WorldWideScience

Sample records for accelerator source compared

  1. Particle Acceleration in Astrophysical Sources

    CERN Document Server

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

  2. Neutron Source from Laser Plasma Acceleration

    Science.gov (United States)

    Jiao, Xuejing; Shaw, Joseph; McCary, Eddie; Downer, Mike; Hegelich, Bjorn

    2016-10-01

    Laser driven electron beams and ion beams were utilized to produce neutron sources via different mechanism. On the Texas Petawatt laser, deuterized plastic, gold and DLC foil targets of varying thickness were shot with 150 J , 150 fs laser pulses at a peak intensity of 2 ×1021W /cm2 . Ions were accelerated by either target normal sheath acceleration or Breakout Afterburner acceleration. Neutrons were produced via the 9Be(d,n) and 9Be(p,n) reactions when accelerated ions impinged on a Beryllium converter as well as by deuteron breakup reactions. We observed 2 ×1010 neutron per shot in average, corresponding to 5 ×1018n /s . The efficiencies for different targets are comparable. In another experiment, 38fs , 0.3 J UT3 laser pulse interacted with mixed gas target. Electrons with energy 40MeV were produced via laser wakefield acceleration. Neutron flux of 2 ×106 per shot was generated through bremsstrahlung and subsequent photoneutron reactions on a Copper converter.

  3. Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources

    Energy Technology Data Exchange (ETDEWEB)

    Geddes, Cameron G.R.; Cormier-Michel, Estelle; Esarey, Eric H.; Schroeder, Carl B.; Vay, Jean-Luc; Leemans, Wim P.; Bruhwiler, David L.; Cary, John R.; Cowan, Ben; Durant, Marc; Hamill, Paul; Messmer, Peter; Mullowney, Paul; Nieter, Chet; Paul, Kevin; Shasharina, Svetlana; Veitzer, Seth; Weber, Gunther; Rubel, Oliver; Ushizima, Daniela; Bethel, Wes; Wu, John

    2009-03-20

    Compared to conventional particle accelerators, plasmas can sustain accelerating fields that are thousands of times higher. To exploit this ability, massively parallel SciDAC particle simulations provide physical insight into the development of next-generation accelerators that use laser-driven plasma waves. These plasma-based accelerators offer a path to more compact, ultra-fast particle and radiation sources for probing the subatomic world, for studying new materials and new technologies, and for medical applications.

  4. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  5. Laser ion source for particle accelerators

    CERN Document Server

    Sherwood, T R

    1995-01-01

    There is an interest in accelerating atomic nuclei to produce particle beams for medical therapy, atomic and nuclear physics, inertial confinement fusion and particle physics. Laser Ion Sources, in which ions are extracted from plasma created when a high power density laser beam pulse strikes a solid surface in a vacuum, are not in common use. However, some new developments in which heavy ions have been accelerated show that such sources have the potential to provide the beams required for high-energy accelerator systems.

  6. The Spallation Neutron Source accelerator system design

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, S., E-mail: stuarth@fnal.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Abraham, W. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Aleksandrov, A. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Allen, C. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Alonso, J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Anderson, D. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Arenius, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Arthur, T. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Assadi, S. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Ayers, J.; Bach, P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Badea, V. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Battle, R. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Beebe-Wang, J. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); and others

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ∼100 high-power RF power systems, a 2 K cryogenic plant, ∼400 DC and pulsed power supply systems, ∼400 beam diagnostic devices and a distributed control system handling ∼100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  7. The Spallation Neutron Source accelerator system design

    Science.gov (United States)

    Henderson, S.; Abraham, W.; Aleksandrov, A.; Allen, C.; Alonso, J.; Anderson, D.; Arenius, D.; Arthur, T.; Assadi, S.; Ayers, J.; Bach, P.; Badea, V.; Battle, R.; Beebe-Wang, J.; Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E.; Blaskiewicz, M.; Blind, B.; Blokland, W.; Bookwalter, V.; Borovina, D.; Bowling, S.; Bradley, J.; Brantley, C.; Brennan, J.; Brodowski, J.; Brown, S.; Brown, R.; Bruce, D.; Bultman, N.; Cameron, P.; Campisi, I.; Casagrande, F.; Catalan-Lasheras, N.; Champion, M.; Champion, M.; Chen, Z.; Cheng, D.; Cho, Y.; Christensen, K.; Chu, C.; Cleaves, J.; Connolly, R.; Cote, T.; Cousineau, S.; Crandall, K.; Creel, J.; Crofford, M.; Cull, P.; Cutler, R.; Dabney, R.; Dalesio, L.; Daly, E.; Damm, R.; Danilov, V.; Davino, D.; Davis, K.; Dawson, C.; Day, L.; Deibele, C.; Delayen, J.; DeLong, J.; Demello, A.; DeVan, W.; Digennaro, R.; Dixon, K.; Dodson, G.; Doleans, M.; Doolittle, L.; Doss, J.; Drury, M.; Elliot, T.; Ellis, S.; Error, J.; Fazekas, J.; Fedotov, A.; Feng, P.; Fischer, J.; Fox, W.; Fuja, R.; Funk, W.; Galambos, J.; Ganni, V.; Garnett, R.; Geng, X.; Gentzlinger, R.; Giannella, M.; Gibson, P.; Gillis, R.; Gioia, J.; Gordon, J.; Gough, R.; Greer, J.; Gregory, W.; Gribble, R.; Grice, W.; Gurd, D.; Gurd, P.; Guthrie, A.; Hahn, H.; Hardek, T.; Hardekopf, R.; Harrison, J.; Hatfield, D.; He, P.; Hechler, M.; Heistermann, F.; Helus, S.; Hiatt, T.; Hicks, S.; Hill, J.; Hill, J.; Hoff, L.; Hoff, M.; Hogan, J.; Holding, M.; Holik, P.; Holmes, J.; Holtkamp, N.; Hovater, C.; Howell, M.; Hseuh, H.; Huhn, A.; Hunter, T.; Ilg, T.; Jackson, J.; Jain, A.; Jason, A.; Jeon, D.; Johnson, G.; Jones, A.; Joseph, S.; Justice, A.; Kang, Y.; Kasemir, K.; Keller, R.; Kersevan, R.; Kerstiens, D.; Kesselman, M.; Kim, S.; Kneisel, P.; Kravchuk, L.; Kuneli, T.; Kurennoy, S.; Kustom, R.; Kwon, S.; Ladd, P.; Lambiase, R.; Lee, Y. Y.; Leitner, M.; Leung, K.-N.; Lewis, S.; Liaw, C.; Lionberger, C.; Lo, C. C.; Long, C.; Ludewig, H.; Ludvig, J.; Luft, P.; Lynch, M.; Ma, H.; MacGill, R.; Macha, K.; Madre, B.; Mahler, G.; Mahoney, K.; Maines, J.; Mammosser, J.; Mann, T.; Marneris, I.; Marroquin, P.; Martineau, R.; Matsumoto, K.; McCarthy, M.; McChesney, C.; McGahern, W.; McGehee, P.; Meng, W.; Merz, B.; Meyer, R.; Meyer, R.; Miller, B.; Mitchell, R.; Mize, J.; Monroy, M.; Munro, J.; Murdoch, G.; Musson, J.; Nath, S.; Nelson, R.; Nelson, R.; O`Hara, J.; Olsen, D.; Oren, W.; Oshatz, D.; Owens, T.; Pai, C.; Papaphilippou, I.; Patterson, N.; Patterson, J.; Pearson, C.; Pelaia, T.; Pieck, M.; Piller, C.; Plawski, T.; Plum, M.; Pogge, J.; Power, J.; Powers, T.; Preble, J.; Prokop, M.; Pruyn, J.; Purcell, D.; Rank, J.; Raparia, D.; Ratti, A.; Reass, W.; Reece, K.; Rees, D.; Regan, A.; Regis, M.; Reijonen, J.; Rej, D.; Richards, D.; Richied, D.; Rode, C.; Rodriguez, W.; Rodriguez, M.; Rohlev, A.; Rose, C.; Roseberry, T.; Rowton, L.; Roybal, W.; Rust, K.; Salazer, G.; Sandberg, J.; Saunders, J.; Schenkel, T.; Schneider, W.; Schrage, D.; Schubert, J.; Severino, F.; Shafer, R.; Shea, T.; Shishlo, A.; Shoaee, H.; Sibley, C.; Sims, J.; Smee, S.; Smith, J.; Smith, K.; Spitz, R.; Staples, J.; Stein, P.; Stettler, M.; Stirbet, M.; Stockli, M.; Stone, W.; Stout, D.; Stovall, J.; Strelo, W.; Strong, H.; Sundelin, R.; Syversrud, D.; Szajbler, M.; Takeda, H.; Tallerico, P.; Tang, J.; Tanke, E.; Tepikian, S.; Thomae, R.; Thompson, D.; Thomson, D.; Thuot, M.; Treml, C.; Tsoupas, N.; Tuozzolo, J.; Tuzel, W.; Vassioutchenko, A.; Virostek, S.; Wallig, J.; Wanderer, P.; Wang, Y.; Wang, J. G.; Wangler, T.; Warren, D.; Wei, J.; Weiss, D.; Welton, R.; Weng, J.; Weng, W.-T.; Wezensky, M.; White, M.; Whitlatch, T.; Williams, D.; Williams, E.; Wilson, K.; Wiseman, M.; Wood, R.; Wright, P.; Wu, A.; Ybarrolaza, N.; Young, K.; Young, L.; Yourd, R.; Zachoszcz, A.; Zaltsman, A.; Zhang, S.; Zhang, W.; Zhang, Y.; Zhukov, A.

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ~100 high-power RF power systems, a 2 K cryogenic plant, ~400 DC and pulsed power supply systems, ~400 beam diagnostic devices and a distributed control system handling ~100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  8. Negative hydrogen ion sources for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Moehs, D.P.; /Fermilab; Peters, J.; /DESY; Sherman, J.; /Los Alamos

    2005-08-01

    A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

  9. Livermore Accelerator Source for Radionuclide Science (LASRS)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bleuel, Darren [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, Micah [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rusnak, Brian [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soltz, Ron [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tonchev, Anton [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-05-05

    The Livermore Accelerator Source for Radionuclide Science (LASRS) will generate intense photon and neutron beams to address important gaps in the study of radionuclide science that directly impact Stockpile Stewardship, Nuclear Forensics, and Nuclear Material Detection. The co-location of MeV-scale neutral and photon sources with radiochemical analytics provides a unique facility to meet current and future challenges in nuclear security and nuclear science.

  10. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  11. CAS Accelerator Physics (Ion Sources) in Slovakia

    CERN Multimedia

    CAS School

    2012-01-01

    The CERN Accelerator School (CAS) and the Slovak University of Technology jointly organised a specialised course on ion sources, held at the Hotel Senec, Senec, Slovakia, from 29 May to 8 June, 2012.   Following some background lectures on accelerator physics and the fundamental processes of atomic and plasma physics, the course covered a wide range of topics related to ion sources and highlighted the latest developments in the field. Realistic case studies and topical seminars completed the programme. The school was very successful, with 69 participants representing 25 nationalities. Feedback from the participants was extremely positive, reflecting the high standard of the lectures. The case studies were performed with great enthusiasm and produced some excellent results. In addition to the academic programme, the participants were able to take part in a one-day excursion consisting of a guided tour of Bratislava and free time. A welcome event was held at the Hotel Senec, with s...

  12. An Accelerator Neutron Source for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Thomas, E

    2006-03-14

    The overall goal of this project was to develop an accelerator-based neutron source (ABNS) for Boron Neutron Capture Therapy (BNCT). Specifically, our goals were to design, and confirm by measurement, a target assembly and a moderator assembly that would fulfill the design requirements of the ABNS. These design requirements were 1) that the neutron field quality be as good as the neutron field quality for the reactor-based neutron sources for BNCT, 2) that the patient treatment time be reasonable, 3) that the proton current required to treat patients in reasonable times be technologially achievable at reasonable cost with good reliability, and accelerator space requirements which can be met in a hospital, and finally 4) that the treatment be safe for the patients.

  13. Applications of laser wakefield accelerator-based light sources

    Science.gov (United States)

    Albert, Félicie; Thomas, Alec G. R.

    2016-11-01

    Laser-wakefield accelerators (LWFAs) were proposed more than three decades ago, and while they promise to deliver compact, high energy particle accelerators, they will also provide the scientific community with novel light sources. In a LWFA, where an intense laser pulse focused onto a plasma forms an electromagnetic wave in its wake, electrons can be trapped and are now routinely accelerated to GeV energies. From terahertz radiation to gamma-rays, this article reviews light sources from relativistic electrons produced by LWFAs, and discusses their potential applications. Betatron motion, Compton scattering and undulators respectively produce x-rays or gamma-rays by oscillating relativistic electrons in the wakefield behind the laser pulse, a counter-propagating laser field, or a magnetic undulator. Other LWFA-based light sources include bremsstrahlung and terahertz radiation. We first evaluate the performance of each of these light sources, and compare them with more conventional approaches, including radio frequency accelerators or other laser-driven sources. We have then identified applications, which we discuss in details, in a broad range of fields: medical and biological applications, military, defense and industrial applications, and condensed matter and high energy density science.

  14. Ion sources for high-power hadron accelerators

    CERN Document Server

    Faircloth, Dan

    2013-01-01

    Ion sources are a critical component of all particle accelerators. They create the initial beam that is accelerated by the rest of the machine. This paper will introduce the many methods of creating a beam for high-power hadron accelerators. A brief introduction to some of the relevant concepts of plasma physics and beam formation is given. The different types of ion source used in accelerators today are examined. Positive ion sources for producing H+ ions and multiply charged heavy ions are covered. The physical principles involved with negative ion production are outlined and different types of negative ion sources are described. Cutting edge ion source technology and the techniques used to develop sources for the next generation of accelerators are discussed.

  15. Compact RF ion source for industrial electrostatic ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyeok-Jung, E-mail: hjkwon@kaeri.re.kr; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub [Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongsangbukdo 38180 (Korea, Republic of)

    2016-02-15

    Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

  16. AREAL test facility for advanced accelerator and radiation source concepts

    Energy Technology Data Exchange (ETDEWEB)

    Tsakanov, V.M., E-mail: tsakanov@asls.candle.am [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Amatuni, G.A.; Amirkhanyan, Z.G.; Aslyan, L.V.; Avagyan, V.Sh.; Danielyan, V.A.; Davtyan, H.D.; Dekhtiarov, V.S.; Gevorgyan, K.L.; Ghazaryan, N.G.; Grigoryan, B.A.; Grigoryan, A.H.; Hakobyan, L.S. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Haroutiunian, S.G. [Yerevan State University, 0025 Yerevan (Armenia); Ivanyan, M.I.; Khachatryan, V.G.; Laziev, E.M. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Manukyan, P.S. [State Engineering University of Armenia, 0009 Yerevan (Armenia); Margaryan, I.N.; Markosyan, T.M. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); and others

    2016-09-01

    Advanced Research Electron Accelerator Laboratory (AREAL) is a 50 MeV electron linear accelerator project with a laser driven RF gun being constructed at the CANDLE Synchrotron Research Institute. In addition to applications in life and materials sciences, the project aims as a test facility for advanced accelerator and radiation source concepts. In this paper, the AREAL RF photoinjector performance, the facility design considerations and its highlights in the fields of free electron laser, the study of new high frequency accelerating structures, the beam microbunching and wakefield acceleration concepts are presented.

  17. Dense plasma focus (DPF) accelerated non radio isotopic radiological source

    Energy Technology Data Exchange (ETDEWEB)

    Rusnak, Brian; Tang, Vincent

    2017-01-31

    A non-radio-isotopic radiological source using a dense plasma focus (DPF) to produce an intense z-pinch plasma from a gas, such as helium, and which accelerates charged particles, such as generated from the gas or injected from an external source, into a target positioned along an acceleration axis and of a type known to emit ionizing radiation when impinged by the type of accelerated charged particles. In a preferred embodiment, helium gas is used to produce a DPF-accelerated He2+ ion beam to a beryllium target, to produce neutron emission having a similar energy spectrum as a radio-isotopic AmBe neutron source. Furthermore, multiple DPFs may be stacked to provide staged acceleration of charged particles for enhancing energy, tunability, and control of the source.

  18. High Intensity Accelerator and Neutron Source in China

    Science.gov (United States)

    Guan, Xialing; Wei, J.; Loong, Chun

    2011-06-01

    High intensity Accelerator is being studied all over world for numerous applications, which includes the waste transmutation, spallation neutron source and material irradiation facilities. The R/D activities of the technology of High intensity accelerator are also developed in China for some year, and have some good facilities around China. This paper will reports the status of some high intensity accelerators and neutron source in China, which including ADS/RFQ; CARR; CSNS; PKUNIFTY & CPHS. This paper will emphatically report the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China.

  19. Electron acceleration in a post-flare decimetric continuum source

    CERN Document Server

    Subramanian, P; Karlick'y, M; Sych, R; Sawant, H S; Ananthakrishnan, S; Subramanian, Prasad

    2007-01-01

    Aims: To calculate the power budget for electron acceleration and the efficiency of the plasma emission mechanism in a post-flare decimetric continuum source. Methods: We have imaged a high brightness temperature ($\\sim 10^{9}$K) post-flare source at 1060 MHz with the Giant Metrewave Radio Telescope (GMRT). We use information from these images and the dynamic spectrum from the Hiraiso spectrograph together with the theoretical method described in Subramanian & Becker (2006) to calculate the power input to the electron acceleration process. The method assumes that the electrons are accelerated via a second-order Fermi acceleration mechanism. Results: We find that the power input to the nonthermal electrons is in the range $3\\times 10^{25}$--$10^{26}$ erg/s. The efficiency of the overall plasma emission process starting from electron acceleration and culminating in the observed emission could range from $2.87\\times 10^{-9}$ to $2.38 \\times 10^{-8}$.

  20. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  1. An accelerator-based epithermal photoneutron source for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Nigg, D.W.; Mitchell, H.E.; Harker, Y.D.; Yoon, W.Y. [and others

    1995-11-01

    Therapeutically-useful epithermal-neutron beams for BNCT are currently generated by nuclear reactors. Various accelerator-based neutron sources for BNCT have been proposed and some low intensity prototypes of such sources, generally featuring the use of proton beams and beryllium or lithium targets have been constructed. This paper describes an alternate approach to the realization of a clinically useful accelerator-based source of epithermal neutrons for BNCT that reconciles the often conflicting objectives of target cooling, neutron beam intensity, and neutron beam spectral purity via a two stage photoneutron production process.

  2. Laser-accelerated proton beams as a new particle source

    Energy Technology Data Exchange (ETDEWEB)

    Nuernberg, Frank

    2010-11-15

    plasma physics group of the Technische Universitat Darmstadt initiated the development of a test stand to transport, focus and bunch rotate these beams by conventional ion optics and RF technology. The field strength of 7.5 T enabled collimation of protons with an energy of >10 MeV for the first time. In addition, the focusing capability of the solenoid provided a flux increase in the focal spot of about a factor of 174 at a distance of 40 cm from the source, compared to a beam without using the magnetic field. For a quantitative analysis of the experiment numerical simulations with the WarpRZ code were performed. The code, which was originally developed to study high current ion beams and aid in the pursuit of heavy-ion driven inertial confinement fusion, was modified to enable the use of laser-accelerated proton beams as particle source. The calculated energy-resolved beam parameters of RIS could be included, and the plasma simulation criteria were studied in detail. The geometrical boundaries of the experimental setup were used in the simulations. 2.99 x 10{sup 9} collimated protons in the energy range of 13.5{+-}1 MeV could be transported over a distance of 40 cm. In addition, 8.42 x 10{sup 9} protons in the energy range of 6.7{+-}0.2 MeV were focused into a spot of <2 mm in diameter. The transmission through the solenoid for both cases was about 18%. (orig.)

  3. An overview of an accelerator-based neutron spallation source

    Energy Technology Data Exchange (ETDEWEB)

    Lessner, E.S.

    1996-06-01

    An overview of the feasibility study of a 1-MW pulsed spallation source is presented. The machine delivers 1 MW of proton beam power to spallation targets where slow neutrons are produced. The slow neutrons can be used for isotope production, materials irradiation, and neutron scattering research. The neutron source facility is based on a rapid cycling synchrotron (RCS) and consists of a 400-MeV linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The RCS accelerates an average proton beam current of 0.5 mA, corresponding to 1.04 x 10{sup 14} protons per pulse. This intensity is about two times higher than that of existing machines. A key feature of this accelerator system design is that beam losses are minimized from injection to extraction, reducing activation to levels consistent with hands-on maintenance.

  4. Polarized ionic source of the tandem accelerator in Kyoto University

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masanobu; Kuwamoto, Shuichi; Takahashi, Seiji [Kyoto Univ. (Japan). Dept. of Physics] [and others

    1997-02-01

    A polarized ion source developed under the National Laboratory of High Energy Physics was transferred to the tandem accelerator in Kyoto University at beginning of 1993 to constitute a displacement of incidence into the accelerator. This was an atomic beam type polarized ion source, which is designed to adopt permanent magnets for 6 poles magnet to polarize the electron, to take out atomic nucleus on a shape of positive ion by ECR ionizer after transferring its polarization through transition using radio frequency (RFT), to make it negative ion by charge conversion using alkaline metal vapor, and to put it into the tandem accelerator. Test of the positive ion was finished at the National Laboratory of High Energy Physics, and test in Kyoto University was required after its negative ionization. As the estimated cost was unsufficient and entrance into the ion source facility in the tandem accelerator building was limited in Kyoto University, step of development was slow. Here is reported on present state of the ion source which is now operating stably. (G.K.)

  5. The accelerator neutron source for boron neutron capture therapy

    Science.gov (United States)

    Kasatov, D.; Koshkarev, A.; Kuznetsov, A.; Makarov, A.; Ostreinov, Yu; Shchudlo, I.; Sorokin, I.; Sycheva, T.; Taskaev, S.; Zaidi, L.

    2016-11-01

    The accelerator based epithermal neutron source for Boron Neutron Capture Therapy (BNCT) is proposed, created and used in the Budker Institute of Nuclear Physics. In 2014, with the support of the Russian Science Foundation created the BNCT laboratory for the purpose to the end of 2016 get the neutron flux, suitable for BNCT. For getting 3 mA 2.3 MeV proton beam, was created a new type accelerator - tandem accelerator with vacuum isolation. On this moment, we have a stationary proton beam with 2.3 MeV and current 1.75 mA. Generation of neutrons is carried out by dropping proton beam on to lithium target as a result of threshold reaction 7Li(p,n)7Be. Established facility is a unique scientific installation. It provides a generating of neutron flux, including a monochromatic energy neutrons, gamma radiation, alpha-particles and positrons, and may be used by other research groups for carrying out scientific researches. The article describes an accelerator neutron source, presents and discusses the result of experiments and declares future plans.

  6. Research opportunities with compact accelerator-driven neutron sources

    Science.gov (United States)

    Anderson, I. S.; Andreani, C.; Carpenter, J. M.; Festa, G.; Gorini, G.; Loong, C.-K.; Senesi, R.

    2016-10-01

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target-moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  7. Electron Accelerator Shielding Design of KIPT Neutron Source Facility

    OpenAIRE

    Zhaopeng Zhong; Yousry Gohar

    2016-01-01

    The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nu...

  8. Pulsed neutron source based on accelerator-subcritical-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Makoto; Noda, Akira; Iwashita, Yoshihisa; Okamoto, Hiromi; Shirai, Toshiyuki [Kyoto Univ., Uji (Japan). Inst. for Chemical Research

    1997-03-01

    A new pulsed neutron source which consists of a 300MeV proton linac and a nuclear fuel subcritical assembly is proposed. The proton linac produces pulsed spallation neutrons, which are multipied by the subcritical assembly. A prototype proton linac that accelerates protons up to 7MeV has been developed and a high energy section of a DAW structure is studied with a power model. Halo formations in high intensity beam are also being studied. (author)

  9. Multi-pass Accelerator-Recuperator (MARS) as Coherent X-ray Synchrotron Radiation Source

    Science.gov (United States)

    Kulipanov, Gennady; Skrinsky, Alexander; Vinokurov, Nikolai

    2007-01-01

    Creation of a fully spatial coherent 4th generation SR source is possible in case of a shift from the electron storage rings to accelerators with energy recovery. However, in practice, all the projects assume the use of a single-turn version (ERL) compared to our first proposal of 1997 to use a multi-turn accelerator-recuperator (MARS). The purpose of this report is presentation of the modern conception of MARS and comparison of the ERL and MARS based radiation sources from the viewpoint of their realization in practice.

  10. A review of ion sources for medical accelerators (invited).

    Science.gov (United States)

    Muramatsu, M; Kitagawa, A

    2012-02-01

    There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespread since the 1990s. The energy and intensity are typically over 200 MeV and several 10(10) pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV∕u. Although the beam intensity depends on the irradiation method, it is typically several 10(8) or 10(9) pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are

  11. Dielectric Wakefield Accelerator to drive the future FEL Light Source.

    Energy Technology Data Exchange (ETDEWEB)

    Jing, C.; Power, J.; Zholents, A. (Accelerator Systems Division (APS)); ( HEP); (LLC)

    2011-04-20

    X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall layout, the transform ratio enhancement scheme used to increase the drive to main beam efficiency, main wakefield linac design, cooling of the structure, etc.

  12. Electron Accelerator Shielding Design of KIPT Neutron Source Facility

    Directory of Open Access Journals (Sweden)

    Zhaopeng Zhong

    2016-06-01

    Full Text Available The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nuclear specialists. The biological shield of the accelerator building was designed to reduce the biological dose to less than 5.0e-03 mSv/h during operation. The main source of the biological dose for the accelerator building is the photons and neutrons generated from different interactions of leaked electrons from the electron gun and the accelerator sections with the surrounding components and materials. The Monte Carlo N-particle extended code (MCNPX was used for the shielding calculations because of its capability to perform electron-, photon-, and neutron-coupled transport simulations. The photon dose was tallied using the MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is very small, ∼0.01 neutron for 100-MeV electron and even smaller for lower-energy electrons. This causes difficulties for the Monte Carlo analyses and consumes tremendous computation resources for tallying the neutron dose outside the shield boundary with an acceptable accuracy. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were utilized for this study. The generated neutrons were banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron dose. The weight windows variance reduction technique was also utilized for both

  13. Electron accelerator shielding design of KIPT neutron source facility

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Zhao Peng; Gohar, Yousry [Argonne National Laboratory, Argonne (United States)

    2016-06-15

    The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nuclear specialists. The biological shield of the accelerator building was designed to reduce the biological dose to less than 5.0e-03 mSv/h during operation. The main source of the biological dose for the accelerator building is the photons and neutrons generated from different interactions of leaked electrons from the electron gun and the accelerator sections with the surrounding components and materials. The Monte Carlo N-particle extended code (MCNPX) was used for the shielding calculations because of its capability to perform electron-, photon-, and neutron-coupled transport simulations. The photon dose was tallied using the MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is very small, ∼0.01 neutron for 100-MeV electron and even smaller for lower-energy electrons. This causes difficulties for the Monte Carlo analyses and consumes tremendous computation resources for tallying the neutron dose outside the shield boundary with an acceptable accuracy. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were utilized for this study. The generated neutrons were banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron dose. The weight windows variance reduction technique was also utilized for both neutron and photon dose

  14. New modes of particle accelerations techniques and sources. Formal report

    Energy Technology Data Exchange (ETDEWEB)

    Parsa, Z. [ed.

    1996-12-31

    This Report includes copies of transparencies and notes from the presentations made at the Symposium on New Modes of Particle Accelerations - Techniques and Sources, August 19-23, 1996 at the Institute for Theoretical Physics, University of California, Santa Barbara California, that was made available by the authors. Editing, reduction and changes to the authors contributions were made only to fulfill the printing and publication requirements. We would like to take this opportunity and thank the speakers for their informative presentations and for providing copies of their transparencies and notes for inclusion in this Report.

  15. Fermions as sources of accelerated regimes in cosmology

    CERN Document Server

    Ribas, M O; Kremer, G M

    2005-01-01

    In this work it is investigated if fermionic sources could be responsible for accelerated periods during the evolution of a universe where a matter field would answer for the decelerated period. The self-interaction potential of the fermionic field is considered as a function of the scalar and pseudo-scalar invariants. Irreversible processes of energy transfer between the matter and gravitational fields are also considered. It is shown that the fermionic field could behave like an inflaton field in the early universe and as dark energy for an old universe.

  16. A high current, short pulse electron source for wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ching-Hung

    1992-12-31

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  17. A high current, short pulse electron source for wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  18. Electron string ion sources for carbon ion cancer therapy accelerators

    CERN Document Server

    Boytsov, A Yu; Donets, E D; Donets, E E; Katagiri, K; Noda, K; Ponkin, D O; Ramzdorf, A Yu; Salnikov, V V; Shutov, V B

    2015-01-01

    The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.

  19. Negative hydrogen ion source research and beam parameters for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zolkin, Timofey V.; /Fermilab

    2006-09-01

    H{sup -} beams are useful for multi-turn charge-exchange stripping injection into circular accelerators. Studies on a modified ion source for this purpose are presented. This paper includes some theory about a H{sup -} magnetron discharge, ion-electron emission, emittance and problems linked with emittance measurement and calculations. Investigated parameters of the emittance probe for optimal performance give a screen voltage of 150 V and a probe step of about 5 mil. Normalized 90% emittance obtained for this H{sup -} source is 0.22 {pi} mm-mr, for an extraction voltage of 18 kV at a beam energy of 30 keV and a beam current of 11 mA.

  20. Comparing current cluster, massively parallel, and accelerated systems

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Kevin J [Los Alamos National Laboratory; Davis, Kei [Los Alamos National Laboratory; Hoisie, Adolfy [Los Alamos National Laboratory; Kerbyson, Darren J [Los Alamos National Laboratory; Pakin, Scott [Los Alamos National Laboratory; Lang, Mike [Los Alamos National Laboratory; Sancho Pitarch, Jose C [Los Alamos National Laboratory

    2010-01-01

    Currently there is large architectural diversity in high perfonnance computing systems. They include 'commodity' cluster systems that optimize per-node performance for small jobs, massively parallel processors (MPPs) that optimize aggregate perfonnance for large jobs, and accelerated systems that optimize both per-node and aggregate performance but only for applications custom-designed to take advantage of such systems. Because of these dissimilarities, meaningful comparisons of achievable performance are not straightforward. In this work we utilize a methodology that combines both empirical analysis and performance modeling to compare clusters (represented by a 4,352-core IB cluster), MPPs (represented by a 147,456-core BG/P), and accelerated systems (represented by the 129,600-core Roadrunner) across a workload of four applications. Strengths of our approach include the ability to compare architectures - as opposed to specific implementations of an architecture - attribute each application's performance bottlenecks to characteristics unique to each system, and to explore performance scenarios in advance of their availability for measurement. Our analysis illustrates that application performance is essentially unrelated to relative peak performance but that application performance can be both predicted and explained using modeling.

  1. Ion source memory in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany); Arnold, Maurice; Aumaitre, Georges; Bourles, Didier; Martschini, Martin [ASTER, Aix-en-Provence (France); Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Steier, Peter [VERA, Vienna (Austria)

    2013-07-01

    Since the DREAMS (Dresden Accelerator Mass Spectrometry) facility went operational in 2011, constant effort was put into enabling routine measurements of long-lived radionuclides as {sup 10}Be, {sup 26}Al and {sup 41}Ca. For precise AMS-measurements of the volatile element Cl the key issue is the minimization of the long term memory effect. For this purpose one of the two original HVE sources was mechanically modified, allowing the usage of bigger cathodes with individual target apertures. Additionally a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, a small inter-laboratory comparison had been initiated. The long-term memory effect in the Cs sputter ion sources of the AMS facilities VERA, ASTER and DREAMS had been investigated by running samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples containing highly enriched {sup 35}Cl({sup 35}Cl/{sup 37}Cl > 500). Primary goals of the research are the time constants of the recovery from the contaminated sample ratio to the initial ratio of the sample and the level of the long-term memory effect in the sources.

  2. Beam dynamics simulation of the Spallation Neutron Source linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, H.; Billen, J.H.; Bhatia, T.S.

    1998-12-31

    The accelerating structure for Spallation Neutron Source (SNS) consists of a radio-frequency-quadrupole-linac (RFQ), a drift-tube-linac (DTL), a coupled-cavity-drift-tube-linac (CCDTL), and a coupled-cavity-linac (CCL). The linac is operated at room temperature. The authors discuss the detailed design of linac which accelerates an H{sup {minus}} pulsed beam coming out from RFQ at 2.5 MeV to 1000 MeV. They show a detailed transition from 402.5 MHz DTL with a 4 {beta}{lambda} structure to a CCDTL operated at 805 MHz with a 12 {beta}{lambda} structure. After a discussion of overall feature of the linac, they present an end-to-end particle simulation using the new version of the PARMILA code for a beam starting from the RFQ entrance through the rest of the linac. At 1000 MeV, the beam is transported to a storage ring. The storage ring requires a large ({+-}500-keV) energy spread. This is accomplished by operating the rf-phase in the last section of the linac so the particles are at the unstable fixed point of the separatrix. They present zero-current phase advance, beam size, and beam emittance along the entire linac.

  3. Note: A pulsed laser ion source for linear induction accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H., E-mail: bamboobbu@hotmail.com [Institute of Fluid Physics, China Academy of Engineering Physics, P.O. Box 919-106, Mianyang 621900 (China); School of Physics, Peking University, Beijing 100871 (China); Zhang, K.; Shen, Y.; Jiang, X.; Dong, P.; Liu, Y.; Wang, Y.; Chen, D.; Pan, H.; Wang, W.; Jiang, W.; Long, J.; Xia, L.; Shi, J.; Zhang, L.; Deng, J. [Institute of Fluid Physics, China Academy of Engineering Physics, P.O. Box 919-106, Mianyang 621900 (China)

    2015-01-15

    We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 10{sup 8} W/cm{sup 2}. The laser-produced plasma supplied a large number of Cu{sup +} ions (∼10{sup 12} ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm{sup 2} from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.

