Recent research is shaking up conventional scientific beliefs regarding the boundaries of the nuclear chart in scorching stellar conditions with temperatures soaring into the billions of degrees Celsius.
The nuclear chart serves as a method for charting different atomic nuclei based on their count of protons and neutrons, and the “drip lines” signify the perimeters or confines of this chart. Scholars from the University of Surrey and the University of Zagreb have unearthed that these drip lines, which establish the maximum count of protons and neutrons within a nucleus, exhibit dynamic changes in response to temperature fluctuations.
These discoveries challenge the established perspective that drip lines and the quantity of securely bound nuclei remain unaffected by temperature shifts. Dr. Esra Yuksel, a co-author of the study from the University of Surrey, contends that the scientific community must grasp the constraints of the nuclear chart. She articulates, “Considering that nuclei play a pivotal role in most universal processes, it is imperative to comprehend how many protons and neutrons unite under extreme conditions. We aim to ascertain which nuclei can participate in nuclear reactions and processes, particularly in exceedingly hot celestial surroundings like supernovae and neutron star mergers. These exceedingly hot scenarios are the crucibles where the majority of elements beyond iron are forged. Prior to our investigation, our comprehension of these ‘drip lines’ (limitations) at temperatures registering in the billions of degrees Celsius was scant.”
The study, featured in Nature Communications, discloses that elevating temperatures substantially modify the boundaries of the nuclear chart. This revelation illustrates that more nuclei exist within the drip lines when nuclei are heated as opposed to their cold counterparts.
Researchers hailing from Surrey and Zagreb employed theoretical calculations to anticipate nuclear attributes and drip lines at temperatures escalating to 20 billion degrees Celsius. They discerned that at temperatures approaching 10 billion degrees Celsius, alterations in the drip lines and the count of firmly bound nuclei were already underway. As temperatures rise further, shell effects vanish, making these alterations increasingly conspicuous.
Dr. Yuksel elucidates, “Our research underscores that the nuclear drip lines should be seen as mutable constraints that evolve with temperature. Prior to this inquiry, the existence of nuclear drip lines at finite temperatures remained obscure, and our comprehension of nuclei in hot celestial contexts was limited because the majority of theoretical and experimental investigations were confined to zero temperatures exclusively. These fresh insights aid our comprehension of how temperature influences the stability and composition of atomic nuclei. This knowledge holds significance not solely in nuclear physics but also in enhancing our comprehension of the modeling of extraordinary astrophysical phenomena, such as neutron star mergers and core-collapse supernovae.”
Source: University of Surrey