[ Identification | Description | Input parameters | Output parameters | Links ]
Collimator_radial
ComponentRadial Soller collimator with rectangular opening and specified length. The collimator is made of many rectangular channels stacked radially. Each channel is a set of transmitting layers, separated by an absorbing material, the whole stuff is inside an absorbing housing. The component should be positioned at the radius center. When specifying the divergence parameter, the transmission function is an average (triangular approximation) and does not utilize knowledge of the actual neutron trajectory. On the other hand, when specifying the number of blades, model is exact, but statistics is lowered by a factor 2. A zero divergence disables collimation (then the component works as a double slit). If the input/output (w1, w2) width are 0, then a perfect collimator is assumed (no slit check except for the total angular range and height). The component can be made oscillating (usual on diffractometers and TOF machines) with the 'roc' parameter. The neutron beam outside the collimator area is transmitted unaffected. Example: Contains shadow parts due to radial geometry Collimator_radial(w1=0.015, h1=.3, w2=0.015, h2=.3, len=.35, divergence=40,transmission=1, theta_min=5, theta_max=165, nchan=128, radius=0.9) Ideal: Collimator_radial(w1=0, h1=.3, w2=0, h2=.3, len=.35, divergence=40,transmission=1, theta_min=5, theta_max=165, radius=0.9)
Name | Unit | Description | Default |
---|---|---|---|
w1 | m | Input window width | 0.015 |
h1 | m | Input window height | .3 |
w2 | m | Output window width | 0.015 |
h2 | m | Output window height | .3 |
len | m | Length/Distance between slits | .35 |
divergence | min of arc | Divergence angle. May also be specified with the nblades parameter | 40 |
transmission | 1 | Transmission of Soller (0<=t<=1) | 1 |
theta_min | deg | Minimum Theta angle for the radial setting | 5 |
theta_max | deg | Maximum Theta angle for the radial setting | 165 |
nchan | 1 | Number of channels in the theta range | 128 |
radius | m | Radius of the collimator (to entry window) | 0 |
nblades | 1 | Number of blades composing each Soller. Overrides the divergence parameter | 0 |
roc | 1 | Enable oscillation of collimator with an amplitude of 'roc' times a single soller size (w1). | 0 |
verbose | 0/1 | Gives additional information | 0 |
Name | Unit | Description | Default |
---|---|---|---|
soller_theta1 | |||
soller_theta2 | |||
window_theta | |||
use_approx | |||
ideal |
Collimator_radial.comp
.
[ Identification | Description | Input parameters | Output parameters | Links ]
Generated automatically by McDoc, Peter Willendrup <peter.willendrup@risoe.dk> / Wed Nov 25 02:51:42 2009