Publications (34)
Weak binding effects on the structure of Mg
A. O. Macchiavelli, H. L. Crawford, P. Fallon +2
While the phenomenon of one- and two-neutron ground-state halo nuclei is well established, the effects of weak binding on nuclear excitation properties remain largely unexplored. M…
UCGretina GEANT4 Simulation of the GRETINA Gamma-Ray Energy Tracking Array
L. A. Riley, D. Weisshaar, H. L. Crawford +12
UCGretina, a GEANT4 simulation of the GRETINA gamma-ray tracking array of highly-segmented high-purity germanium detectors is described. We have developed a model of the array, in…
Prompt-delayed -ray spectroscopy of neutron-rich In isotopes
S. Biswas, A. Lemasson, M. Rejmund +23
The fusion and transfer induced fission reaction Be(U,~f) with 6.2 MeV/u beam energy, using a unique setup consisting of AGATA, VAMOS++ and EXOGAM detectors, was used…
Spectroscopy of Mg with knockout reactions
D. Bazin, N. Aoi, H. Baba +16
The structure of Mg was investigated by means of two knockout reactions, one-neutron removal from Mg and one-proton removal from Al. Using comparative analysis…
Unexpected distribution of strength in the calcium isotopes at =30
H. L. Crawford, A. O. Macchiavelli, P. Fallon +30
The calcium isotopes have emerged as an important testing ground for new microscopically derived shell-model interactions, and a great deal of focus has been directed toward this r…
Understanding the Low-Energy Enhancement of the -ray Strength Function of Fe
M. D. Jones, A. O. Macchiavelli, M. Wiedeking +27
A model-independent technique was used to determine the -ray Strength Function (SF) of Fe down to -ray energies less than 1 MeV for the first time with GRETINA u…
Evidence for rigid triaxial deformation in Ge from a model-independent analysis
A. D. Ayangeakaa, R. V. F. Janssens, S. Zhu +25
An extensive, model-independent analysis of the nature of triaxial deformation in Ge, a candidate for neutrinoless double-beta () decay, was carried out following m…
Towards the Discovery of New Elements: Production of Livermorium (Z=116) with 50Ti
J. M. Gates, R. Orford, D. Rudolph +51
The Pu(Ti,)Lv reaction was investigated at Lawrence Berkeley National Laboratory's 88-Inch Cyclotron facility. The experiment was aimed at the producti…
The Core of F in the Rotational Model
A. O. Macchiavelli, R. M. Clark, H. L. Crawford +6
In a recent experiment, carried out at RIBF/RIKEN, the FO reaction was studied at 270 MeV/A in inverse kinematics. Derived spectroscopic factors suggest that…
Border of the Island of Inversion: Unbound states in Ne
M. Holl, S. Lindberg, A. Heinz +89
The nucleus Ne is situated at the border of the island of inversion. Despite significant efforts, no bound low-lying intruder -state, which would place Ne fi…
Collective T=0 pairing in N=Z nuclei? Pairing vibrations around 56Ni revisited
A. O. Macchiavelli, P. Fallon, R. M. Clark +9
We present a new analysis of the pairing vibrations around 56Ni, with emphasis on odd-odd nuclei. This analysis of the experimental excitation energies is based on the subtraction…
Search for Strange Matter by Heavy Ion Activation
M. C. Perillo Isaac, Y. D. Chan, R. Clark +12
We present the results of an experimental search for stable strange matter using the heavy ion activation technique. We studied samples of a meteorite, terrestrial nickel ore, and…
Superdeformation in Po
D. P. McNabb, G. Baldsiefen, L. A. Bernstein +17
The Yb(Si,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in Po. Resulting rays were observed with Gammasphe…
Properties of isocalar-pair condensates
P. Van Isacker, A. O. Macchiavelli, P. Fallon +1
It is pointed out that the ground state of n neutrons and n protons in a single-j shell, interacting through an isoscalar (T=0) pairing force, is not paired, J=0, but rather spin-a…
Global Lifetime Measurements of Highly-Deformed and Other Rotational Structures in the A~135 Light Rare-Earth Region: Probing the Single-Particle Motion in a Rotating Potential
M. A. Riley, R. W. Laird, F. G. Kondev +24
It has been possible, using GAMMASPHERE plus Microball,to extract differential lifetime measurements free from common systematic errors for over 15 different nuclei (various isotop…
Incipient magnetic rotation? A magnetic dipole band in 104Cd
D. G. Jenkins, R. Wadsworth, J. A. Cameron +25
High spin states of the nucleus 104Cd have been studied using the Gammapshere array. The level scheme for 104Cd has been revised and evidence for a structure consisting of magnetic…
Level structure of light neutron-rich La isotopes beyond the N=82 shell closure
A. Navin, E. H. Wang, S. Bhattacharyya +32
The high spin excited states of Lanthanum isotopes La, above the closed shell, have been populated in fission reactions. The prompt -ray transitions were mea…
Coriolis coupling effects in proton-pickup spectroscopic factors from B
A. O. Macchiavelli, H. L. Crawford, R. M. Clark +9
Spectroscopic factors to low-lying negative-parity states in Be extracted from the B(,He)Be proton-removal reaction are interpreted within the rotationa…
Well-developed deformation in 42Si
S. Takeuchi, M. Matsushita, N. Aoi +40
Excited states in 38,40,42Si nuclei have been studied via in-beam gamma-ray spectroscopy with multi-nucleon removal reactions. Intense radioactive beams of 40S and 44S provided at…
Is there np pairing in odd-odd N=Z nuclei?
