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Topic: Lawson criterion

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Nuclear fusion

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	Fusion: Introduction and Beyond
		lso known as the Lawson number or condition, this slightly more advanced concept is a quantitative measure that fusion scientists use to measure their progress towards achieving fusion at a practical level.
		When this number is large enough, the fusion reactions release the same amount of energy that was used to start the reactions, also known as breakeven.
		is the Lawson criterion for the deuterium-tritium reaction at around 100 million K. What this also tells us is that the plasma can either consist of a lot of particles for a short period of time (inertial confinement) or few particles confined for a long period of time (magnetic confinement).
	library.thinkquest.org /17940/texts/fusion_controlled/fusion_controlled.html (771 words)

	EFDA-JET, Year of Physics Calendar (Site not responding. Last check: 2007-10-10)
		Lawson, because of his experience with microwaves, was assigned to lead a section designing a klystron, a valve for producing high power at very short wavelengths, or microwaves, within a group led by Peter Thonemann.
		Lawson (the engineer) insisted that it was important to check that more energy was produced than consumed in a complete system - hence the criterion, which, according to him, was "very simple to deduce".
		The criterion was derived by JD Lawson in his article "Some Criteria for a Useful Thermonuclear Reactor", A.E.R.E. report GP/R 1807, December 1955, declassified April 9th 1957, see full original version.
	www.jet.efda.org /pages/content/news/2005/yop/dec05lawson.html (970 words)

	[No title]
		Lawson also presented evidence of numerous chronic or recurring medical conditions symptomatic of his diabetes, including retinopathy, requiring multiple laser surgeries in each eye; limited joint mobility syndrome, causing pain and swelling in his hands, wrists, elbows, hips, and feet; and a history of attempted suicide and ongoing depression.
		The evidence is sufficient to demonstrate that CSX discriminated against Lawson in violation of the ADA either: (1) by rejecting him because of his disability, or (2) by failing to provide a reasonable accommodation by making an exception to a selection criterion that Lawson could not meet because of his disability.
		Lawson's testimony that he informed Ryan and Layne that he had previously been unable to work because of his diabetes and had been receiving SSDI benefits for 12 years, moreover, establishes a direct link between his record of disability and the very reason CSX gave for rejecting him, i.e., his lack of prior work experience.
	www.eeoc.gov /briefs/lawson.txt (5977 words)

	Lawson criterion - Wikipedia, the free encyclopedia
		For illustration, the Lawson criterion for the D-T reaction will be derived here, but the same principle can be applied to other fusion fuels.
		The Lawson criterion is the requirement that the fusion heating exceed the losses:
		The Lawson criterion applies to inertial confinement fusion as well as to magnetic confinement fusion but is more usefully expressed in a different form.
	en.wikipedia.org /wiki/Lawson_criterion (1270 words)

	Lawson Criteria for Nuclear Fusion
		In addition to providing a sufficiently high temperature to enable the particles to overcome the Coulomb barrier, that temperature must be maintained for a sufficient confinement time and with a sufficient ion density in order to obtain a net yield of energy from a fusion reaction.
		Even given a high enough temperature to overcome the coulomb barrier to nuclear fusion, a critical density of ions must be maintained to make the probability of collison high enough to achieve a net yield of energy from the reaction.
		Once a critical ignition temperature for nuclear fusion has been achieved, it must be maintained at that temperature for a long enough confinement time at a high enough ion density to obtain a net yield of energy.
	hyperphysics.phy-astr.gsu.edu /hbase/nucene/lawson.html (351 words)

	The Criterion Hotel Motel Rockhampton
		The Criterion is an iconic symbol in the history of Hotels in Australia.
		Following the Canoona gold rush of the 1850's the embryo of the Criterion Hotel, Palmers store was situated on the banks of the Fitzroy River opposite the present Criterion.
		George Silus Curtis MLA was well known for his separatist feelings and was the leader of the push for separation of South and North Queensland with Rockhampton being the capital of North Queensland.
	www.thecriterion.com.au (430 words)

	Peopleclick Press Release: Peopleclick Acquires Criterion Incorporated (Site not responding. Last check: 2007-10-10)
		Criterion's proven business intelligence tools allow HR professionals, managers, and employees to work in concert to build targeted development plans that enhance the value of individual employees in the workforce and marketplace.
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		Criterion is located in the Dallas suburb of Irving, Texas.
	www.peopleclick.com /news/asp/12142000.asp (639 words)

	The Fusion Quest
		A convenient way of measuring this progress is the so-called Lawson number, which indicates how close we are to demonstrating energy confinement sufficient for a practical fusion reactor.
		The goal--the value of the Lawson number at which energy confinement is adequate for a reactor--is called the Lawson criterion, after J. Lawson, who first published it in 1956.
		Then, as we are using it here, the Lawson number is just the number we obtain by multiplying the plasma pressure by the energy confinement time.
	partners.nytimes.com /books/first/f/fowler-fusion.html (4799 words)

	ippex online
		Scientific breakeven criterion when the fusion output power is large enough to offset energy losses.
		Together with plasma temperature, the Lawson value of a plasma indicates how close it is to self-sustained (ignited) fusion reactor.
		Ions of deuterium or tritium are accelerated to high energies and then neutralized.
	ippex.pppl.gov /fusion/glossary.html (868 words)

