Electron accelerator modifications for precise atomic displacement threshold energy determinations

1968 ◽  
Vol 63 (2) ◽  
pp. 195-200 ◽  
Author(s):  
F.J. Bryant ◽  
A.F.J. Cox ◽  
R. Kirbitson
Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 46
Author(s):  
Yuhang Tan ◽  
Tao Yang ◽  
Kai Liu ◽  
Congcong Wang ◽  
Xiyuan Zhang ◽  
...  

To meet the high radiation challenge for detectors in future high-energy physics, a novel 3D 4H-SiC detector was investigated. Three-dimensional 4H-SiC detectors could potentially operate in a harsh radiation and room-temperature environment because of its high thermal conductivity and high atomic displacement threshold energy. Its 3D structure, which decouples the thickness and the distance between electrodes, further improves the timing performance and the radiation hardness of the detector. We developed a simulation software—RASER (RAdiation SEmiconductoR)—to simulate the time resolution of planar and 3D 4H-SiC detectors with different parameters and structures, and the reliability of the software was verified by comparing the simulated and measured time-resolution results of the same detector. The rough time resolution of the 3D 4H-SiC detector was estimated, and the simulation parameters could be used as guideline to 3D 4H-SiC detector design and optimization.


A theory for the production of atomic displacements in binary solids by mono-energetic electrons has been developed to yield an expression which may be numerically integrated to give the number of atomic displacements produced at a particular incident electron energy. The theory is applicable to thick samples and for incident electron energies up to the secondary displacement threshold. The variation with incident electron energy of the computed numbers of displaced primary atoms for various displacement threshold energies has been correlated with experimentally induced and determined point defect concentrations and used to give a precise value of the threshold energy for a primary atomic displacement. The atomic displacements were produced by the use of mono-energetic electrons from a 100 to 400 keV Van de Graaff accelerator. The production of point defects was observed experimentally and evaluated quantitatively by photoluminescence or cathodoluminescence techniques. Displacement of tellurium in cadmium telluride was monitored using corresponding changes in the photoluminescence intensity of the 1.13 μ m emission band. No radiation annealing was observed to take place at the electron doses used and a displacement threshold energy of 7.9 ± 0.1 eV was determined for tellurium. Displacement of sulphur in cadmium sulphide was monitored using the changes in the cathodoluminescence intensity of the 1.02 μ m emission band. In this case radiation annealing occurred to such an extent that a phenomenological theory, described here, had to be developed to correct for it. A sulphur displacement threshold energy of 9.6 ± 0.1 eV was determined. In conclusion, it should be stated that direct techniques such as photoluminescence or cathodoluminescence may be used to investigate quantitatively the production of atomic displacements in binary solids and to give a precise determination for displacement threshold energies.


1978 ◽  
Vol 68 (1) ◽  
pp. 95-97 ◽  
Author(s):  
P. Vajda ◽  
F. Maury ◽  
A. Lucasson ◽  
P. Lucasson

Author(s):  
K. Izui ◽  
S. Furuno ◽  
H. Otsu ◽  
T. Nishida ◽  
H. Maeta

Anisotropy of damage productions in crystals due to high energy electron bombardment are caused from two different origins. One is an anisotropic displacement threshold energy, and the other is an anisotropic distribution of electron flux near the atomic rows in crystals due to the electron channeling effect. By the n-beam dynamical calculations for germanium and molybdenum we have shown that electron flux at the atomic positions are from ∽4 to ∽7 times larger than the mean incident flux for the principal zone axis directions of incident 1 MeV electron beams, and concluded that such a locally increased electron flux results in an enhanced damage production. The present paper reports the experimental evidence for the enhanced damage production due to the locally increased electron flux and also the results of measurements of the displacement threshold energies for the <100>,<110> and <111> directions in molybdenum crystals by using a high voltage electron microscope.


1986 ◽  
Vol 135 (2) ◽  
pp. K113-K117
Author(s):  
V. V. Kirsanov ◽  
E. M. Kislitsina

1992 ◽  
Vol 60 (12) ◽  
pp. 1450-1452 ◽  
Author(s):  
J. Koike ◽  
D. M. Parkin ◽  
T. E. Mitchell

The cathodoluminescence emission spectrum of Yb 3+ in zinc selenide has been observed following ion implantation. The complexity of the resulting spectrum has been interpreted in terms of several distinct trigonally distorted lattice sites. The crystal field parameters obtained in this way indicate an appreciable degree of covalency between the rare-earth ions and the lattice. It has been found that all Yb 3+ spectra in zinc selenide are damagesensitive and the resulting effects can be interpreted on the assumption that the excitation mechanism is indirect, resonance transfer between like rare-earth ions is occurring and the concentration of centres is being changed. In turn, these concentration changes are used to determine a threshold energy of 8.0 eV (≡ 199 keV for the incident electron energy) for zinc displacement and an activation energy for thermal annealing of 0.14 + 0.01 eV, tentatively assigned to zinc interstitial motion.


1986 ◽  
Vol 34 (4) ◽  
pp. 2470-2474 ◽  
Author(s):  
B. Massarani ◽  
J. C. Bourgoin

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