A team of Chinese physicists has synthesized two new isotopes: osmium-160 and tungsten-156.
Location of the new isotopes osmium-160 and tungsten-156 on the nuclide chart. Image credit: Huabin Yang.
“The magic numbers of protons and neutrons make the nucleus particularly stable. The traditional magic numbers are 8, 20, 28, 50, 82, and 126,” said Dr. Huabin Yang, a physicist at the Institute of Modern Physics, Chinese Academy of Sciences. said the colleague.
“In previous research, physicists discovered that traditional magic numbers disappear and new magic numbers appear on the neutron-rich side of the nuclide chart.”
“Will other traditional magical numbers also disappear in the nuclear region where there is an extreme lack of neutrons?”
“Further exploration is critical to enriching and developing nuclear theory and improving our understanding of nuclear forces.”
In the new study, Dr. Yang's team conducted experiments at the Gas-Filled Recoil Separator Spectrometer for Heavy Atom and Nuclear Structures (SHANS) in Lanzhou, China.
Researchers have synthesized two new isotopes, osmium-160 and tungsten-156, using nuclear fusion vaporization reactions.
They measured the energy of the alpha particle and the half-life of the alpha-emitting isotope osmium-160.
On the other hand, the daughter nucleus, tungsten-156, was found to be a β+ emitter with a half-life of 291 ms.
The researchers used the newly measured alpha decay data to derive the alpha decay reduction for osmium-160 and compared it to other nuclei with 84 neutrons and fewer protons.
They discovered a surprising trend: the higher the number of protons, the lower the decay rate.
“This trend is interpreted as evidence of enhanced closure of the 82 neutron shell towards the proton drip line, which is supported by the increase in the neutron shell gap predicted by the theoretical model,” Dr. Yang said. said.
“The increased stability of the 82 neutron shell closure is thought to be due to the increasing proximity of the double magic nucleus lead 164, which may be a stable atomic nucleus with 82 protons and 82 neutrons. Masu.”
“Although lead-164 is predicted to cross the proton drip line, enhanced shell effects could make it a bonded or quasi-bonded nucleus.”
of study It was published in the magazine physical review letter.
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HB Yang other. 2024. Discovery of new isotopes 160with oz 156W: Reveals improved stability of N=82 shell closure on the neutron-deficient side. Physics.pastor rhett 132 (7): 072502; doi: 10.1103/PhysRevLett.132.072502
Source: www.sci.news
