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Sample records for texas a and m variable energy cyclotron

  1. Progress in research, April 1, 1991--March 31, 1992, Texas A and M University Cyclotron Institute

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-06-01

    Reports on research activities, facility operation, and facility development of the Texas A and M Cyclotron Institute for the period 1 April 1991--31 March 1992 are presented in this document. During the report period, the ECR-K500 Cyclotron Combination operated 4,377 hours. Of this time, 832 hours was used for beam development, 942 hours was used for tuning and optics, and the beam was available for experiments 2,603 hours. This time was used in a variety of studies including elastic and inelastic scattering, projectile break-up, the production and decay of giant resonances, fusion and fission dynamics, intermediate mass fragment emission, e{sup +}e{sup {minus}} production and molecular dissociation. In addition, studies of surfaces and metastable states in highly charged ions were carried out using the ECR source. Completion of two 19-element BaF{sub 2} arrays, of the focal plane detector for the proton spectrometer and installation of the HiLi multidetector have provided significant new experimental capabilities which have been further enhanced by major additions to the computer network. Progress on the Mass Achromat Recoil Spectrometer (MARS) is such that first operation of that device should occur this summer. Funding for installation of the MDM spectrometer was obtained at the beginning of this year. As this report is being completed, the Enge Split Pole Spectrometer is being disassembled and removed to make room for the MDM spectrometer. The split-pole will be shipped to CEBAF for use in experiments there. Installation of the MDM should be completed within the next year. Also expected in the next year is a 92 element plastic-CsI ball.

  2. Progress in research, April 1, 1992--March 31, 1993, Texas A and M University Cyclotron Institute

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-07-01

    This Institute annual report for the period 1 April 1992--31 March 1993 covers a period which has seen the initial runs of three new spectrometers which constitute a major portion of the new detection capabilities developed for this facility. These devices are the Proton Spectrometer (PSP), the Mass Achromat Recoil Mass Spectrometer (MARS), and the Multipole dipole Multipole (MDM) Particle Spectrometer. These devices are now available to pursue the studies of Gamow Teller states, reactions of astrophysical interest, and giant resonance studies for which they were constructed, as well as for other experiments. A beam analysis system which will deliver high resolution beams to the MDM spectrometer is currently under construction. With the completion of these spectrometer projects, the facility emphasis is now focused on the development of the full capabilities of the K500 cyclotron and on the research program. During the report period, the ECR-K500 cyclotron combination operated 5,849 hours. Theoretical work reported in this document ranges from nuclear structure calculations using the IBM-2 model to calculations of kaon production and the in-medium properties of the rho and phi mesons, the latter as a probe of the QCD phase transition. Nuclear dynamics and exotic shapes and fragmentation modes of hot nuclei are also addressed. In atomic physics, new measurements of x-ray emission from highly ionized ions, of molecular dissociation and of surface interactions are reported.

  3. Preliminary production of 211At at the Texas A&M University Cyclotron Institute.

    Science.gov (United States)

    Martin, Thomas Michael; Bhakta, Vihar; Al-Harbi, Abeer; Hackemack, Michael; Tabacaru, Gabriel; Tribble, Robert; Shankar, Sriram; Akabani, Gamal

    2014-07-01

    A feasibility study for the production of the alpha particle-emitting radionuclide At was performed at the Texas A&M University Cyclotron Institute as part of the Interdisciplinary Radioisotope Production and Radiochemistry Program. The mission of this program centers upon the production of radionuclides for use in diagnostic and therapeutic nuclear medicine with the primary focus on development of novel therapeutic strategies. As a first step in establishing this program, two goals were outlined: (i) verify production of At and compare results to published data, and (ii) evaluate shielding and radiological safety issues for large-scale implementation using an external target. The radionuclide At was produced via the Bi (α, 2n) At reaction using the K500 cyclotron. Two experiments were conducted, using beam energies of 27.8 MeV and 25.3 MeV, respectively. The resulting yields for At were found to be 36.0 MBq μA h and 12.4 MBq μA h, respectively, which fall within the range of published yield data. Strategies for increasing absolute yield and production efficiency were also evaluated, which focused chiefly on using a new target designed for use with the K150 cyclotron, which will enable the use of a higher beam current. Finally, neutron and gamma dose rates during production were evaluated by using the Monte Carlo code MCNPX. It was determined that a simple structure consisting of 4-in thick borated polyethylene will reduce the neutron dose rate within the cyclotron production vault by approximately a factor of 2, thereby decreasing activation of equipment.

  4. Accelerated Learning: Undergraduate Research Experiences at the Texas A&M Cyclotron Institute

    Science.gov (United States)

    Yennello, S. J.

    The Texas A&M Cyclotron Institute (TAMU CI) has had an NSF funded Research Experiences for Undergraduates program since 2004. Each summer about a dozen students from across the country join us for the 10-week program. They are each imbedded in one of the research groups of the TAMU CI and given their own research project. While the main focus of their effort is their individual research project, we also have other activities to broaden their experience. For instance, one of those activities has been involvement in a dedicated group experiment. Because not every experimental group will run during those 10 weeks and the fact that some of the students are in theory research groups, a group research experience allows everyone to actually be involved in an experiment using the accelerator. In stark contrast to the REU students' very focused experience during the summer, Texas A&M undergraduates can be involved in research projects at the Cyclotron throughout the year, often for multiple years. This extended exposure enables Texas A&M students to have a learning experience that cannot be duplicated without a local accelerator. The motivation for the REU program was to share this accelerator experience with students who do not have that opportunity at their home institution.

  5. Progress in research April 1, 1993--March 31, 1994, Texas A and M University Cyclotron Institute

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-07-01

    The period 1 April 1993--31 March 1994 has seen a number of significant developments of the research program as will be noted by the large increase in individual projects reviewed in this annual report. Among the highlights of the K500 experimental program in Sections 1, 2, and 4 are the investigations of excitation energy deposition and of fission dynamics employing both GDR and particle emission probes, measurements of isospin equilibration, studies of (d, {sup 2}He) reactions with the proton spectrometer and of the {beta} decay of {sup 57}Cu with MARS, and the precise studies of ionic charge state distributions using x-ray measurements. Progress in theoretical studies of the nuclear spectral function and the decay of many body systems, on the properties of mesons in hot hadronic matter and on the determination of astrophysical S-factors from experimental studies of very peripheral reactions are presented in Section 3. The status of the LAMPF based MEGA experiment and of the CERN based NA66 experiment, both of which involve institute scientists, is also briefly presented in this report. The shift to a seven day a week operation coupled with installation of cryopanels and more careful temperature control of the cooling water system have resulted in significant improvements in the operational efficiency and beam capabilities. Operating statistics are presented in Section 5.

  6. High energy physics program at Texas A and M University

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    The Texas A M experimental high energy physics program continued to reach significant milestones in each of its research initiatives during the course of the past year. We are participating in two major operating experiments, CDF and MACRO. In CDF, the Texas A M group has spearheaded the test beam program to recalibrate the Forward Hadron Calorimeter for the upcoming CDF data run, as well as contributing to the ongoing analysis work on jets and b-quarks. In MACRO, we have assisted in the development of the final version of the wave form digitizing system being implemented for the entire scintillator system. The construction of the first six supermodules of the detector has been completed and all six are currently taking data with streamer chambers while four have the completed scintillator counter system up and running. We have built and tested prototypes of a liquid-scintillator fiber calorimeter system, in which internally reflecting channels are imbedded in a lead matrix and filled with liquid scintillator. This approach combines the performance features of fiber calorimetry and the radiation hardness of liquid scintillator, and is being developed for forward calorimetry at the SSC. The microstrip chamber is a new technology for precision track chambers that offers the performance required for future hadron colliders. The theoretical high energy physics program has continued to develop during the past funding cycle. We have continued the study of their very successful string-derived model that unifies all known interactions; flipped SU(5), which is the leading candidate for a TOE. Work has continued on some generalizations of the symmetries of string theory, known as W algebras. These are expected to have applications in two-dimensional conformal field theory, two-dimensional extensions of gravity and topological gravity and W-string theory.

  7. Cyclotrons with fast variable and/or multiple energy extraction

    Directory of Open Access Journals (Sweden)

    C. Baumgarten

    2013-10-01

    Full Text Available We discuss the possibility in principle of stripping extraction in combination with reverse bends in isochronous separate-sector cyclotrons (and/or fixed field alternating gradient accelerators. If one uses reverse bends between the sectors (instead of or in combination with drifts and places stripper foils at the sector exit edges, the stripped beam has a reduced bending radius and it should be able to leave the cyclotron within the range of the valley—even if the beam is stripped at less than full energy. We are especially interested in stripping of H_{2}^{+}, as it doubles the charge to mass ratio of the ions. However the method could be applied to other ions or ionized molecules as well. For the production of proton beams by stripping extraction of an H_{2}^{+} beam, we discuss possible designs for three types of machines: First, a low-energy cyclotron for the simultaneous production of several beams at multiple energies—for instance 15, 30, and 70 MeV—thus allowing beam delivery on several isotope production targets. In this case it can be an advantage to have a strong energy dependence of the direction of the extracted beam. Second, we consider a fast variable-energy proton machine for cancer therapy that should allow extraction (of the complete beam at all energies in the range of about 70 MeV to about 250 MeV into the same beam line. Third, we consider a high-intensity high-energy machine, where the main design goals are extraction with low losses, low activation of components, and high reliability. Especially if such a machine is considered for an accelerator driven system (ADS, this extraction mechanism has advantages: Beam trips by the failure of electrostatic elements could be avoided and the turn separation would be less critical, which allows operation at lower main cavity voltages. This would in turn reduce the number of rf trips. The price that has to be paid for these advantages is an increase in size and/or field

  8. Clinical Trial with Sodium 99mTc-Pertechnetate Produced by a Medium-Energy Cyclotron: Biodistribution and Safety Assessment in Patients with Abnormal Thyroid Function.

    Science.gov (United States)

    Selivanova, Svetlana V; Lavallée, Éric; Senta, Helena; Caouette, Lyne; McEwan, Alexander J B; Guérin, Brigitte; Lecomte, Roger; Turcotte, Éric

    2017-05-01

    A single-site prospective open-label clinical study with cyclotron-produced sodium 99mTc-pertechnetate (99mTc-NaTcO4) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional 99mTc-NaTcO4 eluted from a generator. Methods:99mTc-NaTcO4 was produced from enriched 100Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced 99mTc-NaTcO4, whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Results: Cyclotron-produced 99mTc-NaTcO4 showed organ and whole-body distributions identical to those of conventional 99mTc-NaTcO4 and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced 99mTc-NaTcO4 did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced 99mTc was equivalent to that with generator-eluted 99mTc and had no particular features allowing discrimination between the 99mTc production methods. Conclusion: The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced 99mTc-NaTcO4 in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted 99mTc-NaTcO4 in routine clinical practice. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  9. Mr Bikash Sinha, Director of SAHA & VECC and Prof. Rolf Heuer, Director general of CERN, sign a collaboration agreements between SAHA (Saha Institute of Nuclear Physics), VECC (Variable Energy Cyclotron Centre), India and CERN ISOLDE.

    CERN Multimedia

    Maximilien Brice

    2009-01-01

    Mr Bikash Sinha, Director of SAHA & VECC and Prof. Rolf Heuer, Director general of CERN, sign a collaboration agreements between SAHA (Saha Institute of Nuclear Physics), VECC (Variable Energy Cyclotron Centre), India and CERN ISOLDE.

  10. Radioisotopic Purity of Sodium Pertechnetate 99mTc Produced with a Medium-Energy Cyclotron: Implications for Internal Radiation Dose, Image Quality, and Release Specifications.

    Science.gov (United States)

    Selivanova, Svetlana V; Lavallée, Éric; Senta, Helena; Caouette, Lyne; Sader, Jayden A; van Lier, Erik J; Zyuzin, Alexander; van Lier, Johan E; Guérin, Brigitte; Turcotte, Éric; Lecomte, Roger

    2015-10-01

    Cyclotron production of 99mTc is a promising route to supply 99mTc radiopharmaceuticals. Higher 99mTc yields can be obtained with medium-energy cyclotrons in comparison to those dedicated to PET isotope production. To take advantage of this capability, evaluation of the radioisotopic purity of 99mTc produced at medium energy (20-24 MeV) and its impact on image quality and dosimetry was required. Thick 100Mo (99.03% and 99.815%) targets were irradiated with incident energies of 20, 22, and 24 MeV for 2 or 6 h. The targets were processed to recover an effective thickness corresponding to approximately 5-MeV energy loss, and the resulting sodium pertechnetate 99mTc was assayed for chemical, radiochemical, and radionuclidic purity. Radioisotopic content in final formulation was quantified using γ-ray spectrometry. The internal radiation dose for 99mTc-pertechnetate was calculated on the basis of experimentally measured values and biokinetic data in humans. Planar and SPECT imaging were performed using thin capillary and water-filled Jaszczak phantoms. Extracted sodium pertechnetate 99mTc met all provisional quality standards. The formulated solution for injection had a pH of 5.0-5.5, contained greater than 98% of radioactivity in the form of pertechnetate ion, and was stable for at least 24 h after formulation. Radioisotopic purity of 99mTc produced with 99.03% enriched 100Mo was greater than 99.0% decay corrected to the end of bombardment (EOB). The radioisotopic purity of 99mTc produced with 99.815% enriched 100Mo was 99.98% or greater (decay corrected to the EOB). The estimated dose increase relative to 99mTc without any radionuclidic impurities was below 10% for sodium pertechnetate 99mTc produced from 99.03% 100Mo if injected up to 6 h after the EOB. For 99.815% 100Mo, the increase in effective dose was less than 2% at 6 h after the EOB and less than 4% at 15 h after the EOB when the target was irradiated at an incident energy of 24 MeV. Image spatial resolution

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

    Energy Technology Data Exchange (ETDEWEB)

    Akabani, Gamal [Texas A & M Univ., College Station, TX (United States). Dept. of Nuclear Engineering. Dept. of Veterinary Integrative Biosciences

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Akabani, Gamal [Texas A & M Univ., College Station, TX (United States)

    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.

  13. Texas Affordable Baccalaureate Program: A Collaboration between the Texas Higher Education Coordinating Board, South Texas College, and Texas A&M University-Commerce. CBE Case Study

    Science.gov (United States)

    Klein-Collins, Rebecca; Glancey, Kathleen

    2015-01-01

    This case study is part of a series on newer competency-based degree programs that have been emerging in recent years. In January 2014, the Texas Higher Education Coordinating Board (THECB), South Texas College (STC), and Texas A&M University-Commerce (A&M Commerce) launched the Texas Affordable Baccalaureate Program, the state's first…

  14. High energy physics program at Texas A and M University. Annual report, April 1, 1991--March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    The Texas A&M experimental high energy physics program continued to reach significant milestones in each of its research initiatives during the course of the past year. We are participating in two major operating experiments, CDF and MACRO. In CDF, the Texas A&M group has spearheaded the test beam program to recalibrate the Forward Hadron Calorimeter for the upcoming CDF data run, as well as contributing to the ongoing analysis work on jets and b-quarks. In MACRO, we have assisted in the development of the final version of the wave form digitizing system being implemented for the entire scintillator system. The construction of the first six supermodules of the detector has been completed and all six are currently taking data with streamer chambers while four have the completed scintillator counter system up and running. We have built and tested prototypes of a liquid-scintillator fiber calorimeter system, in which internally reflecting channels are imbedded in a lead matrix and filled with liquid scintillator. This approach combines the performance features of fiber calorimetry and the radiation hardness of liquid scintillator, and is being developed for forward calorimetry at the SSC. The microstrip chamber is a new technology for precision track chambers that offers the performance required for future hadron colliders. The theoretical high energy physics program has continued to develop during the past funding cycle. We have continued the study of their very successful string-derived model that unifies all known interactions; flipped SU(5), which is the leading candidate for a TOE. Work has continued on some generalizations of the symmetries of string theory, known as W algebras. These are expected to have applications in two-dimensional conformal field theory, two-dimensional extensions of gravity and topological gravity and W-string theory.

  15. Public Outreach of the South Texas Health Physic Society and Texas A&M University Nuclear Engineering Department

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R. O.

    2003-02-24

    In a cooperative effort of the members of the South Texas Chapter of the Heath Physics Society (STC-HPS) and the Texas A&M University Nuclear Engineering Department, great efforts have been made to reach out and provide educational opportunities to members of the general public, school age children, and specifically teachers. These efforts have taken the form of Science Teacher Workshops (STW), visits to schools all over the state of Texas, public forums, and many other educational arenas. A major motivational factor for these most recent efforts can be directly tied to the attempt of the State of Texas to site a low-level radioactive waste facility near Sierra Blanca in West Texas. When the State of Texas first proposed to site a low level radioactive waste site after the Low-Level Radioactive Waste Policy Act of 1980 was passed, many years of political struggle ensued. Finally, a site at Sierra Blanca in far West Texas was selected for study and characterization for a disposal site for waste generated in the Texas Compact states of Maine, Vermont and Texas. During this process, the outreach to and education of the local public became a paramount issue.

  16. Radioactive beams at Texas A and M University

    CERN Document Server

    Tribble, R E; Gagliardi, C A; Hardy, J C; Mukhamedzhanov, A; Tang, X; Trache, L; Yennello, S J

    2002-01-01

    The combination of the K500 superconducting cyclotron and the recoil spectrometer MARS have been used to generate secondary radioactive ion beams ranging from sup 7 Be at 12 MeV/u to sup 6 sup 2 Ga at 37 MeV/u. Secondary beams are produced via transfer reactions in inverse kinematics using stable beams from the cyclotron on gas targets. The radioactive beams have been used for reaction measurements and beta-decay studies.

  17. A new approach for manufacturing and processing targets to produce 99mTc with cyclotrons

    Science.gov (United States)

    Matei, L.; McRae, G.; Galea, R.; Niculae, D.; Craciun, L.; Leonte, R.; Surette, G.; Langille, S.; Louis, C. St.; Gelbart, W.; Abeysekera, B.; Johnson, R. R.

    2017-06-01

    The most important radioisotope for nuclear medicine is 99mTc. After the supply crisis of 99Mo starting in 2008, the availability of 99mTc became a worldwide concern. Alternative methods for producing the medical imaging isotope 99mTc are actively being developed around the world. The reaction 100Mo(p, 2n)99mTc provides a direct route that can be incorporated into routine production in nuclear medicine centers that possess medical cyclotrons for production of other isotopes, such as those used for Positron Emission Tomography. This paper describes a new approach for manufacturing targets for the (p, 2n) nuclear reaction on 100Mo and the foundation for the subsequent commercial separation and purification of the 99mTc produced. Two designs of targets are presented. The targets used to produce 99mTc are subject to a number of operational constraints.They must withstand the temperatures generated by the irradiation, accommodate temperature gradients from cooling system of the target, must be resilient and must be easily post-processed to separate the 99mTc. After irradiation, the separation of Tc from Mo was carried out using an innovative two-step approach. The process described in this paper can be automated with modules that easily fit in standard production hot cells found in nuclear medicine facilities.

  18. X-ray emission in heavy-ion collisions. Progress report, April 1, 1980-February 28, 1981. [Cyclotron Inst. , Texas A and M Univ. , College Station, 4/1/80-2/28/81

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.L.

    1981-03-01

    During the past year, work on x-ray emission in heavy-ion collisions has concentrated on the following topics: environmental influences on the K..cap alpha.. x-ray spectra of 65-MeV sulfur ions traveling in solids; multiplet structure of few-electron sulfur ions; multiplet structure of Mg K..cap alpha.. x-ray satellites; polarization of 1s2p..-->..1s/sup 2/ transitions in He-like sulfur ions; and interatomic electron transfer in ionic fluorine compounds following 1s2p vacancy production. Among the most significant accomplishments of the program was a study of the dependence of dynamic screening energy shifts on electron density. It was found that the shifts measured for the 2/sup 1/P..-->..1/sup 1/S and 2/sup 2/P..-->..1/sup 2/S x-ray transitions of He- and H-like sulfur ions (respectively) were in remarkably good agreement with theoretical expectations. Another interesting discovery evolved from measurements of fluorine K..cap alpha.. x-ray spectra for the alkali metal and alkaline earth fluorides using 5.5-MeV He/sup +/ ions. The systematics of these spectra provide the first evidence for direct electron transfer between inner levels of neighboring atoms in a solid. 10 figures, 3 tables. (RWR)

  19. Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Anindya, E-mail: r-ani@vecc.gov.in; Bhole, R. B.; Nandy, Partha P.; Yadav, R. C.; Pal, Sarbajit; Roy, Amitava [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India)

    2015-03-15

    The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

  20. Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

    Science.gov (United States)

    Roy, Anindya; Bhole, R. B.; Nandy, Partha P.; Yadav, R. C.; Pal, Sarbajit; Roy, Amitava

    2015-03-01

    The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

  1. mA beam acceleration efforts on 100 MeV H- cyclotron at CIAE

    Science.gov (United States)

    Zhang, Tianjue; An, Shizhong; Lv, Yinlong; Ge, Tao; Jia, Xianlu; Ji, Bin; Yin, Zhiguo; Pan, Gaofeng; Cao, Lei; Guan, Fengping; Yang, Jianjun; Li, Zhenguo; Zhao, Zhenlu; Wu, Longcheng; Zhang, He; Wang, Jingfeng; Zhang, Yiwang; Liu, Jingyuan; Li, Shiqiang; Lu, Xiaotong; Liu, Zhenwei; Li, Yaoqian; Guo, Juanjuan; Cao, Xuelong; Guan, Leilei; Wang, Fei; Wang, Yang; Yang, Guang; Zhang, Suping; Hou, Shigang; Wang, Feng

    2017-09-01

    Various technologies for high current compact H- cyclotron have been developed at CIAE since 1990s. A 375 μA proton beam was extracted from a 30 MeV compact H- cyclotron CYCIAE-30 at the end of 1994. A central region model cyclotron CYCIAE-CRM was developed for the design verification of a 100 MeV high current compact H- cyclotron CYCIAE-100. It is also a 10 MeV proton machine as a prototype for PET application. A 430 μA beam was achieved in 2009. The first beam was extracted from the CYCIAE-100 cyclotron on July 4, 2014, the operation stability has been improved and beam current has been increased gradually. A 1.1 mA proton beam was measured on the internal target in July 2016. The effort for an increasing of proton beam has continued till now. In this paper, the effort on several aspects for mA beam development will be presented, including the multi-cusp source, buncher, matching from the energy of the injected beam, vertical beam line and central region, beam loading of the RF system and instrumentation for beam diagnostics etc.

  2. High energy physics program at Texas A&M University. Final report, April 1, 1990--March 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The Texas A&M experimental high energy physics program has been supported since its inception by DOE Contract DE-AS05-81ER40039. During that period we established a viable experimental program at a university which before this time had no program in high energy physics. In 1990, the experimental program was augmented with a program in particle theory. In the accompanying final report, we outline the research work accomplished during the final year of this contract and the program being proposed for consideration by the Department of Energy for future grant support. Some of the particular areas covered are: Collider detector at Fermilab program; the TAMU MACRO program; SSC R&D program; SSC experimental program; and theoretical physics program.

  3. Cyclotron laboratory of the Institute for Nuclear Research and Nuclear Energy

    Science.gov (United States)

    Tonev, D.; Goutev, N.; Georgiev, L. S.

    2016-06-01

    An accelerator laboratory is presently under construction in Sofia at the Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences. The laboratory will use a TR24 type of cyclotron, which provides a possibility to accelerate a proton beam with an energy of 15 to 24 MeV and current of up to 0.4 mA. An accelerator with such parameters allows to produce a large variety of radioisotopes for development of radiopharmaceuticals. The most common radioisotopes that could be produced with such a cyclotron are PET isotopes like: 11C, 13N, 15O, 18F, 124I, 64Cu, 68Ge/68Ga, and SPECT isotopes like: 123I, 111In, 67Ga, 57Co, 99m Tc. Our aim is to use the cyclotron facility for research in the fields of radiopharmacy, radiochemistry, radiobiology, nuclear physics, solid state physics, applied research, new materials and for education in all these fields including nuclear energy. The building of the laboratory will be constructed nearby the Institute for Nuclear Research and Nuclear Energy and the cyclotron together with all the equipment needed will be installed there.

  4. Direct production of 99mTc using a small medical cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Lapi, Suzanne [Washington Univ., St. Louis, MO (United States)

    2017-10-03

    This project describes an investigation towards the production of 99mTc with a small medical cyclotron. This endeavor addresses the current urgent problem of availability of 99mTc due to the ongoing production reactor failures and the upcoming Canadian reactor shut down. Currently, 99mTc is produced via nuclear fission using highly enriched uranium which is a concern due to nuclear proliferation risks. In addition to this, the United States is dependent solely on currently unreliable foreign sources of this important medical isotope. Clearly, a need exists to probe alternative production routes of 99mTc. In the first year, this project measured cross-sections and production yields of potential pathways to 99mTc and associated radionuclidic impurities produced via these pathways using a small 15 MeV medical cyclotron. During the second and third years target systems for the production of 99mTc via the most promising reaction routes were developed and separation techniques for the isolation of 99mTc from the irradiated target material will be investigated. Systems for the recycling of the enriched target isotopes as well as automated target processing systems were examined in years four and five. This project has the potential to alleviate some of the current crisis in the medical community by developing a technique to produce 99mTc on location at a university hospital. This technology will be applicable at many other sites in the United States as many other similar, low energy (<20 MeV) cyclotrons (currently used for a few hours per day for the production of [18F]fluorodeoxyglucose) are available for production of 99mTc though this method, thus leading to job creation and preservation.

  5. A solvent-extraction module for cyclotron production of high-purity technetium-99m.

    Science.gov (United States)

    Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Uccelli, Licia; Pasquali, Micòl; Duatti, Adriano; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Esposito, Juan

    2016-12-01

    The design and fabrication of a fully-automated, remotely controlled module for the extraction and purification of technetium-99m (Tc-99m), produced by proton bombardment of enriched Mo-100 molybdenum metallic targets in a low-energy medical cyclotron, is here described. After dissolution of the irradiated solid target in hydrogen peroxide, Tc-99m was obtained under the chemical form of 99mTcO4-, in high radionuclidic and radiochemical purity, by solvent extraction with methyl ethyl ketone (MEK). The extraction process was accomplished inside a glass column-shaped vial especially designed to allow for an easy automation of the whole procedure. Recovery yields were always >90% of the loaded activity. The final pertechnetate saline solution Na99mTcO4, purified using the automated module here described, is within the Pharmacopoeia quality control parameters and is therefore a valid alternative to generator-produced 99mTc. The resulting automated module is cost-effective and easily replicable for in-house production of high-purity Tc-99m by cyclotrons. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The First Bachelor of Science Degree in Wind Energy in the US at Texas Tech University Authors: A. Ruiz Columbié, K. Rozsavolgyi, P. Hughes, D. Farris, A. Swift, R. Walker and M. Baker

    Science.gov (United States)

    Ruiz-Columbie, A.

    2010-12-01

    This paper presents a new Bachelor of Science Degree in Wind Energy proposal at Texas Tech University (TTU) beginning the spring 2011. It is designed to prepare the students for admission into a graduate program in wind energy, and/or employment as a professional in wind energy. The program integrates the environmental, social, economic, ethical, technical, scientific principles and practical skills the graduates will need in order to success as professionals in their field of expertise. This degree will provide a multidisciplinary education in the wind energy field through the study of subjects as wind meteorology, wind power generation, wind resource assessment, sustainable energy systems, utility systems operations, and fiscal and operational oversight. Students will be prepared to contribute in areas that include planning, development, operations, analysis and supervision of wind energy systems and projects, as well as to continue in graduate studies. Following the Texas Tech Uniform Undergraduate Degree Requirement Act, the major in Wind Energy will include 47 hours of general education courses from the TTU academic core, 18 hours of junior/senior level electives, and 55 hours of coursework in wind energy topics. A minor of 18 hours is also provided at TTU for those students with a different major who might decide to get a higher education in wind energy.

  7. Steps Towards a 3 mA, 1.8 MW Proton Beam at the PSI Cyclotron Facility

    CERN Document Server

    Schmelzbach, Pierre A; Adelmann, Andreas; Fitze, Hansruedi; Heidenreich, Gerd; Raguin, Jean-Yves; Rohrer, Urs; Sigg, Peter K

    2005-01-01

    The PSI Cyclotron Facility produces routinely a 1.8-1.9 mA proton beam at 590 MeV. The beam power reaches 1.1 MW at the the pion production targets and 0.7 MW at the neutron spallation target SINQ. The accelerator complex will be analysed in respect to his potential for future improvements. The ongoing developments aiming to increase the beam intensity to 3 mA and hence the beam power to 1.8 MW will be discussed. Smooth extrapolations of the observed machine parameters as well as recent advances in the theoretical treatment of space charge dominated beams show that this goal can be achieved with available technologies. IA new RF-cavity operated at a voltage in excess of 1 MV has been successfully tested and installed in the Ring Cyclotron. Bunchers for the low energy and the medium energy transfer lines are in the design phase. A conceptual study of new accelerating cavities to replace the obsolete flattop-cavities of the Injector Cyclotron has been performed. While the upgrade of the Ring Cyclotron with four...

  8. The Nuclear Security Science and Policy Institute at Texas A&M University

    Directory of Open Access Journals (Sweden)

    Claudio A. Gariazzo

    2015-07-01

    Full Text Available The Nuclear Security Science and Policy Institute (NSSPI is a multidisciplinary organization at Texas A&M University and was the first U.S. academic institution focused on technical graduate education, research, and service related to the safeguarding of nuclear materials and the reduction of nuclear threats. NSSPI employs science, engineering, and policy expertise to: (1 conduct research and development to help detect, prevent, and reverse nuclear and radiological proliferation and guard against nuclear terrorism; (2 educate the next generation of nuclear security and nuclear nonproliferation leaders; (3 analyze the interrelationships between policy and technology in the field of nuclear security; and (4 serve as a public resource for knowledge and skills to reduce nuclear threats. Since 2006, over 31 Doctoral and 73 Master degrees were awarded through NSSPI-sponsored research. Forty-one of those degrees are Master of Science in Nuclear Engineering with a specialization in Nuclear Nonproliferation and 16 were Doctorate of Philosophy degrees with a specific focus on nuclear nonproliferation. Over 200 students from both technical and policy backgrounds have taken classes provided by NSSPI at Texas A&M. The model for creating safeguards and security experts, which has in large part been replicated worldwide, was established at Texas A&M by NSSPI faculty and staff. In addition to conventional classroom lectures, NSSPI faculty have provided practical experiences; advised students on valuable research projects that have contributed substantially to the overall nuclear nonproliferation, safeguards and security arenas; and engaged several similar academic and research institutes around the world in activities and research for the benefit of Texas A&M students. NSSPI has had an enormous impact on the nuclear nonproliferation workforce (across the international community in the past 8 years, and this paper is an attempt to summarize the activities

  9. Laser Safety Program Development at Texas A&M University--Issues and Challenges.

    Science.gov (United States)

    Vasudevan, Latha; Menchaca, Daniel I; Tutt, James

    2015-09-01

    Implementing a laser safety program within a University setting encompassing a wide variety of Class 3b and Class 4 lasers with varied potential uses introduces many challenges. Texas A&M University (TAMU) currently has over 310 laser units that are registered with the Texas Department of State Health Services (TDSHS). One primary task in maintaining the laser registration is to have a program that identifies the regulatory responsibilities of the registrant. The Radiological Safety Staff, a part of Environmental Health and Safety (EHS), administers the use of both ionizing and non-ionizing radiation. The Radiological Safety Officer (RSO)/Laser Safety Officer (LSO) maintains the laser registration. This article outlines key elements that were put forth in the development and implementation of the laser safety program at TAMU.

  10. Texas A&M University Industrial Assessment Center Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Heffington, Warren M.; Eggebrecht, James A.

    2007-02-24

    This project benefited the public by assisting manufacturing plants in the United States to save costly energy resources and become more profitable. Energy equivalent to over 75,000 barrels of oil was conserved. The Texas A&M University Industrial Assessment Center (IAC) visited 96 manufacturing plants and spent 101 days in those plants during the contract period from August 9, 2002, through November 30, 2006. Recommended annual energy savings for manufacturers were 37,400,000 kWh (127,600 MMBtu—site basis) of electricity and 309,000 MCF (309,000 MMBtu) of natural gas. Each manufacturer subsequently was surveyed, and based on these surveys reportedly implemented 79% of the electricity savings and 36% of the natural gas savings for an overall energy savings of 48% of recommended. Almost 800 (798) projects were recommended to manufacturers, and they accomplished two-thirds of the projects. Cost savings recommended were $12.3 million and implemented savings were $5.7 million or 47%. During the contract period our average time between site visit and report submittal averaged 46 days; and decreased from 48 days in 2003 to 44 days in 2006. Serving clients well and promptly has been a priority. We visited five ESA overflow clients during FY 06. The Texas A&M University IAC pioneered the presentation of air pollution information in reports, and includes NOx and CO2 reductions due to energy savings in all reports. We also experimented with formal PowerPoint BestPractices presentations called Lunchtime/Showtime in each plant and with delivering electronic versions of the report. During the period of the contract, the director served on the Texas Industries of the Future (IOF) Refining and Chemicals Committee, which oversaw the showcases in 2003 and 2006. The assistant director was the Executive Director of the International Energy Technology Conference held annually. The director and assistant director became qualified specialists in the Process Heating Assessment Scoping

  11. Texas A&M Physics Festival: bringing together the community, faculty, and students

    Science.gov (United States)

    Erukhimova, Tatiana

    Texas A&M Physics Festival started in 2003 with a dozen of hands-on exhibits and an inaugural lecture by Stephen Hawking. Over the years it evolved into one of the largest STEM outreach events in the area. The Festival attracts over 4000 visitors annually from all over Texas and other states. It features over 100 interactive exhibits displayed by faculty and students, public lectures by world-renowned scientists and astronauts, professional bubble shows, and many other activities. I will report on the structure of the Festival as well as strategies for involving undergraduate and graduate students and faculty in public outreach. I will further discuss the results of an independent evaluation of the 2015 Festival by the NSF-funded EvalFest program.

  12. Engineering and management experience at Texas A&M Transportation Institute

    Science.gov (United States)

    Chowdhury, Arif Tahjibul

    This manuscript presents the author's engineering and management experience during his internship in the Materials and Pavements (M&P) Division at the Texas A&M Transportation Institute (TTI), and is a record of study for the Doctor of Engineering at Texas A&M University. Through this internship, he met his established internship objectives of gaining technical knowledge as well as knowledge and skills in project management, organizational communication, and quality management of pavement condition data, and of attaining professional development. In meeting these objectives, the author describes the history, mission, and organizational structure of his workplace. He also presents his experience of developing and delivering a two-week training course on pavement design and construction in Kosovo. Participating in a number of professional development training courses and other activities prepared him for working as an engineering manager. These activities include Delta-T leadership training, an instructor development course, a time management and organizational skills course, and the M&P Division lecture series. Leadership and skills learned through the Delta-T program were beneficial for the employee as well as the employer. For the class project, the author and his teammates performed a study dealing with improving TTI's deliverables. The Delta-T team composed a report summarizing their efforts of examining the current state of TTI's project deliverables, the deliverables' shortcomings, and potential enhancements to expand the deliverables' appeal to additional types of potential users outside the traditional research community. The team also developed a prototype web-based model of deliverables and presented some implementation recommendations. Participating in the Texas Department of Transportation's (TxDOT's) pavement surface distress data collection program enabled the author to become familiar with pavement distress data quality management and thus attain the

  13. Development of a fast scintillator based beam phase measurement system for compact superconducting cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Tanushyam; Kanti Dey, Malay; Dhara, Partha; Roy, Suvodeep; Debnath, Jayanta; Balakrishna Bhole, Rajendra; Dutta, Atanu; Pradhan, Jedidiah; Pal, Sarbajit; Pal, Gautam; Roy, Amitava; Chakrabarti, Alok [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India)

    2013-05-15

    In an isochronous cyclotron, measurements of central phase of the ion beam with respect to rf and the phase width provide a way to tune the cyclotron for maximum energy gain per turn and efficient extraction. We report here the development of a phase measurement system and the measurements carried out at the Variable Energy Cyclotron Centre's (VECC's) K= 500 superconducting cyclotron. The technique comprises detecting prompt {gamma}-rays resulting from the interaction of cyclotron ion beam with an aluminium target mounted on a radial probe in coincidence with cyclotron rf. An assembly comprising a fast scintillator and a liquid light-guide inserted inside the cyclotron was used to detect the {gamma}-rays and to transfer the light signal outside the cyclotron where a matching photo-multiplier tube was used for light to electrical signal conversion. The typical beam intensity for this measurement was a few times 10{sup 11} pps.

  14. Steven Hawking to visit Texas A&M in spring

    CERN Multimedia

    Xavier, D

    2002-01-01

    Stephen Hawking will visit Texas A&M University from Feb. 24 to March 21 2003 to participate in the inaugural meeting of the George P. and Cynthia W. Mitchell Institute for Fundamental Physics. This institute will bring several of the world's top physicists to A&M for a month-long exploration of the latest ideas on topics ranging from superstrings to M-theory and supergravity (1/2 page).

  15. Battling Carpal Tunnel Syndrome through Ergonomics: A Case Study of Texas A&M's Library Provides Insights and Answers.

    Science.gov (United States)

    Thornton, Joyce K.

    1995-01-01

    Current library automation practices and new technologies have forced library managers to seek some means of reducing carpal tunnel syndrome, and a case study of Texas A&M's library provides insights. Highlights include identifying and assessing the injuries, adjusting work surfaces, testing and selecting new keyboards, and developing…

  16. 75 FR 36710 - The Texas Engineering Experiment Station/Texas A&M University System; Notice of Acceptance for...

    Science.gov (United States)

    2010-06-28

    ... COMMISSION The Texas Engineering Experiment Station/Texas A&M University System; Notice of Acceptance for... Facility Operating License No. R-83 (``Application''), which currently authorizes the Texas Engineering Experiment Station/Texas A&M University System (TEES, the licensee) to operate the Nuclear Science Center...

  17. A cyclotron isotope production facility designed to maximize production and minimize radiation dose

    Science.gov (United States)

    Dickie, W. J.; Stevenson, N. R.; Szlavik, F. F.

    1993-06-01

    Continuing increases in requirements from the nuclear medicine industry for cyclotron isotopes is increasing the demands being put on an aging stock of machines. In addition, with the 1990 recommendations of the ICRP publication in place, strict dose limits will be required and this will have an effect on the way these machines are being operated. Recent advances in cyclotron design combined with lessons learned from two decades of commercial production mean that new facilities can result in a substantial charge on target, low personnel dose, and minimal residual activation. An optimal facility would utilize a well engineered variable energy/high current H - cyclotron design, multiple beam extraction, and individual target caves. Materials would be selected to minimize activation and absorb neutrons. Equipment would be designed to minimize maintenance activities performed in high radiation fields.

  18. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, M., E-mail: mmusgrov@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Opsahl, S.P. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States); Mahler, B.J. [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Herrington, C. [City of Austin Watershed Protection Department, Austin, TX 78704 (United States); Sample, T.L. [U.S. Geological Survey, 19241 David Memorial Dr., Ste. 180, Conroe, TX 77385 (United States); Banta, J.R. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States)

    2016-10-15

    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO{sub 3}{sup −}) loading to surface and groundwater. We investigate variability and sources of NO{sub 3}{sup −} in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO{sub 3}{sup −} stable isotopes (δ{sup 15}N and δ{sup 18}O). These data were augmented by historical data collected from 1937 to 2007. NO{sub 3}{sup −} concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO{sub 3}{sup −} concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO{sub 3}{sup −} concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO{sub 3}{sup −}. These results highlight the vulnerability of karst aquifers to NO{sub 3}{sup −} contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO{sub 3}{sup −} than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates

  19. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced (99m)Tc.

    Science.gov (United States)

    Tanguay, J; Hou, X; Esquinas, P; Vuckovic, M; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-11-07

    Cyclotron production of 99mTc through the (100)Mo(p,2n)99mTc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. Like most radioisotope production methods, cyclotron production of 99mTc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced 99mTc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (γ) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of 99mTc and the count-rate limitations of γ spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring γ emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify (99)Mo breakthrough in generator-produced 99mTc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to γ emission rates from impurities per MBq of 99mTc over a large range of clinically-relevant production conditions. We show that estimates of the γ emission rates from Tc impurities per MBq of 99mTc can be used to estimate increases in radiation dose (relative to pure 99mTc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of 93gTc, 93mTc, 94gTc, 94mTc, 95mTc, 95gTc, and 96gTc, in addition to a number of non-Tc impurities.

  20. Analysis of the Cyclotron Facility Calibration and Aircraft Results Obtained by LIULIN-3M Instrument

    Science.gov (United States)

    Dachev, T. P.; Stassinopoulos, E. G.; Tomov, B. T.; Dimitrov, P. G.; Matviichuk, Y. N.; Shurshakov, V. A.; Petrov, V. M.

    1998-01-01

    The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, which has been used on the NffR space station in the 1988-1994 time period, The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and 1 cm(exp 2) area is used in the instrument. Pulse high analysis technique is used for measurement of the energy losses in the detector. The final data sets from the instrument are the flux and the dose rate for the exposition time and 256 channels of LET spectra if a non-nal coincidence of the particles to the detector is considered. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and was used for space radiation measurements during commercial aircraft flights. Obtained calibration and flight results are analyzed in the paper.

  1. Analysis of the Cyclotron Facility calibration and aircraft dosimetry results from the LIULIN-3M instrument.

    Science.gov (United States)

    Dachev, Ts P; Stassinopoulous, E G; Tomov, B T; Dimitrov, Pl G; Matviichuk, Yu N; Shurshakov, V A; Petrov, V M

    2003-01-01

    The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the MIR spacestation during the 1988-1994 time period. The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and cm2 area is contained in the instrument. Pulse high analysis technique is used to determine the energy losses in the detector. The final data from the instrument are the flux and the dose rate for the exposure time and 256 channels of absorbed dose spectra based on the assumption that the particle flux is normal to the detector. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and had been used for radiation measurements during commercial aircraft flights. The calibration procedure and some flight results are presented in this paper. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  2. Energy Policy Case Study - Texas: Wind, Markets, and Grid Modernization

    Energy Technology Data Exchange (ETDEWEB)

    Orrell, Alice C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Homer, Juliet S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bender, Sadie R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-19

    This document presents a case study of energy policies in Texas related to power system transformation, renewable energy and distributed energy resources (DERs). Texas has experienced a dramatic increase in installed wind capacity, from 116 MW in 2000 to over 15,000 MW in 2015. This achievement was enabled by the designation of Competitive Renewable Energy Zones (CREZs) and new transmission lines that transmit wind to load centers. This report highlights nascent efforts to include DERs in the ERCOT market. As costs decline and adoption rates increase, ERCOT expects distributed generation to have an increasing effect on grid operations, while bringing potentially valuable new resources to the wholesale markets.

  3. NuSTAR Discovery of a Luminosity Dependent Cyclotron Line Energy in Vela X-1

    Science.gov (United States)

    Fürst, Felix; Pottschmidt, Katja; Wilms, Jörn; Tomsick, John A.; Bachetti, Matteo; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Grefenstette, Brian W.; Hailey, Charles J.; Harrison, Fiona; Madsen, Kristin K.; Miller, Jon M.; Stern, Daniel; Walton, Dominic J.; Zhang, William

    2014-01-01

    We present NuSTAR observations of Vela X-1, a persistent, yet highly variable, neutron star high-mass X-ray binary (HMXB). Two observations were taken at similar orbital phases but separated by nearly a year. They show very different 3-79 keV flux levels as well as strong variability during each observation, covering almost one order of magnitude in flux. These observations allow, for the first time ever, investigations on kilo-second time-scales of how the centroid energies of cyclotron resonant scattering features (CRSFs) depend on flux for a persistent HMXB. We find that the line energy of the harmonic CRSF is correlated with flux, as expected in the sub-critical accretion regime. We argue that Vela X-1 has a very narrow accretion column with a radius of around 0.4 km that sustains a Coulomb interaction dominated shock at the observed luminosities of L x ~ 3 × 1036 erg s-1. Besides the prominent harmonic line at 55 keV the fundamental line around 25 keV is clearly detected. We find that the strengths of the two CRSFs are anti-correlated, which we explain by photon spawning. This anti-correlation is a possible explanation for the debate about the existence of the fundamental line. The ratio of the line energies is variable with time and deviates significantly from 2.0, also a possible consequence of photon spawning, which changes the shape of the line. During the second observation, Vela X-1 showed a short off-state in which the power-law softened and a cut-off was no longer measurable. It is likely that the source switched to a different accretion regime at these low mass accretion rates, explaining the drastic change in spectral shape.

  4. A Suzaku View of Cyclotron Line Sources and Candidates

    Science.gov (United States)

    Pottschmidt, K.; Suchy, S.; Rivers, E.; Rothschild, R. E.; Marcu, D. M.; Barragan, L.; Kuehnel, M.; Fuerst, F.; Schwarm, F.; Kreykenbohm, I.; hide

    2012-01-01

    Seventeen accreting neutron star pulsars, mostly high mass X-ray binaries with half of them Be-type transients, are known to exhibit Cyclotron Resonance Scattering Features (CRSFs) in their X-ray spectra, with characteristic line energies from 10 to 60 keY. To date about two thirds of them, plus a few similar systems without known CRSFs, have been observed with Suzaku. We present an overview of results from these observations, including the discovery of a CRSF in the transient IA1118-61 and pulse phase resolved spectroscopy of OX 301-2. These observations allow for the determination of cyclotron line parameters to an unprecedented degree of accuracy within a moderate amount of observing time. This is important since these parameters vary - e.g., with orbital phase, pulse phase, or luminosity - depending on the geometry of the magnetic field of the pulsar and the properties of the accretion column at the magnetic poles. We briefly introduce a spectral model for CRSFs that is currently being developed and that for the first time is based on these physical properties. In addition to cyclotron line measurements, selected highlights from the Suzaku analyses include dip and flare studies, e.g., of 4U 1907+09 and Vela X-I, which show clumpy wind effects (like partial absorption and/or a decrease in the mass accretion rate supplied by the wind) and may also display magnetospheric gating effects.

  5. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced (99m)Tc yields.

    Science.gov (United States)

    Tanguay, J; Hou, X; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-05-21

    Cyclotron production of (99m)Tc through the (100)Mo(p,2n) (99m)Tc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional (99m)Tc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity (99m)Tc. However, variations in proton beam currents and the thickness and isotopic composition of enriched (100)Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute (99m)Tc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including (100)Mo target thicknesses and proton beam currents, and reproducibility of absolute (99m)Tc yields (defined as the end of bombardment (EOB) (99m)Tc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB (99m)Tc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in (99m)Tc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of (99m)Tc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average

  6. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced 99mTc yields

    Science.gov (United States)

    Tanguay, J.; Hou, X.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2015-05-01

    Cyclotron production of 99mTc through the 100Mo(p,2n) 99mTc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional 99mTc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity 99mTc. However, variations in proton beam currents and the thickness and isotopic composition of enriched 100Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute 99mTc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including 100Mo target thicknesses and proton beam currents, and reproducibility of absolute 99mTc yields (defined as the end of bombardment (EOB) 99mTc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB 99mTc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in 99mTc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of 99mTc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average 1.2, 1.5 and 1.9 times the

  7. A study of three-half-turn and frame antennae for ion cyclotron range of frequency plasma heating in the URAGAN-3M torsatron

    Energy Technology Data Exchange (ETDEWEB)

    Lysoivan, A.I. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Moiseenko, V.E. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Plyusnin, V.V. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Kasilov, S.V. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Bondarenko, V.N. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Chechkin, V.V. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Fomin, I.P. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Grigor`eva, L.I. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Konovalov, V.G. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Koval`ov, S.V. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Litvinov, A.P. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Mironov, Yu.K. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Nazarov, N.I. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Pavlichenko, O.S. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Pavlichenko, R.O. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Shapoval, A.N. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Skibenko, A.I. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center; Volkov, E.D. [Kharkov Inst. of Phys. and Tech. (Ukraine). Nat. Sci. Center

    1995-01-01

    Numerical and experimental results of Alfven wave heating of plasmas in the frequency range below the ion cyclotron frequency ({omega}<{omega}{sub ci}) are presented. Two different types of antenna were used for plasma production and heating: a frame type antenna (FTA) conventionally used in the URAGAN-3M device and a three-half-turn antenna (THTA) proposed recently to avoid the deleterious effects of conversion of fast wave to slow wave in the plasma periphery and to perform plasma core heating more effectively. Numerical modeling of electromagnetic field excitation in the URAGAN-3M plasma by the FTA and THTA was performed using a one-dimensional code. The results of calculations showed better performance of the compact THTA compared with the FTA for the case of a high density plasma (approximately 10{sup 13}cm{sup -3}). When using the THTA, the experiments performed showed the possibility of dense plasma production (more than 2x10{sup 13}cm{sup -3}) and heating, which had not been obtained earlier in the URAGAN-3M. Shifting the power deposition profile deeper inside the plasma body with the THTA resulted in modification of the plasma density profile and an improvement in plasma confinement. ((orig.)).

  8. Final report for Texas A&M University Group Contribution to DE-FG02-09ER25949/DE-SC0002505: Topology for Statistical Modeling of Petascale Data (and ASCR-funded collaboration between Sandia National Labs, Texas A&M University and University of Utah)

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Joseph Maurice [Texas A& M University

    2013-02-27

    We summarize the contributions of the Texas A\\&M University Group to the project (DE-FG02-09ER25949/DE-SC0002505: Topology for Statistical Modeling of Petascale Data - an ASCR-funded collaboration between Sandia National Labs, Texas A\\&M U, and U Utah) during 6/9/2011 -- 2/27/2013.

  9. History of the discovery of transmutation at Texas A and M University

    Energy Technology Data Exchange (ETDEWEB)

    Bockris, J.O.M. [Molecular Green Technology, College Station, TX 77845 (United States)

    2006-07-01

    Until 1989, to author was a publisher of high temperature physical chemistry, electrochemical and environmental research papers. He was a physical chemist and his contact with nuclear chemistry was only in using it in some tracer techniques. The Fleischmann and Pons announcement of March 1989 was of interest partly because of its radical nature) but also because the author has known Martin Fleischmann since his days as a student at the Imperial College of Science and Technology in London. He had easy access to Fleischmann and he therefore could instruct his co-workers (about 20 at the time) about the technique used in the Fleischmann and Pons work. It was around 3 weeks before they were able to detect strong concentrations of tritium in the solution after prolonged electrolysis and thus prove, for the first time, that the speculation which Fleischmann and Pons had made about their excess heat was indeed; correct and that a nuclear reaction was occurring at or in an electrode in the cold. They continued to work on the new nuclear phenomena, in 1991 discovering excess {sup 4}He in their palladium cathodes. Later in 1991, the author received a phone call from a Joseph Champion. He told him that the long initiation times which he had recorded in its papers could be avoided and that he could 'turn on' what he described as a 'radioactive gas' in less than 1 h. Champion invited him to visit his laboratory (which was in a trailer on the grounds of the University of Tennessee). He could operate his apparatus and see for himself. He asked Dr. Ramesh Kainthla and Mr. Omo Velev, senior researchers in my laboratory, to visit Champion and see if his statements could be confirmed. Upon return to Texas A and M, they told the author that Champion had left them alone in the so-called laboratory, pointed to the apparatus, gave them a few instructions about turning it on, and left them alone. They measured 40% of the excess heat, that he had said was obtainable

  10. Technical note: building a combined cyclotron and MRI facility: implications for interference.

    Science.gov (United States)

    Hofman, Mark B M; Kuijer, Joost P A; de Ridder, Jan Willem; Perk, Lars R; Verdaasdonk, Rudolf M

    2013-01-01

    With the introduction of hybrid PET∕MRI systems, it has become more likely that the cyclotron and MRI systems will be located close to each other. This study considered the interference between a cyclotron and a superconducting MRI system. Interactions between cyclotrons and MRIs are theoretically considered. The main interference is expected to be the perturbation of the magnetic field in the MRI due to switching on or off the magnetic field of the cyclotron. MR imaging is distorted by a dynamic spatial gradient of an external inplane magnetic field larger than 0.5-0.04 μT∕m, depending on the specific MR application. From the design of a cyclotron, it is expected that the magnetic fringe field at large distances behaves as a magnetic dipolar field. This allows estimation of the full dipolar field and its spatial gradients from a single measurement. Around an 18 MeV cyclotron (Cyclone, IBA), magnetic field measurements were performed on 5 locations and compared with calculations based upon a dipolar field model. At the measurement locations the estimated and measured values of the magnetic field component and its spatial gradients of the inplane component were compared, and found to agree within a factor 1.1 for the magnetic field and within a factor of 1.5 for the spatial gradients of the field. In the specific case of the 18 MeV cyclotron with a vertical magnetic field and a 3T superconducting whole body MR system, a minimum distance of 20 m has to be considered to prevent interference. This study showed that a dipole model is sufficiently accurate to predict the interference of a cyclotron on a MRI scanner, for site planning purposes. The cyclotron and a whole body MRI system considered in this study need to be placed more than 20 m apart, or magnetic shielding should be utilized.

  11. Technical Note: Building a combined cyclotron and MRI facility: Implications for interference

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, Mark B. M.; Kuijer, Joost P. A.; Ridder, Jan Willem de; Perk, Lars R.; Verdaasdonk, Rudolf M. [Physics and Medical Technology, VU University Medical Center, Amsterdam 1007 MB (Netherlands) and BV Cyclotron VU, Amsterdam 1081HV (Netherlands)

    2013-01-15

    Purpose: With the introduction of hybrid PET/MRI systems, it has become more likely that the cyclotron and MRI systems will be located close to each other. This study considered the interference between a cyclotron and a superconducting MRI system. Methods: Interactions between cyclotrons and MRIs are theoretically considered. The main interference is expected to be the perturbation of the magnetic field in the MRI due to switching on or off the magnetic field of the cyclotron. MR imaging is distorted by a dynamic spatial gradient of an external inplane magnetic field larger than 0.5-0.04 {mu}T/m, depending on the specific MR application. From the design of a cyclotron, it is expected that the magnetic fringe field at large distances behaves as a magnetic dipolar field. This allows estimation of the full dipolar field and its spatial gradients from a single measurement. Around an 18 MeV cyclotron (Cyclone, IBA), magnetic field measurements were performed on 5 locations and compared with calculations based upon a dipolar field model. Results: At the measurement locations the estimated and measured values of the magnetic field component and its spatial gradients of the inplane component were compared, and found to agree within a factor 1.1 for the magnetic field and within a factor of 1.5 for the spatial gradients of the field. In the specific case of the 18 MeV cyclotron with a vertical magnetic field and a 3T superconducting whole body MR system, a minimum distance of 20 m has to be considered to prevent interference. Conclusions: This study showed that a dipole model is sufficiently accurate to predict the interference of a cyclotron on a MRI scanner, for site planning purposes. The cyclotron and a whole body MRI system considered in this study need to be placed more than 20 m apart, or magnetic shielding should be utilized.

  12. Transfer student and gender issues within the Department of Animal Science at Texas A&M University.

    Science.gov (United States)

    Cleer, J J; Minney, B A; Johnson, B H; Murano, P S; Briers, G E; Greathouse, T R

    2000-12-01

    Graduates with a B.S. or graduate degree from the Department of Animal Science (1986 to 1996) of Texas A&M University were surveyed by mail to gather opinions on the curriculum and satisfaction with their degrees. The survey contained five Likert questions (1 = excellent, 4 = poor) regarding satisfaction with major, educational results, personal growth, professional development, and skills important for employment. Multiple-choice questions (n = 9) addressed education, background, job status, and gender. Surveys (n = 2,192) were sent to students, and 470 responded. The undergraduate respondents (n = 396) comprised 71.2% (n = 282) nontransfer students and 28.8% (n = 114) transfer students. Transfer students reported a mean grade point ratio (GPR) of 3.05 +/- 0.43 at Texas A&M University in comparison to a nontransfer student mean GPR of 3.03 +/- 0.45 for hours completed at Texas A&M University (P = 0.83). The results for time from graduation to full-time employment for transfer students were similar to those of nontransfer students (P = 0.95). Differences in current annual salary between transfer students and nontransfer students were apparent (P job search time (P job. Males and females responded similarly that courses were valuable (P = 0.16) and were taught effectively (P = 0.37) and that teaching assistants made positive contributions (P = 0.43). Females felt a lesser contribution to critical thinking ability, leadership ability, and technical expertise. Results suggest the continuance of current educational practices, but changes to specific issues should be initiated.

  13. A new, simple and precise method for measuring cyclotron proton beam energies using the activity vs. depth profile of zinc-65 in a thick target of stacked copper foils.