	Lawson - Wikipedia, the free encyclopedia
		Lawson Mountain, a peak in the Blue Mountains range in New South Wales, Australia
		Lawson the Tank Engine Twin, twin brother of Dawson the Tank Engine Twin, is from Thomas the Tank Engine and Friends.
		Lawson criterion - an important general measure of a system that defines the conditions needed for a fusion reactor to reach ignition
	en.wikipedia.org /wiki/Lawson (280 words)

	A plasma 10 times as hot as the sun - research at Tokamak Fusion Test Reactor Science News - Find Articles (Site not responding. Last check: 2007-10-10)
		It is 10 times the temperature in the center fo the sun, but more important, it is more than enough for breakeven, the point where fusions produce as much energy as has to be expended to ignite them.
		In April, TFTR experiments at lower temperatures produced a Lawson criterion of 1.5 X 10.sup.14 seconds per cubic centimeter, which is close to the goal for a practical reactor and five to seven times what is needed for break-even.
		However, the 200-MK experiments had a Lawson criterion of 10.sup.13., two or three times too small for break-even.
	www.findarticles.com /p/articles/mi_m1200/is_v130/ai_4610577 (489 words)

	Eurig Estate (Re) (Probate Fees Ruled Excessive) (Site not responding. Last check: 2007-10-10)
		With respect to the first criterion, the levy is compulsory and therefore enforceable by law.
		The probate levy also meets the criterion that the levy be intended for a public purpose, as the revenue obtained from probate fees is used for the public purpose of defraying the costs of court administration in general, and not simply to offset the costs of granting probate.
		Duff J. for the majority concluded that the levy in question was a tax because it was: (1) enforceable by law; (2) imposed under the authority of the legislature; (3) levied by a public body; and (4) intended for a public purpose.
	taxi-reg.home.att.net /eurig.htm (8503 words)

	ORNL Review Vol. 36, No. 1, 2003 - Fusion Energy - Seeking the Ultimate Source
		They are a sufficiently high fusion plasma temperature and density for a long enough timethe so-called Lawson criterion.
		The Lawson criterion was first exceeded in 1983 in a landmark experiment on the Alcator-C tokamak at MIT using a fueling technique pioneered by Stan Milora and others at ORNL in which "bullets" of frozen hydrogen were fired into the plasma chamber from a gas gun.
		In 1986, a record Lawson parameter was set on PPPL's Tokamak Fusion Test Reactor in experiments performed by Milora and PPPL's G. Schmidt using a machine-gun-like fuel injector developed by ORNL.
	www.ornl.gov /info/ornlreview/v36_1_03/article_40.shtml (460 words)

	Star Wars vs Star Trek Hatemail: Stilgar
		Stilgar, you seem to feel that Lawson's criterion is merely a matter of pressure and temperature.
		It discussed Lawson's criterion in detail, along with many other fascinating aspects of fusion reactors, including alternate designs such as stellarators, heliotrons, torsatrons, reversed-field pinch reactors, and of course, tokomaks and inertial-confinement laser-induced fusion.
		This Lawson criterion must be reached to produce ignition, by which we mean a self-sustaining thermonuclear 'burn' that continues after all external heating is turned off.
	www.stardestroyer.net /Empire/HateMail/Stilgar.html (10529 words)

	"Migma" fusion (Arthur Carlson; Gordon D. Pusch)
		Unfortunately, his first company, FEC, was forced to declare bankruptcy after he made the mistake of trying to get an ERDA grant to augment his private funds; the grant was rejected, and his investors abandoned him because of the U.S. Gov't's official seal of DIS-approval...
		Lawson calculated the n*tau required to run a reactor as a function of temperature.
		In short, neither the Lawson criterion nor the limit on the triple product is relevant for migma, except in the negative sense that it requires an ntau and an ntau*T much higher than those required by more conventional configurations.
	yarchive.net /nuke/migma_fusion.html (2056 words)

	Bibliography
		"Responsibility and its Perversions." In Individualism and Social Responsibility, edited by W. Lawson Taitte, 79-99.
		“The Manliness of Theodore Roosevelt.” In The New Criterion, March 2005, Vol.
		"Affirmative Action versus the Constitution." In A Melting Pot or a Nation of Minorities, edited by W. Lawson Taitte, 91-110.
	www.neh.gov /whoweare/Mansfield/HMbibliography.html (1661 words)

	criterion - OneLook Dictionary Search
		Criterion : Wideman Comparative Glossary of Project Management Terms [home, info]
		Phrases that include criterion: lawson criterion, euler's criterion, kelly criterion, rayleigh criterion, akaike's information criterion, more...
		Words similar to criterion: criteria, measure, standard, touchstone, canon, norm, more...
	www.onelook.com /?w=criterion (292 words)

