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	Neutron - Wikipedia, the free encyclopedia
		The neutron and proton are instances of a nucleon.
		Although the neutron has zero net charge, it may interact electromagnetically in two ways: first, the neutron has a magnetic moment of the same order as the proton; second, it is composed of electrically charged quarks.
		Free neutron beams are obtained from neutron sources by neutron transport.
	en.wikipedia.org /wiki/Neutron (1172 words)

	Free neutron - Wikipedia, the free encyclopedia
		A free neutron is a neutron that exists outside of an atomic nucleus.
		While neutrons can be stable when bound inside nuclei, free neutrons are unstable and decay with a half-life of just under 15 minutes.
		Nuclear reactors are designed to produce free neutrons in copious amounts; their role is to sustain the energy-producing chain reaction.
	en.wikipedia.org /wiki/Free_neutron (190 words)

	MSN Encarta - Neutron
		Neutron, electrically neutral elementary particle that is part of the nucleus of the atom.
		The neutron is also affected by the weak nuclear force, an interaction among the building blocks of the neutron that causes the neutron to decay, or break apart.
		The neutrons are responsible for the remaining mass of the atom.
	encarta.msn.com /encyclopedia_761565664/Neutron.html (1526 words)

	Neutron
		The neutron is a particle found in almost every atomic nucleus (the tiny spec of matter at the heart of an atom).
		A free neutron (one not contained in an atomic nucleus) is radioactive.
		The neutron is important in forming a chain reaction in nuclear fission, as used in nuclear reactors and atom bombs.
	www.historyoftheuniverse.com /neutron.html (232 words)

	Learn more about Neutron in the online encyclopedia. (Site not responding. Last check: 2007-11-03)
		Outside the nucleus, neutrons are unstable and have a half-life of about 15 minutes, decaying by emitting an electron and antineutrino to become a proton.
		The neutron, however, is unaffected by such forces; it is affected only by the very short-range strong nuclear force which comes into play when the neutron comes very close indeed to an atomic nucleus.
		The only means we have of controlling free neutrons is to put nuclei in their way so that they will be slowed and deflected or absorbed by collisions.
	www.onlineencyclopedia.org /n/ne/neutron.html (875 words)

	neutron on Encyclopedia.com
		In a nucleus the neutron can be stable, but a free neutron decays with a half-life of about 17 min (1,013 sec), into a proton, an electron, and an antineutrino.
		The neutron and the proton are regarded by physicists as two aspects or states of a single entity, the nucleon.
		The field of neutron optics is concerned with such topics as the diffraction and polarization of beams of neutrons.
	www.encyclopedia.com /html/n1/neutron.asp (1167 words)

	NIST - Neutron Lifetime Experiment
		Free neutrons are unstable and decay with a lifetime of about 15 minutes into a proton, an electron, and an antineutrino.
		Since the dominant uncertainty for the primordial helium abundance comes from the accuracy of the neutron decay rate [1], improved neutron decay rate measurements are needed for sharpening this prediction.
		The measurement of the lifetime of free neutrons in a cold neutron beam was one of the first experiments operating in the NCNR Guide Hall.
	physics.nist.gov /Divisions/Div846/Gp3/FunPhys/lifetime.html (946 words)

	Learn more about Neutron moderator in the online encyclopedia. (Site not responding. Last check: 2007-11-03)
		In nuclear engineering, a neutron moderator is a medium which reduces the velocity of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a chain reaction.
		In a thermal nuclear power reactor, the nucleus of a heavy fuel element such as uranium absorbs a slow-moving free neutron, becomes unstable, and then splits into two smaller atoms.
		Because more free neutrons are released from a uranium fission event than are required to initiate the event, the reaction can become self sustaining--a chain reaction --under controlled conditions, thus producing a tremendous amount of energy.
	www.onlineencyclopedia.org /n/ne/neutron_moderator.html (299 words)

	Nat' Academies Press, Status of the Dosimetry for the Radiation Effects Research Foundation (DS86) (2001) (Site not responding. Last check: 2007-11-03)
		Neutron activation was measured with two fundamentally different types of detection with different types of errors: counting atoms with radiometric methods (beta or gamma counting) and counting atoms with accelerator mass spectroscopy (AMS).
		The free-field neutron fluences are of paramount interest because they are the quantities used to calculate doses to survivors and because they constitute a uniform basis for the comparison of measured values.
		However, there might be sample-specific variables that appreciably affect the neutron activation level of the sample for a given incident bomb fluence (such as boron content or water content) that have not been measured or have not been properly incorporated in the calculated value for the sample.
	www.nap.edu /openbook.php?record_id=10103&page=123 (7979 words)

