Chasing ghosts in reciprocal space—a novel inelastic neutron multiple scattering process

2004 ◽  
Vol 350 (1-3) ◽  
pp. 11-16 ◽  
Author(s):  
H.M. Rønnow ◽  
L.-P. Regnault ◽  
J.E. Lorenzo
Keyword(s):  
Multiple Scattering ◽  
Inelastic Neutron ◽  
Reciprocal Space ◽  
Scattering Process

scholarly journals The ‘momentum problem’ of Wolf-Rayet stars: can it be explained by the multiple scattering mechanism?

1995 ◽  
Vol 163 ◽  
pp. 170-171 ◽  
Author(s):  
U. Springmann ◽  
J. Puls
Keyword(s):  
Velocity Field ◽  
Multiple Scattering ◽  
Diffuse Radiation ◽  
Radial Dependence ◽  
Scattering Process ◽  
Scattering Mechanism ◽  
Radiative Acceleration

The possibility of driving the dense winds of Wolf-Rayet stars via multiple scattering of photons in resonance lines is examined. For the case of many overlapping lines it is found that the diffuse radiation arising from the multiple scattering process leads to a radiative acceleration grad even larger than the commonly used unattenuated flux models where each line is assumed to interact separately with the unattenuated photospheric flux. The radial dependence of grad in the outer parts of the wind is now weaker than r−2, which in turn leads to a steeper rise in the velocity field.

Spurious peaks arising from multiple scattering events involving the sample environment in inelastic neutron scattering

2014 ◽  
Vol 47 (4) ◽  
pp. 1472-1476 ◽  
Author(s):  
Lothar Pintschovius ◽  
Dmitry Reznik ◽  
Frank Weber ◽  
Philippe Bourges ◽  
D. Parshall ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Single Crystals ◽  
Multiple Scattering ◽  
High Intensity ◽  
Inelastic Neutron Scattering ◽  
Time Of Flight ◽  
Inelastic Neutron ◽  
Small Samples ◽  
Sample Environment ◽  
Scattering Events

Well defined peaks with energies of about 18 meV have been observed in a variety of inelastic neutron scattering experiments on both single crystals and powders, using either the triple-axis or the time-of-flight technique. They can easily be mistaken for signatures of real excitations. It has been found that they are due to multiple scattering events involving primarily the walls of the sample environment. Hence, they are particularly troublesome in experiments using very small samples, as have been used with recently developed high-intensity neutron spectrometers. Measures required to reduce the unwanted scattering to a minimum are also discussed.

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