Nuclear Physics

Critical is that point when the population of fission events is neither growing nor decreasing, and that it is sustained by its own means. In this state, on a large scale statistical basis, exactly one neutron produces one fission, which goes one to produce one neutron, which goes on to produce one fission, and so on and so forth. Subcritical is the state where that population is decreasing, and supercritical is where that population is increasing.

Criticality is also related to power output, as the number of fission events is directly tied to energy or power output. When you ramp a nuclear reactor up in power, you go slightly supercritical while you increase the population, and therefore the energy output, but once you achieve your target power, you let your moderator step in and modulate the power in a self-modulating cycle. Similarly, as you trim power down, you go slightly subcritical while you decrease the population, and then you let the moderator kick back in, that is, unless you lose control and you initiate a trip/scram, taking the reactor to shutdown, which is way-way-subcritical.

An alpha particle can be written as ¸He«+ (Sorry, but it will not print properly on this answer page. The notation should be a superscript 4 over a subscript 2, followed by He, and then a superscript 2 over a subscript 2, followed by a superscript + sign).

The sun produces energy via nuclear fusion. Electromagnetic energy in the form of light travels through the vacuum of space to reach earth via what we call radiation.

No, the half-life of a radioactive isotope is a constant property of that particular isotope and does not change as it decays. The half-life is defined as the time it takes for half of the atoms in a sample to decay. Once set, the half-life remains constant regardless of how many atoms have decayed.

Radon-198 does not decay via beta decay. It is thought to decay by alpha decay, but that is not certain. The equation would be ...

86198Rn -> (Alpha, T1/2 = 86 ms) -> 84194Po + 24He2+

Fast neutrons have high kinetic energy, making them less likely to interact with the nucleus compared to slow neutrons. The high energy of fast neutrons means they often pass through the nucleus without being captured. As a result, fast neutrons are less effective in inducing nuclear reactions compared to slower neutrons.

X-rays take more energy to generate compared to microwaves. This is because x-rays are a form of ionizing radiation that requires higher frequencies and more powerful equipment to produce, whereas microwaves are a form of non-ionizing radiation that typically require less energy to generate.

Linear decay is a reduction in a value or quantity at a constant rate over time. In the context of machine learning or reinforcement learning, it can refer to a linear decrease in a parameter, weight, or value over a specified number of steps or episodes. Linear decay is often used to gradually decrease the impact of certain factors or actions in a model to help stabilize or optimize its performance.

Breeder nuclear fission produces more fissile material than it consumes, while conventional nuclear fission produces energy without producing additional fuel. Breeder reactors can create more fuel (like plutonium) for use in other reactors, making them potentially more efficient in terms of fuel usage.

alpha particle dont ask why cuz i dont know

Alpha rays are helium nuclei, two protons and two neutrons, an atomic mass number of 4, and a charge of +2. Beta rays are electrons or, in some cases, positrons, an atomic mass number of 1 / 1854, and a charge of -1, or +1 for the positron.

In a nuclear reactor elements do not simply change into other elements fission occurs and they are split into two smaller nuclei. For example: Uranium when bombarded with a neutron splits into two smaller nuclei; Barium and Krypton. When this happens energy is release in the form of heat and this heat heats water turning it into steam and drives turbines creating electricity.

Elements only really "change" into other elements in fusion reactions when two smaller nuclei come together to form a larger element. However this fusion requires extremely high temperatures and as such only takes place in the centre of the sun.

Bogs have acidic and low-oxygen environments, which slows down the decay process by inhibiting bacteria and fungi that typically break down organic matter. This low rate of decomposition, coupled with the cold temperatures and preservative properties of the bog water, can lead to excellent preservation of bodies found in bogs.

A kidney scanner uses gamma radiation because it has higher penetration ability, allowing it to reach and image deep structures inside the body like the kidneys. Beta and alpha radiation have lower penetration abilities and would not be suitable for this purpose. Additionally, gamma radiation is less likely to be absorbed by surrounding tissues, providing clearer images of the kidneys.

We derive electromagnetic energy from the nuclear fusion reactions on the sun. We also apply nuclear energy (fission) on earth to generate lots of thermal energy, which we use in a steam cycle to generate lots of electric power.

Oil is not generally radioactive unless it was originally located near radioactive material when it was extracted. More often, it only becomes radioactive when exposed to or stored near radioactive materials post processing.

It emits photons of varying energy, energy representing the amount of energy required to step down from the nucleus' excited state to either the ground state or to an intermediate state. These photons are called gamma rays.

The diameter of the helium-4 nucleus is about 1x10-15 m.

An alpha particle is a helium nucleus, which consists of 2 protons and 2 neutrons. When an unstable nucleus emits an alpha particle, it loses 2 protons, which means its atomic number will be reduced by 2.

Only in nuclear physics and nuclear chemistry laboratories; copernicium is an artificial chemical element.

An alpha particle could strike the phosphor screen on the same side of the foil as the alpha particle source if it undergoes a scattering event with a nucleus that causes it to change direction and travel back towards the same side. This scattering event can happen due to the strong Coulomb interaction between the positive charge of the alpha particle and the positive charge of the nucleus.