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A Stark-tuned, far-infrared laser for high frequency plasma diagnostics

Description: A Stark-tuned optically pumped far-infrared methanol laser operating at 119 micrometers has been built. The laser is designed to operate at high power while exhibiting a well-separated Stark doublet. At a pump power of 65 Watts and electric field of 1 kV/cm the laser has delivered over 100 mW c.w. while exhibiting a frequency splitting of 34 MHz. These parameters indicate that this laser would be suitable for use in the present generation of modulated interferometers on large thermonuclear plas… more
Date: March 1, 1992
Creator: Mansfield, D.K.; Vocaturo, M.; Guttadora, L.; Rockmore, M.; Micai, K. (Princeton Univ., NJ (United States). Plasma Physics Lab.) & Krug, P.A. (Sydney Univ. (Australia). School of Physics)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of a Positronium Atom Diagnostic Beam to Study Transport in Tokamaks

Description: Anomalous transport is probably the key physics issue in magnetic confinement fusion. It severely limits our ability to create and maintain a dense, hot, fusion plasma. There is also good evidence that there is a fundamental lack of understanding in this area, namely the transport of particles and energy induced by waves and fluctuations in magnetically confined plasmas. The positronium atom beam diagnostic, if successful, can provide a qualitatively new and different way of studying transport … more
Date: January 1, 1992
Creator: Surko, C. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Review of the Procyon explosive pulsed power system

Description: The Procyon explosive pulsed power system is designed for powering plasma z-pinch experiments. It begins with a helical explosive-driven magnetic flux compression generator (MCG) for amplifying seed current from a capacitor bank into a storage inductor. One conductor element of the storage inductor is an explosively formed fuse (EFF) opening switch tailored to divert current to a plasma flow switch (PFS) in less than 3 [mu]s. The PFS, in turn, delivers current to a z-pinch load. Experiments to … more
Date: January 1, 1993
Creator: Goforth, J.H.; Oona, H. & Greene, A.E. (and others)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Crossed Sightline ECE Diagnostics

Description: It was shown that crossed-sightline ECE (electron-cyclotron-emission) can be used for both local measurement of fluctuating quantities (electron temperature and density), and also for inferring the local value of the absolute magnetic field in present experiments, or in a reactor environment. The absolute magnetic field measurement is a direct measure of the local plasma pressure ([beta]) in currentless devices, and in combination with temperature and pressure measurements is a measurement of t… more
Date: September 8, 1990
Creator: Thomas, C. E., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The charge exchange recombination diagnostic system on the DIII-D tokamak

Description: The charge exchange recombination (CER) diagnostic system on the DIII-D tokamak is used to make spatially and temporally resolved measurements of the ion temperature and toroidal and poloidal rotation velocities. This is performed through visible spectroscopic measurements of the Doppler broadened and Doppler shifted HE II 468.6 nm, the CVI 529.1 nm, and the BV 494.5 nm spectral lines which have been excited by charge exchange recombination interactions between the fully stripped ions and the n… more
Date: November 1, 1991
Creator: Gohil, P.; Burrell, K. H.; Groebner, R. J.; Kim, J.; Martin, W. C.; McKee, E. L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectroscopic diagnostics of high temperature plasmas, January 1, 1991--December 31, 1991

Description: During 1991, the activities of the John Hopkins University Plasma Spectroscopy Group have covered several areas of research, in the domain of XUV spectroscopy of magnetically confined fusion plasmas. While the main effort concentrated on the development of novel diagnostics which utilize Layered Synthetic Microstructures (LSMs) as the dispersive/filtering elements, work has been done in the area of detector development and the physics of the tokamak edge plasma. An XUV monochromator for the 20-… more
Date: January 1, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thomson scattering diagnostic analyses to determine the energetic particle distributions in TFTR

Description: The research completed and in progress for the first period of this grant is reviewed. Specific scattering scenarios for TFTR and JET and ITER were studied. The Lodestar scattering code, SKATR, was upgraded to include anisotropic energetic ion distributions and an analytic diffraction formulation was completed. Research continues on JET studies and upgrading the code for JET and ITER relevant conditions.
Date: February 12, 1993
Creator: Aamodt, R. E.; Cheung, P. & Russell, D. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The status of alpha-particle diagnostics

