The interplay of the focusing index of refraction, and the defocusing plasma makes the formation of a long filament of plasma that can be micrometers to kilometers in length.
22.
The other case, with ? positive, is the defocusing NLS which has dark soliton solutions ( having constant amplitude at infinity, and a local spatial dip in amplitude ).
23.
A common lattice is a FODO lattice consisting of a basis of a focusing quadrupole,'nothing'( often a bending magnet ), a defocusing quadrupole and another length of'nothing '.
24.
The quadrupoles in the lattice are of two types :'F quadrupoles'( which are horizontally focusing but vertically defocusing ) and'D quadrupoles'( which are vertically focusing but horizontally defocusing ).
25.
The quadrupoles in the lattice are of two types :'F quadrupoles'( which are horizontally focusing but vertically defocusing ) and'D quadrupoles'( which are vertically focusing but horizontally defocusing ).
26.
Vector dark bright solitons have been reported in incoherently coupled spatial DBVSs in a self-defocusing medium and matter-wave DBVS in two-species condensates with repulsive scattering interactions, but never verified in the field of optical fiber.
27.
With \ xi the spatial coordinate and \ tau the temporal coordinate . \ psi ( \ xi, \ tau ) being the dispersion is anomalous and the nonlinearity is self-focusing ( note that similar results could be obtained for a normally dispersive medium combined with a defocusing nonlinearity ).
28.
Interstellar scintillation is the observed effect of interference and refractive phenomena due to the ISM . It can be thought of as the ISM focusing and defocusing the radio waves from the source, producing a pattern of dark and bright patches, rather like light and dark patches at the bottom of a fish pond.
29.
The image on the right shows an example of a quadrupole focusing in the vertical direction for a positively charged particle going into the image plane ( forces above and below the center point towards the center ) while defocusing in the horizontal direction ( forces left and right of the center point away from the center ).
30.
That's enough energy to accelerate a Nimitz-class aircraft carrier from rest to more than five knots & mdash; or to push a three-ton SUV to nearly twice the speed of sound : A full-power beam can bore a hole forty meters into a block of solid copper . " Safely " dumping those beams at the end of experimental run requires controlled beam defocusing and scanning across a custom-designed ten-ton cylinder of graphite, embedded within a thousand tons of concrete and steel shielding.
