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Your search keyword '"P.D. O’Malley"' showing total 11 results
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11 results on '"P.D. O’Malley"'

1. Determination of hexadecapole (β4) deformation of the light-mass nucleus 24Mg using quasi-elastic scattering measurements

Author

Y.K. Gupta, B.K. Nayak, U. Garg, K. Hagino, K.B. Howard, N. Sensharma, M. Şenyiğit, W.P. Tan, P.D. O'Malley, M. Smith, Ramandeep Gandhi, T. Anderson, R.J. deBoer, B. Frentz, A. Gyurjinyan, O. Hall, M.R. Hall, J. Hu, E. Lamere, Q. Liu, A. Long, W. Lu, S. Lyons, K. Ostdiek, C. Seymour, M. Skulski, and B. Vande Kolk

Subjects
Physics, QC1-999
Abstract

Quasi-elastic scattering measurements have been performed using 16O and 24Mg projectiles off 90Zr at energies around the Coulomb barrier. Experimental data have been analyzed in the framework of coupled channels (CC) calculations using the code CCFULL. The quasi-elastic scattering excitation function and derived barrier distribution for 16O + 90Zr reaction are well reproduced by the CC calculations using the vibrational coupling strengths for 90Zr reported in the literature. Using these vibrational coupling strengths, a Bayesian analysis is carried out for 24Mg + 90Zr reaction. The β2 and β4 values for 24Mg are determined to be +0.43±0.02 and −0.11±0.02, respectively. The β2 parameter determined in the present work is in good agreement with results obtained using inelastic scattering probes. The hexadecapole deformation of 24Mg has been measured very precisely for the first time. Present results establish that quasi-elastic scattering could provide a useful probe to determine the ground state deformation of atomic nuclei.

Published
2020
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2. The first science result with the JENSA gas-jet target: Confirmation and study of a strong subthreshold F18(p,α)O15 resonance

Author

D.W. Bardayan, K.A. Chipps, S. Ahn, J.C. Blackmon, R.J. deBoer, U. Greife, K.L. Jones, A. Kontos, R.L. Kozub, L. Linhardt, B. Manning, M. Matoš, P.D. O'Malley, S. Ota, S.D. Pain, W.A. Peters, S.T. Pittman, A. Sachs, K.T. Schmitt, M.S. Smith, and P. Thompson

Subjects
Novae, Nucleosynthesis, Nuclear, Reactions, Physics, QC1-999
Abstract

The astrophysical F18(p,α)O15 rate determines, in large part, the extent to which the observable radioisotope 18F is produced in novae. This rate, however, has been extremely uncertain owing to the unknown properties of a strong subthreshold resonance and its possible interference with higher-lying resonances. The new Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas-jet target has been used for the first time to determine the spin of this important resonance and significantly reduce uncertainties in the F18(p,α)O15 rate.

Published
2015
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4. Construction of St. Benedict

Author

M. Brodeur, T. Ahn, D.W. Bardayan, D.P. Burdette, J.A. Clark, A.T. Gallant, J.J. Kolata, B. Liu, P.D. O’Malley, W.S. Porter, R. Ringle, F. Rivero, G. Savard, A.A. Valverde, and R. Zite

Subjects
Nuclear and High Energy Physics, Instrumentation
Published
2023
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5. TriSol: a major upgrade of the TwinSol RNB facility

Author

P.D. O’Malley, T. Ahn, D.W. Bardayan, M. Brodeur, S. Coil, and J.J. Kolata

Subjects
Accelerator Physics (physics.acc-ph), Nuclear and High Energy Physics, FOS: Physical sciences, Physics - Accelerator Physics, Nuclear Experiment (nucl-ex), Instrumentation, Nuclear Experiment
Abstract

We report here on the recent upgrade of the TwinSol radioactive nuclear beam (RNB) facility at the University of Notre Dame. The new TriSol system includes a magnetic dipole to provide a second beamline and a third solenoid which acts to reduce the size of the radioactive beam on target., submitted to Nuclear Instruments and Methods A

