Tomographic method of experimental research of particle distribution in phase space

2002 ◽  
Author(s):  
V.V. Kalashnikov ◽  
V.I. Moisseev ◽  
V.V. Petrenko
Keyword(s):  
Phase Space ◽  
Experimental Research ◽  
Particle Distribution ◽  
Tomographic Method

scholarly journals Use of projectional phase space data to infer a 4D particle distribution

2003 ◽  
Vol 21 (1) ◽  
pp. 17-20 ◽  
Author(s):  
A. FRIEDMAN ◽  
D.P. GROTE ◽  
C.M. CELATA ◽  
J.W. STAPLES
Keyword(s):  
Experimental Data ◽  
Phase Space ◽  
Particle Distribution ◽  
National Laboratory ◽  
Two Dimensional ◽  
High Current ◽  
Current Experiment ◽  
Axial Coordinate ◽  
Small Set ◽  
Space Data

We consider beams that are described by a four-dimensional (4D) transverse distribution f (x, y, x′, y′), where x′ ≡ px /pz and z is the axial coordinate. A two-slit scanner is commonly employed to measure, over a sequence of shots, a two-dimensional (2D) projection of such a beam's phase space, for example, f (x, x′). Another scanner might yield f (y, y′) or, using crossed slits, f (x, y). A small set of such 2D scans does not uniquely specify f (x, y, x′, y′). We have developed “tomographic” techniques to synthesize a “reasonable” set of particles in a 4D phase space having 2D densities consistent with the experimental data. We briefly summarize one method and describe progress in validating it, using simulations of the High Current Experiment at Lawrence Berkeley National Laboratory.

scholarly journals Kinetic theory of phase space plateaux in a non-thermal energetic particle distribution

2015 ◽  
Vol 22 (9) ◽  
pp. 092126 ◽  
Author(s):  
F. Eriksson ◽  
R. M. Nyqvist ◽  
M. K. Lilley
Keyword(s):  
Phase Space ◽  
Kinetic Theory ◽  
Energetic Particle ◽  
Particle Distribution

Transverse Phase Space Measurement Using Tomographic Method

2007 ◽  
Author(s):  
Heishun Zen ◽  
Hideaki Ohgaki ◽  
Kai Masuda ◽  
Toshiteru Kii ◽  
Kohichi Kusukame ◽  
...  
Keyword(s):  
Phase Space ◽  
Tomographic Method ◽  
Space Measurement

Orbit Tomography of energetic particle distribution functions

2021 ◽  
Author(s):  
Luke Stagner ◽  
William W Heidbrink ◽  
Mirko Salewski ◽  
Asger Schou Jacobsen ◽  
Benedikt Geiger
Keyword(s):  
Distribution Function ◽  
Phase Space ◽  
Energetic Particle ◽  
Particle Distribution ◽  
Distribution Functions ◽  
Velocity Space ◽  
Space Distribution ◽  
Weight Functions ◽  
Ion Distribution ◽  
Fast Ions

Abstract Both fast ions and runaway electrons are described by distribution functions, the understanding of which are of critical importance for the success of future fusion devices such as ITER. Typically, energetic particle diagnostics are only sensitive to a limited subsection of the energetic particle phase-space which is often insufficient for model validation. However, previous publications show that multiple measurements of a single spatially localized volume can be used to reconstruct a distribution function of the energetic particle velocity-space by using the diagnostics' velocity-space weight functions, i.e. Velocity-space Tomography. In this work we use the recently formulated orbit weight functions to remove the restriction of spatially localized measurements and present Orbit Tomography, which is used to reconstruct the 3D phase-space distribution of all energetic particle orbits in the plasma. Through a transformation of the orbit distribution, the full energetic particle distribution function can be determined in the standard {energy,pitch,r,z}-space. We benchmark the technique by reconstructing the fast-ion distribution function of an MHD-quiescent DIII-D discharge using synthetic and experimental FIDA measurements. We also use the method to study the redistribution of fast ions during a sawtooth crash at ASDEX Upgrade using FIDA measurements. Finally, a comparison between the Orbit Tomography and Velocity-space Tomography is shown.

The Study of Fault Diagnosis Method Based on Chaos Characteristics

2012 ◽  
Vol 490-495 ◽  
pp. 818-822
Author(s):  
Feng Zhang ◽  
Xiao Li Pang ◽  
Xiao Yan Xiong
Keyword(s):  
Fault Diagnosis ◽  
Phase Space ◽  
Lyapunov Exponent ◽  
Experimental Research ◽  
Correlation Dimension ◽  
Vertical Direction ◽  
Characteristic Parameters ◽  
Vibration Signals ◽  
Vibrating Screen ◽  
Diagnosis Method

Based on chaotic characteristics of vibrating screen sides in vertical direction, the paper used phase space reconstruction theory to calculate the characteristic parameters of vibration signals, which are correlation dimension and Lyapunov exponent. Through experimental research, it was found that there was obvious difference in Correlation dimension and Lyapunov exponent when of vibrating screen has crack and has no crack. The characteristic parameters of vibration signals can be used as the basis to determine vibrating screen has crack or no crack. Using this method for fault diagnosis is simple, intuitive, and convenient for analysis.

Phase-space description of plasma waves. Part 1. Linear theory

1992 ◽  
Vol 47 (3) ◽  
pp. 465-477 ◽  
Author(s):  
T. Biro ◽  
K. Rönnmark
Keyword(s):  
Phase Space ◽  
Continuity Equation ◽  
Particle Distribution ◽  
Plasma Waves ◽  
Current Response ◽  
Time Varying ◽  
Plasma Parameters ◽  
Proper Form ◽  
Window Functions ◽  
Space Description

We develop an (r, k) phase-space description of waves in plasmas by introducing Gaussian window functions to separate short-scale oscillations from long-scale modulations of the wave fields and variations in the plasma parameters. To obtain a wave equation that unambiguously separates conservative dynamics from dissipation in an inhomogeneous and time-varying background plasma, we first discuss the proper form of the current response function. In analogy with the particle distribution function f(v, r, t), we introduce a wave density N(k, r, t) on phase space. This function is proved to satisfy a simple continuity equation. Dissipation is also included, and this allows us to describe the damping or growth of wave density along rays. Problems involving geometric optics of continuous media often appear simpler when viewed in phase space, since the flow of N in phase space is incompressible.

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