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Sample records for californium isotopes

  1. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ostroumov, P. N., E-mail: ostroumov@anl.gov; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Pikin, A. I. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2015-08-15

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.

  2. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    International Nuclear Information System (INIS)

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz

  3. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source.

    Science.gov (United States)

    Ostroumov, P N; Barcikowski, A; Dickerson, C A; Perry, A; Pikin, A I; Sharamentov, S I; Vondrasek, R C; Zinkann, G P

    2015-08-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz. PMID:26329185

  4. Historical review of californium-252 discovery and development

    International Nuclear Information System (INIS)

    This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving 252Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed

  5. Metabolism and toxicity of californium

    International Nuclear Information System (INIS)

    Metabolism of californium can be compared with that of other transplutonium elements. The most important points are as follows: a fast blood clearance and fast bone uptake more important than liver uptake, a relatively high urinary excretion and kidney retention. Blood clearance of californium can be compared with that of americium. Distribution of californium 252 nitrate after intramuscular injection in rats was studied. There are very few experimental data on acute or long term toxicity of californium. (28 references)

  6. Magnetism in californium

    International Nuclear Information System (INIS)

    A SQUID-based magnetic susceptometer has been constructed for studying small radioactive samples at temperatures below 350 K and in magnetic fields up to 50 kilogauss. The device has been used to study californium (element 98) in a number of solid-state forms: the dhcp metal, several oxides (Cf2O3 in both the bcc and monoclinic structures, Cf7O12, CfO2 and BaCfO3), several monopnictides (CfN, CfAs and CfSb) and the trichloride (in both the hexagonal and orthorhombic structures). All of these materials were studied in polycrystalline form, and hexagonal CfCl3 was studied in single-crystal form as well. The susceptometer has the sensitivity to measure samples containing less than 10 micrograms of californium. The magnetic susceptibilities of all of the californium materials at temperatures above about 100 K are described well by the Curie-Weiss relationship. This behavior is consistent with the assumption that the magnetic 5f electrons are localized and that the paramagnetic behavior can be interpreted in terms of the properties of the free ion. The measured values of the effective paramagnetic moment, μ/sub eff/, for all the californium materials that were studied are reasonably consistent with theoretical values based on intermediate coupling models. All of the californium materials showed some indications of cooperative magnetic effects. The dhcp metal was observed to order ferromagnetically at 52 K, and all of the californium compounds studied showed signs of antiferromagnetic ordering, mostly at temperatures below 25 K. 91 refs., 50 figs., 19 tabs

  7. Californium Electrodepositions at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Boll, Rose Ann [ORNL

    2015-01-01

    Electrodepositions of californium isotopes were successfully performed at Oak Ridge National Laboratory (ORNL) during the past year involving two different types of deposition solutions, ammonium acetate (NH4C2H3O2) and isobutanol ((CH3)2CHCH2OH). A californium product that was decay enriched in 251Cf was recovered for use in super-heavy element (SHE) research. This neutron-rich isotope, 251Cf, provides target material for SHE research for the potential discovery of heavier isotopes of Z=118. The californium material was recovered from aged 252Cf neutron sources in storage at ORNL. These sources have decayed for over 30 years, thus providing material with a very high 251Cf-to-252Cf ratio. After the source capsules were opened, the californium was purified and then electrodeposited using the isobutanol method onto thin titanium foils for use in an accelerator at the Joint Institute for Nuclear Research in Dubna, Russia. Another deposition method, ammonium acetate, was used to produce a deposition containing 1.7 0.1 Ci of 252Cf onto a stainless steel substrate. This was the largest single electrodeposition of 252Cf ever prepared. The 252Cf material was initially purified using traditional ion exchange media, such as AG50-AHIB and AG50-HCl, and further purified using a TEVA-NH4SCN system to remove any lanthanides, resulting in the recovery of 3.6 0.1 mg of purified 252Cf. The ammonium acetate deposition was run with a current of 1.0 amp, resulting in a 91.5% deposition yield. Purification and handling of the highly radioactive californium material created additional challenges in the production of these sources.

  8. Californium-252 encapsulation at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    More than 1 g of the neutron-emitting isotope californium-252 has been encapsulated at SRL for worldwide medical, industrial, and research uses. Bulk sales packages have been prepared for the USDOE sales program since 1971. Doubly-encapsulated sources have been prepared for USDOE's market evaluation program since 1968. Californium-252 sources for loan and sales packages satisfy the criteria for Special Form Radioactive Material. Encapsulation is performed in special neutron-shielded containment facilities at SRL. Development of improved source and shipping package designs and processes is continuing. 17 figures

  9. Californium Multiplier (CFX)

    International Nuclear Information System (INIS)

    The availability of 252Cf as an economical high-intensity neutron source has made it possible to construct compact neutron irradiation devices with widespread applications. The simplest such device consists of a single 252Cf source within a moderating and shielding medium. Higher neutron flux levels can be attained either through the use of more 252Cf or through source multiplication by means of a subcritical uranium assembly. Although the use of larger 252Cf sources to achieve higher neutron flux is technically straightforward, an economic penalty is paid as the source strength is increased. Larger californium sources imply larger initial investments to cover the cost of source material and larger operating costs resulting from the decay of the 252Cf source. A Californium Multiplier, the CFX, which produces a flux enhancement of 30 when compared to a conventional moderated 252Cf system has been designed, licensed, built, and tested by IRT Corporation. Such systems are now available on a commercial basis for both neutron radiography and neutron activation analysis. The first commercial CFX system was installed at the Research Laboratories of Eastman Kodak Company in Rochester, NY, in March 1975. This device, using 1 mg of 252Cf, is very stable and the neutron flux generated by the CFX is very reproducible. The performance characteristics of this system are summarized

  10. Californium--palladium metal neutron source material

    Science.gov (United States)

    Dahlen, B.L.; Mosly, W.C. Jr.; Smith, P.K.; Albenesius, E.L.

    1974-01-22

    Californium, as metal or oxide, is uniformly dispersed throughout a noble metal matrix, provided in compact, rod or wire form. A solution of californium values is added to palladium metal powder, dried, blended and pressed into a compact having a uni-form distribution of californium. The californium values are decomposed to californium oxide or metal by heating in an inert or reducing atmosphere. Sintering the compact to a high density closes the matrix around the dispersed californium. The sintered compact is then mechanically shaped into an elongated rod or wire form. (4 claims, no drawings) (Official Gazette)

  11. Californium-252: a remarkable versatile radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Osborne-Lee, I.W.; Alexander, C.W.

    1995-10-10

    A product of the nuclear age, Californium-252 ({sup 252}Cf) has found many applications in medicine, scientific research, industry, and nuclear science education. Californium-252 is unique as a neutron source in that it provides a highly concentrated flux and extremely reliable neutron spectrum from a very small assembly. During the past 40 years, {sup 252}Cf has been applied with great success to cancer therapy, neutron radiography of objects ranging from flowers to entire aircraft, startup sources for nuclear reactors, fission activation for quality analysis of all commercial nuclear fuel, and many other beneficial uses, some of which are now ready for further growth. Californium-252 is produced in the High Flux Isotope Reactor (HFIR) and processed in the Radiochemical Engineering Development Center (REDC), both of which are located at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The REDC/HFIR facility is virtually the sole supplier of {sup 252}Cf in the western world and is the major supplier worldwide. Extensive exploitation of this product was made possible through the {sup 252}Cf Market Evaluation Program, sponsored by the United States Department of Energy (DOE) [then the Atomic Energy Commission (AEC) and later the Energy Research and Development Administration (ERDA)]. This program included training series, demonstration centers, seminars, and a liberal loan policy for fabricated sources. The Market Evaluation Program was instituted, in part, to determine if large-quantity production capability was required at the Savannah River Laboratory (SRL). Because of the nature of the product and the means by which it is produced, {sup 252}Cf can be produced only in government-owned facilities. It is evident at this time that the Oak Ridge research facility can meet present and projected near-term requirements. The production, shipment, and sales history of {sup 252}Cf from ORNL is summarized herein.

  12. Californium-252: a remarkable versatile radioisotope

    International Nuclear Information System (INIS)

    A product of the nuclear age, Californium-252 (252Cf) has found many applications in medicine, scientific research, industry, and nuclear science education. Californium-252 is unique as a neutron source in that it provides a highly concentrated flux and extremely reliable neutron spectrum from a very small assembly. During the past 40 years, 252Cf has been applied with great success to cancer therapy, neutron radiography of objects ranging from flowers to entire aircraft, startup sources for nuclear reactors, fission activation for quality analysis of all commercial nuclear fuel, and many other beneficial uses, some of which are now ready for further growth. Californium-252 is produced in the High Flux Isotope Reactor (HFIR) and processed in the Radiochemical Engineering Development Center (REDC), both of which are located at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The REDC/HFIR facility is virtually the sole supplier of 252Cf in the western world and is the major supplier worldwide. Extensive exploitation of this product was made possible through the 252Cf Market Evaluation Program, sponsored by the United States Department of Energy (DOE) [then the Atomic Energy Commission (AEC) and later the Energy Research and Development Administration (ERDA)]. This program included training series, demonstration centers, seminars, and a liberal loan policy for fabricated sources. The Market Evaluation Program was instituted, in part, to determine if large-quantity production capability was required at the Savannah River Laboratory (SRL). Because of the nature of the product and the means by which it is produced, 252Cf can be produced only in government-owned facilities. It is evident at this time that the Oak Ridge research facility can meet present and projected near-term requirements. The production, shipment, and sales history of 252Cf from ORNL is summarized herein

  13. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies

    International Nuclear Information System (INIS)

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in 248Cm (∼97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

  14. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in Cm-248 samples for transmutation studies

    International Nuclear Information System (INIS)

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (Incineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in 248Cm (similar to 97%) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides' formations ranged from 0. 3% to 1. 3%. This uncertainties' range is quite acceptable for the nuclear data to be used in transmutation studies. (authors)

  15. Californium-252 neutron sources

    International Nuclear Information System (INIS)

    Major production programs for the Savannah River reactors and the High Flux Isotopes Reactor at Oak Ridge have made 252Cf one of the most available and, at the USAEC's sales price of $10/μg, one of the least-expensive isotopic neutron sources. Reactor production has totaled approximately 2 g, and, based on expected demand, an additional 10 g will be produced in the next decade. The approximately 800 mg chemically separated to date has been used to prepare over 600 neutron sources. Most, about 500, have been medical sources containing 1 to 5 μg of 252Cf plated in needles for experimental cancer therapy studies. The remainder have generally been point sources containing 10 μg to 12 mg of oxide for activation, well logging, or radiography uses. Bulk sources have also been supplied to the commercial encapsulators. The latest development has been the production of 252Cf cermet wire which can be cut into almost contamination-free lengths of the desired 252Cf content. Casks are available for transport of sources up to 50 mg. Subcritical assemblies have been developed to multiply the source neutrons by a factor of 10 to 40, and collimators and thermalizers have also been extensively developed to shape the neutron flux and energy distributions for special applications. (U.S.)

  16. Californium-252 Neutron Sources for Medical Applications

    International Nuclear Information System (INIS)

    Californium-252 neutron sources are being prepared to investigate the value of this radionuclide in diagnosing and treating diseases. A source resembling a cell-loaded radium needle was developed for neutron therapy. Since therapy needles are normally implanted in the body, very conservative design criteria were established to prevent leakage of radioactive. Methods are being developed to prepare very intense californium sources that could be used eventually for neutron radiography and for diagnosis by neutron activation analysis. This paper discusses these methods

  17. Californium (252Cf) and its use as neutron source in science medicine and technology

    International Nuclear Information System (INIS)

    The application of radionuclides in science and nuclear techniques basically is related to unstable isotopes, which are produced from stable elements in nuclear reactor. Their specifications are various from view point of application . Using of physical and chemical properties of radionuclides in chemistry, for with marking the organic compounds we can exactly explain the mechanism of chemical reactions in medical, biology and bio-chemistry. In these cases the behaviour of radionuclides is very important and the selection of the suitable radionuclides is determined between the elements for investigation aims. The special specification of radio-nuclides analysis such as, half-life, kind of ray and energy should be considered with an special accuracy as well as the laws security regulations from view point of ray-protection should be completely observed mean time working these radio-nuclides. It should be considered that application of radio-isotopes is very important from their special specifications point of view. Applying the radionuclides from technology point of view in sciences and nuclear techniques aren't only limited to three analyses of α, β, and γ, but we can use the share of neutron which are produced from spli ting of heavy nucleus such as Californium252 as a neutron source in the depths of the sea and also determining the concentration of low quantity elements on moon and other spheres. The radioisotope of Californium252 is a neutron useful radiator for investigation in nuclear medical and technology because of automatically rapid split to 3.2% Californium252 radiates 1.34 * 109N/m in each mil/GH which suitable replacement for neutron sources based on (a, n) reaction, for example, Radium-Brellium or Amersium-Brellium. The energy distribution of radiated neutrons from analyzing of Californium252 like the spectrum of neutron which is produced from splitting of U235, Pu239 nucleus has the maximum energy in quantity, En=1 MeV in the range of 1.5 MeV. The

  18. Californium-252 Neutron Therapy in China

    International Nuclear Information System (INIS)

    Californium-252 brachytherapy, believed to be the most successful source for neutron therapy, gives most of the cures as well as long-term and complication-free survivals. Chinese radiation oncologists were interested in californium neutron therapy (Cf-NT) in the early 1980s, but 252Cf sources for medical use were not available in China until 1992 when a californium joint venture was established by the China Institute of Atomic Energy (Beijing) and the Research Institute for Nuclear Reactors (Dimitrovgrad) of Russia. In 1995, 25 seeds of 252Cf with a strength of 3 μg each were sent to China for preclinical investigation. Three years later, a high dose rate (HDR) 252Cf source was imported and transferred into a home-made remote after-loader for intracavitary treatment in Chongqing, and a clinical trail was started in February 1999. This is the first time that Cf-NT was performed for cancer patients in China. Since then, Cf-NT in China has developed rapidly. It is estimated that one-tenth of those radiation oncology centers with brachytherapy practice will be equipped with californium units in 5 yr. That means more than 30 units will be in use in hospitals. That is significant compared with other countries, but it is just one, on average, for each province or one per 40 million people in China. Progress also has been achieved in the 252Cf treatment delivery equipment. Preliminary clinical trails showed complete response observed in all cases treated, with a rapid clearance of tumors and mild reactions in normal tissues. The short-term results are quite encouraging. To deal with problems due to the demand for Cf-NT in China, attention should be paid to the following particulars: (1) A high-strength miniature source is needed for HDR/MDR interstitial therapy to extend the Cf-NT coverage. (2) Basic work on radiophysics and radiobiology needs to be done, including source calibration, clinical dosimetry, clinical RBE determination, and Cf-NT quality assurance

  19. Californium-252 sales and loans at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The production and distribution in the United States of 252Cf has recently been consolidated at the Oak Ridge National Laboratory (ORNL). The 252Cf Industrial Sales/Loan Program and the 252Cf University Load Program, which were formerly located at the Savannah River Plant (SRP), have been combined with the californium production and distribution activities of the Transuranium Element Production Program at ORNL. Californium-252 is sold to commercial users in the form of bulk californium oxide, palladium-californium alloy pellets, or alloy wires. Neutron source capsules, which are fabricated for loans to DOE or other US government agencies, are still available in all forms previously available. The consolidation of all 252Cf distribution activities at the production site is expected to result in better service to users. In particular, customers for neutrons sources will be ale to select from a wider range of neutron source forms, including custom designs, through a single contact point

  20. Production, distribution and applications of californium-252 neutron sources

    International Nuclear Information System (INIS)

    The radioisotope 252Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-yr half-life. A source the size of a person's little finger can emit up to 1011 neutrons s-1. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement and minerals, as well as for detection and identification of explosives, land mines and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 yr of experience and by US Bureau of Mines tests of source survivability during explosions. The production and distribution center for the US Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells 252Cf to commercial reencapsulators domestically and internationally. Sealed 252Cf sources are also available for loan to agencies and subcontractors of the US government and to universities for educational, research and medical applications. The REDC has established the Californium User Facility (CUF) for Neutron Science to make its large inventory of 252Cf sources available to researchers for irradiations inside uncontaminated hot cells. Experiments at the CUF include a land mine detection system, neutron damage testing of solid-state detectors, irradiation of human cancer cells for boron neutron capture therapy experiments and irradiation of rice to induce genetic mutations

  1. Production, distribution and applications of californium-252 neutron sources.

    Science.gov (United States)

    Martin, R C; Knauer, J B; Balo, P A

    2000-01-01

    The radioisotope 252Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-yr half-life. A source the size of a person's little finger can emit up to 10(11) neutrons s(-1). Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement and minerals, as well as for detection and identification of explosives, land mines and unexploded military ordinance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 yr of experience and by US Bureau of Mines tests of source survivability during explosions. The production and distribution center for the US Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells 252Cf to commercial reencapsulators domestically and internationally. Sealed 252Cf sources are also available for loan to agencies and subcontractors of the US government and to universities for educational, research and medical applications. The REDC has established the Californium User Facility (CUF) for Neutron Science to make its large inventory of 252Cf sources available to researchers for irradiations inside uncontaminated hot cells. Experiments at the CUF include a land mine detection system, neutron damage testing of solid-state detectors, irradiation of human cancer cells for boron neutron capture therapy experiments and irradiation of rice to induce genetic mutations. PMID:11003521

  2. Production, Distribution, and Applications of Californium-252 Neutron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Balo, P.A.; Knauer, J.B.; Martin, R.C.

    1999-10-03

    The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-year half-life. A source the size of a person's little finger can emit up to 10{sup 11} neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells The radioisotope {sup 252}Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6- year half-life. A source the size of a person's little finger can emit up to 10 neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory(ORNL). DOE sells {sup 252}Cf to commercial

  3. Discovery of Isotopes of the Transuranium Elements with 93 <= Z <= 98

    OpenAIRE

    Fry, C; Thoennessen, M

    2012-01-01

    One hundred and five isotopes of the transuranium elements neptunium, plutonium, americium, curium, berkelium and californium have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  4. Design of a homogeneous subcritical nuclear reactor based on thorium with a source of californium 252

    International Nuclear Information System (INIS)

    Full text: One of the energy alternatives to fossil fuels which do not produce greenhouse gases is the nuclear energy. One of the drawbacks of this alternative is the generation of radioactive wastes of long half-life and its relation to the generation of nuclear materials to produce weapons of mass destruction. An option to these drawbacks of nuclear energy is to use Thorium as part of the nuclear fuel which it becomes in U233 when capturing neutrons, that is a fissile material. In this paper Monte Carlo methods were used to design a homogeneous subcritical reactor based on thorium. As neutron reflector graphite was used. The reactor core is homogeneous and is formed of 70% light water as moderator, 12% of enriched uranium UO2(NO3)4 and 18% of thorium Th(NO3)4 as fuel. To start the nuclear fission chain reaction an isotopic source of californium 252 was used with an intensity of 4.6 x 107 s-1. In the design the value of the effective multiplication factor, whose value turned out keff <1 was calculated. Also, the neutron spectra at different distances from the source and the total fluence were calculated, as well as the values of the ambient dose equivalent in the periphery of the reactor. (Author)

  5. Production of extra pure curium and californium preparations

    International Nuclear Information System (INIS)

    Preparations of curium-244,245,248 and californium-249,252 are used for the production of ionizing radiation sources for different applications and fundamental nuclear-physical investigations, placing high requirements on the radiochemical and chemical purity of the preparations. Extraction chromatography using di-(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant was chosen to prepare extra pure curium and californium preparations. In order to identify the optimal conditions of Cm-Cf separation and to remove impurities from them (reagent and other impurities), investigations were performed into the effect of impurities (Na+, Ca2+, Al3+, Fe2+, Fe3+ taken as example), extractant and eluent concentration and solution flow rate on the efficiency of mutual purification of Cm and Cf. Both theoretical and experimental estimations were made of the maximum concentration at which the impurities do not affect the process. The conditions chosen allow mutual purification of milligram amounts of Cm and Cf from impurity elements at E(pur) =102 - 103 during a single chromatographic cycle (E(pur) =>103) using a column with 5 - 10 cm3 volume. In this case the production yield exceeds 98%. The purification of milligram amounts of curium and californium from fission products (lanthanides in general, cerium in particular) was performed in D2EHPA-decane-PbO2-HNO3 and D2EHPA-decane-DTPA-H3-Cit extraction chromatography systems. In order to establish the optimal conditions, the effect of [D2EHPA] and eluent on the mutual purification of Cm and Cf and on their purification from cerium and impurity elements was studied in the D2EHPA-decane-PbO2-HNO3 system. During a single chromatographic cycle the mutual purification factors of TPE and of their purification from impurity cations achieve 102-103, from cerium - E(pur) > 10. In the D2EHPA-decane-DTPA-H3Cit system, the effect of concentration of extractant and eluent pH on the efficiency of Cm and Cf purification from lanthanides was

  6. Prompt neutron spectrum of the spontaneous fission of californium-252

    International Nuclear Information System (INIS)

    The californium-252 spontaneous fission neutron spectrum was measured in the energy range of 0.01 to 10 MeV by the time-of-flight technique using various neutron detectors. The measurements of 252Cf neutron spectrum at energies of 0.01 to 5 MeV were performed as a function of fission fragment kinetic energy. The mean neutron spectrum energy in the range of 0.7 to 10 MeV was found from the results of measurements. The irregularity in the 252Cf neutron spectrum in the neutron energy range of less than 0.7 MeV compared to theoretical values is discussed. The mechanism of 252Cf neutron emission is also discussed on the basis of neutron yield angle measurements. 12 references

  7. Separation of californium from actinides and lanthanides in aqueous solution by electrochemical formation of amalgams

    International Nuclear Information System (INIS)

    The electrochemical reduction of transneptunium elements (Pu to Cf) and rare earths (Eu, Tm) from aqueous complexing solutions to amalgams was studied over a wide range of cathodic potentials in order to achieve optimal separation of californium. The reduction in acetate media (pH 4.5-4.6) at potentials around -1.7 to -1.9 V1 leads to a quantitative extraction of californium into the mercury phase, while more negative potentials are required for the reduction of the lighter transuranium elements and of the lanthanides. Hence, the optimal conditions for the separation of californium from the investigated actinides and lanthanides were determined. Separation factors α between 25 and 90 were found except in the case of Cf/Eu, where poor values (α varying from 7 to 12) were observed. More negative cathodic potentials decrease the selectivity of the reduction process. A similar study with lithium citrate solutions (pH ∝6) shows that satisfactory separation of californium from lighter and heavier actinides is achievable. A separation factor of 88 is obtained for Cf/Am at -1.98 V. The anodic stripping of mixed amalgams (Pu, Am, Cm, Bk, Tm and Cf) Hg in nitric and acetic acid soultions at potentials ranging from +0.1 to -0.7 V proceeds slowly and proved to be ineffective for the separation of californium from light actinides under conditions described. (orig.)

  8. On-line slurry analyses by californium-252

    International Nuclear Information System (INIS)

    In chemical processing technology on-line activation methods gain an increasing importance for process monitoring and control. A method is described according to which the different fluorspar contents at various strategic points of a flotation plant are determined through neutron activation by 100 μg californium-252. A continuous analytical system for onstream process control of slurries was designed and constructed. A compact facility, called SUSAC, allows continuous application of the method on an industrial scale. The main components of the SUSAC facility are the irradiation and measurement cells. The cells are equipped with multistage countercurrent stirrers ensuring a proper radial and vertical distribution of the sample. The hollow shaft of the stirrer of the irradiation cell houses the Cf-source. The NaI-detector has been installed in a recess in the bottom of the measuring cell. The volumes are 9 dm3 for the irradiation cell, 7.5 dm3 for the measuring cell, 1/2 dm3 for the vonnection line and 4 dm3 for feed and drainage lines including the pump. Investigations on the following topics are discussed: selection of stirrers, residence time, flow rate, pulp density, calibration measurements. (T.G.)

  9. Biomedical neutron research at the Californium User Facility for neutron science

    International Nuclear Information System (INIS)

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact 252Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with 252Cf sources. Three projects at the CUF that demonstrate the versatility of 252Cf for biological and biomedical neutron-based research are described: future establishment of a 252Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded 252Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy

  10. Biomedical neutron research at the Californium User Facility for neutron science

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.C. [Oak Ridge National Lab., TN (United States); Byrne, T.E. [Roane State Community College, Harriman, TN (United States); Miller, L.F. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-04-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact {sup 252}Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with {sup 252}Cf sources. Three projects at the CUF that demonstrate the versatility of {sup 252}Cf for biological and biomedical neutron-based research are described: future establishment of a {sup 252}Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded {sup 252}Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy.

  11. Proposed Californium-252 User Facility for Neutron Science at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The Radiochemical Engineering Development Center (REDC) at ORNL has petitioned to establish a Californium-252 User Facility for Neutron Science for academic, industrial, and governmental researchers. The REDC Californium Facility (CF) stores the national inventory of sealed 252Cf neutron source for university and research loans. Within the CF, the 252Cf storage pool and two uncontaminated hot cells currently in service for the Californium Program will form the physical basis for the User Facility. Relevant applications include dosimetry and experiments for neutron tumor therapy; fast and thermal neutron activation analysis of materials; experimental configurations for prompt gamma neutron activation analysis; neutron shielding and material damage studies; and hardness testing of radiation detectors, cameras, and electronics. A formal User Facility simplifies working arrangements and agreements between US DOE facilities, academia, and commercial interests

  12. Emergence of californium as the second transitional element in the actinide series.

    Science.gov (United States)

    Cary, Samantha K; Vasiliu, Monica; Baumbach, Ryan E; Stritzinger, Jared T; Green, Thomas D; Diefenbach, Kariem; Cross, Justin N; Knappenberger, Kenneth L; Liu, Guokui; Silver, Mark A; DePrince, A Eugene; Polinski, Matthew J; Van Cleve, Shelley M; House, Jane H; Kikugawa, Naoki; Gallagher, Andrew; Arico, Alexandra A; Dixon, David A; Albrecht-Schmitt, Thomas E

    2015-01-01

    A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, and show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. The metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence. PMID:25880116

  13. Fissile analysis of Hanford waste using Californium Multiplier/Delayed Neutron Counter system

    International Nuclear Information System (INIS)

    Measurement of low-level (10 ng/g or lower) fissile material (mainly plutonium) in Hanford waste and process samples is becoming increasingly important. A system has been designed consisting of a Californium Multiplier (CFX) and a Delayed Neutron Counter (DNC) to characterize these samples. This report describes hardware and analytical capability of the CFX/DNC system

  14. Study of the shielding for spontaneous fission sources of Californium-252

    International Nuclear Information System (INIS)

    A shielding study is made to attenuate, until maximum permissible levels, the neutrons radiation and photons emitted by spontaneous fission coming from a source of Californium-252. The compound package by a database (Library DLC-23) and the ANISNW code is used, in it version for personal computer. (Author)

  15. Contribution to clinical dosimetry of californium 252 sources used at Gustave Roussy institute

    International Nuclear Information System (INIS)

    The main characteristics of californium 252 sources are presented in the first part of the report. Dose measurements around Californium sources were performed with a pair of ionization multiplication chambers: the first one has an Aluminium wall and is filled with Argon, the second one a plastic tissue-equivalent gas. A set of experiments was performed in order to investigate the relative influence of beta rays on the response of both chambers. Besides the experimental work a computer program was written to calculate the dose distribution around the actual sources made of a series of small active sources placed in catheters. Theoretical data around small sources can be found in the litterature. The comparison between experimental results and theoretical ones has shown a good agreement. The computer program will be included as a sub-routine in the more general computer program used for patients treated with interstitial therapy

  16. Application of SCGE assay, classical cytogenetics and FISH for studying in vitro californium-252 neutrons irradiations and BSH pretreatment on human lymphocytes

    International Nuclear Information System (INIS)

    Recently, there has been observed a tendency to apply various energy neutrons for tumor therapy and particularly low energy neutrons from various sources, including californium-252 source, for cancer radiotherapy based on the neutron capture. In this study peripheral blood lymphocytes were used as a model for human cells and three methods were applied to assess the effectiveness of californium-252 neutrons irradiations in vitro in normal cells or pre-treated with compound enriched in B-10 ion. Human blood samples or isolated lymphocytes were irradiated with neutrons from isotopic 252Cf source at the Faculty of Nuclear Physics and Technics at University of Mining and Metallurgy (both neutron source and samples were placed in polyethylene block). Chemical pretreatment with BSH (Na210B12H11SH) was done to introduce boron-10 ion into cells in order to check any enhancement effect due to the process of boron neutron capture. Comet assay was done to investigate the DNA damage. Classical cytogenetics was applied to assess the frequencies of unstable aberrations (dicentrics and rings). Fluorescence in situ hybridization (FISH) with probes for chromosomes 1, 4 (14.3% of whole genome) and pancentromeric probe was performed to evaluate the frequencies of stable aberrations. Linear (or close to linear) increase of DNA damage and aberration frequency was observed with dose of radiation both for lymphocytes untreated or pre-treated with BSH. Very little differences (statistically insignificant) due to radiation dose and BSH pretreatment were observed in the frequencies of SCEs detected in the second mitosis. There is no significant difference between boron pre-treated and not treated cells, and even slightly higher effects were observed in case of the highest dose without BSH pretreatment. The level of translocations observed is comparable with the frequencies of dicentrics and rings. (author)

  17. Safety Analysis Report for Packaging (SARP) of the Oak Ridge National Laboratory TRU Californium Shipping Container

    International Nuclear Information System (INIS)

    An analytical evaluation of the Oak Ridge National Laboratory TRU Californium Shipping Container was made in order to demonstrate its compliance with the regulations governing off-site shipment of packages that contain radioactive material. The evaluation encompassed five primary categories: structural integrity, thermal resistance, radiation shielding, nuclear criticality safety, and quality assurance. The results of this evaluation demonstrate that the container complies with the applicable regulations

  18. Emergence of californium as the second transitional element in the actinide series

    OpenAIRE

    Cary, Samantha K.; Vasiliu, Monica; Baumbach, Ryan E.; Stritzinger, Jared T.; GREEN, THOMAS D.; Diefenbach, Kariem; Cross, Justin N.; Knappenberger, Kenneth L.; Liu, Guokui; Silver, Mark A.; DePrince, A. Eugene; Polinski, Matthew J.; Van Cleve, Shelley M.; House, Jane H.; Kikugawa, Naoki

    2015-01-01

    A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resu...

  19. Measurements of integral cross sections in the californium-252 fission neutron spectrum

    International Nuclear Information System (INIS)

    In a low-scattering arrangement cross sections averaged over the californium-252 spontaneous fission neutron spectrum were measured. The reactions 27Al(n,α)46Ti, 47Ti, 48Ti(n,p), 54Fe,56Fe(n,p), 58Ni(n,p), 64Zn(n,p), 115In(n,n') were studied in order to obtain a consistent set of threshold detectors used in fast neutron flux density measurements. Overall uncertainties between 2 and 2.5% could be achieved; corrections due to neutron scattering in source and samples are discussed

  20. Measurement of californium-252 gamma photons depth dose distribution in tissue equivalent material. Vol. 4

    International Nuclear Information System (INIS)

    Phantom of tissue equivalent material with and without bone was used measuring depth dose distribution of gamma-rays from californium-252 source. The source was positioned at center of perspex walled phantom. Depth dose measurements were recorded for X, Y and Z planes at different distances from source. TLD 700 was used for measuring the dose distribution. Results indicate that implantation of bone in tissue equivalent medium cause changes in the gamma depth dose distribution which varies according to variation in bone geometry. 9 figs

  1. Spontaneous Partitioning of Californium from Curium: Curious Cases from the Crystallization of Curium Coordination Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Samantha K.; Silver, Mark A.; Liu, Guokui; Wang, Jamie C.; Bogart, Justin A.; Stritzinger, Jared T.; Arico, Alexandra A.; Hanson, Kenneth; Schelter, Eric J.; Albrecht-Schmitt, Thomas E.

    2015-12-07

    The reaction of 248CmCl3 with excess 2,6-pyridinedicarboxylic acid (DPA) under mild solvothermal conditions results in crystallization of the tris-chelate complex Cm(HDPA)3·H2O. Approximately half of the curium remains in solution at the end of this process, and evaporation of the mother liquor results in crystallization of the bis-chelate complex [Cm(HDPA)- (H2DPA)(H2O)2Cl]Cl·2H2O. 248Cm is the daughter of the α decay of 252Cf and is extracted in high purity from this parent. However, trace amounts of 249,250,251Cf are still present in all samples of 248Cm. During the crystallization of Cm(HDPA)3·H2O and [Cm(HDPA)(H2DPA)(H2O)2Cl]Cl·2H2O, californium(III) spontaneously separates itself from the curium complexes and is found doped within crystals of DPA in the form of Cf(HDPA)3. These results add to the growing body of evidence that the chemistry of californium is fundamentally different from that of earlier actinides.

  2. Biological Efficiency of Californium-252 Source Evaluated by Comet Assay, Classical Cytogenetics and FISH in Human Lymphocytes Irradiated without and with BSH Pretreatment

    International Nuclear Information System (INIS)

    Biological effectiveness of californium-252 source was evaluated after irradiations in vitro of normal or pre-treated with compound enriched in B-10 ion cells. Peripheral blood lymphocytes were used as a model for human cells. DNA and chromosomal damage were studied to compare biological effectiveness of irradiation. Human blood samples or isolated lymphocytes were irradiated with the isotopic source of 252Cf, at the Faculty of Physics and Nuclear Techniques at the University of Mining and Metallurgy (both neutron source and samples were placed in ''infinite'' polyethylene block). Chemical pretreatment with Na210B12H11SH (BSH) was performed to introduce boron-10 ion into cells in order to check any enhancement effect due to the process of boron neutron capture. Single cell gel electrophoresis also known as the Comet assay was done to investigate the DNA damage. Classical cytogenetic analysis was applied to assess the frequencies of unstable aberrations (dicentrics, rings and a centric fragments). To evaluate the frequencies of stable aberrations the fluorescence in situ hybridisation (FISH) with probes for chromosomes 1, 4 (14.3% of the whole genome) was performed. Linear (or close to linear) increase with radiation dose were observed for the DNA damage and aberration frequencies in lymphocytes both untreated or pre-treated with BSH. Levels of translocations evaluated for the whole genome were comparable with the frequencies of dicentrics and rings. No significant differences were detected due to radiation dose in the frequencies of sister chromatid exchanges (SCE) detected in the second mitosis. No statistically significant differences were observed in various biological end-points between normal or boron pre-treated cells. (author)

  3. Neutron activation analysis at the Californium User Facility for Neutron Science

    International Nuclear Information System (INIS)

    The Californium User Facility (CUF) for Neutron Science has been established to provide 252Cf-based neutron irradiation services and research capabilities including neutron activation analysis (NAA). A major advantage of the CUF is its accessibility and controlled experimental conditions compared with those of a reactor environment The CUF maintains the world's largest inventory of compact 252Cf neutron sources. Neutron source intensities of ≤ 1011 neutrons/s are available for irradiations within a contamination-free hot cell, capable of providing thermal and fast neutron fluxes exceeding 108 cm-2 s-1 at the sample. Total flux of ≥109 cm-2 s-1 is feasible for large-volume irradiation rabbits within the 252Cf storage pool. Neutron and gamma transport calculations have been performed using the Monte Carlo transport code MCNP to estimate irradiation fluxes available for sample activation within the hot cell and storage pool and to design and optimize a prompt gamma NAA (PGNAA) configuration for large sample volumes. Confirmatory NAA irradiations have been performed within the pool. Gamma spectroscopy capabilities including PGNAA are being established within the CUF for sample analysis

  4. Long-term effects of an intracavitary treatment with californium-252 on normal tissue

    International Nuclear Information System (INIS)

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with 252Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from 252Cf and 7000 rad from 226Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for 252Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from 252Cf and 5000 rad from 226Ra

  5. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source

    International Nuclear Information System (INIS)

    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction 55Mn (n.gamma)56 Mn, high concentration of manganese in the matrix and short half - life of 56Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions 56Fe(n,p)56Mn and 59 Co (n, α)56 were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  6. Five-year cure of cervical cancer treated using californium-252 neutron brachytherapy

    International Nuclear Information System (INIS)

    Female pelvic carcinoma is one of the common malignancies seen at the University of Kentucky Medical Center and often presents in an advanced stage. In 1976, the authors began to test californium-252 neutron brachytherapy (NT) for its efficacy for control of primary and recurrent advanced uterine, cervix, and vaginal cancers. The first protocol used was 5000-5500 rad of whole pelvis irradiation followed by 1-2 Cf-252 insertions using a single tandem placed in the utero-cervico-vaginal region. Of 27 patients with primary carcinomas treated, 10 are alive and well 5 year later (37%). Two of two recurrent tumors were locally controlled but failed later. These patients had advanced cervical, vaginal, or endometrial carcinomas. In 1977, a transitional year, treatment of only unfavorable stages and presentations with NT was initiated. Similar results were obtained with NT as compared to conventional photon therapy (PT). Further improvement in treatment results can be anticipated as NT brachytherapy is used for advanced cancer therapy by more effective treatment schedules and radiation doses. Cf-252 can be used as a radium substitute and achieved similar rates of tumor control and 5-year survivals. 21 references, 2 tables

  7. Uptake and distribution of californium-252 chloride administered intraperitoneally, intravenously or intratracheally and the effect of in vivo DTPA chelation on intratracheal instillation in the rat

    International Nuclear Information System (INIS)

    The first phase of this investigation, comprising of three groups of animals, was designed to study the fate of californium-252 chloride administered intraperitoneally, intravenously or intratracheally. The second phase, which consisted of two groups of animals, was designed to examine the effectiveness of DTPA chelation therapy in accelerating the excretion and preventing the deposition of californium-252 chloride instilled into the lungs of rats. Immediately following the dose administration of 2 uCi of californium-252 chloride which was dissolved in 0.2 ml of 0.9% NaCl at pH 3.5, each rat was placed in a metabolism cage. Each rat in the first group of phase II was given intraperitoneal injection of CaNa3 DTPA (50 mg/kg) and each rat in the second group was given intraperitoneal injections of 0.9% NaCl. Injections of the DTPA or the NaCl sham were initiated immediately after the intratracheal administration of californium-252 chloride and were continued every three days until sacrifice. Following intraperitoneal, intravenous or intratracheal administration, the whole body retention of californium as a function of time was described by a three component exponential equation. For each mode of administration the short term component exhibited a biological half-life of between 5 and 10 hours; the intermediate component between 4 and 6 days; and the long term component between 200 and 300 days. The organ data obtained following intraperitoneal and intravenous administration were indistinguishable. On day one, the liver retained about 9% of the administered dose and the kidneys retained 2.4%. Retention for these organs decreased to about 1% by day 32. The femurs maintained an almost constant level of 4.5% of the injected dose over the 32 days. The lungs, spleen, heart, and testes showed significant retention of californium

  8. ENEA results in the international comparison organized by BIPM for the measurament of neutron fluxes of a Californium source

    International Nuclear Information System (INIS)

    During the period between May 1978 and August 1984 under the auspices of Section III of CCEMRI of CIPM it has been carried out the international intercomparison of Californium neutron source emission rate. The previous intercomparison was based on Ra-Be (α -n) source measuraments, which took place between 1959 and 1965, and the results showed a total spread of +- 3%. Owing to the better accuracy achived over the following decade the Ra-Be intercomparison was no longer representative of the state of the art, therefore it was decided to arrange the intercomparison based on Californium which in the meantime reached a wide use in the world. Contributions to the intercomparison were received from fourteen laboratories representative of twelve Nations plus the BIPM. The results put into evidence a considerable advance on accuracy in the neutron source emission rate measuraments. The standard deviation of the residuals obtained from least square fit of normalized data resulted +- 0,57%. In the present report it is widely described the Manganese bath method used at ENEA, CRE Casaccia in Roma, and the experimental procedure followed for its absolute calibration. All measuraments are reported and analysed, including those effectuated for corrective factors determination. The final results obtained at ENEA for the circulated Californium source is (3,457 +- 0,013) 10*H7 neutron/s. The analysis of data from all partecipantes has been effectuated and concluded by J. Axton in March 1986 and the conclusions which have been showed in the present report put in evidence the satisfactory results achived by the ENEA

  9. Feasibility and market potential of protein determination of wheat using californium-252

    International Nuclear Information System (INIS)

    To evaluate the feasibility of protein determination by capture gamma-ray analysis using californium-252 neutrons, an in-situ protein analysis system for use by grain handlers has been examined. Three 227 kilogram (approximately) lots of wheat were used to determine the amount of nitrogen present. Protein analyses by the Kjeldahl method were obtained from samples taken before and after the capture gamma-ray analyses. The 5.267-MeV gamma-ray was selected for use in this study as a compromise between efficiency and interference from other elements. The associated counting equipment was a multichannel analyzer with pulse shaping electronic and analysis computing equipment. A linear regression program was used to compare the regions of interest to the Kjeldahl protein averages. The counts composing each peak were summed and normalized using the total count of the hydrogen peak. The normalized nitrogen percentages indicate a significant correlation between the spectral regions and the Kjeldahl analyses. To a first approximation, the value of wheat is the wheat protein. At the present time, protein testing of wheat is destructive, cumbersome, and time-consuming as compared to the potential for capture gamma-ray analysis testing. Assuming that such a protein analysis unit can analyze 42 tonne of wheat per hour, over 120 units would be needed to monitor one-half the U.S. annual wheat production. A 0.5% improvement in processor realizations and grain throughput value of $167.00 per tonne will result in a projected savings of $150,000 per year per unit

  10. Oxygen enhancement ratio (OER) and therapeutic gain factor (GF) for californium-252 at low dose rate

    International Nuclear Information System (INIS)

    The potential benefit of the introduction of californium-252 in interstitial and intracavitary therapy is related to the greater efficiency of its neutron emission against anoxic cancer cells. In that respect, the oxygen enhancement ratio (OER) of the 252Cf emission has been determined for a continuous low dose rate irradiation. The biological system is growth inhibition in Vicia faba bean roots. A new Vicia faba ''BelB'' strain has been used, which better tolerates long periods (up to about 10 hours) of anoxia. In a first series of experiments, for a 252Cf (Dsub(n+γ)) dose rate of 0.11 Gy.h-1, an OER of 1.4+-0.1 was observed (the γ contribution Dγ to the total absorbed dose Dsub(n+γ) was 0.35 at the position of the root tips). In a second series of experiments, in somewhat different geometrical conditions with a 252Cf (Dsub(n+γ)) dose rate of 0.13 Gy.h-1, an OER of 1.5+-0.1 was observed (Dγ/Dsub(n+γ)=0.42). The OER values observed for similar irradiation times, with iridium-192 γ-rays, were 2.3+-0.2 and 2.6+-0.1 respectively, which leads to therapeutic gain factors (GF) of 1.6 and 1.7 respectively. These GF values are slightly lower than those previously obtained (GF=1.8) on the same system, with d(50)-Be p(75)-Be and 15 MeV neutron beams

  11. Application of TSH bioindicator for studying the biological efficiency of neutrons from californium-252 source

    International Nuclear Information System (INIS)

    The effectiveness of neutrons from a Californium-252 source in the induction of various abnormalities in the Tradescantia clone 4430 stamen hair cells (TSH-assay) was studied. The special attention was paid to check whether any enhancement in effects caused by process of boron neutron capture is visible in the cells enriched with boron ions. Two chemicals (borax and BSH) were applied to introduce boron-10 ions into cells. Inflorescence, normal or pretreated with chemicals containing boron, were irradiated in the air with neutrons from a Cf-252 source at KAERI, Taejon, Korea. To estimate the relative biological effectiveness (RBE) in the induction of gene mutations of the neutron beam under the study, Tradescantia inflorescences, without any chemical pretreatment, were irradiated with various doses of X-rays. The ranges of radiation doses used were 0-0.1 Gy in neutrons and 0-0.5 Gy in X-rays. After the time needed to complete the postirradiation repair Tradescantia cuttings were transferred to Cracow, where screening of gene and lethal; mutations, cell cycle alterations in somatic cells have been done, and dose response relationships were figured. The maximal RBE values were estimated in the range of 4.6-6.8. Alterations of RBE value were observed; from 6.8 to 7.8 in the case of plants pretreated with 240 ppm of B-10 from borax, and 4.6 to 6.1 in the case of 400 ppm of B-10 from BSH. Results showed a slight, although statistically insignificant increase in biological efficacy of radiation from the Cf-252 source in samples pretreated with boron containing chemicals. (author)

  12. Divalent and trivalent gas-phase coordination complexes of californium: evaluating the stability of Cf(ii).

    Science.gov (United States)

    Dau, Phuong D; Shuh, David K; Sturzbecher-Hoehne, Manuel; Abergel, Rebecca J; Gibson, John K

    2016-08-01

    The divalent oxidation state is increasingly stable relative to the trivalent state for the later actinide elements, with californium the first actinide to exhibit divalent chemistry under moderate conditions. Although there is evidence for divalent Cf in solution and solid compounds, there are no reports of discrete complexes in which Cf(II) is coordinated by anionic ligands. Described here is the divalent Cf methanesulfinate coordination complex, Cf(II)(CH3SO2)3(-), prepared in the gas phase by reductive elimination of CH3SO2 from Cf(III)(CH3SO2)4(-). Comparison with synthesis of the corresponding Sm and Cm complexes reveals reduction of Cf(III) and Sm(III), and no evidence for reduction of Cm(III). This reflects the comparative 3+/2+ reduction potentials: Cf(3+) (-1.60 V) ≈ Sm(3+) (-1.55 V) ≫ Cm(3+) (-3.7 V). Association of O2 to the divalent complexes is attributed to formation of superoxides, with recovery of the trivalent oxidation state. The new gas-phase chemistry of californium, now the heaviest element to have been studied in this manner, provides evidence for Cf(II) coordination complexes and similar chemistry of Cf and Sm. PMID:27424652

  13. Hypoxic versus normoxic external-beam irradiation of cervical carcinoma combined with californium-252 neutron brachytherapy. Comparative treatment results of a 5-year randomized study

    Czech Academy of Sciences Publication Activity Database

    Tačev, T.; Vacek, Antonín; Ptáčková, B.; Strnad, V.

