Cold fission

Cold fission or cold nuclear fission

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts, often producing free neutrons and lighter nuclei, which may eventually produce photons...

is defined as involving fission events for which fission fragments have so low excitation energy that no neutron

Neutron

The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.Neutron are usually found in atomic nuclei. The nuclei of most atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of protons in a...

s or gamma

Gamma

Gamma uppercase Γ, lowercase γ; ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. It was derived from the Phoenician letter Gimel . Letters that arose from Gamma include the Roman C and G and the Cyrillic letters Ge Г and Ghe Ґ.In Modern Greek, it...

s are emitted.

Cold fission events have so low a probability of occurrence that it is necessary to use a high flux nuclear reactor

Reactor

Reactor can mean:* Bioreactor, any device or system that supports a biologically active environment.* Chemical reactor, a device for containing and controlling a chemical reaction* Nuclear reactor, a device for containing and controlling a nuclear reaction...

 to study it.

The first observation of cold fission events was in experiments on fission induced by thermal neutrons of uranium 233, uranium 235  and plutonium 239  using the High Flux Reactor at the Institut Laue-Langevin

Institut Laue-Langevin

The Institut Laue-Langevin, or ILL, is an internationally-financed scientific facility, situated in Grenoble, France. It is one of the world centres for research using neutrons...

 in Grenoble, France.

Cold fission or cold nuclear fission

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts, often producing free neutrons and lighter nuclei, which may eventually produce photons...

is defined as involving fission events for which fission fragments have so low excitation energy that no neutron

Neutron

The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.Neutron are usually found in atomic nuclei. The nuclei of most atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of protons in a...

s or gamma

Gamma

Gamma uppercase Γ, lowercase γ; ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. It was derived from the Phoenician letter Gimel . Letters that arose from Gamma include the Roman C and G and the Cyrillic letters Ge Г and Ghe Ґ.In Modern Greek, it...

s are emitted.

Cold fission events have so low a probability of occurrence that it is necessary to use a high flux nuclear reactor

Reactor

Reactor can mean:* Bioreactor, any device or system that supports a biologically active environment.* Chemical reactor, a device for containing and controlling a chemical reaction* Nuclear reactor, a device for containing and controlling a nuclear reaction...

 to study it.

The first observation of cold fission events was in experiments on fission induced by thermal neutrons of uranium 233, uranium 235  and plutonium 239  using the High Flux Reactor at the Institut Laue-Langevin

Institut Laue-Langevin

The Institut Laue-Langevin, or ILL, is an internationally-financed scientific facility, situated in Grenoble, France. It is one of the world centres for research using neutrons...

 in Grenoble, France. This was Modesto Montoya

Modesto Montoya

Modesto Montoya in Salpo Peru is a nuclear physicist at the in Lima, Peru and member of the . He is past president of that institute, and past president of the .-Education:He holds a B.Sc., a Lic. a M.Sc...

´s thesis work. Other experiments on cold fission were also done involving ²⁴⁸Cm and ²⁵²Cf . A phenomenological interpretation was proposed by Gönnenwein and Duarte et al..

The importance of cold fission phenomena lies in the fact that fragments reaching detectors have the same mass that they obtained at the "scission" configuration, just before the attractive but short-range nuclear force becomes null, and only Coulomb interaction acts between fragments. After this Coulomb potential energy is converted in fragments kinetic energies, which –added to prescission kinetic energies- is measured by detectors.

The fact that cold fission preserves nuclear mass until the fission fragments reach the detectors permits the experimenter to better determine the fission dynamics

Dynamics

Dynamics may refer to:In Physics:*Dynamics , in physics, dynamics refers to time evolution of physical processes...

, especially the aspects related to Coulomb and shell effects in low energy fission. and nucleon pair breaking Adopting several theoretical assumptions about scission configuration one can calculate the maximal value of kinetic energy as a function of charge and mass of fragments and compare them to experimental results.