New discovery may offer clues to 'missing' pulsars

Millisecond pulsars (MSPs) are evolved neutron stars with short spin periods that have gone through a long period of mass transfer in a low-mass X-ray binary phase. Globular clusters (GCs)—conglomerations of tens of thousands ...

Neutrons help track down mammalian ancestors

A team of German and Argentinian researchers has used neutrons in the FRM II research neutron source at the Technical University of Munich (TUM) to identify an animal species that has been extinct for 220 million years. Findings ...

Automating neutron experiments with AI

Oak Ridge National Laboratory researchers are developing a first-of-its-kind artificial intelligence device for neutron scattering called Hyperspectral Computed Tomography, or HyperCT. The fully automated, AI-driven platform ...

Heaviest neutron star to date is a 'black widow' eating its mate

A dense, collapsed star spinning 707 times per second—making it one of the fastest spinning neutron stars in the Milky Way galaxy—has shredded and consumed nearly the entire mass of its stellar companion and, in the process, ...

Assembling the first global map of lunar hydrogen

Using data collected over two decades ago, scientists from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, have compiled the first complete map of hydrogen abundances on the Moon's surface. The map ...

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The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.

Neutrons 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 nucleus is the atomic number and defines the type of element the atom forms. The number of neutrons determines the isotope of an element. For example, the carbon-12 isotope has 6 protons and 6 neutrons, while the carbon-14 isotope has 6 protons and 8 neutrons.

While bound neutrons in stable nuclei are stable, free neutrons are unstable; they undergo beta decay with a lifetime of just under 15 minutes (885.7 ± 0.8 s). Free neutrons are produced in nuclear fission and fusion. Dedicated neutron sources like research reactors and spallation sources produce free neutrons for the use in irradiation and in neutron scattering experiments.

Even though it is not a chemical element, the free neutron is sometimes included in tables of nuclides. It is then considered to have an atomic number of zero and a mass number of one.

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