Science.gov

Sample records for beta-plus decay radioisotopes

  1. Accelerated Decay of Radioisotopes

    DTIC Science & Technology

    2013-01-01

    00-01 -2013 Technical June20 l l-June 2012 4 . TITLE AND SUBTITLE Sa. CONTRACT NUMBER DTRA MIPR 11-2362M Accelerated Decay of Radioisotopes Sb...268 x E +2 4.788 026 x E -2 6.894 757 4.535 924 x E -1 4.214 011 x E -2 1.601 846 x E +1 1.000 000 x E -2 2.579 760 x E - 4 1.000 000 x E -8...c a y o f R a d i o i s o t o p e s " P r o p o s a l # B R C A L L 0 7 - N - 2 - 0 0 4 7 I l l u s t r a t i o n o f \\ P F R P a s p o

  2. On decay constants and orbital distance to the Sun—part III: beta plus and electron capture decay

    NASA Astrophysics Data System (ADS)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2017-02-01

    The hypothesis that seasonal changes in proximity to the Sun cause variation of decay constants at permille level has been tested for radionuclides disintegrating through electron capture and beta plus decay. Activity measurements of 22Na, 54Mn, 55Fe, 57Co, 65Zn, 82+85Sr, 90Sr, 109Cd, 124Sb, 133Ba, 152Eu, and 207Bi sources were repeated over periods from 200 d up to more than four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. Oscillations in phase with Earth’s orbital distance to the sun could not be observed within 10-4-10-5 range precision. The most stable activity measurements of β + and EC decaying sources set an upper limit of 0.006% or less to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months.

  3. Diffusion and decay chain of radioisotopes in stagnant water in saturated porous media.

    PubMed

    Guzmán, Juan; Alvarez-Ramirez, Jose; Escarela-Pérez, Rafael; Vargas, Raúl Alejandro

    2014-09-01

    The analysis of the diffusion of radioisotopes in stagnant water in saturated porous media is important to validate the performance of barrier systems used in radioactive repositories. In this work a methodology is developed to determine the radioisotope concentration in a two-reservoir configuration: a saturated porous medium with stagnant water is surrounded by two reservoirs. The concentrations are obtained for all the radioisotopes of the decay chain using the concept of overvalued concentration. A methodology, based on the variable separation method, is proposed for the solution of the transport equation. The novelty of the proposed methodology involves the factorization of the overvalued concentration in two factors: one that describes the diffusion without decay and another one that describes the decay without diffusion. It is possible with the proposed methodology to determine the required time to obtain equal injective and diffusive concentrations in reservoirs. In fact, this time is inversely proportional to the diffusion coefficient. In addition, the proposed methodology allows finding the required time to get a linear and constant space distribution of the concentration in porous mediums. This time is inversely proportional to the diffusion coefficient. In order to validate the proposed methodology, the distributions in the radioisotope concentrations are compared with other experimental and numerical works.

  4. High efficiency direct thermal to electric energy conversion from radioisotope decay using selective emitters and spectrally tuned solar cells

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Flood, Dennis J.; Lowe, Roland A.

    1993-01-01

    Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

  5. Atomic radiations in the decay of medical radioisotopes: a physics perspective.

    PubMed

    Lee, B Q; Kibédi, T; Stuchbery, A E; Robertson, K A

    2012-01-01

    Auger electrons emitted in nuclear decay offer a unique tool to treat cancer cells at the scale of a DNA molecule. Over the last forty years many aspects of this promising research goal have been explored, however it is still not in the phase of serious clinical trials. In this paper, we review the physical processes of Auger emission in nuclear decay and present a new model being developed to evaluate the energy spectrum of Auger electrons, and hence overcome the limitations of existing computations.

  6. Atomic Radiations in the Decay of Medical Radioisotopes: A Physics Perspective

    PubMed Central

    Lee, B. Q.; Kibédi, T.; Stuchbery, A. E.; Robertson, K. A.

    2012-01-01

    Auger electrons emitted in nuclear decay offer a unique tool to treat cancer cells at the scale of a DNA molecule. Over the last forty years many aspects of this promising research goal have been explored, however it is still not in the phase of serious clinical trials. In this paper, we review the physical processes of Auger emission in nuclear decay and present a new model being developed to evaluate the energy spectrum of Auger electrons, and hence overcome the limitations of existing computations. PMID:22924061

  7. Investigation of the excitation functions for some medical radioisotopes production

    NASA Astrophysics Data System (ADS)

    Kılınç, Fatma; Karpuz, Nurdan; Çetin, Betül

    2016-11-01

    One of the main application fields of nuclear technology is medicine and radioisotopes are used in medicine. Production of those radioisotopes is important and in the production processes the cross section must be known. All the production of radioisotope used in medicine is based on the nuclear reactions means they are not natural. The decay time of produced radioisotopes is important as from production to hospital can take time and thus generally generator is used to produce some radioisotopes. Radioisotopes are widely produced in reactors or cyclotron type accelerator. Type of radioisotopes direct way to be used in production processes. Thus obtaining of cross section becomes crucial. For this purposes the theoretical calculation cross section of some radioisotopes used in medicine will be calculated in this study. The calculations will be done using Monte Carlo code of TALYS 1.6

  8. Silicon Carbide Radioisotope Batteries

    NASA Technical Reports Server (NTRS)

    Rybicki, George C.

    2005-01-01

    The substantial radiation resistance and large bandgap of SiC semiconductor materials makes them an attractive candidate for application in a high efficiency, long life radioisotope battery. To evaluate their potential in this application, simulated batteries were constructed using SiC diodes and the alpha particle emitter Americium Am-241 or the beta particle emitter Promethium Pm-147. The Am-241 based battery showed high initial power output and an initial conversion efficiency of approximately 16%, but the power output decayed 52% in 500 hours due to radiation damage. In contrast the Pm-147 based battery showed a similar power output level and an initial conversion efficiency of approximately 0.6%, but no degradation was observed in 500 hours. However, the Pm-147 battery required approximately 1000 times the particle fluence as the Am-242 battery to achieve a similar power output. The advantages and disadvantages of each type of battery and suggestions for future improvements will be discussed.

  9. Radioisotope trithiol complexes

    DOEpatents

    Jurisson, Silvia S.; Cutler, Cathy S.; Degraffenreid, Anthony J.

    2016-08-30

    The present invention is directed to a series of stable radioisotope trithiol complexes that provide a simplified route for the direct complexation of radioisotopes present in low concentrations. In certain embodiments, the complex contains a linking domain configured to conjugate the radioisotope trithiol complex to a targeting vector. The invention is also directed to a novel method of linking the radioisotope to a trithiol compound to form the radioisotope trithiol complex. The inventive radioisotope trithiol complexes may be utilized for a variety of applications, including diagnostics and/or treatment in nuclear medicine.

  10. Reactor production and processing of radioisotopes for therapeutic applications in nuclear medicine

    SciTech Connect

    Knapp, F.F. Jr.; Mirzadeh, S.; Beets, A.L.

    1995-02-01

    Nuclear reactors continue to play an important role in providing radioisotopes for nuclear medicine. Many reactor-produced radioisotopes are ``neutron rich`` and decay by beta-emission and are thus of interest for therapeutic applications. This talk discusses the production and processing of a variety of reactor-produced radioisotopes of current interest, including those produced by the single neutron capture process, double neutron capture and those available from beta-decay of reactorproduced radioisotopes. Generators prepared from reactorproduced radioisotopes are of particular interest since repeated elution inexpensively provides many patient doses. The development of the alumina-based W-188/Re-188 generator system is discussed in detail.

  11. Radioisotopes: Today's Applications.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    Radioisotopes are useful because of their three unique characteristics: (1) radiation emission; (2) predictable radioactive lives; and (3) the same chemical properties as the nonradioactive atoms of that element. Researchers are able to "order" a radioisotope with the right radiation, half-life, and chemical property to perform a given task with…

  12. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  13. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2016-01-01

    High-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific

  14. Radioisotopes as Political Instruments, 1946-1953.

    PubMed

    Creager, Angela N H

    2009-01-01

    The development of nuclear "piles," soon called reactors, in the Manhattan Project provided a new technology for manufacturing radioactive isotopes. Radioisotopes, unstable variants of chemical elements that give off detectable radiation upon decay, were available in small amounts for use in research and therapy before World War II. In 1946, the U.S. government began utilizing one of its first reactors, dubbed X-10 at Oak Ridge, as a production facility for radioisotopes available for purchase to civilian institutions. This program of the U.S. Atomic Energy Commission was meant to exemplify the peacetime dividends of atomic energy. The numerous requests from scientists outside the United States, however, sparked a political debate about whether the Commission should or even could export radioisotopes. This controversy manifested the tension in U.S. politics between scientific internationalism as a tool of diplomacy, associated with the aims of the Marshall Plan, and the desire to safeguard the country's atomic monopoly at all costs, linked to American anti-Communism. This essay examines the various ways in which radioisotopes were used as political instruments-both by the U.S. federal government in world affairs, and by critics of the civilian control of atomic energy-in the early Cold War.

  15. Radioisotopes as Political Instruments, 1946–1953

    PubMed Central

    Creager, Angela N. H.

    2009-01-01

    The development of nuclear “piles,” soon called reactors, in the Manhattan Project provided a new technology for manufacturing radioactive isotopes. Radioisotopes, unstable variants of chemical elements that give off detectable radiation upon decay, were available in small amounts for use in research and therapy before World War II. In 1946, the U.S. government began utilizing one of its first reactors, dubbed X-10 at Oak Ridge, as a production facility for radioisotopes available for purchase to civilian institutions. This program of the U.S. Atomic Energy Commission was meant to exemplify the peacetime dividends of atomic energy. The numerous requests from scientists outside the United States, however, sparked a political debate about whether the Commission should or even could export radioisotopes. This controversy manifested the tension in U.S. politics between scientific internationalism as a tool of diplomacy, associated with the aims of the Marshall Plan, and the desire to safeguard the country’s atomic monopoly at all costs, linked to American anti-Communism. This essay examines the various ways in which radioisotopes were used as political instruments—both by the U.S. federal government in world affairs, and by critics of the civilian control of atomic energy—in the early Cold War. PMID:20725612

  16. Cyclotron Production of Medical Radioisotopes

    SciTech Connect

    Avila-Rodriguez, M. A.; Zarate-Morales, A.; Flores-Moreno, A.

    2010-08-04

    The cyclotron production of radioisotopes for medical applications is gaining increased significance in diagnostic molecular imaging techniques such as PET and SPECT. In this regard, radioisotope production has never been easier or more convenient until de introduction of compact medical cyclotrons in the last few decades, which allowed the use of short-lived radioisotopes in in vivo nuclear medicine studies on a routine basis. This review outlines some general considerations about the production of radioisotopes using charged particle accelerators.

  17. Radioisotopic heat source

    DOEpatents

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  18. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2015-01-01

    High efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRG) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high specific power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTG). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and DOE called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provide about 50 to 450 watts DC to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and

  19. Safe use of radioisotopes.

    PubMed

    Meisenhelder, Jill; Semba, Kentaro

    2006-09-01

    The use of radioisotopes to label specific molecules in a defined way has greatly furthered the discovery and dissection of biochemical pathways. The development of methods to synthesize such tagged biological compounds inexpensively on an industrial scale has enabled them to be used routinely in laboratory protocols, including many detailed in this manual. Although most of these protocols involve the use of only microcurie amounts of radioactivity, some (particularly those describing the metabolic labeling of proteins or nucleic acids within cells) require amounts on the order of millicuries. In all cases where radioisotopes are used, depending on the quantity and nature of the isotope, certain precautions must be taken to ensure the safety of the scientist. It is essential to use good safety practices and proper protection to handle radioactive substances. This unit discusses handling, storage, and disposal of the isotopes most frequently used in biological research.

  20. Safe use of radioisotopes.

    PubMed

    Meisenhelder, Jill; Semba, Kentaro

    2006-06-01

    The use of radioisotopes to label specific molecules in a defined way has greatly furthered the discovery and dissection of biochemical pathways. The development of methods to synthesize such tagged biological compounds inexpensively on an industrial scale has enabled them to be used routinely in laboratory protocols, including many detailed in this manual. Although most of these protocols involve the use of only microcurie amounts of radioactivity, some (particularly those describing the metabolic labeling of proteins or nucleic acids within cells) require amounts on the order of millicuries. In all cases where radioisotopes are used, depending on the quantity and nature of the isotope, certain precautions must be taken to ensure the safety of the scientist. It is essential to use good safety practices and proper protection to handle radioactive substances. This unit discusses handling, storage, and disposal of the isotopes most frequently used in biological research.

  1. Taming Highly Charged Radioisotopes

    NASA Astrophysics Data System (ADS)

    Chowdhury, Usman; Eberhardt, Benjamin; Jang, Fuluni; Schultz, Brad; Simon, Vanessa; Delheij, Paul; Dilling, Jens; Gwinner, Gerald

    2012-10-01

    The precise and accurate mass of short-lived radioisotopes is a very important parameter in physics. Contribution to the improvement of nuclear models, metrological standard fixing and tests of the unitarity of the Caibbibo-Kobayashi-Maskawa (CKM) matrix are a few examples where the mass value plays a major role. TRIUMF's ion trap for atomic and nuclear physics (TITAN) is a unique facility of three online ion traps that enables the mass measurement of short-lived isotopes with high precision (˜10-8). At present TITAN's electron beam ion trap (EBIT) increases the charge state to increase the precision, but there is no facility to significantly reduce the energy spread introduced by the charge breeding process. The precision of the measured mass of radioisotopes is linearly dependent on the charge state while the energy spread of the charged radioisotopes affects the precision adversely. To boost the precision level of mass measurement at TITAN without loosing too many ions, a cooler Penning trap (CPET) is being developed. CPET is designed to use either positively (proton) or negatively (electron) charged particles to reduce the energy spread via sympathetic cooling. Off-line setup of CPET is complete. Details of the working principles and updates are presented

  2. Work Began on Contracts for Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2005-01-01

    NASA has had a history of successful space flight missions that depended on radioisotope-fueled power systems. These Radioisotope Power Systems (RPSs) converted the heat generated from the decay of radioisotope material into useful electrical power. An RPS is most attractive in applications where photovoltaics are not optimal, such as deep-space applications where the solar flux is too low or extended applications on planets such as Mars where the day/night cycle, settling of dust, and life requirements limit the usefulness of photovoltaics. NASA s Radioisotope Power Conversion Technology (RPCT) Program is developing next-generation power-conversion technologies that will enable future missions that have requirements that cannot be met by the two RPS flight systems currently being developed by the Department of Energy for NASA: the Multi-Mission Radioisotope Thermoelectric Generator and the Stirling Radioisotope Generator (SRG).

  3. Radioisotope Power System Pool Concept

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  4. Safe use of radioisotopes.

    PubMed

    Meisenhelder, Jill; Bursik, Steve

    2010-04-01

    The pursuit of scientific knowledge has been considerably advanced by the use of biochemical molecules that incorporate radioisotopes at specific sites. The fate of these labeled molecules, and/or the radiolabeled products that result from biochemical reactions in which the parent molecule was involved, can be traced using a variety of instruments that detect radioactivity. This appendix begins with a discussion of the principles of radioactivity in order to provide the reader/user with knowledge on which to base a common sense approach to the safe use of isotopes. The characteristics of isotopes most commonly used in a molecular biology laboratory are then detailed, as well as the safety precautions and monitoring methods peculiar to each one. Detection and imaging methods used in experimental analysis are reviewed. Finally, an outline of an orderly response to a spill of radioactive material is presented.

  5. Safe use of radioisotopes.

    PubMed

    Meisenhelder, Jill; Bursik, Steve

    2007-07-01

    The pursuit of scientific knowledge has been considerably advanced by the use of biochemical molecules that incorporate radioisotopes at specific sites. The fate of these labeled molecules, and/or the radiolabeled products that result from biochemical reactions in which the parent molecule was involved, can be traced using a variety of instruments that detect radioactivity. This appendix begins with a discussion of the principles of radioactivity in order to provide the reader/user with knowledge on which to base a common sense approach to the safe use of isotopes. The characteristics of isotopes most commonly used in a molecular biology laboratory are then detailed, as well as the safety precautions and monitoring methods peculiar to each one. Detection and imaging methods used in experimental analysis are reviewed. Finally, an outline of an orderly response to a spill of radioactive material is presented.

  6. Safe use of radioisotopes.

    PubMed

    Meisenhelder, Jill; Bursik, Steve

    2008-08-01

    The pursuit of scientific knowledge has been considerably advanced by the use of biochemical molecules that incorporate radioisotopes at specific sites. The fate of these labeled molecules, and/or the radiolabeled products that result from biochemical reactions in which the parent molecule was involved, can be traced using a variety of instruments that detect radioactivity. This appendix begins with a discussion of the principles of radioactivity in order to provide the reader/user with knowledge on which to base a common sense approach to the safe use of isotopes. The characteristics of isotopes most commonly used in a molecular biology laboratory are then detailed, as well as the safety precautions and monitoring methods peculiar to each one. Detection and imaging methods used in experimental analysis are reviewed. Finally, an outline of an orderly response to a spill of radioactive material is presented.

  7. NASA Radioisotope Power System Program - Technology and Flight Systems

    NASA Technical Reports Server (NTRS)

    Sutliff, Thomas J.; Dudzinski, Leonard A.

    2009-01-01

    NASA sometimes conducts robotic science missions to solar system destinations for which the most appropriate power source is derived from thermal-to-electrical energy conversion of nuclear decay of radioactive isotopes. Typically the use of a radioisotope power system (RPS) has been limited to medium and large-scale missions, with 26 U,S, missions having used radioisotope power since 1961. A research portfolio of ten selected technologies selected in 2003 has progressed to a point of maturity, such that one particular technology may he considered for future mission use: the Advanced Stirling Converter. The Advanced Stirling Radioisotope Generator is a new power system in development based on this Stirling cycle dynamic power conversion technology. This system may be made available for smaller, Discovery-class NASA science missions. To assess possible uses of this new capability, NASA solicited and funded nine study teams to investigate unique opportunities for exploration of potential destinations for small Discovery-class missions. The influence of the results of these studies and the ongoing development of the Advanced Stirling Radioisotope Generator system are discussed in the context of an integrated Radioisotope Power System program. Discussion of other and future technology investments and program opportunities are provided.

  8. Efficient Radioisotope Energy Transfer by Gold Nanoclusters for Molecular Imaging.

    PubMed

    Volotskova, Olga; Sun, Conroy; Stafford, Jason H; Koh, Ai Leen; Ma, Xiaowei; Cheng, Zhen; Cui, Bianxiao; Pratx, Guillem; Xing, Lei

    2015-08-26

    Beta-emitting isotopes Fluorine-18 and Yttrium-90 are tested for their potential to stimulate gold nanoclusters conjugated with blood serum proteins (AuNCs). AuNCs excited by either medical radioisotope are found to be highly effective ionizing radiation energy transfer mediators, suitable for in vivo optical imaging. AuNCs synthesized with protein templates convert beta-decaying radioisotope energy into tissue-penetrating optical signals between 620 and 800 nm. Optical signals are not detected from AuNCs incubated with Technetium-99m, a pure gamma emitter that is used as a control. Optical emission from AuNCs is not proportional to Cerenkov radiation, indicating that the energy transfer between the radionuclide and AuNC is only partially mediated by Cerenkov photons. A direct Coulombic interaction is proposed as a novel and significant mechanism of energy transfer between decaying radionuclides and AuNCs.

  9. Radioisotope Dating with Accelerators.

    ERIC Educational Resources Information Center

    Muller, Richard A.

    1979-01-01

    Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)

  10. Rhenium Radioisotopes for Therapeutic Radiopharmaceutical Development

    SciTech Connect

    Beets, A.L.; Knapp, F.F., Jr.; Kropp, J.; Lin, W.-Y.; Pinkert, J.; Wang, S.-Y.

    1999-01-18

    The availability of therapeutic radioisotopes at reasonable costs is important for applications in nuclear medicine, oncology and interventional cardiology, Rhenium-186 (Re-186) and rhenium-1 88 (Re-188) are two reactor-produced radioisotope which are attractive for a variety of therapeutic applications, Rhenium-186 has a half-life of 90 hours and decays with emission of a &particle with a maximum energy of 1.08 MeV and a 135 keV (9Yo) gamma which permits imaging. In contrast, Re- 188 has a much shorter half-life of 16.9 hours and emits a p-particle with a much higher energy of 2.12 MeV (Em=) and a 155 keV gamma photon (15Yo) for imaging. While Re-186 is unavailable from a generator system and must be directly produced in a nuclear reactor, Re-188 can also be directly produced in a reactor with high specific activity, but is more conveniently and cost-effectively available as carrier-free sodium perrhenate by saline elution of the alumina-based tungsten-188 (W1 88)/Re-l 88 generator system [1-2]. Since a comprehensive overviewofRe-186 and Re-188 therapeutic agents is beyond the scope of this &tended Abstrac4 the goal is to provide key examples of various agents currently in clinical use and those which are being developed for important clinical applications.

  11. Some geophysical considerations in radioisotope dating applications

    NASA Astrophysics Data System (ADS)

    Hayes, Robert

    2016-03-01

    Radioisotope dating only assumes radioactive decay laws are taking place allowing closed form solutions to be obtained in generating a sample date estimate. To be discussed in this work is the isotopic distribution expected in geological samples due to mass diffusion superimposed on that from simple radioactive decay. By taking into consideration the isotope effect (differential mass diffusion rates) when measuring isotopic ratios from very old samples, the distribution dependency will cause a bias if isotopic diffusion rates are not identical throughout a material (or at least across the boundaries of all samples measured). The isotope effect being that isotopes having a smaller atomic mass will diffuse faster in a medium than will their heavier counterparts causing concentration gradients of their ratios even when there are no contributions from radioactive decay which will tend to bias all sample ages (slopes of the isochron) to have a more linear distribution. The application to Sr/Rb dating is evaluated and shown to result in expected age overestimates. Suggested methods to test for this effect along with sample preparation techniques to minimize it are discussed. Special thanks the NCSU Nuclear Engineering Department.

  12. How to Handle Radioisotopes Safely.

    ERIC Educational Resources Information Center

    Sulcoski, John W.

    This booklet is one in a series of instructional aids designed for use by elementary and secondary school science teachers. The various units and forms of radioactive materials used by teachers are first considered. Then, the quantities of radioisotopes that a person may possess without a license from the Atomic Energy Commission (AEC) are…

  13. Development of a radioisotope heat source for the two-watt radioisotope thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Howell, Edwin I.; McNeil, Dennis C.; Amos, Wayne R.

    1992-01-01

    Described is a radioisotope heat source for the Two-Watt Radioisotope Thermoelectric Generator (RTG) which is being considered for possible application by the U.S. Navy and for other Department of Defense applications. The heat source thermal energy (75 Wt) is produced from the alpha decay of plutonium-238 which is in the form of high-fired plutonium dioxide. The capsule is non-vented and consists of three domed cylindrical components each closed with a corresponding sealed end cap. Surrounding the fuel is the liner component, which is fabricated from a tantalum-based alloy, T-111. Also fabricated from T-111 is the next component, the strength member, which serves to meet pressure and impact criteria. The outermost component, or clad, is the oxidation- and corrosion-resistant nickel-based alloy, Hastelloy S. This paper defines the design considerations, details the hardware fabrication and welding processes, discusses the addition of yttrium to the fuel to reduce liner embrittlement, and describes the testing that has been conducted or is planned to assure that there is fuel containment not only during the heat source operational life, but also in case of an accident environment.

  14. Advanced Subcritical Assistance Radioisotope Thermoelectric Generator: An Imperative Solution for the Future of NASA Exploration

    NASA Astrophysics Data System (ADS)

    Arias, F. J.

    A new generation of radioisotope thermoelectrical generator is proposed for very long space exploration missions. The Advanced Subcritical Assistance Radioisotope Thermoelectric Generator (ASA-RTG) amplify the power from natural decay of pu-238 by a small subcritical multiplication produced from the small neutron background generated from (α, n) reactions between the α particles from Pu-238 and beryllium, lithium or other low-Z isotope, extracting the maximum advantage and performance from the precious α disintegration, and then of the very scarce pu-238. The process is self controlled by the natural decay of Pu-238 with the progressive reduction of the power output (RTG) and additionally and simultaneously compensate by the natural decay of a neutronic poisson which increase simultaneously the subcritical multiplication resulting in a contrary effect, i.e., causing an increase in the power. ASA-RTG is not in conflict with previous RTG, and could fit within the type of Radioisotope Thermoelectric Generator developed for NASA space missions as the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and the Advanced Stirling Radioisotope Generator (ASRG).

  15. Progress on 241Am Production for Use in Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Baker, S. R.; Bell, K. J.; Brown, J.; Carrigan, C.; Carrott, M. J.; Gregson, C.; Clough, M.; Maher, C. J.; Mason, C.; Rhodes, C. J.; Rice, T. G.; Sarsfield, M. J.; Stephenson, K.; Taylor, R. J.; Tinsley, T. P.; Woodhead, D. A.; Wiss, T.

    2014-08-01

    Electrical power sources used in outer planet missions are a key enabling technology for data acquisition and communications. Power sources generate electricity from the thermal energy from alpha decay of the radioisotope 238Pu via thermo-electric conversion. Production of 238Pu requires specialist facilities including a nuclear reactor and reprocessing plants that are expensive to build and operate, so naturally, a more economical alternative is attractive to the industry. Within Europe 241Am is a feasible alternative to 238Pu that can provide a heat source for radioisotope thermoelectric generators (RTGs) and radioisotope heating units (RHUs). As a daughter product of 241Pu decay, 241Am is present at 1000s kg levels within the UK civil plutonium stockpile.A chemical separation process is required to extract the 241Am in a pure form and this paper describes such a process, successfully developed to the proof of concept stage.

  16. HFIR-produced medical radioisotopes

    SciTech Connect

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

    1997-12-01

    We have experimentally determined the yields of a number of medical radioisotopes produced in the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) Hydraulic Tube (HT) facility. The HT facility is located in the very high flux region in the flux trap of the reactor, providing on-line access capability while the reactor is operating. The HT facility consists of nine vertically stacked capsules centered just adjacent to the core horizontal midplane. HFIR operates at a nominal power level of 85 MW. The capabilities of the HFIR-HT facilities offer increased efficiency, greater availability, and optimization of radioisotope production, and, as a result, the conservation of rare or expensive target isotopes.

  17. Radioisotope production and its utilization in Malaysia

    SciTech Connect

    Yusof, A.b.A.

    1985-01-01

    The PUSPATI TRIGA MARK II research reactor in Malaysia was commissioned in 1982 and production of radioisotope commenced 2 years later. However, radioisotopes have been utilized in the country since 1960 with medical applications pioneering the field, and later followed by usage in industry and agricultural research. Currently, Malaysia spends more than M$1.5 million (US$0.65 million) annually on the import of radioisotopes and associated products. This paper briefly describes the present status of radioisotope utilization in Malaysia. Radioisotopes are being used in the fields of medicine, industry (NDT and quality control, nuclear gauging, radiotracer), agriculture (animal production, food irradiation, soil-plant relationship and mutation breeding studies) and also in environmental control and basic science research. The paper also gives an account of radioisotope production in Malaysia, its facilities and target handling technique.

  18. Radioisotope Power: A Key Technology for Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    Schmidt, George; Sutliff, Tom; Dudzinski, Leonard

    2008-01-01

    A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future.

  19. Radioisotope Power: A Key Technology for Deep Space Explorations

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.; Sutliff, Thomas J.; Duddzinski, Leonard

    2009-01-01

    A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future.

  20. Feasibility Study of a Three-Stage Radioisotope-Powered Mars Ascent Vehicle

    NASA Astrophysics Data System (ADS)

    Chalpek, T. M.; Allen, R. E.; Guan, J. Y.; Rao, S. S.; Howe, S. D.

    Recent advancements in methods of housing radioisotopes at the Center for Space Nuclear Research have led to the concept of a radioisotope thermal rocket--a rocket powered by the accumulated heat of radioisotope decay. Heat energy from the decay can be accumulated over long periods of time in a material of high heat capacity to create a thermal capacitor. The capacitor can then be discharged at such a rate as to provide high power for short periods of time; in this case, the heat is transferred to a gas propellant. This paper explores the feasibility of using a radioisotope thermal rocket with in-situ atmospheric CO2 propellant to deliver a 10 kg payload from the Martian surface to a 200 km circular orbit about Mars. Models of heat transfer, gas dynamics, and ascent mechanics are constructed to test performance of different core materials and geometries. Of the configurations tested, the best simulation results fail to meet the altitude and velocity requirements by 12 km and 50 m/s respectively. The proximity to success indicates that the given models are capable of reaching orbital parameters if optimization algorithms and closed-loop guidance methods are employed. It is believed, however, that the current models underestimate expansion losses to the degree that if more realistic and computationally-intensive models are incorporated, the effect will definitively disprove the concept with currently available technology. Based on this preliminary research, radioisotope thermal rockets utilizing current technology are not capable of serving as Mars ascent vehicles.

  1. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1985

    SciTech Connect

    Baker, D.A.

    1986-08-01

    This document describes radioisotope distribution from DOE facilities to private firms including foreign and other DOE facilities. The information is divided into five sections: (1) isotope suppliers, facility contacts, and isotopes or services supplied; (2) customers, suppliers, and isotopes purchased; (3) isotopes purchased cross-referenced with customer numbers; (4) geographic locations of radioisotope customers; and (5) radioisotope sales and transfer - FY 1985.

  2. Cosmogenic radioisotopes on LDEF surfaces

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.; Albrecht, A.; Herzog, G.; Klein, J.; Middleton, R.

    1992-01-01

    The radioisotope Be-7 was discovered in early 1990 on the front surface, and the front surface only, of the LDEF. A working hypothesis is that the isotope, which is known to be mainly produced in the stratosphere by spallation of nitrogen and oxygen nuclei with cosmic ray protons or secondary neutrons, diffuses upward and is absorbed onto metal surfaces of spacecraft. The upward transport must be rapid, that is, its characteristic time scale is similar to, or shorter than, the 53 day half-life of the isotope. It is probably by analogy with meteoritic metal atmospheric chemistry, that the form of the Be at a few 100 km altitude is as the positive ion Be(+) which is efficiently incorporated into the ionic lattice of oxides, such as Al2O3, Cr2O3, Fe2O3, etc., naturally occurring on surfaces of Al and stainless steel. Other radioisotopes of Be, Cl, and C are also produced in the atmosphere, and a search was begun to discover these. Of interest are Be-10 and C-14 for which the production cross sections are well known. The method of analysis is accelerator mass spectrometry. Samples from LDEF clamp plates are being chemically extracted, purified, and prepared for an accelerator run.

  3. Power from Radioisotopes, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Corliss, William R.; Mead, Robert L.

    This 1971 revision deals with radioisotopes and their use in power generators. Early developments and applications for the Systems for Nuclear Auxiliary Power (SNAP) and Radioisotope Thermoelectric Generators (RTGs) are reviewed. Present uses in space and on earth are included. Uses in space are as power sources in various satellites and space…

  4. Radioisotope penogram in diagnosis of vasculogenic impotence

    SciTech Connect

    Fanous, H.N.; Jevtich, M.J.; Chen, D.C.; Edson, M.

    1982-11-01

    A radioisotope technique to estimate penile blood flow is described. The radioisotope penogram is noninvasive and gives a dynamic evaluation of the arterial supply, venous drainage, and blood flow in the corporeal bodies. The penogram is a valuable adjunct in evaluation of patients with vasculogenic impotence.

  5. An overview of the Radioisotope Thermoelectric Generator Transportation System Program

    SciTech Connect

    McCoy, J.C.; Becker, D.L.

    1996-03-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The U.S. Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administration{close_quote}s Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent major changes in the U.S. Department of Energy structure and resources will be outlined. {copyright} {ital 1996 American Institute of Physics.}

  6. An overview of the Radioisotope Thermoelectric Generator Transporation System Program

    SciTech Connect

    McCoy, J.C.

    1995-10-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The US Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administrations Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent ma or changes in the US Department of Energy structure and resources will be outlined.

  7. An overview of the Radioisotope Thermoelectric Generator Transportation System Program

    NASA Astrophysics Data System (ADS)

    McCoy, John C.; Becker, David L.

    1996-03-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The U.S. Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administration's Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent major changes in the U.S. Department of Energy structure and resources will be outlined.

  8. US Department of Energy radioisotope customers with summary of radioisotope shipments, FY 1988

    SciTech Connect

    Van Houten, N.C.

    1989-06-01

    Pacific Northwest Laboratory (PNL) prepared this edition of the radioisotope customer list at the request of the Office of Health and Environmental Research (ER-73), Office of Energy Research, US Department of Energy (DOE). This is the 25th report in a series dating from 1964. This report covers DOE radioisotope sales and distribution activities by its facilities to domestic, foreign and other DOE facilities for FY 1988. The report is divided into five sections: radioisotope suppliers, facility contacts, and radioisotopes or services supplied; a list of customers, suppliers, and radioisotopes purchased; a list of radioisotopes purchased cross-referenced to customer numbers; geographic locations of radioisotope customers; and radioisotope sales and transfers -- FY 1988. Radioisotopes not previously reported in this series of reports were argon-37, arsenic-72, arsenic-73, bismuth-207, gadolinium-151, rhenium-188, rhodium-101, selenium-72, xenon-123 and zirconium-88. The total value of DOE radioisotope sales for FY 1988 was $11.1 million, an increase of 3% from FY 1987.

  9. Radioisotope therapy of cystic craniopharyngeomas

    SciTech Connect

    Strauss, L.; Sturm, V.; Georgi, P.; Schlegel, W.; Ostertag, H.; Clorius, J.H.; Van Kaick, G.

    1982-09-01

    Eighteen patients suffering from cystic craniopharyngeoma were treated with intracavitary irradiation. The beta-emitting radioisotope /sup 90/y (2.25 MeV) was instilled into the cyst following stereotactic puncture of the space-occupying lesion. The surgical approach was planned using angiograms and reconstructed transmission computer tomography (TCT) coronal and saggital sections. Therapy was devised to deliver 20,000 rad to the cyst's wall. Eleven patients received follow-up TCT examinations after four months. Eight of 11 patients had a significant volume decrease in the craniopharyngeoma cyst. In two patients, the cystic volume remained unchanged; one had progression of disease. It is concluded that the intracavitary treatment of cystic craniopharyngeoma will result in a reduction of the size of the space-occupying lesion.

  10. BEST medical radioisotope production cyclotrons

    NASA Astrophysics Data System (ADS)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Gelbart, W. Z.; Johnson, Richard R.

    2013-04-01

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 μA to 1000 μA, depending on the cyclotron energy and application [1].

  11. NASA's Radioisotope Power Systems - Plans

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Mccallum, Peter W.; Sandifer, Carl E., II; Sutliff, Thomas J.; Zakrajsek, June F.

    2015-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan and implement content to enable planetary exploration where such systems could be needed, and to prepare more advanced RPS technology for possible infusion into future power systems. The 2014-2015 period saw significant changes, and strong progress. Achievements of near-term objectives have enabled definition of a clear path forward in which payoffs from research investments and other sustaining efforts can be applied. The future implementation path is expected to yield a higher-performing thermoelectric generator design, a more isotope-fuel efficient system concept design, and a robust RPS infrastructure maintained effectively within both NASA and the Department of Energy. This paper describes recent work with an eye towards the future plans that result from these achievements.

  12. Linear accelerator for radioisotope production

    SciTech Connect

    Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.

    1982-02-01

    A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-..mu..A beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.

  13. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1983

    SciTech Connect

    Baker, D.A.

    1984-08-01

    This document lists DOE's radioisotope production and distribution activities by its facilities at Argonne National Laboratory; Pacific Northwest Laboratory; Idaho Operations Office; Los Alamos National Laboratory; Oak Ridge National Laboratory; Savannah River Plant; and UNC Nuclear Industries, Inc. The information is divided into five sections: isotope suppliers, facility contacts, and isotopes or services supplied; lists of customers, suppliers and isotopes purchased; list of isotopes purchased cross-referenced to customer codes; geographic locations of radioisotope customers; and radioisotope sales and transfers - FY 1983.

  14. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1986

    SciTech Connect

    Lamar, D.A.

    1987-10-01

    This document describes radioisotope distribution from DOE facilities to private firms including foreign and other DOE facilities. The information is divided into five sections: (1)isotope suppliers, facility contact, and isotopes or services supplied; (2) customers, suppliers, and isotopes purchased; (3) isotopes purchased cross-referenced with customer numbers; (4) geographic locations of radioisotope customers; and (5) radioisotope sales and transfers for fiscal year 1986.

  15. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1987

    SciTech Connect

    Lamar, D.A.; Van Houten, N.C.

    1988-08-01

    This edition of the radioisotope customer list was prepared at the request of the Office of Health and Environmental Research (ER-73), Office of Energy Research, US Department of Energy (DOE). This document describes radioisotope distribution from DOE facilities to private firms, including foreign and other DOE facilities. The information is divided into five sections: 1) isotope suppliers, facility contact, and isotopes or services supplied; 2) customers, suppliers, and isotopes purchased; 3) isotopes purchased cross- referenced with customer numbers; 4) geographic locations of radioisotope customers; and 5) radioisotope sales and transfers for fiscal year 1987.

  16. Retention of Radium-225 and Its Daughter Radioisotopes in Bone

    SciTech Connect

    Mirzadeh, Saed; Garland, Marc A; Kennel, Steve J

    2008-01-01

    The natural bone seeking tendency of Ra+2, similar to the other alkali metal ions, coupled with the short range high LET of -particle emissions are an ideal combination for localized therapy, and recently 11.4 d 223Ra has been studied for therapy of bone tumors in rats and humans [1,2]. Actinium-225 is also an attractive radioisotope for endo-radiotherapy in a single decay chain from 225Ac, over 26 MeV (~70% of total) is carried by four - particles ranging in energy from 5.7 to 8.4 MeV [3,4]. Although Ac+3 does not home naturally to bone (rather to liver) [5,6], its parent, 225Ra ( -, t1/2 = 15 d), can be used as an in vivo source for 225Ac. A pivotal question for the 225Ra/225Ac in vivo generator system is whether translocation of the daughter nuclei occurs prior to or following the uptake of 225Ra by the bone. In order to assess potential collateral damage to soft tissue organs it is essential to quantitate the extent to which 225Ac is retained in organs following the uptake of 225Ra. We have attempted to answer these questions by investigating the extent of translocation of 225Ac and 213Bi, two daughter radioisotopes of 225Ra, following retention of initially pure 225Ra in bone in normal mice.

  17. Chemistry of Cosmogenic Radioisotopes in the Stratosphere

    NASA Astrophysics Data System (ADS)

    Rowland, F. S.

    2003-12-01

    Bombardment of Earth's atmosphere by Gev cosmic ray protons produces two neutrons/cm2/second, which react with 14N nuclei to form 14C. The initial stratospheric reaction of the bare 14C atom with O2 forms 14CO, which is subsequently oxidized to 14CO2 by HO. The 14CO2 is then the basis for age-dating studies of inorganic carbon, and of organic carbon after incorporation by photosynthesis. Proton spallation of light nuclei (chiefly 14N, 16O) produces various isotopic fragments, many of them radioactive, containing 8 or fewer protons and 10 or fewer neutrons. For geophysical studies, the most important of the radioisotopes so produced are 3H, 7Be, and 10Be. Proton spallation of 40Ar produces many isotopes with atomic weight less than 40, including 34Cl, 36Cl, 38Cl, 39Cl, 35S, 38S, 22Na, 24Na, 32Si, 32P, and 33P, all of which have been detected in the atmosphere. The "million year" isotopes (10Be, 36Cl) are useful for geological dating. The short-lived isotopes were collected both from rainwater captured at ground level, and on filter paper at 18 kilometers altitude carried by an RB-57 aircraft (1970, J. A. Young, C. W. Thomas, N. A. Wogman and R. W. Perkins, JGR, 75, 2385). The radioisotopes were measured with multidimensional gamma ray spectroscopy, which was able to detect 24Na and 38Cl without prior chemical separation. Count rates as low as 0.1 count/minute were monitored, even in the presence of 107 counts/minute of fallout fission products from nuclear testing in the atmosphere. This fallout background is now greatly reduced because of the four decades old ban on nuclear testing in the atmosphere. The stratospheric collection of 24Na (15 hour half-life) was interpreted as scavenging of the radiosodium by particulate matter, and retention on filter paper with an efficiency of 100 percent within the statistical accuracy in comparison with its production in argon tanks carried on the aircraft. The efficiency of collection of radiochlorine atoms was only about 1

  18. Radioisotope Production for Medical and Physics Applications

    NASA Astrophysics Data System (ADS)

    Mausner, Leonard

    2012-10-01

    Radioisotopes are critical to the science and technology base of the US. Discoveries and applications made as a result of the availability of radioisotopes span widely from medicine, biology, physics, chemistry and homeland security. The clinical use of radioisotopes for medical diagnosis is the largest sector of use, with about 16 million procedures a year in the US. The use of ^99Mo/^99mTc generator and ^18F make up the majority, but ^201Tl, ^123I, ^111In, and ^67Ga are also used routinely to perform imaging of organ function. Application of radioisotopes for therapy is dominated by use of ^131I for thyroid malignancies, ^90Y for some solid tumors, and ^89Sr for bone cancer, but production of several more exotic species such as ^225Ac and ^211At are of significant current research interest. In physics ^225Ra is of interest for CP violation studies, and the actinides ^242Am, ^249Bk, and ^254Es are needed as targets for experiments to create superheavy elements. Large amounts of ^252Cf are needed as a fission source for the CARIBU experiment at ANL. The process of radioisotope production is multidisciplinary. Nuclear physics input based on nuclear reaction excitation function data is needed to choose an optimum target/projectile in order to maximize desired isotope production and minimize unwanted byproducts. Mechanical engineering is needed to address issues of target heating, induced mechanical stress and material compatibility of target and claddings. Radiochemists are involved as well since chemical separation to purify the desired final radioisotope product from the bulk target and impurities is also usually necessary. Most neutron rich species are produced at a few government and university reactors. Other radioisotopes are produced in cyclotrons in the commercial sector, university/hospital based facilities, and larger devices at the DOE labs. The landscape of US facilities, the techniques involved, and current supply challenges will be reviewed.

  19. RTGs - The powering of Ulysses. [Radio-isotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Mastal, E. F.; Campbell, R. W.

    1990-01-01

    The radio-isotope thermoelectric generator (RTG) for Ulysses' electronic supply is described noting that lack of sufficient sunlight renders usual solar cell power generation ineffective due to increased distance from sun. The history of the RTG in the U.S.A. is reviewed citing the first RTG launch in 1961 with an electrical output of 2.7 W and the improved Ulysses RTG, which provides 285 W at mission beginning and 250 W at mission end. The RTG concept is discussed including the most recent RTG technology developed by the DOE, the General Purpose Heat Source RTG (GPHS-RTG). The system relies upon heat generated by radioactive decay using radioactive plutonium-238, which is converted directly to energy using the Seebeck method.

  20. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel.

  1. End-on radioisotope thermoelectric generator impact tests

    SciTech Connect

    Reimus, M.A.H.; Hhinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  2. Radioisotope thermoelectric generators for implanted pacemakers

    SciTech Connect

    Pustovalov, A.A.; Bovin, A.V.; Fedorets, V.I.; Shapovalov, V.P.

    1986-08-01

    This paper discusses the development and application of long-life lithium batteries and the problems associated with miniature radioisotope thermoelectric generators (RITEG) with service lives of 10 years or longer. On eof the main problems encountered when devising a radioisotope heat source (RHS) for an RITEG is to obtain biomedical /sup 238/PuO/sub 2/ with a specific neutron yield of 3.10/sup 3/-4.10/sup 3/ (g /SUP ./ sec)/sup -1/, equivalent to metallic Pu 238, and with a content of gamma impurities sufficient to ensure a permissible exposure a permissible exposure does rate (EDR) of a mixture of neutron and gamma radiation. After carrying out the isotope exchange and purifying the initial sample of its gamma impurity elements, the authors obtain biomedical Pu 238 satisfying the indicated requirements king suitable for use in the power packs of medical devices. Taking the indicated specifications into account, the Ritm-1o and gamma radioisotope heat sources were designed, built, tested in models and under natural conditions, and then into production as radioisotope thermoelectric generators designed to power the electronic circuits of implanted pacemakers. The Ritm-MT and Gemma radioisotope thermoelectric generators described are basic units, which can be used as self-contained power supplies for electronic equipment with power requirements in the micromilliwatt range.

  3. NASA's Radioisotope Power Systems Program Status

    NASA Technical Reports Server (NTRS)

    Dudzinski, Leonard A.; Hamley, John A.; McCallum, Peter W.; Sutliff, Thomas J.; Zakrajsek, June F.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Program began formal implementation in December 2010. The RPS Program's goal is to make available RPS for the exploration of the solar system in environments where conventional solar or chemical power generation is impractical or impossible to meet mission needs. To meet this goal, the RPS Program manages investments in RPS system development and RPS technologies. The current keystone of the RPS Program is the development of the Advanced Stirling Radioisotope Generator (ASRG). This generator will be about four times more efficient than the more traditional thermoelectric generators, while providing a similar amount of power. This paper provides the status of the RPS Program and its related projects. Opportunities for RPS generator development and targeted research into RPS component performance enhancements, as well as constraints dealing with the supply of radioisotope fuel, are also discussed in the context of the next ten years of planetary science mission plans.

  4. Commercial Superconducting Electron Linac for Radioisotope Production

    SciTech Connect

    Grimm, Terry Lee; Boulware, Charles H.; Hollister, Jerry L.; Jecks, Randall W.; Mamtimin, Mayir; Starovoitova, Valeriia

    2015-08-13

    The majority of radioisotopes used in the United States today come from foreign suppliers or are generated parasitically in large government accelerators and nuclear reactors. Both of these restrictions limit the availability of radioisotopes and discourage the development and evaluation of new isotopes and for nuclear medicine, science, and industry. Numerous studies have been recommending development of dedicated accelerators for production of radioisotopes for over 20 years (Institute of Medicine, 1995; Reba, et al, 2000; National Research Council, 2007; NSAC 2009). The 2015 NSAC Long Range Plan for Isotopes again identified electron accelerators as an area for continued research and development. Recommendation 1(c) from the 2015 NSAC Isotope report specifically identifies electron accelerators for continued funding for the purpose of producing medical and industrial radioisotopes. Recognizing the pressing need for new production methods of radioisotopes, the United States Congress passed the American Medical Isotope Production Act of 2012 to develop a domestic production of 99Mo and to eliminate the use of highly enriched uranium (HEU) in the production of 99Mo. One of the advantages of high power electron linear accelerators (linacs) is they can create both proton- and neutron-rich isotopes by generating high energy x-rays that knock out protons or neutrons from stable atoms or by fission of uranium. This allows for production of isotopes not possible in nuclear reactors. Recent advances in superconducting electron linacs have decreased the size and complexity of these systems such that they are economically competitive with nuclear reactors and large, high energy accelerators. Niowave, Inc. has been developing a radioisotope production facility based on a superconducting electron linac with liquid metal converters.

  5. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1982

    SciTech Connect

    Richards, M.P.

    1983-08-01

    The radioisotope production and distribution activities by facilities at Argonne National Laboratory, Pacific Northwest Laboratory, Brookhaven National Laboratory, Hanford Engineering Development Laboratory, Idaho Operations Office, Los Alamos Scientific Laboratory, Oak Ridge National Laboratory, Savannah River Laboratory, and UNC Nuclear Industries, Inc. are listed. The information is divided into five sections: isotope suppliers, facility, contacts, and isotopes or services supplied; alphabetical list of customers, and isotopes purchased; alphabetical list of isotopes cross-referenced to customs numbers; geographical location of radioisotope customers; and radioisotope sales and transfers-FY 1982. (MHR)

  6. Is radioactive decay really exponential?

    NASA Astrophysics Data System (ADS)

    Aston, P. J.

    2012-03-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating methods will have been removed, requiring a radical reappraisal both of radioisotope dating methods and of currently predicted dates obtained using these methods.

  7. Structure and manual of radioisotope-production data base, ISOP

    NASA Astrophysics Data System (ADS)

    Hata, Kentaro; Terunuma, Kusuo

    1994-02-01

    We planned on collecting the information of radioisotope production which was obtained from research works and tasks at the Department of Radioisotopes in JAERI, and constructed a proto-type data base ISOP after discussion of the kinds and properties of the information available for radioisotope production. In this report the structure and the manual of ISOP are described.

  8. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1979

    SciTech Connect

    Burlison, J.S.

    1980-06-01

    The fifteenth edition of the radioisotope customer list was prepared at the request of the Division of Financial Services, Office of the Assistant Secretary for Environment, Department of Energy (DOE). This document lists DOE's radioisotope production and distribution activities by its facilities at Argonne National Laboratory; Pacific Northwest Laboratory; Brookhaven National Laboratory; Hanford Engineering Development Laboratory; Idaho Operations Office; Los Alamos Scientific Laboratory; Mound Facility; Oak Ridge National Laboratory; Rocky Flats Area Office; Savannah River Laboratory; and UNC Nuclear Industries, Inc. The information is divided into five sections: Isotope suppliers, facility, contracts and isotopes or services supplied; alphabetical list of customers, and isotopes purchased; alphabetical list of isotopes cross-referenced to customer numbers; geographical location of radioisotope customers; and radioisotope sales and transfers-FY 1979.

  9. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1980

    SciTech Connect

    Burlison, J.S.

    1981-08-01

    The sixteenth edition of the radioisotope customer list was prepared at the request of the Office of Health and Environmental Research, Office of energy Research, Department of Energy (DOE). This document lists DOE's radioisotope production and distribution activities by its facilities at Argonne National Laboratory; Pacific Northwest Laboratory; Brookhaven National Laboraory; Hanford Engineering Development Laboratory; Idaho Operations Office; Los Alamos Scientific Laboratory; Mound Facility; Oak Ridge National Laboratory; Savannah River Laboratory; and UNC Nuclear Industries, Inc. The information is divided into five sections: (1) isotope suppliers, facility, contracts and isotopes or services supplied; (2) alphabetical list of customers, and isotopes purchased; (3) alphabetical list of isotopes cross-referenced to customer numbers; (4) geographical location of radioisotope customers; and (5) radioisotope sales and transfers-FY 1980.

  10. NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Technical Reports Server (NTRS)

    Anderson, David J.

    2005-01-01

    The focus of the National Aeronautics and Space Administration's (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of two to four decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100 W(sub e) scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments.

  11. NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Technical Reports Server (NTRS)

    Anderson, David J.

    2005-01-01

    The focus of the National Aeronautics and Space Administration s (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of 2 to 4 decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100We scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments.

  12. Safety monitoring system for radioisotope thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Zoltan, A.

    1973-01-01

    System alerts personnel of hazards which may develop while they are performing tests on radioisotope thermoelectric generator (RTG). Remedial action is initiated to minimize damage. Five operating conditions are monitored: hot junction temperature, cold junction temperature, thermal shroud coolant flow, vacuum in test chamber, and alpha radiation.

  13. Radioisotopes in management of metastatic prostate cancer

    PubMed Central

    Raval, Amar; Dan, Tu D.; Williams, Noelle L.; Pridjian, Andrew; Den, Robert B.

    2016-01-01

    Introduction: Metastatic prostate cancer continues to be a leading cause of morbidity and mortality in men with prostate cancer. Over the last decade, the treatment landscape for patients with castrate-resistant disease has drastically changed, with several novel agents demonstrating an improvement in overall survival in large, multi-institutional randomized trials. Traditional treatment with radioisotopes has largely been in the palliative setting. However, the first in class radiopharmaceutical radium-223 has emerged as the only bone-directed treatment option demonstrating an improvement in overall survival. Methods: Medline publications from 1990 to 2016 were searched and reviewed to assess the use of currently approved radioisotopes in the management of prostate cancer including emerging data regarding integration with novel systemic therapies. New positron emission tomography-based radiotracers for advanced molecular imaging of prostate cancer were also queried. Results: Radioisotopes play a crucial role in the diagnosis and treatment of prostate cancer in the definitive and metastatic setting. Molecular imaging of prostate cancer and theranostics are currently being investigated in the clinical arena. Conclusions: The use of modern radioisotopes in selected patients with mCRPC is associated with improvements in overall survival, pain control, and quality of life. PMID:27843209

  14. ILLUSTRATIONS OF RADIOISOTOPES--DEFINITIONS AND APPLICATIONS.

    ERIC Educational Resources Information Center

    Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

    THIS PUBLICATION IS COMPOSED OF OVER 150 PAGES OF BLACK AND WHITE ILLUSTRATIONS DEALING WITH RADIOISOTOPES AND THEIR USES. THESE ILLUSTRATIONS CONSIST OF CHARTS, GRAPHS, AND PICTORIAL REPRESENTATIONS WHICH COULD BE PREPARED AS HANDOUTS, TRANSPARENCIES FOR OVERHEAD PROJECTION, OR WHICH COULD BE USED IN A NUMBER OF OTHER WAYS FOR PRESENTING SUCH…

  15. Radioisotope thermal generator (RTG) power conditioner

    NASA Technical Reports Server (NTRS)

    Stacey, W. S.

    1974-01-01

    New regulator: (a) permits operation with high-impedance radioisotope thermal generators at conversion efficiencies typically above 90%; (b) does not require input filtering; (c) eliminates current spiking; and (d) is simple, efficient, and reliable. Converter-charger pair could be adapted for other power levels by changing transistor, diode, capacitor bank, and inductor.

  16. Specific radioactivity of neutron induced radioisotopes: assessment methods and application for medically useful 177Lu production as a case.

    PubMed

    Le, Van So

    2011-01-19

    The conventional reaction yield evaluation for radioisotope production is not sufficient to set up the optimal conditions for producing radionuclide products of the desired radiochemical quality. Alternatively, the specific radioactivity (SA) assessment, dealing with the relationship between the affecting factors and the inherent properties of the target and impurities, offers a way to optimally perform the irradiation for production of the best quality radioisotopes for various applications, especially for targeting radiopharmaceutical preparation. Neutron-capture characteristics, target impurity, side nuclear reactions, target burn-up and post-irradiation processing/cooling time are the main parameters affecting the SA of the radioisotope product. These parameters have been incorporated into the format of mathematical equations for the reaction yield and SA assessment. As a method demonstration, the SA assessment of 177Lu produced based on two different reactions, 176Lu (n,γ)177Lu and 176Yb (n,γ) 177Yb (β- decay) 177Lu, were performed. The irradiation time required for achieving a maximum yield and maximum SA value was evaluated for production based on the 176Lu (n,γ)177Lu reaction. The effect of several factors (such as elemental Lu and isotopic impurities) on the 177Lu SA degradation was evaluated for production based on the 176Yb (n,γ) 177Yb (β- decay) 177Lu reaction. The method of SA assessment of a mixture of several radioactive sources was developed for the radioisotope produced in a reactor from different targets.

  17. Alternative Radioisotopes for Heat and Power Sources

    NASA Astrophysics Data System (ADS)

    Tinsley, T.; Sarsfield, M.; Rice, T.

    Production of 238Pu requires considerable facilities including a nuclear reactor and reprocessing plants that are very expensive to build and operate. Thus, a more economical alternative is very attractive to the industry. There are many alternative radioisotopes that exist but few that satisfy the criteria of performance, availability and cost to produce. Any alternative to 238Pu must exist in a chemical form that is compatible with the materials required to safely encapsulate the heat source at the high temperatures of operation and potential launch failure scenarios. The chemical form must also have suitable thermal properties to ensure maximum energy conversion efficiencies when integrated into radioisotope thermoelectric generators over the required mission durations. In addition, the radiation dose must be low enough for operators during production and not so prohibitive that excessive shielding mass is required on the space craft. This paper will focus on the preferred European alternative of 241Am, and the issues that will need to be addressed.

  18. Advanced Stirling Radioisotope Generator Life Certification Plan

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Zampino, Edward

    2013-01-01

    An Advanced Stirling Radioisotope Generator (ASRG) power supply is being developed by the Department of Energy (DOE) in partnership with NASA for potential future deep space science missions. Unlike previous radioisotope power supplies for space exploration, such as the passive MMRTG used recently on the Mars Curiosity rover, the ASRG is an active dynamic power supply with moving Stirling engine mechanical components. Due to the long life requirement of 17 years and the dynamic nature of the Stirling engine, the ASRG project faced some unique challenges trying to establish full confidence that the power supply will function reliably over the mission life. These unique challenges resulted in the development of an overall life certification plan that emphasizes long-term Stirling engine test and inspection when analysis is not practical. The ASRG life certification plan developed is described.

  19. Reactors are indispensable for radioisotope production.

    PubMed

    Mushtaq, Ahmad

    2010-12-01

    Radioisotopes can be produced by reactors and accelerators. For certain isotopes there could be an advantage to a certain production method. However, nowadays many reports suggest, that useful isotopes needed in medicine, industry and research could be produced efficiently and dependence on reactors using enriched U-235 may be eliminated. In my view reactors and accelerators will continue to play their role side by side in the supply of suitable and economical sources of isotopes.