    2005-01-01

    Roč. 181, č. 5 (2005), s. 273-284. ISSN 0179-7158 Institutional research plan: CEZ:AV0Z50040507 Keywords : cervical carcinoma * hypoxyradiotherapy * californium-252 Subject RIV: BO - Biophysics Impact factor: 3.490, year: 2005

  14. Design of a homogeneous subcritical nuclear reactor based on thorium with a source of californium 252; Diseno de un reactor nuclear subcritico homogeneo a base de Torio con una fuente de Californio 252

    Energy Technology Data Exchange (ETDEWEB)

    Delgado H, C. E.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Sajo B, L., E-mail: ce_delgado89@hotmail.com [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. 89000, 1080A Caracas (Venezuela, Bolivarian Republic of)

    2015-10-15

    Full text: One of the energy alternatives to fossil fuels which do not produce greenhouse gases is the nuclear energy. One of the drawbacks of this alternative is the generation of radioactive wastes of long half-life and its relation to the generation of nuclear materials to produce weapons of mass destruction. An option to these drawbacks of nuclear energy is to use Thorium as part of the nuclear fuel which it becomes in U{sup 233} when capturing neutrons, that is a fissile material. In this paper Monte Carlo methods were used to design a homogeneous subcritical reactor based on thorium. As neutron reflector graphite was used. The reactor core is homogeneous and is formed of 70% light water as moderator, 12% of enriched uranium UO{sub 2}(NO{sub 3}){sub 4} and 18% of thorium Th(NO{sub 3}){sub 4} as fuel. To start the nuclear fission chain reaction an isotopic source of californium 252 was used with an intensity of 4.6 x 10{sup 7} s{sup -1}. In the design the value of the effective multiplication factor, whose value turned out k{sub eff} <1 was calculated. Also, the neutron spectra at different distances from the source and the total fluence were calculated, as well as the values of the ambient dose equivalent in the periphery of the reactor. (Author)

  15. Solving the Hydration Structure of the Heaviest Actinide Aqua Ion Known: The Californium(III) Case

    Energy Technology Data Exchange (ETDEWEB)

    Den Auwer, Ch.; Guillaumont, D. [CEA Marcoule, Nucl Energy Div, Radiochem Proc Dept, SCPS LILA, 30 (France); Galbis, E.; Pappalardo, Rafael R.; Marcos Sanchez, E. [Univ Seville, Dept Quim Fis, E-41012 Seville (Spain); Hernandez-Cobos, J. [Inst Ciencias Fis, Cuernavaca 62251, Morelos (Mexico); Le Naour, C.; Simoni, E. [Univ Paris Sud, Inst Phys Nucl Orsay, Paris (France)

    2010-07-01

    In summary, the first MC simulation of the trivalent cation of californium, based on an exchangeable hydrated ion-water intermolecular potential, has been shown to extend and improve the hydrated ion model. Likewise, the CfL{sub III}-edge EXAFS spectrum of an acidic 1 mm Cf(ClO{sub 4}){sub 3} aqueous solution recorded under optimized experimental conditions has greatly improved the signal/noise ratio of the only previously recorded spectrum. The comparison of the experimental EXAFS spectrum with the two computed ones, obtained from two different intermolecular potentials that predict eight (BP86) or nine (MP2) water molecules in the first coordination shell, leads to the conclusion that the lowest hydration number is preferred. Then, as Cf{sup III} is the heaviest actinide aqua ion for which there is experimental information, the actinide contraction is supported by the present study. (For U{sup III}, R{sub U-O}=2.56 Angstroms, and CN=9{+-}1; for Pu{sup III}, R{sub Pu-O}=2.51 Angstroms and CN=9{+-}1; for Cm{sup III}, R{sub Cm-O}=2.47 Angstroms and CN=9{+-}1). The role of the second hydration shell is important in defining the structure and dynamics of the Cf{sup III} aqua ion, but the contribution of second-shell water molecules to the EXAFS signal as back-scatters is marginal. Finally, this work gives an illustrative example of the benefits which can be achieved from the combination of experimental X-ray absorption spectroscopy and computer simulations. The usefulness of the simultaneous analysis of the results as well as the importance of the structural statistical average has been clearly demonstrated herein. Each technique independently was not adequate. We believe that this study traces out a still poorly explored combined methodology which may be extremely useful for many other complexes and chemical problems. A systematic theoretical and experimental examination of the other known actinide cations on the same basis should be undertaken to confirm the

  16. Design, construction, and characterization of a facility for neutron capture gamma ray analysis of sulfur in coal using californium-252

    International Nuclear Information System (INIS)

    A study of neutron capture gamma ray analysis of sulfur in coal using californium-252 as a neutron source is reported. Both internal and external target geometries are investigated. The facility designed for and used in this study is described. The external target geometry is found to be inappropriate because of the low thermal neutron flux at the sample location, which must be outside the biological shielding. The internal target geometry is found to have a sufficient thermal neutron flux, but an excessive gamma ray background. A water filled plastic facility, rather than the paraffin filled steel one used in this study, is suggested as a means of increasing flexibility and decreasing the beackground in the internal target geometry

  17. Operational experience with the Argonne National Laboratory Californium Rare Ion Breeder Upgrade facility and electron cyclotron resonance charge breeder

    Science.gov (United States)

    Vondrasek, R.; Clark, J.; Levand, A.; Palchan, T.; Pardo, R.; Savard, G.; Scott, R.

    2014-02-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory Argonne Tandem Linac Accelerator System (ATLAS) facility provides low-energy and accelerated neutron-rich radioactive beams to address key nuclear physics and astrophysics questions. A 350 mCi 252Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The ECR charge breeder has achieved stable beam charge breeding efficiencies of 10.1% for 23Na7+, 17.9% for 39K10+, 15.6% for 84Kr17+, and 12.4% for 133Cs27+. For the radioactive beams, a charge breeding efficiency of 11.7% has been achieved for 143Cs27+ and 14.7% for 143Ba27+. The typical breeding times are 10 ms/charge state, but the source can be tuned such that this value increases to 100 ms/charge state with the best breeding efficiency corresponding to the longest breeding times—the variation of efficiencies with breeding time will be discussed. Efforts have been made to characterize and reduce the background contaminants present in the ion beam through judicious choice of q/m combinations. Methods of background reduction are being investigated based upon plasma chamber cleaning and vacuum practices.

  18. Long-term effects of an intracavitary treatment with californium-252 on normal tissue. [Swine, /sup 226/Ra

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, M.F.; Beamer, J.L.; Mahony, T.D.; Cross, F.T.; Lund, J.E.; Endres, G.W.R.

    1976-01-01

    About one hundred fifty swine were exposed to either radium-226 or californium-252 sources in the uterine cervix to determine an RBE for both acute and long-term effects. That value for early changes in the tissues at risk in the treatment of cervical cancer was between 6.2 and 6.8. The incidence of complications increased with time after exposure, especially among animals treated with /sup 252/Cf. Analysis of rectal injury showed that ulceration occurred frequently within a year postexposure at doses between 1600 and 2400 rad calculated at 2 cm lateral to the source midline. Fat necrosis and smooth muscle atrophy, resulting in a local rectal stricture, were delayed changes observed in some animals. The lower ureter was the site for a greater frequency of complications than the GI tract. Ureteral stricture often occurred at doses of 1200 rad from /sup 252/Cf and 7000 rad from /sup 226/Ra. Observation of delayed effects in the uterine-cervix in animals held up to 4 years postexposure indicate that the RBE for /sup 252/Cf may be increased to a value as high as 18, while repair may have even decreased it to about 5.6 in the rectum. Fifty swine are still being observed for long-term effects after doses above 800 rad from /sup 252/Cf and 5000 rad from /sup 226/Ra.

  19. Results with the electron cyclotron resonance charge breeder for the 252Cf fission source project (Californium Rare Ion Breeder Upgrade) at Argonne Tandem Linac Accelerator System

    International Nuclear Information System (INIS)

    The construction of the Californium Rare Ion Breeder Upgrade, a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS), is nearing completion. The facility will use fission fragments from a 1 Ci 252Cf source; thermalized and collected into a low-energy particle beam by a helium gas catcher. In order to reaccelerate these beams, an existing ATLAS electron cyclotron resonance (ECR) ion source was redesigned to function as an ECR charge breeder. Thus far, the charge breeder has been tested with stable beams of rubidium and cesium achieving charge breeding efficiencies of 9.7% into 85Rb17+ and 2.9% into 133Cs20+.

  20. Ab initio full-potential study of mechanical properties and magnetic phase stability of californium monopnictides (CfN and CfP)

    Science.gov (United States)

    Amari, S.; Bouhafs, B.

    2016-09-01

    Based on the first-principles methods, the structural, elastic, electronic, properties and magnetic ordering of californium monopnictides CfX (X = P) have been studied using the full-potential augmented plane wave plus local orbitals (FP-L/APW + lo) method within the framework of density functional theory (DFT). The electronic exchange correlation energy is described by generalized gradient approximation GGA and GGA+U (U is the Hubbard correction). The GGA+U method is applied to the rare-earth 5f states. We have calculated the lattice parameters, bulk modulii and the first pressure derivatives of the bulk modulii. The elastic properties of the studied compounds are only investigated in the most stable calculated phase. In order to gain further information, we have calculated Young's modulus, shear modulus, anisotropy factor and Kleinman parameter by the aid of the calculated elastic constants. The results mainly show that californium monopnictides CfX (X = P) have an antiferromagnetic spin ordering. Density of states (DOS) and charge densities for both compounds are also computed in the NaCl (B1) structure.

  1. Isotopic Biogeochemistry

    Science.gov (United States)

    Hayes, J. M.

    1985-01-01

    An overview is provided of the biogeochemical research. The funding, productivity, personnel and facilities are reviewed. Some of the technical areas covered are: carbon isotopic records; isotopic studies of banded iron formations; isotope effects in microbial systems; studies of organic compounds in ancient sediments; and development in isotopic geochemistry and analysis.

  2. Anatomy of a controversy: Application of the Langevin technique to the analysis of the Californium-252 Source-Driven Noise Analysis method for subcriticality determination

    International Nuclear Information System (INIS)

    The expressions for the power spectral density of the noise equivalent sources have been calculated explicitly for the (a) stochastic transport equation, (b) the one-speed transport equaton, (c) the one-speed P1 equations, (d) the one-speed diffusion equation and (e) the point kinetic equation. The stochastic nature of Fick's law in (d) has been emphasized. The Langevin technique has been applied at various levels of approximation to the interpretation of the Californium-252 Source-Driven Noise Analysis (CSDNA) experiment for determining the reactivity in subcritical media. The origin of the controversy surrounding this method has been explained. The foundations of the CSDNA method as a viable experimental technique to infer subcriticality from a measured ratio of power spectral densities of the outputs of two neutron detectors and a third external source detector has been examined by solving the one-speed stochastic diffusion equation for a point external Californium-252 source and two detectors in an infinite medium. The expression relating reactivity to the measured ratio of PSDs was found to depend implicitly on k itself. Through a numerical analysis fo this expression, the authors have demonstrated that for a colinear detector-source-detector configuration for neutron detectors far from the source, the expression for the subcritical multiplication factor becomes essentially insensitive to k, hence, demonstrating some possibility for the viability of this technique. However, under more realistic experimental conditions, i.e., for finite systems in which diffusion theroy is not applicable, the measurement of the subcritical multiplication factor from a single measured ratio of PSDs, without extensive transport calculations, remains doubtful

  3. Isotopic geology

    International Nuclear Information System (INIS)

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  4. Isotopic clusters

    International Nuclear Information System (INIS)

    Spectra of isotopically mixed clusters (dimers of SF6) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  5. Calculations of Nuclear Astrophysics and Californium Fission Neutron Spectrum Averaged Cross Section Uncertainties Using ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-fidelity Covariances

    International Nuclear Information System (INIS)

    Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed

  6. Californium interrogation prompt neutron (CIPN) instrument for non-destructive assay of spent nuclear fuel-Design concept and experimental demonstration

    Science.gov (United States)

    Henzlova, D.; Menlove, H. O.; Rael, C. D.; Trellue, H. R.; Tobin, S. J.; Park, Se-Hwan; Oh, Jong-Myeong; Lee, Seung-Kyu; Ahn, Seong-Kyu; Kwon, In-Chan; Kim, Ho-Dong

    2016-01-01

    This paper presents results of the first experimental demonstration of the Californium Interrogation Prompt Neutron (CIPN) instrument developed within a multi-year effort launched by the Next Generation Safeguards Initiative Spent Fuel Project of the United States Department of Energy. The goals of this project focused on developing viable non-destructive assay techniques with capabilities to improve an independent verification of spent fuel assembly characteristics. For this purpose, the CIPN instrument combines active and passive neutron interrogation, along with passive gamma-ray measurements, to provide three independent observables. This paper describes the initial feasibility demonstration of the CIPN instrument, which involved measurements of four pressurized-water-reactor spent fuel assemblies with different levels of burnup and two initial enrichments. The measurements were performed at the Post-Irradiation Examination Facility at the Korea Atomic Energy Institute in the Republic of Korea. The key aim of the demonstration was to evaluate CIPN instrument performance under realistic deployment conditions, with the focus on a detailed assessment of systematic uncertainties that are best evaluated experimentally. The measurements revealed good positioning reproducibility, as well as a high degree of insensitivity of the CIPN instrument's response to irregularities in a radial burnup profile. Systematic uncertainty of individual CIPN instrument signals due to assembly rotation was found to be orientation in the instrument.

  7. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  8. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  9. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    International Nuclear Information System (INIS)

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  10. Isotope Spectroscopy

    CERN Document Server

    Caffau, E; Bonifacio, P; Ludwig, H -G; Monaco, L; Curto, G Lo; Kamp, I

    2013-01-01

    The measurement of isotopic ratios provides a privileged insight both into nucleosynthesis and into the mechanisms operating in stellar envelopes, such as gravitational settling. In this article, we give a few examples of how isotopic ratios can be determined from high-resolution, high-quality stellar spectra. We consider examples of the lightest elements, H and He, for which the isotopic shifts are very large and easily measurable, and examples of heavier elements for which the determination of isotopic ratios is more difficult. The presence of 6Li in the stellar atmospheres causes a subtle extra depression in the red wing of the 7Li 670.7 nm doublet which can only be detected in spectra of the highest quality. But even with the best spectra, the derived $^6$Li abundance can only be as good as the synthetic spectra used for their interpretation. It is now known that 3D non-LTE modelling of the lithium spectral line profiles is necessary to account properly for the intrinsic line asymmetry, which is produced ...

  11. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  12. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  13. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  14. Method for separating isotopes

    Science.gov (United States)

    Jepson, B.E.

    1975-10-21

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

  15. Developing isotopic functions

    International Nuclear Information System (INIS)

    Isotopic functions, or ratios of two isotopic variables, are used to verify Pu and U measurements of spent fuels in reprocessing plants. Systematic methods have been developed for forming and evaluating isotopic functions. This paper describes the method used at Battelle to form and evaluate isotopic functions. The data base at Battelle contains measurements and calculations for the fuel from 35 reactors

  16. The isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  17. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    This invention provides a method for separating uranium isotopes comprising the steps of selectively irradiating a photochemically-reactive uranyl source material at a wavelength selective to a desired isotope of uranium at an effective temperature for isotope spectral line splitting below about 77 K, further irradiating the source material within the fluorescent lifetime of the selectively irradiated source material to selectively photochemically reduce the selectively excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  18. Isotopic geology; Geologie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Allegre, C. [Paris-7 Univ. Denis Diderot, 75 (France); Institut de physique du globe de Paris, 75 - Paris (France)

    2005-07-01

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  19. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144Sm and 154Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  20. Statistical clumped isotope signatures.

    Science.gov (United States)

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  1. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source; Determinacao de manganes em minerios, por analise por ativacao, usando californio-252 como fonte de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Antonio

    1976-07-01

    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction {sup 55}Mn (n.gamma){sup 56} Mn, high concentration of manganese in the matrix and short half - life of {sup 56}Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions {sup 56}Fe(n,p){sup 56}Mn and {sup 59} Co (n, {alpha}){sup 56} were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  2. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  3. Stable isotope applications

    International Nuclear Information System (INIS)

    The following domains of stable isotope applications are presented: - isotope dilution analyses as in trace analyses or volume and mass determinations; - stable isotopes as tracers as applied in environmental studies, agricultural research, products and objects authentification, transport phenomena, reaction mechanisms, determinations of structure and complex biological function, metabolism studies, diagnostic respiration tests, positron emission tomography; - equilibrium isotopic effects as investigated in measurements of effects, studies of equilibrium conditions, the mechanism of drug action, study of natural processes, water circuit, temperature measurements; - kinetic isotopic effects, as, for instance, reaction rates and mechanisms, solvent isotopic effects; - stable isotopes for advanced nuclear reactors as, for instance, uranium nitride with 15 N as nuclear fuel or 157 Gd for reactivity control. In spite of the difficulties regarding stable isotope use and first of all, of the difficult and costly analytical techniques, a continuous growth of the number of stable isotope applications in different fields is registered. The number of works and scientific meetings on the subject, as organized by the International Society of Isotopes and IAEA-Vienna, Gordon Conferences, regional meetings in Germany, France, etc. increase continuously. Development of the stable isotope application on a larger scale requires improving both their production technologies as well as those of labelled substances and, at the same time, the analytical methods

  4. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    Chromium (Cr) stable isotopes are a useful tracer of changes in redox conditions because changes in its oxidation state are accompanied by an isotopic fractionation. For this reason the Cr isotope system is being developed as a potential tool for paleo-redox reconstruction. Dissolved Cr in seawater...... is incorporated into carbonates. Hence, ancient carbonates can potentially record the Cr isotopic composition (δ53Cr ‰) of seawater in the geological past. Reliable application and interpretation of this proxy requires a detailed knowledge about processes that fractionate Cr on the Earth’s surface......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river...

  5. Isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    The mechanisms producing isotopic contamination in the electromagnetic separation of isotopes are studied with the aid of the Separator of Saclay and an electrostatic analyzer in cascade. After a separate investigation the result of which is that no contamination comes from the spreading of initial energies of ions, two principal mechanisms are emphasized; scattering and instability of the regime of the sources. The characters of each type of contamination arising from both mechanisms are described in some detail. An unique scheme of isotopic contamination is then derived from the partial ones. This scheme is successfully verified in several experimental separations. The applications concern principally the performances of magnetic cascades and more complex apparatus. It is found that the isotopic purities that such machines can deliver are extremely high. (author)

  6. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

    2011-08-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  7. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  8. Isotope enrichment systems

    International Nuclear Information System (INIS)

    This invention provides a system in which both phases of the countercurrent contact isotope exchange concentration process are recycled continuously and an isotope depleted liquid phase substance thereof has its prior content of the desired isotope of hydrogen and/or oxygen replenished in an isotope regenerator by direct contact isotope exchange with a flow of steam from a source external to the concentrating process, whereby such replenished liquid serves as the feed liquid for the concentration process. As the supply of steam is gaseous, all problems incident to mineral solids in solution in liquid water are eliminated. As the elevated temperature corresponds to that of the steam, the isotope replenishment of the process feed liquid may be conducted without materially altering the characteristics of the steam for use as an energy source in any system

  9. Uses of stable isotopes

    International Nuclear Information System (INIS)

    The most important fields of stable isotope use with examples are presented. In isotope dilution analysis the stable isotopes are used in trace analysis, measurements of volumes and masses. In the field of stable isotope use as tracers the following applications are encountered: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic. In the domain of isotope equilibrium effects applications in the study of mechanism of drug action, study of natural processes, investigation of equilibrium conditions and water cycle as well as in temperature measurements are encountered. Stable isotopes are also used in advanced nuclear reactors, particularly, the uranium nitride with 15 N as nuclear fuel and 157 Gd for reactor control. In spite of some difficulties of stable isotope use, especially related to analytical techniques, which are slow and expensive, the number of papers reporting this subject is steadily growing as well the number of scientific meetings organized by International Isotope Society and IAEA, Gordon Conferences, and regional meetings in Germany, France, etc. Stable isotope application development on large scale is ensured by improving their production technologies, as well as by development of new labelled compounds and of analytical techniques. (author)

  10. Isotopes in hydrogeology

    International Nuclear Information System (INIS)

    Questions of the application of radioactive isotopes in hydrogeology and seismology are considered, as well as their physico-chemical and geochemical properties and the regularities of their occurrence and migration in natural waters. The possibility of application of these isotopes in calculating the age of waters and in solving paleohydrogeological problems is studied. Elucidated are questions of utilization of helium and uranium isotope content in determining the effect of faults on the hydrogeological conditions of regions and in selecting burial sites for industrial wastes. Utilization of changes in the isotopic and gas composition of underground waters during the activization of tectonic movements for earthquake forecasts is considered

  11. PRINCIPAL ISOTOPE SELECTION REPORT

    International Nuclear Information System (INIS)

    Utilizing nuclear fuel to produce power in commercial reactors results in the production of hundreds of fission product and transuranic isotopes in the spent nuclear fuel (SNF). When the SNF is disposed of in a repository, the criticality analyses could consider all of the isotopes, some principal isotopes affecting criticality, or none of the isotopes, other than the initial loading. The selected set of principal isotopes will be the ones used in criticality analyses of the SNF to evaluate the reactivity of the fuel/waste package composition and configuration. This technical document discusses the process used to select the principal isotopes and the possible affect that these isotopes could have on criticality in the SNF. The objective of this technical document is to discuss the process used to select the principal isotopes for disposal criticality evaluations with commercial SNF. The principal isotopes will be used as supporting information in the ''Disposal Criticality Analysis Methodology Topical Report'' which will be presented to the United States Nuclear Regulatory Commission (NRC) when approved by the United States Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM)

  12. The isotope breathe test

    International Nuclear Information System (INIS)

    The foundations of the breath diagnostic test, based on application of the carbon compounds, labeled with the stable (13C) or radioactive isotope are presented. The methodology for conducting the breath isotope test and the apparatuses, making it possible to determine under clinical conditions the isotope composition of the carbon, contained in the expired air, depending on the introduced tracer type, is briefly described. The safety of the method and prospects of its application are discussed. The examples of the breath isotope test practical application are presented

  13. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  14. Mass independent isotope separations

    International Nuclear Information System (INIS)

    Mass independent separations between isotopes of an element were first observed by Clayton on 17 O and 18 O from the Allende meteorite and attributed then to nucleosynthesis. Anomalous ratios of isotope abundance known at that time were due to nuclear processes. Later, atmospheric ozone and stratospheric CO2 were shown to exhibit mass independent isotope composition of oxygen. Several formation mechanisms of these 'anomalous' molecules have been proposed, none being completely satisfactory. In the laboratory, these mass independent chemical separation effects were eventually reproduced. Anomalous separations were also obtained between isotopes of uranium, and even of light elements such as magnesium. These were first connected with irregularities in atomic nucleus volumes. Such effects are not recorded on natural terrestrial samples. Two main reasons prevent such observations from having been made. Firstly, laboratories investigating isotope compositions of elements, publish almost exclusively deltas of one isotope only. But, to look for possible anomalies, one needs to compare each isotope abundance in a sample similar to that in the standard used as origin of deltas. An example of such calculation will be given. Secondly, deltas of isotopes published by different laboratories are usually not comparable to better than a few per mil. The reason is that, to calculate deltas, most laboratories use working standards whose absolute values may not be exactly established as they are not crucial to their work. Several per mil differences will be shown to be implied between the 'absolute' isotope abundance of 13 C of standards, reputedly the same, used by different laboratories. Laboratories making surveys of natural samples should be encouraged, e.g. by IUPAC, to cover every isotope of multiple isotope elements, and to make, at not infrequent intervals, a close comparison of their working standards with internationally distributed ones. (author)

  15. Discovery of the Mercury Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2009-01-01

    Forty mercury isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the Einsteinium Isotopes

    OpenAIRE

    Bury, A.; Fritsch, A; Ginepro, J. Q.; Heim, M; Schuh, A.; Shore, A.; Thoennessen, M.

    2009-01-01

    Seventeen einsteinium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the Titanium Isotopes

    OpenAIRE

    Meierfrankenfeld, D.; Thoennessen, M.

    2009-01-01

    Twentyfive titanium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Discovery of the Scandium Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2010-01-01

    Twenty-three scandium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of the Tungsten Isotopes

    OpenAIRE

    A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the Vanadium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-four vanadium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of the Arsenic Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  2. Discovery of the Barium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  3. Discovery of the Silver Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-eight silver isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  4. Discovery of the Cadmium Isotopes

    OpenAIRE

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  5. Discovery of the Krypton Isotopes

    OpenAIRE

    Heim, M.; A. Fritsch; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-two krypton isotopes have been observed so far; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  6. Discovery of the Iron Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Twenty-eight iron isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  7. Discovery of the Gold Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-six gold isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  8. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T; Thoennessen, M

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  9. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  10. (Carbon isotope fractionation inplants)

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  11. Maximum abundant isotopes correlation

    International Nuclear Information System (INIS)

    The neutron excess of the most abundant isotopes of the element shows an overall linear dependence upon the neutron number for nuclei between neutron closed shells. This maximum abundant isotopes correlation supports the arguments for a common history of the elements during nucleosynthesis. (Auth.)

  12. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  13. Principles of stable isotope distribution

    CERN Document Server

    Criss, Robert E

    1999-01-01

    1. Abundance and Measurement of Stable Isotopes 1.1. Discovery of Isotopes 1.2. Nuclide Types, Abundances, and Atomic Weights 1.3. Properties and Fractionation of Isotopic Molecules 1.4. Material Balance Relationships 1.5. Mass Spectrometers 1.6. Notation and Standards 1.7. Summary 1.8. Problems References 2. Isotopic Exchange and Equilibrium Fractionation 2.1. Isotopic Exchange Reactions 2.2. Basic Equations 2.3. Molecular Models 2.4. Theory of Isotopic Fractionation 2.5. Temperature Dependence of Isotopic Fractionation Factors 2.6. Rule of the Mean 2.7. Isotopic Thermometers

  14. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  15. Rotational-isotopic symmetries

    International Nuclear Information System (INIS)

    In this note we submit a nonlocal (integral) generalization of the rotational-isotopic symmetries O-circumflex(3) introduced in preceding works for nonlinear and nonhamiltonian systems in local approximation. By recalling that the Lie-isotopic theory naturally admits nonlocal terms when all embedded in the isounit, while the conventional symplectic geometry is strictly local-differential, we introduce the notion of symplectic-isotopic two-forms, which are exact symplectic two-forms admitting a factorization into the Kronecker product of a canonical two-form time the isotopic element of an underlying Euclidean-isotopic space. Topological consistency is then achieved by embedding all nonlocal terms in the isounit of the iso-cotangent bundle, while keeping the local topology for the canonical part. In this way, we identify the symplectic-isotopic geometry as being the natural geometrical counterpart of the Lie-isotopic theory. The results are used for the introduction of the notion of Birkhoffian angular momentum, that is, the generalization of the conventional canonical angular momentum which is applicable to Birkhoffian systems with generally nonlinear, nonlocal and nonhamiltonian internal forces. The generators J (and the parameters θ) coincide with the conventional quantities. Nevertheless, the quantity J is defined on the underlying Euclidean-isotopic space, by therefore acquiring a generalized magnitude. The isocommutation rules and isoexponentiation of the Birkhoffian angular momentum are explicitly computed and shown to characterize the most general known nonlinear and nonlocal realization of the isorotational symmetry. The local isomorphisms between the infinitely possible isotopes O-circumflex(3) and the conventional symmetry O(3) is proved. Finally the isosymmetries O-circumflex(3) are used to characterize the conserved, total, Birkhoffian angular momentum of closed nonselfadjoint systems. (author). 4 refs

  16. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  17. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  18. Carbon isotope techniques

    International Nuclear Information System (INIS)

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The 11C, 12C, 13C, and 14C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations

  19. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  20. Method for isotope separation

    International Nuclear Information System (INIS)

    The inventor proposes a method for separating isotopes from gaseous compounds by selective excitation by means of laser beams for such cases where the reaction partners each consist of several isotopes. For example, separation of 235U and 238U in the form of UCl6 is mentioned with 35Cl and 37Cl existing in the natural composition of 76:24. According to the invention, after isolating the reaction product obtained in a way already known, the remaining fraction of the compound mixture is brought together with the reaction partner present in the natural isotope composition, in a heated flow path. Thereby by isotope exchange of the latter regeneration will take place, and the mixture can pass again through the separation plant in initial composition. (orig./PW)

  1. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  2. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  3. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  4. Canada's medical isotope strategy

    International Nuclear Information System (INIS)

    This paper details Canada's medical isotope strategy and the role of the Canadian Government in the security of the isotope supply chain. The government's role is to promote health and safety of Canadians, establish appropriate regulatory framework, allow the markets to work, facilitate international collaboration, fund high-risk early stage research and development, encourage private sector investment in innovation and support and respect environmental and non-proliferation goals.

  5. Separating isotopes by laser

    International Nuclear Information System (INIS)

    Isotope separation by laser radiation is proving a very promising method for obtaining large scale isotope production at low cost and is particularly relevant to the enrichment of 235U for the nuclear power industry. Various methods for laser separation, differing mainly in the way the selectively excited atoms or molecules are extracted, are discussed. The efficiency of the various methods, which is the controlling factor in determining their practical viability and some of the problems encountered are examined. (UK)

  6. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  7. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  8. Isotope heated thermal batteries

    International Nuclear Information System (INIS)

    A deferred action thermal battery is described that includes a quantity of radioactive isotope normally positioned so that only a small part of the thermal energy generated by the isotope is received by the battery, but adapted, when the battery is rendered active, to be moved automatically to a position where a large part of the thermal energy is received. The battery may comprise a chamber containing its cells and a second chamber part of which is remote from the cells for normal storage of the isotope and part of which is adjacent to the cells; the isotope is moved to the latter part when the battery is activated. The cell chamber is preferably toroidal and surrounds the second portion of the isotope chamber. The isotope may be contained in a carriage held by a retaining means adapted for release when the battery is activated, resilient means then moving the carriage to the active position. The retaining means may be a wire that disintegrates on the passage of electric current, the current also igniting a combustible composition to activate the battery. The object is to provide thermal batteries having an extended life. (U.K.)

  9. The isotopic distribution conundrum.

    Science.gov (United States)

    Valkenborg, Dirk; Mertens, Inge; Lemière, Filip; Witters, Erwin; Burzykowski, Tomasz

    2012-01-01

    Although access to high-resolution mass spectrometry (MS), especially in the field of biomolecular MS, is becoming readily available due to recent advances in MS technology, the accompanied information on isotopic distribution in high-resolution spectra is not used at its full potential, mainly because of lack of knowledge and/or awareness. In this review, we give an insight into the practical problems related to calculating the isotopic distribution for large biomolecules, and present an overview of methods for the calculation of the isotopic distribution. We discuss the key events that triggered the development of various algorithms and explain the rationale of how and why the various isotopic-distribution calculations were performed. The review is focused around the developmental stages as briefly outlined below, starting with the first observation of an isotopic distribution. The observations of Beynon in the field of organic MS that chlorine appeared in a mass spectrum as two variants with odds 3:1 lie at the basis of the first wave of algorithms for the calculation of the isotopic distribution, based on the atomic composition of a molecule. From here on, we explain why more complex biomolecules such as peptides exhibit a highly complex isotope pattern when assayed by MS, and we discuss how combinatorial difficulties complicate the calculation of the isotopic distribution on computers. For this purpose, we highlight three methods, which were introduced in the 1980s. These are the stepwise procedure introduced by Kubinyi, the polynomial expansion from Brownawell and Fillippo, and the multinomial expansion from Yergey. The next development was instigated by Rockwood, who suggested to decompose the isotopic distribution in terms of their nucleon count instead of the exact mass. In this respect, we could claim that the term "aggregated" isotopic distribution is more appropriate. Due to the simplification of the isotopic distribution to its aggregated counterpart

  10. Production of Medical Radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for Cancer Treatment and Arterial Restenosis Therapy after PTCA

    Science.gov (United States)

    Knapp, F. F. Jr.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  11. Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA

    International Nuclear Information System (INIS)

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed

  12. Transportation of medical isotopes

    International Nuclear Information System (INIS)

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document

  13. Separation of sulfur isotopes

    Science.gov (United States)

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  14. Laser isotope separation techniques

    International Nuclear Information System (INIS)

    Having examined the high cost and low efficiency of existing processes for separating uranium isotopes in comparison with the encouraging assessed figures for laser separation processes and having considered the high potential separation factors which make possibly very low 235U concentrations in the depleted tailings from laser separation processes, the design of such a system is considered. There are two essential features. Firstly, only one isotope must absorb laser radiation, and secondly that absorption must lead to a successful physical or chemical separation of that species which has been optically excited. Such a scheme is illustrated and discussed. The important aspect of loss mechanisms which can depopulate the selectively excited levels and the ways in which isotopes may exhibit differences in optical absorption frequencies are considered. Examples are given to illustrate techniques used in the separation stage. Finally a summary is presented of those elements in which some enrichment has been achieved by optical techniques. (U.K.)

  15. Lithium isotope separation

    International Nuclear Information System (INIS)

    Published methods for 6Li-7Li lithium isotope separation have been reviewed. Future demand for 6Li, whose main use will be as a tritium breeder in blankets surrounding the core of DT fusion power reactors, is likely to exceed 5 Mg/a in the next century. The applicability of the various available methods to such a large scale production rate has been assessed. Research on improving the effectiveness of current lithium isotope separation processes has been carried out worldwide in several major areas during the past decade; these include two-phase chemical exchange systems, ion exchange resin chromatography, highly isotope-selective techniques like laser photoactivation and radiofrequency spectroscopy. Chemical exchange systems appear to offer good potential in the near term for 6Li enrichment

  16. Isotopes in condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Plekhanov, Vladimir G. [Computer Science College, Tallinn (Estonia). Mathematics and Physics Dept.

    2013-07-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed. The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  17. Isotopes in Condensed Matter

    CERN Document Server

    G Plekhanov, Vladimir

    2013-01-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe  in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed.  The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  18. Environmental isotope survey

    International Nuclear Information System (INIS)

    Work was initiated on the 1st of September 1971 with the objective of finding out how best to use environmental isotopes in the interpretation of the hydrology, particularly subsurface hydrology, of Cyprus through a sparse reconnaissance sampling of all the major aquifers and springs covering the whole island. The distribution of sampling was such that the survey in itself could assist in clarifying particular hydrogeologic problems, provide a better understanding of the water systems of the island, establish a general environmental isotope - framework of the hydrologic regimen of Cyprus as well as to provide the basis for specific, more detailed, studies to be undertaken subsequently

  19. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  20. Zinc isotope anomalies

    International Nuclear Information System (INIS)

    The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion. 32 refs

  1. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  2. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  3. Discoveries of isotopes by fission

    Indian Academy of Sciences (India)

    M Thoennessen

    2015-09-01

    Of the about 3000 isotopes presently known, about 20% have been discovered in fission. The history of fission as it relates to the discovery of isotopes as well as the various reaction mechanisms leading to isotope discoveries involving fission are presented.

  4. Isotope hydrology experiments

    International Nuclear Information System (INIS)

    From the concentrations of H2 and O18 in the examined ground waters in the Lower Muschelkalk of the SW flank of the Asse mine it can be inferred that the flow field of the ground water with the isotopic composition of the recent precipitations has an effect down to a depth of only 611 to 744 m. (DG)

  5. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  6. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090432 Zhou Shuqing (School of Energy Resources, China University of Geosciences Beijing 100083, China); Huang Haiping Stable Isotopic Records vs. Important Events in Life Evolution and the Concurrent Environment (Geological Review, ISSN0371-5736, CN11-1952, 54(2), 2008, p.225-231, 3 illus., 1 table, 77 refs.)

  7. Isotopes in aquaculture research

    International Nuclear Information System (INIS)

    The applications of isotopes in aquaculture research include areas like aquatic production process, nutrient cycles and food chain dynamics, fish nutrition, fish physiology, genetics and immunology. The radioisotopes commonly used are beta emitters. The use of different radioisotopes in aquaculture research are presented. 2 tabs

  8. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  9. Isotopic geochemistry of calcretes

    International Nuclear Information System (INIS)

    Sr, C, O, U and Th isotopes have been studied in calcium carbonates accumulated in soils of semi-arid regions (calcretes). We have investigated 1) the role of in-situ weathering and climatic conditions in the genesis of calcretes from Central Spain (Toledo) and Atlantic Morocco (Sidi Ifni), 2) the origin of Ca, and 3) the age of these accumulations. Our results show that calcium carbonates replace the parent rock (granite) and preserve the bulk-volume. Sr isotopic data suggest that 90 % of Ca in the spanish calcretes is allochthonous and related to atmospheric input. O and C isotopic compositions of the carbonates are compatible with soil temperatures and respiration rates during the beginning of the summer season. U-series disequilibrium in the carbonates suggests ages ranging between 40 to 270 ky, commensurate with the climatic cycle. The Sr isotopic signatures of spanish and moroccan calcretes are similar to those of the Quaternary marine carbonates. Assuming that only Ca-rich aerosols have been the source for calcretes of the studied regions, we propose that the wide continental plateaus exposed during glacial periods (low sea level) provided a major part of the calcic input to the soils. Semi-arid conditions of Spain and Morocco allowed the percolation and precipitation in the soil profiles to form calcretes. (author)

  10. Mercury stable isotope biogeochemistry

    International Nuclear Information System (INIS)

    Full text: Methods for high precision measurement of natural Hg isotope ratios by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) have been developed recently by our group and allow the use of Hg isotopes to trace the biogeochemistry of Hg. Mercury has seven stable isotopes ranging from 196 to 204 amu.We have found that the isotopic composition of Hg varies by both mass dependent fractionation (MDF) and mass independent fractionation (MIF). Even and odd isotopes of Hg are fractionated by mass-dependent processes, whereas odd isotopes are also fractionated in a mass-independent way by photochemical reactions. Isotope ratios are measured relative to the NIST 3133 Hg standard reference material. MDF is reported as δ202Hg (± 0.08 %o, 2 SD) which is the difference in 202Hg/198Hg between a sample and NIST 3133 in permil (%o). MIF is reported as Δ 201Hg (± 0.05 %o, 2 SD), which is the difference in 201Hg/198Hg ratio in permil from what the 201Hg/198Hg ratio would be if the fractionation were entirely mass dependent. In this presentation we summarize the range of Hg isotopic compositions of a variety of environmental and geological materials. In previous work we described biotic and abiotic laboratory fractionation experiments demonstrating the range of mass dependent and mass independent fractionation caused by mercury redox transformations in the surface environment. Thus far we have found that MIF occurs during photochemical reduction of methyl-Hg and Hg2+ following a Rayleigh-like fractionation. Bacterial reduction causes Rayleigh-like MDF but no MIF. Coastal-marine and freshwater fish from North America have positive Δ 201Hg values (0.2 to > 3 %o) reflecting transfer of methyl-Hg into the food web after partial reduction by photochemical reactions. Most coals and the organic horizons of soils from North America have negative Δ 201Hg values (-0.1 to -0.4 %o), possibly reflecting the influence of Hg that was photochemically reduced in

  11. Ensuring reliable medical isotope supply

    International Nuclear Information System (INIS)

    This paper describes the role of MDS Nordion and AECL in ensuring a reliable global supply of medical isotopes. The First part of the paper discusses the uses of medical isotopes, their importance to the medical community, and the benefits to patients of a secure supply of medical isotopes. The second part describes the role of the NRU reactor and the future role of the MAPLE reactors and New Processing Facility being commissioned at AECL's Chalk River Laboratories for production of medical isotopes to meet the world market demand for the next 40 years. MDS Nordion is the world's leading supplier of medical isotopes. These isotopes are used to conduct some 34,000 nuclear medicine procedures performed every day around the world, such as determining the severity of heart disease, the spread of cancer, and diagnosing brain disorders. These medical isotopes are currently produced primarily by AECL in the NRU reactor at Chalk River, Ontario, Canada. (author)

  12. Chromium isotope uptake in carbonates

    DEFF Research Database (Denmark)

    Rodler, Alexandra

    Chromium (Cr) is a redox sensitive element potentially capable of tracing fine-scale fluctuations of the oxygenation of Earth’s early surface environments and seawater. The Cr isotope composition of carbonates could perhaps be used as paleo-redox proxy to elucidate changes in the geological past....... Processes that potentially fractionate Cr isotopes, perhaps during deposition, burial and alteration need to be constrained.Previous studies have shown that Cr isotopes are fractionated during oxidative weathering on land, where heavy Cr isotopes are preferentially removed with Cr(VI) while residual soils...... retain an isotopically light Cr signature. Cr(VI) enriched in heavy Cr isotopes is then transported via river waters to the oceans and sequestered into marine sediments. Marine chemical sediments such asbanded iron formations and modern marine carbonates have proven useful in recording the Cr isotope...

  13. New isotope 265Bh

    International Nuclear Information System (INIS)

    A new isotope 265Bh was produced and identified at the Sector Focus Cyclotron of the Heavy Ion Research Facility in Lanzhou. This experiment was performed via the reaction of an 243Am target with 168 MeV 26Mg ions. Identification was made by observation of correlated α -particle decays between the new isotope 265Bh and its 261Db and 257Lr daughter nuclei using a set of rotating-wheels system. A total of 8 correlated decay events of 265Bh and 4 decay events of 264Bh were observed. 265Bh decays with a 0.94 -0.31+0.70 s half-life by emission of α-particles with an average energy of 9.24 ±0.05 MeV. The half-life and α decay energy of 265Bh from this experiment are in agreement with theoretical predictions. (orig.)

  14. Cyclotrons for isotope production

    International Nuclear Information System (INIS)

    Cyclotrons continue to be efficient accelerators for radioisotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  15. Isotope enrichment systems

    International Nuclear Information System (INIS)

    This patent provides a process for concentrating the heavy isotope of at least one element of the class consisting of hydrogen and oxygen by the dual temperature exchange of the heavy and light isotopes of the element between two separable fluids containing said element. One of the fluids is in the gaseous phase and the other in the liquid phase. The liquid phase is provided as a solution consisting essentially in minor molar proportion, of water and in major molar proportion, of material selected from the class consisting of the water miscible organic hydroxy and/or carboxy compounds which have a ratio of carbon atoms to their alcoholic and acidic hydroxyl groups not greater than 2

  16. Dual isotope assays

    International Nuclear Information System (INIS)

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  17. Carbon isotopes in photosynthesis

    International Nuclear Information System (INIS)

    The efficiency of photosynthesis continues to interest biochemists, biologists, and plant physiologists. Scientists interested in CO2 uptake are concerned about the extent to which the uptake rate is limited by such factors as stomatal diffusion and the chemistry of the CO2 absorption process. The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake

  18. Photochemical separation of isotopes

    International Nuclear Information System (INIS)

    A process for the photochemical separation of carbon 13 and oxygen 18 uses 123.54 nm resonance radiation from a gaseous discharge containing Kr and an inert gas to excite selectively 13C16O, 12C18O, or both with no significant excitation of 12C16O. The excited molecules react with ground state CO to yield CO2 and C3O2. The isotopically-enriched products are removed from the reactants by condensation

  19. Isotopes and agriculture

    International Nuclear Information System (INIS)

    The agriculture is defined as the art of desturbing the ecosystems in economical terms with the minimum of irreversible damage. Man survival in the biosphere will depend on its ability of using four technologies - mechanization, fertilizers, irrigation and pest disease control. The isotopes are usefull to establish means of producing more food and to preserve it; and clains of unbearable damages to the ecosystems caused by fertilizers and pesticides are not true, are presented. (author)

  20. Stable isotope laser spectroscopy

    Science.gov (United States)

    Becker, J. F.; Yaldaei, Ramil; Mckay, Christopher P.

    1989-01-01

    Recent advances in semiconductor laser technology have produced a reliable lightweight device ideally suited for a spacecraft high resolution molecular spectrometer. Lead-salt tunable diode lasers (TDL) emit in several spectral modes, each with a very narrow linewidth of -0.0003/cm. This spectral resolution is much narrower than typical Doppler broadened molecular linewidths in the mid-IR range. Thus it is possible to detect individual rotational lines within the vibrational band and measure their intensity, which can be used to determine gas concentration. The narrow spectral lines of any impurity gas tend to lie between the narrow lines of the gas of interest. This represents a major advantage over the accepted gas chromatograph mass spectrometer (GCMS) technique for measuring gas concentrations and isotope ratios. The careful and extensive gas purification procedures required to remove impurities for reliable GCMS measurements will not be required for an IR laser gas analysis. The infrared laser gas analysis technique is being developed to measure stable isotopic ratios of gases such as CO2, CH4, N2O, and NH3. This will eventually lead to development of instruments capable of in situ istopic measurements on planets such as Mars. The carbon (C-12, C-13) isotope ratio is indicative of the type of carbon fixation mechanisms (e.g., photosynthesis, respiration) in operation on a planet, while the nitrogen (N-14, N-15) isotope ratio can probably be used to date nitrogen-bearing Martian samples. The absorbance ratio of two adjacent lines of CO2 in the 2300/cm (4.3 micron) region of the spectrum was measured. The precision of the measurement is presently better than 1 percent and significant improvement is anticipated as rapid sweep-integration techniques and computer controlled data acquistion capabilities are incorporated.

  1. The isotope correlation experiment

    International Nuclear Information System (INIS)

    The ESARDA working group on Isotopic Correlation Techniques, ICT and Reprocessing Input Analysis performed an Isotope Correlation Experiment, ICE with the aim to check the feasibility of the new technique. Ten input batches of the reprocessing of the KWO fuel at the WAK plant were analysed by 4 laboratories. All information to compare ICT with the gravimetric and volumetric methods was available. ICT combined with simplified reactor physics calculation was included. The main objectives of the statistical data evaluation were detection of outliers, the estimation of random errors and of systematic errors of the measurements performed by the 4 laboratories. Different methods for outlier detection, analysis of variances, Grubbs' analysis for the constant-bias model and Jaech's non-constant-bias model were applied. Some of the results of the statistical analysis may seem inconsistent which is due to the following reasons. For the statistical evaluations isotope abundance data (weight percent) as well as nuclear concentration data (atoms/initial metal atoms) were subjected to different outlier criteria before being used for further statistical evaluations. None of the four data evaluation groups performed a complete statistical data analysis which would render possible a comparison of the different methods applied since no commonly agreed statistical evaluation procedure existed. The results prove that ICT is as accurate as conventional techniques which have to rely on costly mass spectrometric isotope dilution analysis. The potential of outlier detection by ICT on the basis of the results from a single laboratory is as good as outlier detection by costly interlaboratory comparison. The application of fission product or Cm-244 correlations would be more timely than remeasurements at safeguards laboratories

  2. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  3. Nickel isotopes and methanogens

    Science.gov (United States)

    Neubeck, A.; Ivarsson, M.

