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Sean Finch

Research Scientist
Physics
Box 90305, Durham, NC 27708-0305
TUNL Room 402, Durham, NC 27708

Selected Publications


Observation of Low-Lying Isomeric States in ^{136}Cs: A New Avenue for Dark Matter and Solar Neutrino Detection in Xenon Detectors.

Journal Article Physical review letters · August 2023 We report on new measurements establishing the existence of low-lying isomeric states in ^{136}Cs using γ rays produced in ^{136}Xe(p,n)^{136}Cs reactions. Two states with O(100)  ns lifetimes are placed in the decay sequence of the ^{136}Cs levels that ar ... Full text Cite

Testing shell-model interactions at high excitation energy and low spin: Nuclear resonance fluorescence in Ge 74

Journal Article Physical Review C · August 1, 2023 With their complex low-spin structure, the germanium isotopes have accrued a large number of experimental data which challenge nuclear models. The structure of the Ge74 isotope is investigated here with nuclear resonance fluorescence as part of an extensiv ... Full text Cite

Fission product yields from the U 238 (n,f) reaction at En=4.6 MeV

Journal Article Physical Review C · May 1, 2023 We present cumulative fission product yields from the U238(n,f) reaction at an incident energy of 4.6 MeV for fission products with half-lives from less than one second to several hours. We employed direct γ-ray spectroscopy to measure unseparated fission ... Full text Cite

Neutral-current neutrino cross section and expected supernova signals for 40Ar from a three-fold increase in the magnetic dipole strength

Journal Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics · December 10, 2022 In view of the great interest in liquid argon neutrino detectors, the 40Ar(γ,γ′)40Ar reaction was revisited to guide a calculation of the neutral current neutrino cross section at supernova energies. Using the nuclear resonance fluorescence technique with ... Full text Cite

Model-independent determination of the dipole response of Zn 66 using quasimonoenergetic and linearly polarized photon beams

Journal Article Physical Review C · October 1, 2022 Background: Photon strength functions are an important ingredient in calculations relevant for the nucleosynthesis of heavy elements. The relation to the photoabsorption cross section allows to experimentally constrain photon strength functions by investig ... Full text Cite

Investigation of B 11 and Ca 40 levels at 8-9 MeV by nuclear resonance fluorescence

Journal Article Physical Review C · July 1, 2022 We report on the measurement of B11 and Ca40 levels between excitation energies of 8 and 9 MeV using nuclear resonance fluorescence (NRF). The experiment was carried out with nearly monoenergetic and linearly polarized photon beams provided by the High-Int ... Full text Cite

Development of a rapid-transit system for precision nuclear physics measurements

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · February 11, 2022 A Rapid Belt-driven Irradiated Target Transfer System, named RABITTS, was developed for use at the Triangle Universities Nuclear Laboratory. This system allows for cyclic activation with neutron or photon beams, and measurement of reaction products using γ ... Full text Cite

Majorana parameters of the interacting boson model of nuclear structure and their implication for 0νββ decay

Journal Article Physical Review C · December 1, 2021 The well-known spherical-deformed-transitional nucleus and potential 0νββemitter Nd150and its daughter Sm150were investigated in nuclear resonance fluorescence experiments using quasimonoenergetic, linearly polarized γ-ray beams. For both nuclei transition ... Full text Cite

Structure of high-lying levels populated in the 96Y →96Zr β decay

Journal Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics · September 10, 2021 The nature of the high-lying final levels of the 96Ygs β decay, one of the three most important contributors to the high-energy reactor antineutrino spectrum, has been investigated in high-resolution γ-ray spectroscopy following the β decay as well as in a ... Full text Cite

E2 decay characteristics of the M1 scissors mode of Sm 152

Journal Article Physical Review C · May 1, 2021 The E2/M1 multipole mixing ratio of the 1sc+→21+γ-ray transition and therefore the F-vector E2 decay of the scissors mode of the shape-phase transitional nucleus Sm152 have been measured with the nuclear resonance fluorescence method at the High-Intensity ... Full text Cite

Tm 169 (n,2n) Tm 168 and Tm 169 (n,3n) Tm 167 cross-section measurements from 15 to 21 MeV

Journal Article Physical Review C · April 1, 2021 The Tm169(n,2n)Tm168 and Tm169(n,3n)Tm167 cross sections have been measured in the neutron energy range between 15 and 21 MeV using the H3(d,n)He4 neutron source reaction. The Tm169(n,3n)Tm167 data are intended to provide an accurate database for interpret ... Full text Cite

Potential neutron-induced γ -ray background on natural tellurium relevant to Te 130 0νββ decay searches at the CUORE and SNO+ detectors

