Absorption by XeCl* excimer molecules of their own emission of the В–Х transition (λ = 308 nm) in a dense Ar–Xe–CCl4 medium upon pumping by fast electrons and uranium-235 fission fragments

2016 ◽  
Vol 121 (2) ◽  
pp. 165-173 ◽  
Author(s):  
A. I. Mis’kevich ◽  
Yu. A. Dyuzhov ◽  
A. A. Suvorov
Author(s):  
Murray Vernon King ◽  
Donald F. Parsons

Effective application of the high-voltage electron microscope to a wide variety of biological studies has been restricted by the radiation sensitivity of biological systems. The problem of radiation damage has been recognized as a serious factor influencing the amount of information attainable from biological specimens in electron microscopy at conventional voltages around 100 kV. The problem proves to be even more severe at higher voltages around 1 MV. In this range, the problem is the relatively low sensitivity of the existing recording media, which entails inordinately long exposures that give rise to severe radiation damage. This low sensitivity arises from the small linear energy transfer for fast electrons. Few developable grains are created in the emulsion per electron, while most of the energy of the electrons is wasted in the film base.


Author(s):  
M. Libera ◽  
J.A. Ott ◽  
K. Siangchaew ◽  
L. Tsung

Channeling occurs when fast electrons follow atomic strings in a crystal where there is a minimum in the potential energy (1). Channeling has a strong effect on high-angle scattering. Deviations in atomic position along a channel due to structural defects or thermal vibrations increase the probability of scattering (2-5). Since there are no extended channels in an amorphous material the question arises: for a given material with constant thickness, will the high-angle scattering be higher from a crystal or a glass?Figure la shows a HAADF STEM image collected using a Philips CM20 FEG TEM/STEM with inner and outer collection angles of 35mrad and lOOmrad. The specimen (6) was a cross section of singlecrystal Si containing: amorphous Si (region A), defective Si containing many stacking faults (B), two coherent Ge layers (CI; C2), and a contamination layer (D). CBED patterns (fig. lb), PEELS spectra, and HAADF signals (fig. lc) were collected at 106K and 300K along the indicated line.


2019 ◽  
Vol 30 (7) ◽  
pp. 6688-6692
Author(s):  
V. I. Beletskiy ◽  
G. Ya. Khadzhai ◽  
R. V. Vovk ◽  
N. R. Vovk ◽  
A. V. Samoylov ◽  
...  

2020 ◽  
Vol 227 ◽  
pp. 02012
Author(s):  
R. S. Sidhu ◽  
R. J. Chen ◽  
Yu. A Litvinov ◽  
Y. H. Zhang ◽  

The re-analysis of experimental data on mass measurements of ura- nium fission products obtained at the ESR in 2002 is discussed. State-of-the-art data analysis procedures developed for such measurements are employed.


2021 ◽  
Vol 812 ◽  
pp. 136017
Author(s):  
C. Schmitt ◽  
P. Möller

Author(s):  
Hyungjin Kim

Abstract Primordial black holes are a viable dark matter candidate. They decay via Hawking evaporation. Energetic particles from the Hawking radiation interact with interstellar gas, depositing their energy as heat and ionization. For a sufficiently high Hawking temperature, fast electrons produced by black holes deposit a substantial fraction of energy as heat through the Coulomb interaction. Using the dwarf galaxy Leo T, we place an upper bound on the fraction of primordial black hole dark matter. For M < 5 × 10−17M⊙, our bound is competitive with or stronger than other bounds.


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