  4. Interlaboratory study of the ion source memory effect in 36Cl accelerator mass spectrometry

    Science.gov (United States)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Martschini, Martin; Merchel, Silke; Rugel, Georg; Steier, Peter

    2014-06-01

    Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural 35Cl/37Cl-ratio and samples highly-enriched in 35Cl (35Cl/37Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion sources were widely spread between 61 and 1390 s, where the modified DREAMS ion source with values between 156 and 262 s showed the fastest recovery in 80% of the measurements.

  5. Predicting induced radioactivity for the accelerator operations at the Taiwan Photon Source.

    Science.gov (United States)

    Sheu, R J; Jiang, S H

    2010-12-01

    This study investigates the characteristics of induced radioactivity due to the operations of a 3-GeV electron accelerator at the Taiwan Photon Source (TPS). According to the beam loss analysis, the authors set two representative irradiation conditions for the activation analysis. The FLUKA Monte Carlo code has been used to predict the isotope inventories, residual activities, and remanent dose rates as a function of time. The calculation model itself is simple but conservative for the evaluation of induced radioactivity in a light source facility. This study highlights the importance of beam loss scenarios and demonstrates the great advantage of using FLUKA in comparing the predicted radioactivity with corresponding regulatory limits. The calculated results lead to the conclusion that, due to fairly low electron consumption, the radioactivity induced in the accelerator components and surrounding concrete walls of the TPS is rather moderate and manageable, while the possible activation of air and cooling water in the tunnel and their environmental releases are negligible.

  6. Comparative Assessment of Stabilised Polybutadiene Binder under Accelerated Ageing

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Cannaval Sbegue

    2016-04-01

    Full Text Available Polybutadiene elastomers are versatile materials, being employed at several applications from rocket propellant binder to adhesives and sealants. The elastomers derived from hydroxyl-terminated polybutadiene are usually stabilised with antioxidants to prevent degradation. In this study, a comparative assessment among 2,2’-methylene-bis (4-methyl-6-tert-butylphenol (AO2246, 2,6-di-tert-butyl-4-methylphenol (BHT, p-phenylenediamine (pPDA, and triphenylphosphine (TPP regarding stabilisation of hydroxyl-terminated polybutadiene binder under accelerated ageing (six months at 65 °C was carried out. Evaluation of antioxidants effectiveness was examined through Oxidation Induction time, sol/gel extraction, swelling and mechanical testing, dynamic mechanical analysis, and mass variation measurement. AO2246 yielded the best performance, meanwhile BHT was poorly protective. TPP acted as prooxidant, causing a severe degradation of the binder, and pPDA was not manageable to be assessed due to the lower curing degree of the resulted polyurethane.

  7. Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

    Science.gov (United States)

    Blue, Thomas E; Yanch, Jacquelyn C

    2003-01-01

    This paper reviews the development of low-energy light ion accelerator-based neutron sources (ABNSs) for the treatment of brain tumors through an intact scalp and skull using boron neutron capture therapy (BNCT). A major advantage of an ABNS for BNCT over reactor-based neutron sources is the potential for siting within a hospital. Consequently, light-ion accelerators that are injectors to larger machines in high-energy physics facilities are not considered. An ABNS for BNCT is composed of: (1) the accelerator hardware for producing a high current charged particle beam, (2) an appropriate neutron-producing target and target heat removal system (HRS), and (3) a moderator/reflector assembly to render the flux energy spectrum of neutrons produced in the target suitable for patient irradiation. As a consequence of the efforts of researchers throughout the world, progress has been made on the design, manufacture, and testing of these three major components. Although an ABNS facility has not yet been built that has optimally assembled these three components, the feasibility of clinically useful ABNSs has been clearly established. Both electrostatic and radio frequency linear accelerators of reasonable cost (approximately 1.5 M dollars) appear to be capable of producing charged particle beams, with combinations of accelerated particle energy (a few MeV) and beam currents (approximately 10 mA) that are suitable for a hospital-based ABNS for BNCT. The specific accelerator performance requirements depend upon the charged particle reaction by which neutrons are produced in the target and the clinical requirements for neutron field quality and intensity. The accelerator performance requirements are more demanding for beryllium than for lithium as a target. However, beryllium targets are more easily cooled. The accelerator performance requirements are also more demanding for greater neutron field quality and intensity. Target HRSs that are based on submerged-jet impingement and

  8. Observation of Neutron Skyshine from an Accelerator Based Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Franklyn, C. B. [Radiation Science Department, Necsa, PO Box 582, Pretoria 0001 (South Africa)

    2011-12-13

    A key feature of neutron based interrogation systems is the need for adequate provision of shielding around the facility. Accelerator facilities adapted for fast neutron generation are not necessarily suitably equipped to ensure complete containment of the vast quantity of neutrons generated, typically >10{sup 11} n{center_dot}s{sup -1}. Simulating the neutron leakage from a facility is not a simple exercise since the energy and directional distribution can only be approximated. Although adequate horizontal, planar shielding provision is made for a neutron generator facility, it is sometimes the case that vertical shielding is minimized, due to structural and economic constraints. It is further justified by assuming the atmosphere above a facility functions as an adequate radiation shield. It has become apparent that multiple neutron scattering within the atmosphere can result in a measurable dose of neutrons reaching ground level some distance from a facility, an effect commonly known as skyshine. This paper describes a neutron detection system developed to monitor neutrons detected several hundred metres from a neutron source due to the effect of skyshine.

  9. A monolithic relativistic electron beam source based on a dielectric laser accelerator structure

    Energy Technology Data Exchange (ETDEWEB)

    McNeur, Josh; Carranza, Nestor; Travish, Gil; Yin Hairong; Yoder, Rodney [UCLA Dept. of Physics and Astronomy, Los Angeles, CA 90095 (United States); College of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); Manhattanville College, Physics Dept., 2900 Purchase St., Purchase, NY 10577 (United States)

    2012-12-21

    Work towards a monolithic device capable of producing relativistic particle beams within a cubic-centimeter is detailed. We will discuss the Micro-Accelerator Platform (MAP), an optical laser powered dielectric accelerator as the main building block of this chip-scale source along with a field enhanced emitter and a region for sub-relativistic acceleration.

  10. Interlaboratory study of the ion source memory effect in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan, E-mail: s.pavetich@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Akhmadaliev, Shavkat [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Arnold, Maurice; Aumaître, Georges; Bourlès, Didier [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Buchriegler, Josef [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Golser, Robin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Keddadouche, Karim [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Martschini, Martin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Merchel, Silke; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Steier, Peter [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria)

    2014-06-01

    Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of {sup 36}Cl/Cl and {sup 129}I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples highly-enriched in {sup 35}Cl ({sup 35}Cl/{sup 37}Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion

  11. Simulation of diatomic gas-wall interaction and accommodation coefficients for negative ion sources and accelerators

    Science.gov (United States)

    Sartori, E.; Brescaccin, L.; Serianni, G.

    2016-02-01

    Particle-wall interactions determine in different ways the operating conditions of plasma sources, ion accelerators, and beams operating in vacuum. For instance, a contribution to gas heating is given by ion neutralization at walls; beam losses and stray particle production—detrimental for high current negative ion systems such as beam sources for fusion—are caused by collisional processes with residual gas, with the gas density profile that is determined by the scattering of neutral particles at the walls. This paper shows that Molecular Dynamics (MD) studies at the nano-scale can provide accommodation parameters for gas-wall interactions, such as the momentum accommodation coefficient and energy accommodation coefficient: in non-isothermal flows (such as the neutral gas in the accelerator, coming from the plasma source), these affect the gas density gradients and influence efficiency and losses in particular of negative ion accelerators. For ideal surfaces, the computation also provides the angular distribution of scattered particles. Classical MD method has been applied to the case of diatomic hydrogen molecules. Single collision events, against a frozen wall or a fully thermal lattice, have been simulated by using probe molecules. Different modelling approximations are compared.

  12. ACCELERATING THE ADOPTION PROCESS OF RENEWABLE ENERGY SOURCES AMONG SMES

    Directory of Open Access Journals (Sweden)

    Mirjam Leloux

    2015-07-01

    Full Text Available By 2020, intermittent renewable small scale energy sources (e.g. wind and solar energy are expected to represent about 17% of the EU’s total electricity consumption. All national overriding energy policy objectives are to ensure competitive, secure and sustainable energy for the economy and for society. Renewable energy, allied with energy efficiency, is often found crucial to meet these goals of secure sustainable and competitive energy supplies reducing dependency on expensive fossil imports and underpinning the move towards a low carbon economy while delivering green jobs to the economy. This all contributes to national competitiveness and the jobs and economic growth agenda. However, a straight forward implementation of renewable energy options is not easy, due to various barriers and obstacles. For most SMEs, the concept of generating their own renewable energy is still more of academic than genuine interest. In general, several barriers are experienced, such as high capital investments, slow return on investment, and the lack of knowledge of the benefits. There is a need for education on the benefits and drawbacks of sustainable energy, as well as a greater contribution to costs for this to work. In this paper we describe the intermediate outcomes of a European Partnership under the name of GREAT (Growing Renewable Energy Applications and Technologies, funded under the INTERREG IVB NWE Programme. GREAT aims to encourage communities and small to medium size enterprises (SMEs in Ireland, the United Kingdon, Belgium and The Netherlands to develop technological solutions for Smart Grid, Renewable Energy and Distributive Generation; research and develop policy issues for regulatory authorities and provide structured co-operation opportunities between SMEs and research institutes / technology developers. We developed GREAT spreadsheets to facilitate SMEs in each country to calculate the return-on-investment of renewable energy sources, such as

  13. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  14. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    CERN Document Server

    Agosteo, S; D'Errico, F; Nath, R; Tinti, R

    2002-01-01

    Neutron capture in sup 1 sup 0 B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast ...

  15. Laser-driven wakefield electron acceleration and associated radiation sources; Acceleration electronique par sillage laser et sources de rayonnements associees

    Energy Technology Data Exchange (ETDEWEB)

    Davoine, X

    2009-10-15

    The first part of this research thesis introduces the basic concepts needed for the understanding of the laser-driven wakefield acceleration. It describes the properties of the used laser beams and plasmas, presents some notions about laser-plasma interactions for a better understanding of the physics of laser-driven acceleration. The second part deals with the numerical modelling and the presentation of simulation tools needed for the investigation of laser-induced wakefield acceleration. The last part deals with the optical control of the injection, a technique analogous to the impulsion collision scheme.

  16. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    Science.gov (United States)

    Agosteo, S.; Curzio, G.; d'Errico, F.; Nath, R.; Tinti, R.

    2002-01-01

    Neutron capture in 10B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast neutron beam, generated by 7 MeV deuterons impinging on a thick target of beryllium. The neutron field was characterized at several deuteron energies (3.0-6.5 MeV) in an experimental structure installed at the Van De Graaff accelerator of the Laboratori Nazionali di Legnaro, in Italy. Thermal and epithermal neutron fluences were measured with activation techniques and fast neutron spectra were determined with superheated drop detectors (SDD). These neutron spectrometry and dosimetry studies indicated that the fast neutron dose is unacceptably high in the current design. Modifications to the current design to overcome this problem are presented.

  17. Single-shot betatron source size measurement from a laser-wakefield accelerator

    CERN Document Server

    Köhler, A.; Zarini, O.; Jochmann, A.; Irman, A.; Schramm, U.; 10.1016/j.nima.2016.02.031

    2016-01-01

    Betatron radiation emitted by accelerated electrons in laser-wakefield accelerators can be used as a diagnostic tool to investigate electron dynamics during the acceleration process. We analyze the spectral characteristics of the emitted Betatron pattern utilizing a 2D x-ray imaging spectroscopy technique. Together with simultaneously recorded electron spectra and x-ray images, the betatron source size, thus the electron beam radius, can be deduced at every shot.

  18. Laser-Accelerated Proton Beams as a New Particle Source

    OpenAIRE

    Nürnberg, Frank

    2010-01-01

    The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. Today's high power, ultrashort pulse laser systems are capable of achieving laser intensities up to 10^21 W/cm^2. When focused onto thin foil targets, extremely high field gradients of the order of TV/m are produced on the rear side of the target resulting in the acceleration of protons to multi-MeV energies with an exponential spectrum including up to 10^13 particles. This a...

  19. Overview of Accelerator Physics Studies and High Level Software for the Diamond Light Source

    CERN Document Server

    Bartolini, Riccardo; Belgroune, Mahdia; Christou, Chris; Holder, David J; Jones, James; Kempson, Vince; Martin, Ian; Rowland, James H; Singh, Beni; Smith, Susan L; Varley, Jennifer Anne; Wyles, Naomi

    2005-01-01

    DIAMOND is a 3 GeV synchrotron light source under construction at Rutherford Appleton Laboratory in Oxfordshire (UK). The accelerators complex consists of a 100 MeV LINAC, a full energy booster and a 3GeV storage ring with 22 straight sections available for IDs. Installation of all three accelerators has begun, and LINAC commissioning is due to start in Spring 2005. This paper will give an overview of the accelerator physics activity to produce final layouts and prepare for the commissioning of the accelerator complex. The DIAMOND facility is expected to be operational for users in 2007

  20. Framework for a Comparative Accelerated Testing Standard for PV Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.; Wohlgemuth, J.; Yamamichi, M.; Sample, T.; Miller, D.; Meakin, D.; Monokroussos, C.; TamizhMani, M.; Kempe, M.; Jordan, D.; Bosco, N.; Hacke, P.; Bermudez, V.; Kondo, M.

    2013-08-01

    As the photovoltaic industry has grown, the interest in comparative accelerated testing has also grown. Private test labs offer testing services that apply greater stress than the standard qualification tests as tools for differentiating products and for gaining increased confidence in long-term PV investments. While the value of a single international standard for comparative accelerated testing is widely acknowledged, the development of a consensus is difficult. This paper strives to identify a technical basis for a comparative standard.

  1. Uranium target for electron accelerator based neutron source for BNCT

    Science.gov (United States)

    Tonchev, A. P.; Harmon, F.; Collens, T. J.; Kennedy, K.; Sabourov, A.; Harker, Y. D.; Nigg, D. W.; Jones, J. L.

    2001-07-01

    Calculations of the epithermal-neutron yield of photoneutrons from a uranium-beryllium converter using a 27 MeV electron linear accelerator have been investigated. In this concept, relativistic electron beams from a 30 MeV LINAC impinge upon a small uranium sphere surrounded by a cylindrical tank of circulating heavy water (D2O) nested in a beryllium cube. The photo-fission neutron spectrum from the uranium sphere is thermalized in deuterium and beryllium, filtered and moderated in special material (AlF3/Al/LiF), and directed to the patient. The results of these calculations demonstrate that photoneutron devices could offer a promising alternative to nuclear reactors for the production of epithermal neutrons for Neutron Capture Therapy. The predicted parameter for the epithermal flux is more than 108n.cm-2.mA-1.

  2. Terahertz radiation source using an industrial electron linear accelerator

    CERN Document Server

    Kalkal, Yashvir

    2015-01-01

    High power ($\\sim 100$ kW) industrial electron linear accelerators (linacs) are used for irradiation applications e.g., for pasteurization of food products, disinfection of medical waste, etc. We propose that high power electron beam from such an industrial linac can be first passed through an undulator to generate powerful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for industrial applications. This will enhance the utilisation of a high power industrial linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of $\\mu$W can be produced, which may be useful for many scientific applications.

  3. Nonlinear Electromagnetic Fields As a Source of Universe Acceleration

    CERN Document Server

    Kruglov, S I

    2016-01-01

    A model of nonlinear electromagnetic fields with a dimensional parameter $\\beta$ is proposed. From PVLAS experiment the bound on the parameter $\\beta$ was obtained. Electromagnetic fields are coupled with the gravitation field and we show that the universe accelerates due to nonlinear electromagnetic fields. The magnetic universe is considered and the stochastic magnetic field is a background. After inflation the universe decelerates and approaches to the radiation era. The range of the scale factor, when the causality of the model and a classical stability take place, was obtained. The spectral index, the tensor-to-scalar ratio, and the running of the spectral index were estimated which are in approximate agreement with the PLANCK, WMAP, and BICEP2 data.

  4. Lithium target for accelerator based BNCT neutron source: Influence by the proton irradiation on lithium

    Science.gov (United States)

    Fujii, R.; Imahori, Y.; Nakakmura, M.; Takada, M.; Kamada, S.; Hamano, T.; Hoshi, M.; Sato, H.; Itami, J.; Abe, Y.; Fuse, M.

    2012-12-01

    The neutron source for Boron Neutron Capture Therapy (BNCT) is in the transition stage from nuclear reactor to accelerator based neutron source. Generation of low energy neutron can be achieved by 7Li (p, n) 7Be reaction using accelerator based neutron source. Development of small-scale and safe neutron source is within reach. The melting point of lithium that is used for the target is low, and durability is questioned for an extended use at a high current proton beam. In order to test its durability, we have irradiated lithium with proton beam at the same level as the actual current density, and found no deterioration after 3 hours of continuous irradiation. As a result, it is suggested that lithium target can withstand proton irradiation at high current, confirming suitability as accelerator based neutron source for BNCT.

  5. Direct reconstruction of the source intensity distribution of a clinical linear accelerator using a maximum likelihood expectation maximization algorithm.

    Science.gov (United States)

    Papaconstadopoulos, P; Levesque, I R; Maglieri, R; Seuntjens, J

    2016-02-07

    Direct determination of the source intensity distribution of clinical linear accelerators is still a challenging problem for small field beam modeling. Current techniques most often involve special equipment and are difficult to implement in the clinic. In this work we present a maximum-likelihood expectation-maximization (MLEM) approach to the source reconstruction problem utilizing small fields and a simple experimental set-up. The MLEM algorithm iteratively ray-traces photons from the source plane to the exit plane and extracts corrections based on photon fluence profile measurements. The photon fluence profiles were determined by dose profile film measurements in air using a high density thin foil as build-up material and an appropriate point spread function (PSF). The effect of other beam parameters and scatter sources was minimized by using the smallest field size ([Formula: see text] cm(2)). The source occlusion effect was reproduced by estimating the position of the collimating jaws during this process. The method was first benchmarked against simulations for a range of typical accelerator source sizes. The sources were reconstructed with an accuracy better than 0.12 mm in the full width at half maximum (FWHM) to the respective electron sources incident on the target. The estimated jaw positions agreed within 0.2 mm with the expected values. The reconstruction technique was also tested against measurements on a Varian Novalis Tx linear accelerator and compared to a previously commissioned Monte Carlo model. The reconstructed FWHM of the source agreed within 0.03 mm and 0.11 mm to the commissioned electron source in the crossplane and inplane orientations respectively. The impact of the jaw positioning, experimental and PSF uncertainties on the reconstructed source distribution was evaluated with the former presenting the dominant effect.

  6. Genetic mixture of multiple source populations accelerates invasive range expansion.

    Science.gov (United States)

    Wagner, Natalie K; Ochocki, Brad M; Crawford, Kerri M; Compagnoni, Aldo; Miller, Tom E X

    2017-01-01

    A wealth of population genetic studies have documented that many successful biological invasions stem from multiple introductions from genetically distinct source populations. Yet, mechanistic understanding of whether and how genetic mixture promotes invasiveness has lagged behind documentation that such mixture commonly occurs. We conducted a laboratory experiment to test the influence of genetic mixture on the velocity of invasive range expansion. The mechanistic basis for effects of genetic mixture could include evolutionary responses (mixed invasions may harbour greater genetic diversity and thus elevated evolutionary potential) and/or fitness advantages of between-population mating (heterosis). If driven by evolution, positive effects of source population mixture should increase through time, as selection sculpts genetic variation. If driven by heterosis, effects of mixture should peak following first reproductive contact and then dissipate. Using a laboratory model system (beetles spreading through artificial landscapes), we quantified the velocity of range expansion for invasions initiated with one, two, four or six genetic sources over six generations. Our experiment was designed to test predictions corresponding to the evolutionary and heterosis mechanisms, asking whether any effects of genetic mixture occurred in early or later generations of range expansion. We also quantified demography and dispersal for each experimental treatment, since any effects of mixture should be manifest in one or both of these traits. Over six generations, invasions with any amount of genetic mixture (two, four and six sources) spread farther than single-source invasions. Our data suggest that heterosis provided a 'catapult effect', leaving a lasting signature on range expansion even though the benefits of outcrossing were transient. Individual-level trait data indicated that genetic mixture had positive effects on local demography (reduced extinction risk and enhanced

  7. Comparing Production Cross Sections for QCD Matter, Higgs Boson, Neutrino with Dark Energy in Accelerating Universe

    CERN Document Server

    Ghaffary, Tooraj

    2016-01-01

    In this research, the production cross sections for QCD matter, neutrino and dark energy due to acceleration of Universe is calculated. To obtain these cross sections, the Universe production cross section is multiplied by the particle or dark energy distribution in accelerating Universe. Also missing cross section for each matter and dark energy due to formation of event horizon, is calculated. It is clear that the cross section of particles produced near event horizon of Universe is much larger for higher acceleration of Universe. This is because as the acceleration of Universe becomes larger, the Unruh temperature becomes larger and the thermal radiations of particles are enhanced. There are different channels for producing Higgs boson in accelerating Universe. Universe maybe decay to quark and gluons, and then these particles interact with each other and Higgs boson is produced. Also, some Higgs boson are emitted directly from event horizon of Universe. Comparing Higgs boson cross sections via different c...

  8. Comparing acceleration and speed tuning in macaque MT: physiology and modeling.

    Science.gov (United States)

    Price, N S C; Ono, S; Mustari, M J; Ibbotson, M R

    2005-11-01

    Studies of individual neurons in area MT have traditionally investigated their sensitivity to constant speeds. We investigated acceleration sensitivity in MT neurons by comparing their responses to constant steps and linear ramps in stimulus speed. Speed ramps constituted constant accelerations and decelerations between 0 and 240 degrees /s. Our results suggest that MT neurons do not have explicit acceleration sensitivity, although speed changes affected their responses in three main ways. First, accelerations typically evoked higher responses than the corresponding deceleration rate at all rates tested. We show that this can be explained by adaptation mechanisms rather than differential processing of positive and negative speed gradients. Second, we inferred a cell's preferred speed from the responses to speed ramps by finding the stimulus speed at the latency-adjusted time when response amplitude peaked. In most cells, the preferred speeds inferred from deceleration were higher than those for accelerations of the same rate or from steps in stimulus speed. Third, neuron responses to speed ramps were not well predicted by the transient or sustained responses to steps in stimulus speed. Based on these findings, we developed a model incorporating adaptation and a neuron's speed tuning that predicted the higher inferred speeds and lower spike rates for deceleration responses compared with acceleration responses. This model did not predict acceleration-specific responses, in accordance with the lack of acceleration sensitivity in the neurons. The outputs of this single-cell model were passed to a population-vector-based model used to estimate stimulus speed and acceleration. We show that such a model can accurately estimate relative speed and acceleration using information from the population of neurons in area MT.

  9. The influence of external source intensity in accelerator/target/blanket system on conversion ratio and fuel cycle

    Science.gov (United States)

    Kochurov, Boris P.

    1995-09-01

    The analysis of neutron balance relation for a subcritical system with external source shows that a high ratio of neutron utilization (conversion ratio, breeding ratio) much exceeding similar values for nuclear reactors (both thermal or fast spectrum) is reachable in accelerator/target/blanket system with high external neutron source intensity. An accelerator/target/blanket systems with thermal power in blanket about 1850 Mwt and operating during 30 years have been investigated. Continual feed up by plutonium (fissile material) and Tc-99 (transmuted material) was assumed. Accelerator beam intensity differed 6.3 times (16 mA-Case 1, and 100 mA-Case 2). Conversion ratio (CR) was defined as the ratio of Tc-99 nuclei transmuted to the number of Pu nuclei consumed. The results for two cases are as follows: Case 1Case 2CR 0.77 1.66N(LWR) 8.6 19.1Power MWt(el) 512 225 where N(LWR)-number of LWRs(3000 MWt(th)) from which yearly discharge of Tc-99 is transmuted during 30 years. High value of conversion ratio considerably exceeding 1 (CR=1.66) was obtained in the system with high source intensity as compared with low source system (CR=0.77). Net output of electric power of high source intensity system is about twice lower due to consumption of electric power for accelerator feed up. The loss of energy for Tc-99 transmutation is estimated as 40 Mev(el)/nuclei. Yet high conversion ratio (or breeding ratio) achievable in electronuclear installations with high intensity of external source can effectively be used to close fuel cycle (including incineration of wastes) or to develop growing nuclear power production system.

  10. Neutrons production on the IPHI accelerator for the validation of the design of the compact neutron source SONATE

    CERN Document Server

    Menelle, Alain; Prunes, Fabien; Homatter, Benoit; Annighöfer, Burkhard; Porcher, Florence; Chauvin, Nicolas; Schwindling, Jérôme; Letourneau, Alain; Marchix, Anthony; Tran, Ngoc-Hoang

    2016-01-01

    We aim at building an accelerator based compact neutron source which would provide a thermal neutron flux on the order of 4E12 n.s-1.cm-2.sr-1. Such brilliance would put compact neutron sources on par with existing medium flux neutron research reactors. We performed the first neutron production tests on the IPHI proton accelerator at Saclay. The neutron fluxes were measured using gold foil activation and 3He detectors. The measured fluxes were compared with MCNP and GEANT4 Monte Carlo simulations in which the whole experimental setup was modelled. There is a good agreement between the experimental measurements and the Monte-Carlo simulations. The available modelling tools will allow us to optimize the whole Target Moderator Reflector assembly together with the neutron scattering spectrometer geometries.

  11. PROMETHEUS-A: A helicon plasma source for future wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Buttenschoen, Birger; Fahrenkamp, Nils; Grulke, Olaf [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany)

    2015-05-01

    High density plasma sources are of interest for a wide range of applications like plasma-wall interaction studies, plasma thrusters for space propulsion, or future plasma wakefield particle accelerators. In this contribution, we present a high power helicon cell designed for the world's first proton-beam driven plasma wakefield accelerator experiment AWAKE. Using a modular concept with four antennas distributed along a one meter long, five centimeter diameter prototype module providing up to 35 kW of rf power to the plasma, accelerator relevant densities of 6 . 10{sup 20} m{sup -3} are transiently achieved and exceeded. These high density plasmas are characterized for the use with wakefield accelerators, considering density evolution and its reproducibility, plasma profiles and neutral gas inventory.

  12. Laser-plasma electron accelerator for all-optical inverse Compton X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, K. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)], E-mail: koyama@nuclear.jp; Yamazaki, A.; Maekawa, A.; Uesaka, M. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan); Hosokai, T. [Tokyo Institute of Technology, 4259 Nagatsuda-cho, Midori-ku, Yokohama 226-8503 (Japan); Miyashita, M. [Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Masuda, S.; Miura, E. [AIST, Tsukuba-central-2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2009-09-01

    Inverse Compton scattering has been gaining attention as a process for the generation of X/{gamma}-ray, since it produces tunable X/{gamma}-ray pulses with a small cone angle of radiation. A table-top tunable Compton X/{gamma}-ray source would be realized by replacing a radio frequency (rf) linac with a laser wakefield accelerator (LWFA), which is one of the advanced accelerators. An empirical scaling law for the LWFA in the self-injection mode showed that the energy gain was inversely proportional to the plasma density. In order to effectively employ the LWFA as a Compton X/{gamma}-ray source, its stability must be improved. For this purpose, we are developing techniques for the injection of initial electrons by a localized wavebreaking at the density ramp of a plasma. The pointing stability and acceleration efficiency of the electron beam were significantly improved by applying an axial magnetic field to the plasma channel.

  13. Single-shot betatron source size measurement from a laser-wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Köhler, A., E-mail: a.koehler@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Technische Universität Dresden (TUD), 01062 Dresden (Germany); Couperus, J.P.; Zarini, O. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Technische Universität Dresden (TUD), 01062 Dresden (Germany); Jochmann, A.; Irman, A. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Schramm, U. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Technische Universität Dresden (TUD), 01062 Dresden (Germany)

    2016-09-01

    Betatron radiation emitted by accelerated electrons in laser-wakefield accelerators can be used as a diagnostic tool to investigate electron dynamics during the acceleration process. We analyze the spectral characteristics of the emitted Betatron pattern utilizing a 2D x-ray imaging spectroscopy technique. Together with simultaneously recorded electron spectra and x-ray images, the betatron source size, thus the electron beam radius, can be deduced at every shot. - Highlights: • The first experiments for betatron radiation at HZDR are presented. • A setup for simultaneously acquiring electron and betatron spectrum are presented. • As a preliminary result, final source size for three sample shots was estimated. • The result is confirmed by analyzing the edge contrast of a set of wires.

  14. Brilliant research perspectives DESY's accelerator "PETRA" to become a most brilliant light source

    CERN Multimedia

    2003-01-01

    From 2007 onwards, the PETRA accelerator at the Helmholtz research center DESY will be converted into the most brilliant storage-ring-based X-ray source worldwide. Current plans envision 13 to 15 experimental stations, which will be equipped with so-called undulators: long magnet arrangements delivering X-ray radiation with especially high brilliance (1 page).

  15. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, H.E.

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10{sup 7} neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF{sub 3} composite and a stacked Al/Teflon design) at various incident electron energies.

  16. Accelerating the commercialization on new technologies. [free market operation of federal alternate energy sources programs

    Science.gov (United States)

    Kuehn, T. J.; Nawrocki, P. M.

    1978-01-01

    It is suggested that federal programs for hastening the adoption of alternative energy sources must operate within the free market structure. Five phases of the free market commercialization process are described. Federal role possibilities include information dissemination and funding to stimulate private sector activities within these five phases, and federally sponsored procedures for accelerating commercialization of solar thermal small power systems are considered.

  17. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Hannah E. [Georgia Inst. of Technology, Atlanta, GA (United States)

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 107 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF3 composite and a stacked Al/Teflon design) at various incident electron energies.

  18. Magnetic field design for a Penning ion source for a 200 keV electrostatic accelerator

    Science.gov (United States)

    Fathi, A.; Feghhi, S. A. H.; Sadati, S. M.; Ebrahimibasabi, E.

    2017-04-01

    In this study, the structure of magnetic field for a Penning ion source has been designed and constructed with the use of permanent magnets. The ion source has been designed and constructed for a 200 keV electrostatic accelerator. With using CST Studio Suite, the magnetic field profile inside the ion source was simulated and an appropriate magnetic system was designed to improve particle confinement. Designed system consists of two ring magnets with 9 mm distance from each other around the anode. The ion source was constructed and the cylindrical magnet and designed magnetic system were tested on the ion source. The results showed that the ignition voltage for ion source with the designed magnetic system is almost 300 V lower than the ion source with the cylindrical magnet. Better particle confinement causes lower voltage discharge to occur.

  19. Constraining sources of ultrahigh energy cosmic rays and shear acceleration mechanism of particles in relativistic jets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruoyu

    2015-06-10

    Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.

  20. US-Japan IEC Workshop on Small Plasma and Accelerator Neutron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Miley, George H. [Univ. of Illinois, Champaign, IL (United States). Dept. of Nuclear, Plasma, and Radiological Engineering

    2007-05-25

    This report lays out the agenda for the entire workshop and then lists the abstracts for all 29 presentations. All of these presentations cover small plasma and accelerator neutron sources. A few of the presentations include: Comments about IEC History and Future Directions; Characteristics in Pulse Operation of IEC Device with Confronting Two Plasma Sources; Overview of the University of Wisconsin-Madison IEC Program; Improving IEC Particle Confinement Times Using Multiple Grids; Integral Transport Approach for Molecular Ion Processes in IEC Devices; A Counter Stream Beam D-D Neutron Generator; Low Pressure IECF Operation Using Differentially-Pumped Ion Sources, and more.

  1. Introducing Students to Reference Sources in Comparative Politics.

    Science.gov (United States)

    Boenau, A. Bruce

    1990-01-01

    Outlines a project designed to inform students about library reference sources essential to an introductory course in comparative politics. Suggests how the project can incorporate current topics. Stresses the importance of student familiarity with periodical guides, newspaper indexes, standard biographical sources, and yearbooks. (CH)

  2. AMS of heavy elements with an ECR ion source and the ATLAS linear accelerator

    CERN Document Server

    Paul, M; Ahmad, I; Borasi, F; Caggiano, J; Davids, C N; Greene, J P; Harss, B; Heinz, A; Henderson, D J; Henning, W F; Jiang, C L; Pardo, R C; Rehm, K E; Rejoub, R; Seweryniak, D; Sonzogni, A; Uusitalo, J; Vondrasek, R C

    2000-01-01

    Detection of heavy elements by accelerator mass spectrometry with the electron cyclotron resonance ion source, Argonne linear accelerator and fragment mass analyzer (ECRIS-ATLAS-FMA) system has been developed. The use of the ECR-ATLAS system for AMS of heavy elements has two interesting features: (i) the efficient production of high-charge state ions in the ECR source ensures the elimination of molecular ions at the source stage, a highly attractive feature for any mass-spectrometric use not exploited so far; (ii) the linear acceleration based on velocity matching and the beam transport system act as a powerful mass filter for background suppression. We have shown that our system reaches an abundance sensitivity of 1x10 sup - sup 1 sup 4 for Pb isotopes. The sup 2 sup 3 sup 6 U detection sensitivity is sup 2 sup 3 sup 6 U/U > or approx. 1x10 sup - sup 1 sup 2 , limited mainly by the ion source output.

