded virus in infected Sf9 cells. Real-time PCR demonstrated that the ac53 deletion did not affect the levels of viral DNA replication. Electron microscopy showed that many lucent tubular shells devoid of the nucleoprotein core are present in the virogenic stroma and ring zone, indicating that the ac53 knockout affected nucleocapsid assembly. With a recombinant virus expressing an Ac53-GFP fusion protein, we observed that Ac53 was distributed within the cytoplasm and nucleus at 24 h post-infection, but afterwards accumulated predominantly near the nucleus-cytoplasm boundary. These data demonstrate that ac53 is involved in nucleocapsid assembly and is an essential gene for virus production.

  2. Complete Genome Sequences of Seven Helicoverpa armigera SNPV-AC53-Derived Strains

    PubMed Central

    2016-01-01

    Wild-type baculovirus isolates typically consist of multiple strains. We report the full genome sequences of seven alphabaculovirus strains derived by passage through tissue culture from Helicoverpa armigera SNPV-AC53 (KJ909666). PMID:27151787

  3. Complete Genome Sequences of Helicoverpa armigera Single Nucleopolyhedrovirus Strains AC53 and H25EA1 from Australia

    PubMed Central

    Noune, Christopher

    2015-01-01

    We report here the genome sequences of two alphabaculoviruses of Helicoverpa spp. from Australia: AC53, used in the biopesticides ViVUS and ViVUS Max, and H25EA1, used in in vitro production studies. PMID:26404605

  4. The ac53, ac78, ac101, and ac103 Genes Are Newly Discovered Core Genes in the Family Baculoviridae

    PubMed Central

    Garavaglia, Matías Javier; Miele, Solange Ana Belén; Iserte, Javier Alonso; Belaich, Mariano Nicolás

    2012-01-01

    The family Baculoviridae is a large group of insect viruses containing circular double-stranded DNA genomes of 80 to 180 kbp, which have broad biotechnological applications. A key feature to understand and manipulate them is the recognition of orthology. However, the differences in gene contents and evolutionary distances among the known members of this family make it difficult to assign sequence orthology. In this study, the genome sequences of 58 baculoviruses were analyzed, with the aim to detect previously undescribed core genes because of their remote homology. A routine based on Multi PSI-Blast/tBlastN and Multi HaMStR allowed us to detect 31 of 33 accepted core genes and 4 orthologous sequences in the Baculoviridae which were not described previously. Our results show that the ac53, ac78, ac101 (p40), and ac103 (p48) genes have orthologs in all genomes and should be considered core genes. Accordingly, there are 37 orthologous genes in the family Baculoviridae. PMID:22933288

  5. Joule Thomson refrigerator

    NASA Technical Reports Server (NTRS)

    Chan, Chung K. (Inventor); Gatewood, John R. (Inventor)

    1988-01-01

    A bi-directional Joule Thomson refrigerator is described, which is of simple construction at the cold end of the refrigerator. Compressed gas flowing in either direction through the Joule Thomson expander valve and becoming liquid, is captured in a container in direct continuous contact with the heat load. The Joule Thomson valve is responsive to the temperature of the working fluid near the valve, to vary the flow resistance through the valve so as to maintain a generally constant flow mass between the time that the refrigerator is first turned on and the fluid is warm, and the time when the refrigerator is near its coldest temperature and the fluid is cold. The valve is operated by differences in thermal coefficients of expansion of materials to squeeze and release a small tube which acts as the expander valve.

  6. Cycling Joule Thomson refrigerator

    NASA Technical Reports Server (NTRS)

    Tward, E. (Inventor)

    1983-01-01

    A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander, or valve, interposed between the legs thereof for providing a, efficient refrigeration cycle is described. The system further includes a plurality of gas operational heat switches adapted selectively to transfer heat from a thermal load and to transfer or discharge heat through a heat projector, such as a radiator or the like. The heat switches comprise heat pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.

  7. Optimizing Thomson's jumping ring

    NASA Astrophysics Data System (ADS)

    Tjossem, Paul J. H.; Brost, Elizabeth C.

    2011-04-01

    The height to which rings will jump in a Thomson jumping ring apparatus is the central question posed by this popular lecture demonstration. We develop a simple time-averaged inductive-phase-lag model for the dependence of the jump height on the ring material, its mass, and temperature and apply it to measurements of the jump height for a set of rings made by slicing copper and aluminum alloy pipe into varying lengths. The data confirm a peak jump height that grows, narrows, and shifts to smaller optimal mass when the rings are cooled to 77 K. The model explains the ratio of the cooled/warm jump heights for a given ring, the reduction in optimal mass as the ring is cooled, and the shape of the mass resonance. The ring that jumps the highest is found to have a characteristic resistance equal to the inductive reactance of the set of rings.

  8. Thomson scattering from laser plasmas

    SciTech Connect

    Moody, J D; Alley, W E; De Groot, J S; Estabrook, K G; Glenzer, S H; Hammer, J H; Jadaud, J P; MacGowan, B J; Rozmus, W; Suter, L J; Williams, E A

    1999-01-12

    Thomson scattering has recently been introduced as a fundamental diagnostic of plasma conditions and basic physical processes in dense, inertial confinement fusion plasmas. Experiments at the Nova laser facility [E. M. Campbell et al., Laser Part. Beams 9, 209 (1991)] have demonstrated accurate temporally and spatially resolved characterization of densities, electron temperatures, and average ionization levels by simultaneously observing Thomson scattered light from ion acoustic and electron plasma (Langmuir) fluctuations. In addition, observations of fast and slow ion acous- tic waves in two-ion species plasmas have also allowed an independent measurement of the ion temperature. These results have motivated the application of Thomson scattering in closed-geometry inertial confinement fusion hohlraums to benchmark integrated radiation-hydrodynamic modeling of fusion plasmas. For this purpose a high energy 4{omega} probe laser was implemented recently allowing ultraviolet Thomson scattering at various locations in high-density gas-filled hohlraum plasmas. In partic- ular, the observation of steep electron temperature gradients indicates that electron thermal transport is inhibited in these gas-filled hohlraums. Hydrodynamic calcula- tions which include an exact treatment of large-scale magnetic fields are in agreement with these findings. Moreover, the Thomson scattering data clearly indicate axial stagnation in these hohlraums by showing a fast rise of the ion temperature. Its timing is in good agreement with calculations indicating that the stagnating plasma will not deteriorate the implosion of the fusion capsules in ignition experiments.

  9. Nonlinear effects in Thomson backscattering

    NASA Astrophysics Data System (ADS)

    Maroli, C.; Petrillo, V.; Tomassini, P.; Serafini, L.

    2013-03-01

    We analyze the nonlinear classical effects of the X/γ radiation produced by Thomson/Compton sources. We confirm the development of spectral fringes of the radiation on axis, which comports broadening, shift, and deformation of the spectrum. For the nominal parameters of the SPARC-LAB Thomson scattering and of the European Proposal for the gamma source ELI-NP, however, the radiation, when collected in the suitable acceptance angle, does not reveal many differences from that predicted by the linear model and the nonlinear redshift is subdominant with respect to the quantum recoil. An experiment aimed to the study of the nonlinearities is proposed on the SPARC-LAB source.

  10. Rothmund-Thomson syndrome.

    PubMed

    Larizza, Lidia; Roversi, Gaia; Volpi, Ludovica

    2010-01-01

    Rothmund-Thomson syndrome (RTS) is a genodermatosis presenting with a characteristic facial rash (poikiloderma) associated with short stature, sparse scalp hair, sparse or absent eyelashes and/or eyebrows, juvenile cataracts, skeletal abnormalities, radial ray defects, premature aging and a predisposition to cancer. The prevalence is unknown but around 300 cases have been reported in the literature so far. The diagnostic hallmark is facial erythema, which spreads to the extremities but spares the trunk, and which manifests itself within the first year and then develops into poikiloderma. Two clinical subforms of RTS have been defined: RTSI characterised by poikiloderma, ectodermal dysplasia and juvenile cataracts, and RTSII characterised by poikiloderma, congenital bone defects and an increased risk of osteosarcoma in childhood and skin cancer later in life. The skeletal abnormalities may be overt (frontal bossing, saddle nose and congenital radial ray defects), and/or subtle (visible only by radiographic analysis). Gastrointestinal, respiratory and haematological signs have been reported in a few patients. RTS is transmitted in an autosomal recessive manner and is genetically heterogeneous: RTSII is caused by homozygous or compound heterozygous mutations in the RECQL4 helicase gene (detected in 60-65% of RTS patients), whereas the aetiology in RTSI remains unknown. Diagnosis is based on clinical findings (primarily on the age of onset, spreading and appearance of the poikiloderma) and molecular analysis for RECQL4 mutations. Missense mutations are rare, while frameshift, nonsense mutations and splice-site mutations prevail. A fully informative test requires transcript analysis not to overlook intronic deletions causing missplicing. The diagnosis of RTS should be considered in all patients with osteosarcoma, particularly if associated with skin changes. The differential diagnosis should include other causes of childhood poikiloderma (including dyskeratosis

  11. Development of KSTAR Thomson scattering system

    SciTech Connect

    Lee, J. H.; Oh, S. T.; Wi, H. M.

    2010-10-15

    To measure the electron temperature (T{sub e}) and electron density (n{sub e}) profiles in the Korean Superconducting Tokamak Advanced Research (KSTAR) device for the KSTAR third campaign (September 2010), we designed and installed a Thomson scattering system. The KSTAR Thomson scattering system is designed as a tangential Thomson scattering system and utilizes the N-, L-, and B-ports. The N-port is designed for the collection optics with a cassette system, the L-port is the laser input port, and the B-port is the location of the beam dump. In this paper, we will describe the final design of the KSTAR Thomson scattering system.

  12. THE THOMSON SURFACE. I. REALITY AND MYTH

    SciTech Connect

    Howard, T. A.; DeForest, C. E.

    2012-06-20

    The solar corona and heliosphere are visible via sunlight that is Thomson-scattered off free electrons and detected by coronagraphs and heliospheric imagers. It is well known that these instruments are most responsive to material at the 'Thomson surface', the sphere with a diameter passing through both the observer and the Sun. It is less well known that in fact the Thomson scattering efficiency is minimized on the Thomson surface. Unpolarized heliospheric imagers such as STEREO/HI are thus approximately equally responsive to material over more than a 90 Degree-Sign range of solar exit angles at each given position in the image plane. We call this range of angles the 'Thomson plateau'. We observe that heliospheric imagers are actually more sensitive to material far from the Thomson surface than close to it, at a fixed radius from the Sun. We review the theory of Thomson scattering as applied to heliospheric imaging, feature detection in the presence of background noise, geometry inference, and feature mass measurement. We show that feature detection is primarily limited by observing geometry and field of view, that the highest sensitivity for detection of density features is to objects close to the observer, that electron surface density inference is independent of geometry across the Thomson plateau, and that mass inference varies with observer distance in all geometries. We demonstrate the sensitivity results with a few examples of features detected by STEREO, far from the Thomson surface.

  13. THE THOMSON SURFACE. II. POLARIZATION

    SciTech Connect

    DeForest, C. E.; Howard, T. A.; Tappin, S. J.

    2013-03-01

    The solar corona and heliosphere are visible via sunlight that is Thomson-scattered off free electrons, yielding a radiance against the celestial sphere. In this second part of a three-article series, we discuss linear polarization of this scattered light parallel and perpendicular to the plane of scatter in the context of heliospheric imaging far from the Sun. The difference between these two radiances (pB) varies quite differently with scattering angle, compared to the sum that would be detected in unpolarized light (B). The difference between these two quantities has long been used in a coronagraphic context for background subtraction and to extract some three-dimensional information about the corona; we explore how these effects differ in the wider-field heliospheric imaging case where small-angle approximations do not apply. We develop an appropriately simplified theory of polarized Thomson scattering in the heliosphere, discuss signal-to-noise considerations, invert the scattering equations analytically to solve the three-dimensional object location problem for small objects, discuss exploiting polarization for background subtraction, and generate simple forward models of several classes of heliospheric feature. We conclude that pB measurements of heliospheric material are much more localized to the Thomson surface than are B measurements, that the ratio pB/B can be used to track solar wind features in three dimensions for scientific and space weather applications better in the heliosphere than corona, and that,as an independent measurement of background signal, pB measurements may be used to reduce the effect of background radiances including the stably polarized zodiacal light.

  14. 76 FR 27365 - West, A Thomson Reuters Business, Thomson Reuters Legal Division, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... Determination was published in the Federal Register on March 17, 2011 (76 FR 14693). The workers are engaged in... Employment and Training Administration West, A Thomson Reuters Business, Thomson Reuters Legal Division... former workers of West, A Thomson Reuters Business, Thomson Reuters Legal Division, Albuquerque,...

  15. Thomson Scattering Lineshape Fitting for Plasma Diagnostics

    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.

  16. Relativistic Thomson Scatter from Factor Calculation

    2009-11-01

    The purpose of this program is calculate the fully relativistic Thomson scatter from factor in unmagnetized plasmas. Such calculations are compared to experimental diagnoses of plasmas at such facilities as the Jupiter laser facility here a LLNL.

  17. Joule-Thomson expander and heat exchanger

    NASA Technical Reports Server (NTRS)

    Norman, R. H.

    1976-01-01

    The Joule-Thomson Expander and Heat Exchanger Program was initiated to develop an assembly (JTX) which consists of an inlet filter, counterflow heat exchanger, Joule-Thomson expansion device, and a low pressure jacket. The program objective was to develop a JTX which, when coupled to an open cycle supercritical helium refrigerating system (storage vessel), would supply superfluid helium (He II) at 2 K or less for cooling infrared detectors.

  18. Thomson-scattering systems on TMX

    SciTech Connect

    Goodman, R.K.; Clauser, J.F.; Frank, A.M.; Goerz, D.A.; Lang, D.D.

    1982-01-30

    This report summarizes the criteria and designs that were used for the two TMX Thomson-scattering systems. It describes the optical, mechanical, electronic, and computer analysis features of these installations. A brief discussion of general Thomson-scattering principles and sensitivity limits is given. Also included are some plasma electron temperature and density measurements from TMX that were obtained through the use of these systems.

  19. Quantum theory of Thomson scattering

    NASA Astrophysics Data System (ADS)

    Crowley, B. J. B.; Gregori, G.

    2014-12-01

    The general theory of the scattering of electromagnetic radiation in atomic plasmas and metals, in the non-relativistic regime, in which account is taken of the Kramers-Heisenberg polarization terms in the Hamiltonian, is described from a quantum mechanical viewpoint. As well as deriving the general formula for the double differential Thomson scattering cross section in an isotropic finite temperature multi-component system, this work also considers closely related phenomena such as absorption, refraction, Raman scattering, resonant (Rayleigh) scattering and Bragg scattering, and derives many essential relationships between these quantities. In particular, the work introduces the concept of scattering strength and the strength-density field which replaces the normal particle density field in the standard treatment of scattering by a collection of similar particles and it is the decomposition of the strength-density correlation function into more familiar-looking components that leads to the final result. Comparisons are made with previous work, in particular that of Chihara [1].

  20. EDITORIAL: J J Thomson's Electron

    NASA Astrophysics Data System (ADS)

    Adams, Steve

    1997-07-01

    Westminster School, London, UK A few weeks ago David Thomson, J J Thomson's grandson, presented a Friday evening discourse at the Royal Institution. In it he traced the development of JJT's life from his early studies at Owen's College in Manchester, on to Trinity College Cambridge, his work under Rayleigh at the Cavendish, and his succession as Professor of Experimental Physics in 1884 (a post he passed on to Rutherford in 1919). These were years of heroic discoveries that shaped 20th century physics. Looking around the lecture theatre at all the bow-ties and dinner jackets, it must have been rather similar on 30 April 1897 when JJT delivered his famous discourse on 'Cathode Rays' in which he cautiously but confidently announced that his own results together with those of other experimenters (Lenard in particular):

    `....seem to favour the hypothesis that the carriers of the charges are smaller than the atoms of hydrogen.'
    In this issue articles by Leif Gerward and Christopher Cousins, and by Isobel Falconer explore the historical and philosophical context of that discovery. The sound-bites to history in many A-level courses have JJT as both the hero who single-handedly discovered the electron and the rather naive Victorian scientist who thought the atom was a plum pudding. It is valuable to see how Thomson's work pulled the threads of many experiments together and to realize that he may have been first to the post because of a difference in the philosophical approach to cathode rays in Britain compared to Europe. Experimental data must always be interpreted, and divergent philosophies can lead to quite different conclusions. The electron was, of course, the first subatomic particle to be identified. Christine Sutton's article looks at how 20th century discoveries reveal Nature's mysterious habit of repeating successful patterns---electrons for example have very close relations, the muon and the tau---but why? Perhaps the answer will come

  1. Thomson scattering on inhomogeneous targets

    SciTech Connect

    Thiele, R.; Sperling, P.; Bornath, Th.; Kraeft, W.-D.; Redmer, R.; Chen, M.; Faeustlin, R. R.; Toleikis, S.; Fortmann, C.; Glenzer, S. H.; Pukhov, A.; Tschentscher, Th.

    2010-11-15

    The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm dense matter states. For instance, a short-pulse optical laser irradiates a liquid hydrogen jet that is subsequently probed with brilliant soft x-ray radiation. The strongly inhomogeneous plasma prepared by the optical laser is characterized with particle-in-cell simulations. The interaction of the soft x-ray probe radiation for different time delays between pump and probe with the inhomogeneous plasma is also taken into account via radiative hydrodynamic simulations. We calculate the respective scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We can identify plasmon modes that are generated in different target regions and monitor their temporal evolution. Therefore, such pump-probe experiments are promising tools not only to measure the important plasma parameters density and temperature but also to gain valuable information about their time-dependent profile through the target. The method described here can be applied to various pump-probe scenarios by combining optical lasers and soft x ray, as well as x-ray sources.

  2. Thomson parabola ion energy analyzer

    SciTech Connect

    Cobble, James A; Flippo, Kirk A; Letzring, Samuel A; Lopez, Frank E; Offermann, Dustin T; Oertel, John A; Mastrosimone, Dino

    2010-01-01

    A new, versatile Thomson parabola ion energy (TPIE) analyzer has been designed and constructed for use at the OMEGA-EP facility. Multi-MeV ions from EP targets are transmitted through a W pinhole into a (5- or 8-kG) magnetic field and subsequently through a parallel electric field of up to 30 kV/cm. The ion drift region may have a user-selected length of 10, 50, or 80 cm. With the highest fields, 500-Me V C{sup 6+} and C{sup 5+} may be resolved. TPIE is TIM-mounted at OMEGA-EP and is qualified in all existing TIMs. The instrument runs on pressure-interlocked 15-VDC power available in EP TIM carts. It may be inserted to within several inches of the target to attain sufficient flux for a measurement. For additional flux control, the user may select a square-aperture W pinhole of 0.004-inch or 0.010-inch. The detector consists of CR-39 backed by an image plate. The fully relativistic design code and design features are discussed. Ion spectral results from first use at OMEGA-EP are expected.

  3. Radiation Reaction and Thomson Scattering

    SciTech Connect

    Koga, James

    2007-07-11

    In recent years high power high irradiance lasers of peta-watt order have been or are under construction. In addition, in the next 10 years lasers of unprecedented powers, exa-watt, could be built If lasers such as these are focused to very small spot sizes, extremely high laser irradiances will be achieved. When electrons interact with such a laser, they become highly relativistic over very short time and spatial scales. Usually the motion of an electron under the influence of electromagnetic fields is influenced to a small extent by radiation emission from acceleration. However, under such violent acceleration the amount of radiation emitted by electrons can become so large that significant damping of the electron motion by the emission of this radiation can occur. In this lecture note we will study this problem of radiation reaction by first showing how the equations of motion are obtained. Then, we will examine the problems with such equations and what approximations are made. We will specifically examine the effects of radiation reaction on the Thomson scattering of radiation from counter-streaming laser pulses and high energy electrons through the numerical integration of the equations of motion. We will briefly address the fundamental physics, which can be addressed by using such high irradiance lasers interacting with high energy electrons.

  4. Thomson scattering on inhomogeneous targets.

    PubMed

    Thiele, R; Sperling, P; Chen, M; Bornath, Th; Fäustlin, R R; Fortmann, C; Glenzer, S H; Kraeft, W-D; Pukhov, A; Toleikis, S; Tschentscher, Th; Redmer, R

    2010-11-01

    The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm dense matter states. For instance, a short-pulse optical laser irradiates a liquid hydrogen jet that is subsequently probed with brilliant soft x-ray radiation. The strongly inhomogeneous plasma prepared by the optical laser is characterized with particle-in-cell simulations. The interaction of the soft x-ray probe radiation for different time delays between pump and probe with the inhomogeneous plasma is also taken into account via radiative hydrodynamic simulations. We calculate the respective scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We can identify plasmon modes that are generated in different target regions and monitor their temporal evolution. Therefore, such pump-probe experiments are promising tools not only to measure the important plasma parameters density and temperature but also to gain valuable information about their time-dependent profile through the target. The method described here can be applied to various pump-probe scenarios by combining optical lasers and soft x ray, as well as x-ray sources. PMID:21230599

  5. Theory of Thomson scattering in inhomogeneous media

    NASA Astrophysics Data System (ADS)

    Kozlowski, P. M.; Crowley, B. J. B.; Gericke, D. O.; Regan, S. P.; Gregori, G.

    2016-04-01

    Thomson scattering of laser light is one of the most fundamental diagnostics of plasma density, temperature and magnetic fields. It relies on the assumption that the properties in the probed volume are homogeneous and constant during the probing time. On the other hand, laboratory plasmas are seldom uniform and homogeneous on the temporal and spatial dimensions over which data is collected. This is particularly true for laser-produced high-energy-density matter, which often exhibits steep gradients in temperature, density and pressure, on a scale determined by the laser focus. Here, we discuss the modification of the cross section for Thomson scattering in fully-ionized media exhibiting steep spatial inhomogeneities and/or fast temporal fluctuations. We show that the predicted Thomson scattering spectra are greatly altered compared to the uniform case, and may lead to violations of detailed balance. Therefore, careful interpretation of the spectra is necessary for spatially or temporally inhomogeneous systems.

  6. Theory of Thomson scattering in inhomogeneous media.

    PubMed

    Kozlowski, P M; Crowley, B J B; Gericke, D O; Regan, S P; Gregori, G

    2016-01-01

    Thomson scattering of laser light is one of the most fundamental diagnostics of plasma density, temperature and magnetic fields. It relies on the assumption that the properties in the probed volume are homogeneous and constant during the probing time. On the other hand, laboratory plasmas are seldom uniform and homogeneous on the temporal and spatial dimensions over which data is collected. This is particularly true for laser-produced high-energy-density matter, which often exhibits steep gradients in temperature, density and pressure, on a scale determined by the laser focus. Here, we discuss the modification of the cross section for Thomson scattering in fully-ionized media exhibiting steep spatial inhomogeneities and/or fast temporal fluctuations. We show that the predicted Thomson scattering spectra are greatly altered compared to the uniform case, and may lead to violations of detailed balance. Therefore, careful interpretation of the spectra is necessary for spatially or temporally inhomogeneous systems. PMID:27068215

  7. Theory of Thomson scattering in inhomogeneous media

    PubMed Central

    Kozlowski, P. M.; Crowley, B. J. B.; Gericke, D. O.; Regan, S. P.; Gregori, G.

    2016-01-01

    Thomson scattering of laser light is one of the most fundamental diagnostics of plasma density, temperature and magnetic fields. It relies on the assumption that the properties in the probed volume are homogeneous and constant during the probing time. On the other hand, laboratory plasmas are seldom uniform and homogeneous on the temporal and spatial dimensions over which data is collected. This is particularly true for laser-produced high-energy-density matter, which often exhibits steep gradients in temperature, density and pressure, on a scale determined by the laser focus. Here, we discuss the modification of the cross section for Thomson scattering in fully-ionized media exhibiting steep spatial inhomogeneities and/or fast temporal fluctuations. We show that the predicted Thomson scattering spectra are greatly altered compared to the uniform case, and may lead to violations of detailed balance. Therefore, careful interpretation of the spectra is necessary for spatially or temporally inhomogeneous systems. PMID:27068215

  8. Thomson scattering in short pulse laser experiments

    SciTech Connect

    Hill, E. G.; Rose, S. J.

    2012-08-15

    Thomson scattering is well used as a diagnostic in many areas of high energy density physics. In this paper, we quantitatively demonstrate the practicality of using Thomson scattering as a diagnostic of short-pulse laser-plasma experiments in the regime, where the plasmas probed are at solid density and have temperatures of many hundreds of eV using a backlighter produced with an optical laser. This method allows a diagnosis both spatially and temporally of the density and temperature distributions in high energy density laser-plasma interactions which is independent from, and would act as a useful complement to, the existing spectroscopic methods.

  9. A variational proof of Thomson's theorem

    NASA Astrophysics Data System (ADS)

    Fiolhais, Miguel C. N.; Essén, Hanno; Gouveia, Tomé M.

    2016-08-01

    Thomson's theorem of electrostatics, which states the electric charge on a set of conductors distributes itself on the conductor surfaces to minimize the electrostatic energy, is reviewed in this letter. The proof of Thomson's theorem, based on a variational principle, is derived for a set of normal charged conductors, with and without the presence of external electric fields produced by fixed charge distributions. In this novel approach, the variations are performed on both the charge densities and electric potentials, by means of a local Lagrange multiplier associated with Poisson's equation, constraining the two variables.

  10. Recent improvements in Thomson scattering data analysis

    SciTech Connect

    Tillack, M.S.; Lazarus, E.A.

    1980-04-01

    A new profile analysis package for use with the Thomson scattering data on ISX-B has recently been implemented. The primary feature of this package is a weighted least squares fitting of temperature and density data to generate a representative curve, as opposed to the previous hand-fitting technique. The changes will automate the manner in which data are transmitted and manipulated, without affecting the calculational techniques previously used. The computer programs have also been used to estimate the sensitivity of various plasma quantities to the accuracy of the Thomson scattering data.

  11. Alpha particle collective Thomson scattering in TFTR

    SciTech Connect

    Machuzak, J.S.; Woskov, P.P.; Rhee, D.Y.; Gilmore, J.; Bretz, N.L.; Park, H.K.; Aamodt, R.E.; Cheung, P.Y.; Russell, D.A.; Bindslev, H.

    1993-11-01

    A collective Thomson scattering diagnostic is being implemented on TFTR to measure alpha particle, energetic and thermal ion densities and velocity distributions. A 60 GHz, 0.1-1 kW gyrotron will be used as the transmitter source, and the scattering geometry will be perpendicular to the magnetic field in the extraordinary mode polarization. An enhanced scattered signal is anticipated from fluctuations in the lower hybrid frequency range with this scattering geometry. Millimeter wave collective Thomson scattering diagnostics have the advantage of larger scattering angles to decrease the amount of stray light, and long, high power, modulated pulses to obtain improved signal to noise through synchronous detection techniques.

  12. Genetics Home Reference: Rothmund-Thomson syndrome

    MedlinePlus

    ... risk of developing cancer, particularly a form of bone cancer called osteosarcoma. These bone tumors most often develop during childhood ... Rothmund-Thomson syndrome MedlinePlus Encyclopedia: Cataract MedlinePlus Encyclopedia: Osteosarcoma These resources from MedlinePlus offer information about the ...

  13. The AC Repulsion Demonstration of Elihu Thomson.

    ERIC Educational Resources Information Center

    Quinton, Arthur R.

    1979-01-01

    Traces the early history of an experiment, the launching of a copper or aluminum ring above the pole of an alternating current magnet at switch-on, that was conducted by Elihu Thomson in the last century and presents a simple qualitative explanation of the effect involved. (GA)

  14. Thomson semiconductors bipolar IC strategy to 1986

    NASA Astrophysics Data System (ADS)

    Dellamussia, J. P.

    1984-04-01

    The strategy to develop and market bipolar integrated circuits through 1986 by thomson semiconductors is discussed. Current technology and future research on prototype microprocessors using bipolar integrated circuits is evaluated. The physical properties of the circuits such as heat dissipation, energy consumption rates and response times are studied.

  15. The SPARC_LAB Thomson source

    NASA Astrophysics Data System (ADS)

    Vaccarezza, C.; Alesini, D.; Anania, M. P.; Bacci, A.; Biagioni, A.; Bisesto, F.; Bellaveglia, M.; Cardarelli, P.; Cardelli, F.; Cianchi, A.; Chiadroni, E.; Croia, M.; Curcio, A.; Delogu, P.; Giovenale, D. Di; Domenico, G. Di; Pirro, G. Di; Drebot, I.; Ferrario, M.; Filippi, F.; Gallo, A.; Galletti, M.; Gambaccini, M.; Giribono, A.; Golosio, B.; Li, W.; Mostacci, A.; Oliva, P.; Palmer, D.; Petrillo, V.; Petrarca, M.; Pioli, S.; Piersanti, L.; Pompili, R.; Romeo, S.; Rossi, A. R.; Scifo, J.; Serafini, L.; Suliman, G.; Villa, F.

    2016-09-01

    The SPARC_LAB Thomson source is a compact X-ray source based on the Thomson backscattering process presently under its second phase of commissioning at the LNF. The electron beam energy ranges between 30 and 150 MeV, the electrons collide head-on with the Ti:Sapphire FLAME laser pulse the energy of which ranges between 1 and 5 J with pulse lengths in the 25 fs-10 ps range, this provides an X-ray energy tunability in the range of 20-500 keV, with the further capability to generate strongly non-linear phenomena and to drive diffusion processes due to multiple and plural scattering effects. The experimental results of the obtained X-ray radiation are presented.

  16. Thomson scattering for core plasma on DEMO

    SciTech Connect

    Mukhin, E. E.; Kurskiev, G. S.; Tolstyakov, S. Yu.; Bukreev, I. M.; Chernakov, P. V.; Kochergin, M. M.; Koval, A. N.; Litvinov, A. E.; Masyukevich, S. V.; Razdobarin, A. G.; Semenov, V. V.; Kukushkin, A. B.; Sdvizhenskii, P. A.; Andrew, P.

    2014-08-21

    This paper describes the challenges of Thomson scattering implementation for core plasma on DEMO and evaluates the capability to measure extremely high electron temperature range 0.5-40keV. A number of solutions to be developed for ITER diagnostics are suggested in consideration of their realization for DEMO. New approaches suggested for DEMO may also be of interest to ITER and currently operating magnetic confinement devices.

  17. Joule-Thomson Expander Without Check Valves

    NASA Technical Reports Server (NTRS)

    Chan, C. K.; Gatewood, J. R.

    1989-01-01

    Cooling effected by bidirectional, reciprocating flow of gas. Type of Joule-Thomson (J-T) expander for cryogenic cooling requires no check valves to prevent reverse flow of coolant. More reliable than conventional J-T expander, containing network of check valves, each potential source of failure. Gas flows alternately from left to right and right to left. Heat load cooled by evaporation of liquid from left or right compartment, whichever at lower pressure.

  18. Manganese Nitride Sorption Joule-Thomson Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Phillips, Wayne M.

    1992-01-01

    Proposed sorption refrigeration system of increased power efficiency combines MnxNy sorption refrigeration stage with systems described in "Regenerative Sorption Refrigerator" (NPO-17630). Measured pressure-vs-composition isotherms for reversible chemisorption of N2 in MnxNy suggest feasibility to incorporate MnxNy chemisorption stage in Joule-Thomson cryogenic system. Discovery represents first known reversible nitrogen chemisorption compression system. Has potential in nitrogen-isotope separation, nitrogen purification, or contamination-free nitrogen compression.

  19. Joule-Thomson Cooler Produces Nearly Constant Temperature

    NASA Technical Reports Server (NTRS)

    Bard, Steven; Wu, Jiunn-Jeng; Trimble, Curtis A.

    1992-01-01

    Improved Joule-Thomson cooler maintains nearly constant temperature. Absolute-pressure relief valve helps stabilize temperature of cold head despite variations in atmospheric pressure. Feedback-controlled electrical heater provides additional stabilization. Demand-flow Joule-Thomson valve requires less nitrogen than fixed-orifice Joule-Thomson valve providing same amount of cooling. Provides stable low temperatures required for operation of such devices as tunable diode lasers in laboratory and balloon-borne instruments detecting contaminants in atmosphere.

  20. Collection optics design for KSTAR Thomson scattering system

    SciTech Connect

    Oh, S.; Lee, J. H.

    2010-10-15

    The collection optics designs are described for the Thomson scattering diagnostic of the Korea superconducting tokamak advanced research (KSTAR) device. The optical systems collecting the light emission induced through the interaction between the plasma electrons and a laser beam are key components for the Thomson scattering system. A duo-lens system was examined, and the final optical designs were derived for Thomson scattering diagnostic of KSTAR.

  1. J. J. Thomson goes to America.

    PubMed

    Downard, Kevin M

    2009-11-01

    Joseph John (J. J.) Thomson was an accomplished scientist who helped lay the foundations of nuclear physics. A humble man of working class roots, Thomson went on to become one of the most influential physicists of the late 19th century. He is credited with the discovery of the electron, received a Nobel Prize in physics in 1906 for investigations into the conduction of electricity by gases, was knighted in 1908, and served as a Cavendish Professor and Director of the laboratory for over 35 years from 1884. His laboratory attracted some of the world's brightest minds; Francis W. Aston, Niels H. D. Bohr, Hugh L. Callendar, Charles T. R. Wilson, Ernest Rutherford, George F. C. Searle, Geoffrey I. Taylor, and John S. E. Townsend all worked under him. This article recounts J. J. Thomson's visits to North America in 1896, 1903, 1909, and finally 1923. It presents his activities and his personal impressions of the people and society of the U.S.A. and Canada, and the science of atomic physics and chemistry in the late 1800s and early 1900s. PMID:19734055

  2. Thomson scattering at 250 kHz

    NASA Astrophysics Data System (ADS)

    Young, W. C.; Den Hartog, D. J.

    2015-12-01

    Several upgrades have been applied to the high-repetition-rate Thomson scattering diagnostic on the MST experiment, having increased the rate and number of electron temperature measurements. The detector portion of the Thomson scattering system requires 1.5-2.0 J, 10-20 ns laser pulses at 1064 nm. A high-repetition-rate laser produces suitable pulses for short 3-4 pulse bursts with only 3 μs pulse spacing. Alternatively, the laser timing can be optimized to maximize the number of pulses in a single burst, producing up to 44 pulses at a rate of 100 kHz. The laser follows a master oscillator, power amplifier architecture. Upgrades to the laser include: a new acousto-optic modulator chopped CW laser based master oscillator, a sixth power amplifier, optimized Nd doping within Nd:glass amplifiers via optical modeling of the pump chamber, and a yet to be installed new cavity reflector. Additionally, a new long wavelength filter has been added to the Thomson scattering diagnostic's polychromator based detector, allowing possible detection of net electron drift.

  3. Thomson scattering of polarized photons in an intense laser beam

    SciTech Connect

    Byung Yunn

    2006-02-21

    We present a theoretical analysis of the Thomson scattering of linearly and circularly polarized photons from a pulsed laser by electrons. The analytical expression for the photon distribution functions presented in this paper should be useful to designers of Thomson scattering experiments.

  4. Thomson's Theorem of Electrostatics: Its Applications and Mathematical Verification

    ERIC Educational Resources Information Center

    Bakhoum, Ezzat G.

    2008-01-01

    A 100 years-old formula that was given by J. J. Thomson recently found numerous applications in computational electrostatics and electromagnetics. Thomson himself never gave a proof for the formula; but a proof based on Differential Geometry was suggested by Jackson and later published by Pappas. Unfortunately, Differential Geometry, being a…

  5. John Thomson: Photojournalist in Asia, 1862-1872.

    ERIC Educational Resources Information Center

    Parker, Elliott S.

    John Thomson was a nineteenth-century British photojournalist who used the wet-plate process to illustrate his explorations of eastern and Southeast Asia. His travels from 1862 to 1872 took him to the following places, among others: Ceylon, Cambodia, Singapore, Thailand, Saigon, Siam, mainland China, and Taiwan. Thomson chose to use the wet-plate…

  6. Scaling Thomson scattering to big machines

    NASA Astrophysics Data System (ADS)

    Bílková, P.; Walsh, M.; Böhm, P.; Bassan, M.; Aftanas, M.; Pánek, R.

    2016-03-01

    Thomson scattering is a widely used diagnostic tool for local measurement of both electron temperature and electron density. It is used for both low and high temperature plasmas and it is a key diagnostic on all fusion devices. The extremely low cross-section of the reaction increases the complexity of the design. Since the early days of fusion, when a simple single point measurement was used, the design moved to a multi-point system with a large number of spatial points, LIDAR system or high repetition Thomson scattering diagnostic which are used nowadays. The initial low electron temperature approximation has been replaced by the full relativistic approach necessary for large devices as well as for ITER with expected higher plasma temperature. Along the way, the different development needs and the issues that exist need to be addressed to ensure that the technique is developed sufficiently to handle challenges of the bigger devices of the future as well as current developments needed for ITER. For large devices, the achievement of the necessary temperature range represents an important task. Both high and low temperatures can be measured, however, a large dynamic range makes the design difficult as size of detector and dynamic range are linked together. Therefore, the requirements of the new devices are extending the boundaries of these parameters. Namely, ITER presents challenges as access is also difficult but big efforts have been made to cope with this. This contribution contains a broad review of Thomson scattering diagnostics used in current devices together with comments on recent progress and speculation regarding future developments needed for future large scale devices.

  7. Thomson scattering from inertial confinement fusion plasmas

    SciTech Connect

    Glenzer, S.H.; Back, C.A.; Suter, L.J.

    1997-07-08

    Thomson scattering has been developed at the Nova laser facility as a direct and accurate diagnostic to characterize inertial confinement fusion plasmas. Flat disks coated with thin multilayers of gold and beryllium were with one laser beam to produce a two ion species plasma with a controlled amount of both species. Thomson scattering spectra from these plasmas showed two ion acoustic waves belonging to gold and beryllium. The phase velocities of the ion acoustic waves are shown to be a sensitive function of the relative concentrations of the two ion species and are in good agreement with theoretical calculations. These open geometry experiments further show that an accurate measurement of the ion temperature can be derived from the relative damping of the two ion acoustic waves. Subsequent Thomson scattering measurements from methane-filled, ignition-relevant hohlraums apply the theory for two ion species plasmas to obtain the electron and ion temperatures with high accuracy. The experimental data provide a benchmark for two-dimensional hydrodynamic simulations using LASNEX, which is presently in use to predict the performance of future megajoule laser driven hohlraums of the National Ignition Facility (NIF). The data are consistent with modeling using significantly inhibited heat transport at the peak of the drive. Applied to NIF targets, this flux limitation has little effect on x- ray production. The spatial distribution of x-rays is slightly modified but optimal symmetry can be re-established by small changes in power balance or pointing. Furthermore, we find that stagnating plasma regions on the hohlraum axis are well described by the calculations. This result implies that stagnation in gas-filled hohlraums occurs too late to directly affect the capsule implosion in ignition experiments.

  8. Bose-Einstein condensates of bosonic Thomson atoms

    NASA Astrophysics Data System (ADS)

    Schneider, Tobias; Blümel, Reinhold

    1999-10-01

    A system of charged particles in a harmonic trap is a realization of Thomson's raisin cake model. Therefore, we call it a Thomson atom. Bosonic, fermionic and mixed Thomson atoms exist. In this paper we focus on bosonic Thomson atoms in isotropic traps. Approximating the exact ground state by a condensate we investigate ground-state properties at temperature T = 0 using the Hartree-Fock theory for bosons. In order to assess the quality of our mean-field approach we compare the Hartree-Fock results for bosonic Thomson helium with an exact diagonalization. In contrast to the weakly interacting Bose gas (alkali vapours) mean-field calculations are reliable in the limit of large particle density. The Wigner regime (low particle density) is discussed.

  9. Operation of the NSTX Thomson Scattering System

    SciTech Connect

    LeBlanc, B.P.; Bell, R.E.; Johnson, D.W.; Hoffman, D.E.; Long, D.C.; and Palladino, R.W.

    2002-09-03

    The NSTX multi-point Thomson scattering system has been in operation for nearly two years and provides routine Te(R,t) and ne(R,t) measurements. The laser beams from two 30-Hz Nd:YAG lasers are imaged by a spherical mirror onto 36 fiber-optics bundles. In the present configuration, the output ends of 20 of these bundles are instrumented with filter polychromators and avalanche photodiode detectors. In this paper, we discuss the laser implementation and the installed collection optics. We follow with examples of raw and analyzed data. We close with some comments about calibration.

  10. MFTF Thomson scattering: a system study

    SciTech Connect

    Frank, A.M.

    1980-09-11

    This report documents the design effort for a Thomson scattering diagnostic system for MFTF. The principal problem is obtaining enough photons, in the presence of a poorly known background, to make satisfactory measurements. No currently available laser will yield enough photons to do this. Design concepts for imaging and detection are discussed. The ability of components to survive in the high-radiation environment of MFTF is identified as an important problem. The transition to MFTF-B makes many of the problems identified here more serious.

  11. Spring-Loaded Joule-Thomson Valve

    NASA Technical Reports Server (NTRS)

    Jones, J. A.; Britcliffe, M. J.

    1986-01-01

    Improved design reduces clogging and maintains constant pressure drop as flow rate varies. Spring-Loaded Joule-Thomson Valve pressure drop regulated by spring pushing stainless-steel ball against soft brass seat. Pressure drop remains nearly constant, regardless of helium flow rate and of any gas contaminants frozen on valve seat. Because springloaded J-T valve maintains constant pressure drop, upstream roomtemperature throttle valve adjusts flow rate precisely for any given upstream pressure. In addition, new valve relatively invulnerable to frozen gas contaminants, which clog fixed-orifice J-T valves.

  12. 76 FR 50272 - West, A Thomson Reuters Business, Thomson Reuters Legal Division, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... Register on May 11, 2011 (76 FR 27365). On July 20, 2011, the Department issued an amended certification... Employment and Training Administration West, A Thomson Reuters Business, Thomson Reuters Legal Division... Determination Regarding Application for Reconsideration for workers and former workers of West, A...

  13. Multicomponent gas sorption Joule-Thomson refrigeration

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Petrick, S. Walter (Inventor); Bard, Steven (Inventor)

    1991-01-01

    The present invention relates to a cryogenic Joule-Thomson refrigeration capable of pumping multicomponent gases with a single stage sorption compressor system. Alternative methods of pumping a multicomponent gas with a single stage compressor are disclosed. In a first embodiment, the sorbent geometry is such that a void is defined near the output of the sorption compressor. When the sorbent is cooled, the sorbent primarily adsorbs the higher boiling point gas such that the lower boiling point gas passes through the sorbent to occupy the void. When the sorbent is heated, the higher boiling point gas is desorbed at high temperature and pressure and thereafter propels the lower boiling point gas out of the sorption compressor. A mixing chamber is provided to remix the constituent gases prior to expansion of the gas through a Joule-Thomson valve. Other methods of pumping a multicomponent gas are disclosed. For example, where the sorbent is porous and the low boiling point gas does not adsorb very well, the pores of the sorbent will act as a void space for the lower boiling point gas. Alternatively, a mixed sorbent may be used where a first sorbent component physically adsorbs the high boiling point gas and where the second sorbent component chemically absorbs the low boiling point gas.

  14. Thomson scattering in warm dense matter

    NASA Astrophysics Data System (ADS)

    Thiele, R.; Bornath, T.; F"Austlin, R. R.; Fortmann, C.; Glenzer, S.; Gregori, G.; Holst, B.; Tschentscher, T.; Schwarz, V.; Redmer, R.

    2009-11-01

    Free electron lasers employing scattering of high-brilliant, coherent photons in the extreme ultraviolet (VUV), e.g. at FLASH (DESY Hamburg) or LCLS (Stanford), allow for a systematic study of basic plasma properties in the region of warm dense matter (WDM). WDM is characterized by condensed matter-like densities and temperatures of several eV. Collective Thomson scattering with VUV or x-ray has demonstrated its capacity for robust measurements of the free electron density and temperature in WDM. Collective excitations like plasmons (``electron feature'') appear as maxima in the scattering signal. The respective frequencies can be related to the free electron density. Furthermore, the asymmetry of the red- and blue shifted plasmon intensity gives the electron temperature due to detailed balance. We treat collective Thomson scattering in the Born-Mermin-approximation which includes collisions and present a generalized Gross-Bohm dispersion for plasmas. The influence of plasma inhomogeneities on the scattering spectrum is studied by comparing density and temperature averaged scattering signals with calculations assuming homogeneous targets. For the ``ion feature,'' results of semi-classical hypernetted chain (HNC) calculations and of quantum molecular dynamics simulations are shown for dense beryllium.

  15. Prospects for the Thomson scattering system on NSTX-Upgrade

    SciTech Connect

    Diallo, A.; LeBlanc, B. P.; Labik, G.; Stevens, D.

    2012-10-15

    The paper discusses the projected configuration of the Thomson system on the National Spherical Torus Experiment (NSTX-U). In this paper, we discuss the projected configuration of the Thomson system on NSTX-U. More specifically, we determine, through both optical modeling of the collection optics and in-vessel measurements, that the collecting fibers are to be displaced by at most 1 cm toward the imaging plane along the optical axis. Finally, we estimate the performance of the Thomson system in measuring the electron temperature for NSTX-U discharges.

  16. Signal evaluations using singular value decomposition for Thomson scattering diagnostics.

    PubMed

    Tojo, H; Yamada, I; Yasuhara, R; Yatsuka, E; Funaba, H; Hatae, T; Hayashi, H; Itami, K

    2014-11-01

    This paper provides a novel method for evaluating signal intensities in incoherent Thomson scattering diagnostics. A double-pass Thomson scattering system, where a laser passes through the plasma twice, generates two scattering pulses from the plasma. Evaluations of the signal intensities in the spectrometer are sometimes difficult due to noise and stray light. We apply the singular value decomposition method to Thomson scattering data with strong noise components. Results show that the average accuracy of the measured electron temperature (Te) is superior to that of temperature obtained using a low-pass filter (<20 MHz) or without any filters. PMID:25430278

  17. Signal evaluations using singular value decomposition for Thomson scattering diagnostics

    SciTech Connect

    Tojo, H. Yatsuka, E.; Hatae, T.; Itami, K.; Yamada, I.; Yasuhara, R.; Funaba, H.; Hayashi, H.

    2014-11-15

    This paper provides a novel method for evaluating signal intensities in incoherent Thomson scattering diagnostics. A double-pass Thomson scattering system, where a laser passes through the plasma twice, generates two scattering pulses from the plasma. Evaluations of the signal intensities in the spectrometer are sometimes difficult due to noise and stray light. We apply the singular value decomposition method to Thomson scattering data with strong noise components. Results show that the average accuracy of the measured electron temperature (T{sub e}) is superior to that of temperature obtained using a low-pass filter (<20 MHz) or without any filters.

  18. MAST YAG Thomson scattering upgrade alignment system

    SciTech Connect

    Figueiredo, J.; Serra, F.; Naylor, G.; Walsh, M.; Dunstan, M.; Scannell, R.

    2010-10-15

    The recent upgrade to the MAST YAG Thomson scattering while enhancing the diagnostic capabilities increased the complexity of the system. There are eight YAG lasers now operational, doubling the number from the previous setup. This means alignment between each laser individually and reference points is essential to guarantee data quality and diagnostic reliability. To address this issue an alignment system was recently installed. It mimics the beams alignment in MAST by sampling 1% of the laser beam that is sent into a telescope which demagnifies by a factor of 8. The demagnified beam is viewed with a CCD camera. By scanning the camera the profile and position of the beams in the scattering zone and in a range of several meters inside MAST can be determined. Therefore alignment is checked along the beam path without having to sample it inside the vessel. The experimental apparatus and test procedures are described.

  19. A compact multichannel spectrometer for Thomson scattering

    SciTech Connect

    Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R.

    2012-10-15

    The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} < 100 eV are achieved by a 2971 l/mm VPH grating and measurements T{sub e} > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

  20. The PBX-M Thomson scattering system

    SciTech Connect

    LeBlanc, B.; Bell, R.; Dimock, D.; Duperrex, P.; Felt, J.; Palladino, R.; Tolnas, E. )

    1990-10-01

    The PBX-M Thomson scattering system is reviewed after its first 9 months of operation. The system measures {ital T}{sub {ital e}}({ital R}) and {ital n}{sub {ital e}}({ital R}) at 55 radial points on the horizontal midplane with a spatial resolution of {le}1.1 cm. The scattered light is collected by a Bouwers concentric mirror system and imaged onto 12-m-long fiber bundles. A composite entrance slit is used to optimize the system performance. The synchronization between the scattered light and detector gate is done via a laser-triggered spark gap. A penetration in the indentation coil allows the (ruby) laser beam to be dumped away from the plasma chamber. Other aspects of the system will be discussed.

  1. Triple grating polychromator for Thomson scattering.

    PubMed

    Greenwald, M; Smith, W I

    1977-03-01

    A high rejection, high transmission, triple grating polychromator with crossed dispersion has been designed and constructed for Thomson scattering plasma diagnostics. Identical gratings, collimating, and field lenses were used for all three stages. A mechanically convenient arrangement was made possible by using the field lenses to adjust the dispersion of the second stage to the required design value. The transmission in the passband for light polarized perpendicular to the rulings of the grating was measured at 33% for the instrument itself, and at 15% through the instrument and 1.8 m of attached fiber optics. With the 30-nm passband set 4-34-nm wavelengths away from the ruby laser line, the order of 10(-11) of 694-nm light incident in the input slit was present in each 3-nm wide output channel, giving a relative rejection factor of 10(-10). PMID:20168547

  2. Dense Matter Characterization by X-ray Thomson Scattering

    SciTech Connect

    Landen, O L; Glenzer, S H; Edwards, M J; Lee, R W; Collins, G W; Cauble, R C; Hsing, W W; Hammel, B A

    2000-12-29

    We discuss the extension of the powerful technique of Thomson scattering to the x-ray regime for providing an independent measure of plasma parameters for dense plasmas. By spectrally-resolving the scattering, the coherent (Rayleigh) unshifted scattering component can be separated from the incoherent Thomson component, which is both Compton and Doppler shifted. The free electron density and temperature can then be inferred from the spectral shape of the high frequency Thomson scattering component. In addition, as the plasma temperature is decreased, the electron velocity distribution as measured by incoherent Thomson scattering will make a transition from the traditional Gaussian Boltzmann distribution to a density-dependent parabolic Fermi distribution to. We also present a discussion for a proof-of-principle experiment appropriate for a high energy laser facility.

  3. Dual color x rays from Thomson or Compton sources

    NASA Astrophysics Data System (ADS)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Ferrario, M.; Gatti, G.; Maroli, C.; Rau, J. V.; Ronsivalle, C.; Serafini, L.; Vaccarezza, C.; Venturelli, M.

    2014-02-01

    We analyze the possibility of producing two-color x or γ radiation by Thomson/Compton backscattering between a high intensity laser pulse and a two-energy level electron beam, constituted by a couple of beamlets separated in time and/or energy obtained by a photoinjector with comb laser techniques and linac velocity bunching. The parameters of the Thomson source at SPARC_LAB have been simulated, proposing a set of realistic experiments.

  4. Dual color x-rays from Thomson or Compton sources

    NASA Astrophysics Data System (ADS)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Ferrario, M.; Maroli, C.; Rau, J. V.; Ronsivalle, C.; Serafini, L.; Vaccarezza, C.; Venturelli, M.

    2015-05-01

    We analyze the possibility of producing two color X or γ radiation by Thomson/Compton back-scattering between a high intensity laser pulse and a two-energy level electron beam, constituted by a couple of beamlets separated in time and/or energy obtained by a photoinjector with comb laser techniques and linac velocity bunching. The parameters of the Thomson source at SPARC_LAB have been simulated, proposing a set of values for a realistic experiments.

  5. Pulsed Laser Nonlinear Thomson Scattering for General Scattering Geometries

    SciTech Connect

    Geoffrey Krafft; A. Doyuran; James Rosenzweig

    2005-05-01

    In a recent paper it has been shown that single electron Thomson backscatter calculations can be performed including the effects of pulsed high intensity lasers. In this paper we present a more detailed treatment of the problem and present results for more general scattering geometries. In particular, we present new results for 90 degree Thomson scattering. Such geometries have been increasingly studied as X-ray sources of short-pulse radiation. Also, we present a clearer physical basis for these different cases.

  6. Thomson Scattering Measurements of Plasma Dynamics

    SciTech Connect

    Holl, A; Redmer, R; Tschentscher, T; Toleikis, S; Forster, E; Cao, L; Glenzer, S H; Neumayer, P

    2006-03-29

    The authors propose to investigate the dynamics of plasmas in the warm dense matter (WDM) regime on ultra-short time scales. Accessible plasma conditions are in the density range of n = 10{sup 20} - 10{sup 23} cm{sup -3} and at moderate temperatures of T = 1 - 20 eV. These plasmas are of importance for laboratory astrophysics, high energy density science and inertial confinement fusion. They are characterized by a coupling parameter of {Lambda} {approx}> 1, where electromagnetic interactions are of the same order as the kinetic energy. The high density of the plasma makes it opaque to radiation in the visible range and, as a consequence, UV up to x-ray radiation can be used to probe such systems. Therefore a wide range in the temperature-density plane of WDM is presently unexplored and only the VUV-FEL opens for the first time the opportunity for its detailed investigation. In equilibrium, the macroscopic state of the plasma is completely characterized by its density and temperature. In pump-probe experiments however, the plasma is initially in a nonequilibrium state and relaxes towards equilibrium within the relaxation time {tau}{sub R}. For t > {tau}{sub R}, the plasma is in an equilibrium state and expands hydrodynamically on a time scale {tau}{sub H}. The proposed experiment measures the time-resolved Thomson scattering signal with the VUV-FEL radiation characterizing the plasma in equilibrium and nonequilibrium states. Both regimes are extremely interesting and will provide new insight into the following phenomena: (1) details of nonequilibrium correlations, (2) relaxation phenomena, (3) hydrodynamic expansion, (4) recombination kinetics. The time-resolved Thomson scattering signal is obtained in a pump-probe experiment by varying the delay between pump and probe. The final stage of the relaxation process (t {approx} {tau}{sub R}) is of special interest since the plasma components (electrons and ion species) can be assumed to be in quasi-equilibrium. This

  7. Thomson scattering diagnostic systems in ITER

    NASA Astrophysics Data System (ADS)

    Bassan, M.; Andrew, P.; Kurskiev, G.; Mukhin, E.; Hatae, T.; Vayakis, G.; Yatsuka, E.; Walsh, M.

    2016-01-01

    Thomson scattering (TS) is a proven diagnostic technique that will be implemented in ITER in three independent systems. The Edge TS will measure electron temperature Te and electron density ne profiles at high resolution in the region with r/a>0.8 (with a the minor radius). The Core TS will cover the region r/a<0.85 and shall be able to measure electron temperatures up to 40 keV . The Divertor TS will observe a segment of the divertor plasma more than 700 mm long and is designed to detect Te as low as 0.3 eV . The Edge and Core systems are primary contributors to Te and ne profiles. Both are installed in equatorial port 10 and very close together with the toroidal distance between the two laser beams of less than 600 mm at the first wall (~ 6° toroidal separation), a characteristic that should allow to reliably match the two profiles in the region 0.8

  8. Thomson Scattering at 250 kHz

    NASA Astrophysics Data System (ADS)

    Young, William; den Hartog, D. J.; Morton, L. A.; MST Team

    2015-11-01

    The fast Thomson scattering diagnostic on the MST Reversed-Field Pinch experiment now measures electron temperature at rates of up to 250 kHz, allowing for single shot analysis of phenomena that previously required ensembles of measurements from many shots. Recent laser upgrades include the addition of a second Nd:glass amplifier (giving a total of six amplifiers including four Nd:YAG stages) and optimization of neodymium doping levels within the glass amplifier stages to reduce thermal defocusing. The master-oscillator power-amplifier laser system operates in a pulse-burst mode where the laser generates multiple pulses per flashlamp firing and these bursts of laser pulses are repeated multiple times. When optimizing for the largest number of laser pulses, the laser produces up to 30 pulses at a rate of 100 kHz per burst repeated up to 4 times every 2 ms for a total of 120 temperature measurements per MST discharge. When optimizing for fastest pulsing rate, the laser can produce 8 pulses at 250 kHz within a single burst. A laser system upgrade currently underway is replacement of the diode-pumped pulsed Nd:YVO4 master oscillator with a CW laser chopped by an acoustic-optic modulator; this upgrade may enable pulsing rates faster than 250 kHz. This work is supported by the US DOE and NSF.

