Fission, Fusion, and Nuclear Decay - AP Physics 2

Nuclear fusion. Hydrogen nuclei fuse to form helium in the Sun's core.

Nuclear fission is the splitting of a heavy nucleus into lighter nuclei. This releases energy due to the mass difference.

Nuclear fusion is the process of combining light nuclei to form a heavier nucleus. This requires extremely high temperatures to overcome electrostatic repulsion.

Nuclear fusion. Hydrogen nuclei fuse to form helium in the Sun's core.

Hydrogen isotopes, typically deuterium and tritium. Light nuclei overcome strong nuclear force barriers when fused.

Containment of high-temperature plasma. Plasma instabilities can damage reactor components.

Nuclear fission is the splitting of a heavy nucleus into lighter nuclei. This releases energy due to the mass difference.

The binding energy released when a nucleus splits. Mass defect converts to kinetic energy of fission fragments.

Generation of long-lived radioactive waste. Waste remains dangerous for thousands of years.

Fusion produces less radioactive waste. Fusion products are generally stable or short-lived.

A series of nuclear fissions, each initiated by a neutron from the previous fission. Self-sustaining reaction requires critical mass to maintain.

Graphite or heavy water (D$_2$O). Both effectively slow down fast neutrons to thermal energies.

Smoke detectors. Alpha particles ionize air to detect smoke particles.

The minimum amount of fissile material needed to sustain a chain reaction. Below this threshold, chain reaction cannot be sustained.

Uranium-235. Fissile isotope that absorbs thermal neutrons effectively.

Helium and a neutron. $^2H + ^3H \rightarrow ^4He + n$ releases 17.6 MeV.

Radioisotopes are used in PET scans. Radioisotopes emit gamma rays detectable by imaging equipment.

To remove heat from the reactor core. Prevents meltdown by transferring heat to steam generators.

$E = mc^2$. Einstein's equation relating mass and energy equivalence.

An alpha particle, which consists of 2 protons and 2 neutrons. Equivalent to a helium nucleus ($^4He$).

Increases by 1 if it's beta-minus decay; decreases by 1 if it's beta-plus decay. Neutron converts to proton (β⁻) or proton to neutron (β⁺).

Sterilization of medical equipment. High-energy photons kill bacteria and viruses effectively.

Deuterium or tritium. Heavy hydrogen isotopes have lower Coulomb barriers.

A beta particle, which is an electron or positron. Occurs when neutron converts to proton or proton to neutron.

Nuclear fusion is the process of combining light nuclei to form a heavier nucleus. This requires extremely high temperatures to overcome electrostatic repulsion.

Electrostatic repulsion between nuclei. Coulomb barrier requires high kinetic energy to overcome.

A radioactive isotope of hydrogen. Contains one proton, two neutrons, and is unstable.

To absorb excess neutrons and regulate the fission reaction. Insertion/withdrawal controls reaction rate and reactor power.

Gamma rays, which are high-energy photons. No change in mass or atomic number, only energy release.