  3. Cyclinac medical accelerators using pulsed C{sup 6+}/H{sub 2}{sup +} ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Garonna, A; Amaldi, U; Bonomi, R; Campo, D; Degiovanni, A; Garlasche, M; Mondino, I; Rizzoglio, V; Andres, S Verdu, E-mail: Adriano.Garonna@cern.c [TERA Foundation, via G. Puccini 11, 28100 Novara (Italy)

    2010-09-15

    Charged particle therapy, or so-called hadrontherapy, is developing very rapidly. There is large pressure on the scientific community to deliver dedicated accelerators, providing the best possible treatment modalities at the lowest cost. In this context, the Italian research Foundation TERA is developing fast-cycling accelerators, dubbed 'cyclinacs'. These are a combination of a cyclotron (accelerating ions to a fixed initial energy) followed by a high gradient linac boosting the ions energy up to the maximum needed for medical therapy. The linac is powered by many independently controlled klystrons to vary the beam energy from one pulse to the next. This accelerator is best suited to treat moving organs with a 4D multipainting spot scanning technique. A dual proton/carbon ion cyclinac is here presented. It consists of an Electron Beam Ion Source, a superconducting isochronous cyclotron and a high-gradient linac. All these machines are pulsed at high repetition rate (100-400 Hz). The source should deliver both C{sup 6+} and H{sub 2}{sup +} ions in short pulses (1.5 {mu}s flat-top) and with sufficient intensity (at least 10{sup 8} fully stripped carbon ions per pulse at 300 Hz). The cyclotron accelerates the ions to 120 MeV/u. It features a compact design (with superconducting coils) and a low power consumption. The linac has a novel C-band high-gradient structure and accelerates the ions to variable energies up to 400 MeV/u. High RF frequencies lead to power consumptions which are much lower than the ones of synchrotrons for the same ion extraction energy. This work is part of a collaboration with the CLIC group, which is working at CERN on high-gradient electron-positron colliders.

  4. Cyclinac medical accelerators using pulsed C6+/H2+ ion sources

    Science.gov (United States)

    Garonna, A.; Amaldi, U.; Bonomi, R.; Campo, D.; Degiovanni, A.; Garlasché, M.; Mondino, I.; Rizzoglio, V.; Verdú Andrés, S.

    2010-09-01

    Charged particle therapy, or so-called hadrontherapy, is developing very rapidly. There is large pressure on the scientific community to deliver dedicated accelerators, providing the best possible treatment modalities at the lowest cost. In this context, the Italian research Foundation TERA is developing fast-cycling accelerators, dubbed `cyclinacs'. These are a combination of a cyclotron (accelerating ions to a fixed initial energy) followed by a high gradient linac boosting the ions energy up to the maximum needed for medical therapy. The linac is powered by many independently controlled klystrons to vary the beam energy from one pulse to the next. This accelerator is best suited to treat moving organs with a 4D multipainting spot scanning technique. A dual proton/carbon ion cyclinac is here presented. It consists of an Electron Beam Ion Source, a superconducting isochronous cyclotron and a high-gradient linac. All these machines are pulsed at high repetition rate (100-400 Hz). The source should deliver both C6+ and H2+ ions in short pulses (1.5 μs flat-top) and with sufficient intensity (at least 108 fully stripped carbon ions per pulse at 300 Hz). The cyclotron accelerates the ions to 120 MeV/u. It features a compact design (with superconducting coils) and a low power consumption. The linac has a novel C-band high-gradient structure and accelerates the ions to variable energies up to 400 MeV/u. High RF frequencies lead to power consumptions which are much lower than the ones of synchrotrons for the same ion extraction energy. This work is part of a collaboration with the CLIC group, which is working at CERN on high-gradient electron-positron colliders.

  5. Status report on electron cyclotron resonance ion sources at the Heavy Ion Medical Accelerator in Chiba

    CERN Document Server

    Kitagawa, A; Sekiguchi, M; Yamada, S; Jincho, K; Okada, T; Yamamoto, M; Hattori, T G; Biri, S; Baskaran, R; Sakata, T; Sawada, K; Uno, K

    2000-01-01

    The Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences (NIRS) is not only dedicated to cancer therapy, it is also utilized with various ion species for basic experiments of biomedical science, physics, chemistry, etc. Two electron cyclotron resonance (ECR) ion sources are installed for production of gaseous ions. One of them, the NIRS-ECR, is a 10 GHz ECR ion source, and is mainly operated to produce C/sup 4+/ ions for daily clinical treatment. This source realizes good reproducibility and reliability and it is easily operated. The other source, the NIRS-HEC, is an 18 GHz ECR ion source that is expected to produce heavier ion species. The output ion currents of the NIRS-ECR and the NIRS-HEC are 430e mu A for C/sup 4+/ and 1.1e mA for Ar/sup 8+/, respectively. (14 refs).

  6. Evaluation of source term induced by beam loss in the superconducting linear accelerator at RAON

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Jin; Kim, Su Na; Nam, Shin Woo; Chung, Yon Sei [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2014-11-15

    As a new world-class heavy ion accelerator, RAON is able to accelerate heavy ions from proton to uranium with the energy up to -400 MeV/u and produce rare isotopes. These high purity, high intensity, and high energy beams generate the various secondary radiation which will impact on the shielding aspects of the main linear accelerator tunnels. In the main tunnel the secondary neutrons are produced by uniform beam-loss or accident criteria. In this paper evaluations of several source terms induced by beam-loss will be discussed along with the physics model of the Monte Carlo simulation codes. The beam-loss criteria were tested for the evaluation of source term for the main beam line tunnel of the RAON accelerator. It was found that the amount of the secondary neutrons depends on the incident angle of projectile on the beam pipe and the mass and energy of projectile. The influence of selected physics models and libraries of MCNPX and PHITS has been examined. The secondary neutrons were produced most in the CEM and LAQGSM model.

  7. Cyclinac Medical Accelerators Using Pulsed C6+/H2+ Ion Sources

    CERN Document Server

    Garonna, A; Bonomi, R; Campo, D; Degiovanni, A; Garlasché, M; Mondino, I; Rizzoglio, V; Andrés, S Verdú

    2010-01-01

    Charged particle therapy, or so-called hadrontherapy, is developing very rapidly. There is huge pressure on the scientific community to deliver dedicated accelerators, providing the best possible treatment modalities at the lowest cost. In this context, the Italian Research Foundation TERA is developing fast-cycling accelerators, dubbed cyclinacs. These are a combination of a cyclotron (accelerating ions to a fixed initial energy) followed by a high gradient linac boosting the ions energy up to the maximum needed for medical therapy. The linac is powered by many independently controlled klystrons to vary the beam energy from one pulse to the next. This accelerator is best suited to treat moving organs with a 4D multi-painting spot scanning technique. A dual proton/carbon ion cyclinac is here presented. It consists of an Electron Beam Ion Source, a superconducting isochronous cyclotron and a high-gradient linac. All these machines are pulsed at high repetition rate (100-400 Hz). The source should deliver both ...

  8. Laser-driven x-ray and neutron source development for industrial applications of plasma accelerators

    Science.gov (United States)

    Brenner, C. M.; Mirfayzi, S. R.; Rusby, D. R.; Armstrong, C.; Alejo, A.; Wilson, L. A.; Clarke, R.; Ahmed, H.; Butler, N. M. H.; Haddock, D.; Higginson, A.; McClymont, A.; Murphy, C.; Notley, M.; Oliver, P.; Allott, R.; Hernandez-Gomez, C.; Kar, S.; McKenna, P.; Neely, D.

    2016-01-01

    Pulsed beams of energetic x-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal operation of high power laser-solid interactions for neutron and x-ray beam generation. Measurements and Monte Carlo radiation transport simulations show that neutron yield is increased by a factor ~2 when a 1 mm copper foil is placed behind a 2 mm lithium foil, compared to using a 2 cm block of lithium only. We explore x-ray generation with a 10 picosecond drive pulse in order to tailor the spectral content for radiography with medium density alloy metals. The impact of using  >1 ps pulse duration on laser-accelerated electron beam generation and transport is discussed alongside the optimisation of subsequent bremsstrahlung emission in thin, high atomic number target foils. X-ray spectra are deconvolved from spectrometer measurements and simulation data generated using the GEANT4 Monte Carlo code. We also demonstrate the unique capability of laser-driven x-rays in being able to deliver single pulse high spatial resolution projection imaging of thick metallic objects. Active detector radiographic imaging of industrially relevant sample objects with a 10 ps drive pulse is presented for the first time, demonstrating that features of 200 μm size are resolved when projected at high magnification.

  9. A transient MHD model applicable for the source of solar cosmic ray acceleration

    Science.gov (United States)

    Dryer, M.; Wu, S. T.

    1981-01-01

    A two-dimensional, time-dependent magnetohydrodynamic model is used to describe the possible mechanisms for the source of solar cosmic ray acceleration following a solar flare. The hypothesis is based on the propagation of fast mode MHD shocks following a sudden release of energy. In this presentation, the effects of initial magnetic topology and strength on the formation of MHD shocks have been studied. The plasma beta (thermal pressure/magnetic pressure) is considered as a measure of the initial, relative strength of the field. During dynamic mass motion, the Alfven Mach number is the more appropriate measure of the magnetic field's ability to control the outward motion. It is suggested that this model (computed self-consistently) provides the shock waves and the disturbed mass motion behind it as likely sources for solar cosmic ray acceleration.

  10. Development of the C{sup 6+} laser ablation ion source for the KEK digital accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Munemoto, Naoya, E-mail: munemoto.n.ad@m.titech.ac.jp [Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503 (Japan); High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Takayama, Ken [Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503 (Japan); High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Graduate University for Advanced Studies, Hayama, Miura, Kanagawa 240-8550 (Japan); Takano, Susumu [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Okamura, Masahiro [Brookhaven National Laboratory, Upton, New York 11973-5000 (United States); RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kumaki, Masahumi [RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-0072 (Japan)

    2014-02-15

    A laser ion source that provides a fully ionized carbon ion beam is under joint development at the High Energy Accelerator Research Organization and Brookhaven National Laboratory. Long-pulse (6 ns) and short-pulse (500 ps) laser systems were tested by using them to irradiate a graphite target. Notable differences between the systems were observed in these experiments. Preliminary experimental results, such as the charge-state spectrum, beam intensity, and stability, are discussed.

  11. Shaping the electron beams with submicrosecond pulse duration in sources and electron accelerators with plasma emitters

    CERN Document Server

    Gushenets, V I

    2001-01-01

    One studies the techniques in use to shape submicrosecond electron beams and the physical processes associated with extraction of electrons from plasma in plasma emitters. Plasma emitter base sources and accelerators enable to generate pulse beams with currents varying from tens of amperes up to 10 sup 3 A, with current densities up to several amperes per a square centimeter, with pulse duration constituting hundreds of nanoseconds and with high frequencies of repetition

  12. Optimization of an accelerator-based epithermal neutron source for neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kononov, O.E.; Kononov, V.N.; Bokhovko, M.V.; Korobeynikov, V.V.; Soloviev, A.N.; Chu, W.T.

    2004-02-20

    A modeling investigation was performed to choose moderator material and size for creating optimal epithermal neutron beams for BNCT based on a proton accelerator and the 7Li(p,n)7Be reaction as a neutrons source. An optimal configuration is suggested for the beam shaping assembly made from polytetrafluoroethylene and magnesium fluorine. Results of calculation were experimentally tested and are in good agreement with measurements.

  13. Synchronized ion acceleration by ultraintense slow light and electron source for x-ray production from low-density targets

    Science.gov (United States)

    Brantov, A. V.; Bychenkov, V. Yu

    2017-03-01

    Synchronized proton acceleration by ultraintense slow light in a low-density target Brantov et al (2016 Phys. Rev. Lett. 116 085004) is studied for a circularly polarized laser pulse. This study demonstrates the advantage of circularly polarized light compared with linearly polarized light used for high-energy proton generation. At the same time, high-energy electron production for gamma-ray generation is not sensitive to the polarization of the laser pulse. Both the proton and the electron sources are considered in application to petawatt-class lasers.

  14. Intense Combined Source of Neutrons and Photons for Interrogation Based on Compact Deuteron RF Accelerator

    Science.gov (United States)

    Kurennoy, S. S.; Garnett, R. W.; Rybarcyk, L. J.

    Interrogation of special nuclear materials can benefit from mobile sources providing significant fluxes of neutrons (108/s at 2.5 MeV, 1010/s at 14.1 MeV) and of photons (>1012/s at 1-3 MeV). We propose a source that satisfies these requirements simultaneously plus also provides, via the reaction 11B(d,n)12C(γ15.1), a significant flux of 15-MeV photons, which are highly penetrating and optimal for inducing photo-fission in actinides. The source is based on a compact (< 5 m) deuteron RF accelerator that delivers an average current of a few mA of deuterons at 3-4 MeV to a boron target. The accelerator consists of a short RFQ followed by efficient inter-digital H-mode structures with permanent-magnet-quadrupole beam focusing [Kurennoy et al. (2012)], which suit perfectly for deuteron acceleration at low energies. Our estimates, based on recent measurements [Taddeucci et al. (2007)], indicate that the required fluxes of both neutrons and photons can be achieved at ∼1 mA of 4-MeV deuterons. The goal of the proposed study is to confirm feasibility of the approach and develop requirements for future full- system implementation.

  15. FAFNIR: Strategy and risk reduction in accelerator driven neutron sources for fusion materials irradiation data

    CERN Document Server

    Surrey, E; Caballero, A; Davenne, T; Findlay, D; Letchford, A; Thomason, J; Marrow, J; Roberts, S; Seryi, A; Connolly, B; Mummery, P; Owen, H

    2014-01-01

    The need to populate the fusion materials engineering data base has long been recognized, the IFMIF facility being the present proposed neutron source for this purpose. Re-evaluation of the regulatory approach for the EU proposed DEMO device shows that the specification of the neutron source can be reduced with respect to IFMIF, allowing lower risk technology solutions to be considered. The justification for this approach is presented and a description of a proposed facility, FAFNIR, is presented with more detailed discussion of the accelerator and target designs.

  16. Narrow bandwidth Thomson photon source development using Laser-Plasma Accelerators

    Science.gov (United States)

    Geddes, C. G. R.; van Tilborg, J.; Tsai, H.-E.; Toth, Cs.; Vay, J.-L.; Lehe, R.; Schroeder, C. B.; Esarey, E.; Rykovanov, S. G.; Grote, D. P.; Friedman, A.; Leemans, W. P.

    2016-10-01

    Compact, high-quality photon sources at MeV energies are being developed based on Laser-Plasma Accelerators (LPAs). An independent scattering laser with controlled pulse shaping in frequency and amplitude can be used together with laser guiding to realize high photon yield and narrow bandwidth. Simulations are presented on production of controllable narrow bandwidth sources using the beam and plasma capabilities of LPAs. Recent experiments and simulations demonstrate controllable LPAs in the energy range appropriate to MeV Thomson sources. Design of experiments and laser capabilities to combine these elements will be presented, towards a compact photon source system. A dedicated facility under construction will be described. Work supported by US DOE NNSA DNN R&D and by Sc. HEP under contract DE-AC02-05CH11231.

  17. A review of ion sources for medical accelerators (invited)a)

    Science.gov (United States)

    Muramatsu, M.; Kitagawa, A.

    2012-02-01

    There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespread since the 1990s. The energy and intensity are typically over 200 MeV and several 1010 pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV/u. Although the beam intensity depends on the irradiation method, it is typically several 108 or 109 pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are under

  18. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Gyeonju (Korea, Republic of); Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Multipurpose Accelerator Complex, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber.

  19. A study on the design of hexapole in an 18-GHz ECR ion source for heavy ion accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhan; Wei, Shaoqing; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of); Choi, Suk Jin [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2016-06-15

    High charge state electron cyclotron resonance (ECR) ion source is important on the performance of heavy ion accelerators. In this paper, a low temperature superconductor (LTS) was used to make a hexapole coil for an 18-GHz ECR ion source. Several hexapole structures, including racetrack, graded racetrack, and saddle were implemented and analyzed for the hexapole-in-solenoid ECR ion source system. Under the appropriate radial confinement field, the smaller outer radius of hexapole can be better for the solenoid design. Saddle hexapole was selected by comparing the wire length, maximum outer radius of the hexapole, the Lorentz force at the end part of the hexapole and the maximum magnetic field in the coil. Based on saddle hexapole, a new design for hexapoles, the snake hexapole, was developed in this paper. By comparative analysis of the Lorentz force at the end part of the saddle and snake hexapoles, the snake hexapole is much better in the ECR ion source system. The suggested design for the ECR ion source with the snake hexapole is presented in this paper.

  20. Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry.

    Science.gov (United States)

    von Reden, K F; Roberts, M L; Burton, J R; Beaupré, S R

    2012-02-01

    A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C × C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO(2) samples from various preparation sources are injected into the source through a glass capillary at 370 μl∕min. Routine system parameters are about 120-140 μA of negative (12)C current after the C × C, leading to about 400 (14)C counts per second for a modern sample and implying a system efficiency of 0.2%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.

  1. The Project PLASMONX for Plasma Acceleration Experiments and a Thomson X-Ray Source at SPARC

    CERN Document Server

    Serafini, Luca; Alessandria, Franco; Bacci, Alberto; Baldeschi, Walter; Barbini, Alessandro; Bellaveglia, Marco; Bertolucci, Sergio; Biagini, Maria; Boni, Roberto; Bonifacio, Rodolfo; Boscolo, Ilario; Boscolo, Manuela; Bottigli, Ubaldo; Broggi, Francesco; Castellano, Michele; Cecchetti, Carlo A; Cialdi, Simone; Clozza, Alberto; De Martinis, Carlo; Di Pirro, Giampiero; Drago, Alessandro; Esposito, Adolfo; Ferrario, Massimo; Ficcadenti, L; Filippetto, Daniele; Fusco, Valeria; Galimberti, Marco; Gallo, Alessandro; Gatti, Giancarlo; Ghigo, Andrea; Giove, Dario; Giulietti, Antonio; Giulietti, Danilo; Gizzi, Leonida A; Golosio, Bruno; Guiducci, Susanna; Incurvati, Maurizio; Köster, Petra; Labate, Luca; Ligi, Carlo; Marcellini, Fabio; Maroli, Cesare; Mauri, Marco; Migliorati, Mauro; Mostacci, Andrea; Oliva, Pier N; Palumbo, Luigi; Pellegrino, Luigi; Petrillo, Vittoria; Piovella, Nicola; Poggiu, Angela; Pozzoli, Roberto; Preger, Miro; Ricci, Ruggero; Rome, Massimiliano; Rossi, Antonella; Sanelli, Claudio; Serio, Mario; Sgamma, Francesco; Spataro, Bruno; Stecchi, Alessandro; Stella, Angelo; Stumbo, Simone; Tazzioli, Franco; Tommasini, Paolo; Vaccarezza, Cristina; Vescovi, Mario; Vicario, Carlo

    2005-01-01

    We present the status of the activity on the project PLASMONX, which foresees the installation of a multi-TW Ti:Sa laser system at the CNR-ILIL laboratory to conduct plasma acceleration experiments and the construction of an additional beam line at SPARC to develop a Thomson X-ray source at INFN-LNF. After pursuing self-injection experiments at ILIL, when the electron beam at SPARC will be available the SPARC laser system will be upgraded to TW power level in order to conduct either external injection plasma acceleration experiments and ultra-bright X-ray pulse generation with the Thomson source. Results of numerical simulations modeling the interaction of the SPARC electron beam and the counter-propagating laser beam are presented with detailed discussion of the monochromatic X-ray beam spectra generated by Compton backscattering: X-ray energies are tunable in the range 20 to 1000 keV, with pulse duration from 30 fs to 20 ps. Preliminary simulations of plasma acceleration with self-injection are illustrated,...

  2. Cysteine as a Biological Probe for Comparing Plasma Sources

    Science.gov (United States)

    Lackmann, Jan-Wilm; Golda, Judith; Kogelheide, Friederike; Held, Julian; Schulz-von-der-Gathen, Volker; Stapelmann, Katharina

    2016-09-01

    A large variety of plasma sources are available in the plasma medicine community. While enabling to choose the most promising source for a certain biomedical application, comparison of the different sources with a focus on their effect on biological targets is rather challenging. To allow for better comparison of various sources, the recent European COST action MP1101 was used to design the COST reference microplasma jet. Cysteine is a promising candidate investigate the impact of plasma from various sources on a standardized biological molecule, which is especially relevant for the investigations on a molecular level after plasma treatment. The simple structure of cysteine allows for a more in-depth analysis of each chemical group after plasma treatment and enables a comparison between different plasma sources and treatment parameters on each chemical group. The model itself has already been successfully established using a dielectric barrier discharge. Here, additional plasma sources are compared by the means of their impact on cysteine samples, showing e.g. the influence of feed-gas variations by adding oxygen or nitrogen admixture This work was supported by the German Research Foundation (DFG) with the packet grant PAK816 (PlaCID).

  3. Sources for comparative studies of placentation I. Embryological collections

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2008-01-01

    A rich source of material for comparative studies of the placenta is the collections made by pioneers in the field such as H.W. Mossman, A.A.W. Hubrecht and J.P. Hill. This overview gives a brief description of collections known to be available and information on how each can be accessed. Included...

  4. Multipurpose applications of the accelerator-based neutron source[1pt] GENEPI2

    Science.gov (United States)

    Villa, F.; Baylac, M.; Billebaud, A.; Boge, P.; Cabanel, T.; Labussière, E.; Méplan, O.; Rey, S.

    2016-11-01

    GENEPI2 (GEnérateur de NEutrons Pulsé Intense) is an accelerator-based neutron source operating at LPSC laboratory in Grenoble (France). The neutrons are produced at 2.5MeV or 14.2MeV trough fusion reactions. GENEPI2 specifications allow performing efficiently accelerated irradiation tests of integrated circuits. This facility can also be operated to test and calibrate different types of detectors. This paper will describe the facility and its performances. Then, measurements of the neutron production will be presented as well as different types of experiments and irradiations. Finally, we describe upgrades undertaken to increase the neutron flux and optimize the facility for multiple applications.

  5. Status of the advanced photon source and its accelerator control system

    Science.gov (United States)

    McDowell, W.; Knott, M.; Kraimer, M.

    1994-12-01

    This paper presents the current status of the Advanced Photon Source (APS), its control system and the Experimental Physics and Industrial Control System (EPICS) tools being used to implement this control system. The status of the physical plant and each of the accelerators as well as detailed descriptions of the software tools used to build the accelerator control system are presented. The control system uses high-performance graphic workstations and the X-Windows graphical user interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level, using TCP/IP protocols over high-performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  6. Acceleration of conventional data acquisition in dynamic contrast enhancement: comparing keyhole approaches with compressive sensing.

    Science.gov (United States)

    Geethanath, Sairam; Gulaka, Praveen K; Kodibagkar, Vikram D

    2014-01-01

    Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) has become a valuable clinical tool for cancer diagnosis and prognosis. DCE MRI provides pharmacokinetic parameters dependent on the extravasation of small molecular contrast agents, and thus high temporal resolution and/or spatial resolution is required for accurate estimation of parameters. In this article we investigate the efficacy of 2 undersampling approaches to speed up DCE MRI: a conventional keyhole approach and compressed sensing-based imaging. Data reconstructed from variants of these methods has been compared with the full k-space reconstruction with respect to data quality and pharmacokinetic parameters Ktrans and ve. Overall, compressive sensing provides better data quality and reproducible parametric maps than key-hole methods with higher acceleration factors. In particular, an undersampling mask based on a priori precontrast data showed high fidelity of reconstructed data and parametric maps up to 5× acceleration.

  7. COMPARING THE EFFECTS OF VARIOUS WHOLE-BODY VIBRATION ACCELERATIONS ON COUNTER-MOVEMENT JUMP PERFORMANCE

    Directory of Open Access Journals (Sweden)

    David M. Bazett-Jones

    2008-03-01

    Full Text Available While it seems that whole body vibration (WBV might be an effective modality to enhance physical performance, the proper prescription of WBV for performance enhancement remains unknown. The purpose of this study was to compare the immediate effect of various WBV accelerations on counter movement jump (CMJ height, the duration of any effect, and differences between men and women. Forty-four participants (33 men, 11 women participated in no less than four CMJ familiarization sessions and completed all vibration sessions. Participants performed a pre-test (three maximal CMJs, followed randomly by one of five WBV accelerations; 1g (no-WBV control, 2.16g, 2.80g, 4.87g, and 5.83g. Participants performed three maximal CMJs immediately, five, and 10 minutes following each 45 sec WBV session. The mean of the three performances was used and calculated as a percentage of the pre-vibration mean value. A Repeated Measures Analysis of Variance (ANOVA; acceleration x time x gender model was used to analyze the data. The two-way interactions of acceleration-gender (p = 0.033 and time-gender (p = 0.050 were significant. Women performed significantly better following the 2.80g (p = 0.0064 and 5.83g (p = 0. 0125 WBV sessions compared to the 1g (control session. Men, however, did not experience performance enhancing effects following any of the vibration sessions. While significant differences did not occur between time in either gender, the effects of the 45 sec WBV session in women were transient, lasting approximately five minutes. During the prescription of WBV, gender should be considered given that the results of this study seem to indicate that men and women respond differently to WBV. The results of this study suggest that WBV might be a useful modality as applied during the pre-competition warm-up

  8. First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator

    Science.gov (United States)

    Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong; Kim, Seong Jun; Ok, Jung-Woo; Yoon, Jang-Hee; Kim, Hyun Gyu; Shin, Chang Seouk; Hong, Jonggi; Bahng, Jungbae; Won, Mi-Sook

    2016-02-01

    The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted into the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project.

  9. First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong; Kim, Seong Jun; Ok, Jung-Woo; Yoon, Jang-Hee; Kim, Hyun Gyu; Shin, Chang Seouk; Hong, Jonggi; Bahng, Jungbae; Won, Mi-Sook, E-mail: mswon@kbsi.re.kr [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)

    2016-02-15

    The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted into the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project.

  10. A Stable High-Energy Electron Source from Laser Wakefield Acceleration

    Science.gov (United States)

    Zhang, Ping; Zhao, Baozhen; Liu, Cheng; Yan, Wenchao; Golovin, Grigory; Banerjee, Sudeep; Chen, Shouyuan; Haden, Daniel; Fruhling, Colton; Umstadter, Donald

    2016-10-01

    The stability of the electron source from laser wake-field acceleration (LWFA) is essential for applications, such as novel x-ray sources and fundamental experiments in high field physics. To obtain such a stable source, we used an optimal laser pulse and a novel gas nozzle. The high-power laser pulse on target was focused to a diffraction-limited spot by the use of adaptive wavefront correction and the pulse duration was transform limited by the use of spectral feedback control. An innovative design for the nozzle led to a stable, flat-top profile with diameters of 4 mm and 8 mm with a high Mach-number ( 6). In experiments to generate high-energy electron beams by LWFA, we were able to obtain reproducible results with beam energy of 800 MeV and charge >10 pC. Higher charge but broader energy spectrum resulted when the plasma density was increased. These developments have resulted in a laser-driven wakefield accelerator that is stable and robust. With this device, we show that narrowband high-energy x-rays beams can be generated by the inverse-Compton scattering process. This accelerator has also been used in recent experiments to study nonlinear effects in the interaction of high-energy electron beams with ultraintense laser pulses. This material is based upon work supported by NSF No. PHY-153700; US DOE, Office of Science, BES, # DE-FG02-05ER15663; AFOSR # FA9550-11-1-0157; and DHS DNDO # HSHQDC-13-C-B0036.

  11. Development of a large proton accelerator for innovative researches; development of high power RF source

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K. H.; Lee, K. O.; Shin, H. M.; Chung, I. Y. [KAPRA, Seoul (Korea); Kim, D. I. [Inha University, Incheon (Korea); Noh, S. J. [Dankook University, Seoul (Korea); Ko, S. K. [Ulsan University, Ulsan (Korea); Lee, H. J. [Cheju National University, Cheju (Korea); Choi, W. H. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2002-05-01

    This study was performed with objective to design and develop the KOMAC proton accelerator RF system. For the development of the high power RF source for CCDTL(coupled cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. 16 refs., 64 figs., 27 tabs. (Author)

  12. Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, G.A.; Deeney, C.; Cuneo, M. [and others

    1998-06-02

    Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia`s Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3.

  13. In-terminal ECR Ion Source of the Tandem Accelerator at JAERI

    CERN Document Server

    Matsuda, M; Takeuchi, S

    1999-01-01

    Electron Cyclotron Resonance Ion Source(ECRIS)s are able to produce intense beams of highly charged positive ions and used injection system for cyclotron, linac as well as experiments of atomic physics. The tandem accelerator system has been benefiting from use of an electron stripper at the high voltage terminal. The most probable charged state after a foil stripper is, however, much lower than the highest charge state of ions with an intensity of more than several emA from a high performance ECRIS. With respect to beam current, the life time of stripper foils decrease with increasing beam current. Especially for very heavy ions, it is difficult to obtain a stable and intense beam for a long time without foil exchange. Use of an ECRIS in a tandem accelerator is expected to increase beam intensity, beam energy and beam species. A small permanent magnet ECRIS has been installed in the high voltage terminal of the vertical and folded type 20UR Pelletron tandem accelerator at Japan Atomic Energy Research Institu...

  14. INVESTIGATING PARTICLE ACCELERATION IN PROTOSTELLAR JETS: THE TRIPLE RADIO CONTINUUM SOURCE IN SERPENS

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Kamenetzky, Adriana; Valotto, Carlos [Instituto de Astronomía Teórica y Experimental, (IATE-UNC), X5000BGR Córdoba (Argentina); Carrasco-González, Carlos; Rodríguez, Luis F. [Instituto de Radioastronomía y Astrofísica (IRyA-UNAM), 58089 Morelia, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Torrelles, José M. [Institut de Ciències de l’Espai (CSIC-IEEC) and Institut de Ciències del Cosmos (UB-IEEC), Martí i Franquès 1, E-08028 Barcelona (Spain); Anglada, Guillem [Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain); Martí, Josep [Dept. de Física, EPS de Jaén, Universidad de Jaén, Campus Las Lagunillas s/n, A3-402, E-23071 Jaén (Spain)

    2016-02-10

    While most protostellar jets present free–free emission at radio wavelengths, synchrotron emission has also been proposed to be present in a handful of these objects. The presence of nonthermal emission has been inferred by negative spectral indices at centimeter wavelengths. In one case (the HH 80-81 jet arising from a massive protostar), its synchrotron nature was confirmed by the detection of linearly polarized radio emission. One of the main consequences of these results is that synchrotron emission implies the presence of relativistic particles among the nonrelativistic material of these jets. Therefore, an acceleration mechanism should be taking place. The most probable scenario is that particles are accelerated when the jets strongly impact against the dense envelope surrounding the protostar. Here we present an analysis of radio observations obtained with the Very Large Array of the triple radio source in the Serpens star-forming region. This object is known to be a radio jet arising from an intermediate-mass protostar. It is also one of the first protostellar jets where the presence of nonthermal emission was proposed. We analyze the dynamics of the jet and the nature of the emission and discuss these issues in the context of the physical parameters of the jet and the particle acceleration phenomenon.

  15. Low-noise pulsed current source for magnetic-field measurements of magnets for accelerators

    Science.gov (United States)

    Omelyanenko, M. M.; Borisov, V. V.; Donyagin, A. M.; Khodzhibagiyan, H. G.; Kostromin, S. A.; Makarov, A. A.; Shemchuk, A. V.

    2017-01-01

    The schematic diagram, design, and technical characteristics of the pulsed current source developed and produced for the magnetic-field measurement system of superconducting magnets for accelerators are described. The current source is based on the current regulator with pass transistor bank in the linear mode. Output current pulses (0-100 A) are produced by utilizing the energy of the preliminarily charged capacitor bank (5-40 V), which is additionally charged between pulses. The output current does not have the mains frequency and harmonics ripple. The relative noise level is less than-100 dB (or 10-5) of RMS value (it is defined as the ratio of output RMS noise current to a maximal output current of 100 A within the operating bandwidth, expressed in dB). The work was performed at the Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research (JINR).

  16. The Need for a Neutron Source at the Rare Isotope Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ahle, L E; Rusnak, B; Roberts, K E; Roeben, M D; Hausmann, M; Reifarth, R; Vieira, D

    2005-05-13

    An intense neutron source facility with radiochemical processing capability is necessary at the Rare Isotope Accelerator to fully realize its potential benefit to stockpile stewardship and astrophysics. While many of the important physics missions of RIA can be addressed with radioactive ion beams, direct neutron cross-section measurements of interest to stockpile stewardship and astrophysics cannot because one cannot make a neutron target. Thus, one must collect a sufficient amount of the appropriate short-lived isotope, quickly chemically process the material into a target, and promptly radiate the sample with an intense ''beam'' of neutrons. The unprecedented production rates expected at RIA enables many of these direct neutron cross-section measurements, but only if the proper infrastructure is in place. This document not only describes the major piece of this required infrastructure, a neutron source facility with radiochemical processing capabilities, but also the motivation for measuring such direct neutron cross-sections.

  17. X-ray beam source from a Self-modulated laser wakefield accelerator

    Science.gov (United States)

    Lemos, Nuno; Albert, Felicie; Marsh, K. A.; Shaw, J. L.; King, P.; Patankar, S.; Ralph, J.; Pollock, B. B.; Martins, J. L.; Amorim, L. D.; Tsung, F. S.; Goyon, C.; Pak, A.; Moody, J. D.; Schumaker, W.; Fiuza, F.; Glenzer, S. H.; Hegelichand, B. M.; Saunders, A.; Flacone, R. W.; Joshi, C.

    2016-10-01

    To diagnose material properties under extreme conditions of temperature and pressure the development of a directional, small-divergence, small source size and short pulse duration x-ray source has become essential. In this work we explore through experiments and PIC simulations the betatron radiation generated in self-modulated laser-wakefield accelerators. The experiment was preformed at the Jupiter Laser Facility, LLNL where electrons with energies up to 200 MeV and Betatron x-rays with critical energies >10 keV were observed. OSIRIS 2D PIC simulations indicate that the x-ray critical energy directly scales with the a0 of the laser and can easily be increased to critical energies exceeding 50 keV using a laser with a0 of 3.

  18. ACCELERATOR SYSTEMS MODIFICATIONS FOR A SECOND TARGET STATION AT THE OAK RIDGE SPALLATION NEUTRON SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Galambos, John D [ORNL; Kim, Sang-Ho [ORNL; Plum, Michael A [ORNL

    2014-01-01

    A second target station is planned for the Oak Ridge Spallation Neutron Source. The ion source will be upgraded to increase the peak current from 38 to 49 mA, additional superconducting RF cavities will be added to the linac to increase the H beam energy from 938 to 1300 MeV, and the accumulator ring will receive modifications to the injection and extraction systems to accommodate the higher beam energy. After pulse compression in the storage ring one sixth of the beam pulses (10 out of 60 Hz) will be diverted to the second target by kicker and septum magnets added to the existing Ring to Target Beam Transport (RTBT) line. No further modifications will be made to the RTBT so that when the kicker and septum magnets are turned off the original beam transport lattice will be unaffected. In this paper we will discuss these and other planned modifications and upgrades to the accelerator facility.

