Publications (30)
Exploring Isospin Symmetry Breaking in Exotic Nuclei: High-Precision Mass Measurement of 23Si and Shell-Model Calculations of T = 5/2 Nuclei
F. M. Maier, G. Bollen, B. A. Brown +9
We present a high-precision mass measurement of the proton-rich nucleus 23Si, performed with the LEBIT Penning trap at the Facility for Rare Isotope Beams (FRIB) utilizing the time…
First direct determination of the superallowed -decay -value for O
A. A. Valverde, G. Bollen, M. Brodeur +12
We report the first direct measurement of the superallowed Fermi -decay -value, the last of the so-called "traditional nine" superallowed Fermi -dec…
High-precision mass measurement of Si and a refined determination of the process at the waiting point
D. Puentes, Z. Meisel, G. Bollen +11
We report a high precision mass measurement of , performed with the LEBIT facility at the National Superconducting Cyclotron Laboratory. The atomic mass excess, $10\…
Investigation of potential ultra-low -value -decay candidates Sr and Ba using Penning trap mass spectrometry
R. Sandler, G. Bollen, N. D. Gamage +6
Background: Ultra-low -value -decays are interesting processes to study with potential applications to nuclear -decay theory and neutrino physics. While a number of pote…
Lightweight self-conjugate nucleus Zr
A. Hamaker, E. Leistenschneider, R. Jain +10
Protons and neutrons in the atomic nucleus move in shells analogous to the electronic shell structures of atoms. Nuclear shell structure varies across the nuclear landscape due to…
High precision mass measurements of the isomeric and ground states of V: improving constraints on the IMME parameters of the A=44, quintet
D. Puentes, G. Bollen, M. Brodeur +16
The Isobaric Multiplet Mass Equation (IMME) has been successful at predicting the masses of isobaric analogue states in the same multiplet, while its coefficients are known to foll…
Mass Measurement of P to Constrain Type-I X-ray Burst Models and Validate the IMME for the A=27, T= Isospin Quartet
I. T. Yandow, A. Abdullah-Smoot, G. Bollen +12
Light curves are the primary observable of type-I x-ray bursts. Computational x-ray burst models must match simulations to observed light curves. Most of the error in simulated cur…
Precision Mass Measurement of Proton-Dripline Halo Candidate Al
S. E. Campbell, G. Bollen, B. A. Brown +12
We report the first mass measurement of the proton-halo candidate Al performed with the LEBIT facility's 9.4~T Penning trap mass spectrometer at FRIB. This measurement compl…
The cyclotron gas stopper project at the NSCL
C. Guenaut, G. Bollen, S. Chouhan +9
Gas stopping is becoming the method of choice for converting beams of rare isotopes obtained via projectile fragmentation and in-flight separation into low-energy beams. These beam…
A linear radiofrequency ion trap for accumulation, bunching, and emittance improvement of radioactive ion beams
F. Herfurth, J. Dilling, A. Kellerbauer +10
An ion beam cooler and buncher has been developed for the manipulation of radioactive ion beams. The gas-filled linear radiofrequency ion trap system is installed at the Penning tr…
High-precision mass measurement of Cu and the redirection of the rp-process flow
A. A. Valverde, M. Brodeur, G. Bollen +14
We report the mass measurement of Cu, using the LEBIT 9.4T Penning trap mass spectrometer at the National Superconducting Cyclotron Laboratory at Michigan State University.…
Pulsed extraction of ionization from helium buffer gas
D. J. Morrissey, G. Bollen, M. Facina +1
The migration of intense ionization created in helium buffer gas under the influence of applied electric fields is considered. First the chemical evolution of the ionization create…
Atomic mass measurements of short-lived nuclides around the doubly-magic 208Pb
C. Weber, G. Audi, D. Beck +7
Accurate atomic mass measurements of neutron-deficient and neutron-rich nuclides around the doubly-magic 208Pb and of neutron-rich cesium isotopes were performed with the Penning t…
High-precision Penning trap mass measurements of neutron-rich chlorine isotopes at the N=28 shell closure
H. Erington, G. Bollen, G. Dykstra +9
Although it is known that the spherical shell closure erodes, the strength of the closure with decreasing proton number is an open question in nuclear structure. In t…
First Penning trap mass measurement of Ca
J. Surbrook, G. Bollen, M. Brodeur +13
Isobaric quintets provide the best test of the isobaric multiplet mass equation (IMME) and can uniquely identify higher order corrections suggestive of isospin symmetry breaking ef…
