Impurity poloidal rotation velocity in tokamaks

1994 ◽  
Vol 1 (4) ◽  
pp. 960-967 ◽  
Author(s):  
A. G. Meigs ◽  
William L. Rowan
Keyword(s):  
Rotation Velocity ◽  
Poloidal Rotation

scholarly journals Poloidal Rotation and Edge Ion Temperature Measurements Using Spectroscopy Diagnostic on Aditya-U Tokamak

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 93
Author(s):  
Gaurav Shukla ◽  
Malay B. Chowdhuri ◽  
Kajal Shah ◽  
Nandini Yadava ◽  
Ranjana Manchanda ◽  
...  
Keyword(s):  
High Resolution ◽  
Line Emission ◽  
Rotation Velocity ◽  
Spectral Lines ◽  
Tokamak Plasma ◽  
Vacuum Vessel ◽  
Ion Temperature ◽  
Minor Radius ◽  
Impurity Ion ◽  
Poloidal Rotation

The impurity ion poloidal rotation and ion temperature from the Aditya-U tokamak plasma have been measured using a high-resolution spectroscopic diagnostic. It comprises of a high resolution, 1 m, f/8.7, Czerny-Turner configuration spectrometer along with charge coupled device (CCD) detector. The system monitors the spectral line emission of C2+ impurity ions at 464.74 nm from the top port of the Aditya-U vacuum vessel with the lines of sight covering the plasma minor radius from r = 11.55 cm to 21.55 cm. The impurity ion poloidal rotation velocity and temperature have been estimated using the Doppler shift and Doppler broadening of the spectral lines respectively. The maximum poloidal rotation at a radial location of 21.55 cm in the edge of the plasma during the plasma current flat top was observed to be ~4 km/s for the analyzed discharges and the ion temperatures measured in the edge were in the range of 32–40 eV.

scholarly journals Calibration of the charge exchange recombination spectroscopy diagnostic for core poloidal rotation velocity measurements on JET

2004 ◽  
Vol 75 (10) ◽  
pp. 3452-3454 ◽  
Author(s):  
K. Crombé ◽  
Y. Andrew ◽  
C. Giroud ◽  
N. C. Hawkes ◽  
A. Murari ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Rotation Velocity ◽  
Velocity Measurements ◽  
Poloidal Rotation

scholarly journals Measurements of poloidal rotation velocity using cross-correlation spectroscopy in the H-1 heliac

2003 ◽  
Vol 74 (3) ◽  
pp. 2044-2047
Author(s):  
M. G. Shats ◽  
H. Punzmann ◽  
H. Xia ◽  
W. M. Solomon
Keyword(s):  
Cross Correlation ◽  
Rotation Velocity ◽  
Correlation Spectroscopy ◽  
Poloidal Rotation

scholarly journals Direct Measurement of Ion Temperature and Poloidal Rotation Velocity with Doppler Spectroscopy during Bifurcation in Tohoku University Heliac

2014 ◽  
Vol 9 (0) ◽  
pp. 3402051-3402051 ◽  
Author(s):  
Toshihiro OKU ◽  
Sumio KITAJIMA ◽  
Keiichi ISHII ◽  
Yu SATO ◽  
Jo TACHIBANA ◽  
...  
Keyword(s):  
Direct Measurement ◽  
Rotation Velocity ◽  
Ion Temperature ◽  
Doppler Spectroscopy ◽  
Poloidal Rotation

scholarly journals Calculation of edge ion temperature and poloidal rotation velocity from carbon III triplet measurements on the COMPASS tokamak

Nukleonika ◽  
2016 ◽  
Vol 61 (4) ◽  
pp. 443-451
Author(s):  
Matěj Tomeš ◽  
Vladimír Weinzettl ◽  
Tiago Pereira ◽  
Martin Imríšek ◽  
Jakub Seidl
Keyword(s):  
Rotation Velocity ◽  
Calibration Procedure ◽  
Position Estimation ◽  
Spectral Lines ◽  
X Rays ◽  
Ion Temperature ◽  
Median Filters ◽  
Orthogonal Distance Regression ◽  
The Difference ◽  
Poloidal Rotation

Abstract A high-resolution spectroscopic system for the measurements of the CIII triplet at 465 nm was installed at the COMPASS tokamak. The Doppler broadening and shift of the measured spectral lines are used to calculate the edge ion temperature and poloidal plasma rotation. At first, the spectroscopic system based on two-grating spectrometer and the calibration procedure is described. The signal processing including detection and removal of spiky features in the signal caused by hard X-rays based on the difference in the behaviour of Savitzky-Golay and median filters is explained. The detection and position estimation of individual spectral lines based on the continuous wavelet transform is shown. The method of fitting of Gaussians using the orthogonal distance regression and estimation of the error of estimation of the rotation velocity and ion temperature is described. At the end, conclusions about the performance of the spectroscopic system and its shortcomings based on summary of results calculated from 2033 processed spectral lines measured in 61 shots are drawn and the possible enhancements are suggested.

