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1.
Sebban S Mocek T Ros D Upcraft L Balcou P Haroutunian R Grillon G Rus B Klisnick A Carillon A Jamelot G Valentin C Rousse A Rousseau JP Notebaert L Pittman M Hulin D 《Physical review letters》2002,89(25):253901
We report the first experimental demonstration of a Ni-like optical-field ionization collisional soft x-ray laser. The amplifying medium is generated by focusing a circularly polarized 760 mJ, 30 fs, 10-Hz Ti:sapphire laser beam in a few mm cell filled with krypton. We have measured a gain coefficient of 78 cm(-1) on the 3d(9)4d 1S0-3d(9)4p(1)P1 transition at 32.8 nm, which is here amplified for the first time. This radiation source represents the shortest wavelength optical-field ionization collisional soft x-ray laser ever produced. The influence of the gas pressure and the pumping energy on the lasing output are also presented. 相似文献
2.
Jamelot G. Jaegle P. Carillon A. Gadi F. Gauthe B. Guennou H. Klisnick A. Moller C. Sureau A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1988,16(5):497-504
The X-ray laser program at Palaiseau is based on the recombination scheme in lithiumlike ions, which requires a moderate pump power and seems to be promising for the purpose of scaling to shorter wavelengths. In aluminum plasmas, peak gain values of 2-2.5 cm-1 have been obtained at a wavelength of 105.7 Å corresponding to the 3d -5f transition, 6 ns after the top of a 2 ns laser pulse. The same transition in sulfur is emitted at 65.2 Å and has shown a gain of 1 cm-1 in a preliminary time-integrated experiment. Simulations using a collisional-radiative model as the postprocessor of a hydrodynamic numerical code predict amplifications for the 3d -4f , 3d -5f , and 4d -5f transitions. A new experiment, in progress at the present time, has been designed to enhance the gain-length product up to 10-15 at 105.7 Å. The recently extended facilities of the LULI make it possible to produce a 6-cm-long plasma column, keeping the flux density at the same level as in the previous experiments 相似文献
3.
H. Tang O. Guilbaud G. Jamelot D. Ros A. Klisnick D. Joyeux D. Phalippou M. Kado M. Nishikino M. Kishimoto K. Sukegawa M. Ishino K. Nagashima H. Daido 《Applied physics. B, Lasers and optics》2004,78(7-8):975-977
X-ray interference microscopy diagnostics of a nanosecond-pulse pumped Al (Z=13) plasma are presented. A transient picosecond Ni-like Ag X-ray laser (13.9 nm) is used as the probe beam and a wavefront division bi-mirror interferometer is adopted as the diagnosis tool. From the fringe shifts, the two-dimensional plasma density profile at 1 ns after the peak of the heating pulse is deduced. Opposite fringe shifts during the plasma development are observed and possible explanations for this behavior are discussed. This study will contribute to the validation of 1D and 2D hydrodynamic codes as well as to the better understanding of the physics during the development of laser produced plasmas. PACS 41.50.+h; 41.85.Ew; 42.55.Vc 相似文献
4.
Cassou K Kazamias S Ros D Plé F Jamelot G Klisnick A Lundh O Lindau F Persson A Wahlström CG de Rossi S Joyeux D Zielbauer B Ursescu D Kühl T 《Optics letters》2007,32(2):139-141
We report the near-field imaging characterization of a 10 Hz Ni-like 18.9 nm molybdenum soft-x-ray laser pumped in a grazing incidence pumping (GRIP) geometry with a table-top laser driver. We investigate the effect of varying the GRIP angle on the spatial behavior of the soft-x-ray laser source. After multiparameter optimization, we were able to find conditions to generate routinely a high-repetition-rate soft-x-ray laser with an energy level of up to 3 microJ/pulse and to 6x10(17) photons/s/mm2/mrad2/(0.1% bandwidth) average brightness and 1x10(28) photons/s/mm2/mrad2/(0.1% bandwidth) peak brightness. 相似文献
5.
We have successfully developed a high-energy, high-repetition rate Ti:sapphire laser system that delivers 33 J before compression at 0.1 Hz. The final booster amplifier is based on a 100 mm diameter Ti:sapphire crystal pumped with 72 J of energy in six beams delivered by three frequency-doubled high-repetition rate Nd:glass lasers. This system is, to the best of our knowledge, the first demonstrated petawatt class laser system running at a high repetition rate. 相似文献
6.
