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McStas: Tunneling_sample

[ Identification | Description | Input parameters | Links ]

The Tunneling_sample Component

A Double-cylinder shaped all-incoherent scatterer with elastic, quasielastic (Lorentzian), and tunneling (sharp) components.

Identification

  • Site:
  • Author: Kim Lefmann
  • Origin: Risoe
  • Date: 10.05.07

Description

A Double-cylinder shaped all-incoherent scatterer
with both elastic, quasielastic (Lorentzian), and tunneling (sharp)
components. No multiple scattering. Absorbtion included.
The shape of the sample may be a box with dimensions xwidth, yheight, zdepth.
The area to scatter to is a disk of radius 'focus_r' situated at the target.
This target area may also be rectangular if specified focus_xw and focus_yh
or focus_aw and focus_ah, respectively in meters and degrees.
The target itself is either situated according to given coordinates (x,y,z),
or defined with the relative target_index of the component to focus
to (next is +1).
This target position will be set to its AT position. When targeting to
centered components, such as spheres or cylinders, define an Arm component
where to focus to.

The outgoing polarization is calculated as for nuclear spin incoherence:
P' = 1/3*P-2/3P = -1/3P
As above multiple scattering is ignored .

Example: Tunneling_sample(thickness=0.001,radius=0.01,yheight=0.02,focus_r=0.035,
target_index=1)

Input parameters

Parameters in boldface are required; the others are optional.
NameUnitDescriptionDefault
thicknessmThickness of cylindrical sample in (x,z) plane0
radiusmOuter radius of sample in (x,z) plane0.01
focus_rmRadius of disk containing target. Use 0 for full space0
p_interact1
f_QE0
f_tun0
gamma0
E_tun0
target_x0
target_y0
target_z0.235
focus_xw0
focus_yh0
focus_aw0
focus_ah0
xwidth0
yheightmvert. dimension of sample, as a height0.05
zdepth0
sigma_abs5.08
sigma_inc4.935
Vc13.827
target_index1relative index of component to focus at, e.g. next is +10
AT ( , , ) RELATIVE
ROTATED ( , , ) RELATIVE

Links


[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43


Last Modified: Tuesday, 16-Apr-2024 20:05:22 CEST
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