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Topic: Isotope separation


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In the News (Thu 21 Mar 19)

  
  Isotope - MSN Encarta
Research on isotopes was continued by many scientists, notably the British physicist Francis William Aston; their work in detecting and studying isotopes was accelerated by the development of the mass spectrograph.
Full separation in one step by chemical methods is impossible, because isotopes of the same elements have the same chemical properties; physical methods are generally based on the extremely small differences in physical properties caused by the differences in mass of the isotopes.
Electrolytic separation and various exchange procedures for isotope separation, however, depend on chemical rate or equilibrium differences that are based primarily on the difference in energy of chemical bonds, which are a function of isotope mass.
encarta.msn.com /encyclopedia_761575299/Isotope.html   (0 words)

  
 Alsos: Science Browse
Electromagnetic Separation - isotope separation process based on the use of an electromagnetic field
Gas Centrifuge - device used to separate the uranium-235 isotope from the uranium-238 isotope
Tritium - isotope of hydrogen with a mass of three that is used in thermonuclear weapons
alsos.wlu.edu /sciencebrws.aspx   (0 words)

  
 Isotope separation Summary
Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes, for example separating natural uranium into enriched uranium and depleted uranium.
Isotope separation is an important process for both peaceful and military nuclear technology, and therefore the capability that a nation has for isotope separation is of extreme interest to the intelligence community.
Schematic diagram of uranium isotope separation in a calutron.
www.bookrags.com /Isotope_separation   (2388 words)

  
 ISOTOPE,
As atomic number is equivalent to the number of protons in the nucleus, and mass number is the sum total of the protons plus the neutrons in the nucleus, isotopes of the same element differ from one another only in the number of neutrons in their nuclei.
The British physicist Sir Joseph Thomson demonstrated in 1912 the existence of stable isotopes by passing neon through a discharge tube and deflecting the neon ions by means of magnetic and electric fields; this showed that the stable element neon exists in more than one form.
All the isotopes of elements with atomic numbers higher than 83 (above bismuth in the periodic table) are radioactive, and a few of the lighter isotopes, such as potassium-40, are radioactive.
www.history.com /encyclopedia.do?articleId=212961   (1766 words)

  
 Isotope, Radioactivity and Half-life
An example of isomerism is the isotope protactinium-234, which exists in two distinct energy states with the emission of gamma rays signaling the transition from one to the other.
In recent years it has been shown that a number of isotopes, notably uranium-235 and several isotopes of the artificial transuranium elements, are capable of decaying by a spontaneous-fission process, in which the nucleus is split into two fragments.
All the naturally occurring isotopes above bismuth in the periodic table are radioactive and in addition naturally radioactive isotopes of bismuth, thalium, vanadium, indium, neodymium, gadolinium, hafnium, platinum, lead, rhenium, lutetium, rubidium, potassium, hydrogen, carbon, lanthanum, and samarium exist.
members.tripod.com /~peacecraft/isotope.htm   (4792 words)

  
 Isotope separation - Wikipedia, the free encyclopedia
Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes, for example separating natural uranium into enriched uranium and depleted uranium.
Isotope separation is an important process for both peaceful and military nuclear technology, and therefore the capability that a nation has for isotope separation is of extreme interest to the intelligence community.
Schematic diagram of uranium isotope separation in a calutron.
en.wikipedia.org /wiki/Isotope_separation   (1741 words)

  
 [No title]
The separation factor, sometimcs known as the enrich- ment or fractionating factor of a process, is the ratio of the relative concentration of the desired isotope after processing to its relative concentration before processing.
We have pointed out that gravitational separation of two isotopes might occur since the gravitational forces tending to move the molecules downward are proportional to the mole- cular weights, and the intermolecular forces tending to resist the downward motion depend on the electronic configuration, not on the molecular weights.
The great appeal of the centrifuge in the separation of heavy isotopes like uranium is that the separation factor depends on the difference between the masses of the two isotopes, not on the square root of the ratio of the masses as in diffusion methods.
rhizome.org /artbase/22194/HiroshimaProject/Collected/smyth9   (5078 words)

  
 ISIS Issue Brief: The South Korean Laser Isotope Separation Experience
The early South Korean efforts during the mid 1970's were directed towards the separation of isotopes of light elements by the multi-photon dissociation process.
In a 1999 review of the Brazilian uranium laser isotope separation, it was stated that the optogalvanic effect "is a powerful and inexpensive technique for investigation of atomic and molecular species, and is particularly useful in the spectroscopy of refractory elements, like uranium"(23).
D.W. Suh, Apparatus for the Isotope Separation, KAERI/RR-256/80
www.isis-online.org /publications/dprk/sklisword2.html   (5276 words)