  9. Upgrades to the MST Thomson scattering diagnostic

    NASA Astrophysics Data System (ADS)

    Kubala, S. Z.; Borchardt, M. T.; den Hartog, D. J.; Holly, D. J.; Jacobson, C. M.; Morton, L. A.; Young, W. C.

    2015-11-01

    The Thomson scattering diagnostic on MST records both equilibrium and fluctuating electron temperature with a range capability of 10 eV to 5 keV. Standard operation with two modified commercial Nd:YAG lasers allows measurements at rates of 1-25 kHz. A new laser system is being commissioned to enable measurements up to 250 kHz. Other subsystems of the diagnostic are also being improved. The power supplies for the avalanche photodiode detectors (APDs) that record the scattered light are being updated to improve safety, reliability, and maintainablity. Each of the 144 APDs will have an individual rack-mounted switched supply with bias voltage adjustable to match the APD. Long-wavelength filters (1140 nm center, 80 nm bandwidth) are being added to the polychromators to improve capability to resolve non-Maxwellian distributions and to enable electron-velocity measurement. A supercontinuum pulsed white-light source is being implemented to improve spectral calibration of the polychromators. This work is supported by the US DOE and NSF.

  10. Mixed refrigerant Joule-Thomson sorption cryocoolers

    NASA Astrophysics Data System (ADS)

    Tzabar, Nir; Grossman, Gershon

    2014-01-01

    Joule-Thomson (JT) sorption cryocooling is the most mature technology for cooling from a normal Room-Temperature (RT) down to temperatures below 100 K in the absence of moving parts. Therefore, high reliability and no vibrations are attainable, in comparison with other cryocoolers. Cooling to 80 - 100 K with JT cryocoolers is often implemented with pure nitrogen. Alternatively, mixed refrigerants have been suggested for reducing the operating pressures to enable closed cycle cryocooling. There is a variety of publications describing nitrogen sorption cryocoolers with different configurations of sorption compressors. In the present research we suggest a novel sorption JT cryocooler that operates with a mixed refrigerant. Merging of sorption cryocooling and a mixed refrigerant enables the use of a simple, single stage compressor for cooling to 80 - 100 K, lower operating temperatures of the sorption cycle, and thus - reduced power consumption. In previous studies we have analyzed sorption compressors for mixed gases and mixed refrigerants for JT cryocoolers, separately. In this paper the option of mixed refrigerant sorption JT cryocoolers is explored. The considerations for developing mixed refrigerants to be driven by sorption compressors and to be utilized with JT cryocoolers are provided. It appears that, unlike with pure nitrogen, mixed refrigerants can be suitable for JT cryocooling with a single stage sorption compressor.

  11. 78 FR 30797 - Proposed Amendment of Class E Airspace; Point Thomson, AK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ...This action proposes to modify the airspace at Point Thomson, AK by establishing Class E Airspace at Point Thomson Airstrip Airport, Point Thomson, AK. This will accommodate aircraft using a new Area Navigation (RNAV) Global Positioning System (GPS) standard instrument approach procedures at the airport. The FAA is proposing this action to enhance the safety and management of aircraft......

  12. Observation of relativistic effects in collective Thomson scattering

    SciTech Connect

    Ross, J S; Glenzer, S H; Palastro, J P; Pollock, B B; Price, D; Divol, L; Tynan, G R; Froula, D H

    2009-10-08

    We observe relativistic modifications to the Thomson scattering spectrum in a traditionally classical regime: v{sub osc}/c = eE{sub 0}/cm{omega}{sub 0} << 1 and T{sub e} < 1 keV. The modifications result from scattering off electron-plasma fluctuations with relativistic phase velocities. Normalized phase velocities v/c between 0.03 and 0.12 have been achieved in a N{sub 2} gas-jet plasma by varying the plasma density from 3 x 10{sup 18} cm{sup -3} to 7 x 10{sup 19} cm{sup -3} and electron temperature between 85 eV and 700 eV. For these conditions, the complete temporally resolved Thomson scattering spectrum including the electron and ion features has been measured. A fully relativistic treatment of the Thomson scattering form factor has been developed and shows excellent agreement with the experimental data.

  13. Thomson Scattering on the HBT-EP Tokamak

    NASA Astrophysics Data System (ADS)

    Levesque, J. P.; Litzner, K. D.; Hanson, J. M.; James, R.; Maurer, D. A.; Mauel, M. E.; Navratil, G. A.; Pedersen, T. S.

    2007-11-01

    Thomson scattering can be used as a non-invasive method for measuring local electron density and temperature in plasmas. We describe the HBT-EP Thomson Scattering diagnostic, which is based on a design in use at DIII-D [1]. A five-channel interference filter polychrometer measures incoherent scattered light from an 8ns, 800mJ, 1064nm Nd:YAG laser pulse. A set of pre-amplification circuits designed by Princeton Scientific Instruments [2] has recently been installed for signal detection using avalanche photodiodes. System layout, alignment, and straylight level reduction techniques will be outlined. Rayleigh and Raman scattering calibration procedures have been used to absolutely calibrate the collection optics and detection system. Recent progress on diagnosing different HBT-EP plasmas using the Thomson scattering diagnostic will be presented. [1] T. N. Carlstrom, et al, Rev. Sci. Instr. 61, 2858, 1990. [2] D. Johnson, et al, Rev. Sci. Instr. 72, 1, 1129, 2001.

  14. Molecular origin of background light in Thomson scattering measurements

    SciTech Connect

    McNeill, D.H.

    1986-06-01

    The plasma background light in Thomson scattering measurements is often far higher than expected for a pure hydrogen plasma. The spectral distribution of light from three plasmas (duration: 1 ms to steady state; electron density: below 10/sup 12/ to over 10/sup 14/ cm/sup -3/; temperature: below 20 to over 1000 eV) and signal-to-noise and intensity data from the Thomson scattering systems used on them are compared with analytic estimates to show that in two of these plasmas molecular light dominates the spectrum, while in the other, molecular light is present, but bremsstrahlung is usually more intense. Knowledge of the mechanism for background light can aid in designing detection systems for Thomson scattering and provide information on the neutral species composition and effective charge of the plasma.

  15. LIDAR Thomson scattering for advanced tokamaks. Final report

    SciTech Connect

    Molvik, A.W.; Lerche, R.A.; Nilson, D.G.

    1996-03-18

    The LIDAR Thomson Scattering for Advanced Tokamaks project made a valuable contribution by combining LLNL expertise from the MFE Program: tokamak design and diagnostics, and the ICF Program and Physics Dept.: short-pulse lasers and fast streak cameras. This multidisciplinary group evaluated issues involved in achieving a factor of 20 higher high spatial resolution (to as small as 2-3 mm) from the present state of the art in LIDAR Thomson scattering, and developed conceptual designs to apply LIDAR Thomson scattering to three tokamaks: Upgraded divertor measurements in the existing DIII-D tokamak; Both core and divertor LIDAR Thomson scattering in the proposed (now cancelled) TPX; and core, edge, and divertor LIDAR Thomson scattering on the presently planned International Tokamak Experimental Reactor, ITER. Other issues were evaluated in addition to the time response required for a few millimeter spatial resolution. These include the optimum wavelength, 100 Hz operation of the laser and detectors, minimizing stray light - always the Achilles heel of Thomson scattering, and time dispersion in optics that could prevent good spatial resolution. Innovative features of our work included: custom short pulsed laser concepts to meet specific requirements, use of a prism spectrometer to maintain a constant optical path length for high temporal and spatial resolution, the concept of a laser focus outside the plasma to ionize gas and form an external fiducial to use in locating the plasma edge as well as to spread the laser energy over a large enough area of the inner wall to avoid laser ablation of wall material, an improved concept for cleaning windows between shots by means of laser ablation, and the identification of a new physics issue - nonlinear effects near a laser focus which could perturb the plasma density and temperature that are to be measured.

  16. Cathode Ray Research Leading to J.J. Thomson's Discovery

    NASA Astrophysics Data System (ADS)

    Mulligan, Joseph

    1997-04-01

    This paper reviews the research on the properties and nature of cathode rays that led to the discovery of the electron by J. J. Thomson in the years 1897 - 1899. During the period from about 1870 to 1897 important research on cathode rays was carried out by William Crookes and Arthur Schuster in England, by Eugen Goldstein, Heinrich Hertz, Philipp Lenard, Emil Wiechert and Walter Kaufman in Germany, and by Jean Perrin in France. This research was always tedious and often inexact because fast vacuum pumps and convenient vacuum gauges did not yet exist. Still a few of these earlier researchers narrowly missed beating J. J. Thomson to the discover of the electron.

  17. Program For Joule-Thomson Analysis Of Mixed Cryogens

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Lund, Alan

    1994-01-01

    JTMIX computer program predicts ideal and realistic properties of mixed gases at temperatures between 65 and 80 K. Performs Joule-Thomson analysis of any gaseous mixture of neon, nitrogen, various hydrocarbons, argon, oxygen, carbon monoxide, carbon dioxide, and hydrogen sulfide. When used in conjunction with DDMIX computer program of National Institute of Standards and Technology (NIST), JTMIX accurately predicts order-of-magnitude increases in Joule-Thomson cooling capacities occuring when various hydrocarbons added to nitrogen. Also predicts boiling temperature of nitrogen depressed from normal value to as low as 60 K upon addition of neon. Written in Turbo C.

  18. Dust in FTU with the Thomson Scattering diagnostic

    SciTech Connect

    Giovannozzi, E.; Castaldo, C.; Apruzzese, G.; Maddaluno, G.; Rydzy, A.; Ratynskaia, S.

    2008-09-07

    The Thomson scattering diagnostic has been used to measure the dust present in plasma discharges on FTU tokamak after disruption. The vaporization of the dust particles due to the high power of the laser used by the Thomson scattering diagnostic imply that only a rough estimate of the particle size could be derived from the elastic scattering of the laser light. A simple model for dust particle evaporation has been used to infer the size of the dust particle from the scattered light data.

  19. Thomson scattering in a magnetic field. II - Arbitrary field orientation

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara A.

    1991-01-01

    This paper presents solutions to the equation of transfer for Thomson scattering in a constant magnetic field of arbitrary orientation. Results from several atmospheres are combined to give the flux from a dipole star. The results are compared to the polarization data of the magnetic white dwarf Grw + 70 deg 8247. The fit is good, though it implies a very large polarization in the ultraviolet. Thomson scattering is not thought to be an important opacity source in white dwarfs, so the good fit is either fortuitous or is perhaps explained by assuming the magnetic field affects the polarization processes in all opacities similarly.

  20. REACHING ULTRA HIGH PEAK CHARACTERISTICS IN RELATIVISTIC THOMSON BACKSCATTERING.

    SciTech Connect

    POGORELSKY,I.V.; BEN ZVI,I.; HIROSE,T.; KASHIWAGI,S.; YAKIMENKO,V.; KUSCHE,K.; SIDDONS,P.; ET AL

    2001-11-29

    The concept of x-ray laser synchrotron sources (LSS) based on Thomson scattering between laser photons and relativistic electrons leads to future femtosecond light-source facilities fit to multidisciplinary research in ultra-fast structural dynamics. Enticed by these prospects, the Brookhaven Accelerator Test Facility (ATF) embarked into development of the LSS based on a combination of a photocathode RF linac and a picosecond CO{sub 2} laser. We observed the record 1.7 x 10{sup 8} x-ray photons/pulse yield generated via relativistic Thomson scattering between the 14 GW CO{sub 2} laser and 60 MeV electron beam.

  1. Progress of development of Thomson scattering diagnostic system on COMPASS

    SciTech Connect

    Bilkova, P.; Melich, R.; Aftanas, M.; Boehm, P.; Sestak, D.; Jares, D.; Weinzettl, V.; Stoeckel, J.; Hron, M.; Panek, R.; Walsh, M. J.

    2010-10-15

    A new Thomson scattering diagnostic system has been designed and is being built now on the COMPASS tokamak at the Institute of Plasma Physics ASCR in Prague (IPP Prague) in the Czech Republic. This contribution focuses on design, development, and installation of the light collection and detection system. High spatial resolution of 3 mm will be achieved by a combination of design of collection optics and connected polychromators. Imaging characteristics of both core and edge plasma collection objectives are described and fiber backplane design is presented. Several calibration procedures are discussed. The operational deployment of the Thomson scattering diagnostic is planned by the end of 2010.

  2. Warm, Dense Plasma Characterization by X-ray Thomson Scattering

    SciTech Connect

    Landen, O L; Glenzer, S H; Cauble, R C; Lee, R W; Edwards, J E; Degroot, J S

    2000-07-18

    We describe how the powerful technique of spectrally resolved Thomson scattering can be extended to the x-ray regime, for direct measurements of the ionization state, density, temperature, and the microscopic behavior of dense cool plasmas. Such a direct measurement of microscopic parameters of solid density plasmas could eventually be used to properly interpret laboratory measurements of material properties such as thermal and electrical conductivity, EUS and opacity. In addition, x-ray Thomson scattering will provide new information on the characteristics of rarely and hitherto difficult to diagnose Fermi degenerate and strongly coupled plasmas.

  3. Improved thermoelectric cooling based on the Thomson effect

    NASA Astrophysics Data System (ADS)

    Snyder, G. Jeffrey; Khanna, Raghav; Toberer, Eric S.; Heinz, Nicholas A.; Seifert, Wolfgang

    2016-05-01

    Traditional thermoelectric cooling relies on the Peltier effect which produces a temperature drop limited by the figure of merit, zT. This cooling limit is not required from classical thermodynamics but can be traced to problems of thermoelectric compatibility. Alternatively, if a thermoelectric cooler can be designed to achieve full thermoelectric compatibility, lower temperature can be achieved even if the zT is low. In such a device the Thomson effect plays an important role. We present the theoretical concept of a "Thomson cooler," for cryogenic cooling which is designed to maintain thermoelectric compatibility and we derive the requirements for the Seebeck coefficient.

  4. The Thomson deflectometer: a novel use of the Thomson spectrometer as a transient field and plasma diagnostic.

    PubMed

    Ter-Avetisyan, S; Schnürer, M; Nickles, P V; Sokollik, T; Risse, E; Kalashnikov, M; Sandner, W; Priebe, G

    2008-03-01

    Laser accelerated proton beams have been used for field characterization in expanding plasmas. The Thomson parabola spectrometer, as a charged particles analyzer, also allows precise measurement of the charged particles' trajectories. The proton's deflections by fast changing plasma fields can be measured with the new design of the Thomson parabola spectrometer and, therefore, it can be applied for proton deflectometry. It is shown that from resulting spectrograms the plasma field dynamics can be reconstructed with high temporal resolution. In a proof-of-principle experiment, a weakly relativistic plasma expansion is studied as an example. PMID:18377003

  5. The Thomson deflectometer: A novel use of the Thomson spectrometer as a transient field and plasma diagnostic

    SciTech Connect

    Ter-Avetisyan, S.; Schnuerer, M.; Nickles, P. V.; Sokollik, T.; Risse, E.; Kalashnikov, M.; Sandner, W.; Priebe, G.

    2008-03-15

    Laser accelerated proton beams have been used for field characterization in expanding plasmas. The Thomson parabola spectrometer, as a charged particles analyzer, also allows precise measurement of the charged particles' trajectories. The proton's deflections by fast changing plasma fields can be measured with the new design of the Thomson parabola spectrometer and, therefore, it can be applied for proton deflectometry. It is shown that from resulting spectrograms the plasma field dynamics can be reconstructed with high temporal resolution. In a proof-of-principle experiment, a weakly relativistic plasma expansion is studied as an example.

  6. Mixed-Gas Sorption Joule-Thomson Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Petrick, S. Walter; Bard, Steven

    1991-01-01

    Proposed mixed-gas sorption Joule-Thomson refrigerator provides cooling down to temperature of 70 K. Includes only one stage and no mechanical compressor. Simpler, operates without vibrating, and consumes less power in producing same amount of cooling. Same sorption principle of operation applicable in compressor that chemisorbs oxygen or hydrogen from mixture with helium, neon, and/or other nonreactive gases.

  7. Examinations of electron temperature calculation methods in Thomson scattering diagnostics

    SciTech Connect

    Oh, Seungtae; Lee, Jong Ha; Wi, Hanmin

    2012-10-15

    Electron temperature from Thomson scattering diagnostic is derived through indirect calculation based on theoretical model. {chi}-square test is commonly used in the calculation, and the reliability of the calculation method highly depends on the noise level of input signals. In the simulations, noise effects of the {chi}-square test are examined and scale factor test is proposed as an alternative method.

  8. Note: Statistical errors estimation for Thomson scattering diagnostics

    SciTech Connect

    Maslov, M.; Beurskens, M. N. A.; Flanagan, J.; Kempenaars, M.; Collaboration: JET-EFDA Contributors

    2012-09-15

    A practical way of estimating statistical errors of a Thomson scattering diagnostic measuring plasma electron temperature and density is described. Analytically derived expressions are successfully tested with Monte Carlo simulations and implemented in an automatic data processing code of the JET LIDAR diagnostic.

  9. Imaging interferometers for analysis of Thomson scattered spectraa)

    NASA Astrophysics Data System (ADS)

    Howard, J.; Hatae, T.

    2008-10-01

    Polarization interferometers have some potential efficiency advantages for imaging Thomson scattering spectral analysis. In this article we present a number of designs for high-efficiency imaging polarization interferometers for Thomson scattering spectral analysis. The use of high-efficiency crystal polarizing beamsplitters (both displacement and angle) results in low-loss complementary passbands (no edge losses), simple imaging systems, and wide field of view. The efficiency and relative merits of both multiple-filter and dispersive-type configurations are being assessed before installation on the JT-60U ruby-laser Thomson scattering system. Light is transferred from the viewing port via a linear array of optical fiber bundles which will be imaged through the interferometer onto the photocathode of an intensified charge coupled device camera. Because of the broadband nature of the Thomson light, the optical delays required to Fourier analyze the spectrum are quite small. This leads to compact multicolor or dispersive systems based on combinations of Wollaston and Savart splitters and traditional waveplates.

  10. The similarity law for the Joule-Thomson inversion line.

    PubMed

    Apfelbaum, E M; Vorob'ev, V S

    2014-10-23

    We show that the expression for the Joule-Thomson inversion temperature following from the van der Waals equation and recorded in a form reduced to the Boyle values has a universal character and can be applied to many real substances and model systems. PMID:25271782

  11. RELATIVISTIC THOMSON SCATTERING EXPERIMENT AT BNL - STATUS REPORT.

    SciTech Connect

    POGORELSKY,I.V.; BEN ZVI,I.; KUSCHE,K.; SIDDONS,P.; YAKIMENKO,V.; HIROSE,T.; KUMITA,T.; KAMIYA,Y.; ET AL

    2001-12-03

    1.7 x 10{sup 8} x-ray photons per 3.5 ps pulse have been produced in Thomson scattering by focusing CO{sub 2} laser pulse on counter-propagating relativistic electron beam. We explore a possibility of further enhancement of process efficiency by propagating both beams in a plasma capillary. Conventional synchrotron light sources based on using giga-electron-volt electron synchrotron accelerators and magnetic wigglers generate x-ray radiation for versatile application in multi-disciplinary research. An intense laser beam causes relativistic electron oscillations similar to a wiggler. However, because the laser wavelength is thousand times shorter than a wiggler period, very moderate electron energy is needed to produce hard x-rays via Thomson scattering. This allows using relatively compact mega-electron-volt linear accelerators instead of giga-electron-volt synchrotrons. Another important advantage of Thomson sources is a possibility to generate femtosecond x-ray pulses whereas conventional synchrotron sources have typically {approx}300 ps pulse duration. This promises to revolutionize x-ray research in chemistry, physics, and biology expanding it to ultra-fast processes. Thomson sources do not compete in repetition rate and average intensity with conventional light sources that operate at the megahertz frequency. However, Thomson sources have a potential to produce much higher photon numbers per pulse. This may allow developing a single shot exposure important for structural analysis of live biological objects. The BNL Thomson source is a user's experiment conducted at the Accelerator Test Facility since 1998 by an international collaboration in High Energy Physics. Since inception, the ATF source produces the record peak x-ray yield, intensity and brightness among other similar proof-of-principle demonstrations attempted elsewhere. Note that this result is achieved with a moderate laser power of 15 GW. A key to this achievement is in choosing right apparatus and

  12. Electron-exchange and quantum screening effects on the Thomson scattering process in quantum Fermi plasmas

    SciTech Connect

    Lee, Gyeong Won; Jung, Young-Dae; Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590

    2013-06-15

    The influence of the electron-exchange and quantum screening on the Thomson scattering process is investigated in degenerate quantum Fermi plasmas. The Thomson scattering cross section in quantum plasmas is obtained by the plasma dielectric function and fluctuation-dissipation theorem as a function of the electron-exchange parameter, Fermi energy, plasmon energy, and wave number. It is shown that the electron-exchange effect enhances the Thomson scattering cross section in quantum plasmas. It is also shown that the differential Thomson scattering cross section has a minimum at the scattering angle Θ=π/2. It is also found that the Thomson scattering cross section increases with an increase of the Fermi energy. In addition, the Thomson scattering cross section is found to be decreased with increasing plasmon energy.

  13. Design and development of the large helical device TV Thomson scattering

    SciTech Connect

    Yamada, I.; Narihara, K.; Funaba, H.; Hayashi, H.

    2004-10-01

    We have developed a television (TV) Thomson scattering and installed it on the large helical device (LHD). The LHD TV Thomson scattering consists of a yttrium-aluminum-garnet (YAG) laser, beam transport system, scattered light collection optics, spectrometer, intensified charge coupled device camera, and data acquisition system. The spatial and temporal resolutions are about 7 mm and a few seconds, respectively. The temporal resolution of the LHD TV Thomson scattering is not good, but will be enough for long-time, steady-state discharge experiments in LHD. In the initial experiments, we measured electron temperature profiles of LHD plasmas at five spatial points. It has been found that the electron temperatures measured by the LHD TV Thomson scattering reasonably agree with those obtained by the LHD YAG Thomson scattering. We will report the details of the LHD TV Thomson scattering system with some experimental data.

  14. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    SciTech Connect

    Gamboa, E.J.; Huntington, C.M.; Trantham, M.R.; Keiter, P.A; Drake, R.P.; Montgomery, David; Benage, John F.; Letzring, Samuel A.

    2012-05-04

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  15. Thomson scattering diagnostic for the measurement of ion species fraction

    SciTech Connect

    Ross, J. S.; Park, H.-S.; Amendt, P.; Divol, L.; Kugland, N. L.; Glenzer, S. H.; Rozmus, W.

    2012-10-15

    Simultaneous Thomson scattering measurements of collective electron-plasma and ion-acoustic fluctuations have been utilized to determine ion species fraction from laser produced CH plasmas. The CH{sub 2} foil is heated with 10 laser beams, 500 J per beam, at the Omega Laser facility. Thomson scattering measurements are made 4 mm from the foil surface using a 30 J 2{omega} probe laser with a 1 ns pulse length. Using a series of target shots the plasma evolution is measured from 2.5 ns to 9 ns after the rise of the heater beams. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the two-ion species theoretical form factor for the ion feature such that the ion temperature, plasma flow velocity and ion species fraction are determined. The ion species fraction is determined to an accuracy of {+-}0.06 in species fraction.

  16. Edge profile measurements using Thomson scattering on the KSTAR tokamak

    SciTech Connect

    Lee, J. H. Ko, W. H.; Oh, S.; Lee, W. R.; Kim, K. P.; Lee, K. D.; Jeon, Y. M.; Yoon, S. W.; Cho, K. W.; Narihara, K.; Yamada, I.; Yasuhara, R.; Hatae, T.; Yatsuka, E.; Ono, T.; Hong, J. H.

    2014-11-15

    In the KSTAR Tokamak, a “Tangential Thomson Scattering” (TTS) diagnostic system has been designed and installed to measure electron density and temperature profiles. In the edge system, TTS has 12 optical fiber bundles to measure the edge profiles with 10–15 mm spatial resolution. These 12 optical fibers and their spatial resolution are not enough to measure the pedestal width with a high accuracy but allow observations of L-H transition or H-L transitions at the edge. For these measurements, the prototype ITER edge Thomson Nd:YAG laser system manufactured by JAEA in Japan is installed. In this paper, the KSTAR TTS system is briefly described and some TTS edge profiles are presented and compared against the KSTAR Charge Exchange Spectroscopy and other diagnostics. The future upgrade plan of the system is also discussed in this paper.

  17. Edge profile measurements using Thomson scattering on the KSTAR tokamak.

    PubMed

    Lee, J H; Oh, S; Lee, W R; Ko, W H; Kim, K P; Lee, K D; Jeon, Y M; Yoon, S W; Cho, K W; Narihara, K; Yamada, I; Yasuhara, R; Hatae, T; Yatsuka, E; Ono, T; Hong, J H

    2014-11-01

    In the KSTAR Tokamak, a "Tangential Thomson Scattering" (TTS) diagnostic system has been designed and installed to measure electron density and temperature profiles. In the edge system, TTS has 12 optical fiber bundles to measure the edge profiles with 10-15 mm spatial resolution. These 12 optical fibers and their spatial resolution are not enough to measure the pedestal width with a high accuracy but allow observations of L-H transition or H-L transitions at the edge. For these measurements, the prototype ITER edge Thomson Nd:YAG laser system manufactured by JAEA in Japan is installed. In this paper, the KSTAR TTS system is briefly described and some TTS edge profiles are presented and compared against the KSTAR Charge Exchange Spectroscopy and other diagnostics. The future upgrade plan of the system is also discussed in this paper. PMID:25430170

  18. Calculation of Thomson scattering spectral fits for interpenetrating flows

    SciTech Connect

    Swadling, G. F. Lebedev, S. V. Burdiak, G. C.; Suttle, L.; Patankar, S.; Smith, R. A.; Bennett, M.; Suzuki-Vidal, F.; Harvey-Thompson, A. J.; Rozmus, W.; Hall, G. N.; Yuan, J.

    2014-12-15

    Collective mode optical Thomson scattering has been used to investigate the interactions of radially convergent ablation flows in Tungsten wire arrays. These experiments were carried out at the Magpie pulsed power facility at Imperial College, London. Analysis of the scattered spectra has provided direct evidence of ablation stream interpenetration on the array axis, and has also revealed a previously unobserved axial deflection of the ablation streams towards the anode as they approach the axis. It is has been suggested that this deflection is caused by the presence of a static magnetic field, advected with the ablation streams, stagnated and accrued around the axis. Analysis of the Thomson scattering spectra involved the calculation and fitting of the multi-component, non-relativistic, Maxwellian spectral density function S (k, ω). The method used to calculate the fits of the data are discussed in detail.

  19. LIDAR Thomson scattering for ITER core plasma revisited

    NASA Astrophysics Data System (ADS)

    Gowers, C.; Nielsen, P.; Salzmann, H.

    2016-02-01

    The authors have become aware that the development of the hitherto planned time-of-flight Thomson scattering system for the ITER core plasma is not proceeding and that conventional Thomson scattering set-ups are being discussed as an alternative. In this paper, we want to point out the advantages of LIDAR and show how criticized details of the original design can be improved. We present a design of the front optics, which in neutronics terms closely resembles a layout already previously accepted. The presented design does not require Raman scattering calibration for the density measurement. Comparison with the JET Core LIDAR system and simulations at higher temperatures both show that with the new design the specified accuracy can be met with a 1-2 J laser. Current laser and detector technology is reviewed. A strategy for how to proceed is presented.

  20. Upgraded Calibrations of the Thomson System at DIII-D

    SciTech Connect

    B. Bray; C. Hsieh; T.N. Carlstrom; C.C. Makariou

    2000-08-01

    The DIII-D Thomson system measures electron density and temperature with eight pulsed ND:YAG lasers along three paths through the plasma vessel. The components of the Thomson system are absolutely calibrated so the measurements can be combined into a single profile from a normalized plasma radius ({rho}) of about 0.1 to the edge of the plasma. A monochromator calibration and opto-electronic calibration measure the detectors' absolute sensitivity to background and pulsed light. A Rayleigh scattering calibration and transmission calibrations measure the transmission of light to the detectors. The calibration systems are being upgraded to reduce the effect of systematic errors on the temperature and density measurements. The systematic errors can be checked by a comparison of overlapping channels and estimated from fits to the profiles. The contributions of the systematic uncertainties relative to the statistical uncertainties of the measurement are discussed through simulations and experimental data.

  1. Electron Temperature Measurements on BCTX using Thomson Scattering

    NASA Astrophysics Data System (ADS)

    Morse, E.; Coomer, E.

    1997-11-01

    The Berkeley Compact Toroid Experiment (BCTX) is a spheromak configuration with a 70 cm diameter flux conserver. Studies have been undertaken to determine the core energy transport in the spheromak by investigation of the scaling of the core electron temperature (as measured by single point Thomson scattering) with various parameters. Elevated temperatures have been observed with lower core electron densities, as observed by the Thomson system. Careful studies of the magnetic decay have been undertaken using ten edge magnetic field B -dot coils. Density control has been achieved using a Penning discharge mode for the initial gas breakdown in the Marshall gun. A 20 MW lower hybrid heating pulse ( 430 MHz ) was used to study tranisent heating effects on the core plasma. Methods of controlling breakdown at the antenna will be presented, along with data for RF-heated plasma experiments. Comparison with recent theoretical work on spheromak energy transport by T. K. Fowler will be presented.

  2. Thomson scattering in dense plasmas with density and temperature gradients

    NASA Astrophysics Data System (ADS)

    Fortmann, C.; Thiele, R.; Fäustlin, R. R.; Bornath, Th.; Holst, B.; Kraeft, W.-D.; Schwarz, V.; Toleikis, S.; Tschentscher, Th.; Redmer, R.

    2009-09-01

    Collective X-ray Thomson scattering has become a versatile tool for the diagnostics of dense plasmas. Assuming homogeneous density and temperature throughout the target sample, these parameters can be determined directly from the plasmon dispersion and the ratio of plasmon amplitudes via detailed balance. In inhomogeneous media, the scattering signal is an average of the density and temperature dependent scattering cross-section weighted with the density and temperature profiles. We analyse Thomson scattering spectra in the XUV range from near solid density hydrogen targets generated by free electron laser radiation. The influence of plasma inhomogeneities on the scattering spectrum is investigated by comparing density and temperature averaged scattering signals to calculations assuming homogeneous targets. We find discrepancies larger than 10% between the mean electron density and the effective density as well as between the mean temperature and the effective temperature.

  3. Development of a high resolution and high dispersion Thomson parabola

    NASA Astrophysics Data System (ADS)

    Jung, D.; Hörlein, R.; Kiefer, D.; Letzring, S.; Gautier, D. C.; Schramm, U.; Hübsch, C.; Öhm, R.; Albright, B. J.; Fernandez, J. C.; Habs, D.; Hegelich, B. M.

    2011-01-01

    Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE/E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon.

  4. Development of a high resolution and high dispersion Thomson parabola.

    PubMed

    Jung, D; Hörlein, R; Kiefer, D; Letzring, S; Gautier, D C; Schramm, U; Hübsch, C; Öhm, R; Albright, B J; Fernandez, J C; Habs, D; Hegelich, B M

    2011-01-01

    Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE∕E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon. PMID:21280824

  5. Thomson scattering diagnostic for the measurement of ion species fraction

    SciTech Connect

    Ross, J S; Park, H S; Amendt, A; Divol, L; Kugland, N L; Rozmus, W; Glenzer, S H

    2012-05-01

    Simultaneous Thomson scattering measurements of collective electron-plasma and ion-acoustic fluctuations have been utilized to determine ion species fraction from laser produced CH plasmas. The CH{sub 2} foil is heated with 10 laser beams, 500 J per beam, at the Omega Laser facility. Thomson scattering measurements are made 4 mm from the foil surface using a 30 J 2{omega} probe laser with a 1 ns pulse length. Using a series of target shots the plasma evolution is measured from 2.5 ns to 9 ns after the rise of the heater beams. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the two-ion species theoretical form factor for the ion feature such that the ion temperature, plasma flow velocity and ion species fraction are determined. The ion species fraction is determined to an accuracy of {+-}0.06 in species fraction.

  6. Thomson Reuters to release Book Citation Index later this year

    NASA Astrophysics Data System (ADS)

    Aldred, Maxine

    2011-08-01

    Thomson Reuters will launch its new Book Citation Index later this year. Projected to include 25,000 volumes from major publishers and university presses in science, social science, and the humanities, the Book Citation Index will cover scholarly books (both series and nonseries) that present original research or literature reviews. The current effort regarding the science section is focused on books published from 2005 to the present. AGU has sent copies of its catalog for inclusion in the Book Citation Index, but the final selection will be made by Thomson Reuters, using its internal selection criteria, which may be found at http://wokinfo.com/wok/media/pdf/BKCI-SelectionEssay_web.pdf.

  7. A Pulse-Burst Laser System for Thomson Scattering

    NASA Astrophysics Data System (ADS)

    den Hartog, D. J.; Borchardt, M. T.; Yang, Y. M.; Ambuel, J. R.; Holly, D. J.; Mattison, H. E.; Robl, P. E.

    2008-11-01

    A ``pulse-burst'' laser system is being constructed for addition to the Thomson scattering diagnostic on the MST reversed-field pinch. This laser will produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition rates 5--250 kHz. The laser will operate at 1064 nm and is a master oscillator, power amplifier (MOPA) system. Variable pulse-width drive (0.1--20 ms) of the flashlamps is accomplished by IGBT switching of large electrolytic capacitor banks. In the near term, these flashlamp power supplies will be adapted to drive the flashlamps in the two existing commercial Nd:YAG lasers used for Thomson scattering on the MST RFP. This will enable these lasers to produce a burst of up to 40 pulses at repetition frequencies <= 1 kHz. The burst train of laser pulses will enable the study of Te and ne dynamics in a single MST shot.

  8. Applications of phase conjugate mirror to Thomson scattering diagnostics (invited)

    SciTech Connect

    Hatae, T.; Naito, O.; Nakatsuka, M.; Yoshida, H.

    2006-10-15

    A high performance phase conjugate mirror based on stimulated Brillouin scattering (SBS-PCM) has been applied to the Thomson scattering system in the JT-60U tokamak for the first time in order to improve the measurement performance. A SBS-PCM realized a high reflectivity of 95% at a high input power of 145 W (2.9 J, 50 Hz). Using the SBS-PCM, two methods have been developed to increase the intensity of scattered light. For the first method, we have developed a new optical design to provide a double-pass scattering method with the SBS-PCM. A laser beam passing through the plasma is reflected by the SBS-PCM. The reflected beam passes the plasma again along the same path by means of the phase conjugation of the optically nonlinear stimulated Brillouin scattering process. The double-pass Thomson scattering method using the SBS-PCM has demonstrated an increase of the scattered light by a factor of 1.6 compared with the single-pass scattering method in JT-60U. A multipass Thomson scattering method in which the laser beam can be confined between a couple of SBS-PCMs is also proposed. It is estimated that the multipass scattering method generates the scattered light more than several times as large as that of the single-pass scattering method. For the second method, a high-average-power yttrium aluminum garnet (Nd:YAG) laser system has been developed using the SBS-PCM. The SBS-PCM effectively compensated thermal degradation at two amplifier lines, and the average power was increased by a factor of >8 from 45 W (1.5 J, 30 Hz) to 373 W (7.46 J, 50 Hz). A Nd:YAG laser (5 J, 100 Hz) for the edge Thomson scattering in International Thermonuclear Experimental Reactor (ITER) has been designed based on the result.

  9. Aural myiasis caused by Parasarcophaga (Liosarcophaga) dux (Thomson) in Thailand.

    PubMed

    Chaiwong, T; Tem-Eiam, N; Limpavithayakul, M; Boongunha, N; Poolphol, W; Sukontason, K L

    2014-09-01

    Herein is reported the first case in Thailand of aural myiasis caused by the flesh fly, Parasarcophaga (Liosarcophaga) dux (Thomson). A 5-day-old infant was taken to hospital with a slightly bloody ear. Two fly larvae exiting the ear and another recovered by a physician were alive, and confirmed as P. dux species from adult examination results. This case brought attention to the need for protection against synanthropic flies, particularly for infants and/or hearing impaired patients. PMID:25382476

  10. The Structure of Metastable States in The Thomson Problem

    NASA Astrophysics Data System (ADS)

    Bondarenko, A. N.; Karchevskiy, M. N.; Kozinkin, L. A.

    2015-11-01

    A practical numerical method for the effective solution of the Thomson Problem is proposed. The developed iterative algorithm allows to conduct theoretical researches such as study of the number of asymptotic solutions depending on the particle count. Metastable states of charged point systems on a unit sphere were considered and the probability of falling into the basin of each state was obtained. Founded upon the algorithm and dual lattice representation approach, the framework for rapid construction of capped carbon nanotubes was created.

  11. Temporal laser-pulse-shape effects in nonlinear Thomson scattering

    NASA Astrophysics Data System (ADS)

    Kharin, V. Yu.; Seipt, D.; Rykovanov, S. G.

    2016-06-01

    The influence of the laser-pulse temporal shape on the nonlinear Thomson scattering on-axis photon spectrum is analyzed in detail. Using the classical description, analytical expressions for the temporal and spectral structure of the scattered radiation are obtained for the case of symmetric laser-pulse shapes. The possibility of reconstructing the incident laser pulse from the scattered spectrum averaged over interference fringes in the case of high peak intensity and symmetric laser-pulse shape is discussed.

  12. Thomson scattering on a 20-psec time scale.

    PubMed

    Baldis, H A; Walsh, C J; Benesch, R

    1982-01-15

    A technique for high resolution Thomson scattering is discussed. By coupling a spectrograph to a streak camera with high sensitivity detectors, time and spectrally resolved scattered signals are obtained. Time resolutions down to 20 psec have been achieved, with the primary limitation on this figure coming from temporal dispersion in the spectrograph. The results of some laser plasma interaction experiments designed to study plasma instabilities are presented. PMID:20372444

  13. Theoretical study on a Miniature Joule-Thomson & Bernoulli Cryocooler

    NASA Astrophysics Data System (ADS)

    Xiong, L. Y.; Kaiser, G.; Binneberg, A.

    2004-11-01

    In this paper, a microchannel-based cryocooler consisting of a compressor, a recuperator and a cold heat exchanger has been developed to study the feasibility of cryogenic cooling by the use of Joule-Thomson effect and Bernoulli effect. A set of governing equations including Bernoulli equations and energy equations are introduced and the performance of the cooler is calculated. The influences of some working conditions and structure parameters on the performance of coolers are discussed in details.

  14. Collective Thomson scattering measurements with high frequency resolution at TEXTORa)

    NASA Astrophysics Data System (ADS)

    Stejner, M.; Nielsen, S. K.; Korsholm, S. B.; Salewski, M.; Bindslev, H.; Furtula, V.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Bürger, A.; Kantor, M.; de Baar, M.

    2010-10-01

    We discuss the development and first results of a receiver system for the collective Thomson scattering (CTS) diagnostic at TEXTOR with frequency resolution in the megahertz range or better. The improved frequency resolution expands the diagnostic range and utility of CTS measurements in general and is a prerequisite for measurements of ion Bernstein wave signatures in CTS spectra. The first results from the new acquisition system are shown to be consistent with theory and with simultaneous measurements by the standard receiver system.

  15. Development of prototype polychromator system for KSTAR Thomson scattering diagnostic

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Lee, S. H.; Son, S. H.; Ko, W. H.; Seo, D. C.; Yamada, I.; Her, K. H.; Jeon, J. S.; Bog, M. G.

    2015-12-01

    A polychromator is widely used by the Thomson scattering system for measuring the electron temperature and density. This type of spectrometer includes optic elements such as band-pass filters, focusing lens, collimating lens, and avalanche photodiodes (APDs). The characteristics of band-pass filters in the polychromator are determined by the measuring range of the Thomson system. KSTAR edge polychromators were developed by co-works at NIFS in Japan, and the KSTAR core polychromators were developed by NFRI in Korea. The power supply system of these polychromators is connected only to one power supply module and can manually control the APD's voltage at the front side of the power supply by using a potentiometer. In this paper, a prototype polychromator is introduced at the KSTAR. The prototype polychromator system has a built-in power supply unit that includes high voltage for the APD and ± 5 V for an op-amp IC. The high voltage for the APD is finely controlled and monitored using a PC with the LabView software. One out of the six band pass-filters has a center wavelength of 523.5 nm with 2-nm bandwidth, which can measure Zeff, and the other five band-pass filters can simultaneously measure the Thomson signal. In addition, we will show the test result of this prototype polychromator system during the KSTAR experiment campaign (2015).

  16. Thomson scattering from a three-component plasma.

    PubMed

    Johnson, W R; Nilsen, J

    2014-02-01

    A model for a three-component plasma consisting of two distinct ionic species and electrons is developed and applied to study x-ray Thomson scattering. Ions of a specific type are assumed to be identical and are treated in the average-atom approximation. Given the plasma temperature and density, the model predicts mass densities, effective ionic charges, and cell volumes for each ionic type, together with the plasma chemical potential and free-electron density. Additionally, the average-atom treatment of individual ions provides a quantum-mechanical description of bound and continuum electrons. The model is used to obtain parameters needed to determine the dynamic structure factors for x-ray Thomson scattering from a three-component plasma. The contribution from inelastic scattering by free electrons is evaluated in the random-phase approximation. The contribution from inelastic scattering by bound electrons is evaluated using the bound-state and scattering wave functions obtained from the average-atom calculations. Finally, the partial static structure factors for elastic scattering by ions are evaluated using a two-component version of the Ornstein-Zernike equations with hypernetted chain closure, in which electron-ion interactions are accounted for using screened ion-ion interaction potentials. The model is used to predict the x-ray Thomson scattering spectrum from a CH plasma and the resulting spectrum is compared with experimental results obtained by Feltcher et al. [Phys. Plasmas 20, 056316 (2013)]. PMID:25353586

  17. THE THOMSON SURFACE. III. TRACKING FEATURES IN 3D

    SciTech Connect

    Howard, T. A.; DeForest, C. E.; Tappin, S. J.; Odstrcil, D.

    2013-03-01

    In this, the final installment in a three-part series on the Thomson surface, we present simulated observations of coronal mass ejections (CMEs) observed by a hypothetical polarizing white light heliospheric imager. Thomson scattering yields a polarization signal that can be exploited to locate observed features in three dimensions relative to the Thomson surface. We consider how the appearance of the CME changes with the direction of trajectory, using simulations of a simple geometrical shape and also of a more realistic CME generated using the ENLIL model. We compare the appearance in both unpolarized B and polarized pB light, and show that there is a quantifiable difference in the measured brightness of a CME between unpolarized and polarized observations. We demonstrate a technique for using this difference to extract the three-dimensional (3D) trajectory of large objects such as CMEs. We conclude with a discussion on how a polarizing heliospheric imager could be used to extract 3D trajectory information about CMEs or other observed features.

  18. 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.

  19. A reflective optical transport system for ultraviolet Thomson scattering from electron plasma waves on OMEGA

    SciTech Connect

    Katz, J.; Boni, R.; Sorce, C.; Follett, R.; Shoup, M. J. III; Froula, D. H.

    2012-10-15

    A reflective optical transport system has been designed for the OMEGA Thomson-scattering diagnostic. A Schwarzschild objective that uses two concentric spherical mirrors coupled to a Pfund objective provides diffraction-limited imaging across all reflected wavelengths. This enables the operator to perform Thomson-scattering measurements of ultraviolet (0.263 {mu}m) light scattered from electron plasma waves.

  20. 78 FR 8587 - Thomson Reuters, Finance Operations & Technology Division, Including On-Site Leased Workers From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... was published in the Federal Register on August 16, 2012 (77 FR 49459). At the request of the State... Employment and Training Administration Thomson Reuters, Finance Operations & Technology Division, Including... Worker Adjustment Assistance on August 2, 2012, applicable to workers of Thomson Reuters,...

  1. The Kelvin-Thomson Atom. Part 2: The Many-Electron Atoms

    ERIC Educational Resources Information Center

    Walton, Alan J.

    1977-01-01

    Presents part two of a two-part article describing the Kelvin-Thomson atom. This part discusses the arrangement of electrons within the atom and examines some of the properties predicted for elements in the Kelvin-Thomson model. (SL)

  2. Multiple Low Energy Long Bone Fractures in the Setting of Rothmund-Thomson Syndrome

    PubMed Central

    Beckmann, Nicholas

    2015-01-01

    Rothmund-Thomson syndrome is a rare autosomal recessive genodermatosis characterized by a poikilodermatous rash starting in infancy as well as various skeletal anomalies, juvenile cataracts, and predisposition to certain cancers. Although Rothmund-Thomson syndrome is associated with diminished bone mineral density in addition to multiple skeletal abnormalities, there are few reports of the association with stress fractures or pathologic fractures in low energy trauma or delayed healing of fractures. Presented is a case of a young adult male with Rothmund-Thomson syndrome presenting with multiple episodes of long bone fractures caused by low energy trauma with one of the fractures exhibiting significantly delayed healing. The patient was also found to have an asymptomatic stress fracture of the lower extremity, another finding of Rothmund-Thomson syndrome rarely reported in the literature. A thorough review of the literature and comprehensive presentation of Rothmund-Thomson syndrome is provided in conjunction with our case. PMID:26617641

  3. Laser beam combiner for Thomson scattering core LIDARa)

    NASA Astrophysics Data System (ADS)

    Balboa, I.; Huang, B.; Naylor, G.; Walsh, M.; Sirinelli, A.; Parsons, P.; Fessey, J.; Townsend, M.; Beurskens, M.; Conway, N.; Flanagan, J.; Kempenaars, M.; Kirk, A.

    2010-10-01

    The light detection and ranging Thomson scattering (TS) diagnostic is advantageous since it only requires a single view port into the tokamak. This technique requires a short pulse laser at high energy, usually showing a limited repetition rate. Having multiple lasers will increase the repetition rate. This paper presents a scanning mirror as a laser beam combiner. Measurements of the position accuracy and jitter show that the pointing stability of the laser beam is within ±25 μrad for over tens of seconds. A control feedback loop is implemented to demonstrate the long term stability. Such a system could be applied for ITER and JET.

  4. Laser beam combiner for Thomson scattering core LIDAR.

    PubMed

    Balboa, I; Huang, B; Naylor, G; Walsh, M; Sirinelli, A; Parsons, P; Fessey, J; Townsend, M; Beurskens, M; Conway, N; Flanagan, J; Kempenaars, M; Kirk, A

    2010-10-01

    The light detection and ranging Thomson scattering (TS) diagnostic is advantageous since it only requires a single view port into the tokamak. This technique requires a short pulse laser at high energy, usually showing a limited repetition rate. Having multiple lasers will increase the repetition rate. This paper presents a scanning mirror as a laser beam combiner. Measurements of the position accuracy and jitter show that the pointing stability of the laser beam is within ±25 μrad for over tens of seconds. A control feedback loop is implemented to demonstrate the long term stability. Such a system could be applied for ITER and JET. PMID:21033888

  5. Thomson scattering in magnetic fields. [of white dwarf stars

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara

    1989-01-01

    The equation of transfer in Thomson scattering atmospheres with magnetic fields is solved using Monte Carlo methods. Two cases, a plane parallel atmosphere with a magnetic field perpendicular to the atmosphere, and a dipole star, are investigated. The wavelength dependence of polarization from plane-parallel atmosphere is qualitatively similar to that observed in the magnetic white dwarf Grw+70 deg 8247, and the field strength determined by the calculation, 320 MG, is quantitatively similar to that determined from the line spectrum. The dipole model does not resemble the data as well as the single plane-parallel atmosphere.

  6. Laser beam combiner for Thomson scattering core LIDAR

    SciTech Connect

    Balboa, I.; Naylor, G.; Sirinelli, A.; Parsons, P.; Fessey, J.; Townsend, M.; Beurskens, M.; Conway, N.; Kempenaars, M.; Kirk, A.; Walsh, M. [Diagnostics Division, Department of CHD, ITER Organization, CS 90 046, Bulding 155 Flanagan, J.

    2010-10-15

    The light detection and ranging Thomson scattering (TS) diagnostic is advantageous since it only requires a single view port into the tokamak. This technique requires a short pulse laser at high energy, usually showing a limited repetition rate. Having multiple lasers will increase the repetition rate. This paper presents a scanning mirror as a laser beam combiner. Measurements of the position accuracy and jitter show that the pointing stability of the laser beam is within {+-}25 {mu}rad for over tens of seconds. A control feedback loop is implemented to demonstrate the long term stability. Such a system could be applied for ITER and JET.

  7. APD detector electronics for the NSTX Thomson scattering system

    SciTech Connect

    D.W. Johnson; B.P. LeBlanc; D.L. Long; G. Renda

    2000-08-07

    An electronics system has been installed and tested for the readout of APD detectors for the NSTX Thomson scattering system. Similar to previous designs, it features preamps with a fast and a slow output. The fast output uses pulse shaping to optimize sensitivity for the 8 nsec scattered light pulse while rejecting noise in the intrinsic plasma background. A low readout noise of {approximately}25 photoelectrons is achieved at an APD gain of 75. The design incorporates a number of features to provide flexibility for various modes of calibration.

  8. Design of the polarization multi-pass Thomson scattering system

    SciTech Connect

    Yasuhara, R.; Yamada, I.; Kawahata, K.; Funaba, H.; Yoshikawa, M.; Morimoto, M.; Shima, Y.; Kohagura, J.; Sakamoto, M.; Nakashima, Y.; Imai, T.; Minami, T.

    2012-10-15

    A novel configuration of the multi-pass Thomson scattering (TS) system is proposed to improve the time resolution and accuracy of electron temperature measurements by use of a polarization control technique. This configuration can realize a perfect coaxial multi-passing at each pass, and the number of round trips is not limited by the optical configuration. To confirm the feasibility of the new method, we installed this system in the GAMMA 10 plasma system. As a result, the integrated scattering signal of the double-pass configuration is about two times larger than that of the single-pass configuration. These results are in good agreement with the design.

  9. Polychromator for the edge Thomson scattering system in ITERa)

    NASA Astrophysics Data System (ADS)

    Yatsuka, E.; Hatae, T.; Fujie, D.; Kurokawa, A.; Kusama, Y.

    2012-10-01

    A new type polychromator has been designed for the edge Thomson scattering system in ITER. Signal light is parallelly dispersed into two parts at the first interference filter. Spectral transmissivities for some spectral channels may enhance better than the conventional type polychromator. In the new type polychromator, the misalignment due to the machine accuracy is expected to be within the margin of APD area. In order to calibrate the spectral transmissivity using the dual-laser injection method during the plasma discharge, it is preferred that the spectral channels are separated at the geometric mean of the injected two wavelengths.

  10. Collective Thomson scattering for studying plasma instabilities in electric thrusters

    NASA Astrophysics Data System (ADS)

    Tsikata, S.; Honoré, C.; Grésillon, D.

    2013-10-01

    Collective (or coherent) Thomson scattering has recently emerged as an important tool for identifying and characterizing certain instabilities in Hall thrusters. Plasma instabilities in electric thrusters are implicated in diverse phenomena, including reduced efficiency, lifetime and anomalous particle transport. This work discusses the main features of the collective scattering diagnostic PRAXIS, and recent applications of the diagnostic to study the nature of microturbulence at different thruster operating regimes. Early measurements show the presence of a small-scale azimuthal instability may be linked with regimes of unstable thruster operation.

  11. Design of Thomson Scattering Diagnostic for HIT-SI

    NASA Astrophysics Data System (ADS)

    Morgan, Kyle; Fryett, Taylor; Golingo, Raymond; Jarboe, Tom; Victor, Brian

    2012-10-01

    Steady Inductive Helicity Injection (SIHI) is used to create a spheromak inside the HIT-SI machine. A multi-point Thomson scattering diagnostic has been designed and is under construction for the HIT-SI experiment. The system uses a 20J Ruby Laser with 20ns pulse length. The collection system allows for eight spatial measurement locations, with four being active at any time. Four polychromators are being used to spectrally resolve the scattered light. Present Langmuir probe measurements show an electron temperature of about 12eV, within the range the polychromators can resolve. Properties of system and expected measurement are given.

  12. Cavity Enhanced Thomson Scattering for Low Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Yalin, Azer; Friss, Adam; Lee, Brian; Franka, Isaiah

    2013-09-01

    This contribution describes the design, simulation, and initial experimental development of a novel laser Thomson scattering (LTS) system for measurement of weakly-ionized low temperature plasmas. The LTS approach uses a high power intra-cavity beam of power ~10-100 kW to provide increased scattered photon counts and sensitivity as compared to conventional LTS experiments that use light sources with orders of magnitude lower average power. The high power intra-cavity beam is generated by locking a narrow linewidth source laser to a high-finesse optical cavity via Pound-Drever-Hall locking. The plasma (to be studied) is housed with the high-finesse optical cavity. The high-power source is combined with a detection system comprised of a high-suppression triple monochromator and a low-noise photomultiplier tube used in photon counting mode. We present simulations of signal strengths and scattering spectra including elastic scatter background, detector dark counts, and random (counting) noise contributions. Expected experimental performance is assessed from fits to the simulated data. The number density and electron temperature of a 1010 cm-3 plasma should be accurately measurable with standard deviation of <5% in a measurement time of 5 minutes per wavelength channel. We also present experimental development including characterization of laser locking, and initial Rayleigh and Raman signals which will be used to calibrate the Thomson system.

  13. On the calibration of polarimetric Thomson scattering by Raman polarimetry

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Pasqualotto, R.

    2015-12-01

    Polarimetric Thomson scattering (TS) is an alternative method for the analysis of Thomson scattering spectra in which the plasma temperature T e is determined from the depolarization of the TS radiation. This is a relativistic effect and therefore the technique is suitable only for very hot plasmas (T e  >  10 keV) such as those of ITER. The practical implementation of polarimetric TS requires a method to calibrate the polarimetric response of the collection optics carrying the TS light to the detection system, and in particular to measure the additional depolarization of the TS radiation introduced by the plasma-exposed first mirror. Rotational Raman scattering of laser light from diatomic gases such as H2, D2, N2 and O2 can provide a radiation source of predictable intensity and polarization state from a well-defined volume inside the vacuum vessel and is therefore suitable for these calibrations. In this paper we discuss Raman polarimetry as a technique for the calibration of a hypothetical polarimetric TS system operating in the same conditions of the ITER core TS system and suggest two calibration methods for the measurement of the additional depolarization introduced by the plasma-exposed first mirror, and in general for calibrating the polarimetric response of the detection system.

  14. Thomson scattering diagnostic for the Microwave Tokamak Experiment

    SciTech Connect

    Foote, J.H.; Barter, J.D.; Sewall, N.R.; Jolly, J.J.; Schlander, L.F.

    1990-05-04

    The Thomson-scattering diagnostic system (TSS) on the Microwave Tokamak Experiment (MTX) at LLNL routinely monitors electron temperature (T{sub e}) and density. Typical measured values at the plasma center under clean conditions are 900 {plus minus} 70 eV and 1 to 2 {times} 10{sup 14} ({plus minus}30%) cm{sup {minus}3}. The TSS apparatus is compact, with all elements mounted on one sturdy, two-level optics table. Because of this, we maintain with minimum effort the alignment of both the ruby-laser input optics and the scattered-light collecting optics. Undesired background signals, e.g., plasma light as well as ruby-laser light scattered off obstacles and walls, are generally small compared with the Thomson-scattered signals we normally detect. In the MTX T{sub e} region, the TSS data are definitely fitted better when relativistic effects are included in the equations. Besides determining the temperature of the Maxwellian electron distribution, the system is designed to detect electron heating from GW-level free-electron laser (FEL) pulses by measuring large wavelength shifts of the scattered laser photons. TSS data suggest that we may indeed by able to detect these electrons, which can have energies up to 10 keV, according to computer simulation. 7 refs., 4 figs.

