Determination of a Deuteron-Beryllium Neutron Source Spectrum by Multifoil Activation

1999 ◽  
Vol 36 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Fujio Maekawa ◽  
Ulrich von Möllendorff ◽  
Paul P. H. Wilson ◽  
Yujiro Ikeda
Keyword(s):  
Neutron Source ◽  
Source Spectrum

COMPUTATIONAL METHODS FOR ANALYZING AIRCRAFT NOISE ABOVE GROUND WITH GENERAL TOPOGRAPHY AND IMPEDANCE

2012 ◽  
Vol 20 (02) ◽  
pp. 1240001 ◽  
Author(s):  
ROMAN REITBORT ◽  
IDO GUR ◽  
DAN GIVOLI
Keyword(s):  
Computational Methods ◽  
Aircraft Noise ◽  
Impedance Boundary Condition ◽  
Source Spectrum ◽  
Impedance Boundary ◽  
Enriched Finite Element Method ◽  
Enriched Finite Element ◽  
Human Hearing ◽  
The Given

The need to analyze aircraft noise over ground with general properties occurs in various applications, most notably in environmental engineering, where the analysis of the sound pressure level (SPL) distribution near the ground due to aircraft noise is desired. Since the human hearing range is very wide, the determination of the SPL distribution for a given source spectrum is not trivial and may be regarded as a multiscale problem. One has to solve repeatedly, for many different wave numbers, the Helmholtz equation in the upper half space while imposing the given impedance boundary condition on the possibly non-flat ground. An efficient Helmholtz solver must therefore be incorporated in the scheme that finds the SPL distribution. Three totally different computational methods that may be used to solve this problem are considered here: A fictitious sources method, a parabolic approximation method and a wave-enriched finite element method (with two versions: PUM and GFEM). The three methods are compared in terms of their computational properties, and numerical examples are presented to demonstrate their performance.

A quick method for the determination of the Al/Si weight ratio in alumino-silicates using an Am-Be neutron source

2004 ◽  
Vol 262 (2) ◽  
pp. 501-504 ◽  
Author(s):  
S. A. Jonah ◽  
M. O. A. Oladipo ◽  
I. M. Umar ◽  
N. Rabiu ◽  
Y. U. Idris ◽  
...  
Keyword(s):  
Neutron Source ◽  
Weight Ratio ◽  
Quick Method

Determination of 4.438MeV γ-ray to neutron emission ratio from a 241Am–9Be neutron source

2004 ◽  
Vol 60 (6) ◽  
pp. 959-962 ◽  
Author(s):  
Ali Asghar Mowlavi ◽  
Rahim Koohi-Fayegh
Keyword(s):  
Neutron Source ◽  
Neutron Emission ◽  
Emission Ratio ◽  
Γ Ray
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