    2013-12-01

    Methanogens require Ni for their growth and as a consequence the microbial fractionation of Ni isotopes can be used as a biomarker for activity of methanogenic communities1. Anaerobic laboratory experiments was performed using methanogens to investigate methanogenic growth in a modified nutrient media2 with olivine Fo91 (5g/l) added as an additional mineral nutrient source and as the only H2 provider. One of the investigated methanogens showed an increased growth in the experiments with added olivine. There were also a close relationship between the mobilized Ni and the growth of the methanogen. Ni is an element that previously has been neglected in the study of fossilized microorganisms and their interaction with mineral substrates and, thus, there are no records or published data of Ni in association with microfossils. However, we have detected enrichments of Ni in fossilized microorganisms and ichno-fossils, respectively, from three separate locations. Ni is not present in the host rock in any of the samples. Thus, Ni is present in association with fossilized microorganisms from environments and more extensive analysis is required to understand the magnitude, uptake, preservation and fractionation of Ni in microfossils. In order to analyze Ni isotope fractionation from microbe-mineral interaction, we plan to use a high-resolution Laser-Ablation Time-of-Flight Mass Spectrometer (LMS)3. In situ profile ablation will provide detailed and localized data on fractionation patterns between microfossils and their host rock. Also, this technique will allow us to identify the change in Ni isotopic fractionation in rock samples caused by abiotic and biogenic processes in a faster and easier way and with less risk for contamination compared to the wet chemistry analyses of Ni isotopes. 1. Cameron, V., Vance, D., Archer, C. & House, C. H. A biomarker based on the stable isotopes of nickel. Proceedings of the National Academy of Sciences 106, 10944-10948 (2009). 2. Schn

  4. Therapeutic use of radioactive isotopes

    CERN Document Server

    Caroline Duc

    2013-01-01

    In December, researchers from ISOLDE-CERN, the Paul Scherrer Institute (PSI) and the Institut Laue-Langevin (ILL) published the results of an in vivo study which successfully proved the effectiveness of four terbium isotopes for diagnosing and treating cancerous tumours.   Four terbium isotopes suitable for clinical purposes. “ISOLDE is the only installation capable of supplying terbium isotopes of such purity and intensity in the case of three out of the four types used in this study,” explains Karl Johnson, a physicist at ISOLDE.  “Producing over a thousand different isotopes, our equipment offers the widest choice of isotopes in the world!” Initially intended for fundamental physics research, ISOLDE has diversified its activities over time to invest in various projects in the materials science, biochemistry and nuclear medicine fields. The proof-of-concept study has confirmed that the four terbium isotopes 149Tb, 152Tb, 155Tb produ...

  5. Laser Ablation Molecular Isotopic Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Richard E., E-mail: rerusso@lbl.gov [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Applied Spectra, Inc., 46661 Fremont Boulevard, Fremont, CA 94538 (United States); Bol' shakov, Alexander A. [Applied Spectra, Inc., 46661 Fremont Boulevard, Fremont, CA 94538 (United States); Mao Xianglei [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); McKay, Christopher P. [NASA-Ames Research Center, Moffett Field, CA 94035 (United States); Perry, Dale L.; Sorkhabi, Osman [Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)

    2011-02-15

    A new method of performing optical isotopic analysis of condensed samples in ambient air and at ambient pressure has been developed: Laser Ablation Molecular Isotopic Spectrometry (LAMIS). The technique uses radiative transitions from molecular species either directly vaporized from a sample or formed by associative mechanisms of atoms or ions in a laser ablation plume. This method is an advanced modification of a known atomic emission technique called laser-induced breakdown spectroscopy (LIBS). The new method - LAMIS - can determine not only chemical composition but also isotopic ratios of elements in the sample. Isotopic measurements are enabled by significantly larger isotopic shifts found in molecular spectra relative to atomic spectra. Analysis can be performed from a distance and in real time. No sample preparation or pre-treatment is required. Detection of the isotopes of hydrogen, boron, carbon, and oxygen are discussed to illustrate the technique.

  6. Laser Ablation Molecular Isotopic Spectrometry

    Science.gov (United States)

    Russo, Richard E.; Bol'shakov, Alexander A.; Mao, Xianglei; McKay, Christopher P.; Perry, Dale L.; Sorkhabi, Osman

    2011-02-01

    A new method of performing optical isotopic analysis of condensed samples in ambient air and at ambient pressure has been developed: Laser Ablation Molecular Isotopic Spectrometry (LAMIS). The technique uses radiative transitions from molecular species either directly vaporized from a sample or formed by associative mechanisms of atoms or ions in a laser ablation plume. This method is an advanced modification of a known atomic emission technique called laser-induced breakdown spectroscopy (LIBS). The new method — LAMIS — can determine not only chemical composition but also isotopic ratios of elements in the sample. Isotopic measurements are enabled by significantly larger isotopic shifts found in molecular spectra relative to atomic spectra. Analysis can be performed from a distance and in real time. No sample preparation or pre-treatment is required. Detection of the isotopes of hydrogen, boron, carbon, and oxygen are discussed to illustrate the technique.

  7. Isotope effects in lattice dynamics

    International Nuclear Information System (INIS)

    The large number of available stable isotopes and well developed isotope separation technology have enabled growing crystals of C, LiH, ZnO, CuCl, CuBr, Cu2O, CdS, α-Sn, Ge, Si, etc. with a controlled isotope composition. Experimental and theoretical studies provide evidence that the isotope effect has an influence on the thermal, elastic, and vibrational properties of crystals. In this paper it is shown that in Ge and C crystals isotope effect causes only weak phonon scattering whereas in LiH the scattering potential changes are so strong that they lead to experimentally observable phonon localization. It is emphasized that a systematic description of isotope effects requires that anharmonicity be taken into account. (reviews of topical problems)

  8. Isotope thermometery in nuclear multifragmentation

    OpenAIRE

    Agrawal, B. K.; Samaddar, S. K.; Sil, Tapas; J. N.

    1998-01-01

    A systematic study of the effect of fragment$-$fragment interaction, quantum statistics, $\\gamma$-feeding and collective flow is made in the extraction of the nuclear temperature from the double ratio of the isotopic yields in the statistical model of one-step (Prompt) multifragmentation. Temperature is also extracted from the isotope yield ratios generated in the sequential binary-decay model. Comparison of the thermodynamic temperature with the extracted temperatures for different isotope r...

  9. Iodine isotopes in radiation hygiene

    International Nuclear Information System (INIS)

    Radioactive iodine isotopes belong among the factors of anthropogenic contamination of the biosphere. A radiation hygiene survey is presented of literary data and the author's own results of studies of the metabolism and biological effect of radioactive isotopes of iodine. The risk of their intake by the human organism is evaluated. Particular attention is paid to 132-135I and 129I. Data on the biological danger of these isotopes are scarce in the literature. (author)

  10. Metal Stable Isotopes in Paleoceanography

    Science.gov (United States)

    Anbar, Ariel D.; Rouxel, Olivier

    2007-05-01

    Considered esoteric only a few years ago, research into the stable isotope geochemistry of transition metals is moving into the geoscience mainstream. Although initial attention focused on the potential use of some of these nontraditional isotope systems as biosignatures, they are now emerging as powerful paleoceanographic proxies. In particular, the Fe and Mo isotope systems are providing information about changes in oxygenation and metal cycling in ancient oceans. Zn, Cu, Tl, and a number of other metals and metalloids also show promise. Here we review the basis of stable isotope fractionation as it applies to these elements, analytical considerations, and the current status and future prospects of this rapidly developing research area.

  11. Advanced isotope separation

    International Nuclear Information System (INIS)

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  12. Insects, isotopes and radiation

    International Nuclear Information System (INIS)

    The sterile insect technique (SIT), which uses radiation to sexually sterilize insects and prevent reproduction, is particularly effective in eradicating harmful insects. The Joint Division of the IAEA/FAO has been involved in the use of isotopes and radiation in insect control since 1964. Efforts by the IAEA and FAO to transfer the SIT technology to developing countries are continuing by providing valuable research and development support for field projects. The cooperative SIT project against the tse tse fly was very successful in eradicating this harmful pest from the north-central Nigeria. A similar SIT project is actually underway to eradicate the Mediteranean fruit fly in Mexico

  13. Cold regions isotope applications

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids

  14. Tank waste isotope contributions

    International Nuclear Information System (INIS)

    This document presents the results of a calculation to determine the relative contribution of selected isotopes to the inhalation and ingestion doses for a postulated release of Hanford tank waste. The fraction of the dose due to 90Sr, 90Y, 137Cs and the alpha emitters for single shell solids and liquids, double shell solids and liquids, aging waste solids and liquids and all solids and liquids. An effective dose conversion factor was also calculated for the alpha emitters for each composite of the tank waste

  15. ISOTOPE FRACTIONATION PROCESS

    Science.gov (United States)

    Clewett, G.H.; Lee, DeW.A.

    1958-05-20

    A new method is described for isotopic enrichment of uranium. It has been found that when an aqueous acidic solution of ionic tetravalent uraniunn is contacted with chelate complexed tetravalent uranium, the U/sup 238/ preferentially concentrates in the complexed phase while U/sup 235/ concentrates in the ionic phase. The effect is enhanced when the chelate compound is water insoluble and is dissolved in a water-immiscible organic solvent. Cupferron is one of a number of sultable complexing agents, and chloroform is a suitable organic solvent.

  16. Cold regions isotope applications

    Energy Technology Data Exchange (ETDEWEB)

    Perrigo, L.D.; Divine, T.E.

    1976-04-01

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids. (TFD)

  17. Isotope effect and isotope separation. A chemist's view

    International Nuclear Information System (INIS)

    What causes the isotope effects (IE)? This presentation will be centered around the equilibrium isotope effects due to the differences in the nuclear masses. The occurrence of the equilibrium constant, K, of isotope exchange reactions which differ from the values predicted by the classical theory of statistical mechanics, Kcl, is explored. The non-classical K corresponds to the unit-stage separation factor, α, that is different from unity and forms a basis of an isotope separation process involving the chemical exchange reaction. Here, the word 'chemical exchange' includes not only the isotope exchange chemical reactions between two or more chemical species but also the isotope exchanges involving the equilibria between liquid and vapor phases and liquid-gas, liquid solution-gas, liquid-liquid, and solid-liquid phases. In Section I, origins of the isotope effect phenomena will be explored and, in the process, various quantities used in discussions of isotope effect that have often caused confusions will be unambiguously defined. This Section will also correlate equilibrium constant with separation factor. In Section II, various forms of temperature-dependence of IE and separation factor will be discussed. (author)

  18. Hydrogen isotope exchange reactions

    International Nuclear Information System (INIS)

    The two most widely used methods for following hydrogen isotope exchange reactions, namely dedeuteriation and detritiation, involve in the first place the synthesis of an appropriately labelled compound. Rates of dedeuteriation are usually followed by measuring changes in the 1H n.m.r. spectrum of the substrate (examples are given); the method not only gives the rate but also the site(s) of exchange. It is limited to rather slow reactions and is not as accurate as some of the other methods. The development of deuterium n.m.r. spectroscopy means that changes in the 2H n.m.r. spectrum can also be used to measure rates of dedeuteriation. The development of liquid scintillation counting greatly eased the problem of how to detect weak β emitters; the attractions of tritium as a tracer were thereby much enhanced. Nowadays the study of rates of detritiation constitutes one of the most versatile and accurate methods of following hydrogen isotope exchange. Examples of the technique are given. (U.K.)

  19. Isotope techniques for hydrology

    International Nuclear Information System (INIS)

    In the body of the Panel's report specific conclusions and recommendations are presented in the context of each subject. The general consensus of the Panel is as follows: by the study of this report, the 1961 Panel report, the Proceedings of the March 1963 Tokyo Symposium and other reports of research and technological advances, isotope-technique applications to hydrologic problems have provided some useful avenues for understanding the nature of the hydrologic cycle and in the solution of specific engineering problems. Some techniques are developed thoroughly enough for fairly routine application as tools for use in the solution of practical problems, but further research and development is needed on other concepts to determined whether or not they can be beneficially applied to either research or engineering problems. A concerted effort is required on the part of both hydrologists and isotope specialists working as teams to assure that proper synthesis of scientific advances in the respective fields and translation of these advances into practical technology is achieved

  20. Desalination and isotope hydrology

    International Nuclear Information System (INIS)

    With ever increasing demand for fresh water, the need to look at new sources of water is becoming imperative. Isotope hydrology is a powerful technique to explore such new sources of ground water and to also understand the origins of contamination of water. The sea is also becoming important as the only perennial source of water. Moreover, groundwater is increasingly becoming saline due to over-withdrawal, and there is a need to improve its quality. Desalination is the process that removes salts from water or water from salts, the end objective being fresh water. The former represents the case where it is the minor constituents that are actually removed-as, for example, in electrodialysis-whereas the latter would represent the case of removing the major constituent, i.e., water itself, distillation being the most common example. Despite the seeming attractiveness of removing minor constituents, the reality is that in most approaches to practical desalination it is the major constituent, i.e., water, which is removed. The presentation will dwell on the twin aspects of identification of newer ground water sources and also increasing the public water supply through desalination. More particularly, our focus will be on the science behind the technologies of isotope hydrology and desalination. Given that desalination requires external energy input, the available options for desalination will be shown to rest largely on the appropriateness of energy supply and the level of sophistication of operation desirable. (author)

  1. Si Isotopes of Brownleeite

    Science.gov (United States)

    Nakamura-Messenger, K.; Messenger, Scott R.; Ito, M.; Keller, L. P.; Clemett, S. J.; Jones, J. H.; Tatsuoka, H.; Zolensky, M. E.; Tatsuoka, H.

    2010-01-01

    Brownleeite is a manganese silicide, ideally stoichiometric MnSi, not previously observed in nature until its discovery within an interplanetary dust particle (IDP) that likely originated from a comet [1]. Three discrete brownleeite grains in the IDP L2055 I3 (4 microns in size, hereafter IDP I3) were identified with maximum dimensions of 100, 250 and 600 nm and fully analyzed using scanning-transmission electron microscopy (STEM) [1]. One of the grains (100 nm in size) was poikilitically enclosed by low-Fe, Mn-enriched (LIME) olivine. LIME olivine is epitaxial to the brownleeite with the brownleeite (200) parallel to the olivine c* [1]. LIME olivine is an enigmatic phase first reported from chondritic porous IDPs and some unequilibrated ordinary chondrites [ 2], that is commonly observed in chondritic-porous IDPs. Recently, LIME olivine has been also found in comet Wild-2 (Stardust) samples [3], indicating that LIME olivine is a common mineral component of comets. LIME olivine has been proposed to form as a high temperature condensate in the protosolar nebula [2]. Brownleeite grains also likely formed as high-temperature condensates either in the early Solar System or in the outflow of an evolved star or supernova explosion [1]. The isotopic composition of the brownleeite grains may strongly constrain their ultimate source. To test this hypothesis, we performed isotopic analyses of the brownleeite and the associated LIME olivine, using the NASA/JSC NanoSIMS 50L ion microprobe.

  2. Isotopic geochemistry at Wairakei

    International Nuclear Information System (INIS)

    Deuterium measurements on geothermal water at Wairakei are consistent with the water being derived from rainfall which has percolated down from the surface. The oxygen-18 content, however, is enriched compared to average rainfall. This 18O shift is due to isotopic exchange between water and rock at greater-than-explored depths. The magnitude of the shift implied that the mass ration (W/R) of water that has passed through the system (W) to the rock it has exchanged with (R) is about 1 assuming open (i.e. single-pass) conditions. (The ratio is about 2 if it has been a closed system, but this is thought to be less likely). The residence time of water underground cannot be determined from tritium and carbon-14 measurements at present, but arguments based on the argon isotope and deuterium contents suggest mean residence times of a few tens of thousand years. The water-rock ratio and large natural outflow of thermal water prior to exploitation are consistent with this. The 18O content of the water has changed only slightly, and the D content not at all, during exploitation at Wairakei (measurements from 1963, 1974 and 1981). An initial tendency for the 18O to increase because of steam loss (also shown more clearly by chloride), has been followed by decrease of 18O (and chloride) because of dilution with infiltrating near-surface water in parts of the field

  3. Laser isotope separation

    International Nuclear Information System (INIS)

    A gas mixture of 235UF6, and carrier gas is pushed through a converging - diverging nozzle with supersonic speed and is than adiabatically expanded in order to produce an oversaturated gas cooled down to about 125 K. According to the two-photon method the oversaturated mixture is a) irradiated with infrared laser light of a frequency selectively exciting only UF6 molecules containing 235U and at the same time b) irradiated with ultraviolet laser light of a frequency producing photodissociation of those UF6 molecules being selectively excited by the infrared laser light. The products of photodissociation containing 235U are separated from the non-excited UF6 according to a known method. The application of the method according to the invention is not limited to the uranium isotopes mentioned above, but extends to all uranium isotopes. The application further is not limited to fluorides of uranium. The method may be extended to all halides of uranium. (GG) 891 GG

  4. Isotope separation with improved selective ionization

    International Nuclear Information System (INIS)

    Method and apparatus for isotope separation by selective ionization of a desired isotope in an environment of plural isotopes without corresponding ionization of the other isotopes in the environment. The selective ionization is achieved through a three step excitation of atoms of the desired isotope in response to laser radiations applied to the environment. The transition for each step is selected to be less than one half the ionization potential for the isotopes to avoid two step nonselective ionization

  5. Calcium isotopes in wine

    Science.gov (United States)

    Holmden, C. E.

    2011-12-01

    The δ 44/40Ca values of bottled wine vary between -0.76% to -1.55% on the seawater scale and correlate weakly with inverse Ca concentration and Mg/Ca ratio, such that the lowest δ 44/40Ca values have the highest Ca concentrations and lowest Mg/Ca ratios. The correlation is notable in the sense that the measured wines include both whites and reds sampled from different wine growing regions of the world, and cover a wide range of quality. Trends among the data yield clues regarding the cause of the observed isotopic fractionation. White wines, and wines generally perceived to be of lower quality, have lower δ 44/40Ca values compared to red wines and wines of generally perceived higher quality. Quality was assessed qualitatively through sensory evaluation, price, and scores assigned by critics. The relationship between δ 44/40Ca and wine quality was most apparent when comparing wines of one varietal from one producer from the same growing region. In the vineyard, wine quality is related to factors such as the tonnage of the crop and the ripeness of the grapes at the time of harvesting, the thickness of the skins for reds, the age of the vines, as well as the place where the grapes were grown (terroir). Quality is also influenced by winemaking practices such as fermentation temperature, duration of skin contact, and barrel ageing. Accordingly, the relationship between δ 44/40Ca and wine quality may originate during grape ripening in the vineyard or during winemaking in the cellar. We tested the grape ripening hypothesis using Merlot grapes sampled from a vineyard in the Okanagan, British Columbia, using sugar content (degrees Brix) as an indicator of ripeness. The grapes were separated into pulp, skin, and pip fractions and were analyzed separately. Thus far, there is no clear evidence for a systematic change in δ 44/40Ca values associated with progressive ripening of grapes in the vineyard. On the day of harvesting, the δ 44/40Ca value of juice squeezed from

  6. Laser isotope separation of gadolinium

    International Nuclear Information System (INIS)

    Basic studies on laser isotope separation of gadolinium were performed. Spectroscopic data were obtained such as isotope shifts and hyperfine structures using an atomic beam. Enrichment of 157Gd up to 80% was observed by three-step photoionization experiment using linearly polarized dye lasers. Design of an separation system was discussed by the help of computer calculation of excitation dynamics. (author)

  7. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    Gaseous isotopes are separated from a mixture in a vertically elongated chamber by subjecting the mixture to a nonuniform transverse electric field. Dielectrophoretic separation of the isotopes is effected, producing a transverse temperature gradient in the chamber, thereby enhancing the separation by convective countercurrent flow. In the example given, the process and apparatus are applied to the production of heavy water from steam

  8. Boron isotopes in geothermal systems

    International Nuclear Information System (INIS)

    Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO2 boron isotope ratios from a volatile B source can also be inferred. (auth)

  9. Exotic structure of carbon isotopes

    International Nuclear Information System (INIS)

    Ground state properties of C isotopes, deformation and electromagnetic moments, as well as electric dipole transition strength are investigated. We first study the ground state properties of C isotopes using a deformed Hartree-Fock (HF) + BCS model with Skyrme interactions. Isotope dependence of the deformation properties is investigated. Shallow deformation minima are found in several neutron-rich C isotopes. It is also shown that the deformation minima appear in both the oblate and the prolate sides in 17C and 19C having almost the same binding energies. Next, we carry out shell model calculations to study electromagnetic moments and electric dipole transitions of C isotopes. We point out the clear configuration dependence of the quadrupole and magnetic moments in the odd C isotopes, which will be useful to find out the deformation and spin-parties of the ground states of these nuclei. Electric dipole states of C isotopes are studied focusing on the interplay between low energy Pigmy strength and giant dipole resonances. Low peak energies, two-peak structure and large widths of the giant resonances show deformation effects. Calculated transition strength below dipole giant resonance in heavier C isotopes than 15C is found to exhaust 12∼15% of the Thomas-Reiche-Kuhn sum rule value and 50∼ 80% of the cluster sum rule value. (author)

  10. Isotopically labelled benzodiazepines

    International Nuclear Information System (INIS)

    This paper reports on the benzodiazepines which are a class of therapeutic agents. Improvements in the analytical methodology in the areas of biochemistry and pharmacology were significant, particularly in the application of chromatographic and spectroscopic techniques. In addition, the discovery and subsequent development of tritium and carbon-14 as an analytical tool in the biological sciences were essentially post-world war II phenomena. Thus, as these new chemical entities were found to be biologically active, they could be prepared in labeled form for metabolic study, biological half-life determination (pharmacokinetics), tissue distribution study, etc. This use of tracer methodology has been liberally applied to the benzodiazepines and also more recently to the study of receptor-ligand interactions, in which tritium, carbon-11 or fluorine-18 isotopes have been used. The history of benzodiazepines as medicinal agents is indeed an interesting one; an integral part of that history is their use in just about every conceivable labeled form

  11. Container for hydrogen isotopes

    International Nuclear Information System (INIS)

    A container for the storage, shipping and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same which has compactness, which is safe against fracture or accident, and which is reusable is described. The container consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example, of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and will be retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates

  12. Container for hydrogen isotopes

    Science.gov (United States)

    Solomon, David E.

    1977-01-01

    A container for the storage, shipping and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same which has compactness, which is safe against fracture or accident, and which is reusable. The container consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example, of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and will be retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates.

  13. Review of RBE and OER values for Cf-neutrons

    International Nuclear Information System (INIS)

    Californium-252, an isotope emitting neutrons, gamma photons and alpha particles, is being investigated for its practical use in intracavitary and interstitial brachytherapy. A review of published RBE and OER values for californium neutrons as a function of dose rate for a variety of biological endpoints is given. (Auth.)

  14. Radioactive and stable isotope geology

    International Nuclear Information System (INIS)

    Aimed at post-graduate and post-doctoral researchers in geochemistry, this book reflects the rapid changes in the applications of radioactive and stable isotope analysis to a range of geological and geochemical problems. Isotropic chemistry and methods used in mass spectroscopy are discussed initially. The second section deals with radiometric dating methods. The role of isotopes in climate and environmental research is also explored. The book closes with a section on extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth's lithosphere. (UK)

  15. Compelling Research Opportunities using Isotopes

    International Nuclear Information System (INIS)

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1) medicine

  16. Compelling Research Opportunities using Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-04-23

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1

  17. Apparatus and process for separating hydrogen isotopes

    Science.gov (United States)

    Heung, Leung K; Sessions, Henry T; Xiao, Xin

    2013-06-25

    The apparatus and process for separating hydrogen isotopes is provided using dual columns, each column having an opposite hydrogen isotopic effect such that when a hydrogen isotope mixture feedstock is cycled between the two respective columns, two different hydrogen isotopes are separated from the feedstock.

  18. Isotope dilution mass spectrometry

    Science.gov (United States)

    Heumann, Klaus G.

    1992-09-01

    In the past isotope dilution mass spectrometry (IDMS) has usually been applied using the formation of positive thermal ions of metals. Especially in calibrating other analytical methods and for the certification of standard reference materials this type of IDMS became a routine method. Today, the progress in this field lies in the determination of ultra trace amounts of elements, e.g. of heavy metals in Antarctic ice and in aerosols in remote areas down to the sub-pg g-1 and sub-pg m-3 levels respectively, in the analysis of uranium and thorium at concentrations of a few pg g-1 in sputter targets for the production of micro- electronic devices or in the determination of sub-picogram amounts of230Th in corals for geochemical age determinations and of226Ra in rock samples. During the last few years negative thermal ionization IDMS has become a frequently used method. The determination of very small amounts of selenium and technetium as well as of other transition metals such as vanadium, chromium, molybdenum and tungsten are important examples in this field. Also the measurement of silicon in connection with a re-determination of Avogadro's number and osmium analyses for geological age determinations by the Re/Os method are of special interest. Inductively-coupled plasma mass spectrometry is increasingly being used for multi-element analyses by the isotope dilution technique. Determinations of heavy metals in samples of marine origin are representative examples for this type of multi-element analysis by IDMS. Gas chromatography-mass spectrometry systems have also been successfully applied after chelation of metals (for example Pt determination in clinical samples) or for the determination of volatile element species in the environment, e.g. dimethyl sulfide. However, IDMS--specially at low concentration levels in the environment--seems likely to be one of the most powerful analytical methods for speciation in the future. This has been shown, up to now, for species of

  19. Alignments in the nobelium isotopes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Zie; XU Fu-Rong; YUAN Cen-Xi; QI Chong

    2009-01-01

    Total-Routhian-Surface calculations have been performed to investigate the deformation and align-ment properties of the No isotopes. It is found that normal deformed and superdeformed states in these nuclei can coexist at low excitation energies. In neutron-deficient No isotopes, the superdeformed shapes can even become the ground states. Moreover, we plotted the kinematic moments of inertia of the No isotopes, which follow very nicely available experimental data. It is noted that, as the rotational frequency increases, align-ments develop at hω=0.2-0.3 MeV. Our calculations show that the occupation of the vj orbital plays an important role in the alignments of the No isotopes.

  20. Isotope analysis in petroleum exploration

    International Nuclear Information System (INIS)

    The study about isotopic analysis in petroleum exploration performed at Petrobras Research Center is showed. The results of the petroleum recuperation in same Brazilian basin and shelves are comented. (L.H.L.L.)

  1. Atlas of isotope hydrology - Africa

    International Nuclear Information System (INIS)

    Although there are abundant water resources in Africa - about 17 large rivers and 160 lakes greater than 27 km2 - most of these resources are located in the humid and sub-humid regions around the equator. The surface runoff in Africa, on average, is much lower than average precipitation as a result of high evaporation and evapotranspiration, resulting in endemic drought in parts of the continent. Consequently, groundwater is a very important resource for Africa, providing nearly two-thirds of drinking water on the continent, and an even greater proportion in northern Africa. Despite the importance of groundwater for many societies, there is a lack of corresponding public concern about its protection, perhaps because the extent and availability of groundwater are not easily measured. The impact of increasing degrees of temporal and spatial climatic variability on water resources is also an important consideration, and groundwater to some extent provides an opportunity to mitigate the impacts of climate change. Applications of isotopes in hydrology are based on the general concept of 'tracing', in which naturally occurring or environmental isotopes (either radioactive or stable) are used to study hydrological processes on large temporal and spatial scales through their natural distribution in a hydrological system. Thus, environmental isotope methodologies are unique in regional studies of water resources to obtain integrated characteristics of groundwater systems. The most frequently used environmental isotopes include those of the water molecule, hydrogen (2H or D, also called deuterium, and 3H, also called tritium) and oxygen (18O), as well as of carbon (13C and 14C, also called radiocarbon or carbon-14) occurring in water as constituents of dissolved inorganic and organic carbon compounds. 2H, 13C and 18O are stable isotopes of the respective elements, whereas 3H and 14C are radioactive isotopes. Among the most important areas where isotopes are useful in

  2. Isotope-based quantum information

    CERN Document Server

    G Plekhanov, Vladimir

    2012-01-01

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial...

  3. Nuclear deformation of lutetium isotopes

    CERN Document Server

    Ekström, C

    1974-01-01

    For odd-A lutetium isotopes the ground-state equilibrium deformations ( epsilon , epsilon /sub 4/) and the Nilsson model Z=71 single proton levels in an ( epsilon , epsilon /sub 4/)-representation are considered.

  4. Special isotope production and separations

    International Nuclear Information System (INIS)

    Operations and production of transuranium elements (Cf, Es) at the Transuranium Processing Plant (TRU) are reported. Isotopic separations of Pu, Tl, Zn, Te, and Pb are reported. Separator R and D were conducted for Xe, Ti, Hg, and Tl

  5. Isotopes and radiations in agriculture

    International Nuclear Information System (INIS)

    Some of the spectacular advances in agriculture in developing nations have stimulated wide interest both in basic as well as adaptive research and in harnessing all the tools that science can offer for progress of agriculture. The nuclear tools are relevant in this respect and also offer particular promise in some areas. Ionising radiations and isotopes have immense applications in agriculture. Both radioisotopes and stable isotopes are being used

  6. Neutron skin in Osmium isotopes

    International Nuclear Information System (INIS)

    Here we have made an attempt to calculate neutron skin thickness in rare earth even-even osmium isotopes. The selected isotopes ranges from 2-p to 2-n drip line. Neutron skin is an important feature of neutron rich nuclei. The ground state proton and neutron rms radii have been calculated using HFB approximation. A comparison of calculated radii have been done by using two different Skyrme parameterizations and two different basis

  7. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    This invention relates to a process for the separation of gaseous isotopes by electrophoresis assisted by convective countercurrent flow and to an apparatus for use in the process. The invention is especially applicable to heavy water separation from steam; however, it is to be understood that the invention is broadly applicable to the separation of gaseous isotopes having different dipole moments and/or different molecular weights. (author)

  8. New berkelium isotope: 242Bk

    International Nuclear Information System (INIS)

    A new isotope of berkelium, 242Bk, was produced with a cross section of approx. 10 μb in reactions of boron on uranium and nitrogen on thorium. It decays by electron capture with a half-life of 7 +- 1.3 minutes. The branching ratio for this isotope for alpha decay is less than 1% and that for spontaneous fission is less than 0.03%. 2 figures, 2 tables

  9. Photo-induced isotopic fractionation

    OpenAIRE

    Miller, Charles E.; Yung, Yuk L.

    2000-01-01

    This paper presents a systematic method for the analysis of photo-induced isotopic fractionation. The physical basis for this fractionation mechanism centers on the fact that isotopic substitution alters the energy levels, molecular symmetries, spin statistical weights and other fundamental molecular properties, producing spectroscopic signatures distinguishable from that of the parent isotopomer. These mass-dependent physical properties are identical to those invoked by Urey to explain stabl...

  10. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13C, 15N, and 2H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2H, 13C, and 15N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  11. Isotope effects in photochemical rearrangements

    International Nuclear Information System (INIS)

    Taking anthracene resp. 9-deuteroanthracene as the initial substance, different substitution products have been prepared. The products originating by direct photolysis have been characterized and their structure has been determined. By comparing the measured kinetic isotope effect and the quantum yield of the nondeuterated and the monodeuterated fluorenes formed it could been demonstrated that the isotope effect mainly is due to the reaction rates and the influence of the deuterium substitution upon the radiationless desactivation against that is small. (HBR)

  12. Isotope ratio mass spectrometry in oceanic studies

    International Nuclear Information System (INIS)

    Isotope ratio mass spectrometry (IRMS) is an important and well established method in many scientific fields as analytical chemistry (isotope dilution MS), physical chemistry, nuclear sciences and technology, environmental, agricultural, geological isotope dating, archaeometric, cosmic, bioavailability and nutrition studies, food authentication and adulteration control, elucidation of chemical reaction mechanism, isotope effect studies on chemical reactions and isotope enrichment/separation processes. This paper is aimed to provide a brief summary of IRMS contribution to sea and oceanic studies

  13. Isotope-based quantum information

    International Nuclear Information System (INIS)

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial distribution of isotopes with nuclear spins is a prerequisite to implement the quantum bits (or qbits). Therefore, stable semiconductor isotopes are important elements in the development of solid-state quantum information. There are not only different algorithms of quantum computation discussed but also the different models of quantum computers are presented. With numerous illustrations this small book is of great interest for undergraduate students taking courses in mesoscopic physics or nanoelectronics as well as quantum information, and academic and industrial researches working in this field.

  14. Isotopic study of Karst water

    International Nuclear Information System (INIS)

    Measurement of the isotopic composition of water formed part of an extended investigation of the water drainage system in the Slovenian Karst. These studies were planned to complement geological and speleological investigations which are already being performed in this area, with the knowledge of the mechanism of changes in the isotopic composition of water in the natural environment on some smaller locations, Planina cave near Postojna where the vertical percolation of meteoric water through the karstified carbonate ceiling was studied and the water catchment areas of some small rivers, Ljubljanica, Rizana and Idrijca. Mass spectrometric investigations of the isotopic composition of some elements (18O, D, 13C and T) in water and in dissolved carbonates, as well as the isotopic composition of 18O and 13C in cave carbonates were performed. The results allow to conclude that the waters in karst aquifers in spite of producing the homogenisation to a great extent, qualitative determination of the retention time and of the prevailing sources for some springs and surface and underground water flows is nevertheless possible. The isotopic composition of 18O in water and of 18O and 13C in dissolved carbonates depends on climatic conditions and on denudation processes. The investigation of cave carbonates revealed that they have different isotopic compositions of 18O and 13C because of different locations and also different ages

  15. Insects, isotopes and radiations

    International Nuclear Information System (INIS)

    The IAEA activity on coordinating the IAEA member-state efforts in the field of pest control is considered. A complex program of agricultural pest control (IPM), applied in many parts of the world is developed. The program provides for the use of natural means of control and cases of critical pest numbers-the use of insecticides. When controlling certain types of insects it is advisable to apply the 'large area control' methods which provide for the insect destruction in places of their concentration prior to migration. Methods of pest control over large areas also include radiation sexual sterilization method (SSM), application of insect phoromons (sexual attractants) to prevent mating, other types of chemical attractants, traps, mass cultivation and reproduction of parasite plants and animals, destroying insects, as well as improvement of host-plant resistance. A great attention is paid to isotope and radiation application in pest control (labelling, sexual sterilization using ionising radiation, radiation application in genetic engineering, mutant plant cultivation)

  16. Hydrogen isotope technology

    International Nuclear Information System (INIS)

    Hydrogen pumping speeds on panels of molecular sieve types 5A and Na-Y were compared for a variety of sieve (and chevron) temperatures between 10 and 30 K. Although pumping speeds declined with time, probably because of the slow diffusion of hydrogen from the surface of the sieve crystals into the internal regions, the different sieve materials and operating conditions could be compared using time-averaged pump speeds. The (average) pumping speeds declined with increasing temperature. Under some conditions, the Na-Y sieve performed much better than the 5A sieve. Studies of the effect of small concentrations (approx. 4%) of hydrogen on helium pumping indicate that compound cryopumps in fusion reactors will not have to provide complete screening of hydrogen from helium panels. The concentrations of hydrogen did not lower effective helium pumping speeds or shorten the helium operating period between instabilities. Studies of tritium recovery from blankets of liquid lithium focused on design and construction of a flowing-lithium test system and on ultimate removal of tritium from yttrium sorbents. At 5050C, tritium release from yttrium behaves as a diffusion-controlled process, but the release rates are very low. Apparently, higher temperatures will be required for effective sorbent regeneration. An innovative technique for separating hydrogen isotopes by using bipolar electrolysis with permeable electrodes was analyzed to determine its potential usefulness in multistage separation

  17. ITER isotope separation system

    International Nuclear Information System (INIS)

    This document presents the results of a study that examined the technical operating and economic viability of an alternative Isotope Separation System (ISS) design based on the distributed design concept. In the distributed design, the ISS is broken up into local independently operable subsystems matched to local processing requirements. The distributed design accepts the same feeds and produces essentially the same products as the reference design. The distributed design consists of two separate, independent subsystems. The first, called ISS-H, receives only protium-dominated streams and waste water from tritium extraction. It has two cryogenic distillation columns and can produce a 50 percent D, 50 percent T product since it lacks D/T separation capability. A final 80 percent T2 concentration product can be obtained by blending the 50 percent T2 stream from ISS-H with the more than 99 percent T2 stream from the second subsystem, ISS-D. The second subsystem receives only deuterium-dominated feeds, which also contain some protium. ISS-D is as complex as the reference design, but smaller. Although each subsystem has some advantages, such as only two cryogenic distillation columns in ISS-H and better than 99 percent steady state T2 product in ISS-D, the combined subsystems do not offer any real advantage compared to the reference IISS. The entire distributed ISS design has been simulated using Ontario Hydro's FLOSHEET steady state process simulator. Dynamic analysis has not been done for the distributed design. (10 refs., 3 figs., 8 tabs.)

  18. Recent applications of isotope geothermometers

    International Nuclear Information System (INIS)

    Isotopic geothermometers relative to H-O-C stable isotopes in the gas mixture of geothermal fluids were applied in the Larderello area during 1978 within a programme sponsored by the IAEA. The reservoir temperatures obtained differed depending on the isotopic exchange reaction used. Figure 1 shows the differences between calculated (Ti) and measured (Tm) temperatures for selected geothermal wells spread over the field. Depending on the different kinetics of the isotopic exchange reactions considered, Δ(CO2-H2O) gives very similar values to those measured at the well head and Δ(CH4-CO2) shows the strongest deviations (up to 170 deg. C). The CH4-H2 and H2O- H2 pairs are in an intermediate position, with values that are 100 and 40 deg. C higher respectively than the measured ones. The last two groups of temperatures were considered useful for evaluating thermal conditions in the deepest part of the geothermal reservoir. Incongruent results were obtained in 1986 from the application of the same geothermometers to the gas mixtures delivered from the seven productive wells in the Larderello area. A contrasting pattern with respect to the results presented is shown. The geothermometers indicate temperature values lower than those observed at the surface, with the exception of Δ(CH4-CO2), which nevertheless gives values that are generally lower than the 1978 data. This discrepancy may be due either to isotopic disequilibrium conditions at depth or to different thermal conditions in certain parts of the reservoir. Changes in the physico-chemical conditions of the geothermal reservoir may be ascribed to: (1) the effect of continual exploitation of the steam, which may determine pressure differentials between the reservoir and surrounding groundwater; (2) the effect of reinjection of waste waters into the field, a process occurring in the Larderello area since the end of the 1970s. Although the seven wells studied were selected so as to avoid any direct influence of the

  19. Exotic Structure of Carbon Isotopes

    CERN Document Server

    Suzuki, T; Hagino, K; Suzuki, Toshio; Sagawa, Hiroyuki; Hagino, Kouichi

    2002-01-01

    We studied firstly the ground state properties of C-isotopes using a deformed Hartree-Fock (HF)+ BCS model with Skyrme interactions. Shallow deformation minima are found in several neutron$-$rich C-isotopes. It is shown also that the deformation minima appear in both the oblate and the prolate sides in $^{17}$C and $^{19}$C having almost the same binding energies. Secondly, we carried out shell model calculations to study electromagnetic moments and electric dipole transitions of the C-isotopes. We point out the clear configuration dependence of the quadrupole and magnetic moments in the odd C-isotopes, which will be useful to find out the deformations and the spin-parities of the ground states of these nuclei. We studied electric dipole states of C-isotopes focusing on the interplay between low energy Pigmy strength and giant dipole resonances. Reasonable agreement is obtained with available experimental data for the photoreaction cross sections both in the low energy region below $\\hbar \\omega $=14 MeV and ...

  20. Handbook of environmental isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baskaran, Mark (ed.) [Wayne State Univ., Detroit, MI (United States). Dept. Geology

    2011-07-01

    Applications of radioactive and stable isotopes have revolutionized our understanding of the Earth and near-earth surface processes. The utility of the isotopes are ever-increasing and our sole focus is to bring out the applications of these isotopes as tracers and chronometers to a wider audience so that they can be used as powerful tools to solve environmental problems. New developments in this field remain mostly in peer-reviewed journal articles and hence our goal is to synthesize these findings for easy reference for students, faculty, regulators in governmental and non-governmental agencies, and environmental companies. While this volume maintains its rigor in terms of its depth of knowledge and quantitative information, it contains the breadth needed for wide variety problems and applications in the environmental sciences. This volume presents all of the newer and older applications of isotopes pertaining to the environmental problems in one place that is readily accessible to readers. This book not only has the depth and rigor that is needed for academia, but it has the breadth and case studies to illustrate the utility of the isotopes in a wide variety of environments (atmosphere, oceans, lakes, rivers and streams, terrestrial environments, and sub-surface environments) and serves a large audience, from students and researchers, regulators in federal, state and local governments, and environmental companies. (orig.)

  1. Nickel isotopes in stellar matter

    Energy Technology Data Exchange (ETDEWEB)

    Nabi, Jameel-Un [GIK Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences, Swabi, Khyber Pakhtunkhwa (Pakistan); The Abdus Salam ICTP, Trieste (Italy)

    2012-06-15

    Isotopes of nickel play a key role during the silicon burning phase up to the presupernova phase of massive stars. Electron capture rates on these nickel isotopes are also important during the phase of core contraction. I present here the microscopic calculation of ground- and excited-states Gamow-Teller (GT) strength distributions for key nickel isotopes. The calculation is performed within the frame-work of the pn-QRPA model. A judicious choice of model parameters, specially of the Gamow-Teller strength parameters and the deformation parameter, resulted in a much improved calculation of GT strength functions. The excited-state GT distributions are much different from the corresponding ground-state distributions resulting in a failure of the Brink's hypothesis. The electron capture and positron decay rates on nickel isotopes are also calculated within the framework of pn-QRPA model relevant to the presupernova evolution of massive stars. The electron capture rates on odd-A isotopes of nickel are shown to have dominant contributions from parent excited states during as early as silicon burning phases. Comparison is being made with the large-scale shell model calculation. During the silicon burning phases of massive stars the electron capture rates on {sup 57,} {sup 59}Ni are around an order of magnitude bigger than shell model rates and can bear consequences for core-collapse simulators. (orig.)

  2. Nickel isotopes in stellar matter

    CERN Document Server

    Nabi, Jameel-Un

    2014-01-01

    Isotopes of nickel play a key role during the silicon burning phase up to the presupernova phase of massive stars. Electron capture rates on these nickel isotopes are also important during the phase of core contraction. I present here the microscopic calculation of ground and excited states Gamow-Teller (GT) strength distributions for key nickel isotopes. The calculation is performed within the frame-work of pn-QRPA model. A judicious choice of model parameters, specially of the Gamow-Teller strength parameters and the deformation parameter, resulted in a much improved calculation of GT strength functions. The excited state GT distributions are much different from the corresponding ground-state distributions resulting in a failure of the Brink's hypothesis. The electron capture and positron decay rates on nickel isotopes are also calculated within the framework of pn-QRPA model relevant to the presupernova evolution of massive stars. The electron capture rates on odd-A isotopes of nickel are shown to have dom...

  3. Process for separating zirconium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, P.T.; Lahoda, E.J.; Burgman, H.A.

    1986-04-22

    A method is described of separating a feed stream consisting essentially of an aqueous solution of a mixture of /sup 90/Zr and /sup 91 to 96/Zr salts selected from group consisting of thiocyanate, nitrate, sulfate, chloride, perchlorate, and mixtures thereof, into two aqueous product streams, each containing both a /sup 90/Zr isotopic portion and a /sup 91 to 96/Zr isotopic portion, but in different ratios. The method consists of: (A) contacting the feed stream with methylisobutyl ketone or an organic water-immiscible solvent containing an extractant medium selected from the group consisting of quaternary ammonium salts, organic phosphonates, organic phosphinates, organic phosphates, organic sulfonates, primary amines, tertiary amines, polyethers, betadiketones, and mixtures thereof, that preferentially extracts one of the isotopic portions, leaving an aqueous raffinate depleted in that isotopic portions and enriched in the other isotopic portion; (B) stripping the organic solvent of its zirconium with an aqueous acidic strip medium to produce a first aqueous product stream; (C) recycling the stripped organic solvent to step (A); (D) evaporating water from a portion of the aqueous raffinate to produce a concentrated aqueous raffinate and a second aqueous product stream; and (E) recycling the concentrated aqueous raffinate to the feed stream.

  4. Isotopes a very short introduction

    CERN Document Server

    Ellam, Rob

    2016-01-01

    An isotope is a variant form of a chemical element, containing a different number of neutrons in its nucleus. Most elements exist as several isotopes. Many are stable while others are radioactive, and some may only exist fleetingly before decaying into other elements. In this Very Short Introduction, Rob Ellam explains how isotopes have proved enormously important across all the sciences and in archaeology. Radioactive isotopes may be familiar from their use in nuclear weapons, nuclear power, and in medicine, as well as in carbon dating. They have been central to establishing the age of the Earth and the origins of the solar system. Combining previous and new research, Ellam provides an overview of the nature of stable and radioactive isotopes, and considers their wide range of modern applications. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subjec...

  5. Opportunities for isotope discoveries at FRIB

    Science.gov (United States)

    Baumann, T.; Hausmann, M.; Sherrill, B. M.; Tarasov, O. B.

    2016-06-01

    Expected production yields of the Facility for Rare Isotope Beams (FRIB) were calculated for a wide range of rare isotopes using the code LISE++ and planned performance parameters (Tarasov and Bazin, 2008; Bollen et al., 2011 [2]). A comparison between isotope discoveries of the last decade and expected particle yields indicates the range of isotopes that can likely be detected at FRIB. This paper will highlight recent isotope discoveries at NSCL's Coupled Cyclotron Facility and deduce how far the limits could be pushed with the Facility for Rare Isotope Beams.

