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Wilhelm F. Maier 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1990,102(8):965-966
135.
Summary A short introduction into the phenomenon of kinetic ioninduced secondary electron emission from solids is given. The basic
features of proton-induced secondary electron spectra from thin foils in forward-(beam-) direction are briefly discussed.
Summarium Post brevem introductionem in phaenomenon emissionis cineticae electroniorum secundariorum ioniis inductae e corporibus solidis structurae praevalentes spectrorum energiae electroniorum secundariorum ex foliis tenibus protoniis inductorum prorsus rectorum, id est in directionem radii, proponuntur.相似文献
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S. Hansen U. Holzwarth M. Tongbhoyai T. Wider K. Maier 《Applied Physics A: Materials Science & Processing》1997,65(1):47-52
+ -γ coincidence measurement, which has been applied to in-situ examinations of microstructural evolution processes during the
fatigue of copper single crystals, is described. Since no sandwich-type geometry is required, it is applicable to all specimen
geometries commonly used in materials testing and to the non-destructive testing of engineering parts in service. As a radioactive
source 72Se generates the positron-emitting 72As, which provides two positron spectra with maximum energies of 2.5 MeV and 3.3 MeV and a prompt γ quantum of 835 keV. The
positrons emitted in the direction towards the specimen pass through a fast plastic scintillator and produce a scintillation
signal, thereby losing about 150 keV of their energy. This signal serves as a start signal for the positron-lifetime measurement
and is measured in coincidence with the subsequent 511 keV annihilation quantum. After passage through the plastic scintillator
the remaining positron energy is still high enough to penetrate deep into the material and to allow for real bulk examinations.
The prompt γ quantum may serve as an on-line control of the stability of the electronic system which will be useful under
non-constant service conditions in a proposed field application.
Received: 8 January 1997/Accepted: 14 March 1997 相似文献
138.
M. K. Kabadiyski F. Cristancho C. J. Gross A. Jungclaus K. P. Lieb D. Rudolph H. Grawe J. Heese K. -H. Maier J. Eberth S. Skoda W. -T. Chou E. K. Warburton 《Zeitschrift für Physik A Hadrons and Nuclei》1992,343(2):165-177
The reaction58Ni(36Ar, 4p)90Mo has been studied at a beam energy of 149 MeV. A detector array consisting of the OSIRIS spectrometer (12 Compton-suppressed Ge detectors), four charged-particleδE detectors and seven NE-213 neutron detectors at the VICKSI accelerator in Berlin has been used to measure the gamma radiation inγγ- and particle-γγ-coincidence mode. An additional Ge detector was placed at 162? to the beam direction to provide information on DCO ratios. The level scheme of90Mo has been extended up to an excitation energy of about 12 MeV and probable spin 23?. Some 70 transitions and 40 levels have been newly identified. Spin assignments have been proposed on the basis of measured DCO ratios. Shell model calculations in a model space consisting of the proton 1f 5/2, 2p 3/2, 2p 1/2, and 1g 9/2 orbits and the neutron 2p 1/2, 1g 9/2, 1g 7/2, 2d 5/2, 2d 3/2, and 3s 1/2 orbits with some truncation were made for states above 9? and the predicted structure of these states is discussed. 相似文献
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