P. Jaeglé A. Carillon B. Gauthé P. Goedtkindt H. Guennou G. Jamelot A. Klisnick C. Möller B. Rus A. Sureau P. Zeitoun 《Applied physics. B, Lasers and optics》1993,57(5):313-318
In this paper we present the recent results obtained on X-ray lasers with the new facility of LULI (Palaiseau, France). As regards the study of collisional-excitation pumping we show that the J=0–1 line of neon-like zinc, at 212 Å, exhibits a surprisingly large gain coefficient of 4.9 cm–1. A detailed comparison of the time-dependent intensities of the J=0–1 and the J=2–1 line at 267 Å leads to the conclusion that these two lines are not emitted in the same region of the plasma. On the other hand we performed a theoretical and experimental study of 5g-4f lasing line of lithium-like sulphur at 206.5 Å. For the first time, in the case of plasma recombination pumping, we did not observe any reduction of the gain coefficient when the plasma length is raised from 1 cm to 2 cm. From numerical simulation this is likely due to radiation trapping and similar processes having much less influence on 5g-4f population inversion than on previously observed lithium-like lasing transitions. These results show that large gain-length values should be obtained with 0.5 kJ driving laser pulses. 相似文献
7.
Erell Jamelot 《Comptes Rendus Mathematique》2004,339(11):809-814
An original approach of the singular complement method for Maxwell's equations in bounded polygonal domains is presented. A splitting of the electric field à la Moussaoui is proposed: , where , λ depends on the data and domain and is known explicitly. The same splitting can be used for the magnetic field. No cut-off function is needed and improved error estimates are derived. To cite this article: E. Jamelot, C. R. Acad. Sci. Paris, Ser. I 339 (2004). 相似文献
8.
T. Mocek S. Sebban I. Bettaibi L.M. Upcraft P. Balcou P. Breger P. Zeitoun S. Le Pape D. Ros A. Klisnick A. Carillon G. Jamelot B. Rus J.F. Wyart 《Applied physics. B, Lasers and optics》2004,78(7-8):939-944
We give an overview of recent experimental results on optical-field-ionization collisional soft X-ray lasers developed at LOA. By focusing a 30-fs, circularly polarized Ti-sapphire laser pulse at an intensity of up to 8×1017 Wcm-2 into a low-density gas cell containing Xe or Kr, we produced a few mm long plasma column for soft X-ray amplifier. Saturated amplification has been achieved on the 4d95d(1S0)–4d95p(1P1) transition at 41.8 nm in Xe8+, and on the 3d94d(1S0)–3d94p(1P1) transition in Kr8+ at 32.8 nm. Under optimum pumping conditions the Xe8+ laser provides about (5±2)×109 photons per pulse whilst the Kr8+ laser delivers up to (2.5±1)×109 photons per shot. The repetition rate of these soft X-ray lasers is 10 Hz. The beam wavefront of the Xe8+ laser has been measured by a Shack–Hartmann soft X-ray wavefront sensor, and the pulse duration by a cross-correlation technique. PACS 42.55.Vc; 32.30.Rj; 52.50.Jm 相似文献
9.
O. Guilbaud A. Klisnick D. Joyeux D. Benredjem K. Cassou S. Kazamias D. Ros D. Phalippou G. Jamelot C. Möller 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(1):125-132
The spectral width of a Ni-like silver transient soft X-ray laser (4d-4p λ= 13.9 nm) was experimentally inferred from the
measurement of its temporal coherence, performed with a novel wavefront division interferometer. The measured coherence time
of 3 ps corresponds to a spectral linewidth of 0.7 m? which is narrow. We compare this experimental result to numerical simulations
of the amplified line profile, performed along two different approaches. Both calculations predict a spectral linewidth that
is about 3 times larger than the experimental value. We discuss several effects that might explain this discrepancy. We show
that, due to the short duration of the X-ray laser pulse, the assumption of a stationary electromagnetic field used in both
the experimental analysis and in the calculations need to be reconsidered. 相似文献
10.
G. Jamelot A. Carillon A. Klisnick P. Jaeglé 《Applied physics. B, Lasers and optics》1990,50(4):239-246
Recombination in lithium-like ions in a fast cooling plasma is an alternative attractive approach to the X-ray laser because, at a given lasing wavelength, it requires the lowest pumping energy of the main pumping schemes. In this paper we give a status report on recent experiments concerning the Li-like X-ray laser, and we discuss the problem of lengthening of the active medium necessary to obtain a true X-ray laser. 相似文献