  6. Process and apparatus for isotopic enrichment

    International Nuclear Information System (INIS)

    Process and apparatus for separating an isotope of an element from other isotopes of the element in a compound, where the compound is deposited as a monolayer on small beads, and the coated beads entrained in a carrier gas containing a scavenger gas. The entrained, coated beads are exposed to light e.g. from a laser that excites the one isotopic compound and causes reaction thereof with the scavenger gas, to form a reaction product, while the other isotopic compounds remain stable. The other isotopic compounds are then separated from the reaction product and the reaction product removed from the beads to provide the desired isotope. (author)

  7. Isotopes in chemical analysis for water management

    International Nuclear Information System (INIS)

    Surface or underground water circulations and interactions are more and more often studied with the help of geochemistry and more particularly by using isotopic tracers. These isotopic tracer techniques allow, in particular, to define for each system under study, the natural or anthropic origin of the chemical elements, their behaviour, their transport in the different compartments, the circulation schemes of deep fluids and their interaction with the surrounding rocks. This article presents: 1 - the isotopes: definition, measurements and uses (stable and instable isotopes, measurement means, some examples: stable isotopes of the water molecule, boron isotopes, sulfur and oxygen isotopes of sulfates, strontium isotopes, nitrogen isotopes of nitrates); 2 - isotopes and water cycle: atmospheric tracing (rainfall signal at the drainage basin scale and at the country scale, aerosols characterization in urban areas), management of alluvial aquifers, underground waters and origin of nitrogenous contaminations, underground and surface waters in the context of aquifer floods: the case of the Somme basin, underground waters at the basin scale: heterogeneities, interactions and management processes (stable isotopes of the water molecule, S and O isotopes of dissolved sulfates, strontium isotopes); 3 - conclusion. (J.S.)

  8. Oak Ridge National Laboratory's isotope enrichment program

    International Nuclear Information System (INIS)

    The Isotope Enrichment Program (IEP) at Oak Ridge National Laboratory (ORNL) is responsible for the production and distribution of ∼225 enriched stable isotopes from 50 multi-isotopic elements. In addition, ORNL distributes enriched actinide isotopes and provides extensive physical- and chemical-form processing of enriched isotopes to meet customer requirements. For more than 50 yr, ORNL has been a major provider of enriched isotopes and isotope-related services to research, medical, and industrial institutions throughout the world. Consolidation of the Isotope Distribution Office (IDO), the Isotope Research Materials Laboratory (IRML), and the stable isotope inventories in the Isotope Enrichment Facility (IEF) have improved operational efficiencies and customer services. Recent changes in the IEP have included adopting policies for long-term contracts, which offer program stability and pricing advantages for the customer, and prorated service charges, which greatly improve pricing to the small research users. The former U.S. Department of Energy (DOE) Loan Program has been converted to a lease program, which makes large-quantity or very expensive isotopes available for nondestructive research at a nominal cost. Current efforts are being pursued to improve and expand the isotope separation capabilities as well as the extensive chemical- and physical-form processing that now exists. The IEF's quality management system is ISO 9002 registered and accredited in the United States, Canada, and Europe

  9. Isotopic composition of past precipitation

    International Nuclear Information System (INIS)

    The distribution of stable isotopes in precipitation provides critical quantitative information about the global water cycle. The first PAGES/IAEA ISOMAP workshop was held at the IAEA headquarters in Vienna, 24-26 August 1998, which gathered 32 participants. The presentation and discussions demonstrated that a high level of sophistication already exists in the development of transfer functions between measured parameters and precipitation, as a result of the extensive use of water isotope tracers in paleo-environmental investigations, but a major challenge facing both producers and users of paleo-isotope data is the effective management of data and meta-data, to permit ready retrieval of raw and inferred data for comparison and reinterpretation. This will be in important goal of future ISOMAP activities. The critical need for more paleo-data from low latitudes was clearly recognized

  10. Lithium isotopic separation: preliminary studies

    International Nuclear Information System (INIS)

    In order to get the separation of natural isotopes of lithium by electrolytic amalgamation, an electrolytic cell with a confined mercury cathode was used to obtain data for the design of a separation stage. The initial work was followed by the design of a moving mercury cathode electrolytic cell and three experiments with six batches stages were performed for the determination of the elementary separation factor. The value obtained, 1.053, was ill agreement: with the specialized literature. It was verified in all experiments that the lithium - 6 isotope concentrated in the amalgam phase and that the lithium - 7 isotope concentrated in the aqueous phase. A stainless-steel cathode for the decomposition of the lithium amalgam and the selective desamalgamation were also studied. In view of the results obtained, a five stages continuous scheme was proposed. (author)

  11. Non-linear Isotope Effects

    DEFF Research Database (Denmark)

    Schmidt, Johan Albrecht

    The isotopic fractionation associated with photodissociation of N2O, OCS and CO2, at different altitudes in Earth’s atmosphere, is investigated theoretically using constructed quantum mechanical models of the dissociation processes (i.e. potential energy surfaces and relevant coupling elements for......’s stratosphere is nearly mass dependent, and only a small fraction of the observed anomalous oxygen-17 excess can be attributed to N2O photolysis. In contrast, stratospheric photolysis produces a significant inverse clumped isotope effect.(ii) Stratospheric OCS photolysis significantly enrich the remaining OCS...... or moderate, and overall sulfur fractionation in the stratosphere is very weak which does not exclude OCS from being an acceptable background the Stratospheric Sulfate Aerosol layer. (iii) CO2 photolysis in the upper stratosphere and lower mesosphere is highly fractionating in both isotopes...

  12. Photonuclear reactions on titanium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Belyshev, S. S. [Moscow State University (Russian Federation); Dzhilavyan, L. Z. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Ishkhanov, B. S.; Kapitonov, I. M. [Moscow State University (Russian Federation); Kuznetsov, A. A., E-mail: kuznets@depni.sinp.msu.ru; Orlin, V. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2015-03-15

    The photodisintegration of titanium isotopes in the giant-dipole-resonance energy region is studied by the photon-activation method. Bremsstrahlung photons whose spectrum has the endpoint energy of 55 MeV is used. The yields and integrated cross sections are determined for photoproton reactions on the titanium isotopes {sup 47,48,49,50}Ti. The respective experimental results are compared with their counterparts calculated on the basis of the TALYS code and a combined photonucleon-reaction model. The TALYS code disregards the isospin structure of the giant dipole resonance and is therefore unable to describe the yield of photoproton reactions on the heavy titanium isotopes {sup 49,50}Ti.

  13. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  14. Plasma oscillation and isotope effect

    International Nuclear Information System (INIS)

    Superconducting isotropic crystal is presented by two subsystems in terms of anharmonic oscillation model. The superconducting energy gap below the phase transition temperature is deduced by the free electron plasma energy. The anisotropic nature of the materials is appeared by the superconducting gaps in x, y, z directions. The phase transition temperature-square plasma energy relation is established. The observed facts for high temperature superconductors are consistent with the plasma theory. The isotope phase transition temperature shift is connected with the plasma energy. The fixing temperature divided by the phase transition temperature is the function of the molecular mass divided by effective mass density. The phase transition temperature depends on the interaction parameter. The equations for mercury and MgB2 isotopes are given. The interaction parameters reduce with the phase transition temperature rise. The isotope distinctions in the superconducting lines are explained. The phonon mechanism is concluded to be special case of the plasma mechanism

  15. Plasma oscillation and isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Netesova, Nadezhda P. [M.V. Lomonosov Moscow State University, Physics Faculty, LTPS Department, Moscow 119992 (Russian Federation)], E-mail: npn@mig.phys.msu.ru

    2007-09-01

    Superconducting isotropic crystal is presented by two subsystems in terms of anharmonic oscillation model. The superconducting energy gap below the phase transition temperature is deduced by the free electron plasma energy. The anisotropic nature of the materials is appeared by the superconducting gaps in x, y, z directions. The phase transition temperature-square plasma energy relation is established. The observed facts for high temperature superconductors are consistent with the plasma theory. The isotope phase transition temperature shift is connected with the plasma energy. The fixing temperature divided by the phase transition temperature is the function of the molecular mass divided by effective mass density. The phase transition temperature depends on the interaction parameter. The equations for mercury and MgB{sub 2} isotopes are given. The interaction parameters reduce with the phase transition temperature rise. The isotope distinctions in the superconducting lines are explained. The phonon mechanism is concluded to be special case of the plasma mechanism.

  16. Isotope specific arbitrary material sorter

    Energy Technology Data Exchange (ETDEWEB)

    Barty, Christopher P.J.

    2015-12-08

    A laser-based mono-energetic gamma-ray source is used to provide a rapid and unique, isotope specific method for sorting materials. The objects to be sorted are passed on a conveyor in front of a MEGa-ray beam which has been tuned to the nuclear resonance fluorescence transition of the desired material. As the material containing the desired isotope traverses the beam, a reduction in the transmitted MEGa-ray beam occurs. Alternately, the laser-based mono-energetic gamma-ray source is used to provide non-destructive and non-intrusive, quantitative determination of the absolute amount of a specific isotope contained within pipe as part of a moving fluid or quasi-fluid material stream.

  17. Natural fractionation of uranium isotopes

    International Nuclear Information System (INIS)

    The topic of this thesis was the investigation of U (n(238U) / n(235U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n(238U) and n(235U), on Earth.

  18. Method for separation of isotopes

    International Nuclear Information System (INIS)

    The initial material UCl6 flows through the separation facility in vaporous form, the mixture of isotopes being selectively excited by means of lasers. Separation of the excited molecules is done chemically or physically. The non-excited molecules get to an isotope balancing section, where the chlorine gas is supplied in natural composition with a quantitative ratio of 76 : 24 for 35Cl : 37Cl, and the UCl6 is restored to its original composition. This cycle is repeated for enrichment of 235U or 238U. (DG)

  19. Electron scattering off palladium isotopes

    International Nuclear Information System (INIS)

    The low-lying states of the even Pd isotopes are characterized by vibrator-like properties. In this thesis the results of an electron scattering experiment on the Pd isotopes, designed to study the description of such nuclei in the Anharmonic Vibrator Model (AVM) and the Interacting Boson Approximation (IBA), are presented and discussed. Data have been taken at the high-resolution electron scattering facility of NIKHEF-K and covered a momentum-transfer range of 0.4 to 2.5 fm-1. (Auth.)

  20. Feasibility of Isotopic Measurements: Graphite Isotopic Ratio Method

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Thomas W.; Gerlach, David C.; Reid, Bruce D.; Morgan, W. C.

    2001-04-30

    This report addresses the feasibility of the laboratory measurements of isotopic ratios for selected trace constituents in irradiated nuclear-grade graphite, based on the results of a proof-of-principal experiment completed at Pacific Northwest National Laboratory (PNNL) in 1994. The estimation of graphite fluence through measurement of isotopic ratio changes in the impurity elements in the nuclear-grade graphite is referred to as the Graphite Isotope Ratio Method (GIRM). Combined with reactor core and fuel information, GIRM measurements can be employed to estimate cumulative materials production in graphite moderated reactors. This report documents the laboratory procedures and results from the initial measurements of irradiated graphite samples. The irradiated graphite samples were obtained from the C Reactor (one of several production reactors at Hanford) and from the French G-2 Reactor located at Marcoule. Analysis of the irradiated graphite samples indicated that replicable measurements of isotope ratios could be obtained from the fluence sensitive elements of Ti, Ca, Sr, and Ba. While these impurity elements are present in the nuclear-grade graphite in very low concentrations, measurement precision was typically on the order of a few tenths of a percent to just over 1 percent. Replicability of the measurements was also very good with measured values differing by less than 0.5 percent. The overall results of this initial proof-of-principal experiment are sufficiently encouraging that a demonstration of GIRM on a reactor scale basis is planned for FY-95.

  1. Recent development in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Within the limited of this review the following topics will be briefly discussed: a) Accuracy, precision, internal relative standard deviation (RISD) and external relative standard deviation (RESD) of isotope ratio measurements. With advanced instrumentation and use of standard reference materials, high accuracy and RESD = 0.002% (or better) may be achieved; b) The advantages of modern automatic isotope ratio mass spectrometer are briefly described. Computer controlled operation and data acquisition, and multiple ion collection are the recent important improvement; c) The isotopic fractionation during the course of isotope ratio measurement is considered as a major source of errors in thermal ionization of metallic elements. The phenomenon in strontium, neodymium, uranium, lead and calcium and methods to correct the measured data are discussed; d) Applications of isotope ratio mass spectrometry in atomic weight determinations, the isotope dilution technique, isotope geology, and isotope effects in biological systems are described together with specific applications in various research and technology area. (author)

  2. Cosmology: Rare isotopic insight into the Universe

    Science.gov (United States)

    Prantzos, Nikos

    2016-01-01

    Light isotopes of hydrogen and helium formed minutes after the Big Bang. The study of one of these primordial isotopes, helium-3, has now been proposed as a useful strategy for constraining the physics of the standard cosmological model.

  3. Developmentand Application of Accelerator Isotopes in China

    OpenAIRE

    YANG Yuan-you; LI Fei-ze; LIAO Jia-li; Liu, Ning

    2015-01-01

    Compared with the isotopes generated by nuclear reactor, the isotopes prepared by accelerator always show high specific activity and short half-life period. And most of such isotopes always were neutron-deficient nuclides, giving β+ or single energy γ ray. As one of the most important methods preparing radionuclides, the preparation of isotopes by accelerator has attracted more and more attention from the beginning of 21th century. The development of the preparation and application of the acc...

  4. Isotope mixtures of hydrogen in vanadium

    International Nuclear Information System (INIS)

    The properties of isotope-mixtures of Protium and Deuterium stored in Vanadium have been studied. Protium and Deuterium are existing as interstitial-atoms on tetrahedral sites as well as on octahedral sites in this system. This feature leads to large isotopic-effects between the two isotopes. The dependence of the thermodynamic functions like heat of solution, nonconfigurational entropy, specific heat and ordering temperatures from the composition of the isotope-mixture has been determined. (orig.)

  5. Dry phase reactor for generating medical isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, Thomas Rockwell; Heltemes, Thad Alexander

    2016-05-03

    An apparatus for generating medical isotopes provides for the irradiation of dry-phase, granular uranium compounds which are then dissolved in a solvent for separation of the medical isotope from the irradiated compound. Once the medical isotope is removed, the dissolved compound may be reconstituted in dry granular form for repeated irradiation.

  6. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope ra

  7. Isotope exchange reactions in hydrogen mixtures

    International Nuclear Information System (INIS)

    The rates of isotopic exchange for the excited states of muonic hydrogen are calculated as functions of collision energy. Ground state population q1s for different collision energies, target densities and isotope concentrations is obtained. It is shown that for principal quantum numbers n > 5 the isotopic exchange still considerably influences the value of q1s. (author)

  8. Discovery of the Isotopes with Z <= 10

    OpenAIRE

    Thoennessen, M

    2010-01-01

    A total of 126 isotopes with Z $\\le$ 10 have been identified to date. The discovery of these isotopes which includes the observation of unbound nuclei, is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  9. Brief review on the development of isotope hydrology in China

    Institute of Scientific and Technical Information of China (English)

    汪集旸; 孙占学

    2001-01-01

    The development of isotope hydrology in China is briefly reviewed. It includes oxygen and hydrogen isotopes of precipitation, application of isotope hydrological methodologies in solving water resources problems, isotope hydrological studies on brines and salt lake waters, as well as isotope hydrological investigations of thermal waters. The review focuses on isotope hydrology in China during the last two decades.

  10. A NICHE FOR ISOTOPIC ECOLOGY

    Science.gov (United States)

    Fifty years ago, GE Hutchinson defined the ecological niche as a hypervolume in n-dimensional space with environmental variables as axes. Ecologists have recently developed renewed interest in the concept, and technological advances now allow us to use stable isotope analyses to ...

  11. Generalized Isoscaling of Isotopic Distributions

    CERN Document Server

    Shomin, R; Bjarki, O; Gelbke, C K; Kunde, G J; Lemmon, R C; Lynch, W G; Magestro, D; Popescu, R; Van der Molen, A; Verde, G; Westfall, G D; Xi Hong Fei; Friedman, W A; Imme, G; Maddalena, V; Nociforo, C; Raciti, G; Riccobene, G; Romano, F; Saija, A; Sfienti, C; Fritz, S; Gross, C; Odeh, T; Schwarz, C; Nadasen, A; Sisan, D R; Rao, K A G

    2002-01-01

    Generalized isoscaling relationships are proposed that may permit one to relate the isotopic distributions of systems that may not be at the same temperature. The proposed relationships are applied to multifragmentation excitation functions for central Kr+Nb and Ar+Sc collisions.

  12. Subsea isotope power system (sips)

    International Nuclear Information System (INIS)

    TRW/DSSG initiated an in-house development program using hardware developed on the Small Compact Auxiliary Power System (SCAPS) program. This latter in-house program was concerned with the development of a Dynamic Isotope Power System (DIPS) for use on various DoD and NASA applications. The SIPS design requirements are summarized. 5 refs

  13. Charge radii of radium isotopes

    NARCIS (Netherlands)

    Wansbeek, L. W.; Schlesser, S.; Sahoo, B. K.; Dieperink, A. E. L.; Onderwater, C. J. G.; Timmermans, R. G. E.

    2012-01-01

    We present a combined analysis of the available isotope-shift data from the optical spectra of Ra atoms and Ra+ ions. Atomic structure calculations of the field-shift and specific mass-shift constants of the low-lying levels in Ra+ are used. The nuclear radial differences delta for the radium

  14. Isotopic Fractionation in Interstellar Chemistry

    Science.gov (United States)

    Charnley, Steven

    2009-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is thought, in some cases, to trace interstellar material that was incorporated into the solar sys tem without undergoing significant processing. In this poster, we sho w the results of several models of the nitrogen, oxygen, and carbon f ractionation in proto-stellar cores.

  15. My academic life with isotopes

    International Nuclear Information System (INIS)

    The present article outlines investigations and experience made by the author in carrying out a variety of studies on isotopes since 1939. First, he was interested in transuranic elements and his studies on artificial radioactive isotopes covered the detection of plutonium at Nagasaki, chemical separation of plutomium from atmosphere at Tokyo, spectral analysis of alpha rays from plutomium, application of 113mIn to emission spectral analysis as a tracer, chemical enrichment of 76As hot atom, and non-destructive analysis of the chemical state of 119Sn produced through EC disintegration in solid material. His studies on natural radioactivity include measurement of the radium content in rock and mineral samples collected in the Korean Peninsula, investigation on the formation process of minerals found around hot springs and determination of the age of rock and mineral samples. He started investigations on isotope enrichment around 1965. Studies in this field cover the application of cataphoretic processes to separation of 23Na and 22Na, enrichment of 7Li and other alkali metals, enrichment of 6Li by isotope exchange, derivation of an empirical equation (Saito-Kanno Equation) for mass effect in couter-current cataphoresis of molten halides, etc. (Nogami, K.)

  16. Isotope hydrology: Investigating groundwater contamination

    International Nuclear Information System (INIS)

    Groundwater quality has worsened in many regions, with sometimes serious consequences. Decontaminating groundwater is an extremely slow process, and sometimes impossible, because of the generally long residence time of the water in most geological formations. Major causes of contamination are poor groundwater management (often dictated by immediate social needs) and the lack of regulations and control over the use and disposal of contaminants. These types of problems have prompted an increasing demand for investigations directed at gaining insight into the behaviour of contaminants in the hydrological cycle. Major objectives are to prevent pollution and degradation of groundwater resources, or, if contamination already has occurred, to identify its origin so that remedies can be proposed. Environmental isotopes have proved to be a powerful tool for groundwater pollution studies. The IAEA has had a co-ordinated research programme since 1987 on the application of nuclear techniques to determine the transport of contaminants in groundwater. An isotope hydrology project is being launched within the framework of the IAEA's regional co-operative programme in Latin America (known as ARCAL). Main objectives are the application of environmental isotopes to problems of groundwater assessment and contamination in Latin America. In 1989, another co-ordinated research programme is planned under which isotopic and other tracers will be used for the validation of mathematical models in groundwater transport studies

  17. Isotopic anomalies - Chemical memory of Galactic evolution

    Science.gov (United States)

    Clayton, Donald D.

    1988-01-01

    New mechanisms for the chemical memory of isotopic anomalies are proposed which are based on the temporal change during the chemical evolution of the Galaxy of the isotopic composition of the mean ejecta from stars. Because of the differing temporal evolution of primary and secondary products of nucleosynthesis, the isotopic composition of the bulk interstellar medium changes approximately linearly with time, and thus any dust component having an age different from that of average dust will be isotopically anomalous. Special attention is given to C, O, Mg, Si, and isotopically heavy average-stellar condensates of SiC.

  18. 2. Workshop 'Isotopes in Nature'. 1

    International Nuclear Information System (INIS)

    The workshop was aimed at discussing in detail the following problems: (1) distribution of stable and radioactive isotopes in nature, (2) theoretical and experimental studies of isotopic effects in natural processes, (3) problems of sample preparation and sample measurement in determining the relative abundance of stable isotopes or radioactive isotopes in nature, (4) age estimations of samples from different areas of the geosphere, (5) contributions to the specification of global and regional substance cycles in nature with the aid of isotopic and geochemical studies. 75 summaries are included

  19. Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Nimz, G. J., LLNL

    1998-06-01

    A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and

  20. New Isotopes In Hydrology And Their Applications

    International Nuclear Information System (INIS)

    In recent years, new isotopes have been being used in hydrology. The increase in the number of the hydrologic problems in time, and the necessity of more detailed information about the origin and the dynamics of the water cause to apply these new isotopes. There are lots of isotopes can be used in problems where the oxygen, hydrogen and the carbon isotopes are not sufficient or can not be used any more (such as the recession of tritium to background level, the requirement of dating much older water than the range of 14C). Some of these are used for groundwater dating, and some are used in origin and pollution problems. In this study, the hydrologic application areas of the helium, krypton, argon, chlorine, strontium, nitrogen and iodine isotopes are summarized. The technological enhancements in laboratories will result the extensive use of these isotopes and the newer isotopes, which will provide to solutions to new hydrological problems

  1. Measuring SNM Isotopic Distributions using FRAM

    Energy Technology Data Exchange (ETDEWEB)

    Geist, William H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-02

    The first group of slides provides background information on the isotopic composition of plutonium. It is shown that 240Pu is the critical isotope in neutron coincidence/multiplicity counting. Next, response function analysis to determine isotopic composition is discussed. The isotopic composition can be determined by measuring the net peak counts from each isotope and then taking the ratio of the counts for each isotope relative to the total counts for the element. Then FRAM (Fixed energy Response function Analysis with Multiple efficiencies) is explained. FRAM can control data acquisition, automatically analyze newly acquired data, analyze previously acquired data, provide information on the quality of the analysis, and facilitate analysis in unusual situations (non-standard energy calibrations, gamma rays from non-SNM isotopes, poor spectra (within limits)).

  2. Developing a Clinically Useful Calcium Isotope Biomarker

    Science.gov (United States)

    Romaniello, Stephen J.; Anbar, Ariel D.; Gordon, Gwyneth W.; Skulan, Joseph L.; Smith, Scott M.; Zwart, Sara R.; Monge, Jorge; Fonseca, Rafael

    2016-01-01

    Naturally-occurring Ca is mixture of six isotopes Ca-40, Ca-42, Ca-43, Ca-44, Ca-46, Ca-48). Biological reaction rates and equilibrium constants depend slightly, but measurably, on atomic mass, causing the relative abundances of Ca isotopes to vary between different tissues. During bone formation, light isotopes of Ca are preferentially incorporated into bone, leaving soft tissue depleted in light isotopes. In contrast, bone resorption exhibits no isotopic preference, and thus transfers the light isotope signature of bone back to soft tissue. This balance makes the Ca isotope composition of soft tissue (e.g. serum, urine) a highly sensitive, quantitative tracer for whole-body bone mineral balance (BMB).

  3. Laser ablation molecular isotopic spectrometry of carbon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bol' shakov, Alexander A. [Applied Spectra, Inc., Fremont, CA (United States); Jain, Jinesh [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Russo, Richard E. [Applied Spectra, Inc., Fremont, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McIntyre, Dustin [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Mao, Xianglei [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-28

    Quantitative determination of carbon isotopes using Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is described. Optical emission of diatomic molecules CN and C2 is used in these measurements. Two quantification approaches are presented:empirical calibration of spectra using a set of reference standards and numerical fitting of a simulated spectrum to the experimental one. Formation mechanisms of C2 and CN in laser ablation plasma are briefly reviewed to provide insights for implementation of LAMIS measurements. A simulated spectrum of the 12C2 Swan system was synthesized using four constituents within 473.5–476.5 nm. Simulation included three branches of 12C2 (1-0), branches R(0-0) and R(1-1), and branch P(9-8) of 12C2. Spectral positions of the tail lines in R(0-0) and R(1-1) were experimentally measured, since they were not accurately known before. The Swan band (1-0) of the isotopologue 13C12C was also simulated. Fitting to the experimental spectrumyielded the ratio 13C/12C = 1.08% in a good agreement with measurements by isotope ratio mass spectrometry. LAMIS promises to be useful in coal, oil and shale exploration, carbon sequestration monitoring, and agronomy studies

  4. Laser ablation molecular isotopic spectrometry of carbon isotopes

    Science.gov (United States)

    Bol‧shakov, Alexander A.; Mao, Xianglei; Jain, Jinesh; McIntyre, Dustin L.; Russo, Richard E.

    2015-11-01

    Quantitative determination of carbon isotopes using Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is described. Optical emission of diatomic molecules CN and C2 is used in these measurements. Two quantification approaches are presented: empirical calibration of spectra using a set of reference standards and numerical fitting of a simulated spectrum to the experimental one. Formation mechanisms of C2 and CN in laser ablation plasma are briefly reviewed to provide insights for implementation of LAMIS measurements. A simulated spectrum of the 12C2 Swan system was synthesized using four constituents within 473.5-476.5 nm. Simulation included three branches of 12C2 (1-0), branches R(0-0) and R(1-1), and branch P(9-8) of 12C2. Spectral positions of the tail lines in R(0-0) and R(1-1) were experimentally measured, since they were not accurately known before. The Swan band (1-0) of the isotopologue 13C12C was also simulated. Fitting to the experimental spectrum yielded the ratio 13C/12C = 1.08% in a good agreement with measurements by isotope ratio mass spectrometry. LAMIS promises to be useful in coal, oil and shale exploration, carbon sequestration monitoring, and agronomy studies.

  5. Deposition station for selenium isotopes

    International Nuclear Information System (INIS)

    Complete text of publication follows. Isotopic tracing of nanoparticles mostly involved in environmental and metabolic processes, industrial, and agricultural technologies, attracts an increasing attention nowadays. As an experimental goal, for proposed tracing studies selenium was chosen, which is an essential trace element for the nutrition of almost all living organisms, since it plays a crucial role in the antioxidant activity of seleno-enzymes. Selenium in forms of nanoparticles being synthesized by wet chemical or microbial dissimilatory processes, turned out to possess new functionality as examplified in affecting semiconductor properties, toxicity, and growth factors, which are important for both nutritional supplements and potential cancer therapy agents. Stable isotope tracing of selenium nanoparticles under in vivo conditions would then yield relevant information on biodistributions, efficiency and safety issues of applications. A prototype version of a deposition station for enrichment of stable selenium isotopes was constructed and installed downstream to the sector magnet of the DiSP isotope separator. The deposition of the isotopic beam particles was carried out with the use of selfsputtering technique. The beam with a kinetic energy of 25-30 keV was first guided through electrostatic elements, where it was focused and decelerated to 300-500 eV (Fig. 1). The geometry of the electrostatic lenses was designed with the simulation code SIMION 8. The outcoming beam impinged upon the surface of a tungsten disc, on which recombination and selfsputtering of selenium ions occurred. Sputtering yields and efficiencies were measured as a function of beam intensities. It was concluded that emission of the selenium atoms can be predominantly attributed to heat spike mechanism due to large differences in evaporation characteristics of selenium and tungsten. The selenium atoms were then deposited as a thin film on a polypropylene (PP) surface with a conical geometry

  6. Nuclides and isotopes. Twelfth edition

    International Nuclear Information System (INIS)

    This explanatory booklet was designed to be used with the Chart of the Nuclides. It contains a brief history of the atomic theory of matter: ancient speculations, periodic properties of elements (Mendeleev table), radioactivity, early models of atomic structure, the Bohr atom, quantum numbers, nature of isotopes, artificial radioactivity, and neutron fission. Information on the pre-Fermi (natural) nuclear reactor at Oklo and the search for superheavy elements is given. The booklet also discusses information presented on the Chart and its coding: stable nuclides, metastable states, data display and color, isotopic abundances, neutron cross sections, spins and parities, fission yields, half-life variability, radioisotope power and production data, radioactive decay chains, and elements without names. The Periodic Table of the Elements is appended. 3 figures, 3 tables

  7. Pairing effects in Sn isotopes

    International Nuclear Information System (INIS)

    An extensive study of pairing effects in the Sn isotopes is carried out. The pairing Hamiltonian is treated by the chain-calculation method which provides practically exact solutions while involving less computational work than a complete-basis diagonalization. The coupling strength is fixed by reproducing the energy of the 9- state in 116Sn, while the single-particle energies have been determined by an analysis of the experimental low-energy spectra of the odd-A isotopes. A detailed comparison of the calculated results with experimental data evidences the importance of neutron pairing correlations in the 50-82 shell. The results of this paper complement those of our previous study of the N=82 isotones. It turns out that the role of pairing correlations is similar to a large extent in both cases. (orig.)

  8. Pairing effects in Sn isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, F. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Coraggio, L. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Covello, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Gargano, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Porrino, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy)

    1996-04-01

    An extensive study of pairing effects in the Sn isotopes is carried out. The pairing Hamiltonian is treated by the chain-calculation method which provides practically exact solutions while involving less computational work than a complete-basis diagonalization. The coupling strength is fixed by reproducing the energy of the 9{sup -} state in {sup 116}Sn, while the single-particle energies have been determined by an analysis of the experimental low-energy spectra of the odd-A isotopes. A detailed comparison of the calculated results with experimental data evidences the importance of neutron pairing correlations in the 50-82 shell. The results of this paper complement those of our previous study of the N=82 isotones. It turns out that the role of pairing correlations is similar to a large extent in both cases. (orig.)

  9. Apparatus for detecting iodine isotopes

    International Nuclear Information System (INIS)

    An apparatus for detecting iodine isotopes in the exhaust gas of a nuclear installation includes a duct for a partial exhaust gas stream, which duct includes an absorption chamber which is disposed in a radiation shielding structure and through which the exhaust gas flows and which has associated therewith means for admitting absorption material and for removing it therefrom. Radiation detectors are supported in the radiation shielding structure at opposite sides of the absorption chamber for monitoring radiation of iodine isotopes collected therein, the cavity in the shielding structure in which the absorption chamber is disposed being larger than the absorption chamber and the absorption chamber being supported so as to be movable in the cavity relative to said detectors to permit calibrating the apparatus. (orig./HP)

  10. Interstellar Isotopes: Prospects with ALMA

    Science.gov (United States)

    Charnley Steven B.

    2010-01-01

    Cold molecular clouds are natural environments for the enrichment of interstellar molecules in the heavy isotopes of H, C, N and O. Anomalously fractionated isotopic material is found in many primitive Solar System objects, such as meteorites and comets, that may trace interstellar matter that was incorporated into the Solar Nebula without undergoing significant processing. Models of the fractionation chemistry of H, C, N and O in dense molecular clouds, particularly in cores where substantial freeze-out of molecules on to dust has occurred, make several predictions that can be tested in the near future by molecular line observations. The range of fractionation ratios expected in different interstellar molecules will be discussed and the capabilities of ALMA for testing these models (e.g. in observing doubly-substituted isotopologues) will be outlined.

  11. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Report 5 contains 24 papers from most regions of Canada, but particularly from British Columbia. The Geochronology Laboratory has, over the years, provided substantial U-Pb dating for the Cordilleran Division of the Geological Survey of Canada in Vancouver, and the results of a number of these studies are presented this year. A compilation of K-Ar ages is given. (figs., tabs., refs.)

  12. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Reports in this issue give U-Pb zircon ages for rocks in Newfoundland, Yukon Territory, Manitoba, Ontario, and the Northwest Territories; present a compilation of K-Ar ages; and discuss Precambrian activity in New Brunswick, the geochronology of rock from the Northwest Territories, and reconnaissance Nd studies of rocks from the Northwest Territories. (figs., tabs., refs.)

  13. Unconventional isotope effects in superconductors

    International Nuclear Information System (INIS)

    The value of the isotope coefficient could be greatly affected by a number of factors not related to the lattice dynamics. Among them are magnetic scattering, the presence of a normal film (proximity effect), and nonadiabaticity (dynamic Jahn-Teller effect). The results are in good agreement with existing experimental data for oxygen isotope substitution (O16→O18) in the YBa2Cu3O7-δ, Y1-xPrxBa2Cu3O7-δ, YBa2(Cu1-xZnx)3O7-δ compounds. In addition, we make several predictions related to conventional as well as to high-Tc materials. copyright 1997 The American Physical Society

  14. Bayesian Stable Isotope Mixing Models

    OpenAIRE

    Parnell, Andrew C.; Phillips, Donald L.; Bearhop, Stuart; Semmens, Brice X.; Ward, Eric J.; Moore, Jonathan W.; Andrew L Jackson; Inger, Richard

    2012-01-01

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixture. The most widely used application is quantifying the diet of organisms based on the food sources they have been observed to consume. At the centre of the multivariate statistical model we propose is a compositional m...

  15. Cluster radioactivity from Osmium isotopes

    International Nuclear Information System (INIS)

    The spontaneous emission of fragments heavier than alpha particle and lighter than the lightest fission fragment from a nucleus is called cluster radioactivity. It is a cold nuclear phenomenon predicted based on Quantum Mechanical Fragmentation Theory (QMFT). Cluster radioactivity is studied using Unified Fission Model (UFM). Present study is conducted using proton rich osmium isotopes with mass ranging from 162-190. The interacting potential chosen is the Effective Liquid Drop Model (ELDM). The total potential in one dimensional case is the sum of Coulomb, surface and centrifugal potential. Here centrifugal part is not considered. Barrier penetrability (P) is calculated using one dimensional WKB approximation. The decay constant is obtained as λ = νoP where νo is the assault frequency. From the calculated values we have found that osmium isotopes in the mass range between 162-168 is highly unstable against alpha decay. Mass range of osmium isotopes found favourable to 8Be decay are 162-170, to 12C decay are 162-172, to 16O decay are 162-172, to 20Ne decay are 163-169, and to 24Mg decay are 162-171

  16. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Reports in this issue cover methods for Rb-Sr and Sm-Nd isotopic analyses; 40Ar-39Ar ages for the New Quebec Crater and for basaltic rocks; U-Pb ages for a differentiated mafic sill in the Ogilvie Mountains, plutonic rocks in the Contwoyto-Nose Lakes are, zircons from the Anton Complex, the Clinton-Colden gabbro-anorthosite intrusion, the Himag plutonic suite, the Campbell granite, the Central Gneiss Belt, Silurian granites, a metarhyolite, plagiogranite and gabbro, and the Wage shear zone; Rb-Sr ages for granitic rocks; K-Ar and Rb-Sr geochronology of granites; a compilation of K-Ar ages; ages of archean and proterozoic mylonites and pre-Misi granitoid domes; and reconnaissance geochronology of Baffin Island

  17. Quadrupole Deformation of Barium Isotopes

    CERN Document Server

    Sugita, M; Furuno, K

    1998-01-01

    The B(E2:0_1^+ -> 2_1^+) values of the Ba isotopes (Z=56) exhibit a sharp increase in deformation as the neutron numbers approach the mid-shell value of N=66. This behavior is anomalous because the 2_1^+ level energies are very similar to those of the neighboring isotopes. By means of the axially-symmetric deformed Woods-Saxon (WS) hamiltonian plus the BCS method, we investigated the systematics of B(E2) of the Ba isotopes. We showed that 15% of the B(E2) values at N=66 was due to the level crossing, occurring at the deformation with beta being nearly 0.3, between the proton orbits originating from the orbits Omega=1/2^-(h11/2) and 9/2^+(g9/2) at zero deformation. The latter of these two was an intruder orbit originating from below the energy gap at Z=50, rising higher in energy with the deformation and intruding the Z=50-82 shell. These two orbits have the largest magnitude of the quadrupole moment with a different sign among the orbits near and below the Fermi surface. Occupancy and non-occupancy of these o...

  18. Isotopes for medicine and the life sciences

    International Nuclear Information System (INIS)

    Both radioisotopes and enriched stable isotopes are essential to a wide variety of applications in medicine, where they are used in the diagnosis and treatment of illnesses. This report focuses primarily on those medical uses and those in allied life sciences. In addition, other applications of isotopes are discussed; isotopes also find wide parallel uses in research in chemistry, physics, biology, and geosciences, with additional needs existing in the commercial sector. Topic areas include the following: enriched stable isotopes; reactor-produced radionuclides; accelerator-produced radionuclides and a national biomedical tracer facility; public-private partnership models for NBTF; a national isotope policy: proposal for a new way to manage the nation's isotope resources

  19. The use of magnetic isotope effect for the separation of uranium isotopes

    International Nuclear Information System (INIS)

    The influence of the magnetic isotope effect on the reaction of radical pairs containing radical-ion UO22+, is investigated. This can be further used in the new method of uranium isotope separation in chemical reaction

  20. Isotope Selection Characteristics of MOT for the Detection of the Sr Rare Isotopes

    International Nuclear Information System (INIS)

    Trace isotope analysis has become an essential tool in basic research, environmental science, archaeological dating and geology. Especially, the detection of the trace radio isotope 90Sr, which is a fission product, has been of an interest because of the nuclear industry and environmental assessment. Recently, the neutral atom trap method has been developed for analyzing ultra trace isotopes, such as 81Kr, 85Kr and 41Ca. This method is not only free of contamination from different isotopes or isobar, but it is also a higher isotope selective method than any other laser based methods. To develop the higher isotope selective analytical system to detect rare 90Sr, MOT(magneto optical trap) has been applied as an isotope selective excitation method. In this paper, MOT has been demonstrated and the fluorescence characteristics have been investigated to have knowledge of the isotope selective process of MOT

  1. Zinc isotope effects in complex formation with a crown ether

    International Nuclear Information System (INIS)

    Isotope effects for zinc upon complex formation with dicyclohexano-18-crown-6 were investigated. The single stage separation factor for unit mass difference (α = 1.013) was great compared with that of calcium isotopes. One of the isotopes, 67Zn, showed a larger isotope effect than the other isotopes of even mass number. 7 refs., 1 fig

  2. Measuring In Vivo Ureagenesis With Stable Isotopes

    OpenAIRE

    Yudkoff, Marc; Mew, Nicholas Ah; Daikhin, Yevgeny; Horyn, Oksana; Nissim, Ilana; Nissim, Itzhak; Payan, Irma; Tuchman, Mendel

    2010-01-01

    Stable isotopes have been an invaluable adjunct to biomedical research for more than 70 years. Indeed, the isotopic approach has revolutionized our understanding of metabolism, revealing it to be an intensely dynamic process characterized by an unending cycle of synthesis and degradation. Isotopic studies have taught us that the urea cycle is intrinsic to such dynamism, since it affords a capacious mechanism by which to eliminate waste nitrogen when rates of protein degradation (or dietary pr...

  3. Multiple linear regression for isotopic measurements

    Science.gov (United States)

    Garcia Alonso, J. I.

    2012-04-01

    There are two typical applications of isotopic measurements: the detection of natural variations in isotopic systems and the detection man-made variations using enriched isotopes as indicators. For both type of measurements accurate and precise isotope ratio measurements are required. For the so-called non-traditional stable isotopes, multicollector ICP-MS instruments are usually applied. In many cases, chemical separation procedures are required before accurate isotope measurements can be performed. The off-line separation of Rb and Sr or Nd and Sm is the classical procedure employed to eliminate isobaric interferences before multicollector ICP-MS measurement of Sr and Nd isotope ratios. Also, this procedure allows matrix separation for precise and accurate Sr and Nd isotope ratios to be obtained. In our laboratory we have evaluated the separation of Rb-Sr and Nd-Sm isobars by liquid chromatography and on-line multicollector ICP-MS detection. The combination of this chromatographic procedure with multiple linear regression of the raw chromatographic data resulted in Sr and Nd isotope ratios with precisions and accuracies typical of off-line sample preparation procedures. On the other hand, methods for the labelling of individual organisms (such as a given plant, fish or animal) are required for population studies. We have developed a dual isotope labelling procedure which can be unique for a given individual, can be inherited in living organisms and it is stable. The detection of the isotopic signature is based also on multiple linear regression. The labelling of fish and its detection in otoliths by Laser Ablation ICP-MS will be discussed using trout and salmon as examples. As a conclusion, isotope measurement procedures based on multiple linear regression can be a viable alternative in multicollector ICP-MS measurements.

  4. Quantitative microbial ecology through stable isotope probing.

    Science.gov (United States)

    Hungate, Bruce A; Mau, Rebecca L; Schwartz, Egbert; Caporaso, J Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J; Liu, Cindy M; McHugh, Theresa A; Marks, Jane C; Morrissey, Ember M; Price, Lance B

    2015-11-01

    Bacteria grow and transform elements at different rates, and as yet, quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to stable isotope probing (SIP) that enables the isotopic composition of DNA from individual bacterial taxa after exposure to isotope tracers to be determined. In our modification, after isopycnic centrifugation, DNA is collected in multiple density fractions, and each fraction is sequenced separately. Taxon-specific density curves are produced for labeled and nonlabeled treatments, from which the shift in density for each individual taxon in response to isotope labeling is calculated. Expressing each taxon's density shift relative to that taxon's density measured without isotope enrichment accounts for the influence of nucleic acid composition on density and isolates the influence of isotope tracer assimilation. The shift in density translates quantitatively to isotopic enrichment. Because this revision to SIP allows quantitative measurements of isotope enrichment, we propose to call it quantitative stable isotope probing (qSIP). We demonstrated qSIP using soil incubations, in which soil bacteria exhibited strong taxonomic variations in (18)O and (13)C composition after exposure to [(18)O]water or [(13)C]glucose. The addition of glucose increased the assimilation of (18)O into DNA from [(18)O]water. However, the increase in (18)O assimilation was greater than expected based on utilization of glucose-derived carbon alone, because the addition of glucose indirectly stimulated bacteria to utilize other substrates for growth. This example illustrates the benefit of a quantitative approach to stable isotope probing. PMID:26296731

  5. Studies on sulphur isotope variations in nature

    International Nuclear Information System (INIS)

    The variations of sulphur isotopes in natural compounds (and of oxygen isotopes in sulphates) provide a powerful method of investigation in various fields of earth sciences such as hydrology, geochemistry, geothermal exploration, volcanology, oceanography, sedimentology, ore formation, environmental sciences and others, although probably the method is not equally mature in all these fields, because of the inherent complexity and, sometimes, insufficient basic data. To review the current situation, and to identify trends of research and application of sulphur isotopes, the International Atomic Energy Agency held an Advisory Group Meeting on the Hydrology and Geochemistry of Sulphur Isotopes, which took place in Vienna at the IAEA Headquarters from 17 to 20 June 1985. Most of the papers presented at the meeting are included in this publication under the following titles: Isotopic composition of dissolved oceanic sulphate; Sulphur isotopes in the water of Lake Neusiedl, Austria; Relationships between the sulphur and oxygen isotope composition of dissolved sulphate; Sulphur and sulphate-oxygen isotopes in New Zealand geothermal systems and volcanic discharges; Isotopic composition and origin of sulphur compounds in groundwaters and brines in the Po Valley (northern Italy); Two case studies on the origin of aqueous sulphate in deep crystalline rocks; Sulphur and oxygen isotopic compositions of groundwater - and sabkha - sulphate in the Middle East; Radiolytic oxidation of sulphides and geochemical behaviour of sulphur isotopes in uranium deposits; On bias in 34S/32S data obtained using SO2 gas in mass spectrometry; Sulphur isotope analyses of trace sulphide and sulphate in various materials using Kiba reagent. Refs, figs and tabs

  6. Medical isotopes and emerging nuclear medicine technologies

    International Nuclear Information System (INIS)

    This presentation discusses medical isotopes and the emerging nuclear medicine technologies as well as the impact of Chalk River reactor shutdown on patient management and diseases. It outlines the chain of supply of isotopes across the globe and isotope shortage impact. It recommends the following mitigating strategies: modifications of scanning techniques, adjustment of patient scheduling, optimization of Tc-99m generator use, patient prioritization, alternate procedures and PET scanning.

  7. New approaches to the Moon's isotopic crisis

    OpenAIRE

    Melosh, H. J.

    2014-01-01

    Recent comparisons of the isotopic compositions of the Earth and the Moon show that, unlike nearly every other body known in the Solar System, our satellite's isotopic ratios are nearly identical to the Earth's for nearly every isotopic system. The Moon's chemical make-up, however, differs from the Earth's in its low volatile content and perhaps in the elevated abundance of oxidized iron. This surprising situation is not readily explained by current impact models of the Moon's origin and offe...

  8. Zinc isotopic compositions of breast cancer tissue.

    OpenAIRE

    Larner, F; Woodley, LN; Shousha, S; Moyes, A; Humphreys-Williams, E; Strekopytov, S; Halliday, AN; Rehkämper, M; Coombes, RC

    2015-01-01

    An early diagnostic biomarker for breast cancer is essential to improve outcome. High precision isotopic analysis, originating in Earth sciences, can detect very small shifts in metal pathways. For the first time, the natural intrinsic Zn isotopic compositions of various tissues in breast cancer patients and controls were determined. Breast cancer tumours were found to have a significantly lighter Zn isotopic composition than the blood, serum and healthy breast tissue in both groups. The Zn i...