Journal Article Physical Review C · April 1, 2021 Gamma-ray production cross-section data have been obtained for the inelastic neutron scattering reactions Te126,128,130(n,n′γ) at five neutron energies between 3.6 and 10 MeV. We report data for the γ-ray energy region relevant to 0νββ decay of Te130 with ... Full text Cite

Measurements of Short-Lived Isomers from Photofission as a Method of Active Interrogation for Special Nuclear Materials

Journal Article Physical Review Applied · March 1, 2021 Isomeric fission products, such as 134mTe (T1/2=164 ns) and 136mXe (T1/2=2.95μs), are proposed as a signature of special nuclear materials in active interrogation applications. To test this conjecture, monoenergetic 9, 11, and 13 MeV photons from the HIγS ... Full text Cite

Electric and magnetic dipole strength in Zn 66

Journal Article Physical Review C · February 1, 2021 The dipole strength of the nuclide Zn66 was studied in photon-scattering experiments using bremsstrahlung produced with electron beams of energies of 7.5 and 13.4 MeV at the γELBE facility as well as using quasimonoenergetic and linearly polarized photon b ... Full text Cite

Firm spin and parity assignments for high-lying, low-spin levels in stable Si isotopes

Journal Article European Physical Journal A · April 1, 2020 A natural silicon target was investigated in a natSi(γ, γ′) photon-scattering experiment with fully linearly-polarised, quasi-monochromatic γ rays in the entrance channel. The mean photon energies used were ⟨ Eγ⟩ = 9.33, 9.77, 10.17, 10.55, 10.93, and 11.3 ... Full text Cite

Fission Product Yield Measurements from Neutron-Induced Fission of 235,238 U and 239Pu

Conference EPJ Web of Conferences · 2020 Fission product yields (FPY) are one of the most fundamental quantities that can be measured for a fissioning nucleus and are important for basic and applied nuclear physics. Recent measurements using mono-energetic and pulsed neutron beams generat ... Full text Cite

Toward short-lived and energy-dependent fission product yields from neutron-induced fission

Conference EPJ Web of Conferences · 2020 Fission product yields (FPYs) are an important source of information that are used for basic and applied physics. They are essential observables to address questions relevant to nucleosynthesis in the cosmos that created the elements from iron to u ... Full text Cite

Validating the Bohr hypothesis: Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of Pu

Conference EPJ Web of Conferences · 2020 The Bohr hypothesis, one of the most fundamental assumptions in nuclear fission theory, states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation. Using fission product yields (FPYs) ... Full text Cite

Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of 239Pu as a test of the Bohr hypothesis in nuclear fission

Journal Article EPJ Web of Conferences · 2020 Fission product yields (FPYs) are a uniquely sensitive probe of the fission process, with well established dependence on the species of nucleus undergoing fission, its excitation energy and spin. Thus FPYs are well suited for testing Bohr’s hypothe ... Full text Cite

Measurements of short-lived fission product yields using monoenergetic neutron and photon beams

Journal Article EPJ Web of Conferences · 2020 A joint TUNL-LLNL-LANL collaboration was formed to measure the absolute fission product yields from the 235 U, 238 U, and 239 Pu isotopes. Our goal is to study the energy evolution of f ... Full text Cite

Observation of Low-Lying Isomeric States in ^{136}Cs: A New Avenue for Dark Matter and Solar Neutrino Detection in Xenon Detectors.

Journal Article Physical review letters · August 2023 We report on new measurements establishing the existence of low-lying isomeric states in ^{136}Cs using γ rays produced in ^{136}Xe(p,n)^{136}Cs reactions. Two states with O(100)  ns lifetimes are placed in the decay sequence of the ^{136}Cs levels that ar ... Full text Cite

Testing shell-model interactions at high excitation energy and low spin: Nuclear resonance fluorescence in Ge 74

Journal Article Physical Review C · August 1, 2023 With their complex low-spin structure, the germanium isotopes have accrued a large number of experimental data which challenge nuclear models. The structure of the Ge74 isotope is investigated here with nuclear resonance fluorescence as part of an extensiv ... Full text Cite

Fission product yields from the U 238 (n,f) reaction at En=4.6 MeV

Journal Article Physical Review C · May 1, 2023 We present cumulative fission product yields from the U238(n,f) reaction at an incident energy of 4.6 MeV for fission products with half-lives from less than one second to several hours. We employed direct γ-ray spectroscopy to measure unseparated fission ... Full text Cite

Neutral-current neutrino cross section and expected supernova signals for 40Ar from a three-fold increase in the magnetic dipole strength

Journal Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics · December 10, 2022 In view of the great interest in liquid argon neutrino detectors, the 40Ar(γ,γ′)40Ar reaction was revisited to guide a calculation of the neutral current neutrino cross section at supernova energies. Using the nuclear resonance fluorescence technique with ... Full text Cite

