Criticality may refer to:

Physics terms

Critical phenomena In physics, critical phenomena is the collective name associated with the physics of critical points. Most of them stem from the divergence of the correlation length, but also the dynamics slows down. Critical phenomena include scaling relatio ...

, the collective name associated with the physics of critical points **

Critical point (thermodynamics) In thermodynamics, a critical point (or critical state) is the end point of a phase equilibrium curve. The most prominent example is the liquid–vapor critical point, the end point of the pressure–temperature curve that designates conditions ...

, the end point of a phase equilibrium curve **

Quantum critical point A quantum critical point is a point in the phase diagram of a material where a continuous phase transition takes place at absolute zero. A quantum critical point is typically achieved by a continuous suppression of a nonzero temperature phase t ...

, a special class of continuous phase transition that takes place at absolute zero

Nuclear-physics terms

Critical mass In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fis ...

, referring to criticality in nuclear physics, when a nuclear reactor's fissionable material can sustain a chain reaction by itself *

Criticality (status) In the operation of a nuclear reactor, criticality is the state in which a nuclear chain reaction is self-sustaining—that is, when reactivity is zero. In supercritical states, reactivity is greater than zero. Applications Criticality is the n ...

, a milestone in the commissioning of a nuclear power plant *

Criticality accident A criticality accident is an accidental uncontrolled nuclear fission chain reaction. It is sometimes referred to as a critical excursion, critical power excursion, or divergent chain reaction. Any such event involves the unintended accumulation ...

, an uncontrolled nuclear chain reaction *

Nuclear criticality safety Nuclear criticality safety is a field of nuclear engineering dedicated to the prevention of nuclear and radiation accidents resulting from an inadvertent, self-sustaining nuclear chain reaction. Nuclear criticality safety is concerned with miti ...

, the prevention of nuclear and radiation accidents resulting from an inadvertent, self-sustaining nuclear chain reaction *

Prompt critical In nuclear engineering, prompt criticality describes a nuclear fission event in which criticality (the threshold for an exponentially growing nuclear fission chain reaction) is achieved with prompt neutrons alone (neutrons that are released immed ...

, an assembly for each nuclear fission event

Other terms

Critical thinking Critical thinking is the analysis of available facts, evidence, observations, and arguments to form a judgement. The subject is complex; several different definitions exist, which generally include the rational, skeptical, and unbiased an ...

, in education *

Criticality index Criticality index is mainly used in risk analysis. The Criticality Index of an activity (task) can be expressed as a ratio (between 0 and 1) but is more often expressed as a percentage. During a (e.g. Monte Carlo) simulation tasks can join or leav ...

, in risk analysis * Criticality matrix, a representation (often graphical) of failure modes along with their probabilities and severities *

Self-organized criticality Self-organized criticality (SOC) is a property of dynamical systems that have a critical point as an attractor. Their macroscopic behavior thus displays the spatial or temporal scale-invariance characteristic of the critical point of a phase ...

, a property of (classes of) dynamical systems which have a critical point as an attractor {{disambiguation