    Science.gov (United States)

    Asad, A H; Chan, S; Cryer, D; Burrage, J W; Siddiqui, S A; Price, R I

    2015-11-01

    The proton beam energy of an isochronous 18MeV cyclotron was determined using a novel version of the stacked copper-foils technique. This simple method used stacked foils of natural copper forming 'thick' targets to produce Zn radioisotopes by the well-documented (p,x) monitor-reactions. Primary beam energy was calculated using the (65)Zn activity vs. depth profile in the target, with the results obtained using (62)Zn and (63)Zn (as comparators) in close agreement. Results from separate measurements using foil thicknesses of 100, 75, 50 or 25µm to form the stacks also concurred closely. Energy was determined by iterative least-squares comparison of the normalized measured activity profile in a target-stack with the equivalent calculated normalized profile, using 'energy' as the regression variable. The technique exploits the uniqueness of the shape of the activity vs. depth profile of the monitor isotope in the target stack for a specified incident energy. The energy using (65)Zn activity profiles and 50-μm foils alone was 18.03±0.02 [SD] MeV (95%CI=17.98-18.08), and 18.06±0.12MeV (95%CI=18.02-18.10; NS) when combining results from all isotopes and foil thicknesses. When the beam energy was re-measured using (65)Zn and 50-μm foils only, following a major upgrade of the ion sources and nonmagnetic beam controls the results were 18.11±0.05MeV (95%CI=18.00-18.23; NS compared with 'before'). Since measurement of only one Zn monitor isotope is required to determine the normalized activity profile this indirect yet precise technique does not require a direct beam-current measurement or a gamma-spectroscopy efficiency calibrated with standard sources, though a characteristic photopeak must be identified. It has some advantages over published methods using the ratio of cross sections of monitor reactions, including the ability to determine energies across a broader range and without need for customized beam degraders. Copyright © 2015 Elsevier Ltd. All rights

  14. Radiation surveillance in and around cyclotron facility

    Science.gov (United States)

    Kaur, Amandeep; Sharma, Sarika; Mittal, BR

    2012-01-01

    The cyclotron is the most widely used particle accelerator for producing medically important radio nuclides. Many medical centers in India have installed compact medical cyclotrons for on-site production of short-lived positron-emitting radio nuclides such as 18F, 13N, and 11C. A mandatory requirement for cyclotron installation is radiation control permit from Atomic Energy Regulatory Board. Cyclotron radiation survey is an integral part of the overall radiation safety in the cyclotron facility. Radiation surveillance in and around a newly installed cyclotron was performed using ionization chamber counter and Geiger Muller counter before, during and after operating the cyclotron. The readings were recorded at various locations where a high radiation field was expected. The results were recorded, tabulated and analyzed. The highest exposure level (0.93 μSv) was found at the back wall of the radiochemistry lab facing the cyclotron vault. Reason for the high exposure of 0.93 μSv/h: Synthesis of 18F-Fluoro-Deoxy-Glucose (18F-FDG) was going in the synthesis module and activity (18F) was present in the synthesis module when reading was taken. All other values were found to be below the recommended levels of exposure. PMID:24019654

  15. Ion source and injection line for high intensity medical cyclotron.

    Science.gov (United States)

    Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

    2014-02-01

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

  16. Texas flexible pavements and overlays : calibration plans for M-E models and related software.

    Science.gov (United States)

    2013-06-01

    This five-year project was initiated to collect materials and pavement performance data on a minimum of 100 highway test sections around the State of Texas, incorporating flexible pavements and overlays. Besides being used to calibrate and validate m...

  17. 29 August 2013 - Director Variable Energy Cyclotron Centre, India D. Srivastava signing the guest book with CERN Director-General R. Heuer. Coordinator of India-ALICE Collaboration T. Nayak present throughout.

    CERN Multimedia

    Jean-Claude Gadmer

    2013-01-01

    29 August 2013 - Director Variable Energy Cyclotron Centre, India D. Srivastava signing the guest book with CERN Director-General R. Heuer. Coordinator of India-ALICE Collaboration T. Nayak present throughout.

  18. A Variable Energy CW Compact Accelerator for Ion Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Carol J. [Fermilab; Taylor, J. [Huddersfield U.; Edgecock, R. [Huddersfield U.; Schulte, R. [Loma Linda U.

    2016-03-10

    Cancer is the second-largest cause of death in the U.S. and approximately two-thirds of all cancer patients will receive radiation therapy with the majority of the radiation treatments performed using x-rays produced by electron linacs. Charged particle beam radiation therapy, both protons and light ions, however, offers advantageous physical-dose distributions over conventional photon radiotherapy, and, for particles heavier than protons, a significant biological advantage. Despite recognition of potential advantages, there is almost no research activity in this field in the U.S. due to the lack of clinical accelerator facilities offering light ion therapy in the States. In January, 2013, a joint DOE/NCI workshop was convened to address the challenges of light ion therapy [1], inviting more than 60 experts from diverse fields related to radiation therapy. This paper reports on the conclusions of the workshop, then translates the clinical requirements into accelerat or and beam-delivery technical specifications. A comparison of available or feasible accelerator technologies is compared, including a new concept for a compact, CW, and variable energy light ion accelerator currently under development. This new light ion accelerator is based on advances in nonscaling Fixed-Field Alternating gradient (FFAG) accelerator design. The new design concepts combine isochronous orbits with long (up to 4m) straight sections in a compact racetrack format allowing inner circulating orbits to be energy selected for low-loss, CW extraction, effectively eliminating the high-loss energy degrader in conventional CW cyclotron designs.

  19. Design and Research of Electron Cyclotron Resonance Heating and Current Dive System on HL-2M Tokamak

    Science.gov (United States)

    Huang, Mei; Rao, Jao; Song, Shaodong; Wang, He; Chen, Gangyu; Kang, Zhihua; Zhang, Feng; Wang, Jieqiong; Ye, Jiruo; Feng, Kun; Lu, Bo; Huang, Bo; Wang, Chao; Wang, Mingwei; Xuan, Weimin; Rao, Lieying; Li, Qing; Mao, Xiaohui; Duan, Xuru; Liu, Yong

    2017-07-01

    A research has been conducted to develop an 8MW electron cyclotron resonance heating and current drive (ECRH/ECCD) system on HL-2M tokamak. The ECRH system compromise eight 1MW gyrotrons, eight evacuated transmission lines and three launchers. The main purpose of the ECRH system was to suppress the neo-classical tearing modes and control the plasma profile. This paper presents an overview of the design and studies performed in this framework. Some primary test results of the critical components have been released in this paper, e.g. polarizers, power monitor and fast steering launchers.

  20. Continuation application for the Amarillo National Resource Center for Plutonium, a higher education consortium consisting of Texas A and M University, Texas Tech University, and the University of Texas at Austin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-29

    This report describes the 5 tasks to be covered under this project and compiles budget information. Task 1 is to establish a Plutonium Information Resource, which has been established in Amarillo, Texas. Task 2, Advisory Functions, coordinates studies and activities relating to the disposition of excess weapons-grade plutonium. Task 3, Environmental, Public Health, and Safety, supports soil remediation activities. Task 4, Education and Outreach, is supporting four programs: K--12 education improvement in science and math courses; Academic intervention to identify and encourage high ability high school and middle school students with potential to become scientists and engineers; Graduate education evaluation; and Public outreach programs. Task 5, Plutonium and other Materials Studies, is currently funding two projects for the disposition of high explosives: a feasibility study of burning a mixture of high explosives and other materials in a commercial coal-fired power plant and synthesis of diamond by shock compression of bucky ball with explosives.

  1. Outburst of GX304-1 Monitored with INTEGRAL: Positive Correlation Between the Cyclotron Line Energy and Flux

    Science.gov (United States)

    Klochkov, D.; Doroshenko, V.; Santangelo, A.; Staubert, R.; Ferrigno, C.; Kretschmar, P.; Caballero, I.; Wilms, J.; Kreykenbohm, I.; Pottschmidt, I.; hide

    2012-01-01

    Context. X-ray spectra of many accreting pulsars exhibit significant variations as a function of flux and thus of mass accretion rate. In some of these pulsars, the centroid energy of the cyclotron line(s), which characterizes the magnetic field strength at the site of the X-ray emission, has been found to vary systematically with flux. Aims. GX304-1 is a recently established cyclotron line source with a line energy around 50 keV. Since 2009, the pulsar shows regular outbursts with the peak flux exceeding one Crab. We analyze the INTEGRAL observations of the source during its outburst in January-February 2012. Methods. The observations covered almost the entire outburst, allowing us to measure the source's broad-band X-my spectrum at different flux levels. We report on the variations in the spectral parameters with luminosity and focus on the variations in the cyclotron line. Results. The centroid energy of the line is found to be positively correlated with the luminosity. We interpret this result as a manifestation of the local sub-Eddington (sub-critical) accretion regime operating in the source.

  2. A Citation Analysis of Atmospheric Science Publications by Faculty at Texas A&M University

    Science.gov (United States)

    Kimball, Rusty; Stephens, Jane; Hubbard, David; Pickett, Carmelita

    2013-01-01

    A citation analysis of publications produced by the Department of Atmospheric Sciences faculty at Texas A&M University was conducted. This study included a detailed analysis of 5,082 cited publications by source, format, and age. TAMU Libraries holdings were then assessed using the works cited within the context of the 80/20 rule. The sources…

  3. Summary of proceedings: Oklahoma and Texas wind energy forum, April 2-3, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S. C.; Ball, D. E.

    1981-06-01

    The Wind Energy Forum for Oklahoma and Texas was held at the Amarillo Quality Inn in Amarillo, Texas on April 2-3, 1981. Its purpose was to bring together the diverse groups involved in wind energy development in the Oklahoma and Texas region to explore the future commercial potential and current barriers to achieving this potential. Major topics of discussion included utility interconnection of wind machines and the buy-back rate for excess power, wind system reliability and maintenance concerns, machine performance standards, and state governmental incentives. A short summary of each presentation is included.

  4. Collaboration in nuclear engineering education between France and the United States: Participation of French students at Texas A M University

    Energy Technology Data Exchange (ETDEWEB)

    Peddicord, K.L.; Durand, J.L.; Gousty, Y.; Jeneveau, A.; Erdman, C.A. (Texas A M Univ., College Station (USA))

    1988-01-01

    Universities in the United States have had a long tradition of accepting students from other countries to pursue graduate degrees. This has particularly been the case in the fields of engineering and science. This trend has grown to the point that in several graduate engineering fields, the percentage of foreign nationals outnumbers US enrollees. Historically, most foreign students studying in the US universities have been from developing countries. Usually these students apply and are accepted on a case-by-case basis. For a number of reasons, less emphasis has been placed on programs with western Europe. In this paper, a program of collaboration is described in which the Department of Nuclear Engineering at Texas A M University has entered into memoranda of agreement with two institutions in France. The two universities are the Institut National Polytechnique de Grenoble (INPG) in Grenoble and the Ecole Polytechnique Feminine (EPF) in Sceaux. The purpose of the program is to enable students in nuclear engineering to simultaneously complete requirements for the diploma and the MS degree.

  5. Toward a green campus : a transportation strategy for Texas A&M University.

    Science.gov (United States)

    2009-03-01

    This research study produces a recommended sustainable transportation implementation plan for Texas : A&M University (TAMU) to enhance the environmental performance of its campus transportation system. : To achieve the goal, this study followed a his...

  6. Texas A and M University student/professional nuclear science and engineering conference

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-12

    Abstracts of papers presented at the meeting are included. Topics discussed include: reactor engineering; space nuclear power systems; health physics and dosimetry; fusion engineering and physics; and reactor physics and theory.

  7. Measurements of injected beam deflections at the exit of a cyclotron inflector as a function of applied field or beam energy perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Dehnel, M.P.; Erdman, K.L. [Ebco Technologies Inc., Richmond B.C. (Canada); Root, L.; Kuo, T. [TRIUMF, Vancouver B.C. (Canada)

    1999-07-01

    Measurements of the central trajectories of 25 keV H{sup -} beams at the exit of the EBCO/TRIUMF 1 MeV Test Cyclotron's spiral inflector have been made using quartz scintillators, a TV Camera, and image analysis equipment and software. Plots of the displacement of the central trajectories as a function of inflector electric potential, cyclotron magnetic field and beam injection energy changes are shown, and are compared to numerically computed data generated from an inflector design program. Details of the experimental methods, the hardware set-up and the results are reported. (author)

  8. An automated module for the separation and purification of cyclotron-produced 99mTcO4-.

    Science.gov (United States)

    Morley, Thomas J; Dodd, Maurice; Gagnon, Katherine; Hanemaayer, Vicky; Wilson, John; McQuarrie, Stephen A; English, Wade; Ruth, Thomas J; Bénard, François; Schaffer, Paul

    2012-05-01

    The shortage of reactor-produced molybdenum-99 ((99)Mo, t(½)=66 h) has renewed interest in alternative production methods of its daughter isotope, technetium-99m ((99m)Tc, t(½)=6.02 h). While adsorption chromatography serves as a mechanism for selective elution of sodium pertechnetate from technetium generators, this method of purification is not sufficient for many alternative production methods. Several ion-separation/solid phase extraction chromatography methods are known, yet none have been demonstrated on cyclotron-produced [(99m)Tc]TcO(4)(-). Herein we describe the design, manufacture and optimization of a remotely operated module for the purification of sodium pertechnetate from a bulk solution of molybdate. The automated purification module was designed to separate [(99m)Tc]TcO(4)(-) using either Dowex 1x8 or an Aqueous Biphasic Extraction Chromatography (ABEC) resin. (100)Mo composite targets were irradiated with 18.5 MeV protons for 10 μA·h using an ASCI TR19 cyclotron. Once purified, the radiopharmaceutical quality of (99m)TcO(4)(-) isolated from each process (Dowex and/or ABEC) was established by assaying for molybdate breakthrough, alumina levels and, in the case of the Dowex approach, residual organics. The separation processes are efficient (75% for Dowex, 90% for ABEC) and complete in less than 30 min. Overall, up to 2.1 GBq of (99m)Tc was produced using the (100)Mo(p,2n)(99m)Tc transformation, processed using the separation module and subjected to a detailed chemical and radionuclidic analysis. Due to its expense and limited availability, (100)MoO(4)(2-) was recovered in >90% yield using a precipitation/filtration/lyophilization approach. Na[(99m)Tc]TcO(4) was produced using a medical cyclotron, recovered using an automated purification module and found to exceed all established quality control parameters. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. The Spirit of Aggieland: Neoliberalism, Militarization, and Football Culture at Texas A&M University

    Science.gov (United States)

    Ternes, Neal

    2016-01-01

    Significant scholarship exists indicating an increase in militarization within the neoliberal university (see Armitage 2005; Giroux 2008; Giroux 2013), which has transformed the academic institution into "a factory that is engaged in the militarization of knowledge, namely, in the militarization of the facts, information and abilities…

  10. A simple and powerful XY-Type current monitor for 30 MeV IPEN/CNEN-SP cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos, Henrique; Matsuda, Hylton; Sumyia, Luiz Carlos do A.; Junqueira, Fernando de C.; Costa, Osvaldo L. da, E-mail: hbolivei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    A water-cooled XY-type current monitor was designed and built in the Cyclotrons Laboratory of the Nuclear and Energy Research Institute (IPEN). It is a very simple design and easily adaptable to the cyclotron beam lines. Tests were done demonstrating to be an instrument of great assistance in proton beam position along beam transport line and target port. Nowadays the XY-type current monitor has been widely used in {sup 18}F-FDG routine productions, employing irradiation system which were originally designed for productions on 18 MeV cyclotron accelerator only, however, applying the XY-type current monitor the target port may be exchanged between the 30 MeV and 18 MeV cyclotrons and the observed results are in perfect agreement with expected. (author)

  11. Residential Energy Efficiency Potential: Texas

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-02

    Energy used by Texas single-family homes that can be saved through cost-effective improvements. Prepared by Eric Wilson and Noel Merket, NREL, and Erin Boyd, U.S. Department of Energy Office of Energy Policy and Systems Analysis.

  12. SPES: A new cyclotron-based facility for research and applications with high-intensity beams

    Science.gov (United States)

    Maggiore, M.; Campo, D.; Antonini, P.; Lombardi, A.; Manzolaro, M.; Andrighetto, A.; Monetti, A.; Scarpa, D.; Esposito, J.; Silvestrin, L.

    2017-06-01

    In 2016, Laboratori Nazionali di Legnaro (Italy) started the commissioning of a new accelerator facility based on a high-power cyclotron able to deliver proton beams up to 70 MeV of energy and 700 μA current. Such a machine is the core of the Selective Production of Exotic Species (SPES) project whose main goal is to provide exotics beam for nuclear and astrophysics research and to deliver high-intensity proton beams for medical applications and neutrons generator.

  13. Mechanical design control and implementation of a new movable diagnostic probe for the TRIUMF cyclotron

    Science.gov (United States)

    Ries, Thomas C.

    1994-10-01

    A new movable probe has been installed into the TRIUMF H- cyclotron. It is intended to measure the distribution of betatron amplitudes, in the vertical plane, of the circulating beam and to scrape halo. The probe, however, may also be scanned in the radial direction. The head may be positioned vertically and horizontally to an accuracy of 0.002`. The device is mechanically modular to facilitate fast and easy handling for maintenance in a radioactive area. The beam sensor on the probe head is a 1.25`×3`×0.003` tantalum foil and its overall coverage is 3.00`×7.25` in a vertical plane orthogonal to, and crossing through the beam orbit plane. Presently its radial center line location corresponds to a proton beam energy of about 430 MeV at radius 296`, however, the probe device may be easily relocated to operate from any 4` port, and, with an adaptor port flange, may be installed into any port in the cyclotron vacuum tank. A stationary catcher below the probe path collects those electrons stripped from the H- beam and scattered out from the probe head. The probe axis is vertical and the tank aperture is narrow so a worm gear arrangement combined with a modified ``Evans''-parallel linkage mechanism is used to transform vertical rotary motion into horizontal linear motion. The actuators are dc servo motors with tachometers driven by pulse width modulated servo amplifiers. Position sensing is done by variable reluctance type absolute rotary encoders and the higher level positioning is performed by TRIMAC based control software. The precision of movement and jitter was measured in the laboratory. Examples will be given of the probe use with beam.

  14. Experimental measurement and Monte Carlo assessment of Argon-41 production in a PET cyclotron facility.

    Science.gov (United States)

    Infantino, Angelo; Valtieri, Lorenzo; Cicoria, Gianfranco; Pancaldi, Davide; Mostacci, Domiziano; Marengo, Mario

    2015-12-01

    In a medical cyclotron facility, (41)Ar (t1/2 = 109.34 m) is produced by the activation of air due to the neutron flux during irradiation, according to the (40)Ar(n,γ)(41)Ar reaction; this is particularly relevant in widely diffused high beam current cyclotrons for the production of PET radionuclides. While theoretical estimations of the (41)Ar production have been published, no data are available on direct experimental measurements for a biomedical cyclotron. In this work, we describe a sampling methodology and report the results of an extensive measurement campaign. Furthermore, the experimental results are compared with Monte Carlo simulations performed with the FLUKA code. To measure (41)Ar activity, air samples were taken inside the cyclotron bunker in sealed Marinelli beakers, during the routine production of (18)F with a 16.5 MeV GE-PETtrace cyclotron; this sampling thus reproduces a situation of absence of air changes. Samples analysis was performed in a gamma-ray spectrometry system equipped with HPGe detector. Monte Carlo assessment of the (41)Ar saturation yield was performed directly using the standard FLUKA score RESNUCLE, and off-line by the convolution of neutron fluence with cross section data. The average (41)Ar saturation yield per one liter of air of (41)Ar, measured in gamma-ray spectrometry, resulted to be 3.0 ± 0.6 Bq/µA*dm(3) while simulations gave a result of 6.9 ± 0.3 Bq/µA*dm(3) in the direct assessment and 6.92 ± 0.22 Bq/µA*dm(3) by the convolution neutron fluence-to-cross section. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. Reduction of axial kinetic energy induced perturbations on observed cyclotron frequency.

    Science.gov (United States)

    Kaiser, Nathan K; Weisbrod, Chad R; Webb, Brian N; Bruce, James E

    2008-04-01

    With Fourier transform ion cyclotron resonance (FTICR) mass spectrometry one determines the mass-to-charge ratio of an ion by measuring its cyclotron frequency. However, the need to confine ions to the trapping region of the ion cyclotron resonance (ICR) cell with electric fields induces deviations from the unperturbed cyclotron frequency. Additional perturbations to the observed cyclotron frequency are often attributed to changes in space charge conditions. This study presents a detailed investigation of the observed ion cyclotron frequency as a function of ion z-axis kinetic energy. In a perfect three-dimensional quadrupolar field, cyclotron frequency is independent of position within the trap. However, in most ICR cell designs, this ideality is approximated only near the trap center and deviations arise from this ideal quadrupolar field as the ion moves both radially and axially from the center of the trap. To allow differentiation between deviations in observed cyclotron frequency caused from changes in space charge conditions or differences in oscillation amplitude, ions with identical molecular weights but different axial kinetic energy, and thus amplitude of z-axis motion, were simultaneously trapped within the ICR cell. This allows one to attribute deviations in observed cyclotron frequency to differences in the average force from the radial electric field experienced by ions of different axial amplitude. Experimentally derived magnetron frequency is compared with the magnetron frequency calculated using SIMION 7.0 for ions of different axial amplitude. Electron promoted ion coherence, or EPIC, is used to reduce the differences in radial electric fields at different axial positions. Thus with the application of EPIC, the differences in observed cyclotron frequencies are minimized for ions of different axial oscillation amplitudes.

  16. Texas A&M University in the JET Collaboration - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer [Texas A & M Univ., College Station, TX (United States); Ko, Che-Ming [Texas A & M Univ., College Station, TX (United States)

    2016-05-02

    This final report summarizes the work done by PIs at Texas A&M University within the JET Topical Collaboration. The main focus of the group at Texas A&M has been the development and implementation of a hadronization model suitable to calculate hadronization of jet showers in heavy ion collisions event by event. The group successfully developed a hybrid model of parton recombination and remnant string fragmentation including recombination with thermal partons. A code realizing this model was developed and shared with other JET members. In addition, the group at Texas A&M worked on both open and hidden heavy flavor probes. In particular, they developed a description of heavy flavor hadronization based on recombination, and consistent with in-medium scattering rates of heavy quarks, and suggested the Ds meson as a precise probe of the hadronization mechanism. Another noteworthy focus of their work was electromagnetic probes, in particular, dileptons and photons from interactions of jets with the medium. In the soft sector the group has made several contributions to modern topics, e.g. the splitting of elliptic flow between isospin partners and the role of the initial strong gluon fields.

  17. Physiological studies of methane- and methanol-oxidizing bacteria: comparison of a primary alcohol dehydrogenase from Methylococcus capsulatus (Texas strain) and Pseudomonas species M27.

    Science.gov (United States)

    Patel, R N; Bose, H R; Mandy, W J; Hoare, D S

    1972-05-01

    A primary alcohol dehydrogenase has been purified from Methylococcus capsulatus (Texas strain). The purified enzyme catalyzes the oxidation of methanol and formaldehyde to formate; other primary alcohols are oxidized to their corresponding aldehydes. Ammonium ions are required for enzyme activity. The enzyme has a molecular weight of 120,000 daltons and consists of two 62,000 molecular-weight subunits which dissociate at acidic pH. The enzyme is similar to an alcohol dehydrogenase enzyme isolated from Pseudomonas sp. M27.

  18. Comparison of neutron fluxes in an 18-MeV unshielded cyclotron room and a 16.5-MeV self-shielded cyclotron room.

    Science.gov (United States)

    Fujibuchi, Toshioh; Horitsugi, Genki; Yamaguchi, Ichiro; Eto, Akihisa; Iwamoto, Yasuo; Obara, Satoshi; Iimori, Takashi; Masuda, Yoshitada; Watanabe, Hiroshi; Hatazawa, Jun

    2012-07-01

    Some medical compact cyclotrons have self-shielding to reduce neutron fluxes. Thermal neutron fluxes in an 18-MeV unshielded cyclotron room and in a 16.5-MeV self-shielded cyclotron room were evaluated. In addition, the radioactivities in concrete and metals due to thermal neutrons in the cyclotron rooms for 30 years were calculated of operation such that the sum of the ratio of the nuclide concentration to the nuclide clearance level was equal to 1. The thermal neutron flux from the unshielded cyclotron was approximately 10(2) cm(-2) s(-1), whereas that from the self-shielded cyclotron was approximately 10(2) cm(-2) s(-1). The thermal neutron fluxes for concrete, stainless steel, vessel steel, and aluminum that reached their clearance levels were 9.80 × 10(4), 2.17 × 10(3), 1.87 × 10(4), and 2.41 × 10(5) cm(-2) s(-1), respectively. The specific activities in the cyclotron room were found to be sufficiently below the clearance level when the self-shield was employed.

  19. Reflection and backscattering of microwaves under doubling of the plasma density and displacement of the gyroresonance region during electron cyclotron resonance heating of plasma in the l-2M stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Batanov, G. M.; Borzosekov, V. D.; Vasilkov, D. G.; Kolik, L. V.; Konchekov, E. M., E-mail: konchekov@fpl.gpi.ru; Malakhov, D. V.; Vafin, I. Yu.; Petrov, A. E.; Sarksyan, K. A.; Sakharov, A. S.; Stepakhin, V. D.; Kharchev, N. K. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2016-08-15

    Reflection and backscattering of high-power (400 kW) gyrotron radiation creating and heating plasma at the second harmonic of the electronic cyclotron frequency in the L-2M stellarator have been investigated experimentally. The effect of the displacement of the gyroresonance region from the axis of the plasma column under doubling of the plasma density on the processes of reflection and backscattering of microwave radiation has been examined. A near doubling of short-wavelength (k{sub ⊥} ≈ 30 cm{sup –1}) turbulent density fluctuations squared is observed. The change in the energy confinement time under variations of plasma parameters and characteristics of short-wavelength turbulence is discussed. A discrepancy between the measured values of the reflection coefficient from the electron cyclotron resonance heating region and predictions of the one-dimensional model is revealed.

  20. Method and apparatus for ion cyclotron spectrometry

    Science.gov (United States)

    Dahl, David A [Idaho Falls, ID; Scott, Jill R [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

    2010-08-17

    An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber that includes at least a first section that induces a first magnetron effect that increases a cyclotron frequency of an ion and at least a second section that induces a second magnetron effect that decreases the cyclotron frequency of an ion. The cyclotron frequency changes induced by the first and second magnetron effects substantially cancel one another so that an ion traversing the at least first and second sections will experience no net change in cyclotron frequency.

  1. New radionuclides production on the isochronous cyclotron U-120M

    Energy Technology Data Exchange (ETDEWEB)

    Stursa, J.; Cihak, M.; Krivanek, M.; Kucera, J.; Lacman, J. [Nuclear Physics Institute, Prague (Czech Republic)

    1999-07-01

    The production of {sup 18}F for positron emission tomography (PET) applications and manufacturing of the {sup 81}Rb for the {sup 81}Rb/{sup 81m}Kr radionuclidic generator (used in lung ventilation studies) have been introduced as a new program of the twenty year old cyclotron U-120M(K=40, A/Z=1-2.8). The cyclotron conversion from positive to H/{sup -}D{sup -} accelerating regimes and the extraction by means of stripping were necessary for obtaining sufficiently high beam intensities. Two possible solutions of H{sup -} gain - either from the external high intensive (1 mA DC) old TRIUMF CUSP ion source or from the internal ion source with a cold cathode developed in our laboratory - are described. Axial injector characteristics for H{sup -} currents up to 1 mA together with optimizing the central region, the ion extraction system and upgrade of the vacuum system are presented. The realization of the enriched H{sub 2}O{sup 18} target, its setting into operation and the first results of {sup 18}F production (average yields {approx} 2 GBq/{mu}A. hour at EOB) are briefly discussed. (authors)

  2. The Energy-Water Nexus in Texas

    OpenAIRE

    Ashlynn S. Stillwell; Carey W. King; Michael E. Webber; Ian J. Duncan; Amy Hardberger

    2011-01-01

    Understanding the nexus between energy and water - water used for energy and energy used for water - has become increasing important in a changing world. As growing populations demand more energy supplies and water resources, research aims to analyze the interconnectedness of these two resources. Our study sought to quantify the energy-water relationship in Texas, specifically the relationship between electricity generation and water resources as it pertains to policy and society. We examined...

  3. Ion cyclotron waves at unmagnetized bodies: a comparison of Mars, Venus and Titan

    Science.gov (United States)

    Wei, H.; Russell, C. T.; Cowee, M.; Blanco-Cano, X.; Zhang, T.; Dougherty, M. K.

    2009-12-01

    Mars, Venus and Titan do not have appreciable global magnetic fields. Their high-altitude neutral atmospheres are not shielded from being lost to the solar wind and the Saturnian magnetosphere. When the atmospheric hydrogen atoms of Mars and Venus are ionized and picked up by the solar wind, proton cyclotron waves are created from the free energy of the ring-beam distribution of the pick-up ions. At Mars, proton cyclotron waves observed by Mars Global Surveyor extend from the magnetosheath to over 12 Mars radii, with intermittent occurrence and amplitudes slowly varying with distance. The wave occurrence pattern indicates a disk-shaped hydrogen exosphere of Mars with asymmetry in the direction of the interplanetary electric field. Fast neutrals produced by neutralization of the pickup ions can travel across fieldlines to distant regions where they get re-ionized and produce waves far downstream. Thus the top of Mars exosphere extends in a disk to high altitude, with its orientation controlled by the interplanetary magnetic field. At Venus, plasma waves having properties similar to ion cyclotron waves are observed in the solar wind around the planet by Venus Express, with wave frequencies that range from 0.2 to 5.9 times of the proton gyrofrequency. Statistical study shows that the waves with frequency higher than 1.5 times the proton gyrofrequency are not generated locally and are similar to the waves observed at 0.3 AU and 1 AU which appear to be created near the Sun and convected outward with the solar wind. The rest of the waves are mostly magnetically connected to the bow shock, so they are probably generated by particles backstreaming from the shock and propagate out further from the foreshock. At Titan, ion cyclotron waves are not observed although wave generation is expected due to the large pickup rate of hydrocarbon ions at high altitude of Titan. We attempt to understand the lack of ion cyclotron waves at Titan using hybrid simulations. Studying and

  4. Single-electron detection and spectroscopy via relativistic cyclotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Bradley, Rich; De Viveiros Souza Filho, Luiz A.; Doe, Peter J.; Fernandes, Justin L.; Fertl, M.; Finn, Erin C.; Formaggio, Joseph; Furse, Daniel L.; Jones, Anthony M.; Kofron, Jared N.; LaRoque, Benjamin; Leber, Michelle; MCBride, Lisa; Miller, M. L.; Mohanmurthy, Prajwal T.; Monreal, Ben; Oblath, Noah S.; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Rysewyk, Devyn M.; Sternberg, Michael G.; Tedeschi, Jonathan R.; Thummler, Thomas; VanDevender, Brent A.; Woods, N. L.

    2015-04-01

    It has been understood since 1897 that accelerating charges should emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spectrometer. We observe the cyclotron radiation emitted by individual electrons that are produced with mildly-relativistic energies by a gaseous radioactive source and are magnetically trapped. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work is a proof-of-concept for future neutrino mass experiments using this technique.

  5. Quench analysis of a novel compact superconducting cyclotron

    Science.gov (United States)

    Ghosh, Sundeep; Dutta Gupta, Anjan; Kanti Dey, Malay; Pal, Gautam

    2017-02-01

    Design and analysis of a compact superconducting cyclotron dedicated for medical applications in the fields of nuclear medicine and therapy is presently being pursued in our organization. The novelty of this cyclotron lies in the fact that it does not consist of any iron-pole. The cyclotron magnet will be made of a set of NbTi coils comprising of solenoid and sector coils which are housed in two halves on either sides of the median plane. The average magnetic field is 1.74 T and the maximum extraction energy is 25 MeV, which is sufficient for production of 99mTc from Mo. In this paper, quench analyses of the coils have been discussed in details considering adiabatic condition. The entire cryostat magnet along with coils, formers and support links were modelled for the quench simulation. Self and mutual inductances of all the coils were obtained from a separate magnetic analysis and used in the simulation. Parametric analyses were carried out with different quench initiation energy at various critical locations on the coil surface. The corresponding quench behaviour, i.e. maximum temperature rise, maximum voltage and current decay in each of the coils have been studied.

  6. Recoverable Resource Estimate of Identified Onshore Geopressured Geothermal Energy in Texas and Louisiana (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A.; Augustine, C.

    2012-04-01

    Geopressured geothermal reservoirs are characterized by high temperatures and high pressures with correspondingly large quantities of dissolved methane. Due to these characteristics, the reservoirs provide two sources of energy: chemical energy from the recovered methane, and thermal energy from the recovered fluid at temperatures high enough to operate a binary power plant for electricity production. Formations with the greatest potential for recoverable energy are located in the gulf coastal region of Texas and Louisiana where significantly overpressured and hot formations are abundant. This study estimates the total recoverable onshore geopressured geothermal resource for identified sites in Texas and Louisiana. In this study a geopressured geothermal resource is defined as a brine reservoir with fluid temperature greater than 212 degrees F and a pressure gradient greater than 0.7 psi/ft.

  7. SC Cyclotron and RIB Facilities in Kolkata

    CERN Document Server

    Sinha, Bikash; Chakrabarti, Alok

    2005-01-01

    The superconducting cyclotron under construction at this Centre has bending limit (K-bend) of 520 and focusing limit (K-foc) of 160. It is being constructed, primarily, for nuclear physics experiments with heavy ion beams at intermediate energies. The 100-ton main magnet is currently in the commissioning phase with the main coil already at 4.2K temperature. Magnetic field measurements will be carried out over the next several months. All other systems of the cyclotron are in an advanced stage of fabrication or development. We plan to start assembly of the complete cyclotron around the end of 2005. In the phase-I of the project one beam line has been provided. Construction of three more beam lines and various experimental facilities for nuclear physics as well as irradiation experiments has also been funded and the work is well on its way. An ISOL type Radioactive Ion Beam (RIB) facility is being built with the existing K=130 room temperature cyclotron, VEC, as the primary beam source. In-beam RIB production a...

  8. Simulation, design, and testing of a high power collimator for the RDS-112 cyclotron.

    Science.gov (United States)

    Peeples, Johanna L; Stokely, Matthew H; Poorman, Michael C; Bida, Gerald T; Wieland, Bruce W

    2015-03-01

    A high power [F-18] fluoride target package for the RDS-112 cyclotron has been designed, tested, and commercially deployed. The upgrade includes the CF-1000 target, a 1.3kW water target with an established commercial history on RDS-111/Eclipse cyclotrons, and a redesigned collimator with improved heat rejection capabilities. Conjugate heat transfer analyses were employed to both evaluate the existing collimator capabilities and design a suitable high current replacement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Relationships between sea surface temperature anomalies in the Pacific and Atlantic Oceans and South Texas precipitation and streamflow variability

    Science.gov (United States)

    Murgulet, Dorina; Valeriu, Murgulet; Hay, Richard R.; Tissot, Philippe; Mestas-Nuñez, Alberto M.

    2017-07-01

    While many studies have described linkages between large-scale climate phenomena and precipitation and streamflow, fewer studies explicitly address the climatic modulations at sub-regional scales. This study quantifies statistically the temporal variability in precipitation and streamflow at a regional scale in the semi-arid area of South Texas associated with three climate indices: El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). Results show that ENSO and PDO strongly modulate rainfall during the cold season and, to various extents, streamflow during the cold and warm seasons. In addition, this study shows that in South Texas streamflow is consistently below normal (i.e. means) while precipitation slightly increases during AMO-warm. To different extents, the Pacific and Atlantic sea surface temperature (SST) anomalies show stronger influences on the climate of South Texas when coupled. Droughts are more correlated with La Niña events but these events play a secondary role during PDO-cold. Although the PDO-cold phase is the dominant driver of droughts in this area, our analyses also show that the coupled effect of the PDO-cold/AMO-warm phases significantly increases the intensity of drought conditions to a degree similar to the PDO-cold/La Niña coupled effect. Given its stronger response to climate anomalies, streamflow offers a more effective tool for predicting climate variability impacts on South Texas water resources when compared to precipitation.

  10. The Energy-Water Nexus in Texas

    Directory of Open Access Journals (Sweden)

    Ashlynn S. Stillwell

    2011-03-01

    Full Text Available Understanding the nexus between energy and water - water used for energy and energy used for water - has become increasing important in a changing world. As growing populations demand more energy supplies and water resources, research aims to analyze the interconnectedness of these two resources. Our study sought to quantify the energy-water relationship in Texas, specifically the relationship between electricity generation and water resources as it pertains to policy and society. We examined the water requirements for various types of electricity generating facilities, for typical systems both nationwide and in Texas. We also addressed the energy requirements of water supply and wastewater treatment systems, comparing national averages with Texas-specific values. Analysis of available data for Texas reveals that approximately 595,000 megaliters of water annually - enough water for over three million people for a year - are consumed by cooling the state's thermoelectric power plants while generating approximately 400 terawatt-hours of electricity. At the same time, each year Texas uses an estimated 2.1 to 2.7 terawatt-hours of electricity for water systems and 1.8 to 2.0 terawatt-hours for wastewater systems - enough electricity for about 100,000 people for a year. In preparing our analysis, it became clear that substantially more site-specific data are necessary for a full understanding of the nature of the energy-water nexus and the sustainability of economic growth in Texas. We recommend that Texas increase efforts to collect accurate data on the withdrawal and consumption of cooling and process water at power plants, as well as data on electricity consumption for public water supply and wastewater treatment plants and distribution systems. The overarching conclusion of our work is that increased efficiency advances the sustainable use of both energy and water. Improving water efficiency will reduce power demand, and improving energy

  11. A simple thick target for production of 89Zr using an 11 MeV cyclotron

    Science.gov (United States)

    Link, Jeanne M.; Krohn, Kenneth A.; O’Hara, Matthew J.

    2017-01-01

    The growing interest but limited availability of 89Zr for PET led us to test targets for the 89Y(p,n) reaction. The goal was an easily constructed target for an 11 MeV Siemens cyclotron. Yttrium foils were tested at different thicknesses, angles and currents. A 90° foil tolerated 41 μA without damage and produced ~800 MBq/h, > 20 mCi, an amount adequate for radiochemistry research and human doses in a widely available accelerator. This method should translate to higher energy cyclotrons. PMID:28187357

  12. Cyclotrons and positron emitting radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A.P.; Fowler, J.S.

    1984-01-01

    The state of the art of Positron Emission Tomography (PET) technology as related to cyclotron use and radiopharmaceutical production is reviewed. The paper discusses available small cyclotrons, the positron emitters which can be produced and the yields possible, target design, and radiopharmaceutical development and application. 97 refs., 12 tabs. (ACR)

  13. Magnetic field calculation for a 13 MeV PET cyclotron

    CERN Document Server

    Yang, W Y; Oh, S; Chai, J S; Ha, J H

    1999-01-01

    A design study of the main magnet for a 13 MeV cyclotron has been carried out in a joint collaboration between the Korea Cancer Center Hospital (KCCH) and POSTECH. A maximum energy of 13 MeV has been chosen to produce radioisotopes such as /sup 18/F. There are four magnet sectors, each with radial-ridged shape. Maximum magnetic fields are 1.85 T and 0.48 T at hill and valley centers, respectively. The total size of the cyclotron is less than 2 m in diameter. The program TOSCA has been utilized for the field calculation and optimization. In this paper, we describe design parameters of the 13 MeV PET cyclotron, with emphasis on the magnetic field shape and the beam optics calculation. (3 refs).

  14. 77 FR 39996 - Department of Mechanical Engineering, Texas A&M University, Notice of Decision on Application for...

    Science.gov (United States)

    2012-07-06

    ... International Trade Administration Department of Mechanical Engineering, Texas A&M University, Notice of...., Washington, D.C. Docket Number: 12-024. Applicant: Department of Mechanical Engineering, Texas A&M University..., 2012. Gregory W. Campbell, Director, Subsidies Enforcement Office, Import Administration. BILLING CODE...

  15. Integrated Energy-Water Planning in the Western and Texas Interconnections (Invited)

    Science.gov (United States)

    Tidwell, V. C.

    2013-12-01

    While thermoelectric power generation accounts for less than one percent of total water consumption in the western U.S, steady growth in demand is projected for this sector. Complexities and heterogeneity in water supply, water demand, and institutional controls make water development a challenging proposition throughout the West. A consortium of National Laboratories, the University of Texas and the Electric Power Research Institute are working with the Western Governors' Association and Western States Water Council to assist the Western Electricity Coordinating Council and the Electric Reliability Council of Texas to integrate water related issues into long-term transmission planning. Specifically, water withdrawal and consumption have been estimated for each western power plant and their susceptibility to climate impacts assessed. To assist with transmission planning, water availability and cost data have been mapped at the 8-digit Hydrologic Unit Code level for the conterminous western U.S. (1208 watersheds). Five water sources were individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water, municipal wastewater and brackish groundwater. Also mapped is projected growth in consumptive water demand to 2030. The relative costs (capital and O&M) to secure, convey, and treat the water as necessary have also been estimated for each source of water. These data configured into watershed level supply curves were subsequently used to constrain West-wide transmission planning. Results across a range of alternative energy futures indicate the impact of water availability and cost on the makeup and siting of future power generation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Water budgets at a 8

  16. AUTOMATED FLOWCHART SYSTEM FROM TEXAS A&M UNIVERSITY

    Science.gov (United States)

    Woodford, W.

    1994-01-01

    An accurate flowchart is an important part of the documentation for any computer program. The flowchart offers the user an easy to follow overview of program operation and the maintenance programmer an effective debugging tool. The TAMU FLOWCHART System was developed to flowchart any program written in the FORTRAN language. It generates a line printer flowchart which is representative of the program logic. This flowchart provides the user with a detailed representation of the program action taken as each program statement is executed. The TAMU FLOWCHART System should prove to be a valuable aid to groups working with complex FORTRAN programs. Each statement in the program is displayed within a symbol which represents the program action during processing of the enclosed statement. Symbols available include: subroutine, function, and entry statements; arithmetic statements; input and output statements; arithmetical and logical IF statements; subroutine calls with or without argument list returns; computed and assigned GO TO statements; DO statements; STOP and RETURN statements; and CONTINUE and ASSIGN statements. Comment cards within the source program may be suppressed or displayed and associated with a succeeding source statement. Each symbol is annotated with a label (if present in the source code), a block number, and the statement sequence number. Program flow and options within the program are represented by line segments and direction indicators connecting symbols. The TAMU FLOWCHART System should be able to accurately flowchart any working FORTRAN program. This program is written in COBOL for batch execution and has been implemented on an IBM 370 series computer with an OS operating system and with a central memory requirement of approximately 380K of 8 bit bytes. The TAMU FLOWCHART System was developed in 1977.

  17. Cyclotron produced 198gAu, a potential radionuclide for diagnostic and therapeutic applications

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Haba, Hiromitsu; Kassim, Hasan Abu

    2016-02-01

    Production cross-sections of the natPt(d,x)198Au reactions have been measured from a 24-MeV deuteron energy down to the threshold by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. Only a partial agreement is obtained with the existing literature data and the theoretical data extracted from the TENDL-2013 library. Physical thick target yield for the 198Au radionuclide was deduced using the measured cross-sections, and found a general agreement with the directly measured yield available in the literature. This study reveals that a low deuteron energy (<15 MeV) cyclotron and an enriched 198Pt (100%) target could be used to obtain 198Au in no carrier added form.

  18. Cyclotron produced {sup 67}Ga, a potential radionuclide for diagnostic and therapeutic applications

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu-khandaker@um.edu.my; Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2015-04-29

    Production cross-sections of the {sup nat}Zn(d,x){sup 67}Ga reactions have been measured from a 24-MeV deuteron energy down to the threshold by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library. Physical thick target yield for the {sup 67}Ga radionuclide was deduced using the measured cross-sections, and found in agreement with the directly measured yield available in the literature. This study reveals that a low deuteron energy (<11 MeV) cyclotron and an enriched {sup 66}Zn target could be used to obtain {sup 67}Ga in no carrier added form.

  19. Cyclotron produced 67Ga, a potential radionuclide for diagnostic and therapeutic applications

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Haba, Hiromitsu; Kassim, Hasan Abu

    2015-04-01

    Production cross-sections of the natZn(d,x)67Ga reactions have been measured from a 24-MeV deuteron energy down to the threshold by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library. Physical thick target yield for the 67Ga radionuclide was deduced using the measured cross-sections, and found in agreement with the directly measured yield available in the literature. This study reveals that a low deuteron energy (<11 MeV) cyclotron and an enriched 66Zn target could be used to obtain 67Ga in no carrier added form.

  20. Nuclear safety analyses and core design calculations to convert the Texas A & M University Nuclear Science Center reactor to low enrichment uranium fuel. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parish, T.A.

    1995-03-02

    This project involved performing the nuclear design and safety analyses needed to modify the license issued by the Nuclear Regulatory Commission to allow operation of the Texas A& M University Nuclear Science Center Reactor (NSCR) with a core containing low enrichment uranium (LEU) fuel. The specific type of LEU fuel to be considered was the TRIGA 20-20 fuel produced by General Atomic. Computer codes for the neutronic analyses were provided by Argonne National Laboratory (ANL) and the assistance of William Woodruff of ANL in helping the NSCR staff to learn the proper use of the codes is gratefully acknowledged. The codes applied in the LEU analyses were WIMSd4/m, DIF3D, NCTRIGA and PARET. These codes allowed full three dimensional, temperature and burnup dependent calculations modelling the NSCR core to be performed for the first time. In addition, temperature coefficients of reactivity and pulsing calculations were carried out in-house, whereas in the past this modelling had been performed at General Atomic. In order to benchmark the newly acquired codes, modelling of the current NSCR core with highly enriched uranium fuel was also carried out. Calculated results were compared to both earlier licensing calculations and experimental data and the new methods were found to achieve excellent agreement with both. Therefore, even if an LEU core is never loaded at the NSCR, this project has resulted in a significant improvement in the nuclear safety analysis capabilities established and maintained at the NSCR.

  1. Assessment of radionuclidic impurities in cyclotron produced (99m)Tc.

    Science.gov (United States)

    Lebeda, Ondřej; van Lier, Erik J; Štursa, Jan; Ráliš, Jan; Zyuzin, Alexander

    2012-11-01

    The commercial viability of cyclotron-produced (99m)Tc as an alternative to generator-produced (99m)Tc depends on several factors. These include: production yield, ease of target processing and recycling of (100)Mo, radiochemical purity, specific activity as well as the presence of other radionuclides, particularly various Tc radioisotopes that cannot be separated chemically and will remain in the final clinical preparation. These Tc radionuclidic impurities are derived from nuclear interactions of the accelerated protons with other stable Mo isotopes present in the enriched (100)Mo target. The aim of our study was to determine experimentally the yields of Tc radioisotopes produced from these stable Mo isotopes as a function of incident beam energy in order to predict radionuclidic purity of (99m)Tc produced in highly enriched (100)Mo targets of known isotopic composition. Enriched molybdenum targets of (95)Mo, (96)Mo, (97)Mo, (98)Mo and (100)Mo were prepared by pressing powdered metal into an aluminum target support. The thick targets were bombarded with 10 to 24MeV protons using the external beam line of the U-120M cyclotron of the Nuclear Physics Institute, Řež. The thick target yields of (94)Tc, (94m)Tc, (95)Tc, (95m)Tc, (96m+g)Tc and (97m)Tc were derived from their activities measured by γ spectrometry using a high purity Ge detector. These data were then used to assess the effect of isotopic composition of highly enriched (100)Mo targets on the radionuclidic purity of (99m)Tc as a function of proton beam energy. Estimates were validated by comparison to measured activities of Tc radioisotopes in proton irradiated, highly enriched (100)Mo targets of known isotopic composition. The measured thick target yields of (94)Tc, (94m)Tc, (95)Tc, (95m)Tc, (96m+g)Tc and (97m)Tc correspond well with recently published values calculated via the EMPIRE-3 code. However, the measured yields are more favourable with regard to achievable radionuclidic purity of (99m

  2. Oceanography and Geoscience Scholars at Texas A&M University Funded through the NSF S-STEM (Scholarships in Science, Technology, Engineering and Mathematics) Program

    Science.gov (United States)

    Richardson, M. J.; Gardner, W. D.

    2016-02-01

    Over the last seven years we have led the creation and implementation of the Oceanography and Geoscience Scholars programs at Texas A&M University. Through these programs we have been able to provide scholarship support for 92 undergraduates in Geosciences and 29 graduate students in Oceanography. Fifty-seven undergraduate scholars have graduated in Geosciences: 30 undergraduate students in Meteorology, 7 in Geology, and 20 in Environmental Geosciences. Two students have graduated in other STEM disciplines. Twenty-four students are in the process of completing their undergraduate degrees in STEM disciplines. Twenty-three students have graduated with MS or PhD degrees in Oceanography and five PhD students are completing their dissertations. As specified in the program solicitation all of the scholars are academically talented students with demonstrated financial need as defined by the FAFSA (Free Application for Federal Student Aid). We have endeavored to recruit students from underrepresented groups. One-third of the undergraduate scholars were from underrepresented groups; 28% of the graduate students. We will present the challenges and successes of these programs.

  3. A BaF2 crystal array for high energy-ray measurements

    Indian Academy of Sciences (India)

    Abstract. We shall discuss about the scientific motivation and construction of a 7 × 7 BaF2 crystal array at Variable Energy Cyclotron Centre, Calcutta. This detector would be used to measure high energy -ray photons from GDR decay and proton–neutron bremsstrahlung reactions at the present 88'' cyclotron and upcoming ...

  4. Comprehensive UAV agricultural remote-sensing research at Texas A M University

    Science.gov (United States)

    Thomasson, J. Alex; Shi, Yeyin; Olsenholler, Jeffrey; Valasek, John; Murray, Seth C.; Bishop, Michael P.

    2016-05-01

    Unmanned aerial vehicles (UAVs) have advantages over manned vehicles for agricultural remote sensing. Flying UAVs is less expensive, is more flexible in scheduling, enables lower altitudes, uses lower speeds, and provides better spatial resolution for imaging. The main disadvantage is that, at lower altitudes and speeds, only small areas can be imaged. However, on large farms with contiguous fields, high-quality images can be collected regularly by using UAVs with appropriate sensing technologies that enable high-quality image mosaics to be created with sufficient metadata and ground-control points. In the United States, rules governing the use of aircraft are promulgated and enforced by the Federal Aviation Administration (FAA), and rules governing UAVs are currently in flux. Operators must apply for appropriate permissions to fly UAVs. In the summer of 2015 Texas A&M University's agricultural research agency, Texas A&M AgriLife Research, embarked on a comprehensive program of remote sensing with UAVs at its 568-ha Brazos Bottom Research Farm. This farm is made up of numerous fields where various crops are grown in plots or complete fields. The crops include cotton, corn, sorghum, and wheat. After gaining FAA permission to fly at the farm, the research team used multiple fixed-wing and rotary-wing UAVs along with various sensors to collect images over all parts of the farm at least once per week. This article reports on details of flight operations and sensing and analysis protocols, and it includes some lessons learned in the process of developing a UAV remote-sensing effort of this sort.

  5. Method and apparatuses for ion cyclotron spectrometry

    Science.gov (United States)

    Dahl, David A [Idaho Falls, ID; Scott, Jill R [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

    2012-03-06

    An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

  6. The 88-Inch Cyclotron: A One-Stop Facility for Electronics Radiation and Detector Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kireeff Covo, M.; Albright, R. A.; Ninemire, B. F.; Johnson, M. B.; Hodgkinson, A.; Loew, T.; Benitez, J. Y.; Todd, D. S.; Xie, D. Z.; Perry, T.; Phair, L.; Bernsteiny, L. A.; Bevins, J.; Brown, J. A.; Goldblum, B. L.; Harasty, M.; Harrig, K. P.; Laplace, T. A.; Matthews, E. F.; Bushmaker, A.; Walker, D.; Oklejas, V.; Hopkins, A. R.; Bleuel, D. L.; Chen, J.; Cronin, S. B.

    2017-10-01

    In outer space down to the altitudes routinely flown by larger aircrafts, radiation can pose serious issues for microelectronics circuits. The 88-Inch Cyclotron at Lawrence Berkeley National Laboratory is a sector-focused cyclotron and home of the Berkeley Accelerator Space Effects Facility, where the effects of energetic particles on sensitive microelectronics are studied with the goal of designing electronic systems for the space community. This paper describes the flexibility of the facility and its capabilities for testing the bombardment of electronics by heavy ions, light ions, and neutrons. Experimental capabilities for the generation of neutron beams from deuteron breakups and radiation testing of carbon nanotube field effect transistor will be discussed.

  7. Time evolution of endpoint energy of Bremsstrahlung spectra and ion production from an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie [Los Alamos National Laboratory; Ropponen, Tommi [JYFL; Jones, Peter [JYFL; Kalvas, Taneli [JYFL

    2008-01-01

    Electron cyclotron resonance ion sources (ECRIS) are used to produce high charge state heavy ion beams for the use of nuclear and materials science, for instance. The most powerful ECR ion sources today are superconducting. One of the problems with superconducting ECR ion sources is the use of high radio frequency (RF) power which results in bremsstrahlung radiation adding an extra heat load to the cryostat. In order to understand the electron heating process and timescales in the ECR plasma, time evolution measurement of ECR bremsstrahlung was carried out. In the measurements JYFL 14 GHz ECRIS was operated in a pulsed mode and bremsstrahlung data from several hundred RF pulses was recorded. Time evolution of ion production was also studied and compared to one of the electron heating theories. To analyze the measurement data at C++ program was developed. Endpoint energies of the bremsstrahlung spectra as a function of axial magnetic field strength, pressure and RF power are presented and ion production timescales obtained from the measurements are compared to bremsstrahlung emission timescales and one of the stochastic heating theories.

  8. Cyclotron Phase-Coherent Ion Spatial Dispersion in a Non-Quadratic Trapping Potential is Responsible for FT-ICR MS at the Cyclotron Frequency

    Science.gov (United States)

    Nagornov, Konstantin O.; Kozhinov, Anton N.; Tsybin, Yury O.

    2017-11-01

    Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) at the cyclotron frequency instead of the reduced cyclotron frequency has been experimentally demonstrated using narrow aperture detection electrode (NADEL) ICR cells. Here, based on the results of SIMION simulations, we provide the initial mechanistic insights into the cyclotron frequency regime generation in FT-ICR MS. The reason for cyclotron frequency regime is found to be a new type of a collective motion of ions with a certain dispersion in the initial characteristics, such as pre-excitation ion velocities, in a highly non-quadratic trapping potential as realized in NADEL ICR cells. During ion detection, ions of the same m/z move in phase for cyclotron ion motion but out of phase for magnetron (drift) ion motion destroying signals at the fundamental and high order harmonics that comprise reduced cyclotron frequency components. After an initial magnetron motion period, ion clouds distribute into a novel type of structures - ion slabs, elliptical cylinders, or star-like structures. These structures rotate at the Larmor (half-cyclotron) frequency on a plane orthogonal to the magnetic field, inducing signals at the true cyclotron frequency on each of the narrow aperture detection electrodes. To eliminate the reduced cyclotron frequency peak upon dipolar ion detection, a number of slabs or elliptical cylinders organizing a star-like configuration are formed. In a NADEL ICR cell with quadrupolar ion detection, a single slab or an elliptical cylinder is sufficient to minimize the intensity of the reduced cyclotron frequency components, particularly the second harmonic. [Figure not available: see fulltext.

  9. Study of the Polarization Strategy for Electron Cyclotron Heating Systems on HL-2M

    Science.gov (United States)

    Zhang, F.; Huang, M.; Xia, D. H.; Song, S. D.; Wang, J. Q.; Huang, B.; Wang, H.

    2016-06-01

    As important components integrated in transmission lines of electron cyclotron heating systems, polarizers are mainly used to obtain the desired polarization for highly efficient coupling between electron cyclotron waves and plasma. The polarization strategy for 105-GHz electron cyclotron heating systems of HL-2M tokamak is studied in this paper. Considering the polarizers need high efficiency, stability, and low loss to realize any polarization states, two sinusoidal-grooved polarizers, which include a linear polarizer and an elliptical polarizer, are designed with the coordinate transformation method. The parameters, the period p and the depth d, of two sinusoidal-grooved polarizers are optimized by a phase difference analysis method to achieve an almost arbitrary polarization. Finally, the optimized polarizers are manufactured and their polarization characteristics are tested with a low-power test platform. The experimental results agree well with the numerical calculations, indicating that the designed polarizers can meet the polarization requirements of the electron cyclotron heating systems of HL-2M tokamak.

