scholarly journals Synthesizing a four-dimensional beam particle distribution frommultiple two-dimensional views

2002 ◽  
Author(s):  
A. Friedman ◽  
D.P. Grote ◽  
C.M. Celata ◽  
J.W. Staples
Keyword(s):  
Particle Distribution ◽  
Two Dimensional ◽  
Beam Particle

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.

Two-Dimensional Small-Angle X-ray Scattering Investigation of Stretched Borosilicate Glasses

1997 ◽  
Vol 30 (4) ◽  
pp. 487-494 ◽  
Author(s):  
S. Polizzi ◽  
P. Riello ◽  
G. Fagherazzi ◽  
M. Bark ◽  
N. F. Borrelli
Keyword(s):  
Small Angle ◽  
Particle Distribution ◽  
Suitable Model ◽  
Two Dimensional ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Ellipsoidal Particles ◽  
Ray Scattering

A two-dimensional fit of a suitable model for interpreting small-angle X-ray scattering (SAXS) has been shown to be a valuable tool in obtaining quantitative microstructural information. The model is based on the hypothesis that dilute ellipsoidal particles are arranged parallel to each other. The method has been applied to two glasses containing oriented particles. The investigated materials are both alkali aluminoborosilicate glasses, thermally treated and redrawn at a temperature above their softening point. The Ag(Cl, Br) crystalline droplets, formed during the preliminary thermal treatment, assume, after drawing, a cigar-like shape, oriented in the stretching direction, and give the material birefringence properties. The volumetric particle distribution has an average of 22 × 70 nm and is skewed up to length values of about 1200 nm. The composition of the solid solution, determined by X-ray diffraction (XRD), is Ag(Cl0.35, Br0.65). When the Ag(Cl, Br) particles on the surface are chemically reduced to Ag, a material with polarizing properties is obtained (PolarcorTM). For this sample, two distributions of particles have been found: one with an average of 18 x 230 nm and skewed up to 600 nm, and one, very sharp, of much shorter particles (14 × 30 nm).

MESOSCOPIC SPECTRA IN TWO-DIMENSIONAL DECAYING TURBULENCE

2006 ◽  
Vol 17 (04) ◽  
pp. 531-543 ◽  
Author(s):  
GÁBOR HÁZI
Keyword(s):  
Lattice Boltzmann ◽  
Particle Distribution ◽  
Power Spectra ◽  
Collision Operator ◽  
Distribution Functions ◽  
Lattice Boltzmann Model ◽  
Two Dimensional ◽  
Decaying Turbulence ◽  
The One ◽  
Boltzmann Model

Two-dimensional decaying turbulence is simulated using a lattice Boltzmann model with the Bhatnagar–Gross–Krook collision operator. Auto-power spectra of the one-velocity particle distribution functions are presented. The relation between the spectrum of the kinetic energy and the spectra of the distribution functions is given. An interpretation of the non-equilibrium spectra as a measure of the dissipation in different scales is given. A peak in the spectrum of the resting particle distribution functions is observed exactly at the ultraviolet cutoff. It is shown that the peak can be associated with enhanced acoustic activity, which might be a numerical artifact or a consequence of the compressibility of the lattice Boltzmann fluid.

scholarly journals Theoretical and Experimental Study of Particle Distribution from Magnetron Sputtering with Masks for Accurate Thickness Profile Control

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
Yingna Shi ◽  
Qiushi Huang ◽  
Runze Qi ◽  
Zhengxiang Shen ◽  
Zhong Zhang ◽  
...  
Keyword(s):  
High Precision ◽  
Particle Distribution ◽  
Beam Width ◽  
Mean Square ◽  
Two Dimensional ◽  
Thickness Profile ◽  
Ring Shape ◽  
Profile Control ◽  
Circular Holes ◽  
Flat Mirror

Differential deposition and profile coating are two common deterministic fabrication methods for figure correction of high-precision mirrors. The generation of the desired particle distribution on the substrate as the growing function is an important prerequisite, especially for two-dimensional correction. A model of particle distribution considering the etched ring shape, mask structure, and mask distance between the target and substrate is established. The model is verified by deposition experiments using a series of circular holes with different hole sizes and distances of the mask from the substrate. According to the model, a smallest deposition beam width of 2.79 mm can be obtained using a hole with a 3 mm diameter. The shape of the particle distribution gradually changes from convex to concave as the mask moves away from the substrate for different holes. A two-dimensional figure correction of a flat mirror was demonstrated using a hole with a 6 mm diameter. The peak-to-valley (PV) value is reduced from 74.23 nm to 10.09 nm, and the root mean square (RMS) value is reduced from 18.38 nm to 1.36 nm within a 130 mm × 20 mm area. The model could provide useful guidance for high-precision two-dimensional figure correction applications.

scholarly journals Development of Magnetic Particle Distribution Imaging Using Magnetic Field Reconstruction for Biopsy of the Sentinel Lymph Node

2021 ◽  
Vol 7 (6) ◽  
pp. 85
Author(s):  
Akari Inagaki ◽  
Tomoko Suzuki ◽  
Yuki Mima ◽  
Kenjiro Kimura
Keyword(s):  
Magnetic Field ◽  
Lymph Node ◽  
Sentinel Lymph Node ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Cancer Metastasis ◽  
Particle Distribution ◽  
Magnetic Sensor ◽  
Lymphoid Tissues ◽  
Two Dimensional

The sentinel lymph node is the first lymph-node-draining cancer metastasis. The identification of the sentinel lymph node using magnetic particles and a magnetic sensor has attracted attention in recent years, as this method is less invasive than the conventional method of radiotracer injection. However, the development of a two-dimensional measurement method for sentinel lymph nodes using magnetic nanoparticles remains an issue. In the present study, a method and apparatus for the two-dimensional imaging of magnetic particle distribution were developed to detect a lymph node with magnetic particles concentrated within lymphoid tissues. The method comprises the reconstruction of the magnetic field measured with a high-sensitivity magnetic sensor and with a magnetic detection ability of 2 nT/√Hz at 100 Hz (5 nT/√Hz at 1 Hz). The proposed system measures the two-dimensional magnetic field distribution in an area of up to 25 × 25 mm2 using a coil generating a 0.77 mT external magnetic field applied to the measurement target. The improved spatial resolution of the images makes it possible to use two-dimensional imaging for diagnostics of breast cancer metastases.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

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