23.10.12 / 14:00

Science with Photons: Amplified spontaneous X-ray emission in atomic and molecular gases

Veranstalter:	Helmholtz-Zentrum Berlin, Institut Methoden und Instrumentierung der Synchrotronstrahlung
Ort:	Albert-Einstein-Straße 15, 12489 Berlin
Raum:	BESSY-Hörsaal
Referent:	Dr. Nina Rohringer, Max Planck Advanced Study Group, Center for Free-Electron Laser Science

X-ray free-electron lasers (XFELs) provide ultra-short x-ray pulses of unprecedented peak brightness, opening a pathway to transfer quantum electronics and quantum optical processes to the x-ray domain. We present results of the first experimental demonstration of an x-ray laser based on amplification of x-ray radiation on an atomic inner-shell transition in Neon [1]. The population inversion is achieved by rapid K-shell photo-ionization [2,3] or resonant excitation [4] with an XFEL pulse. Gain saturation of the K- a transition in Neon could be demonstrated in a recent experiment at the Linac Coherent Light Source.

In addition to experimental results, we present numerical solutions of the generalized Maxwell-Bloch equations. The emitted x-ray pulses have ultra short time durations, ranging from sub femtoseconds to a few femtoseconds and are nearly transform limited, despite pumping with a stochastic XFEL source of only limited temporal coherence. We will discuss the extension of the x-ray lasing scheme to amplified spontaneous emission and self-stimulated x-ray Raman scattering in diatomic molecules, thereby creating a tunable x-ray laser based on inner-shell transitions in molecules.