
	Where results make sense

Topic: Neutron activation

Related Topics

Tritium

Heavy water

5th century BC

In the News (Wed 30 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Neutron Activation Analysis
		Neutron Activation Analysis is an analytical technique based on the measurement of characteristic gamma rays emitted by isotopes of the sample that are produced by irradiation with thermal neutrons.
		Neutron Activation Analysis is a comparative technique; standards are prepared from certified solutions of known concentration of the elements of interest.
		The sensitivity obtained by activation analysis is a function of the neutron cross section of the element in question, available neutron flux, length of irradiation, resolution of the detector, matrix composition, and the "total" sample size.
	www.ne.ncsu.edu /NRP/naa.html (677 words)

	NS&T : Industry : Neutron Activation
		Neutron Activation is a method of determining the concentration of elements in a wide variety of samples, accurately and precisely.
		Neutron activation is capable of simultaneous determination of many elements in samples even when parameters are selected to optimize detection sensitivity of one particular element.
		Neutron activation can also detect elements at extremely low concentrations, at sensitivity levels that are superior to those attainable by non-nuclear methods, on the order of parts per billion or better.
	www.aboutnuclear.org /view.cgi?fC=Industry,Neutron_Activation (378 words)

	[N] TERMS & DEFINITIONS IN NUCLEAR CHEMISTRY
		NEUTRON CAPTURE A nuclear reaction in which a neutron is absorbed by a target nucleus producing an isotope one mass number greater in its ground or excited states.
		NEUTRON DEPTH PROFILING A method of charged particle activation analysis in which deuterons of specific energy undergo (d,n) reactions in which the neutron energy spectrum is measured by time-of-flight techniques.
		NEUTRON DIAGNOSTIC PROBE A device for prompt analysis that is a combination of a neutron generator, an alpha-particle counter for time-of-flight neutron spectrometry, and a detector for inelastic gamma-ray spectroscopy.
	www.radiochemistry.org /nomenclature/n.htm (1195 words)

	PSU Neutron Beam Group (NBG)
		Neutron activation analysis stands at the forefront of techniques for the quantitative multi-element analysis of major, minor, trace and rare elements.
		Neutron activation analysis, which was discovered in 1936, is one of the most potent techniques for multi-element analysis.
		Neutron activation analysis was one of the methods used here at Radiation Science and Engineering Center, Breazeale Nuclear Reactor to determine experimentally periods of global environmental stress during the past six thousand years using tree samples already collected and dated.
	www.engr.psu.edu /nbg/NeutronActAnalysis.html (445 words)

	Neutron activation - Wikipedia, the free encyclopedia
		Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when nuclei capture free neutrons, becoming heavier and entering excited states.
		In places with high neutron fluxes (primarily the cores of nuclear reactors) neutron activation contributes to material erosion, and the materials themselves must be disposed of as low-level radioactive waste.
		The lasting radiation from a nuclear weapon is in large part due to the neutron activation of the bomb itself and the surrounding material.
	en.wikipedia.org /wiki/Neutron_activation (329 words)

	Neutron Activation of Silver
		Thermal neutrons, which are neutrons in thermal equilibrium with their surroundings, can be produced by passing neutrons through materials containing a high concentration of light nuclei.
		After neutron irradiation, the foil is removed from the neutron flux and the induced activity (beta decay) is measured using a thin-walled Geiger counter.
		However, the neutron source should be well shielded from the counter, and at a sufficient distance so that the background count is not raised appreciably by gamma rays from the radium.
	www.fas.harvard.edu /~scdiroff/lds/QuantumRelativity/NeutronActivationofSilver/NeutronActivationofSilver.html (1264 words)

	MIT EAPS Instrumental Neutron Activation Analysis Introduction & Principle page
		Extensive bibliography of the use of neutron activation analysis for the period 1950-1970, categorized alphabetically not only by the names of the elements but also by the name of the authors was provided by De Soete, Gibels and Hoste.
		Neutron Activation Analysis is a nuclear analytical technique.The procedure consists of irradiating a sample with neutrons generated in the MIT nuclear reactor and measuring the activities from the resulting radioactive isotopes; using a standard (known abundances), the concentrations in the sample (unknown) are determined precisely and accurately.
		Neutron capture is the most important nuclear reaction for activation analysis, especially for thermal neutron activation analysis.
	web.mit.edu /pila/www/INAAIntro.HTM (567 words)