  9. Isotopes in Australian environmental analysis

    International Nuclear Information System (INIS)

    Full text: ANSTO Environment is playing a pioneering role in developing new methods for monitoring adherence to the Nuclear Non-proliferation Treaty. Working with the IAEA Department of Safeguards, new analytical procedures have been developed to assist with their environmental monitoring programme. Signatures of nuclear activities, in the form of trace amounts of radioisotopes in environmental samples, can be used to identify undeclared nuclear facilities or undeclared activities at declared facilities. At ANSTO we have developed the use of Accelerator Mass Spectrometry (AMS) for analysis of 236U in environmental samples. 236U is a sensitive indicator of irradiated uranium. AMS is also used to detect the long- lived fission product 129I at extremely low levels. The presence of 129I can be a signature of reprocessing. ANSTO performs analyses of these radioisotopes as an accredited member of the IAEA Safeguards network of analytical laboratories. Australian soldiers on duty in the Gulf risk possible exposure to depleted uranium. Depleted uranium is the uranium that is left after most of the radioactive isotopes are removed for nuclear fuel. Due to its high density, it is the ideal material for use in armour-piercing ammunition and in armour for fighting vehicles. However, like any heavy metal, it is toxic in high doses. Depleted uranium enters the body through inhalation of the dust- like particles, ingestion of contaminated food or through wounds. At ANSTO, a sensitive analytical technique based on isotope dilution and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect depleted uranium in urine samples. By addition of known quantities of 236U (isotope dilution) to the urine samples and measuring the relative abundances of different isotopes (236U, 235U and 238U) of uranium by ICP-MS, we are able to quantify (quantification limit of 20 ng/L) and distinguish between natural and depleted uranium. In Australia, there are legislative limits on the

  10. Newtonian Kinetic Isotope Effects. Observation, Prediction, and Origin of Heavy-Atom Dynamic Isotope Effects

    OpenAIRE

    Kelly, Kelmara K.; Hirschi, Jennifer S.; Singleton, Daniel A.

    2009-01-01

    Intramolecular 13C kinetic isotope effects were determined for the dimerization of cyclopentadiene. Substantial isotope effects were observed in three positions, despite the C2 symmetry of the cycloaddition transition state and the absence of dynamical bottlenecks after this transition state. The observed isotope effects were predicted well from trajectory studies by extrapolating the outcomes of trajectories incorporating superheavy isotopes of carbon, ranging from 20C to 140C. Trajectory st...

  11. High resolution measurements of isotope shifts and hyperfine structure in stable and radioactive lead isotopes

    International Nuclear Information System (INIS)

    We present new measurements of isotopic shifts and hyperfine structure in the lead resonance line for a total of 15 isotopes. The experimental accuracy is of order 4 MHz. Using independent measurements of the nuclear parameter lambda for the stable isotopes we have derived lambda for all measured isotopes. The derived lambda values are compared with various theoretical predictions for the lead nuclei. We also give values for the nuclear magnetic dipole and electric quadrupole moments deduced from our measurements. (orig.)

  12. Isotopic investigation of an Australian island environment

    International Nuclear Information System (INIS)

    Collagen has been extracted from fossil bones of mega-fauna herbivores from Kangaroo Island, South Australia (Australia). Carbon and nitrogen stable isotope analyses of collagen have provided an insight into the palaeo-ecology of these late Pleistocene herbivores. In comparison with continental fossil localities in South Australia, the island herbivores have elevated nitrogen isotopic abundances. Carbon isotopic abundances suggest that browsing species had a mixed diet of grasses and leaves on the island, in contrast to the specimens from mainland Australia. Possible causes regarding elevated nitrogen isotope abundances and dietary shifts in this palaeo-ecology are discussed. (authors). 24 refs., 2 figs., 1 tab

  13. Stable isotope analysis in the ivory

    International Nuclear Information System (INIS)

    Stable isotope ratio in an ivory collagen reflects the isotope ratio of the plants they are eaten by the elephant. From the stable isotope ratios of carbon (δ 13C) and nitrogen (δ 15N) in a ivory collagen the habitat of the elephant can be estimated. The 118 pieces of the ivory were analyzed for detecting the isotope ratios, which are kept in the Kruger National Park, South Africa. The result shows the grouping of the ivory related to the area in which elephant were captured. (H. Katsuta)

  14. Stable isotope analysis in the ivory

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, H.; Koike, H. [Graduate School of Social and Cultural Studies, Kyushu University, Fukuoka (Japan); Takeuchi, Takayuki [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    2001-01-01

    Stable isotope ratio in an ivory collagen reflects the isotope ratio of the plants they are eaten by the elephant. From the stable isotope ratios of carbon ({delta} {sup 13}C) and nitrogen ({delta} {sup 15}N) in a ivory collagen the habitat of the elephant can be estimated. The 118 pieces of the ivory were analyzed for detecting the isotope ratios, which are kept in the Kruger National Park, South Africa. The result shows the grouping of the ivory related to the area in which elephant were captured. (H. Katsuta)

  15. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32S vs. 34S were 1.127 for H2S, 1.048 for COS, 0.838 for SF4, and 1.058 for CH3SH. Relative volatilities of 32S vs. 34S are 1.0006 for COS and 0.9976 for SF4. There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H2Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF4. 8 refs., 2 tabs

  16. Isotope effects in the diffusion of hydrogen

    International Nuclear Information System (INIS)

    Isotope effects in diffusion of hydrogen atoms are investigated theoretically. It is shown that isotope effect is reduced by a nonadiabatic effect of the heat bath so that the classical-quantum crossover temperature and quantum tunneling rate lose their mass dependence. On the other hand, isotope effect is reversed in classical hopping rate under strong spatial confinement at the barrier top. These results indicate that isotope effects can be the means of observing influences of many degrees of freedom characterizing environment in diffusion process

  17. Use of environmental natural isotopes in hydrology

    International Nuclear Information System (INIS)

    The principle of natural tracing using environmental isotopes in hydrology (water isotopes 18O, 2H, 3H and dissolved isotopes 14C, 34S, 15N) are presented. The applications in hydrology are reviewed: surface water (flood discharge, snow, lakes, stagnant water); non-saturated zone (water transfer from the surface to aquifers); aquifers (recharge conditions for unconfined aquifers, origin and flow velocity of confined ground water, geothermal circuit). The use of isotopes in environment problems are also examined: pollution by sulfates, origin of dissolved nitrogen in surface and ground waters

  18. Stable isotope labeled L-tryptophan

    International Nuclear Information System (INIS)

    Stable isotope labeled L-tryptophan is an application of nucleus technology in amino acids. Progresses in stable isotope labeled L-tryptophan in recent years are reviewed.. In the respect of synthesis, in addition to the methods of organic synthesis and isotope exchange, the microbial technology which has the advantage of U-label and construct has been used widely. In the respect of applications, stable isotope labeled L-tryptophan as trace has been used widely in yields of medicine, biology and chemistry et al. Along with the development of protein engineering, molecular biology and peptide drugs, they will have a fine future. (authors)

  19. Radio-isotopic myocardial study

    International Nuclear Information System (INIS)

    The non invasive study of the myocardium with radio-isotopes is effected either with radio-elements labeling on recently infarcted myocardium, such as PYP Tc 99m, or after I.V. injection of Tl 201 extracted by normal myocardium or after I.V. injection of radio-element which study the myocardial metabolism. The fixation of PYP Tc 99m, bordering that of calcium, appears 24 hours after the onset of the myocardial infarction; then it reduces and disappears a week later; its persistency gives evidence of an evolution to ventricular anevrism. The relatively low sensitivity and specificity of this test should induce to reserve if for precise cases. 201 Tl realizes a map of the myocardial flow because this radio-isotope reflects with damping the variations of coronary flow. The scintigraphy is made either after stress test or after I.V. injection of dipyridamole, and the sensitivity and specificity of the test is better than electrocardiographic exercise stress test. The predictive value of the test for a patient highly depends of the prevalence of the coronary disease for this patient; however the results of Tl scintigraphy are far from an ideal test; quantitative or semi-quantitative analysis of the image compared to the analogical image seems to improve sensitivity for detection of coronary disease. After myocardial infarction, its best use is to detect a left anterior descending stenosis after posterior or inferior infarction. Among the possible radio-elements of myocardial metabolism, scintigraphy with fatty acids opens interesting prospects for the study of the myocardial clearance of the radio-isotope, that reflects the global or regional myocardial metabolism

  20. Uranium isotopes fingerprint biotic reduction

    Science.gov (United States)

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J.; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-01-01

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium. PMID:25902522

  1. Tank waste isotope contributions; FINAL

    International Nuclear Information System (INIS)

    This document presents the results of a calculation to determine the relative contribution of selected isotopes to the inhalation and ingestion doses for a postulated release of Hanford tank waste. The fraction of the dose due to(sup 90)Sr,(sup 90)Y,(sup 137)Cs and the alpha emitters for single shell solids and liquids, double shell solids and liquids, aging waste solids and liquids and all solids and liquids. An effective dose conversion factor was also calculated for the alpha emitters for each composite of the tank waste

  2. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl-13C-butanoic-3,4-13C2 acid (DL-valine-13C3); methyl oleate-1-13C; thymine-2,6-13C2; 2-aminoethanesulfonic-13C acid (taurine-13C); D-glucose-6-13C; DL-2-amino-3-methylpentanoic-3,4-13C2 acid (DL-isoleucine-13C2); benzidine-15N2; and 4-ethylsulfonyl-1-naphthalene-sulfonamide-15N

  3. Isotopic diagnosis of peripheral thrombosis

    International Nuclear Information System (INIS)

    Radio-isotope diagnosis of peripheral venous thrombosis, using tracer doses of iodine-labelled fibrinogen, provides an important contribution to the solution of the worrying problem of pulmonary embolism due to latent phlebitis. This elegant and precise technique permits early diagnosis of venous thrombosis of the lower limbs at a subclinical stage. It has permitted determination of the frequency, both after surgery and after myocardial infarction, and above all, it provides an objective criterion for assessment of the efficacy of prophylactic measures proposed

  4. Atomic vapour laser isotope separation of zirconium

    International Nuclear Information System (INIS)

    The possibility of separating the 91Zr isotope from the rest of the isotopes of zirconium were investigated. The current interest in zirconium arise from the fact that zirconium is an important element in the construction of nuclear reactors. The technique proposed for the isotope separation process is different from those currently in use for the separation of isotopes of refractory elements such as uranium. The proposed isotope separation process is based on the multi-step selective excitation of the isotope to be extracted, which in this case is 91Zr. The isotope-selective laser excitation relies on the angular-momentum selection rules for the absorption of circularly polarized light. The theory governing the isotope separation process is discussed and the various parameters in the practical implementation of the theory are investigated. The suitability of a demountable hollow cathode lamp as zirconium atomic vapour source was investigated. The optimum working conditions for the demountable hollow cathode lamp was determined and fluorescence, absorption and emission measurements were made. In order to realize a selective two-step excitation process, relevant energy levels must exist which fulfill certain requirements as discussed in the thesis. Energy levels fulfilling the necessary conditions for isotope separation are not readily available and an intensive study of the zirconium energy levels were made. Non-selective two-step excitation of the zirconium atoms was realized. These fluorescence measurements gave information regarding the optical alignment of the laser beams as well as the construction of the demountable hollow cathode lamp as atomic vapour source for the two-step excitation process. Although selective two-step excitation of the 91Zr isotope could not be achieved, a number of valuable results were obtained during the project. Proposals on how the necessary selective excitation could be achieved, in order to realize the separation of the 91Zr

  5. Exploring the isotopic niche: isotopic variance, physiological incorporation, and the temporal dynamics of foraging

    Directory of Open Access Journals (Sweden)

    Justin Douglas Yeakel

    2016-01-01

    Full Text Available Consumer foraging behaviors are dynamic, changing in response to prey availability, seasonality, competition, and even the consumer's physiological state. The isotopic composition of a consumer is a product of these factors as well as the isotopic `landscape' of its prey, i.e. the isotopic mixing space. Stable isotope mixing models are used to back-calculate the most likely proportional contribution of a set of prey to a consumer's diet based on their respective isotopic distributions, however they are disconnected from ecological process. Here we build a mechanistic framework that links the ecological and physiological processes of an individual consumer to the isotopic distribution that describes its diet, and ultimately to the isotopic composition of its own tissues, defined as its `isotopic niche’. By coupling these processes, we systematically investigate under what conditions the isotopic niche of a consumer changes as a function of both the geometric properties of its mixing space and foraging strategies that may be static or dynamic over time. Results of our derivations reveal general insight into the conditions impacting isotopic niche width as a function of consumer specialization on prey, as well as the consumer's ability to transition between diets over time. We show analytically that moderate specialization on isotopically unique prey can serve to maximize a consumer's isotopic niche width, while temporally dynamic diets will tend to result in peak isotopic variance during dietary transitions. We demonstrate the relevance of our theoretical findings by examining a marine system composed of nine invertebrate species commonly consumed by sea otters. In general, our analytical framework highlights the complex interplay of mixing space geometry and consumer dietary behavior in driving expansion and contraction of the isotopic niche. Because this approach is established on ecological mechanism, it is well-suited for enhancing the

  6. Discovery of Isotopes of Elements with Z $\\ge$ 100

    OpenAIRE

    Thoennessen, M

    2012-01-01

    Currently, 163 isotopes of elements with Z $\\ge$ 100 have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  7. On anomalous isotope composition of lithium in commercial reagents used as standards in isotope analysis

    International Nuclear Information System (INIS)

    Using the spectral method the isotope analysis of lithium is carried out to specify the value of anomalies of lithium isotope composition in salts. Accuracy of the results obtained has been checked according to standard mixtures, prepared of isotopically enriched lithium chlorides (lithium-6 chloride-90.5% 6Li and 9.5% 7Li; lithium-7 chloride-0.02% 6Li and 99.98% 7Li). The analysis has shown that commercial salts of lithium can have considerably shifted isotope composition, which must be taken into account when calibrating the instruments and applying salts as standards of isotope ratio

  8. From application of isotope enriched mercury in environmental studies to fractionation of mercury isotopes

    International Nuclear Information System (INIS)

    Full text: This overview on using isotope enriched Hg in environmental studies summarizes results from a whole ecosystem experiment to illustrate aspects of sample preparation and instrumental requirements. Building on our experience in working with isotope-enriched material, our group recently progressed to using multicollector ICPMS for ultra precise isotope ratio determinations, revealing variations in natural Hg isotope ratios. Fractionation is triggered by mass dependent (e.g. reduction and volatilization) and mass independent processes (e.g. photochemical reactions). The presentation will give examples of both mechanisms and discuss Hg isotope fingerprinting as a tool for tracking sources of Hg in the environment. (author)

  9. New isotope {sup 265}Bh

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Z.G.; Guo, J.S.; Wu, X.L.; Qin, Z.; Fan, H.M.; Lei, X.G.; Liu, H.Y.; Guo, B.; Xu, H.G.; Chen, R.F.; Dong, C.F.; Zhang, F.M.; Wang, H.L.; Xie, C.Y.; Feng, Z.Q.; Zhen, Y.; Song, L.T.; Luo, P.; Xu, H.S.; Zhou, X.H. [Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou (China); Jin, G.M.; Ren, Zhongzhou

    2004-06-01

    A new isotope {sup 265}Bh was produced and identified at the Sector Focus Cyclotron of the Heavy Ion Research Facility in Lanzhou. This experiment was performed via the reaction of an {sup 243}Am target with 168 MeV {sup 26}Mg ions. Identification was made by observation of correlated {alpha} -particle decays between the new isotope {sup 265}Bh and its {sup 261}Db and {sup 257}Lr daughter nuclei using a set of rotating-wheels system. A total of 8 correlated decay events of {sup 265}Bh and 4 decay events of {sup 264}Bh were observed. {sup 265}Bh decays with a 0.94 {sub -0.31}{sup +} {sup 0.70} s half-life by emission of {alpha}-particles with an average energy of 9.24 {+-}0.05 MeV. The half-life and {alpha} decay energy of {sup 265}Bh from this experiment are in agreement with theoretical predictions. (orig.)

  10. Isotope separation by rotating plasmas

    International Nuclear Information System (INIS)

    A steady-state model of a fully ionized plasma column in a concentric cylindrical electrodes structures is proposed to study the plasma separation properties of its singly ionized ionic species, composed of two isotopes of the element. In this model (a one-fluid model) rotation is imparted to the plasma column through the J (vector) x B (vector) interaction. Radial pressure balance is mainly between the radial component of the J (vector) x B (vector) force and the pressure gradient plus centrifugal force and the azimutal component of the J (vector) x B (vector) force is balanced purely by viscous force. A pressure tensor 31 describes the viscoys effect and the heat balance provides an equation for temperature. A uranium gas with is two main isotopes (U235 and U238) was used for the ionic component of the plasma. The computing code to solve the resulting, system of equations in tems of density, temperature, and velocity as functions of the radial independent variable was set up to yield solutions satisfying null velocity conditions on both boundaries (inner and outer electrodes). (M.A.F.)

  11. Isotope hydrology in northern Chile

    International Nuclear Information System (INIS)

    Environmental isotope analyses were done on samples from aquifers in the Pampa del Tamarugal and the Salar de Atacama drainage basin in northern Chile. In the Pampa it is possible to delineate individual groundwater bodies on the basis of their 18O and deuterium contents and, in some cases, to relate these to specific recharge areas. A marked displacement from the meteoric water line indicates that river recharge is an important mechanism for groundwater renewal. Groundwater ages appear high at distance from the Andes and much of the water found in the Pampa may have to be treated as a non-renewable resource. The groundwaters, springs and rivers of the Salar de Atacama drainage basin vary between -6.09 and -8.06%. No difference between the different waters can be recognized and an evaporative isotope enrichment indicates that also here river recharge is an important process. Some groundwaters adjacent to the Salar are very salty but 18O and deuterium data show that these waters are not refluxed brines but simply salty freshwater. The 14C contents in groundwaters and springs are very low but their delta13C values are high. It is concluded that this is probably due to the uptake of volcanic CO2. 14C age dating is thus not possible unless the delta13C values of all possible carbon sources can be defined and the geochemical evolution of the groundwaters is better understood. (author)

  12. Isotopic scintigraphy in kidney grafting

    International Nuclear Information System (INIS)

    Isotopic explorations of kidney transplants were performed on sixty-six patients. Three scintigraphic techniques were used: labelled ferrous ascorbate scintigraphy, sequential 99m technetium DTPA scintigraphy and the 131I hippuran nephrogram. The aim of this study is to analyse the results obtained under different pathological circumstances affecting the transplant, to discuss the advantages of the techniques and to propose a working procedure. The most reliable and accurate technique is the 131I hippuran nephrogram combined with sequential 99mTc DTPA, by which renal vascularisation may be judged labelled ferrous ascorbate on the other hand is too insensitive. Although the information supplied is mostly contained in the scintigraphic images, the nephrographic curves and the blood radioactivity decay time and rad V/rad R ratio measurements are very helpful in the early diagnosis and differential diagnosis of complications affecting the transplant. The proper use of isotopic scintigraphy in kidney grafting should provide optimum conditions for better survival of the transplant at minimum risk to the patient

  13. Lithium and magnesium isotopes fractionation by zone melting

    Science.gov (United States)

    Akimov, D. V.; Egorov, N. B.; Dyachenko, A. N.; Pustovalova, M. P.; Podoinikov, I. R.

    2016-06-01

    The process of changing isotopic composition of the lithium and magnesium salts was studied by using the process of zone melting. It was founded in the paper that the process of separation of the lithium isotopes is more effective than for magnesium isotopes when the conditions of process were the same. The coefficients of isotopes separation were calculated and have the next value: α = 1.006 for 26Mg isotope and α = 1.0022 for 6Li isotope.

  14. Xenon Isotope Releases from Buried Transuranic Waste

    Science.gov (United States)

    Dresel, P. E.; Waichler, S. R.; Kennedy, B. M.; Hayes, J. C.; McIntyre, J. I.; Giles, J. R.; Sondrup, A. J.

    2004-12-01

    Xenon is an inert rare gas produced as a fission product in nuclear reactors and through spontaneous fission of some transuranic isotopes. Thus, xenon will be released from buried transuranic waste. Two complementary methods are used to measure xenon isotopes: radiometric analysis for short-lived radioxenon isotopes and mass spectrometry for detection of stable xenon isotopes. Initial measurements near disposal facilities at the U.S. Department of Energy's Hanford Site show radioxenon and stable xenon isotopic signatures that are indicative of transuranic waste. Radioxenon analysis has greater sensitivity due to the lower background concentrations and indicates spontaneous fission due to the short half life of the isotopes. Stable isotope ratios may be used to distinguish irradiated fuel sources from pure spontaneous fission sources and are not as dependent on rapid release from the waste form. The release rate is dependent on the type of waste and container integrity and is the greatest unknown in application of this technique. Numerical multi-phase transport modeling of burial grounds at the Idaho National Engineering and Environmental Laboratory indicates that, under generalized conditions, the radioxenon isotopes will diffuse away from the waste and be found in the soil cap and adjacent to the burial ground at levels many orders of magnitude above the detection limit.

  15. Isotope hydrology. Raigon aquifer hydrochemistry - Uruguay

    International Nuclear Information System (INIS)

    The purpose of this study is the Raigon Acuifer investigation by isotopic techniques as well as the dynamic behavior in the water resources. These techniques are based on the natural water isotope deuterium, oxygen-18, tritium and carbon-14 measurement. The hydrochemistry is used like a complementary tool

  16. Isotope hydrology 1970. Proceedings of a symposium

    International Nuclear Information System (INIS)

    These proceedings contain the papers from the Symposium on Isotope Hydrology held 9-13 March 1970 in Vienna, Austria. The topics of the sessions were as follows: Thermal water studies, groundwater dating, hydrology of arid and semi-arid areas, field studies with environmental isotopes, precipitation-surface-groundwater relationships, pollution, artificial tracers and sediment transport

  17. Safeguards implications of laser isotope separation

    International Nuclear Information System (INIS)

    The purpose of this report is to describe and emphasise the safeguards and relevant features of atomic vapour laser isotope separation (AVLIS) and molecular laser isotope separation (MLIS), and to consider the issues that must be addressed before a safeguards approach at a commercial AVLIS or MLIS facility can be implemented. (Author)

  18. [Carbon isotope fractionation inplants]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    O`Leary, M.H.

    1990-12-31

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  19. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  20. Contrasting styles of oxygen isotope exchange

    OpenAIRE

    Valley, J. W.; Eiler, J. M.; Kohn, M.J.; Spicuzza, M.J; Baumgartner, L. P.; Elsenheimer, D.; Graham, C. M.

    1994-01-01

    Exchange of oxygen isotopes encrypts a sensitive record of the thermal evolution and fluid-exchange history of igneous and metamorphic rocks. Deciphering this record requires measurement of isotope ratios at an appropriate scale together with understanding of the processes involved: diffusion, recrystallization, new mineral growth, and fluid flow.

  1. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Chastagner, P.

    2001-08-01

    This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

  2. Isotope separation with use of macrocyclic polyesters

    International Nuclear Information System (INIS)

    Review of experimental data on isotope separation with use of macrocyclic compounds-crown ethers and cryptands is given. The table of isotope separation factors of hydrogen, lithium, sodium, potassium, calcium, strontium, barium, zinc, cerium and uranium is presented. Refs. 43, tab. 1

  3. Second international conference on isotopes. Conference proceedings

    International Nuclear Information System (INIS)

    The Second International Conference on Isotopes (2ICI) was hosted by the Australian Nuclear Association in Sydney, NSW, Australia. The Theme of the Second Conference: Isotopes for Industry, Health and a Better Environment recognizes that isotopes have been used in these fields successfully for many years and offer prospects for increasing use in the future. The worldwide interest in the use of research reactors and accelerators and in applications of stable and radioactive isotopes, isotopic techniques and radiation in industry, agriculture, medicine, environmental studies and research in general, was considered. Other radiation issues including radiation protection and safety were also addressed. International and national overviews and subject reviews invited from leading experts were included to introduce the program of technical sessions. The invited papers were supported by contributions accepted from participants for oral and poster presentation. A Technical Exhibition was held in association with the Conference. This volume contains the full text or extended abstracts of papers number 61- to number 114

  4. Second international conference on isotopes. Conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, C.J. [ed.

    1997-10-01

    The Second International Conference on Isotopes (2ICI) was hosted by the Australian Nuclear Association in Sydney, NSW, Australia. The Theme of the Second Conference: Isotopes for Industry, Health and a Better Environment recognizes that isotopes have been used in these fields successfully for many years and offer prospects for increasing use in the future. The worldwide interest in the use of research reactors and accelerators and in applications of stable and radioactive isotopes, isotopic techniques and radiation in industry, agriculture, medicine, environmental studies and research in general, was considered. Other radiation issues including radiation protection and safety were also addressed. International and national overviews and subject reviews invited from leading experts were included to introduce the program of technical sessions. The invited papers were supported by contributions accepted from participants for oral and poster presentation. A Technical Exhibition was held in association with the Conference. This volume contains the full text or extended abstracts of papers number 61- to number 114

  5. Advances in optical water isotope ratio measurements

    International Nuclear Information System (INIS)

    Isotope ratio mass spectrometers routinely achieve impressive measurement precision and high throughput. In spite of this, a number of fundamental and practical problems are encountered. These are most notable in the case of water, arguably the most important molecule in the environment. Optical techniques to measure stable isotope ratios are able to address at least some of these issues; particularly, in relation to sample pretreatment and the difficulty of in-situ measurements. After discussing some general design criteria for infrared laser-based isotope ratio spectrometers, the case made above will be illustrated with a number of different instruments in applications from earthbound to the atmospheric: From laboratory based ice-core water isotope analyses to in-situ water isotope measurements in the upper troposphere and lower stratosphere. (author)

  6. Carbon isotope effects associated with aceticlastic methanogenesis

    Science.gov (United States)

    Gelwicks, J. T.; Risatti, J. B.; Hayes, J. M.

    1994-01-01

    The carbon isotope effects associated with synthesis of methane from acetate have been determined for Methanosarcina barkeri 227 and for methanogenic archaea in sediments of Wintergreen Lake, Michigan. At 37 degrees C, the 13C isotope effect for the reaction acetate (methyl carbon) --> methane, as measured in replicate experiments with M. barkeri, was - 21.3% +/- 0.3%. The isotope effect at the carboxyl portion of acetate was essentially equal, indicating participation of both positions in the rate-determining step, as expected for reactions catalyzed by carbon monoxide dehydrogenase. A similar isotope effect, - 19.2% +/- 0.3% was found for this reaction in the natural community (temperature = 20 degrees C). Given these observations, it has been possible to model the flow of carbon to methane within lake sediment communities and to account for carbon isotope compositions of evolving methane. Extension of the model allows interpretation of seasonal fluctuations in 13C contents of methane in other systems.

  7. Isotopic ratios in the solar system

    International Nuclear Information System (INIS)

    This colloquium is aimed at presentation of isotope ratio measurements in different objects of solar system and surrounding interstellar space and evaluation of what information on composition and structure of primitive solar nebula and on chemical evolution of interstellar space in this part of the galaxy can be deduced from it. Isotope ratio in solar system got from laboratory study of extraterrestrial materials is a subject of this colloquium. Then isotope ratio measured in solar wind, planets and comets. Measurements either are made in-situ by mass spectrometry of ions in solar wind or planetery atmosphere gases either are remote measurements of spectra emitted by giant planets and comets. At last, planetology and astrophysics implications are presented and reviewed. Consraints for solar system formation model can be deduced from isotope ratio measurement. Particularly, isotope anomalies are marks of the processes, which have influenced the primitive solar nebula contraction

  8. An ionic cyclotron resonance isotopic separation device

    International Nuclear Information System (INIS)

    Isotopes are separated using ion cyclotron resonance. The process takes place under vacuum in a vertical cylindrical vessel, with means for creating a plasma containing ions of the isotope to be separated. An electrical field is generated, perpendicular to a vertical magnetic field and oscillating at a frequency near to the cyclotron frequency of the isotope in question. Mixtures enriched and depleted in the isotopes in question are collected separately in the upper part of the vessel. The plasma generator includes a container for the element for treatment made of electro-conducting material which does not melt at operating temperature, open at the top. During operation part of the container is held at a high enough temperature to provoke evaporation or sublimation of the element being treated, while its upper part stays cooler. An ionizer is situated above the container. Isotopes of metals such as zinc, cadmium, tin, calcium and particularly gadolinium can be separated. 1 fig

  9. Manus Water Isotope Investigation Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Jessica L [University of Illinois, Urbana-Champaign; Cobb, Kim M [Georgia Institute of Technology; Noone, David [University of Colorado, Boulder

    2016-03-01

    The objective of this field campaign was to investigate climatic controls on the stable isotopic composition of water vapor, precipitation, and seawater in the western tropical Pacific. Simultaneous measurements of the stable isotopic composition of vapor and precipitation from April 28 to May 8, 2013, at the Manus Tropical Western Pacific Atmospheric Radiation Measurement site, provided several key insights into the nature of the climate signal archived in precipitation and vapor isotope ratios. We observed a large shift from lower to higher isotopic values in vapor and precipitation because of the passage of a mesoscale convective system west of the site and a transition from a regional stormy period into a more quiescent period. During the quiescent period, the stable isotopic composition of vapor and precipitation indicated the predominance of oceanic evaporation in determining the isotopic composition of boundary-layer vapor and local precipitation. There was not a consistent relationship between intra-event precipitation amount at the site and the stable isotopic composition of precipitation, thus challenging simplified assumptions about the isotopic “amount effect” in the tropics on the time scale of individual storms. However, some storms did show an amount effect, and deuterium excess values in precipitation had a significant relationship with several meteorological variables, including precipitation, temperature, relative humidity, and cloud base height across all measured storms. The direction of these relationships points to condensation controls on precipitation deuterium excess values on intra-event time scales. The relationship between simultaneous measurements of vapor and precipitation isotope ratios during precipitation events indicates the ratio of precipitation-to-vapor isotope ratios can diagnose precipitation originating from a vapor source unique from boundary-layer vapor and rain re-evaporation.

  10. Isotopic Measurement of Uranium by Mass Spectrometry

    International Nuclear Information System (INIS)

    The growing application of atomic energy creates a wider need for precise and accurate knowledge of the isotopic composition of uranium. This information is particularly of great importance in the accountability and transfer of enriched uranium for reactor and research applications involving millions of dollars worth of fissionable materials. Reliable isotopic measurements are also necessary to ensure compliance of fuel element compositions with the reactor design specifications and to permit calculation of process and fuel burn-up losses. Mass spectrometry methods, which far surpass the capabilities of other methods, Were developed for very precise isotopic determinations. These methods, ''Single Standard'' and ''Double Standard'', involve the comparison of measurements of an unknown sample to similar measurements on known standards. Use of the ''Double Standard'' method eliminates the effects of instrument bias, thus permitting isotopic determinations with precisions (95% limit of error) of the order of ± 0.02% of the values. Accuracies are limited only by the knowledge of the standard values used, which are referenced to the series of uranium isotopic standards available from the US National Bureau of Standards. The mass spectrometers are also useful for the absolute determination of isotopic composition of uranium, especially in forms other than UF6. Thermal ionization techniques using high-resolution (approximately 12-in. radius) spectrometers permit the absolute isotopic characterization of the minor isotopes (i.e. those less than 10 wt.%) with an accuracy and precision of about 0.5% of the values per analysis. These analyses are particularly useful in calibrating highly enriched and highly depleted uranium for subsequent use as blending materials in an isotopic standards programme. Both relative and absolute isotopic measurement methods are described as well as their application in the accountability and operational analytical programmes. These applications

  11. Isotope investigation of Lake Malawi

    International Nuclear Information System (INIS)

    A vertical tritium and stable isotope profile shows that in the meromictic Lake Malawi water mixes slowly but at a significantly higher rate than in Lake Tanganyika, which has similar morphological characteristics. The tritium balance indicates that half or more of the tritium stored in the lake derives from molecular exchange with the atmospheric moisture. The tritium profile enables the vertical mixing rate in the lake to be computed. For this, a three-box model is used corresponding to epilimnion, metalimnion and hypolimnion. The computation indicates that on the average about 25% of the water is exchanged every year between the epilimnion and the metalimnion and about 20% between the metalimnion and the hypolimnion. (author)

  12. Isotope-committee reports 1999

    International Nuclear Information System (INIS)

    In this compilation the use of radioactive substances in therapies and in vivo examinations during 1999 is presented. For each examination the nuclide, chemical form, way of administration, number of hospitals, total number of examinations, mean activity used, interval of mean activity for the different hospitals and maximum activity is presented. Some examinations may be found at several different places. This is due to diverse routines of reporting and the confused use of old and new classifications. A certain caution is recommended when interpreting the data. Of the compilation it becomes known that during 1999 approximately 109,000 examinations and 2900 therapies were performed. The isotope committees at two hospitals have not presented their statistics

  13. Apparatus for storing hydrogen isotopes

    International Nuclear Information System (INIS)

    An improved method and apparatus for storing isotopes of hydrogen (especially tritium) are provided. The hydrogen gas(es) is (are) stored as hydrides of material (for example uranium) within boreholes in a block of copper. The mass of the block is critically important to the operation, as is the selection of copper, because no cooling pipes are used. Because no cooling pipes are used, there can be no failure due to cooling pipes. And because copper is used instead of stainless steel, a significantly higher temperature can be reached before the eutectic formation of uranium with copper occurs, (the eutectic of uranium with the iron in stainless steel forming at a significantly lower temperature)

  14. Fully isotopic model of fragmentation

    International Nuclear Information System (INIS)

    A general model for the fragmentation of a two-component or bipartite system (e.g., protons and neutrons) is proposed and solved exactly. The extension of this model to any number of components is also shown to be exactly solvable. A connection between this model and the permutation group is discussed and used to obtain closed-form solutions. The notion of isotopic equivalence is defined in order to evaluate the equivalence of these models to earlier one-component models. All the one-component models considered in earlier papers are shown to be equivalent to a particular subclass of two-component models. A simplified model applicable to the case of nuclear fragmentation is introduced and analyzed. Modifications to this model to include effects such as pairing and Coulomb interactions are discussed

  15. A Canadian isotope success story

    International Nuclear Information System (INIS)

    This paper provides some historical background on the commercial production of radioisotopes in Canada, and the evolution of the present vendor, MDS Nordion. The chief isotopes are molybdenum 99, iodine 131, and cobalt 60. Cobalt 60 for medical sterilization and irradiation is considered to be a significant growing market. Food irradiation is believed to be a big marketing opportunity, although attempts to popularize it have so far met with limited success. Candu reactors supply the bulk of the world's 60Co supply. Eighty percent of the world's 99Mo supply for medical imaging comes from Canada, and is at present produced in NRU Reactor, which is to be replaced by two Maple reactors coming into production in 1999 and 2000

  16. Isotopic signatures by bulk analyses

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has developed a series of measurement techniques for identification of nuclear signatures by analyzing bulk samples. Two specific applications for isotopic fingerprinting to identify the origin of anthropogenic radioactivity in bulk samples are presented. The first example is the analyses of environmental samples collected in the US Arctic to determine the impact of dumping of radionuclides in this polar region. Analyses of sediment and biota samples indicate that for the areas sampled the anthropogenic radionuclide content of sediments was predominantly the result of the deposition of global fallout. The anthropogenic radionuclide concentrations in fish, birds and mammals were very low. It can be surmised that marine food chains are presently not significantly affected. The second example is isotopic fingerprinting of water and sediment samples from the Rocky Flats Facility (RFP). The largest source of anthropogenic radioactivity presently affecting surface-waters at RFP is the sediments that are currently residing in the holding ponds. One gram of sediment from a holding pond contains approximately 50 times more plutonium than 1 liter of water from the pond. Essentially 100% of the uranium in Ponds A-1 and A-2 originated as depleted uranium. The largest source of radioactivity in the terminal Ponds A-4, B-5 and C-2 was naturally occurring uranium and its decay product radium. The uranium concentrations in the waters collected from the terminal ponds contained 0.05% or less of the interim standard calculated derived concentration guide for uranium in waters available to the public. All of the radioactivity observed in soil, sediment and water samples collected at RFP was naturally occurring, the result of processes at RFP or the result of global fallout. No extraneous anthropogenic alpha, beta or gamma activities were detected. The plutonium concentrations in Pond C-2 appear to vary seasonally

  17. Isotopic yield in cold binary fission of even-even 244-258Cf isotopes

    Science.gov (United States)

    Santhosh, K. P.; Cyriac, Annu; Krishnan, Sreejith

    2016-05-01

    The cold binary fission of even-even 244-258Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. The favorable fragment combinations are obtained from the cold valley plot (plot of driving potential vs. mass number of fragments) and by calculating the yield for charge minimized fragments. It is found that for 244,246,248Cf isotopes highest yield is for the fragments with isotope of Pb (Z = 82) as one fragment, whereas for 250Cf and 252Cf isotopes the highest yield is for the fragments with isotope of Hg (Z = 80) as one fragment. In the case of 254,256,258Cf isotopes the highest yield is for the fragments with Sn (Z = 50) as one fragment. Thus, the fragment combinations with maximum yield reveal the role of doubly magic and near doubly magic nuclei in binary fission. It is found that asymmetric splitting is favored for Cf isotopes with mass number A ≤ 250 and symmetric splitting is favored for Cf isotopes with A > 252. In the case of Cf isotope with A = 252, there is an equal probability for asymmetric and symmetric splitting. The individual yields obtained for the cold fission of 252Cf isotope are compared with the experimental data taken from the γ- γ- γ coincidences technique using Gammasphere.

  18. Process and apparatus for isotopic enrichment using lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lahoda, E.J.; Burgman, H.A.; Snyder, T.S.

    1986-04-22

    A process is described for the separation of a first isotope of an element from other isotopes of the element. The isotopes are present as a mixture in an isotopic compound, and one of the isotopic compounds is excitable by light at a wavelength where the other isotopic compounds remain stable. The process consists of: coating discrete, small bead particles, which particles are transparent at the wavelength, with a monolayer of the mixture of isotopic compound; entraining the coated particles in a carrier gas containing a scavenger gas for an excited one of the isotopic compounds; exposing the coated particles, while so entrained to light, to excite one of the isotopic compounds and cause reaction thereof with the scavenger gas and form a reaction product, while the other isotopic compounds remain stable; and separating the reaction product from the other isotopic compounds. An apparatus is also described for use in separating one isotope of an element from other isotopes of the element wherein the isotopes are present as a mixture in an isotopic compound, and where one of the isotopic compounds is excitable by light at a wavelength where the other isotopic compounds remain stable. The apparatus consists of: means for coating discrete, small bead particles, which particles are transparent at the wavelength, with a monolayer of the mixture of isotopic compound; means for entraining the coated bead particles with a carrier gas containing a scavenger gas for an excited one of the isotopic compounds; a reaction in which the coated entrained beads are charged; a light source directing light of the wavelength onto the coated entrained beads in the reaction vessel, whereby one of the isotopic compounds is excited by the light and reacts with the scavenger gas to form a reaction product, while the other isotopic compounds remain stable; and means for separating the reaction product from the other isotopic compounds.

  19. Process and apparatus for isotopic enrichment using lasers

    International Nuclear Information System (INIS)

    A process is described for the separation of a first isotope of an element from other isotopes of the element. The isotopes are present as a mixture in an isotopic compound, and one of the isotopic compounds is excitable by light at a wavelength where the other isotopic compounds remain stable. The process consists of: coating discrete, small bead particles, which particles are transparent at the wavelength, with a monolayer of the mixture of isotopic compound; entraining the coated particles in a carrier gas containing a scavenger gas for an excited one of the isotopic compounds; exposing the coated particles, while so entrained to light, to excite one of the isotopic compounds and cause reaction thereof with the scavenger gas and form a reaction product, while the other isotopic compounds remain stable; and separating the reaction product from the other isotopic compounds. An apparatus is also described for use in separating one isotope of an element from other isotopes of the element wherein the isotopes are present as a mixture in an isotopic compound, and where one of the isotopic compounds is excitable by light at a wavelength where the other isotopic compounds remain stable. The apparatus consists of: means for coating discrete, small bead particles, which particles are transparent at the wavelength, with a monolayer of the mixture of isotopic compound; means for entraining the coated bead particles with a carrier gas containing a scavenger gas for an excited one of the isotopic compounds; a reaction in which the coated entrained beads are charged; a light source directing light of the wavelength onto the coated entrained beads in the reaction vessel, whereby one of the isotopic compounds is excited by the light and reacts with the scavenger gas to form a reaction product, while the other isotopic compounds remain stable; and means for separating the reaction product from the other isotopic compounds

  20. An attempt for the precise isotope analysis

    International Nuclear Information System (INIS)

    A compact virtual image double focusing mass spectrometer was adopted for the precise isotope analysis with surface ionization ion source. A interface with 16-bit DA converter was set into the computer for automatic control of magnetic field. This new system enabled to measure isotopic ratios by peak hopping method. To obtain high precision, the digital voltmeter under computer control was introduced for collecting data and processing them successively. The flatness of the peak top and the stability of the magnetic field during the single run were checked and found to be satisfactory. For the test of the measuring system, the isotopic ratios of K, Rb and Sr were measured using shelf reagents. It was concluded that (1) by the Faraday collector, the isotopic ratio could be measured with the precision better than 0.01 % when the ion currents for both isotopes were higher than 10-11 A, (2) for the isotope less abundant than 10-4, the precision achieved a few percent by Faraday collector with ion current of 10-15 A, while the precision was within 1 % by SEM collector with ion current of 10-17 A. The performance of the mass spectrometer was found to be satisfactory to measure isotopic ratios with a high precision. (author)

  1. Carbon isotope separation by absorptive distillation

    International Nuclear Information System (INIS)

    The feasibility of separating carbon isotopes by absorptive distillation has been studied for CO absorption by cryogenic solvents. Phase equilibrium, isotopic separation, and mass transfer data were taken between 77.4 and 114.3 K for the following solvents: propane, propylene, 1:1 propane-propylene, 1-butene, isobutane and nitrogen. Carbon monoxide solubility followed Henry's Law, with a maximum experimental solubility of 6.5 mole percent. Isotopic separation between CO in the gas and liquid phases using hydrocarbon solvents was several times that for pure CO vapor-liquid equilibrium. The maximum observed isotopic separation factor was 1.029 at 77.4 K with the propane-propylene solvent mixture. Mass transfer measurements yielded calculated HETP's of 2 to 5 cm for a possible separation system. An attempt has been made to correlate isotopic separation data using Hildebrand's theory of solutions. The differential absorption of isotopic CO species is expressed as a difference in solubility of the isotopic CO molecules. Data for propane, propylene, and 1-butene show approximately the same behavior at varying temperatures

  2. Deconstructing nitrate isotope dynamics in aquifers

    Science.gov (United States)

    Granger, J.

    2012-12-01

    The natural abundance N and O stable isotope ratios of nitrate provide an invaluable tool to differentiate N sources to the environment, track their dispersal, and monitor their attenuation by biological transformations. The interpretation of patterns in isotope abundances relies on knowledge of the isotope ratios of the source end-members, as well as on constraints on the isotope discrimination imposed on nitrate by respective biological processes. Emergent observations from mono-culture experiments of denitrifying bacteria reveal nitrate fractionation trends that appear at odds with trends ascribed to denitrification in soils and aquifers. This discrepancy raises the possibility that additional biological N transformations may be acting in tandem with denitrification. Here, the N and O isotope enrichments associated with nitrate removal by denitrification in aquifers are posited to bear evidence of coincident biological nitrate production - from nitrification and/or from anammox. Simulations are presented from a simple time-dependent one-box model of a groundwater mass ageing that is subject to net nitrate loss by denitrification with coincident nitrate production by nitrification or anammox. Within boundary conditions characteristic of freshwater aquifers, the apparent slope of the parallel enrichments in nitrate N and O isotopes associated with net N loss to denitrification can vary in proportion to the nitrate added simultaneous by oxidative processes. Pertinent observations from nitrate plumes in suboxic to anoxic aquifers are examined to validate this premise. In this perspective, nitrate isotope distributions suggest that we may be missing important N fluxes inherent to most aquifers.

  3. Isotope effects in the gadolinium amalgam system

    International Nuclear Information System (INIS)

    Gadolinium is a good neutron absorbent used in uranium oxide nuclear fuel for LWR. The157 Gd has a very large cross section for neutron absorption, namely 254000 barn. One of the isotope separation method for gadolinium is the isotopic exchange in the Gd3+ - GdHg system. In this work, the separation elemental factors for this isotopic exchange reaction, determined experimentally, are presented. Gadolinium amalgam was prepared by electrolysis of aqueous solution of gadolinium acetate with lithium citrate as complexing agent ([Li+]/[Gd3+] = 12), in a glass electrolyzer with a Hg cathode and a Pt anode. The gadolinium amalgam was treated with HCl 1-2N and the extracted Gd3+ was precipitated as oxalate and converted in Gd2O3. Gadolinium in acetic solution was precipitated as oxalate and converted in Gd2O3. The isotopic ratios 154 Gd/160 Gd, 155 Gd/160 Gd, 156 Gd/160 Gd, 157 Gd/160 Gd and 158 Gd/160 Gd were determined in Gd2O3 samples by a mass spectrometer MAT 261 equipped with thermoionization ion source. After the isotopic exchange, GdHg enriches with the light Gd isotopes and the solution (Gd3+) enriches with 160 Gd. The dependence of separation elemental factor on mass difference between gadolinium isotopes is presented. (authors)

  4. Carbon isotope separation by absorptive distillation

    International Nuclear Information System (INIS)

    The feasibility of separating carbon isotopes by absorptive distillation has been studied for CO absorption by cryogenic solvents. Phase equilibrium, isotopic separation, and mass transfer data were taken between 77.4 and 114.3 K for the following solvents: propane, propylene, 1:1 propane-propylene, 1-butene, isobutane and nitrogen. Carbon monoxide solubility followed Henry's Law, with a maximum experimental solubility of 6.5 mole per cent. Isotopic separation between CO in the gas and liquid phases using hydrocarbon solvents was several times that for pure CO vapor-liquid equilibrium. The maximum observed isotopic separation factor was 1.029 at 77.4 K with the propane-propylene solvent mixture. Mass transfer measurements yielded calculated HTU's of 2 to 5 cm for a possible separation system. An attempt has been made to correlate isotopic separation data using Hildebrand's theory of solutions. The differential absorption of isotopic CO species is expressed as a difference in solubility of the isotopic CO molecules. Data for propane, propylene, and 1-butene show approximately the same behavior at varying temperatures

  5. The isotope effect: Prediction, discussion, and discovery

    CERN Document Server

    Kragh, Helge

    2011-01-01

    The precise position of a spectral line emitted by an atomic system depends on the mass of the atomic nucleus and is therefore different for isotopes belonging to the same element. The possible presence of an isotope effect followed from Bohr's atomic theory of 1913, but it took several years before it was confirmed experimentally. Its early history involves the childhood not only of the quantum atom, but also of the concept of isotopy. Bohr's prediction of the isotope effect was apparently at odds with early attempts to distinguish between isotopes by means of their optical spectra. However, in 1920 the effect was discovered in HCl molecules, which gave rise to a fruitful development in molecular spectroscopy. The first detection of an atomic isotope effect was no less important, as it was by this means that the heavy hydrogen isotope deuterium was discovered in 1932. The early development of isotope spectroscopy illustrates the complex relationship between theory and experiment, and is also instructive with...