  19. Prospect for application of compact accelerator-based neutron source to neutron engineering diffraction

    Science.gov (United States)

    Ikeda, Yoshimasa; Taketani, Atsushi; Takamura, Masato; Sunaga, Hideyuki; Kumagai, Masayoshi; Oba, Yojiro; Otake, Yoshie; Suzuki, Hiroshi

    2016-10-01

    A compact accelerator-based neutron source has been lately discussed on engineering applications such as transmission imaging and small angle scattering as well as reflectometry. However, nobody considers using it for neutron diffraction experiment because of its low neutron flux. In this study, therefore, the neutron diffraction experiments are carried out using Riken Accelerator-driven Compact Neutron Source (RANS), to clarify the capability of the compact neutron source for neutron engineering diffraction. The diffraction pattern from a ferritic steel was successfully measured by suitable arrangement of the optical system to reduce the background noise, and it was confirmed that the recognizable diffraction pattern can be measured by a large sampling volume with 10 mm in cubic for an acceptable measurement time, i.e. 10 min. The minimum resolution of the 110 reflection for RANS is approximately 2.5% at 8 μs of the proton pulse width, which is insufficient to perform the strain measurement by neutron diffraction. The moderation time width at the wavelength corresponding to the 110 reflection is estimated to be approximately 30 μs, which is the most dominant factor to determine the resolution. Therefore, refinements of the moderator system to decrease the moderation time by decreasing a thickness of the moderator or by applying the decoupler system or application of the angular dispersive neutron diffraction technique are important to improve the resolution of the diffraction experiment using the compact neutron source. In contrast, the texture evolution due to plastic deformation was successfully observed by measuring a change in the diffraction peak intensity by RANS. Furthermore, the volume fraction of the austenitic phase in the dual phase mock specimen was also successfully evaluated by fitting the diffraction pattern using a Rietveld code. Consequently, RANS has been proved to be capable for neutron engineering diffraction aiming for the easy access

  20. Particle-fluid interaction forces as the source of acceleration PDF invariance in particle size

    CERN Document Server

    Meller, Yosef

    2014-01-01

    The conditions allowing particle suspension in turbulent flow are of interest in many applications, but understanding them is complicated both by the nature of turbulence and by the interaction of flow with particles. Observations on small particles indicate an invariance of acceleration PDFs of small particles independent of size. We show to be true the postulated role of particle/fluid interaction forces in maintaining suspension. The 3D-PTV method, applied for two particle phases (tracers and inertial particles) simultaneously, was used to obtain velocity and acceleration data, and through the use of the particle's equation of motion the magnitude of forces representing either the flow or the particle interaction were derived and compared. The invariance of PDFs is shown to extend to the component forces, and lift forces are shown to be significant.

  1. Comparative Analysis of Torque and Acceleration of Pre- and Post-Transmission Parallel Hybrid Drivetrains

    Directory of Open Access Journals (Sweden)

    Zulkifli Saiful A.

    2016-01-01

    Full Text Available Parallel hybrid electric vehicles (HEV can be classified according to the location of the electric motor with respect to the transmission unit for the internal combustion engine (ICE: they can be pre-transmission or posttransmission parallel hybrid. A split-axle parallel HEV – in which the ICE and electric motor provide propulsion power to different axles – is a sub-type of the post-transmission hybrid, since addition of torque and power from the two power sources occurs after the vehicle’s transmission. The term ‘through-the-road’ (TTR hybrid is also used for the split-parallel HEV, since power coupling between the ICE and electric motor is not through some mechanical device but through the vehicle itself, its wheels and the road on which it moves. The present work presents torquespeed relationship of the split-parallel hybrid and analyses simulation results of torque profiles and acceleration performance of pre-transmission and post-transmission hybrid configurations, using three different sizes of electric motor. Different operating regions of the pre-trans and post-trans motors are observed, leading to different speed and torque profiles. Although ICE average efficiency in the post-trans hybrid is slightly lower than in the pre-trans hybrid, the post-trans hybrid vehicle has better fuel economy and acceleration performance than the pre-trans hybrid vehicle.

  2. Performance analysis of GPU-accelerated filter-based source finding for HI spectral line image data

    Science.gov (United States)

    Westerlund, Stefan; Harris, Christopher

    2015-03-01

    Searching for sources of electromagnetic emission in spectral-line radio astronomy interferometric data is a computationally intensive process. Parallel programming techniques and High Performance Computing hardware may be used to improve the computational performance of a source finding program. However, it is desirable to further reduce the processing time of source finding in order to decrease the computational resources required for the task. GPU acceleration is a method that may achieve significant increases in performance for some source finding algorithms, particularly for filtering image data. This work considers the application of GPU acceleration to the task of source finding and the techniques used to achieve the best performance, such as memory management. We also examine the changes in performance, where the algorithms that were GPU accelerated achieved a speedup of around 3.2 times the 12 core per node CPU-only performance, while the program as a whole experienced a speedup of 2.0 times.

  3. Performance Analysis of GPU-Accelerated Filter-Based Source Finding for HI Spectral Line Image Data

    CERN Document Server

    Westerlund, Stefan

    2015-01-01

    Searching for sources of electromagnetic emission in spectral-line radio astronomy interferometric data is a computationally intensive process. Parallel programming techniques and High Performance Computing hardware may be used to improve the computational performance of a source finding program. However, it is desirable to further reduce the processing time of source finding in order to decrease the computational resources required for the task. GPU acceleration is a method that may achieve significant increases in performance for some source finding algorithms, particularly for filtering image data. This work considers the application of GPU acceleration to the task of source finding and the techniques used to achieve the best performance, such as memory management. We also examine the changes in performance, where the algorithms that were GPU accelerated achieved a speedup of around 3.2 times the 12 core per node CPU-only performance, while the program as a whole experienced a speedup of 2.0 times.

  4. Laser-wakefield accelerators as hard x-ray sources for 3D medical imaging of human bone.

    Science.gov (United States)

    Cole, J M; Wood, J C; Lopes, N C; Poder, K; Abel, R L; Alatabi, S; Bryant, J S J; Jin, A; Kneip, S; Mecseki, K; Symes, D R; Mangles, S P D; Najmudin, Z

    2015-08-18

    A bright μm-sized source of hard synchrotron x-rays (critical energy Ecrit > 30 keV) based on the betatron oscillations of laser wakefield accelerated electrons has been developed. The potential of this source for medical imaging was demonstrated by performing micro-computed tomography of a human femoral trabecular bone sample, allowing full 3D reconstruction to a resolution below 50 μm. The use of a 1 cm long wakefield accelerator means that the length of the beamline (excluding the laser) is dominated by the x-ray imaging distances rather than the electron acceleration distances. The source possesses high peak brightness, which allows each image to be recorded with a single exposure and reduces the time required for a full tomographic scan. These properties make this an interesting laboratory source for many tomographic imaging applications.

  5. Ultracompact Accelerator Technology for a Next-Generation Gamma-Ray Source

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, R A; Albert, F; Anderson, S G; Gibson, D J; Wu, S S; Hartemann, F V; Barty, C J

    2012-05-14

    This presentation reported on the technology choices and progress manufacturing and testing the injector and accelerator of the 250 MeV ultra-compact Compton Scattering gamma-ray Source under development at LLNL for homeland security applications. This paper summarizes the status of various facets of current accelerator activities at LLNL. The major components for the X-band test station have been designed, fabricated, and await installation. The XL-4 klystron has been delivered, and will shortly be dressed and installed in the ScandiNova modulator. High power testing of the klystron into RF loads will follow, including adjustment of the modulator for the klystron load as necessary. Assembly of RF transport, test station supports, and accelerator components will follow. Commissioning will focus on processing the RF gun to full operating power, which corresponds to 200 MV/m peak electric field on the cathode surface. Single bunch benchmarking of the Mark 1 design will provide confidence that this first structure operates as designed, and will serve as a solid starting point for subsequent changes, such as a removable photocathode, and the use of various cathode materials for enhanced quantum efficiency. Charge scaling experiments will follow, partly to confirm predictions, as well as to identify important causes of emittance growth, and their scaling with charge. Multi-bunch operation will conclude testing of the Mark 1 RF gun, and allow verification of code predictions, direct measurement of bunch-to-bunch effects, and initial implementation compensation mechanisms. Modeling will continue and focus on supporting the commissioning and experimental program, as well as seeking to improve all facets of linac produced Compton gamma-rays.

  6. Magnetospheric Eternally Collapsing Objects (MECOs): Likely New Class of Source of COsmic Particle Acceleration

    CERN Document Server

    Mitra, A

    2005-01-01

    It is known that spinning pulsars could be source of VHE-UHE cosmic particle acceleration. It is also conjectured that (fictitious) spinning Black Holes (BH) could be sites of cosmic particle acceleration. However, it has been shown by Mitra and Leiter and Robertson that General Relativity (GR) actually does not allow the existence or formation of finite mass BHs. It was predicted that the BH Candiadates (BHCs) have strong intrinsic magnetic fields (like pulsars) instead of Event Horizons. And this prediction has tentatively been verified in a series of papers by Robertson & Leiter. Thus all observed BH Candidates are actually not BHs, and, they are expected to be MECOs. Stellar mass MECOs are GR analogs of conventionally known isolated pulsars. While pulsars are/have (i) COLD, i.e., not supported by radiation pressure, MECOs are HOT, i.e., supported primarily by trapped radiation pressure, (ii) upper mass limit of 3-4 $M_solar$ MECOs, being HOT, have no Upper Mass Limit, (iii) surface gravitational red s...

  7. Conceptual design of an RFQ accelerator-based neutron source for boron neutron-capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wangler, T.P.; Stovall, J.E.; Bhatia, T.S.; Wang, C.K.; Blue, T.E.; Gahbauer, R.A.

    1989-01-01

    We present a conceptual design of a low-energy neutron generator for treatment of brain tumors by boron neutron capture theory (BNCT). The concept is based on a 2.5-MeV proton beam from a radio-frequency quadrupole (RFQ) linac, and the neutrons are produced by the /sup 7/Li(p,n)/sup 7/Be reaction. A liquid lithium target and modulator assembly are designed to provide a high flux of epithermal neutrons. The patient is administered a tumor-specific /sup 10/Be-enriched compound and is irradiated by the neutrons to create a highly localized dose from the reaction /sup 10/B(n,..cap alpha..)/sup 7/Li. An RFQ accelerator-based neutron source for BNCT is compact, which makes it practical to site the facility within a hospital. 11 refs., 5 figs., 1 tab.

  8. OpenSource lab-on-a-chip physiometer for accelerated zebrafish embryo biotests.

    Science.gov (United States)

    Akagi, Jin; Hall, Chris J; Crosier, Kathryn E; Cooper, Jonathan M; Crosier, Philip S; Wlodkowic, Donald

    2014-01-02

    Zebrafish (Danio rerio) embryo assays have recently come into the spotlight as convenient experimental models in both biomedicine and ecotoxicology. As a small aquatic model organism, zebrafish embryo assays allow for rapid physiological, embryo-, and genotoxic tests of drugs and environmental toxins that can be simply dissolved in water. This protocol describes prototyping and application of an innovative, miniaturized, and polymeric chip-based device capable of immobilizing a large number of living fish embryos for real-time and/or time-lapse microscopic examination. The device provides a physical address designation to each embryo during analysis, continuous perfusion of medium, and post-analysis specimen recovery. Miniaturized embryo array is a new concept of immobilization and real-time drug perfusion of multiple individual and developing zebrafish embryos inside the mesofluidic device. The OpenSource device presented in this protocol is particularly suitable to perform accelerated fish embryo biotests in ecotoxicology and phenotype-based pharmaceutical screening.

  9. Compact tunable Compton x-ray source from laser-plasma accelerator and plasma mirror

    CERN Document Server

    Tsai, Hai-En; Shaw, Joseph; Li, Zhengyan; Arefiev, Alexey V; Zhang, Xi; Zgadzaj, Rafal; Henderson, Watson; Khudik, V; Shvets, G; Downer, M C

    2014-01-01

    We present results of the first tunable Compton backscattering (CBS) x-ray source that is based on the easily aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The LPA is driven in the blowout regime by 30 TW, 30 fs laser pulses, and produces high-quality, tunable, quasi-monoenergetic electron beams. A thin plastic film near the gas jet exit efficiently retro-reflects the LPA driving pulse with relativistic intensity into oncoming electrons to produce $2\\times10^{7}$ CBS x-ray photons per shot with 10-20 mrad angular divergence and 50 % (FWHM) energy spread without detectable bremsstrahlung background. The x-ray central energy is tuned from 75 KeV to 200 KeV by tuning the LPA e-beam central energy. Particle-in-cell simulations of the LPA, the drive pulse/PM interaction and CBS agree well with measurements.

  10. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  11. Accelerator Science and Technology in Canada -- From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source

    Science.gov (United States)

    Craddock, M. K.; Laxdal, R. E.

    As elsewhere, accelerators in Canada have evolved from modest beginnings to major facilities such as TRIUMF (currently with the highest-power driver for rare isotope beam production) and the third generation Canadian Light Source. Highlights along the way include construction of the first microtron, the first racetrack microtron and the first superconducting cyclotron (to which list might have been added the first pulse stretcher ring, had it been funded sooner). This article will summarize the history of accelerators in Canada, documenting both the successes and the near-misses. Besides the research accelerators, a thriving commercial sector has developed, manufacturing small cyclotrons and linacs, beam line components and superconducting rf cavities.

  12. Accelerator Science and Technology in Canada — From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source

    Science.gov (United States)

    Craddock, M. K.; Laxdal, R. E.

    As elsewhere, accelerators in Canada have evolved from modest beginnings to major facilities such as TRIUMF (currently with the highest-power driver for rare isotope beam production) and the third generation Canadian Light Source. Highlights along the way include construction of the first microtron, the first racetrack microtron and the first superconducting cyclotron (to which list might have been added the first pulse stretcher ring, had it been funded sooner). This article will summarize the history of accelerators in Canada, documenting both the successes and the near-misses. Besides the research accelerators, a thriving commercial sector has developed, manufacturing small cyclotrons and linacs, beam line components and superconducting rf cavities.

  13. Big data and comparative effectiveness research in radiation oncology: synergy and accelerated discovery

    Directory of Open Access Journals (Sweden)

    Daniel eTrifiletti

    2015-12-01

    Full Text Available Several advances in large data set collection and processing have the potential to provide a wave of new insights and improvements in the use of radiation therapy for cancer treatment. The era of electronic health records, genomics, and improving information technology resources creates the opportunity to leverage these developments to create a learning healthcare system that can rapidly deliver informative clinical evidence. By merging concepts from comparative effectiveness research with the tools and analytic approaches of big data, it is hoped that this union will accelerate discovery, improve evidence for decision-making, and increase the availability of highly relevant, personalized information. This combination offers the potential to provide data and analysis that can be leveraged for ultra-personalized medicine and high quality, cutting-edge radiation therapy.

  14. Treatment of industrial effluents using electron beam accelerator and adsorption with activated carbon: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Sampa, M.H. de E-mail: mhosampa@ipen.br; Rela, Paulo Roberto; Las Casas, Alexandre; Nunes Mori, Manoel; Lopes Duarte, Celina

    2004-10-01

    This paper presents preliminary results of a study that compares the use of electron beam processing and activated carbon adsorption to clean up a standardized organic aqueous solution and a real industrial effluent. The electron beam treatment was performed in a batch system using the IPEN's Electron Beam Accelerators from Radiation Dynamics Inc., Dynamitron 37.5 kW. The granular activated carbon removal treatment was performed using charcoal made from wood 'pinus'. If the adequate irradiation dose is delivered to the organic pollutant, it is possible to conclude for the studied compounds that the Electron Beam Process is similar to the activated carbon process in organic removal efficiency.

  15. Lithium antineutrino source in the tandem scheme of the accelerator and neutron producting tungsten target

    CERN Document Server

    Lyashuk, V I

    2016-01-01

    The antineutrinos of the neutron rich 8Li isotope is characterized by hard and good defined spectrum - averaged energy is 6.5 MeV and maximal - up to 13 MeV. An intensive antineutrino source with such parameters can be unique instrument for neutrino investigations and especially for search of sterile neutrinos. The 8Li can be produced by (n,gamma)-activation of 7Li isotope. The proposed scheme of the antineutrino source is based on the lithium blanket around the accelerator neutron producting target. We propose to use heavy water solution of the lithium hydroxide instead of lithium in metallic state. Such solution for lithium blanket substance ensure the large perspectives in real steps for creation of this installation. An analyses of neutron fields in the blanket and distribution of 8Li creation allows to propose the next principal steps in the construction of the lithium blanket. We propose to enclose the blanket volume isolating it's central part with more high 8Li production. This solution allows to decr...

  16. Laser-plasma accelerator and femtosecond photon sources-based ultrafast radiation chemistry and biophysics

    Science.gov (United States)

    Gauduel, Y. A.

    2017-02-01

    The initial distribution of energy deposition triggered by the interaction of ionizing radiations (far UV and X rays, electron, proton and accelerated ions) with molecular targets or integrated biological systems is often decisive for the spatio-temporal behavior of radiation effects that take place on several orders of magnitude. This contribution deals with an interdisciplinary approach that concerns cutting-edge advances on primary radiation events, considering the potentialities of innovating strategies based on ultrafast laser science, from femtosecond photon sources to laser-driven relativistic particles acceleration. Recent advances of powerful TW laser sources (~ 1019 Wcm‑2) and laser-plasma interactions providing ultrashort relativistic particle beams in the energy domain 2.5–150 MeV open exciting opportunities for the development of high-energy radiation femtochemistry (HERF). Early radiation damages being dependent on the survival probability of secondary electrons and radial distribution of short-lived radicals inside ionization clusters, a thorough knowledge of these processes involves the real-time probing of primary events in the temporal range 10‑14–10‑11 s. In the framework of a closed synergy between low-energy radiation femtochemistry (LERF) and the emerging domain of HERF, the paper focuses on early phenomena that occur in the prethermal regime of low-energy secondary electrons, considering very short-lived quantum effects in aqueous environments. A high dose-rate delivered by femtosecond electron beam (~ 1011–1013 Gy s‑1) can be used to investigate early radiation processes in native ionization tracks, down to 10‑12 s and 10‑9 m. We explain how this breakthrough favours the innovating development of real-time nanodosimetry in biologically relevant environments and open new perspectives for spatio-temporal radiation biophysics. The emerging domain of HERF would provide guidance for understanding the specific bioeffects of

  17. A multi-sample changer coupled to an electron cyclotron resonance source for accelerator mass spectrometry experiments.

    Science.gov (United States)

    Vondrasek, R; Palchan, T; Pardo, R; Peters, C; Power, M; Scott, R

    2014-02-01

    A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving between samples in 1 min. The sample changer is part of a project using Accelerator Mass Spectrometry (AMS) at the Argonne Tandem Linac Accelerator System (ATLAS) facility to measure neutron capture rates on a wide range of actinides in a reactor environment. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly charged positive ions in an electron cyclotron resonance ion source followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation chosen to limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples.

  18. Measuring Velocity and Acceleration Using Doppler Shift of a Source with an Example of Jet in SS433

    Indian Academy of Sciences (India)

    Sanjay M. Wagh

    2014-12-01

    We describe here as to how the Doppler shift of a source needs to be used to measure its velocity and acceleration. We also apply this method, as an example here, to spectral lines of the blue-shifted jet in micro-quasar SS433 and discuss the intricacies of these measurements.

  19. Solar energetic particles a modern primer on understanding sources, acceleration and propagation

    CERN Document Server

    Reames, Donald V

    2017-01-01

    This concise primer introduces the non-specialist reader to the physics of solar energetic particles (SEP) and systematically reviews the evidence for the two main mechanisms which lead to the so-called impulsive and gradual SEP events. More specifically, the timing of the onsets, the longitude distributions, the high-energy spectral shapes, the correlations with other solar phenomena (e.g. coronal mass ejections), as well as the all-important elemental and isotopic abundances of SEPs are investigated. Impulsive SEP events are related to magnetic reconnection in solar flares and jets. The concept of shock acceleration by scattering on self-amplified Alfvén waves is introduced, as is the evidence of reacceleration of impulsive-SEP material in the seed population accessed by the shocks in gradual events. The text then develops processes of transport of ions out to an observer. Finally, a new technique to determine the source plasma temperature in both impulsive and gradual events is demonstrated. Last but not ...

  20. Particle Acceleration Inside Thunderstorms and the Variation in Source Spectra of Terrestrial Gamma-ray Flashes

    Science.gov (United States)

    Cramer, Eric; Dwyer, Joseph R.; Briggs, Michael S.; Rassoul, Hamid K.

    2016-03-01

    One of the unresolved questions in the atmospheric sciences is the origin of Terrestrial Gamma-ray Flashes (TGFs). These flashes are short but intense gamma ray bursts emanating from Earth's atmosphere. This phenomenon has been observed by gamma ray detectors on orbiting satellites, e.g. NASA Fermi, intended to study astrophysical phenomena such as Gamma-ray Bursts. TGFs are thought to originate inside thunderstorms where electrons can be accelerated and emit radiation in the multi MeV range due to bremsstrahlung interactions with air molecules. These so called ``runaway electrons'' are seeded from cosmic ray air showers hitting the Earth's atmosphere from (extra) galactic sources. In this work, we present a Monte Carlo model that simulates particle physics inside a thunderstorm region. The subsequent transport of high energy gamma rays through the Earth's atmosphere and up to satellite orbit is also included. We show that by varying both the potential difference and the ambient electric field inside the thundercloud, different electron and photon energy distributions are produced. This effect may be detectable by orbiting spacecraft, and therefore serves as a method to remote sense the electric fields that exist inside thunderstorms.

  1. Applications of Accelerators and Radiation Sources in the Field of Space Research and Industry.

    Science.gov (United States)

    Campajola, Luigi; Di Capua, Francesco

    2016-12-01

    Beyond their important economic role in commercial communications, satellites in general are critical infrastructure because of the services they provide. In addition to satellites providing information which facilitates a better understanding of the space environment and improved performance of physics experiments, satellite observations are also used to actively monitor weather, geological processes, agricultural development and the evolution of natural and man-made hazards. Defence agencies depend on satellite services for communication in remote locations, as well as for reconnaissance and intelligence. Both commercial and government users rely on communication satellites to provide communication in the event of a disaster that damages ground-based communication systems, provide news, education and entertainment to remote areas and connect global businesses. The space radiation environment is an hazard to most satellite missions and can lead to extremely difficult operating conditions for all of the equipment travelling in space. Here, we first provide an overview of the main components of space radiation environment, followed by a description of the basic mechanism of the interaction of radiation with matter. This is followed by an introduction to the space radiation hardness assurance problem and the main effects of natural radiation to the microelectronics (total ionizing dose, displacement damage and the single-event effect and a description of how different effects occurring in the space can be tested in on-ground experiments by using particle accelerators and radiation sources. We also discuss standards and the recommended procedures to obtain reliable results.

  2. Arab Americans: A Comparative Critical Analysis of Leading Reference Sources.

    Science.gov (United States)

    Wertsman, Vladimir F.

    2001-01-01

    Examines eight reference sources on Arab Americans to investigate how complete the information is on various facets of Arab American presence, history, community life, heritage preservation, organizations, and the press, concluding that the reference sources complement each other, but taken together, they do not cover the entire multidimensional…

  3. Femtosecond timing distribution and control for next generation accelerators and light sources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li -Jin [Idesta Quantum Electronics, LLC, Newton, NJ (United States)

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even attosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objective of the work described in this proposal is to set up an optical timing distribution system based on mode locked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the

  4. FEMTOSECOND TIMING DISTRIBUTION AND CONTROL FOR NEXT GENERATION ACCELERATORS AND LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li-Jin [Idesta Quantum Electronics, LLC

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even at-tosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objec-tive of the work described in this proposal is to set up an optical timing distribution sys-tem based on modelocked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the

  5. MR imaging of the cervical spine: assessment of image quality with parallel imaging compared to non-accelerated MR measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noebauer-Huhmann, I.M.; Imhof, Herwig [Medical University of Vienna, Department of Radiology, Vienna (Austria); Glaser, Christian; Dietrich, Olaf; Wallner, C.P.; Klinger, Wolfgang; Schoenberg, Stefan O. [Ludwig-Maximilians-University of Munich, Institute of Clinical Radiology, Munich (Germany)

    2007-05-15

    To compare the quality of cervical spine MR images obtained by parallel imaging [generalized autocalibrating partially parallel acquisition (GRAPPA)] with those of non-accelerated imaging, we conducted both phantom studies and examinations of ten volunteers at 1.5Tesla with a dedicated 12-element coil system and a head-spine-neck coil combination. Acquisitions included axial T2-weighted (T2w) images with both methods, and sagittal T2w and T1w images in vivo with the latter coil combination. Non-accelerated MRI with two averages and GRAPPA (acceleration factor 2) with two averages (GRAPPA/2AV, time reduction of approximately 50%) and four averages (GRAPPA/4AV) were compared. In the phantom, the signal-to-noise ratio of the GRAPPA/2AV was lower than that of the other two settings. In vivo, the image inhomogeneity (non-uniformity, NU) was significantly higher in T2w GRAPPA/2AV than in both other settings, and in T1w GRAPPA/2AV compared to GRAPPA/4AV. Subjectively, the delineation of anatomical structures was sufficient in all sequences. Only the spinal cord was considered to be better delineable on the non-accelerated T1w sequence compared to GRAPPA/2AV. In part, GRAPPA/4AV performed better than the other settings. The subjective image noise was lowest with GRAPPA/4AV. In cervical spine MRI, the examination time can be reduced by nearly 42% with GRAPPA, while preserving sufficient image quality. (orig.)

  6. Fermi acceleration at fast shock in a solar flare and impulsive loop-top hard X-ray source

    CERN Document Server

    Tsuneta, S; Tsuneta, Saku; Naito, Tsuguya

    1998-01-01

    We propose that non-thermal electrons are efficiently accelerated by first-order Fermi process at the fast shock, as a natural consequence of the new magnetohydrodynamic picture of the flaring region revealed with Yohkoh. An oblique fast shock is naturally formed below the reconnection site, and boosts the acceleration to significantly decrease the injection energy. The slow shocks attached to the reconnection X-point heat the plasma up to 10--20 MK, exceeding the injection energy. The combination of the oblique shock configuration and the pre-heating by the slow shock allows bulk electron acceleration from the thermal pool. The accelerated electrons are trapped between the two slow shocks due to the magnetic mirror downstream of the fast shock, thus explaining the impulsive loop-top hard X-ray source discovered with Yohkoh. Acceleration time scale is ~ 0.3--0.6 s, which is consistent with the time scale of impulsive bursts. When these electrons stream away from the region enclosed by the fast shock and the s...

  7. Alternative uses of a megavolt tandem accelerator for few-keV studies with ion-source SIMS monitoring

    Science.gov (United States)

    Mello, S. L. A.; Codeço, C. F. S.; Magnani, B. F.; Sant'Anna, M. M.

    2016-06-01

    We increase the versatility of a tandem electrostatic accelerator by implementing simple modifications to the standard operation procedure. While keeping its ability to deliver MeV ion beams, we show that the experimental setup can (i) provide good quality ion beams in the few-keV energy range and (ii) be used to study ion-beam surface modification with simultaneous secondary ion mass spectrometry. This latter task is accomplished without using any chamber connected to the accelerator exit. We perform mass spectrometry of the few-keV anions produced in the ion source by measuring their neutral counterparts at the accelerator exit with energies up to 1.7 MeV. With an additional modification, a high-current few-keV regime is obtained, using the ion source as an irradiation chamber and the accelerator itself only as a mass spectrometer. As an example of application, we prepare a sample for the study of ion-beam assisted dewetting of a thin Au film on a Si substrate.

  8. Ambulatory blood pressure status in children: comparing alternate limit sources.

    Science.gov (United States)

    Bell, Cynthia S; Poffenbarger, Tim S; Samuels, Joshua A

    2011-12-01

    The American Heart Association has included alternate ambulatory blood pressure (ABP) limits for children published by Wühl in 2002. These updated limits employ the same pediatric cohort data as the previous ABP limits published by Soergel in 1997 but differ in analysis technique. The implications of changing ABP limit source on the diagnosis of hypertension has yet to be examined in a large pediatric cohort. We reviewed 741 ABP monitorings performed in children referred to our hypertension clinic between 1991-2007. Hypertension was defined as 24-h mean blood pressure ≥ 95 th percentile or 24-h blood pressure load ≥ 25%, by Soergel and Wühl limits separately. Six hundred seventy-three (91%) children were classified the same by both limit sources. Wühl limits were more likely than Soergel to classify a child as hypertensive (443 vs. 409, respectively). There was an increased classification of prehypertension and decreased white-coat hypertension by the Wühl method, whereas ambulatory and severe hypertension counts remained relatively the same by both limits sources. The use of either limit source will not significantly affect most clinical outcomes but should remain consistent over long-term research projects. Collection of new normative data from a larger, multiethnic population is needed for better measurement of ABP in children.

  9. Solar release time of solar energetic particles and associated acceleration source in corona

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Solar energetic particles (SEPs) are accelerated in corona at an early phase of solar energetic particle events (SEPE). The acceleration mechanism of SEPs in corona can only be inferred from an analysis of multi-band observational data, as the observation of SEPs is usually made around 1AU. In this context,people have investigated spectrums, charge state, solar release time (SRT), and multi-band data of SEPEs, in an attempt to judge the acceleration mechanism of SEPs. The SRT computation of SEPs is an important and commonly used approach to study the acceleration mechanism of SEPs in corona.This paper reviews some important findings concerning the SRT computation of SEPs, and analyzes different merits of each approach for such calculation, based on a range of SEPE case studies. This paper also analyzes and discusses both possible and actual acceleration mechanisms of a number of SEPEs, by calculating the SRT of the SEPEs. Finally, the paper summarizes the possible problems in studying an acceleration mechanism of SEPEs inferred from the SRT of SEP.

  10. Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Kitagawa, A.; Drentje, A. G.; Fujita, T.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Fukushima, K.; Shiraishi, N.; Suzuki, T.; Takahashi, K.; Takasugi, W. [Accelerator Engineering Corporation, Chiba (Japan); Biri, S.; Rácz, R. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Kato, Y. [Graduate School of Engineering, Osaka University, Osaka (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe (Japan)

    2016-02-15

    With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

  11. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Döpp, A., E-mail: andreas.doepp@polytechnique.edu [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Centro de Laseres Pulsados, Parque Cientfico, 37185 Villamayor, Salamanca (Spain); Guillaume, E.; Thaury, C.; Lifschitz, A. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Sylla, F. [SourceLAB SAS, 86 rue de Paris, 91400 Orsay (France); Goddet, J-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Conejero, E.; Ruiz, C. [Departamento de Física Aplicada, Universidad de Salamanca, Plaza de laMerced s/n, 37008 Salamanca (Spain); Ta Phuoc, K.; Malka, V. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France)

    2016-09-11

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  12. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    Science.gov (United States)

    Döpp, A.; Guillaume, E.; Thaury, C.; Lifschitz, A.; Sylla, F.; Goddet, J.-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P.; Conejero, E.; Ruiz, C.; Ta Phuoc, K.; Malka, V.

    2016-09-01

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  13. Particle Accelerators in China

    Science.gov (United States)

    Zhang, Chuang; Fang, Shouxian

    As the special machines that can accelerate charged particle beams to high energy by using electromagnetic fields, particle accelerators have been widely applied in scientific research and various areas of society. The development of particle accelerators in China started in the early 1950s. After a brief review of the history of accelerators, this article describes in the following sections: particle colliders, heavy-ion accelerators, high-intensity proton accelerators, accelerator-based light sources, pulsed power accelerators, small scale accelerators, accelerators for applications, accelerator technology development and advanced accelerator concepts. The prospects of particle accelerators in China are also presented.

  14. Comparative Study on Accelerated Thermal Ageing of Vegetable Insulating Oil-paperboard and Mineral Oil-paperboard

    Science.gov (United States)

    Zhou, Zhu-Jun; Hu, Ting; Cheng, Lin; Tian, Kai; Yang, Jun; Wang, Xuan; Fang, Fu-Xin; Kong, Hai-Yang; Qian, Hang

    2016-05-01

    To comparatively study the insulation ageing life of vegetable insulating oil-paperboard and mineral oil-paperboard, we conducted accelerated thermal ageing experiments at 170°C. Then according to the temperature rise of vegetable insulating oil transformer, we conducted accelerated thermal ageing experiments at 150°C for vegetable insulating oil-paperboard and at 140°C for mineral oil-paperboard. The appearance, polymerization degree, and SEM microstructure of the paperboard after different ageing experiments were comparative analyzed. The results show that after the oil-paperboard system is accelerated ageing for 1 000 h at 170°C, that is equivalent to 20 years natural ageing, the structure of paperboard in vegetable insulating oil is damaged severely, which indicates that the lifetime of transformer are in the late stage; while the structure of paperboard in mineral oil maintain complete, and the polymerization degree is still above 500, which indicate that the lifetime of transformer are in the middle stage. The accelerated ageing rate of the vegetable insulating oil-paperboard system at 150°C is slower than that of the mineral oil-paperboard system, which indicates that the lifetime of the vegetable insulating oil-paperboard is longer than that of the mineral oil-paperboard.

  15. Comparing sourcing strategies in two-echelon supply chains

    DEFF Research Database (Denmark)

    Sajadieh, Mohsen S.; Thorstenson, Anders; Akbari Jokar, Mohammad R.

    elements: inventory holding costs at the buyer and the vendors, backorder costs and ordering costs at the buyer, and setup costs at the vendors. The objective is to minimize the total system costs incurred by the buyer and the vendors. As there is no dominating combined strategy, a major finding...... is that determining the best strategy requires a detailed analysis. Furthermore, when total system costs are taken into account, dual sourcing does not appear as beneficial as sometimes claimed in the literature on lot splitting....

