News tagged with neutrons
Theoretical physics breakthrough: Generating matter and antimatter from the vacuum
Under just the right conditions -- which involve an ultra-high-intensity laser beam and a two-mile-long particle accelerator -- it could be possible to create something out of nothing, according to University of Michigan ...
Dec 08, 2010 |
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Discovery could challenge established theory of the nucleus
(PhysOrg.com) -- By analyzing data from experiments performed earlier this decade at the Oak Ridge Electron Linear Accelerator (ORELA), physicists have made observations that seem to conflict with the widely accepted theory ...
Aug 26, 2010 |
4.9 / 5 (58) |
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Bound neutrons pave way to free ones
(PhysOrg.com) -- A study of bound protons and neutrons conducted at the Department of Energy's Thomas Jefferson National Accelerator Facility has allowed scientists, for the first time, to extract information ...
Feb 07, 2011 |
4.9 / 5 (52) |
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Radio pulses from pulsar appear to move faster than light
(PhysOrg.com) -- Laboratory experiments in the last few decades have shown that some things can appear to move faster than light without contradicting Einstein's special theory of relativity, but now astrophysicists ...
Jan 14, 2010 |
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New type of nuclear fission discovered
(PhysOrg.com) -- Nuclear fission, or the splitting of a heavy nucleus, usually results in symmetrical fragments of the same mass. Physicists attribute the few known examples of fission that is asymmetric to ...
Dec 06, 2010 |
4.7 / 5 (52) |
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Magnetic monopoles detected in a real magnet for the first time
Researchers from the Helmholtz Centre Berlin, in cooperation with colleagues from Dresden, St. Andrews, La Plata and Oxford, have for the first time observed magnetic monopoles and how they emerge in a real ...
Sep 03, 2009 |
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Giant ring of black holes
(PhysOrg.com) -- Just in time for Valentine's Day comes a new image of a ring -- not of jewels -- but of black holes.
Feb 09, 2011 |
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Strange Antihyperparticle Created
(PhysOrg.com) -- Physicists, including nine from UC Davis, working at the U.S. Department of Energy's Brookhaven National Laboratory recently created some strange matter not seen since just after the Big Bang -- an "antihypertriton" ...
Mar 30, 2010 |
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Scientists investigate the possibility of wormholes between stars
(PhysOrg.com) -- Wormholes are one of the stranger objects that arise in general relativity. Although no experimental evidence for wormholes exists, scientists predict that they would appear to serve as shortcuts ...
Feb 25, 2011 |
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Astronomers discover most massive neutron star yet known (w/ Video)
(PhysOrg.com) -- Astronomers using the National Science Foundation's Green Bank Telescope (GBT) have discovered the most massive neutron star yet found, a discovery with strong and wide-ranging impacts across ...
Oct 27, 2010 |
4.7 / 5 (33) |
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Fahrenheit -459: Neutron stars and string theory in a lab
(PhysOrg.com) -- Using lasers to contain some ultra-chilled atoms, a team of scientists has measured the viscosity or stickiness of a gas often considered to be the sixth state of matter. The measurements ...
Dec 09, 2010 |
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Mass limits of dark matter derived from 'strange' stars
(PhysOrg.com) -- Much of the matter in our universe may be made of a type of dark matter called weakly interacting massive particles, better known as WIMPs. Although some scientists predict that these hypothetical ...
Oct 12, 2010 |
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Ytterbium's broken symmetry: The largest parity violations ever measured in an atom
Ytterbium was discovered in 1878, but until it recently became useful in atomic clocks, the soft metal rarely made the news. Now ytterbium has a new claim to scientific fame. Measurements with ytterbium-174, ...
Jul 22, 2009 |
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Nuclear missing link created at last: Superheavy element 117 (Update)
(PhysOrg.com) -- A collaboration of Russian and US physicists has finally created element 117 - a superheavy element made of atoms containing 117 protons that is roughly 40% heavier than lead.
Apr 06, 2010 |
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Puzzled Physicists Solve Decade-Long Discrepancies
(PhysOrg.com) -- A team led by physicists at the Science and Technology Facilities Council (STFC) and Brookhaven National Laboratory (BNL) have resolved a decade-long puzzle that is set to have huge implications ...
Oct 09, 2009 |
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Neutron
The neutron is a subatomic hadron particle which has the symbol n or n0, no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of 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. Neutrons are necessary within an atomic nucleus as they bind with protons via the strong force; protons are unable to bind with each other due to their mutual electromagnetic repulsion being stronger than the attraction of the strong force. The number of neutrons is the neutron number and determines the isotope of an element. For example, the abundant carbon-12 isotope has 6 protons and 6 neutrons, while the very rare radioactive 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 mean lifetime of just under 15 minutes (881.5±1.5 s). Free neutrons are produced in nuclear fission and fusion. Dedicated neutron sources like research reactors and spallation sources produce free neutrons for 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, and is sometimes referred to as neutronium.[citation needed]
The neutron has been the key to nuclear power production. After the neutron was discovered in 1932, it was realized in 1933 that it might mediate a nuclear chain reaction. In the 1930s, neutrons were used to produce many different types of nuclear transmutations. When nuclear fission was discovered in 1938, it was soon realized that this might be the mechanism to produce the neutrons for the chain reaction, if the process also produced neutrons, and this was proven in 1939, making the path to nuclear power production evident. These events and findings led directly to the first man-made nuclear chain reaction which was self-sustaining (Chicago Pile-1, 1942) and to the first nuclear weapons (1945).
For more information about Neutron, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
