The discoveries, made at MSU’s National Superconducting Cyclotron Laboratory using an isotope purification device, will help to refine theoretical models about how elements are created in the cosmos. Until now, this was beyond the technical reach of nearly all of the world's nuclear science facilities.
To be published December 12 in Physical Review Letters, the paper details how the researchers were able to measure the nuclei of tin, cadmium and indium.
"Tin-100, in particular, has been sort of a holy grail of experimental nuclear physics," said NSCL senior physicist Daniel Bazin of one of the isotopes, with 50 protons and 50 neutrons, described in the paper.
Within nuclear science, 50 is considered "magic" because it's one of a handful of numbers associated with extra stability. The other magic numbers are 2, 8, 20, 28, 82 and 126.
It takes a magic number of protons or neutrons to fill the nested energetic shells that form the nucleus like stacking Russian matryoshka dolls. To understand the concept, consider that each carved doll similarly has a magic number of marbles that precisely and completely fills the hollow interior. And just as a doll full of marbles neatly packed together is probably sturdier than one that's only half or a quarter full, so too is a closed-shell nucleus more stable than its counterparts.
Tin-100 is one of the few “doubly magic” nuclei with magic numbers of both protons and neutrons. Such nuclei are generally far more stable than other particles, especially at the fleeting, shape-shifting edge of nuclear existence. Because of this stability, doubly magic nuclei serve as useful semi-permanent signposts to rare isotope researchers who troll the unexplored terrain of the nuclear landscape seeking to answer basic questions about the structure of nuclear matter and processes that create chemical elements inside stars.
The new experimental device, the radio frequency fragment separator, provides at least a hundredfold boost to NSCL's ability to filter out the few exotic isotopes from the vast sea of other particles produced by its coupled superconducting cyclotrons and downstream magnets. Funding for the equipment was provided by the National Science Foundation.
This newfound filtering ability resulted in the first production and measurement in North America of tin-100, which has been eagerly pursued by experimentalists since at least the mid-1990s. GSI in Germany and GANIL in France are the only other nuclear science facilities in the world to have successfully produced and studied the rare, proton-rich isotope of tin, an element extensively used for thousands of years in everything from ancient spears and knives to cars and modern electronics.
In their paper, a draft version of which is available online on the arxiv.org preprint server (http://arxiv.org/abs/0810.3597), Bazin and his collaborators also report the measurement of half-lives of the cadmium-96 (48 protons and 48 neutrons) and indium-98 (49 protons and 49 neutrons) isotopes.
The announcement of the observation of the three rare isotopes builds on recent NSCL success in creating nuclear matter that otherwise only exists in extreme environments in space, such as exploding stars. In fall 2007, the laboratory reported the discovery of three neutron-rich isotopes of magnesium and aluminum in the journal Nature, a finding that received considerable media attention in the science and mainstream press.
The laboratory is currently undertaking a major MSU-funded upgrade, the centerpiece of which is a new low-energy reaccelerator that will be used to conduct astrophysical research. When this upgrade is completed in summer 2010, NSCL will be only facility in the world capable of offering experimentalists the chance to conduct research with fast, stopped and reaccelerated beams of rare isotopes.
A world leader in rare isotope research and nuclear science education, NSCL is a user facility serving 700 researchers in 32 countries.
Geoff Koch | Newswise Science News
Molecule flash mob
19.01.2017 | Technische Universität Wien
Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy