scholarly journals INVERSION OF BACKSCATTER IONOGRAMS INTO QUASI-PARABOLIC IONOSPHERIC LAYER PARAMETERS

2020 ◽  
Vol 6 (3) ◽  
pp. 82-87
Author(s):  
Sergey Ponomarchuk ◽  
Maksim Penzin
Keyword(s):  
Electron Density ◽  
Leading Edge ◽  
Signal Propagation ◽  
Electron Density Profile ◽  
Intersection Point ◽  
Ionospheric Layer ◽  
Backscatter Signal ◽  
Minimum Group ◽  
Dimensional Distribution ◽  
Frequency Dependences

We present an inversion scheme of the backscatter signal leading edge into parameters of the quasi-parabolic electron density profile, which is based on the comparison of experimental and calculated minimum delays of scattered signals with corresponding distance to the skip zone border. Input parameters are frequency dependences of minimum group path of signal propagation, derived from processing and interpreting backscatter ionograms. For a fixed sounding frequency, the ionospheric parameter pair — the critical frequency and height of the F2-layer maximum — is defined as the intersection point of two curves representing solutions of minimization problems for discrepancy functionals of the minimum group path and the range to the skip zone border. Determining the ionospheric parameters by this inversion scheme on the sounding frequency grid allows us to construct a two-dimensional distribution of electron density in the direction of backscatter sounding.

scholarly journals INVERSION OF BACKSCATTER IONOGRAMS INTO QUASI-PARABOLIC IONOSPHERIC LAYER PARAMETERS

2020 ◽  
Vol 6 (3) ◽  
pp. 67-71
Author(s):  
Sergey Ponomarchuk ◽  
Maksim Penzin
Keyword(s):  
Electron Density ◽  
Leading Edge ◽  
Signal Propagation ◽  
Electron Density Profile ◽  
Intersection Point ◽  
Ionospheric Layer ◽  
Backscatter Signal ◽  
Minimum Group ◽  
Dimensional Distribution ◽  
Frequency Dependences

We present an inversion scheme of the backscatter signal leading edge into parameters of the quasi-parabolic electron density profile, which is based on the comparison of experimental and calculated minimum delays of scattered signals with corresponding distance to the skip zone border. Input parameters are frequency dependences of minimum group path of signal propagation, derived from processing and interpreting backscatter ionograms. For a fixed sounding frequency, the ionospheric parameter pair — the critical frequency and height of the F2-layer maximum — is defined as the intersection point of two curves representing solutions of minimization problems for discrepancy functionals of the minimum group path and the range to the skip zone border. Determining the ionospheric parameters by this inversion scheme on the sounding frequency grid allows us to construct a two-dimensional distribution of electron density in the direction of backscatter sounding.

Estimation of the electron density profile in the D region from rocket measurement of VLF signals from a ground based transmitter

1981 ◽  
Vol 64 (11) ◽  
pp. 68-74
Author(s):  
Isamu Nagano ◽  
Masayoshi Mambo ◽  
Tetsuo Fukami ◽  
Koji Namba ◽  
Iwane Kimura
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Electron Density Profile ◽  
Rocket Measurement ◽  
D Region

scholarly journals Radial density profile and stability of capillary discharge plasma waveguides of lengths up to 40 cm

2021 ◽  
Vol 9 ◽  
Author(s):  
M. Turner ◽  
A. J. Gonsalves ◽  
S. S. Bulanov ◽  
C. Benedetti ◽  
N. A. Bobrova ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Electron Density ◽  
Density Profile ◽  
Pulse Propagation ◽  
Spot Size ◽  
Capillary Discharge ◽  
Electron Density Profile ◽  
Plasma Waveguide ◽  
Wakefield Acceleration ◽  
Plasma Wakefield

Abstract We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650 $\mathrm{\mu} \mathrm{m}$ to 2 mm and lengths of 9 to 40 cm. To the best of the authors’ knowledge, 40 cm is the longest discharge capillary plasma waveguide to date. This length is important for $\ge$ 10 GeV electron energy gain in a single laser-driven plasma wakefield acceleration stage. Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to $<0.2$ % and their average on-axis plasma electron density to $<1$ %. These variations explain only a small fraction of laser-driven plasma wakefield acceleration electron bunch variations observed in experiments to date. Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and is in excellent agreement with magnetohydrodynamic simulation results. We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel. However, they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.

Impurity effects on trapped electron modes in tokamak plasmas with inverted electron density profile

2021 ◽  
Vol 28 (5) ◽  
pp. 052510
Author(s):  
X. R. Zhang ◽  
J. Q. Dong ◽  
H. R. Du ◽  
J. Y. Liu ◽  
Y. Shen ◽  
...  
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Electron Density Profile ◽  
Tokamak Plasmas ◽  
Impurity Effects ◽  
Trapped Electron

Ultrashort pulse reflectometry for electron density profile measurements

1999 ◽  
Vol 70 (1) ◽  
pp. 1038-1041 ◽  
Author(s):  
C. W. Domier ◽  
Y. Roh ◽  
N. C. Luhmann
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Ultrashort Pulse ◽  
Electron Density Profile

Improved reflectometer electron density profile measurements on DIII-D

2003 ◽  
Vol 74 (3) ◽  
pp. 1525-1529 ◽  
Author(s):  
G. Wang ◽  
L. Zeng ◽  
E. J. Doyle ◽  
T. L. Rhodes ◽  
W. A. Peebles
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Electron Density Profile
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