A. O. Macchiavelli, P. Fallon, R. M. Clark +9
The binding energies of even-even and odd-odd N=Z nuclei are compared. After correcting for the symmetry energy we find that the lowest T=1 state in odd-odd N=Z nuclei is as bound…
Fast Rotation of the N=Z Nucleus 36Ar
C. E. Svensson, A. O. Macchiavelli, A. Juodagalvis +30
A highly-deformed rotational band has been identified in the N=Z nucleus 36Ar. At high spin the band is observed to its presumed termination at I=16+, while at low spin it has been…
Search for the intruder state in P
M. Salathe, H. L. Crawford, A. O. Macchiavelli +13
The excitation energy of deformed intruder states (specifically the 2p2h bandhead) as a function of proton number along is of interest both in terms of better understand…
Analysis of Spectroscopic Factors in 11Be and 12Be in the Nilsson Strong Coupling Limit
A. O. Macchiavelli, H. L. Crawford, C. M. Campbell +6
Spectroscopic factors in 10Be, 11Be and 12Be, extracted from (d,p), one neutron knockout, and (p,d) reactions are interpreted within the rotational model. Assuming that the ground…
Extending the Southern Shore of the Island of Inversion to F
A. Revel, O. Sorlin, F. M. Marques +89
Detailed spectroscopy of the neutron-unbound nucleus F has been performed for the first time following proton/neutron removal from Ne/F beams at energies aroun…
A New Measurement of the Partial 0+->0+ Half Life of 10C with GAMMASPHERE
B. K. Fujikawa, S. J. Asztalos, R. M. Clark +13
We report on a new measurement of the strength of the superallowed 0+->0+ transition in the beta-decay of 10C: 10C(0+,g.s.)->10B(0+,1.74MeV)+e+nu. The experiment was done at the LB…
The Core of F studied by the F(-1p)O reaction
H. L. Crawford, M. D. Jones, A. O. Macchiavelli +19
The F(O reaction was studied at the NSCL using the S800 spectrometer. The experimental spectroscopic factor for the ground-state to ground-state transiti…
Intruder configurations in Ne at the transition into the island of inversion: Detailed structure study of Ne
H. Wang, M. Yasuda, Y. Kondo +92
Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed for the first time using the one-neutron removal reaction from Ne on a liquid hydrogen…
Structure of 29F in the Rotation-aligned Coupling Scheme of the Particle-Rotor Model
A. O. Macchiavelli, P. Fallon, H. L. Crawford +6
Recent results from RIKEN/RIBF on the low-lying level structure of 29F are interpreted within the Particle-Rotor Model. We show that the experimental data can be understood in the…
Structure of P and Si in a two-level shape-coexistence model
A. O. Macchiavelli, H. L. Crawford, C. M. Campbell +7
Exclusive cross sections for the PSi reaction to the lowest and states, measured at NSCL with GRETINA and the S800, are interpreted in terms of a two…
Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich Sb isotopes
S. Biswas, A. Lemasson, M. Rejmund +58
The neutron-rich Sb isotopes were produced as fission fragments in the reaction Be(U,~f) with 6.2 MeV/u beam energy. An unique setup, consisting of AGATA,…
Onset of Collectivity in Neutron Deficient Po
L. A. Bernstein, J. A. Cizewski, H. -Q. Jin +30
We have studied via in-beam -ray spectroscopy Po and Po, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The rati…
Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB
T. J. Gray, J. M. Allmond, Z. Xu +63
Excited-state spectroscopy from the first Facility for Rare Isotope Beams (FRIB) experiment is reported. A 24(2)-s isomer was observed with the FRIB Decay Station initiator (FD…
E2 Rotational Invariants of and states for Cd: the Emergence of Collective Rotation
T. J. Gray, J. M. Allmond, R. V. F. Janssens +29
The collective structure of Cd is elucidated by multi-step Coulomb excitation of a 3.849 MeV/ beam of Cd on a 1.1 mg/cm Pb target using GRETINA-CHICO…
Probing the role of proton cross-shell excitations in 70Ni using nucleon knockout reactions
B. Elman, A. Gade, R. V. F. Janssens +21
The neutron-rich Ni isotopes have attracted attention in recent years due to the occurrence of shape or configuration coexistence. We report on the difference in population of exci…