  20. NEW DIRECTIONS IN RADIOISOTOPE SPECTRUM IDENTIFICATION

    SciTech Connect

    Salaymeh, S.; Jeffcoat, R.

    2010-06-17

    Recent studies have found the performance of commercial handheld detectors with automatic RIID software to be less than acceptable. Previously, we have explored approaches rooted in speech processing such as cepstral features and information-theoretic measures. Scientific advances are often made when researchers identify mathematical or physical commonalities between different fields and are able to apply mature techniques or algorithms developed in one field to another field which shares some of the same challenges. The authors of this paper have identified similarities between the unsolved problems faced in gamma-spectroscopy for automated radioisotope identification and the challenges of the much larger body of research in speech processing. Our research has led to a probabilistic framework for describing and solving radioisotope identification problems. Many heuristic approaches to classification in current use, including for radioisotope classification, make implicit probabilistic assumptions which are not clear to the users and, if stated explicitly, might not be considered desirable. Our framework leads to a classification approach with demonstrable improvements using standard feature sets on proof-of-concept simulated and field-collected data.

  1. Integration of Radioisotope Heat Source with Stirling Engine and Cooler for Venus Internal-Structure Mission

    SciTech Connect

    Schock, Alfred

    1993-10-01

    The primary mission goal is to perform long-term seismic measurements on Venus, to study its largely unknown internal structure. The principal problem is that most payload components cannot long survive Venus's harsh environment, 90 bars at 500 degrees C. To meet the mission life goal, such components must be protected by a refrigerated payload bay. JPL Investigators have proposed a mission concept employing a lander with a spherical payload bay cooled to 25 degrees C by a Stirling cooler powered by a radioisotope-heated Sitrling engine. To support JPL's mission study, NASA/Lewis and MTI have proposed a conceptual design for a hydraulically coupled Stirling engine and cooler, and Fairchild Space - with support of the Department of Energy - has proposed a design and integration scheme for a suitable radioisotope heat source. The key integration problem is to devise a simple, light-weight, and reliable scheme for forcing the radioisotope decay heat to flow through the Stirling engine during operation on Venus, but to reject that heat to the external environment when the Stirling engine and cooler are not operating (e.g., during the cruise phase, when the landers are surrounded by heat shields needed for protection during subsequent entry into the Venusian atmosphere.) A design and integration scheme for achieving these goals, together with results of detailed thermal analyses, are described in this paper. There are 7 copies in the file.

  2. Vitrified chemically bonded phosphate ceramics for immobilization of radioisotopes

    DOEpatents

    Wagh, Arun S.

    2016-04-05

    A method of immobilizing a radioisotope and vitrified chemically bonded phosphate ceramic (CBPC) articles formed by the method are described. The method comprises combining a radioisotope-containing material, MgO, a source of phosphate, and optionally, a reducing agent, in water at a temperature of less than 100.degree. C. to form a slurry; curing the slurry to form a solid intermediate CBPC article comprising the radioisotope therefrom; comminuting the intermediate CBPC article, mixing the comminuted material with glass frits, and heating the mixture at a temperature in the range of about 900 to about 1500.degree. C. to form a vitrified CBPC article comprising the radioisotope immobilized therein.

  3. Spark Plasma Sintering of simulated radioisotope materials within tungsten cermets

    NASA Astrophysics Data System (ADS)

    O'Brien, R. C.; Ambrosi, R. M.; Bannister, N. P.; Howe, S. D.; Atkinson, H. V.

    2009-08-01

    A Spark Plasma Sintering (SPS) furnace was used to produce ceramic-metallic sinters (cermets) containing a simulated loading of radioisotope materials. CeO 2 was used to simulate loadings of PuO 2, UO 2 or AmO 2 within tungsten-based cermets due to the similar kinetic properties of these materials, in particular the respective melting points and Gibbs free energies. The work presented demonstrates the capability and suitability of the SPS process for the production of radioisotope encapsulates for nuclear fuels and other applications (including waste disposal and radioisotope power and heat source fabrication) where the mechanical capture of radioisotope materials is required.

  4. Markets for reactor-produced non-fission radioisotopes

    SciTech Connect

    Bennett, R.G.

    1995-01-01

    Current market segments for reactor produced radioisotopes are developed and reported from a review of current literature. Specific radioisotopes studied in is report are the primarily selected from those with major medical or industrial markets, or those expected to have strongly emerging markets. Relative market sizes are indicated. Special emphasis is given to those radioisotopes that are best matched to production in high flux reactors such as the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory or the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory. A general bibliography of medical and industrial radioisotope applications, trends, and historical notes is included.

  5. U.S. Space Radioisotope Power Systems and Applications: Past, Present and Future

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.; Bennett, Gary L.

    2011-01-01

    Radioisotope power systems (RPS) have been essential to the U.S. exploration of outer space. RPS have two primary uses: electrical power and thermal power. To provide electrical power, the RPS uses the heat produced by the natural decay of a radioisotope (e.g., plutonium-238 in U.S. RPS) to drive a converter (e.g., thermoelectric elements or Stirling linear alternator). As a thermal power source the heat is conducted to whatever component on the spacecraft needs to be kept warm; this heat can be produced by a radioisotope heater unit (RHU) or by using the excess heat of a radioisotope thermoelectric generator (RTG). As of 2010, the U.S. has launched 41 RTGs on 26 space systems. These space systems have ranged from navigational satellites to challenging outer planet missions such as Pioneer 10/11, Voyager 1/2, Galileo, Ulysses, Cassini and the New Horizons mission to Pluto. In the fall of 2011, NASA plans to launch the Mars Science Laboratory (MSL) that will employ the new Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) as the principal power source. Hundreds of radioisotope heater units (RHUs) have been launched to provide warmth to Apollo 11, used to provide heating of critical components in a seismic experiment package, Pioneer 10/11, Voyager 1/2, Galileo, Cassini, Mars Pathfinder, MER rovers, etc. to provide temperature control to critical spacecraft electronics and other mechanical devices such as propulsion system propellant valves. A radioisotope (electrical) power source or system (RPS) consists of three basic elements: (1) the radioisotope heat source that provides the thermal power, (2) the converter that transforms the thermal power into electrical power and (3) the heat rejection radiator. Figure 1 illustrates the basic features of an RPS. The idea of a radioisotope power source follows closely after the early investigations of radioactivity by researchers such as Henri Becquerel (1852-1908), Marie Curie (1867-1935), Pierre Curie (1859

  6. Miniaturized radioisotope solid state power sources

    NASA Astrophysics Data System (ADS)

    Fleurial, J.-P.; Snyder, G. J.; Patel, J.; Herman, J. A.; Caillat, T.; Nesmith, B.; Kolawa, E. A.

    2000-01-01

    Electrical power requirements for the next generation of deep space missions cover a wide range from the kilowatt to the milliwatt. Several of these missions call for the development of compact, low weight, long life, rugged power sources capable of delivering a few milliwatts up to a couple of watts while operating in harsh environments. Advanced solid state thermoelectric microdevices combined with radioisotope heat sources and energy storage devices such as capacitors are ideally suited for these applications. By making use of macroscopic film technology, microgenrators operating across relatively small temperature differences can be conceptualized for a variety of high heat flux or low heat flux heat source configurations. Moreover, by shrinking the size of the thermoelements and increasing their number to several thousands in a single structure, these devices can generate high voltages even at low power outputs that are more compatible with electronic components. Because the miniaturization of state-of-the-art thermoelectric module technology based on Bi2Te3 alloys is limited due to mechanical and manufacturing constraints, we are developing novel microdevices using integrated-circuit type fabrication processes, electrochemical deposition techniques and high thermal conductivity substrate materials. One power source concept is based on several thermoelectric microgenerator modules that are tightly integrated with a 1.1W Radioisotope Heater Unit. Such a system could deliver up to 50mW of electrical power in a small lightweight package of approximately 50 to 60g and 30cm3. An even higher degree of miniaturization and high specific power values (mW/mm3) can be obtained when considering the potential use of radioisotope materials for an alpha-voltaic or a hybrid thermoelectric/alpha-voltaic power source. Some of the technical challenges associated with these concepts are discussed in this paper. .

  7. Medical Radioisotope Data Survey: 2002 Preliminary Results

    SciTech Connect

    Siciliano, Edward R.

    2004-06-23

    A limited, but accurate amount of detailed information about the radioactive isotopes used in the U.S. for medical procedures was collected from a local hospital and from a recent report on the U.S. Radiopharmaceutical Markets. These data included the total number of procedures, the specific types of procedures, the specific radioisotopes used in these procedures, and the dosage administered per procedure. The information from these sources was compiled, assessed, pruned, and then merged into a single, comprehensive and consistent set of results presented in this report. (PIET-43471-TM-197)

  8. High efficiency radioisotope thermophotovoltaic prototype generator

    NASA Technical Reports Server (NTRS)

    Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

    1995-01-01

    A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With

  9. Evidence against solar influence on nuclear decay constants.

    PubMed

    Pommé, S; Stroh, H; Paepen, J; Van Ammel, R; Marouli, M; Altzitzoglou, T; Hult, M; Kossert, K; Nähle, O; Schrader, H; Juget, F; Bailat, C; Nedjadi, Y; Bochud, F; Buchillier, T; Michotte, C; Courte, S; van Rooy, M W; van Staden, M J; Lubbe, J; Simpson, B R S; Fazio, A; De Felice, P; Jackson, T W; Van Wyngaardt, W M; Reinhard, M I; Golya, J; Bourke, S; Roy, T; Galea, R; Keightley, J D; Ferreira, K M; Collins, S M; Ceccatelli, A; Unterweger, M; Fitzgerald, R; Bergeron, D E; Pibida, L; Verheyen, L; Bruggeman, M; Vodenik, B; Korun, M; Chisté, V; Amiot, M-N

    2016-10-01

    The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10(-6) to 10(-5) range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  10. Evidence against solar influence on nuclear decay constants

    PubMed Central

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M.W.; van Staden, M.J.; Lubbe, J.; Simpson, B.R.S.; Fazio, A.; De Felice, P.; Jackson, T.W.; Van Wyngaardt, W.M.; Reinhard, M.I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J.D.; Ferreira, K.M.; Collins, S.M.; Ceccatelli, A.; Unterweger, M.; Fitzgerald, R.; Bergeron, D.E.; Pibida, L.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2016-01-01

    The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth’s orbital distance to the Sun could not be observed within a 10−6 to 10−5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards. PMID:28057978

  11. Evidence against solar influence on nuclear decay constants

    NASA Astrophysics Data System (ADS)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Unterweger, M.; Fitzgerald, R.; Bergeron, D. E.; Pibida, L.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2016-10-01

    The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10-6 to 10-5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  12. Reliability Issues in Stirling Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Shah, Ashwin R.; Schreiber, Jeffrey G.

    2004-01-01

    Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive material. Reliability of an RPS that utilizes Stirling power conversion technology is important in order to ascertain long term successful performance. Owing to long life time requirement (14 years), it is difficult to perform long-term tests that encompass all the uncertainties involved in the design variables of components and subsystems comprising the RPS. The requirement for uninterrupted performance reliability and related issues are discussed, and some of the critical areas of concern are identified. An overview of the current on-going efforts to understand component life, design variables at the component and system levels, and related sources and nature of uncertainties are also discussed. Current status of the 110 watt Stirling Radioisotope Generator (SRG110) reliability efforts is described. Additionally, an approach showing the use of past experience on other successfully used power systems to develop a reliability plan for the SRG110 design is outlined.

  13. Cosmogenic radioisotopes in Gebel Kamil meteorite

    NASA Astrophysics Data System (ADS)

    Taricco, C.; Colombetti, P.; Bhandari, N.; Sinha, N.; Di Martino, M.; Vivaldo, G.

    2012-04-01

    Recently a small (45 m in diameter) and very young (< 5,000 years) impact crater was discovered in Egypt (Folco et al., 2010, 2011); it was generated by an iron meteorite named Gebel Kamil (Meteoritical Bulletin No. 98, Weisberg et al. 2010). During systematic searches, many specimens were found in the area surrounding the crater. We present the gamma-activity measurement of a 672 g fragment using a highly selective Ge-NaI spectrometer operating at Monte dei Cappuccini Laboratory (IFSI, INAF) in Torino, Italy. This apparatus allows to reveal the radioisotope activity generated by cosmic rays in the meteoroids as they travel through the interplanetary space before falling on the Earth. From the 26Al activity measurement and its depth production profiles, we infer (i) that the radius of the meteoroid should be about 1 m, constraining to 30-40 ton the range of pre-atmospheric mass previously proposed and (ii) that the fragment should have been located deeply inside the meteoroid, at a depth > 0.7 m. The 44Ti activity is under the detection threshold of the apparatus; using the depth production profiles of this radioisotope and its half-life T1/2 = 59.2 y, we deduce an upper limit to the date of fall.

  14. Actinium radioisotope products of enhanced purity

    SciTech Connect

    Meikrantz, David Herbert; Todd, Terry Allen; Tranter, Troy Joseph; Horwitz, E. Philip

    2010-06-15

    A product includes actinium-225 (.sup.225Ac) and less than about 1 microgram (.mu.g) of iron (Fe) per millicurie (mCi) of actinium-225. The product may have a radioisotopic purity of greater than about 99.99 atomic percent (at %) actinium-225 and daughter isotopes of actinium-225, and may be formed by a method that includes providing a radioisotope mixture solution comprising at least one of uranium-233 (.sup.233U) and thorium-229 (.sup.229Th), extracting the at least one of uranium-233 and thorium-229 into an organic phase, substantially continuously contacting the organic phase with an aqueous phase, substantially continuously extracting actinium-225 into the aqueous phase, and purifying the actinium-225 from the aqueous phase. In some embodiments, the product may include less than about 1 nanogram (ng) of iron per millicurie (mCi) of actinium-225, and may include less than about 1 microgram (.mu.g) each of magnesium (Mg), Chromium (Cr), and manganese (Mn) per millicurie (mCi) of actinium-225.

  15. Preparing for Harvesting Radioisotopes from FRIB

    SciTech Connect

    Peaslee, Graham F.; Lapi, Suzanne E.

    2015-02-02

    The Facility for Rare Isotope Beams (FRIB) is the next generation accelerator facility under construction at Michigan State University. FRIB will produce a wide variety of rare isotopes by a process called projectile fragmentation for a broad range of new experiments when it comes online in 2020. The accelerated rare isotope beams produced in this facility will be more intense than any current facility in the world - in many cases by more than 1000-fold. These beams will be available to the primary users of FRIB in order to do exciting new fundamental research with accelerated heavy ions. In the standard mode of operation, this will mean one radioisotope will be selected at a time for the user. However, the projectile fragmentation process also yields hundreds of other radioisotopes at these bombarding energies, and many of these rare isotopes are long-lived and could have practical applications in medicine, national security or the environment. This project developed new methods to collect these long-lived rare isotopes that are by-products of the standard FRIB operation. These isotopes are important to many areas of research, thus this project will have a broad impact in several scientific areas including medicine, environment and homeland security.

  16. RADIOISOTOPE EXPERIMENTS IN HIGH SCHOOL BIOLOGY, AN ANNOTATED SELECTED BIBLIOGRAPHY.

    ERIC Educational Resources Information Center

    HURLBURT, EVELYN M.

    SELECTED REFERENCES ON THE USE OF RADIOISOTOPES IN BIOLOGY ARE CONTAINED IN THIS ANNOTATED BIBLIOGRAPHY FOR SECONDARY SCHOOL STUDENTS. MATERIALS INCLUDED WERE PUBLISHED AFTER 1960 AND DEAL WITH THE PROPERTIES OF RADIATION, SIMPLE RADIATION DETECTION PROCEDURES, AND TECHNIQUES FOR USING RADIOISOTOPES EXPERIMENTALLY. THE REFERENCES ARE LISTED IN…

  17. Collinear laser spectroscopy of radioisotopes of zirconium

    NASA Astrophysics Data System (ADS)

    Thayer, H. L.; Billowes, J.; Campbell, P.; Dendooven, P.; Flanagan, K. T.; Forest, D. H.; Griffith, J. A. R.; Huikari, J.; Jokinen, A.; Moore, R.; Nieminen, A.; Tungate, G.; Zemlyanoi, S.; Äystö, J.

    2003-09-01

    Isotope shifts and hyperfine structures have been measured for radioisotopes of ionic zirconium using on-line laser spectroscopy at the IGISOL facility in Jyväskylä, where the installation of an ion beam cooler/buncher has significantly improved the experimental sensitivity. Measurements have been made on all the neutron-deficient isotopes from 87Zr to 90Zr, including the isomers 87m,89mZr, and the neutron-rich isotopes from 96Zr to 102Zr. The change in mean square charge radii between the isotopes and the nuclear moments of the odd isotopes have been extracted. The data show a sudden increase in the mean square charge radius at mass A = 100, consistent with an onset of nuclear deformation which has been observed in the gamma ray spectroscopy of isotope chains in this region of the nuclear chart.

  18. Energy Recovery Linacs for Commercial Radioisotope Production

    SciTech Connect

    Sy, Amy; Krafft, Geoffrey A.; Johnson, Rolland; Roberts, Tom; Boulware, Chase; Hollister, Jerry

    2015-09-01

    Photonuclear reactions with bremsstrahlung photon beams from electron linacs can generate radioisotopes of critical interest. An SRF Energy Recovery Linac (ERL) provides a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes in a more compact footprint and at a lower cost than those produced by conventional reactor or ion accelerator methods. Use of an ERL enables increased energy efficiency of the complex through energy recovery of the waste electron beam, high electron currents for high production yields, and reduced neutron production and shielding activation at beam dump components. Simulation studies using G4Beamline/GEANT4 and MCNP6 through MuSim, as well as other simulation codes, will design an ERL-based isotope production facility utilizing bremsstrahlung photon beams from an electron linac. Balancing the isotope production parameters versus energy recovery requirements will inform a choice of isotope production target for future experiments.

  19. Radioisotope Power Systems Program: A Program Overview

    NASA Technical Reports Server (NTRS)

    Hamley, John A.

    2016-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan, mature research in energy conversion, and partners with the Department of Energy (DOE) to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet potential future mission needs. Recent programs responsibilities include providing investment recommendations to NASA stakeholders on emerging thermoelectric and Stirling energy conversion technologies and insight on NASA investments at DOE in readying a generator for the Mars 2020 mission. This presentation provides an overview of the RPS Program content and status and the approach used to maintain the readiness of RPS to support potential future NASA missions.

  20. Induced radioisotopes in a linac treatment hall.

    PubMed

    Vega-Carrillo, Héctor René; de Leon-Martinez, Héctor Asael; Rivera-Perez, Esteban; Luis Benites-Rengifo, Jorge; Gallego, Eduardo; Lorente, Alfredo

    2015-08-01

    When linacs operate above 8MV an undesirable neutron field is produced whose spectrum has three main components: the direct spectrum due to those neutrons leaking out from the linac head, the scattered spectrum due to neutrons produced in the head that collides with the nuclei in the head losing energy and the third spectrum due to room-return effect. The third category of spectrum has mainly epithermal and thermal neutrons being constant at any location in the treatment hall. These neutrons induce activation in the linac components, the concrete walls and in the patient body. Here the induced radioisotopes have been identified in concrete samples located in the hall and in one of the wedges. The identification has been carried out using a gamma-ray spectrometer.

  1. Thermophotovoltaic Converter Design for Radioisotope Power Systems

    SciTech Connect

    Crowley, Christopher J.; Elkouh, Nabil A.; Murray, Susan; Murray, Christopher

    2004-02-04

    The development of lightweight, efficient power for emerging NASA missions and recent advances in thermophotovoltaic (TPV) conversion technology have renewed interest in combining radioisotope heat sources with photovoltaic energy conversion. Thermophotovoltaic power conversion uses advanced materials able to utilize a broader, spectrally tuned range of wavelengths for more efficient power conversion than solar cells. Spectral control, including selective emitters, TPV module, and filters, are key to high-efficiency operation. This paper outlines the mechanical, thermal, and optical designs for the converter, including the heat source, the selective emitter, filters, photovoltaic (PV) cells, and optical cavity components. Focus is on the emitter type and the band-gap of InGaAs PV cells in developing the design. Any component and converter data available at the time of publication will also be presented.

  2. Status of the NASA Stirling Radioisotope Project

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    2007-01-01

    Free-piston Stirling power conversion has been considered a candidate for radioisotope power systems for space for more than a decade. Prior to the free-piston Stirling architecture, systems were designed with kinematic Stirling engines that used linkages and rotary alternators to convert heat to electricity. These systems were able to achieve long life by lightly loading the linkages; however, the live was nonetheless limited. When the free-piston configuration was initially proposed, it was thought to be attractive due to the relatively high conversion efficiency, acceptable mass, and the potential for long life and high reliability based on wear-free operation. These features have consistently been recognized by teams that have studied technology options for radioisotope space power systems. Since free-piston Stirling power conversion was first considered for space power applications, there have been major advances in three general areas of development: hardware that has demonstrated long-life and reliability, the success achieved by Stirling cryocoolers in space, and the overall developmental maturity of the technology for both space and terrestrial applications. Based on these advances, free-piston Stirling convertors are currently being developed for space power, and for a number of terrestrial applications. They commonly operate with the power, efficiency, life, and reliability as intended, and much of the development now centers on system integration. This paper will summarize the accomplishments of free-piston Stirling power conversion technology over the past decade, review the status of development with regard to space power, and discuss the challenges that remain.

  3. Production of medical radioisotopes with linear accelerators.

    PubMed

    Starovoitova, Valeriia N; Tchelidze, Lali; Wells, Douglas P

    2014-02-01

    In this study, we discuss producing radioisotopes using linear electron accelerators and address production and separation issues of photoneutron (γ,n) and photoproton (γ,p) reactions. While (γ,n) reactions typically result in greater yields, separating product nuclides from the target is challenging since the chemical properties of both are the same. Yields of (γ,p) reactions are typically lower than (γ,n) ones, however they have the advantage that target and product nuclides belong to different chemical species so their separation is often not such an intricate problem. In this paper we consider two examples, (100)Mo(γ,n)(99)Mo and (68)Zn(γ,p)(67)Cu, of photonuclear reactions. Monte-Carlo simulations of the yields are benchmarked with experimental data obtained at the Idaho Accelerator Center using a 44MeV linear electron accelerator. We propose using a kinematic recoil method for photoneutron production. This technique requires (100)Mo target material to be in the form of nanoparticles coated with a catcher material. During irradiation, (99)Mo atoms recoil and get trapped in the coating layer. After irradiation, the coating is dissolved and (99)Mo is collected. At the same time, (100)Mo nanoparticles can be reused. For the photoproduction method, (67)Cu can be separated from the target nuclides, (68)Zn, using standard exchange chromatography methods. Monte-Carlo simulations were performed and the (99)Mo activity was predicted to be about 7MBq/(g(⁎)kW(⁎)h) while (67)Cu activity was predicted to be about 1MBq/(g(⁎)kW(⁎)h). Experimental data confirm the predicted activity for both cases which proves that photonuclear reactions can be used to produce radioisotopes. Lists of medical isotopes which might be obtained using photonuclear reactions have been compiled and are included as well.

  4. Advanced Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2004-01-01

    NASA's Radioisotope Power Conversion Technology program is developing next generation power conversion technologies that will enable future missions that have requirements that cannot be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power System (RPS) technology. Performance goals of advanced radioisotope power systems include improvement over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. NASA has awarded ten contracts in the technology areas of Brayton, Stirling, Thermoelectric, and Thermophotovoltaic power conversion including five development contracts that deal with more mature technologies and five research contracts. The Advanced RPS Systems Assessment Team includes members from NASA GRC, JPL, DOE and Orbital Sciences whose function is to review the technologies being developed under the ten Radioisotope Power Conversion Technology contracts and assess their relevance to NASA's future missions. Presented is an overview of the ten radioisotope power conversion technology contracts and NASA's Advanced RPS Systems Assessment Team.

  5. Report on audit of funding for advanced radioisotope power systems

    SciTech Connect

    1997-10-17

    The U.S. Department of Energy`s (Department) Advanced Radioisotope Power Systems Program maintains the sole national capability and facilities to produce radioisotope power systems for the National Aeronautics and Space Administration (NASA), the Department of Defense, and other Federal agencies. Projects are conducted with these agencies in accordance with written agreements and are dependent on cost sharing by the user agencies. For the past seven years the program emphasis has been on providing power systems for NASA`s Cassini mission to Saturn, which was launched earlier this month. We initiated this audit to determine whether the Department received proper reimbursement from NASA for the radioisotope power systems produced.

  6. Radioisotope Reduction Using Solar Power for Outer Planetary Missions

    NASA Technical Reports Server (NTRS)

    Fincannon, James

    2008-01-01

    Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.

  7. RADIOISOTOPE POWER SYSTEM CAPABILITIES AT THE IDAHO NATIONAL LABORATORY (INL)

    SciTech Connect

    Kelly Lively; Stephen Johnson; Eric Clarke

    2014-07-01

    --Idaho National Laboratory’s, Space Nuclear Systems and Technology Division established the resources, equipment and facilities required to provide nuclear-fueled, Radioisotope Power Systems (RPS) to Department of Energy (DOE) Customers. RPSs are designed to convert the heat generated by decay of iridium clad, 238PuO2 fuel pellets into electricity that is used to power missions in remote, harsh environments. Utilization of nuclear fuel requires adherence to governing regulations and the INL provides unique capabilities to safely fuel, test, store, transport and integrate RPSs to supply power—supporting mission needs. Nuclear capabilities encompass RPS fueling, testing, handling, storing, transporting RPS nationally, and space vehicle integration. Activities are performed at the INL and in remote locations such as John F. Kennedy Space Center and Cape Canaveral Air Station to support space missions. This paper will focus on the facility and equipment capabilities primarily offered at the INL, Material and Fuel Complex located in a security-protected, federally owned, industrial area on the remote desert site west of Idaho Falls, ID. Nuclear and non-nuclear facilities house equipment needed to perform required activities such as general purpose heat source (GPHS) module pre-assembly and module assembly using nuclear fuel; RPS receipt and baseline electrical testing, fueling, vibration testing to simulate the launch environment, mass properties testing to measure the mass and compute the moment of inertia, electro-magnetic characterizing to determine potential consequences to the operation of vehicle or scientific instrumentation, and thermal vacuum testing to verify RPS power performance in the vacuum and cold temperatures of space.

  8. Radioactive Decay

    EPA Pesticide Factsheets

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  9. Tooth Decay

    MedlinePlus

    You call it a cavity. Your dentist calls it tooth decay or dental caries. They're all names for a hole in your tooth. The cause of tooth decay is plaque, a sticky substance in your mouth made up mostly of germs. Tooth decay starts in the outer layer, called the enamel. Without ...

  10. A power conditioning system for radioisotope thermoelectric generator energy sources

    NASA Technical Reports Server (NTRS)

    Gillis, J. A., Jr.

    1974-01-01

    The use of radioisotope thermoelectric generators (RTG) as the primary source of energy in unmanned spacecraft is discussed. RTG output control, power conditioning system requirements, the electrical design, and circuit performance are also discussed.

  11. Determining Molar Combining Ratios Using Radioisotopes--A Student Experiment

    ERIC Educational Resources Information Center

    Sears, Jerry A.

    1976-01-01

    Outlines an experimental procedure in which an iodine radioisotope is used to determine molar combining ratios of lead and silver with the iodine. Tables and graphs show the definitive results that should be attainable. (CP)

  12. Therapeutic clinical applications of reactor-produced radioisotopes

    SciTech Connect

    Knapp, F.F. Jr.

    1997-12-01

    One of the most rapidly growing areas of clinical nuclear medicine is the therapeutic use of radioisotopes for applications in oncology, rheumatology and, more recently, interventional cardiology. With the rapidly increasing development and evaluation of new agents, their introduction into clinical use, and commercialization, the availability of high levels of therapeutic reactor-produced neutron-rich radioisotopes is of increasing importance. The goals of this paper are to discuss the issues associated with optimization of the production and processing of reactor-produced radioisotopes for therapy, with special emphasis on {sup 188}W, and the optimization of the use of the {sup 188}W/{sup 188}Re generator. In addition, other key examples of therapeutic radioisotopes of current interest and their specific clinical applications are discussed.

  13. Radioisotope Electric Propulsion (REP) for Selected Interplanetary Science Missions

    NASA Technical Reports Server (NTRS)

    Oh, David; Bonfiglio, Eugene; Cupples, Mike; Belcher, Jeremy; Witzberger, Kevin; Fiehler, Douglas; Artis, Gwen

    2005-01-01

    This viewgraph presentation analyzes small body targets (Trojan Asteroids), Medium Outer Planet Class (Jupiter Polar Orbiter with Probes), and Main Belt Asteroids and Comets (Comet Surface Sample Return), for Radioisotope Electric Propulsion (REP).

  14. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This presentation describes the capabilities of three-dimensional thermal power model of advanced stirling radioisotope generator (ASRG). The performance of the ASRG is presented for different scenario, such as Venus flyby with or without the auxiliary cooling system.

  15. Evaluation of the β+-decay log ft value with inclusion of the neutron-proton pairing and particle-number projection

    NASA Astrophysics Data System (ADS)

    Kerrouchi, S.; Allal, N. H.; Fellah, M.; Oudih, M. R.

    2016-01-01

    The neutron-proton isovector pairing effect on the beta-plus decay log ft values is studied in typical mirror N≃Z nuclei. The log ft values are calculated by including or not the isovector pairing before and after a particle-number projection using the Sharp-Bardeen-Cooper-Schrieffer (SBCS) method. It is shown that the values obtained after projection in the isovector pairing case are the closest ones to experimental data. The effect of the deformation of the mother and daughter nuclei on the log ft is also studied.

  16. Efficiency of Pm-147 direct charge radioisotope battery.

    PubMed

    Kavetskiy, A; Yakubova, G; Yousaf, S M; Bower, K; Robertson, J D; Garnov, A

    2011-05-01

    A theoretical analysis is presented here of the efficiency of direct charge radioisotope batteries based on the efficiency of the radioactive source, the system geometry, electrostatic repulsion of beta particles from the collector, the secondary electron emission, and backscattered beta particles from the collector. Efficiency of various design batteries using Pm-147 sources was experimentally measured and found to be in good agreement with calculations. The present approach can be used for predicting the efficiency for different designs of direct charge radioisotope batteries.

  17. Reliability of Radioisotope Stirling Convertor Linear Alternator

    NASA Technical Reports Server (NTRS)

    Shah, Ashwin; Korovaichuk, Igor; Geng, Steven M.; Schreiber, Jeffrey G.

    2006-01-01

    Onboard radioisotope power systems being developed and planned for NASA s deep-space missions would require reliable design lifetimes of up to 14 years. Critical components and materials of Stirling convertors have been undergoing extensive testing and evaluation in support of a reliable performance for the specified life span. Of significant importance to the successful development of the Stirling convertor is the design of a lightweight and highly efficient linear alternator. Alternator performance could vary due to small deviations in the permanent magnet properties, operating temperature, and component geometries. Durability prediction and reliability of the alternator may be affected by these deviations from nominal design conditions. Therefore, it is important to evaluate the effect of these uncertainties in predicting the reliability of the linear alternator performance. This paper presents a study in which a reliability-based methodology is used to assess alternator performance. The response surface characterizing the induced open-circuit voltage performance is constructed using 3-D finite element magnetic analysis. Fast probability integration method is used to determine the probability of the desired performance and its sensitivity to the alternator design parameters.

  18. Radioisotopic heater units warm an interplanetary spacecraft

    SciTech Connect

    Franco-Ferreira, E.A.; Rinehart, G.H.

    1998-01-01

    The Cassini orbiter and Huygens probe, which were successfully launched on October 15, 1997, constitute NASA`s last grand-scale interplanetary mission of this century. The mission, which consists of a four-year, close-up study of Saturn and its moons, begins in July 2004 with Cassini`s 60 orbits of Saturn and about 33 fly-bys of the large moon Titan. The Huygens probe will descend and land on Titan. Investigations will include Saturn`s atmosphere, its rings and its magnetosphere. The atmosphere and surface of Titan and other icy moons also will be characterized. Because of the great distance of Saturn from the sun, some of the instruments and equipment on both the orbiter and the probe require external heaters to maintain their temperature within normal operating ranges. These requirements are met by Light Weight Radioisotope Heater Units (LWRHUs) designed, fabricated and safety tested at Los Alamos National Laboratory, New Mexico. An improved gas tungsten arc welding procedure lowered costs and decreased processing time for heat units for the Cassini spacecraft.

  19. Implanted artificial heart with radioisotope power source.

    PubMed

    Shumakov, V I; Griaznov, G M; Zhemchuzhnikov, G N; Kiselev, I M; Osipov, A P

    1983-02-01

    An atomic artificial heart for orthotopic implantation was developed with the following characteristics: volume, 1.2 L; weight, 1.5 kg; radioisotope power, 45 W; operating life, up to 5 years; hemodynamics, similar to natural hemodynamics. The artificial heart includes a thermal drive with systems for regulating power, feeding steam into the cylinders, return of the condensate to the steam generator, and delivery of power to the ventricles and heat container. The artificial heart is placed in an artificial pericardium partially filled with physiologic solution. It uses a steam engine with two operating cylinders that separately drive the left and right ventricles. There is no electronic control system in the proposed design. The operation of the heat engine is controlled, with preservation of autoregulation by the vascular system of the body. The separate drives for the ventricles is of primary importance as it provides for operation of the artificial heart through control of cardiac activity by venous return. Experimental testing on a hydromechanical bench demonstrated effective autoregulation.

  20. Effect of Inert Cover Gas on Performance of Radioisotope Stirling Space Power System

    SciTech Connect

    Carpenter, Robert; Kumar, V; Ore, C; Schock, Alfred

    2001-01-01

    This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al. 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission.

  1. Light-Weight Radioisotope Heater Unit

    SciTech Connect

    Schock, Alfred

    1981-04-01

    DOE is developing a new generation of radioisotope-fueled 1-watt heaters, for initial use on NASA's upcoming Galileo and International Solar-Polar Missions. Each heater must contain passive safety provisions to ensure fuel retention under all credible accident conditions. Initial design reviews raised some concern about the accuracy of the predicted peak reenetry temperature, and about the adequacy of the safety margin under certain unlikely - but not impossible-reentry modes. Of particular concern was the possile release of the accumulated helium inventory from the fuel during the reentry heat pulse, and the potential effect of enhanced heat conduction due to helium buildup in gaps. The latter problem had not been addressed in previous studies. Fairchild carried out a large number of reentry thermal analyses to resolve the analytical uncertainties, and proposed design changes to reduce the thermal coupling between the aeroshell and the fuel capsule. For the computed reentry temperature history of the modified design, the rate of helium buildup in the gaps was analyzed. The analysis accounted for temperature-dependent helium diffusion through the fuel pellet and for leakage to space through the permeable aeroshell. It showed that most of the helium inventory leaves the fuel during reentry, but that it never reaches a continuum pressure in the gaps, and therefore has no significant thermal effect. Under these conditions, the Fairchild-modified design provides ample safety margin against clad failure, even for very unlikely reenty trajectories. The modified design was successfully vibration-tested and was subsequently adopted by the project. Cross Reference CID #8517. There are two copies in the file.

  2. Radioactive decay.

    PubMed

    Groch, M W

    1998-01-01

    When a parent radionuclide decays to its daughter radionuclide by means of alpha, beta, or isomeric transition, the decay follows an exponential form, which is characterized by the decay constant lambda. The decay constant represents the probability per unit time that a single radioatom will decay. The decay equation can be used to provide a useful expression for radionuclide decay, the half-life, the time when 50% of the radioatoms present will have decayed. Radiotracer half-life has direct implications in nuclear imaging, radiation therapy, and radiation safety because radionuclide half-life affects the ability to evaluate tracer kinetics and create appropriate nuclear images and also affects organ, tumor, and whole-body radiation dose. The number of radioatoms present in a sample is equal to the activity, defined as the number of transitions per unit time, divided by the decay constant; the mass of radioatoms present in a sample can be calculated to determine the specific activity (activity per unit mass). The dynamic relationship between the number of parent and daughter atoms present over time may lead to radioactive equilibrium, which takes two forms--secular and transient--and has direct relevance to generator-produced radionuclides.

  3. A compendium of the radioisotope thermoelectric generator transportation system and recent programmatic changes

    SciTech Connect

    Becker, D.L.; McCoy, J.C.

    1996-03-01

    Because RTGs contain significant quantities of radioactive materials, usually plutonium-238 and its decay products, they must be transported in packages built in accordance with 10 CFR 71 (1994). To meet these regulatory requirements, US DOE commissioned Westinghouse Hanford Co. in 1988 to develop a Radioisotope Thermoelectric Generator Transportation System (RTGTS) that would fully comply while protecting RTGs from adverse environmental conditions during normal transport conditions (eg, mainly shock and heat). RTGTS is scheduled for completion Dec. 1996 and will be available to support NASA`s Cassini mission to Saturn in Oct. 1997. This paper provides an overview of the RTGTS project, discusses the hardware being produced, and summarizes various programmatic and management innovations required by recent changes at DOE.

  4. Advanced Stirling Radioisotope Generator Thermal Power Model in Thermal Desktop SINDA/FLUINT Analyzer

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen; Fabanich, William A.; Schmitz, Paul C.

    2012-01-01

    This paper presents a three-dimensional Advanced Stirling Radioisotope Generator (ASRG) thermal power model that was built using the Thermal Desktop SINDA/FLUINT thermal analyzer. The model was correlated with ASRG engineering unit (EU) test data and ASRG flight unit predictions from Lockheed Martin's Ideas TMG thermal model. ASRG performance under (1) ASC hot-end temperatures, (2) ambient temperatures, and (3) years of mission for the general purpose heat source fuel decay was predicted using this model for the flight unit. The results were compared with those reported by Lockheed Martin and showed good agreement. In addition, the model was used to study the performance of the ASRG flight unit for operations on the ground and on the surface of Titan, and the concept of using gold film to reduce thermal loss through insulation was investigated.

  5. Daily intakes of naturally occurring radioisotopes in typical Korean foods.

    PubMed

    Choi, Min-Seok; Lin, Xiu-Jing; Lee, Sun Ah; Kim, Wan; Kang, Hee-Dong; Doh, Sih-Hong; Kim, Do-Sung; Lee, Dong-Myung

    2008-08-01

    The concentrations of naturally occurring radioisotopes ((232)Th, (228)Th, (230)Th, (228)Ra, (226)Ra, and (40)K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: (232)Th, 0.00-0.23; (228)Th, 0.00-2.04; (230)Th, 0.00-0.26; (228)Ra, 0.02-2.73; (226)Ra, 0.01-4.37 mBq/day; and (40)K, 0.01-5.71 Bq/day. The total daily intake of the naturally occurring radioisotopes measured in this study from food was 39.46 Bq/day. The total annual internal dose resulting from ingestion of radioisotopes in food was 109.83 muSv/y, and the radioisotope with the highest daily intake was (40)K. These values were same level compiled in other countries.

  6. Lightweight Radiators Being Developed or Advanced Stirling Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Tew, Roy C.; Thieme, Lanny G.

    2001-01-01

    The thermodynamic heat-to-electric power conversion efficiency of Stirling systems is 3 to 5 times higher than that of thermoelectric converters. Hence for unmanned deep space probes, Stirling advanced radioisotope power systems (ARPS) could deliver up to 5 times as much power as radioisotope thermoelectric generators for the same amount of radioisotope, or they could require one-third to one-fifth as much isotope inventory for the same power output. However, Stirling power systems reject unconverted heat at much lower temperatures than radioisotope thermoelectric generators. Normally, this requires larger and heavier heat-rejection subsystems because of the greater radiator areas, which are proportional to the first power of the heat rejected and the fourth power of the absolute heat-rejection temperature, as specified by the Stefan-Boltzmann radiation heat transfer law. The development of directly coupled disk radiators using very high conductivity encapsulated thermopyrolitic graphite materials represents a significant advance in Stirling ARPS space heat-rejection subsystem technology. A conceptual Stirling ARPS with two engines coupled to a radioisotope general-purpose heat source (GPHS) is shown in the illustration.

  7. NASA's Advanced Radioisotope Power Conversion Technology Development Status

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Sankovic, John; Wilt, David; Abelson, Robert D.; Fleurial, Jean-Pierre

    2007-01-01

    NASA's Advanced Radioisotope Power Systems (ARPS) project is developing the next generation of radioisotope power conversion technologies that will enable future missions that have requirements that cannot be met by either photovoltaic systems or by current radioisotope power systems (RPSs). Requirements of advanced RPSs include high efficiency and high specific power (watts/kilogram) in order to meet future mission requirements with less radioisotope fuel and lower mass so that these systems can meet requirements for a variety of future space applications, including continual operation surface missions, outer-planetary missions, and solar probe. These advances would enable a factor of 2 to 4 decrease in the amount of fuel required to generate electrical power. Advanced RPS development goals also include long-life, reliability, and scalability. This paper provides an update on the contractual efforts under the Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) for research and development of Stirling, thermoelectric, and thermophotovoltaic power conversion technologies. The paper summarizes the current RPCT NRA efforts with a brief description of the effort, a status and/or summary of the contractor's key accomplishments, a discussion of upcoming plans, and a discussion of relevant system-level benefits and implications. The paper also provides a general discussion of the benefits from the development of these advanced power conversion technologies and the eventual payoffs to future missions (discussing system benefits due to overall improvements in efficiency, specific power, etc.).

  8. Operations of a Radioisotope-based Propulsion System Enabling CubeSat Exploration of the Outer Planets

    SciTech Connect

    Dr. Steven Howe; Nathan Jerred; Troy Howe; Adarsh Rajguru

    2014-05-01

    Exploration to the outer planets is an ongoing endeavor but in the current economical environment, cost reduction is the forefront of all concern. The success of small satellites such as CubeSats launched to Near-Earth Orbit has lead to examine their potential use to achieve cheaper science for deep space applications. However, to achieve lower cost missions; hardware, launch and operations costs must be minimized. Additionally, as we push towards smaller exploration beds with relative limited power sources, allowing for adequate communication back to Earth is imperative. Researchers at the Center for Space Nuclear Research are developing the potential of utilizing an advanced, radioisotope-based system. This system will be capable of providing both the propulsion power needed to reach the destination and the additional requirements needed to maintain communication while at location. Presented here are a basic trajectory analysis, communication link budget and concept of operations of a dual-mode (thermal and electric) radioisotope-based propulsion system, for a proposed mission to Enceladus (Saturnian icy moon) using a 6U CubeSat payload. The radioisotope system being proposed will be the integration of three sub-systems working together to achieve the overall mission. At the core of the system, stored thermal energy from radioisotope decay is transferred to a passing propellant to achieve high thrust – useful for quick orbital maneuvering. An auxiliary closed-loop Brayton cycle can be operated in parallel to the thrusting mode to provide short bursts of high power for high data-rate communications back to Earth. Additionally, a thermal photovoltaic (TPV) energy conversion system will use radiation heat losses from the core. This in turn can provide the electrical energy needed to utilize the efficiency of ion propulsion to achieve quick interplanetary transit times. The intelligent operation to handle all functions of this system under optimized conditions adds

  9. High Efficiency Thermoelectric Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed; Saber, Hamed; Caillat, Thierry

    2004-01-01

    The work performed and whose results presented in this report is a joint effort between the University of New Mexico s Institute for Space and Nuclear Power Studies (ISNPS) and the Jet Propulsion Laboratory (JPL), California Institute of Technology. In addition to the development, design, and fabrication of skutterudites and skutterudites-based segmented unicouples this effort included conducting performance tests of these unicouples for hundreds of hours to verify theoretical predictions of the conversion efficiency. The performance predictions of these unicouples are obtained using 1-D and 3-D models developed for that purpose and for estimating the actual performance and side heat losses in the tests conducted at ISNPS. In addition to the performance tests, the development of the 1-D and 3-D models and the development of Advanced Radioisotope Power systems for Beginning-Of-Life (BOM) power of 108 We are carried out at ISNPS. The materials synthesis and fabrication of the unicouples are carried out at JPL. The research conducted at ISNPS is documented in chapters 2-5 and that conducted at JP, in documented in chapter 5. An important consideration in the design and optimization of segmented thermoelectric unicouples (STUs) is determining the relative lengths, cross-section areas, and the interfacial temperatures of the segments of the different materials in the n- and p-legs. These variables are determined using a genetic algorithm (GA) in conjunction with one-dimensional analytical model of STUs that is developed in chapter 2. Results indicated that when optimized for maximum conversion efficiency, the interfacial temperatures between various segments in a STU are close to those at the intersections of the Figure-Of-Merit (FOM), ZT, curves of the thermoelectric materials of the adjacent segments. When optimizing the STUs for maximum electrical power density, however, the interfacial temperatures are different from those at the intersections of the ZT curves, but

  10. Investigation of Miniaturized Radioisotope Thermionic Power Generation for General Use

    NASA Technical Reports Server (NTRS)

    Duzik, Adam J.; Choi, Sang H.

    2016-01-01

    Radioisotope thermoelectric generators (RTGs) running off the radioisotope Pu238 are the current standard in deep space probe power supplies. While reliable, these generators are very inefficient, operating at only approx.7% efficiency. As an alternative, more efficient radioisotope thermionic emission generators (RTIGs) are being explored. Like RTGs, current RTIGs concepts use exotic materials for the emitter, limiting applicability to space and other niche applications. The high demand for long-lasting mobile power sources would be satisfied if RTIGs could be produced inexpensively. This work focuses on exposing several common materials, such as Al, stainless steel, W, Si, and Cu, to elevated temperatures under vacuum to determine the efficiency of each material as inexpensive replacements for thermoelectric materials.

  11. Hair radioactivity as a measure of exposure to radioisotopes

    NASA Technical Reports Server (NTRS)

    Strain, W. H.; Pories, W. J.; Fratianne, R. B.; Flynn, A.

    1972-01-01

    Since many radioisotopes accumulate in hair, this tropism was investigated by comparing the radioactivity of shaved with plucked hair collected from rats at various time intervals up to 24 hrs after intravenous injection of the ecologically important radioisotopes, iodine-131, manganese-54, strontium-85, and zinc-65. The plucked hair includes the hair follicles where biochemical transformations are taking place. The data indicate a slight surge of each radioisotpe into the hair immediately after injection, a variation of content of each radionuclide in the hair, and a greater accumulation of radioactivity in plucked than in shaved hair. These results have application not only to hair as a measure of exposure to radioisotopes, but also to tissue damage and repair at the hair follicle.

  12. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  13. Procurement of a fully licensed radioisotope thermoelectric generator transportation system

    SciTech Connect

    Adkins, H.E.; Bearden, T.E.

    1990-10-01

    A fully licensed transportation system for Radioisotope Thermoelectric Generators and Light-Weight Radioisotope Heater Units is currently being designed and built. The system will comply with all applicable US Department of Transportation regulations without the use of a DOE Alternative.'' The US Department of Transportation has special double containment'' requirements for plutonium. The system packaging uses a doubly contained bell jar'' concept. A refrigerated trailer is used for cooling the high-heat payloads. The same packaging is used for both high- and low-heat payloads. The system is scheduled to be available for use by mid-1992. 4 refs., 4 figs., 2 tabs.

  14. Methods of Fabricating Scintillators with Radioisotopes for Beta Battery Applications

    NASA Technical Reports Server (NTRS)

    Rensing, Noa M.; Squillante, Michael R.; Tieman, Timothy C.; Higgins, William; Shiriwadkar, Urmila

    2013-01-01

    Technology has been developed for a class of self-contained, long-duration power sources called beta batteries, which harvest the energy contained in the radioactive emissions from beta decay isotopes. The new battery is a significant improvement over the conventional phosphor/solar cell concept for converting this energy in three ways. First, the thin phosphor is replaced with a thick scintillator that is transparent to its own emissions. By using a scintillator sufficiently thick to completely stop all the beta particles, efficiency is greatly improved. Second, since the energy of the beta particles is absorbed in the scintillator, the semiconductor photodetector is shielded from radiation damage that presently limits the performance and lifetime of traditional phosphor converters. Finally, instead of a thin film of beta-emitting material, the isotopes are incorporated into the entire volume of the thick scintillator crystal allowing more activity to be included in the converter without self-absorption. There is no chemical difference between radioactive and stable strontium beta emitters such as Sr-90, so the beta emitter can be uniformly distributed throughout a strontium based scintillator crystal. When beta emitter material is applied as a foil or thin film to the surface of a solar cell or even to the surface of a scintillator, much of the radiation escapes due to the geometry, and some is absorbed within the layer itself, leading to inefficient harvesting of the energy. In contrast, if the emitting atoms are incorporated within the scintillator, the geometry allows for the capture and efficient conversion of the energy of particles emitted in any direction. Any gamma rays associated with secondary decays or Bremsstrahlung photons may also be absorbed within the scintillator, and converted to lower energy photons, which will in turn be captured by the photocell or photodiode. Some energy will be lost in this two-stage conversion process (high-energy particle

  15. The Mars Hopper: a radioisotope powered, impulse driven, long-range, long-lived mobile platform for exploration of Mars

    SciTech Connect

    Steven D. Howe; Robert C. O'Brien; William Taitano; Doug Crawford; Nathan Jerred; Spencer Cooley; John Crapeau; Steve Hansen; Andrew Klein; James Werner

    2011-02-01

    Planetary exploration mission requirements are becoming more demanding. Due to the increasing cost, the missions that provide mobile platforms that can acquire data at multiple locations are becoming more attractive. Wheeled vehicles such as the MER rovers have proven extremely capable but have very limited range and cannot traverse rugged terrain. Flying vehicles such as balloons and airplanes have been proposed but are problematic due to the very thin atmospheric pressure and the strong, dusty winds present on Mars. The Center for Space Nuclear Research has designed an instrumented platform that can acquire detailed data at hundreds of locations during its lifetime - a Mars Hopper. The Mars Hopper concept utilizes energy from radioisotopic decay in a manner different from any existing radioisotopic power sources—as a thermal capacitor. By accumulating the heat from radioisotopic decay for long periods, the power of the source can be dramatically increased for short periods. The platform will be able to "hop" from one location to the next every 5-7 days with a separation of 5-10 km per hop. Preliminary designs show a platform that weighs around 52 kgs unfueled which is the condition at deployment. Consequently, several platforms may be deployed on a single launch from Earth. With sufficient lifetime, the entire surface of Mars can be mapped in detail by a couple dozen platforms. In addition, Hoppers can collect samples from all over the planet, including gorges, mountains and crevasses, and deliver them to a central location for eventual pick-up by a Mars Sample Return mission. The status of the Mars Hopper development project at the CSNR is discussed.

  16. Measuring the beta-neutrino angular correlation in the 6 He decay

    NASA Astrophysics Data System (ADS)

    Bagdasarova, Yelena; Garicia, Alejandro; Hong, Ran; Sternberg, Matthew; Storm, Derek; Swanson, Erik; Wauters, Frederik; Zumwalt, David; Leredde, Arnaud; Bailey, Kevin; Mueller, Peter; O'Connor, Thomas P.; Flechard, Xavier; Lienard, Etienne; Naviliat-Cuncic, Oscar

    2015-04-01

    We have set up an experiment to determine the electron-antineutrino correlation from 6 He decay with the aim of searching for tensor currents in the electroweak interaction, which would constitute physics beyond the Standard Model. Our setup consists of a 6 He production target connected to a laser cooling and magneto-optical trapping system which confines the atoms in a small region surrounded by detectors. The detection system entails a combination of a multiwire proportional chamber and scintillator (for the beta) plus an electric field guide and a microchannel plate detector (for the Li recoil ions). I will give an overview of the setup, a summary of expected systematic uncertainties, and the current status of the experiment. This work is supported by DOE, Office of Nuclear Physics, under Contract Nos. DE-AC02-06CH11357 and DE-FG02-97ER41020.

  17. Targets for the production of radioisotopes and method of assembly

    DOEpatents

    Quinby, Thomas C.

    1976-01-01

    A target for preparation of radioisotopes by nuclear bombardment, and a method for its assembly are provided. A metallic sample to be bombarded is enclosed within a metallic support structure and the resulting target subjected to heat and pressure to effect diffusion bonds therebetween. The bonded target is capable of withstanding prolonged exposure to nuclear bombardment without thermal damage to the sample.

  18. A Concept for a Radioisotope Powered Lunar CubeSat

    NASA Astrophysics Data System (ADS)

    Cataldo, R. L.

    2016-11-01

    Presented is a concept for a small lander or cubesat lunar mission that would benefit from a low-power milli-watt radioisotope power source (RPS). A RPS would provide long-lived electrical and thermal power enabling a long-lived lunar mission.

  19. Radioisotope production and management at Oak Ridge National Laboratory

    SciTech Connect

    Collins, E.D.; Aaron, W.S.; Alexander, C.W.; Bigelow, J.E.; Parks, J.T.; Tracy, J.G.; Wham, R.M.

    1994-09-01

    The production of radioisotopes has been one of the basic activities at Oak Ridge since the end of World War II. The importance of this work was best described by Alvin Weinberg, former Laboratory Director, when he wrote ``... If God has a golden book and writes down what it is that Oak Ridge National Laboratory did that had the biggest influence on science, I would guess that was the production and distribution of isotopes.`` Radioisotopes production continues to be an important aspect of Oak Ridge programs today and of those planned for the future. Past activities, current projects, and future plans and potentials will be described briefly in this paper. Also, some of the major issues facing the continued production of radioisotopes will be described. The scope of the program has always been primarily that of process development, followed by special batch-type productions, where no other supply exists. The technology developed has been available for adoption by US commercial corporations, and in cases where this has occurred, Oak Ridge has withdrawn as a supplier of the particular isotopes involved. One method of production that will not be described is that of target bombardment with an accelerator. This method was used at Oak Ridge prior to 1978 in the 86-inch Cyclotron. However, this method has not been used at Oak Ridge since then for radioisotope production, except as a research tool.

  20. Anthropogenic radioisotopes to estimate rates of soil redistribution by wind

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion of soil by wind and water is a degrading process that affects millions of hectares worldwide. Atmospheric testing of nuclear weapons and the resulting fallout of anthropogenic radioisotopes, particularly Cesium 137, has made possible the estimation of mean soil redistribution rates. The pe...

  1. A time like our own? Radioisotopic calibration of the Ordovician greenhouse to icehouse transition

    NASA Astrophysics Data System (ADS)

    Smith, M. Elliot; Singer, Brad S.; Simo, Toni

    2011-11-01

    Tiered interpolation, a new timescale methodology, was used to construct the first radioisotopically-calibrated composite δ 13C curve for the Ordovician period using sanidine 40Ar/ 39Ar age determinations and existing U-Pb geochronology and biostratigraphic zonation. Tiered interpolation intercalates and temporally scales the numerical age of lithostratigraphic horizons by conducting a series of nested projections between hierarchical temporal control points. For primary control points, new 40Ar/ 39Ar ages and legacy U-Pb geochronology were screened to avoid analyses affected by inheritance and daughter loss and calibrated to reflect modern decay constants and standard values. Ages for secondary, tertiary, etc.… control points are obtained via linear interpolation of between higher order control points. In scaling the Ordovician δ 13C composite, the following control point order was applied: (1) radioisotopic ages (2) graptolite Zones, (3) index taxa-based on speciation events (North Atlantic conodont Zones), (4) North American Mid-continent conodont zones, and (5) stratal thicknesses at δ 13C sampled sections. The resulting timescale utilizes the highest resolution of each component, is internally consistent, and is re-scalable as more precise radioisotopic ages become available. It provides a robust framework for independently assessing the accuracy of biostratigraphic composite timescales because it does not rely an assumption of quasi-continuous sediment accumulation and/or speciation. To better calibrate the Late Ordovician and resolve a discrepancy between U-Pb and 40Ar/ 39Ar ages, three new 40Ar/ 39Ar ages were determined via the laser fusion of multiple single sanidine phenocrysts from three bentonitic ash beds from the Late Ordovician marine strata of the upper Mississippi valley where the record of Taconic volcanism is most complete. Fusions of 275 individual sanidine crystals from the Millbrig, Dygerts, and Rifle Hill bentonites yield largely

  2. Production capabilities in US nuclear reactors for medical radioisotopes

    SciTech Connect

    Mirzadeh, S.; Callahan, A.P.; Knapp, F.F. Jr. ); Schenter, R.E. )

    1992-11-01

    The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the radioisotopes required for DOE-supported radionuclide generators were made available at the Brookhaven National Laboratory (BNL) High Flux Beam Reactor (HFBR). In March 1988, however, the HFBR was temporarily shut down which forced investigators to look at other reactors for production of the radioisotopes. During this period the Missouri University Research Reactor (MURR) played an important role in providing these services. The HFIR resumed routine operation in July 1990 at 85 MW power, and the HFBR resumed operation in June 1991, at 30 MW power. At the time of the HFBR shutdown, there was no available comprehensive overview which could provide information on status of the reactors operating in the US and their capabilities for radioisotope production. The obvious need for a useful overview was thus the impetus for preparing this survey, which would provide an up-to-date summary of those reactors available in the US at both the DOE-funded national laboratories and at US universities where service irradiations are currently or expected to be conducted.