Published
2022

6. Use of Bayesian Optimization to Understand the Structure of Nuclei

Author

J. Hooker, J. Kovoor, K.L. Jones, R. Kanungo, M. Alcorta, J. Allen, C. Andreoiu, L. Atar, D.W. Bardayan, S.S. Bhattacharjee, D. Blankstein, C. Burbadge, S. Burcher, W.N. Catford, S. Cha, K. Chae, D. Connolly, B. Davids, N. Esker, F.H. Garcia, S. Gillespie, R. Ghimire, A. Gula, G. Hackman, S. Hallam, M. Hellmich, J. Henderson, M. Holl, P. Jassal, S. King, T. Knight, R. Kruecken, A. Lepailleur, J. Liang, L. Morrison, P.D. O’Malley, S.D. Pain, X. Pereira-Lopez, A. Psaltis, A. Radich, A.C. Shotter, M. Vostinar, M. Williams, and O. Workman

Subjects
Nuclear and High Energy Physics, Direct reaction, FOS: Physical sciences, Transfer reaction, 01 natural sciences, Atomic, Stable ion beam, Particle and Plasma Physics, Affordable and Clean Energy, 0103 physical sciences, Nuclear, Nuclear Experiment (nucl-ex), 010306 general physics, Instrumentation, Nuclear Experiment, Bayesian optimization, Applied Physics, 010308 nuclear & particles physics, Low-energy reactions, Geant4 simulation, Molecular, Computational Physics (physics.comp-ph), Geochemistry, Interdisciplinary Engineering, Radioactive ion beam, Physics - Computational Physics
Abstract

Monte Carlo simulations are widely used in nuclear physics to model experimental systems. In cases where there are significant unknown quantities, such as energies of states, an iterative process of simulating and fitting is often required to describe experimental data. We describe a Bayesian approach to fitting experimental data, designed for data from a $^{12}$Be(d,p) reaction measurement, using simulations made with GEANT4. Q-values from the $^{12}$C(d,p) reaction to well-known states in $^{13}$C are compared with simulations using BayesOpt. The energies of the states were not included in the simulation to reproduce the situation for $^{13}$Be where the states are poorly known. Both cases had low statistics and significant resolution broadening owing to large proton energy losses in the solid deuterium target. Excitation energies of the lowest three excited states in $^{13}$C were extracted to better than 90 keV, paving a way for extracting information on $^{13}$Be., 8 pages, 6 figures

Published
2021

8. Commissioning of the St. Benedict RF carpet

Author

C. Davis, R. Bualuan, O. Bruce, D.P. Burdette, A. Cannon, T. Florenzo, D. Gan, J. Harkin, B. Liu, J. Long, P.D. O’Malley, W.S. Porter, F. Rivero, M.A. Yeck, R. Zite, and M. Brodeur

Subjects
Nuclear and High Energy Physics, Instrumentation
Published
2022
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10. The Notre-Dame Cube: An active-target time-projection chamber for radioactive beam experiments and detector development

Author

T. Ahn, J.S. Randhawa, S. Aguilar, D. Blankstein, L. Delgado, N. Dixneuf, S.L. Henderson, W. Jackson, L. Jensen, S. Jin, J. Koci, J.J. Kolata, J. Lai, J. Levano, X. Li, A. Mubarak, P.D. O’Malley, S. Ramirez Martin, M. Renaud, M.Z. Serikow, A. Tollefson, J. Wilson, and L. Yan

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, fungi, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation
Abstract

Active-target detectors have the potential to address the difficulties associated with the low intensities of radioactive beams. We have developed an active-target detector, the Notre Dame Cube (ND-Cube), to perform experiments with radioactive beams produced at $\mathit{TwinSol}$ and to aid in the development of active-target techniques. Various aspects of the ND-Cube and its design were characterized. The ND-Cube was commissioned with a $^{7}$Li beam for measuring $^{40}$Ar + $^{7}$Li fusion reaction cross sections and investigating $^{7}$Li($\alpha$,$\alpha$)$^{7}$Li scattering events. The ND-Cube will be used to study a range of reactions using light radioactive ions produced at low energy., Comment: 13 pages, 12 figures

Published
2022
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