Relative energy deposition of electrons in a magnetic guide field

1982 ◽  
Vol 41 (5) ◽  
pp. 422-424 ◽  
Author(s):  
M. W. McGeoch
Keyword(s):  
Energy Deposition ◽  
Relative Energy ◽  
Guide Field

scholarly journals Some Considerations on the Energy Deposition During a RIA Transient Based On Monte Carlo Simulations

2021 ◽  
Vol 253 ◽  
pp. 04005
Author(s):  
Julia Bartos ◽  
Adrien Gruel ◽  
Claire Vaglio-Gaudard ◽  
Christine Coquelet-Pascal
Keyword(s):  
Monte Carlo ◽  
Energy Distribution ◽  
Energy Deposition ◽  
Relative Energy ◽  
Helium Pressure ◽  
Neutron Absorber ◽  
The Core ◽  
Test Loop ◽  
Transient Energy ◽  
The Impact

Specific research reactors are capable of reproducing reactivity injection accidents in order to study the behavior of the nuclear fuel pins in accidental situations. In the CABRI research reactor, the fuel pin to be examined (test pin) is placed in the center of the core in a dedicated test loop. It is then subjected to a power transient, obtained by the fast depressurization of the 3He neutron absorber gas from the transient rods located in the core. One of the central parameters of the experiment is the energy deposition in the test pin, which is currently not measured during a transient. Instead, it is assumed that the relative energy distribution between the core and the test pin is constant regardless the operational state of the reactor. Currently, this correlation is measured in steady state. As such, the impact of the variations in the neutron flux, fuel and moderator temperatures during the transient is assumed equivalent on the energy deposition in the core and in the test pin. The goal of this work is to improve our knowledge on the mechanisms involved in the transient energy deposition. The aim of this paper is to present a methodological approach for the energy deposition estimation during a CABRI transient, based on static Monte Carlo calculations. The results suggest that the transient energy deposition rate is mainly dependent on the helium pressure and the Doppler feedback, and the relative energy distribution between the core and test pin changes during the transient.

The Possibilities for Analytical Methods in Photoemission and Low-Energy Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 348-349
Author(s):  
Ernst Bauer
Keyword(s):  
Chemical Characterization ◽  
Emission Angle ◽  
Relative Energy ◽  
Objective Lens ◽  
Chemical Information ◽  
Magnetic Lens ◽  
Incident Intensity ◽  
X Ray ◽  
Leed Pattern ◽  
Image Position

One of the major shortcomings of conventional PEEM and of LEEM is the lack of chemical information about the surface. Although the imaging of the LEED pattern in the back focal plane of the objective lens of a LEEM instrument allows chemical characterization via the crystalline structure derived from the LEED pattern, this method fails in the absence of a characteristic LEED pattern. Direct information about the atomic composition of the surface is then needed which can be best obtained from inner shell electrons either directly by x-ray-induced photoemission (XPEEM) or by x-ray- or electron-induced Auger electron emission (AEEM). These modes of excitation and imaging can be combined with conventional PEEM and LEEM in one instrument which is presently being developed. Thus a complete structural and chemical characterization becomes possible in one instrument, with parallel detection and high resolution.In contrast to LEEM, in which up to more than 50% of the incident intensity is available for image formation, the intensity of the emitted electrons is much lower in XPEEM and AEEM and the signal is much lower than the background in AEEM. Therefore, intensity I and resolution d have to be optimized simultaneously which is best done by maximizing Q = I/d2 with respect to maximum emission angle α and relative energy distribution ε = ΔVo/V accepted by the instrument. For a well-designed magnetic lens section of the cathode lens its aberrations are determined by the accelerating field F in front of the specimen. For a homogeneous accelerating field F and a cosine emission distribution one obtains for the optimum α and ε values αo,εo a radius of the minimum disc of confusion of

Blunt-body wave drag reduction using focused energy deposition

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 460-467 ◽  
Author(s):  
David Riggins ◽  
H. F. Nelson ◽  
Eric Johnson
Keyword(s):  
Drag Reduction ◽  
Energy Deposition ◽  
Blunt Body ◽  
Body Wave ◽  
Wave Drag ◽  
Wave Drag Reduction
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