  15. Thomson scattering measurements in the RFX reversed field pinch

    SciTech Connect

    Bassan, M.; Bilato, R.; Giudicotti, L.; Pasqualotto, R.; Sardella, A.

    1997-01-01

    The first systematic measurements of the electron temperature (T{sub e}) spatial profile have been obtained in the reversed field pinch experiment RFX with a single pulse Thomson scattering (TS) diagnostic. Scattered light from a ruby laser pulse (E{le}15 J, {Delta}t=30 ns) is collected through three objectives from 10 positions along a diameter in the plasma equatorial plane, with a spatial resolution of 2.5 cm. Plasma discharges with current in the range 700{endash}900 kA have been investigated finding evidence of a quite flat T{sub e} profile. Data dispersion significantly greater than experimental uncertainties provides an indication of remarkable plasma fluctuations. Results are in good agreement with T{sub e} measurements from other single chord spectroscopic diagnostics (SiLi detector and SXR double filter), showing a reliable operation down to an electron density n{sub e}=3{times}10{sup 19} m{sup {minus}3}. Integration of this apparatus with a ND:YLF laser system for multipulse Thomson scattering measurements, sharing the same input optics, is under way. {copyright} {ital 1997 American Institute of Physics.}

  16. Imaging Thomson scattering measurements of radiatively heated Xe

    SciTech Connect

    Pollock, B; Meinecke, J; Kuschel, S; Ross, J S; Divol, L; Glenzer, S H; Tynan, G R

    2012-05-01

    Uniform density and temperature Xe plasmas have been produced over >4 mm scale-lengths using x-rays generated in a cylindrical Pb cavity. The cavity is 750 {micro}m in depth and diameter, and is heated by a 300 J, 2 ns square, 1054 nm laser pulse focused to a spot size of 200 {micro}m at the cavity entrance. The plasma is characterized by simultaneous imaging Thomson scattering measurements from both the electron and ion scattering features. The electron feature measurement determines the spatial electron density and temperature profile, and using these parameters as constraints in the ion feature analysis allows an accurate determination of the charge state of the Xe ions. The Thomson scattering probe beam is 40 J, 200 ps, and 527 nm, and is focused to a 100 {micro}m spot size at the entrance of the Pb cavity. Each system has a spatial resolution of 25 {micro}m, a temporal resolution of 200 ps (as determined by the probe duration), and a spectral resolution of 2 nm for the electron feature system and 0.025 nm for the ion feature system. The experiment is performed in a Xe filled target chamber at a neutral pressure of 3-10 Torr, and the x-rays produced in the Pb ionize and heat the Xe to a charge state of 20 {+-} 4 at up to 200 eV electron temperatures.

  17. Thomson Scattering Measurements on HIT-SI3

    NASA Astrophysics Data System (ADS)

    Everson, C. J.; Morgan, K. D.; Jarboe, T. R.

    2015-11-01

    A multi-point Thomson Scattering diagnostic has been implemented on HIT-SI3 (Helicity Injected Torus - Steady Inductive 3) to measure electron temperature. The HIT-SI3 experiment is a modification of the original HIT-SI apparatus that uses three injectors instead of two. This modification alters the configuration of magnetic fields and thus the plasma behavior in the device. The scientific aim of HIT-SI3 is to develop a deeper understanding of how injector behavior and interactions influence current drive and plasma performance in the spheromak. The Thomson Scattering system includes a 20 J (1 GW pulse) Ruby laser that provides the incident beam, and collection optics that are installed such that measurements can be taken at four spatial locations in HIT-SI3 plasmas. For each measurement point, a 3-channel polychromator is used to detect the relative level of scattering. These measurements allow for the presence of temperature gradients in the spheromak to be investigated. Preliminary HIT-SI3 temperature data are presented and can be compared to predictions from computational models. Work supported by the D.O.E.

  18. Exact relativistic expressions for polarization of incoherent Thomson scattering

    NASA Astrophysics Data System (ADS)

    Mirnov, V. V.; Den Hartog, D. J.; Parke, E.

    2016-05-01

    We present a derivation of the degree of polarization for incoherent Thomson scattering (TS) using Mueller matrix formalism. An exact analytic solution is obtained for spectrum-integrated matrix elements. The solution is valid for the full range of incident polarizations, scattering angles, and electron thermal motion from non-relativistic to ultra-relativistic. It is based on a newly developed theoretical model, a finite transit time (FTT) correction to previous theoretical work on TS polarization. The Mueller matrix elements are substantially different from previous calculations without the FTT correction, even to the lowest linear order in Te/mec2≪1 . Mathematically, the derivation is a unique example of fully analytical integration of the 3D scattering operator over a relativistic Maxwellian distribution function; experimentally, the results have application to the use of the polarization properties of Thomson scattered light as a method of electron temperature measurement. The results can also be used as a reliable tool for benchmarking and verification of numerical codes for frequency resolved properties of TS polarization.

  19. Design of and data reduction from compact Thomson parabola spectrometers

    NASA Astrophysics Data System (ADS)

    Morrison, J. T.; Willis, C.; Freeman, R. R.; Van Woerkom, L.

    2011-03-01

    Thomson parabola spectrometers are used to characterize MeV ion beams produced in high intensity laser interactions. These spectrometers disperse multiple ion species according to their charge to mass ratio through the use of parallel electric and magnetic fields. Analytical solutions for ion deflection in electric and magnetic fields have been used to extract ion spectra with the assumption that fringing effects are negligible. Experimental space restrictions and dynamic range requirements necessitate designs that stress the analytical assumptions. Depending on design parameters, the error in the analytical assumption can be comparable to the energy resolution. Estimates are provided to approximate the error on the total ion deflection. A method for modeling ion trajectories including fringing effects is presented using software freely available or in common use. The magnetostatic fields are modeled in 3D, including material properties of nearby magnetic materials using RADIA. Electrostatic fields are modeled in 2D for a spectrometer implementing angled plates using the partial differential equation toolbox in MATLAB®. Using these models to calculate the ion trajectory allows for analysis of a Thomson parabola spectrometer with an arbitrary field configuration.

  20. Cytogenetic analysis in Rothmund-Thomson syndrome with osteosarcoma

    SciTech Connect

    Amar, M.; Sutphen, R.; Kousseff, B.G.

    1994-09-01

    Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive condition of poikiloderma, erythema, depigmentation, hyperpigmentation, musculoskeletal abnormalities and abnormalities of hair, teeth and nails. Osteogenic sacoma has been reported in 8 patients. Abnormal chromosome studies have been reported in only two patients. Chromosome analysis of tumor or bone marrow has not been reported. We performed cytogenetic studies on a patient with Rothmund-Thomson syndrome and osteogenic sarcoma. Analysis of peripheral lymphocytes revealed 46, XX karyotype by GTW banding. Both spontaneous and chemically-induced chromosome breakage (0.35 and 0.8 breaks/cell) were increased but not significantly different from the age-matched control levels (0.05 and 0.25 breaks/cell). Analysis of mitogen-stimulated bone marrow by Giemsa banding showed slightly increased aneuploidy (20% of cells with random loss of 1 to 5 chromosomes each) and non-specific chromatid despiralization. All 34 cells analyzed from the tumor had normal diploid karyotype, 46.XX. Five of 40 cells derived from skin of the amputated right leg were hyperdiploid with karyotype 47, XX, +7. Skin from the right forearm showed normal karyotype, 46,XX. These results suggest that RTS is associated with chromosomal rearrangement causing acquired somatic mosaicism, including trisomy 7 anomalies. These abnormalities may aid in the diagnosis of RTS and provide clues to the location of the causative gene(s).

  1. Pulse-Burst Laser Systems for Thomson Scattering on MST

    NASA Astrophysics Data System (ADS)

    den Hartog, D. J.; Borchardt, M. T.; Harris, W. S.; Reusch, J. A.; Yang, Y. M.

    2009-11-01

    A new purpose-built ``pulse-burst'' laser system is being constructed for the Thomson scattering diagnostic on the MST reversed-field pinch. This new laser will produce a burst of 1--2 J Q-switched pulses at repetition rates 5--250 kHz. It will operate at 1064 nm and is a master oscillator, power amplifier (MOPA) system. Variable pulse-width drive (0.15--20 ms) of the flashlamps in this laser will be accomplished by IGBT switching of large electrolytic capacitor banks. A subset of these power supplies has already been constructed and is currently being used to drive the flashlamps in the two existing commercial Nd:YAG lasers used for Thomson scattering on MST. Each of these upgraded lasers now produces a burst of up to fifteen 2 J Q-switched pulses (1064 nm) at repetition rates 1--12.5 kHz. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are currently being used to study the dynamic evolution of electron temperature in MST. The new purpose-built ``pulse-burst'' laser system will further expand this capability.

  2. Design of and data reduction from compact Thomson parabola spectrometers.

    PubMed

    Morrison, J T; Willis, C; Freeman, R R; Van Woerkom, L

    2011-03-01

    Thomson parabola spectrometers are used to characterize MeV ion beams produced in high intensity laser interactions. These spectrometers disperse multiple ion species according to their charge to mass ratio through the use of parallel electric and magnetic fields. Analytical solutions for ion deflection in electric and magnetic fields have been used to extract ion spectra with the assumption that fringing effects are negligible. Experimental space restrictions and dynamic range requirements necessitate designs that stress the analytical assumptions. Depending on design parameters, the error in the analytical assumption can be comparable to the energy resolution. Estimates are provided to approximate the error on the total ion deflection. A method for modeling ion trajectories including fringing effects is presented using software freely available or in common use. The magnetostatic fields are modeled in 3D, including material properties of nearby magnetic materials using RADIA. Electrostatic fields are modeled in 2D for a spectrometer implementing angled plates using the partial differential equation toolbox in MATLAB(®). Using these models to calculate the ion trajectory allows for analysis of a Thomson parabola spectrometer with an arbitrary field configuration. PMID:21456736

  3. Events Leading to J. J. Thomson's Electron in 1897

    NASA Astrophysics Data System (ADS)

    Dahl, Per F.

    1997-03-01

    The electron had its genesis in the glow discharge studies of the German school of Julius Plucker and company, who viewed their Kathodenstrahlen as a form of aetheral wave propagation. Next on the scene came the Victorian amateur scientists, personified by the incomparable William Crookes, who interpreted the rays in terms of material particulate behavior. Back on the Continent, meanwhile, there was Heinrich Hertz and his disciple Philipp Lenard--the latter with his metallic ``window'' and all it stood for. In England, an experimental rivalry ensued between J. J. Thomson and Arthur Schuster, who nearly beat ``J.J.'' to his corpuscle in 1890, while in Paris, about then, Jean Perrin's cathode ray studies were provoked by the lingering anti-atomic stance of his academic countrymen. The chronicle culminated in the charge-to-mass experiments of 1896-97, in which Emil Wiechert and Walter Kaufmann narrowly missed the electron in favor of Thomson and his classic e/m determinations.

  4. Comparative electron temperature measurements of Thomson scattering and electron cyclotron emission diagnostics in TCABR plasmas

    SciTech Connect

    Alonso, M. P.; Figueiredo, A. C. A.; Berni, L. A.; Machida, M.

    2010-10-15

    We present the first simultaneous measurements of the Thomson scattering and electron cyclotron emission radiometer diagnostics performed at TCABR tokamak with Alfven wave heating. The Thomson scattering diagnostic is an upgraded version of the one previously installed at the ISTTOK tokamak, while the electron cyclotron emission radiometer employs a heterodyne sweeping radiometer. For purely Ohmic discharges, the electron temperature measurements from both diagnostics are in good agreement. Additional Alfven wave heating does not affect the capability of the Thomson scattering diagnostic to measure the instantaneous electron temperature, whereas measurements from the electron cyclotron emission radiometer become underestimates of the actual temperature values.

  5. Performance of JT-60SA divertor Thomson scattering diagnostics

    SciTech Connect

    Kajita, Shin; Hatae, Takaki; Tojo, Hiroshi; Hamano, Takashi; Shimizu, Katsuhiro; Kawashima, Hisato; Enokuchi, Akito

    2015-08-15

    For the satellite tokamak JT-60 Super Advanced (JT-60SA), a divertor Thomson scattering measurement system is planning to be installed. In this study, we improved the design of the collection optics based on the previous one, in which it was found that the solid angle of the collection optics became very small, mainly because of poor accessibility to the measurement region. By improvement, the solid angle was increased by up to approximately five times. To accurately assess the measurement performance, background noise was assessed using the plasma parameters in two typical discharges in JT-60SA calculated from the SONIC code. Moreover, the influence of the reflection of bremsstrahlung radiation by the wall is simulated by using a ray tracing simulation. The errors in the temperature and the density are assessed based on the simulation results for three typical field of views.

  6. Thomson scattering in high-intensity chirped laser pulses

    NASA Astrophysics Data System (ADS)

    Holkundkar, Amol R.; Harvey, Chris; Marklund, Mattias

    2015-10-01

    We consider the Thomson scattering of an electron in an ultra-intense laser pulse. It is well known that at high laser intensities, the frequency and brilliance of the emitted radiation will be greatly reduced due to the electron losing energy before it reaches the peak field. In this work, we investigate the use of a small frequency chirp in the laser pulse in order to mitigate this effect of radiation reaction. It is found that the introduction of a negative chirp means the electron enters a high frequency region of the field while it still has a large proportion of its original energy. This results in a significant enhancement of the frequency and intensity of the emitted radiation as compared to the case without chirping.

  7. Thomson scattering in high-intensity chirped laser pulses

    SciTech Connect

    Holkundkar, Amol R.; Harvey, Chris Marklund, Mattias

    2015-10-15

    We consider the Thomson scattering of an electron in an ultra-intense laser pulse. It is well known that at high laser intensities, the frequency and brilliance of the emitted radiation will be greatly reduced due to the electron losing energy before it reaches the peak field. In this work, we investigate the use of a small frequency chirp in the laser pulse in order to mitigate this effect of radiation reaction. It is found that the introduction of a negative chirp means the electron enters a high frequency region of the field while it still has a large proportion of its original energy. This results in a significant enhancement of the frequency and intensity of the emitted radiation as compared to the case without chirping.

  8. Joule-Thomson cryogenic cooler with extremely high thermal stability

    NASA Technical Reports Server (NTRS)

    Bard, Steven; Wu, J. J.; Trimble, Curt

    1991-01-01

    An 80-K Joule-Thomson (J-T) cooling system designed for the Probe Infrared Laser Spectrometer (PIRLS) proposed for the Huygens Titan Probe of the Cassini Saturn orbiter mission is presented. The cryogenic cooling requirements of the PIRLS instrument are listed, and the cooler system design including details of a J-T cryostat, cold head, and dewar design is described along with the results of a thermal modeling effort and lab cooler performance testing. It is shown that by using active feedback temperature control of the cold head in combination with the self-regulating action of the J-T cryostat, a temperature stability of less than 0.1 mK/min is achieved by the cooler weighting 1.8 kg.

  9. Fluctuations and Gibbs-Thomson Law - the Simple Physics.

    SciTech Connect

    Chernov, A A; De Yoreo, J J; Rashkovich, L N

    2006-09-15

    Crystals of slightly soluble materials should be subject of relatively weak attachment/detachment fluctuations on their faces so that steps on that faces have low kink density. These steps are parallel to the most close packed lattice rows and form polygons on a crystal surface. The process responsible for implementation of the classical Gibbs-Thomson law (GTL) for the polygonal step (in two dimensions, 2D) is kink exchange between the step corners. For the 3D crystallites, this mechanism includes step exchange. If these mechanisms do not operate because of slow fluctuations the GTL is not applicable. Physics of these processes and conditions for the GTL applicability are discussed on a simple qualitative level.

  10. Thomson scattering measurements from asymmetric interpenetrating plasma flows.

    PubMed

    Ross, J S; Moody, J D; Fiuza, F; Ryutov, D; Divol, L; Huntington, C M; Park, H-S

    2014-11-01

    Imaging Thomson scattering measurements of collective ion-acoustic fluctuations have been utilized to determine ion temperature and density from laser produced counter-streaming asymmetric flows. Two foils are heated with 8 laser beams each, 500 J per beam, at the Omega Laser facility. Measurements are made 4 mm from the foil surface using a 60 J 2ω probe laser with a 200 ps pulse length. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the multi-ion species, asymmetric flows theoretical form factor for the ion feature such that the ion temperatures, ion densities, and flow velocities for each plasma flow are determined. PMID:25430359

  11. Thomson scattering in a magnetic field. I - Field along z

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara A.

    1991-01-01

    The Monte Carlo method is used here to solve the radiative transfer equation for Thomson scattering in a constant magnetic field perpendicular to the atmosphere. Emergent radiation and polarization are presented for various atmospheric thicknesses. The circular polarization peaks at frequencies near the cyclotron, omega(c), and for propagation direction along the field. At low field strengths, the circular polarization is roughly proportional to omega(c)/omega; the linear polarization is proportional to the square of omega(c)/omega and the amount of circular polarization present at each scatter and is therefore much smaller than the circular polarization. The linear polarization is large for propagation direction perpendicular to the magnetic field and at frequencies near the cyclotron and in the strong-field limit. The position angle of the linear polarization undergoes a rotation of 90 deg at a value of omega(c)/omega near the square root of three.

  12. Performance of JT-60SA divertor Thomson scattering diagnostics.

    PubMed

    Kajita, Shin; Hatae, Takaki; Tojo, Hiroshi; Enokuchi, Akito; Hamano, Takashi; Shimizu, Katsuhiro; Kawashima, Hisato

    2015-08-01

    For the satellite tokamak JT-60 Super Advanced (JT-60SA), a divertor Thomson scattering measurement system is planning to be installed. In this study, we improved the design of the collection optics based on the previous one, in which it was found that the solid angle of the collection optics became very small, mainly because of poor accessibility to the measurement region. By improvement, the solid angle was increased by up to approximately five times. To accurately assess the measurement performance, background noise was assessed using the plasma parameters in two typical discharges in JT-60SA calculated from the SONIC code. Moreover, the influence of the reflection of bremsstrahlung radiation by the wall is simulated by using a ray tracing simulation. The errors in the temperature and the density are assessed based on the simulation results for three typical field of views. PMID:26329196

  13. Multipoint Thomson scattering diagnostic for the ETE tokamak

    SciTech Connect

    Berni, L.A.; Alonso, M.P.; Oliveira, R.M.

    2004-10-01

    To measure the electron temperature and plasma density profiles on the Experimento Tokamak Esferico tokamak a multiplexed Thomson scattering diagnostic was implemented. The diagnostic is based on a 10 J ruby laser and a single five spectral channel filter polychromator. A collection lens with f/6.3 relay the scattered light from 23 spatial points to optical fibers. The fibers have a monotonous increasing length and are inserted into the polychromator. Between the collection lens and each fiber optic we have a microlens to match the numerical aperture and to enlarge the plasma observation volume. This work describes the project, the simulations, and the preliminary results obtained with the first four optical fibers.

  14. Thomson scattering diagnostic upgrade on DIII-D

    SciTech Connect

    Ponce-Marquez, D. M.; Bray, B. D.; Deterly, T. M.; Liu, C.; Eldon, D.

    2010-10-15

    The DIII-D Thomson scattering system has been upgraded. A new data acquisition hardware was installed, adding the capacity for additional spatial channels and longer acquisition times for temperature and density measurements. Detector modules were replaced with faster transimpedance circuitry, increasing the signal-to-noise ratio by a factor of 2. This allows for future expansion to the edge system. A second phase upgrade scheduled for 2010-2011 includes the installation of four 1 J/pulse Nd:YAG lasers at 50 Hz repetition rate. This paper presents the first completed phase of the upgrade and performance comparison between the original system and the upgraded system. The plan for the second phase is also presented.

  15. Unveiling the physics of the Thomson jumping ring

    NASA Astrophysics Data System (ADS)

    Ladera, Celso L.; Donoso, Guillermo

    2015-04-01

    We present a new theoretical model and validating experiments that unveil the rich physics behind the flight of the conductive ring in the Thomson experiment—physics that is hard to see because of the rapid motion. The electrodynamics of the flying ring exhibits interesting features, e.g., varying mutual inductance between the ring and the electromagnet. The dependences of the ring electrodynamics upon time and position as the ring travels upward are conveniently separated and determined to obtain a comprehensive view of the ring motion. We introduce a low-cost jumping ring setup that incorporates pickup coils connected in opposition, allowing us to scrutinize the ring electrodynamics and confirm our theoretical model with good accuracy. This work is within the reach of senior students of science or engineering, and it can be implemented either as a teaching laboratory experiment or as an open-ended project.

  16. Thomson parabola spectrometry for gold laser-generated plasmas

    SciTech Connect

    Torrisi, L.; Cutroneo, M.; Ando, L.; Ullschmied, J.

    2013-02-15

    The plasma generated from thin gold films irradiated in high vacuum at high intensity ({approx}10{sup 15} W/cm{sup 2}) laser shot is characterized in terms of ion generation through time-of-flight techniques and Thomson parabola spectrometry. Gold ions and protons, accelerated in forward direction by the electric field developed in non-equilibrium plasma, have been investigated. Measurements, performed at PALS laboratory, give information about the gold charge states distributions, the ion energy distributions and the proton acceleration driven as a function of film thickness, laser parameters, and angular emission. The ion diagnostics of produced plasma in forward direction permits to understand some mechanisms developed during its expansion kinetics. The role of the focal position of a laser beam with respect to the target surface, plasma properties, and the possibility to accelerate protons up to energies above 3 MeV has been presented and discussed.

  17. Collective Thomson scattering investigations of the Hall thruster plasma

    NASA Astrophysics Data System (ADS)

    Tsikata, Sedina; Honore, Cyrille; Gresillon, Dominique; Lemoine, Nicolas; Cavalier, Jordan

    2012-10-01

    Anomalous electron transport outside the Hall thruster channel is believed to be due to plasma turbulence. Recent experiments using a specially-designed collective Thomson scattering diagnostic on a 5kW thruster have permitted the identification of a wave believed to be involved in transport. The observed properties of the mode, which is naturally driven by the fast azimuthal electron drift, are in line with predictions from PIC simulations and linear kinetic theory analysis. Detailed characterizations of mode properties, including dispersion relation, directivity, spatial extent and fluctuation amplitude have been obtained. These studies are now extended to consider the universality of mode features in a 200W permanent magnet Hall thruster and links between thruster performance, operating r'egimes and the presence of such a mode.

  18. Pulse-burst laser systems for fast Thomson scattering (invited).

    PubMed

    Den Hartog, D J; Ambuel, J R; Borchardt, M T; Falkowski, A F; Harris, W S; Holly, D J; Parke, E; Reusch, J A; Robl, P E; Stephens, H D; Yang, Y M

    2010-10-01

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to "pulse-burst" capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned. PMID:21033868

  19. Pulse-burst laser systems for fast Thomson scattering (invited)

    SciTech Connect

    Den Hartog, D. J.; Ambuel, J. R.; Holly, D. J.; Robl, P. E.; Borchardt, M. T.; Falkowski, A. F.; Harris, W. S.; Parke, E.; Reusch, J. A.; Stephens, H. D.; Yang, Y. M.

    2010-10-15

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to ''pulse-burst'' capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned.

  20. Thomson scattering measurements from asymmetric interpenetrating plasma flows

    SciTech Connect

    Ross, J. S. Moody, J. D.; Fiuza, F.; Ryutov, D.; Divol, L.; Huntington, C. M.; Park, H.-S.

    2014-11-15

    Imaging Thomson scattering measurements of collective ion-acoustic fluctuations have been utilized to determine ion temperature and density from laser produced counter-streaming asymmetric flows. Two foils are heated with 8 laser beams each, 500 J per beam, at the Omega Laser facility. Measurements are made 4 mm from the foil surface using a 60 J 2ω probe laser with a 200 ps pulse length. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the multi-ion species, asymmetric flows theoretical form factor for the ion feature such that the ion temperatures, ion densities, and flow velocities for each plasma flow are determined.

  1. Development of a nine spatial point, multipulse Thomson scattering diagnostic.

    PubMed

    Glass, F; Deng, B H; Garate, E; Gornostaeva, O; Schroeder, J

    2010-10-01

    A Thomson scattering diagnostic has been developed for the C-2 field-reversed configuration device. Based on a multipulse ruby laser, the system measures the electron temperature at nine spatial points. These points are chosen from 22 selectable positions covering r≈1-41 cm. Twin collection lenses couple the scattered photons to nine optical fiber pairs. Extra fiber lengths delay the signals from different spatial points relative to each other, allowing up to three points to be analyzed by a single polychromator. The polychromator, using compact photomultipliers as detectors, has six spectral channels covering the range of 685-725 nm and is able to estimate electron temperatures of ≈10-200 eV. The photomultiplier output signals are recorded by digital storage oscilloscopes integrated with the main MDSplus database, with temperature and error estimates generated automatically at the conclusion of each plasma discharge. PMID:21033861

  2. Subterahertz gyrotron developments for collective Thomson scattering in LHD.

    PubMed

    Notake, T; Saito, T; Tatematsu, Y; Kubo, S; Shimozuma, T; Tanaka, K; Nishiura, M; Fujii, A; Agusu, La; Ogawa, I; Idehara, T

    2008-10-01

    Collective Thomson scattering (CTS) is expected to provide the spatially resolved velocity distribution functions of not only thermal and tail ions but also alpha particles resulting from fusion reactions. CTS using gyrotrons with frequency higher than the conventional ones used for plasma heating would have advantages to alleviate refraction, cutoff effects, and background electron cyclotron emission noise. Therefore, a high-power pulse gyrotron operating at approximately 400 GHz is being developed for CTS in Large Helical Device (LHD). A single-mode oscillation with a frequency greater than 400 GHz, applying the second-harmonic resonance, was successfully demonstrated in the first stage. At the same time, concrete feasibility study based on ray tracing, scattering spectra, and electron cyclotron emission calculations has been conducted. PMID:19044548

  3. Subterahertz gyrotron developments for collective Thomson scattering in LHD

    SciTech Connect

    Notake, T.; Saito, T.; Tatematsu, Y.; Fujii, A.; Agusu, La; Ogawa, I.; Idehara, T.; Kubo, S.; Shimozuma, T.; Tanaka, K.; Nishiura, M.

    2008-10-15

    Collective Thomson scattering (CTS) is expected to provide the spatially resolved velocity distribution functions of not only thermal and tail ions but also alpha particles resulting from fusion reactions. CTS using gyrotrons with frequency higher than the conventional ones used for plasma heating would have advantages to alleviate refraction, cutoff effects, and background electron cyclotron emission noise. Therefore, a high-power pulse gyrotron operating at approximately 400 GHz is being developed for CTS in Large Helical Device (LHD). A single-mode oscillation with a frequency greater than 400 GHz, applying the second-harmonic resonance, was successfully demonstrated in the first stage. At the same time, concrete feasibility study based on ray tracing, scattering spectra, and electron cyclotron emission calculations has been conducted.

  4. Calibration of a Thomson scattering diagnostic for fluctuation measurements

    SciTech Connect

    Stephens, H. D.; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Holly, D. J.; O'Connell, R.; Reusch, J. A.

    2008-10-15

    Detailed calibrations of the Madison Symmetric Torus polychromator Thomson scattering system have been made suitable for electron temperature fluctuation measurements. All calibrations have taken place focusing on accuracy, ease of use and repeatability, and in situ measurements wherever possible. Novel calibration processes have been made possible with an insertable integrating sphere (ISIS), using an avalanche photodiode (APD) as a reference detector and optical parametric oscillator (OPO). Discussed are a novel in situ spatial calibration with the use of the ISIS, the use of an APD as a reference detector to streamline the APD calibration process, a standard dc spectral calibration, and in situ pulsed spectral calibration made possible with a combination of an OPO as a light source, the ISIS, and an APD used as a reference detector. In addition a relative quantum efficiency curve for the APDs is obtained to aid in uncertainty analysis.

  5. The Thomson scattering systems of the ASDEX upgrade tokamak

    SciTech Connect

    Murmann, H.; Goetsch, S.; Roehr, H.; Salzmann, H.; Steuer, K.H. )

    1992-10-01

    The Thomson scattering system of the ASDEX upgrade (AUG) tokamak is described. One of the main objectives of AUG is to investigate plasma wall interaction in reactor relevant discharges with a magnetic divertor. The very successful Nd:YAG scattering system developed for its predecessor ASDEX, has been upgraded to give higher spatial and temporal resolution, reliability, and flexibility to different discharge conditions. The system consists of two independently operating devices, each using a cluster of six lasers: One measures the electron temperature and density along three possible vertical chords alternatively through the magnetic axis, or the inner or outer boundary layer; a second chord in the equatorial plane will always cover the magnetic center even in the case of considerable Shafranov shifts. An additional compact spectrometer has been designed for measurements with high radial resolution in the equatorial plane across the separatrix. A third system, using the laser beams for the vertical arrangement once again, has been designed for profile measurements in the energy deposition zone 2 cm above the outer divertor plate. Each laser is run at a repetition rate of 20 Hz and 1 J per pulse. A variety of synchronization modes are available, e.g., 20 Hz/6 J, 120 Hz/1 J etc., or repetitive bursts at 20 Hz. In this case the minimum delay between two pulses is presently limited to {approx}30 {mu}s by the existing data acquisition. This mode will be used for investigating fast phenomena such as sawteeth or disruptive instabilities. During the time intervals between the laser pulses the bremsstrahlung radiation (line integral) will be measured by the Thomson scattering detection system to calculate {ital Z}{sub eff}.

  6. Horizontal Thomson Scattering Systems for DIII-D and SSPX

    SciTech Connect

    Nilson, D.G.; Hill, D.N.; Wood, R.D.; McClean, H.; Moeller, J.M.; Labik, G.; Carlstron, T.N.; Bray, B.; Hsieh, C.L.

    1999-08-01

    DIII-D--Three of the seven existing core Thomson scattering laser beams were redirected to probe the previously unmeasured central region of the DIII-D plasma. Modifications to the existing collection optics system and support tower were made to inject the lasers and collect scattered light in this new extended region. Stray light levels were reduced to acceptable levels to permit Rayleigh scattering calibration on five of the six new channels, indicating that the new in-vessel dump operates well. Measurements of the plasma temperature and density from the plasma edge to the center are now possible. Peaked density profiles are now observed in this new measurement region. SSPX--We have completed the design and installation of a 10-spatial channel Thomson scattering system to measure the plasma temperature and density profile on SSPX. A single-pulsed YAG laser operating at 0.7 J and 8 ns is used to scatter photons into a 7-element collection optic that provides a spatial resolution of 1.5 cm at the outer plasma edge and 7.5 cm at the inner edge of a .5 m radius spheromak plasma. The collected light is then analyzed by a 4-channel interference filtered polychromator which has been optimized to measure temperatures between 2 eV and 2 keV and densities as low as 1 x 10{sup 12} cm{sup 3}. We use an in-vessel beam dump and a series of entrance and exit baffles to reduce the stray laser light and provide for an absolute density calibration by Rayleigh scattering in argon gas.

  7. Detection of dust on JET with the high resolution Thomson scattering system

    SciTech Connect

    Giovannozzi, E.; Rydzy, A.; Beurskens, M.; Kempenaars, M.; Collaboration: JET EFDA Contributors

    2010-10-15

    Dust particles have been observed with Thomson scattering systems on several tokamaks. We present here the first evidence of dust particles observed by the new high resolution Thomson scattering system on JET. The system consists of filter spectrometers that analyze the Thomson scattering spectrum from 670 to 1050 nm in four spectral channels. The laser source is a 5 J Q-switched Nd:YAG laser. Without a spectral channel at the laser wavelength, only dust particles that emit broadband light could be detected; these particles have been observed on JET after disruptions. The timing of their emission is clearly different from that expected for a Thomson scattering pulse. The light pulse from dust happens after the peak of the laser light and has a long tail.

  8. Frequency scaling law for nonlinear Compton and Thomson scattering: Relevance of spin and polarization effects

    NASA Astrophysics Data System (ADS)

    Krajewska, K.; Kamiński, J. Z.

    2014-11-01

    The distributions of Compton and Thomson radiation for a shaped laser pulse colliding with a free electron are calculated in the framework of quantum and classical electrodynamics, respectively. We introduce a scaling law for the Compton and the Thomson frequency distributions which universally applies to long and short incident pulses. Thus, we extend the validity of frequency scaling postulated in previous studies comparing nonlinear Compton and Thomson processes. The scaling law introduced in this paper relates the Compton no-spin flipping process to the Thomson process over nearly the entire spectrum of emitted radiation, including its high-energy portion. By applying the frequency scaling, we identify that both spin and polarization effects are responsible for differences between classical and quantum results. The same frequency scaling applies to angular distributions and to temporal power distributions of emitted radiation, which we illustrate numerically.

  9. Detection of dust on JET with the high resolution Thomson scattering systema)

    NASA Astrophysics Data System (ADS)

    Giovannozzi, E.; Beurskens, M.; Kempenaars, M.; Pasqualotto, R.; Rydzy, A.; JET EFDA Contributors

    2010-10-01

    Dust particles have been observed with Thomson scattering systems on several tokamaks. We present here the first evidence of dust particles observed by the new high resolution Thomson scattering system on JET. The system consists of filter spectrometers that analyze the Thomson scattering spectrum from 670 to 1050 nm in four spectral channels. The laser source is a 5 J Q-switched Nd:YAG laser. Without a spectral channel at the laser wavelength, only dust particles that emit broadband light could be detected; these particles have been observed on JET after disruptions. The timing of their emission is clearly different from that expected for a Thomson scattering pulse. The light pulse from dust happens after the peak of the laser light and has a long tail.

  10. A Virial Treatment of the Joule and Joule-Thomson Coefficients.

    ERIC Educational Resources Information Center

    Rybolt, Thomas R.

    1981-01-01

    Provides background information designed to aid a physical chemistry student in using the virial equation of state in deriving expressions for other thermodynamic properties, such as writing the Joule and Joule-Thomson coefficients in terms of virial expansions. (CS)

  11. Study of the effects of photon statistics on Thomson scattering data

    SciTech Connect

    Hart, G.W.; Levinton, F.M.; McNeill, D.H.

    1985-12-01

    A computer code has been developed which simulates the counting statistics of a Thomson scattering measurement. The scattered and background signals in each of the wavelength channels are assumed to obey Poisson statistics, and the spectral data are fitted to a Gaussian curve using a nonlinear least-squares fitting algorithm. This method should be applicable to Thomson scattering measurements in which the signal-to-noise ratio is low due to low signal or high background. Thomson scattering data from the S-1 Spheromak have been compared to this simulation, and they have been found to be in good agreement. This code has proved to be useful assessing the effects of counting statistics relative to shot-to-shot variability in producing the observed spread in the data. It was also useful for designing improvements for the S-1 Thomson scattering system, and this method would be applicable to any measurements affected by counting statistics. 5 refs., 1 fig.

  12. In-line phase-contrast imaging based on Tsinghua Thomson scattering x-ray source.

    PubMed

    Zhang, Zhen; Du, Yingchao; Yan, Lixin; Hua, Jianfei; Yang, Jin; Xiao, Yongshun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2014-08-01

    Thomson scattering x-ray sources can produce ultrashort, energy tunable x-ray pulses characterized by high brightness, quasi-monochromatic, and high spatial coherence, which make it an ideal source for in-line phase-contrast imaging. We demonstrate the capacity of in-line phase-contrast imaging based on Tsinghua Thomson scattering X-ray source. Clear edge enhancement effect has been observed in the experiment. PMID:25173262

  13. Electron-ion collision-frequency for x-ray Thomson scattering in dense plasmas

    NASA Astrophysics Data System (ADS)

    Faussurier, Gérald; Blancard, Christophe

    2016-01-01

    Two methods are presented to calculate the electron-ion collision-frequency in dense plasmas using an average-atom model. The first one is based on the Kubo-Greenwood approach. The second one uses the Born and Lenard-Balescu approximations. The two methods are used to calculate x-ray Thomson scattering spectra. Illustrations are shown for dense beryllium and aluminum plasmas. Comparisons with experiment are presented in the case of an x-ray Thomson scattering spectrum.

  14. Structures in Te profiles: High resolution Thomson scattering in the Rijnhuizen tokamak project

    NASA Astrophysics Data System (ADS)

    Beurskens, M. N. A.; Barth, C. J.; Lopes Cardozo, N. J.; van der Meiden, H. J.

    1999-01-01

    In the Rijnhuizen tokamak project, the double pulse multiposition Thomson scattering diagnostic is in full operation. Its high spatial resolution enables the measurement of small scale structures in Te, ne, and pe. Thomson scattering profiles during an ordinary sawtooth crash show the displacement of the hot core in great detail. Measurements on off-axis sawtoothing plasmas show that a small central part remains unaffected. Filaments are observed in plasmas which show a transient central temperature rise in response to fast edge cooling.

  15. Commissioning of Thomson Scattering on the PEGASUS Toroidal Experiment

    NASA Astrophysics Data System (ADS)

    Schlossberg, D. J.; Fonck, R. J.; Peguero, L. M.; Winz, G. R.

    2013-10-01

    A new multipoint Thomson scattering diagnostic has been installed on the PEGASUS Toroidal Experiment. It employs a frequency-doubled Nd:YAG laser (λ0 = 532 nm) and spectrometers using volume phase holographic gratings and gated, intensified CCD cameras. Spectral, temporal and intensity calibrations of the spectrometer systems were conducted. Sources of laser energy loss were identified and reduced, beam termination was optimized to minimize reflections during collection time, and inter-shot alignment monitoring was installed. Rayleigh and Raman calibration efforts revealed significant stray light from in-vessel reflections; hence, a vacuum-compatible optical baffling system was designed, fabricated, and is being installed. Operation of the diagnostic will support characterization of helicity dissipation mechanisms and confinement scaling during local DC helicity injection startup on PEGASUS. Additionally, H-mode temperature and density profiles will be obtained to support equilibrium reconstructions and stability studies of ELMs in the H-mode plasma edge. Initial measurements will be conducted with an 8-spatial channel array; expansion to 24 channels is in progress. Work supported by US DOE Grant DE-FG02-96ER54375.

  16. Implementation of a Thomson Scattering Diagnostic on Pegasus

    NASA Astrophysics Data System (ADS)

    Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Moritz, J. I.; Schoenbeck, N. L.; Winz, G. R.

    2011-10-01

    The multipoint Thomson scattering system on PEGASUS will diagnose point-source helicity-driven plasmas, including dominant particle transport mechanisms and sources of helicity dissipation. Helicity-driven plasmas are estimated to have áTe ñ ~ 50 eV for stochastic field line confinement and ~200 eV for standard Ohmic closed flux surface confinement. To accurately characterize these regimes, a novel system is being designed, installed, and calibrated. A Nd:YAG laser is frequency doubled to provide a 9 ns, 2 J pulse radially across the plasma. Remote alignment of steering mirrors can be performed between shots along the 6 m length of the external laser beam-line. The 532 nm laser beam is focused to a <= 3 mm diameter beam within the plasma. Plasma background measurements are made simultaneously with data collection. A custom optical system collects signal from >70% of the plasma cross-section with 1.4 cm radial resolution. Optical fibers relay light to a high-efficiency volume phase holographic grating spectrometer coupled to a high quantum efficiency image intensified CCD camera, gated at >= 2 ns. Signal levels for plasmas with ne >1018 m-3 and 10 eV

  17. Miniature Piezoelectric Compressor for Joule-Thomson Cryocoolers

    NASA Astrophysics Data System (ADS)

    Sobol, Sergey; Tzabar, Nir; Grossman, Gershon

    Joule-Thomson (JT) cryocoolers operate with a continuous flow of the working fluid that enters the cooler at a high pressure and leaves it at a lower pressure. Ideally, the temperature of the outgoing fluid equals the temperature of the entering fluid. JT cryocoolers that operate with pure refrigerants require high pressure of a few tens of MPa where the low pressure is usually around 0.1 MPa. Circulation of the working fluid in such cases requires high pressure ratio compressors that evidently have large dimensions. JT cryocoolers can operate with much lower pressure ratios by using mixed-refrigerants. Cooling from 300 K to about 80 K in a single stage cryocooler normally requires a pressure ratio of about 1:25. In the present research a miniature compressor driven by piezoelectric elements is developed in collaboration between Rafael and the Technion. This type of compressor has the advantage of improved long life compared to other mechanical compressors, very low vibrations, and silent operation. In the current case, the design goal of the intake and discharge pressures has been 0.1 and 2.5 MPa, respectively, with a flow rate of 0.06 g/s. The compressor has two compression stages; 1:5 and 5:25. Several configurations have been considered, fabricated, and tested. The performance of the last configuration approaches the desired specification and is presented in the current paper together with the design concept.

  18. Multipoint Thomson scattering diagnostic for DIII-D

    NASA Astrophysics Data System (ADS)

    Hsieh, C. L.; Chase, R.; Deboo, J. C.; Evanko, R. G.; Gohil, P.; Snider, R. T.; Stockdale, R. E.

    1988-02-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 10 to the 12th/cu cm and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnositic system consist of a 10-J ruby laser, many stages of funnel shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through re-entrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an focal length/1.9 spectrometer, an intensified CCD camera system capable of single photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest.

  19. Multipoint Thomson scattering diagnostic for DIII-D

    NASA Astrophysics Data System (ADS)

    Hsieh, C. L.; Chase, R.; DeBoo, J. C.; Evanko, R. G.; Gohil, P.; Snider, R. T.; Stockdale, R. E.

    1988-08-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 1012 cm-3 and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnostic system consist of a 10-J ruby laser, many stages of funnel-shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through reentrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an f/1.9 spectrometer, an intensified CCD camera system capable of single-photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest.

  20. Design of multipulse Thomson scattering diagnostic for SST-1 tokamak

    NASA Astrophysics Data System (ADS)

    Kumar, Ajai; Chavda, Chhaya; Saxena, Y. C.; Singh, Ranjeet; Thakar, Aruna; Thomas, Jinto; Patel, Kiran; Pandya, Kaushal; Bedakihale, Vijay

    2007-04-01

    A multipulse Nd:YAG (Yttrium aluminum garnet) Thomson scattering (TS) system is designed and developed for measuring electron temperature (Te) and density (ne) profiles of SST-1 tokamak. The system operates at vertical, divertor, and horizontal (midplane) regions of plasma and measures the electron temperature of 20eVto1.5keV and density of 1018-1019m-3. Six Nd:YAG lasers synchronized with external control is used to get three different temporal resolutions (30Hz, 180Hz, and 1kHz). The entire system is laboratory tested for the stability of alignment and performance over a distance of 30m. Different imaging lens assemblies are designed to image the scattered photons from each of the scattering region to an array of optical fibers. A low cost and compact five-channel interference filter polychromator is designed, fabricated, and tested for its image quality and the filter transmission characteristics. Detection system with an avalanche photodiode and required signal conditioning electronics is developed for detecting the scattered photons. A data acquisition and control module operating on PXI bus is developed for the real time data acquisition and system control. A detailed description of design and testing of TS subsystems is presented in this article.

  1. 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.

  2. 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.

  3. Characterization of a thermoelectric/Joule-Thomson hybrid microcooler

    NASA Astrophysics Data System (ADS)

    Cao, H. S.; Vanapalli, S.; Holland, H. J.; Vermeer, C. H.; ter Brake, H. J. M.

    2016-07-01

    Micromachined Joule-Thomson (JT) coolers are attractive for cooling small electronic devices. However, microcoolers operated with pure gases, such as nitrogen gas require high pressures of about 9 MPa to achieve reasonable cooling powers. Such high pressures severely add complexity to the development of compressors. To overcome this disadvantage, we combined a JT microcooler with a thermoelectric (TE) pre-cooler to deliver an equivalent cooling power with a lower pressure or, alternatively, a higher cooling power when operating with the same pressure. This hybrid microcooler was operated with nitrogen gas as the working fluid at a low pressure of 0.6 MPa. The cooling power of the microcooler at 101 K operating with a fixed high pressure of 8.8 MPa increased from 21 to 60 mW when the precooling temperature was reduced by the thermoelectric cooler from 295 to 250 K. These tests were simulated using a dynamic numerical model and the accuracy of the model was verified through the comparison between experimental and simulation results. Based on the model, we found the high pressure of the microcooler can be reduced from 8.8 to 5.5 MPa by lowering the precooling temperature from 295 to 250 K. Moreover, the effect of TE cooler position on the performance of the hybrid microcooler was evaluated through simulation analysis.

  4. Multipoint Thomson scattering diagnostic for DIII-D

    SciTech Connect

    Hsieh, C.L.; Chase, R.; DeBoo, J.C.; Evanko, R.G.; Gohil, P.; Snider, R.T.; Stockdale, R.E.

    1988-08-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 10/sup 12/ cm/sup -3/ and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnostic system consist of a 10-J ruby laser, many stages of funnel-shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through reentrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an f/1.9 spectrometer, an intensified CCD camera system capable of single-photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest.

  5. Multipoint Thomson scattering diagnostic for DIII-D

    SciTech Connect

    Hsieh, C.L.; Chase, R.; DeBoo, J.C.; Evanko, R.G.; Gohil, P.; Snider, R.T.; Stockdale, R.E.

    1988-02-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 10/sup 12/ cm/sup -3/ and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnositic system consist of a 10-J ruby laser, many stages of funnel shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through re-entrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an /line integral/1.9 spectrometer, an intensified CCD camera system capable of single photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest. 2 refs., 7 figs.

  6. Nonlinear Thomson scattering of an ultrashort laser pulse

    SciTech Connect

    Golovinski, P. A. Mikhin, E. A.

    2011-10-15

    The nonlinear scattering of an ultrashort laser pulse by free electrons is considered. The pulse is described in the 'Mexican hat' wavelet basis. The equation of motion for a charged particle in the field of a plane electromagnetic wave has an exact solution allowing, together with the instant spectrum approximation, the calculation of the intensity of nonlinear Thomson scattering for a high-intensity laser pulse. The spectral distribution of scattered radiation for the entire pulse duration is found by integrating with respect to time. The maximum of the emission spectrum of a free electron calculated in 10{sup 19}-10{sup 21} W/cm{sup 2} fields lies in the UV spectral region between 3 and 12 eV. A part of the continuous spectrum achieves high photon energies. One percent of the scattered energy for the field intensity 10{sup 20} W/cm{sup 2} is concentrated in the range h{omega} > 2.7 Multiplication-Sign 10{sup 2} eV, for a field intensity of 10{sup 21} W/cm{sup 2} in the range h{Omega} > 7.9 Multiplication-Sign 10{sup 2} eV, and for an intensity of 10{sup 22} W/cm{sup 2} in the range h{Omega} > 2.45 Multiplication-Sign 10{sup 5} eV. These results allow us to estimate nonlinear scattering as a source of hard X-rays.

  7. Optical Thomson scattering measurements of cylindrical wire array parameters

    SciTech Connect

    Harvey-Thompson, A. J.; Lebedev, S. V.; Patankar, S.; Bland, S. N.; Burdiak, G.; Chittenden, J. P.; Colaitis, A.; De Grouchy, P.; Hall, G. N.; Khoory, E.; Pickworth, L.; Suzuki-Vidal, F.; Smith, R. A.; Skidmore, J.; Suttle, L.; Swadling, G. F.; Hohenberger, M.

    2012-05-15

    A Thomson scattering diagnostic has been used to measure the parameters of cylindrical wire array Z pinch plasmas. The scattering operates in the collective regime ({alpha}>1) allowing spatially localised measurements of the ion or electron plasma temperatures and of the plasma bulk velocity. The ablation flow is found to accelerate towards the axis reaching peak velocities of 1.2-1.3 Multiplication-Sign 10{sup 7} cm/s in aluminium and {approx}1 Multiplication-Sign 10{sup 7} cm/s in tungsten arrays. Measurements of the precursor ion temperature shortly after formation are found to correspond to the kinetic energy of the converging ablation flow. Measurements during the implosion phase of tungsten arrays show the main imploding mass reaches velocities of {approx}1.4-1.7 Multiplication-Sign 10{sup 7} cm/s and is non-zero even at large radii close to the start of the x-ray pulse indicating current flow in the trailing mass.

  8. Radial resolution enhancement of the NSTX Thomson scattering diagnostic

    SciTech Connect

    LeBlanc, B. P.; Diallo, A.; Labik, G.; Stevens, D. R.

    2012-10-15

    Current magnetic confinement plasma physics research has increased the demand for radial resolution in profile diagnostics, in particular in the edge and pedestal regions. On NSTX, an upgrade of the existing multi-point Thomson scattering diagnostic has been implemented in order to respond to the research program needs. Twelve new radial channels have been added bringing the total number of positions to 42. Four previously un-instrumented fiber bundles were put in service. Eight existing 'active' fiber bundles were divided in two sub-bundles each in order to increase spatial resolution. Twelve radial channels now cover the pedestal region with a resolution near one centimeter. Fifteen radial channels cover the core and internal transport barrier regions. Two additional channels were added, one near the inner edge and one in the outer scrape-off layer. The intersection of the focused viewing optics field of view with a finite-width laser beam results in major-radius cross talk between adjacent fiber sub-bundles. A discussion and calculation of the cross talk will be presented.

  9. Chevron beam dump for ITER edge Thomson scattering system.

    PubMed

    Yatsuka, E; Hatae, T; Vayakis, G; Bassan, M; Itami, K

    2013-10-01

    This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated. PMID:24182106

  10. Conceptual design of a polarimetric Thomson scattering diagnostic in ITER

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Bassan, M.; Orsitto, F. P.; Pasqualotto, R.; Kempenaars, M.; Flanagan, J.

    2016-01-01

    Polarimetric Thomson scattering (TS) is a novel diagnostic technique proposed as an alternative to conventional (spectral) TS, for the measurement of the electron temperature Te and density ne in very hot fusion plasmas. Contrary to spectral TS, which is based on the reconstruction of the Doppler broadened frequency spectrum, in polarimetric TS Te is determined from the depolarization of the scattered radiation. The technique is suitable for ITER, where it is expected to be competitive with conventional spectral TS for measurements in the highest Te range, specially in backward-like conditions with the scattering angle 90° ll θ <= 180°. In this paper we consider a hypothetical polarimetric TS diagnostic for ITER and evaluate its performance for the θ = 145° scattering condition typical of the core TS system and also for a different scattering geometry in which, using a tangential laser beam, the central region of the ITER plasma can be observed under a scattering angle θ ~ 75°. In both cases we calculate the expected errors on the measured Te and ne that can be obtained with a simple, two-channel polarimeter, and taking into account that only a fraction of the TS wavelength spectrum is detected. In both cases the expected performances are compared with those of the conventional spectral core TS diagnostic to determine the plasma conditions in which the polarimetric technique is more advantageous. A measurement of the depolarization effect of the TS radiation using the JET High Resolution TS system of JET is also discussed.

  11. Chevron beam dump for ITER edge Thomson scattering system

    SciTech Connect

    Yatsuka, E.; Hatae, T.; Bassan, M.; Itami, K.; Vayakis, G.

    2013-10-15

    This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.

  12. High-resolution Thomson parabola for ion analysis.

    PubMed

    Cobble, J A; Flippo, K A; Offermann, D T; Lopez, F E; Oertel, J A; Mastrosimone, D; Letzring, S A; Sinenian, N

    2011-11-01

    A new, versatile Thomson parabola ion energy (TPIE) analyzer has been designed, constructed, and used at the OMEGA-EP facility. Laser-accelerated multi-MeV ions from hemispherical C targets are transmitted through a W pinhole into a multi-kG magnetic field and subsequently through a parallel electric field of up to 25 kV/cm. The ion drift region has a user-selected length of 10, 50, or 80 cm. With the highest fields, 400-MeV C(6+) and C(5+) may be resolved. TPIE is ten-inch manipulator (TIM)-mounted at OMEGA-EP and can be used opposite either of the EP ps beams. The instrument runs on pressure-interlocked 15-Vdc power available in EP TIM carts. Flux control derives from the insertion depth into the target chamber and the user-selected pinhole dimensions. The detector consists of CR39 backed by an image plate. A fully relativistic simulation code for calculating ion trajectories was employed for design optimization. Excellent agreement of code predictions with the actual ion positions on the detectors is observed. Through pit counting of carbon-ion tracks in CR39, it is shown that conversion efficiency of laser light to energetic carbon ions exceeds ~5% for these targets. PMID:22128973

  13. Linear plasma response, electrostatic fluctuations and Thomson scattering

    NASA Astrophysics Data System (ADS)

    Rozmus, Wojciech; Zheng, Zhen; Bychenkov, Valery Yu.; Brantov, Andrei V.

    2011-10-01

    Our nonlocal and nonstationary transport theory provides a method of solution of the initial value problem for the full set of linearized Fokker-Planck kinetic equations with Landau collision operators. The closure relations reduce the problem of finding particle distribution functions to the solution of the close set of fluid equations. This has been recently realized for the electron-ion plasma in the entire range of plasma collisionality. No particular choice of the initial distribution function is necessary to derive the longitudinal plasma susceptibility from the full set of kinetic equations. We will discuss new complete results for in electron-ion plasmas. The full description of the longitudinal plasma response is used in the derivation of damping and dispersion relations for electrostatic fluctuations such as Langmuir waves, ion-acoustic and entropy modes. Particle collision effects are rigorously accounted for. The Onsager's regression of fluctuations method is applied to derive dynamical form factor S(k,w) and Thomson scattering (TS) cross-section from the set of fluid equations. We will discuss application of the nonlocal hydrodynamics to the derivation of S(k,w). In particular, we will examine the importance of an entropy mode peak as the direct measure of ion temperature in TS experiments.

  14. 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.

  15. High resolution Thomson scattering for Joint European Torus (JET)

    SciTech Connect

    Pasqualotto, R.; Nielsen, P.; Gowers, C.; Beurskens, M.; Kempenaars, M.; Carlstrom, T.; Johnson, D.

    2004-10-01

    A Thomson scattering system is being developed for Joint European Torus with 15 mm spatial resolution and a foreseen accuracy for temperature better than 15% at a density of 10{sup 19} m{sup -3}. This resolution is required at the internal transport barrier and edge pedestal and it can not be fully achieved with the present light detection and ranging systems. The laser for this system is Nd:YAG, 5 Joule, 20 Hz. Scattering volumes from R=2.9 m to R=3.9 m are imaged onto 1 mm diameter fibers, with F/25 collection aperture. Two fibers are used per scattering volume. Using optical delay lines, three scattering volumes are combined in each of the 21 filter polychromators. The signals are recorded with transient digitizers, which allow the combined time delayed signals to be resolved. Knowledge of the time delay between signals allows the use of correlation techniques in determining signal levels. The ac output of the amplifier is used, which tolerates a higher level of background signal without affecting dynamic range. The noise resulting from plasma light is determined directly.

  16. The LIDAR Thomson scattering diagnostic on JET (invited)

    NASA Astrophysics Data System (ADS)

    Salzmann, H.; Bundgaard, J.; Gadd, A.; Gowers, C.; Hansen, K. B.; Hirsch, K.; Nielsen, P.; Reed, K.; Schrödter, C.; Weisberg, K.

    1988-08-01

    By combining the time-of-flight or LIDAR principle with a Thomson backscatter diagnostic, spatial profiles of the electron temperature and density are measured in a magnetically confined fusion plasma. This technique was realized for the first time on the JET tokamak. A ruby laser (3-J pulse energy, 300-ps pulse duration, 0.5-Hz repetition rate) together with a 700-MHz bandwidth detection and registration system yields a spatial resolution of about 12 cm. A spectrometer with six channels in the wavelength range 400-800 nm gives a dynamic range of the temperature measurements of 0.3-20 keV. The stray light problem in the backscatter geometry is overcome by spectral discrimination and gating of the photomultipliers. A ruby filter in the spectral channel containing the laser wavelength allows calibration of the vignetting along the line of sight by means of Raman scattering, enabling the measurement of density profiles. The low level of background signal due to the short integration time for a single spatial point yields low statistical errors (ΔTe /Te ≊6%, Δne /ne ≊4% at Te =6 keV, ne =3×1019 m-3 ). Goodness-of-fit tests indicate that the systematic errors are within the same limits. The system is described and examples of measurements are given.

  17. Electron beam final focus system for Thomson scattering at ELBE

    NASA Astrophysics Data System (ADS)

    Krämer, J. M.; Budde, M.; Bødker, F.; Irman, A.; Jochmann, A.; Kristensen, J. P.; Lehnert, U.; Michel, P.; Schramm, U.