Model-independent determination of the dipole response of Zn 66 using quasimonoenergetic and linearly polarized photon beams

Journal Article Physical Review C · October 1, 2022 Background: Photon strength functions are an important ingredient in calculations relevant for the nucleosynthesis of heavy elements. The relation to the photoabsorption cross section allows to experimentally constrain photon strength functions by investig ... Full text Cite

Investigation of B 11 and Ca 40 levels at 8-9 MeV by nuclear resonance fluorescence

Journal Article Physical Review C · July 1, 2022 We report on the measurement of B11 and Ca40 levels between excitation energies of 8 and 9 MeV using nuclear resonance fluorescence (NRF). The experiment was carried out with nearly monoenergetic and linearly polarized photon beams provided by the High-Int ... Full text Cite

Development of a rapid-transit system for precision nuclear physics measurements

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · February 11, 2022 A Rapid Belt-driven Irradiated Target Transfer System, named RABITTS, was developed for use at the Triangle Universities Nuclear Laboratory. This system allows for cyclic activation with neutron or photon beams, and measurement of reaction products using γ ... Full text Cite

Majorana parameters of the interacting boson model of nuclear structure and their implication for 0νββ decay

Journal Article Physical Review C · December 1, 2021 The well-known spherical-deformed-transitional nucleus and potential 0νββemitter Nd150and its daughter Sm150were investigated in nuclear resonance fluorescence experiments using quasimonoenergetic, linearly polarized γ-ray beams. For both nuclei transition ... Full text Cite

Structure of high-lying levels populated in the 96Y →96Zr β decay

Journal Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics · September 10, 2021 The nature of the high-lying final levels of the 96Ygs β decay, one of the three most important contributors to the high-energy reactor antineutrino spectrum, has been investigated in high-resolution γ-ray spectroscopy following the β decay as well as in a ... Full text Cite

E2 decay characteristics of the M1 scissors mode of Sm 152

Journal Article Physical Review C · May 1, 2021 The E2/M1 multipole mixing ratio of the 1sc+→21+γ-ray transition and therefore the F-vector E2 decay of the scissors mode of the shape-phase transitional nucleus Sm152 have been measured with the nuclear resonance fluorescence method at the High-Intensity ... Full text Cite

Tm 169 (n,2n) Tm 168 and Tm 169 (n,3n) Tm 167 cross-section measurements from 15 to 21 MeV

Journal Article Physical Review C · April 1, 2021 The Tm169(n,2n)Tm168 and Tm169(n,3n)Tm167 cross sections have been measured in the neutron energy range between 15 and 21 MeV using the H3(d,n)He4 neutron source reaction. The Tm169(n,3n)Tm167 data are intended to provide an accurate database for interpret ... Full text Cite

Potential neutron-induced γ -ray background on natural tellurium relevant to Te 130 0νββ decay searches at the CUORE and SNO+ detectors

Journal Article Physical Review C · April 1, 2021 Gamma-ray production cross-section data have been obtained for the inelastic neutron scattering reactions Te126,128,130(n,n′γ) at five neutron energies between 3.6 and 10 MeV. We report data for the γ-ray energy region relevant to 0νββ decay of Te130 with ... Full text Cite

Measurements of Short-Lived Isomers from Photofission as a Method of Active Interrogation for Special Nuclear Materials

Journal Article Physical Review Applied · March 1, 2021 Isomeric fission products, such as 134mTe (T1/2=164 ns) and 136mXe (T1/2=2.95μs), are proposed as a signature of special nuclear materials in active interrogation applications. To test this conjecture, monoenergetic 9, 11, and 13 MeV photons from the HIγS ... Full text Cite

Electric and magnetic dipole strength in Zn 66

Journal Article Physical Review C · February 1, 2021 The dipole strength of the nuclide Zn66 was studied in photon-scattering experiments using bremsstrahlung produced with electron beams of energies of 7.5 and 13.4 MeV at the γELBE facility as well as using quasimonoenergetic and linearly polarized photon b ... Full text Cite

Firm spin and parity assignments for high-lying, low-spin levels in stable Si isotopes

Journal Article European Physical Journal A · April 1, 2020 A natural silicon target was investigated in a natSi(γ, γ′) photon-scattering experiment with fully linearly-polarised, quasi-monochromatic γ rays in the entrance channel. The mean photon energies used were ⟨ Eγ⟩ = 9.33, 9.77, 10.17, 10.55, 10.93, and 11.3 ... Full text Cite

Fission Product Yield Measurements from Neutron-Induced Fission of 235,238 U and 239Pu

Conference EPJ Web of Conferences · 2020 Fission product yields (FPY) are one of the most fundamental quantities that can be measured for a fissioning nucleus and are important for basic and applied nuclear physics. Recent measurements using mono-energetic and pulsed neutron beams generat ... Full text Cite