  10. Texas transportation planning for future renewable energy projects : final report.

    Science.gov (United States)

    2017-03-01

    There will be a significant increase in the number of renewable energy production facilities in Texas. The : construction of wind farms requires the transport of wind turbine components that create increased loads on : rural roads and bridges. These ...

  11. Ernest Orlando Lawrence (1901-1958), Cyclotron and Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Chu, William T.

    2005-09-01

    On August 8, 2001, Lawrence Berkeley National Laboratory celebrated the centennial of the birth of its founder (and namesake), Ernest Orlando Lawrence. For the occasion, many speeches were given and old speeches were remembered. We recall the words of the late Luis Alvarez, a Nobel Laureate and one of the Lawrence's closest colleagues: ''Lawrence will always be remembered as the inventor of the cyclotron, but more importantly, he should be remembered as the inventor of the modern way of doing science''. J. L. Heilbron and R. W. Seidel, in the introduction of their book, ''Lawrence and His Laboratory'' stated, ''The motives and mechanisms that shaped the growth of the Laboratory helped to force deep changes in the scientific estate and in the wider society. In the entrepreneurship of its founder, Ernest Orlando Lawrence, these motives, mechanisms, and changes came together in a tight focus. He mobilized great and small philanthropists, state and local governments, corporations, and plutocrats, volunteers and virtuosos. The work they supported, from astrophysics and atomic bombs, from radiochemistry to nuclear medicine, shaped the way we observe, control, and manipulate our environment.'' Indeed, all over the civilized world, the ways we do science changed forever after Lawrence built his famed Radiation Laboratory. In this editorial, we epitomize his legacy of changing the way we do medicine, thereby affecting the health and well being of all humanity. This year marks the 75th anniversary of the invention of the cyclotron by Ernest Orlando Lawrence at the University of California at Berkeley. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideroe on high-energy accelerators. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston

  12. EC-5 fifth international workshop on electron cyclotron emission and electron cyclotron heating

    Energy Technology Data Exchange (ETDEWEB)

    Prater, R.; Lohr, J. [eds.

    1985-12-31

    This report contains papers on the following topics: electron cyclotron emission measurements; electron cyclotron emission theory; electron cyclotron heating; gyrotron development; and ECH systems and waveguide development. These paper have been indexed separately elsewhere. (LSP).

  13. Initial experiments with the Nevis Cyclotron, the Brookhaven Cosmotron, the Brookhaven AGS and their effects on high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Lindenbaum, S.J.

    1988-01-01

    The first experiment at the Nevis Cyclotron by Bernardini, Booth and Lindenbaum demonstrated that nuclear stars are produced by a nucleon-nucleon cascade within the nucleon. This solved a long standing problem in Cosmic rays and made it clear that where they overlap cosmic ray investigation would not be competitive with accelerator investigations. The initial experiments at the Brookhaven Cosmotron by Lindenbaum and Yuan demonstrated that low energy pion nucleon scattering and pion production were unexpectedly mostly due to excitation of the isotopic spin = angular momentum = 3/2 isobaric state of the nucleon. This contradicted the Fermi statistical theory and led to the Isobar model proposed by the author and a collaborator. The initial experiments at the AGS by the author and collaborators demonstrated that the Pomeronchuck Theorem would not come true till at least several hundred GeV. These scattering experiments led to the development of the ''On-line Computer Technique'' by the author and collaborators which is now the almost universal technique in high energy physics. The first accomplishment which flowed from this technique led to contradiction of the Regge pole theory as a dynamical asymptotic theory, by the author and collaborators. The first critical experimental proof of the forward dispersion relation in strong interactions was accomplished by the author and collaborators. They were then used as a crystal ball to predict that ''Asymptopia''---the theoretically promised land where all asymptotic theorems come true---would not be reached till at least 25,000 BeV and probably not before 1,000,000 BeV. 26 refs., 11 figs., 2 tabs.

  14. NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1

    DEFF Research Database (Denmark)

    Fuerst, Felix; Pottschmidt, Katja; Wilms, Joern

    2014-01-01

    We present NuSTAR observations of Vela X-1, a persistent, yet highly variable, neutron star high-mass X-ray binary (HMXB). Two observations were taken at similar orbital phases but separated by nearly a year. They show very different 3-79 keV flux levels as well as strong variability during each...

  15. Texas State Building Energy Code: Analysis of Potential Benefits and Costs of Commercial Lighting Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Richman, Eric E.; Belzer, David B.; Winiarski, David W.

    2005-09-15

    The State Energy Conservation Office of Texas has asked the U.S. Department of Energy to analyze the potential energy effect and cost-effectiveness of the lighting requirements in the 2003 IECC as they consider adoption of this energy code. The new provisions of interest in the lighting section of IECC 2003 include new lighting power densities (LPD) and requirements for automatic lighting shutoff controls. The potential effect of the new LPD values is analyzed as a comparison with previous values in the nationally available IECC codes and ASHRAE/IESNA 90.1. The basis for the analysis is a set of lighting models developed as part of the ASHRAE/IES code process, which is the basis for IECC 2003 LPD values. The use of the models allows for an effective comparison of values for various building types of interest to Texas state. Potential effects from control requirements are discussed, and available case study analysis results are provided but no comprehensive numerical evaluation is provided in this limited analysis effort.

  16. EBCO Technologies TR Cyclotrons, Dynamics, Equipment, and Applications

    Science.gov (United States)

    Johnson, R. R.; Erdman, K. L.; Gyles, Wm.; Burbee, J.; VanLier, E.; Kovacs, M.; Perron, F.

    2003-08-01

    The Ebco Technologies TR cyclotrons have a common parent in the 500 MeV negative ion cyclotron at TRIUMF in Vancouver. As such, the TR cyclotrons have features that can be adapted for specific application. The cyclotron design is modularized into ion source and injection system, central region and then extraction. The cyclotron ion source is configured for cyclotron beam currents ranging from 50 microAmps to 2 milliAmps. The injection line can be operated in either continuous (CW) or in pulsed mode. The center region of the cyclotron is configured to match the ion source configuration. The extracted beams are directed either to a local target station or to beam lines and thence to target stations. There has been development both in solid, liquid and gas targets. There has been development in radioisotope handling techniques, target material recovery and radiochemical synthesis.

  17. Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital-based clinical cyclotron.

    Science.gov (United States)

    Jones, Kevin C; Vander Stappen, François; Bawiec, Christopher R; Janssens, Guillaume; Lewin, Peter A; Prieels, Damien; Solberg, Timothy D; Sehgal, Chandra M; Avery, Stephen

    2015-12-01

    To measure the acoustic signal generated by a pulsed proton spill from a hospital-based clinical cyclotron. An electronic function generator modulated the IBA C230 isochronous cyclotron to create a pulsed proton beam. The acoustic emissions generated by the proton beam were measured in water using a hydrophone. The acoustic measurements were repeated with increasing proton current and increasing distance between detector and beam. The cyclotron generated proton spills with rise times of 18 μs and a maximum measured instantaneous proton current of 790 nA. Acoustic emissions generated by the proton energy deposition were measured to be on the order of mPa. The origin of the acoustic wave was identified as the proton beam based on the correlation between acoustic emission arrival time and distance between the hydrophone and proton beam. The acoustic frequency spectrum peaked at 10 kHz, and the acoustic pressure amplitude increased monotonically with increasing proton current. The authors report the first observation of acoustic emissions generated by a proton beam from a hospital-based clinical cyclotron. When modulated by an electronic function generator, the cyclotron is capable of creating proton spills with fast rise times (18 μs) and high instantaneous currents (790 nA). Measurements of the proton-generated acoustic emissions in a clinical setting may provide a method for in vivo proton range verification and patient monitoring.

  18. 76 FR 20968 - Application To Export Electric Energy; DC Energy Texas, LLC

    Science.gov (United States)

    2011-04-14

    ... energy that DCE Texas proposes to export to Mexico would be surplus energy purchased from electric... listed above. Comments on the DCE Texas application to export electric energy to Mexico should be clearly... Application To Export Electric Energy; DC Energy Texas, LLC AGENCY: Office of Electricity Delivery and Energy...

  19. Study on phylogenetic relationships, variability, and correlated mutations in M2 proteins of influenza virus A.

    Directory of Open Access Journals (Sweden)

    Ly Le

    Full Text Available M2 channel, an influenza virus transmembrane protein, serves as an important target for antiviral drug design. There are still discordances concerning the role of some residues involved in proton transfer as well as the mechanism of inhibition by commercial drugs. The viral M2 proteins show high conservativity; about 3/4 of the positions are occupied by one residue in over 95%. Nine M2 proteins from the H3N2 strain and possibly two proteins from H2N2 strains make a phylogenic cluster closely related to 2RLF. The variability range is limited to 4 residues/position with one exception. The 2RLF protein stands out by the presence of 2 serines at the positions 19 and 50, which are in most other M2 proteins occupied by cysteines. The study of correlated mutations shows that there are several positions with significant mutational correlation that have not been described so far as functionally important. That there are 5 more residues potentially involved in the M2 mechanism of action. The original software used in this work (Consensus Constructor, SSSSg, Corm, Talana is freely accessible as stand-alone offline applications upon request to the authors. The other software used in this work is freely available online for noncommercial purposes at public services on bioinformatics such as ExPASy or NCBI. The study on mutational variability, evolutionary relationship, and correlated mutation presented in this paper is a potential way to explain more completely the role of significant factors in proton channel action and to clarify the inhibition mechanism by specific drugs.

  20. A micropulse monitor for control of cyclotron beams

    Science.gov (United States)

    Lind, D. A.; Peterson, R. J.; Da Silva, A. G.; Auler, L. T.; de Barros, S.

    1990-07-01

    A system using wall current monitors to observe the time structure of the individual beam current pulses of the Cyclotron Corp. CV28 cyclotron installed at the Instituto de Engenharia Nuclear of CNEN in Rio de Janeiro is described. The monitors are designed to give a faithful representation of the actual beam pulse, so the effects on the longitudinal phase space could be seen as the cyclotron parameters were changed. Beam pulses of width in the range of 1 to 4 ns and with a charge of 7 × 10-16 C or greater can be observed. With two units in the line transit times permit beam energy determination as well as charge distribution. For timing purposes a unit placed in front of a target is used to generate a start signal for time-of-flight measurements, and to monitor the effects of all parameters of the cyclotron tune. By measuring flight times in the beamlines of this machine, the energy for 28 MeV protons can be determined to about 50 keV and for the other available particles to about 30 keV.

  1. Turbulent flux variability and energy balance closure in the TERENO prealpine observatory: a hydrometeorological data analysis

    Science.gov (United States)

    Soltani, Mohsen; Mauder, Matthias; Laux, Patrick; Kunstmann, Harald

    2017-07-01

    The temporal multiscale variability of the surface heat fluxes is assessed by the analysis of the turbulent heat and moisture fluxes using the eddy covariance (EC) technique at the TERrestrial ENvironmental Observatories (TERENO) prealpine region. The fast and slow response variables from three EC sites located at Fendt, Rottenbuch, and Graswang are gathered for the period of 2013 to 2014. Here, the main goals are to characterize the multiscale variations and drivers of the turbulent fluxes, as well as to quantify the energy balance closure (EBC) and analyze the possible reasons for the lack of EBC at the EC sites. To achieve these goals, we conducted a principal component analysis (PCA) and a climatological turbulent flux footprint analysis. The results show significant differences in the mean diurnal variations of the sensible heat (H) and latent heat (LE) fluxes, because of variations in the solar radiation, precipitation patterns, soil moisture, and the vegetation fraction throughout the year. LE was the main consumer of net radiation. Based on the first principal component (PC1), the radiation and temperature components with a total mean contribution of 29.5 and 41.3%, respectively, were found to be the main drivers of the turbulent fluxes at the study EC sites. A general lack of EBC is observed, where the energy imbalance values amount 35, 44, and 35% at the Fendt, Rottenbuch, and Graswang sites, respectively. An average energy balance ratio (EBR) of 0.65 is obtained in the region. The best closure occurred in the afternoon peaking shortly before sunset with a different pattern and intensity between the study sites. The size and shape of the annual mean half-hourly turbulent flux footprint climatology was analyzed. On average, 80% of the flux footprint was emitted from a radius of approximately 250 m around the EC stations. Moreover, the overall shape of the flux footprints was in good agreement with the prevailing wind direction for all three TERENO EC sites.

  2. Evidence of local power deposition and electron heating by a standing electromagnetic wave in electron-cyclotron-resonance plasma.

    Science.gov (United States)

    Durocher-Jean, A; Stafford, L; Dap, S; Makasheva, K; Clergereaux, R

    2014-09-01

    Microwave plasmas excited at electron-cyclotron resonance were studied in the 0.5-15 mTorr pressure range. In contrast with low-limit pressure conditions where the plasma emission highlights a fairly homogeneous spatial structure, a periodic spatial modulation (period ∼6.2 cm) appeared as pressure increased. This feature is ascribed to a local power deposition (related to the electron density) due to the presence of a standing electromagnetic wave created by the feed electromagnetic field (2.45 GHz) in the cavity formed by the reactor walls. Analysis of the electron energy probability function by Langmuir probe and optical emission spectroscopy further revealed the presence of a high-energy tail that showed strong periodic spatial modulation at higher pressure. The spatial evolution of the electron density and of the characteristic temperature of these high-energy electrons coincides with the nodes (maximum) and antinodes (minimum) of the standing wave. These spatially-modulated power deposition and electron heating mechanisms are then discussed.

  3. A mobile system for quantifying the spatial variability of the surface energy balance: design and application.

    Science.gov (United States)

    Wohlfahrt, Georg; Tasser, Erich

    2015-05-01

    We present a mobile device for the quantification of the small-scale (a few square meters) spatial variability in the surface energy balance components and several auxiliary variables of short-statured (ecological research questions. The potential of the new device is demonstrated through four selected case studies, which cover the issues of net radiation heterogeneity within the footprint of eddy covariance flux measurements due to (1) land use and (2) slope and aspect of the underlying surface, (3) controls on landscape-scale variability in soil temperature and albedo and (4) the estimation of evapotranspiration based exclusively on measurements with the mobile device.

  4. Molybdenum target specifications for cyclotron production of 99mTc based on patient dose estimates.

    Science.gov (United States)

    Hou, X; Tanguay, J; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2016-01-21

    In response to the recognized fragility of reactor-produced (99)Mo supply, direct production of (99m)Tc via (100)Mo(p,2n)(99m)Tc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with (99m)Tc, other technetium (Tc) radioactive isotopes (impurities) will be produced. They will be incorporated into the labeled radiopharmaceuticals and result in increased patient dose. The isotopic composition of the target and beam energy are main factors that determine production of impurities, thus also dose increases. Therefore, they both must be considered when selecting targets for clinical (99m)Tc production. Although for any given Mo target, the patient dose can be predicted based on complicated calculations of production yields for each Tc radioisotope, it would be very difficult to reverse these calculations to specify target composition based on dosimetry considerations. In this article, a relationship between patient dosimetry and Mo target composition is studied. A simple and easy algorithm for dose estimation, based solely on the knowledge of target composition and beam energy, is described. Using this algorithm, the patient dose increase due to every Mo isotope that could be present in the target is estimated. Most importantly, a technique to determine Mo target composition thresholds that would meet any given dosimetry requirement is proposed.

  5. Impact of a Stochastic Energy Backscatter Scheme on Climate and Variability across Timescales and Resolutions

    Science.gov (United States)

    Sanchez, C.

    2012-12-01

    Stochastic physics is one of most widely used methods to represent model uncertainty in ensemble prediction systems of weather and climate models. These schemes aim to represent absent or poorly simulated process whose scales are below the truncation scale, they have been proven to be a skilful tool against the common underdispersiveness (lack of internal variability) of these models, as well as theoretically able to improve the mean climate through a noise-induced drift (better variability leads to a better mean climate). However, the formulation of these schemes often relies in pragmatic assumptions with limited scientific basis, and their physical realism is often challenged. The stochastic energy backscatter method is one of the main formulations of stochastic physics. It is designed to stochastically simulate upscale cascades of energy coming from numerical dissipation, convective subgrid-scale events or subgrid mountain drag. This scheme has been successfully implemented in many of the most important numerical weather prediction models across the world. It improves the ensemble skill scores, and under some configurations the mean climate too. In order to understand the impacts of the stochastic energy backscatter concept in a deterministic framework, we use the Stochastic Kinetic Energy Backscatter (SKEB2) scheme in the Met Office Unified Model (MetUM). We explore the impact of SKEB2 across timescales and resolutions in terms of usual model evaluation metrics such as biases or root mean error square, as well as some process-based techniques to diagnose the simulation of tropical and extra-tropical variability, such as cyclone tracking, Lorenz Energy Cycle or Madden Julian Oscillation diagnostics. Our results show that the extra kinetic energy added by SKEB2 can improve the representation of key processes that drive the atmospheric variability, leading to a slight improvement of climate biases. However it degrades the skill of short-range (less than 5 days

  6. Critical energy in the cyclotron heating of ions in a mirror machine; Energia critica en el calentamiento ciclotronico de los iones en una maquina espejo

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Hernandez A, O. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The problem of heating in the plasma sources where the geometry of the magnetic field forms a magnetic mirror as it is the case of the Ecr sources type, for maintaining the reload, it continues being an actual important problem. There are two methods for the analysis of this problem. The first of these methods is the stochastic mechanism of a particle where it is considered the existence of three characteristic frequencies as the cyclotron frequency, the electromagnetic field frequency and the transit frequency. The second method is that related with the non linear interaction of waves where the collective effects of the particles are the most important. In this work, in the Hamiltonian formalism, the stochastic mechanism in the cyclotron heating is analysed. It is considered the particular case of a plasma source with an external magnetic field, type mirror where a TE{sub 11} electromagnetic wave is injected. The critical energy in the resonance mixing is calculated by the Poincare mapping method. The heterogeneity of the magnetic field is analysed. (Author)

  7. Variable stiffness actuators: A port-based analysis and a comparison of energy efficiency

    NARCIS (Netherlands)

    Visser, L.C.; Carloni, Raffaella; Stramigioli, Stefano

    In this paper, a metric for comparing different designs of variable stiffness actuators is introduced. For the formulation of this metric, we focus on the energy efficiency of the actuators. In particular, we propose a metric that is a measure of how much energy is used by the actuator for changing

  8. Variable stiffness actuators : A port-based analysis and a comparison of energy efficiency

    NARCIS (Netherlands)

    Visser, L. C.; Carloni, R.; Stramigioli, S.

    2010-01-01

    In this paper, a metric for comparing different designs of variable stiffness actuators is introduced. For the formulation of this metric, we focus on the energy efficiency of the actuators. In particular, we propose a metric that is a measure of how much energy is used by the actuator for changing

  9. A variable for measuring masses at hadron colliders when missing energy is expected; m{sub T2}: the truth behind the glamour

    Energy Technology Data Exchange (ETDEWEB)

    Barr, Alan; Lester, Christopher; Stephens, Phil [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge, CB3 0HE (United Kingdom)

    2003-10-01

    We present the kinematic variable,m{sub T2}, which is in some ways similar to the more familiar 'transverse mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m{sub T2} is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the large hadron collider.

  10. A variable for measuring masses at hadron colliders when missing energy is expected; $m_{T2}$ : the truth behind the glamour

    CERN Document Server

    Barr, A J; Stephens, P

    2003-01-01

    We present the kinematic variable, m/sub T2/, which is in some ways similar to the more familiar 'transverse mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m/sub T2/ is vital when reconstructing the masses of supersymmetric particles in mSUGRA- like and AMSB-like scenarios at the Large Hadron Collider. (16 refs).

  11. A variable for measuring masses at hadron colliders when missing energy is expected; mT2: the truth behind the glamour

    Science.gov (United States)

    Barr, Alan; Lester, Christopher; Stephens, Phil

    2003-10-01

    We present the kinematic variable,mT2, which is in some ways similar to the more familiar 'transverse mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how mT2 is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the large hadron collider.

  12. Electron cyclotron resonance discharge as a source for hydrogen and deuterium ions production

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Velasco, A.J. [Universidad de Pamplona, Pamplona (Colombia); Dougar-Jabon, V.D. [Universidad Industrial de Santander, Bucaramanga (Colombia)

    2004-07-01

    In this report, we describe characteristics of a ring-structure hydrogen plasma heated in electron cyclotron resonance conditions and confined in a mirror magnetic trap and discuss the relative efficiency of secondary electrons and thermo-electrons in negative hydrogen and deuterium ion production. The obtained data and calculations of the balance equations for possible reactions demonstrate that the negative ion production is realized in two stages. First, the hydrogen and deuterium molecules are excited in collisions with the plasma electrons to high-laying Rydberg or vibrational levels in the plasma volume. The second stage leads to the negative ion production through the process of dissociative attachment of low energy electrons. The low energy electrons are originated due to a bombardment of the plasma electrode by ions of one of the driven rings and thermo-emission from heated tungsten filaments. Experiments seem to indicate that the negative ion generation occurs predominantly in the limited volume filled with thermo-electrons. Estimation of the negative ion generation rate shows that the main channel of H{sup -} and D{sup -} ion production involves the process of high Rydberg state excitation. (authors)

  13. Recent achievements in Tc-99m radiopharmaceutical direct production by medical cyclotrons.

    Science.gov (United States)

    Boschi, Alessandra; Martini, Petra; Pasquali, Micol; Uccelli, Licia

    2017-09-01

    99mTc is the most commonly used radionuclide in the field of diagnostic imaging, a noninvasive method intended to diagnose a disease, assess the disease state and monitor the effects of treatments. Annually, the use of 99mTc, covers about 85% of nuclear medicine applications. This isotope releases gamma rays at about the same wavelength as conventional X-ray diagnostic equipment, and owing to its short half-life (t½ = 6 h) is ideal for diagnostic nuclear imaging. A patient can be injected with a small amount of 99mTc and within 24 h almost 94% of the injected radionuclide would have decayed and left the body, limiting the patient's radiation exposure. 99mTc is usually supplied to hospitals through a 99Mo/99mTc radionuclide generator system where it is produced from the β decay of the parent nuclide 99Mo (t½ = 66 h), which is produced in nuclear reactors via neutron fission. Recently, the interruption of the global supply chain of reactor-produced 99Mo, has forced the scientific community to investigate alternative production routes for 99mTc. One solution was to consider cyclotron-based methods as potential replacement of reactor-based technology and the nuclear reaction 100Mo(p,2n)99mTc emerged as the most worthwhile approach. This review reports some achievements about 99mTc produced by medical cyclotrons. In particular, the available technologies for target design, the most efficient extraction and separation procedure developed for the purification of 99mTc from the irradiated targets, the preparation of high purity 99mTc radiopharmaceuticals and the first clinical studies carried out with cyclotron produced 99mTc are described.

  14. Report of the Advisory Committee on Agriculturally Derived Fuels to the Texas Energy and Natural Resources Advisory Council

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Reagan V.; Clayton, Bill; Armstrong, Bob; Walton, Bill; Baen, Jr., Spencer; Carmichael, Jack; Cowley, Raymond; Quick, Joe; King, Carl; Harp, Elbert; Nelson, Bill; Wagoner, Ed; McDonald, Dr., Richard; Swanson, Stan

    1979-09-03

    For the purpose of the Committee, biomass was defined as the volume of living material or residues of living material (organic material) available in Texas for conversion into energy. Statistical reports from the Texas Agricultural Experiment Station and other sources indicate that in addition to surplus and distressed grains and certain other crops, there are roughly 27 million tons of agricultural residues currently being left in the fields or at the processing plants after harvest. The average annual residue from five crops - sorghum, corn, wheat, rice and cotton - is more than 20 million tons with a theoretical heat value of 270 trillion Btus. This represents 64 percent of the total energy input for Texas agriculture in 1973. Additionally, 4.1 million tons of dry manure is economically recoverable from Texas feedlots which could be converted into 14 trillion Btus of energy each year in the form of methane gas. Municipal solid waste, much of which is comprised of residues of living materials, currently amounts to about 13 million tons annually. The principal processes for converting the referenced resources into energy include: (1) direct combustion; (2) fermentation; (3) gasification/pyrolysis; (4) anaerobic digestion; and (5) petroculture - the production of certain non-traditional plants. Texas produces huge quantities of biomass, and has the potential of producing even more, which can be converted through various processes into significant quantities of usable energy to help meet the needs of the agricultural industry and the general public. Some of the technology required for the conversion processes is already sufficiently advanced to support immediate production and use while others will require additional research and development. The report discusses the current level of development of the relevant technologies.

  15. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Testing Activity, Frio Formation, Texas and Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    This Environmental Assessment (EA) has been prepared to provide the environmental input into the Division of Geothermal Energy's decisions to expand the geothermal well testing activities to include sites in the Frio Formation of Texas and Louisiana. It is proposed that drilling rigs be leased before they are removed from sites in the formation where drilling for gas or oil exploration has been unsuccessful and that the rigs be used to complete the drilling into the geopressured zone for resource exploration. This EA addresses, on a regional basis, the expected activities, affected environment, and the possible impacts in a broad sense as they apply to the Gulf Coast well testing activity of the Geothermal Energy Geopressure Subprogram of the Department of Energy. Along the Texas and Louisiana Gulf Coast (Plate 1 and Overlay, Atlas) water at high temperatures and high pressures is trapped within Gulf basin sediments. The water is confined within or below essentially impermeable shale sequences and carries most or all of the overburden pressure. Such zones are referred to as geopressured strata. These fluids and sediments are heated to abnormally high temperatures (up to 260 C) and may provide potential reservoirs for economical production of geothermal energy. The obvious need in resource development is to assess the resource. Ongoing studies to define large-sand-volume reservoirs will ultimately define optimum sites for drilling special large diameter wells to perform large volume flow production tests. in the interim, existing well tests need to be made to help define and assess the resource.

  16. The ion cyclotron turbulence generated by a low frequency kinetic Alfvén wave and turbulent heating of ions

    Science.gov (United States)

    Mikhailenko, V. S.; Mikhailenko, V. V.; Lee, Hae June

    2018-01-01

    The ion cyclotron instability driven by a strong kinetic Alfvén wave is investigated as a possible source of anisotropic heating of ions in the sun's corona. We present a novel model of a plasma with coupled inhomogeneous current and shearing flow, which results from the particle's motion in the electric field of the kinetic Alfvén wave of finite wavelength. The investigation is performed employing the non-modal kinetic theory grounded on the shearing mode approach. The solution of the governing linear integral equation for the perturbed potential displays that the flow velocity shear, which for the corona conditions may be above the growth rate of the ion cyclotron instability in the plasma with steady current, changes the exponential growth of the ion cyclotron potential on the power function of time, that impedes the growth of the unstable ion cyclotron wave and reduces the turbulent heating rate of ions across the magnetic field.

  17. Opening a Can of wERMS: Texas A&M University's Experiences in Implementing Two Electronic Resource Management Systems

    Science.gov (United States)

    Hartnett, Eric; Price, Apryl; Smith, Jane; Barrett, Michael

    2010-01-01

    Over the past few years, Texas A&M University (TAMU) has searched for a way to administer its electronic subscriptions as well as the electronic subscriptions shared among the TAMU System. In this article, we address our attempts to implement an effective electronic resource management system (ERMS), both for subscriptions on the main campus…

  18. Hydrological extremes and their agricultural impacts under a changing climate in Texas

    Science.gov (United States)

    Lee, K.; Gao, H.; Huang, M.; Sheffield, J.

    2015-12-01

    With the changing climate, hydrologic extremes (such as floods, droughts, and heat waves) are becoming more frequent and intensified. Such changes in extreme events are expected to affect agricultural production and food supplies. This study focuses on the State of Texas, which has the largest farm area and the highest value of livestock production in the U.S. The objectives are two-fold: First, to investigate the climatic impact on the occurrence of future hydrologic extreme events; and second, to evaluate the effects of the future extremes on agricultural production. The Variable Infiltration Capacity (VIC) model, which is calibrated and validated over Texas river basins during the historical period, is employed for this study. The VIC model is forced by the statistically downscaled climate projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5) model ensembles at a spatial resolution of 1/8°. The CMIP5 projections contain four different scenarios in terms of Representative Concentration Pathway (RCP) (i.e. 2.6, 4.5, 6.0 and 8.5 w/m2). To carry out the analysis, VIC outputs forced by the CMIP5 model scenarios over three 30-year periods (1970-1999, 2020-2049 and 2070-2099) are first evaluated to identify how the frequency and the extent of the extreme events will be altered in the ten Texas major river basins. The results suggest that a significant increase in the number of extreme events will occur starting in the first half of the 21st century in Texas. Then, the effects of the predicted hydrologic extreme events on the irrigation water demand are investigated. It is found that future changes in water demand vary by crop type and location, with an east-to-west gradient. The results are expected to contribute to future water management and planning in Texas.

  19. Community Energy Systems and the Law of Public Utilities. Volume Forty-five. Texas

    Energy Technology Data Exchange (ETDEWEB)

    Feurer, D.A.; Weaver, C.L.

    1981-01-01

    A detailed description is presented of the laws and programs of the State of Texas governing the regulation of public energy utilities, the siting of energy generating and transmission facilities, the municipal franchising of public energy utilities, and the prescription of rates to be charged by utilities including attendant problems of cost allocations, rate base and operating expense determinations, and rate of return allowances. These laws and programs are analyzed to identify impediments which they may present to the implementation of Integrated Community Energy Systems (ICES). This report is one of fifty-one separate volumes which describe such regulatory programs at the Federal level and in each state as background to the report entitled Community Energy Systems and the Law of Public Utilities - Volume One: An Overview. This report also contains a summary of a strategy described in Volume One - An Overview for overcoming these impediments by working within the existing regulatory framework and by making changes in the regulatory programs to enhance the likelihood of ICES implementation.

  20. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas

    Directory of Open Access Journals (Sweden)

    Evan J Kipp

    Full Text Available We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris and Texas mouse (Peromyscus attwateri at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR. A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States.

  1. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas.

    Science.gov (United States)

    Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth

    2016-10-01

    We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris) and Texas mouse (Peromyscus attwateri) at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR). A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States.

  2. A Hamiltonian theory for an elastic earth - Canonical variables and kinetic energy

    Science.gov (United States)

    Getino, Juan; Ferrandiz, Jose M.

    1990-09-01

    This paper describes the first part of a project dedicated to elaborating a Hamiltonian theory for the rotational motion of a deformable earth. Here only the perturbation due to the deformation of the elastic mantle by tidal body force is studied. Two canonical systems of variables are developed, known as elastic variables of Euler and Andoyer, respectively. Next, they are used to obtain the canonical expression of rotational kinetic energy, which is valid for any earth model satisfying hypotheses as general as those established here.

  3. A Detailed Study of the Variable Stars in Five Galactic Globular Clusters: IC4499, NGC4833, NGC6171 (M107), NGC6402 (M14), and NGC6584

    Science.gov (United States)

    Murphy, Brian W.; Darragh, Andrew; Hettinger, Paul; Hibshman, Adam; Johnson, Elliott W.; Liu, Z. J.; Pajkos, Michael A.; Stephenson, Hunter R.; Vondersaar, John R.; Conroy, Kyle E.; McCombs, Thayne A.; Reinhardt, Erik D.; Toddy, Joseph

    2015-08-01

    We present the results of an extensive study intended to search for and properly classify the variable stars in five galactic globular clusters. Each of the five clusters was observed hundreds to thousands of times over a time span ranging from 2 to 4 years using the SARA 0.6m located at Cerro Tololo Interamerican Observatory. The images were analyzed using the image subtract method of Alard (2000) to identify and produce light curves of all variables found in each cluster. In total we identified 373 variables with 140 of these being newly discovered increasing the number of known variables stars in these clusters by 60%. Of the total we have identified 312 RR Lyrae variables (187 RR0, 18 RR01, 99 RR1, 8 RR2), 9 SX Phe stars, 6 Cepheid variables, 11 eclipsing variables, and 35 long period variables. For IC4499 we identified 64 RR0, 18 RR01, 14 RR1, 4 RR2, 1 SX Phe, 1 eclipsing binary, and 2 long period variables. For NGC4833 we identified 10 RR0, 7 RR1, 2 RR2, 6 SX Phe, 5 eclipsing binaries, and 9 long period variables. For NGC6171 (M107) we identified 13 RR0, 7 RR1, and 1 SX Phe. For NGC6402 (M14) we identified 52 RR0, 56 RR1, 1 RR2, 1 SX Phe, 6 Cepheids, 1 eclipsing binary, and 15 long period variables. For NGC6584 we identified 48 RR0, 15 RR1, 1 RR2, 5 eclipsing binaries, and 9 long period variables. Using the RR Lyrae variables we found the mean V magnitude of the horizontal branch to be VHB = ⟨V ⟩RR = 17.63, 15.51, 15.72, 17.13, and 16.37 magnitudes for IC4499, NGC4833, NGC6171 (M107), NGC6402 (M14), and NGC6584, respectively. From our extensive data set we were able to obtain sufficient temporal and complete phase coverage of the RR Lyrae variables. This has allowed us not only to properly classify each of the RR Lyrae variables but also to use Fourier decomposition of the light curves to further analyze the properties of the variable stars and hence physical properties of each clusters. In this poster we will give the temperature, radius, stellar mass

  4. Factors influencing the choice of a career in food-animal practice among recent graduates and current students of Texas A&M University, College of Veterinary Medicine.

    Science.gov (United States)

    Lenarduzzi, Roland; Sheppard, Guy A; Slater, Margaret R

    2009-01-01

    Concerns about a shortage of large and mixed-animal veterinarians have been discussed in the profession. To better understand veterinary career choices among currently enrolled veterinary students (classes of 2007-2010) and recent graduate veterinarians in Texas (classes of 2002-2006), an online survey was developed. The objectives were to examine: (1) the respondents' backgrounds, demographic data, and experiences; (2) the respondents' working conditions and rural lifestyle considerations; (3) the respondents' perceptions of large/mixed-animal practice; and (4) the factors that have influenced respondents' career choices. The response rate was 37% (390/1,042). Overall, 72% of students and 55% of recent graduates were interested in large/mixed-animal practice. More than 70% of respondents indicated that veterinary practitioners had the strongest personal influence on career choices. Respondents who were no longer interested in large/mixed-animal practice, or who had never been interested, reported no experience with large animals (42% and 64%, respectively) as the most common reason for their lack of interest. Previous and current interest in large/mixed-animal practice were associated with working in a large/mixed-animal practice, any agricultural experience, and working for at least 6 months on a farm or ranch. Any 4-H experience increased the likelihood of previous interest, while being married decreased the likelihood of current interest. Student contact with practitioners (82%) and financial considerations (77%) were most commonly cited as factors that would make a career in large/mixed-animal practice more attractive. Rural lifestyle drawbacks influenced respondents' career choices. Many forms of agricultural experience may expose and encourage students to consider large/mixed-animal practice.

  5. Renewable Energy Opportunities at Fort Hood, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Solana, Amy E.; Warwick, William M.; Orrell, Alice C.; Russo, Bryan J.; Parker, Kyle R.; Weimar, Mark R.; Horner, Jacob A.; Manning, Anathea

    2011-11-14

    This report presents the results of Pacific Northwest National Laboratory's (PNNL) follow-on renewable energy (RE) assessment of Fort Hood. Fort Hood receives many solicitations from renewable energy vendors who are interested in doing projects on site. Based on specific requests from Fort Hood staff so they can better understand these proposals, and the results of PNNL's 2008 RE assessment of Fort Hood, the following resources were examined in this assessment: (1) Municipal solid waste (MSW) for waste-to-energy (WTE); (2) Wind; (3) Landfill gas; (4) Solar photovoltaics (PV); and (5) Shale gas. This report also examines the regulatory issues, development options, and environmental impacts for the promising RE resources, and includes a review of the RE market in Texas.

  6. Texas M-E flexible pavement design system: literature review and proposed framework.

    Science.gov (United States)

    2012-04-01

    Recent developments over last several decades have offered an opportunity for more rational and rigorous pavement design procedures. Substantial work has already been completed in Texas, nationally, and internationally, in all aspects of modeling, ma...

  7. A gain and bandwidth enhanced transimpedance preamplifier for Fourier-transform ion cyclotron resonance mass spectrometry

    Science.gov (United States)

    Lin, Tzu-Yung; Green, Roger J.; O'Connor, Peter B.

    2011-01-01

    The nature of the ion signal from a 12-T Fourier-transform ion cyclotron resonance mass spectrometer and the electronic noise were studied to further understand the electronic detection limit. At minimal cost, a new transimpedance preamplifier was designed, computer simulated, built, and tested. The preamplifier design pushes the electronic signal-to-noise performance at room temperature to the limit, because of its enhanced tolerance of the capacitance of the detection device, lower intrinsic noise, and larger flat mid-band gain (input current noise spectral density of around 1 pA/\\documentclass[12pt]{minimal}\\begin{document}$\\sqrt{\\mbox{Hz}}$\\end{document}Hz when the transimpedance is about 85 dBΩ). The designed preamplifier has a bandwidth of ∼3 kHz to 10 MHz, which corresponds to the mass-to-charge ratio, m/z, of approximately 18 to 61 k at 12 T. The transimpedance and the bandwidth can be easily adjusted by changing the value of passive components. The feedback limitation of the circuit is discussed. With the maximum possible transimpedance of 5.3 MΩ when using an 0402 surface mount resistor, the preamplifier was estimated to be able to detect ∼110 charges in a single scan. PMID:22225232

  8. A new way to measure the electron cyclotron frequency

    Science.gov (United States)

    Palmer, F. L.

    1993-03-01

    A method is described for using spin flips to measure the 0 to 1 cyclotron transition frequency of a single electron in a Penning trap. Detection can be accomplished with magnetic bottles of 10 T/m2 or less, thereby greatly reducing the thermal broadening of the cyclotron line. This method complements a recently published technique for measuring the anomaly frequency, making a more precise measurement of the electron anomaly ratio possible.

  9. Southwest Regional Clean Energy Incubation Initiative (SRCEII)

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Michael [Univ. of Texas, Austin, TX (United States)

    2017-10-31

    The Austin Technology Incubator’s (ATI’s) Clean Energy Incubator at the University of Texas at Austin (ATI-CEI) utilized the National Incubator Initiative for Clean Energy (NIICE) funding to establish the Southwest Regional Clean Energy Incubation Initiative, composed of clean energy incubators from The University of Texas at Austin (UT-Austin), The University of Texas at El Paso (UTEP), The University of Texas at San Antonio (UTSA), and Texas A&M University (TAMU).

  10. Physical trajectory profile data from glider Stommel deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Gulf of Mexico from 2017-01-20 to 2017-05-07 (NCEI Accession 0162538)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monitoring the baseline water quality across the Texas shelf. The National Centers for Environmental Information (NCEI) received the data in this archival package...

  11. Physical trajectory profile data from glider Stommel deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Gulf of Mexico from 2017-06-27 to 2017-07-05 (NCEI Accession 0164085)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monitoring the baseline water quality across the Texas shelf. The National Centers for Environmental Information (NCEI) received the data in this archival package...

  12. Variable Renewable Energy: a Regulatory Roadmap (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-10-01

    There is not a one-size-fits-all approach to the regulation of variable renewable energy (VRE), but international experience reveals many approaches that are proving successful. Drawing upon research and experiences from various international contexts, the 21st Century Power Partnership in conjunction with the Clean Energy Solutions Center and Clean Energy Regulators Initiative identified key issues and ideas that have emerged as variable deployment has grown. The Power Partnership research, published in 2014, identified four broad categories of regulatory issues.

  13. Filling and Recycling Apparatus of a Cyclotron Target with Enriched Krypton for Production of Radiopharmaceuticals

    Directory of Open Access Journals (Sweden)

    M. Vognar

    2001-01-01

    Full Text Available An apparatus for multiple filling of a cyclotron target with enriched Kr gas is described. The system is based on recycling pressurized gas by cryogenic pumping between the target tube and storage containers. The design and construction makes use of previous experience in the construction and operation of two analogue apparatuses for Xe124 high pressure gas targets, but major modifications have been incorporated, evoked by the different physical properties of Kr, by the character of the nuclear reaction, and by the demand for automation from the side of the end user.

  14. Operation of a quasioptical electron cyclotron maser

    Energy Technology Data Exchange (ETDEWEB)

    Morse, E.C.; Pyle, R.V.

    1984-12-01

    The electron cyclotron maser or gyrotron concept has been developed to produce sources producing 200 kW at 28 GHz continuously, and higher power outputs and frequencies in pulsed mode. These sources have been useful in electron cyclotron resonance heating (ECRH) in magnetically confined fusion devices. However, higher frequencies and higher power levels will be required in reactor-grade fusion plasmas, with likely requirements of 1.0 MW or more per source at 140 GHz. Conventional gyrotrons follow a trend of decreasing power for increasing frequency. In order to circumvent this problem, the quasioptical electron cyclotron maser was proposed. In this device, the closed resonator of the conventional gyrotron is replaced with an open, Fabry-Perot type resonator. The cavity modes are then the TEM-type modes of an optical laser. The advantage of this configuration is that the cavity size is not a function of frequency, since the length can be any half-integer number of wavelengths. Furthermore, the beam traverses across the cavity transverse to the direction of radiation output, and thus the rf window design is less complicated than in conventional tubes. The rf output, if obtained by diffraction coupling around one of the mirrors, could be in a TEM mode, which would allow for quasioptical transmission of the microwaves into the plasma in fusion devices. 4 references, 1 figure.

  15. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron.

    Science.gov (United States)

    Hojo, S; Katagiri, K; Nakao, M; Sugiura, A; Muramatsu, M; Noda, A; Okada, T; Takahashi, Y; Komiyama, A; Honma, T; Noda, K

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C(4+) ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C(4+), for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

  16. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron

    Science.gov (United States)

    Hojo, S.; Katagiri, K.; Nakao, M.; Sugiura, A.; Muramatsu, M.; Noda, A.; Okada, T.; Takahashi, Y.; Komiyama, A.; Honma, T.; Noda, K.

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C4+ ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C4+, for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

  17. A simple thick target for production of 89Zr using an 11MeV cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Link, Jeanne M.; Krohn, Kenneth A.; O' Hara, Matthew J.

    2017-04-01

    The growing interest but limited availability of 89Zr for PET led us to test targets for the 89(p,n) reaction. The goal was an easily constructed target for an 11 MeV Siements cyclotron. Yttrium foils were tested at different thicknesses, angles and currents. A 90 degree foil tolerated 41 microAmp without damage and produced ~800 MBq/hr, >20 mCi, an amount adequate for radiochemistry research and human doses in a widely available accelerator. This method should translate to higher energy cyclotrons.

  18. Proceedings of second geopressured geothermal energy conference, Austin, Texas, February 23--25, 1976. Volume V. Legal, institutional, and environmental

    Energy Technology Data Exchange (ETDEWEB)

    Vanston, J.H.; Elmer, D.B.; Gustavson, T.C.; Kreitler, C.W.; Letlow, K.; Lopreato, S.C.; Meriwether, M.; Ramsey, P.; Rogers, K.E.; Williamson, J.K.

    1976-01-01

    Three separate abstracts were prepared for Volume V of the Proceedings of the Conference. Sections are entitled: Legal Issues in the Development of Geopressured--Geothermal Resources of Texas and Louisiana Gulf Coast; The Development of Geothermal Energy in the Gulf Coast; Socio-economic, Demographic, and Political Considerations; and Geothermal Resources of the Texas Gulf Coast--Environmental Concerns arising from the Production and Disposal of Geothermal waters. (MCW)

  19. Influence of injection beam emittance on beam transmission efficiency in a cyclotron.

    Science.gov (United States)

    Kurashima, Satoshi; Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Yoshida, Ken-Ichi; Okumura, Susumu

    2014-02-01

    The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10(-9)-10(-6) ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a (12)C(5+) beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased.

  20. E1 and M1 strength functions at low energy

    Science.gov (United States)

    Schwengner, Ronald; Massarczyk, Ralph; Bemmerer, Daniel; Beyer, Roland; Junghans, Arnd R.; Kögler, Toni; Rusev, Gencho; Tonchev, Anton P.; Tornow, Werner; Wagner, Andreas

    2017-09-01

    We report photon-scattering experiments using bremsstrahlung at the γELBE facility of Helmholtz-Zentrum Dresden-Rossendorf and using quasi-monoenergetic, polarized γ beams at the HIγS facility of the Triangle Universities Nuclear Laboratory in Durham. To deduce the photoabsorption cross sections at high excitation energy and high level density, unresolved strength in the quasicontinuum of nuclear states has been taken into account. In the analysis of the spectra measured by using bremsstrahlung at γELBE, we perform simulations of statistical γ-ray cascades using the code γDEX to estimate intensities of inelastic transitions to low-lying excited states. Simulated average branching ratios are compared with model-independent branching ratios obtained from spectra measured by using monoenergetic γ beams at HIγS. E1 strength in the energy region of the pygmy dipole resonance is discussed in nuclei around mass 90 and in xenon isotopes. M1 strength in the region of the spin-flip resonance is also considered for xenon isotopes. The dipole strength function of 74Ge deduced from γELBE experiments is compared with the one obtained from experiments at the Oslo Cyclotron Laboratory. The low-energy upbend seen in the Oslo data is interpreted as M1 strength on the basis of shell-model calculations.

  1. Cyclotron Production of (99m)Tc using (100)Mo2C targets.

    Science.gov (United States)

    Richards, Vernal N; Mebrahtu, Efrem; Lapi, Suzanne E

    2013-10-01

    An investigative study of the (100)Mo (p,2n)(99m)Tc reaction on a medical cyclotron using (100)Mo2C is reported. This is the first report of this compound being used as a target for this reaction. (100)Mo2C, a refractory carbide with high thermal conductivity, properties which underscore its use on a cyclotron, was synthesized using (100)MoO3. Its ease of oxidation back to (100)MoO3 under air at elevated temperatures facilitates the use of thermo-chromatography, a high temperature gas phase separation technique for the separation and isolation of (99m)Tc. Activity yields for (99m)Tc averaged 84% of the calculated theoretical yields. Additionally, the percent recovery of MoO3, the precursor for Mo2C, was consistently high at 85% ensuring a good life cycle for this target material. The produced (99m)Tc was radio-chemically pure and easily labeled MDP for imaging purposes. © 2013.

  2. Cultural resources survey and assessment of the proposed Department of Energy Freeport to Texas City pipeline, Brazoria and Galveston Counties, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Castille, G.J.; Whelan, J.P. Jr.

    1986-01-01

    An intensive survey and testing program of selected segments of a proposed Department of Energy pipeline were conducted by Coastal Environments, Inc., Baton Rouge, Louisiana, during December 1985 and January 1986. The proposed pipeline runs from Texas City, Galveston County to Bryan Mound, Brazoria County. The pedestrian survey was preceded by historical records survey to locate possible historic sites within the DOE righ-of-way. Four prehistoric sites within the ROW (41BO159, 160, 161, 162) and one outside the ROW (41BO163) were located. All are Rangia cuneata middens. The survey results are discussed with particular reference to the environmental settings of the sites and the effectiveness of the survey procedure. Two of the sites located within the ROW were subjected to additional testing. The results of the backhoe testing program are included in the site descriptions, and the scientific value of the sites are presented. 52 refs., 20 figs., 10 tabs.

  3. A mobile system for quantifying the spatial variability of the surface energy balance: design and application

    Science.gov (United States)

    Wohlfahrt, Georg; Tasser, Erich

    2015-05-01

    We present a mobile device for the quantification of the small-scale (a few square meters) spatial variability in the surface energy balance components and several auxiliary variables of short-statured (wind speed, soil temperature and soil water content. Data are acquired by a battery-powered data logger, which is mounted on a backpack together with the auxiliary sensors. The proposed device was developed to bridge between the spatial scales of satellite/airborne remote sensing and fixed, stationary tower-based measurements with an emphasis on micrometeorological, catchment hydrological and landscape-ecological research questions. The potential of the new device is demonstrated through four selected case studies, which cover the issues of net radiation heterogeneity within the footprint of eddy covariance flux measurements due to (1) land use and (2) slope and aspect of the underlying surface, (3) controls on landscape-scale variability in soil temperature and albedo and (4) the estimation of evapotranspiration based exclusively on measurements with the mobile device.

  4. Trapping, detection, and mass measurement of individual ions in a Fourier transform ion cyclotron resonance mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, J.E.; Cheng, X.; Bakhtiar, R.; Wu, Q.; Hofstadler, S.A.; Anderson, G.A.; Smith, R.D. [Pacific Northwest Lab., Richland, WA (United States)

    1994-08-24

    A fourier transform ion cyclotron resonance (FTICR) mass spectrometer has been used to trap individual multiply charged ions of several high molecular weight polymers, including poly(ethylene oxide), sodium poly(styrene sulfonate), and the protein bovine serum albumin. Detection of these ions is performed with the nondestructive method distinctive of FTICR, which also allows remeasurement of the same ion or ion population over several hours. For the determination of the charge states (and hence the masses) of individual ions, a new scheme was developed on the basis of the observation of the stepwise m/z shifts that results from charge exchange reactions or adduction of a substance of known mass. A novel technique for mass determination of individual ions has been made possible with the observation of cyclotron frequency shifts during the time-domain acquisition period. This time-resolved ion correlation (TRIC) technique allows reactant and product ions to be correlated with confidence and provides the basis for simultaneously studying a moderate number of ions. In this work, a range of observations related to the detection and measurement of individual ions is presented, as are examples of mass determinations of individual ions performed by utilizing the TRIC technique. 47 refs., 9 figs., 2 tabs.

  5. Direct utilization of geothermal energy for space and water heating at Marlin, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conover, M.F.; Green, T.F.; Keeney, R.C.; Ellis, P.F. II; Davis, R.J.; Wallace, R.C.; Blood, F.B.

    1983-05-01

    The Torbett-Hutchings-Smith Memorial Hospital geothermal heating project, which is one of nineteen direct-use geothermal projects funded principally by DOE, is documented. The five-year project encompassed a broad range of technical, institutional, and economic activities including: resource and environmental assessments; well drilling and completion; system design, construction, and monitoring; economic analyses; public awareness programs; materials testing; and environmental monitoring. Some of the project conclusions are that: (1) the 155/sup 0/F Central Texas geothermal resource can support additional geothermal development; (2) private-sector economic incentives currently exist, especially for profit-making organizations, to develop and use this geothermal resource; (3) potential uses for this geothermal resource include water and space heating, poultry dressing, natural cheese making, fruit and vegetable dehydrating, soft-drink bottling, synthetic-rubber manufacturing, and furniture manufacturing; (4) high maintenance costs arising from the geofluid's scaling and corrosion tendencies can be avoided through proper analysis and design; (5) a production system which uses a variable-frequency drive system to control production rate is an attractive means of conserving parasitic pumping power, controlling production rate to match heating demand, conserving the geothermal resource, and minimizing environmental impacts.

  6. EURAC: A liquid target neutron spallation source using cyclotron technology

    Science.gov (United States)

    Perlado, J. M.; Mínguez, E.; Sanz, J.; Piera, M.

    1995-09-01

    Euratom/JRC Ispra led some years ago the design of an accelerator based neutron spallation source EURAC, with special emphasis as a fusion material testing device. DENIM was involved in the development of the last version of this source. EURAC proposes to use a beam of 600 MeV or 1.5 GeV protons, produced by an effective and low cost ring cyclotron with a current of 6 mA impinging in a liquid lead, or lead-bismuth, target. It will use an advanced cyclotron technology which can be implemented in the next future, in the line of the actual technology of the upgraded SIN-type cyclotron. The adjacent rows to the target correspond to the lead, or Li17Pb83, cooled channels where the samples will be located. The available volumes there were shown enough for material testing purposes. Here, proposal of using those experimental areas to introduce small masses of radioactive wastes for testing of transmutation in spallation source is made. In addition, extrapolation of present conceptual design to make available larger volumes under flexible conditions seems to be possible. Neutrons leaking from the test zone drive a subcritical booster (hidrogen moderator in the center.

  7. Medium to large scale radioisotope production for targeted radiotherapy using a small PET cyclotron

    DEFF Research Database (Denmark)

    Thisgaard, Helge; Jensen, Mikael; Elema, Dennis Ringkjøbing

    2011-01-01

    In recent years the use of radionuclides in targeted cancer therapy has increased. In this study we have developed a high-current solid target system and demonstrated that by the use of a typical low-energy medical cyclotron, it is possible to produce tens of GBq's of many unconventional radionuc......In recent years the use of radionuclides in targeted cancer therapy has increased. In this study we have developed a high-current solid target system and demonstrated that by the use of a typical low-energy medical cyclotron, it is possible to produce tens of GBq's of many unconventional...

  8. Unidirectional stripping extraction from a cyclotron which accelerates light as well as heavy ions

    Directory of Open Access Journals (Sweden)

    Jasna L. Ristić-Djurović

    2003-03-01

    Full Text Available The VINCY Cyclotron (VINča CYclotron is a multipurpose machine intended to accelerate light as well as heavy ions. To extract heavy ions with low energy and light ions an extraction system with stripping foil is used. Heavy ions with high energy will be extracted by means of an electrostatic deflector. The former extraction system will be manufactured and used first. The proposed unidirectional stripping extraction system is the optimal balance between the placement of the extraction line and the required diversity and quality of the extracted beam. The available range of extraction directions is set by geometry limitations.

  9. A Border vs. Nonborder Comparison of Food Environment, Poverty, and Ethnic Composition in Texas Urban Settings

    Directory of Open Access Journals (Sweden)

    Jennifer J Salilnas

    2015-04-01

    Full Text Available Purpose: The goal was to examine the relationship between the food environment and selected socioeconomic variables and ethnic/racial makeup in the eight largest urban settings in Texas so as to gain a better understanding of the relationships among Hispanic composition, poverty and urban foodscapes, comparing border to non-border urban environments. Methods: Census-tract level data on (a socioeconomic factors, like percentage below the poverty line and number of households on foodstamps, and (b ethnic variables, like percent of Mexican origin and percent foreign born, were obtained from the U.S. Census. Data at the census-tract level on the total number of healthy (e.g., supermarkets and less-healthy (e.g., fast food outlets food retailers were acquired from the CDC’s Modified Retail Food Environment Index (mRFEI. Variation among urban settings in terms of the relationship between mRFEI scores and socioeconomic and ethnic context was tested using a mixed-effect model, and linear regression was used to identify significant factors for each urban location. A jackknife variance estimate was used to account for clustering and autocorrelation of adjacent census tracts.Results: Average census-tract mRFEI scores exhibited comparatively small variation across Texas urban settings, while socioeconomic and ethnic factors varied significantly. The only covariates significantly associated with mRFEI score were percent foreign born and percent Mexican origin. Compared to the highest-population county (Harris, which incorporates most of Houston, the only counties that had significantly different mRFEI scores were Bexar, which is analogous to San Antonio (2.12 lower, El Paso (2.79 higher, and Neuces, which encompasses Corpus Christi (2.90 less. Significant interaction effects between mRFEI and percent foreign born (El Paso, Tarrant – Fort Worth, Travis – Austin, percent Mexican origin (Hidalgo – McAllen, El Paso, Tarrant, Travis, and percent living

  10. Converting an AEG Cyclotron to H- Acceleration and Extraction

    Science.gov (United States)

    Ramsey, Fred; Carroll, Lewis; Rathmann, Tom; Huenges, Ernst; Bechtold, Matthias Mentler Volker

    2009-03-01

    Clinical Trials are under way to evaluate agents labeled with the nuclide 225Ac and its decay product 213Bi, in targeted alpha-immuno-therapy [1]. 225Ac can be produced on a medium-energy cyclotron via the nuclear reaction 226Ra(p,n)225Ac. To demonstrate proof-of-principle, a vintage AEG cyclotron, Model E33 [2], with an internal target, had been employed in a pilot production program at the Technical University of Munich (TUM). To enhance production capability and further support the clinical studies, the TUM facility has recently been refurbished and upgraded, adding a new external beam-line, automated target irradiation and transport systems, new laboratories, hot cells, etc. [3]. An improved high-power rotating target has been built and installed [4]. The AEG cyclotron itself has also been modified and upgraded to accelerate and extract H- ions. We have designed, built, and tested a new axial Penning-type ion source which is optimized for the production of H- ions. The ion source has continued to evolve through experiment and experience. Steady improvements in materials and mechanics have led to enhanced source stability, life-time, and H- production. We have also designed and built a precision H- charge-exchange beam-extraction system which is equipped with a vacuum lock. To fit within the tight mechanical constraint imposed by the narrow magnet gap, the system incorporates a novel chain-drive foil holder and foil-changer mechanism. The reconfigured cyclotron system has now been in operation for more than 1 year. Three long-duration target irradiations have been conducted. The most recent bombardment ran 160 continuous hours at a beam on target of ˜80 microamperes for a total yield of ˜70 milli-curies of 225Ac.

  11. Powering Ahead 2010. An outlook for renewable energy M and A

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-05-15

    This report is KPMG's annual review of M and A (mergers and acquisitions) activity within the renewable energy sector; it takes a look at the changes and trends in the sector to provide insight on where the market is heading.

