Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Nine 100x100x600 mm3 plastic scintillators, formerly built for the neutron time
of ight measurements at iThemba LABS, were refurbished. The position resolution
of these detectors was determined using muon cosmic rays and coincident
measurement techniques. Average position resolution of 4.28 cm (FWHM)
was found. In order to predict the time spectrum of the large-volume detector
Monte Carlo simulations have been performed. These simulations aimed at
anticipating the separation of statistical neutrons, prompt gamma rays and
uncorrelated gamma rays from the fast neutrons emitted in the reaction of
interest. One of the neutron detectors was tested using fast neutrons from
the 232Th( ,xn) reaction at 42 MeV. Statistical neutrons from fusion evaporation
reactions were produced in 152Sm(12C,xn) fusion evaporation reaction.
Coincidences between neutrons and gamma rays were successfully identi ed.
Prompt gamma rays and uncorrelated gamma rays were also identi ed. / AFRIKAANSE OPSOMMING: Nege 100x100x600 mm3 plastiese scintillators, wat aanvanklik gebou was vir
neutron vlugtyds meetings by iThemba LABS, was hernu. Die posisie resolusie
van die detektore was bepaal deurmiddel van muon kosmiese straling en koïnsidensie
meet tegnieke. Posisie resolusie van 4.28 cm (FWHM) was verkry.
Monte Carlo simulasies is gebruik om die posisie resolusie van'n groot volume
detektor te voorspel. Hierdie simulasies is daarop gemik om onderskeid te
maak tussen statistiese neutrone, gelyktydige gamma strale en ongekorreleerde
gamma strale vanaf vinnige neutrone in die reaksie van belang uitgestraal word.
Een neutron detektor was getoets deur gebruik te maak van vinnige neutrone
wat uit die reaksie 232Th( ,xn) by 42 MeV ontstaan. Statistiese neutrone vanaf
splitsings verdampingsreaksies, gelyktydige gamma strale en ongekorreleerde
gamma strale was geidenti seer. Statistiese neutrone van samesmelting verdamping
reaksies was geproduseer in die reaksie 152Sm(12C,xn). Toeval tussen
neutrone en gamma strale was suksesvol geïdenti seer, gevra gamma strale en
ongekorreleerd gamma strale was ook geïdenti seer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/20123 |
| Date | 03 1900 |
| Creators | Elbasher, Mohamed Elbasher Ahmed |
| Contributors | Papka, P., Lawrie, E. A., Wyngaardt, S. M., Stellenbosch University. Faculty of Science. Dept. of Physics. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 73 p. : ill. |
| Rights | Stellenbosch University |
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