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

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Drop a star in a river [closed]

I (as I am sure you will be able to tell) know very little about nuclear physics, so please understand if something here seems dumb or obvious. I am going to question some Hollywood physics here. At ...
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How can radioactivity change depending on the number of nuclei? [closed]

I came across this problem. Please help me solve it. A radioactive sample S1 having an activity of $5\ \mathrm{\mu Ci}$ has twice the number of nuclei as another sample S2 which has an activity ...
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Why is it necessary to enrich Uranium and Plutonium before they can be used in nuclear warheads?

The World Nuclear Association(WNA) states: Weapons-grade uranium is highly enriched, to over 90% U-235 (the fissile isotope).Weapons-grade plutonium has over 93% Pu-239 However, what WNA or ...
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60 views

Radioactive decay-Why does it depend on numbers left

As textbooks describe the rate law for radioactive decay as a first order reaction dN/dt=kN,why is it so(mine does not give the reason)? How is the radioactive decay of one atom depeendent on the ...
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55 views

Why is there only alpha and beta (and gamma) decay?

Why is it that we mostly speak of alpha and beta decay (when looking at emitted particles with rest mass)? Why don't we speak of decays that emit something like $2n3p$, $3n2p$ and so on? Do they occur ...
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Nuclear bound states

"The $3/2$$^-$ ground state of gallium-61, Ga-61, is bound by only $190$ keV relative to the system: Zn-60 + p, where p is a proton. There are excited Ga-61 states at $271$ keV and $1000$ keV" How do ...
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Are Geiger counters isotope-specific?

I was talking with an employee at a company that does I-131 therapy for hyperthyroidism and they said that the Geiger counters they use are "tuned" for I-131, implying that regular Geiger counters are ...
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How much energy is released from the splitting of a single hydrogen atom?

My question is a fairly simple one that I cant seem to find on Google: How much energy, in both technical and laymans' terms, is released from the splitting of a single hydrogen atom?
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255 views

Do electrons get accelerated or decelerated by the atoms of the anode during X-rays production?

The electrons striking the anode get deflected by the heavy nucleus. Though the speed may or may not change, the direction of motion changes which leads to acceleration. The charged particles emit ...
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Is it really possible to create some mass only from equivalent energy? [duplicate]

From Special theory of relativity we know that $E=m_0 c^2$, which says about mass energy equivalency. But my question : **Is there any real experiment where some mass is created purely from energy? ...
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90 views

Why do Nuclei lose mass?

When it comes to things like gravity and the electromagnetic force, masses aren't reduced-but with nuclei the mass difference is noticeable. What about nuclear forces makes them capable of putting ...
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Interaction photons-matter and dimensional analysis

I know that when photons pass through matter, the law that describes the intensity in function of the thickness is: $$I(x)=I_0 e^{-\mu x}$$ where $\mu = \rho \frac{N_a}{A} \sigma$ and ...
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Synthesizing elements (Nuclear Physics/Alchemy?)

Based on my limited knowledge of nuclear physics, it seems that one day it may/will be possible to synthesize whatever elements we may need, given enough energy. Is this accurate? Is there a table ...
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657 views

What is the influence of the nuclear leakage in Japan

The recent news says that Japanese authorities confirmed Saturday that radiation had leaked from a quake-hit nuclear plant after an explosion destroyed a building at the site. What will be the ...
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24 views

Prompt gamma emission vs gamma decay

I understand prompt gamma emission to mean gamma emission in a time period shorter than a second. I understand gamma decay to be the relaxion of a nucleus into a lower energy level by emission of a ...
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Change in the half-life of a neutron

What would happen if the half-life of a neutron was much more less than it is now? How could this affect the nuclei?
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How to determine whether a nuclear transition would be electric octupole, or hexadecapole?

The transition from one nuclear state to another is classified as quadrupole/octupole, etc, depending on the units on angular momentum transferred. But depending on the angular momentum of the two ...
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59 views

Is it possible to create helium atoms by bombarding heavy water with neutrons?

If heavy water is bombarded by neutrons is it possible that any of the deuterium atoms can capture neutrons and transmute to helium atoms? I suspect the more probable event would be knocking protons ...
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159 views

What triggers a nuclear chain reaction?

A nuclear fission works by spliting atom's neutrons by neutrons which release energy but how is the chain reaction triggered because at first the nucleus is bond by a strong nuclear force so what ...
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Semi-empirical mass formula

The mass formula is given by $M(Z,A) = ZM_{p}+(A-Z)M_{n}-a_{1}A+a_{2}A^\frac{2}{3}+a_{3}\frac{Z(Z-1)}{A^\frac{1}{3}}+a_{4}\frac{(Z-A/2)^2}{A}+a_{5}A^\frac{-1}{2}$ So I am just wondering here what ...
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62 views

Do the nuclear reactions produced by different elements release different amounts of energy?

Does the nuclear reactions in an element like Uranium produce a different amount of energy than the nuclear reactions in Plutonium? I am not concerned with those elements in particular, they just seem ...
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141 views

Isotope with longest decay chain to reach a stable isotope

Which decay chain of a radioactive isotope has the most 'steps' before reaching a stable isotope, i.e. decays into the most other isotopes before becoming stable?
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What is the relation between the half-time and the line-width of a radioactive nucleus?