  16. Exit from accelerated regimes by symmetry breaking in a universe filled with fermionic and bosonic sources

    CERN Document Server

    Ribas, Marlos O; Devecchi, Fernando P; Kremer, Gilberto M

    2014-01-01

    In this work we investigate a universe filled with a fermionic field and a complex scalar field, exchanging energy through a Yukawa potential; the model encodes a symmetry breaking mechanism (on the bosonic sector). In a first case, when the mechanism is not included, the cosmological model furnishes a pure accelerated regime. In a second case, when including the symmetry breaking mechanism, we verify that the fermion and one of the bosons, of Higgs type, become massive, while the other boson is massless. Besides, the mechanism shows to be responsible for a transition from an accelerated to a decelerated regime, which certifies the importance, in cosmological terms, of its role. After symmetry breaking, the total pressure of the fields change its sign from negative to positive corresponding to the accelerated-decelerated transition. For large times the universe becomes a dust (pressureless) dominated Universe.

  17. Comparative Analysis Study of Open Source GIS in Malaysia

    Science.gov (United States)

    Rasid, Muhammad Zamir Abdul; Kamis, Naddia; Khuizham Abd Halim, Mohd

    2014-06-01

    Open source origin might appear like a major prospective change which is qualified to deliver in various industries and also competing means in developing countries. The leading purpose of this research study is to basically discover the degree of adopting Open Source Software (OSS) that is connected with Geographic Information System (GIS) application within Malaysia. It was derived based on inadequate awareness with regards to the origin ideas or even on account of techie deficiencies in the open origin instruments. This particular research has been carried out based on two significant stages; the first stage involved a survey questionnaire: to evaluate the awareness and acceptance level based on the comparison feedback regarding OSS and commercial GIS. This particular survey was conducted among three groups of candidates: government servant, university students and lecturers, as well as individual. The approaches of measuring awareness in this research were based on a comprehending signal plus a notion signal for each survey questions. These kinds of signs had been designed throughout the analysis in order to supply a measurable and also a descriptive signal to produce the final result. The second stage involved an interview session with a major organization that carries out available origin internet GIS; the Federal Department of Town and Country Planning Peninsular Malaysia (JPBD). The impact of this preliminary study was to understand the particular viewpoint of different groups of people on the available origin, and also their insufficient awareness with regards to origin ideas as well as likelihood may be significant root of adopting level connected with available origin options.

  18. AMS-02 data confront acceleration of cosmic ray secondaries in nearby sources

    DEFF Research Database (Denmark)

    Mertsch, Philipp; Sarkar, Subir

    2014-01-01

    We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons...

  19. Shielding analysis of proton therapy accelerators: a demonstration using Monte Carlo-generated source terms and attenuation lengths.

    Science.gov (United States)

    Lai, Bo-Lun; Sheu, Rong-Jiun; Lin, Uei-Tyng

    2015-05-01

    Monte Carlo simulations are generally considered the most accurate method for complex accelerator shielding analysis. Simplified models based on point-source line-of-sight approximation are often preferable in practice because they are intuitive and easy to use. A set of shielding data, including source terms and attenuation lengths for several common targets (iron, graphite, tissue, and copper) and shielding materials (concrete, iron, and lead) were generated by performing Monte Carlo simulations for 100-300 MeV protons. Possible applications and a proper use of the data set were demonstrated through a practical case study, in which shielding analysis on a typical proton treatment room was conducted. A thorough and consistent comparison between the predictions of our point-source line-of-sight model and those obtained by Monte Carlo simulations for a 360° dose distribution around the room perimeter showed that the data set can yield fairly accurate or conservative estimates for the transmitted doses, except for those near the maze exit. In addition, this study demonstrated that appropriate coupling between the generated source term and empirical formulae for radiation streaming can be used to predict a reasonable dose distribution along the maze. This case study proved the effectiveness and advantage of applying the data set to a quick shielding design and dose evaluation for proton therapy accelerators.

  20. Development of the RF Ion Sources for Focused Ion Beam Accelerators

    Directory of Open Access Journals (Sweden)

    V. Voznyi

    2014-01-01

    Full Text Available The paper presents the results of investigations of ion sources developed in the IAP of NAS of Ukraine for generation of high brightness ion beams with small energy spread. A series of RF ion sources operated at the frequency of 27.12 MHz were studied: the inductive RF ion source, the helicon ion source, the multi-cusp RF ion source, and the sputter type RF source of metal ions. A global model and transformer model were applied for calculation of RF source plasma parameters. Ion energy spread, ion mass, and ion current density of some sources were measured in the wide range of RF power, extraction voltage and gas pres-sure.

  1. A comparative study of challenges in integrating Open Source Software and Inner Source Software

    NARCIS (Netherlands)

    Stol, Klaas-Jan; Babar, Muhammad Ali; Avgeriou, Paris; Fitzgerald, Brian

    2011-01-01

    Context: Several large software-developing organizations have adopted Open Source Software development (OSSD) practices to develop in-house components that are subsequently integrated into products. This phenomenon is also known as "Inner Source". While there have been several reports of successful

  2. Comparative study of wild edible mushrooms as sources of antioxidants.

    Science.gov (United States)

    Witkowska, Anna M; Zujko, Małgorzata E; Mirończuk-Chodakowska, Iwona

    2011-01-01

    The purpose of the study was to explore sixteen of the most popular edible species of wild-growing mushrooms as potential sources of antioxidants. Among the mushrooms tested, the highest total polyphenol contents, exceeding 100 mg/100 g fresh mass, were found in five mushrooms: Boletus chrysenteron, B. edulis, Leccinum scabrum, L. aurantiacum, and Macrolepiota procera. Antioxidant activity was measured with the FRAP, TEAC, DPPH scavenging ability and ferrous ions chelating ability assays. Results of the study show that wild mushrooms vary according to their antioxidant properties. The highest FRAP potentials, exceeding 1 mmol/100 g, were found in five species ofBoletales: Boletus edulis, B. chrysenteron, Leccinum scabrum, L. aurantiacum, and Suillus grevillei. TEAC values were from 1.07 to 4.01 mmol/100 g fresh mass. High TEAC values (>2.3 mmol/100 g) were found in Leccinum scabrum, L. aurantiacum, Macrolepiota procera, Boletus chrysenteron, and B. edulis. The DPPH radical scavenging effectiveness of mushroom extracts, expressed as EC50 values, was in range 2.91-13.86 mg/mL. Scavenging ability was the highest for B. edulis and B. chrysenteron. The metal chelating ability of mushroom extracts expressed as ECso values of chelating ability on ferrous ions were from 8.02 mg/mL in Cantharellus cibarius to 12.10 mg/mL in Suillus luteus. Among the mushrooms tested, Boletus chrysenteron and B. edulis were characterized by high scores of polyphenol contents and antioxidant activity in the FRAP, TEAC, and DPPH assays. These results place these culinary species of wild-growing mushrooms among products with considerable antioxidant potential.

  3. 150 keV accelerator as pulsed neutron source; Acelerador de 150 keV como fuente de neutrones pulsada

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, F.

    1970-07-01

    The project of a 150 keV Cockcroft-Walton accelerator built at J.E.N. is described. Beam currents of more than 10 mA, with a neutron intensity of 10{sup 1}1 n.s{sup 1}, are obtained. Also, we report some research made in connection with that project. The role of the contamination in the vacuum system and the performance of the pumps and gauges pumping deuterium gas are studied. Sinusoidal pulses are employed as an analysis method of the discharge in the ion source and the performance of the extracting-focusing system. The parameters of the beam leaving the ion source have been determined; these are used to calculate the electrostatic lenses with the gaussian optics. Measurements concerning deuterium and tritium targets as neutron sources have been made and the processes affecting their practical service life are analyzed. (Author) 71 refs.

  4. Evaluation of effective source position for local linear accelerator and inserts

    CERN Document Server

    Mansy, M; Sharaf, M; El-Fiki, M A; Sherif, M

    1999-01-01

    All types of treatment planning systems need some input measured beam data. Such data differ in type and number depending on the model of electron beam algorithm used inside. In addition to the number of percentage depth dose (%DD) and cross beam profiles, the effective source surface distance parameter SSD sub e sub f sub f was also recommended to be measured and transferred to the planning system. Output measurements were carried out using 0.6cc cylindrical Farmer type ion chamber placed in water phantom at depth of dose maximum, in Radiat. Phys. Dep., Malmoe Hospital, Lund University, Sweden. Results were collected for all available energies combined with both applicators and inserts on a Varian Clinac 2100C. SSD sub e sub f sub f was determined from the ionization measurements using equation given by Khan et al.(1991). Comparing the results with those obtained by Roback et al. (1995) on a similar Varian Clinac 2100C, it was found that the deviation of SSD sub e sub f sub f was <=7.5% for combination of...

  5. Development of high intensity ion sources for a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Igarzabal, M.; Suarez Sandin, J.C. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina); Somacal, H.R. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Thatar Vento, V. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Huck, H.; Valda, A.A. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Repetto, M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)

    2011-12-15

    Several ion sources have been developed and an ion source test stand has been mounted for the first stage of a Tandem-Electrostatic-Quadrupole facility For Accelerator-Based Boron Neutron Capture Therapy. A first source, designed, fabricated and tested is a dual chamber, filament driven and magnetically compressed volume plasma proton ion source. A 4 mA beam has been accelerated and transported into the suppressed Faraday cup. Extensive simulations of the sources have been performed using both 2D and 3D self-consistent codes.

  6. Self-modulated laser wakefield accelerators as x-ray sources

    CERN Document Server

    Lemos, N; Tsung, F S; Shaw, J L; Marsh, K A; Albert, F; Pollock, B B; Joshi, C

    2015-01-01

    The development of a directional, small-divergence, and short-duration picosecond x-ray probe beam with an energy greater than 50 keV is desirable for high energy density science experiments. We therefore explore through particle-in-cell (PIC) computer simulations the possibility of using x-rays radiated by betatron-like motion of electrons from a self-modulated laser wakefield accelerator as a possible candidate to meet this need. Two OSIRIS 2D PIC simulations with mobile ions are presented, one with a normalized vector potential a0 = 1.5 and the other with an a0 = 3. We find that in both cases direct laser acceleration (DLA) is an important additional acceleration mechanism in addition to the longitudinal electric field of the plasma wave. Together these mechanisms produce electrons with a continuous energy spectrum with a maximum energy of 300 MeV for a0 = 3 case and 180 MeV in the a0 = 1.5 case. Forward-directed x-ray radiation with a photon energy up to 100 keV was calculated for the a0 = 3 case and up t...

  7. An Analytic Linear Accelerator Source Model for Monte Carlo dose calculations. II. Model Utilization in a GPU-based Monte Carlo Package and Automatic Source Commissioning

    CERN Document Server

    Tian, Zhen; Li, Yongbao; Shi, Feng; Jiang, Steve B; Jia, Xun

    2015-01-01

    We recently built an analytical source model for GPU-based MC dose engine. In this paper, we present a sampling strategy to efficiently utilize this source model in GPU-based dose calculation. Our source model was based on a concept of phase-space-ring (PSR). This ring structure makes it effective to account for beam rotational symmetry, but not suitable for dose calculations due to rectangular jaw settings. Hence, we first convert PSR source model to its phase-space let (PSL) representation. Then in dose calculation, different types of sub-sources were separately sampled. Source sampling and particle transport were iterated. So that the particles being sampled and transported simultaneously are of same type and close in energy to alleviate GPU thread divergence. We also present an automatic commissioning approach to adjust the model for a good representation of a clinical linear accelerator . Weighting factors were introduced to adjust relative weights of PSRs, determined by solving a quadratic minimization ...

  8. A singly charged ion source for radioactive 11C ion acceleration

    Science.gov (United States)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-01

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  9. A singly charged ion source for radioactive {sup 11}C ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)

    2016-02-15

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive {sup 11}C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  10. Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations

    Science.gov (United States)

    Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin

    2016-04-01

    Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns.

  11. Comparative Genomic Analysis of Mannheimia haemolytica from Bovine Sources.

    Directory of Open Access Journals (Sweden)

    Cassidy L Klima

    Full Text Available Bovine respiratory disease is a common health problem in beef production. The primary bacterial agent involved, Mannheimia haemolytica, is a target for antimicrobial therapy and at risk for associated antimicrobial resistance development. The role of M. haemolytica in pathogenesis is linked to serotype with serotypes 1 (S1 and 6 (S6 isolated from pneumonic lesions and serotype 2 (S2 found in the upper respiratory tract of healthy animals. Here, we sequenced the genomes of 11 strains of M. haemolytica, representing all three serotypes and performed comparative genomics analysis to identify genetic features that may contribute to pathogenesis. Possible virulence associated genes were identified within 14 distinct prophage, including a periplasmic chaperone, a lipoprotein, peptidoglycan glycosyltransferase and a stress response protein. Prophage content ranged from 2-8 per genome, but was higher in S1 and S6 strains. A type I-C CRISPR-Cas system was identified in each strain with spacer diversity and organization conserved among serotypes. The majority of spacers occur in S1 and S6 strains and originate from phage suggesting that serotypes 1 and 6 may be more resistant to phage predation. However, two spacers complementary to the host chromosome targeting a UDP-N-acetylglucosamine 2-epimerase and a glycosyl transferases group 1 gene are present in S1 and S6 strains only indicating these serotypes may employ CRISPR-Cas to regulate gene expression to avoid host immune responses or enhance adhesion during infection. Integrative conjugative elements are present in nine of the eleven genomes. Three of these harbor extensive multi-drug resistance cassettes encoding resistance against the majority of drugs used to combat infection in beef cattle, including macrolides and tetracyclines used in human medicine. The findings here identify key features that are likely contributing to serotype related pathogenesis and specific targets for vaccine design

  12. Primary gamma-rays with E gamma or = to 10(15) eV: Evidence for ultrahigh energy particle acceleration in galactic sources

    Science.gov (United States)

    Aharonian, F. A.; Mamidjanian, E. A.; Nikolsky, S. I.; Tukish, E. I.

    1985-01-01

    The recently observed primary ultra high energy gamma-rays (UHEGR) testify to the cosmic ray (CR) acceleration in the Galaxy. The available data may be interpreted as gamma-ray production due to photomeson production in CR sources.

  13. Synchrotron light sources and free-electron lasers accelerator physics, instrumentation and science applications

    CERN Document Server

    Khan, Shaukat; Schneider, Jochen; Hastings, Jerome

    2016-01-01

    Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources dri...

  14. Studies on high-quality electron beams and tunable x-ray sources produced by laser wakefield accelerators

    Science.gov (United States)

    Zeng, Ming; Luo, Ji; Chen, Min; Sheng, Zheng-Ming

    2016-11-01

    The applications of laser wake field accelerators (LWFA) rely heavily on the quality of produced high energy electron beams and X-ray sources. We present our recent progress on this issue. Firstly we propose a bichromatic laser ionization injection scheme for obtaining high quality electron beams. With the laser pulse combinations of 800 nm and 267 nm, or 2400 nm and 800 nm in wavelengths, electron beams with energy spread of 1% or lower can be produced. Secondly we propose polarization tunable X-ray sources based on LWFA. By shooting a laser pulse into a preformed plasma channel with a skew angle referring to the channel axis, the plasma channel can act as a helical undulator for elliptically polarized X-rays.

  15. Basic design of shield blocks for a spallation neutron source under the high-intensity proton accelerator project

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Katsuhiko; Maekawa, Fujio; Takada, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Under the JAERI-KEK High-Intensity Proton Accelerator Project (J-PARC), a spallation neutron source driven by a 3 GeV-1 MW proton beam is planed to be constructed as a main part of the Materials and Life Science Facility. Overall dimensions of a biological shield of the neutron source had been determined by evaluation of shielding performance by Monte Carlo calculations. This report describes results of design studies on an optimum dividing scheme in terms of cost and treatment and mechanical strength of shield blocks for the biological shield. As for mechanical strength, it was studied whether the shield blocks would be stable, fall down or move to a horizontal direction in case of an earthquake of seismic intensity of 5.5 (250 Gal) as an abnormal load. For ceiling shielding blocks being supported by both ends of the long blocks, maximum bending moment and an amount of maximum deflection of their center were evaluated. (author)

  16. Customizable electron beams from optically controlled laser plasma acceleration for γ-ray sources based on inverse Thomson scattering

    Science.gov (United States)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Shadwick, B. A.

    2016-09-01

    Laser wakefield acceleration of electrons in the blowout regime can be controlled by tailoring the laser pulse phase and the plasma target. The 100 nm-scale bandwidth and negative frequency chirp of the optical driver compensate for the nonlinear frequency red-shift imparted by wakefield excitation. This mitigates pulse self-steepening and suppresses continuous injection. The plasma channel suppresses diffraction of the pulse leading edge, further reducing self-steepening, making injection even quieter. Besides, the channel destabilizes the pulse tail confined within the accelerator cavity (the electron density "bubble"), causing oscillations in the bubble size. The resulting periodic injection generates background-free comb-like beams - sequences of synchronized, low phase-space volume bunches. Controlling the number of bunches, their energy, and energy spacing by varying the channel radius and the pulse length (as permitted by the large bandwidth) enables the design of a tunable, all-optical source of polychromatic, pulsed γ-rays using the mechanism of inverse Thomson scattering. Such source may radiate ~107 quasi-monochromatic 10 MeV-scale photons per shot into a microsteradian-scale observation angle. The photon energy is distributed among several distinct bands, each having sub-25% energy spread dictated by the mrad-scale divergence of electron beam.

  17. Union of Compact Accelerator-Driven Neutron Sources (UCANS) I & II Neutron applications laboratory for ESS-Bilbao

    Science.gov (United States)

    Terrón, S.; Magán, M.; Sordo, F.; Ghiglino, A.; Mart«ınez, F.; Bermejo, F. J.; Perlado, J. M.

    The ESS-Bilbao Accelerator Center site at Lejoa UPV/EHU campus will be provided with a proton accelerator up to 300-400 MeV. In the first construction phase, a beam extraction will be set at the end of the DTL, which will produce a 50 MeV proton beam with an average current of 2.25 mA and 1.5 ms pulses at a frequency of 20 Hz. These beam characteristics allow to configure a low intensity neutron source based on Be (p, n) reactions, which enables experimentation with cold neutrons similar to that of LENS. The total beam power will be 112 kW, so the configuration of the neutron production target will be based on a rotating disk of beryllium slabs facing the beam on one side and a cryogenic methane moderator on the other, with the target-moderator system surrounded by a beryllium reflector. In this paper, first estimates will be presented for thermomechanical conditions of the target cooling scheme, neutron source intensities, and cold neutron pulses.

  18. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    CERN Document Server

    Döpp, A; Thaury, C; Lifschitz, A; Sylla, F; Goddet, J-P; Tafzi, A; Iaquanello, G; Lefrou, T; Rousseau, P; Conejero, E; Ruiz, C; Phuoc, K Ta; Malka, V

    2016-01-01

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately linear with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance wit...

  19. AMS-02 data confront acceleration of cosmic ray secondaries in nearby sources

    DEFF Research Database (Denmark)

    Mertsch, Philipp; Sarkar, Subir

    2014-01-01

    We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons...... and positrons in nearby supernova remnants which results in an additional, harder component that becomes dominant at high energies. By fitting this to AMS-02 data we can calculate the expected concomitant rise of the boron-to-carbon ratio, as well as of the fraction of antiprotons. If these predictions...... are confirmed by the forthcoming AMS-02 data it would conclusively rule out all other proposed explanations, in particular, dark matter annihilations or decays....

  20. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30

    Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1 × 10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs.

  1. Systematic neutron guide misalignment for an accelerator-driven spallation neutron source

    Science.gov (United States)

    Zendler, C.; Bentley, P. M.

    2016-08-01

    The European Spallation Source (ESS) is a long pulse spallation neutron source that is currently under construction in Lund, Sweden. A considerable fraction of the 22 planned instruments extend as far as 75-150 m from the source. In such long beam lines, misalignment between neutron guide segments can decrease the neutron transmission significantly. In addition to a random misalignment from installation tolerances, the ground on which ESS is built can be expected to sink with time, and thus shift the neutron guide segments further away from the ideal alignment axis in a systematic way. These systematic errors are correlated to the ground structure, position of buildings and shielding installation. Since the largest deformation is expected close to the target, even short instruments might be noticeably affected. In this study, the effect of this systematic misalignment on short and long ESS beam lines is analyzed, and a possible mitigation by overillumination of subsequent guide sections investigated.

  2. Accelerating finite-rate chemical kinetics with coprocessors: comparing vectorization methods on GPUs, MICs, and CPUs

    CERN Document Server

    Stone, Christopher P

    2016-01-01

    Efficient ordinary differential equation solvers for chemical kinetics must take into account the available thread and instruction-level parallelism of the underlying hardware, especially on many-core coprocessors, as well as the numerical efficiency. A stiff Rosenbrock and nonstiff Runge-Kutta solver are implemented using the single instruction, multiple thread (SIMT) and single instruction, multiple data (SIMD) paradigms with OpenCL. The performances of these parallel implementations were measured with three chemical kinetic models across several multicore and many-core platforms. Two runtime benchmarks were conducted to clearly determine any performance advantage offered by either method: evaluating the right-hand-side source terms in parallel, and integrating a series of constant-pressure homogeneous reactors using the Rosenbrock and Runge-Kutta solvers. The right-hand-side evaluations with SIMD parallelism on the host multicore Xeon CPU and many-core Xeon Phi co-processor performed approximately three ti...

  3. Cortical porosity exhibits accelerated rate of change in peri- compared with post-menopausal women.

    Science.gov (United States)

    Burt, L A; Bhatla, J L; Hanley, D A; Boyd, S K

    2017-01-10

    The rate of change in bone density was not different between peri- and post-menopausal women. Differences in rate of change were observed in bone microarchitecture, specifically cortical porosity (Ct.Po), where peri-menopausal women increased +9% per year compared with the +6% per year for post-menopausal women.

  4. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  5. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Science.gov (United States)

    Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

    2014-02-01

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  6. Compact muon source with electron accelerator for a mobile muSR facility

    Energy Technology Data Exchange (ETDEWEB)

    Nagamine, K., E-mail: kanetada.nagamine@ucr.ed [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Muon Science Laboratory, IMSS, KEK, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Atomic Physics Laboratory, RIKEN, Wako, Saitama 351-0191 (Japan); Miyadera, H.; Jason, A. [AOT-ABS, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Seki, R. [Department of Physics, State University of California, Northridge, CA 91330-8268 (United States)

    2009-04-15

    In order to increase accessibility to the muSR spectroscopy for people in various fields of science and engineering, a conceptual design study was made to realize a compact and inexpensive muon source by using 300 MeV electron microtron and a large-acceptance muon-capture. Advanced radiography imaging with muon spin probes will become possible for bio-medical studies, inspection of re-enforced architectures, etc.

  7. Characterization of the primary source of electrons in linear accelerators in clinical use; Caracterizacion de la fuente primaria de electrones en aceleradores lineales de uso clinico

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Extremera, M.; Gonzalez Infantes, W.; Lallena rojo, A. M.; Anguiano Millan, M.

    2013-07-01

    Monte Carlo simulation is currently considered the most accurate method for calculations of doses due to electrons. The objective of the work is the characterization of the primary source of electrons from an accelerator of clinical use with Monte Carlo simulation, in order to build a model of sources involving a substantial saving of time of calculation in the simulation of treatment. (Author)

  8. Time-resolved X-ray diffraction with accelerator- and laser-plasma-based X-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Nicoul, Matthieu

    2010-09-01

    Femtosecond X-ray pulses are a powerful tool to investigate atomic motions triggered by femtosecond pump pulses. This thesis is dedicated to the production of such pulses and their use in optical pump - X-ray probe measurement. This thesis describes the laser-plasma-based sources available at the University of Duisburg-Essen. Part of it consists of the description of the design, built-up and characterization of a new ''modular'' X-ray source dedicated to optimize the X-ray flux onto the sample under investigation. The acoustic wave generation in femtosecond optically excited semiconductor (gallium arsenide) and metal (gold) was performed using the sources of the University of Duisburg-Essen. The physical answer of the material was modeled by a simple strain model for the semiconductor, pressure model for the metal, in order to gain information on the interplay of the electronic and thermal pressures rising after excitation. Whereas no reliable information could be obtain in gallium arsenide (principally due to the use of a bulk), the model for gold achieved very good agreement, providing useful information. The relaxation time of the electron to lattice energy was found to be (5.0{+-}0.3) ps, and the ratio of the Grueneisen parameters was found to be {gamma}{sub e} / {gamma}{sub i} = (0.5{+-}0.1). This thesis also describes the Sub-Picosecond Pulse Source (SPPS) which existed at the (formally) Stanford Linear Accelerator Center, an accelerator-based X-ray source, and two measurements performed with it. The first one is the detailed investigation of the phonon softening of the A{sub 1g} mode launch in bismuth upon fluence excitation. Detailed information concerning the new equilibrium position and phonon frequency were obtained over extended laser pump fluences. The second measurement concerned the study of the liquid phase dynamics in a newly formed liquid phase following ultrafast melting in indium antimonide. The formation of the liquid phase

  9. High power operation of the polyphase resonant converter modulator system for the spallation neutron source linear accelerator

    CERN Document Server

    Reass, W A; Baca, D M; Doss, J D; Gonzáles, J M; Gribble, R F; Trujillo, P G

    2003-01-01

    The spallation neutron source (SNS) is a new 1.4 MW average power beam, 1 GeV accelerator being built at Oak Ridge national laboratory. The accelerator requires 15 "long-pulse" converter-modulator stations each providing a maximum of 11 MW pulses with a 1.1 MW average power. Two variants of the converter-modulator are utilized, an 80 kV and a 140 kV design, the voltage dependant on the type of klystron load. The converter-modulator can be described as a resonant zero-voltage- switching polyphase boost inverter. As noted in Figure 1, each converter modulator derives its buss voltage from a standard 13.8 kV to 2100 Y (1.5 MVA) substation cast-core transformer. The substation also contains harmonic traps and filters to accommodate IEEE 519 and 141 regulations. Each substation is followed by an SCR preregulator to accommodate system voltage changes from no load to full load, in addition to providing a soft-start function. Energy storage and filtering is provided by special low inductance self-clearing metallized ...

  10. A proposal to protect privacy of health information while accelerating comparative effectiveness research.

    Science.gov (United States)

    Peddicord, Douglas; Waldo, Ann B; Boutin, Marc; Grande, Tina; Gutierrez, Luis

    2010-11-01

    Current laws, practices, and concerns about privacy inhibit access to health data for research. Barriers include inconsistent Institutional Review Board policies and complicated and costly procedures to obtain the consent of patients for release of their information. To realize the promise of comparative effectiveness research, it is essential to develop a new policy framework that will allow and encourage the use of health information in all forms--fully identifiable, partially anonymized, and deidentified. We propose that health data be made available for information-based research under a so-called research safe harbor. The arrangement would include strict data security controls, standards, and practices to be promulgated by the secretary of health and human services, and an annual third-party audit to ensure compliance.

  11. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee, E-mail: symolloi@uci.edu

    2015-04-11

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm{sup 3} Lithium Niobate (LiNbO{sub 3}) pyroelectric crystal maintained in a 3–12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  12. A neutron booster for spallation sources--application to accelerator driven systems and isotope production

    CERN Document Server

    Galy, J; Van Dam, H; Valko, J

    2002-01-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the mu m-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology--for example in the design neutron amplifiers for medical applications and 'fast' islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module cou...

  13. Cost Optimisation of an Instrument Suite at an Accelerator-Driven Spallation Source

    CERN Document Server

    Bentley, P M

    2016-01-01

    This artcile presents an optimisation of performance and cost of neutron scattering instrumentation at the European Spallation Source. This is done by trading detailed cost functions against beam transmission functions in a multi-dimensional, yet simple, parameter space. On the one hand, the neutron guide cost increases as a power of the desired beam divergence, and inversely with the minimum wavelength, due to the supermirror coating needed. On the other hand, the more neutrons are transported to the instrument the greater are the shielding costs to deal with the gamma rays that result from the eventual absorption of the neutrons. There are additional factors in that many of the parameters defining the neutron guide geometry are continuous variables, and the straightness of the guide increases the transmission of high energy spallation products, which affect the specifications of particularly heavy hardware, such as heavy shutters and additional shielding, beam stops etc. Over the suite of 16 instruments, a ...

  14. Non-Linear Transmission Line (NLTL) Microwave Source Lecture Notes the United States Particle Accelerator School

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Steven J. [Los Alamos National Laboratory; Carlsten, Bruce E. [Los Alamos National Laboratory

    2012-06-26

    We will quickly go through the history of the non-linear transmission lines (NLTLs). We will describe how they work, how they are modeled and how they are designed. Note that the field of high power, NLTL microwave sources is still under development, so this is just a snap shot of their current state. Topics discussed are: (1) Introduction to solitons and the KdV equation; (2) The lumped element non-linear transmission line; (3) Solution of the KdV equation; (4) Non-linear transmission lines at microwave frequencies; (5) Numerical methods for NLTL analysis; (6) Unipolar versus bipolar input; (7) High power NLTL pioneers; (8) Resistive versus reactive load; (9) Non-lineaer dielectrics; and (10) Effect of losses.

  15. Installation of an injector for SNICS source of the Tandem Accelerator; Instalacion de un Inyector para fuente SNICS del Acelerador Tandem

    Energy Technology Data Exchange (ETDEWEB)

    Villasenor S, P. [ININ, Centro Nuclear Nabor Carrillo (Mexico)]. e-mail: peguvi@nuclear.inin.mx

    2006-07-01

    Presently work, the adaptation and installation of an accelerating tube (that operates as Injector of 75 KV), to the source of ions 'Sputtering Negative Ion Cesium Source', (SNICS), of the Tandem Accelerator EN of the Nuclear Center is presented. This work allowed to increase the acceleration energy from the negative ions to the beginning of the tank. Since the beam energy that it was possible to obtain from the source, it was very below the design parameters, what limited in great measure the reach of the experiments that could be carried out, was urgent to carry out the installation of the accelerator tube mentioned to the source. The limitations in the available resources had impeded this improvement and it took time being deferred. The added value of this adaptation, it resides in that it is a specialized work and it was, finally, carried out with success by the workers of the Accelerator, adapting to the few existent resources and achieving with it a substantial improvement of the bombing currents obtained for the samples of the investigators. (Author)

  16. Study on bulk shielding for a spallation neutron source facility in the high-intensity proton accelerator project

    CERN Document Server

    Maekawa, F; Takada, H; Teshigawara, M; Watanabe, N

    2002-01-01

    Under the JAERI-KEK High-Intensity Proton Accelerator Project, a spallation neutron source driven by a 3 GeV-1 MW proton beam is planed to be constructed in a main part of the Materials and Life Science Facility. This report describes results of a study on bulk shielding performance of a biological shield for the spallation neutron source by means of a Monte Carlo calculation method, that is important in terms of radiation safety and cost reduction. A shielding configuration was determined as a reference case by considering preliminary studies and interaction with other components, then shielding thickness that was required to achieve a target dose rate of 1 mu Sv/h was derived. Effects of calculation conditions such as shielding materials and dimensions on the shielding performance was investigated by changing those parameters. By taking all the results and design margins into account, a shielding configuration that was identified as the most appropriate was finally determined as follows. An iron shield regi...

  17. RECIRCULATING ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.; GARREN,A.A.; JOHNSTONE,C.

    2000-04-07

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous.

  18. A Comparative Study of the Least Squares Method and the Genetic Algorithm in Deducing Peak Ground Acceleration Attenuation Relationships

    Directory of Open Access Journals (Sweden)

    Ching-Yun Kao

    2010-01-01

    Full Text Available In engineering applications, the development of attenuation relationships in a seismic hazard analysis is a useful way to plan for earthquake hazard mitigation. However, finding an optimal solution is difficult using traditional mathematical methods because of the nonlinearity of many relationships. Furthermore, using unweighted regression analysis in which each recording carries an equal weight is often problematic because of the non-uniform distribution of the data with respect to distance. In this study, the least squares method (LSM and a genetic algorithm (GA were employed as optimization methods for an attenuation model to compare the robustness and prediction accuracy of the two methods. Different (equal and unequal weights of each recording were used to compare the adaptability of the weighting for practical application. The unequal weights of each recording were defined as functions of the hypocentral distance or the shortest distance from a station to the fault on the _ surface. Finally, regression analysis of horizontal peak ground acceleration (PGA attenuation model in southwest Taiwan was shown.

  19. 3-dimensional shielding design for a spallation neutron source facility in the high-intensity proton accelerator project

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Masaya; Maekawa, Fujio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Evaluation of shielding performance for a 1 MW spallation neutron source facility in the Materials and Life Science Facility being constructed in the High-Intensity Proton Accelerator Project (J-PARC) is important from a viewpoint of radiation safety and optimization of arrangement of components. This report describes evaluated results for the shielding performance with modeling three-dimensionally whole structural components including gaps between them in detail. A Monte Carlo calculation method with MCNPX2.2.6 code and LA-150 library was adopted. Streaming and void effects, optimization of shield for cost reduction and optimization of arrangement of structures such as shutters were investigated. The streaming effects were investigated quantitatively by changing the detailed structure of components and gap widths built into the calculation model. Horizontal required shield thicknesses were ranged from about 6.5 m to 7.5 m as a function of neutron beam line angles. A shutter mechanism for a horizontal neutron reflectometer that was directed downward was devised, and it was shown that the shielding performance of the shutter was acceptable. An optimal biological shield configuration was finally determined according to the calculated results. (author)

  20. A comparative study of an accelerated life-test model and a toxicokinetics-based model for the analysis of Porcellio scaber survival data.