Toward short-lived and energy-dependent fission product yields from neutron-induced fission

Conference EPJ Web of Conferences · 2020 Fission product yields (FPYs) are an important source of information that are used for basic and applied physics. They are essential observables to address questions relevant to nucleosynthesis in the cosmos that created the elements from iron to u ... Full text Cite

Validating the Bohr hypothesis: Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of Pu

Conference EPJ Web of Conferences · 2020 The Bohr hypothesis, one of the most fundamental assumptions in nuclear fission theory, states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation. Using fission product yields (FPYs) ... Full text Cite

Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of 239Pu as a test of the Bohr hypothesis in nuclear fission

Journal Article EPJ Web of Conferences · 2020 Fission product yields (FPYs) are a uniquely sensitive probe of the fission process, with well established dependence on the species of nucleus undergoing fission, its excitation energy and spin. Thus FPYs are well suited for testing Bohr’s hypothe ... Full text Cite

Measurements of short-lived fission product yields using monoenergetic neutron and photon beams

Journal Article EPJ Web of Conferences · 2020 A joint TUNL-LLNL-LANL collaboration was formed to measure the absolute fission product yields from the 235 U, 238 U, and 239 Pu isotopes. Our goal is to study the energy evolution of f ... Full text Cite

Measurement of the in 115 (γ,γ′) in 115m inelastic scattering cross section in the 1.8 to 3.7 MeV energy range with monoenergetic photon beams MEASUREMENT of the in 115 (γ, ... W. TORNOW et al.

Journal Article Physical Review C · December 6, 2018 For the first time the excitation cross section of In115 to its first excited state at 336.24 keV has been measured with monoenergetic photon beams at 15 energies between 1.8 and 3.7 MeV. The measurements were performed at the High-Intensity Gamma-ray Sour ... Full text Cite

Nuclear structure of 82Kr and 82Se relevant for neutrinoless double-beta decay

Conference EPJ Web of Conferences · November 14, 2018 Nuclear Resonance Fluorescence (NRF) experiments on the nuclei 82Kr and 82Se were performed, that are a candidates for a mother-daughter pair for the hypothetical neutrinoless double-beta (0νββ) decay. The experiment aimed at providing high-precision data ... Full text Cite

Partial cross section of neutron-induced reactions on 136Xe at e n = 5 MeV for 0νββ background studies

Journal Article Journal of Physics G: Nuclear and Particle Physics · November 12, 2018 Partial cross section measurements were carried out on 136Xe at Triangle Universities Nuclear Laboratory (TUNL) using 5 MeV monoenergetic neutrons. These results are important for estimating potential neutron-induced backgrounds in the nEXO and KamLAND2-Ze ... Full text Cite

Photofission cross-section ratio measurement of 235 U/238 U using monoenergetic photons in the energy range of 9.0–16.6 MeV

Journal Article Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · 2017 Cite

Search for the β decay of 96Zr

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · January 11, 2016 96Zr and 48Ca are unique among double-β decay candidate nuclides in that they may also undergo single-β decay. In the case of 96Zr, the single-β decay mode is dominated by the fourth-forbidden β decay with a 119 keV Q value. A search was conducted for the ... Full text Cite

Search for neutrinoless double-electron capture of Dy 156

Journal Article Physical Review C - Nuclear Physics · December 31, 2015 Background: Multiple large collaborations are currently searching for neutrinoless double-β decay, with the ultimate goal of differentiating the Majorana-Dirac nature of the neutrino. Purpose: Investigate the feasibility of resonant neutrinoless double-ele ... Full text Cite

Search for two-neutrino double- β decay of Zr 96 to excited states of Mo 96

Journal Article Physical Review C - Nuclear Physics · October 8, 2015 Background: Double-β decay is a rare second-order nuclear decay. The importance of this decay stems from the possibility of neutrinoless double-β decay and its applications to neutrino physics. Purpose: A search was conducted for the 2νββ decay of Zr96 to ... Full text Cite

136Xe(n,2n)135Xe cross section between 9 and 15 MeV

Journal Article Physical Review C - Nuclear Physics · January 22, 2013 The cross section of the reaction 136Xe(n,2n)135Xe to both the ground state and the 526.6 keV isomeric states of 135Xe was measured between 9.0 and 14.9 MeV. These data are important to guide evaluations and theoretical calculations aimed at estimating the ... Full text Cite

40Ar(n,p)40Cl reaction cross section between 9 and 15 MeV

Journal Article Physical Review C - Nuclear Physics · October 11, 2012 The activation technique was used to measure the cross section for the reaction 40Ar(n,p)40Cl in 0.5 MeV energy steps in the neutron energy range between 9 and 15 MeV. These data are important for estimating background contributions in neutrinoless double- ... Full text Cite