    2016-09-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and divergences of about 10 mrad using the FFS.

  18. Thomson scattering calibration with ultrabright supercontinuum light source

    SciTech Connect

    Pasqualotto, R.; Alfier, A.

    2006-10-15

    The recently developed supercontinuum light source (SLS) finds a useful application in the calibration of a Thomson scattering (TS) diagnostic. When filter polychromators are used, the relative responsivity of the spectral channels is generally measured with a cw halogen light source from the dc output of the detectors, while the TS signal is measured from an ac output. In a TS system with optical delay lines, like in RFX-mod, a cw light source cannot discriminate differences between the relative responsivities of the positions that share the same polychromator but are connected to different delay lines: this can be achieved with a pulsed white light source instead. In addition a pulsed source with a time response similar to the TS signals would avoid any frequency response problem, because the same ac output of the detectors used for the TS signals could also be used for the calibration. An SLS produces a 5 ns Gaussian pulse, with a wide and smooth spectrum that covers the range of 550-1600 nm. The SLS provides a light source sufficiently bright to calibrate simultaneously all spectrometers. The experimental setup used for the calibration and obtained results are presented.

  19. Observation of Hot Remnant Islands using Fast Thomson Scattering

    NASA Astrophysics Data System (ADS)

    Morton, L. A.; Young, W. C.; den Hartog, D. J.; Hegna, C. C.; Parke, E.; Reusch, J. A.; Jacobson, C. M.

    2015-11-01

    The MST Fast Thomson Scattering Laser, operating with repetition rates of up to 100 kHz for up to 25 laser pulses, has allowed direct observation of temperature structures produced by tearing modes rotating at 10 - 20 kHz. A hot spot observed by Fast TS coincides with the O-point of the dominant m/n = 1/6 mode reconstructed by MHD modeling from edge magnetic measurements. The electron thermal conductivity inside the island is estimated from power balance to be 75 m2/s. However, MHD modeling also predicts overlap between the n =6 and n =7 islands, producing chaotic field lines and total loss of the island flux surfaces. Ensemble-averaged data from the slower burst laser (25 kHz for 8 pulses) also indicates overlap between the temperature fluctuations associated with these modes. These temperature fluctuation also exhibits the large higher-harmonic content that characterizes the hot island in the single-shot cases. DEBS finite-beta MHD simulations qualitatively reproduce MST temperature structures in certain cases. This work is supported by the US DoE and the NSF.

  20. Analysis of two-stage Joule-Thomson expansion

    NASA Astrophysics Data System (ADS)

    Narasaki, Katsuhiro

    2016-03-01

    To cool far infrared detectors for infrared observation or superconductor-insulator-superconductor (SIS) mixers for atmospheric observation, 1 K-class and 4 K-class coolers have been developed. These coolers consist of a two-stage Stirling cooler for pre-cooling and a Joule-Thomson (JT) cooler with a single JT valve. This paper presents descriptions of theoretical analyses based on enthalpy balance to elucidate the benefits of a two-stage JT valve type compared with those of a single JT valve type in a JT cooler. First, relational expressions for heat balance analysis of enthalpy for single-stage JT expansion are introduced. Then similar relational expressions for two-stage JT expansion are introduced under some assumptions. Results of heat balance analyses using several parameters demonstrated that, using two-stage JT expansion, the cooling capacity for a 1 K-class cooler is improved by 100%; that of a 4 K-class cooler is improved by about 30%.

  1. Central Thomson scattering upgrade on DIII-D

    SciTech Connect

    Nilson, D.G.; Stallard, B.W.; Carlstrom, T.N.; Hsieh, C.L.; Stockdale, R.E.

    1997-11-01

    The existing 36 channel Thomson scattering system on the DIII-D tokamak measures the plasma temperature and density in the core region. However, with the recent interest in core peaked density profiles, coverage needs to be extended into the magnetic axis. This paper addresses the technical issues involved with extending the viewing region from a major radius of 194 cm to 165 cm. At least one of the existing seven core laser beams will be rerouted to probe the plasma horizontally instead of vertically. To do this, a rigid extension of the existing laser/collection optics tower will be built to route the laser to a nearby tangential port. A fiber bundle array from one of the two existing core plasma collection optics sets will be rotated to allow up to 10 of the 36 core channels to view along this new beam path. A new in-vessel absorbing glass laser dump must be developed since there are no appropriate laser beam exit ports. The close proximity of this laser dump to the viewing region presents stray light issues that must be resolved to allow for an accurate density calibration using Rayleigh scattering in argon gas.

  2. Thomson scattering diagnostic for the TdeV tokamak

    NASA Astrophysics Data System (ADS)

    Côté, A.; Michaud, D.; Richard, N.; Neufeld, R.; Legros, C.

    1995-01-01

    The Thomson scattering diagnostic system on the TdeV tokamak (R/a=87/27 cm, BT=1.5 T, Ip<300 kA) routinely monitors electron temperature (Te) and density (ne). The scattered light from a vertically oriented Nd:YAG laser beam (E=0.8 J, f=50 Hz, Δt=30 ns) is analyzed by six polychromators looking at different vertical positions. Each polychromator splits the light into three spectral bands by means of bandpass interference filters. Avalanche photodiode detectors are used to measure the scattered radiation. These detectors also measure the plasma radiation (including bremsstrahlung) between laser pulses. Two polychromators are optimized for edge temperature measurements (50

  3. Improving Control in a Joule-Thomson Refrigerator

    NASA Technical Reports Server (NTRS)

    Borders, James; Pearson, David; Prina, Mauro

    2005-01-01

    A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system.

  4. Progress of microwave collective Thomson scattering in LHD

    NASA Astrophysics Data System (ADS)

    Tanaka, K.; Nishiura, M.; Kubo, S.; Shimozuma, T.; Saito, T.

    2015-12-01

    Microwave collective Thomson scattering (CTS) by using a 77 GHz gyrotron is routinely working in LHD and the improvements of the system is now underway. The targets of this diagnostic are measurements of energetic fast ion distribution and ion ratio. In the present system, 800kW 77 GHz gyrotron is injected horizontally and scattered radiation is received changing scattering angle. The system works with existence of electron cyclotron resonance layer. Thus, most of the power is absorbed at the layer like beam damping and stray radiation dramatically decreases. Gyrotron is modulated at 40 Hz, then, background ECE, which is signal in gyrotron off phase, is subtracted from scattered signal in gyrotron on phase. The perturbation of electron temperature due to the gyrotron injection is almost negligible. Temporal evolution of CTS spectrum is obtained by 32ch filter bank receiver through discharge and fine spectrum is obtained by 10 GHz sampling fast digitizer for 80 ms. Change of the width and asymmetry of CTS spectrum is observed after turning off of tangentially injected neutral beam (NB). This is qualitatively consistent with reduction of fast ion density. Preliminary data of ion ratio between hydrogen and helium are also obtained.

  5. X-Ray Thomson Scattering Without the Chihara Decomposition

    NASA Astrophysics Data System (ADS)

    Magyar, Rudolph; Baczewski, Andrew; Shulenburger, Luke; Hansen, Stephanie B.; Desjarlais, Michael P.; Sandia National Laboratories Collaboration

    X-Ray Thomson Scattering is an important experimental technique used in dynamic compression experiments to measure the properties of warm dense matter. The fundamental property probed in these experiments is the electronic dynamic structure factor that is typically modeled using an empirical three-term decomposition (Chihara, J. Phys. F, 1987). One of the crucial assumptions of this decomposition is that the system's electrons can be either classified as bound to ions or free. This decomposition may not be accurate for materials in the warm dense regime. We present unambiguous first principles calculations of the dynamic structure factor independent of the Chihara decomposition that can be used to benchmark these assumptions. Results are generated using a finite-temperature real-time time-dependent density functional theory applied for the first time in these conditions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Security Administration under contract DE-AC04-94AL85000.

  6. New Thomson scattering Laser Control for DIII-D

    SciTech Connect

    Makariou, C.C.; Stockdale, R.E.; Carlstrom, T.N.; Hsieh, C.L.; Bramson, G.

    1993-10-01

    A Laser Control system has been built for the DIII-D Scattering Diagnostic. This new system has provided the capability to place the laser probe pulses with one microsecond timing precision throughout the DIII-D shot. The new system fires the eight lasers with a programmable sequence which repeats ever 50 ms. If one wants to probe the plasma at a higher rate to study a fast paced event, the new control circuit can fire all charged lasers in rapid succession (BURST MODE). This burst rate is programmable. The new Laser Control system successfully replaced the previous control scheme which consisted of three VME Motorola 68030 computers (one host under UNIX VME V/68 and two interrupt driven targets under VME Exec. The old system was not successful due to the many VME interrupts needed to service the lasers. The new hardware approach is much more reliable. The old system still controls data acquisition and as a monitoring system since it does not have the burden of controlling the lasers. A brief description of the Thomson Scattering diagnostic will be presented with emphasis in the new upgraded laser firing control system and data acquisition timing control.

  7. Beam-shape effects in nonlinear Compton and Thomson scattering

    SciTech Connect

    Heinzl, T.; Seipt, D.; Kaempfer, B.

    2010-02-15

    We discuss intensity effects in collisions between beams of optical photons from a high-power laser and relativistic electrons. Our main focus is on the modifications of the emission spectra due to realistic finite-beam geometries. By carefully analyzing the classical limit we precisely quantify the distinction between strong-field QED Compton scattering and classical Thomson scattering. A purely classical, but fully covariant, calculation of the bremsstrahlung emitted by an electron in a plane-wave laser field yields radiation into harmonics, as expected. This result is generalized to pulses of finite duration and explains the appearance of line broadening and harmonic substructure as an interference phenomenon. The ensuing numerical treatment confirms that strong focusing of the laser leads to a broad continuum while higher harmonics become visible only at moderate focusing, and hence lower intensity. We present a scaling law for the backscattered photon spectral density which facilitates averaging over electron beam phase space. Finally, we propose a set of realistic parameters such that the observation of intensity-induced spectral red shift, higher harmonics, and their substructure becomes feasible.

  8. DIII-D Thomson Scattering Diagnostic Data Acquisition, Processing and Analysis Software

    SciTech Connect

    Middaugh, K.R.; Bray, B.D.; Hsieh, C.L.; McHarg, B.B., Jr.; Penaflor, B.G.

    1999-06-01

    One of the diagnostic systems critical to the success of the DIII-D tokamak experiment is the Thomson scattering diagnostic. This diagnostic is unique in that it measures local electron temperature and density: (1) at multiple locations within the tokamak plasma; and (2) at different times throughout the plasma duration. Thomson ''raw'' data are digitized signals of scattered light, measured at different times and locations, from the laser beam paths fired into the plasma. Real-time acquisition of this data is performed by specialized hardware. Once obtained, the raw data are processed into meaningful temperature and density values which can be analyzed for measurement quality. This paper will provide an overview of the entire Thomson scattering diagnostic software and will focus on the data acquisition, processing, and analysis software implementation. The software falls into three general categories: (1) Set-up and Control: Initializes and controls all Thomson hardware and software, synchronizes with other DIII-D computers, and invokes other Thomson software as appropriate. (2) Data Acquisition and Processing: Obtains raw measured data from memory and processes it into temperature and density values. (3) Analysis: Provides a graphical user interface in which to perform analysis and sophisticated plotting of analysis parameters.

  9. Spatial Expansion and Automation of the Pegasus Thomson Scattering Diagnostic System

    NASA Astrophysics Data System (ADS)

    Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Reusch, J. A.; Schlossberg, D. J.; Winz, G. R.

    2015-11-01

    The Pegasus Thomson scattering diagnostic system has recently undergone modifications to increase the spatial range of the diagnostic and automate the Thomson data collection process. Two multichannel spectrometers have been added to the original configuration, providing a total of 24 data channels to view the plasma volume. The new system configuration allows for observation of three distinct regions of the plasma: the local helicity injection (LHI) source (R ~ 67-73.8 cm), the plasma edge (R ~ 51.5-57.6 cm), and the plasma core (R ~ 35-41.1 cm). Each spectrometer utilizes a volume-phase holographic (VPH) grating and a gated-intensified CCD camera. The edge and the LHI spectrometers have been fitted with low-temperature VPH gratings to cover Te = 10 - 100 eV, while the core spectrometer has been fitted with a high-temperature VPH grating to cover Te = 0 . 1 - 1 . 0 keV. The additional spectrometers have been calibrated to account for detector flatness, detector linearity, and vignetting. Operation of the Thomson system has been overhauled to utilize LabVIEW software to synchronize the major components of the Thomson system with the Pegasus shot cycle and to provide intra-shot beam alignment. Multi-point Thomson scattering measurements will be obtained in the aforementioned regions of LHI and Ohmic discharges and will be compared to Langmuir probe measurements. Work supported by US DOE grant DE-FG02-96ER54375.

  10. Effects of environmental temperature on performance of the Joule-Thomson refrigerator

    NASA Astrophysics Data System (ADS)

    Hong, Yong-Ju; Kim, Hyobong; Park, Seong-Je

    2012-06-01

    Miniature Joule-Thomson refrigerators have been widely used for rapid cooling of infrared detectors, probes of cryosurgery, thermal cameras, missile homing head and guidance system, due to their special features of simple configuration, compact structure and rapid cool-down characteristics. Typical performance factors of the Joule-Thomson refrigerator are cool-down time, temperature of the cold end, running time and gas consumption. Those depend on operating conditions such as the pressure of the gas, thermal environment and etc.. In this study, experimental study of a miniature Joule- Thomson refrigerator with the gas pressure up to 12 MPa were performed to investigate the effects of the thermal environment (-40 ~ 50 °C). In experiments, to obtain the information of cool-down time, gas consumption and etc., the temperature of the cold end, mass flow rate and pressure of the argon gas are simultaneously measured. The Joule-Thomson refrigerator in cold thermal environment has rapid cool-down characteristics and small gas consumption. In the cold environmental condition, the Joule-Thomson refrigerator has high mass flow rate during cool-down process and in steady state.

  11. Godfrey Thomson and the Rise of University Pedagogical Study: A Recorded Lecture Delivered at the University of Edinburgh in November 1950 by Godfrey H. Thomson--A Transcript with Commentary

    ERIC Educational Resources Information Center

    Lawn, Martin; Deary, Ian J.; Brett, Caroline; Bartholomew, David J.

    2009-01-01

    Professor Sir Godfrey Thomson is one of the key foundational actors in the history of the educational sciences in the UK. At a time when educational studies and the study of educational psychology were very closely linked, in the decades of the mid-twentieth century, Thomson was a crucial figure in education research. He is known for his work on…

  12. 76 FR 70979 - Notice of Availability of the Draft Environmental Impact Statement for the Proposed Point Thomson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... infrastructure and produce liquid hydrocarbon resources near Point Thomson, Alaska. The proposed project includes... application on November 1, 2011. The Applicant's purpose is to produce liquid hydrocarbons and delineate and evaluate hydrocarbon resources in the Point Thomson area. Two natural gas production wells have...

  13. 75 FR 1015 - Directing Certain Actions with Respect to Acquisition and Use of Thomson Correctional Center to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    .... (Presidential Sig.) THE WHITE HOUSE, Washington, December 15, 2009 [FR Doc. 2010-227 Filed 1-7-10; 8:45 am... expeditiously as possible with respect to the facility known as the Thomson Correctional Center (TCC) in Thomson, Illinois: 1. The Attorney General shall acquire and activate the TCC as a United States Penitentiary,...

  14. Progress on Thomson scattering in the Pegasus Toroidal Experiment

    NASA Astrophysics Data System (ADS)

    Schlossberg, D. J.; Bongard, M. W.; Fonck, R. J.; Schoenbeck, N. L.; Winz, G. R.

    2013-11-01

    A novel Thomson scattering system has been implemented on the Pegasus Toroidal Experiment where typical densities of 1019 m-3 and electron temperatures of 10 to 500 eV are expected. The system leverages technological advances in high-energy pulsed lasers, volume phase holographic (VPH) diffraction gratings, and gated image intensified (ICCD) cameras to provide a relatively low-maintenance, economical, robust diagnostic system. Scattering is induced by a frequency-doubled, Q-switched Nd:YAG laser (2 J at 532 nm, 7 ns FWHM pulse) directed to the plasma over a 7.7 m long beam path, and focused to < 3 mm throughout the collection region. Inter-shot beam alignment is adjustable with less than a 0.01 mm spatial resolution in the collection region. A custom lens system collects scattered photons at radii 15 cm to 85 cm from the machine's center, at ~ F/6 with 14 mm radial resolution. The initial configuration provides scattering measurements at 12 spatial locations and 12 simultaneous background measurements at adjacent locations. If plasma background subtraction proves to be insignificant, these background channels will be used as viewing channels. Each spectrometer supports 8 spatial channels and can provide 8 or more spectral bins each. The spectrometers use high-efficiency VPH transmission gratings (eff. > 80%) and fast-gated ICCDs (gate > 2 ns, Gen III intensifier) with high-throughput (F/1.8), achromatic lensing. A stray light mitigation facility has been implemented, consisting of a multi-aperture optical baffle system and a simple beam dump. Successful stray light reduction has enabled detection of scattered signal, and Rayleigh scattering has been used to provide a relative calibration. Initial temperature measurements have been made and data analysis algorithms are under development.

  15. Kinetic Enhancement of Raman Backscatter, and Electron Acoustic Thomson Scatter

    SciTech Connect

    Strozzi, D J; Williams, E A; Langdon, A B; Bers, A

    2006-09-01

    1-D Eulerian Vlasov-Maxwell simulations are presented which show kinetic enhancement of stimulated Raman backscatter (SRBS) due to electron trapping in regimes of heavy linear Landau damping. The conventional Raman Langmuir wave is transformed into a set of beam acoustic modes [L. Yin et al., Phys. Rev. E 73, 025401 (2006)]. For the first time, a low phase velocity electron acoustic wave (EAW) is seen developing from the self-consistent Raman physics. Backscatter of the pump laser off the EAW fluctuations is reported and referred to as electron acoustic Thomson scatter. This light is similar in wavelength to, although much lower in amplitude than, the reflected light between the pump and SRBS wavelengths observed in single hot spot experiments, and previously interpreted as stimulated electron acoustic scatter [D. S. Montgomery et al., Phys. Rev. Lett. 87, 155001 (2001)]. The EAW observed in our simulations is strongest well below the phase-matched frequency for electron acoustic scatter, and therefore the EAW is not produced by it. The beating of different beam acoustic modes is proposed as the EAW excitation mechanism, and is called beam acoustic decay. Supporting evidence for this process, including bispectral analysis, is presented. The linear electrostatic modes, found by projecting the numerical distribution function onto a Gauss-Hermite basis, include beam acoustic modes (some of which are unstable even without parametric coupling to light waves) and a strongly-damped EAW similar to the observed one. This linear EAW results from non-Maxwellian features in the electron distribution, rather than nonlinearity due to electron trapping.

  16. Clogging of Joule-Thomson Devices in Liquid Hydrogen Handling

    NASA Technical Reports Server (NTRS)

    Jurns, John M.; Lekki, John D.

    2009-01-01

    Experiments conducted at the NASA Glenn Research Center indicate that Joule-Thomson devices become clogged when transferring liquid hydrogen (LH2), operating at a temperature range from 20.5 to 24.4 K. Blockage does not exist under all test conditions but is found to be sensitive to the inlet temperature of the LH2. At a subcooled inlet temperature of 20.5 K blockage consistently appears but is dissipated when the fluid temperature is raised above 24.5 K. Clogging steadily reduced flow rate through the orifices, eventually resulting in complete blockage. This tendency poses a threat to spacecraft cryogenic propulsion systems that would utilize passive thermal control systems. We propose that this clogging is due to trace amounts of neon in the regular LH2 supply. Neon freezes at 24.5 K at one atmosphere pressure. It is postulated that between 20.5 and 24.5 K, neon remains in a meta-stable, supercooled liquid state. When impacting the face of an orifice, liquid neon droplets solidify and accumulate, blocking flow over time. The purpose of this test program was to definitively quantify the phenomena experimentally by obtaining direct visual evidence of orifice clogging by accretion from neon contaminates in the LH2 flow stream, utilizing state of the art imaging technology. Tests were conducted with LH2 flowing in the temperature range of 20.5 to 24.4 K. Additional imaging was also done at LH2 temperatures with no flow to verify clear view through the orifice.

  17. Conceptual design of new polychromator on Thomson scattering system to measure Z{sub eff}

    SciTech Connect

    Lee, Jongha; Oh, Seungtae; Wi, Hanmin; Oh, Youngkook; Yamada, I.; Narihara, K.; Kawahata, K.; Jeon, Jongsu

    2012-10-15

    To measure the Z{sub eff} with electron temperature (T{sub e}) and electron density (n{sub e}) profiles at the same time and the same position in the KSTAR tokamak, we design a new polychromator for Thomson scattering system that has additional function. The additional function is measuring bremsstrahlung intensity to calculate Z{sub eff} independent of Thomson signals. For this new polychromator, we design and fabricate a collimation lens set, and interference filter that has center wavelength of 523 nm and 2 nm FWHM. Finally, we change the lenses, detector diodes, and add the bremsstrahlung filter on the KSTAR edge Thomson scattering polychromator. Then this new polychromator was tested by Tungsten light and monochromator.

  18. Synoptic maps constructed from brightness observations of Thomson scattering by heliospheric electrons

    NASA Technical Reports Server (NTRS)

    Hick, P.; Jackson, B.; Schwenn, R.

    1991-01-01

    Observations of the Thomson scattering brightness by electrons in the inner heliosphere provide a means of probing the heliospheric electron distributions. An extensive data base of Thomson scattering observations, stretching over many years, is available from the zodiacal light photometers on board the two Helios spacecraft. A survey of these data is in progress, presenting these scattering intensities in the form of synoptic maps for successive Carrington rotations. The Thomson scattering maps reflect conditions at typically several tenths of an astronomical unit from the sun. Some representative examples from the survey in comparison with other solar/heliospheric data, such as in situ observations of the Helios plasma experiment and synoptic maps constructed from magnetic field, H alpha and K-coronameter data are presented. The comparison will provide some information about the extension of solar surface features into the inner heliosphere.

  19. Improvements of data quality of the LHD Thomson scattering diagnostics in high-temperature plasma experiments

    SciTech Connect

    Yamada, I.; Narihara, K.; Funaba, H.; Hayashi, H.; Kohmoto, T.; Takahashi, H.; Shimozuma, T.; Kubo, S.; Yoshimura, Y.; Igami, H.; Tamura, N.

    2010-10-15

    In Large Helical Device (LHD) experiments, an electron temperature (T{sub e}) more than 15 keV has been observed by the yttrium-aluminum-garnet (YAG) laser Thomson scattering diagnostic. Since the LHD Thomson scattering system has been optimized for the temperature region, 50 eV{<=}T{sub e}{<=}10 keV, the data quality becomes worse in the higher T{sub e} region exceeding 10 keV. In order to accurately determine T{sub e} in the LHD high-T{sub e} experiments, we tried to increase the laser pulse energy by simultaneously firing three lasers. The technique enables us to decrease the uncertainties in the measured T{sub e}. Another signal accumulation method was also tested. In addition, we estimated the influence of high-energy electrons on T{sub e} obtained by the LHD Thomson scattering system.

  20. 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.

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

    SciTech Connect

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

    2012-12-15

    An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f /3) transmission grating spectrometer equipped with an intensified charged coupled device camera. The system is able to measure electron density (n{sub e}) and temperature (T{sub e}) profiles close to the output of the plasma source and, at a distance of 1.25 m, just in front of a target. The detection system enables to measure 50 spatial channels of about 2 mm each, along a laser chord of 95 mm. By summing a total of 30 laser pulses (0.6 J, 10 Hz), an observational error of 3% in n{sub e} and 6% in T{sub e} (at n{sub e}= 9.4 Multiplication-Sign 10{sup 18} m{sup -3}) can be obtained. Single pulse Thomson scattering measurements can be performed with the same accuracy for n{sub e} > 2.8 Multiplication-Sign 10{sup 20} m{sup -3}. The minimum measurable density and temperature are n{sub e} < 1 Multiplication-Sign 10{sup 17} m{sup -3} and T{sub e} < 0.07 eV, respectively. In addition, using the Rayleigh peak, superimposed on the Thomson scattered spectrum, the neutral density (n{sub 0}) of the plasma can be measured with an accuracy of 25% (at n{sub 0}= 1 Multiplication-Sign 10{sup 20} m{sup -3}). In this report, the performance of the Thomson scattering system will be shown along with unprecedented accurate Thomson-Rayleigh scattering measurements on a low-temperature argon plasma expansion into a low-pressure background.

  2. Onciderini Thomson, 1860 (Coleoptera: Cerambycidae: Lamiinae) types of The Natural History Museum (BMNH).

    PubMed

    Nearns, Eugenio H; Barclay, Maxwell V L; Tavakilian, Gérard L

    2014-01-01

    The primary types of Onciderini Thomson, 1860 deposited at The Natural History Museum (BMNH), London, United Kingdom, are catalogued and illustrated. Data on the original combination, current name, and type locality are verified and presented. There are 39 primary types of Onciderini including 11 in Oncideres Lacordaire, 1830; and three each in Hesycha Fairmaire & Germain, 1859; Hypselomus Perty, 1832; Lamia Fabricius, 1775; and Tybalmia Thomson, 1868. Of the 39 primary types, 17 were described by H. W. Bates and seven by F. P. Pascoe. Five lectotypes are designated. Notes on additional Onciderini types once believed to be deposited at the BMNH are presented.  PMID:25283108

  3. Short-interval multi-laser Thomson scattering measurements of hydrogen pellet ablation in LHD.

    PubMed

    Yasuhara, R; Sakamoto, R; Yamada, I; Motojima, G; Hayashi, H

    2014-11-01

    Thomson scattering forms an important aspect of measuring the electron density and temperature profiles of plasmas. In this study, we demonstrate Thomson scattering measurements obtained over a short interval (<1 ms) by using an event triggering system with a multi-laser configuration. We attempt to use our system to obtain the electron temperature and density profiles before and immediately after pellet injection into the large helical device. The obtained profiles exhibit dramatic changes after pellet injection as per our shot-by-shot measurements. We believe that this measurement technique will contribute towards a better understanding of the physics of the pellet deposition. PMID:25430235

  4. Experimental evidence of the effect of heat flux on thomson scattering off ion acoustic waves

    PubMed

    Amiranoff; Baton; Huller; Malka; Modena; Mounaix; Galloudec; Rousseaux; Salvati

    2000-02-01

    Thomson self-scattering measurements are performed in a preionized helium gas jet plasma at different locations along the laser propagation direction. A systematic and important variation of the intensity ratio between the blue and the red ion spectral components is observed, depending on whether the location of the probed region is in front of or behind the focal plane. A simple theoretical calculation of Thomson scattering shows that this behavior can be qualitatively understood in terms of a deformation of the electron distribution function due to the return current correlated with the classical thermal heat flux. PMID:11046481

  5. Short-interval multi-laser Thomson scattering measurements of hydrogen pellet ablation in LHD

    SciTech Connect

    Yasuhara, R. Sakamoto, R.; Yamada, I.; Motojima, G.; Hayashi, H.

    2014-11-15

    Thomson scattering forms an important aspect of measuring the electron density and temperature profiles of plasmas. In this study, we demonstrate Thomson scattering measurements obtained over a short interval (<1 ms) by using an event triggering system with a multi-laser configuration. We attempt to use our system to obtain the electron temperature and density profiles before and immediately after pellet injection into the large helical device. The obtained profiles exhibit dramatic changes after pellet injection as per our shot-by-shot measurements. We believe that this measurement technique will contribute towards a better understanding of the physics of the pellet deposition.

  6. Mass- and energy-analyses of ions from plasma by means of a miniature Thomson spectrometer

    SciTech Connect

    Sadowski, M. J.; Czaus, K.; Malinowski, K.; Skladnik-Sadowska, E.; Zebrowski, J.

    2009-05-15

    The paper presents an improved version of a miniature mass-spectrometer of the Thomson-type, which has been adopted for ion analysis near the dense plasma region inside a vacuum chamber. Problems connected with the separation of ions from plasma streams are considered. Input diaphragms and pumping systems, needed to ensure good vacuum inside the analyzing region, are described. The application of the miniature Thomson-type analyzer is illustrated by ion parabolas recorded in plasma-focus facility and rod plasma injector experiment. A quantitative analysis of the recorded ion parabolas is presented. Factors influencing accuracy of the ion analysis are discussed and methods of the spectrometer calibration are described.

  7. An ethics ensemble: abortion, Thomson, Finnis and the case of the violin-player.

    PubMed

    Williams, Melanie

    2004-09-01

    This paper considers approaches to the ethics of abortion and putative links to "rights" debates. In particular, it revisits two papers on the topic from the early 1970's, written by Judith Jarvis Thomson and John Finnis respectively. Consideration of the discourse produced by these papers to some extent reveals the strategic importance of linguistic and conceptual organisation--the rhetorical forces underlying claims to disinterested, analytical standing. In particular, the paper reviews the practical ethics analogy proposed by Thomson; the deployment of "Hohfeldian" rights analysis by John Finnis, the link to the abortion debate and the broader implications of such deployment in its relation to current "rights" discourse. PMID:16602213

  8. Mass- and energy-analyses of ions from plasma by means of a miniature Thomson spectrometer

    NASA Astrophysics Data System (ADS)

    Sadowski, M. J.; Czaus, K.; Malinowski, K.; Skladnik-Sadowska, E.; Zebrowski, J.

    2009-05-01

    The paper presents an improved version of a miniature mass-spectrometer of the Thomson-type, which has been adopted for ion analysis near the dense plasma region inside a vacuum chamber. Problems connected with the separation of ions from plasma streams are considered. Input diaphragms and pumping systems, needed to ensure good vacuum inside the analyzing region, are described. The application of the miniature Thomson-type analyzer is illustrated by ion parabolas recorded in plasma-focus facility and rod plasma injector experiment. A quantitative analysis of the recorded ion parabolas is presented. Factors influencing accuracy of the ion analysis are discussed and methods of the spectrometer calibration are described.

  9. Raman calibration of the HT-7 yttrium aluminum garnet Thomson scattering for electron density measurements

    SciTech Connect

    Zang Qing; Zhao Junyu; Gao Xiang; Shi Lingwei; Zhang Tao; Xi Xiaoqi; Yang Li; Hu Qingsheng; Sajjad, S.

    2007-11-15

    A multipulse neodym doped yttrium aluminum garnet laser Thomson scattering system calibrated by the anti-Stokes rotational Raman scattering from nitrogen gas had been developed in the HT-7 superconducting Tokmak. By virtue of this system, measured electron density results of the plasma were obtained. The results showed good repeatability and its total uncertainty was estimated to be {+-}18%.

  10. The Case of Perrin and Thomson: An Example of the Use of a Mini-Corpus

    ERIC Educational Resources Information Center

    Banks, David

    2005-01-01

    Although recent trends have been towards large corpora, there is a valid place for the study of small corpora. This article is an example of one such study using a corpus of late 19th century texts, consisting of 1783 words in French by Perrin, and 2824 words in English by Thomson. Perrin uses more first person pronouns in a wider range of…

  11. Multipoint Thomson Scattering Diagnostic For The TCABR Tokamak With Centimeter Spatial Resolution

    SciTech Connect

    Alonso, M. P.; Varandas, C. A. F.; Berni, L. A.; Severo, J. H.; Borges, F. O.; Elizondo, J. I.; Galvao, R. M. O.; Machida, M.

    2008-04-07

    This paper describes a multi-point Thomson scattering system that is being developed for the TCABR tokamak based on a signal delay technique, which allows the determination of the electron temperature and plasma density radial profiles, with approximately 1 cm spatial resolution, employing just one spectrometer.

  12. Euconnus franzi Asenjo, new name on  Neotropical Euconnus Thomson (Coleoptera: Staphylinidae: Scydmaeninae: Glandulariini).

    PubMed

    Asenjo, Angélico

    2016-01-01

    During my doctoral studies, while assembling a taxonomic list of the Staphylindae of Brazil (Asenjo et al. 2013: 229), I found a primary junior homonym in the genus Euconnus Thomson. The purpose of this note is to provide a correction to this problem. PMID:27394212

  13. Improvement in data processing of Thomson scattering diagnostic on HL-2A tokamak

    NASA Astrophysics Data System (ADS)

    Liu, C. H.; Wang, Y. Q.; Feng, Z.; Huang, Y.

    2015-12-01

    There are two types of digitizers to acquire the values of Thomson scattering signals in HL-2A tokamak. One is charge-sensitive analogue-to-digital converters (Q-ADCs) which simply integrates the signal over a gate interval, and the other is transient recorders with 12 bits resolution and 1 GHz sampling rate at each channel. Because the Thomson scattering diagnostic is prone to electrical noisy environment, in which Q-switched Nd:YAG lasers and polychromators are located closely to the HL-2A device, the high speed transient digitizers are found helpful to reduce noise overlapped in Thomson scattering signals. After triggered by the front of TTL pulse generated by laser light, data acquisition is fulfilled from -250 ns to 250 ns, so that the temporal evolution of Thomson scattering signals is obtained. A Gaussian function is utilized to fit the pulse shape of the digitized scattering signal by nonlinear least square methods. By pulse fitting and data processing, the influence of background perturbations is substantially reduced.

  14. Mechanical design aspects of the Advanced Toroidal Facility Thomson scattering diagnostic

    SciTech Connect

    Shipley, W.D.; Kindsfather, R.R.; Rasmussen, D.A.

    1987-01-01

    A two-dimensional Thomson scattering system has been designed for the Advanced Toroidal Facility (ATF), a torsatron experiment at the Oak Ridge National Laboratory (ORNL). The system is a modification of the Thomson scattering system used on the Impurity Study Experiment (ISX-B) tokamak. It will provide measurements of electron temperature (T/sub e/) and density (n/sub e/) at 15 points along a vertical chord. With multiple shots, a T/sub e/ and n/sub e/ map of a toroidal cross section of ATF can be obtained. The horizontal Thomson scattering viewing port is offset by 15/sup 0/ toroidally from the ports through which the vertical laser beam passes. The modifications to the ISX-B Thomson scattering system are either changes required to adapt the system to the ATF device geometry or changes that result in improvements to the original system. This paper deals with the mechanical design aspects of the laser light baffle plates that reduce the amount of extraneous light entering the plasma, the upper and lower vacuum extensions that contain the baffles and attach to the ATF vacuum vessel, the entrance window assembly, the laser dump assembly, the viewing window and shutter assembly, and the alignment target mechanism and drive used to determine the ampping of data points in the plasma cross section.

  15. Joseph John Thomson's models of matter and radiation in the early 1890s.

    PubMed

    Bordoni, Stefano

    In the late nineteenth century, Joseph John Thomson moved away from Maxwell's specific theoretical models of matter and energy, even though he continued to rely on the general framework of Maxwell's electromagnetic theory. In his 1893 book, he accomplished the conceptual drift towards a discrete model for matter, electricity, and fields. In Thomson's model, energy was linked to tubes of force, in particular to the aether contained in them and surrounding them: the energy was the kinetic energy of aether, of both a rotational and translational kind. Starting from Maxwell's electromagnetic fields, namely stresses propagating through a continuous solid medium, Thomson arrived at a representation of fields as a sea of discrete units carrying energy and momentum. He tried to transform Maxwell's theory into a unified picture in which atomic models of matter stood beside atomic models of fields. In 1904 his interpretation of X-rays was based on the integration between two complementary features of electromagnetic radiation, the continuity and the discreteness, and on some kind of fibrous aether. In recent secondary literature, the problematic conceptual link between J. J. Thomson's theory and contemporary theories on electromagnetic radiation has been underestimated. On the contrary, in the first half of the twentieth century, some physicists inquired into that link, and a widespread debate emerged, misunderstandings included. PMID:25029824

  16. Mirror system for collecting Thomson-scattered light in a tangential direction.

    PubMed

    Barth, C J; Grobben, B J; Verhaag, G C

    1994-09-01

    We describe an optical system for collecting Thomson-scattering light in the tangential direction of a tokamak. The key part of the optics is a set of mirrors arranged as a Venetian blind. This system makes it possible to look around the corner of the tokamak vessel. Design considerations and test performance are presented. PMID:20936021

  17. A reflective image-rotating periscope for spatially resolved Thomson-scattering experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Katz, J.; Ross, J. S.; Sorce, C.; Froula, D. H.

    2013-12-01

    A reflective image rotating periscope has been deployed on the Thomson-scattering system at the Laboratory for Laser Energetics, enabling the capability to make spatially resolved measurements of plasma conditions using either the 2ω (527-nm) or 4ω (263-nm) probe beam. The spectral content of ion-acoustic and electron plasma wave Thomson-scattering features are analyzed along the probe beam's axis of propagation using a pair of imaging Czerny-Turner spectrometers. A method for calculating image rotation was applied to design a translating periscope mirror assembly that provides fine adjustment of the image orientation at the spectrometer input plane. Spectrally dispersed Thomson-scattering signals are recorded using time-gated intensified charge-coupled-device cameras. Spectral resolution of up to 0.03 nm (0.2 nm) is achieved using a 1-m (0.3-m) spectrometer, allowing for simultaneous measurements of the ion-acoustic and electron plasma wave features. The optical system's 20-μm imaging resolution provides excellent noise rejection and spatial definition of the Thomson-scattering volume.

  18. X-ray generation at SPARC_LAB Thomson backscattering source

    NASA Astrophysics Data System (ADS)

    Giribono, Anna

    2015-03-01

    In the last years, the phase contrast X-ray imaging became a very promising technique, in particular for medical application. At this purpose, several compact and very performing X-ray sources are growing up all around the world and most of them are based upon the Thomson backscattering phenomenon. This is the context of the SPARC_LAB Thomson backscattering X-ray source, presently under commissioning at INFN-LNF. Here a head-on collision is foreseen at the Thomson Interaction Point between a 30 to 150MeV electron beam and the 250TW FLAME laser pulse, providing a photon energy tunability in the range from 20 to 250keV. The first experiment foresees the generation of a X-ray beam, useful for X-ray imaging of mammographic phantoms with the phase contrast technique. In February 2014, the SPARC_LAB Thomson source produced its very first X-ray beam. The shift and the obtained results are presented.

  19. A New Lease of Life for Thomson's Bonds Model of Intelligence

    ERIC Educational Resources Information Center

    Bartholomew, David J.; Deary, Ian J.; Lawn, Martin

    2009-01-01

    Modern factor analysis is the outgrowth of Spearman's original "2-factor" model of intelligence, according to which a mental test score is regarded as the sum of a general factor and a specific factor. As early as 1914, Godfrey Thomson realized that the data did not require this interpretation and he demonstrated this by proposing what became…

  20. 75 FR 49528 - Thomson Reuters Legal, Legal Editorial Operations Cleveland Office Including Workers Whose...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... FR 39047). The notice was amended on July 27, 2010 to include workers whose unemployment insurance... Including Workers Whose Unemployment Insurance (UI) Wages Are Paid Through West Services, Inc. and West... unemployment insurance (UI) tax account under the name West Publishing Corporation, a Thomson Reuters...

  1. Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering.

    PubMed

    Follett, R K; Edgell, D H; Henchen, R J; Hu, S X; Katz, J; Michel, D T; Myatt, J F; Shaw, J; Froula, D H

    2015-03-01

    A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPD EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability. PMID:25871046

  2. Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering

    SciTech Connect

    Follett, R. K.; Edgell, D. H.; Henchen, R. J.; Hu, S. X.; Katz, J.; Michel, D. T.; Myatt, J. F.; Shaw, J.; Froula, D. H.

    2015-03-26

    A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPD EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability.

  3. Short Pulse High Brightness X-ray Production with the PLEIADES Thomson Scattering Source

    SciTech Connect

    Anderson, S G; Barty, C P J; Betts, S M; Brown, W J; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Hartemann, F V; Kuba, J; LaSage, G P; Rosenzweig, J B; Slaughter, D R; Springer, P T; Tremaine, A M

    2003-07-01

    We describe PLEIADES, a compact, tunable, high-brightness, ultra-short pulse, Thomson x-ray source. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm{sup 2}/mrad{sup 2}. Initial results are reported and compared to theoretical calculations.

  4. Double-confocal resonator for X-ray generation via intracavity Thomson scattering

    SciTech Connect

    Xie, M.

    1995-12-31

    There has been a growing interest in developing compact X-ray sources through Thomson scattering of a laser beam by a relativistic electron beam. For higher X-ray flux it is desirable to have the scattering to occur inside an optical resonator where the laser power is higher. In this paper I propose a double-confocal resonator design optimized for head-on Thomson scattering inside an FEL oscillator and analyze its performance taking into account the diffraction and FEL gain. A double confocal resonator is equivalent to two confocal resonators in series. Such a resonator has several advantages: it couples electron beam through and X-ray out of the cavity with holes on cavity mirrors, thus allowing the system to be compact; it supports the FEL mode with minimal diffraction loss through the holes; it provides a laser focus in the forward direction for a better mode overlap with the electron beam; and it provides a focus at the same location in the backward direction for higher Thomson scattering efficiency; in addition, the mode size at the focal point and hence the Rayleigh range can be adjusted simply through intracavity apertures; furthermore, it gives a large mode size at the mirrors to reduce power loading. Simulations as well as analytical results will be presented. Also other configurations of intracavity Thomson scattering where the double-confocal resonator could be useful will be discussed.

  5. Initial simultaneous Thomson-scattering measurements in the TMX-U tandem mirror

    SciTech Connect

    Goodman, R.K.; Rognlien, T.D.

    1983-12-27

    In this report, we briefly describe the TMX-U Thomson-scattering systems; we compare TMX-U velocity-distribution measurements with computer modeling; and we present and discuss our first simultaneous measurements of end-plug and central-cell electron temperatures.

  6. 78 FR 50322 - Amendment of Class E Airspace; Point Thomson, AK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... controlled airspace at Point Thomson, AK (78 FR 30797). Interested parties were invited to participate in... a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979..., 40113, 40120; E. O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0 2. The...

  7. First results from the Thomson scattering diagnostic on Proto-MPEX

    SciTech Connect

    Biewer, Theodore M; Meitner, Steven J; Rapp, Juergen

    2016-01-01

    A Thomson scattering diagnostic has been successfully implemented on the prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory. The diagnostic collects the light scattered by plasma electrons and spectroscopically resolves the Doppler shift imparted to the light by the velocity of the electrons. The spread in velocities is proportional to the electron temperature, while the total number of photons is proportional to the electron density. Thomson scattering is a technique used on many devices to measure the electron temperature (Te) and electron density (ne) of the plasma. A challenging aspect of the technique is to discriminate the small number of Thomson scattered photons against the large peak of background photons from the high-power laser used to probe the plasma. A variety of methods are used to mitigate the background photons in Proto-MPEX, including Brewster angled windows, viewing dumps, and light baffles. With these methods, first results were measured from Argon plasmas in Proto-MPEX, indicating Te ~ 2 eV and ne ~ 1x1019 m-3. The configuration of the Proto-MPEX Thomson scattering diagnostic will be described and plans for improvement will be given.

  8. 3 CFR - Directing Certain Actions With Respect to Acquisition and Use of Thomson Correctional Center To...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Correctional Center (TCC) in Thomson, Illinois: 1. The Attorney General shall acquire and activate the TCC as a... sufficient portion of the TCC to serve as a detention facility to be operated by the Department of Defense in... General, shall prepare the TCC for secure housing of detainees currently held at the Guantanamo Bay...

  9. Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System

    DOE Data Explorer

    Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

    2016-08-12

    This public data set contains openly-documented, machine readable digital research data corresponding to figures published in G.M. Bodner et al., 'Control and Automation of the Pegasus Multi-point Thomson Scattering System,' Rev. Sci. Instrum. 87, 11E523 (2016).

  10. Performance analysis of small capacity liquid nitrogen generator based on Joule-Thomson refrigerator coupled with air separation membrane

    NASA Astrophysics Data System (ADS)

    Piotrowska-Hajnus, Agnieszka; Chorowski, Maciej

    2012-06-01

    Joule - Thomson small capacity refrigerators supplied with gas mixture are studied theoretically and experimentally for a variety of applications. They can be especially promising when coupled with membrane air separators. We present liquid nitrogen generation system based on Joule - Thomson cooler joined with air separation membrane. Hollow fiber membrane is used for nitrogen separation from compressed and purified atmospheric air. Joule-Thomson refrigerator operates with a dedicated nitrogen - hydrocarbons mixture and provides a cooling power used for the separated nitrogen liquefaction. Special attention has been paid to a heat exchanger coupling the Joule- Thomson refrigerator with the membrane air separator. This paper describes the system design, the procedure of its working parameters optimization and tests results.

  11. Fast ion dynamics measured by collective Thomson scattering

    NASA Astrophysics Data System (ADS)

    Bindslev, Henrik

    2001-10-01

    In magnetically confined fusion plasmas, fast ions, from fusion reactions and auxiliary heating, typically carry a third of the total plasma kinetic energy, and even more of the free energy. This free energy must be channelled into heating the bulk plasma, but is also available for driving waves in the plasma, affecting confinement of bulk and fast ions. We know that fast ions can drive Alfvén waves, affect sawteeth and fishbones. In turn all three can redistribute or ejects the fast ions. Wave particle interaction, also the basis of Ion Cyclotron Resonance Heating (ICRH), depends crucially on the phase space distribution of the fast ions. Conversely the effect waves and instabilities have of fast ions will manifest itself in the detail of the fast ion phase space distribution. To explore the dynamics of fast ions and their interaction with the plasma thus begs for measurements of the fast ion distribution resolved in space, time and velocity. This has long been the promise of Collective Thomson Scattering (CTS) [1]. First demonstrated at JET [2]and subsequently at TEXTOR [3], CTS is living up to its promise and is now contributing to the understanding of fast ion dynamics. With the TEXTOR CTS, temporal behaviours of fast ion velocity distributions have been uncovered. The fast ion populations are produced by ICRH and Neutral Beam Injection (NBI). At sawteeth, we see clear variations in the fast ion population, which depend on ion energy, pitch angle and spatial location. Investigating the region just inside the inversion radius, we find that ions with small parallel energy, and with perpendicular energies up to a soft threshold well above thermal, are lost from the high field side near the inversion radius, while more energetic ions in the same pitch angle range remain insensitive to the sawteeth. The sensitive population could include the potato and stagnation orbit particles identified theoretically as being sensitive the sawteeth [4]. Under the same conditions

  12. A new dump system design for stray light reduction of Thomson scattering diagnostic system on EAST.

    PubMed

    Xiao, Shumei; Zang, Qing; Han, Xiaofeng; Wang, Tengfei; Yu, Jin; Zhao, Junyu

    2016-07-01

    Thomson scattering (TS) diagnostic is an important diagnostic for measuring electron temperature and density during plasma discharge. However, the measurement of Thomson scattering signal is disturbed by the stray light easily. The stray light sources in the Experimental Advanced Superconducting Tokamak (EAST) TS diagnostic system were analyzed by a simulation model of the diagnostic system, and simulation results show that the dump system is the primary stray light source. Based on the optics theory and the simulation analysis, a novel dump system including an improved beam trap was proposed and installed. The measurement results indicate that the new dump system can reduce more than 60% of the stray light for the diagnostic system, and the influence of stray light on the error of measured density decreases. PMID:27475558

  13. Kinetic Transition Networks for the Thomson Problem and Smale's Seventh Problem

    NASA Astrophysics Data System (ADS)

    Mehta, Dhagash; Chen, Jianxu; Chen, Danny Z.; Kusumaatmaja, Halim; Wales, David J.

    2016-07-01

    The Thomson problem, arrangement of identical charges on the surface of a sphere, has found many applications in physics, chemistry and biology. Here, we show that the energy landscape of the Thomson problem for N particles with N =132 , 135, 138, 141, 144, 147, and 150 is single funneled, characteristic of a structure-seeking organization where the global minimum is easily accessible. Algorithmically, constructing starting points close to the global minimum of such a potential with spherical constraints is one of Smale's 18 unsolved problems in mathematics for the 21st century because it is important in the solution of univariate and bivariate random polynomial equations. By analyzing the kinetic transition networks, we show that a randomly chosen minimum is, in fact, always "close" to the global minimum in terms of the number of transition states that separate them, a characteristic of small world networks.

  14. Imaging x-ray Thomson scattering spectrometer design and demonstration (invited)

    SciTech Connect

    Gamboa, E. J.; Huntington, C. M.; Trantham, M. R.; Keiter, P. A.; Drake, R. P.; Montgomery, D. S.; Benage, J. F.; Letzring, S. A.

    2012-10-15

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  15. Conceptual design of a divertor Thomson scattering diagnostic for NSTX-U.

    PubMed

    McLean, A G; Soukhanovskii, V A; Allen, S L; Carlstrom, T N; LeBlanc, B P; Ono, M; Stratton, B C

    2014-11-01

    A conceptual design for a divertor Thomson scattering (DTS) diagnostic has been developed for the NSTX-U device to operate in parallel with the existing multipoint Thomson scattering system. Higher projected peak heat flux in NSTX-U will necessitate application of advanced magnetics geometries and divertor detachment. Interpretation and modeling of these divertor scenarios will depend heavily on local measurement of electron temperature, Te, and density, ne, which DTS provides in a passive manner. The DTS design for NSTX-U adopts major elements from the successful DIII-D DTS system including 7-channel polychromators measuring Te to 0.5 eV. If implemented on NSTX-U, the divertor TS system would provide an invaluable diagnostic for the boundary program to characterize the edge plasma. PMID:25430390

  16. First measurement of electron temperature from signal ratios in a double-pass Thomson scattering system

    SciTech Connect

    Tojo, H.; Itami, K.; Hatae, T.; Ejiri, A.; Yamaguchi, T.; Takase, Y.; Hiratsuka, J.

    2012-02-15

    This paper presents an experimental demonstration to determine electron temperature (T{sub e}) with unknown spectral sensitivity (transmissivity) in a Thomson scattering system. In this method, a double-pass scattering configuration is used and the scattered lights from each pass (with different scattering angles) are measured separately. T{sub e} can be determined from the ratio of the signal intensities without knowing a real chromatic dependence in the sensitivity. Note that the wavelength range for each spectral channel must be known. This method was applied to the TST-2 Thomson scattering system. As a result, T{sub e} measured from the ratio (T{sub e,r}) and T{sub e} measured from a standard method (T{sub e,s}) showed a good agreement with <|T{sub e,r}-T{sub e,s}|/T{sub e,s}>= 7.3%.

  17. Improving measurement accuracy by optimum data acquisition for Nd:YAG Thomson scattering system.

    PubMed

    Minami, T; Itoh, Y; Yamada, I; Yasuhara, R; Funaba, H; Nakanishi, H; Hatae, T

    2014-11-01

    A new high speed Nd:YAG Thomson scattering AD Convertor (HYADC) that can directly convert the detected scattered light signal into a digital signal is under development. The HYADC is expected to improve a signal to noise ratio of the Nd:YAG Thomson scattering measurement. The data storage of the HYADC which is required for the direct conversion of whole plasma discharge is drastically reduced by a ring buffer memory and a stop trigger system. Data transfer of the HYADC is performed by the SiTCP. The HYADC is easily expandable to a multi-channel system by the distributed data processing, and is very compact and easy to implement as a built-in system of the polychromators. PMID:25430250

  18. Narrow-band emission in Thomson sources operating in the high-field regime.

    PubMed

    Terzić, Balša; Deitrick, Kirsten; Hofler, Alicia S; Krafft, Geoffrey A

    2014-02-21

    We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation idea in terms of a chirped-beam-driven free electron laser oscillator configuration and show that significant compensation can occur, even with the imperfect matching to be expected in these conditions. PMID:24579606

  19. Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak

    SciTech Connect

    Berni, L. A.; Albuquerque, B. F. C.

    2010-12-15

    Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esferico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times.

  20. Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak.

    PubMed

    Berni, L A; Albuquerque, B F C

    2010-12-01

    Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esférico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times. PMID:21198020

  1. Narrowband Emission in Compton/Thomson Sources Operating in the High-Field Regime

    DOE PAGESBeta

    Terzic, Balsa; Deitrick, Kirsten E.; Hofler, Alicia S.; Kraff, Geoffrey A.

    2014-02-21

    We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the upshifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications, and reduces the spectral brilliance. In this paper we show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Further, we suggest a practical realizationmore » of this compensation idea in terms of a chirped-beam driven FEL oscillator configuration, and show that significant compensation can occur, even with the imperfect matching to be expected in these conditions.« less

  2. 4{omega} Thomson scattering probe for high-density plasma characterization at Titan

    SciTech Connect

    Ross, J. S.; Pollock, B. B.; Kline, J. L.; Yang, S.; Henesian, M.; Weiland, T.; Price, D.; Glenzer, S. H.

    2010-10-15

    In preparation for the upcoming experiments on the Titan laser at the Jupiter Laser Facility, a new Thomson scattering system has been designed and implemented. This system allows electron temperature and density measurements in a high-density regime (n{sub e}>10{sup 21} cm{sup -3}). A 263 nm probe has been demonstrated to produce a total energy of 15 J at 4{omega}(263 nm) in a 1 ns square pulse with a focal spot size of 100 {mu}m. This probe has been used for imaging Thomson scattering of the ion feature. The goal of this study is to investigate the heating of a preformed plasma by a short-pulse heater beam.

  3. Optimal Design of a Tunable Thomson-Scattering Based Gamma-Ray Source

    SciTech Connect

    Gibson, D J; Anderson, S G; Betts, S M; Hartemann, F V; Jovanovic, I; McNabb, D P; Messerly, M J; Pruet, J A; Shverdin, M Y; Siders, C W; Tremaine, A M; Barty, C J

    2007-06-07

    Thomson-Scattering based systems offer a path to high-brightness high-energy (> 1 MeV) x-ray and {gamma}-ray sources due to their favorable scaling with electron energy. LLNL is currently engaged in an effort to optimize such a device, dubbed the ''Thomson-Radiated Extreme X-Ray'' (T-REX) source, targeting up to 680 keV photon energy. Such a system requires precise design of the interaction between a high-intensity laser pulse and a high-brightness electron beam. Presented here are the optimal design parameters for such an interaction, including factors such as the collision angle, focal spot size, optimal bunch charge, and laser energy. These parameters were chosen based on extensive modeling using PARMELA and in-house, well-benchmarked scattering simulation codes.

  4. A scalable multipass laser cavity based on injection by frequency conversion for noncollective Thomson scattering

    SciTech Connect

    Schaeffer, D. B.; Constantin, C. G.; Everson, E. T.; Van Compernolle, B.; Kugland, N. L.; Niemann, C.; Ebbers, C. A.; Glenzer, S. H.

    2010-10-15

    A scalable setup using injection by frequency conversion to establish a multipassing cavity for noncollective Thomson scattering on low density plasmas is presented. The cavity is shown to support >10 passes through the target volume with a 400% increase in energy on target versus a single-pass setup. Rayleigh scattering experiments were performed and demonstrate the viability of the cell to study low density plasmas of the order of 10{sup 12}-10{sup 13} cm{sup -3}. A high-repetition, low-energy, single-pass Thomson scattering setup was also performed on the University of California, Los Angeles Large Plasma Device and shows that the multipass cavity could have a significant advantage over the high-repetition approach due to the cavity setup's inherently higher signal per shot.

  5. A scalable multipass laser cavity based on injection by frequency conversion for noncollective Thomson scattering.

    PubMed

    Schaeffer, D B; Kugland, N L; Constantin, C G; Everson, E T; Van Compernolle, B; Ebbers, C A; Glenzer, S H; Niemann, C

    2010-10-01

    A scalable setup using injection by frequency conversion to establish a multipassing cavity for noncollective Thomson scattering on low density plasmas is presented. The cavity is shown to support >10 passes through the target volume with a 400% increase in energy on target versus a single-pass setup. Rayleigh scattering experiments were performed and demonstrate the viability of the cell to study low density plasmas of the order of 10(12)-10(13) cm(-3). A high-repetition, low-energy, single-pass Thomson scattering setup was also performed on the University of California, Los Angeles Large Plasma Device and shows that the multipass cavity could have a significant advantage over the high-repetition approach due to the cavity setup's inherently higher signal per shot. PMID:21033873

  6. A new dump system design for stray light reduction of Thomson scattering diagnostic system on EAST

    NASA Astrophysics Data System (ADS)

    Xiao, Shumei; Zang, Qing; Han, Xiaofeng; Wang, Tengfei; Yu, Jin; Zhao, Junyu

    2016-07-01

    Thomson scattering (TS) diagnostic is an important diagnostic for measuring electron temperature and density during plasma discharge. However, the measurement of Thomson scattering signal is disturbed by the stray light easily. The stray light sources in the Experimental Advanced Superconducting Tokamak (EAST) TS diagnostic system were analyzed by a simulation model of the diagnostic system, and simulation results show that the dump system is the primary stray light source. Based on the optics theory and the simulation analysis, a novel dump system including an improved beam trap was proposed and installed. The measurement results indicate that the new dump system can reduce more than 60% of the stray light for the diagnostic system, and the influence of stray light on the error of measured density decreases.