Are they inversely proportional to each other? This is the case for the atoms, I think. The problem is that, for those isotopes like uranium 238, the half-time is as long as 4.4 billion years, and ...
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60 views

Big bang theory

How much energy and heat were produced by the big bang? I'm reading Bill Bryson's Short history.... He mentioned a point that to forage light elements like hydrogen, helium and lithium into elements ...
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Detecting radioactive material at a distance

I have heard a lot about the failures of even the best-funded anti-ballistic missile technology. The usual explanation is that ABM is very hard after the boost phase because of evasion techniques and ...
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Working of fusion reactor

The present type fusion reactors use the magnetic confinement technique for the production of energy. Moreover only 48% for the energy is only absorbed and converted into useful energy . Why we are ...
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Nuclear reactions conservation laws

I'd want to know the basic rules to apply the conservation laws in nuclear reactions (nuclear fusion, nuclear fission, radioactive decays, etc.) to determine parity and angular momentum of the ...
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Bremsstrahlung: why is electron slowed/stopped by the positive nucleus?

I can't understand why the electron is slowed/stopped by the nucleus. The electron is a negative charge and the nucleus is positive... they should attract each other...
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Developments originating from $E=mc^2$

What kind of significant impacts have originated from $E=mc^2$. Generally, it is regarded as the most famous equation of all time. Except for nuclear energy (fission and fusion) I do not know any ...
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energy production in the nuclear fission

according to this image of nuclear fission, before fisson reaction, the total mass of uranium and the slow neutron is 236 amu. and after adding the masses of Barium, krypton and the 3 neutrons after ...
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90 views

Non-conversion of mass & energy?

This article is certainly an interesting alternative perspective, but is it factual or does it contain fallacies? http://www.circlon-theory.com/HTML/EmcFallacies.html Are mass and energy not ...
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25 views

Is there any experimental evidence to distinguish the total gravitational force exerted by the two proton and a helium nucleus?

I know that the sum of the mass of the two proton is greater than the mass of a helium nucleus (two proton). As the mass different is transformed into energy by the Einstein mass energy-equivalence. ...
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Binding energy per nucleon in radioisotopes of hydrogen

I understand that greater binding energy per nucleon implies a more stable atom and atoms undergo nuclear fusion and fission to attain higher binding energy per nucleon. The binding energy per nucleon ...
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Calculating released energy of a fission reaction

I have a question regarding the power of a fission reaction: You have a Uranium U235 atom, in which you send a neutron at to cause it to split into two (or more?) new cores. This reaction also sends ...
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Isoscalar and isovector terms in optical model potential

How does one obtain the isoscalar and isovector terms of the nucleus-nucleus interaction potential and what do they signify?
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Conceptual doubt regarding Nuclear Energy Levels

I was recently studying about nuclear energy levels and frankly, I thought that I understood the concept pretty well. However, this little problem showed me how wrong I was. The problem is given ...
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Why can't a nuclear reactor be used as a rocket motor?

Nuclear fission, and potentially fusion, reactors generate vast amounts of energy, primarily as heat. What stops us from harnessing that energy to propel spacecraft at or above escape velocity from ...
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251 views

When does electron capture occur and when does positron emission occur?

I’ve been told that electron capture occurs when there isn’t enough energy to produce a positron by beta plus decay. Exactly why is this the case? Why does it take more energy for positron emission ...
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Is there a directional aspect to Beta decay dependant on nucleus orientation

Does beta decay occur in certain directions relative to a nucleus orientation? Would the nucleus geometry or spin direction have an impact? This effect could may be tested if a radioactive nucleus ...
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Trying to locate information on alpha particle scattering/peak resonance energies for elements

On our campus we have an ion beam analysis lab. It is used for compositional analysis through the firing of alpha particles at MeV energies at target samples. From here it is a simple matter of back ...
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Stopping a nuclear missile

I had been thinking about whether it is possible to stop an incoming missile or not. I found something quite interesting here. So, there many people said that it will be possible to stop an incoming ...
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Discrepancy problem in lithium?

Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?
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Mass of an Atom

So the mass deficit of an atom, denoted by $\Delta M(Z,A)$, is given by the following formula, $\Delta M(Z,A) = M(Z,A) - Z(M_{p} + m_{e}) -NM_{n}$ However since the rest mass of an electron is a lot ...
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What is the reduced width amplitude of an unstable state?

Particularly used in nuclear physics when describing the lifetime (i.e. partial decay width) of a resonant state (a.k.a resonance) is the term "reduced width amplitude". I have searched online, and ...
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What's the difference between binding energy and separation energy?

My understanding of the two was as follows: the binding energy of a nucleus is, classically speaking, the energy needed to put together/take apart that nucleus completely (i.e. a measure of the strong ...
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Is chain reaction possible in stable isotopes?

Is nuclear chain reaction possible in isotope that is considered stable? Are there examples?
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Are we close enough to objects?

Are we able to touch the atomic orbital of an element ? If so, wouldn't there be a current flowing ? If not, then where do we actually touch when we hold it ?
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How do we know that nuclear physics corresponds to low energy QCD?

One often hears the phrase "most of nuclear physics is in the low energy regime of QCD, where strong coupling constant is large ...", with the following diagram being invoked: How does one know ...
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What is the half-life threshold for an isotope to be considered stable?

What minimum half-life an isotope should have to be considered stable?
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4 element super conductor without oxygen and iron

I am trying to find a list with super conductors. In particular I am searching for a superconductor, that consists of 4 elements none of which is Oxygen. The reason I rejected Oxygen, is because(from ...