Ultrashort 1-kHz laser plasma hard x-ray source

Abstract

We achieved a continuous, stable, ultrashort pulse hard x-ray point source by focusing 1.8-W, 1-kHz, 50-fs laser pulses onto a novel, 30-microm -diameter, high-velocity, liquid-metal gallium jet. This target geometry avoids most of the debris problems of solid targets and provides nearly 4pi illumination. Photon fluxes of 5x10(8) photons/s are generated in a two-component spectrum consisting of a broad continuum from 4 to 14 keV and strong K(alpha) and K(beta) emission lines at 9.25 and 10.26 keV. This source will find wide use in time-resolved x-ray diffraction studies and other applications.

Fitting coupled potential energy surfaces for large systems: Method and construction of a 3-state representation for phenol photodissociation in the full 33 internal degrees of freedom using multireference configuration interaction determined data

“…[25][26][27][28][29][30][31] The strong electric field of the pulse extracts electrons from the metal surface by field ionization. The generated free electrons are subsequently accelerated for a half cycle of the driving field into the vacuum, a process called vacuum heating, 27 and in the next half cycle of opposite sign smashed back into the target.…”

Non-equilibrium dynamics of lipid bilayers

“…Among the most prominent techniques are higher harmonic generation [56,57], gas based laser plasma sources [58] and laser plasma sources using solid state targets [59,60,61,62,63], all being based on high intensity short pulse laser systems. As the outlined biophysical questions require spatial resolution in the sub-angstrom range we will focus on the latter one, producing femtosecond pulsed hard x-ray radiation.…”

“…Dierent approaches have been proposed in order to solve this issue, including wire based solutions [67,61] and the use of liquid metal jets [63,68]. In the case of the PXS a 20µm thin and 2cm wide copper tape is used.…”

Recent Progress in Ultrafast X‐ray Diffraction

“…While the first generation of X-ray plasma sources worked at a low repetition rate of 1 to 20 Hz, much more stable sources with kiloHertz repetition rates have been demonstrated recently, combining advanced Ti:sapphire laser systems with metal jet or tape targets. [30,34,36] A typical setup as it exists at the Max-Born Institute in Berlin [34] is shown in Figure 2 A. Pulses of 45 fs duration from a Ti:sapphire laser system are focused onto a copper tape target (thickness 20 mm) to generate Cu Ka emission (E = 8 keV) in forward direction. A polymer tape protects the focusing lens against debris emanating from the target.…”