  12. Direct Technetium radiopharmaceuticals production using a 30MeV Cyclotron

    Science.gov (United States)

    Jalilian, AR.; Targholizadeh, H.; Raisali, GR.; Zandi, H.; Kamali Dehgan, M.

    2011-01-01

    Background and the purpose of the study Technetium-99m is the major radionuclide used in the world and mainly is provided by fission product. However extensive research has been conducted on the use of accelerators for production of 99mTc. This investigation reports the production of 99mTc radioisotope using cyclotrons and the preparation, quality control and biodistribution studies of four major Tc-radiopharmaceuticals. Methods The high purity molybdenum natural target (130 mg/cm2) was irradiated in a Cyclone 30 accelerator using 160 µA of 25 MeV proton beam energy for 1000 µA-h. After dissolution, the technetium radionuclides were extracted using methyl ethyl ketone (MEK) followed by preparation of Tc-MIBI, Tc-DTPA, Tc-DMSA and Tc-phytate as radiopharmaceutical samples. Results The results of quality controls and animal biodistribution studies showed successful production of Tc radionuclides (including 99mTc) in the bombarded target and subsequent labelling of the kit with Tc. Conclusion The developed high power Mo target if constructed using enriched 100Mo, could be a practical method for large-scale production of 99mTc and promising as an alternative to fission product 99Mo-99mTc generators for local applications near cyclotron facilities. PMID:22615656

  13. Direct Technetium radiopharmaceuticals production using a 30MeV Cyclotron

    Directory of Open Access Journals (Sweden)

    M Kamali Dehgan

    2011-07-01

    Full Text Available Background and purpose of the study: Technetium-99m is the major radionuclide used in the world and mainly is provided by fission product. However extensive research has been conducted on the use of accelerators for production of 99mTc. This investigation reports the production of 99mTc radioisotope using cyclotrons followed by the preparation, quality control and biodistribution studies of four major Tc-radiopharmaceuticals. Methods: The high purity molybdenum natural target (130mg/cm2 was irradiated in a Cyclone 30 accelerator using 160 µA of 25 MeV proton beam energy for 1000 µA-h. After dissolution, the technetium radionuclides were extracted using methyl ethyl ketone (MEK followed by preparation of Tc-MIBI, Tc-DTPA, Tc-DMSA and Tc-phytate as radiopharmaceutical samples. Results: The results of quality controls and animal biodistribution studies showed successful production of Tc radionuclides (including 99mTc in the bombarded target and subsequent labelling of the kit with Tc. Conclusion: The developed high power Mo target if constructed using enriched 100Mo, could be a practical method for large-scale production of 99mTc and promising as an alternative to fission product 99Mo-99mTc generators for local applications near cyclotron facilities.

  14. Theoretical and experimental study of cyclotronic waves in a fusion plasma; Etude theorique et experimentale des ondes cyclotroniques electroniques dans un plasma de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Vezard, D.

    1994-12-20

    This thesis presents a study concerning cyclotronic waves in a plasma. It starts with an illustration of the elementary interaction between electromagnetic waves and matter.It shows that electrons from tokamak absorbs waves at cyclotronic frequency. Cyclotronic waves are studied by solving the dispersion relation in plasma; it concerns polarisation, absorption, dispersion, extinction. Then, classical theories are reminded in order to speak about decoupled electrons and their interactions. Absorption and emission properties of cyclotronic waves by electrons from a queue are described. After that, cyclotronic waves propagation is studied taking into account resonance. The last part of this thesis is dedicated to the electronic distribution function that is made by a wave spectra at a inferior hybrid frequency. (TEC). 129 refs., 75 figs.

  15. Neutron field inside a PET Cyclotron vault room

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [UAZ, C. Cipres 10, 98068 Zacatecas (Mexico); Mendez, R. [CIEMAT, Ave. Complutense 22, 28040 Madrid (Spain); Iniguez, M.P. [Universidad de Valladolid, Po Prado de la Magdalena s/n, 47011 Valladolid (Spain); Climent, J.M.; Penuelas, I. [Servicio de Medicina Nuclear de la Clinica Universitaria de Navarra, Pamplona (Spain); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain)]. e-mail: fermineutron@yahoo.com

    2006-07-01

    The neutron field around a Positron Emission Tomography cyclotron was investigated during {sup 18} F radioisotope production with an 18 MeV proton beam. In this study the Ion Beam Application cyclotron, model Cyclone 18/9, was utilized. Measurements were carried out with a Bonner sphere neutron spectrometer with pairs of thermoluminescent dosemeters (TLD600 and TLD700) as thermal neutron detector. The TLDs readouts were utilized to unfold the neutron spectra at three different positions inside the cyclotron's vault room. With the spectra the Ambient dose equivalent was calculated. Neutron spectra unfolding were performed with the BUNKIUT code and the UTA4 response matrix. Neutron spectra were also determined by Monte Carlo calculations using a detailed model of cyclotron and vault room. (Author)

  16. The DarkSide-50 Experiment: Electron Recoil Calibrations and A Global Energy Variable

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, Brianne Rae [Hawaii U.

    2017-01-01

    Over the course of decades, there has been mounting astronomical evidence for non-baryonic dark matter, yet its precise nature remains elusive. A favored candidate for dark matter is the Weakly Interacting Massive Particle (WIMP) which arises naturally out of extensions to the Standard Model. WIMPs are expected to occasionally interact with particles of normal matter through nuclear recoils. DarkSide-50 aims to detect this type of particle through the use of a two-phase liquid argon time projection chamber. To make a claim of discovery, an accurate understanding of the background and WIMP search region is imperative. Knowledge of the backgrounds is done through extensive studies of DarkSide-50's response to electron and nuclear recoils. The CALibration Insertion System (CALIS) was designed and built for the purpose of introduc- ing radioactive sources into or near the detector in a joint eort between Fermi National Laboratory (FNAL) and the University of Hawai'i at Manoa. This work describes the testing, installation, and commissioning of CALIS at the Laboratori Nazionali del Gran Sasso. CALIS has been used in mul- tiple calibration campaigns with both neutron and sources. In this work, DarkSide-50's response to electron recoils, which are important for background estimations, was studied through the use of calibration sources by constructing a global energy variable which takes into account the anti- correlation between scintillation and ionization signals produced by interactions in the liquid argon. Accurately reconstructing the event energy correlates directly with quantitatively understanding the WIMP sensitivity in DarkSide-50. This work also validates the theoretically predicted decay spectrum of 39Ar against 39Ar decay data collected in the early days of DarkSide-50 while it was lled with atmospheric argon; a validation of this type is not readily found in the literature. Finally, we show how well the constructed energy variable can predict

  17. Complete excavation and mapping of a Texas leafcutting ant nest

    Science.gov (United States)

    John C. Moser

    2006-01-01

    A medium-sized nest of the Texas leafcutting ant, Atta texana (Buckley), in northern Louisiana was excavated completely, and a three-dimensional model of its external and subterranean features was constructed. In total, 97 fungus gardens, 27 dormancy cavities, and 45 detritus cavities were located. At the lower center of the funnel-shaped nest was a...

  18. Effective Discharge Calculation Methods and Variability: Application to the Trinity and Brazos Rivers, Texas

    Science.gov (United States)

    Hosseiny, H.; Strom, K.

    2014-12-01

    Effective discharge calculations are based on continuous recordings of daily discharge, cross-sectional stream properties, and measured or calculated sediment transport rates. This study investigates how different flow frequency analysis and varying amounts of collected on-site cross sectional and sediment data impact the final calculated effective discharge. The analysis is carried out for six river stations on the lower Brazos River and four stations on the middle Trinity River in the state of Texas, USA. Data obtained at each site includes mean daily flow discharge, measured suspended sediment concentration over a range of flow conditions, bed sediment samples and cross sectional geometry. Bed load rating curves are developed based on bed sediment samples and the Einstein-Brown formula. The flow frequency analysis is carried out using (1) equal arithmetic intervals with bin numbers of 25, 50 and 100, and (2) the kernel density estimate method. To answer the question of what kind of on-site measured data is essential for calculating the effective discharge, 4 scenarios using different combinations of measured and unmeasured data are defined. At one end of the scenario spectrum, all measured data is used. At the other end, the only on-site data used is the bed material grain size distribution. Results show that if a smoothed sediment load histogram is used, then the effective discharge is not sensitive to the flow frequency analysis method or to the varying levels of on-site data used in the analysis. The outcome of this is that on the Trinity and Brazos rivers, effective discharge can be adequately calculated using only the bed material size information, USGS daily flow data, and the top width of the river obtained from Google Earth. Comparing the calculated effective discharge to other flow metrics showed that the effective discharge on the Trinity is significantly smaller than the bankfull discharge. Effective discharge on the Trinity ranges between 15000 to

  19. Variability and minimum detectable change for walking energy efficiency variables in children with cerebral palsy.

    Science.gov (United States)

    Thomas, Susan Sienko; Buckon, Cathleen E; Schwartz, Michael H; Russman, Barry S; Sussman, Michael D; Aiona, Michael D

    2009-08-01

    For individuals with neuromuscular disorders, the assessment of walking energy efficiency is useful as a clinical outcome measure. Issues surrounding data collection methodology, normalization of the data, and variability and clinical utility of energy efficiency data preclude universal application. This study examined the variability and the clinical utility of velocity, energy efficiency index (EEI), gross cost, and net nondimensional cost (NNcost) in children and adolescents with spastic diplegic cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels I to III. The energy efficiency of walking was evaluated in 23 children and adolescents (12 males, 11 females, mean age 11y 3mo [SD 3y 5mo]; range 7-17y). Day-to-day variability was similar for all energy efficiency variables, with no significant differences in magnitude of variability between GMFCS levels. Correlations between EEI and gross cost and EEI and NNcost were fairly good (r=0.65, penergy used to ambulate.

  20. Investigations of proton beam energy of the MC-50 cyclotron at KIRAMS

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Kim, Guinyun; Kim, Kwangsoo; Bin Abu Kassim, Hasan; Nikouravan, Bijan

    2011-07-01

    The accuracy of the measured excitation functions of nuclear reactions largely depend on the precise measurements of the exposed beam energy in activation experiment. We investigated the proton beam energy of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) employing the method natCu(p,xn)62Zn / natCu(p,xn)65Zn together with a stacked-foil activation technique. The beam energy along with the stacked samples was also theoretically calculated using computer program SRIM-2003. The measured beam energy showed generally a good agreement with the calculated ones, and this fact demonstrated that the energy (<30 MeV) of the proton beam could be determined by irradiating thin metallic Cu foil target with natural isotopic compositions. Hence, this may be considered as a useful technique for beam monitoring purposes in activation experiment.

  1. The cyclotron laboratory and the RFQ accelerator in Bern

    Science.gov (United States)

    Braccini, S.; Ereditato, A.; Kreslo, I.; Nirkko, M.; Scampoli, P.; von Bremen, K.; Weber, M.

    2013-07-01

    Two proton accelerators have been recently put in operation in Bern: an 18 MeV cyclotron and a 2 MeV RFQ linac. The commercial IBA 18/18 cyclotron, equipped with a specifically conceived 6 m long external beam line ending in a separate bunker, will provide beams for routine 18-F and other PET radioisotope production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building hosting two physics laboratories and four Good Manufacturing Practice (GMP) laboratories. This project is the result of a successful collaboration between the Inselspital, the University of Bern and private investors, aiming at the constitution of a combined medical and research centre able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. The cyclotron is complemented by the RFQ with the primary goals of elemental analysis via Particle Induced Gamma Emission (PIGE), and the detection of potentially dangerous materials with high nitrogen content using the Gamma-Resonant Nuclear Absorption (GRNA) technique. In this context, beam instrumentation devices have been developed, in particular an innovative beam profile monitor based on doped silica fibres and a setup for emittance measurements using the pepper-pot technique. On this basis, the establishment of a proton therapy centre on the campus of the Inselspital is in the phase of advanced study.

  2. The cyclotron laboratory and the RFQ accelerator in Bern

    Energy Technology Data Exchange (ETDEWEB)

    Braccini, S.; Ereditato, A.; Kreslo, I.; Nirkko, M.; Weber, M. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Scampoli, P. [Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland and Department of Physical Sciences, University Federico II, Via Cintia, I-60126 Napoli (Italy); Bremen, K. von [SWAN Isotopen AG, Inselspital, CH-3010 Bern (Switzerland)

    2013-07-18

    Two proton accelerators have been recently put in operation in Bern: an 18 MeV cyclotron and a 2 MeV RFQ linac. The commercial IBA 18/18 cyclotron, equipped with a specifically conceived 6 m long external beam line ending in a separate bunker, will provide beams for routine 18-F and other PET radioisotope production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building hosting two physics laboratories and four Good Manufacturing Practice (GMP) laboratories. This project is the result of a successful collaboration between the Inselspital, the University of Bern and private investors, aiming at the constitution of a combined medical and research centre able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. The cyclotron is complemented by the RFQ with the primary goals of elemental analysis via Particle Induced Gamma Emission (PIGE), and the detection of potentially dangerous materials with high nitrogen content using the Gamma-Resonant Nuclear Absorption (GRNA) technique. In this context, beam instrumentation devices have been developed, in particular an innovative beam profile monitor based on doped silica fibres and a setup for emittance measurements using the pepper-pot technique. On this basis, the establishment of a proton therapy centre on the campus of the Inselspital is in the phase of advanced study.

  3. A remotely steered millimetre wave launcher for electron cyclotron heating and current drive on ITER

    NARCIS (Netherlands)

    Bongers, W. A.; M. F. Graswinckel,; Goede, A. P. H.; Kasparek, W.; Danilov, I.; Curto, A. F.; M.R. de Baar,; van den Berg, M. A.; Donne, A. J. H.; Elzendoorn, B. S. Q.; Heidinger, R.; Ivanov, P.; Kruijt, O. G.; Lamers, B.; Meier, A.; Piosczyk, B.; Plaum, B.; Ronden, D. M. S.; Thoen, D. J.; Schmid, M.; Verhoeven, A. G. A.

    2010-01-01

    High-power millimetre wave beams employed on ITER for heating and Current drive at the 170 GHz electron cyclotron resonance frequency require agile steering and tight focusing of the beams to suppress neoclassical tearing modes. This paper presents experimental validation of the remote steering (RS)

  4. Discovery and modelling of a flattening of the positive cyclotron line/luminosity relation in GX 304-1 with RXTE

    Science.gov (United States)

    Rothschild, Richard E.; Kühnel, Matthias; Pottschmidt, Katja; Hemphill, Paul; Postnov, Konstantin; Gornostaev, Mikhail; Shakura, Nikolai; Fürst, Felix; Wilms, Jörn; Staubert, Rüdiger; Klochkov, Dmitry

    2017-04-01

    The Rossi X-ray Timing Explorer (RXTE) observed four outbursts of the accreting X-ray binary transient source, GX 304-1 in 2010 and 2011. We present results of detailed 3-100 keV spectral analysis of 69 separate observations, and report a positive correlation between cyclotron line parameters, as well as other spectral parameters, with power-law flux. The cyclotron line energy, width and depth versus flux, and thus luminosity, correlations show a flattening of the relationships with increasing luminosity, which are well described by quasi-spherical or disc accretion that yield the surface magnetic field to be ˜5 × 1012 Gauss. Since HEXTE (High Energy X-ray Timing Experiment) cluster A was fixed aligned with the Proportional Counter Array field of view and cluster B was fixed viewing a background region 1.5° off of the source direction during these observations near the end of the RXTE mission, the cluster A background was estimated from cluster B events using HEXTEBACKEST. This made possible the detection of the ˜55 keV cyclotron line and an accurate measurement of the continuum. Correlations of all spectral parameters with the primary 2-10 keV power-law flux reveal it to be the primary driver of the spectral shape. The accretion is found to be in the collisionless shock braking regime.

  5. The ion cyclotron turbulence generated by a low frequency kinetic Alfven wave, and the related turbulent heating of ions

    Science.gov (United States)

    Mykhaylenko, Volodymyr S.; Mykhaylenko, Volodymyr V.; Lee, Hae June

    2017-10-01

    The ion cyclotron instability driven by the strong kinetic Alfven wave is investigated as a possible source of the anisotropic heating of ions in the coronal holes and solar wind. We present a novel model of a plasma with coupled inhomogeneous current and the sheared flow, which follows from the studies of the particles motion in the electric field of the kinetic Alfven wave of the finite wavelength. The investigation is performed employing the non-modal kinetic theory grounded on the shearing modes approach. The solution of the governing linear integral equation for the perturbed potential displays that the flow velocity shear, which for the corona conditions may be above the growth rate of the ion cyclotron instability in plasma with steady current, changes the exponential growth of the ion cyclotron potential on the power function of time, that impedes the growth of the unstable ion cyclotron wave and reduces the turbulent heating rate of ions across the magnetic field. This work was funded by National R&D Program through the National Research Foundation of Korea (NRF) (Grant No. NRF-2015R1D1A1A01061160).

  6. Benchmarking of codes for electron cyclotron heating and electron cyclotron current drive under ITER conditions

    NARCIS (Netherlands)

    Prater, R.; Farina, D.; Gribov, Y.; Harvey, R. W.; Ram, A. K.; Lin-Liu, Y. R.; Poli, E.; Smirnov, A. P.; Volpe, F.; Westerhof, E.; Zvonkovo, A.

    2008-01-01

    Optimal design and use of electron cyclotron heating requires that accurate and relatively quick computer codes be available for prediction of wave coupling, propagation, damping and current drive at realistic levels of EC power. To this end, a number of codes have been developed in laboratories

  7. Electrostatic ion cyclotron waves in a plasma with an ion beam and counterstreaming bulk electrons - Waves in the zero-frequency band. [in aurora

    Science.gov (United States)

    Singh, N.; Conrad, J. R.; Schunk, R. W.

    1985-01-01

    A common feature of the auroral plasma in the region above field-aligned (parallel) potential drops are electrostatic hydrogen cyclotron (EHC) waves. The present paper has the objective to show that wave excitation in the zero-frequency band can occur when the ion beams and the current-carrying bulk electrons counterstream. The instability mechanism involves the Landau interaction of the slow (negative energy) ion-beam-cyclotron waves with the drifting electrons and also with the target (background) ions. Only the latter resonant interaction between the beam and the target ions was considered by Okuda and Nishikawa (1984). In this study, it is shown that an electron drift makes an additional unstable contribution to the waves in the zero-frequency band, including those discussed by Okuda and Nishikawa.

  8. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

    Directory of Open Access Journals (Sweden)

    H. W. Zhao

    2017-09-01

    Full Text Available The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24–28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of ^{40}Ar^{12+} and ^{129}Xe^{26+} have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL, China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24+18  GHz heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

  9. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

    Science.gov (United States)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

    2017-09-01

    The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

  10. Safety and protection problems in the management of a plant with cyclotron, radiopharmacy laboratory and PET/CT equipment

    Energy Technology Data Exchange (ETDEWEB)

    Russo, A.; Speranza, A.; Panico, M. [University Federico-2, National Research Council - Institute of Biostructures and Bioimaging and Dept. of Bio-morphological and Functional Sciences, Napoli (Italy); Delia, R. [University La Sapienza - sez. Rieti, Faculty of Medicine, Rome (Italy); Casale, M. [University Federico-2, Dept. of Physics - Health Physics School, Napoli (Italy); Salvatore, M. [University Federico-2 and National Research Council - Institute of Biostructures and Bioimaging, Dept. of Bio-morphological and Functional Sciences, Napoli (Italy)

    2006-07-01

    The importance of Positron Emission Tomography (PET) is spreading and increasing in many clinical diagnostic fields, as well as the oncology, the cardiology, the neurology and so on. A strong input to the diffusion of this imaging technique from the research field to clinical one has been given either by the development of knowledge about PET or the modern technologies, which allow to set up at very suitable prices and in very little volumes, like in an hospital site, complete systems, which consist of: Cyclotron; Radiopharmacy Laboratory; one or more either PET or PET/CT. Such set-up arrangement allows to carry out highly innovative diagnostic examinations with a remarkable achievement of diagnostic quality and large number of daily examinations. In this paper the authors show the achieved know-how with respect to radioprotection for the set-up and running management of two systems such as PET/CT tomography unit, cyclotron and radiopharmacy laboratory, installed one in the Imaging Diagnostic Department of the Hospital of Naples University and used only for medical and research purposes, and the other one in A.C.O.M. (Advanced Center of Oncology in Macerata), used for commercial and research purposes. The following safety problems have been considered: the facility lay-out; the optimisation of the paths either for the operator, or the patients and the radiotracers; the guide lines for the protection and the safety of the patients, operators and general population, in relation to the utilization and the management of either the more common radiotracers (18 F and 11 C) or those in research progress, for example 64 Cu and 124 I; the protocol set up for the image quality control in relation to the patient protection and safety. The above problems have also been considered, taking into account the Italian regulation and the International Recommendations. (authors)

  11. The radioprotection management of a PET department with a cyclotron and radiopharmacy laboratory, in accordance with Italian legislation.

    Science.gov (United States)

    Russo, A A; Ferrari, P; Casale, M; Delia, R

    2011-09-01

    The possibility of setting up a positron emission tomography (PET) facility with a cyclotron and radiopharmaceutical laboratory in situ, at a feasible price and in a very restricted space, has led to a steady increase both in the use of the PET technique in diagnostic clinical routine imaging and in the number of cyclotrons for drug production. Owing to the progress made in the PET procedures, it is now possible to have not only a highly innovative system of diagnostic examination, with a remarkable improvement in the diagnostic quality and patient care, but also a considerable increase in the number of daily examinations. In this paper, the authors show how the acquired know-how, with respect to radioprotection, has applied to the planning, running and management of the PET/CT unit, installed in the Imaging Diagnostic Department of the Policlinico Tor Vergata (PTV), at Tor Vergata University, Rome.

  12. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie A [Los Alamos National Laboratory; Kurennoy, Sergey [Los Alamos National Laboratory

    2008-01-01

    A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

  13. How a disaster preparedness rotation helps teach the seven NAVMEC professional competencies: the Texas A&M University Experience.

    Science.gov (United States)

    Bissett, Wesley T; Zoran, Debra L; Clendenin, Angela; Espitia, Noberto F; Moyer, William; Rogers, Kenita S

    2013-01-01

    Changing societal expectations provide new challenges and opportunities for the veterinary medical profession. These changing expectations and approaches to the education of veterinary students in the future are reflected in the North American Veterinary Medical Education Consortium's report "Roadmap for Veterinary Medical Education in the 21st Century: Responsive, Collaborative, Flexible." They are also reflected in the expectations of the populace, who no longer find it acceptable that animals are not included in both planning for and responding to natural or manmade disasters. In response to the changing needs of society and the veterinary profession, Texas A&M University College of Veterinary Medicine has developed a required rotation in the fourth-year curriculum on emergency planning and response. The unique requirements of emergency preparedness and response and the design of the rotation provide an ideal platform for providing this valued public service while simultaneously addressing the seven professional competencies outlined in the NAVMEC roadmap. This article describes an overview of the rotation and its content and identifies opportunities for students to practice these important professional competencies using the tools introduced in this new rotation.

  14. Coaxial ring cyclotron as a perspective nuclear power engineering machine

    CERN Document Server

    Tumanyan, A R; Mkrtchyan, R L; Amatuni, T A; Avakian, R O; Khudaverdian, A G

    1995-01-01

    Coaxial Ring Cyclotron (CRC) is described, and its main advantages, such as simple injection technique, several injected beams summation option, high efficiency, are considered. The proposed proton accelerator is a perspective machine for the solution of the main problems of the present day nuclear power engineering as well as for the next-generation nuclear power plants, representing a combination of subcritical reactors and particle accelerators. The possibility of installation of CRCs into ring accelerators with an average diameter from 60 to 100m, e.g., the Yerevan electron synchrotron, is considered.

  15. Cyclotron for Beam Therapy Application

    CERN Document Server

    Alenitsky, Yu G; Karamysheva, G A; Kostromin, S A; Mitsyn, G V; Molokanov, A G; Onishchenko, L M; Samsonov, E V; Vorozhtsov, S B; Zaplatin, N L

    2005-01-01

    The basic parameters of the proton isochronous cyclotron on the fixed energy are considered. The energy of protons is $E_{p}\\sim $ 220~MeV, intensity of the extracted beam is $I_{p}\\sim $ 0.1~$\\mu$A. The cyclotron is projected on the basis of compact magnet with four sectors and the diameter of poles 300 cm. Two dees of the accelerating system are located in valleys.

  16. Energy, variability and weather finance engineering

    Science.gov (United States)

    Roussis, Dimitrios; Parara, Iliana; Gournari, Panagiota; Moustakis, Yiannis; Dimitriadis, Panayiotis; Iliopoulou, Theano; Koutsoyiannis, Demetris; Karakatsanis, Georgios

    2017-04-01

    Most types of renewable energies are characterized by intense intermittency, causing significant instabilities to the grid; further requiring additional infrastructure (e.g. pumped-storage) for buffering hydrometeorological uncertainties, as well as complex operational rules for load balancing. In addition, most intermittent renewable units are subsidized, creating significant market inefficiencies. Weather derivatives comprise mature financial tools for integrating successfully the intermittent-load and base-load components into a unified hybrid energy system and establish their operation within a generalized uncertainty management market. With a growing global market share and 46% utilization of this financial tool by the energy industry and 12% by agriculture (that partially concerns biofuel resources), weather derivatives are projected to constitute a critical subsystem of many grids for buffering frequent hydrometeorological risks of low and medium impacts -which are not covered by standard insurance contracts that aim exclusively at extreme events and high financial damages. In this context, we study the attributes of hydrometeorological time series in a remote and small island in Greece, powered by an autonomous hybrid energy system. Upon the results we choose the optimal underlying index and we further compose and engineer a weather derivative with features of a typical option contract -which we consider most flexible and appropriate for the case- to test our assumptions on its beneficiary effects for both the budget of private energy producers and the island's public administration. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  17. RXTE Observations of the 1A 1118-61 in an Outburst, and the Discovery of a Cyclotron Line

    Science.gov (United States)

    Doroshenko, V.; Suchy, S.; Santangelo, A; Staubert, R.; Kreykenbohm, I.; Rothschild, R.; Pottschmidt, K.; Wilms, J.

    2010-01-01

    We present the analysis of RXTE monitoring data obtained during the January 2009 outburst of the hard X-ray transient IA 1118-61. Using these observations the broadband (3.5-120 keV) spectrum of the source was measured for the first time ever. We have found that the broadband continuum spectrum of the source is similar to other accreting pulsars and is well described by several conventionally used phenomenological models. We have discovered that regardless of the applied continuum model, a prominent broad absorption feature at approx. 55 keV is observed. We interpret this feature as a Cyclotron Resonance Scattering Feature (CRSF). The observed CRSF energy is one of the highest known and corresponds to a magnetic field of B approx. 4.8 x 10(exp 12) G in the scattering region. Furthermore, our data suggests an iron emission line presence, which was not reported previously for lA 1118-61 as well. Timing properties of the source, including a strong spin-up, were found to be similar to those observed by CGRO/BATSE during the previous outburst, however the broadband capabilities of RXTE reveal a more complicated energy dependency of the pulse-profile.

  18. Ion Anisotropy and High-Energy Variability of Large Solar Particle Events: A Comparative Study

    Science.gov (United States)

    Tan, Lun C.; Reames, Donald V.; Ng, Chee K.

    2008-01-01

    We have made comparative studies of ion anisotropy and high-energy variability of solar energetic particle (SEP) events previously examined by the Solar, Heliospheric, and Interplanetary Environment (SHINE) Workshop campaign. We have found distinctly different characteristics of SEPs between two large "gradual" events having very similar solar progenitors (the 2002 April 21 and August 24 events). Since the scattering centers of SEPs are approximately frozen in the solar wind, we emphasize work in the solar-wind frame where SEPs tend to be isotropized, and small anisotropies are easier to detect. While in the August event no streaming reversal occurred, in the April event the field-aligned anisotropy of all heavy ions showed sign of streaming reversal. The difference in streaming reversal was consistent with the difference in the presence of the outer reflecting boundary. In the April event the magnetic mirror, which was located behind the interplanetary shock driven by the preceding coronal mass ejection (CME), could block the stream of SEPs, while in the August event SEPs escaped freely because of the absence of nearby boundary. The magnetic mirror was formed at the bottleneck of magnetic field lines draped around a flank of the preceding CME. In the previous SHINE event analysis the contrasting event durations and Fe/O ratios of the both events were explained as the interplay between shock geometry and seed population. Our new findings, however, indicate that event duration and time as well as spectral variation are also affected by the presence of a nearby reflecting boundary.

  19. Stochasticity of the energy absorption in the electron cyclotron resonance; Estocasticidad de la absorcion de energia en la resonancia electron-ciclotronica

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C. [Departamento de Fisica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Hernandez A, O

    1998-07-01

    The energy absorption mechanism in cyclotron resonance of the electrons is a present problem, since it could be considered from the stochastic point of view or this related with a non-homogeneous but periodical of plasma spatial structure. In this work using the Bogoliubov average method for a multi periodical system in presence of resonances, the drift equations were obtained in presence of a RF field for the case of electron cyclotron resonance until first order terms with respect to inverse of its cyclotron frequency. The absorbed energy equation is obtained on part of electrons in a simple model and by drift method. It is showed the stochastic character of the energy absorption. (Author)

  20. Top Operations and Maintenance (O&M) Efficiency Opportunities at DoD/Army Sites - A Guide for O&M/Energy Managers and Practitioners

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Gregory P.; Dean, Jesse D.; Dixon, Douglas R.

    2007-05-25

    This report, sponsored the Army's Energy Engineering Analysis Program, provides the Operations and Maintenance (O&M) Energy manager and practitioner with useful information about the top O&M opportunities consistently found across the DoD/Army sector. The target is to help the DoD/Army sector develop a well-structured and organized O&M program.

  1. Developing and Planning a Texas Based Homeschool Curriculum

    Science.gov (United States)

    Terry, Bobby K.

    2011-01-01

    Texas has some of the lowest SAT scores in the nation. They are ranked 36th nationwide in graduation rates and teacher salaries rank at number 33. The public school system in Texas has problems with overcrowding, violence, and poor performance on standardized testing. Currently 300,000 families have opted out of the public school system in order…

  2. Mitchell Energy foam fracs tight zones. [Texas

    Energy Technology Data Exchange (ETDEWEB)

    Bleakley, W.B.

    1980-12-01

    Wells that produced one billion cubic feet of gas over an 11-yr period could have produced that much in one year, according to results of recent massive foam frac jobs. Mitchell Energy and Development Corp. experienced that kind of performance from wells completed in the Cotton Valley Lime gas reservoir of Central Texas, just south of Mexia. One well, the No. 1 Stone, in Limestone County, was completed in Dec., 1969 at 11,200 ft, exposing a gross interval of 200 ft and a net pay of 26 ft. Cumulative production to early this year was approx. 578 mmcf and the well was producing at 50 to 75 mcfd through a full-open 2-in. choke with flowing tubing pressure of 640 psi. The formation was fractured in March, 1980, using foam, and present producing rate of 600 mcfd against 800-psi line pressure, in spite of a screen-out during the frac treatment that permitted only half of the designed-for one million pounds of sand to be put away. This is believed to be the first foam job at that depth, however, and the first to get 500,000 lb of sand into a fracture, using foam.

  3. Absorption and emission of extraordinary-mode electromagnetic waves near cyclotron frequency in nonequilibrium plasmas

    Science.gov (United States)

    Wu, C. S.; Lin, C. S.; Wong, H. K.; Tsai, S. T.; Zhou, R. L.

    1981-01-01

    An investigation is presented of two cases: (1) weakly relativistic electrons with a loss-cone type distribution, and (2) electrons with a drift velocity parallel to the ambient magnetic field. Numerical computations are given for physical parameters close to those in the polar region of the earth magnetosphere and laboratory experiments, with attention to the fast extraordinary-mode radiation whose frequency is near that of the electron cyclotron frequency. The fast extraordinary mode can escape from a strong field region to the weaker field region and may therefore be measured outside the plasma. It is found that the X mode radiation can be amplified by means of a cyclotron maser effect when the electrons have a loss-cone distribution, and it is concluded that, when the electron energy is sufficiently high, the X mode cutoff frequency may be lower than the cyclotron frequency.

  4. Prediction of neutron induced radioactivity in the concrete walls of a PET cyclotron vault room with MCNPX.

    Science.gov (United States)

    Martínez-Serrano, J Javier; Díez de los Ríos, Antonio

    2010-11-01

    The authors want to assess the relevance of the neutron activation of the concrete vault of the PET cyclotron at CIMES (Universidad de Malaga) by predicting specific activities of the main activation products in the vault and their variation profiles as a function of penetration depth into concrete at present and after 10 yr of cyclotron operation. The dual proton cyclotron is used for PET isotopes production, mainly 18F. During the years 2006 and 2008, the using rate has been 1 h/day at single beam (40 microA). From January 2008, using rate is 4 h/day at dual beam (80 microA). The energy of the cyclotron proton beam is 18 MeV. Four point locations were chosen on the walls of the cyclotron room to assess neutron induced activity concentrations. In each wall point location, neutron induced radionuclide specific activity was assessed from the wall surface to a depth of 120 cm within concrete. Simulations were carried out with the Monte Carlo based radiation transport code MCNPX (v2.6.0). According to MCNPX calculations, activity depth profiles of activation products studied, except 54Mn, have a maximum at variable depths from the wall surface never beyond 12 cm. 54Mn activity decreases exponentially in all the studied depth ranges within wall concrete. The activity of 152Eu, 154Eu, 60CO, 134Cs, 46Sc, and 65Zn decreases exponentially beyond a 30 cm depth into concrete. 54Mn activity presents the faster decrease within a concrete vault with an attenuation length of 21 cm. According to MCNPX estimations, present activity in the cyclotron vault is mostly due to 46Sc and 60Co, with highest specific activity near the vault surface of 146 +/- 16 and 50 +/- 4.6 Bq/kg, respectively. 46Sc and 60Co activity measurements near the surface wall present an acceptable match with the estimation within the uncertainties, but measured activities of the other radionuclides are quite over the MCNPX estimations. The calculations after 10 yr of cyclotron operation predict a slight increase

  5. Measurements of beam emittance, accelerated RF phase band, and centring in a 1 MeV test cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Dehnel, M.P.; Erdman, K.L. [Obco Technologies Inc., Richmond B.C. (Canada); Kuo, T. [TRIUMF, Vancouver B.C. (Canada)

    1999-07-01

    Differential probe measurements of radial and axial circulating beam intensity in the EBCO/TRIUMF 1 MeV H{sup -} Test Cyclotron have been made. Intensity profile simulations from an analytical model compare well with the measured beam intensity data, and yield important beam related quantities such as the emittance, the accelerated RF phase band and the beam centring. The experimental hardware details, comparisons of measured and computed data, and a description of the analytical model are reported. (authors)

  6. Whistler-cyclotron spontaneous fluctuations. A proxy to identify thermal and non-thermal electrons?

    Science.gov (United States)

    Moya, P. S.; López, R. A.; Navarro, R.; Vinas, A. F.; Munoz, V.; Araneda, J. A.; Valdivia, J. A.

    2016-12-01

    Observed electron velocity distributions in the space plasmas exhibit a variety of non-thermal features which deviate from thermal equilibrium, in the form of temperature anisotropies, suprathermal tails, and field aligned beams. The state close to thermal equilibrium and its departure from it provides a source for spontaneous emissions of electromagnetic fluctuations. For example, the whistler cyclotron waves at electron scales. Here we present a comparative analysis of these fluctuations based upon anisotropic plasma modeled with thermal and non-thermal particle distributions. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic magnetized electron-proton plasma modeled with bi-Maxwellian and kappa-like distributions. Dispersion analysis and stability thresholds are derived for these non-thermal distributions and compared with similar results obtained from PIC simulations using plasma and field parameters relevant to space nearly collisionless environments. Our results indicate that there is a strong dependence between the shape of the velocity distribution function and the spontaneous magnetic fluctuations wave spectrum. This feature may be used proxy to identify the nature of electron populations in space plasmas when high resolution particle instruments are not available.

  7. Evaporation from a shallow, saline lake in the Nebraska Sandhills: Energy balance drivers of seasonal and interannual variability

    Science.gov (United States)

    Riveros-Iregui, Diego A.; Lenters, John D.; Peake, Colin S.; Ong, John B.; Healey, Nathan C.; Zlotnik, Vitaly A.

    2017-10-01

    Despite potential evaporation rates in excess of the local precipitation, dry climates often support saline lakes through groundwater inputs of water and associated solutes. These groundwater-fed lakes are important indicators of environmental change, in part because their shallow water levels and salinity are very sensitive to weather and climatic variability. Some of this sensitivity arises from high rates of open-water evaporation, which is a dominant but poorly quantified process for saline lakes. This study used the Bowen ratio energy budget method to calculate open-water evaporation rates for Alkali Lake, a saline lake in the Nebraska Sandhills region (central United States), where numerous groundwater-fed lakes occupy the landscape. Evaporation rates were measured during the warm season (May - October) over three consecutive years (2007-2009) to gain insights into the climatic and limnological factors driving evaporation, as well as the partitioning of energy balance components at seasonal and interannual time scales. Results show a seasonal peak in evaporation rate in late June of 7.0 mm day-1 (on average), with a maximum daily rate of 10.5 mm day-1 and a 3-year mean July-September (JAS) rate of 5.1 mm day-1, which greatly exceeds the long-term JAS precipitation rate of 1.3 mm day-1. Seasonal variability in lake evaporation closely follows that of net radiation and lake surface temperature, with sensible heat flux and heat storage variations being relatively small, except in response to short-term, synoptic events. Interannual changes in the surface energy balance were weak, by comparison, although a 6-fold increase in mean lake level over the three years (0.05-0.30 m) led to greater heat storage within the lake, an enhanced JAS lake-air temperature gradient, and greater sensible heat loss. These large variations in water level were also associated with large changes in absolute salinity (from 28 to 118 g kg-1), with periods of high salinity characterized

  8. Production of copper-64 and gallium-68 with a medical cyclotron using liquid targets

    Science.gov (United States)

    Alves, F.; Alves, V. H. P.; Do Carmo, S. J. C.; Neves, A. C. B.; Silva, M.; Abrunhosa, A. J.

    2017-06-01

    This work describes the production of two clinically relevant metal radioisotopes 64Cu and 68Ga with a medical cyclotron by the irradiation of liquid targets. New results are presented for the implementation of this methodology in a fully automated system, using commercially available equipment. Liquid target solutions containing enriched 64Ni and 68Zn were loaded, bombarded and transferred to synthesis modules where a purified solution containing the desired radiometal is obtained and can then be used to further radiolabeling within only one hour after End-Of-Bombardment (EOB). Typical production runs using enriched material lead to the production of 5 GBq and 6 GBq (0.14 MBq/(μAh ṡ mg) and 1.5 MBq/(μAh ṡ mg)) of 64Cu and 68Ga; although the technique can be used to obtain up to 25 GBq and 40 GBq, respectively, by simply scaling up the amount of the enriched material. Purified solutions containing 64Cu and 68Ga were obtained within 30 min after EOB and used to produce 64Cu-ATSM and 68Ga-DOTA-NOC, respectively, with quality parameters suitable for human use.

  9. Measurement and control of the air contamination generated in a medical cyclotron facility for PET radiopharmaceuticals.

    Science.gov (United States)

    Calandrino, R; del Vecchio, A; Todde, S; Fazio, F

    2007-05-01

    The aim of this paper is to report the data concerning the contamination of the exhausted air from the hot cells dedicated to the large-scale synthesis of positron emission tomography (PET) radiopharmaceuticals. Two cyclotrons are currently operating in Ospedale San Raffaele for the routine production of C and F. They are linked with four radiochemistry laboratories by means of shielded radioisotope delivery lines. The above labs are dedicated both to the large scale preparation and to the research and development of PET radiopharmaceuticals. The department hosts four CT-PET scanners, which operate with a mean patient workload of 40 per day. Radiosyntheses are performed using automated modules located in 10 hot cells. The air outlets are monitored online by a 2-inch NaI(Tl) counter in a Marinelli geometry counting volume. Contamination values up to 10(5) Bq L(-1) have been measured at the hot cell exit point during the synthesis. The corresponding concentrations at the point of release in atmosphere are largely above the threshold of 1.29 Bq L(-1), defined by national regulations as the limit for free environmental release. A shielded gas storage system controlled by a dedicated, customized software program has thus been installed to prevent the potentially hazardous release of gaseous radioactive contaminants. The system has allowed us to maintain the effective dose to neighboring population groups below the limit of 10 muSv y(-1).

  10. Variably spaced superlattice energy filter, a new device design concept for high-energy electron injection

    Science.gov (United States)

    Summers, C. J.; Brennan, K. F.

    1986-01-01

    A new variably spaced superlattice energy filter is proposed which provides high-energy injection of electrons into a bulk semiconductor layer based on resonant tunneling between adjacent quantum well levels which are brought into alignment by an applied bias. Applications of this concept to a variety of optoelectronic devices and to thin-film electroluminescent devices and photodetectors are discussed.

  11. Electron-cyclotron maser utilizing free-electron two-quantum magnetic-wiggler radiation, and explanation of effective laser injection in an electron cyclotron maser as lift-up of saturated power level arisen from uncertainty in electron energy due to electron's transverse wiggling

    Science.gov (United States)

    Kim, S. H.

    2017-12-01

    We reason that in the free-electron radiation if the transition rate τ is less than the radiation frequency ν, the radiation is of broad-band spectrum whereas if τ ≫ ν, the radiation is of monochromatic. We find that when a weaker magnetic wiggler (MW) is superpositioned on a predominantly strong uniform magnetic field, free-electron two-quantum magnetic-wiggler (FETQMW) radiation takes place. In FETQMW radiation, the MW and the electron's intrinsic motivity to change its internal configuration through radiation play as two first-order perturbers while the uniform magnetic field acts as the sole zeroth-order perturber. When Δ E≪ hν, where Δ E is the uncertainty in the electron energy produced by transverse wiggling due to the MW in conjuction with a Heisenberg's uncertainty principle Δ EΔ x h and E = ( m 2 c 4 + c 2 p 2)1/2, the power of FETQMW radiation cannot exceed hν 2. However, we find that this power cap is lifted by the amount of νΔ E when Δ E ≫ hν holds [1,2]. This lift-up of the saturated radiation power is the responsible mechanism for the effective external injection of a 20 kW maser in an electron-cyclotron maser (ECM). We find that an MW-added ECM with radius 5 cm and length 1 m and operating parameters of the present beam technology can yield laser power of 50 MW at the radiation wavelength of 0.001 cm.

  12. Cyclotron waves in plasma

    CERN Document Server

    Lominadze, D G

    2013-01-01

    Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

  13. No Anticorrelation between Cyclotron Line Energy and X-ray Flux in 4U 0115+634

    Science.gov (United States)

    2013-01-01

    University of California, San Diego, La Jolla, CA 92093, USA 10 Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, University of...Space Agency CNES through CNRS. S.M.N. and J.M.T. acknowledge support from the Spanish Ministerio de Ciencia , Tecnología e Innovación (MCINN) through

  14. Resource Management in a Changing Climate: Understanding the Relationships between Water Quality and Golden Alga Distribution in the Pecos River, New Mexico and Texas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Texas Tech University will conduct sampling at a wide variety of sites in the Middle and Lower Pecos River for golden alga and environmental variables. The toxins...

  15. Practical experience and challenges in the operation of medical cyclotron.

    Science.gov (United States)

    Kumar, Rajeev; Sonkawade, Rajendra G; Pandey, Anil K; Tripathi, Madhavi; Damle, Nishikant A; Kumar, Praveen; Bal, Chandra S

    2017-01-01

    The aim of this article was to share 10 years of operational experience of medical cyclotron and to provide working knowledge on the same. This experience has helped us gain working knowledge on cyclotron operation with practical points, which may help in improving F yield, minimizing the breakdown time, and help in the prevention of the occurrence of unusual events. Our facility has a self-shielded radioisotope delivery system eclipse 111 medical cyclotron with an 11 MeV proton beam in use for the past 10 years to produce positron emitters - namely, F, N, and F-2 gas - for PET imaging. During F production, we have followed a set protocol comprising the following: monitoring target pressure, rinsing the target with O water just immediately after bombardment, ion source feedback, radiofrequency (RF) feedback, and recording any unusual events that occurred during the operation. Besides this, enrichment of O water, target volume, target current, energy of the beam, variation in argon pressure on the target, bombardment duration, target status (new or old target or total number of previous bombardments on the same target), status of the delivery lines from target to the radiochemistry module (old or new) were also recorded. Rinsing with O water immediately after bombardment increases the life of the target and delivery line. The frequent problems encountered were with the ion source, RF, and target foil rupture. These problems were solved by rebuilding the ion source, changing the fuse of RF, and rebuilding the target. F yield can be increased by rinsing with O water immediately after bombardment. The effect of target leak - that is, rupture of vacuum window - can be avoided by immediate stoppage of bombardment.

  16. TRIUMF cyclotron vacuum system refurbishing

    Science.gov (United States)

    Sekachev, I.

    2008-03-01

    The cyclotron at TRIUMF was commissioned to full energy in 1974. The volume of the cyclotron vacuum tank is about 100 m3 and it operates at 5×10-8 Torr pressure during beam production. The pumping is mainly based on a Phillips B-20 cryogenerator (Stirling cycle 4-cylinder engine). The cryogenerator supplies helium gas at 16 K and 70 K to cryopanels in the tank. The decreasing reliability of the B-20 and demanding maintenance requirements triggered the decision to completely overhaul or replace the cryogenerator. Replacement with the LINDE-1630 helium refrigerator was found to be the most attractive (technically and economically) option. The details of the proposal with installation of the helium refrigerator and with a continuous flow liquid nitrogen shield cooling system are presented.

  17. Distribution of thermal neutron flux around a PET cyclotron.

    Science.gov (United States)

    Ogata, Yoshimune; Ishigure, Nobuhito; Mochizuki, Shingo; Ito, Kengo; Hatano, Kentaro; Abe, Junichiro; Miyahara, Hiroshi; Masumoto, Kazuyoshi; Nakamura, Hajime

    2011-05-01

    The number of positron emission tomography (PET) examinations has greatly increased world-wide. Since positron emission nuclides for the PET examinations have short half-lives, they are mainly produced using on-site cyclotrons. During the production of the nuclides, significant quantities of neutrons are generated from the cyclotrons. Neutrons have potential to activate the materials around the cyclotrons and cause exposure to the staff. To investigate quantities and distribution of the thermal neutrons, thermal neutron fluxes were measured around a PET cyclotron in a laboratory associating with a hospital. The cyclotron accelerates protons up to 18 MeV, and the mean particle current is 20 μA. The neutron fluxes were measured during both 18F production and C production. Gold foils and thermoluminescent dosimeter (TLD) badges were used to measure the neutron fluxes. The neutron fluxes in the target box averaged 9.3 × 10(6) cm(-2) s(-1) and 1.7 × 10(6) cm(-2) s(-1) during 18F and 11C production, respectively. Those in the cyclotron room averaged 4.1 × 10(5) cm(-2) s(-1) and 1.2 × 10(5) cm(-2) s(-1), respectively. Those outside the concrete wall shielding were estimated as being equal to or less than ∼3 cm s, which corresponded to 0.1 μSv h(-1) in effective dose. The neutron fluxes outside the concrete shielding were confirmed to be quite low compared to the legal limit.

  18. A line-of-sight electron cyclotron emission receiver for electron cyclotron resonance heating feedback control of tearing modes

    DEFF Research Database (Denmark)

    Oosterbeek, J.W.; Bürger, A.; Westerhof, E.

    2008-01-01

    An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) beam...

  19. ROKCY-12 (KCCH PET-dedicated cyclotron): main features and improvements

    Energy Technology Data Exchange (ETDEWEB)

    Chai, J. S.; Kim, Y. S.; Yang, Y. T.; Jung, I. S.; Hong, S. S.; Lee, M. Y.; Jang, H. S.; Kim, J. H. [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    2002-07-01

    In this paper, we describe the development of 13 MeV cyclotron (ROKCY-12) that can be used for a Position Emission Tomography(PET) purpose. This cyclotron with a maximum beam energy of 13 MeV can produce radio isotopes especially {sup 18}F which has a relatively short half lifetime of 110 minutes. First, we show the beam characteristics can be used to carry out the operation of ROCKY-12. Based on this, a computer program has been developed to determine main cyclotron parameters such as cyclotron magnet, RF system, ion source, vacuum system and other cyclotron operation parameters. And then we show the result of design and manufacturing feature of ROKCY-12. By using this design program, one can determines magnet yoke geometry and the average magnetic fields etc. And then the three-dimensional computer program OPERA-3D has been invoked to determine magnet pole tips. Validity of the design can be seen by investigating magnetic fields, radial and vertical focusing frequencies as a function of the beam energy. In this paper, we show the results of cyclotron beam by ROCKY-12. We designed 77.3 MHz RF system and ion source system. We tested RF resonance each coupling methods. We show the result of RF design and prototype operation. Developed ion source is PIG type. We described our design methods and implementation. We report the result of getting negative hydrogen ion. Cyclotron controller asks inputs of every sensor and output of every instrument for notifying current condition to operator. It has independent controllers, for example DC power supply, vacuum system, beam profile system, beam extraction system, RF system, ion source, cooling unit and so on. Basically, each control system uses RS-485 for communication to main control computer. Consumers reward products and services that feature quality, originality, a distinct personality and charm. The International Standardization Organization (ISO) requires, as its mission, that we achieve competitive superiority by

  20. DNA contents in Texas bluegrass (Poa arachnifera) selected in Texas and Oklahoma determined by flow cytometry

    Science.gov (United States)

    Texas bluegrass (Poa arachnifera Torr.) is a dioecious, perennial, cool-season grass native to southern Kansas, Oklahoma, western Arkansas and most of Texas. Its major use has been for forage on rangelands in Texas and Oklahoma. More recently, interspecific hybrids between Texas bluegrass and Kentuc...

  1. BEST medical radioisotope production cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Johnson, Richard R. [Best Cyclotron Systems Inc., 7-8765 Ash Street, Vancouver, British Columbia, V6P 6T3 (Canada); Gelbart, W. Z. [Advanced System Designs Inc., 5295 Bear Bay Road, Garden Bay, BC, V0N 1S1 (Canada)

    2013-04-19

    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 {mu}A to 1000 {mu}A, depending on the cyclotron energy and application.

  2. Whistler Cyclotron Electromagnetic Fluctuations in a Maxwellian and Tsallis-kappa-like Plasma

    Science.gov (United States)

    Vinas, A. F.; Moya, P. S.; Navarro, R.; Araneda, J. A.

    2014-12-01

    Observed electron velocity distributions in the Earth's magnetosphere and the solar wind exhibit a variety of non-thermal features which deviate from thermal equilibrium, for example, in the form of temperature anisotropies, suprathermal tail extensions, and field aligned beams. The state close to thermal equilibrium and its departure from it provides a source for spontaneous emissions of electromagnetic fluctuations, such as the whistler. Here we present a comparative analysis of whistler-cyclotron fluctuations based upon anisotropic plasma modeled with Maxwellian and Tsallis kappa-like particle distributions, to explain the correspondence relationship of the magnetic fluctuations as a function of the electron temperature and thermal anisotropy in the solar wind and magnetosphere plasmas. The analysis presented here considers correlation theory of the fluctuation-dissipation theorem and the dispersion relation of transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature anisotropic thermal bi-Maxwellian and non-thermal Tsallis-kappa-like magnetized electron-proton plasma. Dispersion analysis and stability thresholds are derived for these thermal and non-thermal distributions using plasma and field parameters relevant to the solar wind and magnetosphere environments. Our results indicate that there is an enhancement of the fluctuations level in the case of non-thermal distributions due to the effective higher-temperature and the excess of suprathermal particles. These results suggest that a comparison of the electromagnetic fluctuations due to thermal and non-thermal distributions provides a diagnostic signature by which inferences about the nature of the particle velocity distribution function can be ascertained without in-situ particle measurements.

  3. RR Lyrae Variables in M32 and the Disk of M31

    Science.gov (United States)

    Fiorentino, Giuliana; Monachesi, Antonela; Trager, Scott C.; Lauer, Tod R.; Saha, Abhijit; Mighell, Kenneth J.; Freedman, Wendy; Dressler, Alan; Grillmair, Carl; Tolstoy, Eline

    2010-01-01

    We observed two fields near M32 with the Advanced Camera for Surveys/High Resolution Channel (ACS/HRC) on board the Hubble Space Telescope. The main field, F1, is 1farcm8 from the center of M32; the second field, F2, constrains the M31 background, and is 5farcm4 distant. Each field was observed for 16 orbits in each of the F435W (narrow B) and F555W (narrow V) filters. The duration of the observations allowed RR Lyrae stars to be detected. A population of RR Lyrae stars determined to belong to M32 would prove the existence of an ancient population in that galaxy, a subject of some debate. We detected 17 RR Lyrae variables in F1 and 14 in F2. A 1σ upper limit of 6 RR Lyrae variables belonging to M32 is inferred from these two fields alone. Use of our two ACS/WFC parallel fields provides better constraints on the M31 background, however, and implies that 7+4 -3 (68% confidence interval) RR Lyrae variables in F1 belong to M32. We have therefore found evidence for an ancient population in M32. It seems to be nearly indistinguishable from the ancient population of M31. The RR Lyrae stars in the F1 and F2 fields have indistinguishable mean V-band magnitudes, mean periods, distributions in the Bailey diagram, and ratios of RRc to RRtotal types. However, the color distributions in the two fields are different, with a population of red RRab variables in F1 not seen in F2. We suggest that these might be identified with the detected M32 RR Lyrae population, but the small number of stars rules out a definitive claim. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with GO proposal 10572.

  4. Thermohaline variability and mesoscale activities observed at the E2M3A deep site in the south Adriatic Sea

    Science.gov (United States)

    Bensi, M.; Cardin, V.; Gačić, M.

    2012-04-01

    The south Adriatic Sea is recognized as a dense water formation site which is able to oxygenate the deep layer of the whole eastern Mediterranean Sea. The entrance of salty water from the Ionian Sea represents a preconditioning factor for the deep convection which can occur during winters characterized by particularly vigorous air-sea heat exchanges. Continuous sampling measurements are strictly essential to better understand the deep convection. For that reason, the south Adriatic Sea has been constantly monitored by means of the E2M3A deep mooring site located in its central part (Latitude 41° 50' N, Longitude 17° 45' E, maximum depth 1250m) since 2006. Temperature, salinity and currents time series at the E2M3A site from 2006 till 2010 are analyzed. They represent currently the longest timeseries available for this region. Moreover, their integration with data obtained from several oceanographic cruises provides the necessary spatial distribution of the thermohaline properties in the study area. Here we report on the abrupt temperature and salinity decrease particularly evident down to 600m depth from March 2008 on. In fact, the intermediate layer shows a maximum temperature and salinity decrease of ~0.3°C and ~0.06 respectively, clearly evident after each severe winter. The bottom layer (~1200m) shows an opposite behaviour: it suffered an unforeseen and continous temperature and salinity increase (linear trend of ~0.05 °C y-1 and ~0.004 psu y-1respectively) during the whole observational period. The results show a strong relationship between the recently discovered variability of the Ionian surface circulation (Gačić et al. 2010) and the thermohaline variability observed in the south Adriatic. In particular, we demonstrate here the role of the winter convection in trasferring fresher surface waters towards deeper layers triggering salt content changes in the Adriatic. The intrusion of fresher water at the depth of about 700-800m noticed in the mooring

  5. Inverse ion-cyclotron damping and excitation of multiharmonic ion-cyclotron waves in the northern magnetospheric cusp

    Science.gov (United States)

    Slapak, Rikard; Gunell, Herbert; Hamrin, Maria

    2017-04-01

    We have investigated a case of inverse ion-cyclotron damping taking place in the northern terrestrial magnetospheric cusp, exciting waves at the ion-cyclotron frequency and its harmonics. Magnetosheath influx in the cusps and the effect of convection and magnetic mirroring give rise to parallel velocity shears, dvallel/dx\\perp, often associated with instabilities in the plasma and corresponding ion-cyclotron waves, whose evolution is described by a damping factor. This damping factor depends on, for example, the wave numbers and the velocity shear itself and can under certain conditions be negative, hence describing inverse damping (or wave growth). However, an additional required condition for inverse ion-cyclotron damping is a velocity shear in the magnetic field-aligned ion-bulk flow, and this condition is only met for magnetosheath influx in the northern cusp, as oppose to the southern cusp. The ion-cyclotron waves are primarily seen as peaks in the magnetic-field spectral densities, as presented by Slapak et al., [GRL (2016), doi:10.1002/2016GL071680]. The corresponding peaks in the electric-field spectral densities are not as profound, suggesting a background electric field noise or other processes of wave generation causing the electric spectral densities to smoothen out more compared to the magnetic counterpart. We note that some ion-cyclotron wave activity is present in a few similar shear events in the southern cusp, which indicates that other mechanisms generating ion-cyclotron waves may also be present during such conditions.

