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Topic: Beta emission

	Beta decay - Wikipedia, the free encyclopedia
		In nuclear physics, beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
		In some nuclei, beta decay is energetically prevented, and in some of these cases the nuclei may undergo double beta decay.
		Beta decay can be considered as a perturbation as described in quantum mechanics, and thus follow Fermi's Golden Rule.
	www.wikipedia.org /wiki/Beta_decay (382 words)

	beta emission (Site not responding. Last check: 2007-11-07)
		Beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
		In beta minus decay, a neutron is converted to a proton via the weak nuclear force and a beta particle (an electron) and an anti-neutrino are emitted.
		In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta minus particle (a positron) and a neutrino are emitted.
	www.yourencyclopedia.net /Beta_emission.html (251 words)

	ninemsn Encarta - Radioactivity
		In an electric field the path of the beta particles is greatly deflected towards the positive electric pole, and that of the alpha particles to a lesser extent towards the negative pole, while gamma rays are not deflected at all.
		Then alpha and beta particles were recognized to be discrete units of matter and radioactivity to be a process in which atoms are transformed by the emission of one or the other of these particles into new kinds of atoms possessing new chemical properties.
		Beta emission is accomplished by the transformation of a neutron into a proton, thus resulting in an increase in nuclear charge (or atomic number) of one unit.
	au.encarta.msn.com /encyclopedia_761569327/Radioactivity.html (1883 words)

	MSN Encarta - Search View - Radioactivity
		According to current theory, beta emission is accomplished by the transformation of a neutron into a proton, thus resulting in an increase in nuclear charge (or atomic number) of one unit.
		The emission of gamma rays is a compensation by the atomic nucleus for the unstable state that follows alpha and beta processes in the nucleus.
		Positron emission is thought to be accomplished through the conversion, in the nucleus, of a proton into a neutron, resulting in a decrease of the atomic number by one unit.
	encarta.msn.com /text_761569327__1/Radioactivity.html (3103 words)

	MSN Encarta - Radioactivity
		Radioactivity, spontaneous disintegration of atomic nuclei by the emission of subatomic particles called alpha particles and beta particles, or of electromagnetic rays called X rays and gamma rays.
		In an electric field the path of the beta particles is greatly deflected toward the positive electric pole, that of the alpha particles to a lesser extent toward the negative pole, and gamma rays are not deflected at all.
		Beta particles were subsequently shown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy.
	ca.encarta.msn.com /encyclopedia_761569327/Radioactivity.html (1816 words)

	Radioactivity
		Beta particles are just electrons from the nucleus, the term "beta particle" being an historical term used in the early description of radioactivity.
		Beta emission is accompanied by the emission of an electron antineutrino which shares the momentum and energy of the decay.
		The emission of a positron is accompanied by a neutrino.
	hyperphysics.phy-astr.gsu.edu /hbase/nuclear/beta.html (364 words)

	Beta emission (Site not responding. Last check: 2007-11-07)
		Beta Beta Beta - Pi Lambda Chapter At the University of Kansas in Lawrence.
		Beta Beta Beta - Eta Eta Chapter HH chapter of Tri-Beta at Roanoke College in Salem, Virginia.
		Emission Measurement Center The Emission Measurement Center provides access to air emission test methods and testing information for the development and enforcement of national, state, and local emission prevention and control programs.
	www.serebella.com /encyclopedia/article-Beta_emission.html (301 words)

	EPA - Beta Particles (EPA's Radiation Protection Program: Understanding Radiation) (Site not responding. Last check: 2007-11-07)
		Beta particles have a mass of 549 millionths of one atomic mass unit, or AMU, which is about 1/2000 of the mass of a proton or neutron.
		When the beta particle ejection doesn't rid the nucleus of the extra energy, the nucleus releases the remaining excess energy in the form of a gamma photon.
		Beta emitters are also used in a variety of industrial instruments, such as industrial thickness gauges, using their weak penetrating power to measure very thin materials.
	www.epa.gov /radiation/understand/beta.htm (1424 words)

	Part 1. Physical Principles of Ionizing Radiations
		The proton remains in the nucleus, and the antineutrino and beta particle are expelled from the nucleus.
		Beta emitters that are not pure emit electromagnetic radiation in the form of gamma photons.
		With beta decay, a neutron is converted to a proton with the release of a beta particle and an antineutrino; in positron decay, a proton is converted into a neutron with a positron and a neutrino ejected from the nucleus.
	www.radiographicceu.com /article8.html (9783 words)

