Paul Garrett - Academia.edu (original) (raw)
Papers by Paul Garrett
... SJ Williams, MA Bentley, DD Warner, AM Bruce, JA Cameron, MP Carpenter, P. Fallon, L. Frankla... more ... SJ Williams, MA Bentley, DD Warner, AM Bruce, JA Cameron, MP Carpenter, P. Fallon, L. Frankland, W. Gelletly, RVF Janssens, DT Joss, CD O'Leary, CJ Lister, A. Poves, PH Regan, P. Reiter, B. Rubio, D. Seweryniak, CE Svensson, and SM Vincent, Phys. Rev. ...
AIP Conference Proceedings
The (n,n'gamma) reaction has been used to study the properties of low-lying excited states o... more The (n,n'gamma) reaction has been used to study the properties of low-lying excited states of 207Pb. Gamma-ray excitation functions, angular distributions, and coincidences have been measured, and the lifetimes of many excited levels were determined with the Doppler-shift attenuation method (DSAM). A sextuplet of states near 3.2 MeV is interpreted as resulting from particle-vibration coupling of the f5/2 neutron hole, the first excited state of 207Pb, with the octupole phonon of the 208Pb core. .
AIP Conference Proceedings
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
EPJ Web of Conferences
There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume t... more There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we have observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.
Proceedings of The 26th International Nuclear Physics Conference — PoS(INPC2016)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
The purpose of this LDRD was to establish a program at LLNL in radioactive ion beam (RIB) experim... more The purpose of this LDRD was to establish a program at LLNL in radioactive ion beam (RIB) experiments that would use these experiments to address a wide range physics issues in both stellar nucleosynthesis and stockpile stewardship radiochemistry. The LDRD was funded for a total of two years (fiscal years 2000 and 2001) and transferred to the Physical Data Research Program in fiscal year 2002. Reactions on unstable nuclei and isomeric states play a central role in the formation of elements in both stars and nuclear devices. However, the abilities of reaction models to predict cross sections on radioactive nuclei are uncertain at best. This can be attributed to the lack of experimental data to guide reaction-modeling efforts. Only the 10% of all bound nuclei that can be formed with stable targets and beams have been accessed and studied. The proposed Rare Isotope Accelerator (RIA) and existing RIB facilities offer an unprecedented opportunity to address many of the outstanding questions in nuclear structure, reactions and astrophysics by enabling the observation of nuclear reactions with radioactive targets and/or beams. The prima12¢ goal of this LDRD is to develop three experimental capabilities for use with RIB experiments: Level density and Tray strength function measurements using statistical Trays. Charged particle-induced cross sections measurements on radioactive nuclei. Neutron-induced cross section measurements on a radioactive target.
AIP Conference Proceedings
ABSTRACT
EPJ Web of Conferences
The even-even Cd isotopes have long been cited as one of the prime examples of vibrational behavi... more The even-even Cd isotopes have long been cited as one of the prime examples of vibrational behaviour, identified soon after the Bohr model was developed in the early 1950's. By the late 1970's, the presence of intruder states and shape coexistence were identified, but the underlying vibrational nature remained intact. More recently, the robustness of the multiphonon states was questioned, prompting detailed spectroscopic investigations at a number of facilities, including the use of the (n, n ′ γ) reaction and βdecay studies with modern γ-ray spectrometers. Combining results from these studies, a re-examination of the structure of the mid-shell Cd isotopes suggests that they may represent deformed γ-soft rotors rather than spherical vibrators.
AIP Conference Proceedings
Recent experiments at the GEANIE/WNR facility and the University of Kentucky accelerator have yie... more Recent experiments at the GEANIE/WNR facility and the University of Kentucky accelerator have yielded strong evidence for a two-gamma excitation in 170Er. This new case can be added to a handful of previously identified examples of two-gamma vibrations, all of them discovered in this decade. In this paper the experimental evidence for a two-phonon excitation 170Er is presented and the
AIP Conference Proceedings
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
AIP Conference Proceedings
Appro ved for public release; distribution is unlimited.
![Research paper thumbnail of [sup 170]Er: The search for multiphonon vibrations in a rotational nucleus](https://attachments.academia-assets.com/69916141/thumbnails/1.jpg)
](AIP Conference Proceedings, 2000
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author.
AIP Conference Proceedings, 2000
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author.
