Mar 8 2019
Nuclear reactions cause the Sun to shine and have a key role to play in the chemical evolution of the cosmos. The human body and matter everywhere are made up of chemical elements largely created in stars via nuclear reactions and intricate nuclear reaction networks. To comprehend these processes, one needs to be aware properties of participating nuclei, for example, their masses. Here precision is key as even a minute variation in the nuclear mass can have a substantial impact on reaction rates and ultimately on the abundances of formed elements.
Laetitia Canete, in a doctoral thesis in the field of nuclear physics at the University of Jyväskylä, has measured the atomic masses of the radioactive isotope of six elements. The measurement data can be used to properly model various space processes.
Stable ion beams from the K-130 cyclotron in the JYFL Accelerator Laboratory of the University of Jyväskylä, was used to create nuclei applicable for nuclear astrophysics by impinging them into a thin target foil at the Ion Guide Isotope Separator On-Line (IGISOL) facility. The produced radioactive isotopes were conveyed into the JYFLTRAP double Penning trap mass spectrometer where their atomic mass values are established with a precision of about 10 ppb. During her PhD, Laetitia Canete measured masses of six radioactive nuclei, 25Al, 30P, 31Cl, 67Fe, 69Co and 70Co.
The measurements are applicable to different astrophysical issues. The production of the observed cosmic 1809-keV g-rays emanating from 26Al can be sidestepped by proton captures on 25Al. The proton-capture rate, and thereby the amount of generated 1809-keV g-rays, is impacted by the mass of 25Al. The mass of 30P is vital for constraining the proton-capture rate on 30P (p,g) 31S regulating the creation of elements heavier than sulfur in novae. The mass of 31Cl plays a role in type I X-ray bursts, and is also crucial for getting an insight into the central properties of the nuclear force between neutrons and protons. The masses of 67Fe, 69Co, and 70Co impact the rapid neutron capture process, making about half of the elements heavier than iron.
In 2014, Laetitia Canete received her Master’s degree in subatomic physics and astrophysics at University Lyon, France. In the summer of 2014, she entered the Department of Physics of the University of Jyväskylä and began her doctoral studies within the IGISOL group in the Accelerator Laboratory of the University of Jyväskylä.