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Study of Nuclear Level Densities from Deuteron-Induced Reactions on <sup>54,56,58</sup>Fe and <sup>63,65</sup>CuRamirez, Anthony Paul D. January 2014 (has links)
No description available.
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Nuclear level densities and gamma-ray strength functions in Ta isotopes and nucleo-synthesis of ¹⁸ᴼTaMalatji, Kgashane Leroy January 2016 (has links)
>Magister Scientiae - MSc / Most stable and extremely low abundance neutron deficient nuclei with Z ≥ 34 are referred to as p-nuclei. Nearly all p-nuclei with A < 110 are most likely produced in the rp-process while almost all A > 110 are thought to be produced by the photodisintegration of s- and r- process seed nuclei. However, for some nuclear systems, these processes are not sufficient to explain their observed solar abundance. Results from calculations in ¹⁸ᴼTa generally provoke debates since several processes are able, sometimes exclusively, to reproduce the observed ¹⁸ᴼTa abundance in the cosmos, making it a unique case study. Some of the main sources of errors in the predicted reaction rates of ¹⁸ᴼTa arise due to the absence of nuclear data or due to large uncertainties in the nuclear properties such as the nuclear level densities (NLD) and gamma-ray strength functions (γSF) of ¹⁸ᴼ,¹⁸¹Ta. The NLD and γSF are primary ingredients for astrophysical reaction rate calculations based on the Hauser-Feshbach approach. These parameters need to be well understood to improve our
understanding of ¹⁸ᴼTa production in astrophysical environments. In this thesis, new experimental data for the low-energy part of the γSF and NLD in ¹⁸ᴼ,¹⁸¹Ta were extracted, using the so-called Oslo method. An experiment was performed and the NaI(Tl) gamma-ray array and silicon particle telescopes at the Oslo cyclotron laboratory were utilized to measure particle-γ coincidence events from which the NLDs and γSFs are extracted below the neutron separation energy threshold Sn. A beam of ³He was used to populate excited states in ¹⁸ᴼ,¹⁸¹Ta through the inelastic scattering (³He,³He’𝛾)
and the transfer reaction (³He,𝜶𝛾). Based on results from this measurements, the Maxwellian averaged (n, 𝛾) cross sections for the 179Ta(n, γ) and ¹⁸ᴼTa(n, 𝛾) reactions, at the s-process thermal energy of kT = 30 keV (i.e. a temperature of T = 3.5 × 10⁸ K) and p-process thermal energy of 215 keV (T = 2.5 × 10⁹ K), respectively, were computed with the TALYS reaction code. These results can be used to place the nuclear physics aspects of the large network abundance calculations on a solid footing and have potential to improve our understanding of the astrophysical processes and sites involved in the production of nature’s rarest isotope ¹⁸ᴼTa. / National Research Foundation (NRF)
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Study of Nuclear Level Density and γ-Strength Function in <sup>90</sup>Zr, <sup>196</sup>Pt, and <sup>197</sup>PtByun, Youngshin January 2013 (has links)
No description available.
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Study Of Nuclear Level Densities From Evaporation Of Compound Nuclei Of Mass Numbers 61, 64, 65, And 82Oginni, Babatunde M. 11 August 2009 (has links)
No description available.
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Fotonové silové pole v izotopech Gd studované rezonančním záchytem elektronů / Photon strength functions in Gd isotopes studied from resonance neutron captureKroll, Jiří January 2013 (has links)
Title: Photon strength functions in Gd isotopes studied from resonance neutron capture Author: RNDr. Jiří Kroll Department: Intitute of particle and nuclear physics Supervisor: doc. Mgr. Milan Krtička, Ph.D., Intitute of particle and nuclear physics Abstract: Photon strength functions have been studied for more than sixty years. A number of theoretical models was proposed to describe experimental data during that time. However, the correctness of these models is still very questionable and its verification is the subject of very intensive experimental and theoretical activity at present time. In this thesis the analysis of spectra of γ rays following the radiative capture of neutrons on isolated neutron resonances of 152,154−158 Gd nuclei is used to study photon strength functions. Experimental data were measured using segmented DANCE calorimeter that is installed at Los Alamos Neutron Scattering Center in New Mexico, USA. Experimental spectra are then compared with the outputs of Monte Carlo simulation of nuclear elec- tromagnetic decay, performed by DICEBOX code, that is based on the validity of the so-called Extreme Statistical Model. The response of the detector system to generated γ cascades was subsequently calculated using the Geant4 code. An analysis of the data clearly indicates that magnetic...
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Investigating the Gamma-ray Strength Function in 74Ge using the Ratio MethodSowazi, Khanyisa January 2018 (has links)
>Magister Scientiae - MSc / An increasing number of measurements reveal the presence of a low-energy enhancement
in the gamma-ray strength function (GSF). The GSF, which is the
ability of nuclei to absorb or emit
rays, provides insight into the statistical properties
of atomic nuclei. For this project the GSF was studied for 74Ge which was
populated in the reaction 74Ge(p,p')74Ge* at a beam energy of 18 MeV. The data
were collected with the STARS-LIBERACE array at Lawrence Berkeley National
Laboratory. Silicon detector telescopes were used for particle identi cation and
rays in coincidence were detected with 5 clover-type high-purity germanium detectors.
Through the analysis particle-
-
coincidence events were constructed.
These events, together with well-known energy levels, were used to identify primary
rays from the quasicontinuum. Primary
rays from a broad excitation
energy region, which decay to six 2+ states could be identi ed. These states and
the associated primary
rays are used to measure the GSF for 74Ge with the
Ratio Method [1], which entails taking ratios of e ciency-corrected primary
-ray
intensities from the quasicontinuum. Results from the analysis of the data and
focus on the existence of the low-energy enhancement in 74Ge will be discussed.
The results are further discussed in the context of other work done on 74Ge using
the (
,
') [2], (3He,3He') [3] and ( , ') [4] reactions.
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