Questions tagged [nuclear-physics]

Nuclear physics is the study of the composition, behavior and interaction of atomic nuclei and their constituent parts.

Nuclear physics is the study of the composition, behavior and interaction of atomic nuclei and their constituent parts. It differs from particle physics in that it spans a lower energy range where nucleons and even nuclei are stable and interactions can generally be described in terms of nucleon and meson degrees of freedom instead of quark and gluon degrees of freedom.

The effective theory known as Quantum Hadron Dynamics (QHD) and Chiral Perturbation Theory are useful for some problems in nuclear regime despite being known to be incomplete. Nuclear physicists also study the transition region where QCD corrections become important but the theory is not fully perturbative.

Nuclear physics provides the basic tools for nuclear power engineering and nuclear weaponry, though most nuclear physicists are not-involved in either of these fields.

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Why is nuclear waste more dangerous than the original nuclear fuel?

I know the spent fuel is still radioactive. But it has to be more stable than what was put in and thus safer than the uranium that we started with. That is to say, is storage of the waste such a big deal? If I mine the uranium, use it, and then bury…
Anthony B
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Why do fusion and fission both release energy?

I only have high school physics knowledge, but here is my understanding: Fusion: 2 atoms come together to form a new atom. This process releases the energy keeping them apart, and is very energetic. Like the sun! Fission: Something fast (like an…
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Why does the Sun's (or other stars') nuclear reaction not use up all its "fuel" immediately?

The temperature and pressure everywhere inside the Sun reach the critical point to start nuclear reactions - there is no reason for it to take such a long time to complete the reaction process. Just like a nuclear bomb will complete all the reaction…
user.3898215
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Why is there a scarcity of lithium?

One of the major impediments to the widespread adoption of electric cars is a shortage of lithium for the batteries. I read an article a while back that says that there is simply not enough lithium available on the entire planet to make enough…
Mason Wheeler
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Why didn't the Big Bang create heavy elements?

In the case of a supernova explosion it is possible to create heavy elements through fusion. Supernovae have a tremendous amount of energy in a very small volume but not as much energy per volume as there was in our early universe. So, what is the…
Alex
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In the earth's crust, why is there far more uranium than gold?

In parts per million in the Earth's crust Uranium is around 1.8ppm and Gold 0.003ppm. Given that it takes far more energy to create Uranium than Gold, why is this?
user56903
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Why can Hiroshima be inhabited when Chernobyl cannot?

There was an atomic bomb dropped in Hiroshima, but today there are residents in Hiroshima. However, in Chernobyl, where there was a nuclear reactor meltdown, there are no residents living today (or very few). What made the difference?
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Why doesn't a nucleus-like body made up of just neutrons exist?

We know that neutrons exert short ranged nuclear forces over other nucleons in a nucleus, and these forces are only attractive in nature. Also this force is universal and doesn't differentiate between charged or uncharged bodies. So why doesn't a…
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How does an ordinary object become radioactive?

In the 2019 miniseries "Chernobyl", ordinary objects are depicted as being capable of becoming radioactive, such as clothes, water, stones. How exactly does something composed of a non-radioactive mass, become radioactive? I'm aware of the…
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Why is a neutron in free state unstable?

A neutron is a neutral particle which is merely some times more massive than an electron. What makes it so unstable outside the nucleus that it has a half life only of about 12 min?
kalyani
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Why is technetium unstable?

Is there a simple account of why technetium is unstable? From the Isotopes section of Wikipedia's article on Technetium: Technetium, with atomic number (denoted Z) 43, is the lowest-numbered element in the periodic table that is exclusively…
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Can 1 kilogram of radioactive material with half life of 5 years just decay in the next minute?

I wondered this since my teacher told us about half life of radioactive materials back in school. It seems intuitive to me to think this way, but I wonder if there's a deeper explanation which proves me wrong. When many atoms are involved, half life…
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Why does the same proportion of a radioactive substance decay per time period? (half life)

Just wondering, if decay is random, why does the activity half every half life, as in, why does it have to reduce by the same proportion in the same time period?
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Why is hydrogen the most abundant element in the Universe?

Hydrogen is the most abundant element in nature. Does cosmological nucleosynthesis provide an explanation for why is this the case? Is the explanation quantitatively precise?
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What practical issues remain for the adoption of Thorium reactors?

From what I've read on thorium reactors, there's enormous benefit to them. Their fuel is abundant enough to power human civilization for centuries, their fission products are relatively short-lived, they're far less prone to catastrophic failure,…
GordonM
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