  7. Conceptual design of a divertor Thomson scattering diagnostic for NSTX-U

    SciTech Connect

    McLean, A. G. Soukhanovskii, V. A.; Allen, S. L.; Carlstrom, T. N.; LeBlanc, B. P.; Ono, M.; Stratton, B. C.

    2014-11-15

    A conceptual design for a divertor Thomson scattering (DTS) diagnostic has been developed for the NSTX-U device to operate in parallel with the existing multipoint Thomson scattering system. Higher projected peak heat flux in NSTX-U will necessitate application of advanced magnetics geometries and divertor detachment. Interpretation and modeling of these divertor scenarios will depend heavily on local measurement of electron temperature, T{sub e}, and density, n{sub e}, which DTS provides in a passive manner. The DTS design for NSTX-U adopts major elements from the successful DIII-D DTS system including 7-channel polychromators measuring T{sub e} to 0.5 eV. If implemented on NSTX-U, the divertor TS system would provide an invaluable diagnostic for the boundary program to characterize the edge plasma.

  8. Imaging x-ray Thomson scattering spectrometer design and demonstration (invited).

    PubMed

    Gamboa, E J; Huntington, C M; Trantham, M R; Keiter, P A; Drake, R P; Montgomery, D S; Benage, J F; Letzring, S A

    2012-10-01

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam. PMID:23126930

  9. Imaging x-ray Thomson scattering spectrometer design and demonstration (invited)a)

    NASA Astrophysics Data System (ADS)

    Gamboa, E. J.; Huntington, C. M.; Trantham, M. R.; Keiter, P. A.; Drake, R. P.; Montgomery, D. S.; Benage, J. F.; Letzring, S. A.

    2012-10-01

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  10. A high-power spatial filter for Thomson scattering stray light reduction

    NASA Astrophysics Data System (ADS)

    Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.

    2011-03-01

    The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

  11. Design of a submillimeter laser Thomson scattering system for measurement of ion temperature in SUMMA

    NASA Technical Reports Server (NTRS)

    Praddaude, H. C.; Woskoboinikow, P.

    1978-01-01

    A thorough discussion of submillimeter laser Thomson scattering for the measurement of ion temperature in plasmas is presented. This technique is very promising and work is being actively pursued on the high power lasers and receivers necessary for its implementation. In this report we perform an overall system analysis of the Thomson scattering technique aimed to: (1) identify problem areas; (2) establish specifications for the main components of the apparatus; (3) study signal processing alternatives and identify the optimum signal handling procedure. Because of its importance for the successful implementation of this technique, we also review the work presently being carried out on the optically pumped submillimeter CH3F and D2O lasers.

  12. Ultrafast Materials Probing with the LLNL Thomson X-Ray Source

    SciTech Connect

    Springer, P; Anderson, S; Brown, W; Barty, C; Cauble, R; Crane, J; Cynn, H; Ebbers, C; Fittinghoff, D; Gibson, D; Hartemann, F; Javanovich, I; Kuba, J; LeSage, G; McMahan, A; Minich, R; Moriarty, J; Remington, B; Slaughter, D; Steitz, F H; Tremaine, A; Yoo, C-s; Rosenzweig, J; Ditmire, T

    2002-09-03

    The use of short laser pulses to generate very high brightness, ultra short (fs to ps) x-ray pulses is a topic of great interest. In principle, fantosecond-scale pump-probe experiments can be used to temporally resolve structural dynamics of materials on the time scale of atomic motion. The development of sub-ps x-ray pulses will make possible a wide range of materials and plasma physics studies with unprecedented time resolution. The Thomson scattering project at LLNL will provide such a novel x-ray source of high power using short laser pulses and a high brightness, relativistic electron bunch. The system is based on a 5mm-mrad normalized emittance photoinjector, 100 MeV electron RF linac, and a 300 mJ, 35 fs solid-state laser system. The Thomson source will produce ultra fast pulses with x-ray energies (60 kev) capable of probing into high-Z metals.

  13. Kinetic Transition Networks for the Thomson Problem and Smale's Seventh Problem.

    PubMed

    Mehta, Dhagash; Chen, Jianxu; Chen, Danny Z; Kusumaatmaja, Halim; Wales, David J

    2016-07-01

    The Thomson problem, arrangement of identical charges on the surface of a sphere, has found many applications in physics, chemistry and biology. Here, we show that the energy landscape of the Thomson problem for N particles with N=132, 135, 138, 141, 144, 147, and 150 is single funneled, characteristic of a structure-seeking organization where the global minimum is easily accessible. Algorithmically, constructing starting points close to the global minimum of such a potential with spherical constraints is one of Smale's 18 unsolved problems in mathematics for the 21st century because it is important in the solution of univariate and bivariate random polynomial equations. By analyzing the kinetic transition networks, we show that a randomly chosen minimum is, in fact, always "close" to the global minimum in terms of the number of transition states that separate them, a characteristic of small world networks. PMID:27447530

  14. Quantum Joule-Thomson effect in a saturated homogeneous Bose gas.

    PubMed

    Schmidutz, Tobias F; Gotlibovych, Igor; Gaunt, Alexander L; Smith, Robert P; Navon, Nir; Hadzibabic, Zoran

    2014-01-31

    We study the thermodynamics of Bose-Einstein condensation in a weakly interacting quasihomogeneous atomic gas, prepared in an optical-box trap. We characterize the critical point for condensation and observe saturation of the thermal component in a partially condensed cloud, in agreement with Einstein's textbook picture of a purely statistical phase transition. Finally, we observe the quantum Joule-Thomson effect, namely isoenthalpic cooling of an (essentially) ideal gas. In our experiments this cooling occurs spontaneously, due to energy-independent collisions with the background gas in the vacuum chamber. We extract a Joule-Thomson coefficient μJT>10(9)  K/bar, about 10 orders of magnitude larger than observed in classical gases. PMID:24580421

  15. Narrowband Emission in Compton/Thomson Sources Operating in the High-Field Regime

    SciTech Connect

    Terzic, Balsa; Deitrick, Kirsten E.; Hofler, Alicia S.; Kraff, Geoffrey A.

    2014-02-21

    We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the upshifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications, and reduces the spectral brilliance. In this paper we show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Further, we suggest a practical realization of this compensation idea in terms of a chirped-beam driven FEL oscillator configuration, and show that significant compensation can occur, even with the imperfect matching to be expected in these conditions.

  16. Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons

    NASA Astrophysics Data System (ADS)

    Babzien, Marcus; Ben-Zvi, Ilan; Kusche, Karl; Pavlishin, Igor V.; Pogorelsky, Igor V.; Siddons, David P.; Yakimenko, Vitaly; Cline, David; Zhou, Feng; Hirose, Tachishige; Kamiya, Yoshio; Kumita, Tetsuro; Omori, Tsunehiko; Urakawa, Junji; Yokoya, Kaoru

    2006-02-01

    A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams produced from particle accelerators. The process of single photon absorption and reemission by the electron, so-called linear Thomson scattering, results in radiation that is Doppler shifted into the x-ray and γ-ray regions. At elevated laser intensity, nonlinear effects should come into play when the transverse motion of the electrons induced by the laser beam is relativistic. In the present experiment, we achieved this condition and characterized the second harmonic of Thomson x-ray scattering using the counterpropagation of a 60 MeV electron beam and a subterawatt CO2 laser beam.

  17. Toward the Landau-Lifshitz version of the Thomson electrostatics theorem

    NASA Astrophysics Data System (ADS)

    Grinfeld, Michael; Grinfeld, Pavel

    In the classical textbook (Landau and Lifshitz, 1963), Landau and Lifshtz suggested their version of the famous Thomson variational principle (a.k.a Thomson theorem.) So far, their version has not gained the interest it deserves, either among physicists or among applied mathematicians. Partially, the lack of interest can be explained because of the quality of the suggested proof of the principle. It is considerably lower than the standards accepted in classical electrostatics and mathematical physics. Even more importantly, Landau and Lifshitz did not demostrate the minimum property of the electrostatic energy at equilibrium. In this note, we, first, modify and specify the Landau-Lifshitz formulation of the principle presenting it as the isoperimetric variational problem. Then, for this isoperimetric problem we calculate the first and second variations, and we prove that the first variation vanishes, whereas the second variation appears to be positive.

  18. Joule-Thomson inversion curves and related coefficients for several simple fluids

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Peller, I. C.; Baron, A. K.

    1972-01-01

    The equations of state (PVT relations) for methane, oxygen, argon, carbon dioxide, carbon monoxide, neon, hydrogen, and helium were used to establish Joule-Thomson inversion curves for each fluid. The principle of corresponding states was applied to the inversion curves, and a generalized inversion curve for fluids with small acentric factors was developed. The quantum fluids (neon, hydrogen, and helium) were excluded from the generalization, but available data for the fluids xenon and krypton were included. The critical isenthalpic Joule-Thomson coefficient mu sub c was determined; and a simplified approximation mu sub c approximates T sub c divided by 6P sub c was found adequate, where T sub c and P sub c are the temperature and pressure at the thermodynamic critical point. The maximum inversion temperatures were obtained from the second virial coefficient (maximum (B/T)).

  19. Multi-Point Thomson Scattering First Results in HIT-II Plasmas

    NASA Astrophysics Data System (ADS)

    Smith, R. J.; Hamp, W. T.; Liptac, J. E.; Jarboe, T. R.; Nelson, B. A.; Leblanc, B. P.; Phillips, P.

    2000-10-01

    A multi-point Thomson scattering diagnostic has recently been implemented on the Helicity Injected Torus (HIT-II). The HIT-II device is a low-aspect-ratio (R_o=0.3m, a=0.2m) torus with an on-axis toroidal field of up to 0.5 Tesla. The machine configuration allows both inductive current drive and Coaxial Helicity Injection (CHI) current drive operations and has demonstrated plasma currents on the order of 200 kA in either mode. Electron temperature and density profile measurements for both inductive- and CHI-driven plasmas are presented. The Thomson scattering data is discussed in the context of complimentary diagnostics on the HIT-II device, including: a two-chord FIR interferometer; a 16-channel ion Doppler spectrometer; two tangentially-viewing VUV spectrometers; and, finally, a triple Langmuir probe for direct internal measurements.

  20. A high-power spatial filter for Thomson scattering stray light reduction

    SciTech Connect

    Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.

    2011-03-15

    The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

  1. Micro-scale heat-exchangers for Joule-Thomson cooling.

    SciTech Connect

    Gross, Andrew John

    2014-01-01

    This project focused on developing a micro-scale counter flow heat exchangers for Joule-Thomson cooling with the potential for both chip and wafer scale integration. This project is differentiated from previous work by focusing on planar, thin film micromachining instead of bulk materials. A process will be developed for fabricating all the devices mentioned above, allowing for highly integrated micro heat exchangers. The use of thin film dielectrics provides thermal isolation, increasing efficiency of the coolers compared to designs based on bulk materials, and it will allow for wafer-scale fabrication and integration. The process is intended to implement a CFHX as part of a Joule-Thomson cooling system for applications with heat loads less than 1mW. This report presents simulation results and investigation of a fabrication process for such devices.

  2. 21nm x-ray laser Thomson scattering of laser-heated exploding foil plasmas

    SciTech Connect

    Dunn, J; Rus, B; Mocek, T; Nelson, A J; Foord, M E; Rozmus, W; Baldis, H A; Shepherd, R L; Kozlova, M; Polan, J; Homer, P; Stupka, M

    2007-09-26

    Recent experiments were carried out on the Prague Asterix Laser System (PALS) towards the demonstration of a soft x-ray laser Thomson scattering diagnostic for a laser-produced exploding foil. The Thomson probe utilized the Ne-like zinc x-ray laser which was double-passed to deliver {approx}1 mJ of focused energy at 21.2 nm wavelength and lasting {approx}100 ps. The plasma under study was heated single-sided using a Gaussian 300-ps pulse of 438-nm light (3{omega} of the PALS iodine laser) at laser irradiances of 10{sup 13}-10{sup 14} W cm{sup -2}. Electron densities of 10{sup 20}-10{sup 22} cm{sup -3} and electron temperatures from 200 to 500 eV were probed at 0.5 or 1 ns after the peak of the heating pulse during the foil plasma expansion. A flat-field 1200 line mm{sup -1} variable-spaced grating spectrometer with a cooled charge-coupled device readout viewed the plasma in the forward direction at 30{sup o} with respect to the x-ray laser probe. We show results from plasmas generated from {approx}1 {micro}m thick targets of Al and polypropylene (C{sub 3}H{sub 6}). Numerical simulations of the Thomson scattering cross-sections will be presented. These simulations show electron peaks in addition to a narrow ion feature due to collective (incoherent) Thomson scattering. The electron features are shifted from the frequency of the scattered radiation approximately by the electron plasma frequency {+-}{omega}{sub pe} and scale as n{sub e}{sup 1/2}.

  3. Picosecond Pulse Recirculation for High Average Brightness Thomson Scattering-based Gamma-ray Sources

    SciTech Connect

    Semenov, V

    2009-05-28

    Pulse recirculation has been successfully demonstrated with the interaction laser system of LLNL's Thomson-Radiated Extreme X-ray (T-REX) source. The recirculation increased twenty-eight times the intensity of the light coming out of the laser system, demonstrating the capability of increasing the gamma-ray flux emitted by T-REX. The technical approach demonstrated could conceivably increase the average gamma-ray flux output by up to a hundred times.

  4. Gyrotron collective Thomson scattering from plasma fluctuations in a Tara axicell

    SciTech Connect

    Machuzak, J.S.; Woskov, P.P.; Myer, R.C.; Mulligan, W.J.; Cohn, D.R.; Gerver, M.; Golovato, S.N.; Horne, S.; Kubota, S.; Post, R.S.; and others

    1988-08-01

    Collective Thomson scattering in the Tara Tandem Mirror axicell at MIT was accomplished with a 137-GHz, approx.0.4-kW, 75-ms pulsed gyrotron. Ion cyclotron waves, ion Bernstein wave harmonics, and other plasma fluctuations possibly due to microinstabilities and magnetohydrodynamic (MHD) activity have been observed during ion cyclotron resonance frequency (ICRF) heating. The observation of ion Bernstein waves may be due to an enhanced ion thermal fluctuation spectrum in an ICRF heated plasma.

  5. Edge and core Thomson scattering systems and their calibration on the ASDEX Upgrade tokamak

    SciTech Connect

    Kurzan, B.; Murmann, H. D.

    2011-10-15

    A new 10 channel Thomson scattering (TS) system was installed on the ASDEX Upgrade tokamak to measure radial profiles of electron density and temperature at the plasma edge with high radial resolution. Together with the already existing TS system, which is now used for the core plasma, electron density and temperature profiles extending from the edge to the core are now obtained in a single discharge. The TS systems are relatively calibrated by an optical parametric oscillator.

  6. A large area Thomson-scattering stellar X-ray polarimeter.

    NASA Technical Reports Server (NTRS)

    Novick, R.; Wolff, R. S.

    1971-01-01

    An instrument for measuring the polarization of stellar X-ray emission has been designed, constructed, and tested. The polarization dependence of incoherent Thomson scattering in lithium metal is utilized. Means for suppression of cosmic ray background effects have been provided. The apparatus has been flown in rockets to obtain data in the polarization of X-ray sources in Sco X-1 and Tau X-1.

  7. Temporally resolved plasma composition measurements by collective Thomson scattering in TEXTOR (invited)

    SciTech Connect

    Stejner, M.; Korsholm, S. B.; Nielsen, S. K.; Salewski, M.; Leipold, F.; Michelsen, P. K.; Meo, F.; Bindslev, H.; Moseev, D.; Buerger, A.; Kantor, M.; Baar, M. de

    2012-10-15

    Fusion plasma composition measurements by collective Thomson scattering (CTS) were demonstrated in recent proof-of-principle measurements in TEXTOR [S. B. Korsholm et al., Phys. Rev. Lett. 106, 165004 (2011)]. Such measurements rely on the ability to resolve and interpret ion cyclotron structure in CTS spectra. Here, we extend these techniques to enable temporally resolved plasma composition measurements by CTS in TEXTOR, and we discuss the prospect for such measurements with newly installed hardware upgrades for the CTS system on ASDEX Upgrade.

  8. Out-of-equilibrium conditions in x-ray Thomson scattering experiments.

    PubMed

    Faussurier, Gérald; Blancard, Christophe

    2015-06-01

    We study out-of-equilibrium conditions in recent x-ray Thomson scattering experiments performed in warm dense matter. We use an effective one-component plasma model to characterize the states in which electron and ion temperatures are different. An estimation of the ion temperature is obtained. This method is tested against two recent experiments. Strong out-of-equilibrium conditions are found. PMID:26172805

  9. Examination of scattering volume aligment in Thomson scattering off of a shock front in argon

    SciTech Connect

    Reighard, A B; Froula, D H; Drake, R P; Ross, J S; Divol, L

    2007-07-26

    Thomson scattering in argon gas successfully probed the region of plasma just behind the shock front. The instantaneous shock velocity can be inferred from the duration of the signal, taking into account the size and shape of the scattering volume. Possible misalignment of the probe beam and spectrometer slits greatly affects the size and shape of the scattering volume, and therefore affects the calculation of the instantaneous shock velocity.

  10. High-energy resolution Thomson Parabola spectrometer for laser plasma diagnostics

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Carpinelli, M.; Maggiore, M.; Ter-Avetisyan, S.; Tramontana, A.; Velyhan, A.

    2013-07-26

    Thomson Parabola (TP) spectrometers are widely used devices for laser-driven beam diagnostics as they provide a complete set of information on the accelerated particles. A novel TP has been developed at LNS with a design able to detect protons up to 20 MeV. The layout design and some results obtained during the experimental campaign at PALS laboratory will be reported in the following.

  11. Development of a YAG laser system for the edge Thomson scattering system in ITER

    SciTech Connect

    Hatae, T.; Yatsuka, E.; Hayashi, T.; Ono, T.; Kusama, Y.; Yoshida, H.

    2012-10-15

    A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).

  12. The data acquisition and control system for Thomson Scattering on ATF (Advanced Toroidal Facility)

    SciTech Connect

    Stewart, K.A.; Kindsfather, R.R.; Rasmussen, D.A.

    1989-01-01

    The 2-dimensional Thomson Scattering System measuring electron temperatures and densities in the Advanced Toroidal Facility (ATF) is interfaced to a VAX-8700 computer system running in a clustered configuration. Calibration, alignment, and operation of this diagnostic is under computer control. Extensive CAMAC instrumentation is used for timing control, data acquisition, and laser alignment. This paper will discuss the computer hardware and software, system operations, and data storage and retrieval. 3 refs.

  13. Two new species of Onciderini Thomson, 1860 (Coleoptera, Cerambycidae, Lamiinae) from South America.

    PubMed

    Nearns, Eugenio H; Santos-Silva, Antonio

    2016-01-01

    Two new species of Onciderini are described and illustrated: Oncideres tavakiliani, from Brazil (Pará), and Clavidesmus egeri, from Peru. Oncideres defectiofasciata Gilmour, 1950 is a junior synonym of O. chevrolatii Thomson, 1868. The following four new country records are reported: O. crassicornis Bates, 1865 (Paraguay); O. glebulenta Martins, 1981 (Paraguay); O. gutturator (Fabricius, 1775) (Venezuela); and O. repandator (Fabricius, 1793) (Peru). PMID:27470737

  14. Measurements of Intrinsic Ion Bernstein Waves in a Tokamak by Collective Thomson Scattering

    NASA Astrophysics Data System (ADS)

    Korsholm, S. B.; Stejner, M.; Bindslev, H.; Furtula, V.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Nielsen, S. K.; Salewski, M.; de Baar, M.; Delabie, E.; Kantor, M.; Bürger, A.

    2011-04-01

    In this Letter we report measurements of collective Thomson scattering (CTS) spectra with clear signatures of ion Bernstein waves and ion cyclotron motion in tokamak plasmas. The measured spectra are in accordance with theoretical predictions and show clear sensitivity to variation in the density ratio of the main ion species in the plasma. Measurements with this novel diagnostic demonstrate that CTS can be used as a fuel ion ratio diagnostic in burning fusion plasma devices.

  15. Design Study of Compact Thomson X-Ray Sources for Material and Life Sciences Applications

    NASA Astrophysics Data System (ADS)

    Bessonov, E. G.; Gorbunkov, M. V.; Kostryukov, P. V.; Maslova, Yu. Ya.; Tunkin, V. G.; Postnov, A. A.; Mikhailichenko, A. A.; Shvedunov, V. I.; Ishkhanov, B. S.; Vinogradov, A. V.

    X-ray generators utilizing Thomson scattering fill in the gap existing between conventional and synchrotron based X-ray sources. They are expected to be more intensive than X-ray tubes and more compact, accessible and cheap than synchrotrons. In this work two operation modes of Thomson X-ray source: quasi CW (QCW) and pulsed are considered for material sciences and medical applications being implemented now at synchrotron radiation (SR) facilities. The system contains a ~50 MeV linac and a few picoseconds, few hundred W average power laser. Thomson X-ray source can provide up to 5•1011 photons in a millisecond flash and average flux 1012-1013 phot/sec. To achieve these parameters with existing optical and accelerator technology the system must also contain a ring for storage of e-bunches for 103-105 revolutions and an optical circulator for storage of laser pulses for 102 passes. As possible applications of the considered X-ray source XAFS spectroscopy, small animal angiography and human noninvasive coronary angiography are discussed.

  16. Efficiency and output power of thermoelectric module by taking into account corrected Joule and Thomson heat

    NASA Astrophysics Data System (ADS)

    Kim, Hee Seok; Liu, Weishu; Ren, Zhifeng

    2015-09-01

    The maximum conversion efficiency of a thermoelectric module composed of p- and n-type materials has been widely calculated using a constant property model since the 1950s, but this conventional model is only valid in limited conditions and no Thomson heat is accounted for. Since Thomson heat causes the efficiency under- or over-rated depending on the temperature dependence of Seebeck coefficient, it cannot be ignored especially in large temperature difference between the hot and cold sides. In addition, incorrect Joule heat is taken into consideration for heat flux evaluation of a thermoelectric module at thermal boundaries due to the assumption of constant properties in the conventional model. For this reason, more practical predictions for efficiency and output power and its corresponding optimum conditions of p- and n-type materials need to be revisited. In this study, generic formulae are derived based on a cumulative temperature dependence model including Thomson effect. The formulae reliably predict the maximum efficiency and output power of a thermoelectric module at a large temperature.

  17. RF photoinjector development for a short-pulse, hard x-ray Thomson scattering source

    SciTech Connect

    Le Sage, G P; Anderson, S G; Cowan, T E; Crane, J K; Ditmire, T; Rosenzweig, J B

    2000-08-15

    An important motivation in the development of the next generation x-ray light sources is to achieve picosecond and sub-ps pulses of hard x-rays for dynamic studies of a variety of physical, chemical and biological processes. Present hard x-ray sources are either pulse-width or intensity limited, which allows ps-scale temporal resolution only for signal averaging of highly repetitive processes. A much faster and brighter hard x-ray source is being developed at LLNL, based on Thomson scattering of fs-laser pulses by a relativistic electron beam, which will enable x-ray characterization of the transient structure of a sample in a single shot. Experimental and diagnostic techniques relevant to the development of next generation sources including the Linac Coherent Light Source can be tested with the Thomson scattering hard x-ray source. This source will combine an RF photoinjector with a 100 MeV S-band linac. The photoinjector and linac also provide an ideal test-bed for examining space-charge induced emittance growth effects. A program of beam dynamics and diagnostic experiments are planned in parallel with Thomson source development. Our experimental progress and future plans will be discussed.

  18. Using collective x-ray Thomson scattering to measure temperature and density of warm dense matter

    SciTech Connect

    Doeppner, T; Davis, P F; Kritcher, A L; Landen, O L; Lee, H J; Regan, S P; Glenzer, S

    2009-07-29

    Collective x-ray Thomson scattering allows measuring plasmons, i.e electron plasma oscillations (Langmuir waves). This is manifest in the appearance of spectrally up- and down-shifted spectral features in addition to the Rayleigh signal. The ratio of the up- and down-shifted signals is directly related to detailed balance, allowing to determine the plasma temperature from first principles. The spectral shift of the plasmon signals is sensitive to temperature and electron density. We discuss the experimental considerations that have to be fulfilled to observe plasmon signals with x-ray Thomson scattering. As an example, we describe an experiment that used the Cl Ly-{alpha} x-ray line at 2.96 keV to measure collective Thomson scattering from solid beryllium, isochorically heated to 18 eV. Since temperature measurement based on detailed balance is based on first principles, this method is important to validate models that, for example, calculate the static ion-ion structure factor S{sub ii}(k).

  19. Hampson’s type cryocoolers with distributed Joule-Thomson effect for mixed refrigerants closed cycle

    NASA Astrophysics Data System (ADS)

    Maytal, Ben-Zion

    2014-05-01

    Most previous studies on Joule-Thomson cryocoolers of mixed refrigerants in a closed cycle focus on the Linde kind recuperator. The present study focuses on four constructions of Hampson’s kind miniature Joule-Thomson cryocoolers based on finned capillary tubes. The frictional pressure drop along the tubes plays the role of distributed Joule-Thomson expansion so that an additional orifice or any throttle at the cold end is eliminated. The high pressure tube is a throttle and a channel of recuperation at the same time. These coolers are tested within two closed cycle systems of different compressors and different compositions of mixed coolants. All tests were driven by the same level of discharge pressure (2.9 MPa) while the associated suction pressures and the associated reached temperatures are dependent on each particular cryocooler and on the closed cycle system. The mixture of higher specific cooling capacity cannot reach temperatures below 80 K when driven by the smaller compressor. The other mixture of lower specific cooling capacity driven by the larger compressor reaches lower temperatures. The examined parameters are the cooldown period and the reachable temperatures by each cryocooler.

  20. Electron kinetic effects on interferometry, polarimetry and Thomson scattering measurements in burning plasmas (invited).

    PubMed

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

    2014-11-01

    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. The precision of the previous lowest order linear in τ = Te/mec(2) model may be insufficient; we present a more precise model with τ(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 the 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 Te measurement relevant to ITER operational scenarios. PMID:25430162

  1. Electron kinetic effects on interferometry, polarimetry and Thomson scattering measurements in burning plasmas (invited)

    SciTech Connect

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

    2014-11-15

    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. 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 the 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{sub e} measurement relevant to ITER operational scenarios.

  2. The circuit of polychromator for Experimental Advanced Superconducting Tokamak edge Thomson scattering diagnostic.

    PubMed

    Zang, Qing; Hsieh, C L; Zhao, Junyu; Chen, Hui; Li, Fengjuan

    2013-09-01

    The detector circuit is the core component of filter polychromator which is used for scattering light analysis in Thomson scattering diagnostic, and is responsible for the precision and stability of a system. High signal-to-noise and stability are primary requirements for the diagnostic. Recently, an upgraded detector circuit for weak light detecting in Experimental Advanced Superconducting Tokamak (EAST) edge Thomson scattering system has been designed, which can be used for the measurement of large electron temperature (T(e)) gradient and low electron density (n(e)). In this new circuit, a thermoelectric-cooled avalanche photodiode with the aid circuit is involved for increasing stability and enhancing signal-to-noise ratio (SNR), especially the circuit will never be influenced by ambient temperature. These features are expected to improve the accuracy of EAST Thomson diagnostic dramatically. Related mechanical construction of the circuit is redesigned as well for heat-sinking and installation. All parameters are optimized, and SNR is dramatically improved. The number of minimum detectable photons is only 10. PMID:24089826

  3. 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.

  4. The circuit of polychromator for Experimental Advanced Superconducting Tokamak edge Thomson scattering diagnostic

    SciTech Connect

    Zang, Qing; Zhao, Junyu; Chen, Hui; Li, Fengjuan; Hsieh, C. L.

    2013-09-15

    The detector circuit is the core component of filter polychromator which is used for scattering light analysis in Thomson scattering diagnostic, and is responsible for the precision and stability of a system. High signal-to-noise and stability are primary requirements for the diagnostic. Recently, an upgraded detector circuit for weak light detecting in Experimental Advanced Superconducting Tokamak (EAST) edge Thomson scattering system has been designed, which can be used for the measurement of large electron temperature (T{sub e}) gradient and low electron density (n{sub e}). In this new circuit, a thermoelectric-cooled avalanche photodiode with the aid circuit is involved for increasing stability and enhancing signal-to-noise ratio (SNR), especially the circuit will never be influenced by ambient temperature. These features are expected to improve the accuracy of EAST Thomson diagnostic dramatically. Related mechanical construction of the circuit is redesigned as well for heat-sinking and installation. All parameters are optimized, and SNR is dramatically improved. The number of minimum detectable photons is only 10.

  5. Ultra-high temperature stability Joule-Thomson cooler with capability to accomodate pressure variations

    NASA Technical Reports Server (NTRS)

    Bard, Steven (Inventor); Wu, Jiunn-Jeng (Inventor); Trimble, Curtis A. (Inventor)

    1992-01-01

    A Joule-Thomson cryogenic refrigeration system capable of achieving high temperature stabilities in the presence of varying temperature, atmospheric pressure, and heat load is provided. The Joule-Thomson cryogenic refrigeration system includes a demand flow Joule-Thomson expansion valve disposed in a cryostat of the refrigeration system. The expansion valve has an adjustable orifice that controls the flow of compressed gas therethrough and induces cooling and partial liquefaction of the gas. A recuperative heat exchanger is disposed in the cryostat and coupled to the expansion valve. A thermostatically self-regulating mechanism is disposed in the cryostat and coupled to the J-T expansion valve. The thermostatically self-regulating mechanism automatically adjusts the cross sectional area of the adjustable valve orifice in response to environmental temperature changes and changes in power dissipated at a cold head. A temperature sensing and adjusting mechanism is coupled to a cold head for adjusting the temperature of the cold head in response to the change in heat flow in the cold head. The temperature sensing and adjusting mechanism comprises a temperature sensitive diode, a wound wire heater, and an electrical feedback control circuit coupling the diode to the heater. An absolute pressure relief valve is interposed between the output of the cryostat and an exhaust port for maintaining a constant exhaust temperature in the refrigerating system, independent of the changes in atmospheric pressure.

  6. Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas.

    PubMed

    Washeleski, Robert L; Meyer, Edmond J; King, Lyon B

    2013-10-01

    Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed. PMID:24182157

  7. Ultra-high temperature stability Joule-Thomson cooler with capability to accomodate pressure variations

    NASA Astrophysics Data System (ADS)

    Bard, Steven; Wu, Jiunn-Jeng; Trimble, Curtis A.

    1992-06-01

    A Joule-Thomson cryogenic refrigeration system capable of achieving high temperature stabilities in the presence of varying temperature, atmospheric pressure, and heat load is provided. The Joule-Thomson cryogenic refrigeration system includes a demand flow Joule-Thomson expansion valve disposed in a cryostat of the refrigeration system. The expansion valve has an adjustable orifice that controls the flow of compressed gas therethrough and induces cooling and partial liquefaction of the gas. A recuperative heat exchanger is disposed in the cryostat and coupled to the expansion valve. A thermostatically self-regulating mechanism is disposed in the cryostat and coupled to the J-T expansion valve. The thermostatically self-regulating mechanism automatically adjusts the cross sectional area of the adjustable valve orifice in response to environmental temperature changes and changes in power dissipated at a cold head. A temperature sensing and adjusting mechanism is coupled to a cold head for adjusting the temperature of the cold head in response to the change in heat flow in the cold head. The temperature sensing and adjusting mechanism comprises a temperature sensitive diode, a wound wire heater, and an electrical feedback control circuit coupling the diode to the heater. An absolute pressure relief valve is interposed between the output of the cryostat and an exhaust port for maintaining a constant exhaust temperature in the refrigerating system, independent of the changes in atmospheric pressure.

  8. Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas

    NASA Astrophysics Data System (ADS)

    Washeleski, Robert L.; Meyer, Edmond J.; King, Lyon B.

    2013-10-01

    Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.

  9. Polarization of x-gamma radiation produced by a Thomson and Compton inverse scattering

    NASA Astrophysics Data System (ADS)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Drebot, I.; Giribono, A.; Maroli, C.; Rossi, A. R.; Serafini, L.; Tomassini, P.; Vaccarezza, C.; Variola, A.

    2015-11-01

    A systematic study of the polarization of x-gamma rays produced in Thomson and Compton scattering is presented, in both classical and quantum schemes. Numerical results and analytical considerations let us to establish the polarization level as a function of acceptance, bandwidth and energy. Few sources have been considered: the SPARC_LAB Thomson device, as an example of a x-ray Thomson source, ELI-NP, operating in the gamma range. Then, the typical parameters of a beam produced by a plasma accelerator has been analyzed. In the first case, with bandwidths up to 10%, a contained reduction (<10 % ) in the average polarization occurs. In the last case, for the nominal ELI-NP relative bandwidth of 5 ×1 0-3 , the polarization is always close to 1. For applications requiring larger bandwidth, however, a degradation of the polarization up to 30% must be taken into account. In addition, an all optical gamma source based on a plasma accelerated electron beam cannot guarantee narrow bandwidth and high polarization operational conditions required in nuclear photonics experiments.

  10. Soft X-Ray Thomson Scattering in Warm Dense Hydrogen at FLASH

    SciTech Connect

    Faustlin, R R; Toleikis, S; Bornath, T; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Mithen, J; Przystawik, A; Redlin, H; Redmer, R; Reinholz, H; Ropke, G; Tavella, F; Thiele, R; Tiggesbaumker, J; Uschmann, I; Zastrau, U; Tschentscher, T

    2009-07-15

    We present collective Thomson scattering with soft x-ray free electron laser radiation as a method to track the evolution of warm dense matter plasmas with {approx}200 fs time resolution. In a pump-probe scheme an 800 nm laser heats a 20 {micro}m hydrogen droplet to the plasma state. After a variable time delay in the order of ps the plasma is probed by an x-ray ultra violet (XUV) pulse which scatters from the target and is recorded spectrally. Alternatively, in a self-Thomson scattering experiment, a single XUV pulse heats the target while a portion of its photons are being scattered probing the target. From such inelastic x-ray scattering spectra free electron temperature and density can be inferred giving insight on relaxation time scales in plasmas as well as the equation of state. We prove the feasibility of this method in the XUV range utilizing the free electron laser facility in Hamburg, FLASH. We recorded Thomson scattering spectra for hydrogen plasma, both in the self-scattering and in the pump-probe mode using optical laser heating.

  11. The preliminary design of the optical Thomson scattering diagnostic for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Datte, P.; Ross, J. S.; Froula, D.; Galbraith, J.; Glenzer, S.; Hatch, B.; Kilkenny, J.; Landen, O.; Manuel, A. M.; Molander, W.; Montgomery, D.; Moody, J.; Swadling, G.; Weaver, J.; Vergel de Dios, G.; Vitalich, M.

    2016-05-01

    The National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion programs. We report on the preliminary design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community's understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beamsplitter and gratings before the shot. A deep-UV probe beam (λ0 between 185-215 nm) will optimally collect Thomson scattered light from plasma densities of 5 x 1020 electrons/cm3 while a 3ω probe will optimally collect Thomson scattered light from plasma densities of 1 x 1019 electrons/cm3. We report the phase I design of a two phase design strategy. Phase I includes the OTS recording system to measure background levels at NIF and phase II will include the integration of a probe laser.

  12. Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas

    SciTech Connect

    Washeleski, Robert L.; Meyer, Edmond J. IV; King, Lyon B.

    2013-10-15

    Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.

  13. Thomson Scattering Observation of Non-Maxwellian EEDF and the Effect of Local Electron Heating

    NASA Astrophysics Data System (ADS)

    Kono, A.; Funahashi, H.

    2001-10-01

    Laser Thomson scattering measurements were carried out to study electron energy distribution function (EEDF) of inductively coupled plasmas using C_4F_8/Ar and CF_4/Ar mixture gases. The plasma was produced using a one-turn coil antenna immersed in the plasma at a total pressure of 25 mTorr. A specially designed triple-grating spectrometer was used, which produces Thomson spectra on the output focal plane with the interfering Rayleigh and stray components highly suppressed; an ICCD camera operated in the photon-counting mode was used for multichannel detection of the spectrum. At a RF (13.56 MHz) input power of 300 W in the case of pure Ar plasma, EEDF was Maxwellian with an enectron density >10^12 cm-3. Upon mixing of C_4F8 as well as CF_4, decrease in the electron density and upward bend of the plot of the Thomson spectrum (energy vs. logarithmic scattering intensity) at energies around 5 eV was observed. The mechanism for producing this bend was studied via Monte-Carlo particle simulation. The results indicate that electron heating in a uniform electric field does not lead to upward bend; electrons should be heated locally near the antenna surface where the RF electric field is strong and cooled in other part of the plasma by inelastic collisions.

  14. Interpenetration and deflection phenomena in collisions between supersonic, magnetized, tungsten plasma flows diagnosed using high resolution optical Thomson scattering

    NASA Astrophysics Data System (ADS)

    Swadling, G. F.; Lebedev, S. V.; Harvey-Thompson, A. J.; Rozmus, W.; Burdiak, G.; Suttle, L.; Patankar, S.; Smith, R. A.; Bennett, M.; Hall, G. N.; Suzuki-Vidal, F.; Bland, S.; Yuan, J.

    2015-07-01

    An optical Thomson scattering diagnostic has been used to investigate collisions between supersonic, magnetized plasma flows, in particular the transition from collisionless to collisional interaction dynamics. These flows were produced using tungsten wire array z-pinches, driven by the 1.4 MA 240 ns Magpie generator at Imperial College London. Measurements of the collective-mode Thomson scattering ion-feature clearly indicate that the ablation flows are interpenetrating at 100 ns (after current start), and this interpenetration continues until at least 140 ns. The Thomson spectrum at 150 ns shows a clear change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams near the axis. The Thomson scattering data also provide indirect evidence of the presence of a significant toroidal magnetic field embedded in the "precursor" plasma near the axis of the array over the period 100-140 ns; these observations are in agreement with previous measurements [Swadling et al., Phys. Rev. Lett. 113, 035003 (2014)]. The Thomson scattering measurements at 150 ns suggest that this magnetic field must collapse at around the time the dense precursor column begins to form.

  15. Interpenetration and deflection phenomena in collisions between supersonic, magnetized, tungsten plasma flows diagnosed using high resolution optical Thomson scattering

    SciTech Connect

    Swadling, G. F.; Lebedev, S. V.; Burdiak, G.; Suttle, L.; Patankar, S.; Smith, R. A.; Bennett, M.; Hall, G. N.; Suzuki-Vidal, F.; Bland, S.; Harvey-Thompson, A. J.; Rozmus, W.; Yuan, J.

    2015-07-15

    An optical Thomson scattering diagnostic has been used to investigate collisions between supersonic, magnetized plasma flows, in particular the transition from collisionless to collisional interaction dynamics. These flows were produced using tungsten wire array z-pinches, driven by the 1.4 MA 240 ns Magpie generator at Imperial College London. Measurements of the collective-mode Thomson scattering ion-feature clearly indicate that the ablation flows are interpenetrating at 100 ns (after current start), and this interpenetration continues until at least 140 ns. The Thomson spectrum at 150 ns shows a clear change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams near the axis. The Thomson scattering data also provide indirect evidence of the presence of a significant toroidal magnetic field embedded in the “precursor” plasma near the axis of the array over the period 100–140 ns; these observations are in agreement with previous measurements [Swadling et al., Phys. Rev. Lett. 113, 035003 (2014)]. The Thomson scattering measurements at 150 ns suggest that this magnetic field must collapse at around the time the dense precursor column begins to form.

  16. Frequency tunable x-ray/γ-ray source via Thomson backscattering on flying mirror from laser foil interaction

    NASA Astrophysics Data System (ADS)

    Wen, Meng; Jin, Luling; Lu, Yuanrong; Chen, Jiaer; Yan, Xueqing

    2012-07-01

    A scheme to generate a frequency tunable x-ray/γ-ray source via Thomson backscattering is proposed. In this model, a few-cycle drive pulse with relativistic intensity interacts with a target (combined with a thin and a thick foil) to produce a flying mirror, and a counter propagating probe pulse is applied to generate a high frequency pulse on it. By adjusting the separation between these two foils, the frequency of the Thomson backscattering light generated from the flying mirror can be tuned in a range from ωL to >106ωL, i.e., x-ray or γ-ray with tunable frequency is obtained. The energy dispersion of the flying mirror, as well as the spectrum width of the Thomson backscattering are studied.

  17. J. J. Thomson's Atom: A Number of Negatively Electrified Corpuscles Enclosed in a Sphere of Uniform Positive Electrification

    NASA Astrophysics Data System (ADS)

    Barón, MáXimo

    1996-06-01

    During the 1890s many facts regarding the nature of the atom emerged, the most important being that the atom was composed of even smaller particles. Theoretical and experimental discoveries of the time led to the identification of the first subatomic corpuscle, as J. J. Thomson originally called the electron. The measurement of it's e/m ratio, as well as of the properties of cathode rays, opened up a new perspective of the atom and helped to understand several then unexplained phenomena (e.g., atomic spectra). Reluctant to adopt a planetary view, Thomson deliberately chose an electromagnetic approach that has invoked the image of plum puddings and raisin muffins. Although Thomson's model was unsatisfactory for many reasons, it paved the way for Rutherford, one of his brilliant co-workers.

  18. The influence of Thomson effect in the performance optimization of a two stage thermoelectric cooler

    NASA Astrophysics Data System (ADS)

    Kaushik, S. C.; Manikandan, S.

    2015-12-01

    The exoreversible and irreversible thermodynamic models of a two stage thermoelectric cooler (TTEC) considering Thomson effect in conjunction with Peltier, Joule and Fourier heat conduction effects have been investigated using exergy analysis. New expressions for the interstage temperature, optimum current for the maximum cooling power, energy and exergy efficiency conditions, energy efficiency and exergy efficiency of a TTEC are derived as well. The number of thermocouples in the first and second stages of a TTEC for the maximum cooling power, energy and exergy efficiency conditions are optimized. The results show that the exergy efficiency is lower than the energy efficiency e.g., in an irreversible TTEC with total 30 thermocouples, heat sink temperature (TH) of 300 K and heat source temperature (TC) of 280 K, the obtained maximum cooling power, maximum energy and exergy efficiency are 20.37 W, 0.7147 and 5.10% respectively. It has been found that the Thomson effect increases the cooling power and energy efficiency of the TTEC system e.g., in the exoreversible TTEC the cooling power and energy efficiency increased from 14.87 W to 16.36 W and from 0.4079 to 0.4998 respectively for ΔTC of 40 K when Thomson effect is considered. It has also been found that the heat transfer area at the hot side of an irreversible TTEC should be higher than the cold side for maximum performance operation. This study will help in the designing of the actual multistage thermoelectric cooling systems.

  19. The ITER divertor Thomson scattering system: engineering and advanced hardware solutions

    NASA Astrophysics Data System (ADS)

    Mukhin, E. E.; Semenov, V. V.; Razdobarin, A. G.; Tolstyakov, S. Yu; Kochergin, M. M.; Kurskiev, G. S.; Berezutsky, A. A.; Podushnikova, K. A.; Masyukevich, S. V.; Chernakov, P. V.; Borovkov, A. I.; Modestov, V. S.; Nemov, A. S.; Voinov, A. S.; Kornev, A. F.; Stupnikov, V. K.; Borisov, A. A.; Baranov, G. N.; Koval, A. N.; Makushina, A. F.; Yelizarov, B. A.; Kukushkin, A. S.; Encheva, A.; Andrew, P.

    2012-02-01

    A divertor Thomson scattering (TS) system being developed for ITER has incorporated proven solutions from currently available TS systems. On the other hand any ITER diagnostic has to operate in a hostile environment and very restricted access geometry. Therefore the operation in an environment of intensive stray light, plasma background radiation, the necessity meet the requirement using only a 20 mm gap between divertor cassettes for plasma diagnosis as well as to measure plasma temperatures as low as 1 eV severely constrain the divertor TS diagnostic design. The challenging solutions of this novel diagnostic system which has to ensure its steady performance and also the operability and maintenance are the focus of this report. One of the most demanding parts of the in-vessel diagnostic equipment development is the design assessment using different engineering analyses. The task definition and first results of thermal, e/m and seismic analyses are provided. The process of further improving of the design involves identification of susceptible areas and multiple iterations of the design, as needed. One of the key points for all Thomson scattering diagnostics are the laser capabilities. A high-performance and high-power laser system using a steady-state and high-repetitive mode Nd:YAG laser (2J, 50-100Hz, 3ns) has been developed. The reduced laser pulse duration matched with high-speed low-noise APD detector can be very important under high background light level. For diagnostics such as Thomson scattering and Raman spectroscopy, a high-degree of discrimination against stray light at the laser wavelength is required for successful detection of wavelength-shifted light from the laser-plasma interaction region. For this case of high stray light level, a triple grating polychromator characterized by high rejection and high transmission has been designed and developed. The novel polychromator design minimizes stray light while still maintaining a relatively high

  20. Bi nanowire-based thermal biosensor for the detection of salivary cortisol using the Thomson effect

    NASA Astrophysics Data System (ADS)

    Lee, Seunghyun; Hyun Lee, Jung; Kim, MinGin; Kim, Jeongmin; Song, Min-Jung; Jung, Hyo-Il; Lee, Wooyoung

    2013-09-01

    We present a study of a thermal biosensor based on bismuth nanowire that is fabricated for the detection of the human stress hormone cortisol using the Thomson effect. The Bi nanowire was grown using the On-Film Formation of Nanowires (OFF-ON) method. The thermal device was fabricated using photolithography, and the sensing area was modified with immobilized anti-cortisol antibodies conjugated with protein G for the detection of cortisol. The voltages were measured with two probe tips during surface modification to investigate the biochemical reactions in the fabricated thermal biosensor. The Bi nanowire-based thermal biosensor exhibited low detection limit and good selectivity for the detection of cortisol.

  1. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    NASA Astrophysics Data System (ADS)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang

    2009-06-01

    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  2. LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

    2009-06-01

    Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

  3. Identification of Ions Generated by Ultrashort Laser Pulses using Thomson Spectrometer

    NASA Astrophysics Data System (ADS)

    Oishi, Yuji; Nayuki, Takuya; Fujii, Takashi; Nemoto, Koshichi; Kayoiji, Tsutomu; Horioka, Kazuhiko; Okano, Yasuaki; Hironaka, Yoichiro; Nakamura, Kazutaka G.; Kondo, Ken-ichi

    2002-10-01

    Fast ions generated by irradiation of laser pulses of width 55 fs, intensity 8.6 × 1018 W/cm2 on 5 μ m thickness copper film were measured by use of a Thomson mass spectrometer. From the spectgram, ions ejected from the target surface which was opposite side of the laser irradiation were determined to be protons. Copper ions were not observed. From the enegy measurements using Mylar filter method, the maximum proton energy was estimated more than 650 keV.

  4. Numerical Study of the Structure of Metastable Configurations for the Thomson Problem

    NASA Astrophysics Data System (ADS)

    Bondarenko, A. N.; Bugueva, T. V.; Kozinkin, L. A.

    2016-05-01

    A numerical method is proposed for solving the Thomson problem - finding stable positions for a system of N point charges distributed on a sphere that minimize the potential energy of the system. The behavior of this system is essentially nonlinear, and the number of metastable structures grows exponentially with N. This makes the problem of finding all stable configurations extremely difficult. The results of testing of the developed algorithm and of numerical study of the properties of the local potential energy minima for a system of point charges are presented.

  5. X-ray Thomson scattering diagnostics of impact ionization in laser-driven carbon foils

    NASA Astrophysics Data System (ADS)

    Sperling, P.; Zastrau, U.; Toleikis, S.; Glenzer, S. H.; Redmer, R.

    2015-06-01

    We have studied the light-matter interaction of ultra-short, intense optical laser fields with thin carbon foils via particle-in-cell simulations. Especially, the influence of additional impact ionization on the density and temperature of the generated plasma and on the corresponding Thomson scattering spectra was investigated. We predict a pump-probe experiment at the free electron laser FLASH in order to verify the importance of this effect in the laser-matter interaction on ultra-short time scales and to check our predictions quantitatively.

  6. Report on a case of Rothmund-Thomson syndrome associated with esophageal stenosis.

    PubMed

    Polese, L; Merigliano, S; Mungo, B; Pennelli, G; Norberto, L

    2011-11-01

    Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis. While its incidence is unknown, approximately 300 cases have been reported in the literature. The syndrome typically presents with a characteristic facial rash (poikiloderma), its diagnostic hallmark, and heterogeneous clinical features including congenital skeletal abnormalities, sparse hair distribution, juvenile cataracts, and a predisposition to osteosarcoma. Gastrointestinal symptoms, such as pyloric stenosis, anal atresia, annular pancreas, and rectovaginal fistula, have also been reported sporadically. This is a report describing a patient diagnosed with RTS referred to us because of dysphagia caused by esophageal stenosis. Long-term results of endoscopic dilation are also presented. PMID:21951866

  7. Data processing and analysis of the imaging Thomson scattering diagnostic system on HT-7 tokamak

    SciTech Connect

    Han Xiaofeng; Shao Chunqiang; Xi Xiaoqi; Zhao Junyu; Qing Zang; Yang Jianhua; Dai Xingxing; Shinichiro, Kado

    2013-05-15

    A high spatial resolution imaging Thomson scattering diagnostic system was developed in ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences). After about one month trial running on the superconducting HT-7 (Hefei Tokamak-7) tokamak, the system was proved to be capable of measuring plasma electron temperature. The system setup and data calibration are described in this paper and then the instrument function is studied in detail, as well as the measurement capability, an electron temperature of 50 eV to 2 keV and density beyond 1 Multiplication-Sign 10{sup 19} m{sup -3}. Finally, the data processing method and experimental results are presented.

  8. Thomson scattering measurement of a shock in laser-produced counter-streaming plasmas

    SciTech Connect

    Morita, T.; Kuramitsu, Y.; Moritaka, T.; Sakawa, Y.; Takabe, H.; Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 ; Tomita, K.; Nakayama, K.; Inoue, K.; Uchino, K.; Ide, T.; Tsubouchi, K.; Nishio, K.; Ide, H.; Kuwada, M.

    2013-09-15

    We report the first direct measurement of temporally and spatially resolved plasma temperatures at a shock as well as its spatial structure and propagation in laser-produced counter-streaming plasmas. Two shocks are formed in counter-streaming collisionless plasmas early in time, and they propagate opposite directions. This indicates the existence of counter-streaming collisionless flows to keep exciting the shocks, even though the collisional effects increase later in time. The shock images are observed with optical diagnostics, and the upstream and downstream plasma parameters of one of the shocks are measured using Thomson scattering technique.

  9. Controlling the spectral shape of nonlinear Thomson scattering with proper laser chirping

    NASA Astrophysics Data System (ADS)

    Rykovanov, S. G.; Geddes, C. G. R.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2016-03-01

    Effects of nonlinearity in Thomson scattering of a high intensity laser pulse from electrons are analyzed. Analytic expressions for laser pulse shaping in frequency (chirping) are obtained which control spectrum broadening for high laser pulse intensities. These analytic solutions allow prediction of the spectral form and required laser parameters to avoid broadening. Results of analytical and numerical calculations agree well. The control over the scattered radiation bandwidth allows narrow bandwidth sources to be produced using high scattering intensities, which in turn greatly improves scattering yield for future x- and gamma-ray sources.

  10. Data processing and analysis of the imaging Thomson scattering diagnostic system on HT-7 tokamak.

    PubMed

    Han, Xiaofeng; Shao, Chunqiang; Xi, Xiaoqi; Zhao, Junyu; Qing, Zang; Yang, Jianhua; Dai, Xingxing; Kado, Shinichiro

    2013-05-01

    A high spatial resolution imaging Thomson scattering diagnostic system was developed in ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences). After about one month trial running on the superconducting HT-7 (Hefei Tokamak-7) tokamak, the system was proved to be capable of measuring plasma electron temperature. The system setup and data calibration are described in this paper and then the instrument function is studied in detail, as well as the measurement capability, an electron temperature of 50 eV to 2 keV and density beyond 1 × 10(19) m(-3). Finally, the data processing method and experimental results are presented. PMID:23742546

  11. Edge Thomson scattering diagnostic on COMPASS tokamak: installation, calibration, operation, improvements.

    PubMed

    Bohm, P; Aftanas, M; Bilkova, P; Stefanikova, E; Mikulin, O; Melich, R; Janky, F; Havlicek, J; Sestak, D; Weinzettl, V; Stockel, J; Hron, M; Panek, R; Scannell, R; Frassinetti, L; Fassina, A; Naylor, G; Walsh, M J

    2014-11-01

    The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along the laser beam up to ∼1/100 of the tokamak minor radius, is presented now. The procedure for spatial calibration and alignment of both core and edge systems is described. Several further upgrades of the TS system, like a triggering unit and piezo motor driven vacuum window shutter, are introduced as well. The edge TS system, together with the core TS, is now in routine operation and provides electron temperature and density profiles. PMID:25430338

  12. Tunable all-optical quasimonochromatic thomson x-ray source in the nonlinear regime.

    PubMed

    Khrennikov, K; Wenz, J; Buck, A; Xu, J; Heigoldt, M; Veisz, L; Karsch, S

    2015-05-15

    We present an all-laser-driven, energy-tunable, and quasimonochromatic x-ray source based on Thomson scattering from laser-wakefield-accelerated electrons. One part of the laser beam was used to drive a few-fs bunch of quasimonoenergetic electrons, while the remainder was backscattered off the bunch at weakly relativistic intensity. When the electron energy was tuned from 17-50 MeV, narrow x-ray spectra peaking at 5-42 keV were recorded with high resolution, revealing nonlinear features. We present a large set of measurements showing the stability and practicality of our source. PMID:26024176

  13. Polarization from Thomson scattering of the light of a spherical, limb-darkened star

    NASA Technical Reports Server (NTRS)

    Rudy, R. J.

    1979-01-01

    The polarized flux produced by the Thomson scattering of the light of a spherical, limb-darkened star by optically thin, extrastellar regions of electrons is calculated and contrasted to previous models which treated the star as a point source. The point-source approximation is found to be valid for scattering by particles more than a stellar radius from the surface of the star but is inappropriate for those lying closer. The specific effect of limb darkening on the fractional polarization of the total light of a system is explored. If the principal source of light is the unpolarized flux of the star, the polarization is nearly independent of limb darkening.

  14. Effect of changes in viewing window transmission on high-temperature Thomson scattering data

    SciTech Connect

    McNeill, D.H. )

    1990-04-01

    Unmonitored changes in the transmission of viewing windows owing to deposited films can produce errors in Thomson scattering temperature measurements. This effect is illustrated by a recent run on the Tokamak Fusion Test Reactor (TFTR) where apparent errors of over 25% in peak temperatures of 9 keV owing to carbon films were noted. Since coatings can also be removed by hydrogen discharges, the transmission of a window may change with time, resulting in variable errors in the temperature. It is proposed that these changes be monitored by calibration {ital in} {ital situ} with the aid of a low-pressure hydrogen glow discharge.

  15. Thomson scattering experiments on a 100 MHz inductively coupled plasma calibrated by Raman scattering

    SciTech Connect

    de Regt, J.M.; Engeln, R.A.H.; de Groote, F.P.J.; van der Mullen, J.A.M.; Schram, D.C.

