Steady-state FEL: particle dynamics in the FEL portion of a two-beam accelerator Page: 4 of 37
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
beam radius is assumed small compared with the waveguide dimensions. The 1-D
FEL equations for a TE mode are:2
d'I = ~- asawsin , la)
dz c Yj
d_= (kw - 6ks) - _ (1 + aw - 2aw as cos 'j) + (lb)
dz 2cy2 dz
das = 1p, eff aw <sin > - mas , (c)
dz 2 ac Y
d _p,eff aw <coss,,
dz 2 wcas Y
where j is an index denoting a particular particle and <> indicates an
average over particles. These equations are an extension of the KMR
equations for an FEL. In these equations, the dispersion relation for a
waveguide relates w and ks. The factor 6ks results because the phase
velocity of radiation in a waveguide is not equal to c. Specifically for a
ks = [(C2 - (21)2 - (2bfn)2]% , (2a)
c2 a b
ks = - ks ,(2b)
where a and b are respectively the x and y dimensions of the waveguide. It is
also important to note that the plasma frequency in equations (lc) and (ld) is
an effective plasma frequency given by
2 8TeI 3
p,eff = 8 m Ia , (3)
where I is the total beam current and m and e are respectively the electron
mass and charge. The factor a in Eq. (lc) is a loss factor meant to model
the removal of microwave power from the FEL waveguide.
- 3 -
Here’s what’s next.
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Sternbach, E. & Sessler, A.M. Steady-state FEL: particle dynamics in the FEL portion of a two-beam accelerator, article, September 1, 1985; [Berkeley,] California. (digital.library.unt.edu/ark:/67531/metadc1111506/m1/4/: accessed November 13, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.