140 research outputs found
Atomic masses of intermediate-mass neutron-deficient nuclei with relative uncertainty down to 35-ppb via multireflection time-of-flight mass spectrograph
High-precision mass measurements of Cu, Zn, Ga,
Ge, As, Br, Rb, and Sr were performed
utilizing a multireflection time-of-flight mass spectrograph combined with the
gas-filled recoil ion separator GARIS-II. In the case of Ga, a mass
uncertainty of 2.1 keV, corresponding to a relative precision of , was obtained and the mass value is in excellent agreement
with the 2016 Atomic Mass Evaluation. For Ge and Br, where masses
were previously deduced through indirect measurements, discrepancies with
literature values were found. The feasibility of using this device for mass
measurements of nuclides more neutron-deficient side, which have significant
impact on the -process pathway, is discussed.Comment: 15 pages, 6 figures, 1 tabl
Cardiovascular magnetic resonance tagging imaging correlates with myocardial dysfunction and T2 mapping in idiopathic dilated cardiomyopathy
To evaluate the details of myocardial dysfunction in dilated cardiomyopathy (DCM) patients using tagging images and the correlation of tagging imaging with tissue characteristics. C
The new MRTOF mass spectrograph following the ZeroDegree spectrometer at RIKEN's RIBF facility
A newly assembled multi-reflection time-of-flight mass spectrograph
(MRTOF-MS) at RIKEN's RIBF facility became operational for the first time in
spring 2020; further modifications and performance tests using stable ions were
completed in early 2021. By using a pulsed-drift-tube technique to modify the
ions' kinetic energy in a wide range, we directly characterize the dispersion
function of the system for use in a new procedure for optimizing the voltages
applied to the electrostatic mirrors. Thus far, a mass resolving power of is reached within a total time-of-flight of only
, making the spectrometer capable of studying short-lived
nuclei possessing low-lying isomers. Detailed information about the setup and
measurement procedure is reported, and an alternative in-MRTOF ion selection
scheme to remove molecular contaminants in the absence of a dedicated
deflection device is introduced. The setup underwent an initial on-line
commissioning at the BigRIPS facility at the end of 2020, where more than 70
nuclear masses have been measured. A summary of the commissioning experiments
and results from a test of mass accuracy will be presented.Comment: 13 pages, 11 figure
First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph
The masses of 246Es, 251Fm, and the transfermium nuclei 249−252Md and 254No, 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 246Es and 249,250,252Md were measured for the first time. Using the masses of 249,250Md as anchor points for α decay chains, the masses of heavier nuclei, up to 261Bh and 266Mt, 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 δ2n derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr
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