	[No title]
		Neutron activation analysis is a sensitive multielement analytical method for the accurate and precise determination of elemental concentrations in unknown materials.
		It is generally referred to as INAA (instrumental neutron activation analysis) for the purely instrumental version of the technique.
		FNAA (fast neutron activation analysis) is the form of the technique if higher energy neutrons, usually from an accelerator based neutron generator, are used.
	www.chem.tamu.edu /services/naa/naa.htm (658 words)

	Archaeometry, Neutron Activation Analysis, Jan Gunneweg: The importance and procedure of a nuclear method applied to ...
		Neutron Activation Analysis borrows its name from the BIG BANG during which event a mammoth flux of neutrons was created.
		Neutron Activation Analysis is a collective name for a scientific method to obtain quantification of the chemical elements in the domain of six important fields in Archaeology:
		In 1967, a nuclear technique, Instrumental Neutron Activation Analysis was developed to establish a quantitative chemical "fingerprint" of ceramic and volcanic obsidian, basalt and pumice.
	micro5.mscc.huji.ac.il /~msjan/neutron.html (786 words)

	Neutron activation analysis - Wikipedia, the free encyclopedia
		Neutron Activation Analysis (NAA) is a nuclear process used for determining certain concentrations of elements in a vast amount of materials.
		Neutron Activation Analysis is a sensitive multi-element analytical technique used for both qualitative and quantitative analysis of major, minor, trace and rare elements.
		The use of neutron activation analysis to characterize archaeological specimens (e.g., pottery, obsidian, chert, basalt and limestone) and to relate the artifacts to sources through their chemical signatures is a well-established application of the method.
	en.wikipedia.org /wiki/Neutron_activation_analysis (4236 words)

	Neutron Acitvation Analysis
		Neutron activation analysis (NAA) is a useful technique for identifying unknown materials.
		Neutrons are one of two types of particles found in nuclei, the other being protons.
		In beta decay, the change in binding energy appears as the mass energy and kinetic energy of the beta particle, the energy of the neutrino, and the kinetic energy of the recoiling daughter nucleus.
	ie.lbl.gov /naa (1947 words)

	Method Description - General Activation Analysis, Inc.
		If a neutron approaches the nucleus of an atom, it may be absorbed.
		Since neutrons "activate" the nucleus of an atom, not the electron shell, this method "sees" the total elemental content, regardless of oxidation state, chemical form or physical location.
		If a sample has a high concentration of an element with a large cross section, neutrons may be absorbed near the surface of the sample making the sample less radioactive than it theoretically should be.
	generalactivation.com /method.html (527 words)

	Main IVNAA Page
		When an atom captures a neutron, that atom is transformed to another nuclear state of the same element.
		Neutron activation influences certain elements, such as calcium, to produce gammas for a period of time.
		Neutron activation stimulates some elements, such as nitrogen, to produce very short-lived gammas which must be immediately detected and counted.
	www.bcm.edu /bodycomplab/ivnamainpage.htm (146 words)

	Re: Neutron Activation Analysis and gamma rays
		Neutrons are used to activate the nuclei of the various elements that make up a sample.
		Because they are electrically neutral, the neutrons slip past the electron clouds of the atoms/molecules in the sample and are also unaffected by the positive charges of the protons in the nuclei.
		Neutron activation analysis relies on being able to see the energies of the emitted gamma rays clearly, with high resolution.
	www.madsci.org /posts/archives/aug2001/998312710.Ph.r.html (1130 words)