  3. Measurement of cosmogenic radioisotope production on water at the Kimballton Underground Research Facility

    NASA Astrophysics Data System (ADS)

    Askins, Morgan

    2014-03-01

    The next generation of large water detectors, such as the kiloton-scale Water Cherenkov Monitor for Antineutrinos (WATCHMAN) and the megaton-scale Japanese Hyper-K project, aim to pursue a diverse physics program including low energy antineutrino physics. Muogenic backgrounds in water have been measured by the Superkamiokande collaboration, but for reactor and other low energy antineutrinos these backgrounds are only weakly constrained and may prove important for large water-based reactor-antineutrino detectors. The WATCHMAN collaboration has deployed a water Cherenkov detector to measure the rate of long-lived β- n radioisotopes - 8He, 9Li, 11Li - produced by cosmic ray interactions in water. Our emphasis is on measuring those β- n decay isotopes which mimic the positron-neutron signal from inverse beta decay of antineutrinos on protons. Our detector is a 2 ton cylindrical target of pure water doped with gadolinium for neutron identification, surrounded by a 1.4-meter thick pure water muon veto and neutron/gamma shield. Presented here are the preliminary results of data taken beginning July 2013 at the KURF mine in Virginia at a depth of approximately 300 meters water equivalent with intermittent periods of detector off time.

  4. Kinetics of radioisotope exchange between brine and rock in a geothermal system

    SciTech Connect

    Hammond, D.E.; Zukin, J.G.; Teh-Lung Ku

    1988-11-10

    A wide range of isotopes in the /sup 238/U, /sup 235/U, and /sup 232/Th decay chains was measured in geothermal brines collected from two production zones at 1898 and 3220 m in the Salton Sea Scientific Drilling Project well. High concentrations of radium, radon, and lead isotopes are generated and maintained by the input of these isotopes from solid phases into brine by both recoil and leaching processes, by the high chloride content of the brine which complexes radium and lead, and by the apparent absence of suitable unoccupied adsorption sites. In contrast, uranium, thorium, actinium, bismuth, and polonium isotopes all have low concentrations due to their efficient sorption from brine to rock. Measurements of short-lived isotopes in these decay series yield insights regarding the mechanisms controlling radioisotope exchange, and they permit estimation of rates of brine-rock interaction. For example, the /sup 228/Ac//sup 228/Ra activity ratio of 0.2 in brines indicates that the mean residence time of actinium in solution before sorption onto solid surfaces is less than 2.5 hours.

  5. Simulation of decay processes and radiation transport times in radioactivity measurements

    NASA Astrophysics Data System (ADS)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  6. Investigation of Insulation Materials for Future Radioisotope Power Systems (RPS)

    NASA Technical Reports Server (NTRS)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power System (RPS) Technology Advancement Project is developing next generation high temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center (GRC) on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  7. Radioisotope Electric Propulsion for Fast Outer Planetary Orbiters

    NASA Technical Reports Server (NTRS)

    Oleson, Steven; Benson, Scott; Gefert, Leon; Patterson, Michael; Schreiber, Jeffrey

    2002-01-01

    Recent interest in outer planetary targets by the Office of Space Science has spurred the search for technology options to enable relatively quick missions to outer planetary targets. Several options are being explored including solar electric propelled stages combined with aerocapture at the target and nuclear electric propulsion. Another option uses radioisotope powered electric thrusters to reach the outer planets. Past work looked at using this technology to provide faster flybys. A better use for this technology is for outer planet orbiters. Combined with medium class launch vehicles and a new direct trajectory these small, sub-kilowatt ion thrusters and Stirling radioisotope generators were found to allow missions as fast as 5 to 12 years for objects from Saturn to Pluto, respectively. Key to the development is light spacecraft and science payload technologies.

  8. Outer Planet Exploration with Advanced Radioisotope Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Oleson, Steven; Gefert, Leon; Patterson, Michael; Schreiber, Jeffrey; Benson, Scott; McAdams, Jim; Ostdiek, Paul

    2002-01-01

    In response to a request by the NASA Deep Space Exploration Technology Program, NASA Glenn Research Center conducted a study to identify advanced technology options to perform a Pluto/Kuiper mission without depending on a 2004 Jupiter Gravity Assist, but still arriving before 2020. A concept using a direct trajectory with small, sub-kilowatt ion thrusters and Stirling radioisotope power systems was shown to allow the same or smaller launch vehicle class as the chemical 2004 baseline and allow a launch slip and still flyby in the 2014 to 2020 timeframe. With this promising result the study was expanded to use a radioisotope power source for small electrically propelled orbiter spacecraft for outer planet targets such as Uranus, Neptune, and Pluto.

  9. Process for radioisotope recovery and system for implementing same

    DOEpatents

    Meikrantz, David H.; Todd, Terry A.; Tranter, Troy J.; Horwitz, E. Philip

    2009-10-06

    A method of recovering daughter isotopes from a radioisotope mixture. The method comprises providing a radioisotope mixture solution comprising at least one parent isotope. The at least one parent isotope is extracted into an organic phase, which comprises an extractant and a solvent. The organic phase is substantially continuously contacted with an aqueous phase to extract at least one daughter isotope into the aqueous phase. The aqueous phase is separated from the organic phase, such as by using an annular centrifugal contactor. The at least one daughter isotope is purified from the aqueous phase, such as by ion exchange chromatography or extraction chromatography. The at least one daughter isotope may include actinium-225, radium-225, bismuth-213, or mixtures thereof. A liquid-liquid extraction system for recovering at least one daughter isotope from a source material is also disclosed.

  10. Process for radioisotope recovery and system for implementing same

    DOEpatents

    Meikrantz, David H.; Todd, Terry A.; Tranter, Troy J.; Horwitz, E. Philip

    2007-01-02

    A method of recovering daughter isotopes from a radioisotope mixture. The method comprises providing a radioisotope mixture solution comprising at least one parent isotope. The at least one parent isotope is extracted into an organic phase, which comprises an extractant and a solvent. The organic phase is substantially continuously contacted with an aqueous phase to extract at least one daughter isotope into the aqueous phase. The aqueous phase is separated from the organic phase, such as by using an annular centrifugal contactor. The at least one daughter isotope is purified from the aqueous phase, such as by ion exchange chromatography or extraction chromatography. The at least one daughter isotope may include actinium-225, radium-225, bismuth-213, or mixtures thereof. A liquid-liquid extraction system for recovering at least one daughter isotope from a source material is also disclosed.

  11. Spontaneous intracranial hypotension syndrome: contribution of radioisotope cisternography.

    PubMed

    Suárez, J P; Domínguez, M L; Gómez, M A; Muñoz, J L

    Spontaneous intracranial hypotension is a clinical syndrome caused by a loss of cerebrospinal fluid volume, usually secondary to leaking through structural defects of the spinal dura mater. Radioisotope cisternography (RC) can confirm the diagnosis of spontaneous intracranial hypotension, especially in doubtful or atypical case presentations. A retrospective study was conducted on 8 patients who underwent RC because spontaneous intracranial hypotension was suspected, and they presented with atypical clinical manifestations and/or inconclusive findings in other imaging techniques. RC detected paradural extravasation of cerebrospinal fluid in 7 patients. Moreover, there was indirect evidence of cerebrospinal fluid leaks in all 8 patients (early appearance of radioactivity in the bladder, soft tissue uptake of radioisotope and/or reduction in the amount of radiotracer in the brain at 24hours). RC had a significant impact on the diagnosis of 6 patients, and on the therapeutic management of 4 patients.

  12. Emitted radiation characteristics of plutonium dioxide radioisotope thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Gingo, P. J.; Steyn, J. J.

    1971-01-01

    The nuclear and emitted radiation characteristics of the radioisotope elements and impurities in commercial grade plutonium dioxide are presented in detail. The development of the methods of analysis are presented. Radioisotope thermoelectric generators (RTG) of 1575, 3468 and 5679 thermal watts are characterized with respect to neutron and gamma photon source strength as well as spatial and number flux distribution. The results are presented as a function of detector position and light element contamination concentration for fuel age ranging from 'fresh' to 18 years. The data may be used to obtain results for given O-18 and Pu-236 concentrations. The neutron and gamma photon flux and dose calculations compare favorably with reported experimental values for SNAP-27.

  13. Metal matrix composite fuel for space radioisotope energy sources

    NASA Astrophysics Data System (ADS)

    Williams, H. R.; Ning, H.; Reece, M. J.; Ambrosi, R. M.; Bannister, N. P.; Stephenson, K.

    2013-02-01

    Radioisotope fuels produce heat that can be used for spacecraft thermal control or converted to electricity. They must retain integrity in the event of destruction or atmospheric entry of the parent spacecraft. Addition of a metal matrix to the actinide oxide could yield a more robust fuel form. Neodymium (III) oxide (Nd2O3) - niobium metal matrix composites were produced using Spark Plasma Sintering; Nd2O3 is a non-radioactive surrogate for americium (III) oxide (Am2O3). Two compositions, 70 and 50 wt% Nd2O3, were mechanically tested under equibiaxial (ring-on-ring) flexure according to ASTM C1499. The addition of the niobium matrix increased the mean flexural strength by a factor of about 2 compared to typical ceramic nuclear fuels, and significantly increased the Weibull modulus to over 20. These improved mechanical properties could result in reduced fuel dispersion in severe accidents and improved safety of space radioisotope power systems.

  14. Investigation of Insulation Materials for Future Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Technology Advancement Project is developing next generation high-temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  15. Opportunities for Decay Counting of Environmental Radioisotopes Using Ultra-low-background Detection Systems

    SciTech Connect

    Runkle, Robert C.; Aalseth, Craig E.; Bailey, Vanessa L.; Bonicalzi, Ricco; Moran, James J.; Seifert, Allen; Warren, Glen A.

    2012-08-01

    Executive Summary We present results from a scoping study whose intent was to define challenge measurements to be pursued on the Ultra-Sensitive Nuclear Measurements Initiative. Potential challenge measurements using new radiation detection technology in the shallow underground laboratory that would have substantial impact in environmental science were the focus of this study.

  16. Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela

    SciTech Connect

    Salas, A. Rangel; Viloria, T.; Sajo-Bohus, L.; Barros, H.; Greaves, E. D.; Palacios, D.

    2007-10-26

    Maracaibo Lake is one of the most important water basing and oil producing regions in Venezuela. Changes in the local environment have been monitored for chemical pollution in the past. For this study we selected a set of sediment samples collected in the shore and analyzed for its radioisotope content. Results show the gamma emitting isotopes distribution. Isotopes concentrations have been determined within the natural K, Th and U families.

  17. Isotope Identification in the GammaTracker Handheld Radioisotope Identifier

    SciTech Connect

    Batdorf, Michael T.; Hensley, Walter K.; Seifert, Carolyn E.; Kirihara, Leslie J.; Erikson, Luke E.; Jordan, David V.

    2009-11-13

    GammaTracker is a portable handheld radioisotope identifier using position sensitive CdZnTe crystals. The device uses a peak-based method for isotope identification implemented on an embedded computing platform within the device. This paper presents the run-time optimized algorithms used in this peak-based approach. Performance of the algorithms is presented using measured data from gamma-ray sources.

  18. Plastic Gamma Sensors: An Application in Detection of Radioisotopes

    SciTech Connect

    S. Mukhopadhyay

    2003-06-01

    A brief survey of plastic scintillators for various radiation measurement applications is presented here. The utility of plastic scintillators for practical applications such as gamma radiation monitoring, real-time radioisotope detection and screening is evaluated in laboratory and field measurements. This study also reports results of Monte Carlo-type predictive responses of common plastic scintillators in gamma and neutron radiation fields. Small-size plastic detectors are evaluated for static and dynamic gamma-ray detection sensitivity of selected radiation sources.

  19. Radioisotope powered alkali metal thermoelectric converter design for space systems

    NASA Technical Reports Server (NTRS)

    Sievers, R. K.; Bankston, C. P.

    1988-01-01

    The design concept of an alkali-metal thermoelectric converter (AMTEC) for 15-30-percent-efficient conversion of heat from the General Purpose (radioisotope) Heat Source (GPHS) on spacecraft is presented. The basic physical principles of the conversion cycle are outlined; a theoretical model is derived; a modular design is described and illustrated with drawings; and the overall AMTEC/GPHS system design is characterized. Predicted performance data are presented in extensive tables and graphs and discussed in detail.

  20. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    SciTech Connect

    King, D.A.

    1994-11-10

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan.

  1. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    NASA Astrophysics Data System (ADS)

    King, D. A.

    1994-11-01

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan.

  2. The effects of radioisotopes used in nuclear medicine on diagnostic radioimmunoassay testing. Is there any significant interference

    SciTech Connect

    Riccio, J.A.; Maturani, D.; Wright, J.; Fleetwood, M.K. )

    1990-11-01

    The administration of radioisotopes for diagnostic nuclear medicine scans and therapeutic procedures is quite prevalent today. A period of interference with the counting of a radioimmunoassay (RIA) test may occur with the serum of a patient receiving an in vivo radionuclide that decays by gamma emission. Because the logistics of precounting all specimens may be cumbersome and prohibitive, it is important to determine the degree of this interference. In this study, the authors evaluate the potential interference of the most commonly used radioisotopes with RIA studies. For two months (March and August 1988) 10,650 patient serum specimens were counted for significant background gamma radiation before RIA testing. Forty-three patients, on whom 105 RIA tests were performed, were identified as having preassay gamma radiation in their serum. With the use of selective energy windows for each different interfering radionuclide, proportional determinations were made as to the amount of interfering gamma radiation spilling into the iodine 125 test marker window. It was shown that initial whole serum pretest gamma counts as high as 111,000 counts/minute did not significantly affect the results of the RIA. Because of the meticulous washing and decanting procedures required in modern RIA and the monoclonal nature of most antibodies used currently, it appears the degree of nonspecific binding of this potentially interfering radiation is minuscule. The energy level of cobalt 57, however, and many of the other commonly used radioisotopes, overlaps so closely that it is difficult to window for this interference. It is possible, therefore, that this distinction cannot be made and folate and vitamin B12 test systems using cobalt 57 markers may have to be routinely prescreened.

  3. NASA's Radioisotope Power Systems Planning and Potential Future Systems Overview

    NASA Technical Reports Server (NTRS)

    Zakrajsek, June F.; Woerner, Dave F.; Cairns-Gallimore, Dirk; Johnson, Stephen G.; Qualls, Louis

    2016-01-01

    The goal of NASA's Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet the needs of the missions. To meet this goal, the RPS Program, working closely with the Department of Energy, performs mission and system studies (such as the recently released Nuclear Power Assessment Study), assesses the readiness of promising technologies to infuse in future generators, assesses the sustainment of key RPS capabilities and knowledge, forecasts and tracks the Program's budgetary needs, and disseminates current information about RPS to the community of potential users. This process has been refined and used to determine the current content of the RPS Program's portfolio. This portfolio currently includes an effort to mature advanced thermoelectric technology for possible integration into an enhanced Multi-Mission Radioisotope Generator (eMMRTG), sustainment and production of the currently deployed MMRTG, and technology investments that could lead to a future Stirling Radioisotope Generator (SRG). This paper describes the program planning processes that have been used, the currently available MMRTG, and one of the potential future systems, the eMMRTG.

  4. Radioisotope Electric Propulsion Centaur Orbiter Spacecraft Design Overview

    NASA Technical Reports Server (NTRS)

    Oleson, Steve; McGuire, Melissa; Sarver-Verhey, Tim; Juergens, Jeff; Parkey, Tom; Dankanich, John; Fiehler, Doug; Gyekenyesi, John; Hemminger, Joseph; Gilland, Jim; Colozza, Tony; Packard, Tom; Nguyen, Thahn; Schmitz, Paul; Ostdiek, Paul; Gold, Rob; Lisse, Carey; Hibbits, Karl

    2009-01-01

    Radioisotope electric propulsion (REP) has been shown in past studies to enable missions to outerplanetary bodies including the orbiting of Centaur asteroids. Key to the feasibility for REP missions are long life, low power electric propulsion (EP) devices, low mass radioisotope power systems (RPS) and light spacecraft (S/C) components. In order to determine what are the key parameters for EP devices to perform these REP missions a design study was completed to design an REP S/C to orbit a Centaur in a New Frontiers cost cap. The design shows that an orbiter using several long lived (approximately 200 kg Xenon throughput), low power (approximately 700 W) Hall thrusters teamed with six (150 W each) Advanced Stirling Radioisotope Generators (ASRG) can deliver 60 kg of science instruments to a Centaur in 10 yr within the New Frontiers cost cap. Optimal specific impulses for the Hall thrusters were found to be around 2000 sec with thruster efficiencies over 40%. Not only can the REP S/C enable orbiting a Centaur (when compared to an all chemical mission only capable of flybys) but the additional power from the REP system can be reused to enhance science and simplify communications.

  5. Advanced radioisotope power source options for Pluto Express

    SciTech Connect

    Underwood, M.L.

    1995-12-31

    In the drive to reduce mass and cost, Pluto Express is investigating using an advanced power conversion technology in a small Radioisotope Power Source (RPS) to deliver the required mission power of 74 W(electric) at end of mission. Until this year the baseline power source under consideration has been a Radioisotope Thermoelectric Generator (RTG). This RTG would be a scaled down GPHS RTG with an inventory of 6 General Purpose Heat Sources (GPHS) and a mass of 17.8 kg. High efficiency, advanced technology conversion options are being examined to lower the power source mass and to reduce the amount of radioisotope needed. Three technologies are being considered as the advanced converter technology: the Alkali Metal Thermal-to-Electric Converter (AMTEC), Thermophotovoltaic (TPV) converters, and Stirling Engines. Conceptual designs for each of these options have been prepared. Each converter would require only 2 GPHSs to provide the mission power and would have a mass of 6.1, 7.2, and 12.4 kg for AMTEC, TPV, and Stirling Engines respectively. This paper reviews the status of each technology and the projected performance of an advanced RPS based on each technology. Based on the projected performance and spacecraft integration issues, Pluto Express would prefer to use the AMTEC based RPS. However, in addition to technical performance, selection of a power technology will be based on many other factors.

  6. NASA's Radioisotope Power Systems Planning and Potential Future Systems Overview

    NASA Technical Reports Server (NTRS)

    Zakrajsek, June F.; Woerner, Dave F.; Cairns-Gallimore, Dirk; Johnson, Stephen G.; Qualis, Louis

    2016-01-01

    The goal of NASA's Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet the needs of the missions. To meet this goal, the RPS Program, working closely with the Department of Energy, performs mission and system studies (such as the recently released Nuclear Power Assessment Study), assesses the readiness of promising technologies to infuse in future generators, assesses the sustainment of key RPS capabilities and knowledge, forecasts and tracks the Programs budgetary needs, and disseminates current information about RPS to the community of potential users. This process has been refined and used to determine the current content of the RPS Programs portfolio. This portfolio currently includes an effort to mature advanced thermoelectric technology for possible integration into an enhanced Multi-Mission Radioisotope Generator (eMMRTG), sustainment and production of the currently deployed MMRTG, and technology investments that could lead to a future Stirling Radioisotope Generator (SRG). This paper describes the program planning processes that have been used, the currently available MMRTG, and one of the potential future systems, the eMMRTG.

  7. Stimulus sensitive gel with radioisotope and methods of making

    DOEpatents

    Weller, Richard E [Selah, WA; Lind, Michael A [Kent, WA; Fisher, Darrell R [Richland, WA; Gutowska, Anna [Richland, WA; Campbell, Allison A [Kennewick, WA

    2001-10-02

    The present invention is a thermally reversible stimulus-sensitive gel or gelling copolymer radioisotope carrier that is a linear random copolymer of an [meth]acrylamide derivative and a hydrophilic comonomer, wherein the linear random copolymer is in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff. Addition of a biodegradable backbone and/or a therapeutic agent imparts further utility. The method of the present invention for making a thermally reversible stimulus-sensitive gelling copolymer radionuclcide carrier has the steps of: (a) mixing a stimulus-sensitive reversible gelling copolymer with an aqueous solvent as a stimulus-sensitive reversible gelling solution; and (b) mixing a radioisotope with said stimulus-sensitive reversible gelling solution as said radioisotope carrier. The gel is enhanced by either combining it with a biodegradable backbone and/or a therapeutic agent in a gelling solution made by mixing the copolymer with an aqueous solvent.

  8. Stimulus sensitive gel with radioisotope and methods of making

    DOEpatents

    Weller, Richard E.; Lind, Michael A.; Fisher, Darrell R.; Gutowska, Anna; Campbell, Allison A.

    2005-03-22

    The present invention is a thermally reversible stimulus-sensitive gel or gelling copolymer radioisotope carrier that is a linear random copolymer of an [meth-]acrylamide derivative and a hydrophilic comonomer, wherein the linear random copolymer is in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff. Addition of a biodegradable backbone and/or a therapeutic agent imparts further utility. The method of the present invention for making a thermally reversible stimulus-sensitive gelling copolymer radionuclcide carrier has the steps of: (a) mixing a stimulus-sensitive reversible gelling copolymer with an aqueous solvent as a stimulus-sensitive reversible gelling solution; and (b) mixing a radioisotope with said stimulus-sensitive reversible gelling solution as said radioisotope carrier. The gel is enhanced by either combining it with a biodegradable backbone and/or a therapeutic agent in a gelling solution made by mixing the copolymer with an aqueous solvent.

  9. Generation of Radioisotopes with Accelerator Neutrons by Deuterons

    NASA Astrophysics Data System (ADS)

    Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Sato, Nozomi; Kawabata, Masako; Harada, Hideo; Kin, Tadahiro; Tsukada, Kazuaki; Sato, Tetsuya K.; Minato, Futoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Seki, Yohji; Yokoyama, Kenji; Shiina, Takehiko; Ohta, Akio; Takeuchi, Nobuhiro; Kawauchi, Yukimasa; Sato, Norihito; Yamabayashi, Hisamichi; Adachi, Yoshitsugu; Kikuchi, Yuji; Mitsumoto, Toshinori; Igarashi, Takashi

    2013-06-01

    A new system proposed for the generation of radioisotopes with accelerator neutrons by deuterons (GRAND) is described by mainly discussing the production of 99Mo used for nuclear medicine diagnosis. A prototype facility of this system consists of a cyclotron to produce intense accelerator neutrons from the \\text{natC(d,n) reaction with 40 MeV 2 mA deuteron beams, and a sublimation system to separate \\text{99mTc from an irradiated 100MoO3 sample. About 8.1 TBq/week of 99Mo is produced by repeating irradiation on an enriched 100Mo sample (251 g) with accelerator neutrons for two days three times. It meets about 10% of the 99Mo demand in Japan. The characteristic feature of the system lies in its capability to reliably produce a wide variety of high-quality, carrier-free, carrier-added radioisotopes with a minimum level of radioactive waste without using uranium. The system is compact in size, and easy to operate; therefore it could be used worldwide to produce radioisotopes for medical, research, and industrial applications.

  10. Radioisotopic Tie Points of the Quaternary Geomagnetic Instability Time Scale (GITS): How Accurate and Precise?

    NASA Astrophysics Data System (ADS)

    Singer, B. S.

    2014-12-01

    Reversals and excursions of the geomagnetic field are recorded globally by sedimentary and volcanic rocks. These geodynamo instabilities provide a rich set of chronostratigraphic tie points for the Quaternary period that can provide tests of age models central to paleoclimate studies. Radioisotopic dating of volcanic rocks, mainly 40Ar/39Ar dating of lava flows, coupled with astronomically-dated deep sea sediments, reveals 10 polarity reversals and 27 field excursions during the Quaternary (Singer, 2014). A key question concerns the uncertainties associated with radioisotopic dates of those geodynamo instabilities that have been identified both in terrestrial volcanic rocks and in deep sea sediments. These particular features offer the highest confidence in linking 40Ar/39Ar dates to the global marine climate record. Geological issues aside, for rocks in which the build-up of 40Ar by decay of 40K may be overwhelmed by atmospheric 40Ar at the time of eruption, the uncertainty in 40Ar/39Ar dates derives from three sources: (1) analytical uncertainty associated with measurement of the isotopes; this is straightforward to estimate; (2) systematic uncertainties stemming from the age of standard minerals, such as the Fish Canyon sanidine, and in the 40K decay constant; and (3) systematic uncertainty introduced during analysis, mainly the size and reproducibility of procedural blanks. Whereas 1 and 2 control the precision of an age determination, 2 and 3 also control accuracy. In parallel with an astronomical calibration of 28.201 Ma for the Fish Canyon sanidine standard, awareness of the importance of procedural blanks, and a new generation multi-collector mass spectrometer capable of exceptionally low-blank and isobar-free analysis, are improving both accuracy and precision of 40Ar/39Ar dates. Results from lavas recording the Matuyama-Brunhes reversal, the Santa Rosa excursion, and the reversal at the top of the Cobb Mtn subchron demonstrate these advances. Current best

  11. General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

    1996-07-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  12. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  13. Stirling Convertor for the Stirling Radioisotope Generator Tested as a Prelude to Transition to Flight

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2004-01-01

    The Stirling Radioisotope Generator (SRG) is currently being developed by Lockheed Martin Astronautics (Valley Forge, PA) under contract to the Department of Energy (Germantown, MD). In support of this project, the NASA Glenn Research Center has established a near-term technology effort to provide some of the critical data to ensure a successful transition to flight for what will be the first dynamic power system to be used in space. The generator will be a high-efficiency electric power source for potential use on NASA space science missions. The generator will be able to operate in the vacuum of deep space or in an atmosphere such as on the surface of Mars. High system efficiency is obtained through the use of free-piston Stirling power-conversion technology. The power output of the generator will be greater than 100 W at the beginning of life, with the slow decline in power being largely due to decay of the plutonium heat source. Previously, Glenn's supporting technology efforts focused only on the most critical technical issues.

  14. Phosphorus-32 in the Phage Group: radioisotopes as historical tracers of molecular biology.

    PubMed

    Creager, Angela N H

    2009-03-01

    The recent historiography of molecular biology features key technologies, instruments and materials, which offer a different view of the field and its turning points than preceding intellectual and institutional histories. Radioisotopes, in this vein, became essential tools in postwar life science research, including molecular biology, and are here analyzed through their use in experiments on bacteriophage. Isotopes were especially well suited for studying the dynamics of chemical transformation over time, through metabolic pathways or life cycles. Scientists labeled phage with phosphorus-32 in order to trace the transfer of genetic material between parent and progeny in virus reproduction. Initial studies of this type did not resolve the mechanism of generational transfer but unexpectedly gave rise to a new style of molecular radiobiology based on the inactivation of phage by the radioactive decay of incorporated phosphorus-32. These 'suicide experiments', a preoccupation of phage researchers in the mid-1950s, reveal how molecular biologists interacted with the traditions and practices of radiation geneticists as well as those of biochemists as they were seeking to demarcate a new field. The routine use of radiolabels to visualize nucleic acids emerged as an enduring feature of molecular biological experimentation.

  15. Phosphorus-32 in the Phage Group: radioisotopes as historical tracers of molecular biology

    PubMed Central

    Creager, Angela N.H.

    2009-01-01

    The recent historiography of molecular biology features key technologies, instruments and materials, which offer a different view of the field and its turning points than preceding intellectual and institutional histories. Radioisotopes, in this vein, became essential tools in postwar life science research, including molecular biology, and are here analyzed through their use in experiments on bacteriophage. Isotopes were especially well suited for studying the dynamics of chemical transformation over time, through metabolic pathways or life cycles. Scientists labeled phage with phosphorus-32 in order to trace the transfer of genetic material between parent and progeny in virus reproduction. Initial studies of this type did not resolve the mechanism of generational transfer but unexpectedly gave rise to a new style of molecular radiobiology based on the inactivation of phage by the radioactive decay of incorporated phosphorus-32. These ‘suicide experiments’, a preoccupation of phage researchers in the mid-1950s, reveal how molecular biologists interacted with the traditions and practices of radiation geneticists as well as those of biochemists as they were seeking to demarcate a new field. The routine use of radiolabels to visualize nucleic acids emerged as an enduring feature of molecular biological experimentation. PMID:19268872

  16. Development of Advanced Stirling Radioisotope Generator for Space Exploration

    NASA Technical Reports Server (NTRS)

    Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

    2007-01-01

    Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 to 7 We/kg, along with a 25 percent reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

  17. Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred

    1993-10-01

    The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 5 copies in the file.

  18. Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred

    2012-01-19

    The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 2 copies in the file.

  19. Joint Radioisotope Electric Propulsion Studies - Neptune System Explorer

    NASA Technical Reports Server (NTRS)

    Khan, M. Omair; Amini, Rashied; Ervin, Joan; Lang, Jared; Landau, Damon; Oleson, Steven; Spilker, Thomas; Strange, Nathan

    2011-01-01

    The Neptune System Explorer (NSE) mission concept study assessed opportunities to conduct Cassini-like science at Neptune with a radioisotope electric propulsion (REP) based spacecraft. REP is based on powering an electric propulsion (EP) engine with a radioisotope power source (RPS). The NSE study was commissioned under the Joint Radioisotope Electric Propulsion Studies (JREPS) project, which sought to determine the technical feasibility of flagship class REP applications. Within JREPS, special emphasis was given toward identifying tall technology tent poles, as well as recommending any new RPS technology developments that would be required for complicated REP missions. Based on the goals of JREPS, multiple RPS (e.g. thermoelectric and Stirling based RPS) and EP (e.g. Hall and ion engines) technology combinations were traded during the NSE study to determine the most favorable REP design architecture. Among the findings from the study was the need for >400We RPS systems, which was driven by EP operating powers and the requirement for a long-lived mission in the deep solar system. Additionally multiple development and implementation risks were identified for the NSE concept, as well as REP missions in general. Among the strengths of the NSE mission would be the benefits associated with RPS and EP use, such as long-term power (approx. 2-3kW) at Neptune and flexible trajectory options for achieving orbit or tours of the Neptune system. Although there are still multiple issues to mitigate, the NSE concept demonstrated distinct advantages associated with using REP for deep space flagship-class missions.

  20. Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management

    NASA Technical Reports Server (NTRS)

    Pantano, David R.; Dottore, Frank; Geng, Steven M.; Schrieber, Jeffrey G.; Tobery, E. Wayne; Palko, Joseph L.

    2005-01-01

    One of the advantages of using a Radioisotope Power System (RPS) for deep space or planetary surface missions is the readily available waste heat, which can be used to maintain electronic components within a controlled temperature range, to warm propulsion tanks and mobility actuators, and to gasify liquid propellants. Previous missions using Radioisotope Thermoelectric Generators (RTGs) dissipated a very large quantity of waste heat due to the relatively low efficiency of the thermoelectric conversion technology. The next generation RPSs, such as the 110-watt Stirling Radioisotope Generator (SRG110) will have much higher conversion efficiencies than their predecessors and therefore may require alternate approaches to transferring waste heat to the spacecraft. RTGs, with efficiencies of approx. 6 to 7% and 200 C housing surface temperatures, would need to use large and heavy radiator heat exchangers to transfer the waste heat to the internal spacecraft components. At the same time, sensitive spacecraft instruments must be shielded from the thermal radiation by using the heat exchangers or additional shields. The SRG110, with an efficiency around 22% and 50 C nominal housing surface temperature, can use the available waste heat more efficiently by more direct heat transfer methods such as heat pipes, thermal straps, or fluid loops. The lower temperatures allow the SRG110 much more flexibility to the spacecraft designers in configuring the generator without concern of overheating nearby scientific instruments, thereby eliminating the need for thermal shields. This paper will investigate using a high efficiency SRG110 for spacecraft thermal management and outline potential methods in several conceptual missions (Lunar Rover, Mars Rover, and Titan Lander) to illustrate the advantages with regard to ease of assembly, less complex interfaces, and overall mass savings.

  1. Milliwatt radioisotope power supply for the PASCAL Mars surface stations

    NASA Astrophysics Data System (ADS)

    Allen, Daniel T.; Murbach, Marcus S.

    2001-02-01

    A milliwatt power supply is being developed based on the 1 watt Light-Weight Radioisotope Heater Unit (RHU), which has already been used to provide heating alone on numerous spacecraft. In the past year the power supply has been integrated into the design of the proposed PASCAL Mars Network Mission, which is intended to place 24 surface climate monitoring stations on Mars. The PASCAL Mars mission calls for the individual surface stations to be transported together in one spacecraft on a trajectory direct from launch to orbit around Mars. From orbit around Mars each surface station will be deployed on a SCRAMP (slotted compression ramp) probe and, after aerodynamic and parachute deceleration, land at a preselected location on the planet. During descent sounding data and still images will be accumulated, and, once on the surface, the station will take measurements of pressure, temperature and overhead atmospheric optical depth for a period of 10 Mars years (18.8 Earth years). Power for periodic data acquisition and transmission to orbital then to Earth relay will come from a bank of ultracapacitors which will be continuously recharged by the radioisotope power supply. This electronic system has been designed and a breadboard built. In the ultimate design the electronics will be arrayed on the exterior surface of the radioisotope power supply in order to take advantage of the reject heat. This assembly in turn is packaged within the SCRAMP, and that assembly comprises the surface station. An electrically heated but otherwise prototypical power supply was operated in combination with the surface station breadboard system, which included the ultracapacitors. Other issues addressed in this work have been the capability of the generator to withstand the mechanical shock of the landing on Mars and the effectiveness of the generator's multi-foil vacuum thermal insulation. .

  2. Analytical predictions of RTG power degradation. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Noon, E. L.; Raag, V.

    1979-01-01

    The DEGRA computer code that is based on a mathematical model which predicts performance and time-temperature dependent degradation of a radioisotope thermoelectric generator is discussed. The computer code has been used to predict performance and generator degradation for the selenide Ground Demonstration Unit (GDS-1) and the generator used in the Galileo Project. Results of parametric studies of load voltage vs generator output are examined as well as the I-V curve and the resulting predicted power vs voltage. The paper also discusses the increased capability features contained in DEGRA2 and future plans for expanding the computer code performance.

  3. Nuclear reactors for research and radioisotope production in Argentina

    SciTech Connect

    Duran, H.H.

    1981-01-01

    In Argentina, the construction, operation, and use of research and radioisotope production reactors is and has been an important method of personnel preparation for the nuclear power program. Moreover, it is a very suitable means for technology transfer to countries developing their own nuclear programs. At present, the following research reactors are in operation in Argentina: Argentine Reactor 0 (RA-0); Argentine Reactor 1 (RA-1); Argentine Reactor 2 (RA-2); Argentine Reactor 3 (RA-3); Argentine Reactor 4 (RA-4). The Argentine Reactor 6 (RA-6), under construction, should reach criticality in 1981.

  4. ADVANCED RADIOISOTOPE HEAT SOURCE AND PROPULSION SYSTEMS FOR PLANETARY EXPLORATION

    SciTech Connect

    R. C. O'Brien; S. D. Howe; J. E. Werner

    2010-09-01

    The exploration of planetary surfaces and atmospheres may be enhanced by increasing the range and mobility of a science platform. Fundamentally, power production and availability of resources are limiting factors that must be considered for all science and exploration missions. A novel power and propulsion system is considered and discussed with reference to a long-range Mars surface exploration mission with in-situ resource utilization. Significance to applications such as sample return missions is also considered. Key material selections for radioisotope encapsulation techniques are presented.

  5. Energy-Recovery Linacs for Commercial Radioisotope Production

    SciTech Connect

    Johnson, Rolland Paul

    2016-11-19

    Most radioisotopes are produced by nuclear reactors or positive ion accelerators, which are expensive to construct and to operate. Photonuclear reactions using bremsstrahlung photon beams from less-expensive electron linacs can generate isotopes of critical interest, but much of the beam energy in a conventional electron linac is dumped at high energy, making unwanted radioactivation. The largest part of this radioactivation may be completely eliminated by applying energy recovery linac technology to the problem with an additional benefit that the energy cost to produce a given amount of isotope is reduced. Consequently a Superconducting Radio Frequency (SRF) Energy Recovery Linac (ERL) is a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes at a cost lower than that of isotopes produced by reactors or positive-ion accelerators. A Jefferson Lab approach to this problem involves a thin photon production radiator, which allows the electron beam to recirculate through rf cavities so the beam energy can be recovered while the spent electrons are extracted and absorbed at a low enough energy to minimize unwanted radioactivation. The thicker isotope photoproduction target is not in the beam. MuPlus, with Jefferson Lab and Niowave, proposed to extend this ERL technology to the commercial world of radioisotope production. In Phase I we demonstrated that 1) the ERL advantage for producing radioisotopes is at high energies (~100 MeV), 2) the range of acceptable radiator thickness is narrow (too thin and there is no advantage relative to other methods and too thick means energy recovery is too difficult), 3) using optics techniques developed under an earlier STTR for collider low beta designs greatly improves the fraction of beam energy that can be recovered (patent pending), 4) many potentially useful radioisotopes can be made with this ERL technique that have never before been available in significant commercial quantities

  6. The use of radioisotopes for palliation of metastatic bone pain.

    PubMed

    Gkialas, I; Iordanidou, L; Galanakis, I; Giannopoulos, S

    2008-01-01

    Bone pain associated with advanced prostate and other cancers is a frequent and significant complication. Pharmaceutical therapy of bone pain includes nonsteroidal analgesics and opiates. While external beam radiation therapy remains the mainstay of pain palliation of solitary lesions, bone-seeking radiopharmaceuticals have entered the armamentarium for the treatment of multiple osseous metastases. The 3 radioisotopes currently approved for treatment of pain (strontium-89/(89)Sr, samarium-153/(153)Sm and rhenium-186/(186)Re) are discussed in this review including the approved dose, method of administration and indications for use.

  7. Parametric System Model for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.

    2014-01-01

    A Parametric System Model (PSM) was created in order to explore conceptual designs, the impact of component changes and power level on the performance of Stirling Radioisotope Generator (SRG). Using the General Purpose Heat Source (GPHS approximately 250 watt thermal) modules as the thermal building block around which a SRG is conceptualized, trade studies are performed to understand the importance of individual component scaling on isotope usage. Mathematical relationships based on heat and power throughput, temperature, mass and volume were developed for each of the required subsystems. The PSM uses these relationships to perform component and system level trades.

  8. Parametric System Model for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.

    2015-01-01

    A Parametric System Model (PSM) was created in order to explore conceptual designs, the impact of component changes and power level on the performance of the Stirling Radioisotope Generator (SRG). Using the General Purpose Heat Source (GPHS approximately 250 Wth) modules as the thermal building block from which a SRG is conceptualized, trade studies are performed to understand the importance of individual component scaling on isotope usage. Mathematical relationships based on heat and power throughput, temperature, mass, and volume were developed for each of the required subsystems. The PSM uses these relationships to perform component- and system-level trades.

  9. High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Walker, Kara L.; Anderson, William G.

    2009-01-01

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling convertor provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling convertor. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 C while the heat losses caused by the addition of the VCHP are 1.8 W.

  10. Strontium iodide instrument development for gamma spectroscopy and radioisotope identification

    NASA Astrophysics Data System (ADS)

    Beck, P. R.; Cherepy, N. J.; Payne, S. A.; Swanberg, E. L.; Nelson, K. E.; Thelin, P. A.; Fisher, S. E.; Hunter, S.; Wihl, B. M.; Shah, K. S.; Hawrami, R.; Burger, A.; Boatner, L. A.; Momayezi, M.; Stevens, K. T.; Randles, M. H.; Solodovnikov, D.

    2014-09-01

    Development of the Europium-doped Strontium Iodide scintillator, SrI2(Eu2+), has progressed significantly in recent years. SrI2(Eu2+) has excellent material properties for gamma ray spectroscopy: high light yield (<80,000 ph/MeV), excellent light yield proportionality, and high effective atomic number (Z = 49) for high photoelectric cross-section. High quality 1.5" and 2" diameter boules are now available due to rapid advances in SrI2(Eu) crystal growth. In these large SrI2(Eu) crystals, optical self-absorption by Eu2+ degrades the energy resolution as measured by analog electronics, but we mitigate this effect through on-the-fly correction of the scintillation pulses by digital readout electronics. Using this digital correction technique we have demonstrated energy resolution of 2.9% FWHM at 662 keV for a 4 in3 SrI2(Eu) crystal, over 2.6 inches long. Based on this digital readout technology, we have developed a detector prototype with greatly improved radioisotope identification capability compared to Sodium Iodide, NaI(Tl). The higher resolution of SrI2(Eu) yields a factor of 2 to 5 improvement in radioisotope identification (RIID) error rate compared to NaI(Tl).

  11. Characterization of the Advanced Stirling Radioisotope Generator Engineering Unit 2

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Niholas A.

    2016-01-01

    Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG) 140-W radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA Glenn Research Center recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's Advanced Stirling Convertor E3 (ASC-E3) Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth-generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included measurement of convertor, controller, and generator performance and efficiency; quantification of control authority of the controller; disturbance force measurement with varying piston phase and piston amplitude; and measurement of the effect of spacecraft direct current (DC) bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

  12. Strontium Iodide Instrument Development for Gamma Spectroscopy and Radioisotope Identification

    SciTech Connect

    Beck, P; Cherepy, Nerine; Payne, Stephen A.; Swanberg, E.; Nelson, K.; Thelin, P; Fisher, S E; Hunter, Steve; Wihl, B; Shah, Kanai; Hawrami, Rastgo; Burger, Arnold; Boatner, Lynn A; Momayezi, M; Stevens, K; Randles, M H; Solodovnikov, D

    2014-01-01

    Development of the Europium-doped Strontium Iodide scintillator, SrI2(Eu), has progressed significantly in recent years. SrI2(Eu) has excellent material properties for gamma ray spectroscopy: high light yield (>80,000 ph/MeV), excellent light yield proportionality, and high effective atomic number (Z=49) for high photoelectric cross-section. High quality 1.5 and 2 diameter boules are now available due to rapid advances in SrI2(Eu) crystal growth. In these large SrI2(Eu) crystals, optical self-absorption by Eu2+ degrades the energy resolution as measured by analog electronics, but we mitigate this effect through on-the-fly correction of the scintillation pulses by digital readout electronics. Using this digital correction technique we have demonstrated energy resolution of 2.9% FWHM at 662 keV for a 4 in3 SrI2(Eu) crystal, over 2.6 inches long. Based on this digital readout technology, we have developed a detector prototype with greatly improved radioisotope identification capability compared to Sodium Iodide, NaI(Tl). The higher resolution of SrI2(Eu) yields a factor of 2 to 5 improvement in radioisotope identification (RIID) error rate compared to NaI(Tl).

  13. Sodium Variable Conductance Heat Pipe for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Anderson, William G.; Walker, Kara

    2009-01-01

    In a Stirling radioisotope system, heat must continually be removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. Normally, the Stirling convertor provides this cooling. If the converter stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, and also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) has been designed to allow multiple stops and restarts of the Stirling convertor in an Advanced Stirling Radioisotope Generator (ASRG). When the Stirling convertor is turned off, the VCHP will activate when the temperatures rises 30 C above the setpoint temperature. A prototype VCHP with sodium as the working fluid was fabricated and tested in both gravity aided and against gravity conditions for a nominal heater head temperature of 790 C. The results show very good agreement with the predictions and validate the model. The gas front was located at the exit of the reservoir when heater head temperature was 790 C while cooling was ON, simulating an operating Advanced Stirling Converter (ASC). When cooling stopped, the temperature increased by 30 C, allowing the gas front to move past the radiator, which transferred the heat to the case. After resuming the cooling flow, the front returned at the initial location turning OFF the VCHP. The against gravity working conditions showed a colder reservoir and faster transients.

  14. Radioisotope Electric Propulsion for Deep Space Sample Return

    SciTech Connect

    Noble, Robert J.; /SLAC

    2009-07-14

    The need to answer basic questions regarding the origin of the Solar System will motivate robotic sample return missions to destinations like Pluto, its satellite Charon, and objects in the Kuiper belt. To keep the mission duration short enough to be of interest, sample return from objects farther out in the Solar System requires increasingly higher return velocities. A sample return mission involves several complicated steps to reach an object and obtain a sample, but only the interplanetary return phase of the mission is addressed in this paper. Radioisotope electric propulsion is explored in this parametric study as a means to propel small, dedicated return vehicles for transferring kilogram-size samples from deep space to Earth. Return times for both Earth orbital rendezvous and faster, direct atmospheric re-entry trajectories are calculated for objects as far away as 100 AU. Chemical retro-rocket braking at Earth is compared to radioisotope electric propulsion but the limited deceleration capability of chemical rockets forces the return trajectories to be much slower.

  15. Technology Development for a Stirling Radioisotope Power System

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.; Qiu, Songgang; White, Maurice A.

    2000-01-01

    NASA Glenn Research Center and the Department of Energy are developing a Stirling convertor for an advanced radioisotope power system to provide spacecraft on-board electric power for NASA deep space missions. NASA Glenn is addressing key technology issues through the use of two NASA Phase II SBIRs with Stirling Technology Company (STC) of Kennewick, WA. Under the first SBIR, STC demonstrated a synchronous connection of two thermodynamically independent free-piston Stirling convertors and a 40 to 50 fold reduction in vibrations compared to an unbalanced convertor. The second SBIR is for the development of an Adaptive Vibration Reduction System (AVRS) that will essentially eliminate vibrations over the mission lifetime, even in the unlikely event of a failed convertor. This paper presents the status and results for these two SBIR projects and also discusses a new NASA Glenn in-house project to provide supporting technology for the overall Stirling radioisotope power system development. Tasks for this new effort include convertor performance verification, controls development, heater head structural life assessment, magnet characterization and thermal aging tests, FEA analysis for a lightweight alternator concept, and demonstration of convertor operation under launch and orbit transfer load conditions.

  16. Industrial radiation and radioisotope gauging techniques and applications

    SciTech Connect

    Gardner, R.P.

    1997-12-01

    The radiation and radioisotope gauging industry in the United States has primarily followed a path of development solely by the private sector. It has remained highly proprietary in nature, which is opposite to the path taken by many other countries. In other countries radiation gauge development has been controlled in large part by government-sponsored research and development, which has spawned many more publications in the open literature. Historically, some of the leaders have been Great Britain, Poland, France, Russia, and Australia. This has possibly led to the misconception that the development of this technology is being dominated by countries outside the United States. This is not a healthy situation-it would be good to see our industry begin to publish more in the open literature and to sponsor more research at universities. In efforts to promote more open-literature publication, the American Nuclear Society (ANS) sponsored a topical meeting on Industrial Radiation and Radioisotope Measurement Applications (IRRMA) in 1988 that was held again in 1992.

  17. Multi-Watt Small Radioisotope Thermoelectric Generator Conceptual Design Study

    NASA Astrophysics Data System (ADS)

    Determan, William R.; Otting, William; Frye, Patrick; Abelson, Robert; Ewell, Richard; Miyake, Bob; Synder, Jeff

    2007-01-01

    A need has been identified for a small, light-weight, reliable power source using a radioisotope heat source, to power the next generation of NASA's small surface rovers and exploration probes. Unit performance, development costs, and technical risk are key criteria to be used to select the best design approach. Because safety can be a major program cost and schedule driver, RTG designs should utilize the DOE radioisotope safety program's data base to the maximum extent possible. Other aspects important to the conceptual design include: 1) a multi-mission capable design for atmospheric and vacuum environments, 2) a module size based on one GPHS Step 2 module, 3) use of flight proven thermoelectric converter technologies, 4) a long service lifetime of up to 14 years, 5) maximize unit specific power consistent with all other requirements, and 6) be ready by 2013. Another critical aspect of the design is the thermal integration of the RTG with the rover or probe's heat rejection subsystem and the descent vehicle's heat rejection subsystem. This paper describes two multi-watt RTG design concepts and their integration with a MER-class rover.

  18. GRC Supporting Technology for NASA's Advanced Stirling Radioisotope Generator (ASRG)

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2008-01-01

    From 1999 to 2006, the NASA Glenn Research Center (GRC) supported a NASA project to develop a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions. Lockheed Martin was selected as the System Integration Contractor for the SRG110, under contract to the Department of Energy (DOE). The potential applications included deep space missions, and Mars rovers. The project was redirected in 2006 to make use of the Advanced Stirling Convertor (ASC) that was being developed by Sunpower, Inc. under contract to GRC, which would reduce the mass of the generator and increase the power output. This change would approximately double the specific power and result in the Advanced Stirling Radioisotope Generator (ASRG). The SRG110 supporting technology effort at GRC was replanned to support the integration of the Sunpower convertor and the ASRG. This paper describes the ASRG supporting technology effort at GRC and provides details of the contributions in some of the key areas. The GRC tasks include convertor extended-operation testing in air and in thermal vacuum environments, heater head life assessment, materials studies, permanent magnet characterization and aging tests, structural dynamics testing, electromagnetic interference and electromagnetic compatibility characterization, evaluation of organic materials, reliability studies, and analysis to support controller development.

  19. Utilizing Radioisotope Power Systems for Human Lunar Exploration

    NASA Technical Reports Server (NTRS)

    Schreiner, Timothy M.

    2005-01-01

    The Vision for Space Exploration has a goal of sending crewed missions to the lunar surface as early as 2015 and no later than 2020. The use of nuclear power sources could aid in assisting crews in exploring the surface and performing In-Situ Resource Utilization (ISRU) activities. Radioisotope Power Systems (RPS) provide constant sources of electrical power and thermal energy for space applications. RPSs were carried on six of the crewed Apollo missions to power surface science packages, five of which still remain on the lunar surface. Future RPS designs may be able to play a more active role in supporting a long-term human presence. Due to its lower thermal and radiation output, the planned Stirling Radioisotope Generator (SRG) appears particularly attractive for manned applications. The MCNPX particle transport code has been used to model the current SRG design to assess its use in proximity with astronauts operating on the surface. Concepts of mobility and ISRU infrastructure were modeled using MCNPX to analyze the impact of RPSs on crewed mobility systems. Strategies for lowering the radiation dose were studied to determine methods of shielding the crew from the RPSs.

  20. Characterization of the Advanced Stirling Radioisotope Generator EU2

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Nicholas A.

    2015-01-01

    Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA GRC recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's ASC-E3 Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included: measurement of convertor, controller, and generator performance and efficiency, quantification of control authority of the controller, disturbance force measurement with varying piston phase and piston amplitude, and measurement of the effect of spacecraft DC bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

  1. Future planetary missions potentially requiring Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Mondt, Jack F.; Nesmith, Bill J.

    2000-01-01

    This paper summarizes the potential Radioisotope Power System, (RPS), technology requirements for future missions being planned for NASA's Solar System Exploration (SSE) theme. Many missions to the outer planets (Jupiter and beyond) require completion of the work on advanced radioisotope power systems (ARPS) now underway in NASA's Deep Space Systems Technology Program. The power levels for the ARPS can be divided into four classes. Forty to one hundred milliwatt-class provides both thermal and electric power for small in situ science laboratories on the surface of bodies in the solar system. One to two watt class for surface and aerobot science laboratories. Ten to twenty-watt class for micro satellites in orbit, surface science stations and aerobots. One hundred to two hundred watt class for orbiter science spacecraft, for drilling core samples, for powering subsurface hydrobots and cryobots on accessible bodies and for data handling and communicating data from small orbiters, surface laboratories, aerobots and hydrobots back to Earth. Using the most optimistic solar-based power system instead of advanced RPSs pushes the launch masses of these missions beyond the capability of affordable launch vehicles. Advanced RPS is also favored over solar power for obtaining comet samples on extended-duration missions. .

  2. Semileptonic Decays

    SciTech Connect

    Luth, Vera G.; /SLAC

    2012-10-02

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  3. Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management

    NASA Technical Reports Server (NTRS)

    Pantano, David R.; Dottore, Frank; Tobery, E. Wayne; Geng, Steven M.; Schreiber, Jeffrey G.; Palko, Joseph L.

    2005-01-01

    An advantage of using a Radioisotope Power System (RPS) for deep space or planetary surface missions is the readily available waste heat, which can be used for a number of beneficial purposes including: maintaining electronic components within a controlled temperature range, warming propulsion tanks and mobility actuators, and maintaining liquid propellants above their freezing temperature. Previous missions using Radioisotope Thermoelectric Generators (RTGs) dissipated large quantities of waste heat due to the low efficiency of the thermoelectric conversion technology. The next generation RPSs, such as the 110-Watt Stirling Radioisotope Generator (SRG110) will have higher conversion efficiencies, thereby rejecting less waste heat at a lower temperature and may require alternate approaches to transferring waste heat to the spacecraft. RTGs, with efficiencies of 6 to 7 percent, reject their waste heat at the relatively high heat rejection temperature of 200 C. This is an advantage when rejecting heat to space; however, transferring heat to the internal spacecraft components requires a large and heavy radiator heat exchanger. At the same time, sensitive spacecraft instruments must be shielded from the thermal radiation of the RTG. The SRG110, with an efficiency around 22 percent and 50 C nominal housing surface temperature, can readily transfer the available waste heat directly via heat pipes, thermal straps, or fluid loops. The lower temperatures associated with the SRG110 avoid the chances of overheating other scientific components, eliminating the need for thermal shields. This provides the spacecraft designers more flexibility when locating the generator for a specific mission. A common misconception with high-efficiency systems is that there is not enough waste heat for spacecraft thermal management. This paper will dispel this misconception and investigate the use of a high-efficiency SRG110 for spacecraft thermal management and outline potential methods of

  4. Stirling Convertor Technologies Being Developed for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.

    2003-01-01

    The Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and the NASA Glenn Research Center are developing a high-efficiency Stirling Radioisotope Generator (SRG) for NASA space science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. On Mars, rovers with SRGs would be used for missions that might not be able to use photovoltaic power systems, such as exploration at high Martian latitudes and missions of long duration. The projected SRG system efficiency of 23 percent will reduce the required amount of radioisotope by a factor of 4 or more in comparison to currently used Radioisotope Thermoelectric Generators. The Department of Energy recently named Lockheed Martin as the system integration contractor. Lockheed Martin has begun to develop the SRG engineering unit under contract to the Department of Energy, and has contract options to develop the qualification unit and the first flight units. The developers expect the SRG to produce about 114 Wdc at the beginning of mission, using two opposed Stirling convertors and two General Purpose Heat Source modules. STC previously developed the Stirling convertor under contract to the Department of Energy and is now providing further development as a subcontractor to Lockheed Martin. Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. A key milestone was recently reached with the accumulation of 12 000 hr of long-term aging on two types of neodymium-iron boron permanent magnets. These tests are characterizing any possible aging in the strength or demagnetization resistance of the magnets used in the linear alternator. Preparations are underway for a thermal/vacuum system demonstration and unattended operation during endurance testing of the 55-We Technology Demonstration Convertors. In addition, Glenn is developing a

  5. Space radioisotope power source requirements update and technology status

    SciTech Connect

    Mondt, J.F.

    1998-07-01

    The requirements for a space advanced radioisotope power source are based on potential deep space missions being investigated for the NASA Advanced Space Systems Development Program. Since deep space missions have not been approved, updating requirements is a continuos parallel process of designing the spacecraft and the science instruments to accomplish the potential missions and developing the power source technology to meet changing requirements. There are at least two potential missions, Pluto/Kuiper Express and Europa Orbiter, which may require space advanced radioisotope power sources. The Europa Orbiter has been selected as the preferred first potential mission. However the final decision will depend on the technology readiness of all the subsystems and the project must be able to switch to Pluto Kuiper Express as the first mission as late as the beginning of fiscal year 2000. Therefore the requirements for the power source will cover both potential missions. As the deep space spacecraft design evolves to meet the science requirements and the Alkali Metal Thermal to Electric (AMTEC) technology matures the advanced radioisotope power source design requirements are updated The AMTEC technology developed to date uses stainless steel for the sodium containment material. The higher efficiency required for the space power system dictates that the AMTEC technology must operate at a higher temperature than possible with stainless steel. Therefore refractory materials have been selected as the baseline material for the AMTEC cell. These refractory materials are Nb1Zr for the hot side and Nb1Zr or Nb10Hf1Ti for the cold side. These materials were selected so the AMTEC cell can operate at 1150K to 1350K hot side temperature and 600K to 700K cold side temperature and meet the present power and mass requirements using four to six general purpose heat source modules as the heat source. The new containment materials and brazes will be evaluated as to lifetime

  6. AMTEC radioisotope power system for the Pluto Express mission

    SciTech Connect

    Ivanenok, J.F. III; Sievers, R.K.

    1995-12-31

    The Alkali Metal Thermal to Electric Converter (AMTEC) technology has made substantial advances in the last 3 years through design improvements and technical innovations. In 1993 programs began to produce an AMTEC cell specifically for the NASA Pluto Express Mission. A set of efficiency goals was established for this series of cells to be developed. According to this plan, cell {number_sign}8 would be 17% efficient but was actually 18% efficient. Achieving this goal, as well as design advances that allow the cell to be compact, has resulted in pushing the cell from an unexciting 2 W/kg and 2% efficiency to very attractive 40 W/kg and 18% measured efficiency. This paper will describe the design and predict the performance of a radioisotope powered AMTEC system for the Pluto Express mission.

  7. .sup.82 Sr-.sup.82 Rb Radioisotope generator

    DOEpatents

    Grant, Patrick M.; Erdal, Bruce R.; O'Brien, Harold A.

