Experimental demonstration of a single-spike hard-X-ray free-electron laser starting from noise

• Published in: Applied physics letters Vol. 111; no. 15
• Main Authors: Marinelli, A., MacArthur, J., Emma, P., Guetg, M., Field, C., Kharakh, D., Lutman, A. A., Ding, Y., Huang, Z.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 09-10-2017; American Institute of Physics (AIP)
• Subjects: Applied physics; Electron beams; Emittance; Laser beams; Lasers; PARTICLE ACCELERATORS; Pulse duration; Scaling laws
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4990716

In this letter, we report the experimental demonstration of single-spike hard-X-ray free-electron laser pulses starting from noise with multi-eV bandwidth. This is accomplished by shaping a low-charge electron beam with a slotted emittance spoiler and by adjusting the transport optics to optimize the beam-shaping accuracy. Based on elementary free-electron laser scaling laws, we estimate the pulse duration to be less than 1 fs full-width at half-maximum.