A new radially movable multichannel azimuthal probe system has been developed for measuring azimuthal and radial profiles of electrostatic Reynolds stress (RS) per mass density of microscale fluctuations for a cylindrical laboratory plasma. The system is composed of 16 probe units arranged azimuthally. Each probe unit has six electrodes to simultaneously measure azimuthal and radial electric fields for obtaining RS. The advantage of the system is that each probe unit is radially movable to measure azimuthal RS profiles at arbitrary radial locations as well as two-dimensional structures of fluctuations. The first result from temporal observation of fluctuation azimuthal profile presents that a low-frequency fluctuation (1-2 kHz) synchronizes oscillating Reynolds stress. In addition, radial scanning of the probe system simultaneously demonstrates two-dimensional patterns of mode structure and nonlinear forces with frequency f = 1.5 kHz and azimuthal mode number m = 1.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.3557384 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Developing a novel quasi-3D movable water phantom for radiation therapy workable in the magnetic resonance environment.
Quant Imaging Med Surg
December 2023
Department of Radiation Oncology, Fu Jen Catholic University Hospital, New Taipei City.
Background: The use of magnetic resonance linear accelerators (MR-LINACs) for clinical treatment has opened up new possibilities and challenges in the field of radiation oncology. However, annual quality assurance (QA) is relatively understudied due to practical considerations. Thus, to overcome the difficulty of measuring the dose with a small water phantom for TRS-398 or TG-51 in all external beam radiation treatment unit environments, such as MR compatibility, we designed a remote phantom with a three-axis changeable capacity for QA.
View Article and Find Full Text PDFA circular Airy array beam (CAAB) comprising four symmetric circular Airy beams is proposed and demonstrated for image transmission. It is generated by the Fourier transform of the combined phase, which contains the radial cubic phase, the diffractive axicon phase, and the shift function phase. Two adjustable parameters of the combined phase can control the radius and the initial position of each circular Airy beam at the spatial plane.
View Article and Find Full Text PDFApplication of a hyperspectral camera for in situ plasma-material interaction studies at the linear plasma device PSI-2.
Rev Sci Instrum
August 2023
Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
A hyperspectral camera (HSC-type Specim IQ) has been applied at the linear plasma device PSI-2 under steady-state conditions. The camera has the capacity of hyperspectral imaging (HSI) with the dimension of a data array 512 × 512 × 204 (x, y, λ) covering the spectral span from 400 to 1000 nm with moderate average spectral resolution (FWHM ∼7 nm). After radiometric calibration and background/continuum emission subtraction, two main applications of the camera, (i) plasma diagnostics in helium (He) plasmas and (ii) plasma-material interaction studies with tungsten (W) targets in neon (Ne) plasmas, have been carried out.
View Article and Find Full Text PDFMeasurement and Control of Radially Polarized THz Radiation from DC-Biased Laser Plasma Filaments in Air.
Sensors (Basel)
July 2022
Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
Detection and manipulation of radially polarized terahertz (THz) radiation is essential for many applications. A new measurement scheme is proposed for the diagnosis of radially polarized THz radiation from a longitudinal dc-biased plasma filament, by introducing a movable metal mask. The amplitude and spectrum of the radially polarized THz beam was measured with a <110>-cut ZnTe crystal, where the THz beam pattern was modulated by the mask.
View Article and Find Full Text PDFFree-breathing abdominal T mapping using an optimized MR fingerprinting sequence.
NMR Biomed
July 2021
Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
In this work, we propose a free-breathing magnetic resonance fingerprinting (MRF) method that can be used to obtain B -robust quantitative T maps of the abdomen in a clinically acceptable time. A three-dimensional MRF sequence with a radial stack-of-stars trajectory was implemented, and its k-space acquisition ordering was adjusted to improve motion-robustness in the context of MRF. The flip angle pattern was optimized using the Cramér-Rao Lower Bound, and the encoding efficiency of sequences with 300, 600, 900 and 1800 flip angles was evaluated.
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!