	Confinement in the Phaedrus-T Tokamak: Introduction
		To do so, the fuel must be contained at densities high enough and for a long enough time for a sufficient number of fusion reactions to occur.
		A rough minimum estimate used to describe this condition is Lawson's criterion, n
		The only sustained fusion reactors known, the stars, achieve this criterion through their extremely high gravities and resultant densities.
	ourworld.cs.com /EdgeAle/thesis/thes_in.htm (1181 words)

	82charlie (Site not responding. Last check: 2007-10-10)
		These waves compress lattice cells and heat the trapped deuterium atoms to fusion energy levels.” In solid environments conditions are such that the energy released in thermonuclear fusion goes into random lattice oscillations rather than into radiation.
		Excess heat cannot be generated unless the Lawson criterion is satisfied.
		The essay elaborates on conditions under which that criterion can be satisfied in nanoparticles.
	blake.montclair.edu /~kowalskil/cf/82charlie.html (716 words)

	Lawson Criterion (Site not responding. Last check: 2007-10-10)
		If the energy of the 14 MeV neutrons is captured for further use, it can be counted in the energy gain.
		The Lawson criterion for fusion energy breakeven is found by evaluating the cross section at the ``optimum temperature'', which for technical reasons is not necessarily equal to the temperature at peak cross section.
		Putting in all the numbers, the criterion as a rough guide is
	www.ipp.mpg.de /~bds/phys/lawson-criterion.html (238 words)

	Fusion Basics (Site not responding. Last check: 2007-10-10)
		Three parameters (plasma temperature, density and confinement time) need to be simultaneously achieved for sustained fusion to occur in a plasma.
		The product of these is called the fusion (or triple) product and, for D-T fusion to occur, this product has to exceed a certain quantity - derived from the so-called Lawson Criterion after British scientist John Lawson who formulated it in 1955.
		Attaining conditions to satisfy the Lawson criterion ensures the plasma exceeds Breakeven - the point where the fusion power out exceeds the power required to heat and sustain the plasma.
	www.jet.efda.org /pages/content/fusion2.html (378 words)

	Amazon.com: The Browning Version (Criterion Collection): DVD: Michael Redgrave,Jean Kent,Nigel Patrick,Ronald ... (Site not responding. Last check: 2007-10-10)
		This being a Criterion release there are, of course, extras.
		This review is for the Criterion Collection DVD edition of the film.
		The Browning Version is the story of a school teacher who is beginning to feel that he is flunking life.
	www.amazon.com /Browning-Version-Criterion-Collection/dp/B00092ZLFS (3091 words)

	Lawson criterion - definition from Biology-Online.org
		(Science: physics) scientific breakeven criterion based on the product of energy confinement time and particle density.
		Together with plasma temperature, the Lawson value of a plasma indicates how close it is to self-sustained (ignited) fusion.
		This page was last modified 21:16, 3 October 2005.
	www.biology-online.org /dictionary/Lawson_criterion (115 words)

	Lawson Criterion
		If the energy of the 14 MeV neutrons is captured for further use, it can be counted in the energy gain.
		The Lawson criterion for fusion energy breakeven is found by evaluating the cross section at the ``optimum temperature'', which for technical reasons is not necessarily equal to the temperature at peak cross section.
		Putting in all the numbers, the criterion as a rough guide is
	www.rzg.mpg.de /~bds/phys/lawson-criterion.html (238 words)

	Lawson's Criterion (Site not responding. Last check: 2007-10-10)
		Lawson's criterion is a rough estimate for the conditions required for
		Adding to what Morbius posted, here is a good discussion of the Lawson criterion, and also the 'triple product' which is more commonly used now.
		Getting the 'right' answer is important, but understanding how to solve the problem (i.e.
	www.physicsforums.com /showthread.php?t=72344 (341 words)

	Fusion (Site not responding. Last check: 2007-10-10)
		For example, the ionisation energy gained by adding an electron to hydrogen is 13.6eV - less than one-millionth of the 17MeV released in the D-T (deuterium-tritium) reaction shown below:
		All of the approaches to controlled fusion described below require this criterion to be met.
		A timeline of the development of research on nuclear fusion is presented here.
	astro.ft.uam.es /~mtaylor/fusion.htm (1004 words)

	No Title
		Controlled fusion relies on a plasma or fully ionized hot gas made up of electrons and ions.
		The initial plasma fuel of choice is deuterium-tritium, whose constitutive atoms can be made to fuse in a controlled and sustained way when the ``Lawson'' criterion is satisfied:
		Because of the inherent space- and time-scale disparities involved, most of the outstanding physics questions in fusion cannot be answered analytically or experimentally.
	www.hq.nasa.gov /hpcc/petaflops/paws.96/apps/leboeuf/leboeuf.html (2058 words)

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