  6. A fully discrete energy stable scheme for a phase filed moving contact line model with variable densities and viscosities

    KAUST Repository

    Zhu, Guangpu

    2018-01-26

    In this paper, a fully discrete scheme which considers temporal and spatial discretizations is presented for the coupled Cahn-Hilliard equation in conserved form with the dynamic contact line condition and the Navier-Stokes equation with the generalized Navier boundary condition. Variable densities and viscosities are incorporated in this model. A rigorous proof of energy stability is provided for the fully discrete scheme based on a semi-implicit temporal discretization and a finite difference method on the staggered grids for the spatial discretization. A splitting method based on the pressure stabilization is implemented to solve the Navier-Stokes equation, while the stabilization approach is also used for the Cahn-Hilliard equation. Numerical results in both 2-D and 3-D demonstrate the accuracy, efficiency and decaying property of discrete energy of the proposed scheme.

  7. Graphical user interface for yield and dose estimations for cyclotron-produced technetium.

    Science.gov (United States)

    Hou, X; Vuckovic, M; Buckley, K; Bénard, F; Schaffer, P; Ruth, T; Celler, A

    2014-07-07

    The cyclotron-based (100)Mo(p,2n)(99m)Tc reaction has been proposed as an alternative method for solving the shortage of (99m)Tc. With this production method, however, even if highly enriched molybdenum is used, various radioactive and stable isotopes will be produced simultaneously with (99m)Tc. In order to optimize reaction parameters and estimate potential patient doses from radiotracers labeled with cyclotron produced (99m)Tc, the yields for all reaction products must be estimated. Such calculations, however, are extremely complex and time consuming. Therefore, the objective of this study was to design a graphical user interface (GUI) that would automate these calculations, facilitate analysis of the experimental data, and predict dosimetry. The resulting GUI, named Cyclotron production Yields and Dosimetry (CYD), is based on Matlab®. It has three parts providing (a) reaction yield calculations, (b) predictions of gamma emissions and (c) dosimetry estimations. The paper presents the outline of the GUI, lists the parameters that must be provided by the user, discusses the details of calculations and provides examples of the results. Our initial experience shows that the proposed GUI allows the user to very efficiently calculate the yields of reaction products and analyze gamma spectroscopy data. However, it is expected that the main advantage of this GUI will be at the later clinical stage when entering reaction parameters will allow the user to predict production yields and estimate radiation doses to patients for each particular cyclotron run.

  8. Graphical user interface for yield and dose estimations for cyclotron-produced technetium

    Science.gov (United States)

    Hou, X.; Vuckovic, M.; Buckley, K.; Bénard, F.; Schaffer, P.; Ruth, T.; Celler, A.

    2014-07-01

    The cyclotron-based 100Mo(p,2n)99mTc reaction has been proposed as an alternative method for solving the shortage of 99mTc. With this production method, however, even if highly enriched molybdenum is used, various radioactive and stable isotopes will be produced simultaneously with 99mTc. In order to optimize reaction parameters and estimate potential patient doses from radiotracers labeled with cyclotron produced 99mTc, the yields for all reaction products must be estimated. Such calculations, however, are extremely complex and time consuming. Therefore, the objective of this study was to design a graphical user interface (GUI) that would automate these calculations, facilitate analysis of the experimental data, and predict dosimetry. The resulting GUI, named Cyclotron production Yields and Dosimetry (CYD), is based on Matlab®. It has three parts providing (a) reaction yield calculations, (b) predictions of gamma emissions and (c) dosimetry estimations. The paper presents the outline of the GUI, lists the parameters that must be provided by the user, discusses the details of calculations and provides examples of the results. Our initial experience shows that the proposed GUI allows the user to very efficiently calculate the yields of reaction products and analyze gamma spectroscopy data. However, it is expected that the main advantage of this GUI will be at the later clinical stage when entering reaction parameters will allow the user to predict production yields and estimate radiation doses to patients for each particular cyclotron run.

  9. Source terms, shielding calculations and soil activation for a medical cyclotron.

    Science.gov (United States)

    Konheiser, J; Naumann, B; Ferrari, A; Brachem, C; Müller, S E

    2016-12-01

    Calculations of the shielding and estimates of soil activation for a medical cyclotron are presented in this work. Based on the neutron source term from the 18O(p,n)18F reaction produced by a 28 MeV proton beam, neutron and gamma dose rates outside the building were estimated with the Monte Carlo code MCNP6 (Goorley et al 2012 Nucl. Technol. 180 298-315). The neutron source term was calculated with the MCNP6 code and FLUKA (Ferrari et al 2005 INFN/TC_05/11, SLAC-R-773) code as well as with supplied data by the manufacturer. MCNP and FLUKA calculations yielded comparable results, while the neutron yield obtained using the manufacturer-supplied information is about a factor of 5 smaller. The difference is attributed to the missing channels in the manufacturer-supplied neutron source terms which considers only the 18O(p,n)18F reaction, whereas the MCNP and FLUKA calculations include additional neutron reaction channels. Soil activation was performed using the FLUKA code. The estimated dose rate based on MCNP6 calculations in the public area is about 0.035 µSv h-1 and thus significantly below the reference value of 0.5 µSv h-1 (2011 Strahlenschutzverordnung, 9 Auflage vom 01.11.2011, Bundesanzeiger Verlag). After 5 years of continuous beam operation and a subsequent decay time of 30 d, the activity concentration of the soil is about 0.34 Bq g-1.

  10. Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

    Science.gov (United States)

    Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

    2013-01-01

    In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

  11. Regional Haze Plan for Texas and Oklahoma

    Science.gov (United States)

    EPA partially approved and partially disapproved the Texas regional haze plan. EPA also finalized a plan to limit sulfur dioxide emissions from eight Texas coal-fired electricity generating facilities

  12. Genetic structure and molecular variability of potato virus M populations.

    Science.gov (United States)

    Tabasinejad, Fatemeh; Jafarpour, Behrooz; Zakiaghl, Mohammad; Siampour, Majid; Rouhani, Hamid; Mehrvar, Mohsen

    2014-08-01

    To investigate the genetic diversity of potato virus M (PVM; genus Carlavirus, family Betaflexiviridae), the complete nucleotide sequence of the coat protein gene of 30 PVM isolates from a major potato-growing region in Iran were determined. Phylogenetic analysis of these Iranian PVM isolates together with those available in the GenBank database suggested two divergent evolutionary lineages that did not reflect the origin of the isolates, and these were designated as PVM-o and PVM-d. Examination of the genetic variability of the coat protein of Iranian isolates and their counterparts whose sequences are available in the Genbank database revealed 16 genotype groups in the PVM population. Analysis of the synonymous-tononsynonymous ratio showed strong purifying selection in the CP gene in the genotype groups of divergent clades.

  13. Environmental Assessment: Geothermal Energy Geopressure Subprogram. Gulf Coast Well Drilling and Testing Activity (Frio, Wilcox, and Tuscaloosa Formations, Texas and Louisiana)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-01

    The Department of Energy (DOE) has initiated a program to evaluate the feasibility of developing the geothermal-geopressured energy resources of the Louisiana-Texas Gulf Coast. As part of this effort, DOE is contracting for the drilling of design wells to define the nature and extent of the geopressure resource. At each of several sites, one deep well (4000-6400 m) will be drilled and flow tested. One or more shallow wells will also be drilled to dispose of geopressured brines. Each site will require about 2 ha (5 acres) of land. Construction and initial flow testing will take approximately one year. If initial flow testing is successful, a continuous one-year duration flow test will take place at a rate of up to 6400 m{sup 3} (40,000 bbl) per day. Extensive tests will be conducted on the physical and chemical composition of the fluids, on their temperature and flow rate, on fluid disposal techniques, and on the reliability and performance of equipment. Each project will require a maximum of three years to complete drilling, testing, and site restoration.

  14. Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

    Directory of Open Access Journals (Sweden)

    Taufik

    2014-08-01

    Full Text Available The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°.to 44°

  15. The neutronic design and performance of the Indiana University Cyclotron Facility (IUCF) Low Energy Neutron Source (LENS)

    Science.gov (United States)

    Lavelle, Christopher M.

    Neutron scattering research is performed primarily at large-scale facilities. However, history has shown that smaller scale neutron scattering facilities can play a useful role in education and innovation while performing valuable materials research. This dissertation details the design and experimental validation of the LENS TMR as an example for a small scale accelerator driven neutron source. LENS achieves competitive long wavelength neutron intensities by employing a novel long pulse mode of operation, where the neutron production target is irradiated on a time scale comparable to the emission time of neutrons from the system. Monte Carlo methods have been employed to develop a design for optimal production of long wavelength neutrons from the 9Be(p,n) reaction at proton energies ranging from 7 to 13 MeV proton energy. The neutron spectrum was experimentally measured using time of flight, where it is found that the impact of the long pulse mode on energy resolution can be eliminated at sub-eV neutron energies if the emission time distribution of neutron from the system is known. The emission time distribution from the TMR system is measured using a time focussed crystal analyzer. Emission time of the fundamental cold neutron mode is found to be consistent with Monte Carlo results. The measured thermal neutron spectrum from the water reflector is found to be in agreement with Monte Carlo predictions if the scattering kernels employed are well established. It was found that the scattering kernels currently employed for cryogenic methane are inadequate for accurate prediction of the cold neutron intensity from the system. The TMR and neutronic modeling have been well characterized and the source design is flexible, such that it is possible for LENS to serve as an effective test bed for future work in neutronic development. Suggestions for improvements to the design that would allow increased neutron flux into the instruments are provided.

  16. Electron cyclotron resonance heating in a short cylindrical plasma ...

    Indian Academy of Sciences (India)

    Electron cyclotron resonance (ECR) plasma is produced and studied in a small cylindrical system. Microwave power is delivered by a CW magnetron at 2.45 GHz in TE10 mode and launched radially to have extraordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the first two ...

  17. Electron cyclotron resonance breakdown studies in a linear plasma ...

    Indian Academy of Sciences (India)

    Abstract. Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases – hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02. GHz in TE10 mode and launched radially to have ...

  18. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for dolphins and manatees for the Upper Coast of Texas. Vector polygons in this data set represent marine...

  19. Predicting induced activity in the Havar foils of the (18)F production targets of a PET cyclotron and derived radiological risk.

    Science.gov (United States)

    Martinez-Serrano, J Javier; Diez de Los Rios, Antonio

    2014-08-01

    The PET cyclotron at the Centre of Molecular Imaging of the Universidad de Malaga (CIMES) is a 16.5 MeV GE PETtrace cyclotron working at dual beam (40 μA beam). The cyclotron is dedicated mainly to F production. The F target has two thin circular foils composed of a metal alloy (Havar), that are highly activated by the proton beam and secondary neutrons. The main purpose of this study is to assess induced activity radiological risk derived from the Havar foils activation. Induced activity in Havar foils was estimated by two procedures. One consisted in estimating neutron and proton fluxes with MCNPX and using them as inputs in the activation code ACAB. Alternatively, given the regular periodicity of the irradiation cycles, an analytical expression was derived to estimate activity concentrations of activation products using production rates calculated with MCNPX. Large differences were found in the induced foil activities predicted by the two procedures. Therefore, an irradiated vacuum foil was measured with a Ge detector to analyze activity levels. Cobalt-58 (Co) and Co activities calculated with ACAB match well with measurements. Cobalt-60 (Co) activity estimated with the alternative method agrees acceptably with the measured activity, and Co activity is slightly overestimated. Cobalt-57 (Co) is the activation product of concern in the long term. The vacuum and window foils will be exempted in 3.3 y and 5.5 y, respectively, after replacement. Calculated effective dose with MCNPX and ICRP reference HML phantoms in the foils replacement operation is 0.34 mSv, and annual effective dose would be 2.1 mSv, which is below the annual limits.

  20. Simulation on the electronic wave packet cyclotron motion in a Weyl semimetal slab.

    Science.gov (United States)

    Yao, Haibo; Zhu, Mingfeng; Jiang, Liwei; Zheng, Yisong

    2017-04-20

    We perform a numerical simulation on the time evolution of an electronic wave packet in a Weyl semimetal (WSM) slab driven by a magnetic field. We find that the evolution trajectory of the wave packet depends sensitively on its initial spin state. Only with initial spin state identical to that of the Fermi arc state at the surface it localized, does the wave packet evolution demonstrate the characteristic cyclotron orbit of WSM previously predicted from a semiclassical viewpoint. By analyzing the eigen-expansion of the electronic wave packet, we find the chiral Landau levels (LLs) of the WSM slab, as ingredients of the wave packet, to be responsible for establishing the characteristic WSM cyclotron orbit. In contrast, the nonchiral LLs contribute irregular oscillations to the wave packet evolution, going against the formation of a well-defined cyclotron orbit. In addition, the tilted magnetic field does not affect the motion of the electronic wave packet along the Fermi arcs in the momentum space. It does, however, alter the evolution trajectory of the electronic wave packet in real space and spin space. Finally, the energy disalignment of the Weyl nodes results in a 3D cyclotron orbit in real space.

  1. Fabrication of Natural Uranium UO2 Disks (Phase II): Texas A&M Work for Others Summary Document

    Energy Technology Data Exchange (ETDEWEB)

    Gerczak, Tyler J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baldwin, Charles A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schmidlin, Joshua E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Henry, Jr, John James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-28

    The steps to fabricate natural UO2 disks for an irradiation campaign led by Texas A&M University are outlined. The process was initiated with stoichiometry adjustment of parent, U3O8 powder. The next stage of sample preparation involved exploratory pellet pressing and sintering to achieve the desired natural UO2 pellet densities. Ideal densities were achieved through the use of a bimodal powder size blend. The steps involved with disk fabrication are also presented, describing the coring and thinning process executed to achieve final dimensionality.

  2. A new species of Elasmia Möschler from New Mexico and Texas, and a new subspecies of Elasmia mandela (Druce from Texas and Oklahoma (Lepidoptera, Notodontidae, Nystaleinae

    Directory of Open Access Journals (Sweden)

    Eric Metzler

    2011-11-01

    Full Text Available Hippia packardii (Morrison and Hippia insularis (Grote are moved to the genus Elasmia Möschler as comb. n. Elasmia cave Metzler, sp. n. is described from New Mexico and Texas, and Elasmia mandela santaana Metzler & Knudson, ssp. n. is described from Texas and Oklahoma. A key to the species of Elasmia of southwestern U.S. is provided. Adult male and female moths of Elasmia from southwestern U.S. and their genitalia are illustrated.

  3. Variable speed drives principles and applications for energy cost savings

    CERN Document Server

    Spitzer, David William

    2014-01-01

    Simply put, a variable speed drive is a controller that allows a motor and its associated equipment to run at different speeds depending upon automated input from an industrial process. That in turn provides the ability to provide smoother operations, and most importantly, energy savings by slowing down machinery when a process does not have to run at full speed. Long a leading book on this technology, this new edition by industry authority David William Spitzer provides insights to improving the applications of variable speed drives. Whether you have basic knowledge or advanced knowledge, you will find this book to be an extremely useful introduction to how variable speed drivers work, how they are best applied, and what to do and what to avoid when employing them as part of an overall automated industrial enterprise, all with an eye on energy savings. Inside, you will find: A basic overview of electrical, hydraulic, and instrumentation principles of variable speed drives. Coverage of the role that variabl...

  4. Interacting ghost dark energy models with variable G and Λ

    Science.gov (United States)

    Sadeghi, J.; Khurshudyan, M.; Movsisyan, A.; Farahani, H.

    2013-12-01

    In this paper we consider several phenomenological models of variable Λ. Model of a flat Universe with variable Λ and G is accepted. It is well known, that varying G and Λ gives rise to modified field equations and modified conservation laws, which gives rise to many different manipulations and assumptions in literature. We will consider two component fluid, which parameters will enter to Λ. Interaction between fluids with energy densities ρ1 and ρ2 assumed as Q = 3Hb(ρ1+ρ2). We have numerical analyze of important cosmological parameters like EoS parameter of the composed fluid and deceleration parameter q of the model.

  5. Low current performance of the Bern medical cyclotron down to the pA range

    Science.gov (United States)

    Auger, M.; Braccini, S.; Ereditato, A.; Nesteruk, K. P.; Scampoli, P.

    2015-09-01

    A medical cyclotron accelerating H- ions to 18 MeV is in operation at the Bern University Hospital (Inselspital). It is the commercial IBA 18/18 cyclotron equipped with a specifically conceived 6 m long external beam line ending in a separate bunker. This feature is unique for a hospital-based facility and makes it possible to conduct routine radioisotope production for PET diagnostics in parallel with multidisciplinary research activities, among which are novel particle detectors, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. Several of these activities, such as radiobiology experiments for example, require low current beams down to the pA range, while medical cyclotrons are designed for high current operation above 10 μA. In this paper, we present the first results on the low current performance of a PET medical cyclotron obtained by ion source, radio-frequency and main coil tuning. With this method, stable beam currents down to (1.5+/- 0.5 ) pA were obtained and measured with a high-sensitivity Faraday cup located at the end of the beam transport line.

  6. The Texas Dental Association and advocacy: a TDA president's perspective.

    Science.gov (United States)

    Eggleston, Frank K; Jeske, Arthur H

    2008-08-01

    The TDA can take pride in the joint efforts of its leadership, its grassroots members, and its elected representatives in the middle of the decade of the 1990's. When asked about his legacy for the leadership of our organization, Dr. Eggleston emphatically states, "You have to act. You have to do the right thing even when you have critics and detractors." More recently, during his campaign for ADA President-elect, he constantly stressed the importance of our relationship with each other. Our relationship, in Dr. Eggleston's words now and during his TDA presidency, "is more important than all issues put together". As this brief retrospective illustrates, the issues faced by dentists and the TDA are never trivial and are always tied to the legislative process. Political advocacy by our association is, therefore, our first priority now, no less so than it was in the mid-1990's. As described in the recent "TDA Report Card" on our legislative agenda for the 80th Texas Legislature, our challenges continue unabated, but these challenges are answered, and in many cases, successfully overcome as a result of our advocacy efforts. Our need for constant involvement in the legislative process is perhaps best summarized by advice given to Dr. Eggleston by Senator (and oral surgeon) David Sibley at the 1995 TDA Annual Session. Senator Sibley complimented TDA on its achievements during the 1995 Texas legislative session, and added "but you've got to keep your garden weeded."

  7. Cyclotron Resonance Gain for FIR and THz Radiation in Graphene

    CERN Document Server

    Cole, Nightvid

    2016-01-01

    A cyclotron resonance maser source using low-effective-mass conduction electrons in graphene, if successful, would allow for generation of Far Infrared (FIR) and Terahertz (THz) radiation without requiring magnetic fields running into the tens of Tesla. In order to investigate this possibility, we consider a device in which electrons are effectively injected via pumping from the valence band to the conduction band using an infrared (IR) laser source, subsequently gyrate in a magnetic field applied perpendicular to the plane of the graphene, and give rise to gain for a FIR/THz wave crossing the plane of the graphene. A set of integral expressions is derived by assuming that the non-radiative energy loss processes of the electrons can be adequately represented by a damping force proportional and antiparallel to their momentum. Minimal gain may occur at very short electron damping times of hundreds of femtoseconds.

  8. Spatiotemporal Variability of Turbulence Kinetic Energy Budgets in the Convective Boundary Layer over Both Simple and Complex Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Raj K. [Pacific Northwest National Laboratory, Richland, Washington; Berg, Larry K. [Pacific Northwest National Laboratory, Richland, Washington; Pekour, Mikhail [Pacific Northwest National Laboratory, Richland, Washington; Shaw, William J. [Pacific Northwest National Laboratory, Richland, Washington; Kosovic, Branko [National Center for Atmospheric Research, Boulder, Colorado; Mirocha, Jeffrey D. [Lawrence Livermore National Laboratory, Livermore, California; Ennis, Brandon L. [Sandia National Laboratories, Albuquerque, New Mexico

    2017-12-01

    The assumption of sub-grid scale (SGS) horizontal homogeneity within a model grid cell, which forms the basis of SGS turbulence closures used by mesoscale models, becomes increasingly tenuous as grid spacing is reduced to a few kilometers or less, such as in many emerging high-resolution applications. Herein, we use the turbulence kinetic energy (TKE) budget equation to study the spatio-temporal variability in two types of terrain—complex (Columbia Basin Wind Energy Study [CBWES] site, north-eastern Oregon) and flat (ScaledWind Farm Technologies [SWiFT] site, west Texas) using the Weather Research and Forecasting (WRF) model. In each case six-nested domains (three domains each for mesoscale and large-eddy simulation [LES]) are used to downscale the horizontal grid spacing from 10 km to 10 m using the WRF model framework. The model output was used to calculate the values of the TKE budget terms in vertical and horizontal planes as well as the averages of grid cells contained in the four quadrants (a quarter area) of the LES domain. The budget terms calculated along the planes and the mean profile of budget terms show larger spatial variability at CBWES site than at the SWiFT site. The contribution of the horizontal derivative of the shear production term to the total production shear was found to be 45% and 15% of the total shear, at the CBWES and SWiFT sites, respectively, indicating that the horizontal derivatives applied in the budget equation should not be ignored in mesoscale model parameterizations, especially for cases with complex terrain with <10 km scale.

  9. Demonstration of low energy proton radiography on an 11-MeV cyclotron

    Science.gov (United States)

    Zhang, Xiao Ding; Yang, Guo Jun; Li, Yi Ding; Wei, Tao; He, Xiaozhong; Zhao, Liang Chao; Zhang, Zhuo; Ma, Chaofan; Jiang, Xiaoguo; Shi, Jinshui

    2016-11-01

    Lens focused proton radiograph on thin objects is demonstrated using an 11-MeV proton cyclotron at China Academy of Engineering Physics. The proton beam exiting from the tested objects is focused onto the image plane by a magnetic lens system mitigating image blur caused by multiple Coulomb scattering. Both simulations and experiments show that clear images can be obtained with a lens system for the objects with thickness up to 2.7 × 10-2 g/cm2 and the error for the areal density measurement is measured to be less than 2.3%. For the objects with thickness between 2.7 × 10-3 g/cm2 and 2.7 × 10-2 g/cm2, 100-200 μm of spatial resolution is achieved.

  10. Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc.

    Science.gov (United States)

    Hou, X; Tanguay, J; Vuckovic, M; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2016-12-07

    Cyclotron-produced 99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99mTc. However, the small amount of 92-98Mo in the irradiation of enriched 100Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

  11. Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis

    Science.gov (United States)

    Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.

    2016-01-01

    Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.

  12. Initial operation of the Sherbrooke EBCO 19 MeV cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, K.L.; Cackette, M.; Dehnel, M.P.; Gyles, W.; Johnson, R.R.; Kovac, B.; Popa, I.; Sabaiduc, V.; Watt, R.; Sliwinski, A. [EBCO Technologies Inc., Richmond BC (Canada); Van Lier, J.E. [Sherbrooke Univ., PQ (Canada). Faculte de Medicine

    1999-07-01

    A variable energy TR19 cyclotron built by EBCO Technologies was installed and commissioned at the Centre Hospitalier Universite de Sherbrooke at the end of 1997. This negative ion cyclotron is capable of accelerating a 150 {mu}Amp of protons to over 19 MeV energy and two simultaneous beams of protons of energies between 13 and 19 MeV can be extracted on opposite sides of the magnet. A novel target changer permits the positioning of the variable energy beams, which leave the magnet at different angles, into long gaseous targets. Properties of the beams used for the production of both PET and SPECT isotopes, made possible by the variable energy feature, are discussed. (authors)

  13. Potential environmental impacts arising from geopressured-geothermal energy development Texas--Louisiana Gulf Coast region

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, T.C. (Univ. of Texas, Austin); McGraw, M.M.; Tandy, M.; Parker, F.; Wohlschlag, D.E.; Meriwether, J.

    1977-11-16

    Geopressured-geotheermal resources of the Gulf Coast of Texas and Louisiana are currently being evaluated as thermal-hydraulic energy sources to drive turbines to generate electrical power. Gulf Coast geothermal fluids are brines with salinities generally in excess of 40,000 ppM and tempertures up to 283/sup 0/C (520/sup 0/F). The proportions of dissolved ions in geothermal fluids is markedly different than that of sea water, and the fluids are expected to be saturated with methane. As much as 54,000 m/sup 3/ (310,000 bbls) of fluids per day at a temperature of 049/sup 0/C (300/sup 0/F) will be required to feed one 25 megawatt power plant. The energy resource, the ecological resources of the Gulf Coast, and the potential effects of the development of geothermal energy on ecological resources are described.

  14. The Texas Academy of Mathematics and Science: A 20-Year Perspective

    Science.gov (United States)

    Jones, Brent M.

    2011-01-01

    The Texas Academy of Mathematics and Science (TAMS) is a publicly financed, residential early college entrance institute at the University of North Texas at Denton. Created in 1987, TAMS enables high-achieving students planning STEM careers to complete their last 2 years of high school simultaneously with their first 2 years of college. Admission…

  15. Geopressured geothermal resource of the Texas and Louisiana Gulf Coast: a technology characterization and environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    Usibelli, A.; Deibler, P.; Sathaye, J.

    1980-12-01

    Two aspects of the Texas and Louisiana Gulf Coast geopressured geothermal resource: (1) the technological requirements for well drilling, completion, and energy conversion, and, (2) the environmental impacts of resource exploitation are examined. The information comes from the literature on geopressured geothermal research and from interviews and discussions with experts. The technology characterization section emphasizes those areas in which uncertainty exists and in which further research and development is needed. The environmental assessment section discusses all anticipated environmental impacts and focuses on the two largest potential problems: (a) subsidence and (b) brine disposal.

  16. Economic Development Impact of 1,000 MW of Wind Energy in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Reategui, S.; Hendrickson, S.

    2011-08-01

    Texas has approximately 9,727 MW of wind energy capacity installed, making it a global leader in installed wind energy. As a result of the significant investment the wind industry has brought to Texas, it is important to better understand the economic development impacts of wind energy in Texas. This report analyzes the jobs and economic impacts of 1,000 MW of wind power generation in the state. The impacts highlighted in this report can be used in policy and planning decisions and can be scaled to get a sense of the economic development opportunities associated with other wind scenarios. This report can also inform stakeholders in other states about the potential economic impacts associated with the development of 1,000 MW of new wind power generation and the relationships of different elements in the state economy.

  17. Evaluating the variability of sediment and nutrient loading from riverine systems into Texas estuaries and bays

    Science.gov (United States)

    Lee, Michael T.

    2011-01-01

    The water quality in estuaries and bays and the health of these coastal ecosystems are affected by sediment and nutrient loads transported by streams. Large sediment loads delivered to an estuary or bay can degrade water quality. Concentrations of suspended sediment are affected by natural conditions (such as soil erosion and streambed resuspension) and can also be affected by human activities (such as development, timber harvesting, certain agricultural practices, and hydraulic alteration). An increased sediment load delivered to an estuary or bay can reduce water clarity and light penetration (Senus and others, 2005) in the water column. Senus and others (2005, p. 1) also note that nutrients are needed to sustain life, but excess nutrient loads from human activities may cause unbalanced and unhealthy changes in water quality that are harmful to aquatic organisms. Nitrogen and phosphorus are two known nutrients of concern. Poor water quality caused by an abundance of these nutrients can stimulate the excessive growth of phytoplankton, promote algal blooms, reduce dissolved oxygen levels, and cause fish kills.

  18. One-electron quantum cyclotron (and implications for cold antihydrogen)

    CERN Document Server

    Gabrielse, G; Odom, B; D'Urso, B

    2001-01-01

    Quantum jumps between Fock states of a one-electron oscillator reveal the quantum limit of a cyclotron accelerator. The states live for seconds when spontaneous emission is inhibited by a factor of 140 within a cylindrical Penning trap cavity. Averaged over hours the oscillator is in thermal equilibrium with black-body photons in the cavity. At 80 mK, quantum jumps occur only when resonant microwave photons are introduced into the cavity, opening a route to improved measurements of the magnetic moments of the electron and positron. The temperature demonstrated is about 60 times lower than the 4.2 K temperature at which charged elementary particles were previously stored. Implications for the production of cold antihydrogen are discussed. (21 refs).

  19. Electron Cyclotron Resonance Heating of a High-Density Plasma

    DEFF Research Database (Denmark)

    Hansen, F. Ramskov

    1986-01-01

    Various schemes for electron cyclotron resonance heating of tokamak plasmas with the ratio of electron plasma frequency to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis, are investigated. In particular, a mode conversion scheme is investigated using ordinary waves at the fundamental...

  20. Hot Thermal Storage in a Variable Power, Renewable Energy System

    Science.gov (United States)

    2014-06-01

    commercially proven and available energy collection, conversion , and storage systems and equipment. Chapter IV presents a method for innovative integration of...molten salt. On a grid scale, off-peak electricity, converted by ohmic heating, and thermal energy from a concentrated solar power ( CSP ) plant...renewable generation system with heat storage. It reviews the available energy sources as well as methods for energy conversion and storage. A

  1. Promoting Energy-Balance Behaviors among Ethnically Diverse Adolescents: Overview and Baseline Findings of the Central Texas CATCH Middle School Project

    Science.gov (United States)

    Springer, Andrew E.; Kelder, Steven H.; Byrd-Williams, Courtney E.; Pasch, Keryn E.; Ranjit, Nalini; Delk, Joanne E.; Hoelscher, Deanna M.

    2013-01-01

    The Central Texas Coordinated Approach To Child Health (CATCH) Middle School Project is a 3.5-year school-based project aimed at promoting physical activity (PA), healthy eating, and obesity prevention among public middle school students in Texas. This article describes the CATCH intervention model and presents baseline findings from spring 2009.…

  2. Terahertz cyclotron resonance spectroscopy of an AlGaN/GaN heterostructure using a high-field pulsed magnet and an asynchronous optical sampling technique

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B. F., E-mail: Ben.Spencer@manchester.ac.uk; Smith, W. F.; Hibberd, M. T.; Dawson, P.; Graham, D. M. [School of Physics and Astronomy and the Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom); Beck, M.; Bartels, A. [Laser Quantum GmbH, Max-Stromeyer-Str. 116, 78467 Konstanz (Germany); Guiney, I.; Humphreys, C. J. [Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge, Cambridge CB3 0FS (United Kingdom)

    2016-05-23

    The effective mass, sheet carrier concentration, and mobility of electrons within a two-dimensional electron gas in an AlGaN/GaN heterostructure were determined using a laboratory-based terahertz cyclotron resonance spectrometer. The ability to perform terahertz cyclotron resonance spectroscopy with magnetic fields of up to 31 T was enabled by combining a high-field pulsed magnet with a modified asynchronous optical sampling terahertz detection scheme. This scheme allowed around 100 transmitted terahertz waveforms to be recorded over the 14 ms magnetic field pulse duration. The sheet density and mobility were measured to be 8.0 × 10{sup 12 }cm{sup −2} and 9000 cm{sup 2} V{sup −1} s{sup −1} at 77 K. The in-plane electron effective mass at the band edge was determined to be 0.228 ± 0.002m{sub 0}.

  3. Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, Roberta M.; Davidson, Kris; Hahn, David [Minnesota Institute for Astrophysics, 116 Church St SE, University of Minnesota, Minneapolis, MN 55455 (United States); Martin, John C. [Barber Observatory, University of Illinois, Springfield, IL 62703 (United States); Weis, Kerstin, E-mail: roberta@umn.edu [Astronomical Institute, Ruhr-Universitaet Bochum (Germany)

    2017-07-20

    We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with the infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.

  4. Expanding space-time and variable vacuum energy

    Science.gov (United States)

    Parmeggiani, Claudio

    2017-08-01

    The paper describes a cosmological model which contemplates the presence of a vacuum energy varying, very slightly (now), with time. The constant part of the vacuum energy generated, some 6 Gyr ago, a deceleration/acceleration transition of the metric expansion; so now, in an aged Universe, the expansion is inexorably accelerating. The vacuum energy varying part is instead assumed to be eventually responsible of an acceleration/deceleration transition, which occurred about 14 Gyr ago; this transition has a dynamic origin: it is a consequence of the general relativistic Einstein-Friedmann equations. Moreover, the vacuum energy (constant and variable) is here related to the zero-point energy of some quantum fields (scalar, vector, or spinor); these fields are necessarily described in a general relativistic way: their structure depends on the space-time metric, typically non-flat. More precisely, the commutators of the (quantum field) creation/annihilation operators are here assumed to depend on the local value of the space-time metric tensor (and eventually of its curvature); furthermore, these commutators rapidly decrease for high momentum values and they reduce to the standard ones for a flat metric. In this way, the theory is ”gravitationally” regularized; in particular, the zero-point (vacuum) energy density has a well defined value and, for a non static metric, depends on the (cosmic) time. Note that this varying vacuum energy can be negative (Fermi fields) and that a change of its sign typically leads to a minimum for the metric expansion factor (a ”bounce”).

  5. Texas urban triangle : creating a spatial decision support system for mobility policy and investments that shape the sustainable growth of Texas.

    Science.gov (United States)

    2010-11-01

    This project developed a GIS-based Spatial Decision Support System to help local, metropolitan, and state : jurisdictions and authorities in Texas understand the implications of transportation planning and : investment decisions, and plan appropriate...

  6. Unprecedented conformational variability in main group inorganic chemistry: the tetraazidoarsenite and -antimonite salts A+ [M(N3)4]- (A = NMe4, PPh4, (Ph3P)2N; M = As, Sb), five similar salts, five different anion structures.

    Science.gov (United States)

    Haiges, Ralf; Rahm, Martin; Christe, Karl O

    2013-01-07

    A unique example for conformational variability in inorganic main group chemistry has been discovered. The arrangement of the azido ligands in the pseudotrigonal bipyramidal [As(N(3))(4)](-) and [Sb(N(3))(4)](-) anions theoretically can give rise to seven different conformers which have identical MN(4) skeletons but different azido ligand arrangements and very similar energies. We have now synthesized and structurally characterized five of these conformers by subtle variations in the nature of the counterion. Whereas conformational variability is common in organic chemistry, it is rare in inorganic main group chemistry and is usually limited to two. To our best knowledge, the experimental observation of five distinct single conformers for the same type of anion is unprecedented. Theoretical calculations at the M06-2X/cc-pwCVTZ-PP level for all seven possible basic conformers show that (1) the energy differences between the five experimentally observed conformers are about 1 kcal/mol or less, and (2) the free monomeric anions are the energetically favored species in the gas phase and also for [As(N(3))(4)](-) in the solid state, whereas for [Sb(N(3))(4)](-) associated anions are energetically favored in the solid state and possibly in solutions. Raman spectroscopy shows that in the azide antisymmetric stretching region, the solid-state spectra are distinct for the different conformers, and permits their identification. The spectra of solutions are solvent dependent and differ from those of the solids indicating the presence of rapidly exchanging equilibria of different conformers. The only compound for which a solid with a single well-ordered conformer could not be isolated was [N(CH(3))(4)][As(N(3))(4)] which formed a viscous, room-temperature ionic liquid. Its Raman spectrum was identical to that of its CH(3)CN solution indicating the presence of an equilibrium of multiple conformers.

  7. Neutron spectra due (13)N production in a PET cyclotron.

    Science.gov (United States)

    Benavente, J A; Vega-Carrillo, H R; Lacerda, M A S; Fonseca, T C F; Faria, F P; da Silva, T A

    2015-05-01

    Monte Carlo and experimental methods have been used to characterize the neutron radiation field around PET (Positron Emission Tomography) cyclotrons. In this work, the Monte Carlo code MCNPX was used to estimate the neutron spectra, the neutron fluence rates and the ambient dose equivalent (H*(10)) in seven locations around a PET cyclotron during (13)N production. In order to validate these calculations, H*(10) was measured in three sites and were compared with the calculated doses. All the spectra have two peaks, one above 0.1MeV due to the evaporation neutrons and another in the thermal region due to the room-return effects. Despite the relatively large difference between the measured and calculated H*(10) for one point, the agreement was considered good, compared with that obtained for (18)F production in a previous work. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Meet the aggies; internship experience at the Texas A&M University

    NARCIS (Netherlands)

    Shukla, A.

    2013-01-01

    “Welcome to the United States of America” the lines I had heard quite a few times in movies and sitcoms. Yet here I was listening to it, jet lagged and sleep deprived after roughly 24 hrs of flying, having just completed the immigration clearance at George Bush International Airport, Houston.

  9. Target development for diversified irradiations at a medical cyclotron.

    Science.gov (United States)

    Spellerberg, S; Scholten, B; Spahn, I; Bolten, W; Holzgreve, M; Coenen, H H; Qaim, S M

    2015-10-01

    The irradiation facility at an old medical cyclotron (Ep=17 MeV; Ed=10 MeV) was upgraded by extending the beam line and incorporation of solid state targetry. Tests performed to check the quality of the available beam are outlined. Results on nuclear data measurements and improvement of radiochemical separations are described. Using solid targets, with the proton beam falling at a slanting angle of 20°, a few radionuclides, e.g. (75)Se, (120)I, (124)I, etc. were produced with medium currents (up to 20 µA) in no-carrier-added form in quantities sufficient for local use. The extended irradiation facility has considerably enhanced the utility of the medical cyclotron. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Solid targets for production of radioisotopes with cyclotron; Blancos solidos para produccion de radioisotopos con ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Balcazar G, M. [Instituto Nacional de Investigaciones Nucleares, Direccion de Investigacion Tecnologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The design of targets for production of radioisotopes and radiopharmaceuticals of cyclotron to medical applications requires a detailed analysis of several variables such as: cyclotron operation conditions, choice of used materials as target and their physicochemical characteristics, activity calculation, the yielding of each radioisotope by irradiation, the competition of nuclear reactions in function of the projectiles energy and the collision processes amongst others. The objective of this work is to determine the equations for the calculation for yielding of solid targets at the end of the proton irradiation. (Author)

  11. Offender and victim characteristics of registered female sexual offenders in Texas: a proposed typology of female sexual offenders.

    Science.gov (United States)

    Vandiver, Donna M; Kercher, Glen

    2004-04-01

    Victim and offender characteristic of all registered adult female sexual offenders in Texas (N = 471) were examined. The most common offenses the females were arrested for were indecency with a child--sexual contact, sexual assault on a child, and aggravated sexual assault on a child. The majority (88%) of the females were Caucasian and the ages ranged from 18 to 77 (M = 32). The results of Hierarchical Loglinear Modeling yielded a complex relationship between offender and victim characteristics; thus, identification of preferred victims is mitigated by more than one variable. Additionally, the employment of cluster analysis yielded 6 types of female sexual offenders. The most common group includes 146 offenders, heterosexual nurturers. They were the least likely to have an arrest for a sexual assault. The victims were males who averaged 12 years of age. The other types of offenders included, noncriminal homosexual offenders, female sexual predators, young adult child exploiters, homosexual criminals, and aggressive homosexual offenders.

  12. Design of coupled cavity with energy modulated electron cyclotron resonance ion source for materials irradiation research

    Directory of Open Access Journals (Sweden)

    Z. Wang (王智

    2012-05-01

    Full Text Available The surface topography of samples after irradiation with heavy ions, protons, and helium ions based on accelerators is an important issue in the study of materials irradiation. We have coupled the separated function radio frequency quadrupole (SFRFQ electrodes and the traditional RFQ electrodes into a single cavity that can provide a 0.8 MeV helium beam for our materials irradiation project. The higher accelerating efficiency has been verified by the successful commissioning of the prototype SFRFQ cavity. An energy modulated electron cyclotron resonance (ECR ion source can achieve a well-bunched beam by loading a sine wave voltage onto the extracted electrodes. Bunching is achieved without the need for an external bunch cavity, which can substantially reduce the cost of the system and the length of the beam line. The coupled RFQ-SFRFQ with an energy modulated ECR ion source will lead to a more compact accelerator system. The conceptual design of this novel structure is presented in this paper.

  13. Gamma ray facilities at the University of Maryland cyclotron. [data acquisition and radiation measurement

    Science.gov (United States)

    Hornyak, W. F.

    1978-01-01

    A special beam line was set up in a separate shielded experimental room to provide a low background station for gamma-ray measurements at the University of Maryland cyclotron. The transmitted beam leaving the target is gathered in by a magnetic quadrupole lens located 1.8 m further downstream and focused on a Faraday cup located on the far side of the 2.5 m thick concrete shielding wall of the experimental room. A software computer program permits timing information ot be obtained using the cyclotron beam fine structure as a time reference for the observed gamma-ray events. Measurements indicate a beam fine structure width of less than 1.2 nanoseconds repeated, for example, in the case of 140 MeV alpha particles every 90 nanoseconds. Twelve contiguous time channels of adjustable width may be set as desired with reference to the RF signal. This allows the creation of 12 separate 8192 channel analyzers.

  14. Soybean Yield along the Texas Gulf Coast during Periods of Variable Rainfall as Influenced by Soybean Cultivar and Planting Date

    Directory of Open Access Journals (Sweden)

    W. J. Grichar

    2011-01-01

    Full Text Available Soybeans (Glycine max can be planted along the upper Texas Gulf Coast from mid-March through May to take advantage of early season rains and to complete harvest before hurricane season and fall rains become a problem. When average to above average rainfall was received in May through July, yields were greater with the early April to mid-April planting; however, under high rainfall conditions throughout the season, the mid-April to early May planting produced the highest yields, with yields of over 4000 kg/ha. When rainfall was below normal, late March to early April plantings produced the greatest yields. When rainfall was above average, soybeans took longer to reach harvestability regardless of cultivar or plant dates, while under drought conditions the interval between planting and harvest was reduced. However, when planting was delayed, there was a greater risk of detrimental late-season effects from southern green stink bug (Nezara viridula or the brown stink bug (Euschistus heros.

  15. CLOVERLEAF CYCLOTRON

    Science.gov (United States)

    McMillan, E.M.; Judd, D.L.

    1959-02-01

    A cyclotron is presented embodying a unique magnetic field configuration, which configuration increases in intensity with radius and therefore compensates for the reltivistic mass effect, the field having further convolutions productive of axial stability in the particle beam. By reconciling the seemingly opposed requirements of mass increase compensation on one hand and anial stability on the other, the production of extremely high current particle beams in the relativistie energy range is made feasible. Certain further advantages inhere in the invention, notably an increase in the usable magnet gap, simplified and more efficient extraction of the beam from the accelerator, and ready adaptation to the use of multiply phased excitation as contrasted with the single phased systems herstofore utilized. General

  16. Optimizing C4+ and C5+ beams of the Kei2 electron cyclotron resonance ion source using a special gas-mixing technique

    NARCIS (Netherlands)

    Drentje, A. G.; Muramatsu, M.; Kitagawa, A.

    With the prototype electron cyclotron resonance ion source for the next carbon therapy facility in Japan a series of measurements has been performed in order (a) to find the best condition for producing high beam currents of C4+ ions, and (b) to study the effect of "special" gas mixing by using a

  17. Design and characterization of a 32-channel heterodyne radiometer for electron cyclotron emission measurements on experimental advanced superconducting tokamak.

    Science.gov (United States)

    Han, X; Liu, X; Liu, Y; Domier, C W; Luhmann, N C; Li, E Z; Hu, L Q; Gao, X

    2014-07-01

    A 32-channel heterodyne radiometer has been developed for the measurement of electron cyclotron emission (ECE) on the experimental advanced superconducting tokamak (EAST). This system collects X-mode ECE radiation spanning a frequency range of 104-168 GHz, where the frequency coverage corresponds to a full radial coverage for the case with a toroidal magnetic field of 2.3 T. The frequency range is equally spaced every 2 GHz from 105.1 to 167.1 GHz with an RF bandwidth of ~500 MHz and the video bandwidth can be switched among 50, 100, 200, and 400 kHz. Design objectives and characterization of the system are presented in this paper. Preliminary results for plasma operation are also presented.

  18. Realistic simulations of a cyclotron spiral inflector within a particle-in-cell framework

    Science.gov (United States)

    Winklehner, Daniel; Adelmann, Andreas; Gsell, Achim; Kaman, Tulin; Campo, Daniela

    2017-12-01

    We present an upgrade to the particle-in-cell ion beam simulation code opal that enables us to run highly realistic simulations of the spiral inflector system of a compact cyclotron. This upgrade includes a new geometry class and field solver that can handle the complicated boundary conditions posed by the electrode system in the central region of the cyclotron both in terms of particle termination, and calculation of self-fields. Results are benchmarked against the analytical solution of a coasting beam. As a practical example, the spiral inflector and the first revolution in a 1 MeV /amu test cyclotron, located at Best Cyclotron Systems, Inc., are modeled and compared to the simulation results. We find that opal can now handle arbitrary boundary geometries with relative ease. Simulated injection efficiencies and beam shape compare well with measured efficiencies and a preliminary measurement of the beam distribution after injection.

  19. Independent, additive effects of five dietary variables on ad libitum energy intake in a residential study.

    Science.gov (United States)

    Urban, Lorien E; McCrory, Megan A; Rasmussen, Helen; Greenberg, Andrew S; Fuss, Paul J; Saltzman, Edward; Roberts, Susan B

    2014-09-01

    To examine the relationship between dietary characteristics of self-selected foods and energy balance in a cafeteria-style dining hall. Ad libitum dietary intake from a self-selection menu was measured over two days in 151 adults (70% female, mean age 41 years, mean BMI 24.9 kg/m(2) ). The associations of dietary variables with energy balance (calculated as measured energy intake/predicted energy requirements, pER) were assessed. Measured energy intake was significantly correlated with pER (R(2) =0.83, P < 0.001). In mixed multiple regression models, percent energy from protein was negatively associated with energy balance (R(2) =0.04, P = 0.02), and percent energy from liquid sources (R(2)  = 0.02, P = 0.05), total dietary variety in females (R(2)  = 0.39, P < 0.001), and energy density (R(2)  = 0.57, P < 0.001) were positively associated with energy balance. In addition, glycemic index was inversely associated with energy balance in normal-weight individuals (R(2)  = 0.14, P < 0.001) but not in overweight or obese individuals. There are independent associations of dietary protein, liquid calories, energy density, dietary variety, and glycemic index with energy balance, indicating additive effects of these dietary factors on energy intake and energy balance. Intervention studies are needed to determine whether dietary prescriptions combining these dietary factors facilitate long-term prevention of weight gain. © 2014 The Obesity Society.

  20. MEGHNAD–A multi element detector array for heavy ion collision ...

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... In the coming decade, the expanding field of experimental nuclear physics in our country is going to see a quantum leap in research and developmental activities with new accelerator facilities like the variable energy cyclotron with ECR heavy ion source, the upcoming K-500 superconducting cyclotron, ...

  1. Nuclear Hybrid Energy Systems - Regional Studies. West Texas and Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Humberto E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chen, Jun [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kim, Jong S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); McKellar, Michael G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Deason, Wesley R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Vilim, Richard B. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The primary objective of this study is to conduct a preliminary dynamic analysis of two realistic hybrid energy systems (HES) including a nuclear reactor as the main baseload heat generator (denoted as nuclear HES or nuclear hybrid energy systems [NHES]) and to assess the local (e.g., HES owners) and system (e.g., the electric grid) benefits attainable by the application of NHES in scenarios with multiple commodity production and high penetration of renewable energy. It is performed for regional cases - not generic examples - based on available resources, existing infrastructure, and markets within the selected regions. This study also briefly addresses the computational capabilities developed to conduct such analyses, reviews technical gaps, and suggests some research paths forward.

  2. Feasibility Study of Economics and Performance of Solar Photovoltaics at the Ft. Hood Military Base Outside Killeen, Texas. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, J.; Lisell, L.; Mosey, G.

    2013-10-01

    The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative through the Region 6 contract, selected Ft. Hood Army Base in Killeen, Texas, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this study is to assess the site for possible photovoltaic (PV) system installations and estimate the cost, performance, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.

  3. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone. (a) The following is a safety zone: (1) The west and northwest shores of Snake Island; (2) The...

  4. The response of surface mass and energy balance of a continental glacier to climate variability, western Qilian Mountains, China

    Science.gov (United States)

    Sun, Weijun; Qin, Xiang; Wang, Yetang; Chen, Jizu; Du, Wentao; Zhang, Tong; Huai, Baojuan

    2017-08-01

    To understand how a continental glacier responds to climate change, it is imperative to quantify the surface energy fluxes and identify factors controlling glacier mass balance using surface energy balance (SEB) model. Light absorbing impurities (LAIs) at the glacial surface can greatly decrease surface albedo and increase glacial melt. An automatic weather station was set up and generated a unique 6-year meteorological dataset for the ablation zone of Laohugou Glacier No. 12. Based on these data, the surface energy budget was calculated and an experiment on the glacial melt process was carried out. The effect of reduced albedo on glacial melting was analyzed. Owing to continuous accumulation of LAIs, the ablation zone had been darkening since 2010. The mean value of surface albedo in melt period (June through September) dropped from 0.52 to 0.43, and the minimum of daily mean value was as small as 0.1. From the records of 2010-2015, keeping the clean ice albedo fixed in the range of 0.3-0.4, LAIs caused an increase of +7.1 to +16 W m-2 of net shortwave radiation and an removal of 1101-2663 mm water equivalent. Calculation with the SEB model showed equivalent increases in glacial melt were obtained by increasing air temperature by 1.3 and 3.2 K, respectively.

  5. Integrated O&M for energy generation and exchange facilities; O&M integral para instalaciones de generación e intercambio de energía

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    Ingeteam Service, part of the Ingeteam Group, is a leading company in the provision of integrated O&M services at energy generation and exchange facilities worldwide. From its head office in the Albacete Science and Technology Park, it manages the work of the 1,300 employees that make up its global workforce, rendering services to wind farms, PV installations and power generation plants. In addition, it maintains an active participation strategy in a range of R&D+i programmes that improve the existing technologies and are geared towards new production systems and new diagnostic techniques, applied to renewables installation maintenance. (Author)

  6. Groundwater Challenges of the Lower Rio Grande: A Case Study of Legal Issues in Texas and New Mexico

    Directory of Open Access Journals (Sweden)

    Elizabeth Wheat

    2015-03-01

    Full Text Available In 1938, Texas, New Mexico, and Colorado signed the Rio Grande Compact, establishing terms of apportionment for some of the water from the Rio Grande for the three states. Following congressional approval in 1939, this compact governs water allocation in a region with a variable climate and frequent drought conditions and established the Rio Grande Compact Commission, comprised of a commissioner from each state and one from the federal government, to enforce the compact. With an increasing population and declining surface water supply, the Compact has been tested among the parties and within the states themselves. In a case currently before the U.S. Supreme Court, Texas v. New Mexico and Colorado (2013, Texas claims New Mexico is violating the Compact and Rio Grande Project Act by using water in excess of its apportionment through its allowance of diversions of surface and groundwater. The issue is further compounded by disputes within Texas over separate legal regimes for groundwater and surface water. Combined with growing scarcity issues, the allocation of water in the Lower Rio Grande presents a timely natural resource challenge. This review explores legal issues involved in the case as well as growing challenges of population growth, agricultural development needs, and water shortages.

  7. A Reference Handbook of the Texas Health Professions and their Support Personnel; The Health Professions in Texas.

    Science.gov (United States)

    Texas Nurses Association.

    The fields of dentistry, dietetics, medicine, medical technology, nursing, occupational therapy, pharmacy, physical therapy, and social work are defined in the handbook. The entrance requirements, educational institutions, and licensure regulations in Texas are treated for each major and allied support field. The functions or types of…

  8. On-shell constrained $M_2$ variables with applications to mass measurements and topology disambiguation

    CERN Document Server

    Cho, Won Sang; Kim, Doojin; Matchev, Konstantin T.; Moortgat, Filip; Pape, Luc; Park, Myeonghun

    2014-01-01

    We consider a class of on-shell constrained mass variables that are 3+1 dimensional generalizations of the Cambridge $M_{T2}$ variable and that automatically incorporate various assumptions about the underlying event topology. The presence of additional on-shell constraints causes their kinematic distributions to exhibit sharper endpoints than the usual $M_{T2}$ distribution. We study the mathematical properties of these new variables, e.g., the uniqueness of the solution selected by the minimization over the invisible particle 4-momenta. We then use this solution to reconstruct the masses of various particles along the decay chain. We propose several tests for validating the assumed event topology in missing energy events from new physics. The tests are able to determine: 1) whether the decays in the event are two-body or three-body, 2) if the decay is two-body, whether the intermediate resonances in the two decay chains are the same, and 3) the exact sequence in which the visible particles are emitted from ...

  9. Electron cyclotron resonance ion source plasma characterization by energy dispersive x-ray imaging

    Science.gov (United States)

    Rácz, R.; Mascali, D.; Biri, S.; Caliri, C.; Castro, G.; Galatà, A.; Gammino, S.; Neri, L.; Pálinkás, J.; Romano, F. P.; Torrisi, G.

    2017-07-01

    Pinhole and CCD based quasi-optical x-ray imaging technique was applied to investigate the plasma of an electron cyclotron resonance ion source (ECRIS). Spectrally integrated and energy resolved images were taken from an axial perspective. The comparison of integrated images taken of argon plasma highlights the structural changes affected by some ECRIS setting parameters, like strength of the axial magnetic confinement, RF frequency and microwave power. Photon counting analysis gives precise intensity distribution of the x-ray emitted by the argon plasma and by the plasma chamber walls. This advanced technique points out that the spatial positions of the electron losses are strongly determined by the kinetic energy of the electrons themselves to be lost and also shows evidences how strongly the plasma distribution is affected by slight changes in the RF frequency.

  10. Seminar | Development of a PET Cyclotron Based Irradiation Setup for Proton Radiobiology | 25 June

    CERN Multimedia

    2015-01-01

    Sharif Hasan Mahmoud Ghithan, a Palestinian postdoctoral researcher at the Laboratory of Instrumentation and Experimental Particle Physics (Portugal), will discuss the development of an out-of-yoke irradiation setup using the proton beam from a cyclotron that ordinarily produces radioisotopes for Positron Emission Tomography (PET). The speaker will also discuss possible future use of the results of this research for CERN’s new LEIR biomedical facility. The seminar will be proposed in the framework of a meeting of the CERN Medical Applications Study Group.   25 June, 2 p.m. to 3 p.m. Room 13-2-005 ABSTRACT: In this new irradiation setup, the current from a 20 mm thick aluminum transmission foil is read out by homemade transimpedance electronics, providing online dose information. The main monitoring variables, delivered in real-time, include beam current, integrated charge and dose rate. Hence the dose and integrated current delivered at a given instant to an experimental setu...

  11. Accurate Monte Carlo modeling of cyclotrons for optimization of shielding and activation calculations in the biomedical field

    Science.gov (United States)

    Infantino, Angelo; Marengo, Mario; Baschetti, Serafina; Cicoria, Gianfranco; Longo Vaschetto, Vittorio; Lucconi, Giulia; Massucci, Piera; Vichi, Sara; Zagni, Federico; Mostacci, Domiziano

    2015-11-01

    Biomedical cyclotrons for production of Positron Emission Tomography (PET) radionuclides and radiotherapy with hadrons or ions are widely diffused and established in hospitals as well as in industrial facilities and research sites. Guidelines for site planning and installation, as well as for radiation protection assessment, are given in a number of international documents; however, these well-established guides typically offer analytic methods of calculation of both shielding and materials activation, in approximate or idealized geometry set up. The availability of Monte Carlo codes with accurate and up-to-date libraries for transport and interactions of neutrons and charged particles at energies below 250 MeV, together with the continuously increasing power of nowadays computers, makes systematic use of simulations with realistic geometries possible, yielding equipment and site specific evaluation of the source terms, shielding requirements and all quantities relevant to radiation protection. In this work, the well-known Monte Carlo code FLUKA was used to simulate two representative models of cyclotron for PET radionuclides production, including their targetry; and one type of proton therapy cyclotron including the energy selection system. Simulations yield estimates of various quantities of radiological interest, including the effective dose distribution around the equipment, the effective number of neutron produced per incident proton and the activation of target materials, the structure of the cyclotron, the energy degrader, the vault walls and the soil. The model was validated against experimental measurements and comparison with well-established reference data. Neutron ambient dose equivalent H*(10) was measured around a GE PETtrace cyclotron: an average ratio between experimental measurement and simulations of 0.99±0.07 was found. Saturation yield of 18F, produced by the well-known 18O(p,n)18F reaction, was calculated and compared with the IAEA recommended

  12. Overview of Variable Renewable Energy Regulatory Issues: A Clean Energy Regulators Initiative Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.; Cox, S.