    Science.gov (United States)

    Ren, Shijin

    2004-01-01

    Statistical models have long been used for reliability analysis and risk assessment. In the present study, an accelerated life-test model was used to analyze a set of dose-time-response data obtained with the terrestrial isopod Porcellio scaber. Survival data were experimentally obtained by exposing P. scaber to diazinon (a nonpersistent insecticide) at six concentrations between 2 and 11.31 microg/g (toxicant/soil). Survival data are presented on a weekly basis. The accelerated life-test model assumed a log-normal distribution and constant variance across all diazinon concentrations. Model parameters were obtained by maximum likelihood estimation. The accelerated life-test model was compared to a toxicokinetics-based model reported in the literature. Survival predictions made by both models were compared with the observed data. Both the accelerated life-test model and the toxicokinetics-based model underestimated toxicity at a diazinon concentration of 8 microg/g. Overall, however, the accelerated life-test model outperformed the toxicokinetics-based model, with survival predictions closer to the observed data in most cases and a stronger correlation between predicted and observed survivals. However, as a statistical model, the accelerated life-test model did not reveal mechanistic information, and only statistical and distributional interpretations of its model parameters could be made.

  1. Prospective randomized trial to compare accelerated (six fractions a week radiotherapy against concurrent chemoradiotherapy (using conventional fractionation in locally advanced head and neck cancers

    Directory of Open Access Journals (Sweden)

    Manoj Gupta

    2015-01-01

    Full Text Available Background: Concurrent chemoradiation (CCRT is currently considered to be the standard of care in locally advanced head and neck cancer. The optimum radiotherapy schedule for best local control and acceptable toxicity is not yet clear. We aimed at shortening of treatment time by using accelerated radiation, thereby comparing the disease response, loco-regional tumor control and tolerability of accelerated radiation (six fractions per week against CCRT in locally advanced head and neck cancer. Materials and Methods: We conducted the prospective randomized study for a period of 2 years from June 2011 to May 2013 in 133 untreated patients of histologically confirmed squamous cell carcinoma of head and neck. Study group (66 patients received accelerated radiotherapy with 6 fractions per week (66Gy/33#/5½ weeks. Control group (67 patients received CCRT with 5 fractions per week radiation (66 Gy/33#/6½ weeks along with intravenous cisplatin 30 mg/m 2 weekly. Tumor control, survival, acute and late toxicities were assessed. Results: Median overall treatment time was 38 days and 45 days in the accelerated radiotherapy and concurrent chemoradiation arm, respectively. At a median follow up of 12 months, 41 patients (62.1% in the accelerated radiotherapy arm and 47 patients (70.1% in the CCRT arm were disease free (P = 0.402. Local disease control was comparable in both the arms. Acute toxicities were significantly higher in the CCRT arm as compared with accelerated radiotherapy arm. There was no difference in late toxicities between the two arms. Conclusion: We can achieve, same or near to the same local control, with lower toxicities with accelerated six fractions per week radiation compared with CCRT especially for Indian population.

  2. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

  3. Satellite Technology as a Source of Integration. A Comparative Analyze: Europe MERCOSUR

    Science.gov (United States)

    Castillo Argañarás, Luis F.

    2002-01-01

    Satellite technology as a source of integration. A comparative several changes in the field of international law, creating the need to build a new framework for integration and cooperation. analysis between the development of the European Integration for space activities and the first steps towards the same target by the MERCOSUR with a comparative point of view will show the positive and negative side effects of its development up to our present time.

  4. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...... that have been presented. The presented strategies are also comparatively evaluated to identify their individual advantages and disadvantages, which are subsequently summarized in a comprehensive reference table. Last, simulation and experimental results are included for validating the performances...

  5. White LED compared with other light sources: age-dependent photobiological effects and parameters for evaluation.

    Science.gov (United States)

    Rebec, Katja Malovrh; Klanjšek-Gunde, Marta; Bizjak, Grega; Kobav, Matej B

    2015-01-01

    Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters.

  6. Three methods of multi-source feedback compared: a plea for narrative comments and coworkers' perspectives

    NARCIS (Netherlands)

    K. Overeem; M.J.M.H. Lombarts; O.A. Arah; N.S. Klazinga; R.P.T.M. Grol; H.C. Wollersheim

    2010-01-01

    Doctor performance assessments based on multi-source feedback (MSF) are increasingly central in professional self-regulation. Research has shown that simple MSF is often unproductive. It has been suggested that MSF should be delivered by a facilitator and combined with a portfolio. To compare three

  7. Decommissioning and safety issues of liquid-mercury waste generated from high power spallation sources with particle accelerators

    CERN Document Server

    Chiriki, S; Odoj, R; Moormann, R; Hinssen, H. K; Bukaemskiy, A

    2009-01-01

    Large spallation sources are intended to be constructed in Europe (EURISOL nuclear physics facility and ESS-European Spallation Source). These facilities accumulate more than 20 metric tons of irradiated mercury in the target, which has to be treated as highly radioactive and chemo-toxic waste. Because solids are the only appropriate (immobile) form for this radiotoxic and toxic type of waste solidification is required for irradiated mercury. Our irradiation experimental studies on mercury waste revealed that mercury sulfide is a reasonable solid for disposal and shows larger stability in assumed accidents with water ingress in a repository compared to amalgams. For preparation of mercury sulfide a wet process is more suitable than a dry one. It is easier to perform under hot cell conditions and allows complete Hg-conversion. Embedding HgS in a cementitious matrix increases its stability.

  8. Comparison of laser and diode sources for acceleration of in vitro wound healing by low-level light therapy.

    Science.gov (United States)

    Spitler, Ryan; Berns, Michael W

    2014-03-01

    Low-level light therapy has been shown to improve in vitro wound healing. However, well-defined parameters of different light sources for this therapy are lacking. The goal of this study was (1) to determine if the wavelengths tested are effective for in vitro wound healing and (2) to compare a laser and a light-emitting diode (LED) source at similar wavelengths. We show four wavelengths, delivered by either a laser or LED array, improved in vitro wound healing in A549, U2OS, and PtK2 cells. Improved wound healing occurred through increased cell migration demonstrated through scratch wound and transwell assays. Cell proliferation was tested by the (3-(4,5-dimethylthiazol-2-yl)-5-(3-car-boxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay and was found generally not to be involved in the wound healing process. The laser and LED sources were found to be comparable when equal doses of light were applied. The biological response measured was similar in most cases. We conclude that the laser at 652 (5.57  mW/cm2, 10.02  J/cm2) and 806 nm (1.30  mW/cm2, 2.334  J/cm2) (full bandwidth 5 nm), and LED at 637 (5.57  mW/cm2, 10.02  J/cm2) and 901 nm (1.30  mW/cm2, 2.334  J/cm2) (full bandwidth 17 and 69 nm respectively) induce comparable levels of cell migration and wound closure.

  9. Demonstration of long-pulse acceleration of high power positive ion beam with JT-60 positive ion source in Japan–Korea joint experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, A., E-mail: kojima.atsushi@jaea.go.jp [Japan Atomic Energy Agency, Naka (Japan); Hanada, M. [Japan Atomic Energy Agency, Naka (Japan); Jeong, S.H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Bae, Y.S. [National Fusion Research Institute, Daejeon (Korea, Republic of); Chang, D.H.; Kim, T.S.; Lee, K.W.; Park, M.; Jung, B.K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Mogaki, K.; Komata, M.; Dairaku, M.; Kashiwagi, M.; Tobari, H.; Watanabe, K. [Japan Atomic Energy Agency, Naka (Japan)

    2016-01-15

    The long-pulse acceleration of the high-power positive ion beam has been demonstrated with the JT-60 positive ion source in the joint experiment among Japan Atomic Energy Agency (JAEA), Korea Atomic Energy Research Institute (KAERI) and National Fusion Research Institute (NFRI) under the collaboration program for the development of plasma heating and current drive systems. In this joint experiment, the increase of the heat load and the breakdowns induced by the degradation of the beam optics due to the gas accumulation was one of the critical issues for the long-pulse acceleration. As a result of development of the long-pulse operation techniques of the ion source and facilities of the neutral beam test stand in KAERI, 2 MW 100 s beam has been achieved for the first time. The achieved beam performance satisfies the JT-60SA requirement which is designed to be a 1.94 MW ion beam power from an ion source corresponding to total neutral beam power of 20 MW with 24 ion sources. Therefore, it was found that the JT-60 positive ion sources were applicable in the JT-60SA neutral beam injectors. Moreover, because this ion source is planned to be a backup ion source for KSTAR, the operational region and characteristic has been clarified to apply to the KSTAR neutral beam injector.

  10. Invited Review Article: "Hands-on" laser-driven ion acceleration: A primer for laser-driven source development and potential applications

    Science.gov (United States)

    Schreiber, J.; Bolton, P. R.; Parodi, K.

    2016-07-01

    An overview of progress and typical yields from intense laser-plasma acceleration of ions is presented. The evolution of laser-driven ion acceleration at relativistic intensities ushers prospects for improved functionality and diverse applications which can represent a varied assortment of ion beam requirements. This mandates the development of the integrated laser-driven ion accelerator system, the multiple components of which are described. Relevant high field laser-plasma science and design of controlled optimum pulsed laser irradiation on target are dominant single shot (pulse) considerations with aspects that are appropriate to the emerging petawatt era. The pulse energy scaling of maximum ion energies and typical differential spectra obtained over the past two decades provide guidance for continued advancement of laser-driven energetic ion sources and their meaningful applications.

  11. On accelerator-based neutron sources and neutron field characterization with low energy neutron spectrometer based on position sensitive 3He counter.

    Science.gov (United States)

    Murata, I; Miyamaru, H; Kato, I; Mori, Y

    2009-07-01

    The development of new neutron sources for BNCT applications, based on particle accelerators is currently underway all over the world. Though nuclear reactors were used for a long time as the only neutron source available having the requested flux levels, the accelerator-based ones have recently been investigated on the other hand due to its easy-to-use and acceptable performances. However, when using an accelerator, various secondary particles would be emitted which forms a troublesome background. Moreover, the neutrons produced have usually an energy spectrum somewhat different from the requested one and thus should be largely moderated. An additional issue to be taken into account is the patient positioning, which should be close to the neutron source, in order to take advantage of a neutron flux level high enough to limit the BNCT treatment time within 1h. This implies that, inside a relatively narrow space, neutrons should be moderated, while unnecessary secondary particles should be shielded. Considering that a background-free neutron field from an accelerator-driven neutron source dedicated to BNCT application is generally difficult to be provided, the characterization of such a neutron field will have to be clearly assessed. In the present study, a low energy neutron spectrometer has been thus designed and is now being developed to measure the accelerator-based neutron source performance. The presently proposed spectrometer is based on a (3)He proportional counter, which is 50 cm long and 5 cm in diameter, with a gas pressure of 0.5 MPa. It is quite unique that the spectrometer is set up in parallel with the incident neutron beam and a reaction depth distribution is measured by it as a position sensitive detector. Recently, a prototype detector has been developed and the signal test is now underway. In this paper, the feature of the accelerator-based neutron sources is outlined and importance of neutron field characterization is discussed. And the developed

  12. A comparative study on the analytical utility of atmospheric and low-pressure MALDI sources for the mass spectrometric characterization of peptides.

    Science.gov (United States)

    Moskovets, Eugene; Misharin, Alexander; Laiko, Viktor; Doroshenko, Vladimir

    2016-07-15

    A comparative MS study was conducted on the analytical performance of two matrix-assisted laser desorption/ionization (MALDI) sources that operated at either low pressure (∼1Torr) or at atmospheric pressure. In both cases, the MALDI sources were attached to a linear ion trap mass spectrometer equipped with a two-stage ion funnel. The obtained results indicate that the limits of detection, in the analysis of identical peptide samples, were much lower with the source that was operated slightly below the 1-Torr pressure. In the low-pressure (LP) MALDI source, ion signals were observed at a laser fluence that was considerably lower than the one determining the appearance of ion signals in the atmospheric pressure (AP) MALDI source. When the near-threshold laser fluences were used to record MALDI MS spectra at 1-Torr and 750-Torr pressures, the level of chemical noise at the 1-Torr pressure was much lower compared to that at AP. The dependency of the analyte ion signals on the accelerating field which dragged the ions from the MALDI plate to the MS analyzer are presented for the LP and AP MALDI sources. The study indicates that the laser fluence, background gas pressure, and field accelerating the ions away from a MALDI plate were the main parameters which determined the ion yield, signal-to-noise (S/N) ratios, the fragmentation of the analyte ions, and adduct formation in the LP and AP MALDI MS methods. The presented results can be helpful for a deeper insight into the mechanisms responsible for the ion formation in MALDI.

  13. COMPARATIVE PHARMACOGNOSTIC AND PHYTOCHEMICAL STUDIES OF THE RAW DRUG SOURCES OF PRASARINI USED IN AYURVEDA

    Directory of Open Access Journals (Sweden)

    A. B. Rema Shree et al.

    2012-01-01

    Full Text Available According to classical texts Paederia foetida is used as the genuine source plant of the drug Prasarini, it posses properties like astringent, aphrodisiac, laxative, bitter etc. In Ayurvedic practitioners Merremia tridentata ssp. tridentata and Merremia tridentata ssp. hastata are used as the source plant of this drug. However no conclusive pharmacognostic study of these plants has been performed yet. The present investigation deals with the comparative study of morphological, anatomical, histochemical and phytochemical characters of these three plants. Three plants show similarities and differences between them at morphological, anatomical, histochemical and phytochemical levels. Anatomically these three plants show differences in many characters. But phytochemical studies revealed that these plants show much similarity. - sitosterol was present in all the three plants but their concentrations shows differences. The parameters used in this study will help to identify the genuine and substitute source plants of the drug prasarini for the preparation of ayurvedic medicines and to ensure the quality of formulations.

  14. MEG source localization of spatially extended generators of epileptic activity: comparing entropic and hierarchical bayesian approaches.

    Directory of Open Access Journals (Sweden)

    Rasheda Arman Chowdhury

    Full Text Available Localizing the generators of epileptic activity in the brain using Electro-EncephaloGraphy (EEG or Magneto-EncephaloGraphy (MEG signals is of particular interest during the pre-surgical investigation of epilepsy. Epileptic discharges can be detectable from background brain activity, provided they are associated with spatially extended generators. Using realistic simulations of epileptic activity, this study evaluates the ability of distributed source localization methods to accurately estimate the location of the generators and their sensitivity to the spatial extent of such generators when using MEG data. Source localization methods based on two types of realistic models have been investigated: (i brain activity may be modeled using cortical parcels and (ii brain activity is assumed to be locally smooth within each parcel. A Data Driven Parcellization (DDP method was used to segment the cortical surface into non-overlapping parcels and diffusion-based spatial priors were used to model local spatial smoothness within parcels. These models were implemented within the Maximum Entropy on the Mean (MEM and the Hierarchical Bayesian (HB source localization frameworks. We proposed new methods in this context and compared them with other standard ones using Monte Carlo simulations of realistic MEG data involving sources of several spatial extents and depths. Detection accuracy of each method was quantified using Receiver Operating Characteristic (ROC analysis and localization error metrics. Our results showed that methods implemented within the MEM framework were sensitive to all spatial extents of the sources ranging from 3 cm(2 to 30 cm(2, whatever were the number and size of the parcels defining the model. To reach a similar level of accuracy within the HB framework, a model using parcels larger than the size of the sources should be considered.

  15. Food sources of dominant macrozoobenthos between native and non-native mangrove forests: A comparative study

    Science.gov (United States)

    Chen, Luzhen; Yan, Ting; Xiong, Yiyi; Zhang, Yihui; Lin, Guanghui

    2017-03-01

    The macrozoobenthos is an important link of the food web in coastal wetlands. Diet-habitat relationships may significantly depend on qualitative differences and seasonal availability of food sources. Increasing interest has been shown in food web structure altered by non-native plants. In particular, however, a non-native mangrove species from Bangladesh, Sonneratia apetala, has been widely planted in China, but little is known about its possible impact on food sources of macrozoobenthos living in these non-native mangrove forests. Therefore, in this study, we used fatty acid analysis to compare the food sources of one littorinid snail and two grapsid crab species between two native mangrove forests and one non-native S. apetala plantation in the Zhanjiang Mangrove National Nature Reserve of China. We found that the sediment of all three forests had high diatom and bacteria signals, but low mangrove leaf signals, while the opposite patterns were detected in the three macrozoobenthos. Specifically, the gastropod Littoraria melanostoma relied mainly on mangrove leaves and brown algae as food sources, with significant differences among the three mangrove forests, and showed significant seasonal variation in its diet. The grapsidae species (Perisesarma bidens and Parasesarma plicatum) mainly grazed on mangrove litter, brown and green algae, and occasionally consumed diatoms and bacteria, also showing significant seasonal variation in their diet. Overall, Principle Components Analysis (PCA) of the fatty acid profiles showed a significant overlapping in food sources among the macrozoobenthos living in the non-native and native mangrove forests, but significant seasonal variations in their food sources. This suggests that the planting of non-native S. apetala near original mangrove forests has had little effect on the feeding behavior of macrozoobenthos some 10 years after planting.

  16. Comparative study of ion acceleration by linearly polarized laser pulses from optimized targets of solid and near-critical density

    Science.gov (United States)

    Bychenkov, V. Yu; Brantov, A. V.; Govras, E. A.

    2016-03-01

    The results of a 3D optimization study of ion acceleration from ultrathin solid density foils (Brantov et al 2015 Phys. Rev. Spec. Top. Accel. Beams 18 021301) are complemented with an improved analytic model of the directed Coulomb explosion. Similarly to optimizing overdense targets, we also optimize low-density targets to obtain maximum ion energy, motivated by progress in producing a new generation of low-density slab targets whose density can be very homogeneous and as low as the relativistic critical density. Using 3D simulations, we show that for the same laser pulse, the ion energy can be significantly increased with low-density targets. A new acceleration mechanism is responsible for such an increase. This mechanism is described qualitatively, and it explains an advantage of low-density targets for high-energy ion production by lasers.

  17. Comparative dosimetry of GammaMed Plus high-dose rate 192 Ir brachytherapy source

    Directory of Open Access Journals (Sweden)

    Patel N

    2010-01-01

    Full Text Available The comparative dosimetry of GammaMed (GM Plus high-dose rate brachytherapy source was performed by an experiment using 0.1-cc thimble ionization chamber and simulation-based study using EGSnrc code. In-water dose measurements were performed with 0.1-cc chamber to derive the radial dose function (r = 0.8 to 20.0 cm and anisotropy function (r = 5.0 cm with polar angle from 10° to 170°. The nonuniformity correction factor for 0.1-cc chamber was applied for in-water measurements at shorter distances from the source. The EGSnrc code was used to derive the dose rate constant (L, radial dose function g L (r and anisotropy function F(r, q of GM Plus source. The dosimetric data derived using EGSnrc code in our study were in very good agreement relative to published data for GM Plus source. The radial dose function up to 12 cm derived from measured dose using 0.1-cc chamber was in agreement within ±3% of data derived by the simulation study.

  18. Comparing Evaporative Sources of Terrestrial Precipitation and Their Extremes in MERRA Using Relative Entropy

    Science.gov (United States)

    Dirmeyer, Paul A.; Wei, Jiangfeng; Bosilovich, Michael G.; Mocko, David M.

    2014-01-01

    A quasi-isentropic back trajectory scheme is applied to output from the Modern Era Retrospective-analysis for Research and Applications and a land-only replay with corrected precipitation to estimate surface evaporative sources of moisture supplying precipitation over every ice-free land location for the period 1979-2005. The evaporative source patterns for any location and time period are effectively two dimensional probability distributions. As such, the evaporative sources for extreme situations like droughts or wet intervals can be compared to the corresponding climatological distributions using the method of relative entropy. Significant differences are found to be common and widespread for droughts, but not wet periods, when monthly data are examined. At pentad temporal resolution, which is more able to isolate floods and situations of atmospheric rivers, values of relative entropy over North America are typically 50-400 larger than at monthly time scales. Significant differences suggest that moisture transport may be the key to precipitation extremes. Where evaporative sources do not change significantly, it implies other local causes may underlie the extreme events.

  19. The HIV care cascade: a systematic review of data sources, methodology and comparability

    Directory of Open Access Journals (Sweden)

    Nicholas A Medland

    2015-11-01

    Full Text Available Introduction: The cascade of HIV diagnosis, care and treatment (HIV care cascade is increasingly used to direct and evaluate interventions to increase population antiretroviral therapy (ART coverage, a key component of treatment as prevention. The ability to compare cascades over time, sub-population, jurisdiction or country is important. However, differences in data sources and methodology used to construct the HIV care cascade might limit its comparability and ultimately its utility. Our aim was to review systematically the different methods used to estimate and report the HIV care cascade and their comparability. Methods: A search of published and unpublished literature through March 2015 was conducted. Cascades that reported the continuum of care from diagnosis to virological suppression in a demographically definable population were included. Data sources and methods of measurement or estimation were extracted. We defined the most comparable cascade elements as those that directly measured diagnosis or care from a population-based data set. Results and discussions: Thirteen reports were included after screening 1631 records. The undiagnosed HIV-infected population was reported in seven cascades, each of which used different data sets and methods and could not be considered to be comparable. All 13 used mandatory HIV diagnosis notification systems to measure the diagnosed population. Population-based data sets, derived from clinical data or mandatory reporting of CD4 cell counts and viral load tests from all individuals, were used in 6 of 12 cascades reporting linkage, 6 of 13 reporting retention, 3 of 11 reporting ART and 6 of 13 cascades reporting virological suppression. Cascades with access to population-based data sets were able to directly measure cascade elements and are therefore comparable over time, place and sub-population. Other data sources and methods are less comparable. Conclusions: To ensure comparability, countries wishing

  20. Variable Faint Optical Sources Discovered by Comparing POSS and SDSS Catalogs

    CERN Document Server

    Sesar, B; Ivezic, Z; Lupton, R H; Munn, J A; Finkbeiner, D; Steinhardt, W; Siverd, R J; Johnston, D E; Knapp, G R; Gunn, J E; Rockosi, C M; Schlegel, D J; Vanden Berk, Daniel E; Hall, P; Schneider, D P; Brunner, R J

    2004-01-01

    We present a study of variable faint optical sources discovered by comparing the Sloan Digital Sky Survey (SDSS) and the Palomar Observatory Sky Survey (POSS) catalogs. We use SDSS measurements to photometrically recalibrate several publicly available POSS catalogs; a piecewise recalibration in 100 arcmin2 patches generally results in an improvement of photometric accuracy (rms) by nearly a factor of two, compared to the original data. The POSS I magnitudes can be improved to ~0.15 mag accuracy, and POSS II magnitudes to \\~0.10 mag accuracy. We use the recalibrated catalogs for the ~2,000 deg2 of sky in the SDSS Data Release 1 to construct a catalog of ~60,000 sources variable on time scales 10-50 years. A series of statistical tests based on the morphology of SDSS color-color diagrams, as well as visual comparison of images and comparison with repeated SDSS observations, demonstrate the robustness of the selection methods. We quantify the distribution of variable sources in the SDSS color-color diagrams, and...

  1. Far field acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

  2. Demonstration of a high-intensity neutron source based on a liquid-lithium target for Accelerator based Boron Neutron Capture Therapy.

    Science.gov (United States)

    Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Weissman, L; Berkovits, D; Eliyahu, I; Feinberg, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Tessler, M

    2015-12-01

    A free surface liquid-lithium jet target is operating routinely at Soreq Applied Research Accelerator Facility (SARAF), bombarded with a ~1.91 MeV, ~1.2 mA continuous-wave narrow proton beam. The experiments demonstrate the liquid lithium target (LiLiT) capability to constitute an intense source of epithermal neutrons, for Accelerator based Boron Neutron Capture Therapy (BNCT). The target dissipates extremely high ion beam power densities (>3 kW/cm(2), >0.5 MW/cm(3)) for long periods of time, while maintaining stable conditions and localized residual activity. LiLiT generates ~3×10(10) n/s, which is more than one order of magnitude larger than conventional (7)Li(p,n)-based near threshold neutron sources. A shield and moderator assembly for BNCT, with LiLiT irradiated with protons at 1.91 MeV, was designed based on Monte Carlo (MCNP) simulations of BNCT-doses produced in a phantom. According to these simulations it was found that a ~15 mA near threshold proton current will apply the therapeutic doses in ~1h treatment duration. According to our present results, such high current beams can be dissipated in a liquid-lithium target, hence the target design is readily applicable for accelerator-based BNCT.

  3. Comparative Study on Innovation Incentives for Commercial Open Source Software under Different Licenses

    Directory of Open Access Journals (Sweden)

    Mingqing Xing

    2013-02-01

    Full Text Available This study compares technological innovation incentives for commercial open source software under two typical licenses (the GNU General Public License and the Berkeley Software Distribution License, i.e., GPL and BSD. In the case of private optimum, the incentive towards software features (resp. usability innovation is always higher (resp. lower under BSD than under GPL. Contrast to the private optimum, the social planner expects more investment in software feature under both BSD and GPL, but less (resp. equivalent investment in software usability under BSD (resp. GPL.

  4. Accelerator Technology Division

    Science.gov (United States)

    1992-04-01

    In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  5. HELIOS: An Open-Source, GPU-Accelerated Radiative Transfer Code For Self-Consistent Exoplanetary Atmospheres

    CERN Document Server

    Malik, Matej; Mendonça, João M; Grimm, Simon L; Lavie, Baptiste; Kitzmann, Daniel; Tsai, Shang-Min; Burrows, Adam; Kreidberg, Laura; Bedell, Megan; Bean, Jacob L; Stevenson, Kevin B; Heng, Kevin

    2016-01-01

    We present the open-source radiative transfer code named HELIOS, which is constructed for studying exoplanetary atmospheres. In its initial version, the model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with non-isotropic scattering. The opacities are computed with the opacity calculator HELIOS-K and converted to k-distribution tables by weighing the molecular abundances with analytical chemistry formulae. We validate HELIOS by comparing a model of GJ 1214b to that computed using COOLTLUSTY and from the work of Miller-Ricci & Fortney, and by performing several tests, where we find: model atmospheres with single-temperature layers struggle to converge to radiative equilibrium; k-distribution tables constructed with 1-10% in the synthetic spectra; and a diffusivity factor of 2 approximates well the exact radiative transfer solution in the limit of pure absorption. We construct "null-hypothesis" models (chemic...

  6. Comparing the standards of one metabolic equivalent of task in accurately estimating physical activity energy expenditure based on acceleration.

    Science.gov (United States)

    Kim, Dohyun; Lee, Jongshill; Park, Hoon Ki; Jang, Dong Pyo; Song, Soohwa; Cho, Baek Hwan; Jung, Yoo-Suk; Park, Rae-Woong; Joo, Nam-Seok; Kim, In Young

    2016-08-24

    The purpose of the study is to analyse how the standard of resting metabolic rate (RMR) affects estimation of the metabolic equivalent of task (MET) using an accelerometer. In order to investigate the effect on estimation according to intensity of activity, comparisons were conducted between the 3.5 ml O2 · kg(-1) · min(-1) and individually measured resting VO2 as the standard of 1 MET. MET was estimated by linear regression equations that were derived through five-fold cross-validation using 2 types of MET values and accelerations; the accuracy of estimation was analysed through cross-validation, Bland and Altman plot, and one-way ANOVA test. There were no significant differences in the RMS error after cross-validation. However, the individual RMR-based estimations had as many as 0.5 METs of mean difference in modified Bland and Altman plots than RMR of 3.5 ml O2 · kg(-1) · min(-1). Finally, the results of an ANOVA test indicated that the individual RMR-based estimations had less significant differences between the reference and estimated values at each intensity of activity. In conclusion, the RMR standard is a factor that affects accurate estimation of METs by acceleration; therefore, RMR requires individual specification when it is used for estimation of METs using an accelerometer.

  7. Comparing the health impacts of different sources of energy. Keynote address

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, L.D.

    1981-01-01

    Assessing health impacts of different energy sources requires synthesis of research results from any different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with substantially different end uses, must be put on a common footing. Historically institutional constraints have inhibited agencies from making incisive comparisons necessary for formulating energy policy; this has exacerbated public controversy over appropriate energy sources. Risk assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Uncertainty over the mechanism and size of air pollution health damage is addressed through a probabilistic health-damage function, using sulfate-particle exposure as an indicator. This facilitates intercomparison through analysis of each step in the whole fuel cycle between a typical coal and nuclear powerplant. Occupational health impacts, a significant fraction of overall damage, are illustrated by accident trends in coal mining. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing device as part of an expanded fuel cycle, via input/output methods. Throughout the analysis, uncertainties must be made explicit in the results, including uncertainty of data and uncertainty in choice of appropriate models and methods. No single method of comparative risk assessment is fully satisfactory; each has its limitations. One needs to compare several methods if decision-making is to be realistic.

  8. Beam dynamics study of a 30 MeV electron linear accelerator to drive a neutron source

    Science.gov (United States)

    Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik

    2014-02-01

    An experimental neutron facility based on 32 MeV/18.47 kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E = 30 MeV, P = 18 kW, dE/E E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2π/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32 MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5 × 1011 n/cm2/s/mA. Future development will be the real design of a 30 MeV electron linac based on S band traveling wave.

  9. Beam dynamics study of a 30 MeV electron linear accelerator to drive a neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

    2014-02-14

    An experimental neutron facility based on 32 MeV/18.47 kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E = 30 MeV, P = 18 kW, dE/E < 12.47% for 99% particles). The whole linac comprises mainly E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2π/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32 MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5 × 10{sup 11} n/cm{sup 2}/s/mA. Future development will be the real design of a 30 MeV electron linac based on S band traveling wave.

  10. Zazen meditation and no-task resting EEG compared with LORETA intracortical source localization.

    Science.gov (United States)

    Faber, Pascal L; Lehmann, Dietrich; Gianotti, Lorena R R; Milz, Patricia; Pascual-Marqui, Roberto D; Held, Marlene; Kochi, Kieko

    2015-02-01

    Meditation is a self-induced and willfully initiated practice that alters the state of consciousness. The meditation practice of Zazen, like many other meditation practices, aims at disregarding intrusive thoughts while controlling body posture. It is an open monitoring meditation characterized by detached moment-to-moment awareness and reduced conceptual thinking and self-reference. Which brain areas differ in electric activity during Zazen compared to task-free resting? Since scalp electroencephalography (EEG) waveforms are reference-dependent, conclusions about the localization of active brain areas are ambiguous. Computing intracerebral source models from the scalp EEG data solves this problem. In the present study, we applied source modeling using low resolution brain electromagnetic tomography (LORETA) to 58-channel scalp EEG data recorded from 15 experienced Zen meditators during Zazen and no-task resting. Zazen compared to no-task resting showed increased alpha-1 and alpha-2 frequency activity in an exclusively right-lateralized cluster extending from prefrontal areas including the insula to parts of the somatosensory and motor cortices and temporal areas. Zazen also showed decreased alpha and beta-2 activity in the left angular gyrus and decreased beta-1 and beta-2 activity in a large bilateral posterior cluster comprising the visual cortex, the posterior cingulate cortex and the parietal cortex. The results include parts of the default mode network and suggest enhanced automatic memory and emotion processing, reduced conceptual thinking and self-reference on a less judgmental, i.e., more detached moment-to-moment basis during Zazen compared to no-task resting.

  11. Einstein's $R^{\\hat{0} \\hat{0}}$ equation for non-relativistic sources derived from Einstein's inertial motion and the Newtonian law for relative acceleration

    CERN Document Server

    ,

    2016-01-01

    With Einstein's inertial motion (free-falling and non-rotating relative to gyroscopes), geodesics for non-relativistic particles can intersect repeatedly, allowing one to compute the space-time curvature $R^{\\hat{0} \\hat{0}}$ exactly. Einstein's $R^{\\hat{0} \\hat{0}}$ for strong gravitational fields and for relativistic source-matter is identical with the Newtonian expression for the relative radial acceleration of neighboring free-falling test-particles, spherically averaged.--- Einstein's field equations follow from Newtonian experiments, local Lorentz-covariance, and energy-momentum conservation combined with the Bianchi identity.

  12. Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Goffeney, N.; Henestroza, E. [Lawrence Berkeley Lab., CA (United States)] [and others

    1995-02-22

    A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported.

  13. HELIOS: An Open-source, GPU-accelerated Radiative Transfer Code for Self-consistent Exoplanetary Atmospheres

    Science.gov (United States)

    Malik, Matej; Grosheintz, Luc; Mendonça, João M.; Grimm, Simon L.; Lavie, Baptiste; Kitzmann, Daniel; Tsai, Shang-Min; Burrows, Adam; Kreidberg, Laura; Bedell, Megan; Bean, Jacob L.; Stevenson, Kevin B.; Heng, Kevin

    2017-02-01

    We present the open-source radiative transfer code named HELIOS, which is constructed for studying exoplanetary atmospheres. In its initial version, the model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with nonisotropic scattering. A small set of the main infrared absorbers is employed, computed with the opacity calculator HELIOS-K and combined using a correlated-k approximation. The molecular abundances originate from validated analytical formulae for equilibrium chemistry. We compare HELIOS with the work of Miller-Ricci & Fortney using a model of GJ 1214b, and perform several tests, where we find: model atmospheres with single-temperature layers struggle to converge to radiative equilibrium; k-distribution tables constructed with ≳ 0.01 cm‑1 resolution in the opacity function (≲ {10}3 points per wavenumber bin) may result in errors ≳ 1%–10% in the synthetic spectra; and a diffusivity factor of 2 approximates well the exact radiative transfer solution in the limit of pure absorption. We construct “null-hypothesis” models (chemical equilibrium, radiative equilibrium, and solar elemental abundances) for six hot Jupiters. We find that the dayside emission spectra of HD 189733b and WASP-43b are consistent with the null hypothesis, while the latter consistently underpredicts the observed fluxes of WASP-8b, WASP-12b, WASP-14b, and WASP-33b. We demonstrate that our results are somewhat insensitive to the choice of stellar models (blackbody, Kurucz, or PHOENIX) and metallicity, but are strongly affected by higher carbon-to-oxygen ratios. The code is publicly available as part of the Exoclimes Simulation Platform (exoclime.net).

