Development of Novel Spectroscopic Diagnostics for Plasma Radiation Sources
Development of Novel Spectroscopic Diagnostics for Plasma Radiation Sources

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Published: 1999

Total Pages: 0

ISBN-13:

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This report gives the details of experiments performed to measure the levels and the angular distribution of oscillating electric fields in an aluminum plasma produced by the Phoenix advanced pulsed radiation source. The electric field values were obtained by measuring the L (beta), L (gamma), L (sigma), and L (epsilon) line profiles of Al XIII and fitting the profiles to a model for the Phoenix plasma source. The model attempts to take into account all of the mechanisms which lead to broadening of the observed profiles for the conditions present in the Phoenix plasma. The main broadening mechanisms used in the model include Doppler broadening from the bulk motion of the plasma, stark broadening by electrons, ions and oscillating electric fields, and self absorption. In addition to the flat crystal and two curved crystal spectrometers used to measure the lines profiles, a pinhole camera and a four frame camera were used to try and obtain the size of the most dense retions in the plasma. The size of these "hot spots" were found to be less than 500 microns. From fits of the experimental profiles to the data, the level of anomalous electric fields in the Phoenix plasma source were found to be Eo = 1 - 9 Gv/cm, indicative of a strong Langmuir turbulence. The fields were also found to develop anisotropically, primarily along the direction of the discharge.

Spectroscopic Diagnostics of High Temperature Plasmas, January 1, 1991--December 31, 1991
Spectroscopic Diagnostics of High Temperature Plasmas, January 1, 1991--December 31, 1991

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Published: 1991

Total Pages: 4

ISBN-13:

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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--200Å range, which uses flat LSMs, has been built and is currently operated on the D3-D tokamak at General Atomics in San Diego. A design for a follow-up experiment at D3-D is now in progress. As a preliminary step toward tokamak plasma imaging in the XUV wavelength range using curved LSM coated substrates, a prototype XUV camera was built and operated in our laboratory in image the A1 3 emission at?-175Å from a Penning Ionization Discharge plasma. Based on these laboratory results, the design of the XUV camera, which will image plasma in the Phaedrus T tokamak O VI emission (150Å), has been completed. This instrument is presently under construction. Also a detailed design of a system composed of four LSM based imaging devices for N{sub e}(0) and T{sub e}(0) fluctuation measurements on TEXT has been completed. The accuracy and the uniformity of the LSM coatings on flat and small curved surfaces used in the above-mentioned instruments have been evaluated in our laboratory using an in-house built calibration facility and at the SURF II synchrotron at the National Institute of Standards and Technology.

Density Imaging Diagnostic for Plasma Radiation Sources
Density Imaging Diagnostic for Plasma Radiation Sources

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Published: 2005

Total Pages: 71

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A technique to determine the radial distributions of the electron density and temperature in a plasma radiation source (PRS) from radially resolved spectra of optically thin dopants is described herein. A space and time resolved Johann spectrometer and a version with a modified high spectral resolution film circle were constructed for this purpose. The observed values for the temperature sensitive Ly(sub a) and He(sub a) plus intercombination (IC) line intensity ratio and the density sensitive IC/He(sub a) line ratio is compared to calculated values to determine local values n(sub e) and T(sub e). The density profile inferred this way from Si spectra observed on Double Eagle with Al wire loads coated with 5% Si have a minimum on-axis which increases with radius. The minimum on-axis is attributed to opacity effects whereas the larger value in the corona is attributed to He(sub a) radiation emitted in the core that is absorbed and remitted (scattered) by He ions in the corona. A density profile that monotonically decreases from an on-axis maximum is deduced if this scattering of core radiation is included in this analysis. The calculated spectra are sufficiently sensitive to the assumed radial distributions to provide confidence in their uniqueness.

Spectroscopic Diagnostics of High Temperature Plasmas
Spectroscopic Diagnostics of High Temperature Plasmas

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Published: 1990

Total Pages: 57

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

Spectroscopic Measurement
Spectroscopic Measurement

Author: Mark A. Linne

Publisher: Elsevier

Published: 2002-07-29

Total Pages: 440

ISBN-13: 0080517536

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Electromagnetism, quantum mechanics, statistical mechanics, molecular spectroscopy, optics and radiation form the foundations of the field. On top of these rest the techniques applying the fundamentals (e.g. Emission Spectroscopy, Laser Induced Fluorescence, Raman Spectroscopy). This book contains the basic topics associated with optical spectroscopic techniques. About 40 major sources are distilled into one book, so researchers can read and fully comprehend specific optical spectroscopy techniques without visiting many sources.Optical diagnostics are widely used in combustion research. Ideas first proposed here are now applied in other fields, including reacting flows for materials production (CVD reactors, oxidation reactors and some plasma work), atmospheric sensing, measuring constituents of exhaled human breath (to indicate stress in airway passages and the lungs and hence,e.g., provide a very early indicator of lung cancer).Researchers not formally trained who apply spectroscopy in their research need the detail in this book to ensure accuracy of their technique or to develop more sophisticated measurements. Time is valuable and future research will benefit. Learning "on the fly" can involve direct information on a specific diagnostic technique rather than gaining the background necessary to go into further depth.

Laser-Produced Plasmas and Radiation Sources
Laser-Produced Plasmas and Radiation Sources

Author: D. W. Scudder

Publisher:

Published: 1980

Total Pages: 169

ISBN-13:

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The research performed under this program has covered a broad range of subjects involving laser interaction with both gaseous and solid target laser plasmas, and with development of plasma diagnostic techniques suitable for our laser-produced plasmas. Included are detailed descriptions of research activities during fiscal years 1978 and 1979. These include a study of stimulated Brillouin scattering in transverse magnetic fields; development of X-ray diagnostics including X-ray continuum measurements, spectroscopy, and imaging techniques and their use in studying solid target plasmas; development of a fast schlieren photography system; and a theoretical study of nonlinear scattering techniques for plasma diagnostics.

Spectroscopic Diagnostics of High Temperature Plasmas. [Annual Report].
Spectroscopic Diagnostics of High Temperature Plasmas. [Annual Report].

Author:

Publisher:

Published: 1990

Total Pages: 57

ISBN-13:

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