Fission Definition and 311 Threads

I understand that the vast majority of our atomic warheads are fusion devices. I realize that fusion yields are potentially much larger than fission yields, but our most modern fusion warhead, the W88, has a maximum yield of "only" 475 kilotons, while the maximum theoretical yield of a fission...

Hi all, This is probably a newbie question - I'm a non-physicist but I did do some physics at university. My question is, during fission, when matter is converted into energy, what is the matter/particle that is actually converted into this energy? I would imagine that the particle(s)...

Hey all, For a fission reaction of the type neutron + a -> b + c, where a,b,c are isotopes and the sum of b + c 's mass numbers is a's mass number + 1. What else other than mass number factors into what b and c can be given a?

According to the following website listing the yields of fission products for Uranium and other transuranic isotopes: https://www-nds.iaea.org/sgnucdat/c3.htm The fission product 63-Eu-155 is rare but not impossible. According to my maths, this means there must be another daughter nuclei with...

OK, I understand the idea of neutron bombardment of fissile material causing the nuclei of this material to split, thereby releasing more than 1 neutron, which then go on to bombard other nuclei, such that if more than 1 neutron per reaction ends up causing further reactions, the rate of...

Hey all, Does anyone happen to know the value of ν∑f for natural uranium? Here ν is the average number of neutron released from fission and ∑f is the macroscopic fission cross section of uranium. Kirk

Hi, I have learned that, in a nuclear fission or an alpha decay, the available energy released is the difference of masses between the initial nuclide (+ eventually some other initial particles) and the output particles, times c^2 (as E = mc^2). I'm fine with that. But I wonder : what about...

Hi! I have a question about nuclear fission. Here is the problem: 238_U (B/A = 7.6 MeV/n) is divided into two 119_Pd ( B/A = 8.5 MeV/n). How much energy will be released? I was thinking since the 119_Pd has larger B/A (binding energy per nucleus), energy is needed for this reaction to happen...

http://physics.stackexchange.com/questions/249809/why-only-light-nuclei-are-able-to-undergo-nuclear-fusion-not-heavy-nuclei Can anyone please explain me - what is similar between Nuclear fission & Nuclear fusion? Why are only light nuclei able to undergo nuclear fusion, not heavy nuclei? I am a...

why neutron get so little energy in fission reaction as compare to fission fragments? according to formula Em=Ef(M)/(m+M) m=mass of small fragment M= mass of relatively big fragment Ef=fission energy by the same logic neutron should get highest share due to their lower mass. i am missing...

Homework Statement when fission occurs why neutron get less energy as compare to the daughter nuclei? i need both physical and mathematical explanation. Homework EquationsThe Attempt at a Solution i think it is due to the small mass of neutron. but i am not sure as it is not satisfactory. a...

In small Fission reactors it can be hard to get enough heat in order to boil the water inside the boiler, so why don't we create low pressure boiler systems, where we can boil water at slightly above room temperature, use it to turn the steam turbine as it flows to the similarly low pressure...

Why does fission/fusion occur instead of alpha/beta/gamma radiation?

If the sun and cosmic objects are powered by nuclear fusion.. why is there fission in nature via Uranium or Plutonium.. what purpose does it serve for nature since nature doesn't use it. Unless there are natural processes that uses fission or heat from slow fission (maybe heating up the earth)...

Nuclei of unstable isotopes spontaneously fission in a way that is measured in half-life. So for a particular nucleus at a given time, it is a probability of some amount, thus is a QM fluctuation? Then what is going on in reactors which in effect modify the nucleus half life by introducing extra...

Judging by https://en.wikipedia.org/wiki/Critical_mass , californium-252 has the lowest critical mass among known isotopes and isomeres. But it is still very high. Is there a way to reduce it significantly (down to microgramms) or, perhaps, a semi-stable isotope/isomere, which would have such a...

Hi, I have a question related to 238U. I know of course that it can fission with neutrons above 1 MeV, but there is a elevated risk it would absorb the neutron and produce 239Pu instead. Let's assume you have a ram of metallic 238U, with perhaps 0,7% 235U, and that you collide it very very...

I was fascinated to learn about dusty plasma fission fragment rockets. https://en.wikipedia.org/wiki/Fission-fragment_rocket There's talk that they might enable high delta-V exploration like a manned Jupiter mission! However, they need to be surrounded very many tons of neutron moderator...

I was watching an explanation (found here: youtu.be/yTkojROg-t8 ) on nuclear fission. In the video, he described the process of fission to happen one a random neutron smashes into a uranium nucleus. This causes the necleus to split into krpyton and barium, taking part of the nucleon and...

Hello all, Is this a thing? I understand that a theory of quantum gravity is necessary to explain the physics at the core of a black hole, but it seems a black hole is the only environment energetic and dense enough to ignite a mass-energy feedback loop where colliding photons release the...

I've been thinking... Is there any way that there could be sort of a one-time use pulse laser that uses something like a mini atomic bomb to create a super high energy laser? I found stuff about a Nuclear pumped laser and "Project Excalibur", but I wanted to ask actual people who know a lot...

Hi everybody! Wasn't sure whether to post this here or in Quantum Mechanics, decided I would start here. I was wondering how the entanglement structure between the nucleons of two nuclei would evolve during a fission event. Correct me if I'm wrong but wouldn't the two sets of nucleons...

Now I'm familiar with how nuclear fission works to produce thermal energy and alpha/ beta/gamma radiation, but how do they work in the bomb? When is the high energy neutron fired into the uranium-235, and when does the chain reaction producing the heat begin? Why is it that there's a huge...

Hello I'm working on a project to create spacecraft engines that use fission to produce thrust. I will be coming up with many equations and I wanted to have them checked. If you could review them and give me some feedback that would be great. Here is the first equation that describes how the...

