Tag Archives: nuclear charge radii

Improved evaluation of nuclear charge radii for superheavy nuclei

Although significant progress has been made in the synthesis of superheavy nuclei, the experimental knowledge of them is still very limited while the alpha decay chain is the main tool used to identify newly produced superheavy nuclei. Previously, we have extracted nuclear charge radii of superheavy nuclei via the experimental alpha decay data. As a further step, the density dependent cluster model is improved by introducing the difference between the density distributions of protons and neutrons. Besides, the important quantity, i.e., the alpha preformation factor, is connected with the microscopic correction of nuclear mass during this procedure, to perform a more reasonable description of the alpha decay process. It is found that the present deduced nuclear charge radii of heavy nuclei are in a better agreement with the measured values as compared to those in our previous evaluations. Subsequently, the nuclear radii of heavier even–even isotopes with Z = 98–116 are probed, accompanied by the consistency with the empirical evaluations. Moreover, the effect of the depressed density at the center of superheavy nucleus on the final extracted nuclear radius plus the decay lifetime is discussed, which appears to be different from the case of lighter nuclide.

 

Read full article here

An update of the nuclear moments update: masses and charge radii

For those of you who are following my blog or twitter feed, what I am about to say is not quite new. I have already made a comment a couple of weeks ago regarding the last update of the database I administer. The database contains non-evaluated, experimentally deduced values of nuclear magnetic dipole and electric quadrupole moments. The official release of the database is hosted on IAEA servers and they are responsible for the dissemination of the information included to the world’s nuclear community. However, I keep a test server available for updates and testing new ideas before they appear on the IAEA’s website. This URL is http://magneticmoments.info/data

As I said earlier, a couple of weeks ago I have managed to find the time and upgrade the database with two important observables that people have requested in the recent past. The first one is masses, while the second one is nuclear charge radii. The former is listed in each isotope selected in the database in the form of mass excess Δm (=mass-A). Please notice I do not provide the whole table maintained by the Chinese colleagues (latest AME2012). Rather, I use it as an associate value to the spectroscopic values included when an isotope is selected.

The nuclear charge radii on the other hand is a new addition to the database and I intend to keep updating regardless the official releases (in print format) by IAEA or any other source. The radii are important structure information and as such they will be treated with extra care during each upgrade.

Besides these two extensive updates, lifetimes, spins and parities are slowly being synced with the evaluated data existing in the ENSDF.

You spot a problem or have something to say about the database, please let me know.