	Overturning of Parity Law in Nuclear Physics
		The experiments at NBS showed that emission of electrons in beta decay of cobalt-60 nuclei is greater in the direction of the south pole of the nucleus (pointing toward the north pole of the magnet), as indicated in the drawing.
		After the beta emission had been measured for this condition, the direction of the magnetic field was reversed, and the beta emission again measured for the nuclei now polarized in the opposite direction.
		It was found that the emission of beta particles is greater in the direction opposite to that of the nuclear spin.
	physics.nist.gov /GenInt/Parity/expt.html (1760 words)

	Radiation Safety Manual - Chapter 10 (Site not responding. Last check: 2007-11-07)
		Because of its weak beta emission, Hydrogen-3 is primarily an internal radiation hazard.
		Because of its relatively weak beta emission, Carbon-14 is primarily an internal radiation hazard.
		Beta absorption is relatively independent of atomic number so plastic, glass, wood and other low-Z materials provide shielding which is just as effective at stopping P-32 beta particles as an equal mass of lead or iron, producing fewer X-rays in the process.
	bfa.sdsu.edu /ehs/radch10.htm (2336 words)

	Beta Emission and Isotopes (Site not responding. Last check: 2007-11-07)
		C14 decays to N14 by beta- emission with a half life of 5730 years.C11 decays into B11 by beta+ emission with a half life of 20.5 minutes.
		This is due to the fact that neutron decay produces beta- with about 0.5 MeV energy release (the decay is exothermic) and proton decay, which would produce beta+, does not occur with free protons because it would violate conservation of energy by about 0.5 MeV.
		For a nucleus to emit a beta+ in a radioactive decay, it must have more protons than neutrons, such that the nucleus would be more stable if a proton changed to a neutron, where "more stable" means the binding energy is increased by more than 0.5 MeV.
	www.newton.dep.anl.gov /askasci/phy00/phy00702.htm (531 words)

	Beta emission - Hutchinson encyclopedia article about Beta emission (Site not responding. Last check: 2007-11-07)
		Disintegration of the nucleus of an atom to produce a beta particle, or high-speed electron, and an electron antineutrino.
		During beta decay, a neutron in the nucleus changes into a proton, thereby increasing the atomic number by one while the mass number stays the same.
		Beta decay is caused by the weak nuclear force, one of the fundamental forces of nature operating inside the nucleus.
	encyclopedia.farlex.com /Beta+emission (142 words)

	A world of particles.The standard model. Beta decay. (Site not responding. Last check: 2007-11-07)
		A natural example of beta emission is the decay of carbon-14 into nitrogen-14.
		Beta decay is fundamentally different from alpha decay.
		Beta decay happens when one of the down quarks in a neutron changes into an up quark, making it a proton.
	schoolscience.co.uk /content/4/physics/particles/particlesmodel3.html (514 words)

	Beta decay - Encyclopedia, History and Biography (Site not responding. Last check: 2007-11-07)
		In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
		The energies of electrons emitted by beta decay were observed to be non-discrete (some being more energetic than others).
		A problem arose in trying to explain what happened to the missing energy if an electron was emitted with less than maximum energy — the law of conservation of energy appeared to be violated.
	www.arikah.net /encyclopedia/Beta_emission (262 words)

	Chemical Sciences: Mechanisms of Nuclear Reactions (Site not responding. Last check: 2007-11-07)
		The emission of a beta particle, or beta radiation, is the emission of a very energetic electron from the nucleus of an atom.
		The emission of a beta particle has the effect of leaving the nuclear mass unchanged but increasing the nuclear charge by one, and so the element produced by beta decay is one column to the right in the periodic chart from the original element.
		Emission of gamma radiation is the emission of very high-energy photons, not the emission of particles.
	www.ualberta.ca /~jplambec/che/p101/p05012.htm (464 words)

	[No title] (Site not responding. Last check: 2007-11-07)
		The emission relation between $H\alpha$ and $H\beta$, which is determined by the total optical thickness, confirms earlier findings from spectra with a large sample of data points from six prominences.
		Examples of the observed relation between this ratio and the $H\beta$ emission are given in Figs.~7 and 8 for the faint prominence at E/5S (cf., Fig.~3), and for the bright prominence W/28N (cf., Fig.~2).
		Note that the emission ratio $Ca^+8542/H\beta$ is fairly constant over a large range of observed prominence emissions (particularly for the prominence at W/28N), thus confirming the spectro-photometric observations by Stellmacher and Wiehr (1997), and by De~Boer, Stellmacher and Wiehr (1998).
	www.uni-sw.gwdg.de /~ewiehr/www_prot_2d (1875 words)