  6. Stable isotope composition of Earth's large lakes

    Science.gov (United States)

    Jasechko, S.; Gibson, J. J.; YI, Y.; Birks, S. J.; Sharp, Z. D.

    2011-12-01

    Lakes cover about three percent of Earth's continental area. Large lakes can significantly influence lake shore and regional climates by increasing specific humidity during evaporation and by moderating air temperatures. Stable isotopes of oxygen and hydrogen can be used to quantify lake evaporation, providing a supplementary and often cost-advantageous alternative to conventional hydrologic approaches that require over lake monitoring. Further, stable isotopes in lake sediments are an established tool in paleolimnology; however, interpreting changes to a lake's past isotope composition requires a comprehensive understanding of contemporary controls. Here, δ18O and δ2H values of water in modern lakes exceeding roughly five hundred square kilometres are compiled (n > 35). Voluminous and seasonally mixed lakes - such as the North American Great Lakes - have the most homogenous stable isotope compositions, while perennially-stratified and shallow lakes show greater variability. A rudimentary stable isotope mass balance is used to assess evaporation fluxes from large lakes on Earth. The approach taken simultaneously constrains evaporation outputs for both oxygen and hydrogen stable isotopes by accounting for lake effects on the overlying atmosphere. Model development highlights important considerations such as isotopic stratification (Tanganyika), disequilibrium isotopic mass balances (Baikal), and non-steady hydrologic balances. Further, the isotope composition of Earth's continental surface water reservoir is calculated. This value - weighted to volume - is δ18O = -7.5±1.7 per mille relative to standard mean ocean water. The compiled data may be a useful tracer of continental evaporate in global atmospheric water cycle studies and could be coupled to climate models capable of incorporating oxygen-18 and deuterium tracers to improve or validate calculations of lake effects on regional water cycling.

  7. Stable Vanadium Isotope Fractionation at High Temperatures

    Science.gov (United States)

    Prytulak, J.; Parkinson, I. J.; Savage, P. S.; Nielsen, S. G.; Halliday, A. N.

    2011-12-01

    Vanadium is a redox sensitive transition metal existing in multiple valence states at terrestrial conditions. Stable vanadium isotopes (reported as δ51V in % relative to an Alfa Aesar standard [1]) are a potentially powerful tracer of oxidation-reduction processes. However, the determination of δ51V is analytically challenging, primarily due to the extreme abundance ratio between the only two stable isotopes (51V/50V ~ 400) and, also, significant isobaric interferences of 50Ti and 50Cr on the minor 50V isotope. We have developed the first method able to determine δ51V to a precision (2 s.d. ~ 0.15%, [1,2]) that enables application of this isotope system to geological processes. To usefully investigate high temperature processes using vanadium isotopes, knowledge of the isotope composition and range of values present in the ambient mantle is required. Here we discuss the first δ51V measured in igneous materials encompassing peridotites, MORB, and primitive mantle-derived melts such as picrites. This first dataset provides a preliminary reconnaissance of the magnitude of natural fractionation. We find little isotope fractionation in suites of peridotites and MORB (vanadium isotope fractionation that may be expected at high temperatures. The presence of significant isotope variation outside of analytical precision in these materials bodes well for the use of δ51V to address a variety of broad scale questions in high temperature planetary processes. [1] Nielsen, S.G., Prytulak, J., Halliday, A.N. 2011. Geost. Geoanal. Res., in press. [2] Prytulak, J., Nielsen, S.G., Halliday, A.N. 2011. Geost. Geoanal. Res., in press. [3] Parkinson and Pearce, 1998. Journal of Petrology, 39, 1577-1618. [4] Lee et al., 2005. Journal of Petrology, 46, 2313-2336. [5] Cottrell and Kelley, 2011. Earth and Planetary Sciences Letters, 305, 270-282.

  8. Technical testing of portable isotope identification instruments

    International Nuclear Information System (INIS)

    Radiation detection technology exists in the form of pocket size, hand-held and portal radiation detectors that have the ability to detect radiation with great sensitivity and low false alarm rates. US Customs has chosen to implement pocket size detectors or radiation pagers as the personal tool of each inspector for the detection of radioactive material. First generation portable isotope identifiers were identified and evaluated by US Customs. Instruments from five vendors were put through a battery of tests according to delineated test procedures. The tests fell into five categories: basic operation verification; medical isotope identification; individual isotope identification; isotope pair identification; dose rate calculation. The tests can be summarized as an initial verification of correct instrument operation (including whatever calibration procedure was specified by the vendor), followed by three different isotope identification tests designed to verify the instrument's ability to correctly identify 19 isotopes specified by US Customs. The final test determined each instrument's ability to correctly display the dose rate from a wide energy range of gamma emitters. The individual isotope identification test and the isotope pair identification test were performed with three types of intervening shielding. The isotopes tested were broadly categorized as: special nuclear material, medical, and industrial. These included 17 gamma emitters, 1 beta emitter, and 1 neutron emitter. Each instrument's ability to identify several pairs of isotopes was determined. This test was intended to verify if the instrument could detect SNM when accompanied by a masking isotope. Finally, each instrument's dose rate response to different energy gamma emitters was measured. One section of this test was conducted at a very low exposure rate, 10 micro R/hr above background, and the second section conducted at 2 m R/hr above background. The latter dose rate represented the expected

  9. Beneficial uses and production of isotopes

    CERN Document Server

    2001-01-01

    Isotopes, radioactive and stable, are used worldwide in various applications related to medical diagnosis or care, industry and scientific research. More than fifty countries have isotope production or separation facilities operated for domestic supply, and sometimes for international markets. This publication provides up-to-date information on the current status of, and trends in, isotope uses and production. It also presents key issues, conclusions and recommendations, which will be of interest to policy makers in governmental bodies, scientists and industrial actors in the field.

  10. Isotope separation of gadolinium using optical pumping

    International Nuclear Information System (INIS)

    The gadolinium atoms in the 533 cm-1 metastable level were photoionized by pulsed laser beams after the population of 160Gd in the 533 cm-1 metastable level had been reduced by optical pumping using a continuous wave ring dye laser. Mass spectra of the ionized gadolinium atoms showed that an abundance ratio of 160Gd decreased from natural isotope abundance of 21.8 % to 1 %. This result demonstrates the isotope separation by photoionization of the atoms after decreasing of the photoionized level population of selected isotope using optical pumping. (author)

  11. Pb isotopes during mingling and melting

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Lesher, Charles E.

    2010-01-01

    Pb isotopic data are presented for hybrid rocks formed by mingling between mantle-derived tholeiitic magma of the Eocene Miki Fjord macrodike (East Greenland) and melt derived from the adjacent Precambrian basement. Bulk mixing and AFC processes between end-members readily identified in the field...... grain boundaries during disequilibrium melting of the host rock by the mafic magma. The crustal melt involved in magma interactions was therefore heterogeneous with respect to Pb isotopes on a metre-scale. These results illustrate the difficulties inherent in interpreting isotopic variations...

  12. Elementary excitations in isotope-mixed crystals

    International Nuclear Information System (INIS)

    Over the last five decades, the isotope effect has been one of the major research in solids. Most of the physical properties of a solid depend to a greater or lesser degree on its isotopic composition. Scientific interest, technological promise and increased availability of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor and insulator crystals. A great number of stable isotopes and well-developed methods of their separation has made it possible to date to grow crystals of C, LiH, ZnO, ZnSe, CuCl, GaN, GaAs, CdS, Cu2O, Si, Ge and α-Sn with a controllable isotopic composition. The use of such objects allows the investigation of not only the isotope effects in lattice dynamics (vibrational, elastic and thermal properties) but also the influence of such effects on the electronic states via electron-phonon coupling (the renormalization of the band-to-band transition energy Eg, the exciton binding energy EB and the size of the longitudinal-transverse splitting ΔLT). The thermal conductivity enhancement in the isotopically enriched materials amounts (C; Ge; Si) to almost 10% at room temperature and is close to a factor of six at the thermal conductivity maximum around 20K (Si-case). The change in the lattice constant is Δa/a∼10-3-10-4, while the change δcik in the elastic constants amounts to several percent. The nonlinear dependence of the free exciton luminescence (especially Cx1312C1-x, LiHxD1-x) intensity on the excitation density allows to consider these crystals as potential solid-state lasers in the UV part of the spectrum. Isotopic information storage may consist in assigning the information 'zero' or 'one' to mono-isotopic microislands (or even to single atoms) within a bulk crystalline (or thin film) structure. Isotope information storage and isotope quantum computers are briefly discussed

  13. Isotope effects on desorption kinetics of hydrogen isotopes implanted into stainless steel by glow discharge

    International Nuclear Information System (INIS)

    In a fusion device the control of fuel particles implies to know the desorption rate of hydrogen isotopes by the plasma-facing materials. In this paper desorption kinetics of hydrogen isotopes implanted into type 316L stainless steel by glow discharge have been studied by experiment and numerical calculation. The temperature of a maximum desorption rate depends on glow discharge time and heating rate. Desorption spectra observed under various experimental conditions have been successfully reproduced by numerical simulations that are based on a diffusion-limited process. It is suggested, therefore, that desorption rate of a hydrogen isotope implanted into the stainless steel is limited by a diffusion process of hydrogen isotope atoms in bulk. Furthermore, small isotope effects were observed for the diffusion process of hydrogen isotope atoms. (authors)

  14. Isotope effects on desorption kinetics of hydrogen isotopes implanted into stainless steel by glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, M.; Kondo, M.; Noda, N. [Hydrogen Isotope Research Center, University of Toyama, Gofuku, Toyama (Japan); Tanaka, M.; Nishimura, K. [National Institute for Fusion Science, Toki-shi, Gifu (Japan)

    2015-03-15

    In a fusion device the control of fuel particles implies to know the desorption rate of hydrogen isotopes by the plasma-facing materials. In this paper desorption kinetics of hydrogen isotopes implanted into type 316L stainless steel by glow discharge have been studied by experiment and numerical calculation. The temperature of a maximum desorption rate depends on glow discharge time and heating rate. Desorption spectra observed under various experimental conditions have been successfully reproduced by numerical simulations that are based on a diffusion-limited process. It is suggested, therefore, that desorption rate of a hydrogen isotope implanted into the stainless steel is limited by a diffusion process of hydrogen isotope atoms in bulk. Furthermore, small isotope effects were observed for the diffusion process of hydrogen isotope atoms. (authors)

  15. Laser isotope separation using Ti:sapphire laser

    International Nuclear Information System (INIS)

    The application of Ti:sapphire laser to atomic vapor laser isotope separation is studied. The laser system needs broad tunability, narrow linewidth, high power, high repetition rate, etc. The laser was applied for the laser isotope separation of rubidium. Ion spectra of each isotope indicate that each isotope, 85Rb and 87Rb, was selectively photoionized. (author)

  16. Zinc isotope discrimination effect in inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Inductively coupled plasma mass spectrometry (ICPMS) has recently been used for isotope ratio analysis. The isotope discrimination effect in the mass spectrometer is a primary factor contributing to loss of precision and accuracy in isotope ratio analysis. The discrimination effect of zinc isotopes was investigated by comparing the results obtained using a quadrupole type ICPMS with those obtained using a thermal ionization mass spectrometer

  17. Isotopic fingerprints in surficial waters : Stable isotope methods applied in hydrogeological studies

    OpenAIRE

    Kortelainen, Nina

    2007-01-01

    The driving force behind this study has been the need to develop and apply methods for investigating the hydrogeochemical processes of significance to water management and artificial groundwater recharge. Isotope partitioning of elements in the course of physicochemical processes produces isotopic variations to their natural reservoirs. Tracer property of the stable isotope abundances of oxygen, hydrogen and carbon has been applied to investigate hydrogeological processes in Finland. The work...

  18. Short course on St-02 applications of isotope dilutions and isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Miller, P.

    1998-01-05

    This short course includes information on these topics and subtopics: (I) Nuclear Properties: (A) Historic roots; (B) Nomenclature; (C) Nuclear Stability and abundance; (D) Uses of isotopic techniques; (II) Instrumentation: (A) Sources; (B) Mass resolving elements; (C) Detectors; (III) Making Isotopic Measurements by ICP-MS: (A) Deadtime Correction; (B) Mass Discrimination; (C) Signal /Noise considerations; (IV) Applications and examples: (A) Isotope dilution; (B) Double Spike; (C) Biological Application; (D) Environmental Application; (E) Geological.

  19. Application of heavy stable isotopes in forensic isotope geochemistry: A review

    International Nuclear Information System (INIS)

    Light stable isotopes have been used for many years to characterize the source and transport of materials. More recently heavy isotope systems such as Sr, Nd and Pb have been added to this list in order to aid source identification. With the advent of multiple collector ICP-MS, the range of isotopic tools now available has increased considerably, however, until the isotope systematics of these new non-traditional isotope systems have become better understood, they will not be as useful in characterizing material source and transportation. Applications using heavy metal stable isotopes (mostly traditional heavy isotopes) have reached most avenues in science, including earth sciences, archaeology, anthropology, animal physiology, ecology and toxicology. This field will continue to grow as new applications are developed and techniques become simpler and quicker. This paper provides a review of how this field has grown and presents two new applications using Pb and Sr isotopes in glazes to determine the source of ore used in glazes, and using Sr isotopes to determine the origin of undocumented deceased Mexican border crossers

  20. Isotope pattern deconvolution as rising tool for isotope tracer studies in environmental research

    Science.gov (United States)

    Irrgeher, Johanna; Zitek, Andreas; Prohaska, Thomas

    2014-05-01

    During the last decade stable isotope tracers have emerged as versatile tool in ecological research. Besides 'intrinsic' isotope tracers caused by the natural variation of isotopes, the intentional introduction of 'extrinsic' enriched stable isotope tracers into biological systems has gained significant interest. Hereby the induced change in the natural isotopic composition of an element allows amongst others for studying the fate and fluxes of metals, trace elements and species in organisms or provides an intrinsic marker or tag of particular biological samples. Due to the shoreless potential of this methodology, the number of publications dealing with applications of isotope (double) spikes as tracers to address research questions in 'real world systems' is constantly increasing. However, some isotope systems like the natural Sr isotopic system, although potentially very powerful for this type of application, are still rarely used, mainly because their adequate measurement/determination poses major analytical challenges; as e.g. Sr is available in significant amounts in natural samples. In addition, biological systems underlie complex processes such as metabolism, adsorption/desorption or oxidation/reduction. As a consequence, classic evaluation approaches such as the isotope dilution mass spectrometry equation are often not applicable because of the unknown amount of tracer finally present in the sample. Isotope pattern deconvolution (IPD), based on multiple linear regression, serves as simplified alternative data processing strategy to double spike isotope dilution calculations. The outstanding advantage of this mathematical tool lies in the possibility of deconvolving the isotope pattern in a spiked sample without knowing the quantities of enriched isotope tracer being incorporated into the natural sample matrix as well as the degree of impurities and species-interconversion (e.g. from sample preparation). Here, the potential of IPD for environmental tracer

  1. Laser Ablation Molecular Isotopic Spectrometry: Parameter influence on boron isotope measurements

    International Nuclear Information System (INIS)

    Laser Ablation Molecular Isotopic Spectrometry (LAMIS) was recently reported for optical isotopic analysis of condensed samples in ambient air and at ambient pressure. LAMIS utilizes molecular emissions which exhibit larger isotopic spectral shits than in atomic transitions. For boron monoxide 10BO and 11BO, the isotopic shifts extend from 114 cm-1 (0.74 nm) to 145-238 cm-1 (5-8 nm) at the B2Σ+ (v = 0) → X2Σ+ (v = 2) and A2Πi (v = 0) → X2Σ+ (v = 3) transitions, respectively. These molecular isotopic shifts are over two orders of magnitude larger than the maximum isotopic shift of approximately 0.6 cm-1 in atomic boron. This paper describes how boron isotope abundance can be quantitatively determined using LAMIS and how atomic, ionic, and molecular optical emission develops in a plasma emanating from laser ablation of solid samples with various boron isotopic composition. We demonstrate that requirements for spectral resolution of the measurement system can be significantly relaxed when the isotopic abundance ratio is determined using chemometric analysis of spectra. Sensitivity can be improved by using a second slightly delayed laser pulse arriving into an expanding plume created by the first ablation pulse.

  2. Isotope ratio in stellar atmospheres and nucleosynthesis

    International Nuclear Information System (INIS)

    The determination of isotopic ratios in stellar atmospheres is studied. The isotopic shift of atomic and molecular lines of different species of a certain element is examined. CH and MgH lines are observed in order to obtain the 12C: 13C and 24Mg: 25Mg: 26Mg isotpic ratios. The formation of lines in stellar atmospheres is computed and the resulting synthetic spectra are employed to determine the isotopic abundances. The results obtained for the isotopic ratios are compared to predictions of nucleosynthesis theories. Finally, the concept of primary and secondary element is discussed, and these definitions are applied to the observed variations in the abundance of elements as a function of metallicity. (author)

  3. Isotopic characterisation of groundwater-seawater interactions

    International Nuclear Information System (INIS)

    Isotopic methods for characterisation of groundwater-seawater interactions have been recently developed, and investigations have been carried out in several coastal regions in the framework of the Coordinated Research Project (CRP) on 'Nuclear and Isotopic Techniques for the Characterisation of Submarine Groundwater Discharge in Coastal Zones' coordinated jointly by the IAEA's Isotope Hydrology Section (Vienna) and Marine Environment Laboratories (Monaco). The CRP was carried out in cooperation with UNESCO's Intergovernmental Oceanographic Commission (IOC) and the International Hydrological Programme (IHP), and with several laboratories in Brazil, India, Italy, Japan, Russia, Slovenia, Turkey and US A. An isotopic characterisation of groundwater-seawater interactions is illustrated on a case study carried out in the south-eastern Sicily. (author)

  4. Carbon isotopic fractionation in heterotrophic microbial metabolism

    Science.gov (United States)

    Blair, N.; Leu, A.; Munoz, E.; Olsen, J.; Kwong, E.; Des Marais, D.

    1985-01-01

    Differences in the natural-abundance carbon stable isotopic compositions between products from aerobic cultures of Escherichia coli K-12 were measured. Respired CO2 was 3.4 percent depleted in C-13 relative to the glucose used as the carbon source, whereas the acetate was 12.3 percent enriched in C-13. The acetate C-13 enrichment was solely in the carboxyl group. Even though the total cellular carbon was only 0.6 percent depleted in C-13, intracellular components exhibited a significant isotopic heterogeneity. The protein and lipid fractions were -1.1 and -2.7 percent, respectively. Aspartic and glutamic acids were -1.6 and +2.7 percent, respectively, yet citrate was isotopically identical to the glucose. Probable sites of carbon isotopic fractionation include the enzyme, phosphotransacetylase, and the Krebs cycle.

  5. Water isotope systematics: Improving our palaeoclimate interpretations

    Science.gov (United States)

    Jones, M. D.; Dee, S.; Anderson, L.; Baker, A.; Bowen, G.; Noone, D. C.

    2016-01-01

    The stable isotopes of oxygen and hydrogen, measured in a variety of archives, are widely used proxies in Quaternary Science. Understanding the processes that control δ18O change have long been a focus of research (e.g. Shackleton and Opdyke, 1973; Talbot, 1990; Leng, 2006). Both the dynamics of water isotope cycling and the appropriate interpretation of geological water-isotope proxy time series remain subjects of active research and debate. It is clear that achieving a complete understanding of the isotope systematics for any given archive type, and ideally each individual archive, is vital if these palaeo-data are to be used to their full potential, including comparison with climate model experiments of the past. Combining information from modern monitoring and process studies, climate models, and proxy data is crucial for improving our statistical constraints on reconstructions of past climate variability.

  6. Possible application of laser isotope separation

    International Nuclear Information System (INIS)

    The laser isotope separation process is described and its special economic features discussed. These features are its low cost electric power operation, capital investment costs, and the costs of process materials. (Author)

  7. Isotopic water preparation using AGMD and VEMD

    International Nuclear Information System (INIS)

    The 18O isotope water permeation and separation characteristics of a hydrophobic PTFE membrane using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD) were investigated. Permeation fluxes were measured weighing the collected membrane-permeated water vapor. 18O/16O of each water sample was analyzed by the Tunable Diode Laser Absorption Spectroscopy (TDLAS). We observed the effects of the air filled membrane pores and the temperature gradient applied to membrane surfaces on the vapor permeation flux and the oxygen isotope separation for the first time. For both AGMD and VEMD, the permeation flux and the oxygen isotope separation interfacial temperature gradient increased. Even Through, oxygen isotope separation and the permeation flux for VEMD is slightly higher than AGMD, the latter may be efficient from the system's operational point of view. (author)

  8. Barium Isotopes in Single Presolar Grains

    Science.gov (United States)

    Pellin, M. J.; Davis, A. M.; Savina, M. R.; Kashiv, Y.; Clayton, R. N.; Lewis, R. S.; Amari, S.

    2001-01-01

    Barium isotopic compositions of single presolar grains were measured by laser ablation laser resonant ionization mass spectrometry and the implications of the data for stellar processes are discussed. Additional information is contained in the original extended abstract.

  9. Medium Effects in Reactions with Rare Isotopes

    International Nuclear Information System (INIS)

    We discuss medium effects in knockout reactions with rare isotopes of weakly-bound nuclei at intermediate energies. We show that the poorly known corrections may lead to sizable modifications of knockout cross sections and momentum dsitributions.

  10. A densimeter with radioactive isotope of teaching

    International Nuclear Information System (INIS)

    A densimeter with radioactive isotope beseemed experiment teaching for speciality of nuclear engineering and nuclear technology in higher education is presented. Principle of work and composing of instrument system are introduced briefly

  11. The production of stable isotopes in Spain

    International Nuclear Information System (INIS)

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs

  12. Microscopic description of light Sn isotopes

    International Nuclear Information System (INIS)

    The quasiparticle multistep shell model method is applied to calculate the spectra of light Sn isotopes. A simple interpretation of the main excitations is given. The calculated quantities agree reasonable well with the sparse experimental data which are available. ((orig.))

  13. Quantification of isotopic turnover in agricultural systems

    Science.gov (United States)

    Braun, A.; Auerswald, K.; Schnyder, H.

    2012-04-01

    The isotopic turnover, which is a proxy for the metabolic rate, is gaining scientific importance. It is quantified for an increasing range of organisms, from microorganisms over plants to animals including agricultural livestock. Additionally, the isotopic turnover is analyzed on different scales, from organs to organisms to ecosystems and even to the biosphere. In particular, the quantification of the isotopic turnover of specific tissues within the same organism, e.g. organs like liver and muscle and products like milk and faeces, has brought new insights to improve understanding of nutrient cycles and fluxes, respectively. Thus, the knowledge of isotopic turnover is important in many areas, including physiology, e.g. milk synthesis, ecology, e.g. soil retention time of water, and medical science, e.g. cancer diagnosis. So far, the isotopic turnover is quantified by applying time, cost and expertise intensive tracer experiments. Usually, this comprises two isotopic equilibration periods. A first equilibration period with a constant isotopic input signal is followed by a second equilibration period with a distinct constant isotopic input signal. This yields a smooth signal change from the first to the second signal in the object under consideration. This approach reveals at least three major problems. (i) The input signals must be controlled isotopically, which is almost impossible in many realistic cases like free ranging animals. (ii) Both equilibration periods may be very long, especially when the turnover rate of the object under consideration is very slow, which aggravates the first problem. (iii) The detection of small or slow pools is improved by large isotopic signal changes, but large isotopic changes also involve a considerable change in the input material; e.g. animal studies are usually carried out as diet-switch experiments, where the diet is switched between C3 and C4 plants, since C3 and C4 plants differ strongly in their isotopic signal. The

  14. Groundwater protection and isotope hydrogeology - methodical aspects

    International Nuclear Information System (INIS)

    The importance of groundwater protection increases in all developed countries. The isotope hydrogeology contributes with it's specific methods to the prophylactic protection of groundwater resources especially. Methodical aspects are given. (author)

  15. Isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The potential of isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) was evaluated for the determination of trace amounts of uranium and thorium in silicate rocks. Compared with conventional isotope dilution methods using thermal ionization mass spectrometers, the major benefit is a large increase in sample through-put without a significant decrease in precision and accuracy. This results from direct liquid sampling at atmospheric pressure and from the capability of measuring isotope ratios on raw solutions, without chemical separation of the analytes from the matrix elements. Isotope dilution ICP-MS alleviates the need for matrix-matched standards. Further, it is insensitive to possible causes of intensity drift (e.g., clogging of the plasma/mass spectrometer interface and defocusing of the ion beam) and to chemical effects (e.g. oxide formulation). Results obtained on some international rock standards are in good agreement with recommended values. (author). 26 refs.; 1 fig., tabs

  16. Origin of isotopic spin and strangeness

    International Nuclear Information System (INIS)

    An explanation of the origin of isotopic spin is given by applying the theory and calculations in the author's previous papers. An explanation of the origin of strangeness and broken SU3 is given as well

  17. Implementation of isotope correlation technique for safeguards

    International Nuclear Information System (INIS)

    The isotopic correlation technique (ICT) is based on the fundamental physics principle that the isotopic compositions of nuclear material in the fuel cycle systems contain information regarding the design and history of nuclear material flow from fuel fabrication, reactor operation, and through input to the reprocessing plant. Isotopic Correlation in conjunction with the gravimetric (or Pu/U) method for mass determination can be developed to provide an independent in-field verification of the reprocessing input accountancy at the dissolver and/or accountancy stage of the reprocessing plant. The Argonne National Laboratory program in isotope correlation techniques is based on three-dimensional reactor physics calculations of characteristic geometries/composition in each reactor class. 10 refs., 1 fig., 3 tabs

  18. The anomalous quadrupole collectivity in Te isotopes

    CERN Document Server

    Qi, Chong

    2016-01-01

    We present systematic calculations on the spectroscopy and transition properties of even-even Te isotopes by using the large-scale configuration interaction shell model approach with a realistic interaction. These nuclei are of particular interest since their yrast spectra show a vibrational-like equally-spaced pattern but the few known E2 transitions show anomalous rotational-like behavior, which cannot be reproduced by collective models. Our calculations reproduce well the equally-spaced spectra of those isotopes as well as the constant behavior of the $B(E2)$ values in $^{114}$Te. The calculated $B(E2)$ values for neutron-deficient and heavier Te isotopes show contrasting different behaviors along the yrast line. The $B(E2)$ of light isotopes can exhibit a nearly constant bevavior upto high spins. We show that this is related to the enhanced neutron-proton correlation when approaching $N=50$.

  19. Robust optical carbon dioxide isotope analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Isotopic analysis of carbon dioxide is an important tool for characterization of the exchange and transformation of carbon between the biosphere and the atmosphere....

  20. The Palladium Isotopic Composition in Iron Meteorites

    Science.gov (United States)

    Chen, J. H.; Papanastassiou, D. A.

    2005-01-01

    Ru, Mo and Pd are very useful indicators for the identification of nucleosynthetic components. We have developed techniques for Pd isotopes, in an effort to check the extent of isotopic effects in this mass region and for a Pt-group element which is less refractory than Ru. Stable Pd isotopes are produced by the process only (102Pd), the s-process only (104Pd), the process only (Pd-110) and by both the r- and s-processes (Pd-105, Pd-106, Pd-108). Kelly and Wasserburg reported a hint of a shift in 102Pd (approx. 25(epsilon)u; 1(epsilon)u (triple bonds) 0.01%) in Santa Clara. Earlier searches for Mo and Ru isotopic anomalies were either positive or negative.

  1. Development of proliferation resistant isotope separation technology

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Doyoung; Ko, Kwanghoon; Kim, Taeksoo; Park, Hyunmin; Lim, Gwon; Cha, Yongho; Han, Jaemin; Baik, Sunghoon; Cha, Hyungki

    2012-02-15

    This project was accomplished with an aim of establishing the industrial facilities for isotope separation in Korea. The experiment for the measurement of neutrino mass that has been an issue in physics, needs very much of enriched calcium-48 isotope. However, calcium-48 isotope can be produced only by the electro-magnetic method and, thus, its price is very expensive. Therefore, we expect that ALSIS can replace the electro-magnetic method for calcium-48 isotope production. In this research stage, the research was advanced systematically with core technologies, such as atomic vapor production, the measurement of vapor characteristics and stable and powerful laser development. These researches will be the basis of the next research stages. In addition, the international research trends and cooperation results are reported in this report.

  2. Laser separation methods of uranium isotopes

    International Nuclear Information System (INIS)

    On the basis of numerous investigations main principles and technology of laser method of separation of uranium isotopes are outlined. Lasers characteristic is presented from the viewpoint of possibility of using them for separation of isotopes. The atomic vapour method (working matter-uranium vapour) and the molecular method of laser separation of uranium isotopes are considered. General ideas on econonomics of methods (estimation of capital investments, operating (costs) are presented. It is stressed that main advantage which differ laser methods from other technologies is a high enrichment coefficient attained in one stage of the process. It is assumed that using as feeding of spent materials of traditional plants and not of natural uranium does not essentially spoil the characteristics of the laser isotope separation process

  3. Survey of potential markets for devices using Californium-252

    International Nuclear Information System (INIS)

    Potential applications for devices or systems containing 252Cf in the years from 1975 to 1980 are estimated. The estimated number of devices and associated business value were derived from a survey of 46 industrial, educational and governmental organizations conducted from Jan. to May, 1975. Applications for devices and systems based on 252Cf are expected to increase by a factor of 7 in the 6-y period from 1975 to 1980. The annual business value of 252Cf devices should increase from 1.5 million dollars in 1975 to 10.8 million dollars in 1980. The potential European market should be several times as large as the US market, based on actual sales of 252Cf, which have been two to four times greater in Europe than in the US

  4. The protective cell petrus for the production of californium 252

    International Nuclear Information System (INIS)

    The alpha, beta, gamma, neutron cell which is described in the present paper is devoted to the transplutonium element production and study. It is located at the CEN in Fontenay-aux-Roses (France). The 4 feet ordinary concrete shielding made of stacked blocs allows the manipulation of radioactive sources as high as 1000 curies of 1 MeV gamma rays and with a fast neutrons flux of 109 n.cm-2.s-1. The airtight alpha containment box is equipped with two transfer systems, one consists of a parallelepiped shaped airtight box located in a turntable, the other uses standard cylindrical containers made of polyethylene. The general equipment and the main setting up are also described. (authors)

  5. Californium-252 neutron activation facility at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    A neutron irradiation facility has been established to develop new analytical methods and for the support of research programs. A major component of this facility is a 252Cf source which provides both fission spectrum and thermal neutrons. (U.S.)

  6. Californium-252 brachytherapy for anal and ano-rectal carcinoma

    International Nuclear Information System (INIS)

    Surgery has historically been the standard treatment for anal, ano-rectal and rectal carcinoma but is prone to local or regional failure. Over the past 15 years there has been increasing interest in and success with radiation therapy and combined chemoradiotherapy for treatment of anal and ano-rectal cancers. Cf-252 brachytherapy combined with external beam teletherapy has been investigated for anal and ano-rectal lesions at the Univ. of Kentucky with encouraging results

  7. Mobile equipment for neutron radiography using a californium-252 source

    International Nuclear Information System (INIS)

    The basic requirements for successful neutron radiography are first summarised and the use of 252Cf is placed in perspective by comparing its properties with those of sources based on the Be (γ, n) and Be (α, n) reactions which have a broadly similar range of applications. The more essential design features of mobile neutron radiography equipment are next examined in some detail, to show how the often conflicting requirements of optimum beam production and adequate shielding may be reconciled. An assembly with a maximum dimension around 1 m with a source of 1 mg is used as an example. The design data used are reproduced in graphical form to permit designs to be scaled to suit the source available and the requirements. The selection of suitable image recorders for 252Cf radiography is discussed with the conclusion that the gadolinium foil-film combinations are likely to remain the normal choice. Demonstration radiographs are presented with particular reference to the location of residual casting sand in gas-cooled turbine blades. Finally, it is suggested that other applications for mobile 252Cf-based neutron radiography equipment will be found in the ordnance, aero-space, chemical and nuclear fuel manufacturing industries. (author)

  8. Automated absolute activation analysis with californium-252 sources

    Energy Technology Data Exchange (ETDEWEB)

    MacMurdo, K.W.; Bowman, W.W.

    1978-09-01

    A 100-mg /sup 252/Cf neutron activation analysis facility is used routinely at the Savannah River Laboratory for multielement analysis of many solid and liquid samples. An absolute analysis technique converts counting data directly to elemental concentration without the use of classical comparative standards and flux monitors. With the totally automated pneumatic sample transfer system, cyclic irradiation-decay-count regimes can be pre-selected for up to 40 samples, and samples can be analyzed with the facility unattended. An automatic data control system starts and stops a high-resolution gamma-ray spectrometer and/or a delayed-neutron detector; the system also stores data and controls output modes. Gamma ray data are reduced by three main programs in the IBM 360/195 computer: the 4096-channel spectrum and pertinent experimental timing, counting, and sample data are stored on magnetic tape; the spectrum is then reduced to a list of significant photopeak energies, integrated areas, and their associated statistical errors; and the third program assigns gamma ray photopeaks to the appropriate neutron activation product(s) by comparing photopeak energies to tabulated gamma ray energies. Photopeak areas are then converted to elemental concentration by using experimental timing and sample data, calculated elemental neutron capture rates, absolute detector efficiencies, and absolute spectroscopic decay data. Calculational procedures have been developed so that fissile material can be analyzed by cyclic neutron activation and delayed-neutron counting procedures. These calculations are based on a 6 half-life group model of delayed neutron emission; calculations include corrections for delayed neutron interference from /sup 17/O. Detection sensitivities of < or = 400 ppB for natural uranium and 8 ppB (< or = 0.5 (nCi/g)) for /sup 239/Pu were demonstrated with 15-g samples at a throughput of up to 140 per day. Over 40 elements can be detected at the sub-ppM level.

  9. Californium-based neutron radiography for corrosion detection in aircraft

    International Nuclear Information System (INIS)

    In support of an overall program aimed at minimizing disassembly and reducing inspection time during aircraft maintenance, a series of projects has been carried out to determine the feasibility of applying neutron radiographic techniques to the nondestructive (NDT) inspection of aircraft and aircraft components. These investigations have clearly demonstrated the superiority of neutron radiography over all other NDT techniques in its ability to detect surface and subsurface corrosion in aircraft structure. This capability is particularly significant where the corrosion is hidden behind thick metallic structural members. The neutron radiographic technique has been applied successfully to detect corrosion in the wing tank of E-2C, C-130, and DC-9 aircraft; rear stabilators of F-4 and F-111 aircraft; aft spar, starboard and port wing, and rudder of the F-8; fuselage skin of the 727; rotary blades of AH-1 and SH-3 helicopters; rotary tail flaps of the UH-2 helicopter; and nose landing gear of A-7 aircraft

  10. Automated absolute activation analysis with californium-252 sources

    International Nuclear Information System (INIS)

    A 100-mg 252Cf neutron activation analysis facility is used routinely at the Savannah River Laboratory for multielement analysis of many solid and liquid samples. An absolute analysis technique converts counting data directly to elemental concentration without the use of classical comparative standards and flux monitors. With the totally automated pneumatic sample transfer system, cyclic irradiation-decay-count regimes can be pre-selected for up to 40 samples, and samples can be analyzed with the facility unattended. An automatic data control system starts and stops a high-resolution gamma-ray spectrometer and/or a delayed-neutron detector; the system also stores data and controls output modes. Gamma ray data are reduced by three main programs in the IBM 360/195 computer: the 4096-channel spectrum and pertinent experimental timing, counting, and sample data are stored on magnetic tape; the spectrum is then reduced to a list of significant photopeak energies, integrated areas, and their associated statistical errors; and the third program assigns gamma ray photopeaks to the appropriate neutron activation product(s) by comparing photopeak energies to tabulated gamma ray energies. Photopeak areas are then converted to elemental concentration by using experimental timing and sample data, calculated elemental neutron capture rates, absolute detector efficiencies, and absolute spectroscopic decay data. Calculational procedures have been developed so that fissile material can be analyzed by cyclic neutron activation and delayed-neutron counting procedures. These calculations are based on a 6 half-life group model of delayed neutron emission; calculations include corrections for delayed neutron interference from 17O. Detection sensitivities of 239Pu were demonstrated with 15-g samples at a throughput of up to 140 per day. Over 40 elements can be detected at the sub-ppM level

  11. Reactive transport modeling of Li isotope fractionation

    Science.gov (United States)

    Wanner, C.; Sonnenthal, E. L.

    2013-12-01

    The fractionation of Li isotopes has been used as a proxy for interaction processes between silicate rocks and any kind of fluids. In particular, Li isotope measurements are powerful because Li is almost exclusively found in silicate minerals. Moreover, the two stable Li isotopes, 6Li and 7Li, differ by 17% in mass introducing a large mass dependent isotope fractionation even at high temperature. Typical applications include Li isotope measurements along soil profiles and of river waters to track silicate weathering patterns and Li isotope measurements of geothermal wells and springs to assess water-rock interaction processes in geothermal systems. For this contribution we present a novel reactive transport modeling approach for the simulation of Li isotope fractionation using the code TOUGHREACT [1]. It is based on a 6Li-7Li solid solution approach similar to the one recently described for simulating Cr isotope fractionation [2]. Model applications include the simulation of granite weathering along a 1D flow path as well as the simulation of a column experiment related to an enhanced geothermal system. Results show that measured δ7Li values are mainly controlled by (i) the degree of interaction between Li bearing primary silicate mineral phases (e.g., micas, feldspars) and the corresponding fluid, (ii) the Li isotope fractionation factor during precipitation of secondary mineral phases (e.g., clays), (iii) the Li concentration in primary and secondary Li bearing mineral phases and (iv) the proportion of dissolved Li that adsorbs to negatively charged surfaces (e.g., clays, Fe/Al-hydroxides). To date, most of these parameters are not very well constrained. Reactive transport modeling thus currently has to rely on many assumptions. Nevertheless, such models are powerful because they are the only viable option if individual contributions of all potential processes on the resulting (i.e., measured) Li isotopic ratio have to be quantitatively assessed. Accordingly, we

  12. The stable isotope signature of continental runoff

    International Nuclear Information System (INIS)

    Recent international programmes such as the IAEA coordinated research project on 'Isotope tracing of hydrological processes in large river basins' have increased scientific awareness of the potential value of incorporating isotope tracers in large-scale water cycling studies to trace water origin and residence times, snowmelt processes, surface-groundwater exchange, evaporation-transpiration partitioning, precipitation variability, and climate/land use changes. Although isotope techniques have been widely tested and are operationally applied at the small catchment-scale, theoretical development and testing of isotope-mass balance approaches at the continental scale are still in progress. This paper proposes a theoretical basis for predicting the long-term (interannual) signatures of oxygen-18 and deuterium in continental runoff applicable for describing global isotope variability in the mean flux-weighted discharge of large rivers. For long time periods, the mass and isotope balances for the oceans and continents are given. Changes in atmospheric moisture are expected due to admixture of evaporated and transpired moisture to air masses over the continents. Oceanic moisture in coastal areas is shown as which becomes subsequently modified as it moves across the continent to inland areas (ranging from to). The approximate isotope compositions of components. Long-term differences in precipitation arise from Rayleigh-type fractionation of atmospheric moisture and precipitation during rainout over the continents. Transpired moisture is expected to be similar to precipitation or groundwater recharge for a given location, whereas evaporated moisture will be isotopically depleted (plotting on or above the MWL) and river discharge will tend to be isotopically enriched (plotting on or below the MWL). Shown are specific hydroclimate forcings on the 2H-18O isotopic composition including those related to long-term precipitation input signals (temperature, latitude, altitude

  13. Isotopic fractionation of zinc in tektites

    Science.gov (United States)

    Moynier, Frederic; Beck, Pierre; Jourdan, Fred; Yin, Qing-Zhu; Reimold, Uwe; Koeberl, Christian

    2009-01-01

    Tektites are terrestrial natural glasses produced during a hypervelocity impact of an extraterrestrial projectile onto the Earth's surface. The similarity between the chemical and isotopic compositions of tektites and terrestrial upper continental crust implies that the tektites formed by fusion of such target rock. Tektites are among the driest rocks on Earth. Although volatilization at high temperature may have caused this extreme dryness, the exact mechanism of the water loss and the behavior of other volatile species during tektite formation are still debated. Volatilization can fractionate isotopes, therefore, comparing the isotope composition of volatile elements in tektites with that of their source rocks may help to understand the physical conditions during tektite formation. For this study, we have measured the Zn isotopic composition of 20 tektites from four different strewn fields. Almost all samples are enriched in heavy isotopes of Zn compared to the upper continental crust. On average, the different groups of tektites are isotopically distinct (listed from the isotopically lightest to the heaviest): Muong-Nong type indochinites ( δ66/64Zn = 0.61 ± 0.30‰); North American bediasites ( δ66/64Zn = 1.61 ± 0.49‰); Ivory Coast tektites ( δ66/64Zn = 1.66 ± 0.18‰); the Australasian tektites (others than the Muong Nong-type indochinites) ( δ66/64Zn = 1.84 ± 0.42‰); and Central European moldavites ( δ66/64Zn = 2.04 ± 0.19‰). These results are contrasted with a narrow range of δ66/64Zn = 0-0.7‰ for a diverse spectrum of upper continental crust materials. The elemental abundance of Zn is negatively correlated with δ66/64Zn, which may reflect that isotopic fractionation occurred by evaporation during the heating event upon tektite formation. Simple Rayleigh distillation predicts isotopic fractionations much larger than what is actually observed, therefore, such a model cannot account for the observed Zn isotope fractionation in tektites. We

  14. Isotopes in the Arctic atmospheric water cycle

    OpenAIRE

    Bonne, Jean-Louis; Werner, Martin; Meyer, Hanno; Kipfstuhl, Sepp; Rabe, Benjamin; Behrens, Melanie; Schönicke, Lutz; Steen-Larsen, Hans Christian; Masson-Delmotte, Valérie

    2016-01-01

    The ISO-ARC project aims at documenting the Arctic atmospheric hydrological cycle, by assessing the imprint of the marine boundary conditions (e.g. temperature variations, circulation changes, or meltwater input) to the isotopic composition of the atmospheric water cycle (H218O and HDO) with a focus on North Atlantic and Arctic oceans. For this purpose, two continuous monitoring water vapour stable isotopes cavity ring-down spectrometers have been installed in July 2015: on-boar...

  15. Stable carbon isotope analysis of heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Fixari, B.; Le Perchec, P.; Bigois, M.; Casabianca, H.; Jame, P. [CNRS, Vernaison (France). Lab. des Materiaux Organiques

    1994-03-01

    Stable carbon isotope analysis of various heavy oils and some thermo-catalytically converted products was performed with a thermal analyser coupled with an isotopic ratio mass spectrometer. The temperature-programmed oxidative pyroanalysis technique subdivides the classical {sup 13}C/{sup 12}C ratio, affording new insights into the structural composition of heavy oils such as the contribution of naphthenoaromatics, and appears to be of interest for following their thermal refining. 24 refs., 11 figs., 2 tabs.

  16. Environmental isotope observations on Sishen ground waters

    International Nuclear Information System (INIS)

    Environmental isotope measurements have been conducted on the outputs of some of the main dewatering points in both north and south mining areas as well as on numerous other observation points in the Sishen compartment. The effect of the dykes bounding the compartment could be observed from the behaviour of the isotopic composition of ground waters in the conduit zone. Measurements were done on radiocarbon, tritium oxygen-18 and carbon-13

  17. Isotope shortage triggers delays for patients

    Science.gov (United States)

    Gould, Paula

    2009-07-01

    An unplanned shutdown of a nuclear reactor in Canada is disrupting the supply of medical isotopes across North America and forcing some hospitals to cancel or postpone patients' tests. The closure of the National Research Universal (NRU) reactor in Chalk River, Ontario, has also embarrassed Canadian officials, including a senior government minister who was forced to apologize after calling the isotope shortage a "sexy" career challenge.

  18. Isotopic heterogeneity of East Antarctic mantle

    International Nuclear Information System (INIS)

    Isotopic heterogeneity of deep garnet-bearing mantle xenolytes of East Antarctics is studied to analyze the mechanisms of geochemical heterogeneity occurrence in the Earth mantle. Analysis of isotope data for the system 143Nd/144Nd - Sm/Nd permitted ascertaining the time of the last thermal impact on the mantle material (108-35 bill. years) for certain nodules, which is close to the age of ultra base alkali magmatism intrusion

  19. Mixed Population Screening for Sulfur Isotopes

    Institute of Scientific and Technical Information of China (English)

    CUI Bin; ZHAO Lei; ZHAN Zhaoyang; HE Zhijun

    2004-01-01

    Quantitative research of the origin of sulfur isotopes is a difficult problem that has puzzled geochemists all along. In the study of the middle and lower reaches of the Yangtze River and the Dongpo orefield in Hunan Province,the authors successfully applied the mathematical model of mixed population screening to quantitatively resolving the problem on the origin of sulfur isotopes, which is significant in finding out the source of mineralizing matter and metallogenic mechanisms.