    1976-01-01

    An improved .sup.82 Sr-.sup.82 Rb radioisotope generator system, based upon the complexing ion exchange resin Chelex-100, has been developed. Columns of this material can be easily and rapidly milked, and the Rb-Sr separation factor for a fresh generator was found to be > 10.sup.7. Approximately 80 percent of the .sup.82 Rb present was delivered in a 15-ml volume of aqueous 0.2 M NH.sub.4 Cl solution. After more than 6 liters of eluant had been put through the generator, the Rb-Sr separation factor was still observed to be > 10.sup.5, and no unusual strontium breakthrough behavior was seen in the system over nearly three .sup.82 Sr half lives.

  8. Development and Buildup of a Stirling Radioisotope Generator Electrical Simulator

    NASA Technical Reports Server (NTRS)

    Prokop, Norman F.; Krasowski, Michael J.; Greer, Lawrence C.; Flatico, Joseph M.; Spina, Dan C.

    2008-01-01

    This paper describes the development of a Stirling Radioisotope Generator (SRG) Simulator for use in a prototype lunar robotic rover. The SRG developed at NASA Glenn Research Center (GRC) is a promising power source for the robotic exploration of the sunless areas of the moon. The simulator designed provides a power output similar to the SRG output of 5.7 A at 28 Vdc, while using ac wall power as the input power source. The designed electrical simulator provides rover developers the physical and electrical constraints of the SRG supporting parallel development of the SRG and rover. Parallel development allows the rover design team to embrace the SRG s unique constraints while development of the SRG is continued to a flight qualified version.

  9. Analysis of a case of internal contamination with cobalt radioisotopes.

    PubMed

    Vrba, T; Malatova, I; Jurochova, B

    2007-01-01

    Internal contamination by compounds of cobalt radioisotopes occurs time to time at nuclear power plants. Intakes and committed effective doses are estimated by biokinetic models described in ICRP publications. The paper deals with a case of internal contamination of a worker engaged in a maintenance task at NPP Dukovany. In this case significant discrepancy was observed between intakes based on various datasets (whole body counting, analysis of urine and faeces) when default model setting was used. The reason of this phenomenon was searched for. Three different least square methods of fits were used to find out possible effect of a fitting method. The measured data were fitted by set of biokinetic functions, which covered all intake ways (ingestion and inhalation) and types (M, S, different AMADs and different f1) of the contaminant. The biokinetic model of cobalt needs further improvements as to find better agreement between data fit from direct measurements and bioassay.

  10. Testing to Characterize the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward; Schreiber, Jeffrey

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. Lockheed Martin designed and fabricated an engineering unit (EU), the ASRG EU, under contract to the Department of Energy. This unit is currently undergoing extended operation testing at the NASA Glenn Research Center to generate performance data and validate life and reliability predictions for the generator and the Stirling convertors. It has also undergone performance tests to characterize generator operation while varying control parameters and system inputs. This paper summarizes and explains test results in the context of designing operating strategies for the generator during a space mission and notes expected differences between the EU performance and future generators.

  11. Reliability Demonstration Approach for Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Ha, CHuong; Zampino, Edward; Penswick, Barry; Spronz, Michael

    2010-01-01

    Developed for future space missions as a high-efficiency power system, the Advanced Stirling Radioisotope Generator (ASRG) has a design life requirement of 14 yr in space following a potential storage of 3 yr after fueling. In general, the demonstration of long-life dynamic systems remains difficult in part due to the perception that the wearout of moving parts cannot be minimized, and associated failures are unpredictable. This paper shows a combination of systematic analytical methods, extensive experience gained from technology development, and well-planned tests can be used to ensure a high level reliability of ASRG. With this approach, all potential risks from each life phase of the system are evaluated and the mitigation adequately addressed. This paper also provides a summary of important test results obtained to date for ASRG and the planned effort for system-level extended operation.

  12. Constraining Water Fluxes Through the Streambed of a Semi-arid Losing Stream Using Natural Tracers: Heat and Radioisotopes

    NASA Astrophysics Data System (ADS)

    Andersen, M. S.; Rau, G. C.; McCallum, A. M.; Meredith, K.; Acworth, I.

    2011-12-01

    Natural physical and chemical tracers of flow have different advantages and shortfalls based on their properties and the uncertainty related to variability in their source concentration. Each tracer integrates over a characteristic spatial-temporal scale depending on its decay or production rate and the flow velocity of the system. For instance heat tracing using diurnal temperature fluctuations will, at best, provide information about flow in the upper 1-2 m of the streambed before the signal is dampened below measurement resolution (Constantz et al. 2003). Conversely, radioisotopes used as tracers will integrate over increasing spatio-temporal scales for decreasing decay constants. Radioisotopes with comparatively slow decay rates will be less sensitive for resolving flow conditions on short spatio-temporal scales. Therefore, it is difficult to use these tracers in the streambed of losing systems because the radioactive decay is not discernible against the variability. Consequently, employing a combination of different tracers provides information on different parts of a given flow system. Comparing flow velocities derived from tracers integrating over different scales allows for separating the local hyporheic exchange from the regional groundwater recharge. A field experiment was carried out in a perennial section of the mostly ephemeral Maules Creek in NSW, Australia. Streambed temperature profiles were monitored at three sites along a 400 m stretch of the perennial reach. Streambed temperatures were recorded at 4 depths within one meter below the streambed. Water samples were collected from surface water, streambed and groundwater and analysed for stable water isotopes (18O and 2H) and radioisotopes (222Rn and 3H). The streambed heat profiles provided time series of surface water/groundwater exchange. Using this method it was found that the conditions were losing at all three sites with recharge rates varying between 0 and 0.4 m/d. 222Rn measurements in the

  13. High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    SciTech Connect

    Tarau, Calin; Walker, Kara L.; Anderson, William G.

    2009-03-16

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

  14. INTRACORPOREAL HEAT DISSIPATION FROM A RADIOISOTOPE-POWERED ARTIFICIAL HEART

    PubMed Central

    Huffman, Fred N.; Hagen, Kenneth G.; Whalen, Robert L.; Fuqua, John M.; Norman, John C.

    1974-01-01

    The feasibility of radioisotope-fueled circulatory support systems depends on the ability of the body to dissipate the reject heat from the power source driving the blood pump as well as to tolerate chronic intracorporeal radiation. Our studies have focused on the use of the circulating blood as a heat sink. Initial in vivo heat transfer studies utilized straight tube heat exchangers (electrically and radioisotope energized) to replace a segment of the descending aorta. More recent studies have used a left ventricular assist pump as a blood-cooled heat exchanger. This approach minimizes trauma, does not increase the area of prosthetic interface with the blood, and minimizes system volume. Heat rejected from the thermal engine (vapor or gas cycle) is transported from the nuclear power source in the abdomen to the pump in the thoracic cavity via hydraulic lines. Adjacent tissue is protected from the fuel capsule temperature (900 to 1200°F) by vacuum foil insulation and polyurethane foam. The in vivo thermal management problems have been studied using a simulated thermal system (STS) which approximates the heat rejection and thermal transport mechanisms of the nuclear circulatory support systems under development by NHLI. Electric heaters simulate the reject heat from the thermal engines. These studies have been essential in establishing the location, suspension, surgical procedures, and postoperative care for implanting prototype nuclear heart assist systems in calves. The pump has a thermal impedance of 0.12°C/watt. Analysis of the STS data in terms of an electrical analog model implies a heat transfer coefficient of 4.7 × 10−3 watt/cm2°C in the abdomen compared to a value of 14.9 × 10−3 watt/cm2°C from the heat exchanger plenum into the diaphragm. Images PMID:15215968

  15. Advanced Stirling Convertor Development for NASA Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Scott D.; Collins, Josh

    2015-01-01

    Sunpower Inc.'s Advanced Stirling Convertor (ASC) initiated development under contract to the NASA Glenn Research Center and after a series of successful demonstrations, the ASC began transitioning from a technology development project to a flight development project. The ASC has very high power conversion efficiency making it attractive for future Radioisotope Power Systems (RPS) in order to make best use of the low plutonium-238 fuel inventory in the United States. In recent years, the ASC became part of the NASA and Department of Energy (DOE) Advanced Stirling Radioisotope Generator (ASRG) Integrated Project. Sunpower held two parallel contracts to produce ASCs, one with the DOE and Lockheed Martin to produce the ASC-F flight convertors, and one with NASA Glenn for the production of ASC-E3 engineering units, the initial units of which served as production pathfinders. The integrated ASC technical team successfully overcame various technical challenges that led to the completion and delivery of the first two pairs of flightlike ASC-E3 by 2013. However, in late fall 2013, the DOE initiated termination of the Lockheed Martin ASRG flight development contract driven primarily by budget constraints. NASA continues to recognize the importance of high-efficiency ASC power conversion for RPS and continues investment in the technology including the continuation of ASC-E3 production at Sunpower and the assembly of the ASRG Engineering Unit #2. This paper provides a summary of ASC technical accomplishments, overview of tests at Glenn, plans for continued ASC production at Sunpower, and status of Stirling technology development.

  16. Pathway of radioisotopes from land surface to sewage sludge

    NASA Astrophysics Data System (ADS)

    Fischer, Helmut W.; Yokoo, Yoshiyuki

    2014-05-01

    Radioactive surface contaminations will only partially remain at the original location - a fraction of the inventory will take part in (mainly terrestrial and aquatic) environmental transport processes. The probably best known and most important process comprises the food chain. Besides, the translocation of dissolved and particle-bound radioisotopes with surface waters plays an important role. These processes can have the effect of displacing large radioisotope amounts over considerable distances and of creating new sinks and hot spots, as it is already known for sewage sludge. We are reporting on a combined modeling and experimental project concerning the transport of I-131 and Cs-134/Cs-137 FDNPP 2011 depositions in the Fukushima Prefecture. Well-documented experimental data sets are available for surface deposition and sewage sludge concentrations. The goal is to model the pathway in between, involving surface runoff, transport in the sewer system and processes in the sewage treatment plant. Watershed runoff and sewer transport will be treated with models developed recently by us in other projects. For sewage treatment processes a new model is currently being constructed. For comparison and further validation, historical data from Chernobyl depositions and tracer data from natural and artificial, e.g. medical, isotopes will be used. First results for 2011 data from Fukushima Prefecture will be presented. The benefits of the study are expected to be two-fold: on one hand, the abundant recent and historical data will help to develop and improve environmental transport models; on the other hand, both data and models will help in identifying the most critical points in the envisaged transport pathways in terms of radiation protection and waste management.

  17. Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy.

    PubMed

    Cho, Y J; Kim, K I; Chun, Y S; Rhyu, K H; Kwon, B K; Kim, D Y; Yoo, M C

    2010-07-01

    Radiosynoviorthesis is a safe and easy method for synovectomy in haemophilic arthropathy. Various agents have been used in radiosynoviorthesis, especially newly developed agent Holmium-166-chitosan complex has good clinical outcome. This study analysed clinical results and radiologic evaluation of radioisotope synoviorthesis using Holmium-166-chitosan complex in haemophilic arthropathy. From March 2001 to December 2003, 58 radiosynoviorthesis were performed in 53 haemophiliacs. The average age at procedure was 13.8 years. The Arnold and Hilgartner stage of the patients was from I to IV. Holmium-166-chitosan complex was injected in 31 ankle joints, 19 elbow joints and 8 knee joints. Average follow-up was 33 months since primary procedure. The range of motion of each joint, frequency of intra-articular bleeding and factor dose used were analysed for clinical assessment. There was no significant improvement of range of motion in affected joints. After procedure, the average frequency of bleeding of the elbow joint has decreased from 3.76 to 0.47 times per month, the knee joint from 5.87 to 1.12 times per month, and the ankle joint from 3.62 to 0.73 times per month respectively (P < 0.05). After treatment, the average coagulation factor dose injected was significantly decreased to 779.3 units per month from 2814.8 units per month before treatment (P < 0.001). Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy is a very safe and simple procedure with the expectation of a satisfactory outcome without serious complication. It has excellent bleeding control effect on target joint and the need for substitution of coagulation factor concentrate can be reduced.

  18. An Overview and Status of NASA's Radioisotope Power Conversion Technology NRA

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Wong, Wayne A.; Tuttle, Karen L.

    2005-01-01

    NASA's Advanced Radioisotope Power Systems (RPS) development program is developing next generation radioisotope power conversion technologies that will enable future missions that have requirements that can not be met by either photovoltaic systems or by current Radioisotope Power System (RPS) technology. The Advanced Power Conversion Research and Technology project of the Advanced RPS development program is funding research and technology activities through the NASA Research Announcement (NRA) 02-OSS-01, "Research Opportunities in Space Science 2002" entitled "Radioisotope Power Conversion Technology" (RPCT), August 13, 2002. The objective of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide significant improvements over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, and a brief summary of accomplishments over the first 18 months but focusing on advancements made over the last 6 months.

  19. An in-cell alpha detection system for radioisotope component assembly operations

    SciTech Connect

    Carteret, B.A. ); Goles, R.W. )

    1991-09-01

    A remotely operated alpha detection system is being developed for use at the Radioisotope Power Systems Facility at the US Department of Energy's Hanford Site. It will be used in hot cells being constructed to assemble components of Radioisotope Thermoelectric Generators for space power applications. The in-cell detection equipment will survey radiological swipe samples to determine smearable surface contamination levels on radioisotope fuel, fueled components, and hot-cell work areas. This system is potentially adaptable to other hot cell and glovebox applications where radiation dose rates and contamination levels are expected to be low. 2 figs.

  20. Radioisotope electric propulsion of sciencecraft to the outer solar system and near-interstellar space

    SciTech Connect

    Noble, R.J.

    1998-08-01

    Recent results are presented in the study of radioisotope electric propulsion as a near-term technology for sending small robotic sciencecraft to the outer Solar System and near-interstellar space. Radioisotope electric propulsion (REP) systems are low-thrust, ion propulsion units based on radioisotope electric generators and ion thrusters. Powerplant specific masses are expected to be in the range of 100 to 200 kg/kW of thrust power. Planetary rendezvous missions to Pluto, fast missions to the heliopause (100 AU) with the capability to decelerate an orbiter for an extended science program and prestellar missions to the first gravitational lens focus of the Sun (550 AU) are investigated.

  1. Characterization of front-end electronics for CZT based handheld radioisotope identifier

    NASA Astrophysics Data System (ADS)

    Lombigit, L.; Rahman, Nur Aira Abd; Mohamad, Glam Hadzir Patai; Ibrahim, Maslina Mohd; Yussup, Nolida; Yazid, Khairiah; Jaafar, Zainudin

    2016-01-01

    A radioisotope identifier device based on large volume Co-planar grid CZT detector is current under development at Malaysian Nuclear Agency. This device is planned to be used for in-situ identification of radioisotopes based on their unique energies. This work reports on electronics testing performed on the front-end electronics (FEE) analog section comprising charge sensitive preamplifier-pulse shaping amplifier chain. This test involves measurement of charge sensitivity, pulse parameters and electronics noise. This report also present some preliminary results on the spectral measurement obtained from gamma emitting radioisotopes.

  2. Characterization of front-end electronics for CZT based handheld radioisotope identifier

    SciTech Connect

    Lombigit, L.; Rahman, Nur Aira Abd; Mohamad, Glam Hadzir Patai; Ibrahim, Maslina Mohd; Yussup, Nolida; Yazid, Khairiah; Jaafar, Zainudin

    2016-01-22

    A radioisotope identifier device based on large volume Co-planar grid CZT detector is current under development at Malaysian Nuclear Agency. This device is planned to be used for in-situ identification of radioisotopes based on their unique energies. This work reports on electronics testing performed on the front-end electronics (FEE) analog section comprising charge sensitive preamplifier-pulse shaping amplifier chain. This test involves measurement of charge sensitivity, pulse parameters and electronics noise. This report also present some preliminary results on the spectral measurement obtained from gamma emitting radioisotopes.

  3. Concentration of Uranium Radioisotopes in Albanian Drinking Waters Measured by Alpha Spectrometry

    NASA Astrophysics Data System (ADS)

    Bylyku, Elida; Cfarku, Florinda; Deda, Antoneta; Bode, Kozeta; Fishka, Kujtim

    2010-01-01

    Uranium is a radioactive material that is frequently found in rocks and soil. When uranium decays, it changes into different elements that are also radioactive, including radon, a gas that is known to cause a lung cancer. The main concern with uranium in drinking water is harm to the kidneys. Public water systems are required to keep uranium levels at or below 500 mBq per liter to protect against kidney damage. Such an interest is needed due to safety, regulatory compliance and disposal issue for uranium in the environment since uranium is included as an obligatory controlled radionuclide in the European Legislation (Directive 98/83 CE of Council of 03.11.1998). The aim of this work is to measure the levels of uranium in drinking and drilled well waters in Albania. At first each sample was measured for total Alpha and total Beta activity. The samples with the highest levels of total alpha activity were chosen for the determination of uranium radioisotopes by alpha spectrometry. A radiochemical procedure using extraction with TBP (Tri-Butyl-Phosphate) is used in the presence of U232 as a yield tracer. Thin sources for alpha spectrometry are prepared by electrodepositing on to stainless steel discs. The results of the U238 activity measured in the different samples, depending from their geological origin range between 0.55-13.87 mBq/l. All samples measured results under the European Directive limits for U238 (5-500 mBq/1), Dose Coefficients according to Directive 96/29 EURATOM.

  4. Radiation Environments and Exposure Considerations for the Multi-Mission Radioisotope Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Kelly, William M.; Low, Nora M.; Zillmer, Andrew; Johnson, Gregory A.; Normand, Eugene

    2006-01-01

    The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is the next generation (RTG) being developed by DOE to provide reliable, long-life electric power for NASA's planetary exploration programs. The MMRTG is being developed by Pratt & Whitney Rocketdyne and Teledyne Energy Systems Incorporated (TESI) for use on currently planned and projected flyby, orbital and planet landing missions. This is a significant departure from the design philosophy of the past which was to match specific mission requirements to RTG design capabilities. Undefined mission requirements provide a challenge to system designers by forcing them to put a design envelope around ``all possible missions''. These multi-mission requirements include internal and external radiation sources. Internal sources include the particles ejected by decaying Pu-238 and its daughters plus particles resulting from the interaction of these particles with other MMRTG materials. External sources include the full spectrum of charged particle radiation surrounding planets with magnetic fields and the surfaces of extraterrestrial objects not shielded by magnetic fields. The paper presents the results of investigations into the environments outlined above and the impact of radiation exposure on potential materials to be used on MMRTG and ground support personnel. Mission requirements were also reviewed to evaluate total integrated dose and to project potential shielding requirements for materials. Much of the information on mission shielding requirements was provided by NASA's Jet Propulsion Laboratory. The primary result is an ionizing radiation design curve which indicates the limits to which a particular mission can take the MMRTG in terms of ionizing radiation exposure. Estimates of personnel radiation exposure during ground handling are also provided.

  5. Radiation Environments and Exposure Considerations for the Multi-Mission Radioisotope Thermoelectric Generator

    SciTech Connect

    Kelly, William M.; Low, Nora M.; Zillmer, Andrew; Johnson, Gregory A.; Normand, Eugene

    2006-01-20

    The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is the next generation (RTG) being developed by DOE to provide reliable, long-life electric power for NASA's planetary exploration programs. The MMRTG is being developed by Pratt and Whitney Rocketdyne and Teledyne Energy Systems Incorporated (TESI) for use on currently planned and projected flyby, orbital and planet landing missions. This is a significant departure from the design philosophy of the past which was to match specific mission requirements to RTG design capabilities. Undefined mission requirements provide a challenge to system designers by forcing them to put a design envelope around 'all possible missions'. These multi-mission requirements include internal and external radiation sources. Internal sources include the particles ejected by decaying Pu-238 and its daughters plus particles resulting from the interaction of these particles with other MMRTG materials. External sources include the full spectrum of charged particle radiation surrounding planets with magnetic fields and the surfaces of extraterrestrial objects not shielded by magnetic fields. The paper presents the results of investigations into the environments outlined above and the impact of radiation exposure on potential materials to be used on MMRTG and ground support personnel. Mission requirements were also reviewed to evaluate total integrated dose and to project potential shielding requirements for materials. Much of the information on mission shielding requirements was provided by NASA's Jet Propulsion Laboratory. The primary result is an ionizing radiation design curve which indicates the limits to which a particular mission can take the MMRTG in terms of ionizing radiation exposure. Estimates of personnel radiation exposure during ground handling are also provided.

  6. Kuiper Belt Object Orbiter Using Advanced Radioisotope Power Sources and Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.; Dankanich, John; Colozza, Anthony; Schmitz, Paul; Khan, Omair; Drexler, Jon; Fittje, James

    2011-01-01

    A joint NASA GRC/JPL design study was performed for the NASA Radioisotope Power Systems Office to explore the use of radioisotope electric propulsion for flagship class missions. The Kuiper Belt Object Orbiter is a flagship class mission concept projected for launch in the 2030 timeframe. Due to the large size of a flagship class science mission larger radioisotope power system building blocks were conceptualized to provide the roughly 4 kW of power needed by the NEXT ion propulsion system and the spacecraft. Using REP the spacecraft is able to rendezvous with and orbit a Kuiper Belt object in 16 years using either eleven (no spare) 420 W advanced RTGs or nine (with a spare) 550 W advanced Stirling Radioisotope systems. The design study evaluated integrating either system and estimated impacts on cost as well as required General Purpose Heat Source requirements.

  7. Estimates for production of radioisotopes of medical interest at Extreme Light Infrastructure - Nuclear Physics facility

    NASA Astrophysics Data System (ADS)

    Luo, Wen; Bobeica, Mariana; Gheorghe, Ioana; Filipescu, Dan M.; Niculae, Dana; Balabanski, Dimiter L.

    2016-01-01

    We report Monte Carlo simulations of the production of radioisotopes of medical interest through photoneutron reactions using the high-brilliance γ-beam of the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility. The specific activity for three benchmark radioisotopes, 99Mo/99Tc, 225Ra/225Ac and 186Re, was obtained as a function of target geometry, irradiation time and γ-beam energy. Optimized conditions for the generation of these radioisotopes of medical interest with the ELI-NP γ-beams were discussed. We estimated that a saturation specific activity of the order of 1-2 mCi/g can be achieved for thin targets with about one gram of mass considering a γ-beam flux of 10^{11} photons/s. Based on these results, we suggest that the ELI-NP facility can provide a unique possibility for the production of radioisotopes in sufficient quantities for nuclear medicine research.

  8. Radioisotope Electric Propulsion (REP): A Near-Term Approach to Nuclear Propulsion

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.; Manzella, David H.; Kamhawi, Hani; Kremic, Tibor; Oleson, Steven R.; Dankanich, John W.; Dudzinski, Leonard A.

    2009-01-01

    Studies over the last decade have shown radioisotope-based nuclear electric propulsion to be enhancing and, in some cases, enabling for many potential robotic science missions. Also known as radioisotope electric propulsion (REP), the technology offers the performance advantages of traditional reactor-powered electric propulsion (i.e., high specific impulse propulsion at large distances from the Sun), but with much smaller, affordable spacecraft. Future use of REP requires development of radioisotope power sources with system specific powers well above that of current systems. The US Department of Energy and NASA have developed an advanced Stirling radioisotope generator (ASRG) engineering unit, which was subjected to rigorous flight qualification-level tests in 2008, and began extended lifetime testing later that year. This advancement, along with recent work on small ion thrusters and life extension technology for Hall thrusters, could enable missions using REP sometime during the next decade.

  9. 77 FR 21592 - Guidelines for Preparing and Reviewing Licensing Applications for the Production of Radioisotopes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... Chapters 7-18 of Draft Interim Staff Guidance (ISG) NPR-ISG-2011-002, augmenting NUREG-1537, Part 1...,'' for the production of radioisotopes. The ISG augmenting NUREG-1537, Parts 1 & 2, Chapters 1-6...

  10. RADIOISOTOPE IDENTIFICATION OF SHIELDED AND MASKED SNM RDD MATERIALS

    SciTech Connect

    Salaymeh, S.; Jeffcoat, R.

    2010-06-17

    Sonar and speech techniques have been investigated to improve functionality and enable handheld and other man-portable, mobile, and portal systems to positively detect and identify illicit nuclear materials, with minimal data and with minimal false positives and false negatives. RadSonar isotope detection and identification is an algorithm development project funded by NA-22 and employing the resources of Savannah River National Laboratory and three University Laboratories (JHU-APL, UT-ARL, and UW-APL). Algorithms have been developed that improve the probability of detection and decrease the number of false positives and negatives. Two algorithms have been developed and tested. The first algorithm uses support vector machine (SVM) classifiers to determine the most prevalent nuclide(s) in a spectrum. It then uses a constrained weighted least squares fit to estimate and remove the contribution of these nuclide(s) to the spectrum, iterating classification and fitting until there is nothing of significance left. If any Special Nuclear Materials (SNMs) were detected in this process, a second tier of more stringent classifiers are used to make the final SNM alert decision. The second algorithm is looking at identifying existing feature sets that would be relevant in the radioisotope identification context. The underlying philosophy here is to identify parallels between the physics and/or the structures present in the data for the two applications (speech analysis and gamma spectroscopy). The expectation is that similar approaches may work in both cases. The mel-frequency cepstral representation of spectra is widely used in speech, particularly for two reasons: approximation of the response of the human ear, and simplicity of channel effect separation (in this context, a 'channel' is a method of signal transport that affects the signal, examples being vocal tract shape, room echoes, and microphone response). Measured and simulated gamma-ray spectra from a hand

  11. Potential medical applications of the plasma focus in the radioisotope production for PET imaging

    NASA Astrophysics Data System (ADS)

    Roshan, M. V.; Razaghi, S.; Asghari, F.; Rawat, R. S.; Springham, S. V.; Lee, P.; Lee, S.; Tan, T. L.

    2014-06-01

    Devices other than the accelerators are desired to be investigated for generating high energy particles to induce nuclear reaction and positron emission tomography (PET) producing radioisotopes. The experimental data of plasma focus devices (PF) are studied and the activity scaling law for External Solid Target (EST) activation is established. Based on the scaling law and the techniques to enhance the radioisotopes production, the feasibility of generating the required activity for PET imaging is studied.

  12. SU-E-CAMPUS-I-03: Dosimetric Comparison of the Hypoxia Agent Iodoazomycin Arabinoside (IAZA) Labeled with the Radioisotopes I-123, I-131 and I-124

    SciTech Connect

    Jans, H-S; Stypinski, D; Mcquarrie, S; Kumar, P; Mercer, J; McEwan, S; Wiebe, L

    2014-06-15

    Purpose: To compare the radiation dose to normal organs from the radio-iodinated, hypoxia-binding radiosensitizer iodoazomycin arabinoside (IAZA) for three different isotopes of iodine. Methods: Dosimety studies with normal volunteers had been carried out with [{sup 123}I]IAZA, a drug binding selectively to hypoxic sites. Two other isotopes of iodine, {sup 131}I and {sup 124}I, offer the opportunity to use IAZA as an agent for radioisotope therapy and as an imaging tracer for Positron Emission Tomography. Radioisotope dosimetry for {sup 131}I and {sup 124}I was performed by first deriving from the [{sup 123}I]IAZA studies biological uptake and excretion data. The cumulated activities for {sup 131}I or {sup 124}I where obtained by including their half-lives when integrating the biological data and then extrapolating to infinite time points considering a) physical decay only or b) physical and biological excretion. Doses were calculated using the Medical Internal Radiation Dose (MIRD) schema (OLINDA1.1 code, Vanderbilt 2007). Results: Compared to {sup 123}I, organ doses were elevated on average by a factor 6 and 9 for {sup 131}I and {sup 124}I, respectively, if both physical decay and biological excretion were modeled. If only physical decay is considered, doses increase by a factor 18 ({sup 131}I) and 19 ({sup 124}I). Highest organ doses were observed in intestinal walls, urinary bladder and thyroid. Effective doses increased by a factor 11 and 14 for {sup 131}I and {sup 124}I, respectively, if biological and physical decay are present. Purely physical decay yields a 23-fold increase over {sup 123}I for both, {sup 131}I and {sup 124}I. Conclusion: Owing to the significant dose increase, caused by their longer half life and the approximately 10 times larger electronic dose deposited in tissue per nuclear decay, normal tissue doses of IAZA labeled with {sup 131}I and {sup 124}I need to be carefully considered when designing imaging and therapy protocols for clinical

  13. Personal reflections on the highlights and changes in radiation and radioisotope measurement applications

    NASA Astrophysics Data System (ADS)

    Gardner, Robin P.; Lee, Kyoung O.

    2015-11-01

    This paper describes the recent changes that the authors have perceived in the use of radiation and radioisotope measurement applications. The first change is that due to the increased use of Monte Carlo simulation which has occurred from a normal evolutionary process. This is due in large part to the increased accuracy that is being obtained by the use of detector response functions (DRFs) and the simultaneous increased computational efficiency that has become available with these DRFs, the availability of a greatly improved weight windows variance reduction method, and the availability of inexpensive computer clusters. This first change is a happy one. The other change that is occurring is in response to recent terrorist activities. That change is the replacement or major change in the use of long-lived radioisotopes in radioisotope measurement and other radioisotope source applications. In general this can be done by improving the security of these radioisotope sources or by replacing them altogether by using machine sources of radiation. In either case one would like to preclude altogether or at least minimize the possibility of terrorists being able to obtain radioisotopes and use them for clandestine purposes.

  14. Toward high performance radioisotope thermophotovoltaic systems using spectral control

    NASA Astrophysics Data System (ADS)

    Wang, Xiawa; Chan, Walker; Stelmakh, Veronika; Celanovic, Ivan; Fisher, Peter

    2016-12-01

    This work describes RTPV-PhC-1, an initial prototype for a radioisotope thermophotovoltaic (RTPV) system using a two-dimensional photonic crystal emitter and low bandgap thermophotovoltaic (TPV) cell to realize spectral control. We validated a system simulation using the measurements of RTPV-PhC-1 and its comparison setup RTPV-FlatTa-1 with the same configuration except a polished tantalum emitter. The emitter of RTPV-PhC-1 powered by an electric heater providing energy equivalent to one plutonia fuel pellet reached 950 °C with 52 W of thermal input power and produced 208 mW output power from 1 cm2 TPV cell. We compared the system performance using a photonic crystal emitter to a polished flat tantalum emitter and found that spectral control with the photonic crystal was four times more efficient. Based on the simulation, with more cell areas, better TPV cells, and improved insulation design, the system powered by a fuel pellet equivalent heat source is expected to reach an efficiency of 7.8%.

  15. Accelerator Mass Spectrometry for Measurement of Long-Lived Radioisotopes

    NASA Astrophysics Data System (ADS)

    Elmore, David; Phillips, Fred M.

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes 10Be, 14C, 26Al, 36Cl, and 129I can now be measured in small natural samples having isotopic abundances in the range 10-12 to 10-15 and as few as 105 atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of half-lives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

  16. Radioisotope Electric Propulsion Missions Utilizing a Common Spacecraft Design

    NASA Technical Reports Server (NTRS)

    Fiehler, Douglas; Oleson, Steven

    2004-01-01

    A study was conducted that shows how a single Radioisotope Electric Propulsion (REP) spacecraft design could be used for various missions throughout the solar system. This spacecraft design is based on a REP feasibility design from a study performed by NASA Glenn Research Center and the Johns Hopkins University Applied Physics Laboratory. The study also identifies technologies that need development to enable these missions. The mission baseline for the REP feasibility design study is a Trojan asteroid orbiter. This mission sends an REP spacecraft to Jupiter s leading Lagrange point where it would orbit and examine several Trojan asteroids. The spacecraft design from the REP feasibility study would also be applicable to missions to the Centaurs, and through some change of payload configuration, could accommodate a comet sample-return mission. Missions to small bodies throughout the outer solar system are also within reach of this spacecraft design. This set of missions, utilizing the common REP spacecraft design, is examined and required design modifications for specific missions are outlined.

  17. Radioisotope Power Systems Reference Book for Mission Designers and Planners

    NASA Technical Reports Server (NTRS)

    Lee, Young; Bairstow, Brian

    2015-01-01

    The RPS Program's Program Planning and Assessment (PPA) Office commissioned the Mission Analysis team to develop the Radioisotope Power Systems (RPS) Reference Book for Mission Planners and Designers to define a baseline of RPS technology capabilities with specific emphasis on performance parameters and technology readiness. The main objective of this book is to provide RPS technology information that could be utilized by future mission concept studies and concurrent engineering practices. A progress summary from the major branches of RPS technology research provides mission analysis teams with a vital tool for assessing the RPS trade space, and provides concurrent engineering centers with a consistent set of guidelines for RPS performance characteristics. This book will be iterated when substantial new information becomes available to ensure continued relevance, serving as one of the cornerstone products of the RPS PPA Office. This book updates the original 2011 internal document, using data from the relevant publicly released RPS technology references and consultations with RPS technologists. Each performance parameter and RPS product subsection has been reviewed and cleared by at least one subject matter representative. A virtual workshop was held to reach consensus on the scope and contents of the book, and the definitions and assumptions that should be used. The subject matter experts then reviewed and updated the appropriate sections of the book. The RPS Mission Analysis Team then performed further updates and crosschecked the book for consistency. Finally, a second virtual workshop was held to ensure all subject matter experts and stakeholders concurred on the contents.

  18. Novel production techniques of radioisotopes using electron accelerators

    NASA Astrophysics Data System (ADS)

    Lowe, Daniel Robert

    Non-traditional radioisotope production techniques using a compact, high power linear electron accelerator have been demonstrated and characterized for the production of 18F, 47Sc, 147 Pm, and 99mTc from a variety of target candidates. These isotopes are used extensively in the medical field as diagnostic and therapy radioisotopes, as well as the space industry as RTG's. Primary focus was placed on 99mTc as it constitutes approximately 80% of all diagnostic procedures in the medical community that use radioactive tracers. It was also the prime focus due to recent events at the Chalk River nuclear reactor, which caused global shortages of this isotope a few years ago. A Varian K15 LINAC was first used to show proof of principle in Las Vegas. Various samples were then taken to the Idaho Accelerator Center where they were activated using an electron LINAC capable of electron energies from 4 to 25 MeV at a beam power of approximately 1 kW. Production rates, cross sections, and viability studies were then performed and conducted to assess the effectiveness of the candidate target and the maximum production rate for each radioisotope. Production rates for 18F from lithium fluoride salts were shown to be ideal at 21MeV, namely 1.7 Ci per kg of LiF salt, per kW of beam current, per 10 hour irradiation time. As the typical hospital consumption of 18F is around 500 mCi per day, it is clear that a large amount of 18F can be made from a small (300 gram) sample of LiF salt. However, since there is no current separation process for 18F from 19F, the viability of this technique is limited until a separations technique is developed. Furthermore, the calculated cross section for this reaction is in good agreement with literature, which supports the techniques for the isotopes mentioned below. Production rates for 47Sc from vanadium oxide targets were shown to be a maximum at 25 MeV with a production rate of 2 mCi per day, assuming a 2 kW beam and a 10 kg target. While this

  19. Thermal vacuum life test facility for radioisotope thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Deaton, R. L.; Goebel, C. J.; Amos, W. R.

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG and G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al., (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met.

  20. Production of medical Sc radioisotopes with an alpha particle beam.

    PubMed

    Szkliniarz, Katarzyna; Sitarz, Mateusz; Walczak, Rafał; Jastrzębski, Jerzy; Bilewicz, Aleksander; Choiński, Jarosław; Jakubowski, Andrzej; Majkowska, Agnieszka; Stolarz, Anna; Trzcińska, Agnieszka; Zipper, Wiktor

    2016-12-01

    The internal α-particle beam of the Warsaw Heavy Ion Cyclotron was used to produce research quantities of the medically interesting Sc radioisotopes from natural Ca and K and isotopically enriched (42)Ca targets. The targets were made of metallic calcium, calcium carbonate and potassium chloride. New data on the production yields and impurities generated during the target irradiations are presented for the positron emitters (43)Sc, (44g)Sc and (44m)Sc. The different paths for the production of the long lived (44m)Sc/(44g)Sc in vivo generator, proposed by the ARRONAX team, using proton and deuteron beams as well as alpha-particle beams are discussed. Due to the larger angular momentum transfer in the formation of the compound nucleus in the case of the alpha particle induced reactions, the isomeric ratio of (44m)Sc/(44g)Sc at a bombarding energy of 29MeV is five times larger than previously determined for a deuteron beam and twenty times larger than for proton induced reactions on enriched CaCO3 targets. Therefore, formation of this generator via the alpha-particle route seems a very attractive way to form these isotopes. The experimental data presented here are compared with theoretical predictions made using the EMPIRE evaporation code. Reasonable agreement is generally observed.

  1. Target optimization for the photonuclear production of radioisotopes.

    PubMed

    Howard, Sean; Starovoitova, Valeriia N

    2015-02-01

    In this paper we discuss the optimum shape of a target for photonuclear production of radioisotopes using an electron linear accelerator. Different target geometries such as right cylinder, conical frustum, Gaussian volume of revolution and semi-ellipsoid have been considered for the production of (67)Cu via (68)Zn(γ,p)(67)Cu photonuclear reaction. The specific activity (SA) of (67)Cu was simulated for each target shape. Optimum ratio of radius to height for cylindrical targets was found to be between 0.2 and 0.25 for target masses ranging from 20 g to 100 g. It was shown that while some unconventional target shapes, such as semi-elliptical volume of revolution, result in slightly higher specific activities than cylindrical targets, the advantage is not significant and is outweighed by the complexity of the target production and handling. Power deposition into the target was modeled and the trade-off between the maximization of (67)Cu yield and the minimization of target heating has been discussed. The (67)Cu case can easily be extended for production of many other isotopes.

  2. Accelerator mass spectrometry for measurement of long-lived radioisotopes.

    PubMed

    Elmore, D; Phillips, F M

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

  3. Neptune Orbiters Utilizing Solar and Radioisotope Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Fiehler, Douglas I.; Oleson, Steven R.

    2004-01-01

    In certain cases, Radioisotope Electric Propulsion (REP), used in conjunction with other propulsion systems, could be used to reduce the trip times for outer planetary orbiter spacecraft. It also has the potential to improve the maneuverability and power capabilities of the spacecraft when the target body is reached as compared with non-electric propulsion spacecraft. Current missions under study baseline aerocapture systems to capture into a science orbit after a Solar Electric Propulsion (SEP) stage is jettisoned. Other options under study would use all REP transfers with small payloads. Compared to the SEP stage/Aerocapture scenario, adding REP to the science spacecraft as well as a chemical capture system can replace the aerocapture system but with a trip time penalty. Eliminating both the SEP stage and the aerocapture system and utilizing a slightly larger launch vehicle, Star 48 upper stage, and a combined REP/Chemical capture system, the trip time can nearly be matched while providing over a kilowatt of science power reused from the REP maneuver. A Neptune Orbiter mission is examined utilizing single propulsion systems and combinations of SEP, REP, and chemical systems to compare concepts.

  4. "Stereo Compton cameras" for the 3-D localization of radioisotopes

    NASA Astrophysics Data System (ADS)

    Takeuchi, K.; Kataoka, J.; Nishiyama, T.; Fujita, T.; Kishimoto, A.; Ohsuka, S.; Nakamura, S.; Adachi, S.; Hirayanagi, M.; Uchiyama, T.; Ishikawa, Y.; Kato, T.

    2014-11-01

    The Compton camera is a viable and convenient tool used to visualize the distribution of radioactive isotopes that emit gamma rays. After the nuclear disaster in Fukushima in 2011, there is a particularly urgent need to develop "gamma cameras", which can visualize the distribution of such radioisotopes. In response, we propose a portable Compton camera, which comprises 3-D position-sensitive GAGG scintillators coupled with thin monolithic MPPC arrays. The pulse-height ratio of two MPPC-arrays allocated at both ends of the scintillator block determines the depth of interaction (DOI), which dramatically improves the position resolution of the scintillation detectors. We report on the detailed optimization of the detector design, based on Geant4 simulation. The results indicate that detection efficiency reaches up to 0.54%, or more than 10 times that of other cameras being tested in Fukushima, along with a moderate angular resolution of 8.1° (FWHM). By applying the triangular surveying method, we also propose a new concept for the stereo measurement of gamma rays by using two Compton cameras, thus enabling the 3-D positional measurement of radioactive isotopes for the first time. From one point source simulation data, we ensured that the source position and the distance to the same could be determined typically to within 2 meters' accuracy and we also confirmed that more than two sources are clearly separated by the event selection from two point sources of simulation data.

  5. Assessment of dynamic energy conversion systems for radioisotope heat sources

    SciTech Connect

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

  6. Radioisotope tracer study in a sludge hygienization research irradiator (SHRI).

    PubMed

    Pant, H J; Thýn, J; Zitný, R; Bhatt, B C

    2001-01-01

    A radioisotope tracer study has been carried out in a batch type sludge hygienization research irradiator with flow from top to bottom, the objective being to measure flow rate, circulation and mixing times and to investigate the hydrodynamic behaviour of the irradiator for identifying the cause(s) of malfunction. A stimulus-response technique with NH4(82)Br as a tracer was used to measure the above parameters. Experiments were carried out at three different flow rates, i.e 1.0, 0.64 and 0.33 m3/min. Three combined models based on a set of differential equations are proposed and used to simulate the measured tracer concentration curves. The obtained parameters were used to estimate dead volume and analyse hydrodynamic behaviour of the irradiator. The nonlinear regression problem of model parameter estimation was solved using the Marquardt-Levenberg method. The measured flow rate was found to be in good agreement with the values shown by the flow meter. The circulation times were found to be half of the mixing times. A simple approach for estimation of dose based on a known vertical dose-rate profile inside the irradiator is presented. About one-fourth of the volume of the irradiator was found to be dead at lower flow rates and this decreased with increase in flow rate. At higher flow rates, a semi stagnant volume was found with slow exchange of flow between the active and dead volumes.

  7. Radioisotope-based Nuclear Power Strategy for Exploration Systems Development

    SciTech Connect

    Schmidt, George R.; Houts, Michael G.

    2006-01-20

    Nuclear power will play an important role in future exploration efforts. Its benefits pertain to practically all the different timeframes associated with the Exploration Vision, from robotic investigation of potential lunar landing sites to long-duration crewed missions on the lunar surface. However, the implementation of nuclear technology must follow a logical progression in capability that meets but does not overwhelm the power requirements for the missions in each exploration timeframe. It is likely that the surface power infrastructure, particularly for early missions, will be distributed in nature. Thus, nuclear sources will have to operate in concert with other types of power and energy storage systems, and must mesh well with the power architectures envisioned for each mission phase. Most importantly, they must demonstrate a clear advantage over other non-nuclear options (e.g., solar power, fuel cells) for their particular function. This paper describes a strategy that does this in the form of three sequential system developments. It begins with use of radioisotope generators currently under development, and applies the power conversion technology developed for these units to the design of a simple, robust reactor power system. The products from these development efforts would eventually serve as the foundation for application of nuclear power systems for exploration of Mars and beyond.

  8. Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Anderson, William G.; Tarau, Calin

    2008-01-01

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling convertor provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling engine. A VCHP turns on with a delta T of 30 C, which is high enough to not risk standard ASRG operation but low enough to save most heater head life. This VCHP has a low mass, and low thermal losses for normal operation. In addition to the design, a proof-of-concept NaK VCHP was fabricated and tested. While NaK is normally not used in heat pipes, it has an advantage in that it is liquid at the reservoir operating temperature, while Na or K alone would freeze. The VCHP had two condensers, one simulating the heater head, and the other simulating the radiator. The experiments successfully demonstrated operation with the simulated heater head condenser off and on, while allowing the reservoir temperature to vary over 40 to 120 C, the maximum range expected. In agreement with previous NaK heat pipe tests, the evaporator delta T was roughly 70 C, due to distillation of the NaK in the evaporator.

  9. Disposition of Radioisotope Thermoelectric Generators Currently Located at the Oak Ridge National Laboratory - 12232

    SciTech Connect

    Glenn, J.; Patterson, J.; DeRoos, K.; Patterson, J.E.; Mitchell, K.G.

    2012-07-01

    Under the American Recovery and Reinvestment Act (ARRA), the U.S. Department of Energy (DOE) awarded SEC Federal Services Corporation (SEC) a 34-building demolition and disposal (D and D) project at the Oak Ridge National Laboratory (ORNL) that included the disposition of six Strontium (Sr-90) powered Radioisotope Thermoelectric Generators (RTGs) stored outside of ORNL Building 3517. Disposition of the RTGs is very complex both in terms of complying with disposal facility waste acceptance criteria (WAC) and U.S. Department of Transportation (DOT) requirements for packaging and transportation in commerce. Two of the RTGs contain elemental mercury which requires them to be Land Disposal Restrictions (LDR) compliant prior to disposal. In addition, all of the RTGs exceed the Class C waste concentration limits under Nuclear Regulatory Commission (NRC) Waste Classification Guidelines. In order to meet the LDR requirements and Nevada National Security Site (NNSS) WAC, a site specific treatability variance for mercury was submitted to the U.S. Environmental Protection Agency (EPA) to allow macro-encapsulation to be an acceptable treatment standard for elemental mercury. By identifying and confirming the design configuration of the mercury containing RTGs, the SEC team proved that the current configuration met the macro-encapsulation standard of 40 Code of Federal Regulations (CFR) 268.45. The SEC Team also worked with NNSS to demonstrate that all radioisotope considerations are compliant with the NNSS low-level waste (LLW) disposal facility performance assessment and WAC. Lastly, the SEC team determined that the GE2000 Type B cask met the necessary size, weight, and thermal loading requirements for five of the six RTGs. The sixth RTG (BUP-500) required a one-time DOT shipment exemption request due to the RTG's large size. The DOT exemption justification for the BUP-500 relies on the inherent robust construction and material make-up of the BUP- 500 RTG. DOE-ORO, SEC, and

  10. Baryonic B Decays

    NASA Astrophysics Data System (ADS)

    Chistov, R.

    2016-02-01

    In this talk the decays of B-mesons into baryons are discussed. Large mass of B-meson makes possible the decays of the type B → baryon (+mesons). Experimental observations and measurements of these decays at B-factories Belle and BaBar have stimulate the development of theoretical models in this field. We briefly review the experimental results together with the current theoretical models which describe baryonic B decays.

  11. Radioisotope Power System Delivery, Ground Support and Nuclear Safety Implementation: Use of the Multi-Mission Radioisotope Thermoelectric Generator for the NASA's Mars Science Laboratory

    SciTech Connect

    S.G. Johnson; K.L. Lively; C.C. Dwight

    2014-07-01

    Radioisotope power systems have been used for over 50 years to enable missions in remote or hostile environments. They are a convenient means of supplying a few milliwatts up to a few hundred watts of useable, long-term electrical power. With regard to use of a radioisotope power system, the transportation, ground support and implementation of nuclear safety protocols in the field is a complex process that requires clear identification of needed technical and regulatory requirements. The appropriate care must be taken to provide high quality treatment of the item to be moved so it arrives in a condition to fulfill its missions in space. Similarly it must be transported and managed in a manner compliant with requirements for shipment and handling of special nuclear material. This presentation describes transportation, ground support operations and implementation of nuclear safety and security protocols for a radioisotope power system using recent experience involving the Multi-Mission Radioisotope Thermoelectric Generator for National Aeronautics and Space Administration’s Mars Science Laboratory, which launched in November of 2011.

  12. An Overview and Status of NASA's Radioisotope Power Conversion Technology NRA

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Wong, Wayne A.; Tuttle, Karen L.

    2005-01-01

    NASA's Advanced Radioisotope Power Systems (RPS) development program is developing next generation radioisotope power conversion technologies that will enable future missions that have requirements that can not be met by either photovoltaic systems or by current Radioisotope Power System (RPS) technology. The Advanced Power Conversion Research and Technology project of the Advanced RPS development program is funding research and technology activities through the NASA Research Announcement (NRA) 02- OSS-01, "Research Opportunities in Space Science 2002" entitled "Radioisotope Power Conversion Technology" (RPCT), 13 August 2002. The objective of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide significant improvements over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. These advances would enable a factor of 2 to 4 decrease in the amount of fuel required to generate electrical power. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100We scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, and a brief summary of accomplishments over the first 18 months but focusing on advancements made over the last 6 months.

  13. Radioisotope electric propulsion of sciencecraft to the outer Solar System and near-interstellar space

    SciTech Connect

    Noble, R.J.

    1999-11-01

    Radioisotopes have been used successfully for more than 25 years to supply the heat for thermoelectric generators on various deep-space probes. Radioisotope electric propulsion (REP) systems have been proposed as low-thrust ion propulsion units based on radioisotope electric generators and ion thrusters. The perceived liability of radioisotope electric generators for ion propulsion is their high mass. Conventional radioisotope thermoelectric generators have a specific mass of about 200 kg/kW of electric power. Many development efforts have been undertaken with the aim of reducing the specific mass of radioisotope electric systems. Recent performance estimates suggest that specific masses of 50 kg/kW may be achievable with thermophotovoltaic and alkali metal thermal-to-electric conversion generators. Powerplants constructed from these near-term radioisotope electric generators and long-life ion thrusters will likely have specific masses in the range of 100 to 200 kg/kW of thrust power if development continues over the next decade. In earlier studies, it was concluded that flight times within the Solar System are indeed insensitive to reductions in the powerplant specific mass, and that a timely scientific program of robotic planetary rendezvous and near-interstellar space missions is enabled by primary electric propulsion once the powerplant specific mass is in the range of 100 to 200 kg/kW. Flight times can be substantially reduced by using hybrid propulsion schemes that combine chemical propulsion, gravity assist, and electric propulsion. Hybrid schemes are further explored in this article to illustrate how the performance of REP is enhanced for Pluto rendezvous, heliopause orbiter, and gravitational lens missions.

  14. Interplanetary Sample Return Missions Using Radioisotope Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Williams, R.; Gao, Y.; Kluever, C. A.; Capples, M.; Belcher, J.

    2005-01-01

    Solar electric propulsion (SEP) is being used for a variety of planetary missions sponsored by ESA, JAXA, and NASA and nuclear electric propulsion (NEP) is being considered for future, flagship-class interplanetary missions. Radioisotope electric propulsion (REP) has recently been shown to effectively complement SEP and NEP for missions to high-AU targets with modest payload requirements. This paper investigates the application of an advanced REP for a sample return from the comet Tempel 1. A set of mission and system parameters are varied with the goal of quantifying their impact on total mission payload. Mission parameters considered include trip-time and Earth return entry interface speed of the sample return system. System parameters considered include launch vehicle, power level of spacecraft at beginning of mission, and thruster specific impulse. For the baseline case of Atlas 401 and REP power level of 750 W, the mission time was 12 years, the payload was 144 kg, and the missions optimized to a single specific impulse generally within Hall ion thruster range. Other cases were investigated in support of graduate studies, and include the larger Atlas 551 launch vehicle and extended power level to 1 kW. The Atlas 551 cases tended to optimize dual specific impulses generally in the Hall ion thruster range for both legs of the mission. A power level of at least 1-kW and trip-time of approximately 11 years was required to obtain a total science payload close to 320 kg for the Atlas 401 launch vehicle. An Atlas 551 launch vehicle yielded a science payload of approximately 540 kg for the case of 1-kW of power and an 11-year trip time, and nearly 250 kg of science payload for the case of 1-kW of power and a 6-year trip time. Results are also reported indicating the performance ramifications of meeting a reduced Earth entry interface velocity constraint.

  15. Improving power density and efficiency of miniature radioisotopic thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Whalen, Scott A.; Apblett, Christopher A.; Aselage, Terrence L.

    We have built and tested a prototype miniaturized thermoelectric power source that generates 450 μW of electrical power in a system volume of 4.3 cm 3. The measured power density of 104 μW cm -3 exceeds that of any previously reported thermoelectric power system of equivalent size. This improvement was achieved by implementing a novel thermopile design in which wagon wheel-shaped thermoelectric elements contact the entire circumference of the heat source whereas traditional approaches utilize only one heat source surface. The thermopile consists of 22 wagon wheel-shaped elements (11 P-N thermocouples) fabricated from 215-μm thick bismuth-telluride wafers having ZT = 0.97 at 30 °C. The power source operates on a 150 mW thermal input provided by an electrical resistance heater that simulates a capsule containing 0.4 g of 238PuO 2 located at the center of the device. Our primary research objective was to develop and demonstrate a prototype thermopile and radioisotopic thermoelectric generator (RTG) architecture with improved power density at small scales. Output power from this device, while optimized for efficiency, was not optimized for output voltage, and the maximum power was delivered at 41 mV. We also discuss modifications to our prototype design that result in significantly improved voltage and power. Numerical predictions show that a power output of 1.4 mW, power density of 329 μW cm -3, and voltage of 362 mV, is possible in the same package size.

  16. Small Radioisotope Power System Testing at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Dugala, Gina; Bell, Mark; Oriti, Salvatore; Fraeman, Martin; Frankford, David; Duven, Dennis

    2013-01-01

    In April 2009, NASA Glenn Research Center (GRC) formed an integrated product team (IPT) to develop a Small Radioisotope Power System (SRPS) utilizing a single Advanced Stirling Convertor (ASC) with passive balancer. A single ASC produces approximately 80 We making this system advantageous for small distributed lunar science stations. The IPT consists of Sunpower, Inc., to provide the single ASC with a passive balancer, The Johns Hopkins University Applied Physics Laboratory (JHUAPL) to design an engineering model Single Convertor Controller (SCC) for an ASC with a passive balancer, and NASA GRC to provide technical support to these tasks and to develop a simulated lunar lander test stand. The single ASC with a passive balancer, simulated lunar lander test stand, and SCC were delivered to GRC and were tested as a system. The testing sequence at GRC included SCC fault tolerance, integration, electromagnetic interference (EMI), vibration, and extended operation testing. The SCC fault tolerance test characterized the SCCs ability to handle various fault conditions, including high or low bus power consumption, total open load or short circuit, and replacing a failed SCC card while the backup maintains control of the ASC. The integrated test characterized the behavior of the system across a range of operating conditions, including variations in cold-end temperature and piston amplitude, including the emitted vibration to both the sensors on the lunar lander and the lunar surface. The EMI test characterized the AC and DC magnetic and electric fields emitted by the SCC and single ASC. The vibration test confirms the SCCs ability to control the single ASC during launch. The extended operation test allows data to be collected over a period of thousands of hours to obtain long term performance data of the ASC with a passive balancer and the SCC. This paper will discuss the results of each of these tests.

  17. Small Radioisotope Power System at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Dugala, Gina M.; Fraeman, Martin; Frankford, David P.; Duven, Dennis; Shamkovich, Andrei; Ambrose, Hollis; Meer, David W.

    2012-01-01

    In April 2009, NASA Glenn Research Center (GRC) formed an integrated product team (IPT) to develop a Small Radioisotope Power System (SRPS) utilizing a single Advanced Stirling Convertor (ASC) with passive balancer for possible use by the International Lunar Network (ILN) program. The ILN program is studying the feasibility of implementing a multiple node seismometer network to investigate the internal lunar structure. A single ASC produces approximately 80 W(sub e) and could potentially supply sufficient power for that application. The IPT consists of Sunpower, Inc., to provide the single ASC with balancer, The Johns Hopkins University Applied Physics Laboratory (JHU/APL) to design an engineering model Single Convertor Controller (SCC) for an ASC with balancer, and NASA GRC to provide technical support to these tasks and to develop a simulated lunar lander test stand. A controller maintains stable operation of an ASC. It regulates the alternating current produced by the linear alternator of the convertor, provides a specified output voltage, and maintains operation at a steady piston amplitude and hot end temperature. JHU/APL also designed an ASC dynamic engine/alternator simulator to aid in the testing and troubleshooting of the SCC. This paper describes the requirements, design, and development of the SCC, including some of the key challenges and the solutions chosen to overcome those issues. In addition, it describes the plans to analyze the effectiveness of a passive balancer to minimize vibration from the ASC, characterize the effect of ASC vibration on a lunar lander, characterize the performance of the SCC, and integrate the single ASC, SCC, and lunar lander test stand to characterize performance of the overall system.

  18. Concept for a radioisotope powered dual mode lunar rover

    NASA Technical Reports Server (NTRS)

    Elliott, John O.; Schriener, Timothy M.; Coste, Keith

    2006-01-01

    Over three decades ago, the Apollo missions manifestly demonstrated the value of a lunar rover to expand the exploration activities of lunar astronauts. The stated plan of the new Vision for Space Exploration to establish a permanent presence on the moon in the next decades gives new impetus to providing long range roving and exploration capability in support of the siting, construction, and maintenance of future human bases. The incorporation of radioisotope power systems and telerobotic capability in the design has the potential to significantly expand the capability of such a rover, allowing continuous operation during the full lunar day/night cycle, as well as enabling exploration in permanently shadowed regions that may be of interest to humans for the resources they may hold. This paper describes a concept that builds on earlier studies originated in the Apollo program for a Dual Mode (crewed and telerobotic) Lunar Roving Vehicle (DMLRV). The goal of this vehicle would be to provide a multipurpose infrastructure element and remote science platform for the exploration of the moon. The DMLRV would be essential for extending the productivity of human exploration crews, and would provide a unique capability for diverse long-range, long-duration science exploration between human visits. With minimal reconfiguration this vehicle could also provide the basic platform to support a range of site survey and preparation activities in anticipation of the establishment of a permanent human presence on the moon. A conceptual design is presented for the DMLRV, including discussion of mission architecture, vehicle performance, representative science payload accommodation, and equipment and crew radiation considerations.

