New precise measurements of the masses of two rare isotopes change our understanding of a critical reaction in X-ray bursts
A research team at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) has successfully performed direct mass measurements of two extremely short-lived atomic nuclei: phosphorus-26 and sulfur-27. Achieving this level of precision provides important new data for calculating the rates of nuclear reactions that occur in X-ray bursts, and helps scientists better understand how elements are formed in such extreme environments.
Type I X-ray bursts are common in the galaxy and involve intense thermonuclear explosions. They are typically observed in low-mass X-ray binaries, where a neutron star has accreted material from a companion star.
During these outbursts, hydrogen and helium on the neutron star's surface undergo unstable thermonuclear combustion. This activity drives a series of rapid proton capture events, known as the "proton-capture process."rp". In this reaction sequence, atomic nuclei absorb protons at high speed and heavier elements are formed. The efficiency and direction of these reactions depend largely on the existence of accurate mass measurements of the nuclei involved.
Challenges near the proton drip line
But the rp process involves many nuclei close to the proton drip line, which usually have short lifetimes and unknown masses. Therefore, it is always difficult to calculate the trajectories of nuclear reactions accurately.
According to Dr. Xinliang Yan, one of the authors of the article, the importance of a potential reaction pathway involving phosphorus-26 and sulfur-27 in the rp process has been a topic of debate for years, due to the lack of precise data on the masses of these nuclei.
To obtain precise mass data for phosphorus-26 and sulfur-27, the researchers performed direct measurements using isochronous mass spectrometry at constant magnetic rigidity. They found that the proton separation energy of sulfur-27 was 129–267 keV higher than previously thought, and the accuracy was improved eightfold over previous measurements.
Effect on reaction rates in X-ray bursts
With the new mass data, the researchers found that under X-ray burst conditions, the updated reaction rate, 26P(p,γ)27S, is significantly enhanced in the temperature range 0.4–2 Gigakelvin (GK), reaching up to five times the rate previously estimated at 1 GK. The uncertainty in the reverse reaction rate has been greatly reduced. The new reaction rate was found to increase the abundance ratio of sulfur-27 to phosphorus-26, indicating a more efficient reaction flow to sulfur-27.
"Our highly accurate mass results and corresponding new reaction rate provide more reliable input to astrophysical reaction networks, resolving uncertainties in nucleosynthesis pathways in the phosphorus-sulfur region of X-ray bursts," said Dr. Suching Hu of IMP, another author of the study.
More of the topic in Hayadan:
8 תגובות
Nervous, have you already done the scope experiment with more turns? If not, you will continue to be considered a pathetic babbler and an idler.
Father, it seems to me that if you don't bring back the recent comments like in the old days, you'll only be left with Nerve and two and a half other commenters.
Good morning, soon Aber will open the Museum of the New Exact Sciences, Geometry and Physics.
The new geometry is of closed circular lines, and it already has a museum,
And the new physics is of continuous matter, built from the combination of quantities of energy and passive time.
A. Asbar
Many thanks to Itav Al-Hadan and its editor, Mr. Avi Blizovsky.
You have given me freedom of expression that deserves great appreciation,
The science of exact sciences should thank you.
Avinoam Sadness
Reply to Avi Blizovsky
Scientific writing with peer review hinders any innovation in science, because the peers recite the concept accepted by all scientists. In this way, science freezes and becomes stagnant, and will never be renewed.
The most prominent example of the fossilization of science is in geometry, in the belief of mathematicians, in the false number 3,14.
Suitable for all circles - small and large - to describe how many times larger the circumference of each circle is than its diameter.
Mathematicians never proved this belief, and it delayed the development of geometry for 2000 years, preventing the emergence of the innovative geometry of closed circular lines.
The innovative geometry says
Because for every size of a closed circle, there is a specific number that says how many times larger its circumference is than its diameter.
Just as the church's believers persecuted Galileo for expressing an opinion contrary to the church's, so the church's believers in mathematics persecute Naber, scorn him, and humiliate him.
It's lucky that believers in the Church of Mathematica don't have an Inquisition.
The Honorable Mr. Avi Blizovsky-
A scientific newspaper like yours today works to fossilize science, instead of contributing to the development of science.
The moment you only publish what peer review has qualified, you have contributed to the petrification of science.
Did Galileo pass peer review? Did Kepler pass peer review, did Aristotle pass peer review?