Description: There is a flurry of activity to complete alpha-particle diagnostics so that they can undergo some experimental testing in DT plasmas on JET or TFTR prior to implementation on ITER. Successful measurements of escaping charged fusion products have been made in DD plasmas, and the {alpha}-particle source can be well characterized by neutron profile measurement. These methods can be extrapolated to DT plasmas. Measurement of the confined {alpha}-particles requires a new technique. Collective Thoms… more
Date: January 1, 1992
Creator: Young, K. M. & Johnson, D. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Intense diagnostic neutral beam development for ITER

Description: For the next-generation, burning tokamak plasmas such as ITER, diagnostic neutral beams and beam spectroscopy will continue to be used to determine a variety of plasma parameters such as ion temperature, rotation, fluctuations, impurity content, current density profile, and confined alpha particle density and energy distribution. Present-day low-current, long-pulse beam technology will be unable to provide the required signal intensities because of higher beam attenuation and background bremsst… more
Date: January 1, 1992
Creator: Rej, D.J.; Henins, I. (Oak Ridge National Lab., TN (United States)); Fonck, R.J. & Kim, Y.J. (Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Short wavelength interferometer for ITER

Description: There is a need for a real time, reliable density measurement compatible with the restricted access and radiation environment on ITER. Due to the large plasma path length, high density and field, refraction and Faraday rotation effects makes the use of contemporary long wavelength (>50{mu}m) interferometers impractical. In this paper we consider the design of a short wavelength vibration compensated interferometer which allows operation without a prohibitively large vibration isolated structure… more
Date: April 1, 1992
Creator: Snider, R. T. & Carlstrom, T. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Midplane Faraday Rotation: A densitometer for BPX

Description: The density in a high field, high density tokamak such as BPX can be determined by measuring the Faraday rotation of a 10.6 {mu}m laser directed tangent to the toroidal field. If there is a horizontal array of such beams, then n{sub e}(R) can be readily obtained with a simple Abel version about the center line of the tokamak. For BPX operated at full field and density, the rotation angle would be quite large -- about 75{degrees} per pass. A layout in which a single laser beam is fanned out in t… more
Date: February 1, 1992
Creator: Jobes, F.C. & Mansfield, D.K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The application of X-mode reflectometry to the study of large scale fluctuations in TFTR

Description: It has been suggested for some time that microwave reflectometry, has the potential for measuring the large scale structure of density fluctuations in tokamak turbulence with greatly improved spatial resolution over existing scattering techniques. The motivation for developing fluctuation diagnostics with improved spatial resolution of large scale structures is that such fluctuations may potentially account for the anomalous particle and energy transport observed in tokamaks. On TFTR we now hav… more
Date: March 1, 1993
Creator: Mazzucato, E. & Nazikian, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measurement of impurity ion densities and energies in the divertor and edge regions of Alcator C-Mod tokamak. [Lab. for Plasma Research, Univ. of Maryland, College Park]

Description: A study to investigate impurity production and transport in the divertor and edge regions of the Alcator C-Mod tokamak through spectroscopic techniques is described. A 0.75-meter Czerny-Turner spectrometer with a 1200-g/mm grating and a 35-meter quartz optic bundle transmission line were tested. A high-resolution 2-meter spectrometer will be ordered. Data acquisition considerations are being addressed. (RWR)
Date: January 1, 1992
Creator: Griem, H. R.; Moreno, J. & Welch, B. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The multichannel motional Stark effect diagnostic on TFTR

Description: Although the q profile plays a key role in theories of instabilities and plasma equilibrium, it has been quite difficult to measure until the recent development of the motional Stark effect (MSE) diagnostic. A multichannel motional Stark effect polarimeter system has recently been installed on the Tokamak Fusion Test Reactor (TFTR). The diagnostic can measure the magnetic field pitch angle ({gamma}{sub p} = tan{sup {minus}1} (B{sub T})/(B{sup p})) at ten radial locations. The doppler shifted D{… more
Date: July 1, 1992
Creator: Levinton, F.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas

