Neutron capture Definition and 29 Threads

For neutron inelastic interaction, the nucleus de-excites by emitting gamma-rays or charged particles. However, for neutron capture, the nucleus de-excites by emitting gamma-rays only. Why does the nucleus in the neutron capture interaction de-excite by only emitting gamma-rays? why not by...

Summary: Problem: nuclear physics, neutron capture In the problem one should calculate time dependence of number of nuclei. Problem statement: Neutron beam radiates sample A with initial number of atoms N0. With neutron capture nuclei (cores) of A are transitioning to nuclei B (they are just...

Hi, I've been wondering about this a lot and I didn't find a satisfactory answer by myself. My professor said that in order to promote a fission reaction you need to provide a certain amount of energy (like in a chemical reaction you need to overcome the activation energy) and the easiest way...

Hi, When U-235 captures a neutron, it may end up with a fission reaction or an excited U-236 isotope. This U-236 emits gamma rays as it goes to its ground state. What I want to learn is that how much is the contribution of these gamma rays' energy to overall fission energy. I checked the...

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

When a target is irradiated with neutrons there a number of different nuclear reactions that can occur. In neutron capture, which neutron energy regime is most dominant? I can't seem to find any specific literature about neutron capture and neutron energy, but most of the general stuff I've read...

I'm curious, why does Helium-3 fission into H-3 and H upon neutron absorption? Surely the He-4 nucleus configuration is more stable? I get that the energy release may be what splits the nucleus, because it releases quite a lot of energy if it were to simply absorb the neutron.

How is a continuous chain reaction maintained within a moderator if it is not fissile material? Are the fissile materials mixed with the moderator or are they coalesced at the center of the surrounding moderator? If it is the latter, how would the surrounding moderator allow fissile material to...

A recent issue of Aviation Week described a novel design for a fusion reactor from the Lockheed Skunk Works. It was smaller, simpler and lighter than the extant systems now being built and they're optimistic about it's test run in five years. I wrote a letter to the editor touting this departure...

I would like to ask if any of you can comment on the thermal neutron activation of lithium in order to produce energy as a cold fusion-like process?

Hello All I'm doing my theses in BNCT(Boron neutron capture therapy).I did it with 2.5 Mev imaginary accelerator. there are many reactors to compare my data with theirs.but Unfortunately I couldn't find some Real accelerators based on BNCT to compare my MCNP-X output data with theirs. could u...

Can anyone help me with an approximate answer to this or point me in the direction of avenues to get an answer to this? This has practical applications and is potentially worrying. Roughly how much (or how many atoms) of cobalt-59 exposed to the average neutron radiation at in-flight...

My research is about Design and modeling of beam tube of nuclear reactor for BNCT(Boron Neutron Capture Therapy) application and I need some journals and related books about it.

neutron capture --> gamma's Someone could explain me how neutron capture in Gadolinium happens? If a neutron is captured, an energy of about 8 Mev is released in form of gamma-ray cascade (Ʃγ). But... how many gammas are released? I believe the answer will be in form of probability...

I wish to verify a couple of assertions. From the NNDC and other references, it appears that the neutron capture cross section of 3H (Tritium) is zero to a first approximation. This holds true for all neutron energies, including cold neutrons. These statements are equivalent to asserting that 4H...

Why do different nuclei need different neutron speed to achieve fission?? My understanding is that U-235 requires a thermal neutron in order to be likely to cause a fission reaction, however Pu-239 requires the additional energy of a fast neutron in order to cause the nucleus to undergo fission...

Homework Statement In a reactor, we're making 56Mn by inducing thermal neutron capture. 2g sample of 55Mn is put into the reactor which has a flux of thermal neutrons of 3E13 neutrons/cm^2*s Sample is in the reactor for 8 hours and then removed. a. Calculate the amount and activity of...

If I have a low energy neutron and I bring it close to a nucleus it will be captured when it gets close enough. How can I calculate the shape of the potential well of the nucleus for neutron capture? I keep reading that it is due to the strong force, which I agree with. But it is some...

So I have been reading about the cross section of neutron capture and have been reading about how the cross section for neutrons in a given material depends on neutron energy, the most important factor obviously. But I have not seen as much information on how, for a neutron of a given thermal...

I am working on some neutron experiments and have to calculate the heat released in the boron neutron capture 10B + 1n - > Li + Alpha particle The reaction has a Q value of 2.31 MeV. Is this entire energy converted to heat? Also, in the two types of reactions of neutron with Boron...

Homework Statement A helium-4 nucleus (rest mass 4.00151 u) is formed when a helium-3 nucleus (rest mass 3.01493 u), stationary in the laboratory frame, captures a slow neutron (rest mass 1.00867 u), in the following reaction. 3He+n→4 He+γ Determine the energy (in MeV) of the γ-ray in the...

Hi all. I am going to be doing an experiment involving neutron scatter. I am going to be firing fast neutrons into water and then detecting the thermal neutrons scattered. I am also going to look into thermal neutron capture where the hydrogen atom captures the thermal neutron and gives off a...

Hi! I hope I've posted this in the right section, but it definitely deals with the nucleus, so here goes. I'm doing a presentation on Boron Neutron Capture Therapy, which, if you don't know, puts boron inside tumor cells, shines a neutron beam onto those cells, which causes the boron inside...

I have a decent understanding of neutron-induced reactions in heavy nuclei (fission, capture), but less so when light nuclei are involved. I do know of Li6 + n --> He4 + T and the Li7 equivalent. Those reactions are more like nucleus splitting (fission). My question is: do neutron capture...

Wikipedia said U-238 is better with capturing fast neutrons than slow neutrons. shouldn't it be the other way round? I thought U-238 is not fissile but is fissionble by neutrons with high enough K.E, and doens't fast neutrons have higher K.E.??

Cross section means the effective size of a nucleus for capturing a neutron, am I right? But what makes the cross sections for different nucleus different? I am a bit puzzled, why the cross section for Boron(for example) is so high?

Anybody have good values and a source for thermal neutron capture cross section for Ba-133, both ground and excited states? CRC Handbook gives 4 barns, but wanted to verify it. Thanks.

I'm writing a paper on Thorium utilization in nuclear reactors. In this connection I'm looking for figures which describe the neutron capture and neutron fission cross sections over a wide energy range (not only thermal). There are probably some online resources unbeknown to me, any hints?

taking a set of questions and came across this one: "Capture of a neutron by nickel-60 produces a proton and what new element or isotope ? " I thought it was copper-61 since it goes through beta decay as indicated by the proton but supposedly it is not... please help