  19. [Cancer therapy using unsealed radioisotopes-the present and future].

    PubMed

    Karasawa, Katsuyuki

    2014-12-01

    Iodine-131 (I-131) has been used for the ablation of residual thyroid remnants and cancer cells in well-differentiated thyroid cancers. It has also been used for metastatic well-differentiated thyroid cancers, especially lung and bone metastases. For small lung metastases, I-131 treatment has curative potential, particularly in young patients. Suppression of the thyroid stimulating hormone is also important for prolonging the survival of thyroid cancer patients. Strontium-89 (Sr-89) chloride has a mechanism similar to calcium, and it has been used for the treatment of bone metastases, especially osteoblastic metastases. It has been reported to have analgesic effects in an average of 76% of cases, and it is more effective if used in the early bone metastatic phase. Ibritumomab tiuxetan (Zevalin) is an anti-CD20 mouse monoclonal antibody labeled with Yttrium-90 (Y-90). It is used for treatment-resistant low grade or follicular B-cell non-Hodgkin's lymphomas and mantle lymphomas. Recently, radium-223 (Ra-223) has been used for bone metastases from castration resistant prostate cancers, and in a phase III trial, it has been proven to prolong survival of these patients. Cancer therapy using unsealed radioisotopes has been thought to be promising because it exhibits more targeted therapy than external beam irradiation. Therefore, if many more ideal targeting agents are developed in the future, this treatment might be used more commonly. As many agents such as I-131, Sr-89, and Ra-223 are available for treating bone metastasis, the combined use of other treatments such as high precision radiotherapy, bisphosphonates, hormonal agents, and molecular targeted agents should be investigated.

  20. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This paper presents recent thermal model results of the Advanced Stirling Radioisotope Generator (ASRG). The three-dimensional (3D) ASRG thermal power model was built using the Thermal Desktop(trademark) thermal analyzer. The model was correlated with ASRG engineering unit test data and ASRG flight unit predictions from Lockheed Martin's (LM's) I-deas(trademark) TMG thermal model. The auxiliary cooling system (ACS) of the ASRG is also included in the ASRG thermal model. The ACS is designed to remove waste heat from the ASRG so that it can be used to heat spacecraft components. The performance of the ACS is reported under nominal conditions and during a Venus flyby scenario. The results for the nominal case are validated with data from Lockheed Martin. Transient thermal analysis results of ASRG for a Venus flyby with a representative trajectory are also presented. In addition, model results of an ASRG mounted on a Cassini-like spacecraft with a sunshade are presented to show a way to mitigate the high temperatures of a Venus flyby. It was predicted that the sunshade can lower the temperature of the ASRG alternator by 20 C for the representative Venus flyby trajectory. The 3D model also was modified to predict generator performance after a single Advanced Stirling Convertor failure. The geometry of the Microtherm HT insulation block on the outboard side was modified to match deformation and shrinkage observed during testing of a prototypic ASRG test fixture by LM. Test conditions and test data were used to correlate the model by adjusting the thermal conductivity of the deformed insulation to match the post-heat-dump steady state temperatures. Results for these conditions showed that the performance of the still-functioning inboard ACS was unaffected.

  1. The Texas A&M Radioisotope Production and Radiochemistry Program

    SciTech Connect

    Akabani, Gamal

    2016-08-31

    The main motivation of the project at Texas A&M University was to carry out the production of critically needed radioisotopes used in medicine for diagnostic and therapy, and to establish an academic program in radionuclide production and separation methods. After a lengthy battle with the Texas A&M University Radiation Safety Office, the Texas Department of State Health Services granted us a license for the production of radionuclides in July 2015, allowing us to work in earnest in our project objectives. Experiments began immediately after licensing, and we started the assembly and testing of our target systems. There were four analytical/theoretical projects and two experimental target systems. These were for At-211 production and for Zn- 62/Cu-62 production. The theoretical projects were related to the production of Mo-99/Tc-99m using (a) a subcritical aqueous target system and (b) production of Tc-99m from accelerator-generated Mo-99 utilizing a photon-neutron interaction with enriched Mo-100 targets. The two experimental projects were the development of targetry systems and production of At-211 and Zn-62/Cu-62 generator. The targetry system for At-211 has been tested and production of At-211 is chronic depending of availability of beam time at the cyclotron. The installation and testing of the targetry system for the production of Zn-62/Cu-62 has not been finalized. A description of the systems is described. The academic program in radionuclide production and separation methods was initiated in the fall of 2011; due to the lack of a radiochemistry laboratory, it was suspended. We expect to re-start the academic program at the Texas A&M Institute for Preclinical Studies under the Molecular Imaging Program.

  2. The Texas A&M Radioisotope Production and Radiochemistry Program

    SciTech Connect

    Akabani, Gamal

    2016-10-28

    The main motivation of the project at Texas A&M University was to carry out the production of critically needed radioisotopes used in medicine for diagnostics and therapy, and to establish an academic program in radionuclide production and separation methods. After a lengthy battle with the Texas A&M University Radiation Safety Office, the Texas Department of State Health Services granted us a license for the production of radionuclides in July 2015, allowing us to work in earnest in our project objectives. Experiments began immediately after licensing, and we started the assembly and testing of our target systems. There were four analytical/theoretical projects and two experimental target systems. These were for At-211 production and for Zn-62/Cu-62 production. The theoretical projects were related to the production of Mo-99/Tc-99m using a) a subcritical aqueous target system and b) production of Tc-99m from accelerator generated Mo-99 utilizing a photon-neutron interaction with enriched Mo-100 targets. The two experimental projects were the development of targetry systems and production of At-211 and Zn-62/Cu-62 generator. The targetry system for At-211 has been tested and production of At-211 is chronic depending of availability of beam time at the cyclotron. The installation and testing of the targetry system for the production of Zn-62/Cu-62 has not been finalized. A description of the systems is described. The academic program in radionuclide production and separation methods was initiated in the fall of 2011 and due to the lack of a radiochemistry laboratory it was suspended. We expect to re-start the academic program at the Texas A&M Institute for Preclinical Studies under the Molecular Imaging Program.

  3. The design of a source to simulate the gamma-ray spectrum emitted by a radioisotope thermoelectric generator

    NASA Technical Reports Server (NTRS)

    Reier, M.

    1972-01-01

    A simulated source was designed to duplicate the gamma spectrum of a uniform cylindrical 2200-watt Pu02 radioisotope thermoelectric generator containing 81% Pu-238 and 1.2 ppm Pu-236. Gamma rays from the decay of Pu-238, Am-241, Pu-239, and the 0-18(alpha,n)Ne-21 reaction were catalogued in broad energy groups. Two 46- and one 22-mc Th-228 sources provided simulation at various times in the life of the fuel capsule up to 18 years, which covers the time span of an outer planet mission. Emission from Th-228 represents the overwhelming contribution of the gamma spectrum after the first few years. The sources, in the form of 13-inch rods, were placed in a concentric hole in a cylinder of depleted uranium, which provided shielding equivalent to the self-shielding of the fuel capsule. The thickness of the U-238 cylinder (0.55cm) was determined by Monte Carlo calculations to insure that the spectrum emerging from the simulated source matched that of the fuel capsule.

  4. Reentry response of the light weight radioisotope heater unit resulting from a Venus-Earth-Earth Gravity Assist maneuver accident

    SciTech Connect

    Hagan, J.C.

    1988-10-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Light Weight Radioisotope Heater Unit for Galileo/VEEGA reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, the fuel clad, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is assumed to be recession corresponding to 50% of the wall thickness (the design criterion recommended in the DOE Overall Safety Manual). Although the analyses have been carried far beyond this limit (as presented and discussed herein), JHU/APL endorses the position that failure may occur at the time that this recession is achieved or at lower altitudes within the heat pulse considering the uncertainties in the aerodynamic, thermodynamic, and thermo-structural analyses and modeling. These uncertainties result mainly because of the high energies involved in the VEEGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact until it impacts with a clad that had been molten. 80 refs., 46 figs., 16 tabs.

  5. Planning For Multiple NASA Missions With Use Of Enabling Radioisotope Power

    SciTech Connect

    S.G. Johnson; K.L. Lively; C.C. Dwight

    2013-02-01

    Since the early 1960’s the Department of Energy (DOE) and its predecessor agencies have provided radioisotope power systems (RPS) to NASA as an enabling technology for deep space and various planetary missions. They provide reliable power in situations where solar and/or battery power sources are either untenable or would place an undue mass burden on the mission. In the modern era of the past twenty years there has been no time that multiple missions have been considered for launching from Kennedy Space Center (KSC) during the same year. The closest proximity of missions that involved radioisotope power systems would be that of Galileo (October 1989) and Ulysses (October 1990). The closest that involved radioisotope heater units would be the small rovers Spirit and Opportunity (May and July 2003) used in the Mars Exploration Rovers (MER) mission. It can be argued that the rovers sent to Mars in 2003 were essentially a special case since they staged in the same facility and used a pair of small launch vehicles (Delta II). This paper examines constraints on the frequency of use of radioisotope power systems with regard to launching them from Kennedy Space Center using currently available launch vehicles. This knowledge may be useful as NASA plans for its future deep space or planetary missions where radioisotope power systems are used as an enabling technology. Previous descriptions have focused on single mission chronologies and not analyzed the timelines with an emphasis on multiple missions.

  6. Status of NASA's Advanced Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Anderson, David J.; Tuttle, Karen L.; Tew, Roy C.

    2006-01-01

    NASA s Advanced Radioisotope Power Systems (RPS) development program is funding the advancement of next generation power conversion technologies that will enable future missions that have requirements that can not be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power Systems (RPS). Requirements of advanced radioisotope power systems include high efficiency and high specific power (watts/kilogram) in order to meet mission requirements with less radioisotope fuel and lower mass. Other Advanced RPS development goals include long-life, reliability, and scalability so that these systems can meet requirements for a variety of future space applications including continual operation surface missions, outer-planetary missions, and solar probe. This paper provides an update on the Radioisotope Power Conversion Technology Project which awarded ten Phase I contracts for research and development of a variety of power conversion technologies consisting of Brayton, Stirling, thermoelectrics, and thermophotovoltaics. Three of the contracts continue during the current Phase II in the areas of thermoelectric and Stirling power conversion. The accomplishments to date of the contractors, project plans, and status will be summarized.

  7. Radioisotopes in sedimentary study of the Black Sea and Caspian Sea

    NASA Astrophysics Data System (ADS)

    Laptev, Gennady; Voitsekhovych, Oleg V.

    2013-04-01

    Natural archives, such as lake or marine sediment, are widely used in erosion/sedimentation, water quality, climate change and eutrophication study alongside with the retrospective reanalysis of contaminants fluxes (trace metals, organic pollutants or radionuclides). In order to "read" information stored in sediment sequences a chronostatigraphic method have been developed and used since 1950s which is based upon variation of activity of 210Pb over the sediment profile, natural radioisotope of Uranium decay series with half-life 22 years, and hence valid for the last 100-150 years of recent sedimentation history. The 210Pb chronology is prone to be validated by other time-markers, such as artificial radionuclides globally dispersed after the nuclear weapons tests of 1960s or major accidents on NPP (the Chernobyl accident of 1986 or latest on the Fukushima Daiichi in 2011). In the last decade an intensive study using sediment cores collected from shelf and deep-sea areas in the Black Sea and the Caspian Sea have been undertaken within the framework of a number of international research projects organized by IAEA and UNOPS-GEF and devoted to environmental problems of this enclosed, and therefore sensitive to environmental impact, marine systems. Elaborative analysis of the experimental data and sediment age calculation have been done by application of CRS and CIC dating models to unsupported 210Pb activity over the sediment profile. Measured in sediment 137Cs and 241Am clearly showed well resolved Bomb test and Chernobyl fallout peaks and were used as markers in order to corroborate radiometrically determined age of sediment. Geochronological reconstruction of the fallout radionuclides inventory, fluxes and accumulation rate in the sediment of the Black Sea and Caspian Sea by application of combined radiometric dating technique proved to be very consistent with the historical data of atmospheric fallout observations of that artificial radionuclides recorded worldwide

  8. Radioisotope Power Systems with Skutterudite-Based Thermoelectric Converters

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Saber, Hamed H.

    2005-02-01

    The performance and specific electrical powers of Radioisotope Power Systems (RPSs) with Skutterudite-based Thermoelectric Arrays (SKTAs) of 2×7 and 4×7 unicouples connected electrically in series are calculated as functions of load voltage from 24 to 38 VDC. The p-legs of the unicouples are made of CeFe3.5Co0.5Sb12 and the n-legs are made of CoSb3, and the optimized cross-section areas of these legs for maximum efficiency operation are calculated as functions of the RPS terminal voltage. The RPS employs five General Purpose Heat Source (GPHS) bricks, generating 1250 Wth at BOM, and 40 SKTAs, which are connected in series in two or four parallel strings. The peak electrical power and peak conversion efficiency of the SKTAs (20 mm long) occurs at the same electrical current because the unicouples operate at constant hot junction temperature (973 K) and constant input thermal power. The cold junction temperature of the unicouples and the radiator base temperature are determined from coupling the unicouples performance optimization model with a detailed radiation thermal analysis for sizing the aluminum fins for rejecting waste heat into space. The calculated peak specific powers and the corresponding electrical powers of the RPSs at Beginning-Of Mission (BOM) are compared with those calculated at the peak electric power at different load voltages. Results indicated that the value of the load voltage strongly affects the performance of the RPS. Both the RPS peak specific powers and those corresponding to the peak conversion efficiency / peak electrical power increase with increasing the load voltage up to certain values then drop with further increasing that voltage. The highest BOM specific powers of the RPS is ˜ 6.859 -6.973 We/kg, ˜ 43.3% and 45.7% higher than that of the RTG (4.786 We/kg) with 7 GPHS brick and SiGe unicouples. Such specific electrical powers of the RPS with SKTAs are attainable with 28.6% less 238PuO2 fuel and 2.85% to 11.62% more BOM

  9. Delivery of therapeutic radioisotopes using nanoparticle platforms: potential benefit in systemic radiation therapy

    PubMed Central

    Zhang, Longjiang; Chen, Hongwei; Wang, Liya; Liu, Tian; Yeh, Julie; Lu, Guangming; Yang, Lily; Mao, Hui

    2010-01-01

    Radiation therapy is an effective cancer treatment option in conjunction with chemotherapy and surgery. Emerging individualized internal and systemic radiation treatment promises significant improvement in efficacy and reduction of normal tissue damage; however, it requires cancer cell targeting platforms for efficient delivery of radiation sources. With recent advances in nanoscience and nanotechnology, there is great interest in developing nanomaterials as multifunctional carriers to deliver therapeutic radioisotopes for tumor targeted radiation therapy, to monitor their delivery and tumor response to the treatment. This paper provides an overview on developing nanoparticles for carrying and delivering therapeutic radioisotopes for systemic radiation treatment. Topics discussed in the review include: selecting nanoparticles and radiotherapy isotopes, strategies for targeting nanoparticles to cancers, together with challenges and potential solutions for the in vivo delivery of nanoparticles. Some examples of using nanoparticle platforms for the delivery of therapeutic radioisotopes in preclinical studies of cancer treatment are also presented. PMID:24198480

  10. Nanocluster metal films as thermoelectric material for radioisotope mini battery unit

    NASA Astrophysics Data System (ADS)

    Borisyuk, P. V.; Krasavin, A. V.; Tkalya, E. V.; Lebedinskii, Yu. Yu.; Vasiliev, O. S.; Yakovlev, V. P.; Kozlova, T. I.; Fetisov, V. V.

    2016-10-01

    The paper is devoted to studying the thermoelectric and structural properties of films based on metal nanoclusters (Au, Pd, Pt). The experimental results of the study of single nanoclusters' tunneling conductance obtained with scanning tunneling spectroscopy are presented. The obtained data allowed us to evaluate the thermoelectric power of thin film consisting of densely packed individual nanoclusters. It is shown that such thin films can operate as highly efficient thermoelectric materials. A scheme of miniature thermoelectric radioisotope power source based on the thorium-228 isotope is proposed. The efficiency of the radioisotope battery using thermoelectric converters based on nanocluster metal films is shown to reach values up to 1.3%. The estimated characteristics of the device are comparable with the parameters of up-to-date radioisotope batteries based on nickel-63.

  11. [Application of radioisotopes for theranostics, a combination of diagnostics and therapy].

    PubMed

    Saji, Hideo

    2015-01-01

    Radioisotopes emit radiation with various characteristics. These characteristics have been used for various applications of radioisotopes in clinical fields. For example, diagnostic nuclear medicine is a technique that uses gamma-emitted radionuclides with high permeability into the body and can visualize changes in physiological and biochemical processes throughout the distributed and interrelated systems of living tissues and organs. Therapeutic nuclear medicine is a technique that uses beta-emitted radionuclides with high radiation damage to the cell and can be used for internal radiation therapy. Therefore, a strategy in which the same ligand is labeled with beta-emitted or gamma-emitted radioisotopes, i.e., a theranostics approach, is useful because an extensive availability of diagnostics and therapeutics is possible. In this presentation, some examples of a theranostics approach for radiolabeled compounds will be reported, including the results of our recent research.

  12. Radioisotope Thermophotovoltaic (RTPV) Generator and Its Application to the Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred; Mukunda, Meera; Or, Chuen T; Kumar, Vasanth; Summers, G.

    1994-01-16

    This paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator. Instead of conducting a generic study, it was decided to focus the design by directing it at a specific space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a one-year post-encounter cruise. Because of Pluto's long distance from the sun (30-50 A.U.) and the mission's large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. The chief advantage of Radioisotope Thermophotovoltaic (RTPV) power systems over current Radioisotope Thermoelectric Generators (RTGs) is their much higher conversion efficiency, which greatly reduces the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which - like all NASA missions under current consideration - is severely mass- and cost-limited. The paper describes the design of the radioisotope heat source, the thermophotovoltaic converter, and the heat rejection system; and presents the results of the thermal, electrical, and structural analysis and the design optimization of the integrated RTPV system. It briefly summarizes the RTPV system's current technology status, and lists a number of factors that my greatly reduce the need for long-term tests to demonstrate generator lifetime. Our analytical results show very substantial performance improvements over an RTG designed for the same mission, and suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the PFF mission but also for other future missions requiring small, long-lived, low

  13. Radiative decays at LHCb

    NASA Astrophysics Data System (ADS)

    Giubega, L. E.

    2016-12-01

    Precise measurements on rare radiative B decays are performed with the LHCb experiment at LHC. The LHCb results regarding the ratio of branching fractions for two radiative decays, B 0 → K *0 γ and B s → ϕ γ, the direct CP asymmetry in B 0 → K *0 γ decay channel and the observation of the photon polarization in the B ± → K ±π∓π± γ decay, are included. The first two measurements were performed in 1 fb-1 of pp collisions data and the third one in 3 fb-1 of data, respectively.

  14. Contributions and Future of Radioisotopes in Medical, Industrial and Space Applications

    DOE R&D Accomplishments Database

    Tingey, G. L.; Dix, G. P.; Wahlquist, E. J.

    1990-11-01

    There are 333 isotopes that have a half-life between 1 day and 100,000 years that have a wide variety of applications including public health, medicine,industrial technology, food technology and packaging, agriculture, energy supply, and national security. This paper provides an overview of some of the most extensive applications of radioisotopes including some observations of future uses. Examples are discussed that indicate that the use of radioisotopes is almost unlimited and will continue to grow. There is a growing need for future applications development and production. 12 refs., 1 tab. (BM)

  15. Contributions and future of radioisotopes in medical, industrial and space applications

    SciTech Connect

    Tingey, G.L.; Dix, G.P.; Wahlquist, E.J.

    1990-11-01

    There are 333 isotopes that have a half-life between 1 day and 100,000 years that have a wide variety of applications including public health, medicine,industrial technology, food technology and packaging, agriculture, energy supply, and national security. This paper provides an overview of some of the most extensive applications of radioisotopes including some observations of future uses. Examples are discussed that indicate that the use of radioisotopes is almost unlimited and will continue to grow. There is a growing need for future applications development and production. 12 refs., 1 tab. (BM)

  16. Radioisotopes "economy of promises": on the limits of biomedicine in public legitimization of nuclear activities.

    PubMed

    Boudia, Soraya

    2009-01-01

    This paper aims to examine the rise and the fall of biomedicine in the public legitimization of the development of nuclear energy. Until the late 1950s, biological and medical applications of radioisotopes were presented as the most important successes of the peaceful uses of atomic energy. I will argue that despite the major financial investment, the development of the uses of radioisotopes and their important impact on biology and clinical practices, the assessment of medical uses remained relatively limited. As consequence, the place of biomedicine in the public legitimization of financial investment and civilian uses of nuclear energy began to decline from the late 1950s.

  17. Radioisotope Power Systems for In-situ Exploration of Titan and Venus

    NASA Technical Reports Server (NTRS)

    Balint, Tibor S.

    2006-01-01

    This viewgraph presentation reviews the timeline for the robotic in situ investigation of Titan and Venus, and the use of radioisotope power systems in this exploration. The atmospheric and surface conditions of both sites are reviewed. The presentation also examines the conceptual design of the Venus Mobile Explorer and the Titan orbiter and in situ explorer. After this the presentation reviews the radioisotope power systems for each of the vehicles, with some explanation of the different requirements based on the vastly different environments that they would be investigating

  18. An alternate approach to the production of radioisotopes for nuclear medicine applications

    NASA Astrophysics Data System (ADS)

    D'Auria, John M.; Keller, Roderich; Ladouceur, Keith; Lapi, Suzanne E.; Ruth, Thomas J.; Schmor, Paul

    2013-03-01

    There is a growing need for the production of radioisotopes for both diagnostic and therapeutic medical applications. Radioisotopes that are produced using the (n,γ) or (γ,n) reactions, however, typically result in samples with low specific activity (radioactivity/gram) due to the high abundance of target material of the same element. One method to effectively remove the isotopic impurity is electro-magnetic mass separation. An Ion Source Test Facility has been constructed at TRIUMF to develop high-intensity, high-efficiency, reliable ion sources for purification of radioactive isotopes, particularly those used in nuclear medicine. In progress studies are presented.

  19. An alternate approach to the production of radioisotopes for nuclear medicine applications.

    PubMed

    D'Auria, John M; Keller, Roderich; Ladouceur, Keith; Lapi, Suzanne E; Ruth, Thomas J; Schmor, Paul

    2013-03-01

    There is a growing need for the production of radioisotopes for both diagnostic and therapeutic medical applications. Radioisotopes that are produced using the (n,γ) or (γ,n) reactions, however, typically result in samples with low specific activity (radioactivity∕gram) due to the high abundance of target material of the same element. One method to effectively remove the isotopic impurity is electro-magnetic mass separation. An Ion Source Test Facility has been constructed at TRIUMF to develop high-intensity, high-efficiency, reliable ion sources for purification of radioactive isotopes, particularly those used in nuclear medicine. In progress studies are presented.

  20. Parametric Study of Radiator Concepts for a Stirling Radioisotope Power System Applicable to Deep Space Mission

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Tew, Roy C.; Thieme, Lanny G.

    2000-01-01

    The Department of Energy (DOE) and the NASA Glenn Research Center are developing a Stirling converter for an advanced radioisotope power system to provide spacecraft onboard electric power for NASA deep space missions. This high-efficiency converter is being evaluated as an alternative to replace the much lower efficiency radioisotope thermoelectric generator (RTG). The current power requirement (six years after beginning of mission (BOM) for a mission to Jupiter) is 210 W(sub e) (watts electric) to be generated by two separate power systems, one on each side of the spacecraft. Both two-converter and four-converter system designs are being considered, depending on the amount of required redundancy.

  1. Radioisotope x-ray fluorescence analysis of ancient pottery from Tel Kouzama site in Damascus, Syria.

    PubMed

    Bakraji, Elias Hanna; Romeié, Mouhammad; Issa, Haissam

    2006-01-01

    The radioisotope X-ray fluorescence method has been utilized in the analysis of thirty nine archaeological pottery fragment samples from Tel Kouzama site, Damascus city, Syria. The samples were irradiated by a 109Cd radioisotope source (-9 10(8) Bq) for 1000 s. 17 chemical elements were determined. These elemental concentrations have been processed using two multivariate statistical methods, cluster and factor analysis in order to determine similarities and correlation between the various samples. Factor analysis confirms that samples were correctly classified by cluster analysis. These two methods suggest that samples can be considered to be manufactured using four different sources of raw material.

  2. INNOVATIVE EASY-TO-USE PASSIVE TECHNIQUE FOR 222RN AND 220RN DECAY PRODUCT DETECTION.

    PubMed

    Mishra, Rosaline; Rout, R; Prajith, R; Jalalluddin, S; Sapra, B K; Mayya, Y S

    2016-10-01

    The decay products of radon and thoron are essentially the radioisotopes of polonium, bismuth and lead, and are solid particulates, which deposit in different parts of the respiratory tract upon inhalation, subsequently emitting high-energy alpha particles upon their radioactive decay. Development of passive deposition-based direct progeny sensors known as direct radon and thoron progeny sensors have provided an easy-to-use technique for time-integrated measurements of the decay products only. These dosemeters are apt for large-scale population dosimetry to assign inhalation doses to the public. The paper gives an insight into the technique, the calibration, comparison with the prevalently used active grab filter paper sampling technique, alpha track diameter analysis in these progeny sensors, progeny deposition velocity measurements carried out using these detector systems in the indoor as well as outdoor environment, and applications of these sensors for time-integrated unattached fraction estimation.

  3. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  4. 78 FR 15009 - Consideration of Withdrawal From Commercial Production and Distribution of the Radioisotope...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... Consideration of Withdrawal From Commercial Production and Distribution of the Radioisotope Germanium-68 AGENCY... comment and information from the public to assist in its consideration of DOE withdrawal from the... summary, DOE's evaluation will include consideration of: a demonstrable private capability to produce...

  5. Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

    NASA Astrophysics Data System (ADS)

    Pantano, David R.; Hill, Dennis H.

    2005-02-01

    The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

  6. The radioisotope complex project "RIC-80" at the Petersburg Nuclear Physics Institute.

    PubMed

    Panteleev, V N; Barzakh, A E; Batist, L Kh; Fedorov, D V; Ivanov, V S; Moroz, F V; Molkanov, P L; Orlov, S Yu; Volkov, Yu M

    2015-12-01

    The high current cyclotron C-80 capable of producing 40-80 MeV proton beams with a current of up to 200 μA has been constructed at Petersburg Nuclear Physics Institute. One of the main goals of the C-80 is the production of a wide spectrum of medical radionuclides for diagnostics and therapy. The project development of the radioisotope complex RIC-80 (radioisotopes at the cyclotron C-80) at the beam of C-80 has been completed. The RIC-80 complex is briefly discussed in this paper. The combination of the mass-separator with the target-ion source device, available at one of the new target stations for on-line or semi on-line production of a high purity separated radioisotopes, is explored in greater detail. The results of target and ion source tests for a mass-separator method for the production of high purity radioisotopes (82)Sr and (223,224)Ra are also presented.

  7. Method for detection of long-lived radioisotopes in small biochemical samples

    SciTech Connect

    Turteltaub, Kenneth W.; Vogel, John S.; Felton, James S.; Gledhill, Barton L.; Davis, Jay C.

    1994-01-01

    Disclosed is a method for detection of long-lived radioisotopes in small bio-chemical samples, comprising: a. selecting a biological host in which radioisotopes are present in concentrations equal to or less than those in the ambient biosphere, b. preparing a long-lived radioisotope labeled reactive chemical specie, c. administering said chemical specie to said biologist host in doses sufficiently low to avoid significant overt damage to the biological system thereof, d. allowing a period of time to elapse sufficient for dissemination and interaction of said chemical specie with said host throughout said biological system of said host, e. isolating a reacted fraction of the biological substance from said host in a manner sufficient to avoid contamination of said substance from extraneous sources, f. converting said fraction of biological substance by suitable means to a material which efficiently produces charged ions in at least one of several possible ion sources without introduction of significant isotopic fractionation, and, g. measuring the radioisotope concentration in said material by means of direct isotopic counting.

  8. The radioisotope complex project “RIC-80” at the Petersburg Nuclear Physics Institute

    SciTech Connect

    Panteleev, V. N. Barzakh, A. E.; Batist, L. Kh.; Fedorov, D. V.; Ivanov, V. S.; Moroz, F. V.; Molkanov, P. L.; Orlov, S. Yu.; Volkov, Yu. M.

    2015-12-15

    The high current cyclotron C-80 capable of producing 40-80 MeV proton beams with a current of up to 200 μA has been constructed at Petersburg Nuclear Physics Institute. One of the main goals of the C-80 is the production of a wide spectrum of medical radionuclides for diagnostics and therapy. The project development of the radioisotope complex RIC-80 (radioisotopes at the cyclotron C-80) at the beam of C-80 has been completed. The RIC-80 complex is briefly discussed in this paper. The combination of the mass-separator with the target-ion source device, available at one of the new target stations for on-line or semi on-line production of a high purity separated radioisotopes, is explored in greater detail. The results of target and ion source tests for a mass-separator method for the production of high purity radioisotopes {sup 82}Sr and {sup 223,224}Ra are also presented.

  9. Radioisotope electric propulsion for robotic science missions to near-interstellar space

    SciTech Connect

    Noble, R.J.

    1994-10-01

    The use of radioisotope electric propulsion for sending small robotic probes on fast science missions several hundred astronomical units (AU) from the Sun is investigated. Such missions would address a large variety of solar, interstellar, galactic and cosmological science themes from unique vantage points at 100 to 600 AU, including parallax distance measurements for the entire Milky Way Galaxy, sampling of the interstellar medium and imaging of cosmological objects at the gravitational lens foci of the Sun ({ge} 550 AU). Radioisotope electric propulsion (REP) systems are low-thrust, ion propulsion units based on multi-hundred watt, radioisotope electric generators and ion thrusters. In a previous work, the flight times for rendezvous missions to the outer planets (< 30 AU) using REP were found to be less than fifteen years. However fast prestellar missions to several hundred AU are not possible unless the probe`s energy can be substantially increased in the inner Solar System so as to boost the final hyperbolic excess velocity. In this paper an economical hybrid propulsion scheme combining chemical propulsion and gravity assist in the inner Solar System and radioisotope electric propulsion in the outer Solar System is studied which enables fast prestellar missions. Total hyperbolic excess velocities of 15 AU/year and flight times to 550 AU of about 40 years are possible using REP technology that may be available in the next decade.

  10. Clouds, airplanes, trucks and people: carrying radioisotopes to and across Mexico.

    PubMed

    Mateos, Gisela; Suárez-Díaz, Edna

    2015-01-01

    The aim of this paper is to describe the early stages of Mexican nuclearization that took place in contact with radioisotopes. This history requires a multilayered narrative with an emphasis in North-South asymmetric relations, and in the value of education and training in the creation of international asymmetrical networks. Radioisotopes were involved in exchanges with the United States since the late 1940s, but also with Canada. We also describe the context of implementation of Eisenhower's Atoms for Peace initiative in Mexico that opened the door to training programs at both the Comisión Nacional de Energía Nuclear and the Universidad Nacional Autónoma de México. Radioisotopes became the best example of the peaceful applications of atomic energy, and as such they fitted the Mexican nuclearization process that was and still is defined by its commitment to pacifism. In 1955 Mexico became one of the 16 members of the atomic fallout network established by the United Nations. As part of this network, the first generation of Mexican (women) radio-chemists was trained. By the end of the 1960s, radioisotopes and biological markers were being produced in a research reactor, prepared and distributed by the CNEN within Mexico. We end up this paper with a brief reflection on North-South nuclear exchanges and the particularities of the Mexican case.

  11. Natural radioisotope210Pb as an indicator of origin of fine-grained sediment

    USGS Publications Warehouse

    Holmes, C.W.

    1984-01-01

    Distribution of210Pb in sediments on the South Texas Continental Shelf is related to dynamics of the sedimentary transport processes. This radioisotope, whose concentration is time-dependent, defines three depocenters on the shelf. In addition, the variation of210Pb activity at the sediment/water interface delineates areas of terrigenous sedimentation from hemipelagic sedimentation. ?? 1985 Springer-Verlag New York Inc.

  12. RADIOISOTOPE TECHNIQUES FOR INSTRUCTION IN THE BIOLOGICAL SCIENCES, A LIST OF ANNOTATED REFERENCES.

    ERIC Educational Resources Information Center

    HURLBURT, EVELYN M.

    REFERENCES TO BIOLOGICAL EXPERIMENTS THAT EMPHASIZE THE USE OF RADIOISOTOPES AS TRACERS ARE INCLUDED IN THIS ANNOTATED BIBLIOGRAPHY. MATERIALS INCLUDED ARE CONSIDERED TO BE READILY AVAILABLE AND WERE PUBLISHED AFTER 1960. SECTION I IS COMPOSED OF SELECTED SOURCES. ENTRIES INCLUDE (1) COMPLETE CITATIONS, (2) A BRIEF ANNOTATION, AND (3) LISTS OF…

  13. Fractal Dimensions for Radioisotope Pollution Patterns by Nuclear Power Plant Accidents

    NASA Astrophysics Data System (ADS)

    Saito, K.; Ogawa, S.

    2015-04-01

    The radioisotope pollution shows two types of patterns: dry and wet deposits for nuclear power plant accidents. Two surface pollution patterns were analysed by fractal. In Fukushima nuclear power plant accident, surface pollution by wet deposits was estimated to occur. However, actually it was no rain and white crystals were observed on the surface. Then, fractal analysis was carried out for the spatial distribution patterns of radio isotopes on the surface to judge the types of deposits. As a reference, Chernobyl nuclear power plant accident was checked for the spatial distribution patterns of radioisotopes on the surface. The objective patterns by fractal analysis were the surface pollution maps in Fukushima and Chernobyl, Abukuma river watershed map, and NOAA/AVHRR. The calculation of fractal dimensions was carried out with the box counting for binarized images. Fractal analysis results suggested the next conclusions. The radioisotope pollution in Fukushima might occur in both dry and wet deposits. The dry deposit might make the pollution pattern similar to the watershed, while the wet deposit might make the pollution pattern similar to cloud images. Moreover, most radioisotope contaminants might flow on the road in the forest valley and deposit on forest with and without rainfall in Fukushima.

  14. Method for detection of long-lived radioisotopes in small biochemical samples

    DOEpatents

    Turteltaub, K.W.; Vogel, J.S.; Felton, J.S.; Gledhill, B.L.; Davis, J.C.

    1994-11-22

    Disclosed is a method for detection of long-lived radioisotopes in small biochemical samples, comprising: a. selecting a biological host in which radioisotopes are present in concentrations equal to or less than those in the ambient biosphere, b. preparing a long-lived radioisotope labeled reactive chemical specie, c. administering the chemical specie to the biologist host in doses sufficiently low to avoid significant overt damage to the biological system, d. allowing a period of time to elapse sufficient for dissemination and interaction of the chemical specie with the host throughout the biological system of the host, e. isolating a reacted fraction of the biological substance from the host in a manner sufficient to avoid contamination of the substance from extraneous sources, f. converting the fraction of biological substance by suitable means to a material which efficiently produces charged ions in at least one of several possible ion sources without introduction of significant isotopic fractionation, and, g. measuring the radioisotope concentration in the material by means of direct isotopic counting. 5 figs.

  15. [Radioisotope thermoelectric generators and ancillary activities]. Monthly technical progress report, 1 April--28 April 1996

    SciTech Connect

    1996-06-01

    Tehnical progress achieved during this period on radioisotope thermoelectric generators is described under the following tasks: engineering support, safety analysis, qualified unicouple fabrication, ETG fabrication/assembly/test, RTG shipping/launch support, design/review/mission applications, and project management/quality assurance/reliability.

  16. Radioisotope imaging for the evaluation of thyroid neoplasia and hypothyroidism in a dog

    SciTech Connect

    Branam, J.E.; Leighton, R.L.; Hornof, W.J.

    1982-05-01

    An 11-year-old dog was diagnosed as having concurrent unilateral follicular thyroid carcinoma and hypothyroidism. Radioisotope imaging with /SUP 99m/Tc as sodium pertechnatate identified the extent of thyroid tissue involvement. A combination of surgical resection and hormonal supplementation resulted in a favorable clinical response.

  17. Pyroshock Testing of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)

    NASA Technical Reports Server (NTRS)

    Woerner, David; Fleurial, Jean-Pierre; Bennett, Russell; Hammel, Tom; Otting, William

    2013-01-01

    The Mars Science Laboratory (MSL) Multi-Mission Radioisotope Thermoelectric Generator, or MMRTG, was developed by the Department Of Energy to a set of requirements from multiple NASA mission concepts. Those concepts included deep space missions to the outer planets as well as missions to Mars. The synthesis of that diverse set of requirements addressed functional as well as environmental requirements.

  18. Planetary Protection Concerns During Pre-Launch Radioisotope Power System Final Integration Activities

    NASA Technical Reports Server (NTRS)

    Chen, Fei; McKay, Terri; Spry, James A.; Colozza, Anthony J.; DiStefano, Salvador

    2012-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a next-generation radioisotope-based power system that is currently being developed as an alternative to the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Power sources such as these may be needed for proposed missions to solar system planets and bodies that have challenging Planetary Protection (PP) requirements (e.g. Mars, Europa, Enceladus) that may support NASA s search for life, remnants of past life, and the precursors of life. One concern is that the heat from the ASRG could potentially create a region in which liquid water may occur. As advised by the NASA Planetary Protection Officer, when deploying an ASRG to Mars, the current COSPAR/NASA PP policy should be followed for Category IVc mission. Thus, sterilization processing of the ASRG to achieve bioburden reduction would be essential to meet the Planetary Protection requirements. Due to thermal constraints and associated low temperature limits of elements of the ASRG, vapor hydrogen peroxide (VHP) was suggested as a candidate alternative sterilization process to complement dry heat microbial reduction (DHMR) for the assembled ASRG. The following proposed sterilization plan for the ASRG anticipates a mission Category IVc level of cleanliness. This plan provides a scenario in which VHP is used as the final sterilization process. Keywords: Advanced Stirling Radioisotope Generator (ASRG), Planetary Protection (PP), Vapor hydrogen peroxide (VHP) sterilization.

  19. Radioisotope thermophotovoltaic system design and its application to an illustrative space mission

    SciTech Connect

    Schock, A.; Kumar, V.

    1995-01-05

    The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. Instead of conducting a generic study, it was decided to focus the design effort by directing it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a post-encounter cruise lasting up to one year. Because of Pluto`s long distance from the sun (30--50 A.U.) and the mission`s large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. TRGs have been tentatively selected, because they have been successfully flown on many space missions, and have demonstrated exceptional reliability and durability. The only reason for exploring the applicability of the far less mature RTPV systems is their potential for much higher conversion efficiencies, which would greatly reduce the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which---like all NASA missions under current consideration---is severely mass- and cost-limited. The paper describes the design of the radioisotope heat source, the thermophotovoltaic converter, and the heat rejection system; and depicts its integration with the PFF spacecraft.

  20. A multi-functional electronic program for the management of radioisotopes.

    PubMed

    Ritchot, Nathalie; Santary, William

    2008-05-01

    Everyone will agree that specialized computer programs have done away with the many tedious tasks associated with manually keeping track of radioisotopes. Enhanced electronic programs have virtually cut the time of managing radioisotopes. Agriculture and Agri-Food, Canada's (AAFC) program for the management of radioisotopes, is somewhat different from most electronic programs. It is divided into three levels of management that are dependent on the roles that a user might have when applying the application. These roles include the Departmental Radiation Safety Officer (DRSO), Radiation Safety Officer (RSO), and authorized user, which meets the requirements of the Canadian Nuclear Safety Commission. The DRSO and authorized AAFC Radiation Safety Committee members have access to the first level of management. This is the highest level of control, and only the DRSO has permission to add a nuclear substance to the system with the approval of the Canadian Nuclear Safety Commission (CNSC). This level of management is also responsible for adding authorized users, locations, and managing the Internal Use Permits. The second level of management is for site-specific RSOs. They have access to all information regarding their center of activity, but they cannot change Internal Use Permit data. The RSOs can reset passwords, authorize new users, control the maximum activity limit, etc., but are limited to viewing only the information that relates to their internal use permit. However, they retain significant control within the permit. The third and last level of management is for authorized users who can access the radioisotope order-distribution-disposal section, waste or storage containers creation file, and leak/wipe test procedures. As in the case of the DRSO and RSO, they also have access to all reports and inventories for their center of activity but they cannot change Internal Use Permit or inventories data. This program has proven to be a valuable tool for scientific staff

  1. Use of anthropogenic radioisotopes to estimate rates of soil redistribution by wind I: Historic use of 137Cs

    NASA Astrophysics Data System (ADS)

    Van Pelt, R. Scott

    2013-06-01

    Wind erosion is increasingly scrutinized as a causative factor in soil degradation and fugitive dust emissions. Although models have been developed to predict wind erosion and dust emissions, they are not accurate in all locations. The temporal and spatial variability of aeolian processes makes local estimates of long-term average erosion costly and time consuming. Atmospheric testing of nuclear weapons during the 1950s and 1960s resulted in anthropogenic radioisotopes that had not previously existed being injected into stratospheric global circulation and subsequently deposited on the Earth's surface. Many of these radioisotopes are strongly adsorbed to soil particles and their movement on the landscape is a powerful method for investigating soil redistribution by wind, water, and tillage. 137Cs is the most commonly used anthropogenic radioisotope used to assess soil redistribution rates. Models have been developed to equate differences of radioisotope inventories with rates of soil redistribution and these models have been employed globally to assess soil redistribution on agricultural and natural landscapes. The radioisotope method for assessing soil redistribution rates has many advantages, but also a few limitations. One of the major limitations occurs when local sources of radioisotope contamination, particularly 137Cs, mask the pulse from global fallout, making temporal estimates of redistribution difficult or impossible. In this paper, I explore the importance, history, and applications of the radioisotopic technique using 137Cs, particularly as it applies to soil redistribution by wind.

  2. Analytical solution to the diffusion, sorption and decay chain equation in a saturated porous medium between two reservoirs.

    PubMed

    Guzman, Juan; Maximov, Serguei; Escarela-Perez, Rafael; López-García, Irvin; Moranchel, Mario

    2015-01-01

    The diffusion and distribution coefficients are important parameters in the design of barrier systems used in radioactive repositories. These coefficients can be determined using a two-reservoir configuration, where a saturated porous medium is allocated between two reservoirs filled by stagnant water. One of the reservoirs contains a high concentration of radioisotopes. The goal of this work is to obtain an analytical solution for the concentration of all radioisotopes in the decay chain of a two-reservoir configuration. The analytical solution must be obtained by taking into account the diffusion and sorption processes. Concepts such as overvalued concentration, diffusion and decay factors are employed to this end. It is analytically proven that a factor of the solution is identical for all chains (considering a time scaling factor), if certain parameters do not change. In addition, it is proven that the concentration sensitivity, due to the distribution coefficient variation, depends of the porous medium thickness, which is practically insensitive for small porous medium thicknesses. The analytical solution for the radioisotope concentration is compared with experimental and numerical results available in literature.

  3. Advanced Stirling Radioisotope Generator (ASRG) Thermal Power Model in MATLAB

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen, J.

    2012-01-01

    This paper presents a one-dimensional steady-state mathematical thermal power model of the ASRG. It aims to provide a guideline of understanding how the ASRG works and what can change its performance. The thermal dynamics and energy balance of the generator is explained using the thermal circuit of the ASRG. The Stirling convertor performance map is used to represent the convertor. How the convertor performance map is coupled in the thermal circuit is explained. The ASRG performance characteristics under i) different sink temperatures and ii) over the years of mission (YOM) are predicted using the one-dimensional model. Two Stirling converter control strategies, i) fixing the hot-end of temperature of the convertor by adjusting piston amplitude and ii) fixing the piston amplitude, were tested in the model. Numerical results show that the first control strategy can result in a higher system efficiency than the second control strategy when the ambient gets warmer or the general-purpose heat source (GPHS) fuel load decays over the YOM. The ASRG performance data presented in this paper doesn't pertain to the ASRG flight unit. Some data of the ASRG engineering unit (EU) and flight unit that are available in public domain are used in this paper for the purpose of numerical studies.

  4. RARE KAON DECAYS.

    SciTech Connect

    LITTENBERG, L.

    2005-07-19

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  5. Charmless B Decays

    SciTech Connect

    Gradl, Wolfgang; /Edinburgh U.

    2007-03-06

    Rare charmless hadronic B decays are a good testing ground for the standard model. The dominant amplitudes contributing to this class of B decays are CKM suppressed tree diagrams and b {yields} s or b {yields} d loop diagrams (''penguins''). These decays can be used to study interfering standard model (SM) amplitudes and CP violation. They are sensitive to the presence of new particles in the loops, and they provide valuable information to constrain theoretical models of B decays. The B factories BABAR at SLAC and Belle at KEK produce B mesons in the reaction e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B}. So far they have collected integrated luminosities of about 406 fb{sup -1} and 600 fb{sup -1}, respectively. The results presented here are based on subsets of about 200-500 fb{sup -1} and are preliminary unless a journal reference is given.

  6. Radiative B Decays

    SciTech Connect

    Bard, D.; /Imperial Coll., London

    2011-11-23

    I discuss recent results in radiative B decays from the Belle and BaBar collaborations. I report new measurements of the decay rate and CP asymmetries in b {yields} s{gamma} and b {yields} d{gamma} decays, and measurements of the photon spectrum in b {yields} s{gamma}. Radiative penguin decays are flavour changing neutral currents which do not occur at tree level in the standard model (SM), but must proceed via one loop or higher order diagrams. These transitions are therefore suppressed in the SM, but offer access to poorlyknown SM parameters and are also a sensitive probe of new physics. In the SM, the rate is dominated by the top quark contribution to the loop, but non-SM particles could also contribute with a size comparable to leading SM contributions. The new physics effects are potentially large which makes them theoretically very interesting, but due to their small branching fractions they are typically experimentally challenging.

  7. Decaying radiolabelled lymphocytes and method of using same background of the invention

    SciTech Connect

    Chambers, G.P.

    1994-12-30

    Decaying radiolabelled lymphocytes and a method of using same are disclosed. A radiolabelled T-cell lymphocyte including a T-cell containing a Beta-emitting isotope which decays to an alpha-emitting isotope is provided. Alternatively, the T-cell may contain a Beta-emitting isotope which decays one of an x-ray and gamma-emitting isotope. A therapeutic radioisotope treatment method includes the steps of removing a cancerous nodule containing T-cells from a mammal, introducing into the T-cells a Beta-emitting isotope which decays to an alpha-emitting isotope and infusing the T-cells containing the Beta-emitting isotope which decays to an alpha-emitting isotope into the mammal. As an alternative, the treatment method may introduce into the T-cells a Beta-emitting isotope which decays to an x-ray or gamma-emitting isotope. Then, according to the alternative method, after the radioactive T- cells are infused into the mammal, the patient is monitored with a radiation detector to determine the location of T-cells containing the isotopes.

  8. Absolute age Determinations on Diamond by Radioisotopic Methods: NOT the way to Accurately Identify Diamond Provenance

    NASA Astrophysics Data System (ADS)

    Shirey, S. B.

    2002-05-01

    Gem-quality diamond contains such low abundances of parent-daughter radionuclides that dating the diamond lattice directly by isotopic measurements has been and will be impossible. Absolute ages on diamonds typically are obtained through measurements of their syngenetic mineral inclusions: Rb-Sr in garnet; Sm-Nd in garnet and pyroxene; Re-Os and U-Th-Pb in sulfide; K-Ar in pyroxene; and U-Pb in zircon. The application of the first two isotope schemes in the list requires putting together many inclusions from many diamonds whereas the latter isotope schemes permit ages on single diamonds. The key limitations on the application of these decay pairs are the availability and size of the inclusions, the abundance levels of the radionuclides, and instrumental sensitivity. Practical complications of radioisotope dating of inclusions are fatal to the application of the technique for diamond provenance. In all mines, the ratio of gem-quality diamonds to stones with datable inclusions is very high. Thus there is no way to date the valuable, marketable stones that are part of the conflict diamond problem, just their rare, flawed cousins. Each analysis destroys the diamond host plus the inclusion and can only be carried out in research labs by highly trained scientists. Thus, these methods can not be automated or applied to the bulk of diamond production. The geological problems with age dating are equally fatal to its application to diamond provenance. From the geological perspective, for age determination to work as a tool for diamond provenance studies, diamond ages would have to be specific to particular kimberlites or kimberlite fields and different between fields. The southern African Kaapvaal-Zimbabwe Craton and Limpopo Mobile Belt is the only cratonic region where age determinations have been applied on a large enough scale to a number of kimberlites to illustrate the geological problems in age measurements for diamond provenance. However, this southern African example

  9. A small low energy cyclotron for radioisotope measurements

    SciTech Connect

    Bertsche, K.J.

    1989-11-01

    Direct detection of {sup 14}C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the cyclotrino'') was proposed for direct detection of radiocarbon in 1980. This combined the suppression of background through the use of negative ions, which had been used effectively in tandem accelerators, with the high intrinsic mass resolution of a cyclotron. Development of a small electrostatically-focused cyclotron for use as a mass spectrometer was previously reported but the sensitivity needed for detection of {sup 14}C at natural abundance was not achieved. The major contributions of this work are the integration of a high current external ion source with a small flat-field, electrostatically-focused cyclotron to comprise a system capable of measuring {sup 14}C at natural levels, and the analysis of ion motion in such a cyclotron, including a detailed analysis of phase bunching and its effect on mass resolution. A high current cesium sputter negative ion source generates a beam of carbon ions which is pre-separated with a Wien filter and is transported to the cyclotron via a series of electrostatic lenses. Beam is injected radially into the cyclotron using electrostatic deflectors and an electrostatic mirror. Axial focusing is entirely electrostatic. A microchannel plate detector is used with a phase-grated output. In its present form the system is capable of improving the sensitivity of detecting {sup 14}C in some biomedical experiments by a factor of 10{sup 4}. Modifications are discussed which could bring about an additional factor of 100 in sensitivity, which is important for archaeological and geological applications. Possibilities for measurements of other isotopes, such as {sup 3}H, and {sup 10}Be, and {sup 26}Al, are discussed. 70 refs.

  10. Radioisotopes and the history of nucleosynthesis in the galaxy.

    PubMed

    Hohenberg, C M

    1969-10-10

    Nearly all of the heavier elements seem to have been assembled by successive neutron captures occurring in two distinct processes: the s (slow) process refers to neutron capture at a rate which is slow compared to the intervening beta-decay; the r (rapid) process refers to neutron capture at a rate which is rapid compared to the beta process. It is becoming increasingly apparent that simple models for galactic r-process nucleosynthesis are inadequate. Modern astronomical observations, which indicate that the bulk of r-process synthesis may have occurred early in the life of the galaxy, cannot be ignored. Recent data on the fissiogenic xenon in whitlockite from the St. Severin meteorite also place stringent conditions on permissible models for element synthesis. It appears that neither sudden nor continuous models for element formation are consistent with isotopic data now available. I propose a more complex model for the synthesis of solar system material in which the r-process is allowed to occur in three distinct modes: a "prompt" synthesis early in the history of the galaxy, a "continuous" synthesis whereby r-process products are continuously added to the galactic mix, and a "last-minute" synthesis which enriches the solar nebula with r-process material shortly before the formation of the solar system. Calculations based on the present abundances of uranium-235, uranium-238, and thorium-232 and the measured abundances of iodine-129 and plutonium-244 present when meteorites began to retain xenon indicate that the galactic age is between 8.0 and 8.8 billion years, with the initial "prompt" synthesis accounting for 81 to 89 percent of the total r-process material ever produced, the "last-minute" synthesis contributing between 11 and 13 percent, and 0 to 8 percent occurring in the continuous mode. The time interval between the isolation of the solar nebula from galactic r-process and the onset of xenon retention in meteorites lies between 176 and 179 million years.

  11. Development of a beam line for radio-isotope production at the KOMAC

    NASA Astrophysics Data System (ADS)

    Kim, Han-Sung

    2016-09-01

    A new beam line of the 100-MeV proton linac at the KOMAC (Korea Multi-purpose Accelerator Complex), aiming for RI (radioisotope) production has been constructed reflecting the increasing demands for various RIs (radioisotopes), such as Sr-82 and Cu-67 for medical applications. Proton beam with beam energy of 100 MeV and an average current of 0.6 mA is directed to the 100-mm-diameter production target through a beam window made of aluminum-beryllium alloy. Major components of the newly-installed beam line include electromagnets for bending and focusing, beam diagnostic systems such as a BPM (beam position monitor) and a BCM (beam current monitor), and a vacuum pumping system based on an ion pump. In this paper, the design features and the installation of the RI-production beam line at the KOMAC are given.

  12. Effect of amplified spontaneous emission on selectivity of laser photoionisation of the 177Lu radioisotope

    NASA Astrophysics Data System (ADS)

    D'yachkov, A. B.; Gorkunov, A. A.; Labozin, A. V.; Mironov, S. M.; Panchenko, V. Ya; Firsov, V. A.; Tsvetkov, G. O.

    2016-06-01

    A significant deselecting effect of amplified spontaneous emission has been observed in the experiments on selective laser photoionisation of the 177Lu radioisotope according to the scheme 5d6s2 2D3/2 → 5d6s6p 4Fo5/2 (18505 cm-1) → 5d6s7s 4D3/2(37194 cm-1) → autoionisation state (53375 cm-1). The effect is conditioned by involvement of non-target isotopes from the lower metastable level 5d6s2 2D5/2(1994 cm-1) into the ionisation process. Spectral filtering of spontaneous emission has allowed us to significantly increase the selectivity of the photoionisation process of the radioisotope and to attain a selectivity value of 105 when using saturating light intensities.

  13. Light weight radioisotope heater unit (LWRHU): a technical description of the reference design

    SciTech Connect

    Tate, R.E.

    1982-01-01

    The Light Weight Radioisotope Heater Unit (LWRHU), a new radioisotope heater unit for use in space missions, is a /sup 238/PuO/sub 2/-fueled unit designed to provide a thermal watt in dispersed locations on a spacecraft. The LWRHU is required to maintain the temperature of a component at a level where the component will function reliably in space. Two major constraints are placed on the unit's design; it must be as light as possible and must provide enough protection to immobilize the plutonium fuel to the maximum extent in all phases of the unit's lifetime. The four components are pelletized fuel, platinum-alloy encapsulation, pyrolytic graphite thermal insulation, and high-technology graphite ablation shell. The LWRHU is a cylinder 32 mm (1.26 in.) high and 26 mm (1.02 in.) in diameter. It weighs slightly less than 40 g(.09 lb).

  14. High efficiency β radioisotope energy conversion using reciprocating electromechanical converters with integrated betavoltaics

    NASA Astrophysics Data System (ADS)

    Duggirala, Rajesh; Li, Hui; Lal, Amit

    2008-04-01

    We demonstrate a 5.1% energy conversion efficiency Ni63 radioisotope power generator by integrating silicon betavoltaic converters with radioisotope actuated reciprocating piezoelectric unimorph cantilever converters. The electromechanical energy converter efficiently utilizes both the kinetic energy and the electrical charge of the 0.94μW β radiation from a 9mCi Ni63 thin film source to generate maximum (1) continuous betavoltaic electrical power output of 22nW and (2) pulsed piezoelectric electrical power output of 750μW at 0.07% duty cycle. The electromechanical converters can be potentially used to realize 100year lifetime power sources for powering periodic sampling remote wireless sensor microsystems.

  15. Radioisotope thermal photovoltaic application of the GaSb solar cell

    NASA Technical Reports Server (NTRS)

    Morgan, M. D.; Horne, W. E.; Day, A. C.

    1991-01-01

    An examination of a RTVP (radioisotopic thermophotovoltaic) conceptual design has shown a high potential for power densities well above those achievable with radioisotopic thermoelectric generator (RTG) systems. An efficiency of 14.4 percent and system specific power of 9.25 watts/kg were predicted for a system with sixteen GPHS (general purpose heat source) sources operating at 1100 C. The models also showed a 500 watt system power by the strontium-90 isotope at 1200 C at an efficiency of 17.0 percent and a system specific power of 11.8 watts/kg. The key to this level of performance is a high-quality photovoltaic cell with narrow bandgap and a reflective rear contact. Recent work at Boeing on GaSb cells and transparent back GaAs cells indicate that such a cell is well within reach.

  16. Radioisotope Thermophotovoltaic (RTPV) Generator and Its Applicability to an Illustrative Space Mission

    SciTech Connect

    Schock, A.; Mukunda, M.; Or, T.; Kumar, V.; Summers, G.

    1994-02-14

    The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. Instead of conducting a generic study, it was decided to focus the design effort by directing it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a post-encounter cruise lasting up to one year.

