Encyclopedia > Neutron degeneracy pressure

  Article Content

Degenerate matter

Redirected from Neutron degeneracy pressure

Degenerate matter is matter which has sufficiently high density that the dominant contribution to its pressure arises from the Pauli exclusion principle. The pressure maintained by a body of degenerate matter is called the degeneracy pressure, and arises because the Pauli principle forbids the constituent particles from occupying identical quantum states. Therefore, reducing the volume requires forcing the particles into higher-energy quantum states. The species of fermion is sometimes identified, so that we may speak of electron degeneracy pressure, neutron degeneracy pressure, and so forth.

Unlike gases, degenerate matter is difficult to compress and the volume of degenerate matter does not change much in response to changes in temperature or pressure.

Degeneracy pressure may be calculated using the model of a particle in a box.

Exotic examples of degenerate matter include neutronium, strange matter, metallic hydrogen and white dwarf matter. Degeneracy pressure contributes to the pressure of conventional solids, but these are not usually considered to be degenerate matter as a significant contribution to their pressure is provided by the interplay between the electrical repulsion of atomic nuclei and the screening of nuclei from each other by electrons allocated among the quantum states determined by the nuclear electrical potentials. In metals it is useful to treat the conduction electrons alone as a degenerate, free electron gas while the majority of the electrons are regarded as occupying bound quantum states. This contrasts with the case of the degenerate matter that forms the body of a white dwarf where all the electrons would be treated as occupying free particle momentum states.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Digital Rights Management

... copy-prevention codes embedded in broadcast HDTV signals and the Palladium operating system. A wide variety of DRM systems have also been employed to restrict access to ...

 
 
 
This page was created in 29.8 ms