AIP Conference Proceedings, 2004
Recent results pertaining to nuclear structure from neutron-induced reactions on 90 Zr, 193 Ir, 1... more Recent results pertaining to nuclear structure from neutron-induced reactions on 90 Zr, 193 Ir, 196 Pt and 238 U are presented. The data were taken using the GEANIE spectrometer comprised of 26 high-purity Ge detectors with 20 BGO escape-suppression shields. The broad-spectrum pulsed neutron source of the Los Alamos Neutron Science Center's WNR facility provided neutrons in the energy range from 0.6 to 200 MeV. The time-of-flight technique was used to determine the incident neutron energies. Results from shell model calculations for 90 Zr and from IBM-2 calculations for 196 Pt are generally in good agreement with the observed spectrum of excited states.
J Phys G Nucl Particle Phys, 2001
![Research paper thumbnail of Collectivity of the “three-phonon” region in [sup 100]Ru](https://attachments.academia-assets.com/69916115/thumbnails/1.jpg)
](AIP Conference Proceedings, 2000
We have studied the quadrupole degree of freedom in a typical vibrational nucleus, looRu. From in... more We have studied the quadrupole degree of freedom in a typical vibrational nucleus, looRu. From inelastic neutron scattering at the Van de Graaff accelerator of the University of Kentucky, lifetimes of states in looRu were determined. Absolute transition rates or limits thereon were extracted and compared to the theoretical description of this nucleus.
AIP Conference Proceedings, 2003
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
AIP Conference Proceedings, 2003
Average nuclear level densities close to the nuclear binding energy in 56Fe and 57Fe are extracte... more Average nuclear level densities close to the nuclear binding energy in 56Fe and 57Fe are extracted from primary y-ray spectra. Thermal properties of 56Fe are studied within the statistical canonical ensemble. The experimental heat capacity is compared with the theoretical heat capacity calculated within the shell model Monte Carlo approach.
AIP Conference Proceedings, 2008
Levels in {sup 186,188}Os have been investigated using the (³He,d) reaction with 30 MeV ³He beams... more Levels in {sup 186,188}Os have been investigated using the (³He,d) reaction with 30 MeV ³He beams. Absolute level-population cross sections have been determined, and angular distributions measured between 5 deg. and 50 deg. The 4{sup +} levels are observed to be some of the strongest populated states below 2 MeV excitation energy, and the magnitudes of the 5/2{sup +}[402]{sub }+3/2{sup
... SJ Williams, MA Bentley, DD Warner, AM Bruce, JA Cameron, MP Carpenter, P. Fallon, L. Frankla... more ... SJ Williams, MA Bentley, DD Warner, AM Bruce, JA Cameron, MP Carpenter, P. Fallon, L. Frankland, W. Gelletly, RVF Janssens, DT Joss, CD O'Leary, CJ Lister, A. Poves, PH Regan, P. Reiter, B. Rubio, D. Seweryniak, CE Svensson, and SM Vincent, Phys. Rev. ...
AIP Conference Proceedings
The (n,n'gamma) reaction has been used to study the properties of low-lying excited states o... more The (n,n'gamma) reaction has been used to study the properties of low-lying excited states of 207Pb. Gamma-ray excitation functions, angular distributions, and coincidences have been measured, and the lifetimes of many excited levels were determined with the Doppler-shift attenuation method (DSAM). A sextuplet of states near 3.2 MeV is interpreted as resulting from particle-vibration coupling of the f5/2 neutron hole, the first excited state of 207Pb, with the octupole phonon of the 208Pb core. .
AIP Conference Proceedings
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
EPJ Web of Conferences
There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume t... more There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we have observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.
Proceedings of The 26th International Nuclear Physics Conference — PoS(INPC2016)
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
The purpose of this LDRD was to establish a program at LLNL in radioactive ion beam (RIB) experim... more The purpose of this LDRD was to establish a program at LLNL in radioactive ion beam (RIB) experiments that would use these experiments to address a wide range physics issues in both stellar nucleosynthesis and stockpile stewardship radiochemistry. The LDRD was funded for a total of two years (fiscal years 2000 and 2001) and transferred to the Physical Data Research Program in fiscal year 2002. Reactions on unstable nuclei and isomeric states play a central role in the formation of elements in both stars and nuclear devices. However, the abilities of reaction models to predict cross sections on radioactive nuclei are uncertain at best. This can be attributed to the lack of experimental data to guide reaction-modeling efforts. Only the 10% of all bound nuclei that can be formed with stable targets and beams have been accessed and studied. The proposed Rare Isotope Accelerator (RIA) and existing RIB facilities offer an unprecedented opportunity to address many of the outstanding questions in nuclear structure, reactions and astrophysics by enabling the observation of nuclear reactions with radioactive targets and/or beams. The prima12¢ goal of this LDRD is to develop three experimental capabilities for use with RIB experiments: Level density and Tray strength function measurements using statistical Trays. Charged particle-induced cross sections measurements on radioactive nuclei. Neutron-induced cross section measurements on a radioactive target.
