An automatic beam alignment system based on relative reference points for Thomson scattering diagnosis system

Wei-qiang Tan; Peng Yuan; Peng Wang; Wen-zhe Mao; Jin-lin Xie; Tao Lan; Wei-xing Ding; Hong Li; Ge Zhuang; Wan-dong Liu; Jian Zheng

doi:10.1063/1.5123301

MAST YAG Thomson scattering upgrade alignment system

Review of Scientific Instruments ◽

10.1063/1.3475377 ◽

2010 ◽

Vol 81 (10) ◽

pp. 10D521 ◽

Cited By ~ 8

Author(s):

J. Figueiredo ◽

G. Naylor ◽

M. Walsh ◽

M. Dunstan ◽

R. Scannell ◽

...

Keyword(s):

Thomson Scattering ◽

Alignment System

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Automatic Beam Alignment System for Thomson Scattering Diagnostic on Experimental Advanced Superconducting Tokamak

Journal of Fusion Energy ◽

10.1007/s10894-015-9922-7 ◽

2015 ◽

Vol 34 (5) ◽

pp. 1051-1059 ◽

Cited By ~ 2

Author(s):

Hui Chen ◽

Qing Zang ◽

Xiao Feng Han ◽

Shu Mei Xiao ◽

Teng Fei Wang ◽

...

Keyword(s):

Thomson Scattering ◽

Alignment System ◽

Thomson Scattering Diagnostic ◽

Superconducting Tokamak

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Reference Coordinate System Requirements for Geophysics

International Astronomical Union Colloquium ◽

10.1017/s0252921100050946 ◽

1975 ◽

Vol 26 ◽

pp. 87-92

Author(s):

P. L. Bender

Keyword(s):

Coordinate System ◽

Polar Motion ◽

Main Part ◽

Measurement Techniques ◽

Reference Points ◽

Angular Motion ◽

Coordinate Systems ◽

Axis Of Rotation ◽

The Earth ◽

Fixed System

AbstractFive important geodynamical quantities which are closely linked are: 1) motions of points on the Earth’s surface; 2)polar motion; 3) changes in UT1-UTC; 4) nutation; and 5) motion of the geocenter. For each of these we expect to achieve measurements in the near future which have an accuracy of 1 to 3 cm or 0.3 to 1 milliarcsec.From a metrological point of view, one can say simply: “Measure each quantity against whichever coordinate system you can make the most accurate measurements with respect to”. I believe that this statement should serve as a guiding principle for the recommendations of the colloquium. However, it also is important that the coordinate systems help to provide a clear separation between the different phenomena of interest, and correspond closely to the conceptual definitions in terms of which geophysicists think about the phenomena.In any discussion of angular motion in space, both a “body-fixed” system and a “space-fixed” system are used. Some relevant types of coordinate systems, reference directions, or reference points which have been considered are: 1) celestial systems based on optical star catalogs, distant galaxies, radio source catalogs, or the Moon and inner planets; 2) the Earth’s axis of rotation, which defines a line through the Earth as well as a celestial reference direction; 3) the geocenter; and 4) “quasi-Earth-fixed” coordinate systems.When a geophysicists discusses UT1 and polar motion, he usually is thinking of the angular motion of the main part of the mantle with respect to an inertial frame and to the direction of the spin axis. Since the velocities of relative motion in most of the mantle are expectd to be extremely small, even if “substantial” deep convection is occurring, the conceptual “quasi-Earth-fixed” reference frame seems well defined. Methods for realizing a close approximation to this frame fortunately exist. Hopefully, this colloquium will recommend procedures for establishing and maintaining such a system for use in geodynamics. Motion of points on the Earth’s surface and of the geocenter can be measured against such a system with the full accuracy of the new techniques.The situation with respect to celestial reference frames is different. The various measurement techniques give changes in the orientation of the Earth, relative to different systems, so that we would like to know the relative motions of the systems in order to compare the results. However, there does not appear to be a need for defining any new system. Subjective figures of merit for the various system dependon both the accuracy with which measurements can be made against them and the degree to which they can be related to inertial systems.The main coordinate system requirement related to the 5 geodynamic quantities discussed in this talk is thus for the establishment and maintenance of a “quasi-Earth-fixed” coordinate system which closely approximates the motion of the main part of the mantle. Changes in the orientation of this system with respect to the various celestial systems can be determined by both the new and the conventional techniques, provided that some knowledge of changes in the local vertical is available. Changes in the axis of rotation and in the geocenter with respect to this system also can be obtained, as well as measurements of nutation.

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On-line alignment and astigmatism correction using a TV and personal computer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146850 ◽

1993 ◽

Vol 51 ◽

pp. 202-203

Author(s):

F. Hosokawa ◽

Y. Kondo ◽

T. Honda ◽

Y. Ishida ◽

M. Kersker

Keyword(s):

High Resolution ◽

Personal Computer ◽

Block Diagram ◽

Incident Beam ◽

Ccd Camera ◽

Alignment Procedure ◽

Astigmatism Correction ◽

Transmission Electron ◽

Alignment System ◽

On Line

High-resolution transmission electron microscopy must attain utmost accuracy in the alignment of incident beam direction and in astigmatism correction, and that, in the shortest possible time. As a method to eliminate this troublesome work, an automatic alignment system using the Slow-Scan CCD camera has been introduced recently. In this method, diffractograms of amorphous images are calculated and analyzed to detect misalignment and astigmatism automatically. In the present study, we also examined diffractogram analysis using a personal computer and digitized TV images, and found that TV images provided enough quality for the on-line alignment procedure of high-resolution work in TEM. Fig. 1 shows a block diagram of our system. The averaged image is digitized by a TV board and is transported to a computer memory, then a diffractogram is calculated using an FFT board, and the feedback parameters which are determined by diffractogram analysis are sent to the microscope(JEM- 2010) through the RS232C interface. The on-line correction system has the following three modes.

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Cognitive Reflection Effects on Time Discounting

Journal of Individual Differences ◽

10.1027/1614-0001/a000254 ◽

2018 ◽

Vol 39 (2) ◽

pp. 99-106 ◽

Cited By ~ 4

Author(s):

Michał Białek ◽

Przemysław Sawicki

Keyword(s):

Individual Differences ◽

Individual Difference ◽

Delay Discounting ◽

Reference Point ◽

Reference Points ◽

Cognitive Reflection Test ◽

Process Information ◽

Time Discounting ◽

Cognitive Reflection ◽

The Way

Abstract. In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

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