Search results
Results From The WOW.Com Content Network
The equations below assume a beam with a circular cross-section at all values of z; this can be seen by noting that a single transverse dimension, r, appears.Beams with elliptical cross-sections, or with waists at different positions in z for the two transverse dimensions (astigmatic beams) can also be described as Gaussian beams, but with distinct values of w 0 and of the z = 0 location for ...
Full width at half maximum. In a distribution, full width at half maximum (FWHM) is the difference between the two values of the independent variable at which the dependent variable is equal to half of its maximum value. In other words, it is the width of a spectrum curve measured between those points on the y-axis which are half the maximum ...
Molecular beams are useful for fabricating thin films in molecular beam epitaxy and artificial structures such as quantum wells, quantum wires, and quantum dots. Molecular beams have also been applied as crossed molecular beams. The molecules in the molecular beam can be manipulated by electrical fields and magnetic fields. [1]
This class applies molecular dynamic calculations that are able to analyze both low and high energy physical interactions taking place in the ion beam analysis. A key and popular feature that accompanies such techniques is the possibility for the computations to be incorporated in real time with the ion beam analysis experiment itself.
The crossed molecular beam technique was developed by Dudley Herschbach and Yuan T. Lee, for which they were awarded the 1986 Nobel Prize in Chemistry. [3] While the technique was demonstrated in 1953 by Taylor and Datz of Oak Ridge National Laboratory, [4] Herschbach and Lee refined the apparatus and began probing gas-phase reactions in unprecedented detail.
A theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other.
X-ray crystallography—or, strictly speaking, an inelastic Compton scattering experiment—has also provided evidence for the partly covalent character of hydrogen bonds. [70] In the field of organometallic chemistry , the X-ray structure of ferrocene initiated scientific studies of sandwich compounds , [ 71 ] [ 72 ] while that of Zeise's salt ...
The half-power point is the angle off boresight at which the antenna gain first falls to half power (approximately −3 dB) [a] from the peak. The angle between the −3 dB points is known as the half-power beam width (or simply beam width). [4] Beamwidth is usually but not always expressed in degrees and for the horizontal plane.