First lasing of the IR upgrade FEL at Jefferson lab

✍ Scribed by C Behre; S Benson; G Biallas; J Boyce; C Curtis; D Douglas; H.F Dylla; L Dillon-Townes; R Evans; A Grippo; J Gubeli; D Hardy; J Heckman; C Hernandez-Garcia; T Hiatt; K Jordan; L Merminga; G Neil; J Preble; H Rutt; M Shinn; T Siggins; H Toyokawa; D.W Waldman; R Walker; N Wilson; B Yunn; S Zhang

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 229 KB
• Volume: 528
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2004.04.010

✦ Synopsis

We report initial lasing results from the IR Upgrade FEL at Jefferson Lab (Proceedings: 2001 Particle Accelerator Conference, IEEE, Piscataway, NJ, 2001). The electron accelerator was operated with low average current beam at 80 MeV. The time structure of the beam was 120 pC bunches at 4.678 MHz with up to 750 ms pulses at 2 Hz. Lasing was established over the entire wavelength range of the mirrors (5.5-6.6 mm). The detuning curve length, turn-on time, and power were in agreement with modeling results assuming a 1 ps FWHM micropulse. The same model predicts over 10 kW of power output with 10 mA of beam and 10% output coupling, which is the ultimate design goal of the IR Upgrade FEL. The behavior of the laser while the dispersion section strength was varied was found to qualitatively match predictions. Initial CW lasing results also will be presented.