Warm Dense Matter
Encyclopedia
Warm dense matter, abbreviated WDM, is the non-equilibrium state of matter between a solid
and a plasma
. It can be defined as the state that is too dense to be described by weakly coupled plasma physics yet that is too energetic to be described by condensed matter physics
. In this state, the potential energy
of the interaction between electrons and nuclei and the kinetic energy
of electrons are of roughly the same magnitude. WDM has a density of the same order as a solid and a temperature of a few tens of thousands of kelvin
s (or a few electronvolt
s in the units favored by practitioners).
WDM is expected in the cores of some large planets, in the Inertial confinement fusion
context during the solid to plasma phase transition driven by laser pulses, and other systems that start as solids and are heated to become plasmas. The latter two categories imply that WDM physics are also relevant to nuclear explosions. Warm Dense Matter is also created during intense laser-target interactions and particle beam-target interactions.
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...
and a plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
. It can be defined as the state that is too dense to be described by weakly coupled plasma physics yet that is too energetic to be described by condensed matter physics
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
. In this state, the potential energy
Potential energy
In physics, potential energy is the energy stored in a body or in a system due to its position in a force field or due to its configuration. The SI unit of measure for energy and work is the Joule...
of the interaction between electrons and nuclei and the kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
of electrons are of roughly the same magnitude. WDM has a density of the same order as a solid and a temperature of a few tens of thousands of kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
s (or a few electronvolt
Electronvolt
In physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
s in the units favored by practitioners).
WDM is expected in the cores of some large planets, in the Inertial confinement fusion
Inertial confinement fusion
Inertial confinement fusion is a process where nuclear fusion reactions are initiated by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium....
context during the solid to plasma phase transition driven by laser pulses, and other systems that start as solids and are heated to become plasmas. The latter two categories imply that WDM physics are also relevant to nuclear explosions. Warm Dense Matter is also created during intense laser-target interactions and particle beam-target interactions.