First direct mass measurements of nuclides around $Z=100$ with a Multireflection Time-of-Flight Mass Spectrograph

Abstract

The masses of ${}^{246}$Es, ${}^{251}$Fm and the transfermium nuclei ${}^{249-252}$Md, and ${}^{254}$No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed $N=152$ neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ${}^{246}$Es and ${}^{249,250,252}$Md were measured for the first time. Using the masses of ${}^{249,250}$Md as anchor points for $\alpha$ decay chains, the masses of heavier nuclei, up to ${}^{261}$Bh and ${}^{266}$Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter ${\delta }_{2n}$ derived from three isotopic masses was updated with the new masses and corroborate the existence of the deformed $N=152$ neutron shell closure for Md and Lr.

References in corpus (11)

• Nuclear ground-state masses and deformations: FRDM(2012)
• Nuclear magic numbers: new features far from stability
• Microscopic mass formulae
• Surface diffuseness correction in global mass formula
• Superheavy nuclei in selfconsistent nuclear calculations
• Shell stabilization of super- and hyperheavy nuclei without magic gaps
• Direct mapping of nuclear shell effects in the heaviest elements
• Nuclear mass predictions with radial basis function approach
• Single-reference high-precision mass measurement with a multi-reflection time-of-flight mass spectrograph
• A novel ion cooling trap for multi-reflection time-of-flight mass spectrograph
• New nuclear structure features in transactinide nuclei

Cited by in corpus (16)

• Nuclear mass predictions with machine learning reaching the accuracy required by $r$-process studies
• Quantified limits of the nuclear landscape
• High-resolution, accurate MR-TOF-MS for short-lived, exotic nuclei of few events in their ground and low-lying isomeric states
• Beyond the proton drip line: Bayesian analysis of proton-emitting nuclei
• Nucleosynthesis and observation of the heaviest elements
• Improving wide-band mass measurements in a multi-reflection time-of-flight mass spectrograph by usage of a concomitant measurement scheme
• New mass anchor points for neutron-deficient heavy nuclei from direct mass measurements of radium and actinium isotopes
• A new study of the $N=32$ and $N=34$ shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI
• Atomic masses of intermediate-mass neutron-deficient nuclei with relative uncertainty down to 35-ppb via multireflection time-of-flight mass spectrograph
• Design of a Multiple-Reflection Time-of-Flight Mass-Spectrometer for Barium-tagging
• Development of an "$\alpha$-ToF" detector for correlated measurement of atomic masses and decay properties
• Limitations of the Geiger-Nuttall Law in heavy cluster decay
• AMC 12 atomic mass compilation data extrapolated for atomic masses of nuclei far from the valley of stability
• Accurately accounting for effects on times-of-flight caused by finite field-transition times during the ejection of ions from a storage trap: A study for TOF and MRTOF mass spectrometry
• Reduction of contaminants originating from primary beam by improving the beam stoppers in GARIS-II
• First high-precision direct determination of the atomic mass of a superheavy nuclide