Fast neutron energy is characterized by high kinetic energy levels, making them effective for inducing nuclear reactions. These reactions can be utilized in nuclear power generation, nuclear weapons, and neutron imaging techniques. Fast neutron reactors can also help reduce nuclear waste and increase fuel efficiency in the nuclear industry.
A wave with high energy has characteristics such as a high amplitude, short wavelength, and fast frequency. It carries a lot of energy and can cause significant impacts or changes in its surroundings.
uranium 238 is a fast neutron absorber the answer is correct but for more explanation:- when uranium 238 is bombard by neutron >>> uranium 238 , undergoes B decay>>>Np 239 ,undergoes B decay >>> Pu 239 finally undergoes alpha decay >>> fissile U
Most of the energy in a nuclear power plant is due to the neutrons. The half-life of a free neutron (a neutron no longer bound to an atom) is about 15 minutes, before it breaks down by radioactive decay. When emitted from an atom in a radioactive decay, it is traveling very fast. It may be slowed down by using a moderator - a material in which it has a high likelyhood of a collision. Since it spends longer in the moderator, there is a greater probability of the energy of the breakup being contained within the moderator. In its decay, it emits energy, and this is perceived as heat, and may then be used to drive a steam generator to make power. So the energy is stored as the element of structure of the neutron, and when that structure breaks down, the energy is emitted. (or at least that part that was binding energy in the neutron).
The initial velocity after fission is something like 30,000 km/sec, 10 percent of the velocity of light. In moderated reactors the neutrons are slowed down by collisions with the moderator atoms and eventually (if not captured) arrive at the mean velocity of the moderator atoms themselves, or more correctly they achieve the same distribution of such velocities, which is around several km/sec depending on the moderator material and its temperature. These neutrons are then said to be thermalised as they have come into equilibrium with the thermal related moderator velocity distribution.
The fast neutron chain reaction triggers multiple fissions at an exponentially increasing rate. This happens so rapidly that all the fissions needed to release the energy for the explosion have split in an interval of time on the order of 10 microseconds.
Helium-3 has a high cross section for thermal neutron absorption. For fast neutrons you must either thermalize the neutrons for use with boron or helium-3 based proportional counters or use a fast fission chamber based on fast fission of uranium. It's worth noting that a uranium based fast fission detector is really only useful in extraordinarily high neutron fluxes like that of a reactor.
In order to cause an atomic nucleus to become unstable so that it will undergo fission, you have to add a neutron. If a slow neutron collides with an atomic nucleus, it will be absorbed into the nucleus and become part of it. The nuclear attraction of the nucleus is strong enough to grab a slow neutron. But a fast neutron cannot be captured because it has too much kinetic energy. The attraction of the nucleus is not enough to stop the motion of a fast neutron. Even if a fast neutron makes a direct hit on an atomic nucleus, it is just going to bounce off.
Beta decay releases a fast-moving electron (beta particle) from a neutron in the nucleus. During beta decay, a neutron is converted into a proton, and the electron and an antineutrino are emitted to conserve charge and energy.
A wave with high energy has characteristics such as a high amplitude, short wavelength, and fast frequency. It carries a lot of energy and can cause significant impacts or changes in its surroundings.
Moderator is not used in case of fast breeder reactor because there is no need to slow down neutron energy. Nuclear fission takes place at high energy of neutrons.
When U-238 absorbs a fast neutron it forms plutonium-239
A thermal neutron has much less energy / velocity than a fast neutron. As a result, it has a much larger neutron absorption cross section, making it easier for it to be absorbed by certain nuclei and subsequently initiate fission. The fast neutrons that result from fission are slowed down, i.e. moderated, usually by water, in order to become thermal neutrons and to sustain the fission chain reaction.
Matiullah. has written: 'Development of an energy and direction independent fast-neutron dosimeter using CR-39 polymeric (nuclear track) detector with front radiators'
The element is determined by the number of protons. When uranium captures a fast neutron it is still uranium but has an increased atomic mass. Fast neutron capture may encourage a further reaction but it depends on which uranium isotope you start with as to the increase in probability some further reaction will occur and which reaction that might be.
uranium 238 is a fast neutron absorber the answer is correct but for more explanation:- when uranium 238 is bombard by neutron >>> uranium 238 , undergoes B decay>>>Np 239 ,undergoes B decay >>> Pu 239 finally undergoes alpha decay >>> fissile U
You may mean 'reactivity'. In a nuclear reactor, this is the measure of how much above or below criticality the reactor state is, which effectively determines how fast the neutron flux increases or decreases.
A nuclear cross section is a "technical" way of saying how large a "target" a given atomic nucleus presents to an incoming neutron. And we need to know that about different elements, and about the different isotopes of those elements. There are some other applications, but this is the "biggie" for the use of the term nuclear cross section. And we need to start with the idea that fission begins with a neutron entering an atomic nucleus to cause fission. If your model of nuclear fission is a cue ball breaking a rack of billliard balls, we need to refine it. Get you from the "B" grade to an "A" grade in physics. A neutron doesn't "smash" an atomic nucleus. It is captured by it (neutron capture) and an instability results. A neutron released in the fission process comes away from the fission event like a bullet out of a gun. Because it is moving so "fast" it has a low probability of being captured. It needs to undergo some scattering (little "collisions" with other atomic nuclei) to slow it down (thermalize it). The thermal neutron has a higher probability of being captured by a given nucleus and causing another fission, if it is captured by a fissionable atom. We've seen how the energy of the neutron affects its probability of being captured, but it turns out that different elements present a different sized "target" for the neutron. The size depends on the energy of that neutron, but also on the element being targeted, and which isotope of that element is under consideration. To repeat, each element has a different nuclear cross section (target size) for a neutron (of a given energy), and each isotope of a given element has a different nuclear cross section (for that same given neutron energy). Three things are at work. The energy of the neutron aside, the element and the different isotopes of each element have different probabilities of capturing a neutron of a given energy. The nuclear cross section is a measure of the "receptivity" of a given nucleus to an incoming neutron. It's that probability of capture. That's it in a nutshell. Links can be found below.