The deep-UV operation of the OK-4/Duke storage ring FEL

Abstract

In this paper we present the result of the deep-UV lasing with the OK-4/Duke storage ring FEL. The OK-4 FEL was initially commissioned in the near-UV at Duke Free Electron Laboratory in November, 1996 followed by a year-long shutdown. After re-establishing the storage ring operation in early 1998, the OK-4 FEL lasing was demonstrated in the wavelength range of 217 to 256 nm in 1998. A number of lasing modes with electron energies ranging from 300 to 750 MeV have been established to accommodate application research. Starting September, 1998, the coherent deep-UV radiation is used for applications in cornea surgery, cell biology, surface physics, and nuclear physics. In this paper we report the results of the deep-UV lasing with the OK-4/Duke storage ring FEL as well as our plans to advance towards the VUV.

Spectral modulation of higher harmonic spontaneous emission from an optical klystron

“…However, the quantity nN u does depend on the higher harmonic order, thus Á n changes with the harmonic order. As with the optical klystron OK-4 in the Duke FEL Laboratory (Litvinenko et al, 1999), because the ETLOK-III could change the K value of the undulator section with fixed magnetic field in the dispersive section we could measure the dependence of Á n on the order of the higher harmonic. Fig.…”

“…Although the energy spread of an electron beam has to be narrow in order to oscillate a free-electron laser (FEL) with an optical klystron, the optical klystron can achieve a high FEL gain given its length. Thus, optical klystrons have been used as an insertion device for the whole storage-ring FEL system (Deacon et al, 1984;Litvinenko, 1988;Couprie et al, 1991;Takano et al, 1993;Yamazaki et al, 1993;Litvinenko et al, 1999;Walker et al, 2001) and have contributed to shorten the FEL wavelength down to the vacuum-ultraviolet region (Litvinenko et al, 2001;Marsi et al, 2002). The characteristics of the optical klystron's spontaneous emission were analyzed by the Novossibirsk group and by the ACO group (Elleaume, 1984a;Vinokurov & Skrinskii, 1977), and these groups reported the results of detailed measurements of the fundamental harmonic spontaneous emission.…”

Strategies towards a compact XUV free electron laser adopted for the LUNEX5 project

“…Then, UV-VUV FEL oscillators [23][24][25][26][27][28][29][30] were actively developed and studied, with short wavelength achievements [31,32]. In the path towards the control of FEL properties, linewidth narrowing has been performed with a Fabry-Perot etalon [33] and possible handling of the temporal structure was carried out [34][35][36][37][38][39].…”