DETERMINATION OF NEUTRON-INDUCED ACTIVATION CROSS SECTIONS USING NIRR-1

Simple item page
dc.contributor.authorUmar, SADIQ
dc.date.accessioned2014-03-04T14:28:15Z
dc.date.available2014-03-04T14:28:15Z
dc.date.issued2007-06
dc.descriptionA DISSERTATION SUBMITTED TO THE POST GRADUATE SCHOOL, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF DOCTOR OF PHILOSOPHY DEGREE (PhD) IN PHYSICS. DEPARTMENT OF PHYSICS, AHMADU BELLO UNIVERSITY, ZARIA JUNE, 2007en_US
dc.description.abstractThe full-energy peak efficiency (FEP) curves of the gamma-ray spectrometry setup for use with the newly commissioned Nigeria Research Reactor-1 (NIRR-1) have been determined at three source-detector positions aimed at routine neutron activation analysis with the reactor. Standard gamma ray sources were used to determine the efficiency curves in the energy range of 59.5-2240.1 keV and a semi-empirical approach was used to extend the efficiency data from 2204.1 keV to 4000 keV. The semi-empirical method has been found to be reasonably accurate within experimental uncertainties. The neutron spectrum parameters (i.e. the thermal-to-epithermal flux ratio, f, and the epithermal flux shape factor, α) for one inner and one outer (A1 and A2) irradiation channels of NIRR-1, required (or needed) for the extension of its applicability to k0-NAA, were determined using the “Cd-ratio for multi-monitor method”. For the general applicability of the k0-NAA to deal with “non-1/v” (n, γ) reactions, the modified spectral index, r(α)√(Tn/T0), and Westcott’s g(Tn) factor for monitoring neutron temperature Tn were also determined for the two irradiation channels. Neutron spectrum parameters determined in the inner channel A1, are: α = -0.046 ± 0.005; f = 18.4 ± 0.34 ; r(α)√(Tn/T0) = 0.04878 ; Tn = 38.810(Holden) and g(Tn) = 11.30, 1.883. For the outer channel A2, the values are: α = +0.024 ± 0.002; f = 49.5 ± 0.96; r(α)√(Tn/T0) = 0.01786 ; Tn = 30.220(Holden) and g(Tn) = 13.89, 1.821. The results are in good agreement with reported values from other reactor facilities with similar core configuration. The thermal radiative capture cross sections, σ0 and k0-factors for ten (n,γ) reactions i.e. 197Au (n, γ) 198Au; 94Zr (n, γ) 95Zr ; 96Zr (n, γ) 97Zr ; 238U (n, γ) 239U ; 55Mn (n, γ) 56Mn ; 109 Ag (n, γ) 110mAg ; 48Ca (n, γ) 49Ca ; 71Ga (n, γ) 72Ga ; 74Se (n, γ) 75Se and 75As (n, γ) 76As have been reevaluated and the results compare well with evaluated data from libraries and Mughabghab, (2003). This work has been undertaken as part of an IAEA Coordinated Research Project No.13728 entitled “Reference Database for NAA”.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/3220
dc.language.isoenen_US
dc.subjectDETERMINATION,en_US
dc.subjectNEUTRON,en_US
dc.subjectINDUCED,en_US
dc.subjectACTIVATION,en_US
dc.subjectCROSS,en_US
dc.subjectSECTIONS,en_US
dc.subjectNIRR-1,en_US
dc.titleDETERMINATION OF NEUTRON-INDUCED ACTIVATION CROSS SECTIONS USING NIRR-1en_US
dc.typeThesisen_US
Files
Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
DETERMINATION OF NEUTRON-INDUCED ACTIVATION CROSS SECTIONS USING NIRR-1.pdf
Size:
3.34 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.58 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
SCIENCE