	Dainis Dravins (Lund Observatory)
		Beta Hydri (of the constellation Hydrus, not Hydra) is the closest subgiant (G2 IV) and one of the oldest stars in the solar Galactic neighborhood.
		The emission variations are small (30%), and are characterized by smooth and systematic changes, suggesting continuous changes in the chromospheric structure, rather than the sudden emergence of active regions.
		For Beta Hyi, the average profile over twelve years is shown (bold), while the dotted curve is the spectrum of integrated sunlight, as revealed by an IUE observation of the Moon with nominally identical instrumental settings.
	www.astro.lu.se /~dainis/HTML/ACTIVITY.html (1211 words)

	AllRefer.com - beta particle (Physics) - Encyclopedia
		Beta radiation (or beta rays) was identified and named by E. Rutherford, who found that it consists of high-speed electrons.
		Unlike alpha and gamma particles, whose energy can be explained as the difference of the energies of the radioactive nucleus before and after emission, beta particles emerge with a variable energy.
		This apparent violation of the law of conservation of energy (see conservation laws) led to the hypothesis that a second undetected particle, the neutrino, is emitted along with the electron and shares the total available energy.
	reference.allrefer.com /encyclopedia/B/betapart.html (234 words)

	Theory: Radioactive Decay
		Some nuclei instead undergo beta plus decay, in which a proton decays to become a neutron plus a positron (anti-electron or beta-plus particle) and an electron-type neutrino.
		Beta decay and gamma decay often occur as steps in a chain of radioactive decays that begins with the fission of some heavy element.
		Secondary transitions in which a proton moves from a higher level to a lower one with emission of a photon are then common, as are beta-emission transitions in which either a proton or a neutron moves to lower energy level (and changes type).
	www2.slac.stanford.edu /vvc/theory/nuclearstability.html (694 words)

	Nuclear Chemistry
		The large mass nuclei tend to use alpha emission because it is a quick way for a large mass atom to lose a lot of nucleons.
		As a result of the addition of the proton, the atomic number of an element increases during beta emission.
		Beta emission can be a significant health risk.
	www.bcpl.net /~kdrews/nuclearchem/nuclear.html (680 words)

	Nuclear Chemistry (Site not responding. Last check: 2007-11-07)
		Beta emission is when a high speed electron (negative charge) leaves the nucleus.
		Beta emission occurs in elements with more neutons than protons, so a neutron splits into a proton and an electron.
		Gamma Emission is when an excited nucleus gives off a ray in the gamma part of the spectrum.
	library.thinkquest.org /10429/low/nuclear/nuclear.htm?tqskip=1 (517 words)

	Neutron emission - Encyclopedia.WorldSearch (Site not responding. Last check: 2007-11-07)
		Neutron emission is a type of radioactive decay in which a neutron is simply ejected from the nucleus.
		Neutron Emission Spectroscopy Studies of Fusion Plasmas of Deuterium - Tritium in Tokamaks
		Evaluation of the angle integrated neutron emission cross sections from the interaction of 14 MeV neutrons with medium and heavy nuclei (Physics data)
	encyclopedia.worldsearch.com /neutron_emission.htm (137 words)

	BETA EMISSION
		Beta (Β β) is the 2nd letter of the Greek alphabet and has a numeric value of 2.
		BETA is a pure object-oriented language from the Scandinavian School in System Development where the first object-oriented language Simula was developed.
		BETA is a strongly typed language like Simula, Eiffel and C++, with most of the type checking being carried out at compile-time.
	www.websters-online-dictionary.org /definition/BETA+EMISSION (647 words)

	Beta Emission (Site not responding. Last check: 2007-11-07)
		The second type of radioactive emission is beta particle emission.
		Note that the isotopic mass for the electron is considered to be zero because it is much, much less than that of a proton or neutron.
		For example, Carbon-14 is used to date ancient objects like mummies, and it decays by beta emission.
	www.dallassd.com /our%20schools/high%20School/Chemsite/nucleareqns/types2.html (111 words)

	beta decay -- Encyclopædia Britannica (Site not responding. Last check: 2007-11-07)
		In the most common form of gamma decay, known as gamma emission, gamma rays (photons, or packets of electromagnetic energy, of extremely short wavelength) are radiated.
		In elements lighter than lead, beta-particle decay—in which a neutron is transformed into a proton or vice versa by emission of either an electron or a positron or by electron capture—is the main type of decay observed.
		Emission of a beta particle produces an energy change in the nucleus.
	www.britannica.com /eb/article-9078953?tocId=9078953 (739 words)

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