  17. Integration of Americium Heat Source into the Advanced Stirling Radioisotope Generator

    NASA Astrophysics Data System (ADS)

    Schulze, Erich; Quinn, Richard

    2014-08-01

    The Lockheed Martin developed Advanced Stirling Radioisotope Generator (ASRG) design uses similar technology as proposed for the European Space Agency (ESA) Radioisotope Power System (RPS) development program but different isotopes. The RPS uses americium, 241Am isotope, while the ASRG uses plutonium, 238Pu isotope. The 238Pu isotope provides four times greater thermal output per kilogram than the 241Am isotope. Lockheed Martin performed an internally funded feasibility assessment that determined integration of a 241Am fueled heat source into the ASRG is achievable with no changes to ASRG technology and only structural and volumetric design considerations required. Lockheed Martin is interested in developing collaborative partnerships with the United Kingdom (UK) for the ESA RPS development program.

  18. Usage of Multi-Mission Radioisotope Thermoelectric Generators (MMRTGs) for Future Potential Missions

    NASA Technical Reports Server (NTRS)

    Zakrajsek, June F.; Cairns-Gallimore, Dirk; Otting, Bill; Johnson, Steve; Woerner, Dave

    2016-01-01

    The goal of NASAs Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet the needs of the missions. To meet this goal, the RPS Program, working closely with the Department of Energy, performs mission and system studies (such as the recently released Nuclear Power Assessment Study), evaluates the readiness of promising technologies to infuse in future generators, assesses the sustainment of key RPS capabilities and knowledge, forecasts and tracks the Programs budgetary needs, and disseminates current information about RPS to the community of potential users. This presentation focuses on the needs of the mission community and provides users a better understanding of how to integrate the MMRTG (Multi-Mission Radioisotope Thermoelectric Generator).

  19. COMPASS Final Report: Radioisotope Electric Propulsion (REP) Centaur Orbiter New Frontiers Mission

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2011-01-01

    Radioisotope Electric Propulsion (REP) has been shown in past studies to enable missions to outer planetary bodies including the orbiting of Centaur asteroids. Key to the feasibility for REP missions are long life, low power electric propulsion (EP) devices, low mass Radioisotope Power System (RPS) and light spacecraft (S/C) components. In order to determine the key parameters for EP devices to perform these REP missions a design study was completed to design an REP S/C to orbit a Centaur in a New Frontiers (NF) cost cap. The design shows that an orbiter using several long lived (approx.200 kg xenon (Xe) throughput), low power (approx.700 W) Hall thrusters teamed with six (150 W each) Advanced Stirling Radioisotope Generators (ASRG) can deliver 60 kg of science instruments to a Centaur in 10 yr within the NF cost cap. Optimal specific impulses (Isp) for the Hall thrusters were found to be around 2000 s with thruster efficiencies over 40 percent. Not only can the REP S/C enable orbiting a Centaur (when compared to an all chemical mission only capable of flybys) but the additional power from the REP system can be used to enhance science and simplify communications. The mission design detailed in this report is a Radioisotope Power System (RPS) powered EP science orbiter to the Centaur Thereus with arrival 10 yr after launch, ending in a 1 yr science mapping mission. Along the trajectory, approximately 1.5 yr into the mission, the REP S/C does a flyby of the Trojan asteroid Tlepolemus. The total (Delta)V of the trajectory is 8.9 km/s. The REP S/C is delivered to orbit on an Atlas 551 class launch vehicle with a Star 48 B solid rocket stage

  20. Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

    SciTech Connect

    Robert C. O'Brien; Andrew C. Klein; William T. Taitano; Justice Gibson; Brian Myers; Steven D. Howe

    2011-02-01

    Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

  1. Development of a propulsion system and component test facility for advanced radioisotope powered Mars Hopper platforms

    SciTech Connect

    Robert C. O'Brien; Nathan D. Jerred; Steven D. Howe

    2011-02-01

    Verification and validation of design and modeling activities for radioisotope powered Mars Hopper platforms undertaken at the Center for Space Nuclear Research is essential for proof of concept. Previous research at the center has driven the selection of advanced material combinations; some of which require specialized handling capabilities. The development of a closed and contained test facility to forward this research is discussed within this paper.

  2. Vibration Testing of the Pluto/New Horizons Radioisotope Thermoelectric Generator

    SciTech Connect

    Charles D. Griffin

    2006-06-01

    The Radioisotopic Thermal Generator (RTG) for the Pluto/New Horizons spacecraft was subjected to a flight dynamic acceptance test to demonstrate that it would perform successfully following launch. Seven RTGs of this type had been assembled and tested at Mound, Ohio from 1984 to 1997. This paper chronicles major events in establishing a new vibration test laboratory at the Idaho National Laboratory and the nineteen days of dynamic testing.

  3. A simple and selective method for the separation of Cu radioisotopes from nickel.

    PubMed

    Fan, Xianfeng; Parker, David J; Smith, Mike D; Ingram, Andy; Yang, Zhufang; Seville, Jonathan P K

    2006-10-01

    Separation of copper radioisotopes from a nickel target is normally performed using solvent extraction or anion exchange rather than using cationic exchange. A commonly held opinion is that cationic exchangers have very similar thermodynamic complexation constants for metallic ions with identical charges, therefore making the separation very difficult or impossible. The results presented in this article indicate that the selectivity of Chelex-100 (a cationic ion exchanger) for Cu radioisotope and Ni ions not only depends on the thermodynamic complexation constant in the resin but also markedly varies with the concentration of mobile H+. In our developed method, separation of copper radioisotopes from a nickel target was fulfilled in a column filled with Chelex-100 via controlling the HNO3 concentration of the eluent, and the separation is much more effective, simple and economical in comparison with the common method of anion exchange. For an irradiated nickel target with 650 mg Ni, after separation, the loss of Cu radioisotopes in the nickel portion was reduced from 30% to 0.33% of the total initial radioactivity and the nickel mixed into the radioactive products was reduced from 9.5 to 0.5 mg. This significant improvement will make subsequent labeling much easier and reduce consumption of chelating agents and other chemicals during labeling. If the labeled agent is used in human medical applications, the developed method will significantly decrease the uptake of Ni and chelating agents by patients, therefore reducing both the stress on human body associated with clearing the chemicals from blood and tissue and the risk of various types of acute and chronic disorder due to exposure to Ni.

  4. Polymethylmethacrylate and radioisotopes in vertebral augmentation: an explanation of underlying principles.

    PubMed

    Hirsch, Ariel E; Rosenstein, Barry S; Medich, David C; Martel, Christopher B; Hirsch, Joshua A

    2009-01-01

    We recently reported a novel concept for combining radioactive isotope technology with polymethylmethacrylate (PMMA) cement used for vertebral augmentation and have advocated that pain physicians become aware of this new concept when treating malignant compression fractures. The use of vertebral augmentation for malignant compression fractures is steadily increasing, and the goal of this novel approach would be to stabilize the fractured vertebral body while also controlling proliferation of the tumor cells in the vertebral body that caused the vertebral fracture. This approach would therefore provide mechanical stabilization of the fractured vertebral body at the same time as direct targeting of the cancer cells causing the fracture. For our analysis, we investigated six specific radioisotopes with regard to physical and biologic properties as they would interact with PMMA and local bone metastatic disease, taking into consideration anatomical, biological and physical characteristics. The radioisotopes investigated include beta emitting (plus and minus) sources, as well as low energy and mid-energy photon sources and are: P-32, Ho-166, Y-90, I-125, F-18, and Tc-99m. We review the advantages and disadvantages of each radioisotope. In addition, this paper serves to provide pain physicians with a basic background of the biologic principles (Biologically Effective Dose) and statistical modeling (Monte Carlo method) used in that analysis. We also review the potential complications when using radioactive sources in a clinical setting. Understanding the methodologies employed in determining isotope selection empowers the practitioner by fostering understanding of this presently theoretical treatment option. We believe that embedding radioisotopes in PMMA is merely a first step in the road of local treatment for symptomatic local lesions in the setting of systemic disease.

  5. Advanced Radioisotope Power System Enabled Titan Rover Concept with Inflatable Wheels

    NASA Technical Reports Server (NTRS)

    Balint, Tibor S.; Schriener, Timothy M.; Shirley, James H.

    2006-01-01

    This viewgraph presentation reviews study into exploration of Titan. Including a possible Titan Rover that would use the advanced radioisotope power system (RPS). The goal of the study is to demonstrate a simple, credible and affordable rover mission concept for Titan in-situ exploration, enabled by an Advanced RPS. The presentation reviews the possible launch vehicle, and trajectory options; desired instrumentation that would be aboard the rover; and considerations for the design of the rover.

  6. Theoretical cross section calculations of medical 13N and 18F radioisotope using alpha induced reaction

    NASA Astrophysics Data System (ADS)

    Kılınç, F.; Karpuz, N.; ćetin, B.

    2017-02-01

    In medical physics, radionuclides are needed to diagnose functional disorders of organs and to diagnose and treat many diseases. Nuclear reactions are significant for the productions of radionuclides. It is important to analyze the cross sections for much different energy. In this study, reactional cross sections calculations on 13N, 18F radioisotopes are with TALYS 1.6 nuclear reaction simulation code. Cross sections calculated and experimental data taken from EXFOR library were compared

  7. Nuclear energy in the service of biomedicine: the U.S. Atomic Energy Commission's radioisotope program, 1946-1950.

    PubMed

    Creager, Angela N H

    2006-01-01

    The widespread adoption of radioisotopes as tools in biomedical research and therapy became one of the major consequences of the "physicists' war" for postwar life science. Scientists in the Manhattan Project, as part of their efforts to advocate for civilian uses of atomic energy after the war, proposed using infrastructure from the wartime bomb project to develop a government-run radioisotope distribution program. After the Atomic Energy Bill was passed and before the Atomic Energy Commission (AEC) was formally established, the Manhattan Project began shipping isotopes from Oak Ridge. Scientists and physicians put these reactor-produced isotopes to many of the same uses that had been pioneered with cyclotron-generated radioisotopes in the 1930s and early 1940s. The majority of early AEC shipments were radioiodine and radiophosphorus, employed to evaluate thyroid function, diagnose medical disorders, and irradiate tumors. Both researchers and politicians lauded radioisotopes publicly for their potential in curing diseases, particularly cancer. However, isotopes proved less successful than anticipated in treating cancer and more successful in medical diagnostics. On the research side, reactor-generated radioisotopes equipped biologists with new tools to trace molecular transformations from metabolic pathways to ecosystems. The U.S. government's production and promotion of isotopes stimulated their consumption by scientists and physicians (both domestic and abroad), such that in the postwar period isotopes became routine elements of laboratory and clinical use. In the early postwar years, radioisotopes signified the government's commitment to harness the atom for peace, particularly through contributions to biology, medicine, and agriculture.

  8. NASA Glenn Research Center Support of the Advanced Stirling Radioisotope Generator Project

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Wong, Wayne A.

    2015-01-01

    A high-efficiency radioisotope power system was being developed for long-duration NASA space science missions. The U.S. Department of Energy (DOE) managed a flight contract with Lockheed Martin Space Systems Company to build Advanced Stirling Radioisotope Generators (ASRGs), with support from NASA Glenn Research Center. DOE initiated termination of that contract in late 2013, primarily due to budget constraints. Sunpower, Inc., held two parallel contracts to produce Advanced Stirling Convertors (ASCs), one with Lockheed Martin to produce ASC-F flight units, and one with Glenn for the production of ASC-E3 engineering unit "pathfinders" that are built to the flight design. In support of those contracts, Glenn provided testing, materials expertise, Government-furnished equipment, inspection capabilities, and related data products to Lockheed Martin and Sunpower. The technical support included material evaluations, component tests, convertor characterization, and technology transfer. Material evaluations and component tests were performed on various ASC components in order to assess potential life-limiting mechanisms and provide data for reliability models. Convertor level tests were conducted to characterize performance under operating conditions that are representative of various mission conditions. Despite termination of the ASRG flight development contract, NASA continues to recognize the importance of high-efficiency ASC power conversion for Radioisotope Power Systems (RPS) and continues investment in the technology, including the continuation of the ASC-E3 contract. This paper describes key Government support for the ASRG project and future tests to be used to provide data for ongoing reliability assessments.

  9. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    NASA Astrophysics Data System (ADS)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich; Nares, Chankow; Hao, Quang Nguyen

    2016-01-01

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  10. Radioisotopes for the palliation of metastatic bone cancer: a systematic review.

    PubMed

    Finlay, Ilora G; Mason, Malcolm D; Shelley, Mike

    2005-06-01

    Strontium-89 and samarium-153 are radioisotopes that are approved in the USA and Europe for the palliation of pain from metastatic bone cancer, whereas rhenium-186 and rhenium-188 are investigational. Radioisotopes are effective in providing pain relief with response rates of between 40% and 95%. Pain relief starts 1-4 weeks after the initiation of treatment, continues for up to 18 months, and is associated with a reduction in analgesic use in many patients. Thrombocytopenia and neutropenia are the most common toxic effects, but they are generally mild and reversible. Repeat doses are effective in providing pain relief in many patients. The effectiveness of radioisotopes can be greater when they are combined with chemotherapeutic agents such as cisplatin. Some studies with 89Sr and 153Sm indicate a reduction of hot spots on bone scans in up to 70% of patients, and suggest a possible tumoricidal action. Further studies are needed to address the questions of which isotope to use, what dose and schedule to use, and which patients will respond.

  11. The copper radioisotopes: a systematic review with special interest to 64Cu.

    PubMed

    Niccoli Asabella, Artor; Cascini, Giuseppe Lucio; Altini, Corinna; Paparella, Domenico; Notaristefano, Antonio; Rubini, Giuseppe

    2014-01-01

    Copper (Cu) is an important trace element in humans; it plays a role as a cofactor for numerous enzymes and other proteins crucial for respiration, iron transport, metabolism, cell growth, and hemostasis. Natural copper comprises two stable isotopes, (63)Cu and (65)Cu, and 5 principal radioisotopes for molecular imaging applications ((60)Cu, (61)Cu, (62)Cu, and (64)Cu) and in vivo targeted radiation therapy ((64)Cu and (67)Cu). The two potential ways to produce Cu radioisotopes concern the use of the cyclotron or the reactor. A noncopper target is used to produce noncarrier-added Cu thanks to a chemical separation from the target material using ion exchange chromatography achieving a high amount of radioactivity with the lowest possible amount of nonradioactive isotopes. In recent years, Cu isotopes have been linked to antibodies, proteins, peptides, and nanoparticles for preclinical and clinical research; pathological conditions that influence Cu metabolism such as Menkes syndrome, Wilson disease, inflammation, tumor growth, metastasis, angiogenesis, and drug resistance have been studied. We aim to discuss all Cu radioisotopes application focusing on (64)Cu and in particular its form (64)CuCl2 that seems to be the most promising for its half-life, radiation emissions, and stability with chelators, allowing several applications in oncological and nononcological fields.

  12. Accelerator mass spectrometry and radioisotope detection at the Argonne FN tandem facility

    SciTech Connect

    Henning, W.; Kutschera, W.; Paul, M.; Smither, R.K.; Stephenson, E.J.; Yntema, J.L.

    1980-01-01

    The Argonne FN tandem accelerator and standard components of its experimental heavy-ion research facility, have been used as a highly-sensitive mass spectrometer to detect several long-lived radioisotopes and measure their concentration by counting of accelerated ions. Background beams from isobaric nuclei have been eliminated by combining the dispersion from the energy loss in a uniform Al foil stack with the momentum resolution of an Enge split-pole magnetic spectrograph. Radioisotope concentrations in the following ranges have been measured: /sup 14/C//sup 12/C = 10/sup -12/ to 10/sup -13/, /sup 26/Al//sup 27/Al = 10/sup -10/ to 10/sup -12/, /sup 32/Si/Si = 10/sup -8/ to 10/sup -14/, /sup 36/Cl/Cl = 10/sup -10/ to 10/sup -11/. Particular emphasis was put on exploring to what extent the technique of identifying and counting individual ions in an accelerator beam can be conveniently used to determine nuclear quantities of interest when their measurement involves very low radioisotope concentrations. The usefulness of this method can be demonstrated by measuring the /sup 26/Mg(p,n)/sup 26/Al(7.2 x 10/sup 5/ yr) cross section at proton energies in the astrophysically interesting range just above threshold, and by determining the previously poorly known half life of /sup 32/Si.

  13. Test Program for Stirling Radioisotope Generator Hardware at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Bolotin, Gary S.; Oriti, Salvatore M.

    2014-01-01

    Stirling-based energy conversion technology has demonstrated the potential of high efficiency and low mass power systems for future space missions. This capability is beneficial, if not essential, to making certain deep space missions possible. Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. A variety of flight-like hardware, including Stirling convertors, controllers, and housings, was designed and built under the ASRG flight development project. To support future Stirling-based power system development NASA has proposals that, if funded, will allow this hardware to go on test at the NASA Glenn Research Center (GRC). While future flight hardware may not be identical to the hardware developed under the ASRG flight development project, many components will likely be similar, and system architectures may have heritage to ASRG. Thus the importance of testing the ASRG hardware to the development of future Stirling-based power systems cannot be understated. This proposed testing will include performance testing, extended operation to establish an extensive reliability database, and characterization testing to quantify subsystem and system performance and better understand system interfaces. This paper details this proposed test program for Stirling radioisotope generator hardware at NASA GRC. It explains the rationale behind the proposed tests and how these tests will meet the stated objectives.

  14. Test Program for Stirling Radioisotope Generator Hardware at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Bolotin, Gary S.; Oriti, Salvatore M.

    2015-01-01

    Stirling-based energy conversion technology has demonstrated the potential of high efficiency and low mass power systems for future space missions. This capability is beneficial, if not essential, to making certain deep space missions possible. Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-W radioisotope power system. A variety of flight-like hardware, including Stirling convertors, controllers, and housings, was designed and built under the ASRG flight development project. To support future Stirling-based power system development NASA has proposals that, if funded, will allow this hardware to go on test at the NASA Glenn Research Center. While future flight hardware may not be identical to the hardware developed under the ASRG flight development project, many components will likely be similar, and system architectures may have heritage to ASRG. Thus, the importance of testing the ASRG hardware to the development of future Stirling-based power systems cannot be understated. This proposed testing will include performance testing, extended operation to establish an extensive reliability database, and characterization testing to quantify subsystem and system performance and better understand system interfaces. This paper details this proposed test program for Stirling radioisotope generator hardware at NASA Glenn. It explains the rationale behind the proposed tests and how these tests will meet the stated objectives.

  15. Specification for strontium-90 500-watt(e) radioisotopic thermoelectric generator. Final report

    SciTech Connect

    Hammel, T.; Himes, J.; Lieberman, A.; McGrew, J.; Owings, D.; Schumann, F.

    1983-04-01

    A conceptual design for a demonstration 500-watt(e) radioisotopic thermoelectric generator has been created for the Department of Energy. The design effort was divided into two tasks, viz., create a design specification for a capsule strength member that utilizes a standard Strontium-90 fluoride-filled WESF inner liner, and create a conceptual design for a 500-watt(e) RTG. Both tasks have been accomplished. The strength-member specification was designed to survive an external pressure of 24,500 psi and meet the requirements of special-form radioisotope heat sources. Therefore the capsule can, if desired, be licensed for domestic and international transport. The design for the RTG features a radioisotopic heat source, an array of nine capsules in a tungsten biological shield, four current-technology series-connected thermoelectric-conversion modules, low-conductivity thermal insulation, and a passive finned-housing radiator for waste-heat dissipation. The preliminary RTG specification formulated previous to contract award has been met or exceeded. The power source will generate the required power for the required service period at 28 volts dc with a conversion efficiency of 8%, provided the existing in-pool capsules at WESF meet the assumed thermal-inventory requirements.

  16. Radioisotopic neutron transmission spectrometry: Quantitative analysis by using partial least-squares method.

    PubMed

    Kim, Jong-Yun; Choi, Yong Suk; Park, Yong Joon; Jung, Sung-Hee

    2009-01-01

    Neutron spectrometry, based on the scattering of high energy fast neutrons from a radioisotope and slowing-down by the light hydrogen atoms, is a useful technique for non-destructive, quantitative measurement of hydrogen content because it has a large measuring volume, and is not affected by temperature, pressure, pH value and color. The most common choice for radioisotope neutron source is (252)Cf or (241)Am-Be. In this study, (252)Cf with a neutron flux of 6.3x10(6)n/s has been used as an attractive neutron source because of its high flux neutron and weak radioactivity. Pulse-height neutron spectra have been obtained by using in-house built radioisotopic neutron spectrometric system equipped with (3)He detector and multi-channel analyzer, including a neutron shield. As a preliminary study, polyethylene block (density of approximately 0.947g/cc and area of 40cmx25cm) was used for the determination of hydrogen content by using multivariate calibration models, depending on the thickness of the block. Compared with the results obtained from a simple linear calibration model, partial least-squares regression (PLSR) method offered a better performance in a quantitative data analysis. It also revealed that the PLSR method in a neutron spectrometric system can be promising in the real-time, online monitoring of the powder process to determine the content of any type of molecules containing hydrogen nuclei.

  17. A new radioisotope tracing method of UHMWPE wear particle dispersion using 97Ru.

    PubMed

    Warner, Jacob A; Gladkis, Laura G; Timmers, Heiko

    2011-07-01

    A new method of radioisotope labelling, using the reaction 92Zr(12C,α3n)97Ru, has been demonstrated. The method places radioactive 97Ru tracer atoms into ultra-high molecular weight polyethylene (UHMWPE). The radioisotope 97Ru (half-life t1/2=2.9 days) was implanted in 5 mm×5 mm UHMWPE samples to a maximum depth of 5 μm. The radioisotope is identified via a characteristic gamma-ray emission from its daughter 97Tc at 216 keV. The new method is advantageous since the concentration profile of the 97Ru label is almost constant starting at the surface. In order to show the efficacy of the method for wear measurements on prostheses, the labeled UHMWPE samples were worn in a model system. The model system involved bi-directional sliding actuation on a steel block. Debris transport, via the two pathways linking the polymer with the articulating steel surface and with the lubricant, respectively, has been quantified. Surface roughness of the steel and the load on the steel were varied. Changing the surface roughness of the steel from (110±30) to (340±90) nm increased the amount of debris dispersed in the lubricant from (21±3)% to (67±3)%. Furthermore, changing the load from 1 to 5 kg also increased debris transport along this pathway.

  18. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    SciTech Connect

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich Nares, Chankow; Hao, Quang Nguyen

    2016-01-22

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  19. Decay of superdeformed bands

    SciTech Connect

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-12-31

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in {sup 194}Hg. 42 refs., 5 figs.

  20. Suppressed Charmed B Decay

    SciTech Connect

    Snoek, Hella Leonie

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  1. Flavor changing nucleon decay

    NASA Astrophysics Data System (ADS)

    Maekawa, Nobuhiro; Muramatsu, Yu

    2017-04-01

    Recent discovery of neutrino large mixings implies the large mixings in the diagonalizing matrices of 5 bar fields in SU (5) grand unified theory (GUT), while the diagonalizing matrices of 10 fields of SU (5) are expected to have small mixings like Cabibbo-Kobayashi-Maskawa matrix. We calculate the predictions of flavor changing nucleon decays (FCND) in SU (5), SO (10), and E6 GUT models which have the above features for mixings. We found that FCND can be the main decay mode and play an important role to test GUT models.

  2. Search for the decay

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianì, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Matthieu, K.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Ninci, D.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-08-01

    A search for decays is performed using 3 .0 fb1- of pp collision data recorded by the LHCb experiment during 2011 and 2012. The f 0(980) meson is reconstructed through its decay to the π + π - final state in the mass window 900 MeV /c 2 < m( π + π -) < 1080 MeV /c 2. No significant signal is observed. The first upper limits on the branching fraction of are set at 90 % (95 %) confidence level. [Figure not available: see fulltext.

  3. Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

    SciTech Connect

    Guerra Liberal, Francisco D. C. E-mail: adriana-tavares@msn.com; Tavares, Adriana Alexandre S. E-mail: adriana-tavares@msn.com; Tavares, João Manuel R. S.

    2014-11-01

    Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ({sup 32}P), strontium-89 ({sup 89}Sr), yttrium-90 ({sup 90}Y ), tin-117 ({sup 117m}Sn), samarium-153 ({sup 153}Sm), holmium-166 ({sup 166}Ho), thulium-170 ({sup 170}Tm), lutetium-177 ({sup 177}Lu), rhenium-186 ({sup 186}Re), rhenium-188 ({sup 188}Re), and radium-223 ({sup 223}Ra). Results: {sup 223}Ra alpha particles, {sup 177}Lu beta minus particles, and {sup 170}Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by {sup 89}Sr and {sup 153}Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than {sup 177}Lu beta minus particles and {sup 223}Ra alpha particles. Conclusions: {sup 223}Ra and {sup 177}Lu hold the highest potential for palliative treatment of bone metastases of all

  4. Decay Time of Cathodoluminescence

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2009-01-01

    Simple measurements of the decay time of cathodoluminescence are described. Cathodoluminescence is used in many devices, including computer monitors, oscilloscopes, radar displays and television tubes. The experimental setup is simple and easy to build. Two oscilloscopes, a function generator, and a fast photodiode are needed for the experiments.…

  5. Anatomy of decays

    NASA Astrophysics Data System (ADS)

    Bel, Lennaert; De Bruyn, Kristof; Fleischer, Robert; Mulder, Mick; Tuning, Niels

    2015-07-01

    The decays B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} probe the CP-violating mixing phases ϕ d and ϕ s , respectively. The theoretical uncertainty of the corresponding determinations is limited by contributions from penguin topologies, which can be included with the help of the U-spin symmetry of the strong interaction. We analyse the currently available data for B {/d, s 0} → D {/d, s -} D {/d, s +} decays and those with similar dynamics to constrain the involved non-perturbative parameters. Using further information from semileptonic B {/d 0} → D {/d -} ℓ + ν ℓ decays, we perform a test of the factorisation approximation and take non-factorisable SU(3)-breaking corrections into account. The branching ratios of the B {/d 0} → D {/d -} D {/d +}, B {/s 0} → D {/s -} D {/d +} and B {/s 0} → D {/s -} D {/s +}, B {/d 0} → D {/d -} D {/s +} decays show an interesting pattern which can be accommodated through significantly enhanced exchange and penguin annihilation topologies. This feature is also supported by data for the B {/s 0} → D {/d -} D {/d +} channel. Moreover, there are indications of potentially enhanced penguin contributions in the B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} decays, which would make it mandatory to control these effects in the future measurements of ϕ d and ϕ s . We discuss scenarios for high-precision measurements in the era of Belle II and the LHCb upgrade.

  6. Symmetry relations in nucleon decay

    NASA Astrophysics Data System (ADS)

    Hurlbert, Anya; Wilczek, Frank

    1980-05-01

    Some experimental consequences of the structure of the effective hamiltonian for nucleon decay are presented. New results concern relations among inclusive decay rates, a striking test of the kinship hypothesis involving μ+ polarization, and soft π theorems.

  7. Theory of weak hypernuclear decay

    SciTech Connect

    Dubach, J.F.; Feldman, G.B.; Holstein, B.R. |; de la Torre, L.

    1996-07-01

    The weak nomesonic decay of {Lambda}-hypernuclei is studied in the context of a one-meson-exchange model. Predictions are made for the decay rate, the {ital p}/{ital n} stimulation ratio and the asymmetry in polarized hypernuclear decay. Copyright {copyright} 1996 Academic Press, Inc.

  8. B Decays Involving Light Mesons

    SciTech Connect

    Eschrich, Ivo Gough; /UC, Irvine

    2007-01-09

    Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B {yields} {eta}{prime}({pi}, K, {rho}) modes, and a comprehensive Dalitz Plot analysis of B {yields} KKK decays.

  9. Superallowed Fermi beta decay

    SciTech Connect

    Hardy, J. C.; Towner, I. S.

    1998-12-21

    Superallowed 0{sup +}{yields}0{sup +} nuclear beta decay provides a direct measure of the weak vector coupling constant, G{sub V}. We survey current world data on the nine accurately determined transitions of this type, which range from the decay of {sup 10}C to that of {sup 54}Co, and demonstrate that the results confirm conservation of the weak vector current (CVC) but differ at the 98% confidence level from the unitarity condition for the Cabibbo-Kobayashi-Maskawa (CKM) matrix. We examine the reliability of the small calculated corrections that have been applied to the data, and assess the likelihood of even higher quality nuclear data becoming available to confirm or deny the discrepancy. Some of the required experiments depend upon the availability of intense radioactive beams. Others are possible today.

  10. Decay Dynamics of Tumors

    PubMed Central

    2016-01-01

    The fractional cell kill is a mathematical expression describing the rate at which a certain population of cells is reduced to a fraction of itself. We investigate the mathematical function that governs the rate at which a solid tumor is lysed by a cell population of cytotoxic lymphocytes. We do it in the context of enzyme kinetics, using geometrical and analytical arguments. We derive the equations governing the decay of a tumor in the limit in which it is plainly surrounded by immune cells. A cellular automaton is used to test such decay, confirming its validity. Finally, we introduce a modification in the fractional cell kill so that the expected dynamics is attained in the mentioned limit. We also discuss the potential of this new function for non-solid and solid tumors which are infiltrated with lymphocytes. PMID:27310010

  11. Reentry response of the lightweight radioisotope heater unit resulting from a Cassini Venus-Venus-Earth-Jupiter gravity assist maneuver accident

    SciTech Connect

    1996-12-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Lightweight Radioisotope Heater Unit (LWRHU) for Cassini/Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is generally assumed to be recession corresponding to 75% and 100% of the wall thickness. The 75% recession failure criteria allows for uncertainties that result mainly because of the high energies involved in the VVEJGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact with a clad that had been molten. Within the limitations of the methodologies and assumptions of the analyses, the results indicate that: (1) For a side-on stable LWRHU reentry, aeroshell ablation failures occur for all reentry angles. (2)For a side-on spinning LWRHU reentry, aeroshell ablation failures are minimal. (3) For the tumbling LWRHU reentry, the aeroshell survives for most angles. (4) For the thermostructural analyses, using both a 1% and 5% allowable strain, all reentry angles and orientations examined resulted in small localized failures, but aeroshell breach is not predicted for any case. The analyses included in this report concentrate on VVEJGA reentry scenarios. Analyses reported previously have demonstrated that the LWRHU has adequate design margin to survive reentry from orbital decay scenarios and most injection scenarios at speeds up to escape speeds. The exception is a narrow range of flight path angles that produce multiple skip trajectories which may have excessive ablation.

  12. A Saturn Ring Observer Mission Using Multi-Mission Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Abelson, Robert D.; Spilker, Thomas R.; Shirley, James H.

    2006-01-01

    Saturn remains one of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields. The primary objective of the mission would be to understand ring dynamics, including the microphysics of individual particles and small scale (meters to a few kilometers) phenomena such as particle agglomeration behavior. This would be accomplished by multispectral imaging of the rings at multiple key locations within the A and B rings, and by ring-particle imaging at an unprecedented resolution of 0.5 cm/pixel. The SRO spacecraft would use a Venus-Earth-Earth-Jupiter Gravity Assist (VEEJGA) and be aerocaptured into Saturn orbit using an advanced aeroshell design to minimize propellant mass. Once in orbit, the SRO would stand off from the ring plane 1 to 1.4 km using chemical thrusters to provide short propulsive maneuvers four times per revolution, effectively causing the SRO vehicle to ``hop'' above the ring plane. The conceptual SRO spacecraft would be enabled by the use of a new generation of multi-mission Radioisotope Power Systems (RPSs) currently being developed by NASA and DOE. These RPSs include the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and Stirling Radioisotope Generator (SRG). The RPSs would generate all necessary electrical power (>=330 We at beginning of life) during the 10-year cruise and 1-year science mission (~11 years total). The RPS heat would be used to maintain the vehicle's operating and survival temperatures, minimizing the need for electrical heaters. Such a mission could potentially launch in the 2015-2020 timeframe, with operations at Saturn commencing in approximately 2030.

  13. Recoil-Implantation Of Multiple Radioisotopes Towards Wear Rate Measurements And Particle Tracing In Prosthetic Joints

    SciTech Connect

    Warner, Jacob A.; Timmers, Heiko; Smith, Paul N.; Scarvell, Jennifer M.; Gladkis, Laura

    2011-06-01

    This study demonstrates a new method of radioisotope labeling of ultra-high molecular weight polyethylene inserts in prosthetic joints for wear studies. The radioisotopes {sup 97}Ru, {sup 100}Pd, {sup 100}Rh, and {sup 101m}Rh are produced in fusion evaporation reactions induced by {sup 12}C ions in a {sup 92}Zr target foil. The fusion products recoil-implant into ultra-high molecular weight polyethylene plugs, machined to fit into the surface of the inserts. During laboratory simulations of the joint motion, a wear rate of the labeled polyethylene may be measured and the pathways of wear debris particles can be traced by detecting characteristic gamma-rays. The concentration profiles of the radioisotopes extend effectively uniformly from the polyethylene surface to a depth of about 4 {mu}m. The multiplicity of labeling and the use of several gamma-ray lines aids with avoiding systematic measurement uncertainties. Two polyethylene plugs were labeled and one was fitted into the surface of the tibial insert of a knee prosthesis, which had been worn in. Actuation over close to 100,000 cycles with a 900 N axial load and a 24 deg. flexion angle removed (14{+-}1)% of the gamma-ray activity from the plug. Most of this activity dispersed into the serum lubricant identifying this as the important debris pathway. Less than 1% activity was transferred to the femoral component of the prosthesis and the measured activity on the tibial tray was insignificant. Assuming uniform wear across the superior surface of the insert, a wear rate of (12{+-}3) mm{sup 3}/Megacycle was determined. This is consistent with wear rate measurements under similar conditions using other techniques.

  14. Analysis, optimization, and assessment of radioisotope thermophotovoltaic system design for an illustrative space mission

    SciTech Connect

    Schock, A.; Mukunda, M.; Or, C.; Summers, G.

    1995-01-05

    A companion paper presented at this conference described the design of a Radioisotope Thermophotovoltaic (RTPV) Generator for an illustrative space mission (Pluto Fast Flyby). It presented a detailed design of an integrated system consisting of a radioisotope heat source, a thermophotovoltaic converter, and an optimized heat rejection system. The present paper describes the thermal, electrical, and structural analyses which led to that optimized design, and compares the computed RTPV performance to that of a Radioisotope Thermoelectric Generator (RTG) designed for the same mission. RTPVs are of course much less mature than RTGs, but our results indicate that---when fully developed---they could result in a 60% reduction of the heat source`s mass, cost, and fuel loading, a 50% reduction of generator mass, a tripling of the power system`s specific power, and a quadrupling of its efficiency. The paper concludes by briefly summarizing the RTPV`s current technology status and assessing its potential applicability for the PFF mission. For other power systems (e.g., RTGs), demonstrating their flight readiness for a long mission is a very time-consuming process to determine the long-term effect of temperature-induced degradation mechanisms. But for the case of the described RTPV design, the paper lists a number of factors, primarily its cold (0 to 10 {degree}C) converter temperature, that may greatly reduce the need for long-term tests to demonstrate generator lifetime. In any event, our analytical results suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the Pluto mission but also for other future missions requiring small, long-lived, low-mass generators. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. Analysis, Optimization, and Assessment of Radioisotope Thermophotovoltaic System Design for an Illustrative Space Mission

    SciTech Connect

    Schock, Alfred; Mukunda, Meera; Summers, G.

    1994-06-28

    A companion paper presented at this conference described the design of a Radioisotope Thermophotovoltaic (RTPV) Generator for an illustrative space mission (Pluto Fast Flyby). It presented a detailed design of an integrated system consisting of a radioisotope heat source, a thermophotovoltaic converter, and an optimized heat rejection system. The present paper describes the thermal, electrical, and structural analyses which led to that optimized design, and compares the computed RTPV performance to that of a Radioisotope Thermoelectric Generator (RTG) designed for the same mission. RTPV's are of course much less mature than RTGs, but our results indicate that - when fully developed - they could result in a 60% reduction of the heat source's mass, cost, and fuel loading, a 50% reduction of generator mass, a tripling of the power system's specific power, and a quadrupling of its efficiency. The paper concludes by briefly summarizing the RTPV's current technology status and assessing its potential applicability for the PFF mission. For other power systems (e.g. RTGs), demonstrating their flight readiness for a long mission is a very time-consuming process to determine the long-term effect of temperature-induced degradation mechanisms. But for the case of the described RTPV design, the paper lists a number of factors, primarily its cold (0 to 10 degrees C) converter temperature, that may greatly reduce the need for long-term tests to demonstrate generator lifetime. In any event, our analytical results suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the Pluto mission but also for other future missions requiring small, long-lived, low mass generators. Another copy is in the Energy Systems files.

  16. Recoil-Implantation Of Multiple Radioisotopes Towards Wear Rate Measurements And Particle Tracing In Prosthetic Joints

    NASA Astrophysics Data System (ADS)

    Warner, Jacob A.; Smith, Paul N.; Scarvell, Jennifer M.; Gladkis, Laura; Timmers, Heiko

    2011-06-01

    This study demonstrates a new method of radioisotope labeling of ultra-high molecular weight polyethylene inserts in prosthetic joints for wear studies. The radioisotopes 97Ru, 100Pd, 100Rh, and 101mRh are produced in fusion evaporation reactions induced by 12C ions in a 92Zr target foil. The fusion products recoil-implant into ultra-high molecular weight polyethylene plugs, machined to fit into the surface of the inserts. During laboratory simulations of the joint motion, a wear rate of the labeled polyethylene may be measured and the pathways of wear debris particles can be traced by detecting characteristic gamma-rays. The concentration profiles of the radioisotopes extend effectively uniformly from the polyethylene surface to a depth of about 4 μm. The multiplicity of labeling and the use of several gamma-ray lines aids with avoiding systematic measurement uncertainties. Two polyethylene plugs were labeled and one was fitted into the surface of the tibial insert of a knee prosthesis, which had been worn in. Actuation over close to 100,000 cycles with a 900 N axial load and a 24° flexion angle removed (14±1)% of the gamma-ray activity from the plug. Most of this activity dispersed into the serum lubricant identifying this as the important debris pathway. Less than 1% activity was transferred to the femoral component of the prosthesis and the measured activity on the tibial tray was insignificant. Assuming uniform wear across the superior surface of the insert, a wear rate of (12±3) mm3/Megacycle was determined. This is consistent with wear rate measurements under similar conditions using other techniques.

  17. A Saturn Ring Observer Mission Using Multi-Mission Radioisotope Power Systems

    SciTech Connect

    Abelson, Robert D.; Spilker, Thomas R.; Shirley, James H.

    2006-01-20

    Saturn remains one of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields. The primary objective of the mission would be to understand ring dynamics, including the microphysics of individual particles and small scale (meters to a few kilometers) phenomena such as particle agglomeration behavior. This would be accomplished by multispectral imaging of the rings at multiple key locations within the A and B rings, and by ring-particle imaging at an unprecedented resolution of 0.5 cm/pixel. The SRO spacecraft would use a Venus-Earth-Earth-Jupiter Gravity Assist (VEEJGA) and be aerocaptured into Saturn orbit using an advanced aeroshell design to minimize propellant mass. Once in orbit, the SRO would stand off from the ring plane 1 to 1.4 km using chemical thrusters to provide short propulsive maneuvers four times per revolution, effectively causing the SRO vehicle to 'hop' above the ring plane. The conceptual SRO spacecraft would be enabled by the use of a new generation of multi-mission Radioisotope Power Systems (RPSs) currently being developed by NASA and DOE. These RPSs include the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and Stirling Radioisotope Generator (SRG). The RPSs would generate all necessary electrical power ({>=}330 We at beginning of life) during the 10-year cruise and 1-year science mission ({approx}11 years total). The RPS heat would be used to maintain the vehicle's operating and survival temperatures, minimizing the need for electrical heaters. Such a mission could potentially launch in the 2015-2020 timeframe, with operations at Saturn commencing in approximately 2030.

  18. Too Much of a Good Thing ? Radioisotope Power Conversion Technology and `Waste' Heat in the Titan Environment

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph

    Unlike most solar system surface environments, Titan has an atmosphere that is both cold and dense. This means heat transfer to and from a vehicle is determined by convection, rather than by radiation which dominates on Earth and Mars. With surface temperatures near 94K, batteries and systems require heating to operate. Solar power is impractical, so a spacecraft intended to operate for longer than a few hours on Titan must have a radioisotope power source (RPS). Such sources convert heat from Plutonium decay into electricity, with an efficiency that varies from about 5% for thermoelectric systems to 20% for engine cycles such as Stirling. For vehicles with 100-200W electrical power, the 500-4000 W ‘waste’ heat in the Titan environment can be valuable in that it can be exploited to maintain thermal conditions inside the vehicle. The generally benign Titan environment, and the outstanding scientific and popular interest in its exploration, has attracted a number of mission concepts including a lander for Titan’s equatorial dunefields, light gas and hot air (‘Montgolfière’) balloons, airplanes, and capsules that float on its polar seas (e.g. the proposed Titan Mare Explorer.) However, the choice of conversion technology is key to the success of these different platforms. Waste heat can perturb meteorological measurements in several ways. First by creating a warm air plume (an effect observed on Viking and Curiosity.) Second, rain or seaspray falling onto hot radiator surfaces can evaporate causing a local enhancement of methane humidity. Third, sufficiently strong heating could perturb local winds. Similar effects, and the potential generation of effervescence or even fog, may result for capsules floating in liquid hydrocarbons. For landers and drifting buoys, these perturbations may significantly degrade environmental measurements, or at least demand tall meteorology masts, for the higher waste heat output of thermoelectric systems, and a Stirling system

  19. Radioactive decay data tables

    SciTech Connect

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

  20. Radioisotope Thermoelectric Generator Package O-Ring Seal Material Validation Testing

    SciTech Connect

    Adkins, H.E.; Ferrell, P.C.; Knight, R.C.

    1994-09-30

    The Radioisotope Thermoelectric Generator Package O-Ring Seal Material Validation Test was conducted to validate the use of the Butyl material as a primary seal throughout the required temperature range. Three tests were performed at (1) 233 K ({minus}40 {degrees}F), (2) a specified operating temperature, and (3) 244 K ({minus}20 {degrees}F) before returning to room temperature. Helium leak tests were performed at each test point to determine seal performance. The two major test objectives were to establish that butyl rubber material would maintain its integrity under various conditions and within specified parameters and to evaluate changes in material properties.

  1. Radioisotope tracer studies in the NASA Skylab ethothermic brazing experiment M-552

    NASA Technical Reports Server (NTRS)

    Braski, D. N.; Adair, H. L.; Kobisk, E. H.

    1974-01-01

    The first use of radioisotope tracer for mapping flow patterns during brazing of metal components in a space environment (near-zero gravity) proved successful. A nickel ferrule was brazed to a nickel tube with Lithobraze BT (71.8% Ag, 28% Cu, 0.2% Li) which contained a trace amount of radioactive Ag-110. Mapping of the flow of the braze alloy in the annulus formed between the tube and the concentric ferrule was determined by counting the radiation intensity as a function of position in the braze joint. Significant information concerning the thermal history of the braze was determined.

  2. Electronic structure of polycrystalline Cd metal using {sup 241}Am radioisotope

    SciTech Connect

    Dhaka, M. S.; Sharma, G.; Mishra, M. C.; Sharma, B. K.

    2014-04-24

    Electronic structure study of the polycrystalline cadmium metal is reported. The experimental measurement is undertaken on a polycrystalline sheet sample using 59.54 keV radioisotope of {sup 241}Am. These results are compared with the ab initio calculations. The theoretical calculations are performed using linear combination of atomic orbitals (LCAO) method employing the density functional theories (DFT) and Hartree-Fock (HF) and augmented plane wave (APW) methods. The spherically averaged APW and LCAO based theoretical Compton profiles are in good agreement with the experimental measurement however the APW based theoretical calculations show best agreement.

  3. COMPASS Final Report: Saturn Moons Orbiter Using Radioisotope Electric Propulsion (REP): Flagship Class Mission

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2011-01-01

    The COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) team was approached by the NASA Glenn Research Center (GRC) In-Space Project to perform a design session to develop Radioisotope Electric Propulsion (REP) Spacecraft Conceptual Designs (with cost, risk, and reliability) for missions of three different classes: New Frontier s Class Centaur Orbiter (with Trojan flyby), Flagship, and Discovery. The designs will allow trading of current and future propulsion systems. The results will directly support technology development decisions. The results of the Flagship mission design are reported in this document

  4. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  5. Cosmogenic and primordial radioisotopes in copper bricks shortly exposed to cosmic rays

    NASA Astrophysics Data System (ADS)

    Coarasa, I.; Amaré, J.; Cebrián, S.; Cuestá, C.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortíz de Solórzano, A.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.; Villar, P.

    2016-05-01

    Cosmogenic activation is the most common source of radioactivity in copper, being 60 Co the most significant because of its long half-life (5.27 y) and saturation activity at sea level of 1 mBq/kg. Copper bricks, which had been exposed to cosmic rays for 41 days after their casting, were used to replace the internal 10 cm of the lead shielding of a HPGe detector placed at the Canfranc Underground Laboratory. We describe the outcome of the new shielding and the cosmogenic and primordial radioisotopes observed.

  6. NASA's Radioisotope Power Systems Program Overview - A Focus on RPS Users

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; McCallum, Peter W.; Sandifer, Carl E., II; Sutliff, Thomas J.; Zakrajsek, June F.

    2016-01-01

    The goal of NASA's Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet potential future mission needs. To meet this goal, the RPS Program manages investments in RPS technologies and RPS system development, working closely with the Department of Energy. This paper provides an overview of the RPS Program content and status, its collaborations with potential RPS users, and the approach employed to maintain the readiness of RPS to support future NASA mission concepts.

  7. Environmental, health and safety assessment of decommissioning radioisotope thermoelectric generators (RTGs) in northwest Russia.

    PubMed

    Standring, W J F; Dowdall, M; Sneve, M; Selnaes, Ø G; Amundsen, I

    2007-09-01

    This paper presents findings from public health and environmental assessment work that has been conducted as part of a joint Norwegian-Russian project to decommission radioisotope thermoelectric generators (RTG) in northwest Russia. RTGs utilise heat energy from radioactive isotopes, in this case 90Sr and its daughter nuclide 90Y, to generate electricity as a power source. Different accident scenarios based on the decommissioning process for RTGs are assessed in terms of possible radiation effects to humans and the environment. Doses to humans and biota under the worst-case scenario were lower than threshold limits given in ICRP and IAEA literature.

  8. Development of the data base for a degradation model of a selenide RTG. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Truscello, V. C.

    1977-01-01

    The paper is concerned with the evaluation of the materials used in a selenide radioisotope thermoelectric generator (RTG). These materials are composed of n-type gadolinium selenide and n-type copper selenide. A three-fold evaluation approach is being used: (1) the study of the rate of change of the thermal conductivity of the material, (2) the investigation of the long-term stability of the material's Seebeck voltage and electrical resistivity under current and temperature gradient conditions, and (3) determination of the physical behavior and compatibility of the material with surrounding insulation at elevated temperatures. Programmatically, the third category of characteristic evaluation is being emphasized.

  9. Methods for producing Cu-67 radioisotope with use of a ceramic capsule for medical applications

    DOEpatents

    Ehst, David A.; Willit, James L.

    2016-04-12

    The present invention provides a method for producing Cu67 radioisotope suitable for use in medical applications. The method comprises irradiating a metallic zinc-68 (Zn68) target within a sealed ceramic capsule with a high energy gamma ray beam. After irradiation, the Cu67 is isolated from the Zn68 by any suitable method (e.g. chemical and or physical separation). In a preferred embodiment, the Cu67 is isolated by sublimation of the zinc in a ceramic sublimation tube to afford a copper residue containing Cu67. The Cu67 can be further purified by chemical means.

  10. Phosphate and arsenate removal efficiency by thermostable ferritin enzyme from Pyrococcus furiosus using radioisotopes.

    PubMed

    Sevcenco, Ana-Maria; Paravidino, Monica; Vrouwenvelder, Johannes S; Wolterbeek, Hubert Th; van Loosdrecht, Mark C M; Hagen, Wilfred R

    2015-06-01

    Oxo-anion binding properties of the thermostable enzyme ferritin from Pyrococcus furiosus were characterized with radiography. Radioisotopes (32)P and (76)As present as oxoanions were used to measure the extent and the rate of their absorption by the ferritin. Thermostable ferritin proved to be an excellent system for rapid phosphate and arsenate removal from aqueous solutions down to residual concentrations at the picomolar level. These very low concentrations make thermostable ferritin a potential tool to considerably mitigate industrial biofouling by phosphate limitation or to remove arsenate from drinking water.

  11. Enabling Future Low-Cost Small Spacecraft Mission Concepts Using Small Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Lee, Young H.; Bairstow, Brian; Amini, Rashied; Zakrajsek, June; Oleson, Steven R.; Cataldo, Robert L.

    2014-01-01

    For more than five decades, Radioisotope Power Systems (RPS) have played a critical role in the exploration of space, enabling missions of scientific discovery to destinations across the solar system by providing electrical power to explore remote and challenging environments - some of the hardest to reach, darkest, and coldest locations in the solar system. In particular, RPS has met the demand of many long-duration mission concepts for continuous power to conduct science investigations independent of change in sunlight or variations in surface conditions like shadows, thick clouds, or dust.

  12. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    NASA Astrophysics Data System (ADS)

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-01

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor).

  13. Environmental assessment of decommissioning radioisotope thermoelectric generators (RTG) in northwest Russia

    SciTech Connect

    Hosseini, A.; Standring, W.J.F.; Brown, J.E.; Dowdall, M.; Amundsen, I.B.

    2007-07-01

    This article presents some results from assessment work conducted as part of a joint Norwegian-Russian project to decommission radioisotope thermoelectric generators (RTG) in Northwest Russia. Potential worst case accident scenarios, based on the decommissioning procedures for RTGs, were assessed to study possible radiation effects to the environment. Close contact with exposed RTG sources will result in detrimental health effects. However, doses to marine biota from ingestion of radioactivity under the worst-case marine scenario studied were lower than threshold limits given in IAEA literature. (authors)

  14. Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste

    SciTech Connect

    Fiskum, S.K.; Bredt, P.R.; Campbell, J.A.; Farmer, O.T.; Greenwood, L.R.; Hoppe, E.W.; Hoopes, F.V.; Lumetta, G.J.; Mong, G.M.; Ratner, R.T.; Soderquist, C.Z.; Steele, M.J.; Swoboda, R.G.; Urie, M.W.; Wagner, J.J.

    2000-10-17

    Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids.

  15. Work plan for the fabrication of the radioisotope thermoelectric generator transportation system package mounting

    SciTech Connect

    Satoh, J.A.

    1994-11-09

    The Radioisotope Thermoelectric Generator (RTG) has available a dedicated system for the transportation of RTG payloads. The RTG Transportation System (System 100) is comprised of four systems; the Package (System 120), the Semi-trailer (System 140), the Gas Management (System 160), and the Facility Transport (System 180). This document provides guidelines on the fabrication, technical requirements, and quality assurance of the Package Mounting (Subsystem 145), part of System 140. The description follows the Development Control Requirements of WHC-CM-6-1, EP 2.4, Rev. 3.

  16. Evaluation of radioisotope tracer and activation analysis techniques for contamination monitoring in space environment simulation chambers

    NASA Technical Reports Server (NTRS)

    Smathers, J. B.; Kuykendall, W. E., Jr.; Wright, R. E., Jr.; Marshall, J. R.

    1973-01-01

    Radioisotope measurement techniques and neutron activation analysis are evaluated for use in identifying and locating contamination sources in space environment simulation chambers. The alpha range method allows the determination of total contaminant concentration in vapor state and condensate state. A Cf-252 neutron activation analysis system for detecting oils and greases tagged with stable elements is described. While neutron activation analysis of tagged contaminants offers specificity, an on-site system is extremely costly to implement and provides only marginal detection sensitivity under even the most favorable conditions.

  17. [Radiation hazard in the use of radioisotopic neutralizers of static electricity].

    PubMed

    Zhulanov, O V; Gromova, T I; Rudakova, S V; Smolianets, R I; Solov'eva, E I

    2002-01-01

    Spectrometry was used by means of an alpha-radiometer on a [symbol: see text]porpecc-[symbol: see text] hard-and-software complex to study the radioactive contamination of the surfaces of neutralizers with plutonium 239-based ionizing radiation sources, which are employed to remove electrical charges from electrifiable materials. While using the neutralizers, the operating personnel is shown to be exposed to radiation. The level of removed radioactive contamination during half-a-year exploitation of the neutralizers was greater than the maximum allowable values on the average by several times. Radiation hazard in the use of radioisotopic neutralizers of static electricity is outlined.

  18. RADIATIVE PENGUIN DECAYS FROM BABAR

    SciTech Connect

    Eigen, Gerald

    2003-08-28

    Electroweak penguin decays provide a promising hunting ground for Physics beyond the Standard Model (SM). The decay B {yields} X{sub s}{gamma}, which proceeds through an electromagnetic penguin loop, already provides stringent constraints on the supersymmetric (SUSY) parameter space. The present data samples of {approx}1 x 10{sup 8} B{bar B} events allow to explore radiative penguin decays with branching fractions of the order of 10{sup -6} or less. In this brief report they discuss a study of B {yields} K*{ell}{sup +}{ell}{sup -} decay modes and a search for B {yields} {rho}({omega}){gamma} decays.

  19. Charmless b decays at CDF

    SciTech Connect

    Donega, Mauro; /Geneva U.

    2005-07-01

    The authors report on the charmless B decays measurements performed on 180 pb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron collider. This paper describes: the first observation of the decay mode B{sub s} {yields} K{sup +}K{sup -} and the measurement of the direct Cp asymmetry in the ({bar B}){sub d} {yields} K{sup {+-}}{pi}{sup {-+}} decay; the first evidence of the decay mode B{sub s} {yields} {phi}{phi} and the branching ratio and Cp asymmetry for the B{sup {+-}} {yields} {phi}K{sup {+-}} decay.

  20. Peace propaganda and biomedical experimentation: influential uses of radioisotopes in endocrinology and molecular genetics in Spain (1947-1971).

    PubMed

    Santesmases, María Jesús

    2006-01-01

    A political discourse of peace marked the distribution and use of radioisotopes in biomedical research and in medical diagnosis and therapy in the post-World War II period. This occurred during the era of expansion and strengthening of the United States' influence on the promotion of sciences and technologies in Europe as a collaborative effort, initially encouraged by the policies and budgetary distribution of the Marshall Plan. This article follows the importation of radioisotopes by two Spanish research groups, one in experimental endocrinology and one in molecular biology. For both groups foreign funds were instrumental in the early establishment of their laboratories. The combination of funding and access to previously scarce radioisotopes helped position these groups at the forefront of research in Spain.

  1. Monte Carlo calculations of dose distribution for intramural delivery of radioisotopes using a direct injection balloon catheter

    SciTech Connect

    Kassing, William M.; McGoron, Anthony J.; Thomas, Stephen R.; Elson, Howard R.; Pipes, David W

    2002-03-01

    Purpose: A unique method of delivering radiation dose to the coronary vessel wall to prevent restenosis is by direct injection of radioactive compounds into the vessel wall using a specially designed angioplasty balloon catheter. The radiation dose distribution resulting from such intramural delivery was investigated using Monte Carlo simulations. Materials and methods: The radioisotope source distribution was modeled for two configurations within the vessel wall: (1) uniform to a depth of 0.5 mm and (2) confined to discrete pools surrounding the delivery injection ports. Monte Carlo MCNP4B computer simulations were utilized to estimate the associated radiation dose distribution for the following radioisotopes: {sup 188}Re, {sup 186}Re, {sup 32}P, {sup 153}Sm, {sup 111}In, {sup 123}I, and {sup 99m}Tc. Results: For the uniform case where the radioisotopes are distributed uniformly to the depth of 0.5 mm into the vessel wall, an essentially constant radiation dose is delivered within the source distribution. Outside of the source volume, the dose falls off at a rate depending on the emission properties of the particular radioisotope. The nonuniform case involving discrete pools of activity showed the dose distribution being confined largely to the regions surrounding the delivery ports with significant regions between these ports receiving very little dose. Conclusions: Direct injection of selected radioisotopes into the arterial wall appears to represent a potentially effective method for delivering radiation dose for the prevention of restenosis. Sufficiently high doses may be obtained from relatively low activity and the dose falls off rapidly outside of the target area for certain radioisotopes.

  2. Development of a Multi-bus, Multi-source Reconfigurable Stirling Radioisotope Power System Test Bed

    NASA Technical Reports Server (NTRS)

    Coleman, Anthony S.

    2004-01-01

    The National Aeronautics and Space Administration (NASA) has typically used Radioisotope Thermoelectric Generators (RTG) as their source of electric power for deep space missions. A more efficient and potentially more cost effective alternative to the RTG, the high efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed by the Department of Energy (DOE), Lockheed Martin (LM), Stirling Technology Company (STC) and NASA Glenn Research Center (GRC). The SRG110 consists of two Stirling convertors (Stirling Engine and Linear Alternator) in a dual-opposed configuration, and two General Purpose Heat Source (GPHS) modules. Although Stirling convertors have been successfully operated as a power source for the utility grid and as a stand-alone portable generator, demonstration of the technology required to interconnect two Stirling convertors for a spacecraft power system has not been attempted. NASA GRC is developing a Power System Test Bed (PSTB) to evaluate the performance of a Stirling convertor in an integrated electrical power system application. This paper will describe the status of the PSTB and on-going activities pertaining to the PSTB in the NASA Thermal-Energy Conversion Branch of the Power and On-Board Propulsion Technology Division.