Did Einstein pass peer review?
Naber has been enduring opposing and mocking criticism for 20 years, and accepts it with understanding.
But Naber continues his own research based on his natural knowledge, and he knows that he was ahead of his time.
Aber opened the world's first geometric museum,
And it shows the geometry of an infinite number of closed circular lines, from a diameter of zero millimeters to a diameter of infinite millimeters.
This geometry was inhibited by the Lie number 3,14,
And in its place, he placed an infinite number of numbers that are in a narrow range.
Between 3,14 and 3,16, fulfilling the idea of a variable pi
There are infinitely many closed circular lines whose diameter varies between zero mm and infinity mm,
And for each such closed circular line, there is a private pi number, which falls within a narrow range, between 3,14 and 3,16.
Mr. Avi Blizovsky,
Save the 2000-year-old fossilized geometry, publish the idea of the changing pi of the neuter
The advancement of science is done through research and its publication in a peer-reviewed scientific journal, not on a website **that** reports on science.
Hello to those who warned me to slow down.
I don't have time, I'm approaching 86 and I want to do as much as possible to advance science.
Thanks to Yadan and Mr. Avi Blizovsky
A. Asbar
The only exact sciences are geometry and physics.
Geometry deals with continuous quantitative things - length, area, and volume,
And physics deals with continuous quantitative things – passive time and energy.
It is impossible to identify a beginning and an end in a continuous quantitative thing, and therefore great precision is required when dealing with a continuous quantitative thing.
To make dealing with continuous quantitative matter more efficient, we will use the abbreviated name DCR.
Measuring DCR must be very, very accurate, and calculating DCR must also be very precise.
And there are only 5 DCRs in the world, 3 of them in the geometric field, and 2 of them in the physical field.
There are only two exact sciences in the world: geometry and physics.
Aber's natural knowledge revealed to him the five Dhakrim.
And he discovered the existence of a new geometry, and a new physics.
The old geometry, thousands of years old, is the geometry of straight line segments, and the innovative geometry of Aber is the geometry of infinite closed circular lines, whose diameter varies between zero millimeters and infinity millimeters.
In Neber's innovative geometry, each millimeter diameter of a closed circular line has a private pi number.
Individual pi numbers vary between pi 3.16 for a closed circular line with a diameter of zero mm, and pi 3,14 for a closed circular line with a diameter of infinity mm.
Aber has already opened a private museum for the new geometry, located in his home in Ramat Efal, and he will soon open the museum of the new physics, which will be called the Museum of the Exact Sciences.
The Museum of Exact Sciences will present a huge revolution in everything taught in the official Smile system.
A. Asbar
The scientists who are accepted today are already outdated.
Just as there already exists a new geometry of closed circular lines, (instead of the geometry of the straight line)
Thus, there is already a new physics of continuous matter (instead of particulate matter of atoms).
The tangible matter known to man is created from the combination of quantities of passive time and energy, and is continuous, not particulate.
The defining sign of the new physics is passive time, which actually exists in physical reality.
The concept of time that humans talk about exists only in the imagination of humans, and the moment a person thinks about it, it disappears.
The new geometry already has a museum, founded by Abeber, and it is located in his home in Ramat Efal, and soon the museum of the new physics, of continuous matter and passive time, will be established.
The hallmark of the new physics, "the universe operates on its own without a coercive force," and it fulfills natural laws, such as, for example, the law of conservation of energy. A detailed description of the neural universe appears in Aber's first book, published by Niv Publishing, "Aber's Magic Journey on the Wings of Natural Knowledge."
In conclusion: Aber discovered a new geometry and a new physics, and these are the exact sciences.
The geometry of closed circular lines replaces the old geometry of the straight line.
The new physics of continuous matter and passive time replaces the old physics of particle matter and imaginary time.
The new physics proposes an infinite universe that operates on its own without a compelling force, and it fulfills natural laws, miraculously embedded in physical reality.
This wondrous universe lies beyond the imaginary time of humans, which disappears the moment one thinks about it.
This imaginary time was invented by humans so that human society could function better in everyday reality.
In physical reality, passive time is found and is completely at rest and completely cold, and it fills the infinite universe.
Energy is found in physical reality, and it too fills the infinite universe.
And the actual matter that humans perceive "is created by combining quantities of passive time and energy."