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McCleskey, E.

Publications and source records attributed to McCleskey, E..

7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Zirconium and Yttrium (p, d) Surrogate Nuclear Reactions: Measurement and determination of gamma-ray probabilities: Experimental Physics Report

This technical report documents the surrogate reaction method and experimental results used to determine the desired neutron induced cross sections of 87 Y(n,g) and the known 90 Zr(n,g) cross section. This experiment was performed at the STARLiTeR apparatus located at Texas A&M Cyclotron Institute using the K150 Cyclotron which produced a 28.56 MeV proton beam. The proton beam impinged on Y and Zr targets to produce the nuclear reactions 89 Y(p,d) 88 Y and 92 Zr(p,d) 91 Zr. Both particle singles data and particle-gamma ray coincident data were measured during the experiment. This data was used to determine the γ-ray probability as a function of energy for these reactions. The results for the γ-ray probabilities as a function of energy for both these nuclei are documented here. For completeness, extensive tabulated and graphical results are provided in the appendices.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

The hyperion particle-γ detector array

Hyperion is a new high-efficiency charged-particle γ-ray detector array which consists of a segmented silicon telescope for charged-particle detection and up to fourteen high-purity germanium clover detectors for the detection of coincident γ rays. The array will be used in nuclear physics measurements and Stockpile Stewardship studies and replaces the STARLiTeR array. In conclusion, this article discusses the features of the array and presents data collected with the array in the commissioning experiment.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

Decay branching ratios of excited Mg 24

Here, the nuclear reactions 12 C( 12 C, α) 20 Ne, 12 C( 12 C, p) 23 Na, and 12 C( 12 C, n) 23 Mg are the primary reactions in carbon burning, which occurs as part of several stellar processes. The Gamow window, which describes the energy range where most of these reactions take place, is typically around 1.5 MeV in the center-of-mass frame. Direct measurements of the cross sections at this energy are difficult due to the large Coulomb barrier present between the carbon nuclei; however, a successful surrogate measurement can provide the branching ratios between these reactions while avoiding the 12 C + 12 C Coulomb barrier. Finally, an experiment was performed using inelastic scattering of 40 MeV α particles on 24 Mg as a possible surrogate for the 12 C + 12 C compound nucleus.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Investigation of discrete states and quasidiscrete structures observed in 150 Sm and 152 Sm using the (p, tγ) reaction

New levels and γ-ray transitions were identified in 150,152 Sm utilizing the (p,t) reaction and particle-γ coincidence data. A large, peak-like structure observed between 2.3–3.0 MeV in excitation energy in the triton energy spectra was also investigated. The orbital angular-momentum transfer was probed by comparing the experimental angular distributions of the outgoing tritons to calculated distorted wave Born approximation curves. The angular distributions of the outgoing tritons populating the peak-like structure are remarkably similar in the two reactions and are significantly different from the angular distributions associated with the nearby continuum region. Relative partial cross sections for the observed levels, angle averaged between 34 and 58 degrees, were measured. In 150 Sm, 39(4)% of the strength of the peak-like structure could be accounted for by the observed discrete states. This compares with a value of 93(15)% for 152 Sm

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