    1995-05-01

    A new calibration method to obtain the electron density from Thomson scattering on an inductively coupled plasma is discussed. Raman scattering of nitrogen is used for recovering the Rayleigh scattering signal. This has the advantage that no corrections are necessary for stray light, like with other calibration methods, using the direct measured Rayleigh scattering signal on a well-known gas. It is shown that electron densities and electron temperatures can be measured with an accuracy of about 15% in density and of about 150 K in temperature. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  16. Recent electron temperature and density results from the ATF Thomson scattering system

    SciTech Connect

    Rasmussen, D.A.; England, A.C.; Murakami, M.; Howe, H.C.; Clark, T.L.; Kindsfather, R.R.; Rayburn, T.M.; Stewart, K.A.; Rogers, P.S.; Bell, G.L.

    1989-01-01

    A spatial multipoint Thomson scattering system has been developed for the Advanced Toroidal Facility (ATF) torsatron. The system measures temperature and density at 15 vertical locations on a vertical chord for each laser shot (one per plasma discharge). By remotely relocating the laser beam and reconfiguring the viewing optics during a series of ATF discharges, a two-dimensional (2-D) electron temperature and density map of the plasma cross section can be obtained. Results obtained with this system during ATF operation in 1988 and early 1989 are presented. 7 refs., 6 figs.

  17. Edge Thomson scattering diagnostic on COMPASS tokamak: Installation, calibration, operation, improvements

    SciTech Connect

    Bohm, P. Bilkova, P.; Melich, R.; Sestak, D.; Weinzettl, V.; Stockel, J.; Hron, M.; Panek, R.; Mikulin, O.; Scannell, R.; Naylor, G.; Frassinetti, L.; Fassina, A.; Walsh, M. J.

    2014-11-15

    The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along the laser beam up to ∼1/100 of the tokamak minor radius, is presented now. The procedure for spatial calibration and alignment of both core and edge systems is described. Several further upgrades of the TS system, like a triggering unit and piezo motor driven vacuum window shutter, are introduced as well. The edge TS system, together with the core TS, is now in routine operation and provides electron temperature and density profiles.

  18. Generalized Thomson problem in arbitrary dimensions and non-euclidean geometries

    NASA Astrophysics Data System (ADS)

    Batle, J.; Bagdasaryan, Armen; Abdel-Aty, M.; Abdalla, S.

    2016-06-01

    Systems of identical particles with equal charge are studied under a special type of confinement. These classical particles are free to move inside some convex region S and on the boundary of it Ω (the S d - 1 -sphere, in our case). We shall show how particles arrange themselves under the sole action of the Coulomb repulsion in many dimensions in the usual Euclidean space, therefore generalizing the so called Thomson problem to many dimensions. Also, we explore how the problem varies when non-Euclidean geometries are considered. We shall see that optimal configurations in all cases possess a high degree of symmetry, regardless of the concomitant dimension or geometry.

  19. Ultrashort hard x-ray pulses generated by 90 degrees Thomson scattering

    SciTech Connect

    Chin, A.H.; Schoenlein, R.W.; Glover, T.E.

    1997-04-01

    Ultrashort x-ray pulses permit observation of fast structural dynamics in a variety of condensed matter systems. The authors have generated 300 femtosecond, 30 keV x-ray pulses by 90 degrees Thomson scattering between femtosecond laser pulses and relativistic electrons. The x-ray and laser pulses are synchronized on a femtosecond time scale, an important prerequisite for ultrafast pump-probe spectroscopy. Analysis of the x-ray beam properties also allows for electron bunch characterization on a femtosecond time scale.

  20. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering.

    PubMed

    Bindslev, H; Nielsen, S K; Porte, L; Hoekzema, J A; Korsholm, S B; Meo, F; Michelsen, P K; Michelsen, S; Oosterbeek, J W; Tsakadze, E L; Westerhof, E; Woskov, P

    2006-11-17

    Here we present the first measurements by collective Thomson scattering of the evolution of fast-ion populations in a magnetically confined fusion plasma. 150 kW and 110 Ghz radiation from a gyrotron were scattered in the TEXTOR tokamak plasma with energetic ions generated by neutral beam injection and ion cyclotron resonance heating. The temporal behavior of the spatially resolved fast-ion velocity distribution is inferred from the received scattered radiation. The fast-ion dynamics at sawteeth and the slowdown after switch off of auxiliary heating is resolved in time. The latter is shown to be in close agreement with modeling results. PMID:17155690

  1. Femtosecond x-rays from Thomson scattering using laser wakefield accelerators

    SciTech Connect

    Catravas, P.; Esarey, E.; Leemans, W.P.

    2001-03-01

    The possibility of producing femtosecond x-rays through Thomson scattering high power laser beams off laser wakefield generated relativistic electron beams is discussed. The electron beams are produced with either a self-modulated laser wakefield accelerator (SM-LWFA) or through a standard laser wakefield accelerator (LWFA) with optical injection. For a SM-LWFA (LWFA) produced electron beam, a broad (narrow) energy distribution is assumed, resulting in X-ray spectra that are broadband (monochromatic). Designs are presented for 3-100 fs x-ray pulses and the expected flux and brightness of these sources are compared.

  2. Time evolution analysis of the electron distribution in Thomson/Compton back-scattering

    SciTech Connect

    Petrillo, V.; Bacci, A.; Curatolo, C.; Maroli, C.; Serafini, L.; Rossi, A. R.

    2013-07-28

    We present the time evolution of the energy distribution of a relativistic electron beam after the Compton back-scattering with a counter-propagating laser field, performed in the framework of the Quantum Electrodynamics, by means of the code CAIN. As the correct angular distribution of the spontaneous emission is accounted, the main effect is the formation of few stripes, followed by the diffusion of the more energetic particles toward lower values in the longitudinal phase space. The Chapman-Kolmogorov master equation gives results in striking agreement with the numerical ones. An experiment on the Thomson source at SPARC-LAB is proposed.

  3. Temporally resolved plasma composition measurements by collective Thomson scattering in TEXTOR (invited)a)

    NASA Astrophysics Data System (ADS)

    Stejner, M.; Korsholm, S. B.; Nielsen, S. K.; Salewski, M.; Bindslev, H.; Leipold, F.; Michelsen, P. K.; Meo, F.; Moseev, D.; Bürger, A.; Kantor, M.; de Baar, M.

    2012-10-01

    Fusion plasma composition measurements by collective Thomson scattering (CTS) were demonstrated in recent proof-of-principle measurements in TEXTOR [S. B. Korsholm et al., Phys. Rev. Lett. 106, 165004 (2011), 10.1103/PhysRevLett.106.165004]. Such measurements rely on the ability to resolve and interpret ion cyclotron structure in CTS spectra. Here, we extend these techniques to enable temporally resolved plasma composition measurements by CTS in TEXTOR, and we discuss the prospect for such measurements with newly installed hardware upgrades for the CTS system on ASDEX Upgrade.

  4. Numerical analysis of the Gibbs-Thomson effect on trench-filling epitaxial growth of 4H-SiC

    NASA Astrophysics Data System (ADS)

    Mochizuki, Kazuhiro; Ji, Shiyang; Kosugi, Ryoji; Kojima, Kazutoshi; Yonezawa, Yoshiyuki; Okumura, Hajime

    2016-03-01

    A steady-state two-dimensional diffusion equation was numerically analyzed to examine the rate of homoepitaxial growth on a trenched 4H-SiC substrate. The radii of curvature at the top and bottom of the trenches were used to take the Gibbs-Thomson effect into account in the analysis based on the conventional boundary-layer model. When the trench pitch was less than or equal to 6.0 µm, the measured dependence of the growth rate on the trench pitch was found to be explained by the Gibbs-Thomson effect on the vapor-phase diffusion of growing species.

  5. Spectrum bandwidth narrowing of Thomson scattering X-rays with energy chirped electron beams from laser wakefield acceleration

    SciTech Connect

    Xu, Tong; Chen, Min Li, Fei-Yu; Yu, Lu-Le; Sheng, Zheng-Ming; SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG ; Zhang, Jie; Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190

    2014-01-06

    We study incoherent Thomson scattering between an ultrashort laser pulse and an electron beam accelerated from a laser wakefield. The energy chirp effects of the accelerated electron beam on the final radiation spectrum bandwidth are investigated. It is found that the scattered X-ray radiation has the minimum spectrum width and highest intensity as electrons are accelerated up to around the dephasing point. Furthermore, it is proposed that the electron acceleration process inside the wakefield can be studied by use of 90° Thomson scattering. The dephasing position and beam energy chirp can be deduced from the intensity and bandwidth of the scattered radiation.

  6. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    NASA Astrophysics Data System (ADS)

    Yatsuka, E.; Hatae, T.; Suitoh, S.; Ohara, M.; Hagita, K.; Inoue, K.; Bassan, M.; Walsh, M.; Itami, K.

    2016-01-01

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port.

  7. Detecting non-maxwellian electron velocity distributions at JET by high resolution Thomson scattering.

    PubMed

    Beausang, K V; Prunty, S L; Scannell, R; Beurskens, M N; Walsh, M J; de la Luna, E

    2011-03-01

    The present work is motivated by a long standing discrepancy between the electron temperature measurements of Thomson scattering (TS) and electron cyclotron emission (ECE) diagnostics for plasmas with strong auxiliary heating observed at both JET and TFTR above 6–7 keV, where in some cases the ECE electron temperature measurements can be 15%–20% higher than the TS measurements. Recent analysis based on ECE results at JET has shown evidence of distortions to the Maxwellian electron velocity distribution and a correlation with the TS and ECE discrepancies has been suggested. In this paper, a technique to determine the presence of non-Maxwellian behavior using TS diagnostics is outlined. The difficulties and limitations of modern TS system designs to determine the electron velocity distribution are also discussed. It is demonstrated that small deviations such as those suggested by previous ECE analysis could be potentially detected, depending on the spectral layout of the TS polychromators. The spectral layout of the JET high resolution Thomson scattering system is such that it could be used to determine these deviations between 1 and 6 keV, and the results presented here indicate that no evidence of non-Maxwellian behavior is observed in this range. In this paper, a modification to the current polychromator design is proposed, allowing non-Maxwellian distortions to be detected up to at least 10 keV. PMID:21585113

  8. Detecting non-Maxwellian electron velocity distributions at JET by high resolution Thomson scattering

    SciTech Connect

    Beausang, K. V.; Prunty, S. L.; Scannell, R.; Beurskens, M. N.; Walsh, M. J.; Collaboration: JET EFDA Contributors

    2011-03-15

    The present work is motivated by a long standing discrepancy between the electron temperature measurements of Thomson scattering (TS) and electron cyclotron emission (ECE) diagnostics for plasmas with strong auxiliary heating observed at both JET and TFTR above 6-7 keV, where in some cases the ECE electron temperature measurements can be 15%-20% higher than the TS measurements. Recent analysis based on ECE results at JET has shown evidence of distortions to the Maxwellian electron velocity distribution and a correlation with the TS and ECE discrepancies has been suggested. In this paper, a technique to determine the presence of non-Maxwellian behavior using TS diagnostics is outlined. The difficulties and limitations of modern TS system designs to determine the electron velocity distribution are also discussed. It is demonstrated that small deviations such as those suggested by previous ECE analysis could be potentially detected, depending on the spectral layout of the TS polychromators. The spectral layout of the JET high resolution Thomson scattering system is such that it could be used to determine these deviations between 1 and 6 keV, and the results presented here indicate that no evidence of non-Maxwellian behavior is observed in this range. In this paper, a modification to the current polychromator design is proposed, allowing non-Maxwellian distortions to be detected up to at least 10 keV.

  9. Concept to diagnose mix with imaging x-ray Thomson scattering

    SciTech Connect

    Keiter, Paul A.; Gamboa, Eliseo J.; Huntington, Channing M.; Kuranz, Carolyn C.

    2012-10-15

    Turbulent mixing of two fluid species is a ubiquitous problem, prevalent in systems such as inertial confinement fusion (ICF) capsule implosions, supernova remnants, and other astrophysical systems. In complex, high Reynolds number compressible high energy density (HED) flows such as these, hydrodynamic instabilities initiate the turbulent mixing process, which can then feedback and alter the mean hydrodynamic motion through nonlinear processes. In order to predict how these systems evolve under turbulent conditions, models are used. However, these models require detailed quantitative data to validate and constrain their detailed physics models as well as improve them. Providing this much needed data is currently at the forefront of HED research but is proving elusive due to a lack of available diagnostics capable of directly measuring detailed flow variables. Thomson scattering is a promising technique in this regard as it provides fundamental conditions of the flow ({rho}, T, Zbar) due to its direct interaction with the small scales of the fluid or plasma and was recently considered as a possible mix diagnostic. With the development of imaging x-ray Thomson scattering (IXRTS) obtaining spatial profiles of these variables is within reach. We propose a novel use of the IXRTS technique that will provide more detailed quantitative data required for model validation in mix experiments.

  10. Surpassing one x-ray photon per electron in nonlinear Thomson scattering in 180 deg. geometry

    SciTech Connect

    Zhao Shihua; Lv Qingzheng; Yuan Suying; Li Yingjun

    2012-01-15

    We have obtained the general analytical expressions of harmonic radiation for Thomson scattering (TS) of arbitrary polarized laser by virtue of generalized Bessel functions and derived the extremum conditions for backscattered harmonics. Especially, for the fundamental backscattered Thomson scattering x-ray yield, we have shown that at the same conditions, the circular polarization reaches maximum while the linear case minimum. This effect is significant when a{sup 2}{>=}1. With the assumption that the x-ray photon yield of a realistic focused pulse of energy E, wavelength {lambda}, and Rayleigh range z{sub R} is equivalent to a plane wave pulse containing N{sub l} cycles via the relation N{sub l}{lambda}=pz{sub R} where the effective factor p is of order one, we applied the plane wave results to realistic laser pulses and deduced that the backscattered x-ray photon number N{sub f} per electron achieves its peak value when the average dimensionless laser intensity a{sup 2}=0.677 and is irrelevant to the value of p. Since N{sub f} and its maximum N{sub fmax} both scale with the square root of E/{lambda}, it is realizable to attain N{sub f}{>=}1 using joule-scale laser pulses while a great challenge for N{sub f}>10.

  11. Simultaneous imaging electron- and ion-feature Thomson scattering measurements of radiatively heated Xe

    SciTech Connect

    Pollock, B. B.; Meinecke, J.; Kuschel, S.; Ross, J. S.; Divol, L.; Glenzer, S. H.; Shaw, J. L.; Stoafer, C.; Tynan, G. R.

    2012-10-15

    Uniform density and temperature Xe plasmas have been produced over >4 mm scale-lengths using x-rays generated in a cylindrical Pb cavity. The cavity is 750 {mu}m in depth and diameter, and is heated by a 300 J, 2 ns square, 1054 nm laser pulse focused to a spot size of 200 {mu}m at the cavity entrance. The plasma is characterized by simultaneous imaging Thomson scattering measurements from both the electron and ion scattering features. The electron feature measurement determines the spatial electron density and temperature profile, and using these parameters as constraints in the ion feature analysis allows an accurate determination of the charge state of the Xe ions. The Thomson scattering probe beam is 40 J, 200 ps, and 527 nm, and is focused to a 100 {mu}m spot size at the entrance of the Pb cavity. Each system has a spatial resolution of 25 {mu}m, a temporal resolution of 200 ps (as determined by the probe duration), and a spectral resolution of 2 nm for the electron feature system and 0.025 nm for the ion feature system. The experiment is performed in a Xe filled target chamber at a neutral pressure of 3-10 Torr, and the x-rays produced in the Pb ionize and heat the Xe to a charge state of 20{+-}4 at up to 200 eV electron temperatures.

  12. Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source.

    PubMed

    Du, Yingchao; Yan, Lixin; Hua, Jianfei; Du, Qiang; Zhang, Zhen; Li, Renkai; Qian, Houjun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2013-05-01

    Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 × 10(6) per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented. PMID:23742539

  13. Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source

    SciTech Connect

    Du Yingchao; Yan Lixin; Hua Jianfei; Du Qiang; Zhang Zhen; Li Renkai; Qian Houjun; Huang Wenhui; Chen Huaibi; Tang Chuanxiang

    2013-05-15

    Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 Multiplication-Sign 10{sup 6} per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented.

  14. Status of the Alcator C-MOD scanning two-dimensional Thomson scattering diagnostic

    SciTech Connect

    Watterson, R. ); Chen, K. )

    1990-10-01

    The detailed study of noncircular tokamak discharges will require measurements of local {ital T}{sub {ital e}} and {ital n}{sub {ital e}} over a two-dimensional region. A novel scanning Thomson scattering system is under construction for use on the Alcator C-Mod device. A multipulse (50 Hz pulse rate) Nd:YAG laser (1 J, 15 nS) will be used to scan the plasma major radius within a 14 cm range during a 160 mS period with a spatial step size of 2 cm. The laser beam sweep, which is limited by the size of the diagnostic ports, will cover {approximately}50% of the plasma discharge cross section. The scattered laser light spectra at various positions along the vertical laser beam path will be analyzed by a set of up to 11 (initial operation is planned for six) Wadsworth spectrometers. A prototype spectrometer with associated light collection optics has been tested and the total Thomson system optical transmission has been measured to be {approximately}12--15%. System details and performance measurements will be presented.

  15. 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}Thomson scattered laser light, our study yields temperatures close to those obtained by modeling and time-resolved spectroscopic measurements.

  16. Progress on the multipulse Thomson Scattering diagnostic on DIII-D

    SciTech Connect

    Stockdale, R.E.; Carlstrom, T.N.; Hsieh, C.L.; Makariou, C.C.

    1994-05-01

    The DIII-D Thomson scattering diagnostic, operational since 1990, uses 8 Nd: YAG 20 Hz lasers to measure electron temperature and density profiles (40 spatial points) throughout the plasma discharge. Recent progress has enabled a new set of operating modes to better fullfill varying plasma physics requirements. Custom circuitry for laser control (programmable with los precision) has successfully replaced a previous scheme which used real-time 68030 software. Two new modes of operation have been demonstrated. Burst Mode is useful to study a transient plasma event: a series of laser pulses axe fired at a rate {le}10 kHz after an external asynchronous event trigger. Burst Mode is also useful to synchronize the Thomson lasers with other systems, such as an asynchronous Michelson ECE diagnostic scanning near 40 Hz. Group Mode allows a programmed set of lasers to fire simultaneously into the same (65 nanosecond) data acquisition gate. Improved signal/noise then yields smaller statistical errors in the profile results. This provides profile data for lower density plasmas, such as those anticipated during fast wave current drive experiments. Plans for a new CCD-based laser alignment system for position monitoring and feedback control will also be presented.

  17. Thomson Scattering Density Calibration by Rayleigh and Rotational Raman Scattering on NSTX

    SciTech Connect

    B.P. LeBlanc

    2008-07-16

    The multi-point Thomson scattering (MPTS) diagnostic measures the profiles of the electron temperature Te(R) and density ne(R) on the horizontal midplane of NSTX. Normal operation makes use of Rayleigh scattering in nitrogen or argon to derive the density profile. While the Rayleigh scattering ne(R) calibration has been validated by comparison with other density measurements and through its correlation with plasma phenomena, it does require dedicated detectors at the laser wavelength in this filter polychromator based diagnostic. The presence of dust and/or stray laser light precludes routine use of these dedicated spectral channels for Thomson scattering measurement. Hence it is of interest to investigate the use of Raman scattering in nitrogen for the purpose of density calibration, since it could free up detection equipment, which could then be used for the instrumentation of additional radial channels. In this paper the viewing optics "geometrical factor" profiles obtained from Rayleigh and Raman scattering are compared. While both techniques agree nominally, residual effects on the order of 10% remain and will be discussed.

  18. Design and implementation of a Thomson scattering diagnostic for the Compact Toroidal Hybrid Experiment

    NASA Astrophysics Data System (ADS)

    Traverso, P. J.; Maurer, D. A.; Ennis, D. A.; Hartwell, G. J.; Goforth, M. M.; Loch, S. D.; Pearce, A. J.; Cianciosa, M. R.

    2014-10-01

    A Thomson scattering system using standard commercially available components has been designed for the non-axisymmetric plasmas of the Compact Toroidal Hybrid (CTH). The initial system takes a single point measurement and will be used to assess options for an upgrade to a multi-point system providing electron temperature and density profiles. This single point measurement will reduce the uncertainty in the reconstructed peak pressure by an order of magnitude for both ohmically driven, current-carrying plasmas and future gyrotron-heated stellarator plasmas. A principle design goal is to minimize stray laser light, geometrically on the machine side and spectrally on the collection side, to allow measurements of both full and half Thomson scattered spectral profiles. The beam, generated by a frequency doubled Continuum 2 J Nd:YaG laser, is passed vertically through an entrance Brewster window and an aperturing baffle system to minimize stray light. Light collection, spectral processing, and signal detection are accomplished with an f / # ~ 1 aspheric lens, a Holospec f/1.8 spectrometer, and an Andor iStar DH740-18U-C3 image intensified camera. The estimated number of scattered photons per channel will be of the order of 5 ×103 with a signal to noise ratio of S / N = 19 This work is supported by U.S. Department of Energy Grant No. DE-FG02-00ER54610.

  19. Concept to diagnose mix with imaging x-ray Thomson scattering.

    PubMed

    Keiter, Paul A; Gamboa, Eliseo J; Huntington, Channing M; Kuranz, Carolyn C

    2012-10-01

    Turbulent mixing of two fluid species is a ubiquitous problem, prevalent in systems such as inertial confinement fusion (ICF) capsule implosions, supernova remnants, and other astrophysical systems. In complex, high Reynolds number compressible high energy density (HED) flows such as these, hydrodynamic instabilities initiate the turbulent mixing process, which can then feedback and alter the mean hydrodynamic motion through nonlinear processes. In order to predict how these systems evolve under turbulent conditions, models are used. However, these models require detailed quantitative data to validate and constrain their detailed physics models as well as improve them. Providing this much needed data is currently at the forefront of HED research but is proving elusive due to a lack of available diagnostics capable of directly measuring detailed flow variables. Thomson scattering is a promising technique in this regard as it provides fundamental conditions of the flow (ρ, T, Zbar) due to its direct interaction with the small scales of the fluid or plasma and was recently considered as a possible mix diagnostic. With the development of imaging x-ray Thomson scattering (IXRTS) obtaining spatial profiles of these variables is within reach. We propose a novel use of the IXRTS technique that will provide more detailed quantitative data required for model validation in mix experiments. PMID:23127040

  20. A high-resolution Lidar-Thomson scattering diagnostic for JET

    NASA Astrophysics Data System (ADS)

    Fajemirokun, H.; Gowers, C.; Nielsen, P.; Salzmann, H.; Hirsch, K.

    1990-10-01

    A LIDAR-Thomson scattering system with better than 5 cm spatial resolution to resolve edge electron temperature and density gradients in H-mode operation in JET is needed. A dynamic range in measurable electron temperature of 0.1-1.5 keV and a minimum detectable electron density of 1019/m3 are required. To achieve these levels of performance, it is planned to use a modified section of the existing JET LIDAR-Thomson scattering system. A new detection system, consisting of a streak camera and an intensifier unit, will be used. Spectral dispersion is to be performed by a three-channel edge filter spectrometer. Recording and digitization of the scattered signal will be performed by a CCD camera read out by a personal computer. The system is described and results of experiments to determine the minimum visible light levels using a commercial streak camera, intensifier unit, and CCD camera and a pulsed laser diode light source are briefly presented. In addition, simulations of expected signal-to-noise ratio performance are discussed.

  1. Gibbs-Thomson Effect in Planar Nanowires: Orientation and Doping Modulated Growth.

    PubMed

    Shen, Youde; Chen, Renjie; Yu, Xuechao; Wang, Qijie; Jungjohann, Katherine L; Dayeh, Shadi A; Wu, Tom

    2016-07-13

    Epitaxy-enabled bottom-up synthesis of self-assembled planar nanowires via the vapor-liquid-solid mechanism is an emerging and promising approach toward large-scale direct integration of nanowire-based devices without postgrowth alignment. Here, by examining large assemblies of indium tin oxide nanowires on yttria-stabilized zirconia substrate, we demonstrate for the first time that the growth dynamics of planar nanowires follows a modified version of the Gibbs-Thomson mechanism, which has been known for the past decades to govern the correlations between thermodynamic supersaturation, growth speed, and nanowire morphology. Furthermore, the substrate orientation strongly influences the growth characteristics of epitaxial planar nanowires as opposed to impact at only the initial nucleation stage in the growth of vertical nanowires. The rich nanowire morphology can be described by a surface-energy-dependent growth model within the Gibbs-Thomson framework, which is further modulated by the tin doping concentration. Our experiments also reveal that the cutoff nanowire diameter depends on the substrate orientation and decreases with increasing tin doping concentration. These results enable a deeper understanding and control over the growth of planar nanowires, and the insights will help advance the fabrication of self-assembled nanowire devices. PMID:27254592

  2. A parallelized Python based Multi-Point Thomson Scattering analysis in NSTX-U

    NASA Astrophysics Data System (ADS)

    Miller, Jared; Diallo, Ahmed; Leblanc, Benoit

    2014-10-01

    Multi-Point Thomson Scattering (MPTS) is a reliable and accurate method of finding the temperature, density, and pressure of a magnetically confined plasma. Nd:YAG (1064 nm) lasers are fired into the plasma with a frequency of 60 Hz, and the light is Doppler shifted by Thomson scattering. Polychromators on the midplane of the tokamak pick up the light at various radii/scattering angles, and the avalanche photodiode's voltages are added to an MDSplus tree for later analysis. This project ports and optimizes the prior serial IDL MPTS code into a well-documented Python package that runs in parallel. Since there are 30 polychromators in the current NSTX setup (12 more will be added when NSTX-U is completed), using parallelism offers vast savings in performance. NumPy and SciPy further accelerate numerical calculations and matrix operations, Matplotlib and PyQt make an intuitive GUI with plots of the output, and Multiprocessing parallelizes the computationally intensive calculations. The Python package was designed with portability and flexibility in mind so it can be adapted for use in any polychromator-based MPTS system.

  3. a Numerical Study on the Performance of the Miniature Joule-Thomson Refrigerator

    NASA Astrophysics Data System (ADS)

    Hong, Y. J.; Park, S. J.; Choi, Y. D.

    2010-04-01

    Miniature Joule-Thomson refrigerators have been widely used for rapid cooling of infrared detectors, probes of cryosurgery, thermal cameras, and missile homing head and guidance systems, due to their special features of simple configuration, compact structure and rapid cool-down characteristics. The cool-down time, the temperature at the cold end, the running time and the gas consumption are the important indicators of the performance of the Joule-Thomson refrigerator. In this study, a simplified one-dimensional model of momentum and energy transport for the recuperative heat exchanger was adopted to predict the thermodynamic behaviors of the refrigerator. In the analysis, to consider the thermal interactions of the each component of the refrigerator, the momentum and energy equations for the high pressure gas, the low pressure gas, the tube, the Dewar, and the mandrel were simultaneously solved. The thermodynamic properties from the REFPROP were used to account the real gas effects of the gas. The results show the effects of the supply pressure of gas on the transient behaviors of the temperature at the cold end and the thermal performance of the recuperative heat exchanger.

  4. X-ray Thomson scattering measurements of temperature and density from multi-shocked CH capsules

    DOE PAGESBeta

    Fletcher, L. B.; Glenzer, S. H.; Kritcher, A.; Pak, A.; Ma, T.; Doppner, T.; Fortmann, C.; Divol, L.; Landen, O. L.; Vorberger, J.; et al

    2013-05-24

    Proof-of-principle measurements of the electron densities, temperatures, and ionization states of spherically compressed multi-shocked CH (polystyrene) capsules have been achieved using spectrally resolved x-ray Thomson scattering. A total energy of 13.5 kJ incident on target is used to compress a 70 μm thick CH shell above solid-mass density using three coalescing shocks. Separately, a laser-produced zinc He-α x-ray source at 9 keV delayed 200 ps-800 ps after maximum compression is used to probe the plasma in the non-collective scattering regime. The data show that x-ray Thomson scattering enables a complete description of the time-dependent hydrodynamic evolution of shock-compressed CH capsules,more » with a maximum measured density of ρ > 6 g cm–3. Additionally, the results demonstrate that accurate measurements of x-ray scattering from bound-free transitions in the CH plasma demonstrate strong evidence that continuum lowering is the primary ionization mechanism of carbon L-shell electrons.« less

  5. Thomson scattering and ponderomotive intermodulation within standing laser beat waves in plasma.

    PubMed

    Sepke, Scott; Lau, Y Y; Holloway, James Paul; Umstadter, Donald

    2005-08-01

    Electrons in a standing electromagnetic wave--an optical lattice--tend to oscillate due to the quiver and ponderomotive potentials. For sufficiently intense laser fields (Ilamda2 approximately < or = 5 x 10(17) W cm(-2) microm2) and in plasmas with sufficiently low electron densities (n approximately < or = 10(18) cm(-3)), these oscillations can occur faster than the plasma can respond. This paper shows that these oscillations result in Thomson scattering of light at both the laser and ponderomotive bounce frequencies and their harmonics as well as at mixtures of these frequencies. We term this mixing ponderomotive intermodulation. Here, the case of counterpropagating laser beams creating a one-dimensional (1D) optical lattice is analyzed. The near-equilibrium electron orbits and subsequent Thomson scattering patterns are computed in the single-particle limit. Scaling laws are derived to quantify the range of validity of this approach. Finally, collective plasma and laser focusing effects are included by using particle-in-cell (PIC) techniques. This effect resulting in light-frequency conversion has applications both as an infrared light source and as a means to diagnose high laser intensities inside dense plasmas. PMID:16196727

  6. X-ray Thomson scattering measurements of temperature and density from multi-shocked CH capsules

    SciTech Connect

    Fletcher, L. B.; Glenzer, S. H.; Kritcher, A.; Pak, A.; Ma, T.; Doppner, T.; Fortmann, C.; Divol, L.; Landen, O. L.; Vorberger, J.; Chapman, D. A.; Gericke, D. O.; Falcone, R. W.

    2013-05-24

    Proof-of-principle measurements of the electron densities, temperatures, and ionization states of spherically compressed multi-shocked CH (polystyrene) capsules have been achieved using spectrally resolved x-ray Thomson scattering. A total energy of 13.5 kJ incident on target is used to compress a 70 μm thick CH shell above solid-mass density using three coalescing shocks. Separately, a laser-produced zinc He-α x-ray source at 9 keV delayed 200 ps-800 ps after maximum compression is used to probe the plasma in the non-collective scattering regime. The data show that x-ray Thomson scattering enables a complete description of the time-dependent hydrodynamic evolution of shock-compressed CH capsules, with a maximum measured density of ρ > 6 g cm–3. Additionally, the results demonstrate that accurate measurements of x-ray scattering from bound-free transitions in the CH plasma demonstrate strong evidence that continuum lowering is the primary ionization mechanism of carbon L-shell electrons.

  7. X-ray Thomson scattering measurements of temperature and density from multi-shocked CH capsules

    SciTech Connect

    Fletcher, L. B.; Kritcher, A.; Pak, A.; Ma, T.; Döppner, T.; Divol, L.; Landen, O. L.; Glenzer, S. H.; Fortmann, C.; Vorberger, J.; Gericke, D. O.; Chapman, D. A.; Falcone, R. W.

    2013-05-15

    Proof-of-principle measurements of the electron densities, temperatures, and ionization states of spherically compressed multi-shocked CH (polystyrene) capsules have been achieved using spectrally resolved x-ray Thomson scattering. A total energy of 13.5 kJ incident on target is used to compress a 70 μm thick CH shell above solid-mass density using three coalescing shocks. Separately, a laser-produced zinc He-α x-ray source at 9 keV delayed 200 ps-800 ps after maximum compression is used to probe the plasma in the non-collective scattering regime. The data show that x-ray Thomson scattering enables a complete description of the time-dependent hydrodynamic evolution of shock-compressed CH capsules, with a maximum measured density of ρ > 6 g cm{sup −3}. In addition, the results demonstrate that accurate measurements of x-ray scattering from bound-free transitions in the CH plasma demonstrate strong evidence that continuum lowering is the primary ionization mechanism of carbon L-shell electrons.

  8. Public Data Set: A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment

    DOE Data Explorer

    Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586)

    2016-08-13

    This public data set contains openly-documented, machine readable digital research data corresponding to figures published in D.J. Schlossberg et. al., 'A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment,' accepted for publication in Review of Scientific Instruments.

  9. 77 FR 44221 - Notice of Availability of the Final Environmental Impact Statement for the Proposed Point Thomson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ... November 1, 2011. The Applicant's project purpose is to initiate commercial liquid hydrocarbon production (natural gas condensate) and delineate and evaluate hydrocarbon resources in the Point Thomson area. Two... mile long gravel airstrip; 3 hydrocarbon production and/or processing gravel pads; several miles of...

  10. Average-atom treatment of relaxation time in x-ray Thomson scattering from warm dense matter

    NASA Astrophysics Data System (ADS)

    Johnson, W. R.; Nilsen, J.

    2016-03-01

    The influence of finite relaxation times on Thomson scattering from warm dense plasmas is examined within the framework of the average-atom approximation. Presently most calculations use the collision-free Lindhard dielectric function to evaluate the free-electron contribution to the Thomson cross section. In this work, we use the Mermin dielectric function, which includes relaxation time explicitly. The relaxation time is evaluated by treating the average atom as an impurity in a uniform electron gas and depends critically on the transport cross section. The calculated relaxation rates agree well with values inferred from the Ziman formula for the static conductivity and also with rates inferred from a fit to the frequency-dependent conductivity. Transport cross sections determined by the phase-shift analysis in the average-atom potential are compared with those evaluated in the commonly used Born approximation. The Born approximation converges to the exact cross sections at high energies; however, differences that occur at low energies lead to corresponding differences in relaxation rates. The relative importance of including relaxation time when modeling x-ray Thomson scattering spectra is examined by comparing calculations of the free-electron dynamic structure function for Thomson scattering using Lindhard and Mermin dielectric functions. Applications are given to warm dense Be plasmas, with temperatures ranging from 2 to 32 eV and densities ranging from 2 to 64 g/cc.

  11. Geologic Model for Oil and Gas Assessment of the Kemik-Thomson Play, Central North Slope, Alaska

    USGS Publications Warehouse

    Schenk, Christopher J.; Houseknecht, David W.

    2008-01-01

    A geologic model was developed to assess undiscovered oil and gas resources in the Kemik-Thomson Play of the Central North Slope, Alaska. In this model, regional erosion during the Early Cretaceous produced an incised valley system on the flanks and crest of the Mikkelsen High and formed the Lower Cretaceous unconformity. Locally derived, coarse-grained siliciclastic and carbonate detritus from eroded Franklinian-age basement rocks, Carboniferous Kekiktuk Conglomerate (of the Endicott Group), Lisburne Group, and Permian-Triassic Sadlerochit Group may have accumulated in the incised valleys during lowstand and transgression, forming potential reservoirs in the Lower Cretaceous Kemik Sandstone and Thomson sandstone (informal term). Continued transgression resulted in the deposition of the mudstones of the over-lying Cretaceous pebble shale unit and Hue Shale, which form top seals to the potential reservoirs. Petroleum from thermally mature facies of the Triassic Shublik Formation, Jurassic Kingak Shale, Hue Shale (and pebble shale unit), and the Cretaceous-Tertiary Canning Formation might have charged Thomson and Kemik sandstone reservoirs in this play during the Tertiary. The success of this play depends largely upon the presence of reservoir-quality units in the Kemik Sandstone and Thomson sandstone.

  12. Measurements of ion temperature and plasma hydrogenic composition by collective Thomson scattering in neutral beam heated discharges at TEXTOR

    NASA Astrophysics Data System (ADS)

    Stejner, M.; Salewski, M.; Korsholm, S. B.; Bindslev, H.; Delabie, E.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Nielsen, S. K.; Bürger, A.; de Baar, M.; the TEXTOR Team

    2013-08-01

    A method is developed to perform plasma composition and ion temperature measurements across the plasma minor radius in TEXTOR based on ion cyclotron structures in collective Thomson scattering spectra. By gradually moving the scattering volume, we obtain measurements across the outer midplane of the plasma. Results for the ion temperature are compared with ion temperatures measured by active charge-exchange recombination spectroscopy.

  13. Nonlinear relativistic single-electron Thomson scattering power spectrum for incoming laser of arbitrary intensity

    SciTech Connect

    Alvarez-Estrada, R. F.; Pastor, I.; Guasp, J.; Castejon, F.

    2012-06-15

    The classical nonlinear incoherent Thomson scattering power spectrum from a single relativistic electron with incoming laser radiation of any intensity, investigated numerically by the present authors in a previous publication, displayed both an approximate quadratic behavior in frequency and a redshift of the power spectrum for high intensity incoming radiation. The present work is devoted to justify, in a more general setup, those numerical findings. Those justifications are reinforced by extending suitably analytical approaches, as developed by other authors. Moreover, our analytical treatment exhibits differences between the Doppler-like frequencies for linear and circular polarization of the incoming radiation. Those differences depend nonlinearly on the laser intensity and on the electron initial velocity and do not appear to have been displayed by previous authors. Those Doppler-like frequencies and their differences are validated by new Monte Carlo computations beyond our previuos ones and reported here.

  14. Peltier's and Thomson's coefficients of thermoelectric phenomena in the observable formulation.

    PubMed

    Garrido, Javier

    2009-04-15

    Four transport coefficients characterize the thermoelectric properties of materials. Three of them are widely measured and studied. But the number of references on the Peltier coefficient are very limited. This unequal result is a consequence of the Onsager reciprocal relation (ORR). A review on the preciseness and accuracy of Peltier coefficient measurements has been developed in this paper. Thus we can appreciate a low level in the experimental confirmation for the ORR. In order to describe the thermoelectric processes in an advantageous way, the observable formulation has been used. This is characterized by the electric potential measured at the probe terminals and for the heat flux which the conductor laterally dissipates. The energy balance provides the basic relationships among the observables and the Peltier and Thomson coefficients. A new way for measuring the Peltier coefficient has been suggested. PMID:21825373

  15. Thomson scattering from near-solid density plasmas using soft x-ray free electron lasers

    SciTech Connect

    Holl, A; Bornath, T; Cao, L; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gregori, G; Laarmann, T; Meiwes-Broer, K H; Przystawik, A; Radcliffe, P; Redmer, R; Reinholz, H; Ropke, G; Thiele, R; Tiggesbaumker, J; Toleikis, S; Truong, N X; Tschentscher, T; Uschmann, I; Zastrau, U

    2006-11-21

    We propose a collective Thomson scattering experiment at the VUV free electron laser facility at DESY (FLASH) which aims to diagnose warm dense matter at near-solid density. The plasma region of interest marks the transition from an ideal plasma to a correlated and degenerate many-particle system and is of current interest, e.g. in ICF experiments or laboratory astrophysics. Plasma diagnostic of such plasmas is a longstanding issue. The collective electron plasma mode (plasmon) is revealed in a pump-probe scattering experiment using the high-brilliant radiation to probe the plasma. The distinctive scattering features allow to infer basic plasma properties. For plasmas in thermal equilibrium the electron density and temperature is determined from scattering off the plasmon mode.

  16. Development of 1K-class Joule-Thomson cryocooler for next-generation astronomical mission

    NASA Astrophysics Data System (ADS)

    Sato, Yoichi; Sawada, Kenichiro; Shinozaki, Keisuke; Sugita, Hiroyuki; Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Nakagawa, Takao; Tsunematsu, Shoji; Ootsuka, Kiyomi; Narasaki, Katsuhiro

    2016-03-01

    This paper reports on the development of a 1K-class Joule-Thomson (JT) cryocooler in Japan for application to upcoming next-generation astronomy missions. In this development, engineering models (EMs) were designed and manufactured for verification tests. The survival of the models in the mechanical and thermal vacuum environment tests of the JT compressors was proven to be possible with stable compression performance. In addition, the electromagnetic noise and disturbance force associated with the JT compressors were evaluated. Gas analysis showed that the estimated total amount of CO2 gas contaminant was less than the getter capacity for the required lifetime. A nominal cooling power of 10 mW at 1.7 K was verified using the EM test units.

  17. Gifford-McMahon/Joule-Thomson Refrigerator Cools to 2.5 K

    NASA Technical Reports Server (NTRS)

    Britcliffe, Michael; Fernandez, Jose; Hanson, Theodore

    2005-01-01

    A compact refrigerator designed specifically for cooling a microwave maser low-noise amplifier is capable of removing heat at a continuous rate of 180 mW at a temperature of 2.5 K. This refrigerator is a combination of (1) a commercial Gifford-McMahon (GM) refrigerator nominally rated for cooling to 4 K and (2) a Joule-Thomson (J-T) circuit. The GM refrigerator pre-cools the J-T circuit, which provides the final stage of cooling. The refrigerator is compact and capable of operating in any orientation. Moreover, in comparison with a typical refrigerator heretofore used to cool a maser to 4.5 K, this refrigerator is simpler and can be built at less than half the cost.

  18. Gibbs-Thomson condition for the rapidly moving interface in a binary system

    NASA Astrophysics Data System (ADS)

    Salhoumi, A.; Galenko, P. K.

    2016-04-01

    Using a phase-field model for fast phase transformations we derive an interface condition for the rapidly moving solid-liquid interface. The model is described by equations for the hyperbolic transport and fast interface dynamics, which are reduced to a sole equation of the phase field with the driving force given by deviations of temperature and concentration from their equilibrium values within the diffuse interface. It is shown that the obtained interface condition presents the acceleration- and velocity-dependent Gibbs-Thomson interfacial condition. This condition is identical to the advanced Born-Infeld equation for the hyperbolic motion by mean curvature with the driving force. As a limiting case, the interface condition presents "velocity-driving force" relationships found earlier as traveling wave solutions for slow and fast phase field profiles. Predictions of the analytical solutions are qualitatively compared with literature data of atomistic simulations on crystal growth kinetics.

  19. Thomson scattering diagnostics of steady state and pulsed welding processes without and with metal vapor

    NASA Astrophysics Data System (ADS)

    Kühn-Kauffeldt, M.; Marqués, J.-L.; Schein, J.

    2015-01-01

    Thomson scattering is applied to measure temperature and density of electrons in the arc plasma of the direct current gas tungsten arc welding (GTAW) process and pulsed gas metal arc welding (GMAW) process. This diagnostic technique allows to determine these plasma parameters independent from the gas composition and heavy particles temperature. The experimental setup is adapted to perform measurements on stationary as well as transient processes. Spatial and temporal electron temperature and density profiles of a pure argon arc in the case of the GTAW process and argon arc with the presence of aluminum metal vapor in the case of the GMAW process were obtained. Additionally the data is used to estimate the concentration of the metal vapor in the GMAW plasma.

  20. Time resolved Thomson scattering diagnostic of pulsed gas metal arc welding (GMAW) process

    NASA Astrophysics Data System (ADS)

    Kühn-Kauffeldt, M.; Marquès, J. L.; Schein, J.

    2014-11-01

    In this work a Thomson scattering diagnostic technique was applied to obtain time resolved electron temperature and density values during a gas metal arc welding (GMAW) process. The investigated GMAW process was run with aluminum wire (AlMg 4,5 Mn) with 1.2 mm diameter as a wire electrode, argon as a shielding gas and peak currents in the range of 400 A. Time resolved measurements could be achieved by triggering the laser pulse at shifted time positions with respect to the current pulse driving the process. Time evaluation of resulting electron temperatures and densities is used to investigate the state of the plasma in different phases of the current pulse and to determine the influence of the metal vapor and droplets on the plasma properties.

  1. Ab initio calculation of the ion feature in x-ray Thomson scattering.

    PubMed

    Plagemann, Kai-Uwe; Rüter, Hannes R; Bornath, Thomas; Shihab, Mohammed; Desjarlais, Michael P; Fortmann, Carsten; Glenzer, Siegfried H; Redmer, Ronald

    2015-07-01

    The spectrum of x-ray Thomson scattering is proportional to the dynamic structure factor. An important contribution is the ion feature which describes elastic scattering of x rays off electrons. We apply an ab initio method for the calculation of the form factor of bound electrons, the slope of the screening cloud of free electrons, and the ion-ion structure factor in warm dense beryllium. With the presented method we can calculate the ion feature from first principles. These results will facilitate a better understanding of x-ray scattering in warm dense matter and an accurate measurement of ion temperatures which would allow determining nonequilibrium conditions, e.g., along shock propagation. PMID:26274290

  2. Attosecond Thomson-scattering x-ray source driven by laser-based electron acceleration

    SciTech Connect

    Luo, W.; Zhuo, H. B.; Yu, T. P.; Ma, Y. Y.; Song, Y. M.; Zhu, Z. C.; Yu, M. Y.

    2013-10-21

    The possibility of producing attosecond x-rays through Thomson scattering of laser light off laser-driven relativistic electron beams is investigated. For a ≤200-as, tens-MeV electron bunch produced with laser ponderomotive-force acceleration in a plasma wire, exceeding 10{sup 6} photons/s in the form of ∼160 as pulses in the range of 3–300 keV are predicted, with a peak brightness of ≥5 × 10{sup 20} photons/(s mm{sup 2} mrad{sup 2} 0.1% bandwidth). Our study suggests that the physical scheme discussed in this work can be used for an ultrafast (attosecond) x-ray source, which is the most beneficial for time-resolved atomic physics, dubbed “attosecond physics.”.

  3. Sub-MeV tunably polarized X-ray production with laser Thomson backscattering

    NASA Astrophysics Data System (ADS)

    Kawase, K.; Kando, M.; Hayakawa, T.; Daito, I.; Kondo, S.; Homma, T.; Kameshima, T.; Kotaki, H.; Chen, L.-M.; Fukuda, Y.; Faenov, A.; Shizuma, T.; Fujiwara, M.; Bulanov, S. V.; Kimura, T.; Tajima, T.

    2008-05-01

    Reported in this article is the generation of unique polarized x-rays in the sub-MeV region by means of the Thomson backscattering of the Nd:YAG laser photon with a wavelength of 1064nm on the 150MeV electron from the microtron accelerator. The maximum energy of the x-ray photons is estimated to be about 400keV. The total energy of the backscattered x-ray pulse is measured with an imaging plate and a LYSO scintillator. The angular divergence of the x-rays is also measured by using the imaging plate. We confirm that the x-ray beam is polarized according to the laser polarization direction with the Compton scattering method. In addition, we demonstrate the imaging of the object shielded by lead with the generated x-rays.

  4. A 130 point Nd:YAG Thomson scattering diagnostic on MAST

    SciTech Connect

    Scannell, R.; Walsh, M. J.; Dunstan, M. R.; Figueiredo, J.; Naylor, G.; O'Gorman, T.; Shibaev, S.

    2010-10-15

    A Thomson scattering diagnostic designed to measure both edge and core physics has been implemented on MAST. The system uses eight Nd:YAG lasers, each with a repetition rate of 30 Hz. The relative and absolute timing of the lasers may be set arbitrarily to produce fast bursts of measurements to suit the time evolution of the physics being studied. The scattered light is collected at F/6 by a 100 kg six element lens system with an aperture stop of 290 mm. The collected light is then transferred to 130 polychromators by 130 independent fiber bundles. The data acquisition and processing are based on a distributed computer system of dual core processors embedded in 26 chassis. Each chassis is standalone and performs data acquisition and processing for five polychromators. This system allows data to be available quickly after the MAST shot and has potential for real-time operations.

  5. Thomson scattering measurement of a collimated plasma jet generated by a high-power laser system

    NASA Astrophysics Data System (ADS)

    Ishikawa, T.; Sakawa, Y.; Morita, T.; Yamaura, Y.; Kuramitsu, Y.; Moritaka, T.; Sano, T.; Shimoda, R.; Tomita, K.; Uchino, K.; Matsukiyo, S.; Mizuta, A.; Ohnishi, N.; Crowston, R.; Woolsey, N.; Doyle, H.; Gregori, G.; Koenig, M.; Michaut, C.; Pelka, A.; Yuan, D.; Li, Y.; Zhang, K.; Zhong, J.; Wang, F.; Takabe, H.

    2016-03-01

    One of the important and interesting problems in astrophysics and plasma physics is collimation of plasma jets. The collimation mechanism, which causes a plasma flow to propagate a long distance, has not been understood in detail. We have been investigating a model experiment to simulate astrophysical plasma jets with an external magnetic field [Nishio et al., EPJ. Web of Conferences 59, 15005 (2013)]. The experiment was performed by using Gekko XII HIPER laser system at Institute of Laser Engineering, Osaka University. We shot CH plane targets (3 mm × 3 mm × 10 μm) and observed rear-side plasma flows. A collimated plasma flow or plasma jet was generated by separating focal spots of laser beams. In this report, we measured plasma jet structure without an external magnetic field with shadowgraphy, and simultaneously measured the local parameters of the plasma jet, i.e., electron density, electron and ion temperatures, charge state, and drift velocity, with collective Thomson scattering.

  6. Resolving the bulk ion region of millimeter-wave collective Thomson scattering spectra at ASDEX Upgrade.

    PubMed

    Stejner, M; Nielsen, S; Jacobsen, A S; Korsholm, S B; Leipold, F; Meo, F; Michelsen, P K; Moseev, D; Rasmussen, J; Salewski, M; Schubert, M; Stober, J; Wagner, D H

    2014-09-01

    Collective Thomson scattering (CTS) measurements provide information about the composition and velocity distribution of confined ion populations in fusion plasmas. The bulk ion part of the CTS spectrum is dominated by scattering off fluctuations driven by the motion of thermalized ion populations. It thus contains information about the ion temperature, rotation velocity, and plasma composition. To resolve the bulk ion region and access this information, we installed a fast acquisition system capable of sampling rates up to 12.5 GS/s in the CTS system at ASDEX Upgrade. CTS spectra with frequency resolution in the range of 1 MHz are then obtained through direct digitization and Fourier analysis of the CTS signal. We here describe the design, calibration, and operation of the fast receiver system and give examples of measured bulk ion CTS spectra showing the effects of changing ion temperature, rotation velocity, and plasma composition. PMID:25273723

  7. Note: Multi-pass Thomson scattering measurement on the TST-2 spherical tokamak.

    PubMed

    Togashi, H; Ejiri, A; Hiratsuka, J; Nakamura, K; Takase, Y; Yamaguchi, T; Furui, H; Imamura, K; Inada, T; Kakuda, H; Nakanishi, A; Oosako, T; Shinya, T; Sonehara, M; Tsuda, S; Tsujii, N; Wakatsuki, T; Hasegawa, M; Nagashima, Y; Narihara, K; Yamada, I; Tojo, H

    2014-05-01

    In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we performed TS measurements using the coaxial cavity in tokamak plasmas for the first time. In the optical cavity, the laser energy attenuation was approximately 30% in each round trip, and we achieved a photon number gain of about 3 compared with that obtained in the first round trip. In addition, the temperature measurement accuracy was improved by accumulating the first three round trip waveforms. PMID:24880428

  8. Thomson scattering measurements in low-density plasmas in the TST-2 spherical tokamak

    NASA Astrophysics Data System (ADS)

    Togashi, H.; Ejiri, A.; Homma, H.; Shinya, T.; Takase, Y.; Toida, K.; Tsujii, N.; Yamaguchi, T.; Yoshida, Y.; Furui, H.; Sonehara, M.; Nakamura, K.; Takahashi, W.; Takeuchi, T.; Yajima, S.; Yamazaki, H.; Hasegawa, M.; Nagashima, Y.; Tojo, H.

    2015-12-01

    Thomson scattering (TS) diagnostics have been widely used in fusion studies to measure profiles of electron temperature Te and electron density ne. In order to measure the low-density plasmas (ne <= 1018 m-3) in TST-2, which is sustained by lower hybrid wave power, the signal-to-noise ratio in TS measurement has been improved by various means. For instance, optimization of the detecting system, accumulation of TS data obtained from reproducible discharges, and application of a coaxial multi-pass scheme were carried out. As a result, the profiles have been measured successfully and a peaked ne profile and a hollow Te profile were obtained. Additionally, isotropy of Te near the plasma center was confirmed by coaxial double-pass TS measurement.

  9. Radial Electron Temperature and Density Measurements Using Thomson Scattering System in GAMMA 10/PDX

    NASA Astrophysics Data System (ADS)

    Yoshikawa, M.; Ohta, K.; Wang, X.; Chikatsu, M.; Kohagura, J.; Shima, Y.; Sakamoto, M.; Imai, T.; Nakashima, Y.; Yasuhara, R.; Yamada, I.; Funaba, H.; Minami, T.

    2015-11-01

    A Thomson scattering (TS) system in GAMMA 10/PDX has been developed for the measurement of radial profiles of electron temperature and density in a single plasma and laser shot. The TS system has a large solid angle optical collection system and high-sensitivity signal detection system. The TS signals are obtained using four-channel high-speed digital oscilloscopes controlled by a Windows PC. We designed the acquisition program for six oscilloscopes to obtain 10-Hz TS signals in a single plasma shot, following which the time-dependent electron temperatures and densities can be determined. Moreover, in order to obtain larger TS signal intensity in the edge region, we added a second collection mirror. The radial electron temperatures and densities at six radial positions in GAMMA 10/PDX were successfully obtained.

  10. Initial implementation of a Thomson scattering diagnostic for Proto-MPEX.

    PubMed

    Biewer, T M; Shaw, G

    2014-11-01

    Internal funds have been used at Oak Ridge National Laboratory to enable the initial installation of a laser based, Thomson scattering (TS) diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX). Since the funds are limited in amount and duration, the initial TS system has followed a low cost design and rapid implementation. This paper will discuss the design elements of the initial TS configuration on Proto-MPEX and issues encountered during installation. Avenues of response to system limitations will be discussed, along with considerations for further optimization. The laser system will undergo reconfiguration to enable additional project milestones, e.g., laser induced break-down spectroscopy. PMID:25430225

  11. Development of Thomson scattering system on Shenguang-III prototype laser facility.

    PubMed

    Gong, Tao; Li, Zhichao; Jiang, Xiaohua; Ding, Yongkun; Yang, Dong; Wang, Zhebin; Wang, Fang; Li, Ping; Hu, Guangyue; Zhao, Bin; Liu, Shenye; Jiang, Shaoen; Zheng, Jian

    2015-02-01

    A Thomson scattering diagnostic system, using a 263 nm laser as the probe beam, is designed and implemented on Shenguang-III prototype laser facility. The probe beam is provided by an additional beam line completed recently. The diagnostic system allows simultaneous measurements of both ion feature and red-shifted electron feature from plasmas in a high-temperature (≥2 keV) and high-density (≥10(21) cm(-3)) regime. Delicate design is made to satisfy the requirements for successful detection of the electron feature. High-quality ion feature spectra have already been diagnosed via this system in recent experiments with gas-filled hohlraums. PMID:25725836

  12. Resolving the bulk ion region of millimeter-wave collective Thomson scattering spectra at ASDEX Upgrade

    SciTech Connect

    Stejner, M. Nielsen, S.; Jacobsen, A. S.; Korsholm, S. B.; Leipold, F.; Meo, F.; Michelsen, P. K.; Rasmussen, J.; Salewski, M.; Moseev, D.; Schubert, M.; Stober, J.; Wagner, D. H.

    2014-09-15

    Collective Thomson scattering (CTS) measurements provide information about the composition and velocity distribution of confined ion populations in fusion plasmas. The bulk ion part of the CTS spectrum is dominated by scattering off fluctuations driven by the motion of thermalized ion populations. It thus contains information about the ion temperature, rotation velocity, and plasma composition. To resolve the bulk ion region and access this information, we installed a fast acquisition system capable of sampling rates up to 12.5 GS/s in the CTS system at ASDEX Upgrade. CTS spectra with frequency resolution in the range of 1 MHz are then obtained through direct digitization and Fourier analysis of the CTS signal. We here describe the design, calibration, and operation of the fast receiver system and give examples of measured bulk ion CTS spectra showing the effects of changing ion temperature, rotation velocity, and plasma composition.

  13. The multipulse Thomson scattering diagnostic on the DIII-D tokamak

    SciTech Connect

    Carlstrom, T.N.; Campbell, G.L.; DeBoo, J.C.; Evanko, R.G.; Evans, J.; Greenfield, C.M.; Haskovec, J.S.; Hsieh, C.L.; McKee, E.L.; Snider, R.T.; Stockdale, R.E.; Thomas, M.P.; Trost, P.K.