Precision mass measurements of neutron-rich scandium isotopes refine the evolution of and shell closures
E. Leistenschneider, E. Dunling, G. Bollen +17
We report high-precision mass measurements of Sc isotopes performed at the LEBIT facility at NSCL and at the TITAN facility at TRIUMF. Our results provide a substantial r…
Electric and magnetic field optimization procedure for Penning trap mass spectrometers
D. Beck, K. Blaum, G. Bollen +8
Significant systematic errors in high-precision Penning trap mass spectrometry can result from electric and magnetic field imperfections. An experimental procedure to minimize thes…
Particle-in-Cell Techniques for the Study of Space Charge Effects in the Advanced Cryogenic Gas Stopper
R. Ringle, G. Bollen, K. Lund +4
Linear gas stoppers are widely used to convert high-energy, rare-isotope beams and reaction products into low-energy beams with small transverse emittance and energy spread. Stoppi…
Direct determination of the La -decay value using Penning trap mass spectrometry
R. Sandler, G. Bollen, J. Dissanayake +10
Background: The understanding and description of forbidden decays provides interesting challenges for nuclear theory. These calculations could help to test underlying nuclear model…
Identification of a potential ultra-low Q value electron capture decay branch in Se via a precise Penning trap measurement of the mass of As
M. Horana Gamage, R. Bhandari, G. Bollen +8
Background: Low energy and electron capture (EC) decays are important systems in neutrino mass determination experiments. An isotope with an ultra-low Q value -decay to an…
High-precision mass measurements of nickel, copper, and gallium isotopes and the purported shell closure at N=40
C. Guenaut, G. Audi, D. Beck +11
High-precision mass measurements of more than thirty neutron-rich nuclides around the Z=28 closed proton shell were performed with the triple-trap mass spectrometer ISOLTRAP at ISO…
Status of the NSCL Cyclotron Gas Stopper
N. Joshi, G. Bollen, M. Brodeur +2
A gas-filled reverse cyclotron for the thermalisation of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight sepa…
Investigating nuclear structure near and : Precision mass measurements of neutron-rich Ca, Ti and V isotopes
W. S. Porter, E. Dunling, E. Leistenschneider +32
Nuclear mass measurements of isotopes are key to improving our understanding of nuclear structure across the chart of nuclides, in particular for the determination of the appearanc…
High-precision mass measurement of Sn restores smoothness of the mass surface
C. M. Ireland, F. M. Maier, G. Bollen +20
As a step towards the ultimate goal of a high-precision mass measurement of doubly-magic Sn, the mass of Sn was measured at the Low Energy Beam and Ion Trap (LEBIT)…
A high-voltage MR-ToF mass spectrometer and separator for the study of exotic isotopes at FRIB
F. M. Maier, C. M. Ireland, G. Bollen +7
The Facility for Rare Isotope Beams (FRIB) delivers a wide variety of rare isotopes as fast, stopped, or reaccelerated beams to enable forefront research in nuclear structure, astr…
Improved Nuclear Physics Near Refines Urca Neutrino Luminosities in Accreted Neutron Star Crusts
Zach Meisel, Alec Hamaker, G. Bollen +16
We performed a Penning trap mass measurement of at the National Superconducting Cyclotron Laboratory and NuShellX calculations of the and $^{62}{\rm…
Precision Mass Measurements of Neutron-Rich Co Isotopes Beyond N=40
C. Izzo, G. Bollen, M. Brodeur +12
The region near Z=28, N=40 is a subject of great interest for nuclear structure studies due to spectroscopic signatures in Ni suggesting a subshell closure at N=40. Trends i…
High-Precision Mass Measurements of 52Ni and 51Co Reveal Breakdown of the Isobaric Multiplet Mass Equation in the f p Shell
F. M. Maier, G. Bollen, B. A. Brown +10
We performed high-precision mass measurements of the proton-rich nuclei Ni and Co with the LEBIT Penning trap at the Facility for Rare Isotope Beams (FRIB). For $^{52…
First direct Be electron capture -value measurement towards high-precision BSM neutrino physics searches
R. Bhandari, G. Bollen, T. Brunner +12
We report the first direct measurement of the nuclear electron capture (EC) decay -value of Be Li via high-precision Penning trap mass spectrometry (PT…
Measurements and computational analysis on the natural decay of Lu
F. G. A. Quarati, G. Bollen, P. Dorenbos +12
Mainly because of its long half-life and despite its scientific relevance, spectroscopic measurements of Lu forbidden -decays are very limited and lack formulation of s…