Search results for "Extreme ultraviolet"
showing 7 items of 47 documents
Laser driven parametric amplification in the xuv and soft-x-ray spectral range
2011
We present the first experimental realization of a new x-ray laser scheme based on strong-field parametric amplification of high-order harmonic radiation. With a simple semi-classical model, we can identify the most important experimental parameters, the spectral range and the small signal gain in gases. Using a single amplifier stage a small signal gain of 8000 has been obtained in Argon for the spectral range of 40-50 eV, using 350 fs, 7 mJ pulses at 1.05 µm. In Helium, we observed a small signal gain of 280 around 300 eV using 6 fs, 1.5 mJ pulses at 800 nm.
Two-color ionization of hydrogen by short intense pulses
2010
Photoelectron energy spectra resulting by the interaction of hydrogen with two short pulses having carrier frequencies, respectively, in the range of the infrared and XUV regions have been calculated. The effects of the pulse duration and timing of the X-ray pulse on the photoelectron energy spectra are discussed. Analysis of the spectra obtained for very long pulses show that certain features may be explained in terms of quantum interferences in the time domain. It is found that, depending on the duration of the X-ray pulse, ripples in the energy spectra separated by the infrared photon energy may appear. Moreover, the temporal shape of the low frequency radiation field may be inferred by …
Tuning the high-order harmonic lines of a Nd:Glass laser for soft x-ray laser seeding
2010
Taking advantage of the non-adiabatic blue-shift of high-order harmonics generated by a fixed frequency Nd:Glass laser system, we are able to report more than 50 % coverage of the XUV spectral range between 18 nm and 35 nm. The generated harmonic lines are capable of seeding Ni-like Y, Zr and Mo soft x-ray lasers and others.
Stable and long-time operation of a soft x-ray laser for user applications experiments
2011
LASERIX is a high-power laser facility leading to High-repetition-rate XUV laser pumped by Titanium:Sapphire laser. The aim of this laser facility is to offer Soft XRLs in the 30-7 nm range and auxiliary IR beam that could also be used to produce synchronized XUV sources. This experimental configuration highly enhances the scientific opportunities of the facility, giving thus the opportunity to realize both X-ray laser experiments and more generally pump/probe experiments, mixing IR and XUV sources. In this contribution, the main results concerning both the development of XUV sources(X-Ray lasers and HHG sources) and their use for applications are presented.
Post-flare Ultraviolet Light Curves Explained with Thermal Instability of Loop Plasma
2012
In the present work, we study the C8 flare that occurred on 2000 September 26 at 19:49 UT and observed by the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation spectrometer from the beginning of the impulsive phase to well beyond the disappearance in the X-rays. The emission first decayed progressively through equilibrium states until the plasma reached 2-3 MK. Then, a series of cooler lines, i.e., Ca X, Ca VII, Ne VI, O IV, and Si III (formed in the temperature range log T = 4.3-6.3 under equilibrium conditions), are emitted at the same time and all evolve in a similar way. Here, we show that the simultaneous emission of lines with such a different forma…
Modelling the effect of nuclear motion on the attosecond time-resolved photoelectron spectra of ethylene
2014
arXiv:1403.5408
Realization of time-resolved two-vacuum-ultraviolet-photon ionization
2009
International audience; Ultrafast dynamics of excited molecules is studied through time-resolved two-vacuum-ultraviolet (vuv)- photon ionization using a nonlinear volume autocorrelator unit. The two-vuv-photon process is induced by the intense fifth harmonic radiation of a femtosecond Ti:sapphire laser. In a proof-of-principle experiment, ultrafast dynamics of excited ethylene and oxygen molecules are investigated. Molecular decay times are deduced by comparing the experimental data with the results of a numerical model that accounts for the spatial and temporal characteristics of the harmonic field. The present experiments pave a convenient way for time domain investigations in the vuv-xuv s…