  20. Thermal Properties of Isotopically Engineered Graphene

    OpenAIRE

    Chen, Shanshan; Wu, Qingzhi; Mishra, Columbia; Kang, Junyong; Zhang, Hengji; Cho, Kyeongjae; Cai, Weiwei; Balandin, Alexander A.; Ruoff, Rodney S.

    2011-01-01

    In addition to its exotic electronic properties graphene exhibits unusually high intrinsic thermal conductivity. The physics of phonons - the main heat carriers in graphene - was shown to be substantially different in two-dimensional (2D) crystals, such as graphene, than in three-dimensional (3D) graphite. Here, we report our experimental study of the isotope effects on the thermal properties of graphene. Isotopically modified graphene containing various percentages of 13C were synthesized by...

  1. Trophic experiments to estimate isotope discrimination factors

    OpenAIRE

    Caut, Stéphane; Angulo, Elena; Courchamp, Franck; Figuerola, Jordi

    2010-01-01

    : 1. In Caut, Angulo & Courchamp (2008a) rats were fed with experimental diets of distinct isotopic values (_13C and _15N) in order to infer the discrimination factors. We showed negative relationships between discrimination factors and diet isotopic values. In Caut, Angulo & Courchamp (2009), our aim was to generalise these relationships to other taxonomic groups with a view to providing ecologists with a general and flexible method to obtain discrimination factors for diet reconstruction st...

  2. Fission and the discovery of isotopes

    International Nuclear Information System (INIS)

    The discovery of new isotopes requires new developments in accelerator and detector technology. The new RI Beam Factory at RIKEN and the future projects FAIR at GSI and FRIB at MSU promise to expand the nuclear horizon even further. In the talk a short history of the role that fission played in the discovery of isotopes will be presented and future perspectives will be discussed

  3. Test and evaluation of isotope identifiers

    International Nuclear Information System (INIS)

    Three devices were tested against eighteen radio-isotopes ranging in activity from 0.37 kBq (K-40) to 93.24 GBq (Pu-239) to determine their effectiveness as isotope identifiers. Two of the devices were hand-held instruments using NaI(Tl) detectors and the third one was a bench-top instrument using a mechanically-cooled Ge detector. Details of the test and the test results are presented in this paper. (author)

  4. Amalgam-chromatographic separation of magnesium isotopes

    International Nuclear Information System (INIS)

    Separation of magnesium isotopes within Mg(Hg)-MgI2 system (in dimethylformamide) is conducted under amalgam-chromatographic conditions. Separation maximal degree, that is (1.09), for 24 Mg and 26 Mg and separation coefficient (α = 1.0089±0.006) are determined. Light isotopes are found to concentrate in the amalgam. Technique of thermal conversion of flows within amalgam-dimethylformamide system is suggested on the basis of reversible reaction of Ca-Mg element exchange

  5. Uses of Radioactive Isotopes in Industry

    International Nuclear Information System (INIS)

    The present report contains a list of some of the most important problems in industry that have been approached so far by the use of radioactive isotopes. The list has been compiled trough the experience gained by the authors in revising for several years the most important scientific journal and other sources of information on this subject. The classification of industries has been done in an arbitrary way, choosing those isotope uses that have reached a higher degree of development. (Author)

  6. IUPAC Periodic Table of the Isotopes

    Science.gov (United States)

    Holden, N.E.; Coplen, T.B.; Böhlke, J.K.; Wieser, M.E.; Singleton, G.; Walczyk, T.; Yoneda, S.; Mahaffy, P.G.; Tarbox, L.V.

    2011-01-01

    For almost 150 years, the Periodic Table of the Elements has served as a guide to the world of elements by highlighting similarities and differences in atomic structure and chemical properties. To introduce students, teachers, and society to the existence and importance of isotopes of the chemical elements, an IUPAC Periodic Table of the Isotopes (IPTI) has been prepared and can be found as a supplement to this issue.

  7. Isotopic tracing of moisture in buildings

    International Nuclear Information System (INIS)

    The means of tracing the flows of moisture in a building by using the stable isotopes of oxygen-18 and deuterium are described. It is shown that knowledge of the effects of the transport mechanisms and reactions on the isotopic composition can be used to identify the sources of moisture. This is illustrated by an example from a building in the southern part of Sweden

  8. Isotope techniques in water resources development

    International Nuclear Information System (INIS)

    These proceedings contain the papers of 41 oral and the extended synopses of 40 poster presentations at the seventh symposium on the use of isotope techniques in water resources development. The topics of the sessions were as follows: Thermal water studies, groundwater dating, hydrology of arid and semi-arid areas, field studies with environmental isotopes, precipitation-surface-groundwater relationships, pollution, artificial tracers and sediment transport. Refs, figs, tabs

  9. Biogeochemistry of the stable hydrogen isotopes

    International Nuclear Information System (INIS)

    The fractionation of H isotopes between the water in the growth medium and the organically bonded H from microalgae cultured under conditions, where light intensity and wavelength, temperature, nutrient availability, and the H isotope ratio of the water were controlled, is reproducible and light dependent. All studies were based either on the H isotope ratios of the total organic H or on the lipids, where most of the H is firmly bonded to C. H bonded into other macromolecules, proteins, carbohydrates and nucleic acids, does not exchange with water, when algae are incubated in water enriched with deuterium. Only after the destruction of quaternary H bonds are labile hydrogens in macromolecules free to exchange with water. By growing algae (18 strains), including blue-green algae, green algae and diatoms, in continuous light, the isotope fractionations in photosynthesis were reproducibly -93 to -178 per thousand, depending on the organism tested. This fractionation was not temperature dependent. Microalgae grown in total darkness with an organic substrate did not show the isotope fractionation seen in cells grown in light. In both light- and dark-grown algae, however, additional depletion of deuterium (-30 to -60 per thousand) in cellular organic matter occurs during the metabolism of carbohydrates to form lipids. Plants from several natural populations also fractionated isotopes during photosynthesis by an average of -90 to -110 per thousand. In addition, the organically bonded H in nonsaponifiable lipids was further fractionated by -80 per thousand from that in saponifiable lipids, isolated from two geographically distinct populations of marsh plants. This difference between H isotope ratios of these two groups of lipids provides an endogenous isotopic marker. (author)

  10. Study of neutron-deficient Sn isotopes

    International Nuclear Information System (INIS)

    The formation of neutron deficient nuclei by heavy ion reactions is investigated. The experimental technique is presented, and the results obtained concerning Sn et In isotopes reported: first excited states of 106Sn, high spin states in 107Sn and 107In; Yrast levels of 106Sn, 107Sn, 108Sn; study of neutron deficient Sn and In isotopes formed by the desintegration of the compound nucleus 112Xe. All these results are discussed

  11. The distribution of nitrogen isotopes in sediments

    OpenAIRE

    Scholten, S.O.

    1991-01-01

    The results from this thesis elucidate some of the major processes involved in the sedimentary nitrogen distribution, although much research on the sedimentary nitrogen cycle still needs to be done. During early diagenesis the nitrogen isotopic composition of organic matter can be altered strongly through microbial activity (oxidation). An environmental signature, however, remains preserved in the fixed nitrogen isotope ratios. As a result, the ϐ¹⁵N(fix) values in a sediment can be successful...

  12. On the hyperfine anomaly in Eu isotopes

    OpenAIRE

    Persson, J. R.

    2009-01-01

    A new method for determining the hyperfine anomaly, without knowing the nuclear magnetic moment, is used for the first time on a series of unstable isotopes. The relative large number of experimental data in Eu makes it possible to determine the hyperfine anomaly for a number of unstable isotopes. Calculations of the Bohr-Weisskopf effect and hence the hyperfine anomaly has been performed using the particle-rotor formalism. The result from the calculations and experiments is compared with oth...

  13. Isotopic dependence of GCR fluence behind shielding

    International Nuclear Information System (INIS)

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors (±100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid (∼170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past; however, less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies

  14. Isotopic dependence of GCR fluence behind shielding

    Energy Technology Data Exchange (ETDEWEB)

    Cucinotta, Francis A. [NASA, Lyndon B. Johnson Space Center, Houston, TX 77058 (United States)]. E-mail: Francis.A.Cucinotta@nasa.gov; Wilson, John W. [NASA, Langley Research Center, Hampton, VA 23664 (United States); Saganti, Premkumar [Prairie View A and M, Prairie View, TX 94720 (United States); Hu, Xiaodong [NASA, Lyndon B. Johnson Space Center, Houston, TX 77058 (United States); Kim, Myung-Hee Y. [NASA, Lyndon B. Johnson Space Center, Houston, TX 77058 (United States); Cleghorn, Timothy [NASA, Lyndon B. Johnson Space Center, Houston, TX 77058 (United States); Zeitlin, Cary [Lawrence Berkeley National Laboratory Berkeley, CA 94720 (United States); Tripathi, Ram K. [NASA, Langley Research Center, Hampton, VA 23664 (United States)

    2006-10-15

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors ({+-}100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid ({approx}170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past; however, less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies.

  15. Isotopic Dependence of GCR Fluence behind Shielding

    Science.gov (United States)

    Cucinotta, Francis A.; Wilson, John W.; Saganti, Premkumar; Kim, Myung-Hee Y.; Cleghorn, Timothy; Zeitlin, Cary; Tripathi, Ram K.

    2006-01-01

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross-sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple-scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors (+/-100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid (approx.170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past, however less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies.

  16. Steam injection profiling with unstable radioactive isotopes

    International Nuclear Information System (INIS)

    This patent describes a method of determining liquid and vapor phase profiles in a stream injection well. It comprises inserting a well logging tool into a steam injection well at a first location, the logging tool further comprising duel gamma ray detectors separated by a specified distance; measuring a mass flow rate of steam entering the steam injection well; before, during, and after logging the steam injection well; injecting an unstable radioactive isotope into the steam injection well, the isotope being of a type which naturally hydrolyzes from a vapor phase into a liquid phase at a known rate, so that a given time after the isotope injection, the relative proportions of the vapor phase and the liquid phase can be determined; measuring the transit time of the vapor phase isotope and the liquid phase isotope to pass between the gamma ray detectors; moving the logging tool to a second location in the well; calculating vapor phase and liquid phase velocities based on the elapsed time required for the vapor and liquid phase isotopes to pass between the two gamma detectors; and calculating the amount of vapor and liquid entering a formation between the first location and the second location based on the mass flow rate of steam entering the well, the liquid transit times, and the vapor transit times

  17. Manual on mathematical models in isotope hydrogeology

    International Nuclear Information System (INIS)

    Methodologies based on the use of naturally occurring isotopes are, at present, an integral part of studies being undertaken for water resources assessment and management. Quantitative evaluations based on the temporal and/or spatial distribution of different isotopic species in hydrological systems require conceptual mathematical formulations. Different types of model can be employed depending on the nature of the hydrological system under investigation, the amount and type of data available, and the required accuracy of the parameter to be estimated. This manual provides an overview of the basic concepts of existing modelling approaches, procedures for their application to different hydrological systems, their limitations and data requirements. Guidance in their practical applications, illustrative case studies and information on existing PC software are also included. While the subject matter of isotope transport modelling and improved quantitative evaluations through natural isotopes in water sciences is still at the development stage, this manual summarizes the methodologies available at present, to assist the practitioner in the proper use within the framework of ongoing isotope hydrological field studies. In view of the widespread use of isotope methods in groundwater hydrology, the methodologies covered in the manual are directed towards hydrogeological applications, although most of the conceptual formulations presented would generally be valid. Refs, figs, tabs

  18. Transuranic isotopic analysis using gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D; Decman, D

    1998-10-15

    Transuranic waste typically emits gamma rays that are characteristic of the isotopic composition of the materials. If the area of the gamma ray photopeaks in a High Purity Ge (HPGe) spectrum can be accurately determined and if the gamma ray/x-ray branching ratios and half-lives for the radionuclides in the sample are known the relative concentration of each isotope in the waste can be determined using tomographic techniques. Methods used to accurately determine these photopeaks usually requires a computer code that does multi-peak analysis and unfolding of a given part of the gamma-ray spectrum. Computer techniques allow an accurate determination of the photopeaks and hence the isotopic composition of the waste material. These computer techniques can be automated for different spectra within a wide range of possible isotopic compositions. To improve photopeak statistics all of the spectra taken in a tomographic survey of the sample are summed and are used in the isotopic analysis. The method, accuracy, and limitations of this type of isotopic analysis system will be discussed. The gamma ray acquisition system is currently being upgraded with multiple HPGe detectors to improve the counting statistics obtainable in a given amount of time. The results of the DOE performance evaluations and the progress of the multiple detector upgrade will be discussed.

  19. Uranium and plutonium isotopic analysis using MGA++

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, W; Clark, D; Friensehner, A; Parker, W; Raschke, K; Romine, W; Ruhter, W; Wang, T-F; kreek, S

    1998-07-01

    The Lawrence Livermore National Laboratory develops sophisticated gamma-ray analysis codes for the isotopic analysis of nuclear materials based on the principles used in the original MultiGroup Analysis (MGA) code. Over the years, the MGA methodology has been upgraded and expanded far beyond its original capabilities and is now comprised of a suite of codes known as MGA++. The early MGA code analyzed Pu gamma-ray data collected with high-purity germanium (HPGe) detectors to yield Pu isotopic ratios. While the original MGA code relied solely on the lower-energy gamma rays (around 100 keV), the most recent addition to the MGA++ code suite, MGAHI, analyzes Pu data using higher-energy gamma rays (200 keV and higher) and is particulatly useful for Pu samples - that are enclosed in thick-walled containers. The MGA++ suite also includes capabilities to perform U isotopic analysis on data collected with either HPGe or cadmium-zinc-tellutide (CZT) detectors. These codes are commercially available and are known as U235 and CZTU, respectively. A graphical user interface has also been developed for viewing the data and the fitting procedure. In addition, we are developing new codes that will integrate into the MGA++ suite. These will include Pu isotopic analysis capabilities for data collected with CZT detectors, U isotopic analysis with HPGe detectors which utilizes only higher energy gamma rays, and isotopic analyses on mixtures of Pu and U.

  20. Modeling Nitrogen Isotopes in the Global Ocean

    Science.gov (United States)

    Somes, C.; Schmittner, A.

    2008-12-01

    The nitrogen isotopic signal measured in marine sediments has the potential to be a valuable paleoceanographic proxy. It captures the response of different biological processes in the marine ecosystem including photosynthesis, nitrogen fixation, denitrification as well as processes within the food chain. A simple marine ecosystem model that includes the interactive cycling of nitrogen, phosphorus, and oxygen is augmented to record nitrogen isotopes in the University of Victoria Earth System Climate Model. New nitrogen isotopic tracers are employed at all trophic levels of the ecosystem. This includes the δ15N of nitrate, both classes of phytoplankton (nitrogen fixers and all other phytoplankton), zooplankton, and detritus. Despite a few shortcomings, it is shown that the nitrogen isotope model can capture the major trends observed in the modern climate. The ability to model nitrogen isotopes in a global coupled ocean- atmosphere-sea ice-ecosystem model gives us a unique opportunity to directly infer what physical and biological changes in the climate system are driving the δ15N signal on spatial and temporal scales. This is a valuable tool giving us tremendous insight on how to interpret the nitrogen isotopic signal.

  1. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  2. Laser Spectroscopy of Neutron Rich Bismuth Isotopes

    CERN Multimedia

    2002-01-01

    %IS344 :\\\\ \\\\ The aim of the experiment is to measure the optical isotope shifts and hyperfine structures of bismuth isotopes across the N=126 shell closure in order to extract the change in mean square charge radii ($\\delta\\langle r^{2}\\rangle$) and static moments. These include the first isotones of lead to be measured directly above the shell closure and will provide new information on the systematics of the kink ($\\delta\\langle r^{2}\\rangle)$ seen in the lead isotopic chain. After two very successful runs the programme has been extended to include the neutron deficient isotopes below $^{201}$Bi to study the systematics across the $i_{13/2}$ neutron sub-shell closure at N=118.\\\\ \\\\ During the initial 2 runs (9 shifts) the isotope shifts and hyperfine structures of three new isotopes, $ ^{210,212,213}$Bi and the 9$^{-}$ isomer of $^{210}$Bi have been measured. The accuracy of the previous measurements of $^{205,206,208}$Bi have been greatly improved. The samples of $ ^{208,210,210^{m}}$Bi were prepared by c...

  3. The discovery of isotopes a complete compilation

    CERN Document Server

    Thoennessen, Michael

    2016-01-01

    This book describes the exciting discovery of every isotope observed on earth to date, which currently numbers some 3000. For each isotope a short essay highlights the authors of the first publication for the isotope, the laboratory and year where and when the isotope was discovered, as well as details about the production and detection methods used. In controversial cases previously claims are also discussed. At the end a comprehensive table lists all isotopes sorted by elements and a complete list of references. Preliminary versions of these paragraphs have been published over the last few years as separate articles in the journal "Atomic Data and Nuclear Data Tables". The work re-evaluates all assignments judging them with a uniform set of criteria. In addition, the author includes over 100 new isotopes which have been discovered since the articles published. This book is a source of information for researchers as well as enthusiastic laymen alike. From the prepublication review: “The explanations focus ...

  4. Medical application of stable isotopes

    International Nuclear Information System (INIS)

    The application of stable isotopes (SI) to clinical examinations was reviewed. As an example of 14C-breath test, the application of 1-14C-cholate to intestinal bacterial overgrowth syndrome was described, and as an example of 13C-breath test, the application of glycine-1-13C-cholate. The breath test using 13C-galactose and 13C-aminopyrine was applied to liver function tests, that using 13C-trioctanoin, fat absorption test, and that using 13C-glycine and 13C-glucose, congenital abnormalities of metabolism. Moreover, studies of sugar metabolism by means of glucose labelled with SI and protein N metabolism by means of compounds labelled with 15N were reported. Measurement of pulmonary extravascular fluid by heavy water, respiratory function test by 4He gas, and movement of bile acid by 2H-bile acid were also reported. The application of SI to metabolic route examination and serum in vitro examination was also described. (Kanao, N.)

  5. Purdue Rare Isotope Measurement Laboratory

    Science.gov (United States)

    Caffee, M.; Elmore, D.; Granger, D.; Muzikar, P.

    2002-12-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for accelerator mass spectrometry. AMS is an ultra-sensitive analytical technique used to measure low levels of long-lived cosmic-ray-produced and anthropogenic radionuclides, and rare trace elements. We measure 10Be (T1/2 = 1.5 My), 26Al (.702 My), 36Cl (.301 My), and 129I (16 My), in geologic samples. Applications include dating the cosmic-ray-exposure time of rocks on Earth's surface, determining rock and sediment burial ages, measuring the erosion rates of rocks and soils, and tracing and dating ground water. We perform sample preparation and separation chemistries for these radio-nuclides for our internal research activities and for those external researchers not possessing this capability. Our chemical preparation laboratories also serve as training sites for members of the geoscience community developing these techniques at their institutions. Research at Purdue involves collaborators among members of the Purdue Departments of Physics, Earth and Atmospheric Sciences, Chemistry, Agronomy, and Anthropology. We also collaborate and serve numerous scientists from other institutions. We are currently in the process of modernizing the facility with the goals of higher precision for routinely measured radio-nuclides, increased sample throughput, and the development of new measurement capabilities for the geoscience community.

  6. Rare stable isotopes in meteorites

    International Nuclear Information System (INIS)

    Secondary Ion Mass Spectrometry (SIMS) using accelerators has been applied with success to cosmic ray exposure ages and terrestrial residence times of meteorites by measuring cosmogenic nuclides of Be, Cl, and I. It is proposed to complement this work with experiments on rare stable isotopes, in the hope of setting constraints on the processes of solar nebula/meteoritic formation. The relevant species can be classified as: a) daughter products of extinct nuclides (halflife less than or equal to 2 x 108 y) -chronology of the early solar system; b) products of high temperature astrophysical processes - different components incorporated into the solar nebula; and c) products of relatively low temperature processes, stellar winds and cosmic ray reactions - early solar system radiation history. The use of micron-scale primary ion beams will allow detailed sampling of phases within meteorites. Strategies of charge-state selection, molecular disintegration and detection should bring a new set of targets within analytical range. The developing accelerator field is compared to existing (keV energy) ion microprobes

  7. Isotope analytics for the evaluation of the feeding influence on the isotope ratio in beef samples

    International Nuclear Information System (INIS)

    Information about the origin of food and associated production systems has a high significance for food control. An extremely promising approach to obtain such information is the determination of isotope ratios of different elements. In this study the correlation of the isotope ratios C-13/C-12, N-15/N-14, Mg-25/Mg-24, and Sr-87/Sr-86 in bovine samples (milk and urine) and the corresponding isotope ratios in feed was investigated. It was shown that in the bovine samples all four isotope ratios correlate with the isotope composition of the feed. The isotope ratios of strontium and magnesium have the advantage that they directly reflect the isotope ratios of the ingested feed since there is no isotope fractionation in the bovine organism which is in contrast to the case of carbon and nitrogen isotope ratios. From the present feeding study it is evident, that a feed change leads to a significant change in the delta C-13 values in milk and urine within 10 days already. For the deltaN-15 values the feed change was only visible in the bovine urine after 49 days. Investigations of cows from two different regions (Berlin/Germany and Goestling/Austria) kept at different feeding regimes revealed no differences in the N-15/N-14 and Mg-26/Mg-24 isotope ratios. The strongest correlation between the isotope ratio of the bovine samples and the kind of ingested feed was observed for the carbon isotope ratio. With this ratio even smallest differences in the feed composition were traceable in the bovine samples. Since different regions usually coincide with different feeding regimes, carbon isotope ratios can be used to distinguish bovine samples from different regions if the delta C-13 values of the ingested feed are different. Furthermore, the determination of strontium isotope ratios revealed significant differences between bovine and feed samples of Berlin and Goestling due to the different geologic realities. Hence the carbon and strontium isotope ratios allow the best

  8. Magnetic isotope effect and oxygen enrichment by 17O isotope in chain oxidation reactions. Communication 1. Theory

    International Nuclear Information System (INIS)

    The theory of magnetic isotope effect and enrichment of molecular oxygen by 17O isotope in chain oxidation reactions of organic compounds is presented. Recombination probabilities of perioxide radicals differing by isotope composition by oxygen are calculated; the magnetic isotope effect and its dependence on diffusion and viscosity coefficients are determined. Some geochemical and space-chemical consequences of the magnetic isotope effect are discussed

  9. Isotopic exchange reactions. Kinetics and efficiency of the reactors using them in isotopic separation

    International Nuclear Information System (INIS)

    In the first part, some definitions and the thermodynamic and kinetic isotopic effect concepts are recalled. In the second part the kinetic laws are established, in homogeneous and heterogeneous medium (one component being on occasions present in both phases), without and with isotopic effects. Emphasis is put on application to separation of isotopes, the separation factor α being close to 1, one isotope being in large excess with respect to the other one. Isotopic transfer is then given by: J = Ka (x - y/α) where x and y are the (isotopic) mole fractions in both phases, Ka may be either the rate of exchange or a transfer coefficient which can be considered as the 'same in both ways' if α-1 is small compared to the relative error on the measure of Ka. The third part is devoted to isotopic exchange reactors. Relationships between their efficiency and kinetics are established in some simple cases: plug cocurrent flow reactors, perfectly mixed reactors, countercurrent reactors without axial mixing. We treat only cases where α and the up flow to down flow ratio is close to 1 so that Murphee efficiency approximately overall efficiency (discrete stage contactors). HTU (phase 1) approximately HTU (phase 2) approximately HETP (columns). In a fourth part, an expression of the isotopic separative power of reactors is proposed and discussed

  10. Isotopic yield in cold binary fission of even-even $^{244-258}$Cf isotopes

    CERN Document Server

    Santhosh, K P; Krishnan, Sreejith

    2016-01-01

    The cold binary fission of even-even 244-258Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. The favorable fragment combinations are obtained from the cold valley plot (plot of driving potential vs. mass number of fragments) and by calculating the yield for charge minimized fragments. It is found that highest yield for 244,246,248Cf isotopes are for the fragments with isotope of Pb (Z=82) as one fragment, whereas for 250Cf and 252Cf isotopes the highest yield is for the fragments with isotope of Hg (Z=80) as one fragment. In the case of 254,256,258Cf isotopes the highest yield is for the fragments with Sn (Z=50) as one fragment. Thus, the fragment combinations with maximum yield reveal the role of doubly magic and near doubly magic nuclei in binary fission. It is found that asymmetric splitting is favoured for Cf isotopes with mass number A 252. In the case of Cf isotope with A=252, there is an equal probability for asymmetric and symmetric splitti...

  11. Isotope hydrology evolution in Haiti

    International Nuclear Information System (INIS)

    Water in Haiti needs a rational management. In fact, the availability of water in Haiti can be resumed in this manner: The country receives by means 40 milliards cubic meters of water. However, 70% of this water was lost by evapotranspiration and the other part which shows the renewable water is distributed like that: 20% of amount drain along of the surface through the river and go to the sea and 10% filters through the aquifer. In Haiti water is not always on the use place it varies in an area to the other depending of some factors like: precipitation, geology, vegetation, etc. In fact, some difficulties lie in the regulation, protection and mobilization of this resource. Whereas, different needs of utilization sectors, water resources management become a need so as to be able to settle water in quality and in quantity sufficiently for natural preservation, ecosystem and else. In Haiti, we have many plains which contain aquifer. We can name them: Plaine de l'arbre, Cayes, Leogane, Gonaives et Plaine du Cul-de-Sac. The last one is the most exploited because of geographical position. In fact, since 1980 many studies on isotope hydrology have been realized on these. About Plaine du Cul-de-Sac all studies realized show almost the same result: The exploitation limit of this aquifer. Some recommendations have been done in spite of, they still continue with the anarchical exploitation of this aquifer. Many years have been passed but nothing changed. In 2001, with the cooperation of IAEA, the project aquifer integrated management of Plaine du Cul-de-Sac has been started. We have some difficulties but I think it's the one of the best ways in order to solve this problem. (author)

  12. Isotope hydrology evolution in Haiti

    International Nuclear Information System (INIS)

    Water resources in Haiti need a more rational management. In fact, the availability of water in Haiti can be described as follows: the country receives as annual precipitation about 40 billion m3 of water. However, 70% of this water is lost by evapotranspiration and of the remaining fraction, considered as a renewable resource, about 20% drains through rivers and discharges into the sea. The remaining 10 % infiltrates into local aquifers. In Haiti water is not always available in the place where it is needed, depending on the precipitation regime, geography, geology, vegetation, etc. In fact, most difficulties lie in the regulation, protection and mobilization of the available resources. Since each economic sector in Haiti has specific needs, water resources management becomes a very important issue to provide access to water of sufficient quality and quantity to the population. This point is also relevant for adequate preservation of natural ecosystems and other uses. In Haiti there are many areas which contain aquifers: Plaine de l'Arbre, Cayes, Leogane, Gonaives and Plaine du Cul-de-Sac. The last one is heavily exploited due to its geographical location. In fact, since 1980, many studies, using isotope hydrology tools, have been carried out on this aquifer. Almost all studies conducted in the Plaine du Cul-de-Sac showed the same conclusion: the aquifer system is overexploited. Some recommendations have been made, but the anarchical exploitation of this aquifer still continues. Many years after these studies were conducted, the situation has not changed. In 2001, a project dealing with the integrated management of Plaine du Cul-de-Sac aquifer was initiated with the cooperation of the IAEA. Despite the difficulties, it is considered that this is the best way to solve this water resources problem. (author)

  13. Calcium isotopic composition of mantle peridotites

    Science.gov (United States)

    Huang, F.; Kang, J.; Zhang, Z.

    2015-12-01

    Ca isotopes are useful to decipher mantle evolution and the genetic relationship between the Earth and chondrites. It has been observed that Ca isotopes can be fractionated at high temperature [1-2]. However, Ca isotopic composition of the mantle peridotites and fractionation mechanism are still poorly constrained. Here, we report Ca isotope composition of 12 co-existing pyroxene pairs in 10 lherzolites, 1 harzburgite, and 1 wehrlite xenoliths collected from Hainan Island (South Eastern China). Ca isotope data were measured on a Triton-TIMS using the double spike method at the Guangzhou Institute of Geochemistry, CAS. The long-term external error is 0.12‰ (2SD) based on repeated analyses of NIST SRM 915a and geostandards. δ44Ca of clinopyroxenes except that from the wehrlite ranges from 0.85‰ to 1.14‰, while opx yields a wide range from 0.98‰ up to 2.16‰. Co-existing pyroxene pairs show large ∆44Caopx-cpx (defined as δ44Caopx-δ44Cacpx) ranging from 0 to 1.23‰, reflecting equilibrium fractionation controlled by variable Ca contents in the opx. Notably, clinopyroxene of wehrlite shows extremely high δ44Ca (3.22‰). δ44Ca of the bulk lherzolites and harzburgites range from 0.86‰ to 1.14‰. This can be explained by extracting melts with slightly light Ca isotopic compositions. Finally, the high δ44Ca of the wehrlite (3.22‰) may reflect metasomatism by melt which has preferentially lost light Ca isotopes due to chemical diffusion during upwelling through the melt channel. [1] Amini et al (2009) GGR 33; [2] Huang et al (2010) EPSL 292.

  14. Isotopic characterization of groundwater-seawater interactions

    International Nuclear Information System (INIS)

    Studies of groundwater-seawater interactions (GSI) in coastal zones are important for better understanding of coastal processes, input of groundwater to the sea via submarine groundwater discharge (SGD), saltwater intrusion in groundwater reservoirs and coastal land, contamination of groundwater and coastal seawater by land based sources, and generally for proper management of fresh water resources in the region. Investigations of GSI using stable isotopes (2H, 13C, 15N, 18O, 87/86Sr etc.) as well as radioactive isotopes (3H, 14C, Ra, radon etc.) have been recently carried out in several coastal regions. Stable and radioactive isotopes together with salinity and seepage measurements can thus provide a complex approach in GSI investigations, enabling separate estimation of fresh water as well as saline re-circulated groundwater fluxes to the sea. A Coordinated Research Project (CRP) on 'Nuclear and Isotopic Techniques for the Characterisation of SGD in Coastal Zones' coordinated jointly by the IAEA's Isotope Hydrology Section (Vienna) and Marine Environment Laboratory (Monaco), has recently been completed. The CRP was carried out in cooperation with UNESCO's Intergovernmental Oceanographic Commission (IOC) and the International Hydrological Programme (IHP), and with several laboratories in Brazil, India, Italy, Japan, Russia, Slovenia, Turkey and USA. The aim of the CRP was to develop new isotope techniques for studying SGD and GSI. In the framework of the CRP several expeditions were carried out to Sicily, south-eastern Brazil and Mauritius. We present here a complex approach in characterisation of GSI as obtained by different techniques based on stable and radioactive isotopes and non-radioactive tracers. (author)

  15. Enrichment of Gadolinium isotope: column chromatography study

    International Nuclear Information System (INIS)

    Naturally occurring Gadolinium consists of 7 stable isotopes. 152Gd, 154 Gd, 155Gd 156Gd, 157Gd, 158Gd and 160Gd of which abundance ratios are 0.20, 2.18, 14.80, 20.47, 15.65, 24.84 and 21.86% respectively. Gd has the highest cross section for the capture of thermal neutrons of any element due to the high cross section of 157Gd (254,000 barn) and 155Gd (60,900 barn). All the remaining isotopes are having lower values (1.4-735 barn). Gd is used as a burnable poison in nuclear fuel, but the use of 155/157Gd would create an even more effective burnable poison. Gd isotope separation by displacement chromatography was performed in cation exchange resin. Column experiments were performed using 3 jacketed glass columns in series (10 mm dia and 1m length) packed with Dowex 50X8 of bed height of 90 cm. Initially the bed was converted to Cu2+ form. Then 50 cm Gd3+ band was formed using Gd (NO3)3 solution. The band was displaced using (NH4)4-EDTA +NH4NO3 ) solution. The sample was eluted after different migration length of Gd band. The mass spectrometric analysis using TIMS and ICP-MS was performed to measure the enrichment of Gd isotope and the results are found to be encouraging. In the case of natural Gd, the 157/160Gd ratio was found to be 0.7396. The isotopic ratio in the front end was gone down to 0.7077 and in the rear end the value was gone up to 0.7446 which indicates that the front end band is enriched with heavier isotope and rear end is enriched with lighter isotope. Further computational and experimental studies are underway

  16. LANL-IPF responses to isotopes workshop background information survey

    International Nuclear Information System (INIS)

    Responses to the following are provided: (A) Which isotopes do you (company, agency, university, community) currently use in your activities or distribute (repackage) to end-users? (B) Describe generally what these isotopes are used for, i.e. the science or application. (C) Which isotope(s) do you anticipate may have significant future increase in demand. Identify the isotope(s), its priority, possible chemical form and for what purpose it would be used. (D) Are there other isotopes that you might use but are currently unavilable or not available in difficient quantities? If so, please identify this isotope, from whom have you tired to obtain it and for what prupose would it be used. (E) Do you have any specific issues with respect to the purity, availability, reliability of supply, etc. of isotopes at present?

  17. Isotope distribution program at the Oak Ridge National Laboratory with emphasis on medical isotopes

    International Nuclear Information System (INIS)

    The Isotope Distribution Program (IDP) is a group of individual activities with separate and diverse DOE sponsors which share the common mission of the production and distribution of isotope products and the performance of isotope-related services. Its basic mission is to provide isotope products and associated services to the user community by utilizing government-owned facilities that are excess to the primary mission of the DOE. The IDP is in its 41st year of operation. Initially, the program provided research quantities of radioactive materials, and through the 1950's it was the major supplier of radioisotopes for both research and commercial application. Distribution of enriched stable isotopes began in 1954. This paper discusses the use of radioisotopes in medicine and the role that ORNL plays in this field

  18. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  19. The isotopic river continuum model - IRCM

    International Nuclear Information System (INIS)

    Full text: The enrichment of the stable isotopes of water in a water body exposed to evaporative water loss, in particular the change of the d-excess value, is used to quantify the water balance of such a water body. When the rain-fed inflow waters are in isotopic equilibrium with the ambient moisture, this is a straight-forward procedure. In a river system, the interplay of varying inputs, water extraction and evaporative water loss under a non-equilibrium situation along the river pathway, results in a more complex situation where the local character of the hydrological processes act on an isotopic composition inherited from the upstream part of the river system. In analogy to the 'River Continuum Concept' of the Ecologists we propose the IRCM, with the aim of identifying the isotopic parameters which can be employed to characterize the water balance and river/environment interactions along the river course. In a way, this is an extension of the 'string of lakes effect' to include the interaction between the river and its terrestrial environment. The isotope composition of an undisturbed flowing river is the amount-weighted summation of the composition of its tributaries. This usually has a pronounced seasonal pattern and is a sensitive monitor of changes in the structure of the watershed. Bank storage, i.e the infiltration into the adjacent aquifers at high water stage and its release during the low water stage, manifests itself as a phase shift of the seasonal pattern. The water loss by direct evaporation from the watercourse or from lakes or reservoirs manifests itself by a decrease of the d-excess value, especially under arid conditions; however the slope of the evaporation line in the delta plane differs from the classical line obtained under equilibrium conditions between the water and the ambient humidity. The non-evaporative water loss by pumping or other extraction of water from the river is not directly recorded in the isotopic makeup, but manifests

  20. Isotope effects of sulfur in chemical reactions

    International Nuclear Information System (INIS)

    Sulfur is an important component of organic matter because it forms compounds with many elements. Due to high chemical activity of sulfur, it takes part in biological and geological processes in which isotope effects are occurring. It has been shown during last years research of isotope effects that we have take into account not only mass difference but also many other physical properties of nuclides e.g. even or odd number of neutrons in nuclei, shape and distribution of charge, turn of nuclear spin etc. The factor remains that new theoretical ideas have been formed on the base of data, being obtained in fractionation processes of heavy element isotope, particularly uranium. Now it is being well known that effects unconnected with vibration energy have also caused an effect on fractionation of considerably lighter elements like iron and magnesium. The important question is, if these effects would come to light during the separation of sulfur isotopes. Sulfur have three even isotopes M = (32, 34, 36) and one odd M 33). This problem is still open. (author)

  1. Molybdenum isotope systematics in subduction zones

    Science.gov (United States)

    König, Stephan; Wille, Martin; Voegelin, Andrea; Schoenberg, Ronny

    2016-08-01

    This study presents Mo isotope data for arc lavas from different subduction zones that range between δ 98 / 95 Mo = - 0.72 and + 0.07 ‰. Heaviest isotope values are observed for the most slab fluid dominated samples. Isotopically lighter signatures are related to increasing relevance of terrigenous sediment subduction and sediment melt components. Our observation complements previous conclusions that an isotopically heavy Mo fluid flux likely mirrors selective incorporation of isotopically light Mo in secondary minerals within the subducting slab. Analogue to this interpretation, low δ 98 / 95 Mo flux that coincides with terrigenous sediment subduction and sediment melting cannot be simply related to a recycled input signature. Instead, breakdown of the controlling secondary minerals during sediment melting may release the light component and lead to decreasing δ 98 / 95 Mo influx into subarc mantle sources. The natural range between slab dehydration and hydrous sediment melting may thus cause a large spread of δ 98 / 95 Mo in global subduction zone magmas.

  2. Development of helium isotopic database in Japan

    International Nuclear Information System (INIS)

    We constructed “Helium Isotopic Database in Japan”, which includes isotope ratios of noble gases and chemical compositions of gas samples collected from hot springs and drinking water wells. The helium isotopes are excellent natural tracers for indicating the presence of mantle derived volatiles, because they are chemically inert and thus conserved in crustal rock-water systems. It is common knowledge that mantle degassing does not occur homogeneously over the Earth's surface. The 3He/4He ratios higher than the typical crustal values are interpreted to indicate that transfer of mantle volatiles into the crust by processes or mechanisms such as magmatic intrusion, faulting. In particular the spatial variation of helium isotope ratios could provide a valuable information to identify volcanic regions and tectonically active areas. The database was compiled geochemical data of hot spring gas etc. from 108 published papers. As a result of the data compiling, the database has 1728 helium isotopic data. A CD-ROM is attached as an appendix. (author)

  3. Detecting environmental change using stable isotopes

    International Nuclear Information System (INIS)

    Changing land use is one of the primary causes of increased sedimentation and nutrient levels in aquatic systems, resulting in contamination and reduction of biodiversity. Detecting and quantifying these inputs is the first step of remediation, to enable targeted reduction of transport processes into waterways from human impacted land surfaces. More recently, stable isotope analyses are being used as a detection and quantification tool in aquatic environments. Carbon and nitrogen isotopes of sediments, algae and invertebrates from aquatic systems can be used as proxies to record both short and long term environmental change. Excess nutrients derived from urbanization, industry, forestry, farming and agriculture increase the bio-availability of nitrogen to aquatic organisms, changing their natural 15N isotopic signatures. Allochthonous (terrestrial) input from soil destabilization and human activity in surrounding catchments changes the 13C isotope ratios and increases the C:N ratio of sediments. Heavy metal and other organic pollutants can also be used to indicate urbanization and industrial contamination. The combined use of carbon and nitrogen isotopes, C:N ratios and heavy metals are powerful environmental monitoring tools which are useful indicators of source and transport pathways of terrestrial derived material and anthropogenic pollutants into streams, rivers and estuaries. (author).

  4. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13C and 14C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO2 in breath is measured to diagnose diseases. In the early 1970s, 13C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  5. New Stable Isotope Tropical Paleoclimate Proxies

    Science.gov (United States)

    Lawrence, J. R.

    2005-05-01

    Organized tropical rain systems such as tropical cyclones (TC) and mesoscale convective systems (MCS) produce both water vapor and rainfall with distinctly low isotope ratios. This lowering is caused by recyling of water in organized systems. Therefore, fresh water carbonate organisms have considerable potential to act as proxy recorders of these systems. Ostracoda are ephemeral making them especially attractive candidates. Tropical trees offer another opportunity because the low isotopic spikes produced in both soil waters when heavy rains result and ambient water vapor surronding the trees may be recorded in the tree cellulose. Ostracoda living in the surface waters derived from Tropical Storm Allison (2001) document the passage of the storm in their oxygen isotope ratios. The stable isotopic composition of water vapor along the southwest coast of Mexico shows considerable variation in response to TC and MCS activity offshore even when no rain falls in the region. Potentially a long-term record of this activity may be found in the stable isotopic composition of trees providing low elevation trees of sufficient longevity can be found.

  6. Carbon isotopes in mollusk shell carbonates

    Science.gov (United States)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  7. Hydrochemical and isotope study of Lake Titicaca

    International Nuclear Information System (INIS)

    The chemical and isotopic compositions of Lake Titicaca and its inflow waters (precipitation, tributaries, groundwater) were determined with the aim of establishing the lake chemical and isotope balance. The three main regions of the lake, i.e. the Lago Mayor, the eastern and the western basins of Lago Menor, connected in cascade, show significant chemical and isotopic differences. Chloride and sodium balance indicates that an average of about 92% of the inflow water evaporates, and the remaining 8 % is lost through Rio Desaguadero and infiltration. The balance of each basin is also obtained, including the inter-basin fluxes. The stable isotope balance in not possible because no data are available on the mean atmospheric vapour isotopic composition. However, this was tentatively computed using the fluxes obtained from chemistry. The vapour δ-values are slightly more negative than those of rainfall. Tritium, noble gases and chloro-fluoro-carbons in vertical profiles show that the lake is vertically well mixed and there is no water segregation at depth. (author)

  8. Second international conference on isotopes. Conference proceedings

    International Nuclear Information System (INIS)

    The Second International Conference on Isotopes (2ICI) was hosted by the Australian Nuclear Association in Sydney, NSW, Australia. The Theme of the Second Conference: Isotopes for Industry, Health and a Better Environment recognizes that isotopes have been used in these fields successfully for many years and offer prospects for increasing use in the future. The worldwide interest in the use of research reactors and accelerators and in applications of stable and radioactive isotopes, isotopic techniques and radiation in industry, agriculture, medicine, environmental studies and research in general, was considered. Other radiation issues including radiation protection and safety were also addressed. International and national overviews and subject reviews invited from leading experts were included to introduce the program of technical sessions. The invited papers were supported by contributions accepted from participants for oral and poster presentation. A Technical Exhibition was held in association with the Conference. This volume contains the foreword, technical program, the author index and of the papers (1-60) presented at the conference

  9. Isotopic imprints of mountaintop mining contaminants.

    Science.gov (United States)

    Vengosh, Avner; Lindberg, T Ty; Merola, Brittany R; Ruhl, Laura; Warner, Nathaniel R; White, Alissa; Dwyer, Gary S; Di Giulio, Richard T

    2013-09-01

    Mountaintop mining (MTM) is the primary procedure for surface coal exploration within the central Appalachian region of the eastern United States, and it is known to contaminate streams in local watersheds. In this study, we measured the chemical and isotopic compositions of water samples from MTM-impacted tributaries and streams in the Mud River watershed in West Virginia. We systematically document the isotopic compositions of three major constituents: sulfur isotopes in sulfate (δ(34)SSO4), carbon isotopes in dissolved inorganic carbon (δ(13)CDIC), and strontium isotopes ((87)Sr/(86)Sr). The data show that δ(34)SSO4, δ(13)CDIC, Sr/Ca, and (87)Sr/(86)Sr measured in saline- and selenium-rich MTM impacted tributaries are distinguishable from those of the surface water upstream of mining impacts. These tracers can therefore be used to delineate and quantify the impact of MTM in watersheds. High Sr/Ca and low (87)Sr/(86)Sr characterize tributaries that originated from active MTM areas, while tributaries from reclaimed MTM areas had low Sr/Ca and high (87)Sr/(86)Sr. Leaching experiments of rocks from the watershed show that pyrite oxidation and carbonate dissolution control the solute chemistry with distinct (87)Sr/(86)Sr ratios characterizing different rock sources. We propose that MTM operations that access the deeper Kanawha Formation generate residual mined rocks in valley fills from which effluents with distinctive (87)Sr/(86)Sr and Sr/Ca imprints affect the quality of the Appalachian watersheds. PMID:23909446

  10. Second international conference on isotopes. Conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, C.J. [ed.

    1997-10-01

    The Second International Conference on Isotopes (2ICI) was hosted by the Australian Nuclear Association in Sydney, NSW, Australia. The Theme of the Second Conference: Isotopes for Industry, Health and a Better Environment recognizes that isotopes have been used in these fields successfully for many years and offer prospects for increasing use in the future. The worldwide interest in the use of research reactors and accelerators and in applications of stable and radioactive isotopes, isotopic techniques and radiation in industry, agriculture, medicine, environmental studies and research in general, was considered. Other radiation issues including radiation protection and safety were also addressed. International and national overviews and subject reviews invited from leading experts were included to introduce the program of technical sessions. The invited papers were supported by contributions accepted from participants for oral and poster presentation. A Technical Exhibition was held in association with the Conference. This volume contains the foreword, technical program, the author index and of the papers (1-60) presented at the conference.

  11. Dual isotope scintigraphy in stroke patients

    International Nuclear Information System (INIS)

    Platelet scintigraphy is a useful technique to detect atherosclerotic lesions of the neck vessels in stroke patients. The habitual one isotope technique causes false positive and false negative results due to circulating platelet-bound activity. To eliminate these confusing results we performed a dual isotope technique on 20 stroke patients. The new method consists of simultaneous injections of 111-Indium labelled blood platelets and 99mTc labelled red cells, and achieves a calculation of the ratio 111-In/99mTc. Thus the subtraction of the red cell blood flow image can render a pure thrombus formation visible. The habitual visually evaluated one isotope scintigraphy showed positive scans in 11 out of 20 patients, whereas under dual isotope scintigraphy 3 patients showed no 111-Indium excess after subtraction of the red cell image; they can thus be qualified as false positive. In the case of another patient with a visually negative image a thrombus formation could be observed after the subtraction procedure. It seems, that the dual isotope technique in platelet scintigraphy is a valuable refinement on the way to verifiable results. (orig.)

