Physicists in Finland have developed a pumpkin-shaped atomic nucleus that throws protons into a rare type of radioactive decay.
According to PhysicsWorld (opens in a new tab), the nucleus, Lutetium-149, has the shortest half-life of a group of radioactive elements called proton-emitters. It loses half the radiation (decays into other elements) in just 450 nanoseconds, physicists reported on March 16 in the journal Physical Review Letters (opens in a new tab).
Lutetium is a rare earth element found naturally in the form of silver metal with 71 protons and 71 neutrons in its nucleus. It is commonly found next to the metal element ytterbium in the Earth’s crust. In the 1980’s, scientists performed isotope observation of lutetium – the difference of atoms with different numbers of neutrons in the nucleus – known as lutetium-151, which decays and throws out protons from its nucleus while in the ground position. The ground state is the lowest level of energy contained in the electrons of an atom and its most stable configuration. Proton emission is rare, and lutetium-151 was the first isotope in which the proton emitted decays at its steady ground state.
By studying proton decay, researchers can peek inside the nucleus of an atom and understand how protons and neutrons are connected to each other. As part of this line of research, Calle Orenen, a postdoctoral researcher and collaborator in physics at the University of Jevsky, created a new isotope of lutetium, lutetium-149, with 71 protons and 78 neutrons at its center. They found that Lutetium-149 is even more strange than Lutetium-151. For one thing, its nucleus is not a neat round but a rectangular squashed sphere that looks a bit like a pumpkin. This is called olet distortion, and lutetium-149 is the most distorted nucleus ever measured.
Lutetium-149’s blink-and-miss half-life is also significantly shorter than Lutetium-151’s half-life of 80.6 milliseconds.
According to PhysicsWorld, researchers created isotopes by firing on isotopes of nickel, nickel-58, ruthenium, ruthenium-96. New luteinum isotope decay occurs in Yterbium-148, which by itself does not last long: its half-life is 250 milliseconds.
According to PhysicsWorld, it is possible to make lutetium-148, which will last a little longer than lutetium-149.