Description: This report describes recent progress and plans for calendar year 1987 in the Johns Hopkins University program to develop and improve spectroscopic diagnostics for the high temperature plasmas used in magnetic fusion research. An EUV spectrograph which provides time resolved spectra along fifteen chords of a plasma device has been completed and evaluation on DIII-D will began in late 1986. Other instrumentation work includes the evaluation of a sensitive detector for ion temperature/velocity di… more
Date: October 2, 1986
Creator: Moos, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A phase contrast interferometer on DIII-D

Description: A novel imaging diagnostic has recently become operational on the DIII-D tokamak for the study of density fluctuations at the outer edge of the plasma. The phase contrast imaging approach overcomes the limitations of conventional scattering techniques in the spectral range of interest for transport-related phenomena, by allowing detection of long wavelength modes (up to 7.6 cm) with excellent spatial resolution (5 mm) in the radial direction. Additional motivation for the diagnostic is provided… more
Date: April 1, 1992
Creator: Coda, S.; Porkolab, M. & Carlstrom, T. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ion heating and MHD dynamo fluctuations in the reversed field pinch

Description: Ion temperature measurements, time resolved to 10 {mu}s, have been made in the Madison Symmetric Torus reversed-field pinch with a five channel charge exchange analyzer. The ion temperature, T{sub i} {approx} 200 eV for I = 350 kA, increases by as much as 100% during discrete dynamo bursts in MST discharges. Magnetic field fluctuations in the range 0.5--5 MHz were also measured. Structure in the fluctuation frequency spectrum at the ion cyclotron frequency appears as the bursts terminate, sugge… more
Date: January 1, 1992
Creator: Scime, E.; Hokin, S.; Watts, C. & Mattor, N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fast pyrobolometers for measurements of plasma heat fluxes and radiation losses in the MST Reversed Field Pinch

Description: Two types of fast bolometers are described for the plasma energy transport study in the Madison Symmetric Torus plasma confinement device. Both types use pyrocrystals of LiTaO[sub 3] or LiNbO[sub 3] as the sensors. One type is used for measurements of the radiated heat losses and is situated at the vacuum shell inner surface. Another type is insertable in the plasma and measures the plasma particle heat flux. The frequency response of the bolometers is measured to be in the 150--200 kHz range. … more
Date: January 7, 1993
Creator: Fiksel, G.; Frank, J. & Holly, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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X-ray diagnostics of tokamak plasmas

Description: This paper discusses the influence that salinity has on the bioavailability of the two largest classes of contaminants, trace metals and organic compounds will be discussed. Although data on contaminant toxicity will be used to draw inferences about chemical availability, this discussion will focus on the properties that contaminants are likely to exhibit in waters of varying salinities. In addition, information on physiological changes that are affected by salinity will be used to illustrate h… more
Date: April 1, 1993
Creator: Bitter, M.; Hsuan, H.; Hill, K.W. & Zarnstorff, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Far infrared fusion plasma diagnostics

Description: Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several research… more
Date: January 1, 1990
Creator: Luhmann, N. C. Jr. & Peebles, W. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A New Diagnostic Technique to Simultaneously Measure the Electron Temperature, Ionic Charge State, and Plasma Density Near the Critical Surface in Laser-Plasma Interaction Experiments

Description: We have studied the dependence of the second harmonic signature of the ion acoustic decay instability on the target material in laser produced plasmas. Well-defined Stokes peaks were observed. The Stokes peaks were especially sharp for high Z targets. The threshold of the IADI was quite low even in high Z plasma. It increased only weakly with increasing the atomic number. On the other hand, the Stokes intensity decreased strongly with increasing atomic number. Linear theory, combined with the r… more
Date: January 1, 1990
Creator: Mizuno, K.; DeGroot, J. S.; Seka, W. & Drake, R. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

PROPX: An X-ray Manipulation Program

Description: An interactive micro-computer program that performs some manipulations on an input x-ray spectrum is introduced and described. The program is used to calculate the effect of absorption of filters, transmission through fibers, responsivity of photocathodes, responsivity of absorptive detectors, folding of responses, plotting of cross sections, and calculation, as a function of electron temperature, of the response due to a bremsstrahlung spectrum. Fluorescence from the targets is not included. T… more
Date: January 1, 1992
Creator: Kyrala, G. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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