  12. Detecting environmental change using stable isotopes

    International Nuclear Information System (INIS)

    Changing land use is one of the primary causes of increased sedimentation and nturient levels in aquqatic systems, resulting in contamiantion and reduction of biodiversity. Detecting and quantifying these inputs is the first step of remediation, to enable targeted reduction of transport processes into waterways from human impacted land surfaces. More recently, stable isotope analyses are being used as a detection and quantification tool in aquatic environments. Carbon and nitrogen isotopes of sediments, algae and invertebrates from aquatic systems can be used as proxies to record both short and long term enviornmental cahgne. Excess nutrients derived from urbanization, industry, forestry, farming and agriculture increase the bio-availability of nitrogen to aquatic organisms, changing their natural 15N isotopic signatures. Allochthonous (terrestrial) input from soil destabilization and human activity in surrounding catchments changes the 13C isotope ratios and increases the C:N ratio of sediments. Heavy metal and other organic pollutants can also be used to indicate urbanization and industrial contamination. The comined use of carbon and nitrogen isotopes, C:N ratios and heavy metals are powerful environmental monitoring tools which are useful indicators of source and transport pathways of terrestrial derive dmaterial and anthropogenic pollutants into streams, rivers and estuaries. (author). 56 refs., 10 figs., 3 tabs.

  13. CERN to start producing medical isotopes

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    A promising project that was hailed at the ICTR-PHE 2012 medical conference (see Bulletin issues 10-11/2012 and 12-13/2012) has seen the light of day at CERN. The project, known by the name of MEDICIS, will make it possible to produce a large variety of radioactive isotopes for medical research.   This image of a brain, superimposed on a drawing by Leonardo da Vinci, was taken by a PET scanner after injecting a molecule containing a positron-emitting isotope. CERN-MEDICIS will produce new isotopes for imaging which will be able to show up cancerous tissues and destroy them by emitting local radiation as the isotopes decay. In the United States, a new radium-based drug which targets bone metastases is about to go on the market. Radium, which can be brought to bear at the cell level, is a potent weapon in the fight against certain types of cancer, and is opening the way to a new form of medicine. This is the direction that CERN has decided to follow through the CERN-MEDICIS* (Medical Isotopes...

  14. Stable isotope customer list and summary of shipments: FY 1975

    International Nuclear Information System (INIS)

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: an alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; an alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; an alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and a tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope, with the totals for loaned isotopes shown at the end of the table. (auth)

  15. Stable oxygen and hydrogen isotopes of brines - comparing isotope ratio mass spectrometry and isotope ratio infrared spectroscopy

    Science.gov (United States)

    Ahrens, Christian; Koeniger, Paul; van Geldern, Robert; Stadler, Susanne

    2013-04-01

    Today's standard analytical methods for high precision stable isotope analysis of fluids are gas-water equilibration and high temperature pyrolysis coupled to isotope ratio mass spectrometers (IRMS). In recent years, relatively new laser-based analytical instruments entered the market that are said to allow high isotope precision data on nearly every media. This optical technique is referred to as isotope ratio infrared spectroscopy (IRIS). The objective of this study is to evaluate the capability of this new instrument type for highly saline solutions and a comparison of the analytical results with traditional IRMS analysis. It has been shown for the equilibration method that the presence of salts influences the measured isotope values depending on the salt concentration (see Lécuyer et al, 2009; Martineau, 2012). This so-called 'isotope salt effect' depends on the salt type and salt concentration. These factors change the activity in the fluid and therefore shift the isotope ratios measured by the equilibration method. Consequently, correction factors have to be applied to these analytical data. Direct conversion techniques like pyrolysis or the new laser instruments allow the measurement of the water molecule from the sample directly and should therefore not suffer from the salt effect, i.e. no corrections of raw values are necessary. However, due to high salt concentrations this might cause technical problems with the analytical hardware and may require labor-intensive sample preparation (e.g. vacuum distillation). This study evaluates the salt isotope effect for the IRMS equilibration technique (Thermo Gasbench II coupled to Delta Plus XP) and the laser-based IRIS instruments with liquid injection (Picarro L2120-i). Synthetic salt solutions (NaCl, KCl, CaCl2, MgCl2, MgSO4, CaSO4) and natural brines collected from the Stassfurt Salt Anticline (Germany; Stadler et al., 2012) were analysed with both techniques. Salt concentrations ranged from seawater salinity

  16. Isotope separation by chemical exchange

    International Nuclear Information System (INIS)

    Nitrogen-15 and oxygen-18 enrichment by chemical exchange in the (NO/NO2) - (H2O/HNO3) system, using a laboratory-scale experimental plant and a cascade for production of two isotopes, is presented. The results obtained from the laboratory-scale plant indicate that optimal flow rate for 15N separation is 1.55 - 1.86 ml/cm2 · min at 8 - 10 M/l nitric acid and 63.4 mg at. oxygen/cm2 · min for 18O separation at 5.8 M/l nitric acid. The height equivalent to a theoretical plate (HETP) of 4.11 - 4.56 cm is in good agreement with other published data for 15N separation using exchange column with Helipak packing. The HETP of 7.74 - 10.58 cm for 18O separation is greater by 20 - 30 % than those presented by Saxena and Taylor for 'Helipak' column packing, but in good agreement with the HRTP published by Borisov et al. on 'Levina' column packing. The HETP obtained for 15N separation by the production plant is in the range 11.5 - 13.8 cm at a flow rate of 2.2 ml HNO3(10M/l)/cm2 · min for the first column and 4.4 - 4.7 cm at a flow rate of 1.66 ml HNO3(10M/l)/cm2 · min for the second column. The optimal flow rate for 18O separation by the production plant is about 63 mg at. oxygen/cm2 · min (1.01 ml HNO3/cm2 · min). Enrichment of 13C and 18O by chemical exchange of carbon dioxide with its monoethanolamine carbamate in methanol and di-n-butylamine carbamate in triethylamine has also been studied, and optimum operating conditions for the separation of 13C in a packed column was determined. The HETP obtained for the 13C in a packed column was determined. The HETP obtained for the 13C separation column is 3.62 - 8.26 cm at a flow rate of 1.1 - 4.0 mmol carbamate/cm2 · min using the same column packing as for 15N and 18O separation, that is, stainless steel triangular wire springs (2.3 x 2.3 x 0.2 mm). (author)

  17. Isotope effect of potassium in an aqueous/amalgam system

    International Nuclear Information System (INIS)

    The isotope fractionation of potassium in an aqueous (KOH)/amalgam system has been studied. Two types of isotope effects with opposite isotope enrichment directions were observed in the electrolysis of potassium from the aqueous into the amalgam phase under constant electrolytic potentials. It was found that the first isotope effect causing the light isotope enriched in the amalgam is related to the kinetic process of the mass transfer through the aqueous/amalgam interface, while the second one leading to the enrichment of the heavy isotope in the amalgam phase is produced by the isotope-exchange equilibrium. The temperature dependence of the equilibrium isotope effect was also investigated using single-stage and multi-stage techniques. It was observed that the equilibrium isotope effect increases as the temperature increases in the range of 293-371 K. An empirical equation was used to fit the variations of the isotope effects with temperature for potassium together with the other alkaline and alkaline earth metals studied in the same system. The origin of the equilibrium isotope fractionation in the electron-exchange system was discussed. Furthermore, the mass dependence of the separation coefficients of the alkaline and alkaline earth metals observed in aqueous/amalgam and ion-exchange systems were compared. At 293 K the equilibrium isotope separation coefficient for the 39K/41K isotopes in the amalgam system was determined as (5.6 ± 0.6).10-3. (author)

  18. Oxygen isotopes in nitrite: Analysis, calibration, and equilibration

    Science.gov (United States)

    Casciotti, K.L.; Böhlke, J.K.; McIlvin, M.R.; Mroczkowski, S.J.; Hannon, J.E.

    2007-01-01

    Nitrite is a central intermediate in the nitrogen cycle and can persist in significant concentrations in ocean waters, sediment pore waters, and terrestrial groundwaters. To fully interpret the effect of microbial processes on nitrate (NO3-), nitrite (NO2-), and nitrous oxide (N2O) cycling in these systems, the nitrite pool must be accessible to isotopic analysis. Furthermore, because nitrite interferes with most methods of nitrate isotopic analysis, accurate isotopic analysis of nitrite is essential for correct measurement of nitrate isotopes in a sample that contains nitrite. In this study, nitrite salts with varying oxygen isotopic compositions were prepared and calibrated and then used to test the denitrifier method for nitrite oxygen isotopic analysis. The oxygen isotopic fractionation during nitrite reduction to N2O by Pseudomonas aureofaciens was lower than for nitrate conversion to N2O, while oxygen isotopic exchange between nitrite and water during the reaction was similar. These results enable the extension of the denitrifier method to oxygen isotopic analysis of nitrite (in the absence of nitrate) and correction of nitrate isotopes for the presence of nitrite in "mixed" samples. We tested storage conditions for seawater and freshwater samples that contain nitrite and provide recommendations for accurate oxygen isotopic analysis of nitrite by any method. Finally, we report preliminary results on the equilibrium isotope effect between nitrite and water, which can play an important role in determining the oxygen isotopic value of nitrite where equilibration with water is significant. ?? 2007 American Chemical Society.

  19. Isotopes in the Arctic atmospheric water cycle

    Science.gov (United States)

    Bonne, Jean-Louis; Werner, Martin; Meyer, Hanno; Kipfstuhl, Sepp; Rabe, Benjamin; Behrens, Melanie; Schönicke, Lutz; Steen Larsen, Hans Christian; Masson-Delmotte, Valérie

    2016-04-01

    The ISO-ARC project aims at documenting the Arctic atmospheric hydrological cycle, by assessing the imprint of the marine boundary conditions (e.g. temperature variations, circulation changes, or meltwater input) to the isotopic composition of the atmospheric water cycle (H218O and HDO) with a focus on North Atlantic and Arctic oceans. For this purpose, two continuous monitoring water vapour stable isotopes cavity ring-down spectrometers have been installed in July 2015: on-board the Polarstern research vessel and in the Siberian Lena delta Samoylov research station (N 72° 22', E 126° 29'). The Polarstern measurements cover the summer 2015 Arctic campaign from July to mid-October, including six weeks in the Fram Strait region in July- August, followed by a campaign reaching the North Pole and a transect from the Norwegian Sea to the North Sea. These vapour observations are completed by water isotopic measurements in samples from the surface ocean water for Polarstern and from precipitation in Samoylov and Tiksi (120 km south-east of the station). A custom-made designed automatic calibration system has been implemented in a comparable manner for both vapour instruments, based on the injection of different liquid water standards, which are completely vaporised in dry air at high temperature. Subsequent humidity level can be adjusted from 2000 to at least 30000 ppm. For a better resilience, an independent calibration system has been added on the Samoylov instrument, allowing measurements of one standard at humidity levels ranging from 2000 to 15000 ppm: dry air is introduced in a tank containing a large amount of liquid water standard, undergoing evaporation under a controlled environment. The measurement protocol includes an automatic calibration every 25 hours. First instrument characterisation experiments depict a significant isotope-humidity effect at low humidity, dependant on the isotopic composition of the standard. For ambient air, our first isotope

  20. Isotopic analysis using optical spectroscopy (1963)

    International Nuclear Information System (INIS)

    The isotopic displacement in the atomic lines of certain elements (H, He, Li, Ne, Sr, Hg, Pb, U, Pu) is used for dosing these elements isotopically. The use of the Fabry-Perot photo-electric interference spectrometer is shown to be particularly adapted for this sort of problem: in each case we give on the one hand the essential results obtained with this apparatus, and on the other hand the results previously obtained with a conventional apparatus (grating, photographic plate). These results together give an idea of the possibilities of optical spectroscopy: in the best case, the precision which may be expected is of the order of 1 to 2 per cent for isotopes whose concentration is about 1 per cent. (author)

  1. Theoretical isotope shifts in neutral barium

    CERN Document Server

    Nazé, Cédric; Godefroid, Michel

    2015-01-01

    The present work deals with a set of problems in isotope shifts of neutral barium spectral lines. Some well known transitions ($6s^2~^1S_0-6s6p~^{1,3}P^o_1$ and $6s^2~^1S_0-6p^2~^3P_0$) are first investigated. Values of the changes in the nuclear mean-square charge radius are deduced from the available experimental isotope shifts using our ab initio electronic factors. The three sets $\\{ \\delta\\langle r^2\\rangle^{A,A'}\\} $ obtained from these lines are consistent with each other. The combination of the available nuclear mean-square radii with our electronic factors for the $6s5d~^3D_{1,2} -6s6p~^{1}P^o_1$ transitions produces isotope shift values in conflict with the laser spectroscopy measurements of Dammalapati et al. (Eur. Phys. J. D 53, 1 (2009)).

  2. Boron-isotope fractionation in plants

    International Nuclear Information System (INIS)

    Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species have been documented, but no determination as to whether plants fractionate the stable isotopes of boron, 11B and 10B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in 11B relative to the nutrient solution, and the leaves were enriched in 10B and the stem in 11B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. (author)

  3. Carbon isotope geochemistry in the Yalujiang estuary

    Institute of Scientific and Technical Information of China (English)

    吴莹; 张经

    2001-01-01

    The distribution of particulate organic carbon (POC) along the lower reaches is similar between the dry season and the flood season in the Yalujiang Estuary, North China. However, the values of particulate organic carbon of the upperstream in the dry season are one magnitude lower than the concentrations in the flood season. Stable carbon isotope ratios have been used to study the sources of particulate organic carbon in the Yalujiang Estuary. The isotopic composition of POC shows a range from -23.1‰ to -29.4‰ with a little seasonal variation. The isotopic evidence indicates that the POC in the Yalujiang Estuary is predominantly of terrestrial origin rather than a result of in situ plankton. The study of the ratio of POC: Chla shows that the turbidity maximum plays an important role in POC cycle in the Yalujiang Estuary. Organic detritus and soil erosion are the main contributions to POC in the turbidity maximum, especially in the flood season.

  4. Boron isotopic enrichment by displacement chromatography

    International Nuclear Information System (INIS)

    10B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH)4-) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10B and 11B

  5. BWXT Services medical isotope production system status

    International Nuclear Information System (INIS)

    BWXT Services, Inc. (BWXS) a subsidiary of BWX Technologies, Inc., one of the Babcock and Wilcox companies, has for some years conducted small scale development of its patented uranyl nitrate Medical Isotope Production System (MIPS). This application of an Aqueous Homogeneous Reactor (AHR) for isotope production was invented by BWXT's Dr. Russell M. Ball in 1997. The MIPS approach targets commercial scale production of medical isotopes, primarily 99Mo, used to supply 99mTc for diagnostic imaging purposes, using a Low Enriched Uranium (LEU) salt solution as the fuel/target. Recent heightened emphasis on controlling use of Highly Enriched Uranium (HEU) throughout the world in support of nuclear non-proliferation goals has motivated increased commercial interest in this safe and cost effective technology. Conceptual designs for commercial application have been developed and efforts are under way to establish a partnership with an established pharmaceutical firm familiar with current 99Mo production technology and operating practice. (author)

  6. Isotope analysis in the transmission electron microscope

    CERN Document Server

    Susi, Toma; Argentero, Giacomo; Leuthner, Gregor T; Pennycook, Timothy J; Mangler, Clemens; Meyer, Jannik C; Kotakoski, Jani

    2016-01-01

    The {\\AA}ngstr\\"om-sized probe of the scanning transmission electron microscope can visualize and collect spectra from single atoms. This can unambiguously resolve the chemical structure of materials, but not their isotopic composition. Here we differentiate between two isotopes of the same element by quantifying how likely the energetic imaging electrons are to eject atoms. First, we measure the displacement probability in graphene grown from either $^{12}$C or $^{13}$C and describe the process using a quantum mechanical model of lattice vibrations coupled with density functional theory simulations. We then test our spatial resolution in a mixed sample by ejecting individual atoms from nanoscale areas spanning an interface region that is far from atomically sharp, mapping the isotope concentration with a precision better than 20%. Although we use a scanning instrument, our method should be applicable to any atomic resolution transmission electron microscope and to other low-dimensional materials.

  7. Laser Spectroscopy of neutron deficient Sn isotopes

    CERN Multimedia

    We propose to study the ground state properties of neutron-deficient tin isotopes towards the doubly-magic nucleus $^{100}$Sn. Nuclear spins, changes in the rms charge radii and electromagnetic moments of $^{101-121}$Sn will be measured by laser spectroscopy using the CRIS experimental beam line. These ground-state properties will help to clarify the evolution of nuclear structure properties approaching the $\\textit{N = Z =}$ 50 shell closures. The tin isotopic chain is currently the frontier for the application of state-of-the-art ab-initio calculations. Our knowledge of the nuclear structure of the Sn isotopes will set a benchmark for the advances of many-body methods, and will provide an important test for modern descriptions of the nuclear force.

  8. Stable isotope dilution assays in mycotoxin analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rychlik, Michael; Asam, Stefan [Universitaet Muenchen, Lehrstuhl fuer Lebensmittelchemie der Technischen, Garching (Germany)

    2008-01-15

    The principle and applications of stable isotope dilution assays (SIDAs) in mycotoxin analysis are critically reviewed. The general section includes historical aspects of SIDAs, the prerequisites and limitations of the use of stable isotopically labelled internal standards, and possible calibration procedures. In the application section actual SIDAs for the analysis of trichothecenes, zearalenone, fumonisins, patulin, and ochratoxin A are presented. The syntheses and availability of labelled mycotoxins for use as internal standards is reviewed and specific advances in food analysis and toxicology are demonstrated. The review indicates that LC-MS applications, in particular, require the use of stable isotopically labelled standards to compensate for losses during clean-up and for discrimination due to ion suppression. As the commercial availability of these compounds continues to increase, SIDAs can be expected to find expanding use in mycotoxin analysis. (orig.)

  9. Strontium isotope stratigraphy of the Pelotas Basin

    International Nuclear Information System (INIS)

    Strontium isotope data were obtained from foraminifera shells of the Pelotas Basin Tertiary deposits to facilitate the refinement of the chronostratigraphic framework of this section. This represents the first approach to the acquisition of numerical ages for these strata. Strontium isotope stratigraphy allowed the identification of eight depositional hiatuses in the Eocene-Pliocene section, here classified as disconformities and a condensed section. The reconnaissance of depositional gaps based on confident age assignments represents an important advance considering the remarkably low chronostratigraphic resolution in the Cenozoic section of the Pelotas Basin. The recognition of hiatuses that match hiatuses is based on biostratigraphic data, as well as on global events. Furthermore, a substantial increase in the sedimentation rate of the upper Miocene section was identified. Paleotemperature and productivity trends were identified based on oxygen and carbon isotope data from the Oligocene-Miocene section, which are coherent with worldwide events, indicating the environmental conditions during sedimentation. (author)

  10. Iron isotope systematics of the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Lesher, Charles; Lundstrom, C.C.; Barfod, Gry;

    The early Eocene Skaergaard intrusion, central east Greenland, is one of the most thoroughly studied layered mafic intrusions on Earth and an exceptional example of (near) closed-system magmatic differentiation. The Skaergaard intrusion is ideally suited to test models of closed-system fractional....... Forward modeling of closed system fractional crystallization constrained by cumulate volumes, whole rock and mineral compositions, mineral modes and independent constraints on Fe isotope fractionation factors account for the stratigraphic relations, except during the final stages of differentiation of...... crystallization on non-traditional stable isotope systems, particularly iron. FeTi oxide minerals (titanomagnetite and ilmenite) appear after ~60% of the magma had solidified. This was a significant event affecting the liquid line of descent and potentially accompanied by iron isotope fractionation. Here we...

  11. Isotopic analysis of bullet lead samples

    International Nuclear Information System (INIS)

    The possibility of using the isotopic composition of lead for the identification of bullet lead is investigated. Lead from several spent bullets were converted to lead sulphide and analysed for the isotopic abundances using an MS-7 mass spectrometer. The abundances are measured relative to that for Pb204 was too small to permit differentiation, while the range of variation of Pb206 and Pb207 and the better precision in their analyses permitted differentiating samples from one another. The correlation among the samples examined has been pointed out. The method is complementary to characterisation of bullet leads by the trace element composition. The possibility of using isotopically enriched lead for tagging bullet lead is pointed out. (author)

  12. Isotopic studies in soil and plant nutrition

    International Nuclear Information System (INIS)

    One of the most important peaceful applications of isotopes is in research for the enhancement of our understanding for increased crop production and better management of resources with higher economic efficiency and environmental safety. Nuclear techniques helped in generating useful information on such aspects as use-efficiency of fertilizer nutrients, quantifying their losses from soil and their biological transformations. Such information was, hitherto, obtained indirectly by conventional methods. Radio and stable isotopes have also been successfully employed for getting information in such diverse fields as soil erosion, turnover of soil organic matter, pesticide retention in soil ground water recharge etc. The property of 137Cs adhering tightly to certain exchange surface in soil and its chemically inert nature has made it a useful tool for soil erosion studies. In this paper, applications of isotopes in the research and other such studies as degradation, movement and retention of pesticides, movement of nitrate in soil, biological and ammoniacal nitrogen fixation in soil is discussed

  13. Isotope hydrology in Pakistan - instrumentation method applications

    International Nuclear Information System (INIS)

    Isotope hydrology in Pakistan including the development of related instrumentation, methodology of isotopic analysis for /sup 2/H, /sup 13/C, /sup 15/N, /sup 18/ O and /sup 34/ S and applications in selected areas of Pakistan have been presented. UP-gradation of varian Mat GD-150 mass spectrometer through the fabrication of new amplifiers, ultra high vacuum system, digital ratio measurements and on-line data acquisition of mass spectrometric data, have been done. The fabrication of various sample preparation systems on mass spectrometer has also been presented. The use of above isotopic techniques in understanding and solving various hydrological problems of the country has been described. These studies have brought up some definite conclusions about the source of salinity, waterlogging and turnover times of various aquifers. The downward movement of soil moisture in unsaturated zone has been studied in detailed and some recommendations regarding delta of irrigation, presently in practice, has been made. (orig./A.B.)

  14. Isotope characteristics of oils of Lublin region

    International Nuclear Information System (INIS)

    The paper presents brief discussion of the present state of knowledge of the processes of isotope fractionation of coal, proceeding in the nature, with a special attention paid to geochemical cycle of origin of oil. Moreover, the results of isotope studies on 54 samples of Polish oils, and especially those concerning the samples of oils from the Lublin region are briefly discussed. The isotope studies have shown that 8 types of oil derived from Devonian and Carboniferous deposits of that region may be characterized as heavily metamorphosed and well-advanced in maturity processes. A group of 3 oils from Deblin, Abramow and Kock 2 (first horizon) drillings differs from the former in their features, which seems to indicate origin under conditions of lower temperature and lower degree of matamorphism. (author)

  15. Strontium isotope stratigraphy of the Pelotas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Zerfass, Geise de Santana dos Anjos, E-mail: geise.zerfass@petrobras.com.br [Petroleo Brasileiro S.A. (PETROBRAS/CENPES/PDGEO/BPA), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Mello; Chemale Junior, Farid, E-mail: fchemale@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias; Moura, Candido Augusto Veloso, E-mail: candido@ufpa.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias. Dept. de Geoquimica e Petrologia; Costa, Karen Badaraco, E-mail: karen.costa@usp.br [Instituto Oceanografico, Sao Paulo, SP (Brazil); Kawashita, Koji, E-mail: koji@usp.br [Unversidade de Sao Paulo (USP), SP (Brazil). Centro de Pesquisas Geocronologicas

    2014-07-01

    Strontium isotope data were obtained from foraminifera shells of the Pelotas Basin Tertiary deposits to facilitate the refinement of the chronostratigraphic framework of this section. This represents the first approach to the acquisition of numerical ages for these strata. Strontium isotope stratigraphy allowed the identification of eight depositional hiatuses in the Eocene-Pliocene section, here classified as disconformities and a condensed section. The reconnaissance of depositional gaps based on confident age assignments represents an important advance considering the remarkably low chronostratigraphic resolution in the Cenozoic section of the Pelotas Basin. The recognition of hiatuses that match hiatuses is based on biostratigraphic data, as well as on global events. Furthermore, a substantial increase in the sedimentation rate of the upper Miocene section was identified. Paleotemperature and productivity trends were identified based on oxygen and carbon isotope data from the Oligocene-Miocene section, which are coherent with worldwide events, indicating the environmental conditions during sedimentation. (author)

  16. Stable isotopes for heavy element production

    CERN Document Server

    Lommel, B; Hofmann, S; Kindler, B; Klemm, J; Steiner, J; Tinschert, K

    2003-01-01

    The synthesis of heavy elements and the search for new superheavy elements is one of the exciting fields in modern nuclear physics and chemistry. Heavy elements are produced by heavy-ion fusion reactions. Necessary prerequisites are intense heavy-ion beams from pure isotopic material and thin isotopically enriched targets. At GSI the elements from 107 to 112 were produced using targets of Pb and Bi and beams of the most neutron rich isotopes of Cr, Fe, Ni, and Zn. Experimental set-up consisting of target wheel, velocity filter SHIP (Separator for Heavy Ion Reaction Products), and detector system is presented. Status of the ion source techniques for delivering intense and stable beams for this kind of experiment is shortly described. The manufacturing and properties of various source - target combinations used for the synthesis of the elements by now are discussed in detail as well as the possibilities for extending the experiments into the region of superheavy elements.

  17. Assessing wine quality using isotopic methods

    International Nuclear Information System (INIS)

    Full text: The analytical methods used to determine the isotope ratios of deuterium, carbon-13 and oxygen-18 in wines have gained official recognition from the Office International de la Vigne et du Vin (OIV) and National Organisation of Vine and Wine. The amount of stable isotopes in water and carbon dioxide from plant organic materials and their distribution in sugar and ethanol molecules are influenced by geo-climatic conditions of the region, grape varieties and the year of harvest. For wine characterization, to prove the botanical and geographical origin of the raw material, the isotopic analysis by continuous flow mass spectrometry CF-IRMS has made a significant contribution. This paper emphasize the results of a study concerning the assessing of water adulterated wines and non-grape alcohol and sugar additions at different concentration levels, using CF-IRMS analytical technique. (authors)

  18. Predicting the isotopic ratio of western European Precipitation using an isotope trajectory model

    International Nuclear Information System (INIS)

    Full text: Spatial and seasonal variations of isotopic ratios in precipitation across Western Europe are well documented. Locations of moisture uptake, transport pathways, condensation temperatures, and surface temperatures at source region and precipitation location all influence the water isotope cycle. Isotope cycle modelling has been included in Global Circulation Models (GCMs) in order to model all of the controlling factors. However, the relative importance of each of these processes remains unclear due to the difficulties in decoupling these processes in GCMs. A combination of a Lagrangian Particle Dispersion Model and an extended Rayleigh distillation theory model allows the effects of different atmospheric processes on isotopic fractionation to be investigated. This method has previously been used to model precipitation in Antarctica and Greenland with excellent results. However, there are added complications involved when modelling rainfall rather than snowfall, such as isotopic re-equilibration between falling raindrops and the surrounding water vapour. Lower latitude locations also experience more evaporation and re-evaporation along the path of a moist air parcel, increasing opportunities for fractionation. These models have been used to predict the hydrogen and oxygen isotope ratios of rainfall in the U.K and Ireland. The model results have been compared with measured isotopic data from daily rainfall samples in order to test how the modelled processes interact. A case study is presented which incorporates observed data collected throughout November 2005 at stations in Norwich, Birmingham and Dublin, together with the corresponding temporal model predictions at these localities. (author)

  19. Zinc isotope fractionation during magmatic differentiation and the isotopic composition of the bulk Earth

    Science.gov (United States)

    Chen, Heng; Savage, Paul S.; Teng, Fang-Zehn; Helz, Rosalind T.; Moynier, Frédéric

    2013-01-01

    he zinc stable isotope system has been successfully applied to many and varied fields in geochemistry, but to date it is still not completely clear how this isotope system is affected by igneous processes. In order to evaluate the potential application of Zn isotopes as a proxy for planetary differentiation and volatile history, it is important to constrain the magnitude of Zn isotopic fractionation induced by magmatic differentiation. In this study we present high-precision Zn isotope analyses of two sets of chemically diverse, cogenetic samples from Kilauea Iki lava lake, Hawaii, and Hekla volcano, Iceland, which both show clear evidence of having undergone variable and significant degrees of magmatic differentiation. The Kilauea Iki samples display small but resolvable variations in Zn isotope composition (0.26‰66Zn66Zn defined as the per mille deviation of a sample's 66Zn/64Zn compositional ratio from the JMC-Lyon standard), with the most differentiated lithologies exhibiting more positive δ66Zn values. This fractionation is likely a result of the crystallization of olivine and/or Fe–Ti oxides, which can both host Zn in their crystal structures. Samples from Hekla have a similar range of isotopic variation (0.22‰66Zn66Zn=0.28±0.05‰ (2s.d.).

  20. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g-1. The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  1. Ancient iron and lead isotope analysis

    International Nuclear Information System (INIS)

    Full text: Little work has been published to date on the subject of lead isotope analysis of ancient iron artefacts. That which has suffers from a lack of understanding of the nature of ancient iron, and of the behavior of lead in relation to iron oxides. This paper examines data from a lead isotope study of 12th-10th Century B.C.E. iron artefacts from Israel and Palestine, and iron ores from these and surrounding areas, focusing on the issues of iron corrosion and lead contamination. The data shows that experimentally produced bloomery iron contains very little lead (less than O. 1 ppm), with most lead in the ore being reduced in the smelting process and lost to the slag. This low quantity of lead raises the question of contamination in samples which have been corroding whilst buried, in this case, for 3000 years. It is proposed that useful lead isotope data may be obtained where analysis of hydrated iron oxides in particular is avoided, as they commonly make up the outer layers of recovered ancient iron objects, formed in direct association with surrounding soil and rock. Lead contamination of these porous oxides- is a constantly observed feature of the material, and the affinity of lead for such oxides is well documented. Where there exists uncorroded iron (a rare event), or where there exists a core of magnetite beneath the outer hydrated oxide layers, it may be possible to obtain useful lead isotope data, which reflect the isotopic composition of the metal as it emerged from the furnace in antiquity. A magnetic separation process and washing in cold 7M HCl are proposed as means of removing contaminated hydrated iron oxides from this more useful material in the laboratory, prior to lead isotope analysis

  2. Stable Isotope Group 1981 progress report

    International Nuclear Information System (INIS)

    Geothermal studies were reported on the Tauhara, Wairakei, Orakeikorako and Mokai areas. We assisted the two N.Z. geothermal consultant companies with isotope analyses and the Geothermal Institute with lectures on stable isotope aspects of the diploma course. Sample collections were made at Ngawha and Wairakei. Oxygen isotope studies of central North Island volcanics have shown a negative correlation of delta 18O with SiO2 content of dacites and rhyolites; contamination of subcrustal rhyolite differentiates by greywacke appears the best explanation. A series of four papers on 'Environmental Isotopes in New Zealand Hydrology' was published during the year. Parts 1 and 2 described the principles and measurement techniques and Parts 3 and 4 described isotope studies of the Pupu Springs, Takaka and the groundwater resources of the Waimea Plains respectively. Carbon isotopes have proved useful in elucidating the food sources of freshwater insects in forest streams on the West Coast and brachiopods from Fiordland. Potassium-argon dating studies were completed on volcanics of the Auckland Islands, North Canterbury and East Otago, basement granites and meta-sediments of Marie Byrd Land, West Antarctica and slates in Western Tasmania. Rubidium-strontium computer programs were developed to control the solid-source mass spectrometer, chemical methods for preparation of strontium and rubidium samples were substantially improved and the first analyses of USGS rock standards were completed. Fission-track dating on minerals from granites from Buller and Westland have shown ages of 100-150Ma on the West Coast decreasing to about 5Ma at the Alpine Fault, reflecting recent uplift there

  3. Carbonate clumped isotope thermometry in continental tectonics

    Science.gov (United States)

    Huntington, Katharine W.; Lechler, Alex R.

    2015-04-01

    Reconstructing the thermal history of minerals and fluids in continental environments is a cornerstone of tectonics research. Paleotemperature constraints from carbonate clumped isotope thermometry have provided important tests of geodynamic, structural, topographic and basin evolution models. The thermometer is based on the 13C-18O bond ordering in carbonates (mass-47 anomaly, Δ47) and provides estimates of the carbonate formation temperature independent of the δ18O value of the water from which the carbonate grew; Δ47 is measured simultaneously with conventional measurements of carbonate δ13C and δ18O values, which together constrain the isotopic composition of the parent water. Depending on the geologic setting of carbonate growth, this information can help constrain paleoenvironmental conditions or basin temperatures and fluid sources. This review examines how clumped isotope thermometry can shed new light on problems in continental tectonics, focusing on paleoaltimetry, basin evolution and structural diagenesis applications. Paleoaltimetry is inherently difficult, and the precision in carbonate growth temperature estimates is at the limit of what is useful for quantitative paleoelevation reconstruction. Nevertheless, clumped isotope analyses have enabled workers to address previously intractable problems and in many settings offer the best chance of understanding topographic change from the geologic record. The portion of the shallow crust residing at temperatures up to ca. 200 °C is important as host to economic resources and records of tectonics and climate, and clumped isotope thermometry is one of the few proxies that can access this critical range with sensitivity to temperature alone. Only a handful of studies to date have used clumped isotopes to investigate diagenesis and other sub-surface processes using carbonate crystallization temperatures or the sensitivity of Δ47 values to a sample's thermal history. However, the thermometer is

  4. Hitting the moving target: modelling ontogenetic shifts with stable isotopes reveals the importance of isotopic turnover.

    Science.gov (United States)

    Hertz, Eric; Trudel, Marc; El-Sabaawi, Rana; Tucker, Strahan; Dower, John F; Beacham, Terry D; Edwards, Andrew M; Mazumder, Asit

    2016-05-01

    Ontogenetic niche shifts are widely prevalent in nature and are important in shaping the structure and dynamics of ecosystems. Stable isotope analysis is a powerful tool to assess these shifts, with δ(15) N providing a measure of trophic level and δ(13) C a measure of energy source. Previous applications of stable isotopes to study ontogenetic niche shifts have not considered the appreciable time lag between diet and consumer tissue associated with isotopic turnover. These time lags introduce significant complexity into field studies of ontogenetic niche shifts. Juvenile Chinook salmon (Oncorhynchus tshawytscha) migrate from freshwater to marine ecosystems and shift their diet from feeding primarily on invertebrates to feeding primarily on fish. This dual ontogenetic habitat and diet shift, in addition to the long time lag associated with isotopic turnover, suggests that there is potential for a disconnect between the prey sources that juvenile salmon are consuming, and the inferred prey sources from stable isotopes. We developed a model that considered ontogenetic niche shifts and time lags associated with isotopic turnover, and compared this 'ontogeny' model to one that considered only isotopic turnover. We used a Bayesian framework to explicitly account for parameter uncertainty. Data showed overwhelming support for the ontogeny model relative to the isotopic turnover model. Estimated variables from best model fits indicate that the ontogeny model predicts a much greater reliance on fish prey than does the stomach content data. Overall, we found that this method of quantifying ontogenetic niche shifts effectively accounted for both isotopic turnover and ontogenetic diet shifts; a finding that could be widely applicable to a variety of systems. PMID:26880007

  5. Isotope tracing of nitrate : lessons from Malta

    OpenAIRE

    Heaton, Timothy; Stuart, Marianne; Sapiano, M.; Micallef Sultana, M.

    2010-01-01

    Average concentrations of nitrate in Malta’s groundwaters are probably the highest among EU member states. This compromises the quality of an important resource -almost 60% of Malta’s water supply being provided by groundwater. An 15N/14N + 18O/16O isotope study was undertaken as a core part of wide-ranging investigations into the potential sources of the nitrate pollution, its likely future trends, and possible ameliorative actions. The dual isotope (15N/14N + 18O/16O) approach was important...

  6. Utilization of stable isotopes in power reactor

    International Nuclear Information System (INIS)

    The stable isotopes, besides uranium, used in EDF power nuclear reactors are mainly the boron 10 and the lithium 7. Boron is used in reactors as a neutrophagous agent for core reactivity control, and lithium, and more especially lithium 7, is extensively used as a solution in PWR moderators for primary fluid pH control. Boron and lithium ore reserves and producers are presented; industrial isotopic separation techniques are described: for the boron 10, they include dissociative distillation (Sulzer process) and separation on anionic resins, and for lithium 7, ion exchange columns (Cogema). 1 tab

  7. Landfill pollution control with isotope techniques

    International Nuclear Information System (INIS)

    Groundwater and surface water contamination by sanitary landfills is being monitored since 1989 in Italy by using isotope techniques combined with chemical analyses. The results obtained are considered mostly satisfactory for identifying sources of contaminants and predicting their behaviour. We present in this work the results of chemical and isotopic measurements performed on rainwater, surface water and groundwater samples, with the aim of investigating the fate of contaminants released from some landfills located near Ancona, Central Italy. The isotope determinations included δ18O, δ2H and tritium (3H). The first objective of these investigations is establishing the background values of the main environmental parameters related to contamination, and obtaining indication about source and residence time (age) of groundwater in the landfill proximity. In particular, the methods used for detecting groundwater and/or surface waters contamination derived from the landfill, are based on the occurrence of tritium activity anomalies and chemical concentration changes. In order to estimate the regional background of environmental tritium in shallow groundwater, we measured the tritium content of monthly rainwater samples collected in stations on the Apennines in proximity of Ancona. The tritium concentration ranged from 3 to 6 TU in winter months (October to April), and reached the maximum values (up to 14 TU) in summer months. The investigations of groundwater and surface water contamination were undertaken on landfills dismissed from 1986 to 1998. The isotopic and chemical monitoring was started one year ago and was carried out on leachates, surface waters and groundwater (the last sampled in several downstream wells). The tritium concentration in leachates can be very high, due to a still active tritium release from the landfill. Tritium values in wells outside of the landfill area, lower than in leachate but higher than the regional background of environmental

  8. Laser separation of isotopes of hydrogen

    International Nuclear Information System (INIS)

    Laser isotope separation technique is explained and various methods based on the technique are discussed in detail. Requirements of any laser isotope separation method to be acceptable for the production of heavy water are mentioned and economic viability of this process for heavy water production is examined. Investigations carried out to use this technique for deuterium separation using methanol, formaldehyde, propynal, 2,2,-dichloro-1-1-1,-trifluoroethane (Freon 123), polyvinyl chloride and fluoroform-d are reviewed. (M.G.B.)

  9. Isotopic abundance in atom trap trace analysis

    Science.gov (United States)

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  10. Isotopic age determination in Bergslagen, Sweden. 1

    International Nuclear Information System (INIS)

    This paper is an introduction to a series of short communications 'Isotopic age determinations in Bergslagen, Sweden', which will be submitted to this journal. An earlier paper on K-Ar ages of hornblendes in skarns and metabasites in the Hjulsjoe area has been published elsewhere (Moorman et al., 1982). This joint research project of the ZWO-Laboratory of Isotope Geology and the Geological Institute University of Amsterdam forms part of the research program of the 'Stichting voor Isotopen-Geologisch Onderzoek', supported by the Netherlands Organization for the Advancement of Pure Research (Z.W.O.). (Auth.)

  11. Application of Cesium isotopes in daily life

    International Nuclear Information System (INIS)

    In the world of science, the desire of the scientific community to discover new chemical elements is crucial for the development of new technologies in various fields of knowledge. And the main chemical element addressed by this article is Cesium, but specifically 133Cesium isotope and radioisotope 137Cesium, exemplifying their physical and chemical characteristics, and their applications. This article will also show how these isotopes have provided researchers a breakthrough in the field of radiological medicine and in time and frequency metrology. (author)

  12. Carbon isotope analysis of fossil bone apatite

    International Nuclear Information System (INIS)

    The feasibility of using bone apatite for stable carbon isotope analysis of ancient bone for palaeodietary studies has been the subject of much controversy, and attempts to determine whether isotopic signatures are stable over time have produced contradictory results. We have tested this stability by measuring the δ13C values of chemically treated bone or tooth mineral of herbivores of known diet (browsers), in a temporal series. The results indicate that diagenesis of biogenic carbonates in the mineral over time is unexpectedly limited, and that chemical pretreatment further reduces diagenetic alteration of the biogenic signal. Enough biogenic carbonate remains to distinguish clearly between browsers and grazers, even after 3 million years

  13. The isotope effect in gadolinium amalgam system

    International Nuclear Information System (INIS)

    Gadolinium is a neutron absorbing material and has been used as a burnable poison contained in the U fuel pellets for LWRs. Among the 7 isotopes of gadolinium, 157 Gd has a special large neutron absorption cross section of 254 000 barn (10 -24 cm2). In this paper gadolinium isotope separation factor for isotopic exchange between Gd 3+ (in solution) and gadolinium amalgam (GdHg) is determined. By electrolysis of aqueous solutions containing gadolinium acetate and lithium citrate, as complexing agent, using the ratio (Li +/Gd3+) = 12, gadolinium amalgam was prepared using a glass electrolyser with Hg as cathode and platinum as anode. The gadolinium amalgam was stirred with HCl solution 1-2N and Gd 3+ is precipitated as oxalate at weak acid pH and then converted to Gd2O3. The remained gadolinium in acetate solution (after electrolysis) was also precipitated as oxalate and converted to Gd2O3. On Gd2O3 samples the isotopic ratios 156 Gd/160 Gd were determined by mass spectrometry, using MAT 261 equipped with a thermal ionisation ion source. Between Gd3+ and Gadolinium amalgam there is an isotopic exchange, the heavy isotope 160 Gd was found to be enriched in Gd3+ while the lighter isotope, 156 Gd, was enriched in GdHg.. The single stage separation factor α (156 Gd/160 Gd) was determined in different experimental conditions: contact time between Gd3+ and GdHg, the yield of GdHg formation, current density. The range of the measured values of α was 1.0013 - 1.00456, average value being 1.0023 at 26 deg. C. The yield of GdHg formation has increased from 37-75.5% for the electrolyser of 40 mm i.d. (S = 12.56 cm2), to 89.6%, for electrolyser of 53 mm i.d. (S = 22 cm2).. After 30 minutes of contact (in electrolysis conditions) between Gd3+ and GdHg there is not an important passage of Gd between the two phases, in these conditions the isotopic exchange of Gd is studied. (authors)

  14. OXYGEN ISOTOPE FRACTION ATION IN URANIUM OXIDES

    Institute of Scientific and Technical Information of China (English)

    郑永飞

    1995-01-01

    Thermodynamic oxygen isotope factors for uranium oxides have been calculated by means of the modified increment method.The sequence of 18O-enrichment in the uranium oxides with respect to the common rock-forming minerals is predicted as follows:spinelisotopic geothermometry of uranium ores when pairing with other gangue minerals in hydrothermal uranium deposits.

  15. Isotope separation and advanced manufacturing technology

    Science.gov (United States)

    Carpenter, J.; Kan, T.

    This is the fourth issue of a semiannual report for the Isotope Separation and Advanced Materials Manufacturing (ISAM) Technology Program at Lawrence Livermore National Laboratory. Primary objectives include: (1) the Uranium Atomic Vapor Laser Isotope Separation (UAVLIS) process, which is being developed and prepared for deployment as an advanced uranium enrichment capability; (2) Advanced manufacturing technologies, which include industrial laser and E-beam material processing and new manufacturing technologies for uranium, plutonium, and other strategically important materials in support of DOE and other national applications. This report features progress in the ISAM Program from October 1993 through March 1994.

  16. Precision Mass Measurement of Argon Isotopes

    CERN Multimedia

    Lunney, D

    2002-01-01

    % IS388\\\\ \\\\ A precision mass measurement of the neutron-deficient isotopes $^{32,33,34}$Ar is proposed. Mass values of these isotopes are of importance for: a) a stringent test of the Isobaric-Multiplet- Mass-Equation, b) a verification of the correctness of calculated charge-dependent corrections as used in super-allowed $\\beta$- decay studies aiming at a test of the CVC hypothesis, and c) the determination of the kinematics in electron-neutrino correlation experiments searching for scalar currents in weak interaction. The measurements will be carried out with the ISOLTRAP Penning trap mass spectrometer.

  17. Isotope measurement techniques for atmospheric methane

    International Nuclear Information System (INIS)

    Measurement techniques for the carbon isotopic composition of atmospheric methane (δ13C) are described in detail as applied in several leading institutions active in this field since many years. The standard techniques with offline sample preparation and subsequent measurement by dual inlet isotope ratio mass spectrometry (IRMS) are compared with continuous flow IRMS. The potential use of infrared absorption spectroscopy is briefly discussed. Details on quality control and calibration are provided. Basic analytical aspects for the measurement of other species, 2H and 14C, are also given. (author)

  18. [Stable isotopes in biomedical diagnosis and research].

    Science.gov (United States)

    Martínez, J A; Hellerstein, M K; Monreal, I; Neese, R A; Viteri, F E

    1995-01-01

    Atoms that are chemically identical but that differed slightly in weight due to the number of nuclear neutrons are called isotopes stables, meaning that do not degrade spontaneously. Mass spectrometry is the analytical technique to evaluate the enrichment on these isotopes with a variety of applications in the clinical diagnosis of pathological processes and the quantitation of metabolic events such as bacterial growth (Helicobacter pylorii), Phenylketonuria, lactose intolerance, liver and pancreatic function, body composition and energy expenditure, cholesterogenesis, glucose utilization, etc. in an easy, non-invasive and specific way as mass spectrometers develop. PMID:8552917

  19. Scattering lengths of calcium and barium isotopes

    OpenAIRE

    Dammalapati, U.; Willmann, L.; Knoop, S.

    2011-01-01

    We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba), in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that ...

  20. Isotopic signature of Madeira basaltic magmatism

    International Nuclear Information System (INIS)

    Chemical composition of the basalts of Madeira Island is studied. To assess the isotopic sources of magmatism the Pb-Sr, Sm-Nd, U-Th-Pb systems were investigated in a number of basalts. It is shown that the island's rocks are characterized by the mostly deplet sources in relation to Pb-Sr and Sm-Nd systems (87Sr/86Sr - 0.70282-0.70292, 143Nd/144Nd - 0.52303-0.51314). Isotopic composition of lead testifies that the magmatism reservoir is some enriched. It is concluded that the magmatism of Madeira Island is a new example of world ocean island's volcanism