FEL2012 - List of Authors (Wang, G.)

Paper

Title

Page

Growing Modes of the Free-Electron Laser and Their Bandwidth

33

G. Wang, V. Litvinenko
BNL, Upton, Long Island, New York, USA
S.D. Webb
Tech-X, Boulder, Colorado, USA

Forty years after invention of FELs a number of fundamental questions remain unanswered. For example, it is known that for a beam with a Gaussian energy distribution an infinite number of modes exist. But it is unknown how many of these modes are growing, or what frequency cutoffs might exist for these growing modes? In this talk, for the first time, we present the proof that for typical bell-shape energy distribution in the electron beam there is no more that one growing mode - both without [1] and with space charge effects. We also present an analytical expression, which determines the bandwidth of the free-electron laser. Furthermore, we prove that for an energy distribution with N peaks, there is no more than N FEL growing modes. Finally, present a simple method of determining number of growing modes for the case of beam energy distributions with multiple peaks.
[1] On Free-Electron Laser Growing Modes and their Bandwidths, S. Webb, V.N. Litvinenko, G. Wang, Submitted to PR ST-AB

Slides MOOC04 [2.832 MB]

Paper	Title	Page
MOOC04	Growing Modes of the Free-Electron Laser and Their Bandwidth	33
	G. Wang, V. Litvinenko BNL, Upton, Long Island, New York, USA S.D. Webb Tech-X, Boulder, Colorado, USA
	Forty years after invention of FELs a number of fundamental questions remain unanswered. For example, it is known that for a beam with a Gaussian energy distribution an infinite number of modes exist. But it is unknown how many of these modes are growing, or what frequency cutoffs might exist for these growing modes? In this talk, for the first time, we present the proof that for typical bell-shape energy distribution in the electron beam there is no more that one growing mode - both without [1] and with space charge effects. We also present an analytical expression, which determines the bandwidth of the free-electron laser. Furthermore, we prove that for an energy distribution with N peaks, there is no more than N FEL growing modes. Finally, present a simple method of determining number of growing modes for the case of beam energy distributions with multiple peaks. [1] On Free-Electron Laser Growing Modes and their Bandwidths, S. Webb, V.N. Litvinenko, G. Wang, Submitted to PR ST-AB
	Slides MOOC04 [2.832 MB]