  3. Computational modeling of Radioisotope Thermoelectric Generators (RTG) for interplanetary and deep space travel

    NASA Astrophysics Data System (ADS)

    Nejat, Cyrus; Nejat, Narsis; Nejat, Najmeh

    2014-06-01

    This research project is part of Narsis Nejat Master of Science thesis project that it is done at Shiraz University. The goals of this research are to make a computer model to evaluate the thermal power, electrical power, amount of emitted/absorbed dose, and amount of emitted/absorbed dose rate for static Radioisotope Thermoelectric Generators (RTG)s that is include a comprehensive study of the types of RTG systems and in particular RTG’s fuel resulting from both natural and artificial isotopes, calculation of the permissible dose radioisotope selected from the above, and conceptual design modeling and comparison between several NASA made RTGs with the project computer model pointing out the strong and weakness points for using this model in nuclear industries for simulation. The heat is being converted to electricity by two major methods in RTGs: static conversion and dynamic conversion. The model that is created for this project is for RTGs that heat is being converted to electricity statically. The model approximates good results as being compared with SNAP-3, SNAP-19, MHW, and GPHS RTGs in terms of electrical power, efficiency, specific power, and types of the mission and amount of fuel mass that is required to accomplish the mission.

  4. Development of a Power Electronics Controller for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Leland, Douglas K.; Priest, Joel F.; Keiter, Douglas E.; Schreiber, Jeffrey G.

    2008-01-01

    Under a U.S. Department of Energy program for radioisotope power systems, Lockheed Martin is developing an Engineering Unit of the Advanced Stirling Radioisotope Generator (ASRG). This is an advanced version of the previously reported SRG110 generator. The ASRG uses Advanced Stirling Convertors (ASCs) developed by Sunpower Incorporated under a NASA Research Announcement contract. The ASRG makes use of a Stirling controller based on power electronics that eliminates the tuning capacitors. The power electronics controller synchronizes dual-opposed convertors and maintains a fixed frequency operating point. The controller is single-fault tolerant and uses high-frequency pulse width modulation to create the sinusoidal currents that are nearly in phase with the piston velocity, eliminating the need for large series tuning capacitors. Sunpower supports this effort through an extension of their controller development intended for other applications. Glenn Research Center (GRC) supports this effort through system dynamic modeling, analysis and test support. The ASRG design arrived at a new baseline based on a system-level trade study and extensive feedback from mission planners on the necessity of single-fault tolerance. This paper presents the baseline design with an emphasis on the power electronics controller detailed design concept that will meet space mission requirements including single fault tolerance.

  5. ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes

    DOE PAGES

    Dooraghi, Alex A.; Carroll, Lewis; Collins, Jeffrey; ...

    2016-03-09

    Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 (18F). The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes. Results show the combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μLmore » or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average. In conclusion, the integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [18F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL-1) to the low values typical of batches of [18F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL-1).« less

  6. Radioisotope radiotherapy research and achievements at the University of Missouri Research Reactor

    NASA Astrophysics Data System (ADS)

    Ehrhardt, G. J.; Ketring, A. R.; Cutler, C. S.

    2003-01-01

    The University of Missouri Research Reactor (MURR) in collaboration with faculty in other departments at the University of Missouri has been involved in developing new means of internal radioisotopic therapy for cancer for many years. These efforts have centered on methods of targeting radioisotopes such as brachytherapy, embolisation of liver tumors with radioactive microspheres, small-molecule-labelled chelates for the treatment of bone cancer, and various means of radioimmunotherapy or labelled receptor agent targeting. This work has produced two radioactive agents, Sm-153 Quadramet™ and Y-90 TheraSphere™, which have U.S. Food and Drug Administration approval for the palliation of bone cancer pain and treatment of inoperable liver cancer, respectively. MURR has also pioneered development of other beta-emitting isotopes for internal radiotherapy such as Re-186, Re-188, Rh-105, Ho-166, Lu-177, and Pm-149, many of which are in research and clinical trials throughout the U.S. and the world. This important work has been made possible by the very high neutron flux available at MURR combined with MURR's outstanding reliability of operation and flexibility in meeting the needs of researchers and the radiopharmaceutical industry.

  7. Progress in the Use of Isotopes: The Atomic Triad - Reactors, Radioisotopes and Radiation

    DOE R&D Accomplishments Database

    Libby, W. F.

    1958-08-04

    Recent years have seen a substantial growth in the use of isotopes in medicine, agriculture, and industry: up to the minute information on the production and use of isotopes in the U.S. is presented. The application of radioisotopes to industrial processes and manufacturing operations has expanded more rapidly than any one except its most ardent advocates expected. New uses and new users are numerous. The adoption by industry of low level counting techniques which make possible the use of carbon-14 and tritium in the control of industrial processes and in certain exploratory and research problems is perhaps most promising of current developments. The latest information on savings to industry will be presented. The medical application of isotopes has continued to develop at a rapid pace. The current trend appears to be in the direction of improvements in technique and the substitution of more effective isotopes for those presently in use. Potential and actual benefits accruing from the use of isotopes in agriculture are reviewed. The various methods of production of radioisotopes are discussed. Not only the present methods but also interesting new possibilities are covered. Although isotopes are but one of the many peaceful uses of the atom, it is the first to pay its way. (auth)

  8. AMTEC radioisotope power system design and analysis for Pluto Express Fly-By

    SciTech Connect

    Hendricks, T.J.; Huang, C.; Sievers, R.K.

    1997-12-31

    The Pluto Express Fly-By program requires a Radioisotope Power System (RPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, high-efficiency RPS to power the Pluto Express Fly-By spacecraft. An AMTEC-based RPS using the General Purpose Heat Source (GPHS) has been conceptually designed to satisfy the Pluto Express power requirements. Integrated AMTEC cell and system thermal/electrical design analyses, structural design analyses, and mass analyses were performed to define an optimum system design. Using fresh radioisotope fuel at beginning of mission, the RPS produces 102 watts of power, has a mass of 8.35 kg (specific power density = 12.2 watts/kg), with a system conversion efficiency of 20.3%. Mass/power scale-up estimates have also been generated, indicating that a 150-watt version of this RPS would weigh approximately 11.3 kg. This paper presents and discusses the key features of this RPS design, the design and analysis methodology, and the numerous system and AMTEC cell tradeoff studies establishing the optimum AMTEC-based RPS.

  9. InfuShield: a shielded enclosure for administering therapeutic radioisotope treatments using standard syringe pumps.

    PubMed

    Rushforth, Dominic P; Pratt, Brenda E; Chittenden, Sarah J; Murray, Iain S; Causer, Louise; Grey, Matthew J; Gear, Jonathan I; Du, Yong; Flux, Glenn D

    2017-03-01

    The administration of radionuclide therapies presents significant radiation protection challenges. The aim of this work was to develop a delivery system for intravenous radioisotope therapies to substantially moderate radiation exposures to staff and operators. A novel device (InfuShield) was designed and tested before being used clinically. The device consists of a shielded enclosure which contains the therapeutic activity and, through the hydraulic action of back-to-back syringes, allows the activity to be administered using a syringe pump external to the enclosure. This enables full access to the pump controls while simultaneously reducing dose to the operator. The system is suitable for use with all commercially available syringe pumps and does not require specific consumables, maximising both the flexibility and economy of the system. Dose rate measurements showed that at key stages in an I mIBG treatment procedure, InfuShield can reduce dose to operators by several orders of magnitude. Tests using typical syringes and infusion speeds show no significant alteration in administered flow rates (maximum of 1.2%). The InfuShield system provides a simple, safe and low cost method of radioisotope administration.

  10. Safety analysis for the Galileo Light-Weight Radioisotope Heater Unit

    SciTech Connect

    Johnson, E.W.

    1990-01-01

    The Light-Weight Radioisotope Heater Unit (LWRHU) will be used on the NASA Galileo Mission to provide thermal energy to the various systems on the orbiter and probe that are adversely affected by the low temperature a spacecraft encounters during a long interplanetary mission. Using these plutonia-fueled sources in 1-W increments permits employment of a single design and provides the spacecraft user the option of how many to use and where to position them to satisfy the proper thermal environment for components requiring such consideration. The use of the radioisotope {sup 238}Pu in these devices necessitates the assessment of postulated radiological risks which might be experienced in case of accidents or malfunctions of the space shuttle or the spacecraft during phases of the mission in the vicinity of the earth. Included are data for the design, mission descriptions, postulated accidents with their consequences, test data, and the derived source terms and personnel exposures for the various events. 4 refs., 4 figs., 1 tab.

  11. Radioisotopic imaging allows optimization of adenovirus lung deposition for cystic fibrosis gene therapy.

    PubMed

    Lerondel, S; Le Pape, A; Sené, C; Faure, L; Bernard, S; Diot, P; Nicolis, E; Mehtali, M; Lusky, M; Cabrini, G; Pavirani, A

    2001-01-01

    Cystic fibrosis is a common, heriditary disease resulting from mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Airway transfer of the CFTR gene is a potential strategy to treat or prevent the lung pathology that is the main cause of morbidity and mortality. Among the vectors used for gene therapy, adenoviruses have shown their ability to transfer the CFTR gene to respiratory epithelial cells, using either instillation or nebulization. Our objective was to characterize the lung deposition of aerosolized adenovirus by quantitative radioisotopic imaging, the only noninvasive technique allowing in vivo quantitation of inhaled drugs. We first labeled an adenovirus expressing human CFTR with the gamma-emitting radioisotope, technetium 99m (99mTc), and determined the best labeling conditions to allow preservation of virus bioactivity. We then administered the radioaerosol to baboons, determined lung regional deposition of 99mTc-labeled adenovirus, and compared the expression of CFTR transcripts 3 and 21 days after inhalation. The expression of vector-encoded mRNA ranged from 4 to 22% with respect to the endogenous CFTR mRNA depending on the lung segments. Moreover, we have developed a model using 99mTc-DTPA (diethylenetriamine pentaacetic acid), which can be used, as an alternative to adenovirus, to determine the profile of lung deposition of the vector. This study demonstrates that scintigraphy is a useful technique to achieve optimization of gene administration to the airways.

  12. InfuShield: a shielded enclosure for administering therapeutic radioisotope treatments using standard syringe pumps

    PubMed Central

    Pratt, Brenda E.; Chittenden, Sarah J.; Murray, Iain S.; Causer, Louise; Grey, Matthew J.; Gear, Jonathan I.; Du, Yong; Flux, Glenn D.

    2017-01-01

    The administration of radionuclide therapies presents significant radiation protection challenges. The aim of this work was to develop a delivery system for intravenous radioisotope therapies to substantially moderate radiation exposures to staff and operators. A novel device (InfuShield) was designed and tested before being used clinically. The device consists of a shielded enclosure which contains the therapeutic activity and, through the hydraulic action of back-to-back syringes, allows the activity to be administered using a syringe pump external to the enclosure. This enables full access to the pump controls while simultaneously reducing dose to the operator. The system is suitable for use with all commercially available syringe pumps and does not require specific consumables, maximising both the flexibility and economy of the system. Dose rate measurements showed that at key stages in an 131I mIBG treatment procedure, InfuShield can reduce dose to operators by several orders of magnitude. Tests using typical syringes and infusion speeds show no significant alteration in administered flow rates (maximum of 1.2%). The InfuShield system provides a simple, safe and low cost method of radioisotope administration. PMID:28187040

  13. Potential Applications for Radioisotope Power Systems in Support of Human Exploration Missions

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.; Colozza, Anthony J.; Schmitz, Paul C.

    2013-01-01

    Radioisotope power systems (RPS) for space applications have powered over 27 U.S. space systems, starting with Transit 4A and 4B in 1961, and more recently with the successful landing of the Mars Science Laboratory rover Curiosity in August 2012. RPS enable missions with destinations far from the Sun with faint solar flux, on planetary surfaces with dense or dusty atmospheres, and at places with long eclipse periods where solar array sizes and energy storage mass become impractical. RPS could also provide an enabling capability in support of human exploration activities. It is envisioned that with the higher power needs of most human mission concepts, a high efficiency thermal-to-electric technology would be required such as the Advanced Stirling Radioisotope generator (ASRG). The ASRG should be capable of a four-fold improvement in efficiency over traditional thermoelectric RPS. While it may be impractical to use RPS as a main power source, many other applications could be considered, such as crewed pressurized rovers, in-situ resource production of propellants, back-up habitat power, drilling, any mobile or remote activity from the main base habitat, etc. This paper will identify potential applications and provide concepts that could be a practical extension of the current ASRG design in providing for robust and flexible use of RPS on human exploration missions.

  14. New Opportunities for Outer Solar System Science using Radioisotope Electric Propulsion

    SciTech Connect

    Noble, Robert J.; Amini, Rashied; Beauchamp, Patricia M.; Bennett, Gary L.; Brophy, John R.; Buratti, Bonnie J.; Ervin, Joan; Fernandez, Yan R.; Grundy, Will; Khan, Mohammed Omair; King, David Q.; Lang, Jared; Meech, Karen J.; Newhouse, Alan; Oleson, Steven R.; Schmidt, George R.; Spilker, Thomas; West, John L.; /Caltech, JPL

    2010-05-26

    Today, our questions and hypotheses about the Solar System's origin have surpassed our ability to deliver scientific instruments to deep space. The moons of the outer planets, the Trojan and Centaur minor planets, the trans-Neptunian objects (TNO), and distant Kuiper Belt objects (KBO) hold a wealth of information about the primordial conditions that led to the formation of our Solar System. Robotic missions to these objects are needed to make the discoveries, but the lack of deep-space propulsion is impeding this science. Radioisotope electric propulsion (REP) will revolutionize the way we do deep-space planetary science with robotic vehicles, giving them unprecedented mobility. Radioisotope electric generators and lightweight ion thrusters are being developed today which will make possible REP systems with specific power in the range of 5 to 10 W/kg. Studies have shown that this specific power range is sufficient to perform fast rendezvous missions from Earth to the outer Solar System and fast sample return missions. This whitepaper discusses how mobility provided by REP opens up entirely new science opportunities for robotic missions to distant primitive bodies. We also give an overview of REP technology developments and the required next steps to realize REP.

  15. System-Level Testing of the Advanced Stirling Radioisotope Generator Engineering Hardware

    NASA Technical Reports Server (NTRS)

    Chan, Jack; Wiser, Jack; Brown, Greg; Florin, Dominic; Oriti, Salvatore M.

    2014-01-01

    To support future NASA deep space missions, a radioisotope power system utilizing Stirling power conversion technology was under development. This development effort was performed under the joint sponsorship of the Department of Energy and NASA, until its termination at the end of 2013 due to budget constraints. The higher conversion efficiency of the Stirling cycle compared with that of the Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, Pluto New Horizons and Mars Science Laboratory) offers the advantage of a four-fold reduction in Pu-238 fuel, thereby extending its limited domestic supply. As part of closeout activities, system-level testing of flight-like Advanced Stirling Convertors (ASCs) with a flight-like ASC Controller Unit (ACU) was performed in February 2014. This hardware is the most representative of the flight design tested to date. The test fully demonstrates the following ACU and system functionality: system startup; ASC control and operation at nominal and worst-case operating conditions; power rectification; DC output power management throughout nominal and out-of-range host voltage levels; ACU fault management, and system command / telemetry via MIL-STD 1553 bus. This testing shows the viability of such a system for future deep space missions and bolsters confidence in the maturity of the flight design.

  16. ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes

    SciTech Connect

    Dooraghi, Alex A.; Carroll, Lewis; Collins, Jeffrey; van Dam, R. Michael; Chatziioannou, Arion F.

    2016-03-09

    Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 (18F). The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes. Results show the combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μL or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average. In conclusion, the integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [18F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL-1) to the low values typical of batches of [18F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL-1).

  17. E6 Gamma Decay

    SciTech Connect

    Brown, B. Alex; Rae, W. D. M.

    2011-05-06

    Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.

  18. Rare B Decays

    SciTech Connect

    Jackson, P.D.; /Victoria U.

    2006-02-24

    Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.

  19. Rare decays and CP asymmetries in charged B decays

    SciTech Connect

    Deshpande, N.G.

    1991-01-01

    The theory of loop induced rare decays and the rate asymmetry due to CP violation in charged B Decays in reviewed. After considering b {yields} s{gamma} and b {yields} se{sup +}e{sup {minus}} decays, the asymmetries for pure penguin process are estimated first. A larger asymmetry can result in those modes where a tree diagram and a penguin diagram interfere, however these estimates are necessarily model dependent. Estimates of Cabbibo suppressed penguins are also considered.

  20. Radio-isotopic calibration of the Late Eocene - Early Oligocene geomagnetic polarity time scale

    NASA Astrophysics Data System (ADS)

    Sahy, Diana; Fischer, Anne U.; Condon, Daniel J.; Terry, Dennis O.; Hiess, Joe; Abels, Hemmo; Huesing, Silja K.; Kuiper, Klaudia F.

    2013-04-01

    The Geomagnetic Polarity Time Scale (GPTS) has been the subject of several revisions over the last few decades, with a trend toward increasing reliance on astronomically tuned age models over traditional radio-isotopic calibration. In the 2012 Geological Time Scale (GTS12) a comparison between radio-isotopic and astronomical age models for the GPTS yielded partially divergent results, with discrepancies of up to 0.4 Myr in the age of magnetic reversals around the Eocene - Oligocene transition (Vandenberghe et al., 2012). Radio-isotopic constraints on the age of Late Eocene - Early Oligocene magnetic reversals are available from two key sedimentary successions which host datable volcanic tuffs: the marine record of the Umbria-Marche basin in Italy, and the terrestrial White River Group of North America, however concerns have been raised regarding both the accuracy of dates obtained from these successions, and the reliability of their magnetic polarity records (Hilgen and Kuiper, 2009). Here we present a fully integrated radio-isotopic and magnetostratigraphic dataset from the Late Eocene - Early Oligocene North American terrestrial succession with the aim of assessing the accuracy and precision of numerical ages derived from the GPTS. We developed a magnetic polarity record for two partially overlapping sections: Flagstaff Rim in Wyoming and Toadstool Geologic Park in Nebraska, which together provide coverage for the time interval between 36-31 Myr (C16n.2n - C12n) and calibrated this record using an age model based on 14 Pb/U weighted mean ID-TIMS dates obtained on zircons from primary air fall tuffs. The uncertainty of our age model includes random and systematic components for all radio-isotopic tie-points, as well as estimated uncertainties in the stratigraphic position of both the magnetic reversals and the dated tuffs. Our Pb/U dates are 0.4 - 0.8 Myr younger than previously published Ar/Ar data (Swisher and Prothero,1990, recalculated to 28.201 Myr for Fish

  1. An Updated Comprehensive Risk Analysis for Radioisotopes Identified of High Risk to National Security in the Event of a Radiological Dispersion Device Scenario

    NASA Astrophysics Data System (ADS)

    Robinson, Alexandra R.

    An updated global survey of radioisotope production and distribution was completed and subjected to a revised "down-selection methodology" to determine those radioisotopes that should be classified as potential national security risks based on availability and key physical characteristics that could be exploited in a hypothetical radiological dispersion device. The potential at-risk radioisotopes then were used in a modeling software suite known as Turbo FRMAC, developed by Sandia National Laboratories, to characterize plausible contamination maps known as Protective Action Guideline Zone Maps. This software also was used to calculate the whole body dose equivalent for exposed individuals based on various dispersion parameters and scenarios. Derived Response Levels then were determined for each radioisotope using: 1) target doses to members of the public provided by the U.S. EPA, and 2) occupational dose limits provided by the U.S. Nuclear Regulatory Commission. The limiting Derived Response Level for each radioisotope also was determined.

  2. Wood decay at sea

    NASA Astrophysics Data System (ADS)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  3. Rare B Decays at Babar

    SciTech Connect

    Palombo, Fernando; Collaboration, for the BABAR

    2009-01-12

    The author presents some of the most recent BABAR measurements for rare B decays. These include rate asymmetries in the B decays to K{sup (*)}l{sup +}l{sup -} and K{sup +}{pi}{sup -} and branching fractions in the B decays to l{sup +}{nu}{sub l}, K{sub 1}(1270){sup +}{pi}{sup -} and K{sub 1}(1400){sup +}{pi}{sup -}. The author also reports a search for the B{sup +} decay to K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}.

  4. GEANT4 simulation of cyclotron radioisotope production in a solid target.

    PubMed

    Poignant, F; Penfold, S; Asp, J; Takhar, P; Jackson, P

    2016-05-01

    The use of radioisotopes in nuclear medicine is essential for diagnosing and treating cancer. The optimization of their production is a key factor in maximizing the production yield and minimizing the associated costs. An efficient approach to this problem is the use of Monte Carlo simulations prior to experimentation. By predicting isotopes yields, one can study the isotope of interest expected activity for different energy ranges. One can also study the target contamination with other radioisotopes, especially undesired radioisotopes of the wanted chemical element which are difficult to separate from the irradiated target and might result in increasing the dose when delivering the radiopharmaceutical product to the patient. The aim of this work is to build and validate a Monte Carlo simulation platform using the GEANT4 toolkit to model the solid target system of the South Australian Health and Medical Research Institute (SAHMRI) GE Healthcare PETtrace cyclotron. It includes a GEANT4 Graphical User Interface (GUI) where the user can modify simulation parameters such as the energy, shape and current of the proton beam, the target geometry and material, the foil geometry and material and the time of irradiation. The paper describes the simulation and presents a comparison of simulated and experimental/theoretical yields for various nuclear reactions on an enriched nickel 64 target using the GEANT4 physics model QGSP_BIC_AllHP, a model recently developed to evaluate with high precision the interaction of protons with energies below 200MeV available in Geant4 version 10.1. The simulation yield of the (64)Ni(p,n)(64)Cu reaction was found to be 7.67±0.074 mCi·μA(-1) for a target energy range of 9-12MeV. Szelecsenyi et al. (1993) gives a theoretical yield of 6.71mCi·μA(-1) and an experimental yield of 6.38mCi·μA(-1). The (64)Ni(p,n)(64)Cu cross section obtained with the simulation was also verified against the yield predicted from the nuclear database TENDL and

  5. Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

    SciTech Connect

    Schock, A.; Noravian, H.; Or, C.

    1997-12-31

    This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system

  6. Evaluation of nitrogen-rich macrocyclic ligands for the chelation of therapeutic bismuth radioisotopes

    DOE PAGES

    Wilson, Justin J.; Ferrier, Maryline; Radchenko, Valery; ...

    2015-05-01

    The use of α-emitting isotopes for radionuclide therapy is a promising treatment strategy for small micro-metastatic disease. The radioisotope ²¹³Bi is a nuclide that has found substantial use for targeted α-therapy (TAT). The relatively unexplored aqueous chemistry of Bi³⁺, however, hinders the development of bifunctional chelating agents that can successfully deliver these Bi radioisotopes to the tumor cells. Here, a novel series of nitrogen-rich macrocyclic ligands is explored for their potential use as Bi-selective chelating agents. The ligands, 1,4,7,10-tetrakis(pyridin-2-ylmethyl)-1,4,7,10-tetraazacyclododecane (Lpy), 1,4,7,10-tetrakis(3-pyridazylmethyl)-1,4,7,10-tetraazacyclododecane (Lpyd), 1,4,7,10-tetrakis(4-pyrimidylmethyl)-1,4,7,10-tetraazacyclododecane (Lpyr), and 1,4,7,10-tetrakis(2-pyrazinylmethyl)-1,4,7,10-tetraazacyclododecane (Lpz), were prepared by a previously reported method and investigated here for their abilitiesmore » to bind Bi radioisotopes. The commercially available and commonly used ligands 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and N-[(R)-2-amino-3-(p-isothiocyanato-phenyl)propyl]-trans-(S,S)- cyclohexane-1,2-diamine-N,N,N',N",N"-pentaacetic acid (CHX-A''-DTPA) were also explored for comparative purposes. Radio-thin-layer chromatography (TLC) was used to measure the binding kinetics and stabilities of the complexes formed. The long-lived isotope, ²⁰⁷Bi (t1/2 = 32 years), was used for these studies. Density functional theory (DFT) calculations were also employed to probe the ligand interactions with Bi³⁺ and the generator parent ion Ac³⁺.In contrast to DOTA and CHX-A''-DTPA, these nitrogen-rich macrocycles selectively chelate Bi³⁺ in the presence of the parent isotope Ac³⁺. Among the four tested, Lpy was found to exhibit optimal Bi³⁺-binding kinetics and complex stability. Lpy complexes Bi³⁺ more rapidly than DOTA, yet the resulting complexes are of similar stability. DFT

  7. NaK Variable Conductance Heat Pipe for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Anderson, William G.; Walker, Kara

    2008-01-01

    In a Stirling radioisotope power system, heat must continually be removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides most of this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending use of that convertor for the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling convertor. In the design of the VCHP for the Advanced Stirling Radioisotope Generator, the VCHP reservoir temperature can vary between 40 and 120 C. While sodium, potassium, or cesium could be used as the working fluid, their melting temperatures are above the minimum reservoir temperature, allowing working fluid to freeze in the reservoir. In contrast, the melting point of NaK is -12 C, so NaK can't freeze in the reservoir. One potential problem with NaK as a working fluid is that previous tests with NaK heat pipes have shown that NaK heat pipes can develop temperature non-uniformities in the evaporator due to NaK's binary composition. A NaK heat pipe was fabricated to measure the temperature non-uniformities in a scale model of the VCHP for the Stirling Radioisotope system. The temperature profiles in the evaporator and condenser were measured as a function of operating temperature and power. The largest delta T across the condenser was 2S C. However, the condenser delta T decreased to 16 C for the 775 C vapor temperature at the highest heat flux applied, 7.21 W/ square cm. This decrease with increasing heat flux was caused by the increased mixing of the sodium and potassium in the vapor. This temperature differential is similar to the temperature variation in this ASRG heat transfer interface without a heat pipe, so NaK can be used as the VCHP working fluid.

  8. Radioisotope-powered cardiac pacemaker program. Clinical studies of the nuclear pacemaker model NU-5. Final report

    SciTech Connect

    Not Available

    1980-06-01

    Beginning in February, 1970, the Nuclear Materials and Equipment Corporation (NUMEC) undertook a program to design, develop and manufacture a radioisotope powered cardiac pacemaker system. The scope of technical work was specified to be: establish system, component, and process cost reduction goals using the prototype Radioisotope Powered Cardiac Pacemaker (RCP) design and develop production techniques to achieve these cost reduction objectives; fabricate radioisotope powered fueled prototype cardiac pacemakers (RCP's) on a pilot production basis; conduct liaison with a Government-designated fueling facility for purposes of defining fueling requirements, fabrication and encapsulation procedures, safety design criteria and quality control and inspection requirements; develop and implement Quality Assurance and Reliability Programs; conduct performance, acceptance, lifetime and reliability tests of fueled RCP's in the laboratory; conduct liaison with the National Institutes of Health and with Government specified medical research institutions selected for the purpose of undertaking clinical evaluation of the RCP in humans; monitor and evaluate, on a continuing basis, all test data; and perform necessary safety analyses and tests. Pacemaker designs were developed and quality assurance and manufacturing procedures established. Prototype pacemakers were fabricated. A total of 126 radioisotope powered units were implanted and have been followed clinically for approximately seven years. Four (4) of these units have failed. Eighty-three (83) units remain implanted and satisfactorily operational. An overall failure rate of less than the target 0.15% per month has been achieved.

  9. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  10. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  11. Decay of oscillating universes

    NASA Astrophysics Data System (ADS)

    Mithani, Audrey Todhunter

    2016-08-01

    It has been suggested by Ellis et al that the universe could be eternal in the past, without beginning. In their model, the "emergent universe'' exists forever in the past, in an "eternal'' phase before inflation begins. We will show that in general, such an "eternal'' phase is not possible, because of an instability due to quantum tunneling. One candidate model, the "simple harmonic universe'' has been shown by Graham et al to be perturbatively stable; we find that it is unstable with respect to quantum tunneling. We also investigate the stability of a distinct oscillating model in loop quantum cosmology with respect to small perturbations and to quantum collapse. We find that the model has perturbatively stable and unstable solutions, with both types of solutions occupying significant regions of the parameter space. All solutions are unstable with respect to collapse by quantum tunneling to zero size. In addition, we investigate the effect of vacuum corrections, due to the trace anomaly and the Casimir effect, on the stability of an oscillating universe with respect to decay by tunneling to the singularity. We find that these corrections do not generally stabilize an oscillating universe. Finally, we determine the decay rate of the oscillating universe. Although the wave function of the universe lacks explicit time dependence in canonical quantum cosmology, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. Here, we apply this approach to the simple harmonic universe, by extending the model to include a massless, minimally coupled scalar field φ which has little effect on the dynamics but can play the role of a "clock''.

  12. Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs

    SciTech Connect

    Gabriel, D. M.; Miller, G. D.; Bohne, W. A.

    1995-03-16

    The purpose of this document is to serve as the Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) programs performed at EG&G Mound Applied Technologies. As such, it identifies and describes the systems and activities in place to support the requirements contained in DOE Order 5700.6C as reflected in MD-10334, Mound Quality Policy and Responsibilities and the DOE/RPSD supplement, OSA/PQAR-1, Programmatic Quality Assurance Requirements for Space and Terrestrial Nuclear Power Systems. Unique program requirements, including additions, modifications, and exceptions to these quality requirements, are contained in the appendices of this plan. Additional appendices will be added as new programs and activities are added to Mound's HS/RTG mission assignment.

  13. Silica Nanoparticles as Substrates for Chelator-free Labeling of Oxophilic Radioisotopes

    PubMed Central

    2016-01-01

    Chelator-free nanoparticles for intrinsic radiolabeling are highly desirable for whole-body imaging and therapeutic applications. Several reports have successfully demonstrated the principle of intrinsic radiolabeling. However, the work done to date has suffered from much of the same specificity issues as conventional molecular chelators, insofar as there is no singular nanoparticle substrate that has proven effective in binding a wide library of radiosotopes. Here we present amorphous silica nanoparticles as general substrates for chelator-free radiolabeling and demonstrate their ability to bind six medically relevant isotopes of various oxidation states with high radiochemical yield. We provide strong evidence that the stability of the binding correlates with the hardness of the radioisotope, corroborating the proposed operating principle. Intrinsically labeled silica nanoparticles prepared by this approach demonstrate excellent in vivo stability and efficacy in lymph node imaging. PMID:25559467

  14. Sub-Kilowatt Radioisotope Electric Propulsion for Outer Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Gefert, L. P.; Oleson, S. R.; Patterson, M. J.; Schrieber, J.; McAdams, J.

    2001-01-01

    An activity has begun to perform a multi-mission trajectory/systems analysis study that examines the combined benefit of three key technology development areas. The three key technologies leveraged in the study include sub-kilowatt ion propulsion, Stirling radioisotope power systems and microelectronics/lightweight spacecraft bus technologies. This study is being performed jointly by NASA Glenn Research Center and the Applied Physics Laboratory to leverage their combined areas of expertise in advanced power/propulsion and spacecraft design. Missions examined in this study include missions to outer planets' moons, such as Europa, Titan, and Triton, and a Comet Nucleus Sample Return mission. Additional information is contained in the original extended abstract.

  15. Isolated and Passive Power Factor Correction AC/DC Converter for Radioisotope Stirling Generators

    NASA Astrophysics Data System (ADS)

    Garrigos, A.; Blanes, J. M.; Gutierrez, R.; Lizan, J. L.; Carrasco, J. A.; Maset, E.; Montalban, G.; Sanchis-Kilders, E.; Ejea, J. B.; Ferreres, A.

    2014-08-01

    A power processing system is described for low voltage, large inductance, single-phase alternator. This kind of electrical machine appears in Radioisotope Stirling Generators (RSG) as the electrical part attached to the thermodynamic system. The proposed power conditioning system splits into two independent stages; the front-end rectifier performs power factor control by adding a series capacitor in the AC side that forms a resonant filter with the alternator parasitic inductance. Further, the rectifier, thanks to the alternator inductance, behaves as a constant current source that supplies a current-fed, zero-voltage, zero-current push-pull stage. This approach takes advantage of all parasitic elements. Finally, some discussion about linear shunt and reconfigurable power factor filter is provided.

  16. Measurement of urinary histamine: comparison of fluorometric and radioisotopic-enzymatic assay procedures

    SciTech Connect

    Warren, K.; Dyer, J.; Merlin, S.; Kaliner, M.

    1982-02-01

    Assessment of urinary histamine may prove useful in determining the role of histamine in human health and disease. Urinary histamine may be accurately estimated by a modified fluorometric assay employing diamine oxidase (DAO) digestion and cation-exchange chromatography. However, the radioisotopic-enzymatic assay is less expensive, easier to perform, and possibly more sensitive. Therefore the two procedures were compared. The radioenzyme assay was found to be affected by factors in urine (possibly salt concentrations) requiring extraction of histamine from urine by butanol-heptane. Moreover, it was found to be necessary to compare DAO-digested samples with undigested samples to accurately estimate histamine levels and to run the standard curve of histamine in DAO-digested urine. Even with these modifications, the radioenzyme assay was not as accurate as the fluorometric assay for urine samples having histamine values about 60 ng/ml. Therefore we recommend utilization of the modified fluorometric assay for the measurement of urinary histamine levels.

  17. Hydrogen sulfide production in surface layers of sediments in the Atlantic Ocean (from radioisotope data)

    NASA Astrophysics Data System (ADS)

    Lein, A. Yu.; Ivanov, M. V.

    2015-11-01

    The report presents the results of 35S-radioisotope researches of sulfate reduction rates in Holocene sediments (0-20 cm) of the shelf and the continental slope at the eastern coasts of the Atlantic Ocean from 81° N to 25° S, including sediments in the most environmentally hazardous upwelling zones. Data from experiments on the rates of sulfate reduction were used in calculating the production of hydrogen sulfide. The rates of sulfate reduction are comparable at the polar shelf and the equatorial area of the influence of the Congo River (11.9 and 14.96 mg S/m2 day, respectively). It must be acknowledged that the production of microbial diagenetic hydrogen sulfide is first affected by the content and composition of organic matter in the sediments and secondly by the thermal conditions of the basin.

  18. Organic Materials Ionizing Radiation Susceptibility for the Outer Planet/Solar Probe Radioisotope Power Source

    NASA Technical Reports Server (NTRS)

    Golliher, Eric L.; Pepper, Stephen V.

    2001-01-01

    The Department of Energy is considering the current Stirling Technology Corporation 55 We Stirling Technology Demonstration Convertor as a baseline option for an advanced radioisotope power source for the Outer Planets/Solar Probe project of Jet Propulsion Laboratory and other missions. However, since the Technology Demonstration Convertor contains organic materials chosen without any special consideration of flight readiness, and without any consideration of the extremely high radiation environment of Europa, a preliminary investigation was performed to address the radiation susceptibility of the current organic materials used in the Technology Demonstration Convertor. This report documents the results of the investigation. The results of the investigation show that candidate replacement materials have been identified to be acceptable in the harsh Europa radiation environment.

  19. Proton linac for hospital-based fast neutron therapy and radioisotope production

    SciTech Connect

    Lennox, A.J.; Hendrickson, F.R.; Swenson, D.A.; Winje, R.A.; Young, D.E.; Rush Univ., Chicago, IL; Science Applications International Corp., Princeton, NJ; Fermi National Accelerator Lab., Batavia, IL )

    1989-09-01

    Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energies are available for optimizing production of isotopes for Positron Emission Tomography and other medical applications. The linac can be used to produce a horizontal or a gantry can be added to the downstream end of the linac for conventional patient positioning. The 70 MeV protons can also be used for proton therapy for ocular melanomas. 17 refs., 1 fig., 1 tab.

  20. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  1. Advanced Superlattice BiTe-PbTe/TAGS Milliwatt Radioisotope Power System

    NASA Astrophysics Data System (ADS)

    Drinker, Richard W.; Reddy, Anil; Heshmatpour, Ben; Snyder, G. Jeffrey; Tuttle, Karen L.

    2005-02-01

    The objective of this effort, under NASA's Project Prometheus, the Nuclear Systems Program, is to develop a high efficiency thermoelectric (T/E) energy conversion device to power milliwatt radioisotope power systems (mWRPS) for future NASA space science applications. The conversion efficiency goal is 8% at a power output level of 50 to several hundred mW. A two stage cascaded T/E module design is being used to achieve these program objectives. This concept incorporates the advanced superlattice BiTe thermoelectric device technology, which is under development by Research Triangle institute (RTI), with Teledyne's segmented T/E couple technology. The hot stage device in the cascade is comprised of Teledyne's PbTe/TAGS/PbSnTe segmented T/E couple which is glass bonded into a monolithic multicouple configuration. The cold stage device is an RTI developed thin film superlattice BiTe based multicouple device.

  2. Cross section calculations of medical 103Pd radioisotope using α and 3He induced reactions

    NASA Astrophysics Data System (ADS)

    Demir, Bayram; Sarpün, Ismail Hakkı; Dogan, Yunus Emre

    2016-11-01

    One of the most popular radioisotopes used in the prostate brachytherapy is Palladium-103 (103Pd). The radioactive plaque is sewn onto the eye as to cover the intraocular tumor shadow with a 2-3 mm margin. These plaques are temporary and radiation is continuously delivered over 5 to 7 days. At the end of treatment, the plaque is removed from eye. In this study, production cross-section calculations of 103Pd radionuclide used in brachytherapy produced by 101Ru(α,2n), 100Ru(α,n), 102Ru(3He,2n) and 101Ru(3He,n) reactions have been investigated in the different incident energy range up to 35 MeV. Twocomponent Exciton model and Generalized Superfluid model of the TALYS 1.6 code used to perform calculations and calculation results were compared with experimental results reported in the literature.

  3. Mission Steering Profiles of Outer Planetary Orbiters Using Radioisotope Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Fiehler, Douglas; Oleson, Steven

    2004-01-01

    Radioisotope Electric Propulsion (REP) has the potential to enable small spacecraft to orbit outer planetary targets with trip times comparable to flyby missions. The ability to transition from a flyby to an orbiter mission lies in the availability of continuous low power electric propulsion along the entire trajectory. The electric propulsion system s role is to add and remove energy from the spacecraft s trajectory to bring it in and out of a heliocentric hyperbolic escape trajectory for the outermost target bodies. Energy is added and the trajectory is reshaped to rendezvous with the closer-in target bodies. Sample REP trajectories will be presented for missions ranging for distances from Jupiter orbit to the Pluto-Kuiper Belt.

  4. Radioimmunotherapy: a specific treatment protocol for cancer by cytotoxic radioisotopes conjugated to antibodies.

    PubMed

    Kawashima, Hidekazu

    2014-01-01

    Radioimmunotherapy (RIT) represents a selective internal radiation therapy, that is, the use of radionuclides conjugated to tumor-directed monoclonal antibodies (including those fragments) or peptides. In a clinical field, two successful examples of this treatment protocol are currently extended by (90)Y-ibritumomab tiuxetan (Zevalin) and (131)I-tositumomab (Bexxar), both of which are anti-CD20 monoclonal antibodies coupled to cytotoxic radioisotopes and are approved for the treatment of non-Hodgkin lymphoma patients. In addition, some beneficial observations are obtained in preclinical studies targeting solid tumors. To date, in order to reduce the unnecessary exposure and to enhance the therapeutic efficacy, various biological, chemical, and treatment procedural improvements have been investigated in RIT. This review outlines the fundamentals of RIT and current knowledge of the preclinical/clinical trials for cancer treatment.

  5. Silica nanoparticles as substrates for chelator-free labeling of oxophilic radioisotopes.

    PubMed

    Shaffer, Travis M; Wall, Matthew A; Harmsen, Stefan; Longo, Valerie A; Drain, Charles Michael; Kircher, Moritz F; Grimm, Jan

    2015-02-11

    Chelator-free nanoparticles for intrinsic radiolabeling are highly desirable for whole-body imaging and therapeutic applications. Several reports have successfully demonstrated the principle of intrinsic radiolabeling. However, the work done to date has suffered from much of the same specificity issues as conventional molecular chelators, insofar as there is no singular nanoparticle substrate that has proven effective in binding a wide library of radiosotopes. Here we present amorphous silica nanoparticles as general substrates for chelator-free radiolabeling and demonstrate their ability to bind six medically relevant isotopes of various oxidation states with high radiochemical yield. We provide strong evidence that the stability of the binding correlates with the hardness of the radioisotope, corroborating the proposed operating principle. Intrinsically labeled silica nanoparticles prepared by this approach demonstrate excellent in vivo stability and efficacy in lymph node imaging.

  6. Testing of the Advanced Stirling Radioisotope Generator Engineering Unit at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.

    2013-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a high-efficiency generator being developed for potential use on a Discovery 12 space mission. Lockheed Martin designed and fabricated the ASRG Engineering Unit (EU) under contract to the Department of Energy. This unit was delivered to NASA Glenn Research Center in 2008 and has been undergoing extended operation testing to generate long-term performance data for an integrated system. It has also been used for tests to characterize generator operation while varying control parameters and system inputs, both when controlled with an alternating current (AC) bus and with a digital controller. The ASRG EU currently has over 27,000 hours of operation. This paper summarizes all of the tests that have been conducted on the ASRG EU over the past 3 years and provides an overview of the test results and what was learned.

  7. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2009-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

  8. Electrode performance parameters for a radioisotope-powered AMTEC for space power applications

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Bankston, C. P.

    1992-01-01

    The alkali metal thermoelastic converter (AMTEC) is a device for the direct conversion of heat to electricity. Recently a design of an AMTEC using a radioisotope heat source was described, but the optimum condenser temperature was hotter than the temperatures used in the laboratory to develop the electrode performance model. Now laboratory experiments have confirmed the dependence of two model parameters over a broader range of condenser and electrode temperatures for two candidate electrode compositions. One parameter, the electrochemical exchange current density at the reaction interface, is independent of the condenser temperature, and depends only upon the collision rate of sodium at the reaction zone. The second parameter, a morphological parameter, which measures the mass transport resistance through the electrode, is independent of condenser and electrode temperatures for molybdenum electrodes. For rhodium-tungsten electrodes, however, this parameter increases for decreasing electrode temperature, indicating an activated mass transport mechanism such as surface diffusion.

  9. Increasing the Efficiency of the Multi-mission Radioisotope Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Holgate, Tim C.; Bennett, Russell; Hammel, Tom; Caillat, Thierry; Keyser, Steve; Sievers, Bob

    2015-06-01

    The National Aeronautics and Space Administration's Mars Science Laboratory terrestrial rover, Curiosity, has recently completed its first Martian year (687 Earth days) during which it has provided a wealth of information and insight into the red planet's atmosphere and geology. The success of this mission was made possible in part by the reliable electrical power provided by its onboard thermoelectric power source—the multi-mission radioisotope thermoelectric generator (MMRTG). In an effort to increase the output power and efficiency of these generators, a newly designed enhanced MMRTG (eMMRTG) that will utilize the more efficient skutterudite-based thermoelectric materials has been conceptualized and modeled, and is now being developed. A discussion of the motivations, modeling results and key design factors are presented and discussed.

  10. Risk assessment of radioisotope contamination for aquatic living resources in and around Japan

    PubMed Central

    Okamura, Hiroshi; Ikeda, Shiro; Morita, Takami; Eguchi, Shinto

    2016-01-01

    Food contamination caused by radioisotopes released from the Fukushima Dai-ichi nuclear power plant is of great public concern. The contamination risk for food items should be estimated depending on the characteristics and geographic environments of each item. However, evaluating current and future risk for food items is generally difficult because of small sample sizes, high detection limits, and insufficient survey periods. We evaluated the risk for aquatic food items exceeding a threshold of the radioactive cesium in each species and location using a statistical model. Here we show that the overall contamination risk for aquatic food items is very low. Some freshwater biota, however, are still highly contaminated, particularly in Fukushima. Highly contaminated fish generally tend to have large body size and high trophic levels. PMID:26929347

  11. Radioimmunotherapy: A Specific Treatment Protocol for Cancer by Cytotoxic Radioisotopes Conjugated to Antibodies

    PubMed Central

    Kawashima, Hidekazu

    2014-01-01

    Radioimmunotherapy (RIT) represents a selective internal radiation therapy, that is, the use of radionuclides conjugated to tumor-directed monoclonal antibodies (including those fragments) or peptides. In a clinical field, two successful examples of this treatment protocol are currently extended by 90Y-ibritumomab tiuxetan (Zevalin) and 131I-tositumomab (Bexxar), both of which are anti-CD20 monoclonal antibodies coupled to cytotoxic radioisotopes and are approved for the treatment of non-Hodgkin lymphoma patients. In addition, some beneficial observations are obtained in preclinical studies targeting solid tumors. To date, in order to reduce the unnecessary exposure and to enhance the therapeutic efficacy, various biological, chemical, and treatment procedural improvements have been investigated in RIT. This review outlines the fundamentals of RIT and current knowledge of the preclinical/clinical trials for cancer treatment. PMID:25379535

  12. Determination of Radioisotope Content by Measurement of Waste Package Dose Rates - 13394

    SciTech Connect

    Souza, Daiane Cristini B.; Gimenes Tessaro, Ana Paula; Vicente, Roberto

    2013-07-01

    The objective of this communication is to report the observed correlation between the calculated air kerma rates produced by radioactive waste drums containing untreated ion-exchange resin and activated charcoal slurries with the measured radiation field of each package. Air kerma rates at different distances from the drum surface were calculated with the activity concentrations previously determined by gamma spectrometry of waste samples and the estimated mass, volume and geometry of solid and liquid phases of each waste package. The water content of each waste drum varies widely between different packages. Results will allow determining the total activity of wastes and are intended to complete the previous steps taken to characterize the radioisotope content of wastes packages. (authors)

  13. Radioisotope dilution technique for determination of vitamin B/sub 12/ in foods

    SciTech Connect

    Casey, P.J.; Speckman, K.R.; Ebert, F.J.; Hobbs, W.E.

    1982-01-01

    A radioisotope dilution (RID) method for the determination of vitamin B/sub 12/ is presented. The method combines a standard extraction procedure (AOAC 43.108, 12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analysis on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B/sub 12/ content determined by the RID method was 8.01 ..mu../100 g vs a mean of 7.54 ..mu..g/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983.

  14. Titanium tritide radioisotope heat source development : palladium-coated titanium hydriding kinetics and tritium loading tests.

    SciTech Connect

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  15. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  16. Technology Development for a Stirling Radioisotope Power System for Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.; Qiu, Songgang; White, Maurice A.

    2000-01-01

    NASA Glenn Research Center and the Department of Energy (DOE) are developing a Stirling convertor for an advanced radioisotope power system to provide spacecraft on-board electric power for NASA deep space missions. NASA Glenn is addressing key technology issues through the use of two NASA Phase 2 SBIRs with Stirling Technology Company (STC) of Kennewick, WA. Under the first SBIR, STC demonstrated a 40 to 50 fold reduction in vibrations, compared to an unbalanced convertor, with a synchronous connection of two thermodynamically independent free-piston Stirling convertors. The second SBIR is for the development of an Adaptive Vibration Reduction System (AVRS) that will essentially eliminate vibrations over a mission lifetime, even in the unlikely event of a failed convertor. This paper discusses the status and results for these two SBIR projects and also presents results for characterizing the friction factor of high-porosity random fiber regenerators that are being used for this application.

  17. ``Hot'' particles of the Yenisei River: Radioisotope composition, structure, and behavior in natural conditions

    NASA Astrophysics Data System (ADS)

    Chuguevskii, A. V.; Sukhorukov, F. V.; Mel'Gunov, M. S.; Makarova, I. V.; Titov, A. T.

    2010-01-01

    The radioisotope compositions, structure, and behavior of “hot” particles under the natural conditions of the Yenisei River in the nearby influence zone of Krasnoyarsk mining and chemical combine were examined in this study. By the composition of gamma-radiating isotopes, all particles are divided into three groups: mono-isotopic, bi-isotopic and poly-isotopic. Mono-isotopic “hot” particles, containing only 60Co were discovered for the first time. Transuranium elements (241Am and 243Cm) were revealed in poly-isotopic particles. Investigation of poly-isotopic particles by means of a scan electron microscope showed that the presence of UO2 together with the lack of activation of 152Eu testifies to the reactor origin of this particle. Experiments showed that in natural conditions “hot” particles under the influence of filtrating water and moisture of pore solutions are gradually dissolved and radionuclides are repeatedly drawn into migration.

  18. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. An engineering unit, the ASRG engineering unit (EU), was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently under extended operation test at the NASA Glenn Research Center (GRC) to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for the ASRG EU. This paper summarizes details of the test facility design, including the mechanical mounting, heat-rejection system, argon system, control systems, and maintenance. The effort proceeded from requirements definition through design, analysis, build, and test. Initial testing and facility performance results are discussed.

  19. External Magnetic Field Reduction Techniques for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.; Geng, Steven M.

    2013-01-01

    Linear alternators coupled to high efficiency Stirling engines are strong candidates for thermal-to-electric power conversion in space. However, the magnetic field emissions, both AC and DC, of these permanent magnet excited alternators can interfere with sensitive instrumentation onboard a spacecraft. Effective methods to mitigate the AC and DC electromagnetic interference (EMI) from solenoidal type linear alternators (like that used in the Advanced Stirling Convertor) have been developed for potential use in the Advanced Stirling Radioisotope Generator. The methods developed avoid the complexity and extra mass inherent in data extraction from multiple sensors or the use of shielding. This paper discusses these methods, and also provides experimental data obtained during breadboard testing of both AC and DC external magnetic field devices.

  20. Intercalibration of radioisotopic and astrochronologic time scales for the Cenomanian-Turonian boundary interval, western interior Basin, USA

    USGS Publications Warehouse

    Meyers, S.R.; Siewert, S.E.; Singer, B.S.; Sageman, B.B.; Condon, D.J.; Obradovich, J.D.; Jicha, B.R.; Sawyer, D.A.

    2012-01-01

    We develop an intercalibrated astrochronologic and radioisotopic time scale for the Cenomanian-Turonian boundary (CTB) interval near the Global Stratotype Section and Point in Colorado, USA, where orbitally influenced rhythmic strata host bentonites that contain sanidine and zircon suitable for 40Ar/ 39Ar and U-Pb dating. Paired 40Ar/ 39Ar and U-Pb ages are determined from four bentonites that span the Vascoceras diartianum to Pseudaspidoceras flexuosum ammonite biozones, utilizing both newly collected material and legacy sanidine samples of J. Obradovich. Comparison of the 40Ar/ 39Ar and U-Pb results underscores the strengths and limitations of each system, and supports an astronomically calibrated Fish Canyon sanidine standard age of 28.201 Ma. The radioisotopic data and published astrochronology are employed to develop a new CTB time scale, using two statistical approaches: (1) a simple integration that yields a CTB age of 93.89 ?? 0.14 Ma (2??; total radioisotopic uncertainty), and (2) a Bayesian intercalibration that explicitly accounts for orbital time scale uncertainty, and yields a CTB age of 93.90 ?? 0.15 Ma (95% credible interval; total radioisotopic and orbital time scale uncertainty). Both approaches firmly anchor the floating orbital time scale, and the Bayesian technique yields astronomically recalibrated radioisotopic ages for individual bentonites, with analytical uncertainties at the permil level of resolution, and total uncertainties below 2???. Using our new results, the duration between the Cenomanian-Turonian and the Cretaceous-Paleogene boundaries is 27.94 ?? 0.16 Ma, with an uncertainty of less than one-half of a long eccentricity cycle. ?? 2012 Geological Society of America.

  1. Soudan 2 nucleon decay experiment

    SciTech Connect

    Thron, J.L.

    1986-01-01

    The Soudan 2 nucleon decay experiment consists of a 1.1 Kton fine grained iron tracking calorimeter. It has a very isotropic detection structure which along with its flexible trigger will allow detection of multiparticle and neutrino proton decay modes. The detector has now entered its construction stage.

  2. Theoretical understanding of charm decays

    SciTech Connect

    Bigi, I.I.

    1986-08-01

    A detailed description of charm decays has emerged. The various concepts involved are sketched. Although this description is quite successful in reproducing the data the chapter on heavy flavour decays is far from closed. Relevant questions like on th real strength of weak annihilation, Penguin operators, etc. are still unanswered. Important directions in future work, both on the experimental and theoretical side are identified.

  3. On-Site Inspection RadioIsotopic Spectroscopy (Osiris) System Development

    SciTech Connect

    Caffrey, Gus J.; Egger, Ann E.; Krebs, Kenneth M.; Milbrath, B. D.; Jordan, D. V.; Warren, G. A.; Wilmer, N. G.

    2015-09-01

    We have designed and tested hardware and software for the acquisition and analysis of high-resolution gamma-ray spectra during on-site inspections under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The On-Site Inspection RadioIsotopic Spectroscopy—Osiris—software filters the spectral data to display only radioisotopic information relevant to CTBT on-site inspections, e.g.,132I. A set of over 100 fission-product spectra was employed for Osiris testing. These spectra were measured, where possible, or generated by modeling. The synthetic test spectral compositions include non-nuclear-explosion scenarios, e.g., a severe nuclear reactor accident, and nuclear-explosion scenarios such as a vented underground nuclear test. Comparing its computer-based analyses to expert visual analyses of the test spectra, Osiris correctly identifies CTBT-relevant fission product isotopes at the 95% level or better.The Osiris gamma-ray spectrometer is a mechanically-cooled, battery-powered ORTEC Transpec-100, chosen to avoid the need for liquid nitrogen during on-site inspections. The spectrometer was used successfully during the recent 2014 CTBT Integrated Field Exercise in Jordan. The spectrometer is controlled and the spectral data analyzed by a Panasonic Toughbook notebook computer. To date, software development has been the main focus of the Osiris project. In FY2016-17, we plan to modify the Osiris hardware, integrate the Osiris software and hardware, and conduct rigorous field tests to ensure that the Osiris system will function correctly during CTBT on-site inspections. The planned development will raise Osiris to technology readiness level TRL-8; transfer the Osiris technology to a commercial manufacturer, and demonstrate Osiris to potential CTBT on-site inspectors.

  4. Conditionally cleavable radioimmunoconjugates: a novel approach for the release of radioisotopes from radioimmunoconjugates.

    PubMed

    Beeson, Craig; Butrynski, James E; Hart, Michael J; Nourigat, Cynthia; Matthews, Dana C; Press, Oliver W; Senter, Peter D; Bernstein, Irwin D

    2003-01-01

    One of the limitations of therapy with radiolabeled monoclonal antibodies (mAbs) is that significant toxicities can arise from circulating non-tumor-bound radiolabeled conjugate. Here, we describe a new method to reduce systemic radiation exposure from radiolabeled mAbs involving the attachment of the radioisotope through a linker that can be cleaved by an administered enzyme. To demonstrate the feasibility of this approach, we prepared a conditionally cleavable radioimmunoconjugate (RIC) composed of (131)I-labeled cephalosporin conjugated to Tositumomab, a mAb against the CD20 antigen. The cleavable RIC bound antigen identically to directly iodinated antibody, and in the presence of beta-lactamase, about 80-85% of the radioisotope was released. In vivo studies in mice revealed that the cleavable RIC and the directly iodinated anti-CD20 antibody had similar biodistribution patterns. Systemically administered beta-lactamase induced a 2-3-fold decrease in the percent injected dose (ID) of the cleavable RIC/g of blood, marrow, spleen, lung, and liver 1 h after enzyme treatment, and a 4-6-fold decrease 20 h after enzyme treatment. This was accompanied by a 20-fold increase in % ID/g in urine 1 h after enzyme treatment, indicating that the released radiolabel was rapidly excreted through the kidneys. In mice with human tumor xenografts, there was no decrease in the %ID/g in tumor 1 h after enzyme treatment, but by 4 h after enzyme injection, decreases in tumor radioactive content began to diminish the targeting advantage. These studies demonstrate that the cleavable RIC substrate is able to bind to tumor antigens and localize within human tumor xenografts and that accelerated systemic clearance can be induced with beta-lactamase.

  5. Radioisotope fueled pulsed power generation system for propulsion and electrical power for deep space missions

    NASA Astrophysics Data System (ADS)

    Howe, Troy

    Space exploration missions to the moon, Mars, and other celestial bodies have allowed for great scientific leaps to enhance our knowledge of the universe; yet the astronomical cost of these missions limits their utility to only a few select agencies. Reducing the cost of exploratory space travel will give rise to a new era of exploration, where private investors, universities, and world governments can send satellites to far off planets and gather important data. By using radioisotope power sources and thermal storage devices, a duty cycle can be introduced to extract large amounts of energy in short amounts of time, allowing for efficient space travel. The same device can also provide electrical power for subsystems such as communications, drills, lasers, or other components that can provide valuable scientific information. This project examines the use of multiple radioisotope sources combined with a thermal capacitor using Phase Change Materials (PCMs) which can collect energy over a period of time. The result of this design culminates in a variety of possible spacecraft with their own varying costs, transit times, and objectives. Among the most promising are missions to Mars which cost less than 17M, missions that can provide power to satellite constellations for decades, or missions that can deliver large, Opportunity-sized (185kg) payloads to mars for less than 53M. All made available to a much wider range of customer with commercially available satellite launches from earth. The true cost of such progress though lies in the sometimes substantial increase in transit times for these missions.

