Performance of a first generation X-band photoelectron rf gun

Autor: C. Limborg-Deprey, C. Adolphsen, D. McCormick, M. Dunning, K. Jobe, H. Li, T. Raubenheimer, A. Vrielink, T. Vecchione, F. Wang, S. Weathersby
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Physical Review Accelerators and Beams, Vol 19, Iss 5, p 053401 (2016)
Druh dokumentu: article
ISSN: 2469-9888
DOI: 10.1103/PhysRevAccelBeams.19.053401
Popis: Building more compact accelerators to deliver high brightness electron beams for the generation of high flux, highly coherent radiation is a priority for the photon science community. A relatively straightforward reduction in footprint can be achieved by using high-gradient X-band (11.4 GHz) rf technology. To this end, an X-band injector consisting of a 5.5 cell rf gun and a 1-m long linac has been commissioned at SLAC. It delivers an 85 MeV electron beam with peak brightness somewhat better than that achieved in S-band photoinjectors, such as the one developed for the Linac Coherent Light Source (LCLS). The X-band rf gun operates with up to a 200 MV/m peak field on the cathode, and has been used to produce bunches of a few pC to 1.2 nC in charge. Notably, bunch lengths as short as 120 fs rms have been measured for charges of 5 pC (∼3×10^{7} electrons), and normalized transverse emittances as small as 0.22 mm-mrad have been measured for this same charge level. Bunch lengths as short as 400 (250) fs rms have been achieved for electron bunches of 100 (20) pC with transverse normalized emittances of 0.7 (0.35) mm-mrad. We report on the performance and the lessons learned from the operation and optimization of this first generation X-band gun.
Databáze: Directory of Open Access Journals