    2014-05-01

    This CERI report aims to provide an introductory overview of key regulatory issues associated with the deployment of renewable energy -- particularly variable renewable energy (VRE) sources such wind and solar power. The report draws upon the research and experiences from various international contexts, and identifies key ideas that have emerged from the growing body of VRE deployment experience and regulatory knowledge. The report assumes basic familiarity with regulatory concepts, and although it is not written for a technical audience, directs the reader to further reading when available. VRE deployment generates various regulatory issues: substantive, procedural, and public interest issues, and the report aims to provide an empirical and technical grounding for all three types of questions as appropriate.

  13. Angiostrongylus cantonensis Meningitis and Myelitis, Texas, USA.

    Science.gov (United States)

    Al Hammoud, Roukaya; Nayes, Stacy L; Murphy, James R; Heresi, Gloria P; Butler, Ian J; Pérez, Norma

    2017-06-01

    Infection with Angiostrongylus cantonensis roundworms is endemic in Southeast Asia and the Pacific Basin. A. cantonensis meningitis and myelitis occurred in summer 2013 in a child with no history of travel outside of Texas, USA. Angiostrongyliasis is an emerging neurotropic helminthic disease in Texas and warrants increased awareness among healthcare providers.

  14. Physical trajectory profile data from glider Stommel deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Gulf of Mexico from 2016-08-05 to 2016-09-05 (NCEI Accession 0156568)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This deployment is to investigate conditions in the region of the Flower Garden Banks after a die-off was reported. The National Centers for Environmental...

  15. Symmetry Properties of Proton Velocity Distributions: a Vlasov Simulation Study of the Ion Cyclotron Instability

    Science.gov (United States)

    Araneda, J. A.; López, R. A.; Vinas, A. F.

    2014-12-01

    The ion cyclotron instability is driven by a sufficiently large proton temperature anisotropy, generating a spectrum of counterpropagating field-aligned ion cyclotron fluctuations. In this work, we use low-noise one-dimensional electromagnetic Vlasov simulations in a magnetized and collisionless plasma of fluid electrons and one ion species to study the evolution of proton velocity distributions during the thermal relaxation process. Special attention is given to deviations from initial bi-Maxwellian shapes.

  16. A new EMIS facility at the Tohoku University cyclotron

    Science.gov (United States)

    Fujioka, M.; Shinozuka, T.; Tanaka, E.; Arai, Y.; Hayashibe, S.; Ishimatsu, T.

    1981-07-01

    An EMIS facility has begun operation at one of the beam lines of a multipurpose cyclotron of K = 50 MeV. The separator is of a Scandinavian type of 55° deflection and 1500 mm dispersion, and is equipped with three beam-transport lines to which are connected a tape-transport system for ISOL study, a retardation system for implantation work and an optical spectrometer for surface analysis. The status and developments of this facility are reported here for the first time.

  17. Design optimization under uncertainty and speed variability for a piezoelectric energy harvester powering a tire pressure monitoring sensor

    Science.gov (United States)

    Toghi Eshghi, Amin; Lee, Soobum; Kazem Sadoughi, Mohammad; Hu, Chao; Kim, Young-Cheol; Seo, Jong-Ho

    2017-10-01

    Energy harvesting (EH) technologies to power small sized electronic devices are attracting great attention. Wasted energy in a vehicle’s rotating tire has a great potential to enable self-powered tire pressure monitoring sensors (TPMS). Piezoelectric type energy harvesters can be used to collect vibrational energy and power such systems. Due to the presence of harsh acceleration in a rotating tire, a design tradeoff needs to be studied to prolong the harvester’s fatigue life as well as to ensure sufficient power generation. However, the design by traditional deterministic design optimization (DDO) does not show reliable performance due to the lack of consideration of various uncertainty factors (e.g., manufacturing tolerances, material properties, and loading conditions). In this study, we address a new EH design formulation that considers the uncertainty in car speed, dimensional tolerances and material properties, and solve this design problem using reliability-based design optimization (RBDO). The RBDO problem is formulated to maximize compactness and minimize weight of a TPMS harvester while satisfying power and durability requirements. A transient analysis has been done to measure the time varying response of EH such as power generation, dynamic strain, and stress. A conservative design formulation is proposed to consider the expected power from varied speed and stress at higher speed. When compared to the DDO, the RBDO results show that the reliability of EH is increased significantly by scarifying the objective function. Finally, experimental test has been conducted to demonstrate the merits of RBDO design over DDO.

  18. Calibration and use cases of the electron cyclotron emission diagnostic at Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Hoefel, Udo; Hirsch, Matthias; Ewert, Karsten; Hartfuss, Hans-Juergen; Laqua, Heinrich Peter; Stange, Torsten; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Collaboration: the W7-X Team

    2016-07-01

    The world's largest stellarator, Wendelstein 7-X (W7-X), is equipped with a 140 GHz electron cyclotron resonance heating (ECRH) system providing up to 5 MW absorbed power in the first operation phase OP1.1. The foreseen X2-heating scenario uses the high absorption of the second harmonic extraordinary electron cyclotron waves, which leads on the other hand to a black body electron cyclotron emission (ECE) being proportional to the local electron temperature. ECE is one of the fundamental operating diagnostics and is planned to yield the electron temperature profile from the very first discharges onwards. Unlike most other ECE diagnostics, the 32 channel ECE radiometer diagnostic (with additional 16 channels with higher radial resolution) at W7-X is absolutely calibrated. It is planned to use this diagnostic for intensive studies on electron heat transport in the upcoming operational phases of W7-X. Simple switch-off experiments for the determination of the energy confinement time should already be possible within the first plasma shots. Due to the high temporal and radial resolution the ECE will be used also to determine the power deposition by modulation of the heating gyrotron. or the localization of a power modulated ECRH to optimize the power deposition. If reasonably equilibrated plasma conditions could be generated in the first operational phase (OP 1.1), first studies on electron thermal diffusivity could also be possible.

  19. Senior Centers and Nutritional Outcomes: A Texas Example.

    Science.gov (United States)

    Swan, James H; Severance, Jennifer J; Turner, Keith

    2016-01-01

    Healthy diet and weight control are important for elders and senior centers (SCs). The authors consider effects of SCs on attendee nutrition and health and efforts to improve diets and weight. Data derive from surveys in 2006 (N = 798) and 2007 (N = 742) at 21 multipurpose SCs in Tarrant County, Texas, supplemented with data from 2012 (N = 1,402). Measures included attendee agreement that SC meals improved nutrition, improved health, attempts to improve diets, and success in controlling weight. Cumulative and binary logistic regression methods were employed. SC attendance and social engagement explained agreement that SC meals improved nutrition and health but were not shown to predict changes in diet or weight control. Findings suggest success of SC programs, as well as physician recommendations, in influencing attendee nutritional behavior and perceptions of nutrition and health effects. Practice recommendations include SC collaborations with local health providers to promote attendee nutritional health.

  20. Day-to-Day and Within-Day Variability in Glucose-Lowering Effect Between Insulin Degludec and Insulin Glargine (100 U/mL and 300 U/mL): A Comparison Across Studies.

    Science.gov (United States)

    Heise, Tim; Kaplan, Kadriye; Haahr, Hanne L

    2017-09-01

    Insulin degludec (IDeg) has significantly lower day-to-day and within-day variability compared to insulin glargine (IGlar) 100U/mL (U100) and 300U/mL (U300). Here, we report post hoc assessments to confirm the robustness of these observations while accounting for potential experimental confounders. Two euglycemic clamp studies in type 1 diabetes patients, comparing IDeg to IGlar-U100 (Study A, parallel design, 54 patients; Study B, crossover, 22 patients) and one study comparing IDeg to IGlar-U300 (Study C, crossover, 57 patients), all dosed at 0.4U/kg, were evaluated. Pharmacodynamic parameters were assessed at steady state from glucose infusion rate (GIR) profiles following three 24-hour euglycemic clamps in Studies A (162 clamps) and C (342 clamps), and one 42-hour clamp in Study B (44 clamps). Pooled data (Studies A and B) showed that IDeg had an even distribution of glucose-lowering effect over the 24-hour dosing interval that was consistent with Study C. IGlar-U100 showed a constant decrease in glucose-lowering effect over 24 hours while IGlar-U300 had a lower effect in the middle of the dosing interval (6-18 hours). Relative within-day variability of IDeg was 40% and 37% lower than IGlar-U100 and -U300, respectively. Exclusion of profiles with low response in Study C (19/342 clamps) did not impact the difference in the distribution of glucose-lowering effect or within-day variability. Day-to-day variability was significantly lower with IDeg compared to IGlar-U100 and -U300 based on smoothed and unsmoothed GIR data. Significantly lower relative within-day and day-to-day variability was confirmed irrespective of experimental considerations for IDeg compared to IGlar-U100 and IGlar-U300.

  1. Magnetic Cyclotron Waves near the Proton Cyclotron Frequency in the Solar Wind: Wind and ACE Observations in 2005

    Science.gov (United States)

    Broiles, T. W.; Jian, L.; Stevens, M. L.; Gary, S. P.; Lepri, S. T.; Vinas, A. F.; Moya, P. S.; Alexander, R.

    2016-12-01

    Strong narrow-band electromagnetic waves near the proton cyclotron frequency (fpc) have been observed extensively in the solar wind throughout the inner heliosphere. They are transverse and near-circularly polarized, and propagate in directions quasi-parallel or anti-parallel to the magnetic field. Their frequency is a few times of fpc in the spacecraft frame and a fraction of fpc in the plasma frame after removing the Doppler shift effect. These waves are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with otherwise similar characteristics except LH ones appear more often and have higher wave power. Intrinsically they can be LH polarized Alfven-cyclotron waves or RH polarized magnetosonic waves. Through the assistance of audification, we have studied the long-lasting wave events near fpc in 2005 using the high-cadence magnetic field data and well-calibrated plasma data from the Wind mission. A mixture of temperature anisotropies for core protons, beam protons, and alpha particles, as well as proton beam drift are often found for selected events of extensive waves. The wave dispersion analysis using these ion moments indicate these waves are likely to be associated with unstable Alfven-cyclotron anisotropy instability or ion beam instability, and suggest there is a mixture of Alfven-cyclotron waves and magnetosonic waves in the solar wind. Using the conjunction of Wind and ACE spacecraft when they were within 50 Earth radii of each other, we study how often the two spacecraft observe the same waves and whether there is noticeable heating for heavy ions associated with these waves.

  2. STRUCTURE OF THE FRESH ONION MARKET IN THE SPRING SEASON: A FOCUS ON TEXAS AND ITS COMPETITION

    OpenAIRE

    Fuller, Stephen W.; Capps, Oral, Jr.; Bello, Haruna; Shafer, Carl E.

    1991-01-01

    A structural model of the spring onion economy is developed to analyze forces affecting the onion-producing sector in Texas. Spring onion prices in Texas are influenced by own shipments, shipments from storage stocks, and variety. Texas's decline in market share is largely the result of expanded late summer (storage) onion production. A decline in the U.S. real tariff and a weakening of the real exchange rate (pesos/$) encouraged onion imports from Mexico during the study period. However, thi...

  3. Flux measurements of energy and trace gases in urban Houston, Texas

    Science.gov (United States)

    Boedeker, I.; Schade, G. W.; Adams, S.; Park, C.

    2008-12-01

    We describe the setup and some first year results of a new flux measurements tower in an urban area. An existing radio communications tower 4 km north of downtown Houston was equipped with micrometeorological instrumentation and trace gas sampling lines in spring 2007. Wind speed, temperature and relative humidity are recorded at five levels between 12 and 60 m above ground; 3-D wind speed measurements, solar and net radiances, and trace gas sampling are established from the 60 m level. A closed path IRGA is used for CO2 and water vapor fluxes, and independent instrumentation for criteria pollutant and VOC fluxes. Two CSI data loggers and software control the measurements, and EdiRe software is used to analyze turbulence data and compute fluxes. A project description is provided at http://atmo.tamu.edu/yellowcabtower. Surface properties as calculated from the gradient measurements show the site to be surprisingly uniform, with displacement heights between 5 and 9 m and roughness lengths between 0.4 and 0.7 m, despite urban heterogeneity. The latter is investigated through visible/near IR orthoimagery and LIDAR data, which are incorporated into a local GIS. Net radiation was also only marginally affected by surface heterogeneity. At this urban location it is balanced by roughly equal amounts of sensible heat, latent heat, and storage fluxes. Latent heat flux, however, is smaller outside the growing season, with an equivalent increase in winter storage fluxes, as expected. Significant differences are also observed with direction during summer, showing decreased Bowen ratios and lower CO2 emissions from sectors with a larger urban tree canopy cover in the footprint. The largely mature, dominantly oak urban canopy cover alleviates approximately 100 W m- 2 during typical summer days. On the other hand, anthropogenic CO2 emissions dominate over photosynthetic uptake all year round. Measured carbon fluxes peak during morning rush-hour traffic, especially when increasing

  4. Regulation of mTORC1 by growth factors, energy status, amino acids and mechanical stimuli at a glance.

    Science.gov (United States)

    Bond, Peter

    2016-01-01

    The mechanistic/mammalian target of rapamycin complex 1 (mTORC1) plays a pivotal role in the regulation of skeletal muscle protein synthesis. Activation of the complex leads to phosphorylation of two important sets of substrates, namely eIF4E binding proteins and ribosomal S6 kinases. Phosphorylation of these substrates then leads to an increase in protein synthesis, mainly by enhancing translation initiation. mTORC1 activity is regulated by several inputs, such as growth factors, energy status, amino acids and mechanical stimuli. Research in this field is rapidly evolving and unraveling how these inputs regulate the complex. Therefore this review attempts to provide a brief and up-to-date narrative on the regulation of this marvelous protein complex. Additionally, some sports supplements which have been shown to regulate mTORC1 activity are discussed.

  5. Physical trajectory profile data from glider Sverdrup deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Gulf of Mexico from 2017-09-02 to 2017-09-06 (NCEI Accession 0166617)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Qantifying mixing parameters and processes of the northern Gulf of Mexico using gliders. The National Centers for Environmental Information (NCEI) received the data...

  6. Physical trajectory profile data from glider Howdy deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Coastal Waters of Gulf of Mexico from 2016-09-02 to 2016-09-05 (NCEI Accession 0156591)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This deployment is to investigate mixing and microstructure in the Northern Gulf of Mexico. The National Centers for Environmental Information (NCEI) received the...

  7. Two-slope soft X-ray spectra observed in experiments on electron cyclotron resonance plasma heating in the L-2M stellarator

    Science.gov (United States)

    Meshcheryakov, A. I.; Vafin, I. Yu.; Grishina, I. A.; Letunov, A. A.; Tereshchenko, M. A.

    2017-06-01

    In experiments on the generation and electron cyclotron resonance heating (ECRH) of plasma in the L-2M stellarator, non-Maxwellian two-slope soft X-ray (SXR) spectra were observed. The temperatures of the thermal and epithermal components of the spectra were measured as functions of the heating power and plasma density. A hypothesis based on the experimental results is suggested to explain the formation mechanism of two-slope SXR spectra in the ECRH experiments at the L-2M stellarator. The measured SXR spectra are compared with the results of numerical simulations.

  8. DOE Zero Energy Ready Home Case Study: Durable Energy Builders - Houston, Texas

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-11-01

    This case study describes a DOE Zero Energy Ready Home in Houston, Texas, that scored HERS 39 without PV and HERS 29 with PV. This 5,947 ft2 custom home has 11.5-inch ICF walls. The attic is insulated along the roof line with 5 to 7 inches of open-cell spray foam. Most of the home's drinking water is supplied by a 11,500-gallon rainwater cistern. Hurricane strapping connects the roof to the walls. The triple-pane windows are impact resistant. The foundation is a raised slab.

  9. Physical trajectory profile data from glider Revellie deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Coastal Waters of Gulf of Mexico from 2016-06-29 to 2016-07-15 (NCEI Accession 0156372)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This deployment is to investigate hypoxia in the Northern Gulf of Mexico. The National Centers for Environmental Information (NCEI) received the data in this...

  10. Physical trajectory profile data from glider Howdy deployed by Texas A&M University; Texas A&M University - College Station; Geochemical and Environmental Research Group in the Coastal Waters of Gulf of Mexico from 2016-06-30 to 2016-07-14 (NCEI Accession 0156371)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This deployment is to investigate hypoxia in the Northern Gulf of Mexico. The National Centers for Environmental Information (NCEI) received the data in this...

  11. Enhancement of beam pulse controllability for a single-pulse formation system of a cyclotron.

    Science.gov (United States)

    Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu; Taguchi, Mitsumasa; Fukuda, Mitsuhiro

    2015-07-01

    The single-pulse formation technique using a beam chopping system consisting of two types of high-voltage beam kickers was improved to enhance the quality and intensity of the single-pulse beam with a pulse interval over 1 μs at the Japan Atomic Energy Agency cyclotron facility. A contamination rate of neighboring beam bunches in the single-pulse beam was reduced to less than 0.1%. Long-term purification of the single pulse beam was guaranteed by the well-controlled magnetic field stabilization system for the cyclotron magnet. Reduction of the multi-turn extraction number for suppressing the neighboring beam bunch contamination was achieved by restriction of a beam phase width and precise optimization of a particle acceleration phase. In addition, the single-pulse beam intensity was increased by a factor of two or more by a combination of two types of beam bunchers using sinusoidal and saw-tooth voltage waveforms. Provision of the high quality intense single-pulse beam contributed to improve the accuracy of experiments for investigation of scintillation light time-profile and for neutron energy measurement by a time-of-flight method.

  12. 10 GHz ECRIS for Warsaw Cyclotron

    CERN Document Server

    Sudlitz, K

    1999-01-01

    Cusp type, 10 GHz ECRIS has been built and tested earlier. For obtaining intensive beams, more relevant for cyclotron, cusp geometry has been replaced by hexapole. Discharge chamber (stainless steel, 50 mm diameter, 250 mm long) is an extension of a coaxial line, feeding RF (9,6 GHz, up to 200 W) to the plasma. The NdFeB hexapole (0,52 T on the surface) has been used. The axial magnetic field is created by water cooled coils. The axial injection line dedicated to K160 isochronous heavy ion cyclotron has been constructed. The line consists of Glaser lenses, double focusing magnet, solenoid and mirror type inflector. The system provides sufficient transmission of the beam from ECR ion source to the firsts orbits of the cyclotron for m/q ranging from 7 to 2. After successful initial tests which were done in July 1997 the ECRIS serves as an external source for Warsaw Cyclotron.

  13. [Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Some decapods (Crustacea; Brachyura and Stomatopoda) from the Pleistocene Beaumont Formation of Galveston, Texas

    NARCIS (Netherlands)

    Collins, J.S.H.; Garvie, C.L.; Mellish, C.J.T.

    2014-01-01

    Seven species of crab and an indeterminate stomatopod are recorded from the Pleistocene Beaumont Formation of Galveston Island, Texas. Of these, Hepatus pauli sp. nov., plus the extant Persephona aquilonaris and Callinectes danae are recorded as fossils for the first time, whereas the modern

  14. PRODUCTION OF 11 C-METHIONINE BY CYCLOTRON AVF JAERI

    Directory of Open Access Journals (Sweden)

    Sri Hastini

    2010-06-01

    Full Text Available At the Takasaki-site of JAERI, an AVF cyclotron has been constructed for advanced radiation technology research. The cyclotron produces extracted beams particularly light and heavy ions of proton as well as deutron. Target chamber is available for production of 11CO2 a positron emitter radioisotope, by bombardment of proton from nitrogen gas as a target, by 14 N (p,a 11C reaction. The use of incident energy on target was estimated to be 11 MeV for primary proton energy of 20 MeV and the beam current was 0,1 m A and the irradiation time was 10 minutes for production of 11CO2 and the yield was about 30 MBq (EOBand for irradiation time 15 minutes and the beam current was 1 mA for production of 11C-Methionine, the yield was about 70 MBq (EOB. Remotely operated automatic and semiautomatic processing systems are used for the production of the 11 C-Methionine agent and the radiochemical purity of the product obtained was determined by High Performance Liquid Chromatography (HPLC with cation exchange column was LC 10 AD MERCK LICHROSPHER 100 RP-18 and the mobile phase was 10 mM ammonium phormmate, the mean of retention time was 1,815 minutes and the radiochemical purity to be more than 90 %. The product was used for plant studies and visualized by PETIS (Positron Emission Tracer Imaging System   Keywords: cyclotron, Positron emitter, 11C-Methionine.

  15. Cyclotron transitions of bound ions

    Science.gov (United States)

    Bezchastnov, Victor G.; Pavlov, George G.

    2017-06-01

    A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

  16. Results from the Project 8 phase-1 cyclotron radiation emission spectroscopy detector

    Science.gov (United States)

    Ashtari Esfahani, A.; Böser, S.; Claessens, C.; de Viveiros, L.; Doe, P. J.; Doeleman, S.; Fertl, M.; Finn, E. C.; Formaggio, J. A.; Guigue, M.; Heeger, K. M.; Jones, A. M.; Kazkaz, K.; LaRoque, B. H.; Machado, E.; Monreal, B.; Nikkel, J. A.; Oblath, N. S.; Robertson, R. G. H.; Rosenberg, L. J.; Rybka, G.; Saldaña, L.; Slocum, P. L.; Tedeschi, J. R.; Thümmler, T.; Vandevender, B. A.; Wachtendonk, M.; Weintroub, J.; Young, A.; Zayas, E.

    2017-09-01

    The Project 8 collaboration seeks to measure the absolute neutrino mass scale by means of precision spectroscopy of the beta decay of tritium. Our technique, cyclotron radiation emission spectroscopy, measures the frequency of the radiation emitted by electrons produced by decays in an ambient magnetic field. Because the cyclotron frequency is inversely proportional to the electron’s Lorentz factor, this is also a measurement of the electron’s energy. In order to demonstrate the viability of this technique, we have assembled and successfully operated a prototype system, which uses a rectangular waveguide to collect the cyclotron radiation from internal conversion electrons emitted from a gaseous 83m Kr source. Here we present the main design aspects of the first phase prototype, which was operated during parts of 2014 and 2015. We will also discuss the procedures used to analyze these data, along with the features which have been observed and the performance achieved to date.

  17. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  18. Influence of mTOR in energy and metabolic homeostasis.

    Science.gov (United States)

    Haissaguerre, Magalie; Saucisse, Nicolas; Cota, Daniela

    2014-11-01

    The mechanistic (or mammalian) target of rapamycin couples a variety of different environmental signals, including nutrients and hormones, with the regulation of several energy-demanding cellular functions, spanning from protein and lipid synthesis to mitochondrial activity and cytoskeleton dynamics. mTOR forms two distinct protein complexes in cells, mTORC1 and mTORC2. This review focuses on recent advances made in understanding the roles played by these two complexes in the regulation of whole body metabolic homeostasis. Studies carried out in the past few years have shown that mTORC1 activity in the hypothalamus varies by cell and stimulus type, and that this complex is critically implicated in the regulation of food intake and body weight and in the central actions of both nutrients and hormones, such as leptin, ghrelin and triiodothyronine. As a regulator of cellular anabolic processes, mTORC1 activity in the periphery favors adipogenesis, lipogenesis, glucose uptake and beta-cell mass expansion. Much less is known about the function of mTORC2 in the hypothalamus, while in peripheral organs this second complex exerts roles strikingly similar to those described for mTORC1. Deregulation of mTORC1 and mTORC2 is associated with obesity, type 2 diabetes, cancer and neurodegenerative disorders. Insights on the exact relationship between mTORC1 and mTORC2 in the context of the regulation of metabolic homeostasis and on the specific molecular mechanisms engaged by these two complexes in such regulation may provide new avenues for therapy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Energy decay of a variable-coefficient wave equation with nonlinear time-dependent localized damping

    Directory of Open Access Journals (Sweden)

    Jieqiong Wu

    2015-09-01

    Full Text Available We study the energy decay for the Cauchy problem of the wave equation with nonlinear time-dependent and space-dependent damping. The damping is localized in a bounded domain and near infinity, and the principal part of the wave equation has a variable-coefficient. We apply the multiplier method for variable-coefficient equations, and obtain an energy decay that depends on the property of the coefficient of the damping term.

  20. High-harmonic electron bunching in the field of a signal wave and the use of this effect in cyclotron masers with frequency multiplication

    Directory of Open Access Journals (Sweden)

    I. V. Bandurkin

    2005-01-01

    Full Text Available A method of organizing electron-wave interaction at the multiplied frequency of the signal wave is proposed. This type of electron-wave interaction provides multiplied-frequency electron bunching, which leads to formation of an intense harmonic of the electron current at a selected multiplied frequency of the signal wave. This effect is attractive for the use in klystron-type cyclotron masers with frequency multiplication as a way to increase the output frequency and improve the selectivity.

  1. Quantitative assessment of Naegleria fowleri and Escherichia coli concentrations within a Texas reservoir.

    Science.gov (United States)

    Painter, Stephanie M; Pfau, Russell S; Brady, Jeff A; McFarland, Anne M S

    2013-06-01

    Previous presence/absence studies have indicated a correlation between the presence of the pathogenic amoeba Naegleria fowleri and the presence of bacteria, such as the fecal indicator Escherichia coli, in environmental surface waters. The objective of this study was to use quantitative real-time polymerase chain reaction (qPCR) methodologies to measure N. fowleri and E. coli concentrations within a Texas reservoir in late summer, and to determine if concentrations of N. fowleri and E. coli were statistically correlated. N. fowleri was detected in water samples from 67% of the reservoir sites tested, with concentrations ranging up to an estimated 26 CE (cell equivalents)/100 mL. E. coli was detected in water samples from 60% of the reservoir sites tested, with concentrations ranging up to 427 CE/100 mL. In this study, E. coli concentrations were not indicative of N. fowleri concentrations.

  2. The study of acceptance and the transmission efficiency of separated sector cyclotron

    Directory of Open Access Journals (Sweden)

    Li Xiaoni

    2015-01-01

    Full Text Available In this paper we present the study of the transversal and longitudinal acceptance and the transmission efficiency in the injection, acceleration, and extraction systems in the separated sector cyclotron of the heavy ion research facility in Lanzhou, China. The study of cyclotron acceptance is done for 238U36+ with energy of 97 MeV/u and for 70Zn10+ with energy of 5.62 MeV/u under the theoretical isochronous and real magnetic field distribution. From the simulation results it can be seen that the transmission efficiency and the acceptances of separated sector cyclotron can be improved by redesign the curvature of MSI3 deflector or by introducing the magnet shim in MSI3 deflector region to change the distribution of the inner magnetic field. [Projekat Ministarstva nauke Republike Srbije, br. OI-171018

  3. THE TRUE IDENTITY OF COPELAND'S AQUATIC SCUTTLE FLY (DIPTERA: PHORIDAE) FROM INDIANA AND RECOGNITION OF A SIBLING SPECIES FROM TEXAS

    Science.gov (United States)

    Disney, R. Henry L.; Copeland, Robert S.; Murrell, Ebony

    2012-01-01

    Among the insects reported by Copeland (1989) breeding in the waters retained by treeholes in Indiana was a scuttle fly identified by W. H. Robinson as Megaselia scalaris (Loew). It is here reported that in fact this fly, along with fresh material from Illinois and Missouri, is M. imitatrix Borgmeier, whose type series was from Puerto Rico. An aquatic species reported from Texas is recognized as a sibling species of M. imitatrix and is named M. hansonix Disney, sp. nov. A single female from Brazil represents a third species of this complex, thus raising doubts about the identity of specimens from Brazil attributed to M. imitatrix by Benton and Claugher (2000). PMID:22879679

  4. Forests of east Texas, 2015

    Science.gov (United States)

    Kerry J.W. Dooley

    2017-01-01

    This resource update provides an overview of forest resources in east Texas based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station (SRS) in cooperation with Texas A&M Forest Service. The 254 counties of Texas are consolidated into seven FIA survey units—Southeast (unit 1),...

  5. Effects of atmospheric variability on energy utilization and conservation. [Space heating energy demand modeling; Program HEATLOAD

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, E.R.; Johnson, G.R.; Somervell, W.L. Jr.; Sparling, E.W.; Dreiseitly, E.; Macdonald, B.C.; McGuirk, J.P.; Starr, A.M.

    1976-11-01

    Research conducted between 1 July 1975 and 31 October 1976 is reported. A ''physical-adaptive'' model of the space-conditioning demand for energy and its response to changes in weather regimes was developed. This model includes parameters pertaining to engineering factors of building construction, to weather-related factors, and to socio-economic factors. Preliminary testing of several components of the model on the city of Greeley, Colorado, yielded most encouraging results. Other components, especially those pertaining to socio-economic factors, are still under development. Expansion of model applications to different types of structures and larger regions is presently underway. A CRT-display model for energy demand within the conterminous United States also has passed preliminary tests. A major effort was expended to obtain disaggregated data on energy use from utility companies throughout the United States. The study of atmospheric variability revealed that the 22- to 26-day vacillation in the potential and kinetic energy modes of the Northern Hemisphere is related to the behavior of the planetary long-waves, and that the midwinter dip in zonal available potential energy is reflected in the development of blocking highs. Attempts to classify weather patterns over the eastern and central United States have proceeded satisfactorily to the point where testing of our method for longer time periods appears desirable.

  6. American Recovery and Reinvestment Act Federal Energy Management Program Technical Assistance Project 184 U.S. Customs and Border Protection Laboratory, Houston, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Arends, J.; Sandusky, William F.

    2010-09-30

    This report documents the findings of an on-site energy audit of the U.S. Customs and Border Protection (CBP) Laboratory in Houston, Texas. The focus of the audit was to identify various no-cost and low-cost energy efficiency opportunities that, once implemented, would reduce electricity and gas consumption and increase the operational efficiency of the building. This audit also provided an opportunity to identify potential capital cost projects that should be considered in the future to acquire additional energy (electric and gas) and water savings to further increase the operational efficiency of the building.

  7. Tomsk Polytechnic University cyclotron as a source for neutron based cancer treatment.

    Science.gov (United States)

    Lisin, V A; Bogdanov, A V; Golovkov, V M; Musabaeva, L I; Sukhikh, L G; Verigin, D A

    2014-02-01

    In this paper we present our cyclotron based neutron source with average energy 6.3 MeV generated during the 13.6 MeV deuterons interactions with beryllium target, neutron field dosimetry, and dosimetry of attendant gamma fields. We also present application of our neutron source for cancer treatment.

  8. Coupled operation of the Oak Ridge isochronous cyclotron and the 25 MV tandem

    Energy Technology Data Exchange (ETDEWEB)

    Lord, R.S.; Ball, J.B.; Beckers, R.M.; Cleary, T.P.; Hudson, E.D.; Ludemann, C.A.; Martin, J.A.; Milner, W.T.; Mosko, S.W.; Ziegler, N.F.

    1981-01-01

    Coupled operation of the 25 MV tandem and the Oak Ridge Isochronous Cyclotron (ORIC) was achieved on January 27, 1981. A beam of 38 MeV /sup 16/O/sup 2 +/ was injected into ORIC, stripped to 8/sup +/ and accelerated to 324 MeV. Shortly afterwards, the energy was increased to the maximum design value of 25 MeV/amu (400 MeV). A spectrum taken of the scattering of this beam from a thin /sup 208/Pb target in the broad range spectrograh exhibited a resolution of 115 keV (FWHM). Performance of the system was in close agreement with that predicted from calculations.

  9. Gaseous Oxidized Mercury Dry Deposition Measurements in the Southwestern USA: A Comparison between Texas, Eastern Oklahoma, and the Four Corners Area

    Directory of Open Access Journals (Sweden)

    Mark E. Sather

    2014-01-01

    Full Text Available Gaseous oxidized mercury (GOM dry deposition measurements using aerodynamic surrogate surface passive samplers were collected in central and eastern Texas and eastern Oklahoma, from September 2011 to September 2012. The purpose of this study was to provide an initial characterization of the magnitude and spatial extent of ambient GOM dry deposition in central and eastern Texas for a 12-month period which contained statistically average annual results for precipitation totals, temperature, and wind speed. The research objective was to investigate GOM dry deposition in areas of Texas impacted by emissions from coal-fired utility boilers and compare it with GOM dry deposition measurements previously observed in eastern Oklahoma and the Four Corners area. Annual GOM dry deposition rate estimates were relatively low in Texas, ranging from 0.1 to 0.3 ng/m2h at the four Texas monitoring sites, similar to the 0.2 ng/m2h annual GOM dry deposition rate estimate recorded at the eastern Oklahoma monitoring site. The Texas and eastern Oklahoma annual GOM dry deposition rate estimates were at least four times lower than the highest annual GOM dry deposition rate estimate previously measured in the more arid bordering western states of New Mexico and Colorado in the Four Corners area.

  10. A new RF system for a rejuvenated Synchro-cyclotron

    CERN Multimedia

    1975-01-01

    The Synchro-cyclotron is shown here shortly after the completion of the improvement programme, which left the steel magnet yoke as almost the only remaining component of the original machine. On the left can be seen the rotary condenser which produces the frequency modulation required for the acceleration (one of a pair available -in this instance ROTCO II). (see photo 7506015)

  11. Wide-Field Variability Survey of the Globular Cluster M 79 and a New Period-Luminosity Relation for SX Phe Stars

    Science.gov (United States)

    Kopacki, G.

    2015-03-01

    We present the results of a search for variable stars in a 26×39 arcmin2 field around globular cluster M 79 (NGC 1904). The search was made by means of an extended version of image subtraction, which allows us to analyze in a uniform manner CCD frames obtained with different telescopes and cameras of different sizes and resolutions. The search resulted in finding 20 new variable stars, among which 13 are cluster members. The members include one new RR Lyr star of subtype c, three SX Phe stars, and nine variable red giants. We also show that V7 is a W Vir star with a period of 13.985 d. Revised mean periods of RRab and RRc stars, ab=0.71 d and c=0.34 d, respectively, and relative percentage of RRc stars, Nc/(Nab+Nc)=45% confirm that M 79 belongs to the Oosterhoff II group of globular clusters. The mean V magnitude of the horizontal branch of M 79 based on ten RR Lyr stars has been estimated to be VHB=RR=16.11±0.03 mag. In one RRc star, V9, light changes with three close frequencies were detected, indicating excitation of nonradial modes. An SX Phe star, V18, is a double-mode pulsator with two radial modes excited, fundamental and first overtone. Moreover, we have discovered two SX Phe or δ Sct stars and one W UMa type system, all likely field objects. We also studied the period-luminosity relation for SX Phe stars. Using 62 fundamental and fundamentalized periods of radial double-mode and high-amplitude SX Phe stars known in Galactic globular clusters, we have derived the slope and zero point of this relation to be, -3.3±0.27 and 2.68±0.03 mag (at log(P/d)=-1.24), respectively.

  12. Long-term cyclotron dynamics of relativistic wave packets: Spontaneous collapse and revival

    Science.gov (United States)

    Demikhovskii, V. Ya.; Maksimova, G. M.; Perov, A. A.; Telezhnikov, A. V.

    2012-02-01

    In this work we study the effects of collapse and revival, as well as the zitterbewegung (ZB) phenomenon, for the relativistic electron wave packets, which are a superposition of the states with quantum numbers sharply peaked around some Landau level n0 of the order of few tens. The probability densities as well as average velocities of the packet center and the average spin components were calculated analytically and their evolution is visualized. Our computations demonstrate that due to the dephasing of the states for times larger than the cyclotron period the initial wave packet (which includes the states with the positive energy only) loses the spatial localization so that the evolution can no longer be described classically. However, at the half-revival time t=TR/2 its reshaping takes place first. It is shown that the behavior of the wave packet containing the states of both energy bands (with En>0 and Ennegative energy) restores at various points of the cyclotron orbit, which makes reshaping of the initial wave packet impossible, entirely unlike the wave packet which consists of states with energies En>0 only. The obtained results can be useful for the description of electromagnetic radiation and absorption in relativistic plasma on astrophysics objects, where superhigh magnetic field has a value of the order 108-109T, as well as for interpretation of experiments with trapped ions.

  13. Pathways to the Geosciences through 2YR Community Colleges: A Strategic Recruitment Approach being used at Texas A&M University

    Science.gov (United States)

    Houser, C.; Nunez, J.; Miller, K. C.

    2016-12-01

    Department and college operating budgets are increasingly tide to enrollment and student credit hour production, which requires geoscience programs to develop strategic recruitment programs to ensure long-term stability, but also to increase institutional support. There is evidence that proactive high school recruitment programs are successful in engaging students in the geosciences, particularly those that involve the parents, but these programs typically have relatively low-yields and are relatively expensive. This means that increased enrollment of undergraduates in geosciences programs and participation by under-represented groups depends on innovative and effective recruitment and retention practices. The College of Geosciences at Texas A&M University has recently developed a Pathways to the Geosciences program that facilitates the transfer of students from 2-year institutions by providing direction to students interested in the geosciences from one of our partner institutions: Blinn College, Lee College, Houston Community College, San Jacinto College and Lone Star College. Each of the partner institutions offer disciplinary majors related to the geosciences, providing a gateway for students to discover and consider the geosciences starting in their freshman year. The guided pathways provide much needed direction without restricting options and allow students to see connections between courses and their career goals. In its first year, the Pathways to the Geosciences program has resulted in a significant increase in transfer applications and admissions from the partner institutions by 74% and 107% respectively. The program has been successful because we have been proactive in helping students at the partner institutions find the information they need to effectively transfer to a 4-year program. The increase in applications is evidence that students from our partner institutions are being intentional in following a pathway to a major in the College of

  14. Shielding design of the Mayo Clinic Scottsdale cyclotron vault

    Directory of Open Access Journals (Sweden)

    Riper Kenneth A. Van

    2017-01-01

    Full Text Available Mayo Clinic Scottsdale (Scottsdale, Arizona is building a cyclotron vault containing a cyclotron with adjacent targets and a beam line leading to an external target. The targets are irradiated by high energy (15 to 16.5 MeV protons for the production of radioisotopes. We performed Monte Carlo radiation transport simulations to calculate the radiation dose outside of the vault during irradiation of the cyclotron and external targets. We present the Monte Carlo model including the geometry, sources, and variance reduction methods. Mesh tallies surrounding the vault show the external dose rate is within acceptable limits.

  15. Ion cyclotron emission from fusion-born ions in large tokamak plasmas: a brief review from JET and TFTR to ITER

    CERN Document Server

    Dendy, R O

    2014-01-01

    Ion cyclotron emission (ICE) was the first collective radiative instability, driven by confined fusion-born ions, observed from deuterium-tritium plasmas in JET and TFTR. ICE comprises strongly suprathermal emission, which has spectral peaks at multiple ion cyclotron harmonic frequencies as evaluated at the outer mid-plane edge of tokamak plasmas. The measured intensity of ICE spectral peaks scaled linearly with measured fusion reactivity in JET. In other large tokamak plasmas, ICE is currently used as an indicator of fast ions physics. The excitation mechanism for ICE is the magnetoacoustic cyclotron instability (MCI); in the case of JET and TFTR, the MCI is driven by a set of centrally born fusion products, lying just inside the trapped-passing boundary in velocity space, whose drift orbits make large radial excursions to the outer mid-plane edge. Diagnostic exploitation of ICE in future experiments therefore rests in part on deep understanding of the MCI, and recent advances in computational plasma physics...

  16. Coupling of electrostatic ion cyclotron and ion acoustic waves in the solar wind

    Energy Technology Data Exchange (ETDEWEB)

    Sreeraj, T., E-mail: sreerajt13@iigs.iigm.res.in [Indian Institute of Geomagnetism, Navi Mumbai (India); Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Lakhina, G. S., E-mail: gslakhina@gmail.com [Indian Institute of Geomagnetism, Navi Mumbai (India); University of the Western Cape, Bellville 7535, Capetown (South Africa)

    2016-08-15

    The coupling of electrostatic ion cyclotron and ion acoustic waves is examined in three component magnetized plasma consisting of electrons, protons, and alpha particles. In the theoretical model relevant to solar wind plasma, electrons are assumed to be superthermal with kappa distribution and protons as well as alpha particles follow the fluid dynamical equations. A general linear dispersion relation is derived for such a plasma system which is analyzed both analytically and numerically. For parallel propagation, electrostatic ion cyclotron (proton and helium cyclotron) and ion acoustic (slow and fast) modes are decoupled. For oblique propagation, coupling between the cyclotron and acoustic modes occurs. Furthermore, when the angle of propagation is increased, the separation between acoustic and cyclotron modes increases which is an indication of weaker coupling at large angle of propagation. For perpendicular propagation, only cyclotron modes are observed. The effect of various parameters such as number density and temperature of alpha particles and superthermality on dispersion characteristics is examined in details. The coupling between various modes occurs for small values of wavenumber.

  17. NuSTAR Discovery of a Cyclotron Line in KS 1947+300

    Science.gov (United States)

    Furst, Felix; Pottschmidt, Katja; Wilms, Jorn; Kennea, Jamie; Bachetti, Matteo; Bellm, Eric; Boggs, Steven E.; Chakrabarty, Deepto; Christensen, Finn E.; Craig, William W.; hide

    2014-01-01

    We present a spectral analysis of three simultaneous Nuclear Spectroscopy Telescope Array and Swift/XRT observations of the transient Be-neutron star binary KS 1947+300 taken during its outburst in 2013/2014. These broadband observations were supported by Swift/XRTmonitoring snapshots every three days, which we use to study the evolution of the spectrum over the outburst.We find strong changes of the power-law photon index, which shows a weak trend of softening with increasing X-ray flux. The neutron star shows very strong pulsations with a period of P ˜ [almost equal to] 18.8 s. The 0.8-79 keV broadband spectrum can be described by a power law with an exponential cutoff and a blackbody component at low energies. During the second observation we detect a cyclotron resonant scattering feature at 12.5 keV, which is absent in the phase-averaged spectra of observations 1 and 3. Pulse phase-resolved spectroscopy reveals that the strength of the feature changes strongly with pulse phase and is most prominent during the broad minimum of the pulse profile. At the same phases the line also becomes visible in the first and third observation at the same energy. This discovery implies that KS 1947+300 has a magnetic field strength of B ˜ [almost equal to] 1.1 × 1012(1 + z) G, which is at the lower end of known cyclotron line sources.

  18. Development and Implementation of Sargassum Early Advisory System (SEAS): Phase One By Brandon N. Hill Ocean and Coastal Resources bhill8901@yahoo.com Robert K. Webster Ph.D. Candidate, Marine Sciences Department captrwebster@aol.com Texas A & M University at Galveston P.O. Box 1675 Galveston, Texas 77553

    Science.gov (United States)

    Hill, B. N.; Webster, R.; Frazier, J.; Linton, T.

    2013-12-01

    Abstract: Sargassum is a crucial aspect of many oceanic and coastal environments. However, it can inundate a coast if the conditions permit excessive growth and landings. In nature this is not a detriment to the beaches, but actually serves to reduce erosion and provide nutrients. When beaches are relied upon to support the tourism industry abnormally excessive Sargassum landings can become an impediment. This creates a struggle between the environmental good of the beach and the economic good of the tourism industry. The Sargassum Early Advisory System (SEAS) Phase One focuses on increasing the efficiency of the current beach management practices. Phase One begins with the effort to employ NASA Landsat images as early warning devices of Sargassum's impending landfall. Oceanic currents as well as coastal wind patterns are hypothesized to be the primary drivers of Sargassum. The Hybrid Coordinate Ocean Model (HYCOM) as well as the Texas Automated Buoy System (TABS), Weatherbuoy, and beach cameras are used to receive real time data as well as future predictions to allow for the creation of accurate macroalgae forecasts. Landsat imagery has a sufficient resolution that slicks created by the Sargassum's disruption of the water surface can be differentiated. The Landsat's RGB array allows it to identify large Sargassum mats by a distinct green glow. The SEAS Team has created a 555 km X 516 km swath of monitoring that provides two to three week notices of eminent Sargasssum landfall. The remote sensing data is crosschecked with ground-truthing via mounted beach cameras and boating contacts. The SEAS Team creates advisories that are sent out to local beach managers and other stakeholders. These advisories allow for the beach managers to more efficiently allocate resources. If Sargassum is not observed in the Landsat images then beach managers are able to scale back the workforce and equipment committed to removing the Sargassum from the beach. If an excess of Sargassum is

  19. Cyclotron facilities in Brazil: Current status and licensing aspects

    Energy Technology Data Exchange (ETDEWEB)

    Facure, A.; Carvalho, S.M.; Di Prinzio, R.; Silveira, C.S.; Gasparian, P.B.R.; Franca, W.F., E-mail: facure@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-09-01

    Positron Emission Tomography (PET) is a highly sensitive and accurate nuclear medicine imaging technology but the major problem of this technique is the use of radioisotopes with short half-life, less than two hours. The production and selling of short half-life radioisotopes used to be monopoly of the Brazilian Government. In 2006, a Constitutional Amendment revoked the state monopoly due to the need for the use of short half-life radioisotopes in nuclear medicine centers very far from the government production facilities. The aim of this study is to describe the current status of short half-life radioisotopes production in Brazil and discuss some licensing process. In Brazil, as has been occurring worldwide, the number of nuclear medicine centers is increasing. Currently there are 123 services performing PET scans in Brazil. There are 14 cyclotrons operating in Brazil. The type of licensing process conducted in Brazil does not take into account the population density of each state, with a free competition model being adopted. Because of this there is a lot of equipment concentrated in the Southeast and no cyclotrons operating in the Northern part of the country. One of the biggest obstacles during the licensing process is the designation of qualified personnel as operation workers and radiation safety officers. The number of cyclotron accelerators and PET/CT equipment increased in recent years. However, a number of external factors such as the distance from the nuclear medicine centers, and qualified personnel have proved crucial for the economic viability of this type of facility. (author)

  20. The ethics of the Texas death penalty and its impact on a prolonged appeals process.

    Science.gov (United States)

    Pearlman, T

    1998-01-01

    Society remains sharply divided as to the deterrent value of capital punishment. Following the reintroduction of the death penalty in the United States, Texas law mandates the affirmative predictability of future dangerousness beyond a reasonable doubt before a jury can impose the ultimate penalty for capital murder. The validity of prediction of dangerousness has been challenged in three Texas landmark cases before the U.S. Supreme Court. The case of Karla Faye Tucker highlights the moral controversy that occurs when execution follows an appeals process stretching over more than a decade, during which time personality growth and the effects of prison rehabilitation may have eliminated or curbed criminal tendencies.

  1. NuSTAR Discovery of a Cyclotron Line in the Be/X-ray Binary RX J0520.5-6932 During Outburst

    DEFF Research Database (Denmark)

    Tendulkar, Shriharsh P.; Fürst, Felix; Pottschmidt, Katja

    2014-01-01

    We present spectral and timing analysis of NuSTAR observations of RX J0520.5$-$6932 in the 3-79 keV band collected during its outburst in January 2014. The target was observed on two epochs and we report the detection of a cyclotron resonant scattering feature with central energies of $E_\\mathrm{...

  2. Oceanographic data from CTD casts from as part of the Texas-Louisiana Shelf Circulation and Transport Processes Study (LATEX PART A) from 01 May 1992 to 08 May 1992 (NODC Accession 9200259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic data from CTD casts from from 01 May 1992 to 08 May 1992. Data were collected by Texas A&M Universtiy (TAMU) as part of the Texas-Louisiana Shelf...

  3. Assessment of single-turn extraction for a superconducting separated-sector cyclotron

    Directory of Open Access Journals (Sweden)

    J.-W. Kim

    1999-04-01

    Full Text Available We have studied the beam dynamics in a high field separated-sector cyclotron to establish conditions required to achieve single-turn extraction. Extraction efficiency above 99% is aimed to avoid beam-induced damages. A sufficient last-turn separation and a preservation of beam quality throughout the acceleration are the prerequisites. The last-turn separation can be enhanced with the orbital precession induced by an off-centering injection as in existent lower field separated-sector cyclotrons. The beam qualities, on the other hand, are affected by the resonances traversed or approached during the acceleration. Acceleration of light nuclei to the energies of 300–400 MeV/u was especially disturbing because of the broadening of radial beamwidth upon crossing the ν_{r}=3/2 resonance. Tolerance to the third harmonic gradient field, which causes the resonance in lowest order, is set to be 0.1 G/cm. The integer resonance ν_{z}=1 can be avoided with a proper design of the yoke. The longitudinal space charge forces were also investigated to estimate the intensity limits determined by the energy spreads of beam assuming simplified charge distributions. Moreover, beam preparations for injection matching are described in view of reducing the beam losses into the extraction elements.

  4. Promoting energy-balance behaviors among ethnically diverse adolescents: overview and baseline findings of The Central Texas CATCH Middle School Project.

    Science.gov (United States)

    Springer, Andrew E; Kelder, Steven H; Byrd-Williams, Courtney E; Pasch, Keryn E; Ranjit, Nalini; Delk, Joanne E; Hoelscher, Deanna M

    2013-10-01

    The Central Texas Coordinated Approach To Child Health (CATCH) Middle School Project is a 3.5-year school-based project aimed at promoting physical activity (PA), healthy eating, and obesity prevention among public middle school students in Texas. This article describes the CATCH intervention model and presents baseline findings from spring 2009. CATCH comprises six core components: CATCH Team, CATCH PE, CATCH Classroom, CATCH Eat Smart Cafeteria, CATCH Family, and CATCH Social Marketing. A group randomized serial cross-sectional design is being employed to test the effect of three program support conditions (n = 10 schools each) on energy-balance behaviors: Basic (training and curriculum only), Basic Plus (training and curriculum plus CATCH facilitator support), and Basic Plus Social Marketing (all inputs plus social marketing component). The study sample is composed of a cross-sectional sample of eighth-grade students (primary outcome evaluation sample) and sixth- and seventh-grade students (PE process evaluation sample) who are selected and measured each year. At baseline, 37.9% of eight-grade students (n = 2,841; 13.9 years) were overweight/obese and 19.2% were obese. Eighth-grade students reported, on average, consuming sugar-sweetened beverages more than two times on the previous day and fruits and vegetables roughly three times on the previous day; only two of five school districts surpassed the recommended 50% cut-point for class time spent in moderate-and-vigorous PA as measured in classes of sixth- and seventh-grade students. Additional behavioral findings are reported. Body mass index and behaviors were comparable across conditions. Baseline findings underscore the need to promote student energy-balance behaviors.

  5. THE RR LYRAE VARIABLES AND HORIZONTAL BRANCH OF NGC 6656 (M22) {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Kunder, Andrea; Walker, Alistair R.; Paredes Alvarez, Leonardo [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Stetson, Peter B. [Dominion Astrophysical Observatory, NRC-Herzberg, National Research Council, Victoria BC, V9E 2E7 (Canada); Cassisi, Santi [INAF-Osservatorio Astronomico di Collurania, Via M. Maggini, I-64100 Teramo (Italy); Layden, Andrew [Bowling Green State University, Bowling Green, OH 43403 (United States); Bono, Giuseppe [Dipartimento di Fisica, Universita di Roma Tor Vergata, Rome (Italy); Catelan, Márcio [Pontificia Universidad Católica de Chile, Departamento de Astronomía y Astrofísica, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Clem, James L. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Matsunaga, Noriyuki [Department of Astronomy, School of Science, The University of Tokyo (Japan); Salaris, Maurizio [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Lee, Jae-Woo [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Chaboyer, Brian, E-mail: akunder@ctio.noao.edu, E-mail: mcatelan@astro.puc.cl [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2013-11-01

    The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC 6656 (M22), with observations spanning a range of 22 years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are (P) {sub RR0} = 0.66 ± 0.02 days and (P) {sub RR1} = 0.33 ± 0.01 days, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1-type to all RR-type variables is N {sub 1}/N{sub RR} = 0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E( B – – V) = 0.36 ± 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R) = +0.97 ± 0.1 and at least one ''gap'' located in an unusual part of the blue HB, in the middle of the so-called hot HB stars.

  6. Texas Clean Energy Project: Topical Report, Phase 1 - February 2010-December 2012

    Energy Technology Data Exchange (ETDEWEB)

    Mattes, Karl

    2012-11-01

    Summit Texas Clean Energy, LLC (STCE) is developing the Texas Clean Energy Project (TCEP or the project) to be located near Penwell, Texas. The TCEP will include an Integrated Gasification Combined Cycle (IGCC) plant with a nameplate capacity of 400 megawatts electric (MWe), combined with the production of urea fertilizer and the capture, utilization and storage of carbon dioxide (CO2) sold commercially for regional use in enhanced oil recovery (EOR) in the Permian Basin of west Texas. The TCEP will utilize coal gasification technology to convert Powder River Basin subbituminous coal delivered by rail from Wyoming into a synthetic gas (syngas) which will be cleaned and further treated so that at least 90 percent of the overall carbon entering the facility will be captured. The clean syngas will then be divided into two high-hydrogen (H2) concentration streams, one of which will be combusted as a fuel in a combined cycle power block for power generation and the other converted into urea fertilizer for commercial sale. The captured CO2 will be divided into two streams: one will be used in producing the urea fertilizer and the other will be compressed for transport by pipeline for offsite use in EOR and permanent underground sequestration. The TCEP was selected by the U.S. Department of Energy (DOE) Office of Fossil Energy (FE) for cost-shared co-funded financial assistance under Round 3 of its Clean Coal Power Initiative (CCPI). A portion of this financial assistance was budgeted and provided for initial development, permitting and design activities. STCE and the DOE executed a Cooperative Agreement dated January 29, 2010, which defined the objectives of the project for all phases. During Phase 1, STCE conducted and completed all objectives defined in the initial development, permitting and design portions of the Cooperative Agreement. This topical report summarizes all work associated with the project objectives, and additional work

  7. Compensation for Overloads and Summer Employment: A Survey of Current Practice in Texas.

    Science.gov (United States)

    Hardy, James C.

    A survey was sent to 58 chief academic officers to gain information about compensation for instructional overloads and summer employment at public and private Texas colleges and universities. Responses were received from 42 institutions. Only two indicated that their institutions did not have a uniform policy guiding summer compensation amounts.…

  8. Whistler-cyclotron spontaneous fluctuations as a proxy to identify thermal and non-thermal electrons in the solar wind

    Science.gov (United States)

    Moya, P. S.; Vinas, A. F.; Navarro, R.; Araneda, J. A.

    2014-12-01

    Observed electron velocity distributions in the solar wind exhibit a variety of non-thermal features which deviate from thermal equilibrium, in the form of temperature anisotropies, suprathermal tails, and field aligned beams. The state close to thermal equilibrium and its departure from it provides a source for spontaneous emissions of electromagnetic fluctuations as for example the whistler cyclotron waves at electron scales. Here we present a comparative analysis of these fluctuations based upon anisotropic plasma modeled with thermal and non-thermal particle distributions. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic thermal bi-Maxwellian and non-thermal Tsallis-kappa-like magnetized electron-proton plasma. Dispersion analysis and stability thresholds are derived for these non-thermal distributions and compared with similar results obtained from PIC simulations using plasma and field parameters relevant to the solar wind environments. Our results indicate that there is a strong dependence between the shape of the velocity distribution function and the topological regions in the frequency-wave number plane in which the spontaneous fluctuations emerge. In the case of non-thermal plasmas there is an enhancement of the fluctuations level due to the effective higher-temperature effects and the excess of suprathermal particles. This feature may be used proxy to identify the nature of electron populations in space plasmas when high resolution particle instruments are not available.

  9. Water supply and needs for West Texas

    Science.gov (United States)

    This presentation focused on the water supplies and needs of West Texas, Texas High Plains. Groundwater is the most commonly used water resources on the Texas High Plains, with withdrawals from the Ogallala Aquifer dominating. The saturation thickness of the Ogallala Aquifer in Texas is such that t...

  10. Variable speed and constant frequency control of hydraulic wind turbine with energy storage system

    National Research Council Canada - National Science Library

    Liu, Zengguang; Yang, Guolai; Wei, Liejiang; Yue, Daling

    2017-01-01

    ... hydraulic system of hydraulic wind turbine for the first time. The whole hydraulic system consists of a fixed displacement pump, a variable displacement motor, two proportional control valves and an energy storage system...