Poloidal rotation velocity measurement with an MIR system on KSTAR

2013 ◽  
Vol 8 (10) ◽  
pp. C10018-C10018 ◽  
Author(s):  
W Lee ◽  
J Leem ◽  
G S Yun ◽  
H K Park ◽  
J A Lee ◽  
...  
Keyword(s):  
Velocity Measurement ◽  
Rotation Velocity ◽  
Poloidal Rotation

Statistical Study of the Rotation Effect of Am Stars

1976 ◽  
Vol 32 ◽  
pp. 675-683
Author(s):  
Keiichi Kodaira
Keyword(s):  
Statistical Study ◽  
Rotation Velocity ◽  
General View ◽  
Slow Rotation ◽  
Rotation Effect

SummaryExcess of [m1] index of Am stars, relative to normal stars, is statistically found to be correlated with rotation velocity; the coefficient is estimated at ∆׀m1׀ /∆V(km/sec) ˜ - 0.0007 among Am stars. This result supports the general view that slow rotation is essential for Am phenomena.

Needle-disk Electrospinning: Mechanism Elucidation, Parameter Optimization and Productivity Improvement

2020 ◽  
Vol 14 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Zhi Liu ◽  
Lei Zhou ◽  
Fangtao Ruan ◽  
Anfang Wei ◽  
Jianghui Zhao ◽  
...  
Keyword(s):  
Parameter Optimization ◽  
Low Voltage ◽  
Rotation Velocity ◽  
Needle Length ◽  
Productivity Improvement ◽  
Voltage Supply ◽  
Nanofiber Morphology ◽  
Disk Rotation ◽  
Industrial Employment ◽  
Spinning Process

Background: Nanofiber’s productivity plagues nanofibrous membranes’ applications in many areas. Herein, we present the needle-disk electrospinning to improve throughput. In this method, multiple high-curvature mentals are used as the spinning electrode. Methods: Three aspects were investigated: 1) mechanism elucidation of the needle-disk electrospinning; 2) parameter optimization of the needle-disk electrospinning; 3) productivity improvement of the needle-disk electrospinning. Results: Results show that high-curvature electrode evokes high electric field intensity, making lower voltage supply in spinning process. The needle number, needle length and needle curvature synergistically affect the spinning process and nanofiber morphology. Additionally, higher disk rotation velocity and higher voltage supply can also result in higher nanofiber’s productivity. Conclusion: Compared with previous patents related to this topic, the needle-disk electrospinning is featured with the merits of high throughput, low voltage supply, controllable spinning process and nanofiber morphology, benefiting the nanofiber practical industrial employment and further applications of nanofiber-based materials.

scholarly journals Galaxy Formation: Some Comparisons between Theory and Observation

1983 ◽  
Vol 100 ◽  
pp. 391-399 ◽  
Author(s):  
S. Michael Fall
Keyword(s):  
Galaxy Formation ◽  
Total Mass ◽  
Virial Theorem ◽  
Velocity Dispersion ◽  
Rotation Velocity ◽  
Morphological Type ◽  
Fundamental Parameter ◽  
Mass Ratio ◽  
First Approximation ◽  
Type Form

Before theoretical ideas in this subject can be compared with observational data, it is necessary to consider the properties of galaxies that are likely to be relics of their formation. Most astronomers would agree that the list of important parameters should be headed by the total mass M, energy E and angular momentum J. Next on the list should probably be the relative contributions to these quantities from the disc and bulge components of galaxies and denoted D/B for the mass ratio. They can be estimated from the median (i.e. half-mass) radius R, velocity dispersion σ and rotation velocity v of each component, either through the virial theorem or through the luminosity L and an assumed value of M/L. As a first approximation, it is reasonable to suppose that galaxies of a given disc-to-bulge ratio or morphological type form a sequence with mass as the fundamental parameter. The comparison of theory with data is further simplified by considering the extreme cases of ellipticals, with D/B << 1, and late-type spirals, with D/B >> 1. The approach outlined below is to explore the consequences of relaxing in succession the constraints that E, J and M be conserved during the collapse of proto-galaxies. In this article I concentrate on theories that are based on some form of hierarchical clustering because the pancake and related theories are not yet refined enough for a detailed confrontation with observations.

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