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排序方式: 共有9766条查询结果,搜索用时 15 毫秒
991.
Klaus D. A. Wendt Klaus Blaum Christopher Geppert Peter Müller Wilfried Nörtershäuser Annette Schmitt Philipp Schumann Norbert Trautmann Bruce A. Bushaw 《Hyperfine Interactions》2005,162(1-4):147-157
A variety of research activities in the field of fundamental and applied nuclear physics has evolved in the last years using
resonantly tuned radiation from powerful lasers. The technique of resonance ionization spectroscopy has delivered outstanding
results and found broad acceptance in the last years as a particularly efficient and highly selective method for rare and
exotic radioisotope studies. It is used for production, spectroscopy and detection of these species and provides complete
isobaric, high isotopic and even some isomeric selection, which altogether is needed for on-line investigation of short lived
species far off stability as well as for ultra trace determination. Good overall efficiency pushes the experimental limits
of detection in elemental trace analysis down to below 106 atoms per sample, and additionally isotopic selectivity as high as 3 × 1012 has been demonstrated. The widespread potential of resonance ionization techniques is discussed, focusing on the experimental
arrangements for applications in selective on-line isotope production, spectroscopy of rare radioisotopes and ultra trace
determination of radiotoxic isotopes like 238Pu to 244Pu, 135,137Cs, 89,90Sr or 41Ca in environmental, technical and biomedical samples. 相似文献
992.
Klaus Metsch 《Journal of Geometry》2003,76(1-2):216-232
993.
994.
I.D. Jung F.X. Kärtner J. Henkmann G. Zhang U. Keller 《Applied physics. B, Lasers and optics》1997,65(2):307-310
Received: 20 June 1997 相似文献
995.
S.V. Marchese E. Innerhofer R. Paschotta S. Kurimura K. Kitamura G. Arisholm U. Keller 《Applied physics. B, Lasers and optics》2005,81(8):1049-1052
We demonstrate room temperature femtosecond optical parametric generation with high average output power in periodically poled
MgO-doped stoichiometric LiTaO3. Direct pumping with 725-fs pulses from a passively mode-locked thin disk laser at 1030 nm resulted in stable 1.5 W average
signal power at 1484 nm at the full laser repetition rate of 59 MHz. With this demonstration we achieved a significant simplification
of our recently presented red-green-blue laser source because no temperature stabilization of any nonlinear crystal is required.
PACS 42.65.Yj; 42.70.Mp; 42.79.Nv 相似文献
996.
997.
998.
999.
3 is reported. Using an external cavity diode laser, tunable from 795 to 825 nm, and a cw diode-pumped Nd:YAG ring laser at
1064 nm, we produced narrowband mid-ir laser light between 3.16 and 3.67 μm. This broad tuning range of 440 cm-1 can be critically phase-matched by changing the external crystal angle within a range of only 0.4°. Even for a fixed crystal
angle broadband phase-matching over 230 cm-1 was achieved. No realignment was required when tuning the laser over the whole wavelength range, which enabled the use of
a compact 36-m multipass cell as gas chamber. The conversion efficiency could be improved by almost a factor of 3 by applying
noncollinear instead of collinear phase-matching, resulting in 30 nW of idler power with good beam quality. Spectra of methane
were recorded in laboratory air, which demonstrate the rapid and continuous broad tunability at high sensitivity, enabling
sub-ppm detection. Finally, wavelength modulation spectroscopy at high resolution was applied as a promising tool for further
inproving the performance of this laser spectrometer.
Received: 16 March 1998/Revised version: 1 July 1998 相似文献
1000.