Laser ion time-of-flight (LITOF) velocity measurements using N2(+) tracers

The drift velocity of electrons in oxygen at 293 K has been measured over the range 0.8 ≤ E/N ≤ 12 Td by the Bradbury–Nielsen time-of-flight method. The factors governing the range over which measurements can be made are discussed and it is shown that long drift tubes should be used for drift velocity measurements in oxygen at low values of E/N. A 50 cm drift tube is described. The error in the present results is estimated to be less than 1 % for 1.8 E/N E/N > 6 Td and at 1.5 Td, 5 % at 1 Td, and 10 % at 0.8 Td. The present data are in good agreement with those of Fleming et al. (1972) and Nelson and Davis (1972) over the E/N range where the sets of data overlap.

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A pulsed-wire technique for velocity measurements in highly turbulent flows

Journal of Fluid Mechanics ◽

10.1017/s0022112071002313 ◽

1971 ◽

Vol 49 (4) ◽

pp. 657-691 ◽

Cited By ~ 132

Author(s):

L. J. S. Bradbury ◽

I. P. Castro

Keyword(s):

Turbulent Flows ◽

Time Of Flight ◽

Measuring Technique ◽

Velocity Measurements ◽

Heated Air ◽

Resistance Thermometers ◽

Velocity Measuring ◽

Highly Turbulent Flows ◽

Flow Reversals

The velocity measuring technique described in this paper consists of measuring the time of flight of a tracer of heated air from an electrically pulsed wire to one of two sensor wires which are operated as resistance thermometers. These sensor wires are at right angles to the pulsed wire and are placed one on either side of the pulsed wire. The instrument may be used in highly turbulent flows including regions in which flow reversals occur. The paper discusses the theoretical behaviour of the probe and the results of some calibration experiments.

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ABSOLUTE VELOCITY MEASUREMENTS IN A RAREFIED GAS FLOW BY AN ION TIME-OF-FLIGHT TECHNIQUE

Rarefied Gas Dynamics ◽

10.1016/b978-0-12-398150-9.50028-6 ◽

1974 ◽

pp. 245-252 ◽

Cited By ~ 2

Author(s):

K.A. Bütefisch ◽

D. Vennemann

Keyword(s):

Gas Flow ◽

Rarefied Gas ◽

Time Of Flight ◽

Absolute Velocity ◽

Velocity Measurements ◽

Rarefied Gas Flow

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Time-of-flight laser anemometer for velocity measurements in the atmosphere

Applied Optics ◽

10.1364/ao.17.1486_1 ◽

1978 ◽

Vol 17 (10) ◽

pp. 1486_1 ◽

Cited By ~ 20

Author(s):

L. Lading ◽

A. Skov Jensen ◽

C. Fog ◽

H. Andersen

Keyword(s):

Time Of Flight ◽

Velocity Measurements ◽

Laser Anemometer

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Concepts for Dust Velocity Measurements on a Cometary Orbiter

International Astronomical Union Colloquium ◽

10.1017/s0252921100501651 ◽

1996 ◽

Vol 150 ◽

pp. 255-258 ◽

Cited By ~ 1

Author(s):

Sandrine Perruchot ◽

Philippe L. Lamy ◽

Frank Giovane ◽

Bo Å. S. Gustafson

Keyword(s):

Light Scattering ◽

Time Of Flight ◽

Optical Systems ◽

Velocity Measurements ◽

Particle Localization ◽

System Time ◽

Flight Measurements

AbstractWe have studied several optical systems for dust velocity measurements on a cometary orbiter using light scattering to detect particles. Two main concepts are considered. The first relies on trajectory imaging, while the second uses time-of-flight measurements between two or more light sheets. Their merits and disadvantages are discussed. The favored system, time-of-flight between two planes with particle localization, is described.

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A Note on End Effects in Electron Drift Tube Experiments

Australian Journal of Physics ◽

10.1071/ph730685 ◽

1973 ◽

Vol 26 (5) ◽

pp. 685

Author(s):

MT Elford ◽

AG Robertson

Keyword(s):

Drift Velocity ◽

Drift Tube ◽

Time Of Flight ◽

Drift Chamber ◽

Electron Drift Velocity ◽

Electron Drift ◽

Velocity Measurements ◽

End Effects ◽

Time Of Flight Method

Experiments to test the influence of end effects on electron drift velocity measurements by the Bradbury-Nielsen time-of-flight method are described. A comparison of data taken at drift distances of 5, 10, and 50 cm in hydrogen and 5 and 10 cm in helium shows that over the EIN and pressure ranges investigated the results are independent of drift distance and that it is justifiable to consider this distance as that between the mid planes of the grids which terminate the drift chamber.

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