Download or read book Thomson Scattering for Determining Electron Concentrations and Temperatures in an Inductively Coupled Plasma 2 Description and Evaluation of a Multichannel Instrument written by Kim A. Marshall and published by . This book was released on 1988 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new instrument has been assembled to measure Thomson scattering from an inductively coupled plasma. Unlike previous designs, the new system employs a fiber-optic array to measure simultaneously up to 12 channels on a Thomson-scattering spectrum. Shutters enable either side of the nominally symmetrical Thomson spectrum to be examined, or permit summing equally spaced channels on opposite sides of the spectrum from the incident laser wavelength. A central channel, use to monitor Rayleigh scattering, enables a simultaneous determination of true gas-kinetic temperatures. Photodetector fatigue is avoided through a rotating mirror that serves as an optical shutter while individual gated integrators attached to each detector minimize the detection of background radiation from the plasma. The new instrument offers high stray-light rejection capability and provides measurements whose precision is photon-limited. Results obtained with the new instrument are presented in a companion paper.
Download or read book Thomson Scattering for Determining Electron Concentrations and Temperatures in an Inductively Coupled Plasma 1 Assessment of the Technique for a Lo Flow Low Power Plasma written by Kim A. Marshall and published by . This book was released on 1988 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron number densities and electron temperatures have been measured by multichannel Thomson scattering in a low-flow low-power inductively coupled plasma. Preliminary electron-concentration values agree well with those previously determined, and spatial variation in both electron concentration and temperature are largely consistent with existing models of the ICP. One difference is that aqueous aerosol was found here to depress the electron number density throughout the plasma. Unfortunately, the intensities measured in the wings of the Thomson-scattering spectrum large uncertainties, making data analysis difficult and the measured electron temperatures less reliable than desired.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1988-06 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1987 with total page 826 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scattering based Determination of Electron Energies and Concentrations and Gas Kinetic Temperatures in the Inductively Coupled Plasma written by Kim A. Marshall and published by . This book was released on 1987 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1990 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1989 with total page 1004 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics Index written by and published by . This book was released on 1979 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Engineering Index Annual written by and published by . This book was released on 1992 with total page 2264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.
Download or read book A Multichannel Thomson Scattering Apparatus written by N. Bretz and published by . This book was released on 1977 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thomson Scattering at FLASH Status Report written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic idea is to implement Thomson scattering with free electron laser (FEL) radiation at near-solid density plasmas as a diagnostic method which allows the determination of plasma temperatures and densities in the warm dense matter (WDM) regime (free electron density of n{sub e} = 1021-1026 cm−3 with temperatures of several eV). The WDM regime [1] at near-solid density (n{sub e} = 1021-1022 cm−3) is of special interest because, it is where the transition from an ideal plasma to a degenerate, strongly coupled plasma occurs. A systematic understanding of this largely unknown WDM domain is crucial for the modeling and understanding of contemporary plasma experiments, like laser shock-wave or Z-pinch experiments as well as for inertial confinement fusion (ICF) experiments as the plasma evolution follows its path through this domain.
Download or read book A Simple High Performance Thomson Scattering Diagnostic for High Temperature Plasma Research written by and published by . This book was released on 1994 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Electron Velocity Distribution Functions and Thomson Scattering written by Avram L. Milder and published by . This book was released on 2021 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Statistical mechanics governs the fundamental properties of many body systems and the corresponding velocity distributions dictates most material properties. In plasmas, a description through statistical mechanics is challenged by the fact that the movement of one electron effects many others through their Coulomb interactions, leading to collective motion. Although most of the research in plasma physics assumes equilibrium electron distribution functions, or small departures from a Maxwell-Boltzmann (Maxwellian) distribution, this is not a valid assumption in many situations. Deviations from a Maxwellian distribution can have significant ramifications on the interpretation of diagnostic signatures, and more importantly in our ability to understand the basic nature of plasmas. Optical collective Thomson scattering provides precise density and temperature measurements in numerous plasma-physics experiments. A statistically based, quantitative analysis of the errors in the measured electron density and temperature is presented when synthetic data calculated using a non-Maxwellian electron distribution function is fit assuming a Maxwellian electron distribution [A. L. Milder et al., Phys. Plasmas 26, 022711 (2019)]. In the specific case of super-Gaussian distributions, such analysis lead to errors of up to 50% in temperature and 30% in density. Including the proper family of non-Maxwellian electron distribution functions, as a fitting parameter, in Thomson-scattering analysis removes the model-dependent errors in the inferred parameters at minimal cost to the statistical uncertainty. This technique was used to determine the picosecond evolution of non-Maxwellian electron distribution functions in a laser-produced plasma using utrafast Thomson scattering [A. L. Milder et al., Phys. Rev. Lett. 124, 025001 (2020)]. During the laser heating, the distribution was measured to be approximately super-Gaussian due to inverse bremsstrahlung heating. After the heating laser turned off, collisional ionization caused further modification to the distribution function while increasing electron density and decreasing temperature. Electron distribution functions were determined using Vlasov-Fokker-Planck simulations including atomic kinetics. A novel technique that encodes the electron motion to the frequency of scattered light while using collective scattering to improve the scattering efficiency at velocities where the number of electrons are limited was invented to measure non-Maxwellian electron distributions [A. L. Milder et al., in review Phys. Rev. Lett. (2021)]. This angularly resolved Thomson-scattering technique is a novel extension of Thomson scattering, enabling the measurement of the electron velocity distribution function over many orders of magnitude. Electron velocity distribution functions driven by inverse bremsstrahlung heating were measured to be super-Gaussian in the bulk (v/vth 3) and Maxwellian in the tail (v/vth 3) when the laser heating rate dominated over the electron-electron thermalization rate. Simulations with the particle code Quartz showed the shape of the tail was dictated by the uniformity of the laser heating. The reduction of electrons at slow velocities resulted in a ? 40% measured reduction in inverse bremsstrahlung absorption. A reduced model describing the distribution function is given and used to perform a Monte Carlo analysis of the uncertainty in the measurements [A. L. Milder et al., in review Phys. Plasmas (2021)]. The electron density and temperature were determined to a precision of 12% and 21%, respectively, on average while all other parameters defining the distribution function were generally determined to better than 20%. It was found that these uncertainties were primarily due to limited signal to noise and instrumental effects. Distribution function measurements with this level of precision were sufficient to distinguish between Maxwellian and non-Maxwellian distribution functions"--Pages viii-x.
Download or read book On the Theory of Thomson Scattering and Reflectometry in a Relativistic Magnetized Plasma written by Henrik Bindslev and published by . This book was released on 1992 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
