A versatile heterodyne Doppler Backscattering (DBS) system is used to measure density fluctuation levels (in the wavenumber range kρs ≤ 50), and the toroidal E × B flow velocity in the C-2 Field-Reversed Configuration (FRC). Six tunable frequencies in three waveguide bands (26 GHz ≤ f ≤ 90 GHz) are launched using monostatic beam optics, via a quasi-optical beam combiner/polarizer and an adjustable parabolic focusing mirror (inside the vacuum enclosure) achieving Gaussian beam spot sizes of 3-5.5 cm at the X/O-mode cutoff. The DBS system covers plasma densities of 0.8 × 10(13) ≤ ne ≤ 1 × 10(14) cm(-3), and provides access to the FRC core (up to the field null) and across the FRC separatrix into the scrape-off layer plasma.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.4891415 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The microphysical changes in cloud formation and development are closely related to the vertical air motions. It is difficult to simultaneously detect microphysical parameters of drizzle and vertical air motions. This study proposes a method for the drizzle microphysical property and vertical air motions retrieval using Doppler lidar and radar measurements.
View Article and Find Full Text PDFThis study proposes what we believe to be a novel high-spectral-resolution three-frequency Rayleigh lidar for simultaneously measuring middle atmosphere temperature and wind. The temperature and wind could be retrieved without assuming an external reference temperature, as typical for a traditional Rayleigh Doppler lidar. Adopting a similar idea used in sodium temperature/wind lidar, this system alternatively emits laser pulses at three frequencies.
View Article and Find Full Text PDFA Phantom-Free Approach for Estimating the Backscatter Coefficient of Aggregated Red Blood Cells applied to COVID-19 Patients.
IEEE Trans Ultrason Ferroelectr Freq Control
November 2024
Article Synopsis
- * A new method using Gaussian-shaped approximations to analyze ultrasound data was tested against traditional techniques on COVID-19 patients and healthy controls, focusing on red blood cell aggregates as scatterers.
- * Results showed a high consistency in estimating the mean size of blood cell aggregates between the two methods, with significant size differences observed between COVID-19 patients and controls, even when accounting for other factors affecting blood properties.
New millimeter-wave diagnostics to locally probe internal density and magnetic field fluctuations in National Spherical Torus Experiment-Upgrade (invited).
Rev Sci Instrum
August 2024
Physics and Astronomy Department, University of California, Los Angeles, Los Angeles, California 90995, USA.
A set of new millimeter-wave diagnostics will deliver unique measurement capabilities for National Spherical Torus Experiment-Upgrade to address a variety of plasma instabilities believed to be important in determining thermal and particle transport, such as micro-tearing, global Alfvén eigenmodes, kinetic ballooning, trapped electron, and electron temperature gradient modes. These diagnostics include a new integrated intermediate-k Doppler backscattering (DBS) and cross-polarization scattering (CPS) system (four channels, 82.5-87 GHz) to measure density and magnetic fluctuations, respectively.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!