	NEUTRON ACTIVATION ANALYSIS (Site not responding. Last check: 2007-11-05)
		Neutron activation analysis (NAA) is a sensitive analytical technique useful for performing both qualitative and quantitative multi-element analysis of major, minor, and trace elements in samples from almost every conceivable field of scientific or technical interest.
		The sensitivities for NAA are dependent upon the irradiation parameters (i.e., neutron flux, irradiation and decay times), measurement conditions (i.e., measurement time, detector efficiency), nuclear parameters of the elements being measured (i.e., isotope abundance, neutron cross-section, half-life, and gamma-ray abundance).
		The use of neutron activation analysis to characterize archaeological specimens (e.g., pottery, obsidian, chert, and limestone) and to relate the artifacts to source materials through their chemical signatures is a well-established application.
	nucleus.wpi.edu /Reactor/labs/R-naa.html (1366 words)

	Neutron Activation Analysis: Basic Principles and Applications
		Neutron activation analysis (NAA) stands at the forefront of techniques for the quantitative multi-element analysis of major, minor, trace and rare elements.
		Neutron activation analysis sensitivities and accuracy are dependent on the concentration of a particular element and radionuclide parameters (i.e., parent isotope abundance, neutron cross-section, half-life, and gamma ray abundance).
		Accuracy of an neutron activation analysis determination is usually between two and ten percent of the reported value, depending on the element analyzed and its concentration in the sample.
	www.sciner.com /Neutron/naa.html (384 words)

	[No title] (Site not responding. Last check: 2007-11-05)
		The neutron star in today's announcement is part of a binary star system named EXO 0748-676, located in the constellation Volans, or Flying Fish, about 30,000 light-years away, visible in southern skies with a large backyard telescope.
		Since supernova explosions are believed to form both neutron stars and SNRs, a young pulsar and its associated PWN are expected to be surrounded by a SNR.
		The geometry of the neutron star and its disk can be envisioned as a small Saturn with a thick version of its rings, explained David Ballantyne of the Canadian Institute for Theoretical Astrophysics at the University of Toronto.
	www.lycos.com /info/neutron.html (545 words)

	Oak Ridge National Laboratory Review - Neutron Science and Technology Initiatives
		The need for a brighter source of neutrons in the United States is urgent, and because it will take at least six to ten years to design and construct such a source, it is essential to start now to meet the nation's future needs in neutron science.
		Neutron guides work exactly like fiber-optic guides—they are rectangular conduits, typically about 5 × 18 centimeters (2 × 7 inches), whose inside surfaces are coated with a layer or, for greater effectiveness, multiple layers of a material (e.g., nickel) that will reflect neutrons that strike the surface at a glancing angle.
		Neutron activation analysis (NAA) is a sensitive, quick technique for determining the elemental composition, including trace elements, in a sample (such as contaminated soil in a small box).
	www.ornl.gov /ORNLReview/rev30-12/text/neutron.htm (2478 words)

	neutron
		Neutron guides work exactly like fiber optic guides—they are rectangular conduits, typically, 5 × 10 centimeters (2 × 4 inches), whose inside surfaces may be coated with multiple layers of nickel that will reflect any neutrons that strike the surface at a glancing angle, if they are not traveling too fast.
		Because neutrons are now so important to so many fields of science and engineering, the upgrade program is carefully planned to minimize the time that the HFIR will be out of service and to complete the work before the HFBR at Brookhaven shuts down for a planned upgrade of its own.
		Neutron scattering investigations show that in healthy bones, collagen molecules form a regular nearby periodic array with an average spacing of about 1.5 nanometers, and minerals deposit in spaces along this array every 87 nanometers.
	www.ornl.gov /info/ornlreview/rev29-12/text/neutron.htm (2999 words)

	An Overview of Neutron Activation Analysis (Site not responding. Last check: 2007-11-05)
		Neutron Activation Analysis (NAA) is a sensitive analytical technique useful for performing both qualitative and quantitative multi-ele
		The excitation energy of the compound nucleus is due to the binding energy of the neutron with the nucleus.
		Different types of reactors and different positions within a reactor can vary considerably with regard to their neutron energy distributions and fluxes due to the materials used to moderate (or reduce the energies of) the primary fission neutrons.
	www.missouri.edu /~glascock/naa_over.htm (3941 words)