  6. Top decays in extended models

    SciTech Connect

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2009-04-20

    Top quark decays are interesting as a mean to test the Standard Model (SM) predictions. The Cabbibo-Kobayashi-Maskawa (CKM)-suppressed process t{yields}cWW, and the rare decays t{yields}cZ, t{yields}H{sup 0}+c, and t{yields}c{gamma} an excellent window to probe the predictions of theories beyond the SM. We evaluate the flavor changing neutral currents (FCNC) decay t{yields}H{sup 0}+c in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions; the FCNC decays may place at tree level and are only supressed by the mixing between ordinary top and charm quarks. We also comment on the decay process t{yields}c+{gamma}, which involves radiative corrections.

  7. Charm and bottom semileptonic decays

    NASA Astrophysics Data System (ADS)

    O'donnell, Patrick J.; Turan, Gürsevil

    1997-07-01

    We review the present status of theoretical attempts to calculate the semileptonic charm and bottom decays and then present a calculation of these decays in the light-front frame at the kinematic point q2=0. This allows us to evaluate the form factors at the same value of q2, even though the allowed kinematic ranges for charm and bottom decays are very different. Also, at this kinematic point the decay is given in terms of only one form factor A0(0). For the ratio of the decay rates given by the E653 collaboration we show that the determination of the ratio of the Cabibbo-Kobayashi-Maskawa matrix elements is consistent with that obtained from the unitarity constraint, though a new measurement by the E687 Collaboration is about two standard deviations too high. At present, though, the unitarity method still has greater accuracy. Since comparisons of the semileptonic decays into ρ and either electrons or muons will be available soon from the E791 Fermilab experiment, we also look at the massive muon case. We show that for a range of q2 the SU(3)F symmetry breaking is small even though the contributions of the various helicity amplitudes becomes more complicated. For B decays, the decay B-->K*ll¯ at q2=0 involves an extra form factor coming from the photon contribution and so is not amenable to the same kind of analysis, leaving only the decay B-->K*νν¯ as a possibility. As the mass of the decaying particle increases we note that the SU(3) symmetry becomes badly broken at q2=0.

  8. A sequential method for the determination of 210Pb, 226Ra, and uranium and thorium radioisotopes by LSC and alpha-spectrometry.

    PubMed

    Lozano, J C; Tomé, F Vera; Rodríguez, P Blanco; Prieto, C

    2010-01-01

    A procedure for the determination of (210)Pb, and alpha-emitting radioisotopes of uranium, thorium, and radium from the same aliquot of a sample has been proposed. The key step consisted in the recovery of Pb(II) and Ra by precipitation of insoluble Pb(NO(3))(2), the uranium and thorium radioisotopes remaining in solution. Afterwards, the fractions were handled by specific, well consolidated procedures. Lead-210 was determined by the LSC technique while the uranium, thorium, and radium radioisotopes were measured with silicon alpha-spectrometers. The procedure was applied to a reference sample and several environmental samples obtaining satisfactory results.

  9. Semileptonic and leptonic B decays, circa 2016

    NASA Astrophysics Data System (ADS)

    Ricciardi, Giulia

    2017-02-01

    We summarize the status of semileptonic and leptonic B decays, including |Vcb| and |Vub| exclusive and inclusive determinations, decays to excited states of the charm meson spectrum and decays into τ leptons.

  10. TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. I. VARIED SHOCK SPEEDS

    SciTech Connect

    Boss, Alan P.; Keiser, Sandra A.; Ipatov, Sergei I.; Myhill, Elizabeth A.; Vanhala, Harri A. T. E-mail: keiser@dtm.ciw.ed E-mail: elizabeth.myhill@marymount.ed

    2010-01-10

    The discovery of decay products of a short-lived radioisotope (SLRI) in the Allende meteorite led to the hypothesis that a supernova shock wave transported freshly synthesized SLRI to the presolar dense cloud core, triggered its self-gravitational collapse, and injected the SLRI into the core. Previous multidimensional numerical calculations of the shock-cloud collision process showed that this hypothesis is plausible when the shock wave and dense cloud core are assumed to remain isothermal at approx10 K, but not when compressional heating to approx1000 K is assumed. Our two-dimensional models with the FLASH2.5 adaptive mesh refinement hydrodynamics code have shown that a 20 km s{sup -1} shock front can simultaneously trigger collapse of a 1 M{sub sun} core and inject shock wave material, provided that cooling by molecular species such as H{sub 2}O, CO, and H{sub 2} is included. Here, we present the results for similar calculations with shock speeds ranging from 1 km s{sup -1} to 100 km s{sup -1}. We find that shock speeds in the range from 5 km s{sup -1} to 70 km s{sup -1} are able to trigger the collapse of a 2.2 M{sub sun} cloud while simultaneously injecting shock wave material: lower speed shocks do not achieve injection, while higher speed shocks do not trigger sustained collapse. The calculations continue to support the shock-wave trigger hypothesis for the formation of the solar system, though the injection efficiencies in the present models are lower than desired.

  11. Primordial nucleosynthesis with decaying particles. I - Entropy-producing decays. II - Inert decays

    NASA Technical Reports Server (NTRS)

    Scherrer, Robert J.; Turner, Michael S.

    1988-01-01

    The effect of a nonrelativistic particle X, which decays out of equilibrium, on primordial nucleosynthesis is investigated, including both the energy density of the X particle and the electromagnetic entropy production from its decay. The results are parametrized in terms of the X particle lifetime and the density parameter rm(X), where m(X) is the X particle mass and r is the ratio of X number density to photon number density prior to nucleosynthesis. The results rule out particle lifetimes greater than 1-10 s for large values of rm(X). The question of a decaying particle which produces no electromagnetic entropy in the course of its decay is addressed, and particles which produce both entropy and an inert component in their decay are discussed.

  12. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  13. Decay of Solar Active Regions

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Choudhary, Debi Prasad

    2005-01-01

    We examine the record of sunspot group areas observed over a period of 100 years to determine the rate of decay of solar active regions. We exclude observations of groups when they are more than 60deg in longitude from the central meridian and only include data when at least three days of observations are available following the date of maximum area for a spot group's disk passage. This leaves data for some 24,000 observations of active region decay. We find that the decay rate is a constant 20 microHem/day for spots smaller than about 200 microHem (about the size of a supergranule). This decay rate increases linearly to about 90 microHem/day for spots with areas of 1000 microHem. We find no evidence for significant variations in active region decay from one solar cycle to another. However, we do find that the decay rate is slower at lower latitudes. This gives a slower decay rate during the declining phase of sunspot cycles.

  14. Nonleptonic Bc→VV decays

    NASA Astrophysics Data System (ADS)

    Kar, Susmita; Dash, P. C.; Priyadarsini, M.; Naimuddin, Sk.; Barik, N.

    2013-11-01

    We study the exclusive nonleptonic Bc→VV decays, within the factorization approximation, in the framework of the relativistic independent quark model, based on a confining potential in the scalar-vector harmonic form. The weak form factors are extracted from the overlap integral of meson wave functions derived in the relativistic independent quark model. The predicted branching ratios for different Bc-meson decays are obtained in a wide range, from a tiny value of O(10-6) for Bc→D*D(s)* to a large value of 24.32% for Bc→Bs*ρ-, in general agreement with other dynamical-quark-model predictions. The decay modes Bc→Bs*ρ- and Bc→B*ρ- with high branching ratios of 24.32% and 1.73%, respectively, obtained in this model should be detectable at the LHC and Tevatron in the near future. The b→c, u induced decays are predicted predominantly in the longitudinal mode, whereas the c¯→s¯, d¯ induced decays are obtained in a slightly higher transverse mode. The CP-odd fractions (R⊥) for different decay modes are predicted and those for color-favored Bc→D*D*, D*Ds* decays indicate significant CP violation in this sector.

  15. Decays of the b quark

    NASA Astrophysics Data System (ADS)

    Thorndike, Edward H.; Poling, Ronald A.

    1988-01-01

    Recent experimental results on the decay of b-flavored hadrons are reviewed. Substantial progress has been made in the study of exclusive and inclusive B-meson decays, as well as in the theoretical understanding of these processes. The two most prominent developments are the continuing failure to observe evidence of decays of the b quark to a u quark rather than a c quark, and the surprisingly high level of B 0- overlineB0 mi xing which has recently been reported by the ARGUS collaboration. Notwithstanding these results, we conclude that the health of the Standard Model is excellent.

  16. Tensor interactions and τ decays

    NASA Astrophysics Data System (ADS)

    Godina Nava, J. J.; López Castro, G.

    1995-09-01

    We study the effects of charged tensor weak currents on the strangeness-changing decays of the τ lepton. First, we use the available information on the K+e3 form factors to obtain B(τ--->K-π0ντ)~10-4 when the Kπ system is produced in an antisymmetric tensor configuration. Then we propose a mechanism for the direct production of the K*2(1430) in τ decays. Using the current upper limit on this decay we set a bound on the symmetric tensor interactions.

  17. Glueball decay in holographic QCD

    SciTech Connect

    Hashimoto, Koji; Tan, C.-I; Terashima, Seiji

    2008-04-15

    Using holographic QCD based on D4-branes and D8-anti-D8-branes, we have computed couplings of glueballs to light mesons. We describe glueball decay by explicitly calculating its decay widths and branching ratios. Interestingly, while glueballs remain less well understood both theoretically and experimentally, our results are found to be consistent with the experimental data for the scalar glueball candidate f{sub 0}(1500). More generally, holographic QCD predicts that decay of any glueball to 4{pi}{sup 0} is suppressed, and that mixing of the lightest glueball with qq mesons is small.

  18. RARE DECAYS INCLUDING PENGUINS

    SciTech Connect

    Eigen, G

    2003-12-04

    The authors present a preliminary measurement of the exclusive charmless semileptonic B decays, B {yields} {rho}{ell}{nu}, and the extraction of the CKM parameters V{sub ub}. IN a data sample of 55 x 10{sup 6} B{bar B} events they measure a branching fraction of {Beta}(B {yields} {rho}{ell}{nu}) = (3.39 {+-} 0.44{sub stat} {+-} 0.52{sub sys} {+-} 0.60{sub th}) x 10{sup -4} yielding |V{sub ub}| = (3.69 {+-} 0.23{sub stat} {+-} 0.27{sub sys -0.59th}{sup +0.40}) x 10{sup -3}. Next, they report on a preliminary study of the radiative penguin modes B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*{ell}{sup +}{ell}{sup -}. In a data sample of 84 x 10{sup 6} B{bar B} events they observe a significant signal (4.4{sigma}) in B {yields} K{ell}{sup +}{ell}{sup -}, yielding a branching fraction of {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) = (0.78{sub -0.20-0.18}{sup +0.24+0.11}) x 10{sup -6}. In B {yields} K*{ell}{sup +}{ell}{sup -} the observed yield is not yet significant (2.8{sigma}), yielding an upper limit of the branching fraction of {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) 3.0 x 10{sup -6} {at} 90% confidence level. Finally, they summarize preliminary results of searches for B {yields} {rho}({omega}){gamma}, B{sup +} {yields} K{sup +} {nu}{bar {nu}} and B{sup 0} {yields} {ell}{sup +}{ell}{sup -}.

  19. Radiative Leptonic B Decays

    SciTech Connect

    Chen, Edward Tann

    2007-01-01

    We present the results of a search for B+ meson decays into γℓ+v, where ℓ = e,μ. We use a sample of 232 million B$\\bar{B}$ meson pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B factory. We measure a partial branching fraction Δβ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be in the range 1.875 and 2.850 GeV, the photon energy to be in the range 0.45 and 2.35 GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the Υ(4S) center-of-mass frame. We find Δβ(B+ → γℓ+v) = (-0.31.5+1.3(statistical) -0.6+0.6(systematic) ± 0.1(theoretical)) x 10-6, under the assumption of lepton universality. Interpreted as a 90% confidence-level Bayesian upper limit, the result corresponds to 1.7 x 10-6 for a prior at in amplitude, and 2.3 x 10-6 for a prior at in branching fraction.

  20. The Search for Proton Decay.

    ERIC Educational Resources Information Center

    Marshak, Marvin L.

    1984-01-01

    Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

  1. CP violation in K decays

    SciTech Connect

    Gilman, F.J.

    1989-05-01

    Recent theoretical and experimental progress on the manifestation of CP violation in K decays, and toward understanding whether CP violation originates in a phase, or phases, in the weak mixing matrix of quarks is reviewed. 23 refs., 10 figs.

  2. Decoherence delays false vacuum decay

    NASA Astrophysics Data System (ADS)

    Bachlechner, Thomas C.

    2013-05-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling \\Gamma \\sim \\Gamma _{CDL}^{2}, where ΓCDL is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincaré recurrence in de Sitter space.

  3. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  4. Evaluation of nitrogen-rich macrocyclic ligands for the chelation of therapeutic bismuth radioisotopes

    SciTech Connect

    Wilson, Justin J.; Ferrier, Maryline; Radchenko, Valery; Maassen, Joel R.; Engle, Jonathan W.; Batista, Enrique R.; Martin, Richard L.; Nortier, Francois M.; Fassbender, Michael E.; John, Kevin D.; Birnbaum, Eva R.

    2015-05-01

    The use of α-emitting isotopes for radionuclide therapy is a promising treatment strategy for small micro-metastatic disease. The radioisotope ²¹³Bi is a nuclide that has found substantial use for targeted α-therapy (TAT). The relatively unexplored aqueous chemistry of Bi³⁺, however, hinders the development of bifunctional chelating agents that can successfully deliver these Bi radioisotopes to the tumor cells. Here, a novel series of nitrogen-rich macrocyclic ligands is explored for their potential use as Bi-selective chelating agents. The ligands, 1,4,7,10-tetrakis(pyridin-2-ylmethyl)-1,4,7,10-tetraazacyclododecane (Lpy), 1,4,7,10-tetrakis(3-pyridazylmethyl)-1,4,7,10-tetraazacyclododecane (Lpyd), 1,4,7,10-tetrakis(4-pyrimidylmethyl)-1,4,7,10-tetraazacyclododecane (Lpyr), and 1,4,7,10-tetrakis(2-pyrazinylmethyl)-1,4,7,10-tetraazacyclododecane (Lpz), were prepared by a previously reported method and investigated here for their abilities to bind Bi radioisotopes. The commercially available and commonly used ligands 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and N-[(R)-2-amino-3-(p-isothiocyanato-phenyl)propyl]-trans-(S,S)- cyclohexane-1,2-diamine-N,N,N',N",N"-pentaacetic acid (CHX-A''-DTPA) were also explored for comparative purposes. Radio-thin-layer chromatography (TLC) was used to measure the binding kinetics and stabilities of the complexes formed. The long-lived isotope, ²⁰⁷Bi (t1/2 = 32 years), was used for these studies. Density functional theory (DFT) calculations were also employed to probe the ligand interactions with Bi³⁺ and the generator parent ion Ac³⁺.In contrast to DOTA and CHX-A''-DTPA, these nitrogen-rich macrocycles selectively chelate Bi³⁺ in the presence of the parent isotope Ac³⁺. Among the four tested, Lpy was found to exhibit optimal Bi³⁺-binding kinetics and complex stability. Lpy complexes

  5. Radio-isotope production scale-up at the University of Wisconsin

    SciTech Connect

    Nickles, Robert Jerome

    2014-06-19

    Our intent has been to scale up our production capacity for a subset of the NSAC-I list of radioisotopes in jeopardy, so as to make a significant impact on the projected national needs for Cu-64, Zr-89, Y-86, Ga-66, Br-76, I-124 and other radioisotopes that offer promise as PET synthons. The work-flow and milestones in this project have been compressed into a single year (Aug 1, 2012- July 31, 2013). The grant budget was virtually dominated by the purchase of a pair of dual-mini-cells that have made the scale-up possible, now permitting the Curie-level processing of Cu-64 and Zr-89 with greatly reduced radiation exposure. Mile stones: 1. We doubled our production of Cu-64 and Zr-89 during the grant period, both for local use and out-bound distribution to ≈ 30 labs nationwide. This involved the dove-tailing of beam schedules of both our PETtrace and legacy RDS cyclotron. 2. Implemented improved chemical separation of Zr-89, Ga-66, Y-86 and Sc-44, with remote, semi-automated dissolution, trap-and-release separation under LabView control in the two dual-mini-cells provided by this DOE grant. A key advance was to fit the chemical stream with miniature radiation detectors to confirm the transfer operations. 3. Implemented improved shipping of radioisotopes (Cu-64, Zr-89, Tc-95m, and Ho-163) with approved DOT 7A boxes, with a much-improved FedEx shipping success compared to our previous steel drums. 4. Implemented broad range quantitative trace metal analysis, employing a new microwave plasma atomic emission spectrometer (Agilent 4200) capable of ppb sensitivity across the periodic table. This new instrument will prove essential in bringing our radiometals into FDA compliance needing CoA’s for translational research in clinical trials. 5. Expanded our capabilities in target fabrication, with the purchase of a programmable 1600 oC inert gas tube furnace for the smelting of binary alloy target materials. A similar effort makes use of our RF induction furnace, allowing

  6. CP violation in sbottom decays

    NASA Astrophysics Data System (ADS)

    Deppisch, Frank F.; Kittel, Olaf

    2010-06-01

    We study CP asymmetries in two-body decays of bottom squarks into charginos and top quarks. These asymmetries probe the SUSY CP phases of the sbottom and the chargino sector in the Minimal Supersymmetric Standard Model (MSSM). We identify the MSSM parameter space where the CP asymmetries are sizeable. As a result, potentially detectable CP asymmetries in sbottom decays are found, which motivates further detailed experimental studies for probing the SUSY CP phases at the LHC.

  7. Status of an advanced radioisotope space power system using free-piston Stirling technology

    SciTech Connect

    White, M.A,; Qiu, S.; Erbeznik, R.M.; Olan, R.W.; Welty, S.C.

    1998-07-01

    This paper describes a free-piston Stirling engine technology project to demonstrate a high efficiency power system capable of being further developed for deep space missions using a radioisotope (RI) heat source. The key objective is to develop a power system with an efficiency exceeding 20% that can function with a high degree of reliability for 10 years or longer on deep space missions. Primary issues being addressed for Stirling space power systems are weight and the vibration associated with reciprocating pistons. Similar weight and vibration issues have been successfully addressed with Stirling cryocoolers, which are the accepted standard for cryogenic cooling in space. Integrated long-life Stirling engine-generator (or convertor) operation has been demonstrated by the terrestrial Radioisotope Stirling Generator (RSG) and other Stirling Technology Company (STC) programs. Extensive RSG endurance testing includes more than 40,000 maintenance-free, degradation-free hours for the complete convertor, in addition to several critical component and subsystem endurance tests. The Stirling space power convertor project is being conducted by STC under DOE Contract, and NASA SBIR Phase II contracts. The DOE contract objective is to demonstrate a two-convertor module that represents half of a nominal 150-W(e) power system. Each convertor is referred to as a Technology Demonstration Convertor (TDC). The ultimate Stirling power system would be fueled by three general purpose heat source (GPHS) modules, and is projected to produce substantially more electric power than the 150-watt target. The system is capable of full power output with one failed convertor. One NASA contract, nearing completion, uses existing 350-W(e) RG-350 convertors to evaluate interactivity of two back-to-back balanced convertors with various degrees of electrical and mechanical interaction. This effort has recently provided the first successful synchronization of two convertors by means of parallel

  8. Filling a 30 Million Year Gap: Radioisotopic Age Constraints for the Late Triassic Timescale

    NASA Astrophysics Data System (ADS)

    Irmis, R. B.; Mundil, R.

    2011-12-01

    The Triassic Period records a critical interval of Phanerozoic Earth history, including major paleoenvironmental changes in a greenhouse world, recovery from one mass extinction and the onset of another, and the origin of modern terrestrial ecosystems. Recent efforts have been instrumental in calibrating the timing of these events by producing numerous high resolution radioisotopic ages from Early and Middle Triassic marine strata that facilitate building of a robust 20 Ma chronostratigraphic framework. This contrasts starkly with the Late Triassic (Carnian, Norian, and Rhaetian stages), where ~30 Ma of the timescale is virtually uncalibrated by high-resolution radioisotopic data. This is the only interval of such long duration in the Mesozoic or Cenozoic that remains so poorly constrained by reliable absolute ages, despite the occurrence of major events such as the origin and early diversification of dinosaurs, major reef building episodes in marine ecosystems, key paleoenvironmental changes (e.g., Carnian Pluvial Event), and large extraterrestrial bolide impacts (e.g., Manicouagan). An additional challenge is that the biostratigraphically-defined marine timescale cannot be applied globally, so that other areas (e.g., New Zealand) have independent timescales that cannot be confidently correlated to classic Laurasian sections. All of these problems preclude formulating robust first-order hypotheses about the Late Triassic world. We present new CA-TIMS U-Pb zircon data from volcaniclastic units within both marine and terrestrial strata that aim at calibrating the timescale itself and as a result constrain the timing of some of these major events in Earth history. Several preliminary ages support the hypothesis that the Norian Stage was very long, ~20 Ma. Our new data from marine sequences in New Zealand demonstrate that the timescale divisions there do not correlate directly with biostratigraphic boundaries in the Tethys; specifically, the Ladinian-Carnian boundary

  9. Multiscale Modeling of Radioisotope Transfers in Watersheds, Rivers, Reservoirs and Ponds of Fukushima Prefecture

    NASA Astrophysics Data System (ADS)

    Zheleznyak, M.; Kivva, S.; Nanba, K.; Wakiyama, Y.; Konoplev, A.; Onda, Y.; Gallego, E.; Papush, L.; Maderych, V.

    2015-12-01

    The highest densities of the radioisotopes in fallout from the Fukushima Daiichi NPP in March 2011 were measured at the north eastern part of Fukushima Prefecture. The post-accidental aquatic transfer of cesium -134/137 includes multiscale processes: wash-off from the watersheds in solute and with the eroded soil, long-range transport in the rivers, deposition and resuspension of contaminated sediments in reservoirs and floodplains. The models of EU decision support system RODOS are used for predicting dynamics of 137Cs in the Fukushima surface waters and for assessing efficiency of the remediation measures. The transfer of 137Cs through the watershed of Niida River was simulated by DHSVM -R model that includes the modified code of the distributed hydrological and sediment transport model DHSVM (Lettenmayer, Wigmosta et al.) and new module of radionuclide transport. DHSMV-R was tested by modelling the wash-off from the USLE experimental plots in Fukushima prefecture. The model helps to quantify the influence of the differentiators of Fukushima and Chernobyl watersheds, - intensity of extreme precipitation and steepness of watershed, on the much higher values of the ratio "particulated cesium /soluted cesium" in Fukushima rivers than in Chernobyl rivers. Two dimensional model COASTOX and three dimensional model THREETOX are used to simulate the fate of 137Cs in water and sediments of reservoirs in the Manogawa River, Otagawa River, Mizunashigawa River, which transport 137Cs from the heavy contaminated watersheds to the populated areas at the Pacific coast. The modeling of the extreme floods generated by typhoons shows the resuspension of the bottom sediments from the heavy contaminated areas in reservoirs at the mouths of inflowing rivers at the peaks of floods and then re-deposition of 137Cs downstream in the deeper areas. The forecasts of 137Cs dynamics in bottom sediments of the reservoirs were calculated for the set of the scenarios of the sequences of the high

  10. Inorganic, radioisotopic and organic analysis of 241-AP-101 tank waste

    SciTech Connect

    SK Fiskum; PR Bredt; JA Campbell; LR Greenwood; OT Farmer; GJ Lumetta; GM Mong; RT Ratner; CZ Soderquist; RG Swoboda; MW Urie; JJ Wagner

    2000-06-28

    Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids. The characterization of the 241-AP-101 composite samples included: (1) Inductively-coupled plasma spectrometry for Ag, Al, Ba, Bi, Ca, Cd, Cr, Cu, Fe, K, La, Mg, Mn, Na, Nd, Ni, P, Pb, Pd, Ru, Rh, Si, Sr, Ti, U, Zn, and Zr (Note: Although not specified in the test plan, As, B, Be, Co, Li, Mo, Sb, Se, Sn, Tl, V, W, and Y were also measured and reported for information only) (2) Radioisotopic analyses for total alpha and total beta activities, {sup 3}H, {sup 14}C, {sup 60}Co, {sup 79}Se, {sup 90}Sr, {sup 99}Tc as pertechnetate, {sup 106}Ru/Rh, {sup 125}Sb, {sup 134}Cs, {sup 137}Cs, {sup 152}Eu, {sup 154}Eu, {sup 155}Eu, {sup 238}Pu, {sup 239+240}Pu, {sup 241}Am, {sup 242}Cm, and {sup 243+244}Cm; (3) Inductively-coupled plasma mass spectrometry for {sup 237}Np, {sup 239}Pu, {sup 240}Pu, {sup 99}Tc, {sup 126}Sn, {sup 129}I, {sup 231}Pa, {sup 233}U, {sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 241}AMU, {sup 242}AMU, {sup 243}AMU, As, B, Be, Ce, Co, Cs, Eu, I, Li, Mo, Pr, Rb, Sb, Se, Ta, Te, Th, Tl, V, and W; (4) total U by kinetic phosphorescence analysis; (5) Ion chromatography for Cl, F, NO{sub 2}, NO{sub 3}, PO{sub 4}, SO{sub 4}, acetate, formate, oxalate, and citrate; (6) Density, inorganic carbon and organic carbon by two different methods, mercury, free hydroxide, ammonia, and cyanide. The 241-AP-101 composite met all

  11. Thermoelectric Alloys and Devices for Radioisotope Space Power Systems: State of the Art and Current Developments

    SciTech Connect

    Barnett, W.; Dick, P.; Beaudry, B.; Gorsuch, P.; Skrabek, E.

    1989-01-01

    Lead telluride and silicon germanium type alloys have served over the past several decades as the preferred thermoelectric conversion materials for U. S. radioisotope thermoelectric generator (RTG) power systems for planetary deep space exploration missions. The Pioneer missions to Jupiter and Jupiter/Saturn and the Viking Mars Lander missions employed TAGS-2N (lead and germanium telluride derivatives) power conversion devices. Since 1976, silicon germanium (SiGe) alloys, incorporated into the unicouple device, have evolved as the thermoelectric materials of choice for U. S. RTG powered space missions. These include the U. S. Air Force Lincoln Experimental Satellites 8 & 9 for communications, in 1976, followed in 1977 by the National Aeronautics and Space Administration Voyager 1 and 2 planetary missions. In 1989, advanced SiGe RTGs were used to power the Galileo exploration of Jupiter and, in 1990, will be used to power the Ulysses investigation of the Sun. In addition, SiGe technology has been chosen to provide RTG power for the 1995 Comet Rendezvous and Asteroid Flyby mission and the 1996 Cassini Saturn orbiter mission. Summaries of the flight performance data for these systems are presented.; Current U. S. Department of Energy thermoelectric development activities include (1) the development of conversion devices based on hi-density, close packed couple arrays and (2) the development of improved performance silicon germanium type thermoelectric materials. The silicon germanium type "multicouple", being developed in conjunction with the Modular RTG program, is discussed in a companion paper. A lead telluride type close-packed module, discussed herein, offers the promise of withstanding high velocity impacts and, thus, is a candidate for a Mars Penetrator application.; Recent projects sponsored by the U. S. Department of Energy, including the Improved Thermoelectric Materials and Modular Radioisotope Thermoelectric Generator programs, have shown that improvements

  12. Design, Analysis, and Optimization of a Radioisotope Thermophotovoltaic (RTPV) Generator, and its Applicability to an Illustrative Space Mission

    SciTech Connect

    Schock, Alfred; Mukunda, Meera; Or, Chuen T; Kumar, Vasanth; Summers, G.

    1994-10-01

    Paper presented at the 45th Congress of the IAF in Jerusalem, Israel, October 1994. The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the authors. To focus the design effort, it was decided to direct it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by the JPL, envisages a direct eight to nine-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a six-week post-encounter cruise.

  13. Considerations in the fabrication, assembly, and testing of radioisotopic thermo-photovoltaic (RTPV) generators for future space missions

    SciTech Connect

    Barklay, C.D.; Miller, R.G.; Frazier, T.A.

    1996-03-01

    To increase energy output with a smaller size and mass than the radioisotopic thermoelectric generators (RTGs) that were previously used on deep space missions, a radioisotopic thermophotovoltaic (RTPV) system is being developed for the {open_quote}{open_quote}Pluto Express{close_quote}{close_quote} flyby mission. To minimize cost and development time, some facilities and components currently used for RTG production can be used to produce RTPVs. Production options also include out-sourcing and use of off-the-shelf hardware. Necessary modifications to tooling, production equipment, testing and shipping methods can be achieved in a timely manner so that the RTPV will be ready well before the planned launch of {open_quote}{open_quote}Pluto Express.{close_quote}{close_quote} {copyright} {ital 1996 American Institute of Physics.}

  14. An evaluation of the shielding effectiveness of lead aprons used in clinics for protection against ionising radiation from novel radioisotopes.

    PubMed

    Deb, Pradip; Jamison, Robert; Mong, Lisa; U, Paul

    2015-07-01

    The purpose of this study is to evaluate the effectiveness of personal radiation shields currently worn in hospital and other diagnostic environments. This study was performed with four different radioisotopes; (18)F, (99m)Tc, (124)I and (131)I. (18)F results showed a decrease in dose with 0.5-mm Pb shielding but the reduction provided does not warrant its use clinically. (124)I testing demonstrated that dose enhancement can occur in greater shield thicknesses. PET isotope (124)I can be adequately shielded using 0.25-mm Pb equivalent aprons but any higher thickness increase the wearer's dose. As a result more shielding does not always equal more protection. The (131)I test showed that no dose reduction occurred, even when tested with up to 1.25-mm Pb equivalent shielding. Novel radioisotopes being used in the laboratory and clinic should be individually tested as each requires specific shielding testing.

  15. Light-Weight Radioisotope Heater Unit Safety Analysis Report (LWRHU-SAR). Volume II. Accident model document

    SciTech Connect

    Johnson, E.W.

    1985-10-01

    Purposes of this volume (AMD), are to: Identify all malfunctions, both singular and multiple, which can occur during the complete mission profile that could lead to release outside the clad of the radioisotopic material contained therein; provide estimates of occurrence probabilities associated with these various accidents; evaluate the response of the LWRHU (or its components) to the resultant accident environments; and associate the potential event history with test data or analysis to determine the potential interaction of the released radionuclides with the biosphere.

  16. Technical description of candidate fluorescence compounds and radioisotopes for a nuclear smuggling deterrence tag (IL500E)

    SciTech Connect

    Hartenstein, S.D.; Aryaeinejad, R.

    1996-03-01

    This report summarizes the efforts completed in identifying candidate fluorescence compounds and radioisotopes for a developing tagging system. The tagging system is being developed as a deterrent to nuclear smuggling, by providing a means of: (1) tracing materials and pilferers to the facility of origin for any recovered special nuclear materials; (2) inventory control of long-term stored items containing special nuclear materials; and (3) tracking materials transferred between facilities. The tagging system uses four types of tagging materials to cover a range of applications intended to prevent the pilfering of special nuclear materials. One material, fluorescent compounds which are invisible without ultraviolet or near-infrared detection systems, is marked on controlled items with a tracking pattern that corresponds to a specified item in a specified location in the data control system. The tagging system uses an invisible, fluorescent dusting powder to mark equipment and personnel who inappropriately handle the tagged material. The tagging system also uses unique combinations of radionuclides to identify the facility of origin for any special nuclear material. Currently, 18 long-lived radioisotopes, 38 short-live radioisotopes and 10 fluorescent compounds have been selected as candidate materials for the tagging system.

  17. Few body hypernuclear systems: Weak decays

    SciTech Connect

    Dover, C.B.

    1987-01-01

    The experimental and theoretical situation regarding mesonic and non-mesonic decays of light hypernuclei is reviewed. Although some models give reasonable results for pionic decays as well as the total weak decay rate, no existing approach explains, even qualitatively, the observed spin-isospin dependence of ..lambda..N ..-->.. NN non-mesonic weak decays. 31 refs., 2 figs.

  18. Cadmium-109 Radioisotope Adsorption onto Polypyrrole Coated Sawdust of Dryobalanops aromatic: Kinetics and Adsorption Isotherms Modelling

    PubMed Central

    Olatunji, Michael Adekunle; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Mahmud, Habibun Nabi Muhammad Ekramul

    2016-01-01

    A radiotracer study was conducted to investigate the removal characteristics of cadmium (109Cd) from aqueous solution by polypyrrole/ sawdust composite. Several factors such as solution pH, sorbent dosage, initial concentration, contact time, temperature and interfering metal ions were found to have influence on the adsorption process. The kinetics of adsorption was relatively fast, reaching equilibrium within 3 hours. A lowering of the solution pH reduced the removal efficiency from 99.3 to ~ 46.7% and an ambient temperature of 25°C was found to be optimum for maximum adsorption. The presence of sodium and potassium ions inhibited 109Cd removal from its aqueous solution. The experimental data for 109Cd adsorption showed a very good agreement with the Langmuir isotherm and a pseudo-first order kinetic model. The surface condition of the adsorbent before and after cadmium loading was investigated using BET, FESEM and FTIR. Considering the low cost of the precursor’s materials and the toxicity of 109Cd radioactive metal, polypyrrole synthesized on the sawdust of Dryobalanops aromatic could be used as an efficient adsorbent for the removal of 109Cd radioisotope from radionuclide-containing effluents. PMID:27706232

  19. Environmental safety analysis tests on the Light Weight Radioisotope Heater Unit (LWRHU)

    SciTech Connect

    Tate, R.E.; Land, C.C.

    1985-05-01

    A series of safety tests has been performed on the Light Weight Radioisotope Heater Unit (LWRHU), a /sup 238/PuO/sub 2/-fueled device designed to provide thermal energy at selected locations in a spacecraft. The tests simulate the thermal and mechanical environments postulated for spacecraft accidents on the launch pad and on reentry abort. The tests demonstrate almost complete containment of the fuel, or fuel simulant (depleted UO/sub 2/), in (1) an overpressure environment of 12.76 MPa (1850 psi), (2) on impact by an 18-g aluminum fuel-tank fragment at velocities greater than 750 m/s (2460 ft/s) but less than 900 m/s (2950 ft/s), (3) during a 10.5-min burn of a 0.9 x 0.9 x 0.9 m (3 x 3 x 3 ft) block of solid rocket motor propellant, (4) after impact at 49 m/s (161 ft/s) in four different orientations on a hard surface, and (5) during immersion in seawater for 1.75 years at both sea level pressure and at a pressure equivalent to 6000 m (19,700 ft) of ocean depth.

  20. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi.

    PubMed

    Lengemann, F W; Marchell, T F; Chmielewicz, M; Georgi, J R

    1986-07-01

    Ten radioisotopes (133Ba, 207Bi, 109Cd, 51Cr, 59Fe, 203Hg, 54Mn, 125Sb and 75Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for 207Bi and exceeded that of 203Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of 207Bi but increased 203Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the 207Bi was retained; for 203Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the 203Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  1. In vitro radioisotopic labeling of the L-3 stage of Brugia malayi

    SciTech Connect

    Lengemann, F.W.; Marchell, T.F.; Chmielewicz, M.; Georgi, J.R.

    1986-07-01

    Ten radioisotopes (/sup 133/Ba, /sup 207/Bi, /sup 109/Cd, /sup 51/Cr, /sup 59/Fe, /sup 203/Hg, /sup 54/Mn, /sup 125/Sb and /sup 75/Se) were used to label the L-3 stage of Brugia malayi. The in vitro uptake at 4 hours in a buffered salt solution was greatest for /sup 207/Bi and exceeded that of /sup 203/Hg, by a factor of 6 and the rest of the radionuclides by factors of 26 or more. Dimethylsulfoxide (DMSO) (1%) in the medium only slightly enhanced the uptake of /sup 207/Bi but increased /sup 203/Hg uptake by a factor of 2.5. After incubation in non-radioactive medium only 2% of the /sup 207/Bi was retained; for /sup 203/Hg the retention was 70% or better. Increasing the labeling time increased total uptake and retention of the radionuclides. The retention of the /sup 203/Hg injected intraperitoneally into jirds (Meriones unguiculatus) in the form of labeled L-3s was followed over a 16 day period by counting the jirds in a whole animal NaI crystal detector. One L-4 stage of B malayi was recovered at the end of this period.

  2. Electron-beam processing of kilogram quantities of iridium for radioisotope thermoelectric generator applications

    SciTech Connect

    Huxford, T.J.; Ohriner, E.K.

    1992-12-31

    Iridium alloys are used as fuel-cladding materials in radioisotope thermoelectric generators (RTGs). Hardware produced at the Oak Ridge National Laboratory (ORNL) has been used in Voyagers I and 2, Galilee, and Ulysses spacecraft. An integral part of the production of iridium-sheet metal involves electron-beam (EB) processing. These processes include the degassing of powder-pressed compacts followed by multiple meltings in order to purify 500-g buttons of Ir-0.3% W alloy. Starting in 1972 and continuing into 1992, our laboratory EB processing was Performed (ca. 1970) in a 60-kW (20 kV at 3 A), two-gun system. In 1991, a new 150-kW EB gun facility was installed to complement the older unit. This paper describes how the newly installed system was qualified for production of RTG developmental work is discussed that will potentially improve the existing process by utilizing the capabilities of the new EB system.

  3. Electron-beam processing of kilogram quantities of iridium for radioisotope thermoelectric generator applications

    SciTech Connect

    Huxford, T.J.; Ohriner, E.K.

    1992-01-01

    Iridium alloys are used as fuel-cladding materials in radioisotope thermoelectric generators (RTGs). Hardware produced at the Oak Ridge National Laboratory (ORNL) has been used in Voyagers I and 2, Galilee, and Ulysses spacecraft. An integral part of the production of iridium-sheet metal involves electron-beam (EB) processing. These processes include the degassing of powder-pressed compacts followed by multiple meltings in order to purify 500-g buttons of Ir-0.3% W alloy. Starting in 1972 and continuing into 1992, our laboratory EB processing was Performed (ca. 1970) in a 60-kW (20 kV at 3 A), two-gun system. In 1991, a new 150-kW EB gun facility was installed to complement the older unit. This paper describes how the newly installed system was qualified for production of RTG developmental work is discussed that will potentially improve the existing process by utilizing the capabilities of the new EB system.

  4. Assembly and Testing of a Radioisotope Power System for the New Horizons Spacecraft

    SciTech Connect

    Kenneth E. Rosenberg; Stephen G. Johnson

    2006-06-01

    The Idaho National Laboratory (INL) recently fueled and assembled a radioisotope power system (RPS) that was used upon the New Horizons spacecraft which was launched in January 2006. New Horizons is the first mission to the last planet - the initial reconnaissance of Pluto-Charon and the Kuiper Belt, exploring the mysterious worlds at the edge of our solar system. The RPS otherwise known as a "space battery" converts thermal heat into electrical energy. The thermal heat source contains plutonium dioxide in the form of ceramic pellets encapsulated in iridium metal. The space battery was assembled in a new facility at the Idaho National Laboratory site near Idaho Falls, Idaho. The new facility has all the fueling and testing capabilities including the following: the ability to handle all the shipping containers currently certified to ship Pu-238, the ability to fuel a variety of RPS designs, the ability to perform vibrational testing to simulate transportation and launch environments, welding systems, a center of mass determination device, and various other support systems.

  5. Charged-particle cross section database for medical radioisotope production: chapter 3. theoretical evaluations

    SciTech Connect

    Mustafa, M

    1999-06-24

    Creation of a Reference Charged Particle Cross Section Database for Medical Radioisotope Production requires the evaluation of both experimental and modeled cross sections for beam monitor reactions and for radionuclide (positron and gamma emitters) production reactions. It was recognized at the first meeting of this CRP in Vienna in 1995 that modeling will play an important role in predicting cross sections where measurements are either not available or have large discrepancies. Because of the volume of work involving about forty-five reactions in the CRP, it was decided to use modeling as a guide rather than for full evaluation. (Although in some cases the CRP used the modeled cross sections as the recommended values). Thus the modeling was done using global input parameters. In this chapter we describe the modeling by four different groups: Livermore, Obninsk, Beijing and Islamabad. First we give a general overview of nuclear reaction models that may be used in modeling cross sections below 100 MeV. This will be followed by a short description of the codes and calculations actually used by the four groups. (We note that the codes have similar basic reaction physics, but they differ in details and in actual applications.) In the final section we give a discussion of the modeling with its successes and failures in reproducing experimental data using global input parameters.

  6. AlGaAs 55Fe X-ray radioisotope microbattery

    PubMed Central

    Butera, S.; Whitaker, M. D. C.; Lioliou, G.; Barnett, A. M.

    2016-01-01

    This paper describes the performance of a fabricated prototype Al0.2Ga0.8As 55Fe radioisotope microbattery photovoltaic cells over the temperature range −20 °C to 50 °C. Two 400 μm diameter p+-i-n+ (3 μm i-layer) Al0.2Ga0.8As mesa photodiodes were used as conversion devices in a novel X-ray microbattery prototype. The changes of the key microbattery parameters were analysed in response to temperature: the open circuit voltage, the maximum output power and the internal conversion efficiency decreased when the temperature was increased. At −20 °C, an open circuit voltage and a maximum output power of 0.2 V and 0.04 pW, respectively, were measured per photodiode. The best internal conversion efficiency achieved for the fabricated prototype was only 0.95% at −20 °C. PMID:27922093

  7. Reanalysis of radioisotope measurements of the 9Be(γ ,n )8Be cross section

    NASA Astrophysics Data System (ADS)

    Robinson, Alan E.

    2016-08-01

    The 9Be(γ ,n )8Be reaction is enhanced by a near-threshold 1 /2+ state. Contradictions between existing measurements of this reaction cross section affect calculations of astrophysical r -process yields, dark matter detector calibrations, and the theory of the nuclear structure of 9Be. Select well-documented radioisotope 9Be(γ ,n ) source yield measurements have been reanalyzed, providing a set of high-accuracy independently measured cross sections without the large systematic errors from recent beamline experiments [Arnold, Clegg, Iliadis, Karwowski, Rich, Tompkins, and Howell, Phys. Rev. C 85, 044605 (2012), 10.1103/PhysRevC.85.044605; Utsunomiya, Katayama, Gheorghe, Imai, Yamaguchi, Kahl, Sakaguchi, Shima, Takahisa, and Miyamoto, Phys. Rev. C 92, 064323 (2015), 10.1103/PhysRevC.92.064323]. A single-level Breit-Wigner fit of these corrected measurement yields are ER=1736.8 (18 ) keV, Γγ=0.742 (25 ) eV, and Γn=252 (17 ) keV for the 1 /2+ state, excluding a virtual state solution.

  8. Soil to plant transfer of radionuclides: predicting the fate of multiple radioisotopes in plants.

    PubMed

    Willey, Neil J

    2014-07-01

    Predicting soil-to-plant transfer of radionuclides is restricted by the range of species for which concentration ratios (CRs) have been measured. Here the radioecological utility of meta-analyses of phylogenetic effects on alkali earth metals will be explored for applications such as 'gap-filling' of CRs, the identification of sentinel biomonitor plants and the selection of taxa for phytoremediation of radionuclide contaminated soils. REML modelling of extensive CR/concentration datasets shows that the concentrations in plants of Ca, Mg and Sr are significantly influenced by phylogeny. Phylogenetic effects of these elements are shown here to be similar. Ratios of Ca/Mg and Ca/Sr are known to be quite stable in plants so, assuming that Sr/Ra ratios are stable, phylogenetic effects and estimated mean CRs are used to predict Ra CRs for groups of plants with few measured data. Overall, there are well quantified plant variables that could contribute significantly to improving predictions of the fate radioisotopes in the soil-plant system.

  9. Cadmium-109 Radioisotope Adsorption onto Polypyrrole Coated Sawdust of Dryobalanops aromatic: Kinetics and Adsorption Isotherms Modelling.

    PubMed

    Olatunji, Michael Adekunle; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Mahmud, Habibun Nabi Muhammad Ekramul

    2016-01-01

    A radiotracer study was conducted to investigate the removal characteristics of cadmium (109Cd) from aqueous solution by polypyrrole/ sawdust composite. Several factors such as solution pH, sorbent dosage, initial concentration, contact time, temperature and interfering metal ions were found to have influence on the adsorption process. The kinetics of adsorption was relatively fast, reaching equilibrium within 3 hours. A lowering of the solution pH reduced the removal efficiency from 99.3 to ~ 46.7% and an ambient temperature of 25°C was found to be optimum for maximum adsorption. The presence of sodium and potassium ions inhibited 109Cd removal from its aqueous solution. The experimental data for 109Cd adsorption showed a very good agreement with the Langmuir isotherm and a pseudo-first order kinetic model. The surface condition of the adsorbent before and after cadmium loading was investigated using BET, FESEM and FTIR. Considering the low cost of the precursor's materials and the toxicity of 109Cd radioactive metal, polypyrrole synthesized on the sawdust of Dryobalanops aromatic could be used as an efficient adsorbent for the removal of 109Cd radioisotope from radionuclide-containing effluents.

  10. Measurement of urinary histamine: comparison of fluorometric and radioisotopic-enzymatic assay procedures

    SciTech Connect

    Warren, K.; Dyer, J.; Merlin, S.; Kaliner, M.

    1982-02-01

    Assessment of urinary histamine may prove useful in determining the role of histamine in human health and disease. Urinary histamine may be accurately estimated by a modified fluorometric assay employing diamine oxidase (DAO) digestion and cation-exchange chromatography. Normal urine histamine values obtained by this assay are: arithmetic means (+/- SEM), 8.6 +/- 0.6 ng/ml and 10.5 +/- 0.7 micrograms/24 hr; geometric means (+/- SEM), 6.2 +/- 1.1 ng/ml and 10.0 +/- 1.3 micrograms/24 hr. However, the radioisotopic-enzymatic assay is less expensive, easier to perform, and possibly more sensitive. Therefore the two procedures were compared. The radioenzyme assay was found to be affected by factors in urine (possibly salt concentrations) requiring extraction of histamine from urine by butanol-heptane. Moreover, it was found to be necessary to compare DAO-digested samples with undigested samples to accurately estimate histamine levels and to run the standard curve of histamine in DAO-digested urine. Even with these modifications, the radioenzyme assay was not as accurate as the fluorometric assay for urine samples having histamine values about 60 ng/ml. Therefore we recommend utilization of the modified fluorometric assay for the measurement of urinary histamine levels.

  11. Extended Operation Testing of Stirling Convertors in Support of Stirling Radioisotope Power System Development

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Wilson, Scott D.; Oriti, Salvatore M.; Cornell, Peggy; Schifer, Nicholas

    2009-01-01

    100 We class Stirling convertors began extended operation testing at NASA Glenn Research Center (GRC) in 2003 with a pair of Technology Demonstration Convertors (TDCs) operating in air. Currently, the number of convertors on extended operation test has grown to 12, including both TDCs and Advanced Stirling Convertors (ASCs) operating both in air and in thermal vacuum. Additional convertors and an electrically heated radioisotope generator will be put on test in the near future. This testing has provided data to support life and reliability estimates and the quality improvements and design changes that have been made to the convertor. The convertors operated 24/7 at the nominal amplitude and power levels. Performance data were recorded on an hourly basis. Techniques to monitor the convertors for change in internal operation included gas analysis, vibration measurements, and acoustic emission measurements. This data provided a baseline for future comparison. This paper summarizes the results of over 145,000 hr of TDC testing and 40,000 hr of ASC testing and discusses trends in the data. Data shows the importance of improved materials, hermetic sealing, and quality processes in maintaining convertor performance over long life.

  12. Natural Convection Cooling of the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Hill, Dennis

    2011-01-01

    After fueling and prior to launch, the Advanced Stirling Radioisotope Generator (ASRG) will be stored for a period of time then moved to the launch pad for integration with the space probe and mounting on the launch vehicle. During this time, which could be as long as 3 years, the ASRG will operate continuously with heat rejected from the housing and fins. Typically, the generator will be cooled by forced convection using fans. During some of the ground operations, maintaining forced convection may add significant complexity, so allowing natural convection may simplify operations. A test was conducted on the ASRG Engineering Unit (EU) to quantify temperatures and operating parameters with natural convection only and determine if the EU could be safely operated in such an environment. The results show that with natural convection cooling the ASRG EU Stirling convertor pressure vessel temperatures and other parameters had significant margins while the EU was operated for several days in this configuration. Additionally, an update is provided on ASRG EU testing at NASA Glenn Research Center, where the ASRG EU has operated for over 16,000 hr and underwent extensive testing.

  13. Carbon-bonded carbon fiber insulation for radioisotope space power systems

    SciTech Connect

    Wei, G.C.; Robbins, J.M.

    1985-05-01

    A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. Several attributes that make CBCF particularly suitable for the heat source application have been identified. These include light weight, low thermal conductivity, chemical compatibility, and high-temperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific properties of the CBCF were tailored by adjusting material and processing variables to obtain the desired results. 22 references, 13 figures, 4 tables.

  14. Carbon-bonded carbon fiber insulation for radioisotope space power systems

    SciTech Connect

    Wei, G C; Robbins, J M

    1985-05-01

    A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. (Several attributes that make CBCF particularly suitable for the heat source application have been identified.) These include light weight, low thermal conductivity, chemical compatibility, and hightemperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific properties of the CBCF were tailored by adjusting material and processing variables to obtain the desired results.

  15. Persistence and decontamination of surrogate radioisotopes in a model drinking water distribution system

    SciTech Connect

    Szabo, Jeffrey G.; Impellitteri, Christopher A.; Govindaswamy, Shekar; Hall, John S.

    2010-01-12

    Contamination of a model drinking water system with surrogate radioisotopes was examined with respect to persistence on and decontamination of infrastructure surfaces. Cesium and cobalt chloride salts were used as surrogates for cesium-137 and cobalt-60. Studies were conducted in biofilm annular reactors containing heavily corroded iron surfaces formed under shear and constantly submerged in drinking water. Cesium was not detected on the corroded iron surface after equilibration with 10 and 100 mg L{sup -1} solutions of cesium chloride, but cobalt was detected on corroded iron coupons at both initial concentrations. The amount of adhered cobalt decreased over the next six weeks, but was still present when monitoring stopped. X-ray absorption near-edge spectroscopy (XANES) showed that adhered cobalt was in the III oxidation state. The adsorbed cobalt was strongly resistant to decontamination by various physicochemical methods. Simulated flushing, use of free chlorine and dilute ammonia were found to be ineffective whereas use of aggressive methods like 14.5 M ammonia and 0.36 M sulfuric acid removed 37 and 92% of the sorbed cobalt, respectively.

  16. NASA GRC Technology Development Project for a Stirling Radioisotope Power System

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.; Schreiber, Jeffrey G.

    2000-01-01

    NASA Glenn Research Center (GRC), the Department of Energy (DOE), and Stirling Technology Company (STC) are developing a Stirling convertor for an advanced radioisotope power system to provide spacecraft on-board electric power for NASA deep space missions. NASA GRC is conducting an in-house project to provide convertor, component, and materials testing and evaluation in support of the overall power system development. A first characterization of the DOE/STC 55-We Stirling Technology Demonstration Convertor (TDC) under the expected launch random vibration environment was recently completed in the NASA GRC Structural Dynamics Laboratory. Two TDCs also completed an initial electromagnetic interference (EMI) characterization at NASA GRC while being tested in a synchronized, opposed configuration. Materials testing is underway to support a life assessment of the heater head, and magnet characterization and aging tests have been initiated. Test facilities are now being established for an independent convertor performance verification and technology development. A preliminary Failure Mode Effect Analysis (FMEA), initial finite element analysis (FEA) for the linear alternator, ionizing radiation survivability assessment, and radiator parametric study have also been completed. This paper will discuss the status, plans, and results to date for these efforts.

  17. Preliminary evaluation of a fluorescence and radioisotope nuclear smuggling deterrence tag - final report (IL500E)

    SciTech Connect

    Hartenstein, S.D.; Aryaeinejad, R.; Delmastro, J.R.

    1997-04-01

    This report summarizes the efforts completed in identifying candidate fluorescence compounds and radioisotopes for a developing tagging system. The tagging system is being developed as a deterrent to nuclear smuggling, by providing a means of: (1) tracing materials and pilferers to the facility of origin for any recovered special nuclear materials, (2) inventory control of long-term stored items containing special nuclear materials, and (3) tracking materials transferred between facilities. The system uses three types of materials to cover a range of applications intended to prevent the pilfering of special nuclear materials. One material, fluorescent compounds which are invisible without ultraviolet or near-infrared detection systems, is marked on controlled items with a tracking pattern that corresponds to a specified item in a specified location in the data control system. The tagging system uses an invisible, fluorescent dusting powder to mark equipment and personnel who inappropriately handle the tagged material. The tagging system also uses unique combinations of radionuclides to identify the facility of origin for any special nuclear material. This report also summarizes the efforts completed in identifying hardware that will be used for the tagging system. This hardware includes the devices for applying the tagging materials, the commercially available fluorescence detection systems, and gamma ray detection systems assembled from existing, commercially available technologies.

  18. Radioisotopic assays of CoASH and carnitine and their acetylated forms in human skeletal muscle

    SciTech Connect

    Cederblad, G.; Carlin, J.I.; Constantin-Teodosiu, D.; Harper, P.; Hultman, E. )

    1990-03-01

    Radioisotopic assays for the determination of acetyl-CoA, CoASH, and acetylcarnitine have been modified for application to the amount of human muscle tissue that can be obtained by needle biopsy. In the last step common to all three methods, acetyl-CoA is condensed with (14C)oxaloacetate by citrate synthase to give (14C)-citrate. For determination of CoASH, CoASH is reacted with acetylphosphate in a reaction catalyzed by phosphotransacetylase to yield acetyl-CoA. In the assay for acetylcarnitine, acetylcarnitine is reacted with CoASH in a reaction catalyzed by carnitine acetyltransferase to form acetyl-CoA. Inclusion of new simple steps in the acetylcarnitine assay and conditions affecting the reliability of all three methods are also described. Acetylcarnitine and free carnitine levels in human rectus abdominis muscle were 3.0 +/- 1.5 (SD) and 13.5 +/- 4.0 mumol/g dry wt, respectively. Values for acetyl-CoA and CoASH were about 500-fold lower, 6.7 +/- 1.8 and 21 +/- 8.9 nmol/g dry wt, respectively. A strong correlation between acetylcarnitine (y) and short-chain acylcarnitine (x), determined as the difference between total and free carnitine, was found in biopsies from the vastus lateralis muscle obtained during intense muscular effort, y = 1.0x + 0.5; r = 0.976.

  19. Persistence and decontamination of surrogate radioisotopes in a model drinking water distribution system.

    PubMed

    Szabo, Jeffrey G; Impellitteri, Christopher A; Govindaswamy, Shekar; Hall, John S

    2009-12-01

    Contamination of a model drinking water system with surrogate radioisotopes was examined with respect to persistence on and decontamination of infrastructure surfaces. Cesium and cobalt chloride salts were used as surrogates for cesium-137 and cobalt-60. Studies were conducted in biofilm annular reactors containing heavily corroded iron surfaces formed under shear and constantly submerged in drinking water. Cesium was not detected on the corroded iron surface after equilibration with 10 and 100mgL(-1) solutions of cesium chloride, but cobalt was detected on corroded iron coupons at both initial concentrations. The amount of adhered cobalt decreased over the next six weeks, but was still present when monitoring stopped. X-ray absorption near-edge spectroscopy (XANES) showed that adhered cobalt was in the III oxidation state. The adsorbed cobalt was strongly resistant to decontamination by various physicochemical methods. Simulated flushing, use of free chlorine and dilute ammonia were found to be ineffective whereas use of aggressive methods like 14.5M ammonia and 0.36M sulfuric acid removed 37 and 92% of the sorbed cobalt, respectively.

  20. AlGaAs 55Fe X-ray radioisotope microbattery

    NASA Astrophysics Data System (ADS)

    Butera, S.; Whitaker, M. D. C.; Lioliou, G.; Barnett, A. M.

    2016-12-01

    This paper describes the performance of a fabricated prototype Al0.2Ga0.8As 55Fe radioisotope microbattery photovoltaic cells over the temperature range ‑20 °C to 50 °C. Two 400 μm diameter p+-i-n+ (3 μm i-layer) Al0.2Ga0.8As mesa photodiodes were used as conversion devices in a novel X-ray microbattery prototype. The changes of the key microbattery parameters were analysed in response to temperature: the open circuit voltage, the maximum output power and the internal conversion efficiency decreased when the temperature was increased. At ‑20 °C, an open circuit voltage and a maximum output power of 0.2 V and 0.04 pW, respectively, were measured per photodiode. The best internal conversion efficiency achieved for the fabricated prototype was only 0.95% at ‑20 °C.