neutron

Also known as N, n, neutrons

A neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The neutron was discovered by James Chadwick in 1932, leading to the discovery of nuclear fission in 1938, the first self-sustaining nuclear reactor (Chicago Pile-1, 1942), and the first nuclear weapon (Trinity, 1945).

OverviewAI-generated

A neutron is a subatomic particle with an atomic number of 0 and a neutron number of 1. It possesses a spin quantum number of 0.5 and an isospin quantum number of 0.5. The particle has a parity quantum number of 1 and a binding energy of 0. Its electric charge is recorded as 0 and -0.0000000000000000000002.

The mass of a neutron is 939.565413, with a mass excess of 8071.31713. It has a mean lifetime of 1040 and a half-life of 10.183. The magnetic moment is -1.91304273 and -1.9130427. Its g-factor is -3.8260845 and its gyromagnetic ratio is 183247172. The electric dipole moment is 0.000000000000000000000000018.

Neutrons were discovered in 1932. The subject is categorized under "Neutrons" on Commons. It is referenced by 1,673 other encyclopedia articles. There are 44,330 PubMed entries related to the term.

Synthesized by Vinony from 22 facts across 3 sources: Wikidata, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.

Key facts

Particle.classification: Baryon
Particle.name: Neutron
Particle.image: 250px
Particle.caption: The quark content of a neutron. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.
Particle.group: Hadron
Particle.composition: 1 up quark, 2 down quarks
Particle.statistics: Fermionic
Particle.interaction: Gravity, weak, strong, electromagnetic
Particle.antiparticle: Antineutron
Particle.theorized: Ernest Rutherford (1920)
Particle.discovered: James Chadwick (1932)
Particle.symbol: , ,
Particle.mean_lifetime: (free)
Particle.electric_charge: (experimental limits)
Particle.electric_dipole_moment: < (experimental upper limit)
Particle.magnetic_moment: Neutron magnetic moment| J·T−1
Particle.spin:  ħ
Particle.isospin: −

via Wikipedia infobox

Research

44,330 papers

Neutron brachytherapy in the modern era: Indications and evidence.Cancer radiotherapie : journal de la Societe francaise de radiotherapie oncologique · 2023Loap P, Barcellini A, de Marzi L et al.DOI: 10.1016/j.canrad.2022.08.010
Neutron dose and its measurement in proton therapy-current State of Knowledge.ReviewThe British journal of radiology · 2020Hälg RA, Schneider UDOI: 10.1259/bjr.20190412
An investigation into neutron-induced bystander effects: How low can you go?ReviewEnvironmental research · 2019Lad J, Rusin A, Seymour C et al.DOI: 10.1016/j.envres.2019.04.033
Neutron radiotherapy for malignant gliomas.ReviewAmerican journal of clinical oncology · 1989Griffin BR, Berger MS, Laramore GE et al.DOI: 10.1097/00000421-198908000-00007
Neutron dose from a 6-MV X-ray beam in radiotherapy.Radiological physics and technology · 2023Matsubara HDOI: 10.1007/s12194-023-00705-6
Neutron relative biological effectiveness in Hiroshima and Nagasaki atomic bomb survivors: a critical review.ReviewJournal of radiation research · 2016Sasaki MS, Endo S, Hoshi M et al.DOI: 10.1093/jrr/rrw079
Neutron microscopy. The low-damage imaging of specialized organic materials.ReviewCell biophysics · 1985Steinbach ADOI: 10.1007/BF02788636
Neutron dosimetry in low-earth orbit using passive detectors.ReviewRadiation measurements · 2001Benton ER, Benton EV, Frank AL et al.DOI: 10.1016/s1350-4487(01)00047-6

via PubMed

~43 min read

Encyclopedic overview

31 sections

Contents

Discovery
Occurrence
Atomic nucleus
Free neutron
Dineutrons and tetraneutrons
Neutron stars and neutron matter
Composition
Beta decay
Properties
Mass
Spin
Magnetic moment
Electric charge
Electric dipole moment
Antineutron
Detection
Neutron detection by neutron capture
Neutron detection by elastic scattering
Sources and production
Neutron beams and modification of beams after production
Applications
Nuclear energy
Other uses
Medical therapies
Health risks
Neutron temperature
See also
Neutron sources
Processes involving neutrons
References
Further reading

Neutrons are found, together with a similar number of protons in the nuclei of atoms. Atoms of a chemical element that differ only in neutron number are called isotopes. Free neutrons are produced copiously in nuclear fission and fusion. They are a primary contributor to the nucleosynthesis of chemical elements within stars through fission, fusion, and neutron capture processes. Neutron stars, formed from massive collapsing stars, consist of neutrons at the density of atomic nuclei but a total mass more than the Sun.

Excerpted from Wikipedia’s “neutron” article, available under the CC BY-SA 4.0 licence.