    1991-09-01

    This paper describes the design and operation of a 40-spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. Interference filter polychromators disperse the scattered light which is detected by silicon avalanche photodiodes. The measurable temperature range from 10 eV to 20 keV and the minimum detectable density is about 2 {times} 10{sup 18} m{sup {minus}3}. Laser control and data acquisition are performed in real-time by a VME-based microcomputer. Data analysis is performed by a MicroVAX 3400. Unique features of this system include burst mode'' operation, where multiple lasers are fired in rapid succession (< 10 KHz), real-time analysis capability, and laser beam quality and alignment monitoring during plasma operation. Results of component testing, calibration, and plasma operation are presented. 8 refs. 6 figs.

  14. Elevation angle alignment of quasi optical receiver mirrors of collective Thomson scattering diagnostic by sawtooth measurements

    SciTech Connect

    Moseev, D.; Meo, F.; Korsholm, S. B.; Leipold, F.; Michelsen, P. K.; Nielsen, S. K.; Salewski, M.; Stejner, M.; Bindslev, H.; Furtula, V.; Kantor, M.

    2012-10-15

    Localized measurements of the fast ion velocity distribution function and the plasma composition measurements are of significant interest for the fusion community. Collective Thomson scattering (CTS) diagnostics allow such measurements with spatial and temporal resolution. Localized measurements require a good alignment of the optical path in the transmission line. Monitoring the alignment during the experiment greatly benefits the confidence in the CTS measurements. An in situ technique for the assessment of the elevation angle alignment of the receiver is developed. Using the CTS diagnostic on TEXTOR without a source of probing radiation in discharges with sawtooth oscillations, an elevation angle misalignment of 0.9 Degree-Sign was found with an accuracy of 0.25 Degree-Sign .

  15. Design of core and edge Thomson scattering systems for Korea Superconducting Tokamak Advanced Research tokamak

    SciTech Connect

    Lee, H.G.; Lee, J.H.; Johnson, D.; Ellis, R.; Feder, R.; Park, H.

    2004-10-01

    The core and edge Thomson systems on Korea Superconducting Tokamak Advanced Research employ two different sets of lens collection optics. Their collection systems are positioned in the front end of a long reentrant cassette for optimum viewing coverage and optical throughput. Both systems collect the scattered light from a single tangential beam of multiple 50-Hz Nd:YAG lasers and image the scattering volume from core to edge with 40 spatial points. In order to obtain a higher resolution of 5 mm, the edge system has more spatial channels than the core system. Pressure-free heat shield windows, which will absorb the radiation heat flux, are mounted in front of large vacuum windows to protect them from the radiation heat load during long-pulse discharges.

  16. Measurement of electron temperature and density in an argon microdischarge by laser Thomson scattering

    SciTech Connect

    Belostotskiy, Sergey G.; Khandelwal, Rahul; Wang Qiang; Donnelly, Vincent M.; Economou, Demetre J.; Sadeghi, Nader

    2008-06-02

    Laser Thomson scattering in a novel, backscattered configuration was employed to measure the electron temperature (T{sub e}) and electron density (n{sub e}) in argon dc microdischarges, with an interelectrode gap of 600 {mu}m. Measurements were performed at the center of the gap that corresponds to the positive column. For 50 mA microdischarge current and over the pressure range of 300-700 Torr, the plasma parameters were found to be T{sub e}=0.9{+-}0.3 eV and n{sub e}=(6{+-}3)x10{sup 13} cm{sup -3}, in reasonable agreement with the predictions of a mathematical model.

  17. Note: Multi-pass Thomson scattering measurement on the TST-2 spherical tokamak

    SciTech Connect

    Togashi, H. Ejiri, A.; Hiratsuka, J.; Nakamura, K.; Takase, Y.; Yamaguchi, T.; Furui, H.; Imamura, K.; Inada, T.; Kakuda, H.; Nakanishi, A.; Oosako, T.; Shinya, T.; Sonehara, M.; Tsuda, S.; Tsujii, N.; Wakatsuki, T.; Hasegawa, M.; Nagashima, Y.; Narihara, K.; and others

    2014-05-15

    In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we performed TS measurements using the coaxial cavity in tokamak plasmas for the first time. In the optical cavity, the laser energy attenuation was approximately 30% in each round trip, and we achieved a photon number gain of about 3 compared with that obtained in the first round trip. In addition, the temperature measurement accuracy was improved by accumulating the first three round trip waveforms.

  18. Studies on scattering of laser radiation from viewing dump in tokamak Thomson scattering system

    NASA Astrophysics Data System (ADS)

    Kumar, R.; Singh, R.; Kumar, A.

    2012-08-01

    Thomson scattering is among one of the primary diagnostics used for tokamak plasma temperature and density measurements. Spuriously scattered stray signal further deteriorates the already existing poor signal-to-noise ratio in this technique. The present paper reports experimental investigations on the angular distribution of the scattered/stray radiation from graphite and a stack of laser blades dumps for different angles of incidence. Experimental results show a dependence of the stray signal on the dump-edge orientation. It is found that horizontally oriented dump edge produces a minimum level of stray light (around two orders less than in case of plane graphite tiles) in the horizontal plane, in which detectors for most of the diagnostics are installed. Studies are also made for p-polarized and s-polarized incident laser beams of 632.8 nm and 1064 nm wavelengths.

  19. Laser system for high resolution Thomson scattering diagnostics on the COMPASS tokamak

    SciTech Connect

    Bohm, P.; Sestak, D.; Bilkova, P.; Aftanas, M.; Weinzettl, V.; Hron, M.; Panek, R.; Dunstan, M. R.; Naylor, G.

    2010-10-15

    A new Thomson scattering diagnostic has been designed and is currently being installed on the COMPASS tokamak in IPP Prague in the Czech Republic. The requirements for this system are very stringent with approximately 3 mm spatial resolution at the plasma edge. A critical part of this diagnostic is the laser source. To achieve the specified parameters, a multilaser solution is utilized. Two 30 Hz 1.5 J Nd:YAG laser systems, used at the fundamental wavelength of 1064 nm, are located outside the tokamak area at a distance of 20 m from the tokamak. The design of the laser beam transport path is presented. The approach leading to a final choice of optimal focusing optics is given. As well as the beam path to the tokamak, a test path of the same optical length was built. Performance tests of the laser system carried out using the test path are described.

  20. Electron Beam Production and Characterization for the PLEIADES Thomson X-Ray Source

    NASA Astrophysics Data System (ADS)

    Brown, W. J.; Hartemann, F. V.; Tremaine, A. M.; Springer, P. T.; Le Sage, G. P.; Barty, C. P. J.; Rosenzweig, J. B.; Crane, J. K.; Cross, R. R.; Fittinghoff, D. N.; Gibson, D. J.; Slaughter, D. R.; Anderson, S.

    2002-12-01

    We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. Simulations of beam production, transport, and focus are presented. It is shown that a 1 ps, 500 pC electron bunch with a normalized emittance of less than 5 πmm-mrad can be delivered to the interaction point. Initial electron measurements are presented. Calculations of expected x-ray flux are also performed, demonstrating an expected peak spectral brightness of 1020 photons/s/mm2/mrad2/0.1% bandwidth. Effects of RF phase jitter are also presented, and planned phase measurements and control methods are discussed.

  1. High resolution Thomson Parabola Spectrometer for full spectral capture of multi-species ion beams.

    PubMed

    Alejo, A; Kar, S; Tebartz, A; Ahmed, H; Astbury, S; Carroll, D C; Ding, J; Doria, D; Higginson, A; McKenna, P; Neumann, N; Scott, G G; Wagner, F; Roth, M; Borghesi, M

    2016-08-01

    We report on the experimental characterisation of laser-driven ion beams using a Thomson Parabola Spectrometer (TPS) equipped with trapezoidally shaped electric plates, proposed by Gwynne et al. [Rev. Sci. Instrum. 85, 033304 (2014)]. While a pair of extended (30 cm long) electric plates was able to produce a significant increase in the separation between neighbouring ion species at high energies, deploying a trapezoidal design circumvented the spectral clipping at the low energy end of the ion spectra. The shape of the electric plate was chosen carefully considering, for the given spectrometer configuration, the range of detectable ion energies and species. Analytical tracing of the ion parabolas matches closely with the experimental data, which suggests a minimal effect of fringe fields on the escaping ions close to the wedged edge of the electrode. The analytical formulae were derived considering the relativistic correction required for the high energy ions to be characterised using such spectrometer. PMID:27587110

  2. A high- Tc SQUID-based sensor head cooled by a Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Rijpma, A. P.; ter Brake, H. J. M.; de Vries, E.; Nijhof, N.; Holland, H. J.; Rogalla, H.

    2002-08-01

    The goal of the so-called FHARMON project is to develop a high- Tc SQUID-based magnetometer system for the measurement of fetal heart activity in standard clinical environments. To lower the threshold for the application of this fetal heart monitor, it should be simple to operate. It is, therefore, advantageous to replace the liquid cryogen bath by a closed-cycle refrigerator. For this purpose, we selected a mixed-gas Joule-Thomson cooler; the APD Cryotiger ©. Because of its magnetic interference, the compressor of this closed-cycle cooler will be placed at a distance of ≈2 m from the actual sensor, which is an axial second order gradiometer. The gradiometer is formed by three magnetometers placed on an alumina cylinder, which is connected to the cold head of the cooler. This paper describes the sensor head in detail and reports on test experiments.

  3. Numerical simulation for all-optical Thomson scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Tan, Fang; Zhu, Bin; Han, Dan; Xin, Jian-Ting; Zhao, Zong-Qing; Cao, Lei-Feng; Gu, Yu-Qiu; Zhang, Bao-Han

    2014-03-01

    Energy spectra, angular distributions, and temporal profiles of the photons produced by an all-optical Thomson scattering X-ray source are explored through numerical simulations based on the parameters of the SILEX-I laser system (800 nm, 30 fs, 300 TW) and the previous wakefield acceleration experimental results. The simulation results show that X-ray pulses with a duration of 30 fs and an emission angle of 50 mrad can be produced from such a source. Using the optimized electron parameters, X-ray pulses with better directivity and narrower energy spectra can be obtained. Besides the electron parameters, the laser parameters such as the wavelength, pulse duration, and spot size also affect the X-ray yield, the angular distribution, and the maximum photon energy, except the X-ray pulse duration which is slightly changed for the case of ultrafast laser—electron interaction.

  4. Measurement of ionization in shock-compressed deuterium using x-ray Thomson scattering

    NASA Astrophysics Data System (ADS)

    Davis, P.; Doeppner, T.; Rygg, J. R.; Unites, W.; Desjarlais, M.; Collins, G. W.; Landen, O. L.; Falcone, R. W.; Glenzer, S. H.

    2010-11-01

    There is currently significant interest in the behavior of dense hydrogen under shock conditions, with applications ranging from planetary science to inertial confinement fusion. Here, we present the first x-ray Thomson scattering measurements on warm, dense deuterium in the collective regime. The experiment, performed on LLNL's Janus laser, used one 2 ns beam to drive a shock at a nominal pressure of 0.5 MBar into a deuterium target held at liquid conditions (19 K). A second 2 ns pulse pumped the Si Ly-α x-ray probe at 2 keV. Scattered x-rays were collected at 45 degrees in the forward direction and spectrally dispersed with a HOPG crystal spectrometer. A plasmon was detected, providing a direct measure of electron density. Simultaneous velocity interferometry was performed to determine pressure, allowing ionization state to be inferred. These results are compared to ab initio and hydrodynamic simulations.

  5. Temporal Evolution of Self-Modulated Laser Wakefields Measured by Coherent Thomson Scattering

    SciTech Connect

    Ting, A.; Krushelnick, K.; Moore, C.I.; Burris, H.R.; Esarey, E.; Krall, J.; Sprangle, P. |

    1996-12-01

    Coherent Thomson scattering of a picosecond probe laser was used to measure the time evolution of plasma wakefields produced by a high intensity laser pulse (7{times}10{sup 18} W/cm{sup 2}) in an underdense plasma ({ital n}{sub {ital e}}{approx_equal}10{sup 19} cm{sup {minus}3}) in the self-modulated laser wakefield accelerator configuration. Large amplitude plasma wakefields which lasted less than 5ps were observed to decay into ion acoustic waves. The time scales associated with these measurements were consistent with the effects of the modulational instability and the enhancement of scattered signal from plasma channel formation. {copyright} {ital 1996 The American Physical Society.}

  6. Development of Thomson scattering system on Shenguang-III prototype laser facility

    SciTech Connect

    Gong, Tao; Li, Zhichao; Jiang, Xiaohua; Ding, Yongkun Yang, Dong; Wang, Zhebin; Wang, Fang; Li, Ping; Liu, Shenye; Jiang, Shaoen; Hu, Guangyue; Zhao, Bin; Zheng, Jian

    2015-02-15

    A Thomson scattering diagnostic system, using a 263 nm laser as the probe beam, is designed and implemented on Shenguang-III prototype laser facility. The probe beam is provided by an additional beam line completed recently. The diagnostic system allows simultaneous measurements of both ion feature and red-shifted electron feature from plasmas in a high-temperature (≥2 keV) and high-density (≥10{sup 21} cm{sup −3}) regime. Delicate design is made to satisfy the requirements for successful detection of the electron feature. High-quality ion feature spectra have already been diagnosed via this system in recent experiments with gas-filled hohlraums.

  7. Electron Beam Production and Characterization for the PLEIADES Thomson X-ray Source

    SciTech Connect

    Brown, W J; Hartemann, F V; Tremaine, A M; Springer, P T; Le Sage, G P; Barty, C P J; Rosenzweig, J B; Crane, J K; Cross, R R; Fittinghoff, D B; Gibson, D J; Slaughter, D R; Anderson, S

    2002-10-14

    We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. Simulations of beam production, transport, and focus are presented. It is shown that a 1 ps, 500 pC electron bunch with a normalized emittance of less than 5 {pi}mm-mrad can be delivered to the interaction point. Initial electron measurements are presented. Calculations of expected x-ray flux are also performed, demonstrating an expected peak spectral brightness of 10{sup 20} photons/s/mm{sup 2}/mrad{sup 2}/0.1% bandwidth. Effects of RF phase jitter are also presented, and planned phase measurements and control methods are discussed.

  8. An unusual mutation in RECQ4 gene leading to Rothmund-Thomson syndrome.

    PubMed

    Balraj, Pauline; Concannon, Pat; Jamal, Rahman; Beghini, Alessandro; Hoe, T S; Khoo, Alan Soobeng; Volpi, Ludovica

    2002-10-31

    Rothmund-Thomson syndrome (OMIM #268400) is a severe autosomal recessive genodermatosis: characterised by growth retardation, hyperpigmentation and frequently accompanied by congenital bone defects, brittle hair and hypogonadism. Mutations in helicase RECQ4 gene are responsible for a subset of cases of RTS. Only six mutations have been reported, thus, far and each affecting the coding sequence or the splice junctions. We report the first homozygous mutation in RECQ4 helicase: 2746-2756-delTGGGCTGAGGC in IVS8 responsible for the severe phenotype associated with RTS in a Malaysian pedigree. We report also a 5321 G-->A transition in exon 17 and the updated list of the RECQ4 gene mutations. PMID:12379465

  9. Thomson Scattering and Spectroscopy Diagnostics for Low Frequency Turbulence Produced in Dual-wire Implosions

    NASA Astrophysics Data System (ADS)

    Plechaty, Christopher; Hamilton, Andy; Main, Daniel; Zechar, Nate; Sotnikov, Vladimir

    2015-11-01

    Low frequency plasma turbulence can be driven by the presence of inhomogeneity in density, temperature, magnetic field, or by velocity shear. Low Frequency instabilities can play an important role in many different types of processes, such as magnetic reconnection, plasma structuring in the ionosphere's F-layer, structuring of laser-produced plasmas in external magnetic field, and anomalous diffusion processes in theta-pinch and Z-pinch plasmas. We plan to carry out experiments at the Air Force Research Laboratory using a pulsed power generator to study two-wire implosions and the generation of the Lower-Hybrid Drift Instability in the vicinity of the reconnection region. In this work, we develop the Thomson scattering and visible spectroscopy diagnostics that will be ultimately used to characterize the plasma in these types of experiments. Work was performed under the auspices of the Air Force Research Laboratory by Riverside Research, under contract BAA-RQKS-2014-0009.

  10. Construction of a Pulse-Burst Laser System for Fast Thomson Scattering on the MST RFP

    NASA Astrophysics Data System (ADS)

    den Hartog, D. J.

    2007-11-01

    A ``pulse-burst'' laser system is being constructed for addition to the Thomson scattering diagnostic on the MST RFP. This laser will produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition frequencies 5-250 kHz. This laser system will operate at 1064 nm and is a master oscillator, power amplifier (MOPA). The master oscillator is a compact diode-pumped vanadate laser, intermediate amplifier stages are flashlamp-pumped Nd:YAG, and final stage(s) will be flashlamp-pumped Nd:glass (silicate). The burst train of laser pulses will enable the study of Te and ne dynamics in a single MST shot, and with ensembling, will enable correlation of Te and ne fluctuations with other fluctuating quantities.

  11. Pulse-burst laser systems for fast Thomson scattering (invited)a)

    NASA Astrophysics Data System (ADS)

    Den Hartog, D. J.; Ambuel, J. R.; Borchardt, M. T.; Falkowski, A. F.; Harris, W. S.; Holly, D. J.; Parke, E.; Reusch, J. A.; Robl, P. E.; Stephens, H. D.; Yang, Y. M.

    2010-10-01

    Two standard commercial flashlamp-pumped Nd:YAG (YAG denotes yttrium aluminum garnet) lasers have been upgraded to "pulse-burst" capability. Each laser produces a burst of up to 15 2 J Q-switched pulses (1064 nm) at repetition rates of 1-12.5 kHz. Variable pulse-width drive (0.15-0.39 ms) of the flashlamps is accomplished by insulated gate bipolar transistor (IGBT) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, and up to four 2 J laser pulses during one flashlamp pulse. These lasers are used in the Thomson scattering plasma diagnostic system on the MST reversed-field pinch to record the dynamic evolution of the electron temperature profile and temperature fluctuations. To further these investigations, a custom pulse-burst laser system with a maximum pulse repetition rate of 250 kHz is now being commissioned.

  12. Development of a single-shot-imaging thin film for an online Thomson parabola spectrometer

    SciTech Connect

    Sakaki, H.; Fukuda, Y.; Nishiuchi, M.; Hori, T.; Yogo, A.; Jinno, S.; Kanasaki, M.; Niita, K.

    2013-01-15

    A single-shot-imaging thin scintillator film was developed for an online Thomson parabola (TP) spectrometer and the first analysis of laser accelerated ions, using the online TP spectrometer, was demonstrated at the JAEA-Kansai Advanced Relativistic Engineering Laser System (J-KAREN). An energy spectrum of {approx}4.0 MeV protons is obtained using only this imaging film without the need of a microchannel plate that is typically utilized in online ion analyses. A general-purpose Monte Carlo particle and heavy ion-transport code system, which consists of various quantum dynamics models, was used for the prediction of the luminescent properties of the scintillator. The simulation can reasonably predict not only the ion trajectories detected by the spectrometer, but also luminescence properties.

  13. Experimental Investigation on Mixed Refrigerant Joule Thomson (mr J-T Cryocooler

    NASA Astrophysics Data System (ADS)

    Walimbe, N. S.; Narayankhedkar, K. G.; Atrey, M. D.

    2008-03-01

    Mixed Refrigerant Joule Thomson (MR J-T) cryocoolers have obvious advantages, such as low cost, high reliability, higher cooling effect at 80 K, low vibrations and simplicity in design layout. As a result of this, their use for different applications has become a major threat to conventional cryocoolers such as Stirling coolers. The performance of the MR J-T cryocooler, in terms of cooling power at low temperatures, depends significantly on the components of the gas mixture and their concentration. An experimental set up has been developed in our laboratory to analyse various gas mixtures. An efficient Hampson type counter flow heat exchanger has been fabricated and tested in the set up. The present paper gives experimental results for various gas mixtures so as to get maximum cooling effect for a given temperature. The paper also presents the effect of working pressure of the optimized gas mixture on the performance of the cooler.

  14. Optimization of the working fluid for a sorption-based Joule-Thomson cooler

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Zalewski, D. R.; ter Brake, Marcel

    2012-06-01

    Sorption-based Joule-Thomson coolers operate vibration-free, have a potentially long life time, and cause no electromagnetic interference. Therefore, they are appealing to a wide variety of applications, such as cooling of low-noise amplifiers, superconducting electronics, and optical detectors. The required cooling temperature depends on the device to be cooled and extends into the cryogenic range well below 80 K. This paper presents the optimization of the working fluid for sorption-based JT coolers. For specific combination of the cold and warm-end temperatures, the working fluid is optimized based on the overall coefficient of performance that is defined as the heat rejected to the cold tip (i.e. the cooling energy) per unit of the heat supplied to the sorption compressor. In this study, saran carbon is considered as the sorbent material.

  15. Optimization of the working fluid for a sorption-based Joule-Thomson cooler

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Zalewski, D. R.; Vermeer, C. H.; ter Brake, H. J. M.

    2013-12-01

    Sorption-based Joule-Thomson coolers operate vibration-free, have a potentially long life time, and cause no electromagnetic interference. Therefore, they are appealing to a wide variety of applications, such as cooling of low-noise amplifiers, superconducting electronics, and optical detectors. The required cooling temperature depends on the device to be cooled and extends into the cryogenic range well below 80 K. This paper presents a generalized methodology for optimization in a sorption-based JT cooler. The analysis is based on the inherent properties of the fluids and the adsorbent. By using this method, the working fluid of a JT cooler driven by a single-stage sorption compressor is optimized for two ranges of cold-tip operating temperatures: 65-160 K and 16-38 K. The optimization method is also extended to two-stage compression and specifically nitrogen and carbon monoxide are considered.

  16. Use of fast scopes to enable Thomson scattering measurement in presence of fluctuating plasma light.

    SciTech Connect

    McLean, H; Moller, J; Hill, D

    2004-04-19

    The addition of inexpensive high-speed oscilloscopes has enabled higher Te Thomson scattering measurements on the SSPX spheromak. Along with signal correlation techniques, the scopes allow new analyses based on the shape of the scattered laser pulse to discriminate against fluctuating background plasma light that often make gated-integrator measurements unreliable. A 1.4 J Nd:YAG laser at 1064 nm is the scattering source. Spatial locations are coupled by viewing optics and fibers to 4-wavelength-channel filter polychrometers. Ratios between the channels determine Te while summations of the channels determine density. Typically, the channel that provides scattered signal at higher Te is contaminated by fluctuating background light. Individual channels are correlated with either a modeled representation of the laser pulse or a noise-free stray light signal to extract channel amplitudes.

  17. K-(alpha) X-ray Thomson Scattering From Dense Plasmas

    SciTech Connect

    Kritcher, A L; Neumayer, P; Castor, J; Doppner, T; Falcone, R W; Landen, O L; Lee, H J; Lee, R W; Morse, E C; Ng, A; Pollaine, S; Price, D; Glenzer, S H

    2009-05-07

    Spectrally resolved Thomson scattering using ultra-fast K-{alpha} x-rays has measured the compression and heating of shocked compressed matter. The evolution and coalescence of two shock waves traveling through a solid density LiH target were characterized by the elastic scattering component. The density and temperature at shock coalescence, 2.2 eV and 1.7 x 10{sup 23}cm{sup -3}, were determined from the plasmon frequency shift and the relative intensity of the elastic and inelastic scattering features in the collective scattering regime. The observation of plasmon scattering at coalescence indicates a transition to the dense metallic state in LiH. The density and temperature regimes accessed in these experiments are relevant for inertial confinement fusion experiments and for the study of planetary formation.

  18. Nanoscopic Confinement through Self-Assembly: Crystallization within Micellar Cores Exhibits Simple Gibbs-Thomson Behavior

    NASA Astrophysics Data System (ADS)

    Zinn, Thomas; Willner, Lutz; Lund, Reidar

    2014-12-01

    It is well known that liquids confined to small nanoscopic pores and droplets exhibit thermal behavior very different from bulk samples. Less is known about liquids spontaneously confined through self-assembly into micellar structures. Here we demonstrate, using a very well-defined n-alkyl-poly(ethylene oxide) polymer system with a tunable structure, that n -alkane(s) forming 2-3 nm small micellar cores are affected considerably by confinement in the form of melting point depressions. Moreover, comparing the reduction in melting points, Δ Tm, determined through volumetric and calorimetric methods with the micellar core radius, Rc, obtained from small-angle x-ray scattering, we find excellent agreement with the well-known Gibbs-Thomson equation, Δ Tm˜Rc-1 . This demonstrates that the reduced size, i.e., the Laplace pressure, is the dominant parameter governing the melting point depression in micellar systems.

  19. Multi-point Thomson Scattering First Results on the HIT-II Plasma

    NASA Astrophysics Data System (ADS)

    Smith, R. J.; Liptac, J. E.; Jarboe, T. R.; Nelson, B. A.; Leblanc, B. P.; Phillips, P.

    1999-11-01

    A multi-point Thomson scattering diagnostic has recently been implemented on the Helicity Injected Torus--II (HIT--II). The HIT--II device is a low-aspect ratio (Ro = 0.3 m, a = 0.2 m) torus with a 0.5 Tesla field on axis. The machine configuration allows both inductive current drive and Coaxial Helicity Injection (CHI) current drive operations and is capable of producing plasma currents on the order of 200 kA in either mode. Electron temperature and density profile measurements for both inductive and CHI current driven plasmas are presented and discussed along with results from complimentary diagnostics on the HIT--II device --- a two chord FIR interferometer, a 16 channel ion doppler spectrometer and two symmetrically viewing VUV spectrometers.

  20. Single attosecond pulse generation by nonlinear Thomson scattering in a tightly focused intense laser beam

    SciTech Connect

    Lan Pengfei; Lu Peixiang; Cao Wei

    2006-01-15

    The relativistic nonlinear Thomson scattering of a tightly focused intense laser pulse by an electron is investigated, and the temporal and spectral characters of the radiation are discussed. In a tightly focused laser pulse with an intensity of approximately 10{sup 20} W/cm{sup 2} and a pulse duration of 20 fs, the electron is scattered away from the focus quickly by the ponderomotive force and therefore the radiation emitted at the focus is much higher than that at other regions. As a result, a single ultrashort pulse of 3.8 as is generated and its corresponding spectrum is broadened to 200 orders of the frequency of the driving laser. With increasing the laser intensity, the signal-to-noise of the radiated pulse increases, and the pulse duration decreases. Moreover, the phase behavior of the spectral components and the dependence of the radiated power on the laser intensity are discussed.

  1. Ultrahigh Brilliance Multi-MeV γ-Ray Beams from Nonlinear Relativistic Thomson Scattering.

    PubMed

    Sarri, G; Corvan, D J; Schumaker, W; Cole, J M; Di Piazza, A; Ahmed, H; Harvey, C; Keitel, C H; Krushelnick, K; Mangles, S P D; Najmudin, Z; Symes, D; Thomas, A G R; Yeung, M; Zhao, Z; Zepf, M

    2014-11-28

    We report on the generation of a narrow divergence (θ_{γ}<2.5  mrad), multi-MeV (E_{max}≈18  MeV) and ultrahigh peak brilliance (>1.8×10^{20}  photons s^{-1} mm^{-2}  mrad^{-2} 0.1% BW) γ-ray beam from the scattering of an ultrarelativistic laser-wakefield accelerated electron beam in the field of a relativistically intense laser (dimensionless amplitude a_{0}≈2). The spectrum of the generated γ-ray beam is measured, with MeV resolution, seamlessly from 6 to 18 MeV, giving clear evidence of the onset of nonlinear relativistic Thomson scattering. To the best of our knowledge, this photon source has the highest peak brilliance in the multi-MeV regime ever reported in the literature. PMID:25494074

  2. POLIX: A Thomson X-ray polarimeter for a small satellite mission

    NASA Astrophysics Data System (ADS)

    Paul, Biswajit; Gopala Krishna, M. R.; Puthiya Veetil, Rishin

    2016-07-01

    POLIX is a Thomson X-ray polarimeter for a small satellite mission of ISRO. The instrument consists of a collimator, a scatterer and a set proportional counters to detect the scattered X-rays. We will describe the design, specifications, sensitivity, and development status of this instrument and some of the important scientific goals. This instrument will provide unprecedented opportunity to measure X-ray polarisation in the medium energy range in a large number of sources of different classes with a minimum detectable linear polarisation degree of 2-3%. The prime objects for observation with this instrument are the X-ray bright accretion powered neutron stars, accreting black holes in different spectral states, rotation powered pulsars, magnetars, and active galactic nuclei. This instrument will be a bridge between the soft X-ray polarimeters and the Compton polarimeters.

  3. Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering

    SciTech Connect

    Nedanovska, E.; Nersisyan, G.; Lewis, C. L. S.; Riley, D.; Graham, W. G.; Morgan, T. J.; Hüwel, L.; Murakami, T.

    2015-01-07

    We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 10{sup 17 }cm{sup −3} to 9 × 10{sup 13 }cm{sup −3}, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ∼ t{sup 0.4} consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He{sub 2}{sup +} molecular ion play an important role.

  4. Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering

    NASA Astrophysics Data System (ADS)

    Nedanovska, E.; Nersisyan, G.; Morgan, T. J.; Hüwel, L.; Murakami, T.; Lewis, C. L. S.; Riley, D.; Graham, W. G.

    2015-01-01

    We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 1017 cm-3 to 9 × 1013 cm-3, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ˜ t0.4 consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He2+ molecular ion play an important role.

  5. Thomson scattering measurements of ion interpenetration in cylindrically converging, supersonic magnetized plasma flows

    NASA Astrophysics Data System (ADS)

    Swadling, George

    2015-11-01

    Ion interpenetration driven by high velocity plasma collisions is an important phenomenon in high energy density environments such as the interiors of ICF vacuum hohlraums and fast z-pinches. The presence of magnetic fields frozen into these colliding flows further complicates the interaction dynamics. This talk focuses on an experimental investigation of ion interpenetration in collisions between cylindrically convergent, supersonic, magnetized flows (M ~10, Vflow ~ 100km/s, ni ~ 1017cm-3) . The flows used in this study were plasma ablation streams produced by tungsten wire array z-pinches, driven by the 1.4MA, 240ns Magpie facility at Imperial College, and diagnosed using a combination of optical Thomson scattering, Faraday rotation and interferometry. Optical Thomson scattering (TS) provides time-resolved measurements of local flow velocity and plasma temperature across multiple (7 to 14) spatial positions. TS spectra are recorded simultaneously from multiple directions with respect to the probing beam, resulting in separate measurements of the rates of transverse diffusion and slowing-down of the ion velocity distribution. The measurements demonstrate flow interpenetration through the array axis at early time, and also show an axial deflection of the ions towards the anode. This deflection is induced by a toroidal magnetic field (~ 10T), frozen into the plasma that accumulates near the axis. Measurements obtained later in time show a change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams, and rapid radial collapse of the magnetized plasma column. The quantitative nature of the spatial profiles of the density, flow velocities and ion temperatures measured in these experiments will allow detailed verification of MHD and PIC codes used by the HEDP community. Work Supported by EPSRC (Grant No. EP/G001324/1), DOE (Cooperative Agreement Nos. DE-F03-02NA00057 & DE-SC-0001063) & Sandia National

  6. Collective Thomson scattering energetic particle diagnostic in high performance tokamaks. Final report

    SciTech Connect

    Cheung, P.Y.; Aamodt, R.E.; Russell, D.A.

    1997-07-08

    This report summarizes the work performed under DOE grant DE-FG03-95ER54334. Lodestar was an active participant in the low power Collective Thomson Scattering (CTS) diagnostic experiment at TFTR in collaboration with MIT. A simple and effective fitting technique was developed to extract key parameters from the scattered data. Utilizing this new technique, the concept of lower hybrid resonance scattering was adapted for a feasibility study of a low/medium power collective scattering diagnostic for ITER. The implementation and the testing of such a technique for actual parameter extraction using TFTR data, however, was severely limited due to experimental and instrumentation complications. Based on the studies the authors have performed up to date, it is believed that a combination of non-physics related effects such as multiple wall reflection of incident signal and spectral impurity problem o the gyrotron can account for the anomalous signal strength. A collaborative effort with GA was initiated and a feasibility study of developing and implementing a collective thomson scattering (CTS) diagnostic for the detection of energetic particles at DIII-D was completed. Specifically, the process of selecting an optimum receiver location for the diagnostic is discussed in detailed. Results presented here include detailed signal to noise calculations and ray-tracing studies. Critical physics issues and selection criteria are discussed and a procedure to detect anisotropic energetic ion temperatures is also outlined. Favorable results, obtained in the feasibility study, indicate that it should be possible to develop and implement a CTS diagnostic at DIII-D.

  7. Investigation of thermodynamic equilibrium in laser-induced aluminum plasma using the Hα line profiles and Thomson scattering spectra

    NASA Astrophysics Data System (ADS)

    Cvejić, M.; DzierŻega, K.; Pieta, T.

    2015-07-01

    We have studied isothermal equilibrium in the laser-induced plasma from aluminum pellets in argon at pressure of 200 mbar by using a method which combines the standard laser Thomson scattering and analysis of the Hα, Stark-broadened, line profiles. Plasma was created using 4.5 ns, 4 mJ pulses from a Nd:YAG laser at 1064 nm. While electron density and temperature were determined from the electron feature of Thomson scattering spectra, the heavy particle temperature was obtained from the Hα full profile applying computer simulation including ion-dynamical effects. We have found strong imbalance between these two temperatures during entire plasma evolution which indicates its non-isothermal character. At the same time, according to the McWhirter criterion, the electron density was high enough to establish plasma in local thermodynamic equilibrium.

  8. Low-cost Joule Thomson coolers: single-flow flat cooler and two-flow cylindrical cooler

    NASA Astrophysics Data System (ADS)

    Cottereau, Alain

    1998-10-01

    Regardless improvements of Stirling and Pulse Tube coolers performances, Joule Thomson coolers are still interested for systems which require very fast cool down, compactness and high reliability. AIR LIQUIDE-DTA- believes that most of the future applications for Joule Thomson coolers would required devices such as single flow or dual flow coolers if manufacturers are able to increase significantly the performances and decrease the cost of such coolers. AIR LIQUIDE-DTA- has developed recently new technologies in order to match this challenge and to widen its range of low cost coolers. Previous developments such as memory shape valve and flat cooler were improved and adapted for cylindrical coolers. Original heat exchanger was also realized for flat cooler applications. Prototypes and results are presented in this paper for coolers with a target price which shall not exceed 200 USD.

  9. Traveling-wave Thomson scattering and optical undulators for high-yield EUV and X-ray sources

    NASA Astrophysics Data System (ADS)

    Debus, A. D.; Bussmann, M.; Siebold, M.; Jochmann, A.; Schramm, U.; Cowan, T. E.; Sauerbrey, R.

    2010-07-01

    We present a novel high-yield Thomson scattering geometry that takes advantage of compact electron bunches, as available in advanced, low-emittance linear accelerators or laser wakefield accelerators. In order to avoid the restrictions on the X-ray photon yield imposed by the Rayleigh limit, we use ultrashort, pulse-front tilted laser pulses in a side-scattering geometry. Such a traveling-wave setup allows an overlap of electron and laser beams, even after propagating over distances much longer than the Rayleigh length. Experimental designs are discussed and optimized for different scattering angles. Specifically, to minimize group delay dispersion at large scattering angles >10°, we propose the use of varied-line spacing (VLS) gratings for spatio-temporal laser pulse shaping. Compared to head-on (180°) Thomson scattering, interaction lengths are in the centimeter to meter range and photon numbers for ultrashort X-ray pulses can increase by several orders of magnitudes.

  10. Review of Canadian species of the genus Dinaraea Thomson, with descriptions of six new species (Coleoptera, Staphylinidae, Aleocharinae, Athetini)

    PubMed Central

    Klimaszewski, Jan; Webster, Reginald P.; Langor, David W.; Caroline Bourdon; Jacobs, Jenna

    2013-01-01

    Abstract Twelve species of the genus Dinaraea Thomson are recognized in the Nearctic region, ten of which occur in Canada, all east of the Rocky Mountains. Six species are herein described as new to science: Dinaraea bicornis Klimaszewski & Webster, sp. n.; Dinaraea curtipenis Klimaszewski & Webster, sp. n.; Dinaraea longipenis Klimaszewski & Webster, sp. n.; Dinaraea quadricornis Klimaszewski & Webster, sp. n.; Dinaraea worki Klimaszewski & Jacobs, sp. n.; and Dinaraea piceana Klimaszewski & Jacobs, sp. n. Four formerly described species are confirmed in Canada: Dinaraea angustula (Thomson), Dinaraea backusensis Klimaszewski & Brunke, Dinaraea borealis Lohse, and Dinaraea pacei Klimaszewki & Langor. The previously unknown male of Dinaraea borealis Lohse and female of Dinaraea backusensis are described. All species are illustrated with colour habitus images and black and white images of the median lobe of the aedeagus and spermatheca, and tergite VIII and sternite VIII of both sexes. New habitat and distribution data are presented and a key to all Nearctic species of the genus is provided. PMID:24167422

  11. Reconstruction of high temporal resolution Thomson scattering data during a modulated electron cyclotron resonance heating using conditional averaging

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ida, K.; Itoh, K.; Yoshinuma, M.; Moon, C.; Inagaki, S.; Yamada, I.; Funaba, H.; Yasuhara, R.; Tsuchiya, H.; Ohdachi, S.; Yoshimura, Y.; Igami, H.; Shimozuma, T.; Kubo, S.; Tsujimura, T. I.

    2016-04-01

    This paper provides a software application of the sampling scope concept for fusion research. The time evolution of Thomson scattering data is reconstructed with a high temporal resolution during a modulated electron cyclotron resonance heating (MECH) phase. The amplitude profile and the delay time profile of the heat pulse propagation are obtained from the reconstructed signal for discharges having on-axis and off-axis MECH depositions. The results are found to be consistent with the MECH deposition.

  12. Reconstruction of high temporal resolution Thomson scattering data during a modulated electron cyclotron resonance heating using conditional averaging.

    PubMed

    Kobayashi, T; Ida, K; Itoh, K; Yoshinuma, M; Moon, C; Inagaki, S; Yamada, I; Funaba, H; Yasuhara, R; Tsuchiya, H; Ohdachi, S; Yoshimura, Y; Igami, H; Shimozuma, T; Kubo, S; Tsujimura, T I

    2016-04-01

    This paper provides a software application of the sampling scope concept for fusion research. The time evolution of Thomson scattering data is reconstructed with a high temporal resolution during a modulated electron cyclotron resonance heating (MECH) phase. The amplitude profile and the delay time profile of the heat pulse propagation are obtained from the reconstructed signal for discharges having on-axis and off-axis MECH depositions. The results are found to be consistent with the MECH deposition. PMID:27131672

  13. The mathematical models of electromagnetic field dynamics and heat transfer in closed electrical contacts including Thomson effect

    NASA Astrophysics Data System (ADS)

    Kharin, Stanislav; Sarsengeldin, Merey; Kassabek, Samat

    2016-08-01

    We represent mathematical models of electromagnetic field dynamics and heat transfer in closed symmetric and asymmetric electrical contacts including Thomson effect, which are essentially nonlinear due to the dependence of thermal and electrical conductivities on temperature. Suggested solutions are based on the assumption of identity of equipotentials and isothermal surfaces, which agrees with experimental data and valid for both linear and nonlinear cases. Well known Kohlrausch temperature-potential relation is analytically justified.

  14. Thomson-Scattering Study of the Subharmonic Decay of Ion-Acoustic Waves Driven by the Brillouin Instability

    NASA Astrophysics Data System (ADS)

    Bandulet, H. C.; Labaune, C.; Lewis, K.; Depierreux, S.

    2004-07-01

    Thomson scattering (TS) has been used to investigate the two-ion decay instability of ion acoustic waves generated by stimulated Brillouin scattering in an underdense CH plasma. Two complementary TS diagnostics, spectrally and spatially resolved, demonstrate the occurrence of the subharmonic decay of the primary ion acoustic wave into two secondary waves. The study of the laser intensity dependence shows that the secondary ion acoustic waves are correlated with the SBS reflectivity saturation, at a level of a few percent.

  15. Introduction: Andrew Thomson and the Centre for Metalloprotein Spectroscopy and Biology at the University of East Anglia.

    PubMed

    Wilson, Michael T

    2008-12-01

    The present article briefly relates the early history and growth of the Centre for Metalloprotein Spectroscopy and Biology at UEA (University of East Anglia) under the joint directorship of A.J. Thomson and C. Greenwood, and charts the exceptional success that this centre has had in fostering bioinorganic chemistry in the U.K. and the impact that it has had internationally. PMID:19021505

  16. Measurements of Relativistic Effects in Collective Thomson Scattering at Electron Temperatures less than 1 keV

    SciTech Connect

    Ross, James Steven

    2010-01-01

    Simultaneous scattering from electron-plasma waves and ion-acoustic waves is used to measure local laser-produced plasma parameters with high spatiotemporal resolution including electron temperature and density, average charge state, plasma flow velocity, and ion temperature. In addition, the first measurements of relativistic modifications in the collective Thomson scattering spectrum from thermal electron-plasma fluctuations are presented [1]. Due to the high phase velocity of electron-plasma fluctuations, relativistic effects are important even at low electron temperatures (Te < 1 keV). These effects have been observed experimentally and agree well with a relativistic treatment of the Thomson scattering form factor [2]. The results are important for the interpretation of scattering measurements from laser produced plasmas. Thomson scattering measurements are used to characterize the hydrodynamics of a gas jet plasma which is the foundation for a broad series of laser-plasma interaction studies [3, 4, 5, 6]. The temporal evolution of the electron temperature, density and ion temperature are measured. The measured electron density evolution shows excellent agreement with a simple adiabatic expansion model. The effects of high temperatures on coupling to hohlraum targets is discussed [7]. A peak electron temperature of 12 keV at a density of 4.7 × 1020cm-3 are measured 200 μm outside the laser entrance hole using a two-color Thomson scattering method we developed in gas jet plasmas [8]. These measurements are used to assess laser-plasma interactions that reduce laser hohlraum coupling and can significantly reduce the hohlraum radiation temperature.

  17. Continued Development of Python-Based Thomson Data Analysis and Associated Visualization Tool for NSTX-U

    NASA Astrophysics Data System (ADS)

    Wallace, William; Miller, Jared; Diallo, Ahmed

    2015-11-01

    MultiPoint Thomson Scattering (MPTS) is an established, accurate method of finding the temperature, density, and pressure of a magnetically confined plasma. Two Nd:YAG (1064 nm) lasers are fired into the plasma with a effective frequency of 60 Hz, and the light is Doppler shifted by Thomson scattering. Polychromators on the NSTX-U midplane collect the scattered photons at various radii/scattering angles, and the avalanche photodiode voltages are saved to an MDSplus tree for later analysis. IDL code is then used to determine plasma temperature, pressure, and density from the captured polychromator measurements via Selden formulas. [1] Previous work [2] converted the single-processor IDL code into Python code, and prepared a new architecture for multiprocessing MPTS in parallel. However, that work was not completed to the generation of output data and curve fits that match with the previous IDL. This project refactored the Python code into a object-oriented architecture, and created a software test suite for the new architecture which allowed identification of the code which generated the difference in output. Another effort currently underway is to display the Thomson data in an intuitive, interactive format. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Community College Internship (CCI) program.

  18. Quantitative evaluation of the effect of multiphoton ionization in laser Thomson scattering diagnostics of low-temperature plasmas

    NASA Astrophysics Data System (ADS)

    Kono, Akihiro; Matsuda, Yukitaka; Okada, Ken; Aramaki, Mitsutoshi

    2011-10-01

    Laser Thomson scattering technique allows one very high spatial-resolution measurements of electron density and temperature as required in diagnostics of microplasmas or measurement of regions very close to the wall. In such high-resolution measurements, laser energy density in the scattering volume must be very high for obtaining sufficient amount of scattering photons; therefore, electron production via multiphoton ionization by the laser beam may significantly affect Thomson scattering due to plasma electrons. In order to clarify the effect of multiphoton ionization in Thomson scattering diagnostics, we have been measuring absolute efficiency of multiphoton ionization caused by frequency-doubled Nd:YAG laser for various gases including rare gases, N2, O2, CF4 and SF6. It has been found that electrons produced via multiphoton ionization can reach a significant fraction of plasma electrons even at low pressures, depending on the gas species and laser focusing conditions. Details will be given in the presentation, including simulation results about how the escape of photoelectrons from the scattering volume affects the situation.

  19. Influence of local-field corrections on Thomson scattering in collision-dominated two-component plasmas

    SciTech Connect

    Fortmann, Carsten; Wierling, August; Roepke, Gerd

    2010-02-15

    The dynamic structure factor, which determines the Thomson scattering spectrum, is calculated via an extended Mermin approach. It incorporates the dynamical collision frequency as well as the local-field correction factor. This allows to study systematically the impact of electron-ion collisions as well as electron-electron correlations due to degeneracy and short-range interaction on the characteristics of the Thomson scattering signal. As such, the plasmon dispersion and damping width is calculated for a two-component plasma, where the electron subsystem is completely degenerate. Strong deviations of the plasmon resonance position due to the electron-electron correlations are observed at increasing Brueckner parameters r{sub s}. These results are of paramount importance for the interpretation of collective Thomson scattering spectra, as the determination of the free electron density from the plasmon resonance position requires a precise theory of the plasmon dispersion. Implications due to different approximations for the electron-electron correlation, i.e., different forms of the one-component local-field correction, are discussed.

  20. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles.

    PubMed

    Freeman, C G; Fiksel, G; Stoeckl, C; Sinenian, N; Canfield, M J; Graeper, G B; Lombardo, A T; Stillman, C R; Padalino, S J; Mileham, C; Sangster, T C; Frenje, J A

    2011-07-01

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW. PMID:21806176

  1. Influence of local-field corrections on Thomson scattering in collision-dominated two-component plasmas.

    PubMed

    Fortmann, Carsten; Wierling, August; Röpke, Gerd

    2010-02-01

    The dynamic structure factor, which determines the Thomson scattering spectrum, is calculated via an extended Mermin approach. It incorporates the dynamical collision frequency as well as the local-field correction factor. This allows to study systematically the impact of electron-ion collisions as well as electron-electron correlations due to degeneracy and short-range interaction on the characteristics of the Thomson scattering signal. As such, the plasmon dispersion and damping width is calculated for a two-component plasma, where the electron subsystem is completely degenerate. Strong deviations of the plasmon resonance position due to the electron-electron correlations are observed at increasing Brueckner parameters r(s). These results are of paramount importance for the interpretation of collective Thomson scattering spectra, as the determination of the free electron density from the plasmon resonance position requires a precise theory of the plasmon dispersion. Implications due to different approximations for the electron-electron correlation, i.e., different forms of the one-component local-field correction, are discussed. PMID:20365663

  2. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles

    NASA Astrophysics Data System (ADS)

    Freeman, C. G.; Fiksel, G.; Stoeckl, C.; Sinenian, N.; Canfield, M. J.; Graeper, G. B.; Lombardo, A. T.; Stillman, C. R.; Padalino, S. J.; Mileham, C.; Sangster, T. C.; Frenje, J. A.

    2011-07-01

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

  3. Influence of local-field corrections on Thomson scattering in collision-dominated two-component plasmas

    NASA Astrophysics Data System (ADS)

    Fortmann, Carsten; Wierling, August; Röpke, Gerd

    2010-02-01

    The dynamic structure factor, which determines the Thomson scattering spectrum, is calculated via an extended Mermin approach. It incorporates the dynamical collision frequency as well as the local-field correction factor. This allows to study systematically the impact of electron-ion collisions as well as electron-electron correlations due to degeneracy and short-range interaction on the characteristics of the Thomson scattering signal. As such, the plasmon dispersion and damping width is calculated for a two-component plasma, where the electron subsystem is completely degenerate. Strong deviations of the plasmon resonance position due to the electron-electron correlations are observed at increasing Brueckner parameters rs . These results are of paramount importance for the interpretation of collective Thomson scattering spectra, as the determination of the free electron density from the plasmon resonance position requires a precise theory of the plasmon dispersion. Implications due to different approximations for the electron-electron correlation, i.e., different forms of the one-component local-field correction, are discussed.

  4. Thomson scattering diagnostics of SF6 gas-blasted arcs confined by a nozzle under free-recovery conditions

    NASA Astrophysics Data System (ADS)

    Tomita, Kentaro; Gojima, Daisuke; Shimizu, Takahiro; Uchino, Kiichiro; Nakano, Tomoyuki; Tanaka, Yasunori; Suzuki, Katsumi; Iijima, Takanori; Shinkai, Takeshi

    2015-07-01

    Collective Thomson scattering has been applied to gas-blasted arcs confined by a nozzle to measure their decay processes with respect to electron density (ne). Pure SF6 gas, an Ar/SF6 gas mixture (SF6 was 20, 40, 60, and 80% of the mixture), and pure Ar gas were used as arc-quenching media at atmospheric pressure. Copper-tungsten (40% copper) electrodes were installed inside a polytetrafluoroethylene (PTFE) nozzle and 50 mm-long gap arcs were generated between the electrodes. First, steady-state arcs were generated with 50 A current. Then, a semiconductor switch removed the arc current. It was found that after the current decreased to zero, ne exponentially decreased and the decay time constant of ne systematically decreased with an increasing SF6 gas ratio. Thomson scattering measured ne in the range 1021-1023 m-3. Self-emission measurements, which were performed with a high-speed camera at 200 000 frames per second, exhibited good agreement with the results of the Thomson scattering.

  5. Updates on the Optical Emission Spectroscopy and Thomson Scattering Investigations on the Helicon Plasma Experiment (HPX)

    NASA Astrophysics Data System (ADS)

    Duke-Tinson, Omar; Karama, Jackson; Azzari, Phillip; Royce, James; Page, Eric; Schlank, Carter; Sherman, Justin; Stutzman, Brooke; Zuniga, Jonathan

    2014-10-01

    HPX at the Coast Guard Academy Plasma Laboratory (CGAPL) have set up spectral probes to verify plasma mode transitions to the W-mode. These optical probes utilize movable filters, and ccd cameras to gather data at selected spectral frequency bands. Raw data collected will be used to measure the plasma's relative density, temperature, structure, and behavior during experiments. Direct measurements of the plasma's properties can be determined through modeling and by comparison with the state transition tables, using Optical Emission Spectroscopy (OES). The spectral probes will take advantage of HPX's magnetic field structure to define and measure the plasma's radiation temp as a function of time and space. In addition, the Thomson Scattering (TS) device will measure internal temperature and density data as the HPX plasma transitions through capacitive and inductive modes while developing into helicon plasma. Currently CGAPL is focused on building its laser beam transport and scattered light collection optical systems. Recently, HPX has acquired an Andor ICCD spectrometer for the spectral analysis. Data collected by the TS system will be logged in real time by CGAPL's Data Acquisition (DAQ) system with LabView remote access. Further progress on HPX will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY13.

  6. Status of the Thomson Scattering System Developed for Diagnostic Testing on the Helicon Plasma Experiment (HPX)*

    NASA Astrophysics Data System (ADS)

    Duke-Tinson, O.; James, R.; Nolan, S.; Page, E.; Paolino, R.; Romano, B.; Zuniga, J.; Schlank, C.; Lopez, M.; Karama, J.; Sherman, J.; Stutzman, B.

    2013-10-01

    HPX will utilize Electromagnetic Radiation Scattering to make internal plasma temperature and density point measurements. The United States Coast Guard Academy Plasma Laboratory's (CGAPL's) Thompson Scattering single spatial point system employs a 300 W CW YAG laser. We will use the internal temperature and density measurements in conjunction with the particle and spectral probes to track the plasmas transitions through the capacitive and inductive modes to ultimately reach the helicon mode. Once achieved, the system will be invaluable in making plasma quantitative temperature and density observations that will contribute to a comprehensive plasma profile. Most of the efforts thus far have been in the alignment and repair of the laser system. As this stage nears an end, efforts have begun to shift towards installing the aligned Thomson Scattering system (TS) into its permanent location, with mounted collection optics on HPX's top port. HPX will likely employ a polychrometer similar to the ones currently in use by HBTEP at Columbia University, for the spectral analysis of the scattered light. Data collected by the TS system will then be logged in real time by CGAPL's Data Acquisition (DAQ) system currently under construction. Further additions and progress of the TS alignment, installation, and calibration on HPX will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY12.

  7. X-ray Thomson scattering measurements from shock-compressed deuterium

    NASA Astrophysics Data System (ADS)

    Davis, P.; Doeppner, T.; Rygg, J. R.; Fortmann, C.; Unites, W.; Salmonson, J.; Collins, G. W.; Landen, O. L.; Falcone, R. W.; Glenzer, S. H.

    2012-05-01

    X-ray Thomson scattering has recently been shown to be an effective method of diagnosing a variety of high energy density plasma conditions. We apply this powerful technique to the widely studied problem of shock-compressed liquid deuterium. The behavior of deuterium under extreme conditions has received considerable attention due to its central role in models of giant planets and the importance of the high-pressure insulator-metal transition. We have used spectrally resolved x-ray scattering from electron-plasma waves to perform microscopic observations of ionization during compression. In these experiments, a single shock was launched in cryogenic deuterium reaching compressions of 3x. The 2 keV Ly-α line in silicon was used as an x-ray source in a forward scattering geometry. In addition to elastic scattering from tightly bound electrons, this low probe energy accessed the collective plasmon oscillations of delocalized electrons. Inelastic scattering from the plasmons allowed accurate measurements of the free electron density through the spectral position of the resonance and provided an estimate of the temperature through its ratio with the elastic feature. Combined with velocity interferometry from the reflective shock front, this lead to a direct determination of the ionization state. We compare the measured ionization conditions with computational models. Additionally, we discuss the possibility of using this technique to determine electrical conductivity and to directly observe pressure-induced molecular dissociation along the Hugoniot.

  8. X-ray Thomson scattering of warm dense matter on the Z-accelerator

    NASA Astrophysics Data System (ADS)

    Ao, Tommy; Harding, Eric; Bailey, James; Desjarlais, Michael; Hansen, Stephanie; Lemke, Raymond; Rochau, Gregory; Sinars, Daniel; Smith, Ian; Knudson, Marcus; Reneker, Joseph; Kernaghan, Matthew; Gregori, Gianluca

    2013-06-01

    Experiments on the Z-accelerator have demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size. Significant progress to combine x-ray Thomson scattering (XRTS), a powerful diagnostic for WDM, with the extreme environments created at Z has been accomplished. The large Z current is used to magnetically launch Al flyers to impact CH2 foam (0.12 g/cm3) . The uniformly-shocked CH2 volume is 5-10 mm3, and the steady shock phase lasts 10-100 ns, which are roughly 1500 & 100 times larger, respectively, than typical laser shocked samples. The Z-Beamlet laser irradiates a 5 μm thick Mn foil near the load to generate 6.181 keV Mn-He- α x-rays that penetrate into the WDM state and scatter from it. A new high sensitivity x-ray scattering spherical spectrometer (XRS3) with both high spatial (~75 μm) and spectral (E / ΔE ~ 1500) resolution is fielded that enables benchmark quality data by simultaneously measuring x-rays scattered from shocked and ambient regions of the CH2 foam, and the Mn x-ray source. SNL is a multi-program laboratory operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Dept. of Energy's NNSA under contract DE-AC04-94AL85000.

  9. Laser Thomson Scattering, Raman Scattering and laser-absorption diagnostics of high pressure microdischarges

    NASA Astrophysics Data System (ADS)

    Donnelly, Vincent M.; Belostotskiy, Sergey G.; Economou, Demetre J.; Sadeghi, Nader

    2010-05-01

    Laser scattering experiments were performed in high pressure (100s of Torr) parallel-plate, slot-type DC microdischarges operating in argon or nitrogen. Laser Thomson Scattering (LTS) and Rotational Raman Scattering were employed in a novel, backscattering, confocal configuration. LTS allows direct and simultaneous measurement of both electron density (ne) and electron temperature (Te). For 50 mA current and over the pressure range of 300 - 700 Torr, LTS yielded Te = 0.9 ± 0.3 eV and ne = (6 ± 3)·1013 cm-3, in reasonable agreement with the predictions of a mathematical model. Rotational Raman spectroscopy (RRS) was employed for absolute calibration of the LTS signal. RRS was also applied to measure the 3D gas temperature (Tg) in nitrogen DC microdischarges. In addition, diode laser absorption spectroscopy was employed to measure the density of argon metastables (1s5 in Paschen notations) in argon microdischarges. The gas temperature, extracted from the width of the absorption profile, was compared with Tg values obtained by optical emission spectroscopy.