  11. Verification of the shielding built for a Cyclotron accelerator; Verificacao da blindagem construida para um acelerador do tipo Ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Videira, Heber S., E-mail: heber@cyclopet.com [CYCLOPET Radiofarmacos LTDA., Curitiba, PR (Brazil); Passaro, Bruno M.; Gonzalez, Julia A.; Guimaraes, Maria Ines C.C.; Buchpigue, Carlos A. [Centro de Medicina Nuclear (CMN) do InRad HCFMUSP, Sao Paulo, SP (Brazil)

    2012-08-15

    According to the National Nuclear Energy Commission (CNEN) resolution 112/2011, administrative controls must be applied during the construction of a cyclotron and documents must be created showing that the facility can operate without radiological risks, referring even to the shielding efficiency. This study aimed to perform the analysis of the construction and efficiency of the bunker built for shielding, in the cyclotron of University of Sao Paulo Medical School Health System. This was possible through the measurements of a radiometric survey in normal working conditions, and testing related to compression resistance and density. The results showed that the compression resistance of the concrete used is higher than the expected value and the average density value obtained is within the tolerated limits. The radiometric survey results showed that the levels of ionizing radiation are well below the established limits. (author)

  12. Teachers and Teaching Conditions in Rural Texas: Policy Brief

    Science.gov (United States)

    Jimerson, Lorna

    2004-01-01

    Over four milliion children go to public schools in Texas; of these, almost half a million (474,000) students attend school in rural areas. Thirty-six percent of rural Texas students are members of a minority group, 46% are poor, and more than 31,000 students in rural Texas do not speak English well. These are Texas-style large numbers that begin…

  13. Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State

    Energy Technology Data Exchange (ETDEWEB)

    Aharonian, F.; /Heidelberg, Max Planck Inst. /Dublin Inst.; Akhperjanian, A.G.; /Yerevan Phys. Inst.; Anton, G.; /Erlangen - Nuremberg U.; Barres de Almeida, U.; /Durham U.; Bazer-Bachi, A.R.; /Toulouse, CESR; Becherini, Y.; /APC, Paris; Behera, B.; /Heidelberg Observ.; Bernlohr, K.; /Heidelberg, Max Planck Inst. /Humboldt U., Berlin; Boisson, C.; /LUTH, Meudon; Bochow, A.; /Heidelberg, Max Planck Inst.; Borrel, V.; /Toulouse, CESR; Brion, E.; /DAPNIA, Saclay; Brucker, J.; /Erlangen - Nuremberg U.; Brun, P.; /DAPNIA, Saclay; Buhler, R.; /Heidelberg, Max Planck Inst.; Bulik, T.; /Warsaw, Copernicus Astron. Ctr.; Busching, I.; /Western Ontario U.; Boutelier, T.; /Grenoble Observ.; Chadwick, P.M.; /Durham U.; Charbonnier, A.; /Paris U., VI-VII; Chaves, R.C.G.; /Heidelberg, Max Planck Inst. /Durham U. /Ecole Polytechnique /Heidelberg, Max Planck Inst. /Annecy, LAPP /Humboldt U., Berlin /Durham U. /Namibia U. /Western Ontario U. /Ecole Polytechnique /Heidelberg, Max Planck Inst. /Durham U. /APC, Paris /Heidelberg, Max Planck Inst. /Dublin Inst. /Annecy, LAPP /Grenoble Observ. /Warsaw, Copernicus Astron. Ctr. /Cracow, INP /Heidelberg, Max Planck Inst. /Heidelberg Observ. /APC, Paris /Montpellier U. /Montpellier U. /Montpellier U. /Heidelberg, Max Planck Inst. /Ecole Polytechnique /Humboldt U., Berlin /Dublin Inst. /Montpellier U. /APC, Paris /SLAC; /more authors..

    2009-05-07

    We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

  14. Effective production of ⁶⁵Zn with a PET cyclotron.

    Science.gov (United States)

    Lucconi, G; Cicoria, G; Pancaldi, D; Malizia, C; Marengo, M

    2012-08-01

    Cyclotrons dedicated to the production of PET radiopharmaceuticals for clinical use can be a resource also for research in other fields of science. In the present study we assessed the feasibility of (65)Zn production via the (65)Cu(p,n)(65)Zn reaction using a 16.5 MeV GE-PETtrace biomedical cyclotron. The radioisotope (65)Zn (t(1/2)=244.26 zd; decay mode: EC 98.3%, β(+) 1.7%) has a wide range of applications, especially in botany and agriculture; its long half life allows storage and delivery to research centers without a cyclotron on site. Natural copper foils (thickness: 100 μm; purity: >99.9%) were irradiated in a solid target station developed in our institution. The EXFOR and IAEA cross sections databases were carefully studied to optimize the irradiation setup in order to maximize the yield of the radionuclide of interest and minimize the production of isotopic impurities. We performed production runs at 20 μA for 30 min. Activity was measured using a calibrated HPGe gamma ray detector and an ionization chamber radionuclide activity meter. These measures showed the presence of two main contaminants: (63)Zn (t(1/2)=38.47 min) and (64)Cu (t(1/2)=12.7h); we produced (65)Zn with a saturation yield of (1.06 ± 0.07) GBq/μA (E(p)=12.65→10.48 MeV). The irradiated target was dissolved in 1 ml of 6N HNO(3) at the temperature of 90°C and then purified through anion exchange chromatography with BIO RAD AG 1×8 resin. The radionuclidic purity of the final solution of (65)Zn in HCl 0.005 N, expressed in activity, resulted superior to (99.921 ± 0.003) %. Copyright © 2012. Published by Elsevier Ltd.

  15. Climatic variability of a fire-weather index based on turbulent kinetic energy and the Haines Index

    Science.gov (United States)

    Warren E. Heilman; Xindi Bian

    2010-01-01

    Combining the Haines Index (HI) with near-surface turbulent kinetic energy (TKEs) through a product of the two values (HITKEs) has shown promise as an indicator of the atmospheric potential for extreme and erratic fire behavior in the U.S. Numerical simulations of fire-weather evolution during past wildland fire episodes in...

  16. Characteristic Experimentations of Degrader and Scatterer at MC-50 Cyclotron

    CERN Document Server

    Lee Seok Ki; Kim, Kye-Ryung; Lee, Hwa-Ryun; Park, Bum-Sik

    2005-01-01

    Building proton beam user facilities, especially deciding beam energy level, depends on the attached proton accelerator and users' needs. To adjust beam energy level, two methods are generally used. One is to directly adjust the beam in the accelerator. The other is to adjust beam energy after extracting from the accelerator. Degrader/Scatterer System has been installed in the MC-50 Cyclotron to adjust energy level of the beam used for various application fields. Its degrader and scatterer are made of Al foils and Au foils, respectively. Al thickness are 2, 1, 0.5, 0.3, 0.2, 0.1, 0.05, 0.03, 0.02, 0.01mm and Au thickness are 0.2, 0.1, 0.05, 0.03, 0.02, 0.01mm, respectively. In this study, suitable beam condition was adjusted through overlapping Al/Au foils of various thickness through simulation results. After that, LET(Linear Energy Transfer) value was indirectly acquired by measuring the bragg peak of the external beam through PMMA plastic Phantom and profile was measured by film dosimetry.

  17. A Brief Sampling of West Texas Teacher Attitudes Toward Southwest Spanish and English Language Varieties

    Science.gov (United States)

    MacIntosh, Roderick; Ornstein, Jacob

    1974-01-01

    A questionnaire was administered to twenty-five teachers of the El Paso, Texas, area to determine their attitudes toward the Spanish and English spoken in the area. Most viewed the language as a "border slang" not equivalent to correct English or Spanish. (CK)

  18. Radiologic assessment of a self-shield with boron-containing water for a compact medical cyclotron.

    Science.gov (United States)

    Horitsugi, Genki; Fujibuchi, Toshioh; Yamaguchi, Ichiro; Eto, Akihisa; Iwamoto, Yasuo; Hashimoto, Hiromi; Hamada, Seiki; Obara, Satoshi; Watanabe, Hiroshi; Hatazawa, Jun

    2012-07-01

    The cyclotron at our hospital has a self-shield of boron-containing water. The amount of induced radioactivity in the boron-containing water shield of a compact medical cyclotron has not yet been reported. In this study, we measured the photon and neutron dose rates outside the self-shield during cyclotron operation. We estimated the induced radioactivities of the boron-containing water used for the self-shield and then measured them. We estimated the activation of concrete outside the self-shield in the cyclotron laboratory. The thermal neutron flux during cyclotron operation was estimated to be 4.72 × 10(2) cm(-2) s(-1), and the activation of concrete in a cyclotron laboratory was about three orders of magnitude lower than the clearance level of RS-G-1.7 (IAEA). The activity concentration of the boron-containing water did not exceed the concentration limit for radioactive isotopes in drainage in Japan and the exemption level for Basic Safety Standards. Consequently, the boron-containing water is treatable as non-radioactive waste. Neutrons were effectively shielded by the self-shield during cyclotron operation.

  19. Cyclotron Resonance of Electrons Trapped in a Microwave Cavity

    Science.gov (United States)

    Elmore, W. C.

    1975-01-01

    Describes an experiment in which the free-electron cyclotron resonance of electrons trapped in a microwave cavity by a Penning trap is observed. The experiment constitutes an attractive alternative to one of the Gardner-Purcell variety. (Author/GS)

  20. Education for Agricultural Improvement: Teacher Certification at the Agricultural and Mechanical College of Texas

    Science.gov (United States)

    Burlbaw, Lynn M.; Williams, Lauren; Kelly, Larry J.

    2017-01-01

    Texas A&M University has long been known for its engineering and agricultural programs. Only in the last 50 years has its reputation included the preparation of teachers for general education in the public schools of Texas. However, agricultural education has been an integral part of the institution's mandate since early in the 20th century.…

  1. Measuring energy-saving retrofits: Experiences from the Texas LoanSTAR program

    Energy Technology Data Exchange (ETDEWEB)

    Haberl, J.S.; Reddy, T.A.; Claridge, D.E.; Turner, W.D.; O`Neal, D.L.; Heffington, W.M. [Texas A and M Univ., College Station, TX (United States). Energy Systems Lab.

    1996-02-01

    In 1988 the Governor`s Energy Management Center of Texas received approval from the US Department of Energy to establish a $98.6 million state-wide retrofit demonstration revolving loan program to fund energy-conserving retrofits in state, public school, and local government buildings. As part of this program, a first-of-its-kind, statewide Monitoring and Analysis Program (MAP) was established to verify energy and dollar savings of the retrofits, reduce energy costs by identifying operational and maintenance improvements, improve retrofit selection in future rounds of the LoanSTAR program, and initiate a data base of energy use in institutional and commercial buildings located in Texas. This report discusses the LoanSTAR MAP with an emphasis on the process of acquiring and analyzing data to measure savings from energy conservation retrofits when budgets are a constraint. This report includes a discussion of the program structure, basic measurement techniques, data archiving and handling, data reporting and analysis, and includes selected examples from LoanSTAR agencies. A summary of the program results for the first two years of monitoring is also included.

  2. GEANT4 simulation of cyclotron radioisotope production in a solid target.

    Science.gov (United States)

    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

  3. Ion cyclotron resonance heating system on Aditya

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    1Institute for Plasma Research, Bhat, Gandhinagar 382 428, India. 2Variable Electron Cyclotron .... Requirements for RF generators for fusion research include high power, long pulse duration and reliability. ... Output of pre-driver (triode 3CX5000A7) grounded grid amplifier is made tunable within. 20 to 47 MHz by using a ...

  4. Ion Beam Materials Analysis and Modifications at keV to MeV Energies at the University of North Texas

    Science.gov (United States)

    Rout, Bibhudutta; Dhoubhadel, Mangal S.; Poudel, Prakash R.; Kummari, Venkata C.; Lakshantha, Wickramaarachchige J.; Manuel, Jack E.; Bohara, Gyanendra; Szilasi, Szabolcs Z.; Glass, Gary A.; McDaniel, Floyd D.

    2014-02-01

    The University of North Texas (UNT) Ion Beam Modification and Analysis Laboratory (IBMAL) has four particle accelerators including a National Electrostatics Corporation (NEC) 9SDH-2 3 MV tandem Pelletron, a NEC 9SH 3 MV single-ended Pelletron, and a 200 kV Cockcroft-Walton. A fourth HVEC AK 2.5 MV Van de Graaff accelerator is presently being refurbished as an educational training facility. These accelerators can produce and accelerate almost any ion in the periodic table at energies from a few keV to tens of MeV. They are used to modify materials by ion implantation and to analyze materials by numerous atomic and nuclear physics techniques. The NEC 9SH accelerator was recently installed in the IBMAL and subsequently upgraded with the addition of a capacitive-liner and terminal potential stabilization system to reduce ion energy spread and therefore improve spatial resolution of the probing ion beam to hundreds of nanometers. Research involves materials modification and synthesis by ion implantation for photonic, electronic, and magnetic applications, micro-fabrication by high energy (MeV) ion beam lithography, microanalysis of biomedical and semiconductor materials, development of highenergy ion nanoprobe focusing systems, and educational and outreach activities. An overview of the IBMAL facilities and some of the current research projects are discussed.

  5. Modeling of electron cyclotron resonance acceleration in a stationary inhomogeneous magnetic field

    Directory of Open Access Journals (Sweden)

    Valeri D. Dougar-Jabon

    2008-04-01

    Full Text Available In this paper, the cyclotron autoresonance acceleration of electrons in a stationary inhomogeneous magnetic field is studied. The trajectory and energy of electrons are found through a numerical solution of the relativistic Newton-Lorentz equation by a finite difference method. The electrons move along a TE_{112} cylinder cavity in a steady-state magnetic field whose axis coincides with the cavity axis. The magnetic field profile is such that it keeps the phase difference between the electric microwave field and the electron velocity vector within the acceleration phase band. The microwaves amplitude of 6  kV/cm is used for numerical calculations. It is shown that an electron with an initial longitudinal energy of 8 keV can be accelerated up to 260 keV by 2.45 GHz microwaves at a distance of 17 cm.

  6. A LabVIEW based cyclotron magnetic field mapping system

    Energy Technology Data Exchange (ETDEWEB)

    Marti, F.; Johnson, P. [NSCL, Michigan State University, East Lansing, MI (United States)

    1999-07-01

    This paper describes the application of National Instruments LabVIEW to the NSCL K500 magnet mapping, as part of the Coupled Cyclotron Upgrade. LabVIEW provides a fast development environment for hardware control from a PC running Windows NT. The PC and LabVIEW environment allow non-professional computer programmers to obtain a reliable and flexible system where modifications can be quickly implemented. This program supports the use of motor controllers, data acquisition cards, digital I/O modules and GPIB instruments. A complete map of 360 degrees is obtained in approximately 90 minutes, measuring 185000 field values with a spacing of 1.6 mm in radius every degree. (author)

  7. Development of a miniature microwave electron cyclotron resonance plasma ion thruster for exospheric micro-propulsion.

    Science.gov (United States)

    Dey, Indranuj; Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2015-12-01

    A miniature microwave electron cyclotron resonance plasma source [(discharge diameter)/(microwave cutoff diameter) micro-propulsion applications in the exosphere. The discharge source uses both radial and axial magnetostatic field confinement to facilitate electron cyclotron resonance and increase the electron dwell time in the volume, thereby enhancing plasma production efficiency. Performance of the ion thruster is studied at 3 microwave frequencies (1.2 GHz, 1.6 GHz, and 2.45 GHz), for low input powers (<15 W) and small xenon mass flow rates (<40 μg/s), by experimentally measuring the extracted ion beam current through a potential difference of ≅1200 V. The discharge geometry is found to operate most efficiently at an input microwave frequency of 1.6 GHz. At this frequency, for an input power of 8 W, and propellant (xenon) mass flow rate of 21 μg/s, 13.7 mA of ion beam current is obtained, equivalent to an calculated thrust of 0.74 mN.

  8. The activation of W and Zr by deuterons at energies up to 20 MeV

    Directory of Open Access Journals (Sweden)

    Šimečková Eva

    2017-01-01

    Full Text Available The proton and deuteron induced reactions are of a great interest for the assessment of induced radioactivity of accelerator components, target and beam stoppers. In order to investigate the important nuclides, we have carried up the irradiation experiments with the variable-energy cyclotron U-120 M of the NPI CAS Řež. The production cross sections of the nuclides 179,181,182m,182,183,184m,184,186Re and 187W from reaction on natural W were investigated by deuteron beams of 20 MeV energy. A part of preliminary results of deuteron activation of natural Zr is also shown. The stacked-foil technique was utilized. The comparison of present results to data of other authors and to predictions of evaluated data libraries is discussed.

  9. The activation of W and Zr by deuterons at energies up to 20 MeV

    Science.gov (United States)

    Šimečková, Eva; Štefánik, Milan; Bém, Pavel; Mrázek, Jaromír; Novák, Jan

    2017-09-01

    The proton and deuteron induced reactions are of a great interest for the assessment of induced radioactivity of accelerator components, target and beam stoppers. In order to investigate the important nuclides, we have carried up the irradiation experiments with the variable-energy cyclotron U-120 M of the NPI CAS Řež. The production cross sections of the nuclides 179,181,182m,182,183,184m,184,186Re and 187W from reaction on natural W were investigated by deuteron beams of 20 MeV energy. A part of preliminary results of deuteron activation of natural Zr is also shown. The stacked-foil technique was utilized. The comparison of present results to data of other authors and to predictions of evaluated data libraries is discussed.

  10. Shielding for a cyclotron used for medical isotope production in China.

    Science.gov (United States)

    Pevey, R; Miller, L F; Marshall, B J; Townsend, L W; Alvord, B

    2005-01-01

    Monte Carlo and discrete ordinate calculations have been performed to determine the doses at several locations in a positron emission tomography (PET) facility in China, where the radiation source is a cyclotron that is used for the production of the isotopes necessary for PET scans. The energy-dependent neutron source term is obtained by calculations using the ALICE code, and is interpolated for input to Monte Carlo and discrete ordinate calculations. The building that houses the cyclotron has a labyrinth of walls to minimise dose to operators and to other occupants of the building. Unbiased Monte Carlo calculations did not converge after more than one week of CPU time, whereas direction biasing alone resulted in convergence in several days. A study of several biasing techniques indicated that about a factor of 3 in computational efficiency is obtained using evaluated biasing methods. The use of adjoint fluxes for biasing Monte Carlo calculations can improve computational efficiencies by one or two orders of magnitude for some problems.

  11. Texas LPG fuel cell development and demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2004-07-26

    The State Energy Conservation Office has executed its first Fuel Cell Project which was awarded under a Department of Energy competitive grant process. The Texas LPG Fuel Processor Development and Fuel Cell Demonstration Program is a broad-based public/private partnership led by the Texas State Energy Conservation Office (SECO). Partners include the Alternative Fuels Research and Education Division (AFRED) of the Railroad Commission of Texas; Plug Power, Inc., Latham, NY, UOP/HyRadix, Des Plaines, IL; Southwest Research Institute (SwRI), San Antonio, TX; the Texas Natural Resource Conservation Commission (TNRCC), and the Texas Department of Transportation (TxDOT). The team proposes to mount a development and demonstration program to field-test and evaluate markets for HyRadix's LPG fuel processor system integrated into Plug Power's residential-scale GenSys(TM) 5C (5 kW) PEM fuel cell system in a variety of building types and conditions of service. The program's primary goal is to develop, test, and install a prototype propane-fueled residential fuel cell power system supplied by Plug Power and HyRadix in Texas. The propane industry is currently funding development of an optimized propane fuel processor by project partner UOP/HyRadix through its national checkoff program, the Propane Education and Research Council (PERC). Following integration and independent verification of performance by Southwest Research Institute, Plug Power and HyRadix will produce a production-ready prototype unit for use in a field demonstration. The demonstration unit produced during this task will be delivered and installed at the Texas Department of Transportation's TransGuide headquarters in San Antonio, Texas. Simultaneously, the team will undertake a market study aimed at identifying and quantifying early-entry customers, technical and regulatory requirements, and other challenges and opportunities that need to be addressed in planning commercialization of the units

  12. Ion Bernstein instability as a possible source for oxygen ion cyclotron harmonic waves

    Science.gov (United States)

    Min, Kyungguk; Denton, Richard E.; Liu, Kaijun; Gary, S. Peter; Spence, Harlan E.

    2017-05-01

    This paper demonstrates that an ion Bernstein instability can be a possible source for recently reported electromagnetic waves with frequencies at or near the singly ionized oxygen ion cyclotron frequency, ΩO+, and its harmonics. The particle measurements during strong wave activity revealed a relatively high concentration of oxygen ions (˜15%) whose phase space density exhibits a local peak at energy ˜20 keV. Given that the electron plasma-to-cyclotron frequency ratio is ωpe/Ωe≳1, this energy corresponds to the particle speed v/vA≳0.3, where vA is the oxygen Alfvén speed. Using the observational key plasma parameters, a simplified ion velocity distribution is constructed, where the local peak in the oxygen ion velocity distribution is represented by an isotropic shell distribution. Kinetic linear dispersion theory then predicts unstable Bernstein modes at or near the harmonics of ΩO+ and at propagation quasi-perpendicular to the background magnetic field, B0. If the cold ions are mostly protons, these unstable modes are characterized by a low compressibility (|δB∥|2/|δB|2≲0.01), a small phase speed (vph˜0.2vA), a relatively small ratio of the electric field energy to the magnetic field energy (between 10-4 and 10-3), and the Poynting vector directed almost parallel to B0. These linear properties are overall in good agreement with the properties of the observed waves. We demonstrate that superposition of the predicted unstable Bernstein modes at quasi-perpendicular propagation can produce the observed polarization properties, including the minimum variance direction on average almost parallel to B0.

  13. The Texas Experimental Tokamak: A plasma research facility. A proposal submitted to the Department of Energy in response to Program Notice 95-10: Innovations in toroidal magnetic confinement systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-12

    The Fusion Research Center (FRC) at the University Texas will operate the tokamak TEXT-U and its associated systems for experimental research in basic plasma physics. While the tokamak is not innovative, the research program, diagnostics and planned experiments are. The fusion community will reap the benefits of the success in completing the upgrades (auxiliary heating, divertor, diagnostics, wall conditioning), developing diverted discharges in both double and single null configurations, exploring improved confinement regimes including a limiter H-mode, and developing unique, critical turbulence diagnostics. With these new regimes, the authors are poised to perform the sort of turbulence and transport studies for which the TEXT group has distinguished itself and for which the upgrade was intended. TEXT-U is also a facility for collaborators to perform innovative experiments and develop diagnostics before transferring them to larger machines. The general philosophy is that the understanding of plasma physics must be part of any intelligent fusion program, and that basic experimental research is the most important part of any such program. The emphasis of the proposed research is to provide well-documented plasmas which will be used to suggest and evaluate theories, to explore control techniques, to develop advanced diagnostics and analysis techniques, and to extend current drive techniques. Up to 1 MW of electron cyclotron heating (ECH) will be used not only for heating but as a localized, perturbative tool. Areas of proposed research are: (1) core turbulence and transport; (2) edge turbulence and transport; (3) turbulence analysis; (4) improved confinement; (5) ECH physics; (6) Alfven wave current drive; and (7) diagnostic development.

  14. Differences between the Texas phoenix palm phytoplasma and the ...

    African Journals Online (AJOL)

    ntushk

    Restriction fragment length polymorphisms analysis of the PCR-amplified nusA and the ... Four restriction enzymes were used for the nusA gene and 16 were used for the hflB genes. Key words: nusA, hflB, phytoplasma, Texas Phoenix decline. ..... Lee I-M, Gundersen-Rindall DE, Davis RE, Bottner KD, Marcone C,.

  15. Harmony as a convergence attractor that minimizes the energy expenditure and variability in physiological gait and the loss of harmony in cerebellar ataxia.

    Science.gov (United States)

    Serrao, Mariano; Chini, Giorgia; Iosa, Marco; Casali, Carlo; Morone, Giovanni; Conte, Carmela; Bini, Fabiano; Marinozzi, Franco; Coppola, Gianluca; Pierelli, Francesco; Draicchio, Francesco; Ranavolo, Alberto

    2017-10-01

    The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively. The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases. The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R(2)adj=0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026). Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns. Copyright © 2017. Published by Elsevier Ltd.

  16. The Impact of Energy Price Decline on China's Energy-Economy-Environment System Variables Using a CGE Model

    DEFF Research Database (Denmark)

    Guo, Zhengquan; Wang, Daojuan; Chen, Chong

    In recent years, prices of coal and crude oil have fallen significantly. These declines have had a large impact on China’s energy-economy-environment system variables. This paper establishes a computable general equilibrium model to systematically analyse the impact of coal price changes alone...

  17. Characterization and performance of a field aligned ion cyclotron range of frequency antenna in Alcator C-Moda)

    Science.gov (United States)

    Wukitch, S. J.; Garrett, M. L.; Ochoukov, R.; Terry, J. L.; Hubbard, A.; Labombard, B.; Lau, C.; Lin, Y.; Lipschultz, B.; Miller, D.; Reinke, M. L.; Whyte, D.; Alcator C-Mod Team

    2013-05-01

    Ion cyclotron range of frequency (ICRF) heating is expected to provide auxiliary heating for ITER and future fusion reactors where high Z metallic plasma facing components (PFCs) are being considered. Impurity contamination linked to ICRF antenna operation remains a major challenge particularly for devices with high Z metallic PFCs. Here, we report on an experimental investigation to test whether a field aligned (FA) antenna can reduce impurity contamination and impurity sources. We compare the modification of the scrape of layer (SOL) plasma potential of the FA antenna to a conventional, toroidally aligned (TA) antenna, in order to explore the underlying physics governing impurity contamination linked to ICRF heating. The FA antenna is a 4-strap ICRF antenna where the current straps and antenna enclosure sides are perpendicular to the total magnetic field while the Faraday screen rods are parallel to the total magnetic field. In principle, alignment with respect to the total magnetic field minimizes integrated E|| (electric field along a magnetic field line) via symmetry. A finite element method RF antenna model coupled to a cold plasma model verifies that the integrated E|| should be reduced for all antenna phases. Monopole phasing in particular is expected to have the lowest integrated E||. Consistent with expectations, we observed that the impurity contamination and impurity source at the FA antenna are reduced compared to the TA antenna. In both L and H-mode discharges, the radiated power is 20%-30% lower for a FA-antenna heated discharge than a discharge heated with the TA-antennas. However, inconsistent with expectations, we observe RF induced plasma potentials (via gas-puff imaging and emissive probes to be nearly identical for FA and TA antennas when operated in dipole phasing). Moreover, the highest levels of RF-induced plasma potentials are observed using monopole phasing with the FA antenna. Thus, while impurity contamination and sources are indeed

  18. Space-charge compensation measurements in electron cyclotron resonance ion source low energy beam transport lines with a retarding field analyzer.

    Science.gov (United States)

    Winklehner, D; Leitner, D; Cole, D; Machicoane, G; Tobos, L

    2014-02-01

    In this paper we describe the first systematic measurement of beam neutralization (space charge compensation) in the ECR low energy transport line with a retarding field analyzer, which can be used to measure the potential of the beam. Expected trends for the space charge compensation levels such as increase with residual gas pressure, beam current, and beam density could be observed. However, the overall levels of neutralization are consistently low (<60%). The results and the processes involved for neutralizing ion beams are discussed for conditions typical for ECR injector beam lines. The results are compared to a simple theoretical beam plasma model as well as simulations.

  19. The electron-cyclotron maser instability as a source of plasma radiation. [Solar radio bursts

    Science.gov (United States)

    Winglee, R. M.; Dulk, G. A.

    1986-01-01

    The generation of continuum bursts from the sun at dm and m wavelengths (in particular, type IV bursts) via the electron-cyclotron-maser instability is examined. The maser instability can be driven by an electron distribution with either a loss-cone anisotropy or a peak at large pitch angles. For omega(p)/Omega(e) much greater than 1, the maser emission is produced by electrons interacting through a harmonic (cyclotron) resonance and is electrostatic, being in the upper hybrid mode at frequencies approximately equal to omega(p). Coalescence processes are required to convert the electrostatic waves into transverse radiation which can escape from the source region. Whether the resultant spectrum is nearly a smooth continuum or has a zebra-stripe pattern (both of which occur in type IV bursts) depends on the form of the electron distribution, inhomogeneities in the density and magnetic field, and whether the maser reaches saturation. For at least the case of some type IV dm bursts with fine structure, comparison with observations seems to indicate that the electrons producing the emission are more likely to have a loss-cone distribution, and that the maser instability is not at saturation.

  20. NuSTAR detection of high-energy X-ray emission and rapid variability from sagittarius A* flares

    DEFF Research Database (Denmark)

    Barrière, Nicolas M.; Tomsick, John A.; Baganoff, Frederick K.

    2014-01-01

    Sagittarius A* harbors the supermassive black hole that lies at the dynamical center of our Galaxy. Sagittarius A* spends most of its time in a low luminosity emission state but flares frequently in the infrared and X-ray, increasing up to a few hundred fold in brightness for up to a few hours...... at a time. The physical processes giving rise to the X-ray flares are uncertain. Here we report the detection with the NuSTAR observatory in Summer and Fall 2012 of four low to medium amplitude X-ray flares to energies up to 79 keV. For the first time, we clearly see that the power-law spectrum...... of Sagittarius A* X-ray flares extends to high energy, with no evidence for a cutoff. Although the photon index of the absorbed power-law fits are in agreement with past observations, we find a difference between the photon index of two of the flares (significant at the 95% confidence level). The spectra...

  1. Patterns of precipitation and soil moisture extremes in Texas, US: A complex network analysis

    Science.gov (United States)

    Sun, Alexander Y.; Xia, Youlong; Caldwell, Todd G.; Hao, Zengchao

    2018-02-01

    Understanding of the spatial and temporal dynamics of extreme precipitation not only improves prediction skills, but also helps to prioritize hazard mitigation efforts. This study seeks to enhance the understanding of spatiotemporal covariation patterns embedded in precipitation (P) and soil moisture (SM) by using an event-based, complex-network-theoretic approach. Events concurrences are quantified using a nonparametric event synchronization measure, and spatial patterns of hydroclimate variables are analyzed by using several network measures and a community detection algorithm. SM-P coupling is examined using a directional event coincidence analysis measure that takes the order of event occurrences into account. The complex network approach is demonstrated for Texas, US, a region possessing a rich set of hydroclimate features and is frequented by catastrophic flooding. Gridded daily observed P data and simulated SM data are used to create complex networks of P and SM extremes. The uncovered high degree centrality regions and community structures are qualitatively in agreement with the overall existing knowledge of hydroclimate extremes in the study region. Our analyses provide new visual insights on the propagation, connectivity, and synchronicity of P extremes, as well as the SM-P coupling, in this flood-prone region, and can be readily used as a basis for event-driven predictive analytics for other regions.

  2. Principle design of a protontherapy, rapid-cycling, variable energy spiral FFAG

    CERN Document Server

    Antoin, S; Beeckman, W; Collot, J; Conjat, M; Forest, F; Fourrier, J; Froidefond, E; Lancelot, J L; Mandrillon, J; Mandrillon, P; Méot, F; Mori, Y; Neuvéglise, D; Ohmori, C; Pasternak, J; Planche, f, T

    2009-01-01

    The FFAG method is nowadays seen as a potential candidate for the acceleration of protons and light ions for hadrontherapy. This has motivated the design of a principle protontherapy installation, in the frame of the RACCAM project. This article presents the design study, a medical spiral scaling FFAG assembly, capable of producing variable energy proton beams, with potentially high repetition and dose delivery rates.

  3. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Science.gov (United States)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  4. Production of hydrogen and deuterium negative ions in an electron cyclotron resonance driven plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dougar-Jabon, V.D. [Industrial Univ. of Santander, Bucaramanga (Colombia)

    2001-04-01

    An electron cyclotron resonance source with driven plasma rings for hydrogen isotope ion production is studied. Extracted currents of positive and negative ions depending on gas pressure, microwave power value and extraction voltage are obtained. The study shows that the negative ion yield is an order of magnitude higher than the yield of positive particles when a driven ring is in contact with the surface of the plasma electrode. The production of negative ions of deuterium, D{sup -}, is close to the production of negative ions of light hydrogen isotope, H{sup -}. The comparison of the experimental data with the calculated ones shows that the most probable process of the H{sup -} and D{sup -} ion formation in the electron cyclotron driven plasma is dissociative attachment of electrons to molecules in high Rydberg states. For hydrogen ions and ions of deuterium, the negative current at a microwave power of 200 W through a 3-mm aperture and 8 kV extraction voltage are 4.7 mA and 3.1 mA respectively. (orig.)

  5. Accessing Disadvantaged Pregnant Women in Houston, Texas, and Characterizing Biomarkers of Metal Exposure: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Kristina W. Whitworth

    2017-04-01

    Full Text Available Abstract: Communities of color or low socioeconomic status are disproportionately affected by metal exposure given spatial variability of the ambient levels of these contaminants. Despite this, there is little research characterizing metal concentrations in blood among disadvantaged populations in the U.S., especially among pregnant women who are particularly vulnerable and difficult to access. Thus, we conducted a pilot study among disadvantaged pregnant women in Houston, Texas to assess willingness to participate in key activities of an epidemiologic study and characterize exposures to 16 metals. Thirty-one women attending a Medicaid-serving prenatal clinic were included in this pilot study and completed an interviewer-administered questionnaire. We obtained and measured metal compounds in whole blood samples for 22 of these women during third-trimester prenatal visits. Median whole blood concentrations of Ni, As, Cd, and Pb were 27, 1.4, 0.6, and 6.3 µg/L, respectively. Most women were willing to participate in critical aspects of a research study, including wearing a personal air-sampling badge for 2–3 days (87.1%, receiving ultrasounds (83.9%, and providing blood draws (64.5%. Despite the small sample, our results provide evidence of women’s metal exposure and their willingness to participate in future research studies to elucidate exposure pathways and explore related health effects experienced among this population of disadvantaged pregnant women.

  6. Denton, Texas: Using Transportation Data to Reduce Fuel Consumption (City Energy: From Data to Decisions)

    Energy Technology Data Exchange (ETDEWEB)

    Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

    2017-09-29

    This fact sheet "Denton, Texas: Using Transportation Data to Reduce Fuel Consumption" explains how the City of Denton used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

  7. Climate Change Impacts on Texas Water: A White Paper Assessment of the Past, Present and Future and Recommendations for Action

    Energy Technology Data Exchange (ETDEWEB)

    Banner, Jay L.; Jackson, Charles S.; Yang, Zong-Liang; Hayhoe, Katharine; Woodhouse, Connie; Gulden, Lindsey; Jacobs, Kathy; North, Gerald; Leung, Lai-Yung R.; Washington, Warren M.; Jiang, Xiaoyan; Casteel, Richard

    2010-09-01

    Texas comprises the eastern portion of the Southwest region, where the convergence of climatological and geopolitical forces has the potential to put extreme stress on water resources. Geologic records indicate that Texas experienced large climate changes on millennial time scales in the past, and over the last thousand years, tree-ring records indicate that there were significant periods of drought in Texas. These droughts were of longer duration than the 1950s 'drought of record' that is commonly used in planning, and they occurred independently of human-induced global climate change. Although there has been a negligible net temperature increase in Texas over the past century, temperatures have increased more significantly over the past three decades. Under essentially all climate model projections, Texas is susceptible to significant climate change in the future. Most projections for the 21st century show that with increasing atmospheric greenhouse gas concentrations, there will be an increase in temperatures across Texas and a shift to a more arid average climate. Studies agree that Texas will likely become significantly warmer and drier, yet the magnitude, timing, and regional distribution of these changes are uncertain. There is a large uncertainty in the projected changes in precipitation for Texas for the 21st century. In contrast, the more robust projected increase in temperature with its effect on evaporation, which is a dominant component in the region's hydrologic cycle, is consistent with model projections of frequent and extended droughts throughout the state. For these reasons, we recommend that Texas invest resources to investigate and anticipate the impacts of climate change on Texas water resources, with the goal of providing data to inform resource planning. This investment should support development of (1) research programs that provide policy-relevant science; (2) education programs to engage future researchers and policy

  8. A control strategy for a variable-speed wind energy conversion system

    Science.gov (United States)

    Jacob, A.; Rajagopalan, V.; Veillette, D.

    1980-01-01

    In this article, a method of calculating an optimal control strategy for a variable-speed wind power generation scheme incorporating a squirrel cage induction machine and operating in a self-excited induction generator mode is discussed. This scheme also uses a conventional three-phase thyristor rectifier, a line-commutated inverter and an economical auxiliary commutated-voltage-source inverter. The three regulated variables are: (1) drive speed as a function of available mechanical energy by manipulating the resistive torque developed by induction generator; (2) induction motor power consumption during start-up of the wind machine of vertical axis type; (3) operating slip of the induction machine, thereby limiting start-up and braking currents. The developed strategy is also suitable for any other variable-speed drive system incorporating an induction machine.

  9. Renewable Energy Opportunities at Fort Hood, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Chvala, William D.; Warwick, William M.; Dixon, Douglas R.; Solana, Amy E.; Weimar, Mark R.; States, Jennifer C.; Reilly, Raymond W.

    2008-06-30

    The document provides an overview of renewable resource potential at Fort Hood based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 DoD Renewables Assessment. This effort focuses on grid-connected generation of electricity from renewable energy sources and also ground source heat pumps for heating and cooling buildings, as directed by IMCOM.

  10. Ion hole formation and nonlinear generation of electromagnetic ion cyclotron waves: THEMIS observations

    Science.gov (United States)

    Shoji, Masafumi; Miyoshi, Yoshizumi; Katoh, Yuto; Keika, Kunihiro; Angelopoulos, Vassilis; Kasahara, Satoshi; Asamura, Kazushi; Nakamura, Satoko; Omura, Yoshiharu

    2017-09-01

    Electromagnetic plasma waves are thought to be responsible for energy exchange between charged particles in space plasmas. Such an energy exchange process is evidenced by phase space holes identified in the ion distribution function and measurements of the dot product of the plasma wave electric field and the ion velocity. We develop a method to identify ion hole formation, taking into consideration the phase differences between the gyromotion of ions and the electromagnetic ion cyclotron (EMIC) waves. Using this method, we identify ion holes in the distribution function and the resulting nonlinear EMIC wave evolution from Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations. These ion holes are key to wave growth and frequency drift by the ion currents through nonlinear wave-particle interactions, which are identified by a computer simulation in this study.

  11. Risks of developing breast and colorectal cancer in association with incomes and geographic locations in Texas: a retrospective cohort study.

    Science.gov (United States)

    Liu, Zheyu; Zhang, Kai; Du, Xianglin L

    2016-04-26

    No study has been conducted to investigate the spatial pattern and association of socioeconomic status (such as income) with breast and colorectal cancer incidence in Texas, United States. This study aimed to determine whether median household income was associated with the risk of developing breast and colorectal cancer in Texas and to identify higher cancer risks by race/ethnicity and geographic areas. This was a retrospective cohort study with an ecological component in using aggregated measures at the county level. We identified 243,677 women with breast cancer and 155,534 men and women with colorectal cancer residing in 254 counties in Texas in 1995-2011 from the public-use dataset of Texas Cancer Registry. The denominator population and median household income at the county level was obtained from the U.S. Bureau of the Census. Cancer incidence rates were calculated as number of cases per 100,000 persons and age-adjusted using the 2000 US population data. We used the ArcGIS v10.1 (geographic information system software) to identify multiple clustered counties with high and low cancer incidences in Texas. Age-adjusted breast cancer incidence rate in the highest median income quintile group was 151.51 cases per 100,000 in 2008-2011 as compared to 98.95 cases per 100,000 in the lowest median income quintile group. The risk of colorectal cancer appeared to decrease with increasing median income in racial/ethnic population. Spatial analysis revealed the significant low breast cancer incidence cluster regions located in southwest US-Mexico border counties in Texas. This study demonstrated that higher income was associated with an increased risk of breast cancer and a decreased risk of colorectal cancer in Texas. There were geographic variations with cancer incidence clustered in high risk areas in Texas. Future studies may need to explore more factors that might explain income and cancer risk associations and their geographic variations.

  12. DRAFT LANDSAT DATA MOSAIC: MONTGOMERY COUNTY, TEXAS; HARRIS COUNTY, TEXAS; FORT BEND COUNTY, TEXAS; BRAZORIA COUNTY, TEXAS; GALVESTON COUNTY, TEXAS

    Science.gov (United States)

    This is a draft Landsat Data Mosaic, which contains remote sensing information for Montgomery County, Texas Harris County, Texas Fort Bend County, Texas Brazoria County, Texas Galveston County, and Texas Imagery dates on the following dates: October 6, 1999 and September 29, 200...

  13. A rhetorical investigation of energy-related environmental issues and a proposed modeling of variables influencing the employment of domestic solar water heaters with a focus on mobilizing information

    Science.gov (United States)

    Garner, Lilla Gayle

    A rhetorical investigation of energy-related environmental issues identifies significant contextual features and variables that should be considered in designing effective messages and information campaigns for energy consumers. This analysis reveals five components that should be examined and addressed in the construction of such messages and campaigns: (1) exigencies associated with energy-related environmental issues, (2) socio-political contextual features that influence public dialogue and the availability of energy-related environmental information, (3) competing paradigm structures that directly affect the forming of environmental publics, policy, and cultural norms, (4) theoretical concepts and models that can provide frameworks and guidelines for effective construction and promulgation of energy-related environmental messages, and (5) specific variables and factors that comprise and influence energy-related environmental beliefs, attitudes, intentions, and behaviors. The variables that comprise and influence energy-related environmental beliefs, attitudes, intentions, and behaviors are placed within Fishbein's Model of Reasoning so that the relationships among them can be illustrated and examined. This modeling of variables also provides a framework for testing and operationalizing particular variables with message content. Research findings identify four variables that constitute energy-related environmental beliefs: knowledge of the issue (i.e. perception of scarcity, know ledge of energy processes, personal contribution and con sequences, and general solution strategies), knowledge of action strategies and skills, prototypes and referents, and paradigm perspectives. These four beliefs variables, then, influence five variables that constitute energy-related environmental attitudes: personal evaluations of the issue, perception of personal responsibility, locus of control, personal evaluations of normative beliefs, and sensitivity. In order to illustrate

  14. Archaeological Survey of Cooper Lake, Number 6, 1989. Cultural Resource Studies for Cooper Lake, Hopkins and Delta Counties, Texas

    Science.gov (United States)

    1989-01-01

    The disinterment was performed according comnposition cf the historic landscape consisted of to an explicit bioarchaeological and forensic a...consistM solely of One unique item, a Waco sinker formed on a surface collection. Whole (55.8%) and bri)en quartz cobble, was recovered. This artifact is...Hopkins County, Texas. Texian Society, Special Publication No. 1 and Texas Press, Waco , Texas. Memorial Museum Bulletin, No. 4, Austin. Saunders, Joe W

  15. Integrated analysis of production potential and profitability of a horizontal well in the Lower Glen Rose Formation, Maverick County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Ammer, J.R.; Mroz, T.H.; Zammerilli, A.M.; Yost, A.B. II [Dept. of Energy, Morgantown, WV (United States); Muncey, J.G.; Hegeman, P.S.

    1995-03-01

    The U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) awarded a contract in 1991 to Prime Energy Corporation (PEC) to demonstrate the benefit of using horizontal wells to recover gas from low permeability formations. The project area was located in the Chittim field of Maverick County, Texas. The Lower Glen Rose Formation in the Chittim field was a promising horizontal well candidate based on the heterogenous nature of the reservoir (suggested by large well-to-well variances in reserves) and the low percentage of economical vertical wells. Since there was substantial evidence of reservoir heterogeneity, it was unknown whether the selected, wellsite would penetrate a reservoir with the desired properties for a horizontal well. Thus, an integrated team was formed to combine geologic analysis, seismic interpretation, reservoir engineering, reservoir simulation, and economic assessment to analyze the production potential and profitability of completing a horizontal well in the Lower Glen Rose formation.

  16. The TXESS Revolution: A Partnership to Advance Earth and Space Science in Texas

    Science.gov (United States)

    Ellins, K. K.; Olson, H. C.; Willis, M.

    2007-12-01

    The Texas State Board of Education voted in 2006 to require a fourth year of science for graduation from high school and to authorize the creation of a new senior level Earth Systems and Space Science course as an option to fulfill that requirement. The new Earth Systems and Space Science course will be a capstone course for which three required science courses(biology, chemistry and physics)are prerequisites. Here, we summarize the collective efforts of business leaders, scientists and educators who worked collaboratively for almost a decade to successfully reinstate Earth science as part of Texas' standard high school curriculum and describe a new project, the Texas Earth and Space Science (TXESS) Revolution, a 5-year professional development program for 8th -12th grade minority and minority-serving science teachers and teacher mentors in Texas to help prepare them to teach the new capstone course. At the heart of TXESS Revolution is an extraordinary partnership, involving (1) two UT-Austin academic units, the Jackson School of Geosciences and the Department of Petroleum and Geosystems Engineering; (2) TERC, a not-for-profit educational enterprise in Massachusetts with 30 years experience in designing science curriculum; (3) the University of South Florida; and (4) the Texas Regional Collaboratives for Excellence in Science and Mathematics Teaching, a statewide network of teacher mentors and science teachers. With guidance from the Texas Education Agency, the state agency charged with overseeing education, the TXESS Revolution project will provide teachers with access to high quality materials and instruction aligned with the Texas educational standards for the new capstone course through: a program of eight different 3-day professional development academies offered to both teachers and teachers mentors; immersive summer institutes, field experiences, and a Petroleum Science and Technology Institute; training on how to implement Earth Science by Design, a teacher

  17. Why NASA and the Space Electronics Community Cares About Cyclotrons

    Science.gov (United States)

    LaBel, Kenneth A.

    2017-01-01

    NASA and the space community are faced with the harsh reality of operating electronic systems in the space radiation environment. Systems need to work reliably (as expected for as long as expected) and be available during critical operations such as docking or firing a thruster. This talk will provide a snapshot of the import of ground-based research on the radiation performance of electronics. Discussion topics include: 1) The space radiation environment hazard, 2) Radiation effects on electronics, 3) Simulation of effects with cyclotrons (and other sources), 4) Risk prediction for space missions, and, 5) Real-life examples of both ground-based testing and space-based anomalies and electronics performance. The talk will conclude with a discussion of the current state of radiation facilities in North America for ground-based electronics testing.

  18. The Variability and Intermittency of Wind and Solar Power Can Be Overcome Without Storage By Using the National Energy With Weather System (NEWS) Simulator To Design A National US Electric (and Energy) Sector

    Science.gov (United States)

    Clack, C.; MacDonald, A. E.; Wilczak, J. M.; Alexander, A.; Dunbar, A. D.; Xie, Y.; Picciano, P.; Paine, J.; Terry, L.; Marquis, M.

    2015-12-01

    The importance of weather-driven renewable energies for the United States energy portfolio is growing. The main perceived problems with weather-driven renewable energies are their intermittent nature, low power density, and high costs. The Cooperative Institute for the Research in Environmental Sciences at the University of Colorado collaborated with the Earth Systems Research Laboratory of the National Oceanic and Atmospheric Administration to construct a mathematical optimization of a reduced form of the US electric sector. Care was taken to retain salient features of the electric sector, while allowing for detailed weather and power data to be incorporated for wind and solar energies. The National Energy with Weather System (NEWS) simulator was created. With the NEWS simulator tests can be performed that are unique and insightful. The simulator can maintain the status quo and build out a system following costs or imposed targets for carbon dioxide emission reductions. It can find the least cost electric sector for each state, or find a national power system that incorporates vast amounts of variable generation. In the current presentation, we will focus on one of the most unique aspects of the NEWS simulator; the ability to specify a specific amount of wind and/or solar each hour for a three-year historical period for the least total cost. The simulator can find where to place wind and solar to reduce variability (ramping requirements for back-up generators). The amount of variable generation each hour is very different to an RPS type standard because the generators need to work in concert for long periods of time. The results indicate that for very similar costs the amount of back-up generation (natural gas or storage) can be reduced significantly.

  19. Electromagnetic ion/ion cyclotron instability - Theory and simulations

    Science.gov (United States)

    Winske, D.; Omidi, N.

    1992-01-01

    Linear theory and 1D and 2D hybrid simulations are employed to study electromagnetic ion/ion cyclotron (EMIIC) instability driven by the relative streaming of two field-aligned ion beams. The characteristics of the instability are studied as a function of beam density, propagation angle, electron-ion temperature ratios, and ion beta. When the propagation angle is near 90 deg the EMIIC instability has the characteristics of an electrostatic instability, while at smaller angles electromagnetic effects play a significant role as does strong beam coupling. The 2D simulations point to a narrowing of the wave spectrum and accompanying coherent effects during the linear growth stage of development. The EMIIC instability is an important effect where ion beta is low such as in the plasma-sheet boundary layer and upstream of slow shocks in the magnetotail.

  20. Supernova progenitors, their variability and the Type IIP Supernova ASASSN-16fq in M66

    Science.gov (United States)

    Kochanek, C. S.; Fraser, M.; Adams, S. M.; Sukhbold, T.; Prieto, J. L.; Müller, T.; Bock, G.; Brown, J. S.; Dong, Subo; Holoien, T. W.-S.; Khan, R.; Shappee, B. J.; Stanek, K. Z.

    2017-05-01

    We identify a pre-explosion counterpart to the nearby Type IIP supernova ASASSN-16fq (SN 2016cok) in archival Hubble Space Telescope data. The source appears to be a blend of several stars that prevents obtaining accurate photometry. However, with reasonable assumptions about the stellar temperature and extinction, the progenitor almost certainly had an initial mass M* ≲ 17 M⊙, and was most likely in the mass range of M* = 8-12 M⊙. Observations once ASASSN-16fq has faded will have no difficulty accurately determining the properties of the progenitor. In 8 yr of Large Binocular Telescope (LBT) data, no significant progenitor variability is detected to rms limits of roughly 0.03 mag. Of the six nearby supernova (SN) with constraints on the low-level variability, SN 1987A, SN 1993J, SN 2008cn, SN 2011dh, SN 2013ej and ASASSN-16fq, only the slowly fading progenitor of SN 2011dh showed clear evidence of variability. Excluding SN 1987A, the 90 per cent confidence limit implied by these sources on the number of outbursts over the last decade before the SN that last longer than 0.1 yr (full width at half-maximum) and are brighter than MR < -8 mag is approximately Nout ≲ 3. Our continuing LBT monitoring programme will steadily improve constraints on pre-SN progenitor variability at amplitudes far lower than achievable by SN surveys.

  1. Sub-inertial variability in the Cretan Sea from the M3A buoy

    Directory of Open Access Journals (Sweden)

    V. Cardin

    2003-01-01

    Full Text Available One year of continuous records of temperature, salinity data at various depths, and currents obtained from by an upward looking acoustic Doppler current profiler (ADCP moored at a site in the Cretan Sea were analyzed. Temperature and salinity data revealed the influence of a multi-scale circulation pattern prevailing in this area. This pattern consists of mesoscale cyclonic and anticyclonic vortices moving together as a dipole, and inducing downwelling and upwelling in the water column. The dipole movements, which control the circulation in the area, have been evidenced from horizontal current variability in the upper 250 m. The basin-scale circulation also shows a prominent seasonal variability. The Empirical Orthogonal Function analysis applied to either zonal or meridional components of the currents, confirmed the prevalence of a depth-independent mode over the baroclinic-like one for the whole period of measurements and for both current components. Nevertheless, the depth-dependent structure indicated the out-of-phase behaviour of the upper 250 m layer with respect to the deeper one. The first mode of the temperature EOF analysis, which accounts for most of the variance, represents the seasonal heating of the water column being principally associated with the surface mixed layer at the level of the seasonal thermocline. Key words. Oceanography: physical (currents, eddies and mesoscale processes, general circulation

  2. Sub-inertial variability in the Cretan Sea from the M3A buoy

    Directory of Open Access Journals (Sweden)

    V. Cardin

    Full Text Available One year of continuous records of temperature, salinity data at various depths, and currents obtained from by an upward looking acoustic Doppler current profiler (ADCP moored at a site in the Cretan Sea were analyzed. Temperature and salinity data revealed the influence of a multi-scale circulation pattern prevailing in this area. This pattern consists of mesoscale cyclonic and anticyclonic vortices moving together as a dipole, and inducing downwelling and upwelling in the water column. The dipole movements, which control the circulation in the area, have been evidenced from horizontal current variability in the upper 250 m. The basin-scale circulation also shows a prominent seasonal variability. The Empirical Orthogonal Function analysis applied to either zonal or meridional components of the currents, confirmed the prevalence of a depth-independent mode over the baroclinic-like one for the whole period of measurements and for both current components. Nevertheless, the depth-dependent structure indicated the out-of-phase behaviour of the upper 250 m layer with respect to the deeper one. The first mode of the temperature EOF analysis, which accounts for most of the variance, represents the seasonal heating of the water column being principally associated with the surface mixed layer at the level of the seasonal thermocline.

    Key words. Oceanography: physical (currents, eddies and mesoscale processes, general circulation

  3. Production and decay of chlorine ion excited species in an electron cyclotron resonance ion source plasma

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J P; Martins, M C; Parente, F [Centro de Fisica Atomica, CFA, Departamento de Fisica, Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Costa, A M; Marques, J P [Centro de Fisica Atomica, CFA, Departamento de Fisica, Faculdade de Ciencias, FCUL, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Indelicato, P, E-mail: jps@fct.unl.pt [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite P et M Curie-Paris 6, Case 74, 4 place Jussieu, 75252 Paris Cedex 05 (France)

    2011-06-15

    The most important processes for the creation of chlorine ion excited states from the ground configurations of Cl{sup 10+} to Cl{sup 15+} ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, were studied. Theoretical values for inner-shell excitation and ionization cross-sections, including double KL and triple KLL ionization, transition probabilities and energies for the de-excitation processes, were calculated in the framework of the multi-configuration Dirac-Fock method. With reasonable assumptions about the electron energy distribution, a theoretical K{alpha} x-ray spectrum was obtained, which was then compared with recent experimental data.

  4. Quasilinear diffusion coefficients in a finite Larmor radius expansion for ion cyclotron heated plasmas

    Science.gov (United States)

    Lee, Jungpyo; Wright, John; Bertelli, Nicola; Jaeger, Erwin F.; Valeo, Ernest; Harvey, Robert; Bonoli, Paul

    2017-05-01

    In this paper, a reduced model of quasilinear velocity diffusion by a small Larmor radius approximation is derived to couple the Maxwell's equations and the Fokker Planck equation self-consistently for the ion cyclotron range of frequency waves in a tokamak. The reduced model ensures the important properties of the full model by Kennel-Engelmann diffusion, such as diffusion directions, wave polarizations, and H-theorem. The kinetic energy change ( W ˙ ) is used to derive the reduced model diffusion coefficients for the fundamental damping (n = 1) and the second harmonic damping (n = 2) to the lowest order of the finite Larmor radius expansion. The quasilinear diffusion coefficients are implemented in a coupled code (TORIC-CQL3D) with the equivalent reduced model of the dielectric tensor. We also present the simulations of the ITER minority heating scenario, in which the reduced model is verified within the allowable errors from the full model results.

  5. The Texas Youth Fitness Study: Looking at School Policies as They Relate to Physical Fitness and Academic Variables. Program Results Report

    Science.gov (United States)

    Feiden, Karyn

    2011-01-01

    In partnership with three universities, the Cooper Institute, Dallas, completed the Texas Youth Fitness Study from 2008 to 2009. The study explored three key questions: (1) Is physical fitness associated with academic performance?; (2) Can physical education teachers collect high-quality information on student fitness?; and (3) Are school policies…

  6. A gas-jet transport and catcher technique for on-line production of radioactive ion beams using an electron cyclotron resonance ion-source

    Energy Technology Data Exchange (ETDEWEB)

    Naik, V.; Chakrabarti, A.; Bhattacharjee, M.; Karmakar, P.; Bandyopadhyay, A.; Dechoudhury, S.; Mondal, M.; Pandey, H. K.; Lavanyakumar, D.; Mandi, T. K.; Dutta, D. P.; Kundu Roy, T.; Bhowmick, D.; Sanyal, D.; Srivastava, S. C. L.; Ray, A.; Ali, Md. S. [Variable Energy Cyclotron Centre (VECC), Sector-1, Block-AF, Bidhan Nagar, Kolkata 700064 (India); Bhattacharjee, S. [UGC-DAE CSR, Kolkata Centre, III/LB-8, Bidhan Nagar, Kolkata 700098 (India)

    2013-03-15

    Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms/molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms/molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of {sup 14}O (71 s), {sup 42}K (12.4 h), {sup 43}K (22.2 h), and {sup 41}Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10{sup 3} particles per second (pps). About 3.2 Multiplication-Sign 10{sup 3} pps of 1.4 MeV {sup 14}O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

  7. Forest Clearcutting and Site Preparation on a Saline Soil in East Texas: Impacts on Water Quality

    Science.gov (United States)

    Matthew McBroom; Mingteh Chang; Alexander K. Sayok

    2002-01-01

    Three 0.02 hectare plot-watersheds were installed on a saline soil in the Davy Crockett National Forest near Apple Springs, Texas. Each plot was installed with an H-flume, FW-1 automatic water level recorder, Coshocton N-1 runoff sampler, and two storage tanks. One watershed was undisturbed forested and served a control, one was clearcut without any site-preparation,...

