Nanoplasmonic electron acceleration in silver clusters studied by angular-resolved electron spectroscopy

The nanoplasmonic field enhancement effects in the energetic electron emission from few-nm-sized silver clusters exposed to intense femtosecond dual pulses are investigated by high-resolution double differential electron spectroscopy. For moderate laser intensities of 10 14Wcm -2, the delaydependent and angular-resolved electron spectra show laser-aligned emission of electrons up to keV kinetic energies, exceeding the ponderomotive potential by two orders of magnitude. The importance of the nanoplasmonic field enhancement due to resonant Mie-plasmon excitation observed for optimal pulse delays is investigated by a direct comparison with molecular dynamics results. The excellent agreement of the key signatures in the delay-dependent and angular-resolved spectra with simulation results allows for a quantitative analysis of the laser and plasmonic contributions to the acceleration process. The extracted field enhancement at resonance verifies the dominance of surfaceplasmon-assisted re-scattering

Volatile constituents of the leaf, stem, rhizome, root and flower oils of Curcuma harmandii Gagnep. from Vietnam

The volatile oils from Curcuma harmandii Gagnep. (Zingiberaceae), obtained by steam distillation of the fresh leaves, stems, small and large rhizomes, roots and flowers, were examined by high resolution GC and GC/MS. All oils contained substantial fractions of sesquiterpenes and oxygenated terpenes. The major components of the leaf and stem oils were 1,S-cineole (13.5% and 21.S%), germacrone (11.5% and 15.5%) and curdione (36.S% and 25.3%). The oils from the small and large rhizomes also contained ItS-cineole (12.5% and 4.5%) and germacrone (9.0% and 20.5%) as main constituents, in addition to l3-pinene (22.6% and 1.2%), l3-elemene (11.3% and 6.5%) and isocurcumenol (3.7% and 13.4%). The root oil was rich in germacrone (24.4%), isocurcumenol (12.9010) and curcumenoi (lO.S%). The major constituents of the flower oil were curdione (27.0%) and an unidentified oxygenated sesquiterpene with a molecular mass of 234 Da (12.3%). This particular oil consisted for more than 90% of sesquiterpenes and oxygenated components, which contribute to the special odor of the flower oil

A study of the global chirp dependence on the interaction of intense colored double pulses with clusters

The yields of highly charged atomic ions produced in the exposure of xenon clusters embedded in helium nanodroplets by intense colored double pulses show a notable sensitivity on the order of the subpulses. The only slight difference in their spectral composition leads to a flipping of the optimal laser parameters for effective multielectron ionization above certain charge states, which appears to be quite robust with respect to the chosen pulse fluence and reflects an avalanche-like developing cluster ionization scenario

Soft X-ray scattering using FEL radiation for probing near-solid density plasmas at few electron volt temperatures

We report on soft X-ray scattering experiments on cryogenic hydrogen and simple metal samples. As a source of intense, ultrashort soft X-ray pulses we have used free-electron laser radiation at 92 eV photon energy from FLASH at DESY, Hamburg. X-ray pulses with energies up to 150 μJ and durations 15-50 fs provide interaction with the sample leading simultaneously to plasma formation and scattering. Experiments exploiting both of these interactions have been carried out, using the same experimental setup. Firstly, recording of soft X-ray inelastic scattering from near-solid density hydrogen plasmas at few electron volt temperatures confirms the feasibility of this diagnostics technique. Secondly, the soft X-ray excitation of few electron volt solid-density plasmas in bulk metal samples could be studied by recording soft X-ray line and continuum emission integrated over emission times from fs to ns. © 2009 Elsevier B.V

Thomson scattering from near-solid density plasmas using soft X-ray free electron lasers

We discuss a collective Thomson scattering experiment at the VUV free electron laser facility at DESY (FLASH) to diagnose warm dense matter at near-solid density. The plasma region of interest marks the transition from an ideal plasma to a correlated and degenerate many-particle system and is of current interest, e.g., in ICF experiments or laboratory astrophysics. Plasma diagnosis of such plasmas is a longstanding issue which is addressed here using a pump-probe scattering experiment to reveal the collective electron plasma mode (plasmon) using the high-brilliance radiation to probe the plasma. Distinctive scattering features allow one to infer basic plasma properties. For plasmas in thermal equilibrium the electron density and temperature are determined from scattering off the plasmon mode. © 2007 Elsevier B.V. All rights reserved