	Neutron Activation Analysis (Site not responding. Last check: 2007-11-05)
		Neutron Activation Analysis (NAA) is a highly sensitive method for the accurate determination of elemental concentrations in material.
		Samples with unknown elemental concentrations are irradiated with thermal neutrons in a nuclear reactor together with standard materials of known elemental concentrations.
		Neutrons are absorbed in the nuclei of constituent atoms, and later these nuclei emit radiation with energy and quantity characteristic of the particular element.
	reactor.engr.wisc.edu /UWNRNAA.htm (280 words)

	Neutron Activation Analysis (Site not responding. Last check: 2007-11-05)
		A simple example of neutron activation analysis involves the measurement of iridium in soils.
		This is the measurement that led to the theory that the extinction of the dinosaurs, 65 million years ago, was caused by the impact of an asteroid or comet somewhere on Earth.
		In 1979, a group of scientists reported that neutron activation analysis had shown unusual amounts of the element iridium in Italian Cretaceous-Tertiary boundary sediments.
	www.lbl.gov /abc/wallchart/chapters/13/5.html (298 words)

	[No title]
		As for normal stars, the temperature of a neutron star is measured through its colour that indicates the energy the star emits.
		Because it uses short-lived tritium, the neutron generator is one of the components in a nuclear weapon that must be replaced regularly.
		The fact that the electrons produced from the neutron decay had continuous distributions of energy and momentum was a clear indication that there was another particle emitted along with the electron and proton.
	www.lycos.com /info/neutron--neutron-scattering.html?page=2 (653 words)

	ScienceDaily: Neutron Activation Analyses Proves Oswald Acted Alone In JFK Assassination
		The fragments were examined twice by neutron activation analyses, first by the FBI in 1964 and then by Vincent Guinn, a professor of chemistry at the University of California at Irvine in 1977.
		The benefits of nuclear activation analyses extend beyond limiting the hits to two bullets, by providing the only way to prove that Oswald's rifle was fired that day, and thereby quash the rumors that it had been planted to frame Oswald.
		Neutron Physics Instrument May Unlock Mysteries Of Universe (September 17, 2004) -- Fundamental questions that particle physicists have pondered for decades might be answered when a.2 million neutron physics beam line is built at the Department of Energy's Spallation Neutron...
	www.sciencedaily.com /releases/2004/10/041025131255.htm (2137 words)

	Nuclear Reactor Lab: Neutron Activation Analysis (Site not responding. Last check: 2007-11-05)
		Neutron activation analysis is a physical method of analysis of materials for elemental composition.
		A sample is exposed to neutrons, resulting in activation of many of the constituent elements.
		Neutron activation analysis is capable of simultaneous determination of many elements in most samples even when parameters are selected to optimize detection sensitivity of one particular element.
	reactor.engr.wisc.edu /naa.html (454 words)

	Abstract..."Fast Neutron Activation..."
		The resulting fast-neutron beam activated a portion of the concrete wall in the vault, especially around a 40 cm diameter "hot spot" in the forward cone of the neutron beam.
		A careful survey and assay of the activated vault was conducted; concrete core samples at various positions and depths in the activated portion of the wall were drilled and assayed by means of an HPGe gamma ray spectrometer system comprising a 36 mm dia.
		Eu and 1.0 Bq Co at a depth of 15 cm at the center of the hot spot, falling by a nominal factor of 2.5 at positions 75 cm radially distant from the center.
	www.carroll-ramsey.com /abstr1.htm (1165 words)

	Neutron Activation Calculator - HELP
		In the nuclear power industry, neutron activation is a matter of concern in reactors and in spent fuel management.
		For thermal neutrons, the activities of the activation products and their decay products are calculated, while, for fast neutrons, no activities are calculated (since the calculator's cross section database only covers thermal neutrons).
		The calculator performs a complete decay analysis for the activation products and all their decay products, except in case of branching in the forward mode, where only the decay with the highest probability is considered.
	www.wise-uranium.org /rnach.html (1360 words)

Try your search on: Qwika (all wikis)