Optimization and design of a detection system based on transmission tomography with fast neutrons
Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
This thesis is part of a project focusedon investigating the possibility ofmeasuring void distributions usingtransmission tomography with fastneutrons. The measurements are plannedto be conducted at thermal hydraulictest loops. The project, called STUNT,is carried out at Uppsala University atthe division for applied nuclearphysics.The purpose of this work was to designand optimize a detection system for thedetection of fast neutrons in the abovementioned environment. For this purpose,detector elements consisting of theplastic scintillator material EJ208 wasmodeled using the particle transportcode MCNPX.Both plate shaped elements and fibers ofdifferent dimensions where tested forperformance.Through a comparison utilizing severalfigures of merit and MATLAB, the plateshape was selected with an element widthof 2.6 mm. During the optimizationprocess a possible detector design with73 detector plates was chosen. At anenergy threshold of 11 MeV the followingdesign parameters were found; adetection efficiency of 3.0 %, a signalto background ratio of 15, a totalmeasurement time of 3600 s and a pixelresolution of 1.4 mm.A point spread function was produced andtwo projection tests where conductedusing a water filled steel cylinder asobject.
Place, publisher, year, edition, pages
2014. , 72 p.
UPTEC ES, ISSN 1650-8300 ; 14013
Transmission tomography, fast neutrons, scintillator, detector
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-226394OAI: oai:DiVA.org:uu-226394DiVA: diva2:725370
Master Programme in Energy Systems Engineering
2014-05-08, 4001, Lägerhyddsvägen 1, Uppsala, 15:15 (Swedish)
Andersson, Peter, Researcher
Jönsson, Petra, Research assistantSjöstrand, Henrik