AIP Conference Proceedings
ABSTRACT
EPJ Web of Conferences
The even-even Cd isotopes have long been cited as one of the prime examples of vibrational behavi... more The even-even Cd isotopes have long been cited as one of the prime examples of vibrational behaviour, identified soon after the Bohr model was developed in the early 1950's. By the late 1970's, the presence of intruder states and shape coexistence were identified, but the underlying vibrational nature remained intact. More recently, the robustness of the multiphonon states was questioned, prompting detailed spectroscopic investigations at a number of facilities, including the use of the (n, n ′ γ) reaction and βdecay studies with modern γ-ray spectrometers. Combining results from these studies, a re-examination of the structure of the mid-shell Cd isotopes suggests that they may represent deformed γ-soft rotors rather than spherical vibrators.
AIP Conference Proceedings
Recent experiments at the GEANIE/WNR facility and the University of Kentucky accelerator have yie... more Recent experiments at the GEANIE/WNR facility and the University of Kentucky accelerator have yielded strong evidence for a two-gamma excitation in 170Er. This new case can be added to a handful of previously identified examples of two-gamma vibrations, all of them discovered in this decade. In this paper the experimental evidence for a two-phonon excitation 170Er is presented and the
AIP Conference Proceedings
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
AIP Conference Proceedings
Appro ved for public release; distribution is unlimited.
AIP Conference Proceedings, 2000
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author.
AIP Conference Proceedings, 2000
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author.
AIP Conference Proceedings, 2004
Recent results pertaining to nuclear structure from neutron-induced reactions on 90 Zr, 193 Ir, 1... more Recent results pertaining to nuclear structure from neutron-induced reactions on 90 Zr, 193 Ir, 196 Pt and 238 U are presented. The data were taken using the GEANIE spectrometer comprised of 26 high-purity Ge detectors with 20 BGO escape-suppression shields. The broad-spectrum pulsed neutron source of the Los Alamos Neutron Science Center's WNR facility provided neutrons in the energy range from 0.6 to 200 MeV. The time-of-flight technique was used to determine the incident neutron energies. Results from shell model calculations for 90 Zr and from IBM-2 calculations for 196 Pt are generally in good agreement with the observed spectrum of excited states.
J Phys G Nucl Particle Phys, 2001
AIP Conference Proceedings, 2000
We have studied the quadrupole degree of freedom in a typical vibrational nucleus, looRu. From in... more We have studied the quadrupole degree of freedom in a typical vibrational nucleus, looRu. From inelastic neutron scattering at the Van de Graaff accelerator of the University of Kentucky, lifetimes of states in looRu were determined. Absolute transition rates or limits thereon were extracted and compared to the theoretical description of this nucleus.
AIP Conference Proceedings, 2003
This is a preprint of a paper intended for publication in a journal or proceedings. Since changes... more This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. This report has been reproduced directly from the best available copy.
AIP Conference Proceedings, 2003
Average nuclear level densities close to the nuclear binding energy in 56Fe and 57Fe are extracte... more Average nuclear level densities close to the nuclear binding energy in 56Fe and 57Fe are extracted from primary y-ray spectra. Thermal properties of 56Fe are studied within the statistical canonical ensemble. The experimental heat capacity is compared with the theoretical heat capacity calculated within the shell model Monte Carlo approach.
AIP Conference Proceedings, 2008
Levels in {sup 186,188}Os have been investigated using the (³He,d) reaction with 30 MeV ³He beams... more Levels in {sup 186,188}Os have been investigated using the (³He,d) reaction with 30 MeV ³He beams. Absolute level-population cross sections have been determined, and angular distributions measured between 5 deg. and 50 deg. The 4{sup +} levels are observed to be some of the strongest populated states below 2 MeV excitation energy, and the magnitudes of the 5/2{sup +}[402]{sub }+3/2{sup