  10. Sensitivity of Micromachined Joule-Thomson Cooler to Clogging Due to Moisture

    NASA Astrophysics Data System (ADS)

    Cao, H. S.; Vanapalli, S.; Holland, H. J.; Vermeer, C. H.; ter Brake, H. J. M.

    A major issue in long-term operation of micromachined Joule-Thomson coolers is the clogging of the microchannels and/or the restriction due to the deposition of water molecules present in the working fluid. In this study, we present the performance of a microcooler operated with nitrogen gas with different moisture levels. Relatively low-purity nitrogen gas (5.0) is supplied from a gas bottle and led through a filter to control the moisture level. The filter consists of a tube-in-tube counter flow heat exchanger (CFHX) and a heat exchanger that is stabilized at a certain temperature by using a Stirling cooler. The set-point temperature determines the moisture level at the exit of the heat exchanger. It is found that the moisture level has influence on the mass-flow rate during the cool down. Once the microcooler reaches the set cold-end temperature, the main deposition area shifts into the CFHX and the moisture level at the restriction is almost independent on the inlet moisture level of the microcooler. The moisture level at the restriction increases with the increasing cold-end temperature when the cold-end temperature is lower than the saturation temperature of the water in the nitrogen gas. Higher cold-end temperature results in higher clogging rate.

  11. Thomson Scattering from Electron Plasma Waves in a Raman Plasma Amplifier

    NASA Astrophysics Data System (ADS)

    Davies, A.; Haberberger, D.; Bromage, J.; Zuegel, J. D.; Froula, D. H.; Trines, R.; Bingham, R.; Sadler, J.; Norreys, P. A.; Silva, L. O.

    2015-11-01

    Electron plasma waves (EPW's) can be used to transfer significant energy from a long-pulse laser to a short-seed pulse. Raman amplification has the potential to amplify intense pulses beyond the capabilities of current laser technology (~1022 W/cm2) because of the plasma's ability to sustain large-amplitude plasma waves. Having complete knowledge of the EPW amplitude is essential to establishing optimal parameters for efficient Raman amplification. With Thomson scattering it is possible to measure the spatial and temporal distribution of the EPW amplitude and experimentally determine the effect of the EPW profile on Raman scattering. Moving beyond the initial proof-of-principal experiments at the submillijoule level, to amplifying a 75-mJ, 100-fs seed with a 75-J pump has the potential to produce PW-scale laser pulses with Raman amplification. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  12. Properties of Gas Mixtures and Their Use in Mixed-Refrigerant Joule-Thomson Refrigerators

    NASA Astrophysics Data System (ADS)

    Luo, E.; Gong, M.; Wu, J.; Zhou, Y.

    2004-06-01

    The Joule-Thomson (J-T) effect has been widely used for achieving low temperatures. In the past few years, much progress has been made in better understanding the working mechanism of the refrigeration method and in developing prototypes for different applications. In this talk, there are three aspects of our research work to be discussed. First, some special thermal properties of the mixtures for achieving liquid nitrogen temperature range will be presented. Secondly, some important conclusions from the optimization of various mixed-refrigerant J-T cycles such as a simple J-T cycle and an auto-cascade mixed-refrigerant J-T cycle will be presented. Moreover, an auto-cascade, mixed-refrigerant J-T refrigerator with a special mixture capable of achieving about 50K will be mentioned. Finally, various prototypes based on the mixed-refrigerant refrigeration technology will be described. These applications include miniature J-T cryocoolers for cooling infrared detectors and high-temperature superconducting devices, cryosurgical knife for medical treatment, low-temperature refrigerators for biological storage and so forth. The on-going research work and unanswered questions for this technology will be also discussed.

  13. X-ray Thomson scattering of shocked carbon foam on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Ao, Tommy; Harding, Eric; Bailey, James; Lemke, Raymond; Desjarlais, Michael; Hansen, Stephanie; Smith, Ian; Reneker, Joseph; Romero, Dustin; Sinars, Daniel; Rochau, Gregory; Benage, John

    2015-06-01

    Experiments on the Sandia Z pulsed-power accelerator have demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size, which are ideal for investigations of fundamental WDM properties. For the first time, a space-resolved x-ray Thomson scattering (XRTS) spectra from shocked carbon foam was recorded on Z. The large electrical current produced by Z was used to launch Al flyer plates up to 25 km/s. The impact of the flyer plate on a CH2 foam target produced a shocked state with an estimated pressure of 0.75 Mbar, density of 0.52 g/cc, and temperature of 4.3 eV. Both unshocked and shocked portions of the foam target were probed with 6.2 keV x-rays produced by focusing the Z-Beamlet laser onto a nearby Mn foil. The data is comprised of three spatially distinct spectra that were simultaneously captured with a single spectrometer. These three spectra provide detailed information on the following target locations: the laser spot, the unshocked foam, and the shocked foam. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.

  14. Study of Fast, Near-Infrared Photodetectors for the ITER Core LIDAR Thomson Scattering

    SciTech Connect

    Giudicotti, L.; Beurskens, M.; Kempenaars, M.; Walsh, M. J.

    2008-03-12

    A key component for the ITER core LIDAR Thomson Scattering (TS) diagnostic would be a detector with good sensitivity in the 850-1060 nm near infrared (NIR) spectral region. Covering this spectral region becomes necessary if a Nd:YAG laser system operating at {lambda} = 1.06 {mu}m is used as the laser source, which is a very attractive choice in terms of available energy, repetition rate, reliability and cost. In this paper we review the state of the art of two types of detectors available for the above spectral range: the transferred electron (TE) InGaAs/InP hybrid photodiode and the In{sub x}Ga{sub 1-x}As microchannel plate (MCP) image intensifier and we describe the advancements necessary for a possible application in the ITER LIDAR TS. In addition we describe the preliminary characterization of new GaAsP fast MCP photomultipliers (PMTs) suitable for the detection of the visible part of the LIDAR TS spectrum in JET and ITER.

  15. Collective Thomson scattering measurements of the Ion Acoustic Decay Instability. Final report

    SciTech Connect

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

    1993-12-31

    We have developed an uv collective Thomson scattering system for plasma produced by a short wavelength laser. The Ion Acoustic Decay Instabilities are studied in a large ({approximately}mm) scale, hot ({approximately}keV) plasma, which is relevant to a direct-driven laser fusion plasma. The IADI primary decay process is measured by the CTS. We used a random phase plate to minimize the non uniform irradiation of the interaction laser. Nevertheless, the threshold of the most unstable mode driven by the IADI is quite low. The measured threshold value agrees favorably with the theoretical value of the large scale plasma. We have also shown that the CTS from the IADI can be a good tool for measuring a local electron temperature. The measured results agree reasonably with the SAGE computer calculations. We used the real part of the wave (frequency) to estimate T{sub e}. The real part is, in general, reliable compared to the imaginary part such as the damping, and the growth rates. We have shown that the IADI can be easily excited in a large scale, hot plasma. The IADI has potentially important applications to direct drive laser fusion, and also critical surface diagnostic.

  16. Design and Study of the Observation Optics for the Thomson Scattering Planned at Wendelstein 7-X

    SciTech Connect

    Cantarini, J.; Knauer, J. P.; Pasch, E.

    2008-03-19

    The main aim of the Thomson scattering system is the measurement of electron temperature and density profiles with high time and spatial resolution. To cover the whole laser beam line (1.6 m) through the plasma cross section, two ports are provided for the observation optics, which image the scattering volumes (each with 28 mm length and 9 mm diameter) onto fiber bundles. The observation optics are important components of the diagnostic set-up, because their imaging properties determine the spectral and spatial resolution of the whole system. Therefore the design of the optics must be optimized according to the geometrical constrains of the observation ports in terms of position and dimensions. To optimize this optical engineering, the commercial ZEMAX program is used. The composition of the optical system is elaborated to minimize losses of collected light with wavelength from 700 nm up to 1064 nm. Environmental criteria (e.g. neutrons, ECR plasma heating and temperature) will be considered choosing optical materials. First results of calculations will be presented.

  17. Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler

    SciTech Connect

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-01-29

    A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.

  18. Enhancement of the JET edge LIDAR Thomson scattering diagnostic with ultrafast detectors

    SciTech Connect

    Kempenaars, M.; Flanagan, J. C.; Walsh, M. J.; Beurskens, M.; Balboa, I.

    2008-10-15

    The edge light detection and ranging (LIDAR) Thomson scattering diagnostic at the Joint European Torus fusion experiment uses a 3 J ruby laser to measure the electron density and temperature profile at the plasma edge. The original system used a 1 GHz digitizer and detectors with response times of {approx_equal}650 ps and effective quantum efficiencies <7%. This system has recently been enhanced with the installation of a new 8 GHz digitizer and four new ultrafast GaAsP microchannel plate photomultiplier tube detectors with response times of <300 ps and effective quantum efficiencies in the range of {approx}13%-20% (averaged over {lambda}=500-700 nm). This upgrade has enabled the spatial resolution to be reduced to {approx}6.3 cm along the laser line of sight for a laser pulse of 300 ps full width at half maximum, which is close to the requirements for the ITER core LIDAR. Performance analysis shows that the new system will have an effective spatial resolution of up to 1 cm in the magnetic midplane via magnetic flux surface mapping.

  19. The Thomson Scattering System on the Lithium Tokamak eXperiment (LTX)

    SciTech Connect

    T. Strickler, R. Majeski, R. Kaita, B. LeBlanc

    2008-07-31

    The Lithium Tokamak eXperiment (LTX) is a spherical tokamak with R0 = 0.4m, a = 0.26m, BTF ~ 3.4kG, IP ~ 400kA, and pulse length ~ 0.25s. The goal of LTX is to investigate tokamak plasmas that are almost entirely surrounded by a lithium-coated plasma-facing shell conformal to the last closed magnetic flux surface. Based on previous experimental results and simulation, it is expected that the low-recycling liquid lithium surfaces will result in higher temperatures at the plasma edge, flatter overall temperature profiles, centrally-peaked density profiles, and an increased confinement time. To test these predictions, the electron temperature and density profiles in LTX will be measured by a multi-point Thomson scattering system (TVTS). Initially, TS measurements will be made at up to 12 simultaneous points between the plasma center and plasma edge. Later, high resolution edge measurements will be deployed to study the lithium edge physics in greater detail. Technical challenges to implementing the TS system included limited "line of sight" access to the plasma due to the plasma-facing shell and problems associated with the presence of liquid lithium.

  20. Dual-angle, self-calibrating Thomson scattering measurements in RFX-MOD

    SciTech Connect

    Giudicotti, L.

    2014-11-15

    In the multipoint Thomson scattering (TS) system of the RFX-MOD experiment the signals from a few spatial positions can be observed simultaneously under two different scattering angles. In addition the detection system uses optical multiplexing by signal delays in fiber optic cables of different length so that the two sets of TS signals can be observed by the same polychromator. Owing to the dependence of the TS spectrum on the scattering angle, it was then possible to implement self-calibrating TS measurements in which the electron temperature T{sub e}, the electron density n{sub e} and the relative calibration coefficients of spectral channels sensitivity C{sub i} were simultaneously determined by a suitable analysis of the two sets of TS data collected at the two angles. The analysis has shown that, in spite of the small difference in the spectra obtained at the two angles, reliable values of the relative calibration coefficients can be determined by the analysis of good S/N dual‑angle spectra recorded in a few tens of plasma shots. This analysis suggests that in RFX-MOD the calibration of the entire set of TS polychromators by means of the similar, dual-laser (Nd:YAG/Nd:YLF) TS technique, should be feasible.

  1. Synoptic maps for the heliospheric Thomson scattering brightness as observed by the Helios photometers

    NASA Technical Reports Server (NTRS)

    Hick, P.; Jackson, B. V.; Schwenn, R.

    1991-01-01

    A method for displaying the electron Thomson scattering intensity in the inner heliosphere as observed by the zodiacal light photometers on board the Helios spacecraft in the form of synoptic maps is presented. The method is based on the assumption that the bulk of the scattering electrons along the line of sight is located near the point closest to the sun. Inner-heliospheric structures will generally be represented properly in these synoptic maps only if they are sufficiently long-lived (that is, a significant fraction of a solar rotation period). The examples of Helios synoptic maps discussed (from data in April 1976 and November 1978), indicate that it is possible to identify large-scale, long-lived density enhancements in the inner heliosphere. It is expected that the Helios synoptic maps will be particularly useful in the study of corotating structures (e.g., streamers), and the maps will be most reliable during periods when few transient featurs are present in the corona, i.e., during solar minimum.

  2. Nanoscopic confinement through self-assembly: crystallization within micellar cores exhibits simple Gibbs-Thomson behavior.

    PubMed

    Zinn, Thomas; Willner, Lutz; Lund, Reidar

    2014-12-01

    It is well known that liquids confined to small nanoscopic pores and droplets exhibit thermal behavior very different from bulk samples. Less is known about liquids spontaneously confined through self-assembly into micellar structures. Here we demonstrate, using a very well-defined n-alkyl-poly(ethylene oxide) polymer system with a tunable structure, that n-alkane(s) forming 2-3 nm small micellar cores are affected considerably by confinement in the form of melting point depressions. Moreover, comparing the reduction in melting points, ΔT_{m}, determined through volumetric and calorimetric methods with the micellar core radius, R_{c}, obtained from small-angle x-ray scattering, we find excellent agreement with the well-known Gibbs-Thomson equation, ΔT_{m}∼R_{c}^{-1}. This demonstrates that the reduced size, i.e., the Laplace pressure, is the dominant parameter governing the melting point depression in micellar systems. PMID:25526170

  3. Dual-angle, self-calibrating Thomson scattering measurements in RFX-MOD.

    PubMed

    Giudicotti, L; Pasqualotto, R; Fassina, A

    2014-11-01

    In the multipoint Thomson scattering (TS) system of the RFX-MOD experiment the signals from a few spatial positions can be observed simultaneously under two different scattering angles. In addition the detection system uses optical multiplexing by signal delays in fiber optic cables of different length so that the two sets of TS signals can be observed by the same polychromator. Owing to the dependence of the TS spectrum on the scattering angle, it was then possible to implement self-calibrating TS measurements in which the electron temperature Te, the electron density ne and the relative calibration coefficients of spectral channels sensitivity Ci were simultaneously determined by a suitable analysis of the two sets of TS data collected at the two angles. The analysis has shown that, in spite of the small difference in the spectra obtained at the two angles, reliable values of the relative calibration coefficients can be determined by the analysis of good S/N dual‑angle spectra recorded in a few tens of plasma shots. This analysis suggests that in RFX-MOD the calibration of the entire set of TS polychromators by means of the similar, dual-laser (Nd:YAG/Nd:YLF) TS technique, should be feasible. PMID:25430236

  4. X-ray Thomson scattering measurements from shock-compressed deuterium

    SciTech Connect

    Davis, P.; Doeppner, T.; Rygg, J. R.; Fortmann, C.; Unites, W.; Salmonson, J.; Collins, G. W.; Landen, O. L.; Falcone, R. W.; Glenzer, S. H.

    2012-05-25

    X-ray Thomson scattering has recently been shown to be an effective method of diagnosing a variety of high energy density plasma conditions. We apply this powerful technique to the widely studied problem of shock-compressed liquid deuterium. The behavior of deuterium under extreme conditions has received considerable attention due to its central role in models of giant planets and the importance of the high-pressure insulator-metal transition. We have used spectrally resolved x-ray scattering from electron-plasma waves to perform microscopic observations of ionization during compression. In these experiments, a single shock was launched in cryogenic deuterium reaching compressions of 3x. The 2 keV Ly-{alpha} line in silicon was used as an x-ray source in a forward scattering geometry. In addition to elastic scattering from tightly bound electrons, this low probe energy accessed the collective plasmon oscillations of delocalized electrons. Inelastic scattering from the plasmons allowed accurate measurements of the free electron density through the spectral position of the resonance and provided an estimate of the temperature through its ratio with the elastic feature. Combined with velocity interferometry from the reflective shock front, this lead to a direct determination of the ionization state. We compare the measured ionization conditions with computational models. Additionally, we discuss the possibility of using this technique to determine electrical conductivity and to directly observe pressure-induced molecular dissociation along the Hugoniot.

  5. Outline of optical design and viewing geometry for divertor Thomson scattering on MAST upgrade

    NASA Astrophysics Data System (ADS)

    Hawke, J.; Scannell, R.; Harrison, J.; Huxford, R.; Bohm, P.

    2013-11-01

    The super-X divertor on MAST Upgrade will be diagnosed by a Thomson scattering diagnostic. A preliminary design of the collection optics and calculations of the diagnostic's performance are discussed in this paper. As part of the design the location and size of the collection cell were optimized to minimize vignetting, especially in the region of interest close to the divertor strike point. The design process was complicated by the limited access available in the closed divertor geometry. In the study of the diagnostic's performance, the radial resolution, projection of the laser image onto the fiber bundle, and impact of depth of field with a multiple laser system were investigated. In this design there is a trade-off between the resolution of the system and the lifetime of the beam dump. For this reason the beam has its focal point at the start of the viewing region and diverges in width to approximately five millimeters near the divertor tile. The effect of this large variation in beam width is examined primarily at the two extremes by means of ray trace modeling. This model takes an object with dimensions of the beam width imaged onto the fiber bundle to investigate the effect of misalignment for a narrow or broad laser image. In a similar manner ray tracing was performed to determine the effects of depth of field for four and two laser systems. As the electron density of the system may be low, performance analysis considers firing multiple lasers simultaneously to improve photon statistics.

  6. Antenna design for fast ion collective Thomson scattering diagnostic for the international thermonuclear experimental reactor.

    PubMed

    Leipold, F; Furtula, V; Salewski, M; Bindslev, H; Korsholm, S B; Meo, F; Michelsen, P K; Moseev, D; Nielsen, S K; Stejner, M

    2009-09-01

    Fast ion physics will play an important role for the international thermonuclear experimental reactor (ITER), where confined alpha particles will affect and be affected by plasma dynamics and thereby have impacts on the overall confinement. A fast ion collective Thomson scattering (CTS) diagnostic using gyrotrons operated at 60 GHz will meet the requirements for spatially and temporally resolved measurements of the velocity distributions of confined fast alphas in ITER by evaluating the scattered radiation (CTS signal). While a receiver antenna on the low field side of the tokamak, resolving near perpendicular (to the magnetic field) velocity components, has been enabled, an additional antenna on the high field side (HFS) would enable measurements of near parallel (to the magnetic field) velocity components. A compact design solution for the proposed mirror system on the HFS is presented. The HFS CTS antenna is located behind the blankets and views the plasma through the gap between two blanket modules. The viewing gap has been modified to dimensions 30x500 mm(2) to optimize the CTS signal. A 1:1 mock-up of the HFS mirror system was built. Measurements of the beam characteristics for millimeter-waves at 60 GHz used in the mock-up agree well with the modeling. PMID:19791936

  7. Thomson scattering diagnostic system design for the Compact Toroidal Hybrid experiment

    SciTech Connect

    Traverso, P. J. Maurer, D. A.; Ennis, D. A.; Hartwell, G. J.; Goforth, M. M.; Loch, S. D.; Pearce, A. J.; Cianciosa, M. R.

    2014-11-15

    A new Thomson scattering system using standard commercially available components has been designed for the non-axisymmetric plasmas of the Compact Toroidal Hybrid (CTH). The beam, generated by a frequency doubled Continuum PL DLS 2 J Nd:YAG laser, is passed vertically through an entrance Brewster window and an aperturing baffle system to minimize the stray laser light that could enter the collection optics. The beam line has been designed with an 8 m propagation distance to the mid-plane of the CTH device with the beam diameter kept less than 3 mm inside the plasma volume. The beam exits the vacuum system through another Brewster window and enters a beam dump, again to minimize the stray light in the vacuum chamber. Light collection, spectral processing, and signal detection are accomplished with an f/#∼ 1 aspheric lens, a commercially available Holospec f/1.8 spectrometer, and an Andor iStar DH740-18U-C3 image intensified camera. Spectral rejection of stray laser light, if needed, can be performed with the use of an optional interference filter at the spectrometer input. The system has been developed for initial single point measurements of plasmas with core electron temperatures of approximately 20–300 eV and densities of 5 × 10{sup 18} to 5 × 10{sup 19} m{sup −3} dependent upon operational scenario.

  8. Ultrafast K-(alpha) X-ray Thomson Scattering from Shock Compressed Lithium Hydride

    SciTech Connect

    Kritcher, A L; Neumayer, P; Castor, J; Doeppner, T; Falcone, R W; Landen, O L; Lee, H J; Lee, R W; Holst, B; Redmer, R; Morse, E C; Ng, A; Pollaine, S; Price, D; Glenzer, S H

    2008-12-10

    Spectrally and temporally resolved x ray Thomson scattering using ultrafast Ti K-{alpha} x-rays has provided experimental validation for modeling of the compression and heating of shocked matter. The coalescence of two shocks launched into a solid density LiH target by a shaped 6 nanosecond heater beam was observed from rapid heating to temperatures of 2.2 eV, enabling tests of shock timing models. Here, the temperature evolution of the target at various times during shock progression was characterized from the intensity of the elastic scattering component. The observation of scattering from plasmons, electron plasma oscillations, at shock coalescence indicates a transition to a dense metallic plasma state in LiH. From the frequency shift of the measured plasmon feature the electron density was directly determined with high accuracy, providing a material compression of a factor of three times solid density. The quality of data achieved in these experiments demonstrates the capability for single-shot dynamic characterization of dense shock compressed matter. The conditions probed in this experiment are relevant for the study of the physics of planetary formation and to characterize inertial confinement fusion targets for experiments such as on the National Ignition Facility (NIF), LLNL.

  9. Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique

    SciTech Connect

    Yamamoto, N.; Tomita, K.; Sugita, K.; Kurita, T.; Nakashima, H.; Uchino, K.

    2012-07-15

    This paper reports on the development of a method for measuring xenon plasma properties using the laser Thomson scattering technique, for application to ion engine system design. The thresholds of photo-ionization of xenon plasma were investigated and the number density of metastable atoms, which are photo-ionized by a probe laser, was measured using laser absorption spectroscopy, for several conditions. The measured threshold energy of the probe laser using a plano-convex lens with a focal length of 200 mm was 150 mJ for a xenon mass flow rate of 20 {mu}g/s and incident microwave power of 6 W; the probe laser energy was therefore set as 80 mJ. Electron number density was found to be (6.2 {+-} 0.4) Multiplication-Sign 10{sup 17} m{sup -3} and electron temperature was found to be 2.2 {+-} 0.4 eV at a xenon mass flow rate of 20 {mu}g/s and incident microwave power of 6 W. The threshold of the probe laser intensity against photo-ionization in a miniature xenon ion thruster is almost constant for various mass flow rates, since the ratio of population of the metastable atoms to the electron number density is little changed.

  10. Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique.

    PubMed

    Yamamoto, N; Tomita, K; Sugita, K; Kurita, T; Nakashima, H; Uchino, K

    2012-07-01

    This paper reports on the development of a method for measuring xenon plasma properties using the laser Thomson scattering technique, for application to ion engine system design. The thresholds of photo-ionization of xenon plasma were investigated and the number density of metastable atoms, which are photo-ionized by a probe laser, was measured using laser absorption spectroscopy, for several conditions. The measured threshold energy of the probe laser using a plano-convex lens with a focal length of 200 mm was 150 mJ for a xenon mass flow rate of 20 μg/s and incident microwave power of 6 W; the probe laser energy was therefore set as 80 mJ. Electron number density was found to be (6.2 ± 0.4) × 10(17) m(-3) and electron temperature was found to be 2.2 ± 0.4 eV at a xenon mass flow rate of 20 μg/s and incident microwave power of 6 W. The threshold of the probe laser intensity against photo-ionization in a miniature xenon ion thruster is almost constant for various mass flow rates, since the ratio of population of the metastable atoms to the electron number density is little changed. PMID:22852670

  11. Clogging of Joule-Thomson Devices in Liquid Hydrogen-Lunar Lander Descent Stage Operating Regime

    NASA Astrophysics Data System (ADS)

    Jurns, J. M.

    2010-04-01

    Joule-Thomson (J-T) devices have been identified as critical components for future space exploration missions. The NASA Constellation Program lunar architecture considers LOX/LH2 propulsion for the lunar lander descent stage main engine an enabling technology, ensuring the cryogenic propellants are available at the correct conditions for engine operation. This cryogenic storage system may utilize a Thermodynamic Vent System (TVS) that includes J-T devices to maintain tank fluid pressure and temperature. Previous experimental investigations have indicated that J-T devices may become clogged when flowing LH2 while operating at a temperature range from 20.5 K to 24.4 K. It has been proposed that clogging is due to a trace amount of metastable, supercooled liquid neon in the regular LH2 supply. In time, flow blockage occurs from accretion of solid neon on the orifice. This clogging poses a realistic threat to spacecraft propulsion systems utilizing J-T devices in cryogenic pressure control systems. TVS failure due to J-T clogging would prevent removal of environmental heat from the propellant and potential loss of mission. This report describes J-T clogging tests performed with LH2. Tests were performed in the expected Lunar Lander operating regime, and several methods were evaluated to determine the optimum approach to mitigating the potential risk of J-T clogging.

  12. Thomson scattering diagnostic system design for the Compact Toroidal Hybrid experimenta)

    NASA Astrophysics Data System (ADS)

    Traverso, P. J.; Maurer, D. A.; Ennis, D. A.; Hartwell, G. J.; Goforth, M. M.; Loch, S. D.; Pearce, A. J.; Cianciosa, M. R.

    2014-11-01

    A new Thomson scattering system using standard commercially available components has been designed for the non-axisymmetric plasmas of the Compact Toroidal Hybrid (CTH). The beam, generated by a frequency doubled Continuum PL DLS 2 J Nd:YAG laser, is passed vertically through an entrance Brewster window and an aperturing baffle system to minimize the stray laser light that could enter the collection optics. The beam line has been designed with an 8 m propagation distance to the mid-plane of the CTH device with the beam diameter kept less than 3 mm inside the plasma volume. The beam exits the vacuum system through another Brewster window and enters a beam dump, again to minimize the stray light in the vacuum chamber. Light collection, spectral processing, and signal detection are accomplished with an f/{#} ˜ 1 aspheric lens, a commercially available Holospec f/1.8 spectrometer, and an Andor iStar DH740-18U-C3 image intensified camera. Spectral rejection of stray laser light, if needed, can be performed with the use of an optional interference filter at the spectrometer input. The system has been developed for initial single point measurements of plasmas with core electron temperatures of approximately 20-300 eV and densities of 5 × 1018 to 5 × 1019 m-3 dependent upon operational scenario.

  13. First operations with the new Collective Thomson Scattering diagnostic on the Frascati Tokamak Upgrade device

    NASA Astrophysics Data System (ADS)

    Bin, W.; Bruschi, A.; D'Arcangelo, O.; Castaldo, C.; De Angeli, M.; Figini, L.; Galperti, C.; Garavaglia, S.; Granucci, G.; Grosso, G.; Korsholm, S. B.; Lontano, M.; Mellera, V.; Minelli, D.; Moro, A.; Nardone, A.; Nielsen, S. K.; Rasmussen, J.; Simonetto, A.; Stejner, M.; Tartari, U.

    2015-10-01

    Anomalous emissions were found over the last few years in spectra of Collective Thomson Scattering (CTS) diagnostics in tokamak devices such as TEXTOR, ASDEX and FTU, in addition to real CTS signals. The signal frequency, down-shifted with respect to the probing one, suggested a possible origin in Parametric Decay Instability (PDI) processes correlated with the presence of magnetic islands and occurring for pumping wave power levels well below the threshold predicted by conventional models. A threshold below or close to the Electron Cyclotron Resonance Heating (ECRH) power levels could limit, under certain circumstances, the use of the ECRH in fusion devices. An accurate characterization of the conditions for the occurrence of this phenomenon and of its consequences is thus of primary importance. Exploiting the front-steering configuration available with the real-time launcher, the implementation of a new CTS setup now allows studying these anomalous emission phenomena in FTU under conditions of density and wave injection geometry that are more similar to those envisaged for CTS in ITER. The upgrades of the diagnostic are presented as well as a few preliminary spectra detected with the new system during the very first operations in 2014. The present work has been carried out under an EUROfusion Enabling Research project. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  14. X-ray Thomson scattering in warm dense matter at low frequencies

    SciTech Connect

    Murillo, Michael S.

    2010-03-15

    The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure with data from the extreme case of a liquid metal; good agreement is found. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the 'plasmon-pole'-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions.

  15. Design and operation of the multipulse Thomson scattering diagnostic on DIII-D

    SciTech Connect

    Carlstrom, T.N.; Campbell, G.L.; DeBoo, J.C.; Evanko, R.; Greenfield, C.M.; Haskovec, J.; Hsieh, C.L.; McKee, E.; Snider, R.T.; Stockdale, R.; Trost, P.K.; Thomas, M.P.; Evans, J.

    1992-03-01

    This paper describes the design and operation of a 40 spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. As many as eight lasers may be fired alternately for an average measurement frequency of 160 Hz, or they may be fired in rapid succession (< 10 kHz), producing a burst of pulses for measuring transient events. The high spatial resolution (1.3 cm) and wide dynamic range (10 eV to 20 keV) enable this system to resolve large electron density and temperature gradients formed at the plasma edge and in the scrape-off-layer during H-mode operation. These features provide a formidable tool for studying L-H transitions, edge localized modes (ELMs), beta limits, transport, and disruptions in an efficient manner suitable for large tokamak operation where shot-to-shot scans are impractical. The scattered light is dispersed by interference filter polychromators and detected by silicon avalanche photodiodes. Laser control and data acquisition are performed in real-time by a VME based microcomputer. Data analysis is performed by a MicroVAX 3400. Additional features of this system include real-time analysis capability, full statistical treatment of error bars based on the measured background light, and laser beam quality and alignment monitoring during plasma operation. Results of component testing, calibration, plasma operation, and error analysis are presented.

  16. Thomson scattering diagnostic system design for the Compact Toroidal Hybrid experiment.

    PubMed

    Traverso, P J; Maurer, D A; Ennis, D A; Hartwell, G J; Goforth, M M; Loch, S D; Pearce, A J; Cianciosa, M R

    2014-11-01

    A new Thomson scattering system using standard commercially available components has been designed for the non-axisymmetric plasmas of the Compact Toroidal Hybrid (CTH). The beam, generated by a frequency doubled Continuum PL DLS 2 J Nd:YAG laser, is passed vertically through an entrance Brewster window and an aperturing baffle system to minimize the stray laser light that could enter the collection optics. The beam line has been designed with an 8 m propagation distance to the mid-plane of the CTH device with the beam diameter kept less than 3 mm inside the plasma volume. The beam exits the vacuum system through another Brewster window and enters a beam dump, again to minimize the stray light in the vacuum chamber. Light collection, spectral processing, and signal detection are accomplished with an f/#∼ 1 aspheric lens, a commercially available Holospec f/1.8 spectrometer, and an Andor iStar DH740-18U-C3 image intensified camera. Spectral rejection of stray laser light, if needed, can be performed with the use of an optional interference filter at the spectrometer input. The system has been developed for initial single point measurements of plasmas with core electron temperatures of approximately 20-300 eV and densities of 5 × 10(18) to 5 × 10(19) m(-3) dependent upon operational scenario. PMID:25430265

  17. X-ray Thomson scattering in warm dense matter at low frequencies.

    PubMed

    Murillo, Michael S

    2010-03-01

    The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure with data from the extreme case of a liquid metal; good agreement is found. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the "plasmon-pole"-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions. PMID:20365878

  18. X-ray Thomson scattering in warm dense matter at low frequencies

    NASA Astrophysics Data System (ADS)

    Murillo, Michael

    2010-11-01

    The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure factor with data for the extreme case of a liquid metal. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the ``plasmon-pole''-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions. This suggests a method by which viscous transport properties can be measured.

  19. An optical design and accuracy estimation for a JT-60SA edge Thomson scattering diagnostic

    NASA Astrophysics Data System (ADS)

    Tojo, H.; Hatae, T.; Hamano, T.; Sakuma, T.; Itami, K.

    2013-12-01

    This paper presents the design of a collection optics used for the Thomson scattering diagnostic in JT-60SA. Good spatial resolution ( ~ 10mm) is necessary for the optics to measure detailed profiles of electron temperature (Te) and density (ne) in the plasma edge region. Six lenses forming a Petzval-like lens are employed in this design. The use of an anomalous dispersion glass material for two lenses suppresses severe chromatic aberration; two flat mirrors prevent interference with the port plug in which the collection optics is to be installed. The resultant spot radius (resolution) at the image for the peripheral region is approximately 0.2 mm. When another collection optics previously designed for core measurements is used simultaneously, the angle of laser polarization must be considered because the two collection optics are to be installed in different port-plugs accessing the vacuum vessel from the cryostat. Otherwise, the measured signal would be degraded, and the scattered spectra would be different from the expected ones. This paper evaluates the scattered spectra with relativistic effects without any approximations. This paper also provides a means to optimize the polarization angle by considering a simulated profile in JT-60SA and contributes to future devices that have limited space for collection optics.

  20. X-ray Thomson scattering in warm dense matter at low frequencies

    NASA Astrophysics Data System (ADS)

    Murillo, Michael S.

    2010-03-01

    The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure with data from the extreme case of a liquid metal; good agreement is found. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the “plasmon-pole”-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions.

  1. Microchannel heat exchanger for two-phase Mixed Refrigerant Joule Thomson process

    NASA Astrophysics Data System (ADS)

    Baek, Seungwhan; Lee, Jisung; Lee, Cheonkyu; Jeong, Sangkwon

    2014-01-01

    Mixed Refrigerant Joule Thomson (MR-JT) refrigerators are widely used in various kinds of cryogenic systems these days. Printed Circuit Heat Exchanger (PCHE) is one of the promising cryogenic compact recuperators for MR-JT refrigerators due to its compactness, high NTU and robustness. However, PCHE composed with microchannel bundles can cause flow mal-distribution, and it can cause the degradation of thermal performance of the system. To mitigate the flow mal-distribution problem, the cross link (or intra-layer bypass) can be adapted to parallel microchannels. Two heat exchangers are fabricated in this study; one has straight channels, and the other one has intra-layer bypass structure between channels to enhance the flow distribution. The MR-JT refrigerators are operated with these two heat exchanger and the no-load temperatures are compared. The lower no load temperature achieved with the intra-layer bypass structured heat exchanger. The results indicate that the flow mal-distribution in the microchannel heat exchanger can be mitigated with intra-layer bypass structure, and relaxation of flow mal-distribution in the heat exchanger guarantee the MR-JT refrigerator's performance.

  2. The development of Thomson scattering system on HL-2A tokamak

    SciTech Connect

    Huang, Y.; Zhang, P.; Feng, Z.; Liu, C. H.; Shi, P. L.; Ding, X. T.; Liu, Yong

    2007-11-15

    A new Thomson scattering diagnostic system is successfully developed to measure core plasma electron temperature (T{sub e}) and density (n{sub e}) of HL-2A tokamak (major radius R=165 cm, minor radius a=40 cm). In this system, a standard lamp-monochromator combination is utilized for the calibration of spectral responses. By sweeping in the range of 750-1200 nm with a step of 2 nm, the work can be done automatically for one-point calibration and then for other. Electronic gain calibration and gain monitoring are done by pulsed light emitting diode light. By utilizing an intense Nd:YAG laser of pulse energy up to 4 J and employing good quality interference filters in the five-channel filter polychromator to surpress greatly the stray light, the TS system can be routinely used to make measurements with good quality data. After each HL-2A plasma discharge, the measured T{sub e} and n{sub e} data are transferred to HL-2A database for lookup and analyses.

  3. Isotopic imaging via nuclear resonance fluorescence with laser-based Thomson radiation

    DOEpatents

    Barty, Christopher P. J.; Hartemann, Frederic V.; McNabb, Dennis P.; Pruet, Jason A.

    2009-07-21

    The present invention utilizes novel laser-based, high-brightness, high-spatial-resolution, pencil-beam sources of spectrally pure hard x-ray and gamma-ray radiation to induce resonant scattering in specific nuclei, i.e., nuclear resonance fluorescence. By monitoring such fluorescence as a function of beam position, it is possible to image in either two dimensions or three dimensions, the position and concentration of individual isotopes in a specific material configuration. Such methods of the present invention material identification, spatial resolution of material location and ability to locate and identify materials shielded by other materials, such as, for example, behind a lead wall. The foundation of the present invention is the generation of quasimonochromatic high-energy x-ray (100's of keV) and gamma-ray (greater than about 1 MeV) radiation via the collision of intense laser pulses from relativistic electrons. Such a process as utilized herein, i.e., Thomson scattering or inverse-Compton scattering, produces beams having diameters from about 1 micron to about 100 microns of high-energy photons with a bandwidth of .DELTA.E/E of approximately 10E.sup.-3.

  4. Scattering volume in the collective Thomson scattering measurement using high power gyrotron in the LHD

    NASA Astrophysics Data System (ADS)

    Kubo, S.; Nishiura, M.; Tanaka, K.; Moseev, D.; Ogasawara, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tsujimura, T. I.; Makino, R.

    2016-06-01

    High-power gyrotrons prepared for the electron cyclotron heating at 77 GHz has been used for a collective Thomson scattering (CTS) study in LHD. Due to the difficulty in removing fundamental and/or second harmonic resonance in the viewing line of sight, the subtraction of the background ECE from measured signal was performed by modulating the probe beam power from a gyrotron. The separation of the scattering component from the background has been performed successfully taking into account the response time difference between both high-energy and bulk components. The other separation was attempted by fast scanning the viewing beam across the probing beam. It is found that the intensity of the scattered spectrum corresponding to the bulk and high energy components were almost proportional to the calculated scattering volume in the relatively low density region, while appreciable background scattered component remains even in the off volume in some high density cases. The ray-trace code TRAVIS is used to estimate the change in the scattering volume due to probing and receiving beam deflection effect.

  5. Senescence induced by RECQL4 dysfunction contributes to Rothmund-Thomson syndrome features in mice.

    PubMed

    Lu, H; Fang, E F; Sykora, P; Kulikowicz, T; Zhang, Y; Becker, K G; Croteau, D L; Bohr, V A

    2014-01-01

    Cellular senescence refers to irreversible growth arrest of primary eukaryotic cells, a process thought to contribute to aging-related degeneration and disease. Deficiency of RecQ helicase RECQL4 leads to Rothmund-Thomson syndrome (RTS), and we have investigated whether senescence is involved using cellular approaches and a mouse model. We first systematically investigated whether depletion of RECQL4 and the other four human RecQ helicases, BLM, WRN, RECQL1 and RECQL5, impacts the proliferative potential of human primary fibroblasts. BLM-, WRN- and RECQL4-depleted cells display increased staining of senescence-associated β-galactosidase (SA-β-gal), higher expression of p16(INK4a) or/and p21(WAF1) and accumulated persistent DNA damage foci. These features were less frequent in RECQL1- and RECQL5-depleted cells. We have mapped the region in RECQL4 that prevents cellular senescence to its N-terminal region and helicase domain. We further investigated senescence features in an RTS mouse model, Recql4-deficient mice (Recql4(HD)). Tail fibroblasts from Recql4(HD) showed increased SA-β-gal staining and increased DNA damage foci. We also identified sparser tail hair and fewer blood cells in Recql4(HD) mice accompanied with increased senescence in tail hair follicles and in bone marrow cells. In conclusion, dysfunction of RECQL4 increases DNA damage and triggers premature senescence in both human and mouse cells, which may contribute to symptoms in RTS patients. PMID:24832598

  6. Applying the CO2 laser collective Thomson scattering results from JT-60U to other machines

    NASA Astrophysics Data System (ADS)

    Richards, R. K.; Hutchinson, D. P.; Bennett, C. A.; Kondoh, T.; Miura, Y.; Lee, S.

    2003-03-01

    A collective Thomson scattering (CTS) system based on a pulsed CO2 laser is being developed to demonstrate the feasibility of alpha-particle diagnostics. Tests on this system are being conducted on the JT-60U tokamak. The system consists of a pulsed laser (15 J in 1:s at 10.6:m) and a wide band (˜8 GHz) heterodyne receiver with a quantum-well infrared photodetector [Liu et al., IEEE Electron Device Lett. 16, 253 (1995)]. Stray light is reduced by a notch filter containing hot CO2 gas. The heterodyne receiver is absolutely calibrated using a large area blackbody radiation source [Bennett et al., Appl. Opt. 27, 3324 (1988)]. Results from the tests on JT-60U indicate a larger than expected noise background, especially for the lower velocity measurements determined by the smaller frequency shifts from the laser line. These results are used to estimate the signal-to-noise ratio that would be expected for a CTS diagnostic installed on other devices; ITER ("the way" in Latin), Joint European Torus-Enhanced Performance JET-EP, and axially symmetric divertor experiment (ASDEX). Calculations and possible system improvements are presented.

  7. High-power ruby and alexandrite lasers for LIDAR-Thomson scattering diagnostics

    NASA Astrophysics Data System (ADS)

    Gowers, C.; Gadd, A.; Hirsch, Kurt; Nielsen, P.; Salzmann, H.

    1990-08-01

    By combining the time-of-flight or LIDAR principle with a Thomson backscatter diagnostic, spatial profiles of the electron temperature and density can be measured with a single set of detectors for all spatial points. The technique was demonstrated for the first time on the JET tokamak and has been in routine operation since July 1987. Originally a ruby laser (3 J pulse energy, 300 Ps pulse duration, 0.5 Hz repetition rate) was used together with a 700 MHz bandwidth detection and registration system which yielded a spatial resolution of about 12 cm. A large filter spectrometer with 6 spectral channels covering the wavelength range 400 - 800 nm gives a dynamic range for the temperature measurements of 0.2-20 keV. The original system is described, examples of measurements are given and compared with the results of other diagnostics. The system is being upgraded to make measurements at 10 Hz and a major component of the new system is an Alexandrite laser (1-2 J pulse energy, 350+1-50 ps pulse duration, 10 Hz repetition rate) which is currently being constructed. The new laser and other technological improvements being incorporated into the upgraded diagnostic will also be described.

  8. Attosecond and zeptosecond x-ray pulses via nonlinear Thomson backscattering

    SciTech Connect

    Lan Pengfei; Lu Peixiang; Cao Wei; Wang Xinlin

    2005-12-15

    Nonlinear Thomson backscattering of an intense circularly polarized laser by a counterpropagating energetic electron is investigated. The results show that in the scattering of a non-tightly-focused laser pulse with an intensity around 10{sup 19} W/cm{sup 2} and a pulse duration of 100 fs full width at half maximum by a counterpropagating electron with an initial energy of 10 MeV, a crescent-shaped pulse with a pulse duration of 469 as and the photon energy ranging from 230 eV to 2.5 keV is generated in the backward direction. It is shown that the radiated pulse shape and monochromaticity can be modified by changing the laser beam waist, while in the case of a tightly focused laser field, a single peak pulse with a shorter duration and better monochromaticity can be obtained. With increase of the electron initial energy, the peak power of the radiated pulse increases and the pulse duration decreases. An isolated powerful zeptosecond (10{sup -21} s) pulse with a peak power of about 10{sup 10} W/rad{sup 2} and photon energy up to several MeV can be obtained with a 250 MeV electron.

  9. Dual-angle, self-calibrating Thomson scattering measurements in RFX-MOD

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Pasqualotto, R.; Fassina, A.

    2014-11-01

    In the multipoint Thomson scattering (TS) system of the RFX-MOD experiment the signals from a few spatial positions can be observed simultaneously under two different scattering angles. In addition the detection system uses optical multiplexing by signal delays in fiber optic cables of different length so that the two sets of TS signals can be observed by the same polychromator. Owing to the dependence of the TS spectrum on the scattering angle, it was then possible to implement self-calibrating TS measurements in which the electron temperature Te, the electron density ne and the relative calibration coefficients of spectral channels sensitivity Ci were simultaneously determined by a suitable analysis of the two sets of TS data collected at the two angles. The analysis has shown that, in spite of the small difference in the spectra obtained at the two angles, reliable values of the relative calibration coefficients can be determined by the analysis of good S/N dual-angle spectra recorded in a few tens of plasma shots. This analysis suggests that in RFX-MOD the calibration of the entire set of TS polychromators by means of the similar, dual-laser (Nd:YAG/Nd:YLF) TS technique, should be feasible.

  10. Vibration analysis of the Thomson Scattering diagnostics optical transmission system on EAST tokamak

    NASA Astrophysics Data System (ADS)

    Shao, Chunqiang; Zang, Qing; Zhao, Junyu; Hu, Ailan; Han, Xiaofeng; Chen, Hui; He, Liangliang; Wang, Tengfei

    2014-09-01

    A series of vibration source from the EAST tokamak complicated experimental environment would result in the laser path misalignment and the collected scattered laser signal attenuation, which leads to a measurement error of the Thomson Scattering (TS) diagnostics system. Two methods have been designed for the vibration analysis of the TS diagnostics optical transmission system, a passive one and an active one. The optical transmission system contains of a double deck optical table with 4 reflectors and a photon collection system. The vibration analysis includes 4 points of reflectors along the laser path, 1 point of the photon collection system, and the ground of EAST experimental hall. The passive method used a vibration spectrum analyzer and 7 vertical speed sensors measuring the standard deviation of the vibration noise, which refers to the virtual value of vibration, and a data analysis system. The active method used a hammer to simulate the vibration source of the experimental hall ground, and 15 accelerometers to measure the three-dimensional vibration spectrum of 5 points along the optical transmission system. The vibration isolation efficiency (IE) of the optical transmission system has been presented, and the vibration asynchrony of the 5 points also has been observed. The results of two methods are comparatively studied, and the active one is considered to be more credible.

  11. A pulse-burst laser system for a high-repetition-rate Thomson scattering diagnostic

    SciTech Connect

    Den Hartog, D. J.; Jiang, N.; Lempert, W. R.

    2008-10-15

    A ''pulse-burst'' laser system is being constructed for addition to the Thomson scattering diagnostic on the Madison Symmetric Torus (MST) reversed-field pinch. This laser is designed to produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition frequencies 5-250 kHz. This laser system will operate at 1064 nm and is a master oscillator, power amplifier. The master oscillator is a compact diode-pumped Nd:YVO{sub 4} laser, intermediate amplifier stages are flashlamp-pumped Nd:YAG, and final stages will be flashlamp-pumped Nd:glass (silicate). Variable pulse width drive (0.3-20 ms) of the flashlamps is accomplished by insulated-gate bipolar transistor switching of large electrolytic capacitor banks. The burst train of laser pulses will enable the study of electron temperature (T{sub e}) and electron density (n{sub e}) dynamics in a single MST shot, and with ensembling, will enable correlation of T{sub e} and n{sub e} fluctuations with other fluctuating quantities.

  12. A pulse-burst laser system for a high-repetition-rate Thomson scattering diagnostic.

    PubMed

    Den Hartog, D J; Jiang, N; Lempert, W R

    2008-10-01

    A "pulse-burst" laser system is being constructed for addition to the Thomson scattering diagnostic on the Madison Symmetric Torus (MST) reversed-field pinch. This laser is designed to produce a burst of up to 200 approximately 1 J Q-switched pulses at repetition frequencies 5-250 kHz. This laser system will operate at 1064 nm and is a master oscillator, power amplifier. The master oscillator is a compact diode-pumped Nd:YVO(4) laser, intermediate amplifier stages are flashlamp-pumped Nd:YAG, and final stages will be flashlamp-pumped Nd:glass (silicate). Variable pulse width drive (0.3-20 ms) of the flashlamps is accomplished by insulated-gate bipolar transistor switching of large electrolytic capacitor banks. The burst train of laser pulses will enable the study of electron temperature (T(e)) and electron density (n(e)) dynamics in a single MST shot, and with ensembling, will enable correlation of T(e) and n(e) fluctuations with other fluctuating quantities. PMID:19044552

  13. X-ray Thomson Scattering in Warm Dense Matter without the Chihara Decomposition

    NASA Astrophysics Data System (ADS)

    Baczewski, A. D.; Shulenburger, L.; Desjarlais, M. P.; Hansen, S. B.; Magyar, R. J.

    2016-03-01

    X-ray Thomson scattering is an important experimental technique used to measure the temperature, ionization state, structure, and density of warm dense matter (WDM). The fundamental property probed in these experiments is the electronic dynamic structure factor. In most models, this is decomposed into three terms [J. Chihara, J. Phys. F 17, 295 (1987)] representing the response of tightly bound, loosely bound, and free electrons. Accompanying this decomposition is the classification of electrons as either bound or free, which is useful for gapped and cold systems but becomes increasingly questionable as temperatures and pressures increase into the WDM regime. In this work we provide unambiguous first principles calculations of the dynamic structure factor of warm dense beryllium, independent of the Chihara form, by treating bound and free states under a single formalism. The computational approach is real-time finite-temperature time-dependent density functional theory (TDDFT) being applied here for the first time to WDM. We compare results from TDDFT to Chihara-based calculations for experimentally relevant conditions in shock-compressed beryllium.

  14. X-ray Thomson Scattering in Warm Dense Matter without the Chihara Decomposition.

    PubMed

    Baczewski, A D; Shulenburger, L; Desjarlais, M P; Hansen, S B; Magyar, R J

    2016-03-18

    X-ray Thomson scattering is an important experimental technique used to measure the temperature, ionization state, structure, and density of warm dense matter (WDM). The fundamental property probed in these experiments is the electronic dynamic structure factor. In most models, this is decomposed into three terms [J. Chihara, J. Phys. F 17, 295 (1987)] representing the response of tightly bound, loosely bound, and free electrons. Accompanying this decomposition is the classification of electrons as either bound or free, which is useful for gapped and cold systems but becomes increasingly questionable as temperatures and pressures increase into the WDM regime. In this work we provide unambiguous first principles calculations of the dynamic structure factor of warm dense beryllium, independent of the Chihara form, by treating bound and free states under a single formalism. The computational approach is real-time finite-temperature time-dependent density functional theory (TDDFT) being applied here for the first time to WDM. We compare results from TDDFT to Chihara-based calculations for experimentally relevant conditions in shock-compressed beryllium. PMID:27035307

  15. Generation of High Brightness X-rays with the PLEIADES Thomson X-ray Source

    SciTech Connect

    Brown, W J; Anderson, S G; Barty, C P J; Crane, J K; Cross, R R; Fittinghoff, D N; Hartemann, F V; Kuba, J; LeSage, G P; Slaughter, D R; Springer, P T; Tremaine, A M; Rosenzweig, J B; Gibson, D J

    2003-05-28

    The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.

  16. 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.

  17. Health-hazard evaluation report HETA 90-223-2211, Thomson Consumer Electronics, Marion, Indiana

    SciTech Connect

    Lenhart, S.W.; Driscoll, R.

    1992-05-01

    In response to a request from the Corporate Medical Consultant to Thomson Consumer Electronics (SIC-3673), Marion, Indiana, a study was undertaken of an illness outbreak in workers at the facility. There were about 1900 workers at the facility, which produced television picture tubes. Production occurred over three shifts, 6 days a week. Charcoal tube sampling indicated the presence of acetone (67641) n-amyl-acetate (628637), n-butyl-acetate (123864), isoamyl-acetate (123922), toluene (108883), 1,1,1-trichloroethane (71556), and trichloroethylene (79016). No contaminants were detected in the bag samples of air collected from the in/house compressed air system. One or more symptoms were reported by 593 (82%) of the workers. Those most commonly reported included headache (68%), sore throat (53%), fatigue (51%), eye irritation (50%), itchy skin (47%), irritated nose (45%), dizziness (45%), unusual taste in mouth (45%), unusual smell (41%) and cough. The authors conclude that symptoms were consistent with stress related health complaints in occupational settings. Concentrations of chemicals measured in the facility would not be expected to produce the effects seen in the outbreak. The authors recommend that trichloroethylene degreasing units be replaced with equipment which uses a less toxic degreasing agent. The facility should hire a full time industrial hygienist.

  18. X-ray Thomson Scattering for measuring Dense Beryllium Plasma Collisionality

    SciTech Connect

    Doppner, T; Fortmann, C; Davis, P F; Kritcher, A L; Landen, O L; Lee, H J; Redmer, R; Regan, S P; Glenzer, S H

    2009-10-22

    We are developing a target platform that utilizes short-pulse (10 ps) generated hot electrons ({approx}1 MeV) to isochorically heat solid density beryllium up to several 10 eV. X-ray Thomson scattering is employed to characterize the plasma conditions. X-rays from a Cl Ly-{alpha} line source at 2.96 keV are scattered off the plasma in forward direction where the inelastically scattered signal is sensitive to plasma oscillations. Besides Landau-damping the strong energy down-shifted plasmon signal is also broadened by collisions which, in turn, allows to infer the collision rate and thus the conductivity in these plasmas. Recently, we demonstrated that from the ratio of the energy up-shifted to the down-shifted plasmon signals the plasma temperature can be inferred from the detailed balance relation which is based on first principles. Thus from the Plasmon shift and detailed balance we will be able to consistently determine plasma density and temperature, and relate this to the collisionality inferred from the Plasmon broadening. A precise knowledge of the collisionality in the parameter regime we are aiming at with these experiments is important to correctly model the conditions encountered during capsule implosions at the National Ignition Facility.

  19. X-ray Thomson Scattering using the Hybrid X-pinch X-ray Source

    NASA Astrophysics Data System (ADS)

    Hoyt, Cad; Pikuz, Sergei; Shelkovenko, Tania; Hammer, Dave

    2013-10-01

    Stringent photometric and bandwidth requirements have historically relegated X-ray Thomson scattering (XRTS) probe sources to high energy laser plasma sources or free electron lasers. Standard x-pinch configurations in which two or more fine wires cross and subtend an angle of about 30° forming an ``X'' between the anode and cathode of a pulsed power generatorcan produce extremely bright, subnanosecond bursts of continuum and line radiation from micron-scale sources. The hybrid x-pinch is a new configuration based on conical W-Cu alloy electrodes with a short 1-2 mm gap that is bridged by a fine wire resulting in an easier to load setup with improved performance characteristics. We explore the possibility of utilizing the hybid x-pinch as a novel XRTS probe source by examining certain spectral and temporal attributes of a range of materials in a hybrid x-pinch configuration on the XP (500 kA, 50 ns) and COBRA(1MA, 100ns) pulsed power generators. We find that a Ti hybrid x-pinch produces >1012 photons/sr in Ti He-alpha radiation and satisfies the noncollective scattering bandwidth requirement. Measurements of photon fluence, bandwidth and applicability to the relevant scattering regime and initial scattering results will be presented.

  20. Equation-of-State Measurements of Resorcinol Formaldehyde Foam Using Imaging X-Ray Thomson Spectrometer

    NASA Astrophysics Data System (ADS)

    Belancourt, Patrick; Theobald, W.; Keiter, P. A.; Collins, T. J. B.; Bonino, M. J.; Kozlowski, P.; Drake, R. P.

    2015-11-01

    Understanding the equation of state of materials under shocked conditions is important for laboratory astrophysics and high-energy-density physics experiments. This talk will focus on experiments dedicated to developing a platform for measuring the equation of state of shocked foams on OMEGA EP. The foam used in the development of this platform is resorcinol formaldehyde foam with an initial density of 0.34 g/cc. One OMEGA EP beam drives a shock into the foam, while the remaining three beams irradiate a nickel foil to create the x-ray backlighter. The primary diagnostic for this platform, the imaging x-ray Thomson spectrometer (IXTS), spectrally resolves the scattered x-ray beam while imaging in one spatial dimension. The IXTS is ideally suited to measure plasma conditions upstream, downstream and at the shock front in the foam. Preliminary results from these experiments will be shown. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944, the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas DE-NA0001840, and by the National Laser User Facility Program DE-NA0000850.