  14. Operational analysis and comparative evaluation of embedded Z-Source inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Gao, F.; Loh, P.C.;

    2008-01-01

    This paper presents various embedded Z-source (EZ-source) inverters broadly classified as shunt or parallel embedded Z-source inverter. Being different from the traditional Z-source inverter, EZ-source inverters are constructed by inserting dc sources into the X-shaped impedance network so...... that the dc input current flows smoothly during the whole switching period unlike the traditional Z-source inverter. This feature is interesting when PV panels or fuel cells are assumed to power load since the continuous input current flow reduces control complexity of dc source and system design burden....... Carefully analyzing the operational principles for shoot-through and nonshoot-through switching, it is first revealed that the shunt-embedded Z-source inverters with capacitors partially or fully replaced by dc sources can appropriately perform buck-boost operation with rear-end current source inverter (CSI...

  15. Accelerated large-scale multiple sequence alignment

    Directory of Open Access Journals (Sweden)

    Lloyd Scott

    2011-12-01

    Full Text Available Abstract Background Multiple sequence alignment (MSA is a fundamental analysis method used in bioinformatics and many comparative genomic applications. Prior MSA acceleration attempts with reconfigurable computing have only addressed the first stage of progressive alignment and consequently exhibit performance limitations according to Amdahl's Law. This work is the first known to accelerate the third stage of progressive alignment on reconfigurable hardware. Results We reduce subgroups of aligned sequences into discrete profiles before they are pairwise aligned on the accelerator. Using an FPGA accelerator, an overall speedup of up to 150 has been demonstrated on a large data set when compared to a 2.4 GHz Core2 processor. Conclusions Our parallel algorithm and architecture accelerates large-scale MSA with reconfigurable computing and allows researchers to solve the larger problems that confront biologists today. Program source is available from http://dna.cs.byu.edu/msa/.

  16. High-Intensity Proton Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  17. Endogenous formaldehyde turnover in humans compared with exogenous contribution from food sources

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-02-01

    Full Text Available The FEEDAP Panel received a request to deliver a scientific opinion on the safety and efficacy of formaldehyde used in feed for all animal species based on dossiers submitted by applicants. In parallel, the ANS Panel evaluated the safety of formaldehyde formed from endogenous production and from dietary sources of methanol, including aspartame. In order to support both evaluations, assistance was requested to the SCER unit to evaluate the oral internal dose of formaldehyde in humans from endogenous production, food-derived from target animals exposed to formaldehyde-treated feed and formaldehyde generated from dietary sources of methanol, including from food additives such as aspartame. Endogenous turnover of formaldehyde was estimated to be approximately 0.61-0.91 mg/kg bw per minute and 878-1310 mg/kg bw per day assuming a half life of 1 1.5 min. Compared with formaldehyde turnover and the background levels of formaldehyde from food sources (1.7-1.4 mg/kg b. w per day for a 60-70 kg person, including from dietary methanol, the relative contribution of exogenous formaldehyde from consumption of animal products (milk, meat from target animals exposed to formaldehyde-treated feed was negligible (<0.001 %. Oral exposure to formaldehyde from aspartame involves metabolism to methanol and further oxidation to formaldehyde. At the current ADI of 40 mg/kg bw per day for aspartame, formaldehyde would be approximately 4 mg/kg bw per day and represent only 0.3-0.4 % of the endogenous turnover of formaldehyde.

  18. Comparative study of chromosome aberrations yield induced by cesium and cobalt sources in human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Mariana E.; Mendonca, Julyanne C.G.; Souza, Priscilla L.G.; Santos, Neide; Lima, Fabiana F., E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Analysis of chromosome aberrations is the most developed method for biological monitoring. From the frequency of these aberrations it is possible to evaluate the absorbed dose. This technique can ve used to support physical dosimetry or when it is impossible to achieve it. The aim of this research is to compare frequencies of unstable chromosome alterations induce by a gamma beam with two different sources: {sup 137}Cs and {sup 60}Co. The first sample was exposed to {sup 137}Cs resulting in absorbed dose 0.45 Gy, 0.726 Gy and 1.375 Gy and the second one was exposed to {sup 60}Co (Gammacel 220) resulting in absorbed doses 0.51 Gy, 0.77 Gy and 1.5 Gy. Mitotic metaphase cells were obtained by Iymphocyte culture for chromosomal analysis and slides were stained with Giemsa 5%. Among the unstable chromosome aberrations were analyzed dicentrics, ring centric and acentric. These results showed a statistical similarity in the frequencies of dicentrics and acentric per cell, except the frequencies of acentric when irradiated with the lowest dose. However, the dose rate of {sup 137}Cs source is lower than the dose rate of {sup 60}Co source (30.78 mGy/h and 3.277 Gy/h, respectively). This would be a factor to be considered in the analysis of unstable chromosome aberrations once prolonged irradiation time reduces the number of produced aberrations by low LET radiation doses, however further studies with other absorbed doses are necessary in the search for more reliable results for that statement. (author)

  19. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    Energy Technology Data Exchange (ETDEWEB)

    Vivanco, R., E-mail: raul.vivanco.sanchez@gmail.com [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Ghiglino, A.; Vicente, J.P. de; Sordo, F.; Terrón, S.; Magán, M. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Perlado, J.M. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Bermejo, F.J. [Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain)

    2014-12-11

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final k{sub eff} value of around 0.9 after the 50 days cycle.

  20. Comparative phytochemical investigation of the sources of ayurvedic drug Patha: A chromatographic fingerprinting analysis

    Directory of Open Access Journals (Sweden)

    Hullatti K

    2010-01-01

    Full Text Available Standardization of herbal drugs based on their chemical and biological activity profile is an important prerequisite for acquiring the herbal market. The main problem encountered in standardization of Ayurvedic drugs is proper identification of the source plant. The present study was aimed to establish identification characters, quality control parameters, chemical and biological parameters for roots of three plants Cissampelos pareira, Cyclea peltata and Stephania japonica (Fam. Menispermaceae which are being used as source of Patha, in the market. All the three plant were subjected for evaluation of quality control parameters as per WHO guidelines and root extracts and total alkaloidal fractions were subjected for HPTLC and HPLC fingerprinting analysis using a marker compound Bebeerine isolated from roots of Cissampelos pareira. The parameters studied clearly indicated the significant differences among the three plant materials. The roots of Cissampelos pareira can be distinguished from other two plants by presence of high concentration of alkaloids especially the presence of high concentration of pharmacologically active alkaloid bebeerine, which was found to be present in very low concentration in Stephania japonica and absent in roots of Cyclea peltata. The roots of Cyclea peltata were found to contain high concentration of saponins and comparatively in low concentration in Cissampelos pareira where as it was found to be absent in roots of Stephania japonica.

  1. Comparing predictive models of glioblastoma multiforme built using multi-institutional and local data sources.

    Science.gov (United States)

    Singleton, Kyle W; Hsu, William; Bui, Alex A T

    2012-01-01

    The growing amount of electronic data collected from patient care and clinical trials is motivating the creation of national repositories where multiple institutions share data about their patient cohorts. Such efforts aim to provide sufficient sample sizes for data mining and predictive modeling, ultimately improving treatment recommendations and patient outcome prediction. While these repositories offer the potential to improve our understanding of a disease, potential issues need to be addressed to ensure that multi-site data and resultant predictive models are useful to non-contributing institutions. In this paper we examine the challenges of utilizing National Cancer Institute datasets for modeling glioblastoma multiforme. We created several types of prognostic models and compared their results against models generated using data solely from our institution. While overall model performance between the data sources was similar, different variables were selected during model generation, suggesting that mapping data resources between models is not a straightforward issue.

  2. Comparative study of the sources of exergy destruction on four North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian

    2013-01-01

    In this paper, the oil and gas processing systems on four North Sea offshore platforms are reported and discussed. Sources of exergy destruction are identified and the findings for the different platforms are compared. Different platforms have different working conditions, such as reservoir...... the lifetime of an oil field, and to maintain the efficiency of an offshore platform is therefore challenging. In practice, variations in the process feed result in the use of control strategies such as anti-surge recycling, which cause additional power consumption and exergy destruction. For all four...... platforms, more than 27% of the total exergy destruction takes place in the gas treatment section while at least 16% occurs in the production manifold systems. The exact potential for energy savings and for enhancing system performances differ across offshore platforms. However, the results indicate...

  3. Comparative analysis of colorimetric staining in skin using open-source software

    Science.gov (United States)

    Billings, Paul C; Sanzari, Jenine K.; Kennedy, Ann R.; Cengel, Keith A.; Seykora, John T.

    2015-01-01

    Colorimetric staining techniques such as immunohistochemistry (IHC), immunofluorescence (IF) and histochemistry (HC) provide useful information regarding the localization and relative amount of a molecule/substance in skin. We have developed a novel, straightforward method to assess colorimetric staining by combining features from two open-source software programs. As a proof of principle, we demonstrate the utility of this approach by analyzing changes in skin melanin deposition during the radiation-induced tanning response of Yucatan mini-pigs. This method includes a visualization step to validate the accuracy of color selection before quantitation to ensure accuracy. The data show that this method is robust and will provide a means to obtain accurate comparative analyses of staining in IHC/IF/HC samples. PMID:25393687

  4. Comparative analysis of colorimetric staining in skin using open-source software.

    Science.gov (United States)

    Billings, Paul C; Sanzari, Jenine K; Kennedy, Ann R; Cengel, Keith A; Seykora, John T

    2015-02-01

    Colorimetric staining techniques such as immunohistochemistry (IHC), immunofluorescence (IF) and histochemistry (HC) provide useful information regarding the localization and relative amount of a molecule/substance in skin. We have developed a novel, straightforward method to assess colorimetric staining by combining features from two open-source software programs. As a proof of principle, we demonstrate the utility of this approach by analysing changes in skin melanin deposition during the radiation-induced tanning response of Yucatan mini-pigs. This method includes a visualization step to validate the accuracy of colour selection before quantitation to ensure accuracy. The data show that this method is robust and will provide a means to obtain accurate comparative analyses of staining in IHC/IF/HC samples.

  5. Linear accelerator for radioisotope production

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-02-01

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

  6. Combined generating-accelerating buncher for compact linear accelerators

    Science.gov (United States)

    Savin, E. A.; Matsievskiy, S. V.; Sobenin, N. P.; Sokolov, I. D.; Zavadtsev, A. A.

    2016-09-01

    Described in the previous article [1] method of the power extraction from the modulated electron beam has been applied to the compact standing wave electron linear accelerator feeding system, which doesnt require any connection waveguides between the power source and the accelerator itself [2]. Generating and accelerating bunches meet in the hybrid accelerating cell operating at TM020 mode, thus the accelerating module is placed on the axis of the generating module, which consists from the pulsed high voltage electron sources and electrons dumps. This combination makes the accelerator very compact in size which is very valuable for the modern applications such as portable inspection sources. Simulations and geometry cold tests are presented.

  7. Finite element analysis and frequency shift studies for the bridge coupler of the coupled cavity linear accelerator of the spallation neutron source.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. (Zukun)

    2001-01-01

    The Spallation Neutron Source (SNS) is an accelerator-based neutron scattering research facility. The linear accelerator (linac) is the principal accelerating structure and divided into a room-temperature linac and a superconducting linac. The normal conducting linac system that consists of a Drift Tube Linac (DTL) and a Coupled Cavity Linac (CCL) is to be built by Los Alamos National Laboratory. The CCL structure is 55.36-meters long. It accelerates H- beam from 86.8 Mev to 185.6 Mev at operating frequency of 805 MHz. This side coupled cavity structure has 8 cells per segment, 12 segments and 11 bridge couplers per module, and 4 modules total. A 5-MW klystron powers each module. The number 3 and number 9 bridge coupler of each module are connected to the 5-MW RF power supply. The bridge coupler with length of 2.5 {beta}{gamma} is a three-cell structure and located between the segments and allows power flow through the module. The center cell of each bridge coupler is excited during normal operation. To obtain a uniform electromagnetic filed and meet the resonant frequency shift, the RF induced heat must be removed. Thus, the thermal deformation and frequency shift studies are performed via numerical simulations in order to have an appropriate cooling design and predict the frequency shift under operation. The center cell of the bridge coupler also contains a large 4-inch slug tuner and a tuning post that used to provide bulk frequency adjustment and field intensity adjustment, so that produce the proper total field distribution in the module assembly.

  8. Design of a high-yield H{sub 2}{sup +} ion source for commissioning of the IFMIF accelerator using a one-dimensional plasma model

    Energy Technology Data Exchange (ETDEWEB)

    King, R.F. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)], E-mail: robert.king@jet.uk; Surrey, E. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Holmes, A.J.T. [Marcham Scientific Ltd., Sarum House, 10 Salisbury Road, Hungerford, Berkshire RG17 0LH (United Kingdom)

    2008-12-15

    It is desirable to minimise the activation of components during the commissioning phase of the IFMIF accelerator and this can be achieved by using a beam of H{sub 2}{sup +} ions in place of the D{sup +} beam. Having the same charge to mass ratio ensures that the commissioning can be conducted at full power, provided a sufficiently intense source of H{sub 2}{sup +} ions is available. Ideally, the H{sub 2}{sup +} beam current should equal that of the IFMIF D{sup +} beam current, 140 mA, with a species fraction of greater than 85% H{sub 2}{sup +}. This paper describes a study to determine the physical processes and ion source design criteria that optimise H{sub 2}{sup +} yield. Examination of the processes contributing to the yield of H{sub 2}{sup +} ions in a plasma indicate that extraction should occur as close to the ionisation volume as possible. The most suitable ion source is currently the volume discharge. A one-dimensional plasma model of this source has been developed and is validated against experimental measurements. The model has been used to identify those design criteria that most strongly affect the H{sub 2}{sup +} yield and has been used to optimise the design of the volume arc source for the production of H{sub 2}{sup +} ions.

  9. A Comparative Analysis of Reynolds-Averaged Navier-Stokes Model Predictions for Rayleigh-Taylor Instability and Mixing with Constant and Complex Accelerations

    Science.gov (United States)

    Schilling, Oleg

    2016-11-01

    Two-, three- and four-equation, single-velocity, multicomponent Reynolds-averaged Navier-Stokes (RANS) models, based on the turbulent kinetic energy dissipation rate or lengthscale, are used to simulate At = 0 . 5 Rayleigh-Taylor turbulent mixing with constant and complex accelerations. The constant acceleration case is inspired by the Cabot and Cook (2006) DNS, and the complex acceleration cases are inspired by the unstable/stable and unstable/neutral cases simulated using DNS (Livescu, Wei & Petersen 2011) and the unstable/stable/unstable case simulated using ILES (Ramaprabhu, Karkhanis & Lawrie 2013). The four-equation models couple equations for the mass flux a and negative density-specific volume correlation b to the K- ɛ or K- L equations, while the three-equation models use a two-fluid algebraic closure for b. The lengthscale-based models are also applied with no buoyancy production in the L equation to explore the consequences of neglecting this term. Predicted mixing widths, turbulence statistics, fields, and turbulent transport equation budgets are compared among these models to identify similarities and differences in the turbulence production, dissipation and diffusion physics represented by the closures used in these models. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  10. Coupling of Laser-Generated Electrons with Conventional Accelerator Devices

    CERN Document Server

    Antici, P; Benedetti, C; Chiadroni, E; Ferrario, M; Lancia, L; Migliorati, M; Mostacci, A; Palumbo, L; Rossi, A R; Serafini, L

    2011-01-01

    Laser-based electron acceleration is attracting strong interest from the conventional accelerator community due to its outstanding characteristics in terms of high initial energy, low emittance and high beam current. Unfortunately, such beams are currently not comparable to those of conventional accelerators, limiting their use for the manifold applications that a traditional accelerator can have. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both, a versatile electron source and a controllable beam. In this paper we show that some parameters commonly used by the particle accelerator community must be reconsidered when dealing with laser-plasma beams. Starting from the parameters of laser-generated electrons which can be obtained nowadays by conventional multi hundred TW laser systems, we compare different conventional magnetic lattices able to capture and transport those GeV...

  11. The Monte Carlo Simulation of Tsinghua Homo-Source Dual-Beam Medical Accelerator%清华同源双束医用加速器蒙特卡罗模拟

    Institute of Scientific and Technical Information of China (English)

    马悦; 吴朝霞; 王石; 刘亚强

    2011-01-01

    Objective: To apply Monte Carlo method in simulating the Homo-Source Dual-Beam medical accelerator developed by Tsinghua University and lay the foundation for future researches on the Accelerator' s KV energy dose distribution in an image-guided radiotherapy procedure. Methods: (1)Using Monte Carlo's BEAMnrc program for simulating the head of Tsinghua Homo-Source Dual-Beam Medical Accelerator we obtained the Phase Space file which would be used as the source for the next step. (2) Using Monte Carlo' s DOSXYZnre program we calculated the percent depth dose (PDD) and off axis ratio (OAR), dealt the dose data by MATLAB program and displayed them in EXCEL. (3) Analyzed the impact of the Monte Carlo simulated parameters on the final outcome was analyzed. (4)Compared the PDD and OAR calculated with the measured of identical condition. Results: The PDD and OAR in water phantom simulated using Monte Carlo method were well matched with those measured in the actual experiments and the Accelerator' s Monte Carlo model was achieved. Conclusions: The Accelerator's Monte Carlo simulated parameters of KV energy are apparently different from that of High-energy. To obtain the accurate Accelerator's Monte Carlo model, it is important to choose proper electron beam energy and electron space density distribution. The Accelerator's Monte Carlo model can be used in future researches on the image dose distribution.%目的:使用蒙特卡罗方法模拟清华大学自主研制的同源双束医用加速器,为今后研究该设备KV级能量在放射治疗中成像剂量分布奠定基础.方法:(1)借助蒙卡BEAMnrc程序模拟加速器机头得到相空间文件.(2)以该相空间文件为源,使用蒙卡DOSXYZnrc程序计算水模体中百分深度剂量(percent depth dose,PDD)和离轴比(off axis ratio,OAR),采用MATLAB编程提取剂量数据显示于EXCEL.(3)分析蒙卡模拟参数对结果的影响.(4)对比实测调整模拟参数.结果:蒙卡模拟所得水模体中PDD

  12. Is there evidence for accelerated polyethylene wear in uncemented compared to cemented acetabular components? A systematic review of the literature

    NARCIS (Netherlands)

    van der Veen, Hugo; van Jonbergen, H.P.W.; Poolman, R.W.; Bulstra, S.K.; van Raay, J.J.A.M.

    2013-01-01

    Joint arthroplasty registries show an increased rate of aseptic loosening in uncemented acetabular components as compared to cemented acetabular components. Since loosening is associated with particulate wear debris, we postulated that uncemented acetabular components demonstrate a higher polyethyle

  13. Laser ion acceleration for hadron therapy

    Science.gov (United States)

    Bulanov, S. V.; Wilkens, J. J.; Esirkepov, T. Zh; Korn, G.; Kraft, G.; Kraft, S. D.; Molls, M.; Khoroshkov, V. S.

    2014-12-01

    The paper examines the prospects of using laser plasma as a source of high-energy ions for the purpose of hadron beam therapy — an approach which is based on both theory and experimental results (ions are routinely observed to be accelerated in the interaction of high-power laser radiation with matter). Compared to therapy accelerators like synchrotrons and cyclotrons, laser technology is advantageous in that it is more compact and is simpler in delivering ions from the accelerator to the treatment room. Special target designs allow radiation therapy requirements for ion beam quality to be satisfied.

  14. Comparing 20 years of precipitation estimates from different sources over the world ocean

    Science.gov (United States)

    Béranger, Karine; Barnier, Bernard; Gulev, Sergei; Crépon, Michel

    2006-06-01

    The paper compares ten different global precipitation data sets over the oceans and discusses their respective strengths and weaknesses in ocean regions where they are potentially important to the salinity and buoyancy budgets of surface waters. Data sets (acronyms of which are given in Section 2) are categorised according to their source of data, which are (1) in situ for Center for Climatic Research (Legates and Willmott, 1990; Archive of Precipitation Version 3.01, http://climate.geog.udel.edu/~climate ), Southampton Oceanography Centre (SOC) (Josey et al., J Clim 12:2856 2880, 1999) and University of Wisconsin-Milwaukee (UWM) (Da Silva et al. 1994); (2) satellite for Microwave Sounding Unit (MSU) (Spencer, J Clim 6:1301 1326, 1993), TOPEX (Quartly et al., J Geophys Res 104:31489 31516, 1999), and Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite (HOAPS) (Bauer and Schluessel, J Geophys Res 98:20737 20759, 1993); (3) atmospheric forecast model re-analyses for European Centre for Medium-range Weather Forecast (ECMWF) (Gibson et al. 1997) and National Center for Environmental Prediction (NCEP) (Kalnay et al., Bull Am Meteorol Soc 77:437 471, 1996); and (4) composite for Global Precipitation Climatology Project (GPCP) (satellites and rain gauges, Huffman et al., Bull Am Meteorol Soc 78(1):5 20, 1997) and Climate Prediction Center Merged Analysis of Precipitation (CMAP) (satellites, rain gauges and atmospheric forecast model, Xie and Arkin, Bull Am Meteorol Soc 78(11):2539 2558, 1997). Although there is no absolute field of reference, composite data sets are often considered as the best estimates. First, a qualitative comparison is carried out, which provides for each data set, a description of the geographical distribution of the climatological mean precipitation field. A more careful comparison between data sets is undertaken over periods they have in common. First, six among the ten data sets (SOC, UWM, ECMWF, NCEP, MSU and CMAP) are compared over

  15. COMPARATIVE STUDY AMONG HYBRID GROUND SOURCE HEAT PUMP SYSTEM, COMPLETE GROUND SOURCE HEAT PUMP AND CONVENTIONAL HVAC SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Zhu; Yong X. Tao

    2011-11-01

    In this paper, a hotel with hybrid geothermal heat pump system (HyGSHP) in the Pensacola is selected and simulated by the transient simulation software package TRNSYS [1]. To verify the simulation results, the validations are conducted by using the monthly average entering water temperature, monthly facility consumption data, and etc. And three types of HVAC systems are compared based on the same building model and HVAC system capacity. The results are presented to show the advantages and disadvantages of HyGSHP compared with the other two systems in terms of energy consumptions, life cycle cost analysis.

  16. Sentiment Analysis on Movie Reviews: A Comparative Study of Machine Learning Algorithms and Open Source Technologies

    Directory of Open Access Journals (Sweden)

    B. Narendra

    2016-08-01

    Full Text Available Social Networks such as Facebook, Twitter, Linked In etc… are rich in opinion data and thus Sentiment Analysis has gained a great attention due to the abundance of this ever growing opinion data. In this research paper our target set is movie reviews. There are diverge range of mechanisms to express their data which may be either subjective, objective or a mixture of both. Besides the data collected from World Wide Web consists of lot of noisy data. It is very much true that we are going to apply some pre-processing techniques and compare the accuracy using Machine Learning algorithm Naïve Bayes Classifier. With ever growing demand to mine the Big Data the open source software technologies such as Hadoop using map reducing paradigm has gained a lot of pragmatic importance. This paper illustrates a comparitive study of sentiment analysis of movie reviews using Naïve Bayes Classifier and Apache Hadoop in order to calculate the performance of the algorithms and show that Map Reduce paradigm of Apache Hadoop performed better than Naïve Bayes Classifier.

  17. Evaluation of global left ventricular function assessment by dual-source computed tomography compared with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Vleuten, Pieter A. van der; Tio, Rene A.; Zijlstra, Felix [University Medical Centre Groningen, Thoraxcenter, Department of Cardiology, P.O. Box 30001, Groningen (Netherlands); Jonge, Gonda J. de; Lubbers, Daniel D.; Willems, Tineke P.; Oudkerk, Matthijs [University Medical Centre Groningen, Department of Radiology, Groningen (Netherlands)

    2009-02-15

    Left ventricular (LV) function assessment by dual-source computed tomography (DSCT) was compared with the reference standard method using magnetic resonance imaging (MRI). Accurate assessment of LV function is essential for the prediction of prognosis in cardiac disease. Thirty-four patients undergoing DSCT examination of the heart for various clinical indications underwent MRI after DSCT. Short-axis cine images were reconstructed from the DSCT datasets and were analyzed using a dedicated post-processing software-tool to generate global left ventricular function parameters. Five DSCT datasets were considered to be of insufficient image quality. DSCT showed a small overestimation of end-diastolic and end-systolic volumes of 11.0 ml and 3.5 ml, nrespectively. Myocardial mass assessed by DSCT showed an average underestimation of 0.2 g. DSCT showed a small overestimation of LV ejection fraction (LVEF) of 0.4%-point with a Bland-Altman interval of [-8.67 (0.40) 9.48]. Global LV functional parameters calculated from DSCT datasets acquired in daily clinical practice correlated well with MRI and may be considered interchangeable. However, visual assessment of the image quality of the short-axis cine slices should be performed to detect any artifacts in the DSCT data which could influence accuracy. (orig.)

  18. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  19. Valorization of soursop flowers (Annona muricata L.) as potent source of natural antioxidants for stabilization of palm olein during accelerated storage.

    Science.gov (United States)

    Womeni, Hilaire Macaire; Tonfack Djikeng, Fabrice; Iruku, Naga Satya Surya Prabhakar; Karuna, Mallampalli Sri Lakshmi; Prasad, Rachapudi Badari Narayana; Linder, Michel

    2016-11-01

    This study investigates the effect of soursop flowers methanolic extract on the physicochemical characteristics of palm olein during accelerated storage. After analysis of the extract by determining its total phenolic content by colorimetry and identification of some of its phenolic antioxidants by HPLC-DAD(Diode Array Detector), preliminary antioxidants tests have been done. After that, the extract was added in palm olein at concentrations 200-1800 ppm. BHT, at 200 ppm served as standard besides the Control. Induction time, peroxide, p-anisidine, Total oxidation (TOTOX), thiobarbituric acid and iodine values, as well as changes in linoleic acid profile Gas Chromatography/Flamme Ionization Detector (GC/FID) of oil during the storage were evaluated. Results showed soursop flower extract to be rich in phenolic antioxidants and to be efficient, at all concentrations, in delaying palm olein oxidation on Rancimat and accelerated Schaal oven test of 30 days at 70°C. Soursop flowers might be used as potent source of antioxidants for the stabilization of palm olein.

  20. Improvement of dose distribution in phantom by using epithermal neutron source based on the Be(p,n) reaction using a 30 MeV proton cyclotron accelerator.

    Science.gov (United States)

    Tanaka, H; Sakurai, Y; Suzuki, M; Takata, T; Masunaga, S; Kinashi, Y; Kashino, G; Liu, Y; Mitsumoto, T; Yajima, S; Tsutsui, H; Takada, M; Maruhashi, A; Ono, K

    2009-07-01

    In order to generate epithermal neutrons for boron neutron capture therapy (BNCT), we proposed the method of filtering and moderating fast neutrons, which are emitted from the reaction between a beryllium target and 30 MeV protons accelerated by a cyclotron, using an optimum moderator system composed of iron, lead, aluminum, calcium fluoride, and enriched (6)LiF ceramic filter. At present, the epithermal-neutron source is under construction since June 2008 at Kyoto University Research Reactor Institute. This system consists of a cyclotron to supply a proton beam of about 1 mA at 30 MeV, a beam transport system, a beam scanner system for heat reduction on the beryllium target, a target cooling system, a beam shaping assembly, and an irradiation bed for patients. In this article, an overview of the cyclotron-based neutron source (CBNS) and the properties of the treatment neutron beam optimized by using the MCNPX Monte Carlo code are presented. The distribution of the RBE (relative biological effectiveness) dose in a phantom shows that, assuming a (10)B concentration of 13 ppm for normal tissue, this beam could be employed to treat a patient with an irradiation time less than 30 min and a dose less than 12.5 Gy-eq to normal tissue. The CBNS might be an alternative to the reactor-based neutron sources for BNCT treatments.

  1. Why Do We Stay? Career Rural Teachers' Burnout Compared to Personal Motivational Sources and Demographics

    Science.gov (United States)

    Bell, David J.

    2010-01-01

    This study investigated the effects of individual motivational sources, demographics, and levels of burnout within career rural school teachers in Nebraska. The dependent variable was the psychological syndrome burnout as measured by the Maslach Burnout Inventory. Two independent variables were individual motivational sources (a personality trait…

  2. SNEAP 80: symposium of Northeastern Accelerator personnel

    Energy Technology Data Exchange (ETDEWEB)

    Billen, J.H. (ed.)

    1980-01-01

    Reports of operations are presented for twenty-seven facilities, along with reports on accelerators in progress, ion sources, insulating gases, charging systems, stripping foils, accelerating tubes, and upgraded accelerator systems. (GHT)

  3. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    OpenAIRE

    Qiu, Zeyuan

    2013-01-01

    Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs) have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMP...

  4. Peremptory Norms in International Law; Development or Revolution of Sources of International Law (A Comparative Analysis of National Legal Systems)

    OpenAIRE

    Sayyed Fazlollah Mosavi; Hossein Khalaf Rezaee

    2015-01-01

    Contemporary international law introduces a notion of peremptory norms comparable to hierarchy of norms in national legal system. A jus cogens is a norm of international law considered so fundamental that it overrides all other sources of international law. A rule of jus cogens has a specific process of emergence that will be essentially different from other sources of international law which reflected in Article 38(1) of ICJ Statute. Unfortunately, there is not a precise definition of jus co...

  5. Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2012-07-26

    Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

  6. Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

    Directory of Open Access Journals (Sweden)

    Robert G. Hynes

    2012-03-01

    Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

  7. TH-C-BRB-00: Open Source Hardware in Medical Physics and Its Potential to Accelerate Innovation.

    Science.gov (United States)

    Therriault-Proulx, Francois

    2016-06-01

    By definition, Open Source Hardware (OSH) is "hardware whose design is made publicly available so that anyone can study, modify, distribute, make, and sell the design or hardware based on that design". The advantages of OSH are multiple and the movement has been growing exponentially over the last couple years, leading to the spread and evolution of 3D printing technologies, the creation of affordable and easy to use micro-controller boards (Arduino, Raspberry Pi, etc.), as well as a plurality of other "hands-on"/DIY projects. As we have seen over the past few years with 3D printing, where the number of projects benefiting clinical practice as grown significantly, the highly educated and technology savvy Medical Physics community is positioned to take advantage of and benefit from paradigm-shifting movements. Sharing of knowledge, know-how, and technology can be a key factor in furthering the impact medical physicists can have. Whether it is to develop phantoms, applicators, detector holders or devices based on the use of motors and sensors, sharing design files significantly enables further development. Because these designs would be massively peer-reviewed through their online publication, improvements would be made, and the creators of the design would be rewarded with an increase number of citation of their work. A curated database of software and hardware projects can be an invaluable to the field, but a critical mass of contributors is likely needed to guarantee the most impact. This symposium will discuss the benefits and hurdles for such an endeavor.

  8. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    Directory of Open Access Journals (Sweden)

    Zeyuan Qiu

    2013-03-01

    Full Text Available Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMPs for nonpoint source pollution control include cover crops, prescribed grazing, livestock access control, contour farming, nutrient management, and conservation buffers. The selected BMPs for stormwater management are rain gardens, roadside ditch retrofitting, and detention basin retrofitting. Cost-effectiveness is measured by the reduction in pollutant loads in total suspended solids and total phosphorus relative to the total costs of implementing the selected BMPs. The pollution load reductions for these BMPs are based on the total pollutant loads in the watershed simulated by the Soil and Water Assessment Tool and achievable pollutant reduction rates. The total implementation cost includes BMP installation and maintenance costs. The assessment results indicate that the BMPs for the nonpoint source pollution control are generally much more cost-effective in improving water quality than the BMPs for stormwater management.

  9. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Science.gov (United States)

    Zhang, Erfeng; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-01

    We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  10. Three methods of multi-source feedback compared: a plea for narrative comments and coworkers' perspectives.

    NARCIS (Netherlands)

    Overeem, K.; Lombarts, M.J.; Arah, O.A.; Klazinga, N.S.; Grol, R.P.T.M.; Wollersheim, H.C.H.

    2010-01-01

    BACKGROUND: Doctor performance assessments based on multi-source feedback (MSF) are increasingly central in professional self-regulation. Research has shown that simple MSF is often unproductive. It has been suggested that MSF should be delivered by a facilitator and combined with a portfolio. AIMS:

  11. Comparative analysis of automatic approaches to building detection from multi-source aerial data

    NARCIS (Netherlands)

    Frontoni, E.; Khoshelham, K.; Nardinocchi, C.; Nedkov, S.; Zingaretti, P.

    2008-01-01

    Automatic building detection has been a hot topic since the early 1990’s. Early approaches were based on a single aerial image. Detecting buildings is a difficult task so it can be more effective when multiple sources of information are obtained and fused. The objective of this paper is to provide a

  12. Comparing Four Sourcing Scenarios in a Two-echelon Supply Chain

    DEFF Research Database (Denmark)

    Sajadieh, Mohsen Sheikh; Thorstenson, Anders; Akbari Jokar, Mohammad R.

    2009-01-01

    is to minimize the total system costs incurred by the buyer and the vendor(s). A major finding is that determining the best strategy among those considered requires a detailed analysis in each case. Furhtermore, when the total system costs are taken into account, dual sourcing may not be as beneficial...

  13. Critical behaviour of irreversible reaction systems[98.70.Sa Cosmic rays (including sources, origin, acceleration, and interactions);

    Energy Technology Data Exchange (ETDEWEB)

    Loscar, Ernesto; Albano, Ezequiel V [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Sucursal 4, Casilla de Correo 16. (1900) La Plata (Argentina)

    2003-08-01

    An introductory review on the critical behaviour of some irreversible reaction systems is presented. The study of these systems has attracted great attention during the last decades due to, on the one hand, the rich and complex underlying physics, and, on the other, their relevance to numerous technological applications in heterogeneous catalysis, corrosion and coating, development of microelectronic devices, etc. The review focuses on recent advances in the understanding of irreversible phase transitions (IPTs), providing a survey of the theoretical development in the field during the last decade, as well as a detailed discussion of relevant numerical simulations. The Langevin formulation for the treatment of second-order IPTs is discussed. Different Monte Carlo (MC) approaches are also presented in detail and the finite-size-scaling analysis of second-order IPT's is described. Special attention is devoted to the description of the recent progress in the study of first-order IPTs observed upon catalytic oxidation of carbon monoxide and the reduction of nitrogen monoxide, using lattice gas reaction models. Only brief comments are given on other reactions such as the oxidation of hydrogen, ammonia synthesis. Also, a discussion of relevant experiments is presented and measurements are compared with the numerical results. Furthermore, promising areas for further research and open questions are also addressed.

