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961.
Marowsky G. Schäfer E. P. Keto J. W. Tittel F. K. 《Applied Physics A: Materials Science & Processing》1976,9(2):143-146
Fluorescence studies on electron-beam excited mixtures of POPOP dye vapor and various buffer gases are reported. Xenon has
been found to be a promising candidate as a buffer gas for efficient energy deposition of the electron-beam and energy transfer
to the POPOP dye vapor. These experiments may be an important step towards realization of an electrically excited dye vapor
laser.
Work supported in part by the National Aeronautics and Space Administration and the Energy Research and Development Administration. 相似文献
962.
963.
964.
965.
Kurt Schütte 《Mathematische Annalen》1956,132(2):106-120
Ohne Zusammenfassung 相似文献
966.
W. Rüegsegger R. Meier F. K. Kneubühl H. J. Schötzau 《Applied physics. B, Lasers and optics》1985,37(3):115-135
Today, SF6 is used to a great extent as insulating and arc-quenching medium in high-voltage gas-blast circuit breakers. The arcing in SF6 during current interruption forms decomposition products. These can influence the arc-quenching properties of the circuit breaker. Furthermore, they can cause corrosion of the circuit breaker housing. In this comprehensive study we present results obtained for the first time from a direct mass spectrometric investigation of the exhaust gases of a high pressure SF6 arc in a model circuit breaker. Our mass spectrometric system consists of a time-of-flight mass spectrometer (TOFMS) equipped with a molecular beam sampling systems. This device allows us to measure mass spectra of high pressure sources with a time resolution of up to 10,000 spectra per second. We have determined the formation rate of the most abundant decomposition products in a SF6 arc at 1 bar. These products are SF4, CF4, WF6, SOF2, SO2, CS2 S2F2 and HF. The fast detection time inherent to our system permits also the determination of the formation of SF4, which is 0.45–0.50 Vol. %/(kJ/1SF6). In addition, we have studied the influence of water and oxygen impurities which are responsible for the production of highly corrosive HF. Finally, we have considered the influence of the thermal degradation of teflon (P.T.F.E.), which is used as nozzle and insulating material in circuit breakers. On this occasion we have demonstrated that CF4, which exhibits dielectric properties similar to SF6, is the main decomposition product formed from teflon. However, we have found that besides CF4 also excess carbon is formed, which is deposited on insulators of the model circuit breaker.Our time-resolved mass spectra reveal that the CF4 production from teflon is delayed by a few milliseconds with respect to the SF6 dissociation in the arc. This delay can influence the interrupting process of the circuit breaker by changing the plasma composition during the arcing period. Although our experiments have been performed on a model circuit breaker we claim that the results presented in this study can be applied to real circuit breakers, since the arc current density and the energy dissipated per liter SF6 are of the same order of magnitude in both devices. 相似文献
967.
The 230Th(α, α'2n)228Th reaction at Eα = 56 MeV was used to investigate states of moderately high spin in 228Th. Conversion electron and e?-γ coincidence measurements were carried out, where the electrons were detected with an iron-free orange spectrometer. The ground state and low-lying Kπ = 0? rotational bands were observed up to Iπ = 14+ and 13?, respectively. The data are interpreted in terms of an ω-expansion for the ground-state rotational band, and an octupole vibrational band distorted by the Coriolis coupling to the Kπ ? 1? excitations for the Kπ = 0? band. 相似文献
968.
969.
Eva Schürerová 《Czechoslovak Journal of Physics》1960,10(9):689-690
970.
Schüler P. Hardt K. Günther C. Freitag K. Herzog P. Niederwestberg H. Reif H. Shera E. B. Hoehn M. V. 《Zeitschrift für Physik A Hadrons and Nuclei》1983,312(4):305-313
Zeitschrift für Physik A Hadrons and nuclei - The decay of201Tl to201Hg has been investigated withγ- and conversion electron spectroscopic methods. The 26 keV level in201Hg, proposed... 相似文献