Defect structure changes in the single Si-crystals after irradiation by high-energy electrons and long natural aging by high-resolution three-crystal x-ray diffractometry

Author(s):  
V. V. Dovganyuk ◽  
T. V. Lytvynchuk ◽  
V. V. Slobodyan ◽  
M. I. Fodchuk
1994 ◽  
Author(s):  
Salim Abdali ◽  
Finn E. Christensen ◽  
Herbert W. Schnopper ◽  
Thomas H. Markert ◽  
Daniel Dewey ◽  
...  

2021 ◽  
Author(s):  
Qiang Sun ◽  
Ya-Wei Liu ◽  
Yuan-Chen Xu ◽  
Li-Han Wang ◽  
Tian-Jun Li ◽  
...  

Abstract The oscillator strengths of the valence-shell excitations of C2H2 are extremely important for testing theoretical models and studying interstellar gases. In this study, the high-resolution inelastic x-ray scattering (IXS) method is adopted to determine the generalized oscillator strengths (GOSs) of the valence-shell excitations of C2H2 at a photon energy of 10 keV. The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths (OOSs). Through taking a completely different experimental method of the IXS, the present results offer the high energy limit for electron collision to satisfy the first Born approximation (FBA) and cross-check the previous experimental and theoretical results independently. The comparisons indicate that an electron collision energy of 1500 eV is not enough for C2H2 to satisfy the FBA for the large squared momentum transfer, and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.


1992 ◽  
Vol 63 (1) ◽  
pp. 615-618 ◽  
Author(s):  
Y. Nagata ◽  
H. Yamaji ◽  
K. Hayashi ◽  
K. Kawashima ◽  
K. Hyodo ◽  
...  

AIP Advances ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 105122
Author(s):  
Masato Hoshino ◽  
Kentaro Uesugi ◽  
Ryuji Shikaku ◽  
Naoto Yagi

2018 ◽  
Vol 924 ◽  
pp. 15-18
Author(s):  
Masashi Sonoda ◽  
Kentaro Shioura ◽  
Takahiro Nakano ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  

The defect structure at the growth front of 4H-SiC boules grown using the physical vapor transport (PVT) method has been investigated using high resolution x-ray diffraction and x-ray topography. The crystal parameters such as the c-lattice constant exhibited characteristic variations across the growth front, which appeared to be caused by variation in surface morphology of the as-grown surface of the boules rather than the defect structure underneath the surface. X-ray topography also revealed that basal plane dislocations are hardly nucleated at the growth front during PVT growth of 4H-SiC crystals.


1998 ◽  
Vol 188 ◽  
pp. 121-124 ◽  
Author(s):  
Toru Tanimori

In spite of the recent progress of high energy gamma-ray astronomy, there still remains quite unclear and important problem about the origin of cosmic rays. Supernova remnants (SNRs) are the favoured site for cosmic rays up to 1016 eV, as they satisfy the requirements such as an energy input rate. But direct supporting evidence is sparse. Recently intense non-thermal X-ray emission from the rims of the Type Ia SNR SN1006 (G327.6+14.6) has been observed by ASCA (Koyama et al. 1995)and ROSAT (Willingale et al. 1996), which is considered, by attributing the emission to synchrotron radiation, to be strong evidence of shock acceleration of high energy electrons up to ~100 TeV. If so, TeV gamma rays would also be expected from inverse Compton scattering (IC) of low energy photons (mostly attributable to the 2.7 K cosmic background photons) by these electrons. By assuming the magnetic field strength (B) in the emission region of the SNR, several theorists (Pohl 1996; Mastichiadis 1996; Mastichiadis & de Jager 1996; Yoshida & Yanagita 1997) calculated the expected spectra of TeV gamma rays using the observed radio/X-ray spectra. Observation of TeV gamma rays would thus provide not only the further direct evidence of the existence of very high energy electrons but also the another important information such as the strength of the magnetic field and diffusion coefficient of the shock acceleration. With this motivation, SN1006 was observed by the CANGAROO imaging air Cerenkov telescope in 1996 March and June, also 1997 March and April.


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