| dc.description |
The spatial resolution in neutron imaging is often limited by the neutron beam divergence, especially in experiments where the distance between the sample and the detector cannot be very small. Imaging of relatively large or extended objects or tomographic experiments, where samples have to be rotated, typically require several to tens of centimeters distance between the sample and the detector. Moreover, some neutron imaging techniques require placement of components between the sample and the detector, as in the case of magnetic field imaging with polarized neutrons. Compact and efficient policapillary collimators can be an attractive alternative to the conventionally used beam limiting aperture approach. The possible improvement of spatial resolution by a policapillary collimator is studied in experiments where beam divergence limits the quality of neutron transmission imaging. A ∼ 7 mm thick collimator with ∼ 6 μm capillaries demonstrates the possibility to decrease the neutron beam divergence and to diminish the image blurring. The improvement of out-of-angle neutron rejection and peak transmission of our future collimators will be crucial for their effective application in neutron imaging experiments. |