When neutrons are fired at atoms, if at higher speeds they will behave as waves, wander through and scatter, (which can produce something similar to x-ray diffraction images), but if slowed to the right "thermal energy" speed, they will be captured by (say) U-235, making the U atom unstable...

Its been a long time since I've studdied chemistry, I used to have a pretty decent understanding of it, but I've forgotten some of it. I remember that the energy produced from a fission reaction has to do with the number of bonds being broken, and that bonding energy released is obscenely high...

Hello all! In my Nuclear Power assignment I decided to analyse this graph: I mention that "The difference in atomic mass and binding energy per nucleon for deuterium and helium (fusion elements) is ≈3u and 5.96 MeV respectively. However, for all elements past Iron (fission elements) the...

I'm wondering that is it possible? I mean, certain radioactive matter can undergo fission? Sure I know half-life and radioactive decay. This question is asked roughly. I just learn is it possible? Thank you for answers

1. Homework Statement Homework EquationsThe Attempt at a Solution I thought it was because the kinetic energy of the neutron is equal to or larger than the binding energy of Uranium.. But that's not the answer. Can someone please explain why? Thanks

Had been talking NSWRs on a spaceflight forum and a thought occurred to me. Lithium-6 fission can be triggered with relatively low-energy neutrons and releases 4.78 MeV, a helium-4 atom, and a tritium atom. Without a neutron flux, however, lithium-6 is completely stable. With a small...

I can't tell the difference between fusion and fission reactions. I know alpha decay is when when Hydrogen is one of products and beta decay is when there is an electron but how do you tell the difference between fusion and fission?

I'm wondering if a fusion reactor would make its walls more radioactive thru neutron activation than a fission reactor, for a given amount of energy. It seems to me that (hydrogen) fusion produces most of its energy as neutrons that are unlikely to absorbed by the sparse near vacuum plasma...

"Looking at time behaviour of neutrons in a reactor on time scales of both ~sec and ~days/months Start with fission process e.g. 235U + n -> 236U ->fission Usually divide into 2 Fission Fragments 10%-20% of fission emit a scission neutron (i.e. at time of scission)" I've heard...

Is it possible for a nucleus to undergo antisymmetric spontaneous fission? And if so, what is the process responsible? Thanks

a certain fission reaction releases 3 neutrons. how many of these neutrons must go on to produce a subsequent fission if a chain reaction is to be sustained?

If it does, why is that so?

Are there isotopes that decay only through spontaneous fission, or in other words can normally stable nuclei decay through spontaneous fission?

Homework Statement I've attached the question I'm having trouble with. Homework Equations The Attempt at a Solution I got an answer of 1.70375 * 10^-3 for the binding energy of a nucleus of uranium 235. For the third part, "When a uranium-235 nucleus undergoes fission..." I read the value of...

I am curious about the relative dangers of fusion and fission power. Obviously fusion is much safer, but it is not without any risk. Radioactive materials are produced, and containment systems can fail. I am wondering if anyone can give a comparison of a fission meltdown vs. a worst-case...

First of all, let me say I'm not a physicist, an undergrad, study physics or have any particular education surrounding physics. I'm actually simply a photographer with a special interest in science - so if possible, keep any answers simple. Right, so I was reading about the fission of U235, and...

is it possible to create a bike involving nuclear fission and fusion . by using any nuclear reactant.

Homework Statement Ok so i know that the binding energy per nucleon inceases after fission and fusion and the difference in the binding energy is given out as energy. But if the binding enrgy increases shouldn't there be energy taken in(rather than given out)? Also why is the net loss in my =...

According to the experimental curve of Binding Energy per nucleon vs Mass no. , we have come to know that heavier nuclei having less B.E. are fissionable. We have also learned from Neutron vs Proton curve that those nuclei having N/P>1 can show radioactivity. But my question is why not all heavy...

Homework Statement Fission Reaction: Pu-239 + gamma --> Sr-92 + ? + 3n Q-Value = ? (Answer in MeV, correct to 5 significant figures) Atomic Masses (u) Alpha Particle = 4.00150618 He-4 = 4.0026032497 Pu-239 = 239.0521565 Sr-92 = 91.911030 n (neutron) = 1.00866501 Homework Equations...

Dear PF Forum, In previous thread, I am asking about fusion power. But there is one thing that intriguing me. This is one of the reactions that produces tritium. n + _3^6Li -> _2^4He + _1^3H + 4.8 Mev What is this reaction called? 1. Fusion? If yes, why it's called fusion? 2. Fission? 3. Other...

hey guys. i have answered my question but i am not quite sure about it. Four hydrogen atoms fuse to produce one helium nucleus.calculate how many MeV of energy is released in this process. You are calculating how much energy is released by the fusion of four hydrogen atoms. what i have done...

I was reading about control rods in a nuclear reactor. The carbon rods slow down the neutrons so they can interact better and induce fission. Is the reason that they don't interact when raveling fast is this because the have a smaller de broglie wavelength?

Hi, I'm currently doing an assignment on nuclear physics. One of the questions in said assignment is asking me to state the decays which usually happen within a nuclear power plant, as well as stating the fission products, explaining what's happening, and showing the equation. One of the sites...

Why is U-235 better for fission than U-238, i was reading that when a neutron strikes U-235 than it create U-236 which has an even number of nucleons, so it can break apart evenly. When the neutron strikes the uranium it causes it to oscillate and then it breaks apart. Is this like have a...

Homework Statement Our instructor asked to find 6 nuclear fission equations related to 235u. I found only 1-2 example. But none of them has shown the steps about fragments to be stable and thermal energy created in that equation. I know it was a mistake. Please help me out. Homework...