	neutron concept from the Astronomy knowledge base (Site not responding. Last check: 2007-11-03)
		Through beta decay, a neutron may become a proton and an electron; the process occurs in reverse during the formation of a neutron star.
		Free neutrons decay slowly via the weak nuclear force.
		Despite being electrically neutral, the neutron possesses both an electric dipole moment (as if it were made of positive and negative charges separated a minute distance) and a magnetic moment, indicating some internal substructure.
	www.csi.uottawa.ca:4321 /astronomy/neutron.html (286 words)

	thermal neutron -- Encyclopædia Britannica
		any free neutron (one that is not bound within an atomic nucleus) that has an average energy of motion (kinetic energy) corresponding to the average energy of the particles of the ambient materials.
		Because the RIS technique is limited to the study of free atoms or molecules in the gas phase, the analysis of solids and liquids requires a means for releasing atoms from the bulk material.
		Neutrons emanating in fission are very energetic; their average energy is around two million electron volts (MeV), 80 million times higher than the energy of atoms in ordinary matter at room temperature.
	www.britannica.com /eb/article-9072071 (912 words)

	Wikinfo \| Nuclear fission
		The number of protons is equal to the atomic number, Z. The number of neutrons, N, is equal to the difference between the atomic mass number, A, and the atomic number.
		This is not accomplished by ejecting a proton or a neutron but by ejecting a positron or an electron; within the nucleus a proton converts itself into a neutron and positron (or a neutron converts itself into a proton and electron), and the light charged particle is ejected.
		Now the escape of neutrons from a quantity of uranium is a surface effect depending on the area of the surface, but fission capture occurs throughout the material and is therefore a volume effect.
	www.wikinfo.org /wiki.php?title=Nuclear_fission (2802 words)

	Taipei fears China's neutron bomb [Free Republic]
		The neutron bomb disclosure was made in a short statement on the official Xinhua news wire and immediately set off alarm bells around Asia.
		Neutron bombs are as deadly as atom bombs but they do not damage buildings outside the immediate strike area.
		Western diplomats in Beijing said China was unlikely to use its neutron bombs, but the announcement that the People's Liberation Army possesses the weapons is seen as a calculated escalation of the Taiwan conflict.
	www.freerepublic.com /forum/a378ece4847b8.htm (739 words)

	Untitled Document (Site not responding. Last check: 2007-11-03)
		Cold neutrons are free neutrons that are moving so slowly (less than 2000 m/s) that their deBroglie wavelengths are larger than the spacing between atoms in matter, typically in the range 0.2 to 2.0 nm.
		Neutron guides, analogous to fiber optic guides, can be used to transport cold neutrons long distances with very little losses.
		Precise measurements of neutron scattering lengths using a neutron interferometer can be used to improve our understanding of the nucleon-nucleon potential and other parameters such as the charge radius of the neutron.
	www.physics.tulane.edu /fw_r.htm (681 words)

	N C N R
		Since the dominant uncertainty for the primordial helium abundance comes from the accuracy of the neutron decay rate (Refer to Reference 1), improved neutron decay rate measurements are needed for sharpening this prediction.
		The measurement of the lifetime of free neutrons in a cold neutron beam was one of the first experiments operating in the N C N R Guide Hall.
		The charged particles from neutron reactions in the isotopic targets are counted with an accuracy of better than one part per thousand.
	www.ncnr.nist.gov /AnnualReport/FY2001_html/free_neutron_lifetime.htm (954 words)

	The Deuteron (Site not responding. Last check: 2007-11-03)
		The deuteron, composed of a proton and a neutron, is a stable particle.
		It's stability is remarkable since the free neutron is unstable, undergoing beta decay with a halflife of 10.3 minutes.
		When the temperature dropped to the point where neutrons could no longer be produced from protons, the decay of free neutrons began to diminish their population.
	hyperphysics.phy-astr.gsu.edu /hbase/particles/deuteron.html (270 words)

	Nuclear Weapon Diagrams
		In the center is the 'pit' with the neutron source (fission initiator) which usually consists of tritium gas.
		When one of these neutrons collides with a plutonium nucleus, it fissions and releases an additional 4.5 neutrons on average (compared to about 2.9 for fission induced by lower energy fission neutrons).
		Since each fusion neutron directly generates 180 MeV through fission, and another 810 MeV as a result of the second generation neutrons, the energy released by fusion driven fission greatly exceeds that produced by the fusion reaction itself.
	nuclearweaponarchive.org /Library/Brown (1294 words)