  
 The Smyth Report: Chapter IX - General Discussion Of The Separation Of Isotopes
The separation factor, sometimes known as the enrichment or fractionating factor of a process, is the ratio of the relative concentration of the desired isotope after processing to its relative concentration before processing.
We have pointed out that gravitational separation of two isotopes might occur since the gravitational forces tending to move the molecules downward are proportional to the mole-cular weights, and the intermolecular forces tending to resist the downward motion depend on the electronic configuration, not on the molecular weights.
The possibility of accomplishing practical separation of isotopes by thermal diffusion was first suggested by theoretical studies of the details of molecular collisions and of the forces between molecules.
nuclearweaponarchive.org /Smyth/Smyth9.html   (5100 words)

  
 Chromatographic hydrogen isotope separation - Patent 4276060
A method of chromatographically separating hydrogen isotopes in a separation column comprising passing isotopically mixed hydrogen gas through a separation medium comprising a hydride forming intermetallic alloy selected from the group of intermetallic alloys with a CaCu.sub.5 type of crystal structure.
The invention includes improved methods and apparatus for chromatographic separation of hydrogen isotopes, the use of certain hydride-forming intermetallic compounds in chromatographic hydrogen isotope separation columns, and a large-scale multi-stage chromatographic process designed to be run as a secondary process off a hydrogen feedstream from a conventional plant.
The separation factor is defined as the isotopic abundance of deuterium in hydrogen gas divided by the isotopic abundance of deuterium in the metal hydride which is in equilibrium with the gas.
www.freepatentsonline.com /4276060.html   (3698 words)

  
 Draft Public Guidelines to Department of Energy Classification of Information
Technological information regarding isotope separation that would enable other nations or subnational groups to attain or improve a nuclear weapons capability is of particular importance to the common defense and security.
With respect to the gas centrifuge method of isotope separation, it is important that technical information which would enhance the capability of others to exploit this method be kept classified, to the extent practicable, due to the potential of the process to produce clandestinely weapons-grade uranium or other isotopes of military interest.
Laser isotope separation (LIS) is an advanced technology that has received support because of its potential for separating isotopes of uranium and other isotopes of military interest in significant quantities.
www.fas.org /irp/doddir/doe/pubgb.html   (1436 words)

  
 [Napsnet] SPECIAL REPORT: The South Korean Laser Isotope Separation Experience
Molecular Laser Isotope Separation (MLIS) Related Research: The early South Korean efforts during the mid 1970's were directed towards the separation of isotopes of light elements by the multi-photon dissociation process.
In a 1999 review of the Brazilian uranium laser isotope separation, it was stated that the optogalvanic effect "is a powerful and inexpensive technique for investigation of atomic and molecular species, and is particularly useful in the spectroscopy of refractory elements, like uranium"(23).
D.W. Suh, Apparatus for the Isotope Separation, KAERI/RR-256/80 5.
www.nautilus.org /pipermail/napsnet/2004-October/000129.html   (5289 words)

  
 Chapter IX. General Discussion Of The Separation Of Isotopes | Atomic Energy for Military Purposes (The Smyth Report) | ...
The separation factor, sometimcs known as the enrichment or fractionating factor of a process, is the ratio of the relative concentration of the desired isotope after processing to its relative concentration before processing.
We have pointed out that gravitational separation of two isotopes might occur since the gravitational forces tending to move the molecules downward are proportional to the molecular weights, and the intermolecular forces tending to resist the downward motion depend on the electronic configuration, not on the molecular weights.
The general method is well understood, and the separation effects are known to decrease in general with increasing molecular weight, so that there is but a small chance of applying this method successfully to heavy isotopes like uranium.
www.atomicarchive.com /Docs/SmythReport/smyth_ix-a.shtml   (2855 words)

  
 Continuing Efforts on Isotope Separation | The Manhattan Project: Making the Atomic Bomb | History of the Atomic Age | ...
Fabrication of an effective barrier to separate the uranium isotopes seemed so difficult as to relegate gaseous diffusion to a lower priority (the barrier had to be a corrosion-resistant membrane containing millions of submicroscopic holes per square inch).
Both separation methods demanded the design and construction of new technologies and required that parts, many of them never before produced, be finished to tolerances not previously imposed on American industry.
Analyzing the status of the four methods of isotope separation then under consideration- gaseous diffusion, centrifuge, electromagnetic, and pile-the committee decided on May 23 to recommend that all be pushed as fast as possible.
www.atomicarchive.com /History/mp/p2s15.shtml   (834 words)

  
 Previous studies have demonstrated that isotope signals in river discharge can potentially contribute to better ...
Previous studies have demonstrated that isotope signals in river discharge can potentially contribute to better understanding of the continental portion of the hydrological cycle including information such as water origin, mixing history, water balance, water residence times, surface-groundwater exchange and renewal rates, and evaporation-transpiration partitioning.
Isotope fractionation that accompanies free-water evaporation from lakes and soils also permits distinction between the evaporation and transpiration signatures, the latter of which commonly are similar to groundwater.
One key assumption of this derivation is that the isotopic composition of continental groundwater is similar to that of precipitation, although due to selective recharge and storage effects this may not be an appropriate representation for some large river basins.
www.iaea.org /programmes/ripc/ih/rivers_hp/isotope.htm   (1290 words)

