Magnetic mirror
A magnetic mirror is a plasma confinement device which uses a cylindrical plasma with strong magnetic coils at the ends. The combination of a relatively weak magnetic field in the center and strong fields at the ends allows most of the plasma to be confined via the mirror effect. Particles whose velocities are not primarily parallel to the field lines are reflected at the ends. This configuration is still under active investigation for nuclear fusion energy.A charged particle travelling into an increasing magnetic field will (if the field becomes strong enough) reverse direction and be reflected back, provided its velocity perpendicular to the field is sufficiently large relative to its parallel velocity. This magnetic mirror effect is a direct result of the adiabatic invariance of the magnetic moment. Plasmas can be confined by devices which utilize this effect. The mirror effect also occurs in some tokamak plasmas, since the toroidal magnetic field is stronger on the inboard side than on the outboard side; in this case it gives rise to so-called "neoclassical" behavior. The ratio of the maximum and minimum magnetic fields is known as the mirror ratio and determines the fraction of phase space that can be confined.
see: plasma physics
Caught and reflected the flame, as shields of armies the sunshine.
Such as at home, in the olden time, his fathers before him
Close at her father's side was the gentle Evangeline seated,
Silent awhile were its treadles, at rest was its diligent shuttle,
Followed the old man's song, and united the fragments together.
Footfalls are heard in the aisles, or words of the priest at the altar,
Sounded the wooden latch, and the door swung back on its hinges.
And by her beating heart Evangeline knew who was with him.
"Welcome, Basil, my friend! Come, take thy place on the settle
Take from the shelf overhead thy pipe.html">pipe.html">pipe and the box of tobacco;
Smoke of the pipe or the forge thy friendly and jovial face gleams
Then, with a smile of content, thus answered Basil the blacksmith.html">blacksmith.html">blacksmith,
"Benedict Bellefontaine, thou hast ever thy jest and thy ballad!
Gloomy forebodings of ill, and see only ruin before them.
Pausing a moment, to take the pipe that Evangeline brought him,
"Four days now are passed since the English ships at their anchors
What their design may be is unknown; but all are commanded
Will be proclaimed as law in the land. Alas! in the mean time
Then made answer the farmer:--"Perhaps some friendlier purpose
By untimely rains or untimelier heat have been blighted,
"Not so thinketh the folk in the village," said, warmly, the blacksmith,
"Louisburg is not forgotten, nor.html">nor Beau Sejour, nor Port Royal.
Waiting with anxious hearts the dubious fate of to-morrow.
Nothing is left but the blacksmith's sledge and the scythe of the mower."
.
On
wordlookup.net
All is still licensed under the GNU FDL.
It uses material from the wikipedia.
|
|