  8. A Survey of Electron Cyclotron Waves in the Magnetosphere and the Diffuse Auroral Electron Precipitation

    Science.gov (United States)

    1990-03-09

    nature of these waves. Based on the cases examined in detail using the methods presented in Figures 1-6, we have found that the majority of emis- sions...precipitation can be identified, it will be difficult to access quantitatively its effects on the magnetospheric system. It seems that the only method of solving...REFERENCES Ashour-Abdalla, H., and C. F. Kennel, Diffuse auroral precipitation, J. Geomag. Geoelectr ., 30, 239-255, 1978. Barbosa, D. D., On the convective

  9. Implementation of Brackish Groundwater Desalination Using Wind-Generated Electricity: A Case Study of the Energy-Water Nexus in Texas

    OpenAIRE

    Mary E. Clayton; Ashlynn S. Stillwell; Michael E. Webber

    2014-01-01

    Growing populations and periodic drought conditions have exacerbated water stress in many areas worldwide. In response, some municipalities have considered desalination of saline water as a freshwater supply. Unfortunately, desalination requires a sizeable energy investment. However, renewable energy technologies can be paired with desalination to mitigate concern over the environmental impacts of increased energy use. At the same time, desalination can be operated in an intermittent way to m...

  10. Influence of electron injection on electron cyclotron resonance plasma properties and reflected mode electrons (abstract)

    Science.gov (United States)

    Ovsyannikov, V. P.; Ullmann, F.; Zschornack, G.

    2000-02-01

    The injection of an additional strong focused electron beam from a special designed electron gun into a magnetic electron cyclotron resonance (ECR) confinement field is studied. The electron gun uses a cathode with a long lifetime and resistiveness providing high emission current densities with electron currents up to 50 mA and voltages up to 4 keV. A sequence of aluminum foils is used to investigate the trajectories of the electrons in the magnetic field without plasma. The high density electron beam passes through the foils, welds them, and prints its image into the foils. Details of this technique are described in Ref. 1. Using this technique we see that before the electrons enter the sextupole region the beam moves along the magnetic straight lines preserving its structure. Only a central beam passes through the sextupole region, thereby changing its form due to the interaction with radial components of the magnetic field. A new operation method at our 14.5 GHz ECR ion source is based on so-called reflection mode electrons (RMEs) analogous to a known electron beam ion source operation regime.2 The basic idea is that electrons, which traveling from the cathode in a strong axial field, meet an anticathode potential, are reflected from it, move back to the cathode, and will be reflected again and so on. It can be supposed that the electrons will make reflections up to the moment when the anode aperture of the gun is fulfilled and the electrons will be collected on the anode electrode. Investigations are performed extracting nitrogen ions using the RME beam. As a result we got a clear increase in the beam current of the extracted ions (e.g., at 10 mA electron injection an increase of the current of N5+ ions up to 400%) and a shift of the measured ion charge state distribution to higher mean ionization stages. Measured x-ray spectra from a neon loaded plasma show for the case of RME operation increasing energy shifts to the high energy side of the spectra, i.e., the

  11. Preliminary Findings for a Relationship between Instream Flow and Shoal Chub Recruitment in the Lower Brazos River, Texas

    National Research Council Canada - National Science Library

    Rodger, Anthony W; Mayes, Kevin B; Winemiller, Kirk O

    2016-01-01

    ... hyostoma, a broadcast-spawning minnow in the Brazos River, Texas. From March 2013 to March 2014, we collected metalarval and juvenile Shoal Chub bimonthly at night using arrays of stationary drift nets...

  12. Linear solvation energy relationships (LSER): 'rules of thumb' for Vi/100, π*, Βm, and αm estimation and use in aquatic toxicology

    Science.gov (United States)

    Hickey, James P.

    1996-01-01

    This chapter provides a listing of the increasing variety of organic moieties and heteroatom group for which Linear Solvation Energy Relationship (LSER) values are available, and the LSER variable estimation rules. The listings include values for typical nitrogen-, sulfur- and phosphorus-containing moieties, and general organosilicon and organotin groups. The contributions by an ion pair situation to the LSER values are also offered in Table 1, allowing estimation of parameters for salts and zwitterions. The guidelines permit quick estimation of values for the four primary LSER variables Vi/100, π*, Βm, and αm by summing the contribtuions from its components. The use of guidelines and Table 1 significantly simplifies computation of values for the LSER variables for most possible organic comppounds in the environment, including the larger compounds of environmental and biological interest.

  13. Nonflat time-variable dark energy cosmology

    Science.gov (United States)

    Pavlov, Anatoly; Westmoreland, Shawn; Saaidi, Khaled; Ratra, Bharat

    2013-12-01

    We generalize the time-variable dark energy scalar field Φ model (ΦCDM) to nonflat space. We show that even in the space-curvature-dominated epoch the scalar field solution is a time-dependent fixed point or attractor, with scalar field energy density that grows relative to the energy density in spatial curvature. This is the first example of a physically consistent and complete model of dynamical dark energy in a nonflat geometry.

  14. Beam stripping extraction from the VINCY cyclotron

    Directory of Open Access Journals (Sweden)

    Ristić-Đurović Jasna L.

    2006-01-01

    Full Text Available The extraction system of a cyclotron guides an ion beam from a spiral acceleration orbit, through an extraction trajectory, into a high energy transport line. The two methods commonly used to direct an ion into the extraction path are deflection, by the electric field of an electrostatic deflector, and ion stripping, by a thin carbon foil. Compared to the electrostatic deflector system, the stripping extraction provides a fast and easy change of the extracted ion energy and is easier to manufacture operate, and maintain. However, the extraction trajectory and dynamics of an ion beam after stripping are highly dependant on the ion energy and specific charge. Thus, when a multipurpose machine such as the VINCY Cyclotron is concerned, it is far from easy to deliver a variety of ion beams into the same high energy transport line and at the same time preserve a reasonable compactness of the extraction system. The front side stripping extraction system of the VINCY Cyclotron provides high (~70 MeV and mid (~30 MeV energy protons, as well as a number of heavy ions in broad energy ranges. The back side stripping extraction system extracts low energy protons (~18 MeV and enables their simultaneous use with high energy protons at the front side of the machine.

  15. Studies for the ion cyclotron range of frequency heating in a tokamak fusion experimental device

    Energy Technology Data Exchange (ETDEWEB)

    Saigusa, Mikio [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1996-02-01

    Ion cyclotron range of frequency heating has been investigated as an efficient additional plasma heating and non-inductive current driving methods in a tokamak type fusion experimental device. At first, an ICRF antenna coupling code was developed for the estimation of the coupling properties of phased antenna array, so that the ICRF antennas were designed for JT-60 and JT-60U ICRF heating systems using the coupling codes. The ICRF heating experiments had been performed in JT-60 and JT-60U. The coupling properties of ICRF antenna, the physics of peripheral plasma and energy confinement by ICRF heating in various heating regimes have been investigated. Next, the Toroidicity induced Alfven Eigen (TAE) mode have been studied using minority ICRF heating for producing energetic ions which can excite TAE mode. The TAE mode could be suppressed by current profile control using current ramp operation and lower hybrid current drive. (author) 74 refs.

  16. Investigation of UAS-based SfM Photogrammetry and Bathymetric Inversion for Mapping a Shallow Water, Low-energy Littoral Zone

    Science.gov (United States)

    Starek, M. J.

    2016-02-01

    Small-scale Unmanned Aircraft Systems (UAS) enable the integration of light weight, low-cost imaging payloads providing a flexible and efficient means for conducting localized littoral surveys. Through exploitation of high imagery overlap and minimal aiding technology, photogrammetric techniques and structure from motion (SfM) methods can be applied to derive accurate 2D and 3D geospatial data about the observed terrain. Furthermore, small-scale UAS enable rapid response capabilities and provide the potential for collecting repeated observations at high temporal frequency making them an exceptional tool for monitoring dynamic coastal environments. This study examines the accuracy of topographic and bathymetric data derived from a UAS-based photogrammetric survey of a low-energy, shallow-water littoral zone. The study site is, an engineered and restored beach, located on Ward Island in Corpus Christi Bay, TX. Two UAS surveys were conducted roughly two months apart using a system called the SenseFly eBee. The eBee is an ultra-lightweight ( 0.7 kg) fully autonomous platform and it was equipped with a 16 megapixel RGB camera. The objectives were to: (1) assess accuracy differences in SfM derived point clouds over exposed and submerged beach; (2) evaluate effects of scene-to-scene variability and flight design on derived data products. Several key components were analyzed in order to assess the accuracy and usefulness of elevation data derived from the UAS/SfM approach. First, a sensitivity analysis was conducted to examine the impacts of image scale and match constraints on the fidelity of 3D point cloud data derived from the SfM processing workflow. Evaluation focused on differences in accuracy and density of point data over exposed and submerged beach. Second, a noise filter was developed to remove non-subtrate returns from the SfM cloud for bathymetric modeling. Finally, a bathymetric inversion approach was applied to derive an estimate of water depth. Results show

  17. [Decommissioning of the medical cyclotron in National Center of Neurology and Psychiatry].

    Science.gov (United States)

    Ito, Kimiteru; Nakata, Yasuhiro; Matsuda, Hiroshi; Sato, Noriko

    2011-05-01

    In Japan, positron emission tomography has prevailed as a useful procedure for detecting malignancy, myocardial viability, and epileptic foci. Consequently, compact medical cyclotrons have been installed in many hospitals. However, reports about the dismantling or decommissioning of compact medical cyclotrons are rare. This report describes the series of steps involved in the decommissioning of a compact medical cyclotron that had been used to produce radioactively tagged substances over a period of fifteen years at the National Center of Neurology and Psychiatry in Japan. Additionally, this report describes the manner in which the radioactive waste was disposed. The plan to decommission the cyclotron was comprised of three phases: a preliminary survey, the dismantling work, and a reports after the dismantling. We complied with the guidelines for the disposal of radioactive waste published by the Ministry of Education, Culture, Sports, Science and Technology. The most radioactive material was the vacuuming foil used in the window of the target chamber, with a dose rate of 17 microSv/h (gamma rays) and 20 x 10(3) cpm (beta rays). The detected radionuclides were mainly 22Na, 57Co, 60Co and 65Zn. The total numbers of radioactive waste containers were thirteen 200 l containers and one 50 l container. We suspect that the long shutdown period of the cyclotron (more than one year) contributed to the decay of the radioactive waste because the amount of containers was smaller than the initial estimation. The shutdown period of a cyclotron may play a significant role in reducing the amount of radioactive waste.

  18. Wheelerodemus muhlenbergiae, a new genus and new species of Blissidae (Hemiptera: Heteroptera: Lygaeoidea) from Oklahoma and Texas

    Science.gov (United States)

    Abstract.— The new blissid genus Wheelerodemus is described to accommodate the new species W. muhlenbergiae, based on specimens collected on the grasses Muhlenbergia lindheimeri and M. reverchonii from the Arbuckle Mountains in southcentral Oklahoma and the Edward’s Plateau in westcentral Texas. Bec...

  19. Innovative Developmental Education Programs: A Texas Model

    Science.gov (United States)

    Booth, Eric A.; Capraro, Mary Margaret; Capraro, Robert M.; Chaudhuri, Nandita; Dyer, James; Marchbanks, Miner P., III

    2014-01-01

    This article provides insights from a 2-year, cross-site evaluation of state funded developmental education sites and serves as a focus article for response by those sites. Receiving grants from the Texas Higher Education Coordinating Board (THECB), nine sites (5 community colleges and 4 universities) implemented innovative developmental education…

  20. Variable Renewable Energy in Long-Term Planning Models: A Multi-Model Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frew, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bistline, John [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Blanford, Geoffrey [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Young, David [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Marcy, Cara [U.S. Energy Information Administration, Washington, DC (United States); Namovicz, Chris [U.S. Energy Information Administration, Washington, DC (United States); Edelman, Risa [US Environmental Protection Agency (EPA), Washington, DC (United States); Meroney, Bill [US Environmental Protection Agency (EPA), Washington, DC (United States); Sims, Ryan [US Environmental Protection Agency (EPA), Washington, DC (United States); Stenhouse, Jeb [US Environmental Protection Agency (EPA), Washington, DC (United States); Donohoo-Vallett, Paul [Dept. of Energy (DOE), Washington DC (United States)

    2017-11-01

    Long-term capacity expansion models of the U.S. electricity sector have long been used to inform electric sector stakeholders and decision-makers. With the recent surge in variable renewable energy (VRE) generators — primarily wind and solar photovoltaics — the need to appropriately represent VRE generators in these long-term models has increased. VRE generators are especially difficult to represent for a variety of reasons, including their variability, uncertainty, and spatial diversity. This report summarizes the analyses and model experiments that were conducted as part of two workshops on modeling VRE for national-scale capacity expansion models. It discusses the various methods for treating VRE among four modeling teams from the Electric Power Research Institute (EPRI), the U.S. Energy Information Administration (EIA), the U.S. Environmental Protection Agency (EPA), and the National Renewable Energy Laboratory (NREL). The report reviews the findings from the two workshops and emphasizes the areas where there is still need for additional research and development on analysis tools to incorporate VRE into long-term planning and decision-making. This research is intended to inform the energy modeling community on the modeling of variable renewable resources, and is not intended to advocate for or against any particular energy technologies, resources, or policies.

  1. Texas site selection and licensing status

    Energy Technology Data Exchange (ETDEWEB)

    Avant, R.V. Jr.

    1989-11-01

    Texas has identified a potential site in Hudspeth County in far West Texas near the town of Fort Hancock. Over the past year the Texas Low-Level Radioactive Waste Disposal Authority has been conducting detailed geology, hydrology, meteorology, soils, and flora and fauna evaluations. An authorization by the Board of Directors of the Authority to proceed with a license application, assuming that the detailed evaluation indicates that the site is suitable, is expected by September. A prototype license has been prepared in anticipation of the order to proceed with licensing, and the formal license application is expected to be submitted to the Texas Department of Health-Bureau of Radiation Control in December, meeting the license application milestone. Although site selection processes in all siting areas across the country have experienced organized opposition, El Paso County has funded a particularly well-organized, well-financed program to legally and technically stop consideration of the Fort Hancock site prior to the licensing process. Many procedural, regulatory, and technical issues have been raised which have required responses from the Authority in order to proceed with licensing. This has provided a unique perspective of what to expect from well-organized opposition at the licensing stage. This paper presents an update on the Texas siting activity with detailed information on the site evaluation and license application. Experience of dealing with issues raised by opposition relating to NRC guidelines and rules is also discussed.

  2. Characterization of the onset of ion cyclotron parametric decay instability of lower hybrid waves in a diverted tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Baek, S. G., E-mail: sgbaek@mit.edu; Parker, R. R.; Shiraiwa, S.; Wallace, G. M.; Bonoli, P. T.; Porkolab, M.; Brunner, D.; Faust, I. C.; Hubbard, A. E.; LaBombard, B.; Lau, C. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Takase, Y. [University of Tokyo, Kashiwa 277-8561 (Japan)

    2014-06-15

    The goal of the lower hybrid current drive (LHCD) program on Alcator C-Mod is to develop and optimize reactor-relevant steady-state plasmas by controlling current density profile. However, current drive efficiency precipitously decreases as the line averaged density (n{sup ¯}{sub e}) increases above ∼1 × 10{sup 20} m{sup −3}. Previous simulations show that the observed loss of current drive efficiency in high density plasmas stems from the interactions of LH waves with edge/scrape-off layer plasmas [Wallace et al., Phys. Plasmas 19, 062505 (2012)]. A recent observation [Baek et al., Plasma Phys. Controlled Fusion 55, 052001 (2013)] shows that the configuration dependent ion cyclotron parametric decay instability (PDI) is excited in the density range where the discrepancy between the experiments and simulations remains. Comparing the observed spectra with the homogeneous growth rate spectra indicates that the observed ion cyclotron PDI can be excited not only at the low-field-side but also at the high-field-side (HFS) edge of the tokamak. The model analysis shows that a relevant PDI process to Alcator C-Mod LHCD experiments is decay into ion cyclotron quasi-mode driven by parallel coupling. The underlying cause of the observed onset of ion cyclotron PDI is likely due to the weaker radial penetration of the LH wave in high density plasmas, which can lead to enhanced convective growth. Configuration-dependent PDIs are found to be correlated with different edge density profiles in different magnetic configurations. While the HFS edge of the tokamak can be potentially susceptible to PDI, as evidenced by experimental observations and ray-tracing analyses, enhancing single-pass absorption is expected to help recover the LHCD efficiency at reactor-relevant densities because it could suppress several parasitic loss mechanisms that are exacerbated in multi-pass regimes.

  3. Characterization of the onset of ion cyclotron parametric decay instability of lower hybrid waves in a diverted tokamak

    Science.gov (United States)

    Baek, S. G.; Parker, R. R.; Shiraiwa, S.; Wallace, G. M.; Bonoli, P. T.; Porkolab, M.; Takase, Y.; Brunner, D.; Faust, I. C.; Hubbard, A. E.; LaBombard, B.; Lau, C.

    2014-06-01

    The goal of the lower hybrid current drive (LHCD) program on Alcator C-Mod is to develop and optimize reactor-relevant steady-state plasmas by controlling current density profile. However, current drive efficiency precipitously decreases as the line averaged density (n¯e) increases above ˜1 × 1020 m-3. Previous simulations show that the observed loss of current drive efficiency in high density plasmas stems from the interactions of LH waves with edge/scrape-off layer plasmas [Wallace et al., Phys. Plasmas 19, 062505 (2012)]. A recent observation [Baek et al., Plasma Phys. Controlled Fusion 55, 052001 (2013)] shows that the configuration dependent ion cyclotron parametric decay instability (PDI) is excited in the density range where the discrepancy between the experiments and simulations remains. Comparing the observed spectra with the homogeneous growth rate spectra indicates that the observed ion cyclotron PDI can be excited not only at the low-field-side but also at the high-field-side (HFS) edge of the tokamak. The model analysis shows that a relevant PDI process to Alcator C-Mod LHCD experiments is decay into ion cyclotron quasi-mode driven by parallel coupling. The underlying cause of the observed onset of ion cyclotron PDI is likely due to the weaker radial penetration of the LH wave in high density plasmas, which can lead to enhanced convective growth. Configuration-dependent PDIs are found to be correlated with different edge density profiles in different magnetic configurations. While the HFS edge of the tokamak can be potentially susceptible to PDI, as evidenced by experimental observations and ray-tracing analyses, enhancing single-pass absorption is expected to help recover the LHCD efficiency at reactor-relevant densities because it could suppress several parasitic loss mechanisms that are exacerbated in multi-pass regimes.

  4. Spatio-temporal variability of snow water equivalent in the extra-tropical Andes cordillera from a distributed energy balance modeling and remotely sensed snow cover

    Science.gov (United States)

    Cornwell, E.; Molotch, N. P.; McPhee, J.

    2015-09-01

    Seasonal snow cover is the primary water resource precursor for human use and environmental sustain along the extratropical Andes Cordillera. Despite its importance, relatively little research has been devoted to understanding the properties, distribution and variability of this natural resource. This research provides high-resolution distributed estimates of end-of-winter and spring snow water equivalent over a 152 000 km2 domain that includes the mountainous reaches of central Chile and Argentina. Remotely sensed fractional snow covered area and other relevant forcings are combined with extrapolated data from meteorological stations and a simplified physically-based energy balance model in order to obtain melt-season peak SWE. Estimates show an overall coefficient of determination R2 of 0.61 compared to observations at 12 automatic snow water equivalent sensors distributed across the model domain, with R2 values between 0.32 and 0.88. Regional estimates of peak SWE accumulation show differential patterns strongly modulated by elevation, latitude and position relative to the continental divide. Average peak SWE increases by nearly 500 mm for every 1000 m in elevation gain for the central and southern sub-regions of the model domain, but this effect is much less pronounced in the northern reaches. The 3000-4000 m a.s.l. elevation band is the most significant accumulation area for most of the northern and central reaches of the domain, although the 4000-5000 m a.s.l. band, despite a smaller contributing area, almost doubles the accumulation amounts estimated for the lower adjacent subdomain. Snow accumulation reaches an earlier peak in the western Andes, and the eastern side of the continental divide shows lower snow accumulation at all elevations except for the southern region represented by the Neuquén River Basin. The results presented here have the potential of informing applications such as seasonal forecast model assessment and improvement, regional climate

  5. New compact and efficient local oscillator optic system for the KSTAR electron cyclotron emission imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Y. B., E-mail: southub@postech.ac.kr; Yun, G. S. [Department of Physics, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Lee, D. J.; Lee, J.; Lee, W. [Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of); Kim, C. [Pennsylvania State University, Old Main, State College, Pennsylvania 16801 (United States); Park, H. K. [Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of); National Fusion Research Institute, Daejeon 34133 (Korea, Republic of)

    2016-11-15

    Electron cyclotron emission imaging (ECEI) diagnostic on Korean Superconducting Tokamak Advanced Research utilizes quasi-optical heterodyne-detection method to measure 2D (vertical and radial) T{sub e} fluctuations from two toroidally separated poloidal cross section of the plasma. A cylindrical lens local oscillator (LO) optics with optical path length (OPL) 2–2.5 m has been used in the current ECEI system to couple the LO source to the 24 vertically aligned array of ECE detectors. For efficient and compact LO optics employing the Powell lens is proposed so that the OPL of the LO source is significantly reduced from ∼2.0 m to 0.4 m with new optics. The coupling efficiency of the LO source is expected to be improved especially at the edge channels. Results from the optical simulation together with the laboratory test of the prototype optics will be discussed in this paper.

  6. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    Directory of Open Access Journals (Sweden)

    Gaëtan Gruel

    Full Text Available Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This

  7. A Texas Flood from Land to Ocean Observed by SMAP

    Science.gov (United States)

    Fournier, S.; Reager, J. T., II; Lee, T.; Vazquez, J.; David, C. H.; Gierach, M. M.

    2016-12-01

    Floods are natural hazards that can have damaging impacts not only on affected land areas but also on the adjacent coastal waters. NASA's Soil Moisture Active Passive (SMAP) mission provides measurements of both surface soil moisture and sea surface salinity (SSS), offering the opportunity to study the effects of flooding events on both terrestrial and marine environments. Here, we present analysis of a severe flood that occurred in May 2015 in Texas using SMAP observations and ancillary satellite and in situ data that describe the precipitation intensity, the evolving saturation state of the land surface, the flood discharge peak, and the resulting freshwater plume in the Gulf of Mexico. We describe the spatiotemporal evolution of the different variables, their relationships, and the associated physical processes. Specifically, we identify a freshwater plume in the north-central Gulf, being distinct from the typical Mississippi River plume, that is attributable to the Texas flood.

  8. Multi‐instrument observations from Svalbard of a traveling convection vortex, electromagnetic ion cyclotron wave burst, and proton precipitation associated with a bow shock instability

    DEFF Research Database (Denmark)

    Engebretson, M. J.; Yeoman, T. K.; Oksavik, K.

    2013-01-01

    An isolated burst of 0.35 Hz electromagnetic ion cyclotron (EMIC) waves was observed at four sites on Svalbard from 0947 to 0954 UT 2 January 2011, roughly 1 h after local noon. This burst was associated with one of a series of ~50 nT magnetic impulses observed at the northernmost stations......-based observations of the Hα line at Longyearbyen indicated proton precipitation at the same time as the EMIC wave burst, and NOAA-19, which passed over the west coast of Svalbard between 0951 and 0952, observed a clear enhancement of ring current protons at the same latitude. Electron precipitation from this same...... satellite indicated that the EMIC burst was located on closed field lines, but near to the polar cap boundary. We believe these are the first simultaneous observations of EMIC waves and precipitating energetic protons so near to the boundary of the dayside magnetosphere. Although several spacecraft upstream...

  9. Stability of electrostatic ion cyclotron waves in a multi-ion plasma†

    Indian Academy of Sciences (India)

    Abstract. We have studied the stability of the electrostatic ion cyclotron wave in a plasma consisting of isotropic hydrogen ions (H+) and temperature-anisotropic positively. (O+) and negatively (O−) charged oxygen ions, with the electrons drifting parallel to the magnetic field. Analytical expressions have been derived for the ...

  10. Potential impact of neonicotinoid use on Northern bobwhite (Colinus virginianus) in Texas: A historical analysis

    Science.gov (United States)

    Brightsmith, Donald J.; Navarro-Alberto, Jorge A.

    2018-01-01

    The widespread use of neonicotinoid insecticides in recent years has led to increasing environmental concern, including impacts to avian populations. In Texas and across their range, Northern bobwhite (Colinus virginianus) habitat frequently overlaps cultivated cropland protected by neonicotinoids. To address the effects of neonicotinoid use on bobwhites in Texas, we conducted a historical analysis from 1978–2012 in Texas’ ecological regions using quail count data collected from North American Breeding Bird Survey and Texas Parks and Wildlife Department, and neonicotinoid use data from the U.S. Geological Survey. We considered bobwhite abundance, neonicotinoid use, climate, and land-use variables in our analysis. Neonicotinoid use was significantly (pneonicotinoid introduction (1994–2003) or after their widespread use (2004–2012). Our analyses suggest that the use of neonicotinoid insecticides may negatively affect bobwhite populations in crop-producing regions of Texas. PMID:29324902

  11. (44g)Sc production using a water target on a 13MeV cyclotron.

    Science.gov (United States)

    Hoehr, Cornelia; Oehlke, Elisabeth; Benard, Francois; Lee, Chris Jaeil; Hou, Xinchi; Badesso, Brian; Ferguson, Simon; Miao, Qing; Yang, Hua; Buckley, Ken; Hanemaayer, Victoire; Zeisler, Stefan; Ruth, Thomas; Celler, Anna; Schaffer, Paul

    2014-01-01

    Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t1/2=3.97 h, Eavg,β⁺=1.47MeV, branching ratio=94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations. Solutions containing a high concentration (1.44-1.55g/mL) of natural-abundance calcium nitrate tetrahydrate (Ca(NO₃)2·4 H₂O) were irradiated on a 13MeV proton-beam cyclotron using a standard liquid target. (44g)Sc was produced via the ⁴⁴Ca(p,n)(44g)Sc reaction. (44g)Sc was produced for the first time in a solution target with yields sufficient for early radiochemical studies. Saturation yields of up to 4.6 ± 0.3 MBq/μA were achieved using 7.6 ± 0.3 μA proton beams for 60.0 ± 0.2 minutes (number of runs n=3). Experimental data and calculation results are in fair agreement. Scandium was isolated from the target mixture via solid-phase extraction with 88 ± 6% (n=5) efficiency and successfully used for radiolabelling experiments. The demonstration of the production of ⁴⁴Sc in a liquid target greatly improves its availability for tracer development. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.

    Science.gov (United States)

    Nagornov, Konstantin O; Kozhinov, Anton N; Tsybin, Yury O

    2017-04-01

    The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω+), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω+ quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω+ frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω+ frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.

  13. Texas and Louisiana coastal vulnerability and shelf connectivity.

    Science.gov (United States)

    Thyng, Kristen M; Hetland, Robert D

    2017-03-15

    A numerical study of connectivity between the continental shelf and coast in the northwestern Gulf of Mexico using a circulation model and surface-limited numerical drifters shows that despite seasonal changes in winds, the overall connectivity of the shelf with the coastline is similar in the winter and summer, though it extends more offshore in Texas in summer. However, there is a spatial pattern to the connectivity: more of the inner shelf is connected with the coast in Texas as compared with Louisiana. Subsets of the coast do have seasonal variability: the coast near both Galveston and Port Aransas has more connectivity from upcoast in the winter and from offshore and downcoast in the summer. In both seasons, we find drifters reach the Port Aransas coast most frequently, with a stronger trend in the summer. These results are important for assessing likely pathways for spilled oil and other potentially hazardous material. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

    Science.gov (United States)

    Goldstein, E. D.; D'Alessandro, E. K.; Sponaugle, S.

    2017-09-01

    Environmental clines such as latitude and depth that limit species' distributions may be associated with gradients in habitat suitability that can affect the fitness of an organism. With the global loss of shallow-water photosynthetic coral reefs, mesophotic coral ecosystems ( 30-150 m) may be buffered from some environmental stressors, thereby serving as refuges for a range of organisms including mobile obligate reef dwellers. Yet habitat suitability may be diminished at the depth boundary of photosynthetic coral reefs. We assessed the suitability of coral-reef habitats across the majority of the depth distribution of a common demersal reef fish ( Stegastes partitus) ranging from shallow shelf (SS, fish exhibited risk-averse behavior that may restrict foraging. Fish in MP environments had a broader diet niche, higher trophic position, and higher muscle C:N ratios compared to shallower environments. High C:N ratios suggest increased tissue lipid content in fish in MP habitats that coincided with higher investment in reproduction based on gonado-somatic index. These results suggest that peripheral MP reefs are suitable habitats for demersal reef fish and may be important refuges for organisms common on declining shallow coral reefs.

  15. 76 FR 50476 - Application To Export Electric Energy; Glacial Energy of Texas, Inc.

    Science.gov (United States)

    2011-08-15

    ... franchised service area. The electric energy that Glacial proposes to export to Mexico would be ] surplus... Application To Export Electric Energy; Glacial Energy of Texas, Inc. AGENCY: Office of Electricity Delivery.... (Glacial) has applied for authority to transmit electric energy from the United States to Mexico pursuant...

  16. Influence of biomass burning emissions on black carbon and ozone variability in the Southern Himalayas (NCO-P, 5079 m a.s.l.)

    Science.gov (United States)

    Putero, Davide; Landi, Tony Christian; Cristofanelli, Paolo; Marinoni, Angela; Laj, Paolo; Duchi, Rocco; Adhikary, Bhupesh; Calzolari, Francescopiero; Bonafè, Ubaldo; Stocchi, Paolo; Vuillermoz, Elisa; Bonasoni, Paolo

    2013-04-01

    Black carbon (BC) and tropospheric ozone (O3) play a key role in the climate system, since they are short-lived climate forcers (SLCF) that contribute to climate change. BC and O3 precursors are emitted from several natural and anthropogenic sources; one of the most important is biomass burning, i.e. the combustion of organic matter from natural or man-made activities. Studying BC and O3 variations in connection to biomass burning is critical, mainly because of the effects that these SLCF have on the ecosystems, agriculture and human health. The issue appears urgent in several regions of the world, such as South Asia, where a vast region extending from the Indian Ocean to the Himalayas is characterized by large amounts of aerosols and pollutant gases. Here we present the variability of BC and O3 concentrations observed at the Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.), the highest WMO-GAW global station, installed in the high Khumbu valley (Nepal, Everest region) since March 2006. Considering over 5 years of continuous measurements, the BC and O3 concentrations have shown an average value of 48.7 ± 12.6 ppbv and 208.1 ± 364.1 ng m-3, respectively. The possible contribution of open biomass burning to the average BC and O3 levels is investigated, using various satellite observations, such as MODIS fire products, the USGS Land Use Cover Characterization and TRMM rainfall measurements, linking these products to the air-mass back-trajectories reaching the sampling site (computed using LAGRANTO model). On 162 days (9% of the entire dataset), characterized by acute pollution events at NCO-P, 90 days (56%) were characterized by the transport of pollutants originated by agricultural and forest fires located in regions very close to the Himalayan sampling site. These analyses have shown that biomass burning emissions, especially at regional scale, are likely to play a key role in BC and O3 variations at NCO-P, particularly concerning the development of acute

  17. Ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride as a novel matrix for rapid quantitative and qualitative determination of serum free fatty acids by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Zhang, Yaping; Wang, Yanmin; Guo, Shuai; Guo, Yumei; Liu, Hui; Li, Zhili

    2013-09-10

    The blood free fatty acids (FFAs), which provide energy to the cell and act as substrates in the synthesis of fats, lipoproteins, liposaccharides, and eicosanoids, involve in a number of important physiological processes. In the present study, matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) with ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride (ATNEDC) as a novel MALDI matrix in a negative ion mode was employed to directly quantify serum FFAs. Multiple point internal standard calibration curves between the concentration ratios of individual fatty acids to internal standard (IS, C17:0) versus their corresponding intensity ratios were constructed for C14:0, C16:1, C16:0, C18:0, C18:1, C18:2, C18:3, C20:4, and C22:6, respectively, in their mixture, with correlation coefficients between 0.991 and 0.999 and limits of detection (LODs) between 0.2 and 5.4μM, along with the linear dynamic range of more than two orders of magnitude. The results indicate that the multiple point internal standard calibration could reduce the impact of ion suppression and improve quantification accuracy in the MALDI mode. The quantitative results of nine FFAs from 339 serum samples, including 161 healthy controls, 118 patients with hyperglycemia and 60 patients without hyperglycemia show that FFAs levels in hyperglycemic patient sera are significantly higher than those in healthy controls and patients without hyperglycemia, and elevated FFA levels are also associated with increased levels of fasting blood glucose (FBG) in hyperglycemic patient sera. Serum FFAs were identified on the basis of the observed accurate molecular masses and reliable isotope distributions obtained by MALDI-FTICR MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Effect of ion clouds micromotion on measured signal in Fourier transform ion cyclotron resonance: Computer simulation.

    Science.gov (United States)

    Vladimirov, Gleb; Kostyukevich, Yury; Kharybin, Oleg; Nikolaev, Eugene

    2017-08-01

    Particle-in-cell-based realistic simulation of Fourier transform ion cyclotron resonance experiments could be used to generate ion trajectories and a signal induced on the detection electrodes. It has been shown recently that there is a modulation of "reduced" cyclotron frequencies in ion cyclotron resonance signal caused by Coulomb interaction of ion clouds. In this work it was proposed to use this modulation in order to determine frequency difference between an ion of known m/z and all other ions generating signal in ion cyclotron resonance cell. It is shown that with an increase of number of ions in ion cyclotron resonance trap, the modulation index increases, which lead to a decrease in the accuracy of determination of peak intensities by super Fourier transform resolution methods such as filter diagonalization method.

  19. Goodenough Spring, Texas, USA: Discharge and water chemistry of a large spring deeply submerged under the binational Amistad Reservoir

    Science.gov (United States)

    Kamps, Ray H.; Tatum, Gregg S.; Gault, Mike; Groeger, Alan W.

    2009-06-01

    Goodenough Spring (Texas, USA) is a large spring near the border of the American state of Texas and the Mexican state of Coahuila, discharging into the international Amistad Reservoir on the river Rio Grande (Rio Bravo). Discharge was routinely measured from 1928 until 1968 to partition the flow of the river between the two countries in accordance with water-use treaties. Samples were analyzed for water-quality parameters in 1967-1968 prior to inundation under 45 m of Amistad Reservoir in 1968. Subsequently, discharge has been estimated indirectly by the International Boundary and Water Commission (IBWC). For the first direct measurements of the spring in 37 years, velocity and cross-sectional measurements were made and water samples collected in the summer of 2005 using advanced self-contained underwater breathing apparatus (SCUBA) techniques. Spring discharge was calculated at 2.03 m3 s-1, approximately one-half of the historical mean of 3.94 m3 s-1. In situ and laboratory analyses of samples for temperature, pH, dissolved oxygen, specific conductance, alkalinity, nitrate-nitrogen, dissolved solids, chloride, sulfate, fluoride, phosphorus, calcium, sodium, potassium, magnesium, and iron showed the water quality to be very good for human consumption and crop irrigation. Measurement values are relatively unchanged from those reported 37 years prior.

  20. Energy efficiency management in V and M from Brazil; Gestao de eficiencia energetica na V e M do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Felipe Castilho de Souza; Silva, Camila Soares Lana da; Marques, Sergio Grassi Ferreira [V e M do Brasil S.A., Belo Horizonte, MG (Brazil)

    2010-07-01

    This paper describes the management of the energy efficiency program, created by Vallourec Group in 2009, in V and M do Brazil, aiming to minimize the global warming impacts by reducing the greenhouse gases through the rational consumption of electricity and natural gas. The objective of this program is to reduce 20% of the energy consumption and, consequently, the equivalent CO{sub 2} emissions by 2020. From a centralized energy efficiency management, periodical committees and work groups were created to monitor the indicators and directing actions, generating 25% of the total economy of V and M do Brazil in 2010. (author)

  1. Ion cyclotron waves during the Rosetta approach phase: a magnetic estimate of cometary outgassing

    Directory of Open Access Journals (Sweden)

    M. Volwerk

    2013-12-01

    Full Text Available A theoretical model for the ion cyclotron wave generation during the approach phase of Rosetta to 67P/Churyumov–Gerasimenko is presented. For various activity levels of the comet, the crossing of the observational threshold is determined, whose level is derived from the wave power in the undisturbed solar wind near the comet's location during the approach phase at the appropriate frequency. The Giotto flyby at 27P/Grigg–Skjellerup is used to obtain an estimate of how often water-group ion cyclotron waves are observed, and to get insight into the wave forms. At 67P/Churyumov–Gerasimenko one can expect to observe water-group ion cyclotron waves already at a distance of 600 000 km from the nucleus for a nominal outgassing rate of Q = 350 × 1023 molecules per second. The observed first location of cyclotron waves during the Rosetta approach phase will give an indication of the actual outgassing rate of the comet.

  2. A Kinetic Model of Solar Wind Generation by Oblique Ion-cyclotron Waves

    Science.gov (United States)

    Isenberg, Philip A.; Vasquez, Bernard J.

    2011-04-01

    The fast solar wind is generated by extended perpendicular ion heating in coronal holes, but the kinetic mechanism responsible for this heating has not been determined. One long-standing possibility is the resonant-cyclotron dissipation of ion-cyclotron waves, replenished from a turbulent cascade of interacting counter-propagating Alfvén waves. We present results of a kinetic model for proton heating by the quasilinear resonant-cyclotron wave-particle interaction in a coronal hole. The resonant wave spectrum is taken as a power law in wavenumber, uniformly distributed in propagation direction between 0° and 60° with respect to the large-scale radial magnetic field. We obtain the steady-state solution of the kinetic guiding-center equation for the proton distribution in an expanding coronal hole, including the effects of large-scale forces of gravity, charge-separation electric field, Alfvén wave ponderomotive force, and mirror force, along with the small-scale scattering from the wave dissipation. We find that plausible wave intensities can yield reasonable flow speeds and temperatures in the heliocentric radial range between 2 and 6 solar radii. We address the claim in earlier work that dissipation of parallel-propagating ion-cyclotron waves cannot provide enough acceleration and show that claim to be incorrect. We find that the combined action of the large-scale forces and the resonant-cyclotron scattering produces proton distribution functions with a characteristic structure: compressed in the sunward half of velocity space with a high-density shell separate from the origin, and relatively expanded in the anti-sunward half of velocity space. We suggest that qualitatively similar proton distributions would result from the kinetic evolution of any sufficiently effective perpendicular heating mechanism operating in an expanding coronal hole.

  3. Energy Storage on the Grid and the Short-term Variability of Wind

    Science.gov (United States)

    Hittinger, Eric Stephen

    Wind generation presents variability on every time scale, which must be accommodated by the electric grid. Limited quantities of wind power can be successfully integrated by the current generation and demand-side response mix but, as deployment of variable resources increases, the resulting variability becomes increasingly difficult and costly to mitigate. In Chapter 2, we model a co-located power generation/energy storage block composed of wind generation, a gas turbine, and fast-ramping energy storage. A scenario analysis identifies system configurations that can generate power with 30% of energy from wind, a variability of less than 0.5% of the desired power level, and an average cost around $70/MWh. While energy storage technologies have existed for decades, fast-ramping grid-level storage is still an immature industry and is experiencing relatively rapid improvements in performance and cost across a variety of technologies. Decreased capital cost, increased power capability, and increased efficiency all would improve the value of an energy storage technology and each has cost implications that vary by application, but there has not yet been an investigation of the marginal rate of technical substitution between storage properties. The analysis in chapter 3 uses engineering-economic models of four emerging fast-ramping energy storage technologies to determine which storage properties have the greatest effect on cost-of-service. We find that capital cost of storage is consistently important, and identify applications for which power/energy limitations are important. In some systems with a large amount of wind power, the costs of wind integration have become significant and market rules have been slowly changing in order to internalize or control the variability of wind generation. Chapter 4 examines several potential market strategies for mitigating the effects of wind variability and estimate the effect that each strategy would have on the operation and

  4. High Power, High Energy Cyclotrons for Decay-At-Rest Neutrino Sources: The DAEdALUS Project

    CERN Document Server

    ,

    2011-01-01

    Neutrino physics is a forefront topic of today's research. Large detectors installed underground study neutrino properties using neutrino beams from muons decaying in flight. DAEdALUS looks at neutrinos from stopped muons, "decay at rest" (DAR) neutrinos. The DAR neutrino spectrum has effectively no electron antineutrinos (essentially all pi- are absorbed), so a detector with free protons is sensitive to appearance of nu-e-bar oscillating from nu-mu-bar via inverse-beta-decay (IBD). Oscillations are studied using sources relatively near the detector, but which explore the same physics as the high-energy neutrino beams from Long Baseline experiments. As the DAR spectrum is fixed, the baseline is varied: plans call for 3 accelerator-based neutrino sources at 1.5, 8 and 20 km with staggered beam-on times. Compact, cost-effective superconducting ring cyclotrons accelerating molecular hydrogen ions (H2+) to 800 MeV/n with stripping extraction are being designed by L. Calabretta and his group. This revolutionary de...

  5. One-D full-wave description of plasma emission and absorption in the ion cyclotron range of frequency in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Fraboulet, D.; Becoulet, A.; Nguyen, F

    1998-11-01

    To maintain the ignition state in a tokamak fusion reactor, a control must be performed on the population of alpha-products, and this implies the ability to diagnose those {alpha}-particles. It is studied here whether the detection of emission radiated in the ion cyclotron range of frequency be a reactor plasma can provide useful information concerning fusion products, especially concerning their density profile. It is shown that the detection of the radiation emitted by the fast alpha particles along their cyclotron motion can give access to moments of their distribution function. This requires to compute the phase of the emitted field, using a full-wave approach. Such a technique allows to set in a convenient way the inverse problem of the determination of the emitting {alpha}-particles distribution through the radiation detection. A brief analysis of the expected situation in a reactor-relevant plasma is given. In parallel, the 1-D full-wave code developed in this frame is also useful for studying the physics of Fast Wave plasma heating. It enables to take into account the mode conversion of the Fast Wave into the Ion Bernstein Wave that appears near each ion cyclotron resonance. Results show that higher order terms may significantly alter the energy partitioning, in hot plasma cases involving mode conversion heating and/or ion cyclotron high harmonics heating. (author) 47 refs.

  6. A Neural Network Controller for Variable-Speed Variable-Pitch Wind Energy Conversion Systems Using Generalized Minimum Entropy Criterion

    Directory of Open Access Journals (Sweden)

    Mifeng Ren

    2014-01-01

    Full Text Available This paper considers the neural network controller design problem for variable pitch wind energy conversion systems (WECS with non-Gaussian wind speed disturbances in the stochastic distribution control framework. The approach here is used to directly model the unknown control law based on a fixed neural network (the number of layers and nodes in a neural network is fixed without the need to construct a separate model for the WECS. In order to characterize the randomness of the WECS, a generalized minimum entropy criterion is established to train connection weights of the neural network. For the train purpose, both kernel density estimation method and sliding window technique are adopted to estimate the PDF of tracking error and entropies. Due to the unknown process dynamics, the gradient of the objective function in a gradient-descent-type algorithm is estimated using an incremental perturbation method. The proposed approach is illustrated on a simulated WECS with non-Gaussian wind speed.

  7. Production of cyclotron radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Yong Sup; Lim, Sang Moo; Yang, Seung Dae; Chun, Kwon Soo; Ahn, Soon Hyuk; Yun, Yong Kee; Park, Hyun; Lee, Ji Sup; Lee, Jong Doo; Chai, Jong Seo; Kim, Yoo Seok; Hong, Sung Suk; Lee, Min Yong; Beak, Seung Ki [Korea Cancer Center Hospital, Seoul (Korea)

    1999-12-01

    In the project, 11,492mCi of {sup 201}Tl, 4,384mCi of {sup 67}Ga, 1,245mCi of {sup 123}l, 523mCi of [{sup 123}I]mlBG and 1,283mCi of {sup 18}FDG were supplied, and the revenue were 304,723,000won. In the production of RI, 13 deg for {sup 201}Tl and {sup 67}Ga, 45 deg for {sup 123}l angle solid target have been used, and liquid target system has been used for {sup 18}F production. For the efficient use of the cyclotron, the MC-50 cyclotron was opened to outside user and basic research project was carried out. The technical supports and radionuclides analysis were done during the execution of the research. Then the facilities of safety supervision and handling techniques of radioisotope production were improved. 7 refs., 9 figs., 8 tabs. (Author)

  8. Production of cyclotron radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwon Soo; Lim, Sang Moo; Yang, Seung Dae; Suh, Yong Sup; Ahn, Soon Hyuk; Yun, Yong Kee; Park, Hyun; Lee, Ji Sup; Chai, Jong Seo; Kim, Yoo Seok; Hong, Sung Suk; Lee, Min Yong; Beak, Seung Ki; Kim, Jang Hye; Kim, Gi Sup [Korea Cancer Center Hospital, Seoul (Korea)

    2000-12-01

    In the project, 12,077mCi of {sup 201}Tl, 5,717mCi of {sup 67}Ga, 2,096mCi of {sup 123}l, 482mCi of [{sup 123}I]mlBG and 2,738mCi of {sup 18}FDG were supplied, and the revenue were 387,253,000won. In the production of RI, 13 deg for {sup 201}Tl and {sup 67}Ga, 45 deg for {sup 123}l angle solid target have been used, and liquid target system has been used for {sup 18}F production. For the efficient use of the cyclotron, the MC-50 cyclotron was opened to outside user and basic research project was carried out. The technical supports and radionuclides analysis were done during the execution of the research. Then the facilities of safety supervision and handling techniques of radioisotope production were improved. 7 refs., 8 figs., 9 tabs. (Author)

  9. Energy Consumption of a Battery Electric Vehicle with Infinitely Variable Transmission

    Directory of Open Access Journals (Sweden)

    Francesco Bottiglione

    2014-12-01

    Full Text Available Battery electric vehicles (BEVs represent a possible sustainable solution for personal urban transportation. Presently, the most limiting characteristic of BEVs is their short range, mainly because of battery technology limitations. A proper design and control of the drivetrain, aimed at reducing the power losses and thus increasing BEV range, can contribute to make the electrification of urban transportation a convenient choice. This paper presents a simulation-based comparison of the energy efficiency performance of six drivetrain architectures for BEVs. Although many different drivetrain and transmission architectures have been proposed for BEVs, no literature was found regarding BEVs equipped with infinitely variable transmissions (IVTs. The analyzed drivetrain configurations are: single- (1G and two-speed (2G gear drives, half toroidal (HT and full toroidal (FT continuously variable transmissions (CVTs, and infinitely variable transmissions (IVTs with two different types of internal power flow (IVT-I and IVT-II. An off-line procedure for determining the most efficient control action for each drivetrain configuration is proposed, which allows selecting the optimal speed ratio for each operating condition. The energy consumption of the BEVs is simulated along the UDC (Urban Driving Cycle and Japanese 10-15 driving cycle, with a backward facing approach. In order to achieve the lowest energy consumption, a trade-off between high transmission efficiency and flexibility in terms of allowed speed ratios is required.

  10. Promises of cyclotron-produced 44Sc as a diagnostic match for trivalent β--emitters: in vitro and in vivo study of a 44Sc-DOTA-folate conjugate.

    Science.gov (United States)

    Müller, Cristina; Bunka, Maruta; Reber, Josefine; Fischer, Cindy; Zhernosekov, Konstantin; Türler, Andreas; Schibli, Roger

    2013-12-01

    In recent years, implementation of (68)Ga-radiometalated peptides for PET imaging of cancer has attracted the attention of clinicians. Herein, we propose the use of (44)Sc (half-life = 3.97 h, average β(+) energy [Eβ(+)av] = 632 keV) as a valuable alternative to (68)Ga (half-life = 68 min, Eβ(+)av = 830 keV) for imaging and dosimetry before (177)Lu-based radionuclide therapy. The aim of the study was the preclinical evaluation of a folate conjugate labeled with cyclotron-produced (44)Sc and its in vitro and in vivo comparison with the (177)Lu-labeled pendant. (44)Sc was produced via the (44)Ca(p,n)(44)Sc nuclear reaction at a cyclotron (17.6 ± 1.8 MeV, 50 μA, 30 min) using an enriched (44)Ca target (10 mg (44)CaCO3, 97.00%). Separation from the target material was performed by a semiautomated process using extraction chromatography and cation exchange chromatography. Radiolabeling of a DOTA-folate conjugate (cm09) was performed at 95°C within 10 min. The stability of (44)Sc-cm09 was tested in human plasma. (44)Sc-cm09 was investigated in vitro using folate receptor-positive KB tumor cells and in vivo by PET/CT imaging of tumor-bearing mice Under the given irradiation conditions, (44)Sc was obtained in a maximum yield of 350 MBq at high radionuclide purity (>99%). Semiautomated isolation of (44)Sc from (44)Ca targets allowed formulation of up to 300 MBq of (44)Sc in a volume of 200-400 μL of ammonium acetate/HCl solution (1 M, pH 3.5-4.0) within 10 min. Radiolabeling of cm09 was achieved with a radiochemical yield of greater than 96% at a specific activity of 5.2 MBq/nmol. In vitro, (44)Sc-cm09 was stable in human plasma over the whole time of investigation and showed folate receptor-specific binding to KB tumor cells. PET/CT images of mice injected with (44)Sc-cm09 allowed excellent visualization of tumor xenografts. Comparison of cm09 labeled with (44)Sc and (177)Lu revealed almost identical pharmacokinetics. This study presents a high-yield production and

  11. Characterization of Neutron Energy Spectrum at KIRAMS MC- 50 Cyclotron Using Genetic Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Sy Minh Tuan; Sun, Gwang Min; Beak, Ha Ni; Kim, Ji Seok [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The well-established unfolding techniques have been widely used for many years to determination neutron spectra with adopting the interactive recursion method, least-squares fitting techniques, and Tikhonov's regularisation method. These unfolding methods are frameworks to develop the unfolding codes as SAND, STAY' SL, LOUHI-83, etc., which require an initial spectrum to staring up the unfolding procedure of an unknown spectrum. The accuracy and exactness of the resulting spectrum primarily depend on the subjectively chosen guess spectrum. To overcome this drawback, the other approach for unfolding of neutron spectra using a Genetic Algorithm (GA) search process has been implemented to unfold the neutron spectra from a particle accelerator source. The experiment of improving the switch speed of IGBT devices have done based on the generated fast neutron irradiation proving by the MC-50 cyclotron at KIRAMS (Republic of KOREA). The fast neutron spectrum at the irradiated position was necessarily required for the experiments as well as estimations of the radiation damage of fast neutron on the IGBT devices. The GA is a robust problem-solving tool and it can unfold the neutron spectrum successfully without requiring a specific starting parameter as the initial neutron spectrum. This paper validated and demonstrated the GA technique to become a competitive method in unfolding neutron spectra.

  12. Leptin and variables of body adiposity, energy balance, and insulin resistance in a population-based study. The Hoorn Study

    NARCIS (Netherlands)

    Ruige, J B; Dekker, J M; Blum, W F; Stehouwer, C D; Nijpels, G; Mooy, J; Kostense, P J; Bouter, L M; Heine, R J

    OBJECTIVE: Leptin is thought to play a key role in the control of body weight. There is a complex interrelationship between leptin and insulin or insulin resistance, but it is unknown how leptin is regulated. We therefore explored, in a large population-based study of 2,484 Caucasian subjects aged

  13. Stream and Aquifer Biology of South-Central Texas - A Literature Review, 1973-97

    Science.gov (United States)

    2000-01-01

    on seed germination and seedling growth of Texas wild rice (Zizania texana): The Southwestern Naturalist, v. 40, no. 1, p. 1–4. Puente, Celso, 1974... Poaceae Zizania texana Araceae Pistia stratiotes Pontederiaceae Eichhornia crassipes Ceratophyllaceae Ceratophyllum demersum Heteranthera

  14. Examining social, physical, and environmental dimensions of tornado vulnerability in Texas.

    Science.gov (United States)

    Siebeneck, Laura

    2016-01-01

    To develop a vulnerability model that captures the social, physical, and environmental dimensions of tornado vulnerability of Texas counties. Guided by previous research and methodologies proposed in the hazards and emergency management literature, a principle components analysis is used to create a tornado vulnerability index. Data were gathered from open source information available through the US Census Bureau, American Community Surveys, and the Texas Natural Resources Information System. Texas counties. The results of the model yielded three indices that highlight geographic variability of social vulnerability, built environment vulnerability, and tornado hazard throughout Texas. Further analyses suggest that counties with the highest tornado vulnerability include those with high population densities and high tornado risk. This article demonstrates one method for assessing statewide tornado vulnerability and presents how the results of this type of analysis can be applied by emergency managers towards the reduction of tornado vulnerability in their communities.

  15. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

    DEFF Research Database (Denmark)

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob

    2017-01-01

    . For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during......The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt...

  16. Listening to Customers: How Deliberative Polling Helped Build 1,000 MW of New Renewable Energy Projects in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Lehr, R. L.; Guild, W.; Thomas, D. L.; Swezey, B. G.

    2003-06-01

    Between 1996 and 1998, eight Texas electric utilities polled their customers to determine what energy options they preferred to meet future electric requirements. The Deliberative Polls(TM) combined telephone surveys with town meetings where customers learned more about energy choices and discussed energy issues with each other and with panels of experts. After deliberating, they responded to the initial survey again, this time on the basis of their informed opinions. Customers changed their opinions substantially based on the information they gained during the town meetings. The results were unanticipated by either the utilities or their regulators--both entities changed their level of interest in and commitment to renewables and efficiency as a result of what they heard from customers. Subsequent to the Deliberative Polls, utilities and independent suppliers have made substantial investments in new renewable energy-based generation projects. And in 1999, the Texas Legislature included a renewable portfolio standard in the state's electricity restructuring law. All told, more than 1,000 MW of new renewables capacity has been developed in Texas since the deliberative polling events. The important contribution of the deliberative polls was to provide a measurement of what is important to those most affected by energy resource decisions--the public.

  17. mHealthMon: toward energy-efficient and distributed mobile health monitoring using parallel offloading.

    Science.gov (United States)

    Ahnn, Jong Hoon; Potkonjak, Miodrag

    2013-10-01

    Although mobile health monitoring where mobile sensors continuously gather, process, and update sensor readings (e.g. vital signals) from patient's sensors is emerging, little effort has been investigated in an energy-efficient management of sensor information gathering and processing. Mobile health monitoring with the focus of energy consumption may instead be holistically analyzed and systematically designed as a global solution to optimization subproblems. This paper presents an attempt to decompose the very complex mobile health monitoring system whose layer in the system corresponds to decomposed subproblems, and interfaces between them are quantified as functions of the optimization variables in order to orchestrate the subproblems. We propose a distributed and energy-saving mobile health platform, called mHealthMon where mobile users publish/access sensor data via a cloud computing-based distributed P2P overlay network. The key objective is to satisfy the mobile health monitoring application's quality of service requirements by modeling each subsystem: mobile clients with medical sensors, wireless network medium, and distributed cloud services. By simulations based on experimental data, we present the proposed system can achieve up to 10.1 times more energy-efficient and 20.2 times faster compared to a standalone mobile health monitoring application, in various mobile health monitoring scenarios applying a realistic mobility model.

  18. The summertime energy balance of a thermokarst lake in northern Alaska: A three-year study of seasonal and interannual variability

    Science.gov (United States)

    Potter, B. L.; Lenters, J. D.; Hinkel, K. M.; Shulski, M.; Healey, N. C.; Irmak, A.; Jones, S. L.; Sheng, Y.

    2011-12-01

    Shallow, thermokarst lakes - which develop atop permafrost - are a prominent landscape feature on the Arctic Coastal Plain (ACP) of northern Alaska. The ACP is vulnerable to ongoing climate change and landscape modification, as thousands of thaw lakes and ponds are impacted by changes in temperature, precipitation, thawing permafrost, and human activity. Although summer in the Arctic is short, incoming solar radiation and lake evaporation are relatively high, and both factors play a significant role in the landscape water balance. Furthermore, lake evaporation is anticipated to increase as the ice-free season lengthens and water temperatures become warmer. To improve our understanding of these processes, we performed a multi-year energy balance analysis of a thermokarst lake near Barrow, Alaska. The lake is about 4 km from the Arctic coast, and is relatively small having an area of 185.7 Ha. Timeseries of net radiation, Bowen ratio, and the rate of lake heat storage (at hourly, daily, and longer timescales) were used to calculate sensible and latent heat fluxes during the 2008-2010 ice-free periods (roughly early July through late September). Sediment heat flux estimates were included in the calculation of the total heat storage rate and were determined from a simple heat flux model (calibrated using numerous measurements of thermal conductivity and temperature gradient in the lake sediment). Hourly shortwave albedo measurements were collected during a 23-day period in 2008 to generate a diurnal albedo curve, which was found to range from roughly 0.06 in late morning to 0.17 in late evening. Results of the energy balance analysis show rapid warming of the lake water and sediments immediately following ice-off (due to high insolation), followed by similar increases in sensible and latent heat flux. Bowen ratios were typically around 0.7-1.1, indicating that the majority of the available energy was consumed by lake evaporation, which averaged around 1.3 mm/day during