w
wa
wb
wc
wd
we
wf
wh
wi
wk
wm
wo
wp
wr
ws
wt
wu
wv
ww
wy
Перевод: wiggler
вигглер
Тезаурус:
- Wiggler
- The precise wavelength (formula;) emitted by the FEL is given by equation ( i ): where is the period of the wiggler, is the electron energy in units of the rest energy ( ), e is the electron charge, B o is the peak magnetic induction at the electron path, m is the electron rest mass and c is the velocity of light.
- Electrons traversing the wiggler in the laboratory frame ( a ) oscillate with a wavelength ( ) of a few centimetres.
- Because the high power electron beam would damage the magnets, a magnetic transport system (not shown) injects the beam into the wiggler and removes it at the exit.
- In Fig. 1 the wiggler is planar, but a helical wiggler has also been used successfully.
- ( is the precise wavelength emitted by the FEL, and is the period of the wiggler.)
- Mirrors are placed around the wiggler to reflect the emitted light back and forth, causing amplification on each pass by stimulated emission.
- In the electron rest frame - ie the view seem from the electron ( b ) - relativity ( ) shortens the wiggler period by a factor .
- In 1975, Madey and his coworkers amplified the output of a 10.6 CO 2 laser by using a helical wiggler injected by the electron beam of the Stanford superconducting linear accelerator.
- For example, 50 MeV electrons have a , and thus a wiggler period ( ) of 5 cm will generate a laser output at 4 .
- The magnet array is thus called a wiggler or an undulator.
- In principle FELs can have calculated efficiencies as high as 30-;50 per cent when the dimensions of the wiggler are tapered to match the decreasing energy of the electrons traversing it.
|