- Typ
- Bachelorarbeit
- Gebiet
- Detektorentwicklung
- Autor
- Yuliya Shayakubova
- Titel
- Design and Development of a Neutron Collimator
- Datum
- 2021-09
- Reportnummer
- —
- Kurzfassung
- The discovery of the neutron in 1932 by James Chadwick has opened a door to many experiments for the scientific world. Nowadays there is an enormous amount of applications, where neutrons are used, e.g. isotope production, Neutron Activation Analysis (NAA), Neutron Imaging (NI), and many others. Due to the neutral charge of neutrons, they can penetrate deeper into the matter. On the other side, this feature makes it impossible to control them since they can not be accelerated or steered by using Electromagnetic fields in comparison to charged particles.
Due to the fact, that most of the neutron sources deliver a highly divergent beam, scientists were in need to get a homogeneous beam with a small angular distribution especially in the applications of neutron imaging. One way to achieve such a beam is by using a neutron collimator.
The aim of this bachelor thesis is to research one of the most common methods, which was presented in the '70s for the first time but is still being used today - a collimator made of aluminum plates coated with gadolinium (Gd2O3 powder) as a neutron absorbing material. Different methods of gadolinium coating are employed and neutron absorption is studied with the Cf (Californium) source in the Heidelberg University. The results are compared to the reference sample plates prepared by Dr. Markus Köhli from Heidelberg University. In addition, a prototype collimator consisting of combined plates is tested. At the same time, a simulation is done and compared with the experimental results. Furthermore, two different designs for a neutron collimator are presented in this thesis, their characteristics, opportunities, and obstacles are exemplified. Based on the simulation the optimal parameters
for the development of the collimator can be chosen and are proposed at the end of this thesis.
Under the Next Generation Readout Infrastructure for Neutron Detectors (NexGRIND) project, which is taking place now in the University Bonn, a neutron collimator is needed to obtain a divergent thermal beam. For all the beam tests shown in this thesis a Helium-3 detector is used, which was kindly provided in the University Heidelberg.
- Link
- Download