  
 Wave Packet Isotope Separation   (Site not responding. Last check: )
We have suggested a novel approach to laser isotope separation, which is based on short laser pulse excitation of quantum wave packets inside the individual molecules of an isotopic mixture.
The principles of the WIS method were first demonstrated in collaboration with the group of A. Stolow at the Steasie Institute for Molecular Science (Ottawa) by an experiment on separation of a bromine isotopic mixture.
Small differences in the moment of inertia of the isotopes result in distinct transient angular distributions, which may be used for separation and enrichment.
www.weizmann.ac.il /chemphys/averbukh/wave.html   (385 words)

  
 Process for uranium isotope separation - Patent 4097384   (Site not responding. Last check: )
Separation of U.sup.235 and U.sup.238 isotopes by converting a mixture of these isotopes to organic compounds or to silicon compounds and then irradiating the isotope compounds selectively to change their chemical (and/or physical) properties, thereby to facilitate separation.
Isotope separation is an area of profound importance not only to chemists and physicists but to the entire populace as well.
The use of infra-red lasers to separate isotopic species is suggested in the prior art.
www.freepatentsonline.com /4097384.html   (5054 words)

  
 [No title]
The experiment using laser isotope separation technology was a "one-off" case and South Korea has no interest in running a nuclear weapons programme, the government maintained.
The electromagnetic isotope separation (EMIS) process is based on the principle of a simple mass spectrometer, which states that a charged particle will follow a circular path when passing through a uniform magnetic field.
The idea for the molecular laser isotope separation (MLIS) process was conceived by a group of scientists at the Los Alamos National Laboratory in 1971.
lycos.cs.cmu.edu /info/isotope-separation.html   (750 words)

  
 Isotope Separation
The heavier isotopes concentrate in the outer edge of the plasma column resulting in an enriched mixture that can be selectively extracted.
In the Calutron, originally used for electromagnetic separation of isotopes, a long, thin beam of ions is produced from a magnetoelectrically confined plasma discharge (modified Penning discharge).
In the process of isotope separation by laser-induced selective ionization, the uranium 235 photoions are extracted by an electric field and collected on product plates.
www.plasma.inpe.br /LAP_Portal/LAP_Site/Text/Isotope_Separation.htm   (337 words)

  
 [No title]   (Site not responding. Last check: )
In the present context it has to be pointed out that the measurement of the isotope effect is always based on a relative shift in a given position, and absolute values of the C-atom in question are not important.
If the reduced partition function ratio of a pair of isotopic molecules is caste in the form of an infinite power series, it becomes possible to related isotope effects directly to intramolecular and intermolecular forces and to motions of atoms.
Taking this into account, the equilibrium isotope effect on the reaction was determined by incubation of fructose 1,6-bisphosphate of known isotopic pattern with aldolase for a given time in the absence of any other enzyme, and by subsequent pattern analysis of the products in equilibrium.
www.lycoszone.com /info/isotope--isotope-effects.html   (419 words)

  
 New Method For the Separation of Isotopes   (Site not responding. Last check: )
Traditional mechanical methods for separating isotopes, such as those based on the use of centrifuges, are relatively slow and inefficient.
In the past 25 years, highly effective laser methods for isotope separation have appeared, but their use is limited by the need to precisely fine-tune the laser beam to one particular isotope, which renders these approaches quite expensive.
This concept can be applied to isotope separation because different isotopes are clearly distinguishable by the motion patterns of their wavepackets.
www.eurekalert.org /pub_releases/1997-04/1997-02/WI-NMFt-230297.php   (709 words)

  
 Science Homework Help Moderators and Isotope Separation
It was Enrico Fermi and Leo Szilard who first proposed the use of graphite (a form of carbon) as a moderator for a chain reaction.
We have already seen that the probabilities of processes (2)and (4) are different for different isotopes.
Nevertheless, the possibility of separating U-235 was recognized early on in the Manhattan Project as being of the greatest importance.
www.nuclearfiction.com /physics-homework-isotope-separation.php   (0 words)

  
 Laser Isotope Separation
Akerman, Dye-laser isotope separation, in Dye Laser Principles, F. Duarte and L. Hillman, Eds.
Olivares, A. Duarte, E. Saravia, F. Duarte, Lithium isotope separation with tunable diode lasers, Appl.
, Laser isotope separation of lithium by two-step photoionization, J.
www.opticsjournal.com /laserisotopeseparation.htm   (471 words)

  
 EURISOL DS: nuclear physics,nuclear structure
Such a world-class facility, complementary to the “in-flight” facility envisaged elsewhere in Europe, is expected to come into operation in the next decade.
The European Isotope Separation On-Line Radioactive Ion Beam project (EURISOL) is set to design the ‘next-generation’ European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility.
In this high power target station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source.
www.eurisol.org   (0 words)

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