	13 - Kanarev - The Foundations of Physchemistry of Microworld
		If the protons are connected with the neutrons after the destruction of the nuclei of the iron atoms and the potassium atoms, the formation of deuterium, tritium and helium is possible.
		As free protons and neutrons appear during the destruction of the nucleus of the sodium atom, some nuclei of this element begin to form the atomic nuclei of aluminium (Fig.
		But not all free protons and neutrons are spent for the construction of the atomic nuclei of aluminium, chlorine and calcium.
	guns.connect.fi /innoplaza/energy/story/Kanarev/book/13.html (2470 words)

	Protons and neutrons
		The neutron is a baryon and is considered to be composed of two down quarks and one up quark.
		A free neutron will decay with a half-life of about 10.3 minutes but it is stable if combined into a nucleus.
		The decay of the neutron is associated with a quark transformation in which a down quark is converted to an up by the weak interaction.
	hyperphysics.phy-astr.gsu.edu /hbase/particles/proton.html (1082 words)

	b-Decomposition of Polarized Neutron
		Process of free neutron decomposition is presented in such a way that final decomposition products emerge as a result of serial structural changes of the initial particles.
		Free neutron is not resistant to the action of particles fluctuating in vacuum.
		Neutron decomposes with the participation of vacuum pairs e
	www.vertushkov.dp.ua /neutron/Neutron.htm (746 words)

	ZPEnergy.com - Speculation on a FE mechanism with H2O
		The neutron is one of the few candidate particles which will decay leaving a large amount of energy with a small gamma 'footprint,' so as to be nearly undetectable.
		Free neutrons are unstable with a half life of about 636 seconds.
		As with the neutron, there still exists a considerable measure of uncertainty as to the precise value of deuterium half-life, but it is not unfair to suggest that like many other forms of beta decay, the deuterium decay rate, which is difficult to distinguish from deuterium "stripping" may be influenced by strong proximate electric fields.
	www.zpenergy.com /modules.php?name=News&file=article&sid=842 (1640 words)

	intas 93-0298 (Site not responding. Last check: 2007-11-03)
		This project aims at an improved experimental determination of the free neutron lifetime which is of fundamental importance for particle physics and cosmology.
		The most precise values for neutron lifetime were obtained recently by storage of ultracold neutrons (UCN) in material bottles and the project participants were involved in these experiments.
		The neutrons escaping from the trap were recorded by surrounding counters.
	www.intas.be /catalog/93-0298.htm (556 words)

	neutron.d. (Site not responding. Last check: 2007-11-03)
		The free neutron and the free proton possess a Brownian movement.
		The second hypothesis is the following: the desintegration of the neutron, as well as of the proton, is set off by collisions with neutrinos, and in the case of the proton, virtually simultaneous collisions with several neutrinos.
		For the neutron, it appears then that n is in the order of 1.
	perso.wanadoo.fr /charreton.raoul/neutron.d..html (1306 words)

	Reference.com/Encyclopedia/Neutron moderator
		A good neutron moderator is a material full of atoms with light nuclei which do not easily absorb neutrons.
		After sufficiently many such impacts, the velocity of the neutron will be comparable to the thermal velocities of the nuclei; this neutron is then called a thermal neutron.
		This article is licensed under the GNU Free Documentation License.
	www.reference.com /browse/wiki/Neutron_moderator (305 words)

	ScienceDaily: Neutron Physics Instrument May Unlock Mysteries Of Universe (Site not responding. Last check: 2007-11-03)
		Tapping in to those neutrons will be the Fundamental Neutron Physics beam line, which will help physicists exploit neutrons to learn more about the Big Bang, left-right symmetry of the universe and the amount of energy produced in the sun.
		The fact physicists will have many more neutrons available to them greatly increases the accuracy of their experiments, one of which is aimed at pinpointing the lifetime of a free neutron.
		Indeed, to have an instrument like the Fundamental Neutron Physics beam line has been the dream of physicists for years, said Greene, who noted that 65 participants from 20 institutions participated in an organizational meeting of the development team at ORNL in 2001.
	www.sciencedaily.com /releases/2004/09/040917091547.htm (1243 words)

	Lifetime of the Neutron (Site not responding. Last check: 2007-11-03)
		The amount of time that a neutron survives before its decay plays a large role in determining which elements were created during the Big Bang.
		The IUCF Weak Interactions Group is playing an important role in a measurement of the neutron lifetime in progress at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. In this experiment, a polychromatic beam of cold neutrons is extracted from the NIST research reactor.
		The number of trapped protons depends on the number of neutrons that pass through the trap, the velocity of the neutrons as they pass through the trap, and the neutron lifetime.
	www.iucf.indiana.edu /Experiments/WEAK/life.html (446 words)

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