  14. Performance of viruses and bacteriophages for fecal source determination in a multi-laboratory, comparative study.

    Science.gov (United States)

    Harwood, Valerie J; Boehm, Alexandria B; Sassoubre, Lauren M; Vijayavel, Kannappan; Stewart, Jill R; Fong, Theng-Theng; Caprais, Marie-Paule; Converse, Reagan R; Diston, David; Ebdon, James; Fuhrman, Jed A; Gourmelon, Michele; Gentry-Shields, Jennifer; Griffith, John F; Kashian, Donna R; Noble, Rachel T; Taylor, Huw; Wicki, Melanie

    2013-11-15

    An inter-laboratory study of the accuracy of microbial source tracking (MST) methods was conducted using challenge fecal and sewage samples that were spiked into artificial freshwater and provided as unknowns (blind test samples) to the laboratories. The results of the Source Identification Protocol Project (SIPP) are presented in a series of papers that cover 41 MST methods. This contribution details the results of the virus and bacteriophage methods targeting human fecal or sewage contamination. Human viruses used as source identifiers included adenoviruses (HAdV), enteroviruses (EV), norovirus Groups I and II (NoVI and NoVII), and polyomaviruses (HPyVs). Bacteriophages were also employed, including somatic coliphages and F-specific RNA bacteriophages (FRNAPH) as general indicators of fecal contamination. Bacteriophage methods targeting human fecal sources included genotyping of FRNAPH isolates and plaque formation on bacterial hosts Enterococcus faecium MB-55, Bacteroides HB-73 and Bacteroides GB-124. The use of small sample volumes (≤50 ml) resulted in relatively insensitive theoretical limits of detection (10-50 gene copies or plaques × 50 ml(-1)) which, coupled with low virus concentrations in samples, resulted in high false-negative rates, low sensitivity, and low negative predictive values. On the other hand, the specificity of the human virus methods was generally close to 100% and positive predictive values were ∼40-70% with the exception of NoVs, which were not detected. The bacteriophage methods were generally much less specific toward human sewage than virus methods, although FRNAPH II genotyping was relatively successful, with 18% sensitivity and 85% specificity. While the specificity of the human virus methods engenders great confidence in a positive result, better concentration methods and larger sample volumes must be utilized for greater accuracy of negative results, i.e. the prediction that a human contamination source is absent.

  15. Effects of pointing compared with naming and observing during encoding on item and source memory in young and older adults.

    Science.gov (United States)

    Ouwehand, Kim; van Gog, Tamara; Paas, Fred

    2016-10-01

    Research showed that source memory functioning declines with ageing. Evidence suggests that encoding visual stimuli with manual pointing in addition to visual observation can have a positive effect on spatial memory compared with visual observation only. The present study investigated whether pointing at picture locations during encoding would lead to better spatial source memory than naming (Experiment 1) and visual observation only (Experiment 2) in young and older adults. Experiment 3 investigated whether response modality during the test phase would influence spatial source memory performance. Experiments 1 and 2 supported the hypothesis that pointing during encoding led to better source memory for picture locations than naming or observation only. Young adults outperformed older adults on the source memory but not the item memory task in both Experiments 1 and 2. In Experiments 1 and 2, participants manually responded in the test phase. Experiment 3 showed that if participants had to verbally respond in the test phase, the positive effect of pointing compared with naming during encoding disappeared. The results suggest that pointing at picture locations during encoding can enhance spatial source memory in both young and older adults, but only if the response modality is congruent in the test phase.

  16. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Erfeng, E-mail: efzhang@163.com; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-15

    Highlights: • Second-order spatial correlation with entangled and classical light in the far-field is investigated. • The role of photon statistics and detection mode in the second-order spatial correlation are discussed. • The difference of second-order spatial correlation with entangled and classical light sources is deduced. - Abstract: We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  17. Comparing credentialing requirements of substance abuse treatment staff by funding source.

    Science.gov (United States)

    Kubiak, Sheryl Pimlott; Arfken, Cynthia L

    2008-07-01

    Studies have found that clinicians with higher education and/or attainment of national certification have a more favorable outlook regarding the adoption of evidence-based practices. However, staff hiring decisions may be based on a multitude of factors, including available resources and demands stemming from different funders. Using a mixed-methods case study approach with 34 agencies within one state, we assessed administrators' perspectives of the most important funding source, views on clinical hiring practices, and current staffing. We found that funding source predicted views and actual staff level of credentialing and education. Those agencies citing a criminal justice entity as the most important funder had the lowest requirements for credentialing and education. As the substance abuse treatment delivery system evolves and expands, we must ensure that vulnerable groups have access to more highly--rather than less--skilled workers to assess and facilitate recovery.

  18. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  19. Optimization design and compare of different solar-ground source heat pump system of office building in cold regions

    Science.gov (United States)

    Xie, H.; He, S.; Fu, Y.

    2016-08-01

    This paper presents two different operation modes of Solar-Ground Source Heat Pump System (SGSHP(S)). With the simulation tool TRNSYS, two different SGSHP system models were built to taking simulation. After making analysis and compare of different simulation results, series operation mode was believed to be better than parallel in the target building.

  20. Comparing Jupiter and Saturn: dimensionless input rates from plasma sources within the magnetosphere

    Directory of Open Access Journals (Sweden)

    V. M. Vasyliūnas

    2008-06-01

    Full Text Available The quantitative significance for a planetary magnetosphere of plasma sources associated with a moon of the planet can be assessed only by expressing the plasma mass input rate in dimensionless form, as the ratio of the actual mass input to some reference value. Traditionally, the solar wind mass flux through an area equal to the cross-section of the magnetosphere has been used. Here I identify another reference value of mass input, independent of the solar wind and constructed from planetary parameters alone, which can be shown to represent a mass input sufficiently large to prevent corotation already at the source location. The source rate from Enceladus at Saturn has been reported to be an order of magnitude smaller (in absolute numbers than that from Io at Jupiter. Both reference values, however, are also smaller at Saturn than at Jupiter, by factors ~40 to 60; expressed in dimensionless form, the estimated mass input from Enceladus may be larger than that from Io by factors ~4 to 6. The magnetosphere of Saturn may thus, despite a lower mass input in kg s−1, intrinsically be more heavily mass-loaded than the magnetosphere of Jupiter.

  1. KEK digital accelerator

    Science.gov (United States)

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  2. EVALUATION PLAN FOR COMPARATIVE INVESTIGATION OF SOURCE TERM ESTIMATION ALGORITHMS USING FUSION FIELD TRIAL 2007 DATA

    OpenAIRE

    Platt, Nathan; Warner, Steve; Nunes, Steve M.

    2008-01-01

    Abstract: Given a warning based on detection of hazardous materials at just a few sensors, it could be useful to rapidly (minutes) provide an estimate of the source location, time of release, and amount of material released. Such an estimate can lead to refined predictions of the area impacted by the hazardous release, and can support near-term follow-on actions to investigate the cause and nature of the hazardous release. In September 2007, a short-range, highly-instrumented test wa...

  3. Comparing a phased combination of acoustical radiosity and the image source method with other simulation tools

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho;

    2015-01-01

    A phased combination of acoustical radiosity and the image source method (PARISM) has been developed in order to be able to model both specular and diffuse reflections with angle-dependent and complex-valued acoustical descriptions of the surfaces. It is of great interest to model both specular...... and diffuse reflections when simulating the acoustics of small rooms with non-diffuse sound fields, since scattering from walls add to the diffuseness in the room. This room type is often seen in class rooms and offices, as they are often small rectangular rooms with most of the absorption placed...

  4. Comparative analyses of seven technologies to facilitate the integration of fluctuating renewable energy sources

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik

    2009-01-01

    An analysis of seven different technologies is presented. The technologies integrate fluctuating renewable energy sources (RES) such as wind power production into the electricity supply, and the Danish energy system is used as a case. Comprehensive hour-by-hour energy system analyses are conducted...... and feasibility analyses. Large-scale heat pumps prove to be especially promising as they efficiently reduce the production of excess electricity. Flexible electricity demand and electric boilers are low-cost solutions, but their improvement of fuel efficiency is rather limited. Battery electric vehicles...

  5. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  6. Strong Radiation-Damping Effects in a Gamma-Ray Source Generated by the Interaction of a High-Intensity Laser with a Wakefield-Accelerated Electron Beam

    Science.gov (United States)

    Thomas, A. G. R.; Ridgers, C. P.; Bulanov, S. S.; Griffin, B. J.; Mangles, S. P. D.

    2012-10-01

    A number of theoretical calculations have studied the effect of radiation-reaction forces on radiation distributions in strong-field counterpropagating electron-beam-laser interactions, but could these effects—including quantum corrections—be observed in interactions with realistic bunches and focusing fields, as is hoped in a number of soon-to-be-proposed experiments? We present numerical calculations of the angularly resolved radiation spectrum from an electron bunch with parameters similar to those produced in laser-wakefield-acceleration experiments, interacting with an intense, ultrashort laser pulse. For our parameters, the effect of radiation damping on the angular distribution and energy distribution of photons is not easily discernible for a realistic moderate-emittance electron beam. However, experiments using such a counterpropagating beam-laser geometry should be able to measure these effects using current laser systems through measurement of the electron-beam properties. In addition, the brilliance of this source is very high, with peak spectral brilliance exceeding 1029photonss-1mm-2mrad-2(0.1%bandwidth)-1 with an approximately 2% conversion efficiency and with a peak energy of 10 MeV.

  7. Strong radiation damping effects in a gamma-ray source generated by the interaction of a high intensity laser with a wakefield accelerated electron beam

    Science.gov (United States)

    Thomas, Alexander; Ridgers, Christopher; Bulanov, Stepan; Griffin, Blake; Mangles, Stuart

    2012-10-01

    We present numerical calculations of the angularly resolved radiation spectrum from a relativistic electron beam interacting with an ultrashort laser pulse. These calculations include the effect of semi-classical radiation reaction forces including a Gaunt factor for synchrotron radiation. For a laser of 5x10^21 Wcm-2 intensity interacting with a 200 MeV electron beam with an emittance similar to that in laser wakefield acceleration experiments, radiation reaction does not produce a significant change in the angular and energy distribution of photons. However the effects of radiation reaction are clear when observing the electron beam properties. The result is that near-term experiments using such a counter-propagating beam-laser geometry should be able to measure the effects of quantum effects in radiation reaction. The calculations also show that the brilliance of this source is very high, with a peak spectral brilliance exceeding 10^29 photons,s-1mm-2mrad-2(0.1% bandwidth)-1 with approximately 2% efficiency and with a peak energy of 10 MeV.

  8. Conceptual study of a compact accelerator-driven neutron source for radioisotope production, boron neutron capture therapy and fast neutron therapy

    CERN Document Server

    Angelone, M; Rollet, S

    2002-01-01

    The feasibility of a compact accelerator-driven device for the generation of neutron spectra suitable for isotope production by neutron capture, boron neutron capture therapy and fast neutron therapy, is analyzed by Monte Carlo simulations. The device is essentially an extension of the activator proposed by Rubbia left bracket CERN/LHC/97-04(EET) right bracket , in which fast neutrons are diffused and moderated within a properly sized lead block. It is shown that by suitable design of the lead block, as well as of additional elements of moderating and shielding materials, one can generate and exploit neutron fluxes with the spectral features required for the above applications. The linear dimensions of the diffusing-moderating device can be limited to about 1 m. A full-scale device for all the above applications would require a fast neutron source of about 10**1**4 s**-**1, which could be produced by a 1 mA, 30 MeV proton beam impinging on a Be target. The concept could be tested at the Frascati Neutron Gener...

  9. Peremptory Norms in International Law; Development or Revolution of Sources of International Law (A Comparative Analysis of National Legal Systems

    Directory of Open Access Journals (Sweden)

    Sayyed Fazlollah Mosavi

    2015-05-01

    Full Text Available Contemporary international law introduces a notion of peremptory norms comparable to hierarchy of norms in national legal system. A jus cogens is a norm of international law considered so fundamental that it overrides all other sources of international law. A rule of jus cogens has a specific process of emergence that will be essentially different from other sources of international law which reflected in Article 38(1 of ICJ Statute. Unfortunately, there is not a precise definition of jus cogens norms. The vagueness of the definition and thereby its instances is one problematic issue that harden realization of ideals of the international community.

  10. A Comparative Study of Control Methods for Induction Motor and High Performance Z-source Inverter

    Directory of Open Access Journals (Sweden)

    Pham Cong Thanh

    2013-06-01

    Full Text Available Design studies of the most suitable controller for the speed of induction motor (SIM and peak DC-link voltage (PDV of high performance z-source inverter (HP-ZSI greatly affects performance of hybrid electric vehicles. This paper is to give comprehensive analyses comparison and evaluations of the different control techniques as PI controller, self-tuning fuzzy PI controller (SFP and genetic algorithms optimal tuning gains of the PI controller for controlling the SIM based on criteria of the integral of the absolute value of speed error. With control PDV, this paper also presents comparisons of the different techniques as PI controller, fuzzy logic controller, SFP based on observation of its response and total harmonic distortion of current. All methods are applied to the closed loop of the SIM which relies on direct torque control combined with modified space vector modulation and closed loop of PDV in HP-ZSI. These methods are verified by Matlab software.

  11. Comparative Investigation of Source Term Estimation Algorithms for Hazardous Material Atmospheric Transport and Dispersion Prediction Tools

    Science.gov (United States)

    2012-07-01

    DPD DPN DCD DCN 10 Appendix E provides additional plots of miss distance for single...Double-Source Releases 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 SPD SPN SCD SCN 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 DPD DPN DCD DCN E-5 Figure E-7. STE Algorithm...SPN DPD DPN 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 SCD SCN DCD DCN E-6 (This page is intentionally blank.) F-1 Appendix

  12. Terahertz-driven linear electron acceleration

    CERN Document Server

    Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X

    2014-01-01

    The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...

  13. ADS次临界堆脉冲中子源实验动态特性数值模拟研究%Numerical Simulation of Dynamic Characteristic in Accelerator Driven System Sub-critical Reactor Pulse Neutron Source Experiments

    Institute of Scientific and Technical Information of China (English)

    谢芹; 谢金森; 曾文杰; 何丽华; 刘紫静; 于涛

    2015-01-01

    Drive by intense external neutron sources and the deep subcritical levels make Ac-celerator Driven Subcritical reactor have a great difference between traditional critical reactors in neutronics parameters. It makes the deterministic neutronic calculation method could not be used in ADS subcritical reactor calculating directly. In this paper,the pulse neutron source ex-periments in the fast/thermal-combined ADS system facility ( YLINA-Booster expermental facilty) are simulated by Monte Carlo N-Particle eXtended (MCNPX) code. The simulation re-sults are compared with the results of detectors in the experiments. The results clearly indicate that in different reactor core layouts and different neutron source characteristics,the simulation results are in excellent agreement with the experiment,and the MCNPX code could be used to study ADS Subcritical reactor neutronics dynamic parameters.%强外源驱动与深次临界度使得ADS次临界反应堆在中子学特性上与传统临界堆有较大差异,确定论中子学计算方法难以直接应用于ADS次临界堆。本文采用MCNPX程序对“快热”耦合ADS装置YALINA-Booster的PNS实验进行了模拟,并将模拟与实验结果进行比较。结果表明:在不同的堆芯布置方案和不同脉冲中子源特性下,模拟结果与实验结果具有良好的一致性,验证采用MCNPX程序研究ADS次临界堆中子学动态特性的可行性。

  14. Is Financial Development Another Source of Comparative Advantage? Evidence from China

    Institute of Scientific and Technical Information of China (English)

    Qun Bao; Jiayu Yang

    2009-01-01

    Using panel data for 29 provinces in China during 1990-2004, the present paper attempts to explore a possible link between financial development and China' s foreign trade. Three measures of comparative advantage in manufactured goods have been applied in our study, including Balassa's revealed coraparative advantage, the net manufactured export index, and the Michaely index. We also use four indicators of financial development to identify the different fimctions of regional financial development, and to determine both size and efficiency features of financial institutions. The estimation results suggest that besides factor endowments, foreign firms and infrastructure, financial development has a quantitatively large and robust effect on China' s manufactured goods trade. Therefore, further reform of China' s financial system should be encouraged to fully exploit the comparative advantage of China's foreign trade.

  15. METAREP: JCVI metagenomics reports—an open source tool for high-performance comparative metagenomics

    OpenAIRE

    Goll, Johannes; Rusch, Douglas B; Tanenbaum, David M.; Thiagarajan, Mathangi; Li, Kelvin; Methé, Barbara A.; Yooseph, Shibu

    2010-01-01

    Summary: JCVI Metagenomics Reports (METAREP) is a Web 2.0 application designed to help scientists analyze and compare annotated metagenomics datasets. It utilizes Solr/Lucene, a high-performance scalable search engine, to quickly query large data collections. Furthermore, users can use its SQL-like query syntax to filter and refine datasets. METAREP provides graphical summaries for top taxonomic and functional classifications as well as a GO, NCBI Taxonomy and KEGG Pathway Browser. Users can ...

  16. New Sources for Comparative Social Science: Historical Population Panel Data From East Asia.

    Science.gov (United States)

    Dong, Hao; Campbell, Cameron; Kurosu, Satomi; Yang, Wenshan; Lee, James Z

    2015-06-01

    Comparison and comparability lie at the heart of any comparative social science. Still, precise comparison is virtually impossible without using similar methods and similar data. In recent decades, social demographers, historians, and economic historians have compiled and made available a large number of micro-level data sets of historical populations for North America and Europe. Studies using these data have already made important contributions to many academic disciplines. In a similar spirit, we introduce five new micro-level historical panel data sets from East Asia, including the China Multi-Generational Panel Dataset-Liaoning (CMGPD-LN) 1749-1909, the China Multi-Generational Panel Dataset-Shuangcheng (CMGPD-SC) 1866-1913, the Japanese Ninbetsu-Aratame-Cho Population Register Database-Shimomoriya and Niita (NAC-SN) 1716-1870, the Korea Multi-Generational Panel Dataset-Tansung (KMGPD-TS) 1678-1888, and the Colonial Taiwan Household Registration Database (CTHRD) 1906-1945. These data sets in total contain more than 3.7 million linked observations of 610,000 individuals and are the first such Asian data to be made available online or by application. We discuss the key features and historical institutions that originally collected these data; the subsequent processes by which the data were reconstructed into individual-level panels; their particular data limitations and strengths; and their potential for comparative social scientific research.

  17. Comparative assessment of surface fluxes from different sources using probability density distributions

    Science.gov (United States)

    Gulev, Sergey; Tilinina, Natalia; Belyaev, Konstantin

    2015-04-01

    Surface turbulent heat fluxes from modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA) as well as from satellite products (SEAFLUX, IFREMER, HOAPS) were intercompared using framework of probability distributions for sensible and latent heat fluxes. For approximation of probability distributions and estimation of extreme flux values Modified Fisher-Tippett (MFT) distribution has been used. Besides mean flux values, consideration is given to the comparative analysis of (i) parameters of the MFT probability density functions (scale and location), (ii) extreme flux values corresponding high order percentiles of fluxes (e.g. 99th and higher) and (iii) fractional contribution of extreme surface flux events in the total surface turbulent fluxes integrated over months and seasons. The latter was estimated using both fractional distribution derived from MFT and empirical estimates based upon occurrence histograms. The strongest differences in the parameters of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the western boundary current extension regions and high latitudes, while the highest differences in the fractional contributions of surface fluxes may occur in mid ocean regions being closely associated with atmospheric synoptic dynamics. Generally, satellite surface flux products demonstrate relatively stronger extreme fluxes compared to reanalyses, even in the Northern Hemisphere midlatitudes where data assimilation input in reanalyses is quite dense compared to the Southern Ocean regions.

  18. Radiation protection for an intraoperative X-ray source compared to C-arm fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank; Clausen, Sven; Jahnke, Anika; Steil, Volker; Wenz, Frederik [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Radiation Oncology; Bludau, Frederic; Obertacke, Udo [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Trauma Surgery; Suetterlin, Marc [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Obstetrics and Gynaecology

    2014-10-01

    Background: Intraoperative radiotherapy (IORT) using the INTRABEAM {sup registered} system promises a flexible use regarding radiation protection compared to other approaches such as electron treatment or HDR brachytherapy with {sup 192}Ir or {sup 60}Co. In this study we compared dose rate measurements of breast- and Kypho-IORT with C-arm fluoroscopy which is needed to estimate radiation protection areas. Materials and Methods: C-arm fluoroscopy, breast- and Kypho-IORTs were performed using phantoms (silicon breast or bucket of water). Dose rates were measured at the phantom's surface, at 30 cm, 100 cm and 200 cm distance. Those measurements were confirmed during 10 Kypho-IORT and 10 breast-IORT patient treatments. Results: The measured dose rates were in the same magnitude for all three paradigms and ranges from 20 μSv/h during a simulated breast-IORT at two meter distance up to 64 mSv/h directly at the surface of a simulated Kypho-IORT. Those measurements result in a circle of controlled area (yearly doses > 6 mSv) for each paradigm of about 4 m ± 2 m. Discussion/Conclusions: All three paradigms show comparable dose rates which implies that the radiation protection is straight forward and confirms the flexible use of the INTRABEAM {sup registered} system. (orig.)

  19. Individualized Positron Emission Tomography–Based Isotoxic Accelerated Radiation Therapy Is Cost-Effective Compared With Conventional Radiation Therapy: A Model-Based Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, Mathilda L., E-mail: ml.bongers@vumc.nl [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Coupé, Veerle M.H. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); De Ruysscher, Dirk [Radiation Oncology University Hospitals Leuven/KU Leuven, Leuven (Belgium); Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Oberije, Cary; Lambin, Philippe [Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Uyl-de Groot, Cornelia A. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Institute for Medical Technology Assessment, Erasmus University Rotterdam, Rotterdam (Netherlands)

    2015-03-15

    Purpose: To evaluate long-term health effects, costs, and cost-effectiveness of positron emission tomography (PET)-based isotoxic accelerated radiation therapy treatment (PET-ART) compared with conventional fixed-dose CT-based radiation therapy treatment (CRT) in non-small cell lung cancer (NSCLC). Methods and Materials: Our analysis uses a validated decision model, based on data of 200 NSCLC patients with inoperable stage I-IIIB. Clinical outcomes, resource use, costs, and utilities were obtained from the Maastro Clinic and the literature. Primary model outcomes were the difference in life-years (LYs), quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness and cost/utility ratio (ICER and ICUR) of PET-ART versus CRT. Model outcomes were obtained from averaging the predictions for 50,000 simulated patients. A probabilistic sensitivity analysis and scenario analyses were carried out. Results: The average incremental costs per patient of PET-ART were €569 (95% confidence interval [CI] €−5327-€6936) for 0.42 incremental LYs (95% CI 0.19-0.61) and 0.33 QALYs gained (95% CI 0.13-0.49). The base-case scenario resulted in an ICER of €1360 per LY gained and an ICUR of €1744 per QALY gained. The probabilistic analysis gave a 36% probability that PET-ART improves health outcomes at reduced costs and a 64% probability that PET-ART is more effective at slightly higher costs. Conclusion: On the basis of the available data, individualized PET-ART for NSCLC seems to be cost-effective compared with CRT.

  20. Comparative characteristics of human interleukin-2 preparations obtained from various sources

    Energy Technology Data Exchange (ETDEWEB)

    Iobadze, M.S.; Kulikov, V.V.; Kupriyanova, T.A.; Bykovskaya, S.N.; Bakhutashvili, V.I.

    1987-02-20

    Interleukin-2 (IL-2) was produced from donor peripheral blood lymphocytes and JURKAT FHCRC T lymphoma cells. Gel filtration, ion exchange chromatography on DEAE- and CM-Sephadex were used to purify the preparation. As a result of the purification, the specific activity of the preparation increased by a factor of 400. It was shown that optimum proliferation of T lymphocytes requires the successive action of phytohemagglutinin and IL-2, as well as the presence of serum in the medium. The properties and methods of production of a long-proliferating line of IL-2-dependent T cells B-5 are described. The proliferation of B-5 cells depends completely on the presence of IL-2 in the medium, although prolonged proliferation requires periodic stimulation by antigen (allogeneic lymphocytes). In the absence of IL-2 in the medium, B-5 cells die within 36 h. The prospects for the use of IL-2 preparations from human peripheral blood lymphocyte culture fluid for adoptive immunotherapy of tumors and the use of cells of the IL-2-dependent line B-5 in the testing of the activity of IL-2 preparations obtained from various sources are discussed.

  1. Synthesis of calcium hydroxyapatite from calcium carbonate and different orthophosphate sources: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Pham Minh, Doan, E-mail: doan.phamminh@mines-albi.fr [Universite de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi cedex 09 (France); Lyczko, Nathalie; Sebei, Haroun; Nzihou, Ange [Universite de Toulouse, Mines Albi, CNRS, Centre RAPSODEE, Campus Jarlard, F-81013 Albi cedex 09 (France); Sharrock, Patrick [Universite de Toulouse, SIMAD, IUT Paul Sabatier, Avenue Georges Pompidou, 81104 Castres (France)

    2012-08-01

    Highlights: Black-Right-Pointing-Pointer Calcium hydroxyapatite was synthesized from CaCO{sub 3} and four orthophosphates. Black-Right-Pointing-Pointer Only H{sub 3}PO{sub 4} led to the complete precipitation of orthophosphate species. Black-Right-Pointing-Pointer H{sub 3}PO{sub 4} was also the most efficient for calcium dissolution. Black-Right-Pointing-Pointer Reaction pathway was dissolution-precipitation accompanied by agglomeration step. - Abstract: The synthesis of calcium hydroxyapatite (Ca-HA) starting from calcium carbonate and different orthophosphate sources, including orthophosphoric acid, potassium, sodium and ammonium dihydrogen orthophosphates, was investigated under ambient conditions. The reaction started with calcium carbonate dissolution in an acid medium, followed by rapid precipitation of calcium cations with orthophosphate species to form calcium phosphate based particles which were in the size range of 0.4-1 {mu}m. These particles then agglomerated into much larger ones, up to 350 {mu}m in diameter (aggregates). These aggregates possessed an unstable porous structure which was responsible for the porosity of the final products. The highest specific surface area and pore volume were obtained with potassium dihydrogen orthophosphate. On the other hand, orthophosphoric acid led to the highest dissolution of calcium carbonate and the complete precipitation of orthophosphate species. Under ambient conditions, calcium phosphate based solid products of low crystallinity were formed. Different intermediates were identified and a reaction pathway proposed.

  2. Simulation and comparative study of tunneling field effect transistors with dopant-segregated Schottky source/drain

    Science.gov (United States)

    Zhang, Yi Bo; Sun, Lei; Xu, Hao; Han, Jing Wen

    2016-04-01

    Dopant-segregated Schottky source/drain tunneling field effect transistors (STFET) are investigated in this paper. The working mechanisms of STFET and the influence of device parameters are studied with Synopsys Sentaurus. Schottky source/drain MOSFETs possess several advantages over conventional MOSFETs, and dopant segregation can be feasibly achieved within current silicidation process. With dopant segregation, highly doped regions can be obtained after silicidation, which is necessary for band-to-band tunneling. With proper parameter setting, STFET can achieve comparable performance as TFET. High segregation doping for STFET is required to increase band-to-band tunneling probability and suppress bipolar behaviors. Increasing the electron barrier height at source side helps to provide larger drive current and higher on/off ratio. It is also found that STFET’s on-state performance is irrelevant to the segregation length when the segregation length is larger than a certain value. Furthermore, STFET is also insensitive to the Schottky barrier at drain side when the Schottky barrier at source side is fixed, which would relax the requirement for source/drain fabrication.

  3. Source processes at the Chilean subduction region: a comparative analysis of recent large earthquakes seismic sequences in Chile

    Science.gov (United States)

    Cesca, Simone; Tolga Sen, Ali; Dahm, Torsten

    2016-04-01

    Large intraplate megathrust events are common at the western margin of the Southamerican plate, and repeatedly affected the slab segment along Chile, driven by the subduction of the oceanic Nazca plate, with a convergence of almost 7 cm/y. The size and rate of seismicity, including the 1960 Mw 9.5 Chile earthquake, pose Chile among the most highly seismogenic regions worldwide. At the same time, thanks to the significant national and international effort in recent years, Chile is nowadays seismologically well equipped and monitored; the dense seismological network provides a valuable dataset to analyse details of the rupture processes not only for the main events, but also for weaker seismicity preceding, accompanying and following the largest earthquakes. The seismic sequences accompanying recent large earthquakes showed several differences. In some cases, as for the 2014 Iquique earthquake, an important precursor activity took place in the months preceding the main shock, with an accelerating pattern in the last days before the main shock. In other cases, as for the recent Illapel earthquake, the main shock occurred with few precursors. The 2010 Maule earthquake showed an even different patterns, with the activation of secondary faults after the main shock. Recent studies were able to resolve significant changes in specific source parameters, such as changes in the distribution of focal mechanisms, potentially revealing a rotation of the stress tensor, or a spatial variation of rupture velocity, supporting a depth dependence of the rupture speed. An advanced inversion of seismic source parameters and their combined interpretation for multiple sequences can help to understand the diversity of rupture processes along the Chilean slab, and in general for subduction environments. We combine here results of different recent studies to investigate similarity and anomalies of rupture parameters for different seismic sequences, and foreshocks-aftershocks activities

  4. Comparative assessment of surface fluxes from different sources: a framework based on probability distributions

    Science.gov (United States)

    Gulev, S.

    2015-12-01

    Surface turbulent heat fluxes from modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA) as well as from satellite products (SEAFLUX, IFREMER, HOAPS) were intercompared using framework of probability distributions for sensible and latent heat fluxes. For approximation of probability distributions and estimation of extreme flux values Modified Fisher-Tippett (MFT) distribution has been used. Besides mean flux values, consideration is given to the comparative analysis of (i) parameters of the MFT probability density functions (scale and location), (ii) extreme flux values corresponding high order percentiles of fluxes (e.g. 99th and higher) and (iii) fractional contribution of extreme surface flux events in the total surface turbulent fluxes integrated over months and seasons. The latter was estimated using both fractional distribution derived from MFT and empirical estimates based upon occurrence histograms. The strongest differences in the parameters of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the western boundary current extension regions and high latitudes, while the highest differences in the fractional contributions of surface fluxes may occur in mid ocean regions being closely associated with atmospheric synoptic dynamics. Generally, satellite surface flux products demonstrate relatively stronger extreme fluxes compared to reanalyses, even in the Northern Hemisphere midlatitudes where data assimilation input in reanalyses is quite dense compared to the Southern Ocean regions. Our assessment also discriminated different reanalyses and satellite products with respect to their ability to quantify the role of extreme surface turbulent fluxes in forming ocean heat release in different regions.

  5. Optimal moderator materials at various proton energies considering photon dose rate after irradiation for an accelerator-driven ⁹Be(p, n) boron neutron capture therapy neutron source.

    Science.gov (United States)

    Hashimoto, Y; Hiraga, F; Kiyanagi, Y

    2015-12-01

    We evaluated the accelerator beam power and the neutron-induced radioactivity of (9)Be(p, n) boron neutron capture therapy (BNCT) neutron sources having a MgF2, CaF2, or AlF3 moderator and driven by protons with energy from 8 MeV to 30 MeV. The optimal moderator materials were found to be MgF2 for proton energies less than 10 MeV because of lower required accelerator beam power and CaF2 for higher proton energies because of lower photon dose rate at the treatment position after neutron irradiation.

  6. Atmospheric moisture transports to the Arctic from different reanalyses: comparative assessment and analysis of source terms

    Science.gov (United States)

    Dufour, Ambroise; Zolina, Olga; Gulev, Sergey

    2014-05-01

    Accurate knowledge of the Arctic heat and moisture balances is critically important for understanding mechanisms of polar climate change and the observed amplification of the Arctic warming. Basic characteristics of the atmosphere in the Arctic region have quite a large spread in the modern era and first generation reanalyses, thus preventing effective use of reanalyses for the assessment of atmospheric moisture and heat transports and analysis of variability in the source terms. We used Eulerian approach to derive and intercompare to each other estimates of the moisture transports in the atmosphere from 5 reanalyses (ERA-Interim, MERRA, NCEP-CFSR, JRA-25, NCEP-1). Computational procedure involved decomposition of the velocity and moisture fields into mean conditions and variations around the mean. This concept allowed for the further association of the mean and eddy transports with large scale circulation modes (mean component) and synoptic transients (eddy component). The latter was associated with the characteristics of cyclone activity derived from the same reanalyses using state of the art numerical algorithm for cyclone identification and tracking. Atmospheric moisture transport is most intense over the GIN Sea and the North European basin, however over this area of the most intense transports, the contributions from the eddy and mean transport components are not correlated hinting on different pattern of variability in moisture fluxes due to cyclone activity and mean circulation. Decadal scale variability in the atmospheric moisture transports has been further associated with the Arctic-scale and regional differences between local precipitation and evaporation as well as with the magnitude of the storage terms. Potential mechanisms of variability in these terms are discussed.

  7. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also...... with the traditional audit and legal universes and industries are examples of emerging potentials both from a research and business point of view to exploit and explore further. The accelerator approach may therefore be an Idea Watch to consider, no matter which industry you are in, because in essence accelerators...

  8. Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage Source Inverter

    Directory of Open Access Journals (Sweden)

    Zulkifilie Bin Ibrahim

    2014-07-01

    Full Text Available Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM and Space Vector Pulse Width Modulation (SVPWM.  SPWM is the most simple modulation technique that can realize easily in analog circuit.  However, it has some drawbacks such as higher total harmonic distortion (THD, lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results are compared with conventional sinusoidal pulse width modulation (SPWM where SVPWM shows better performance than SPWM in terms of THD.

  9. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    Jonsson, Eythor Ivar

    2015-01-01

    Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored accelera......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...... an approach to facilitate implementation and realization of business ideas and is a lucrative approach to transform research into ventures and to revitalize regions and industries in transition. Investors have noticed that the accelerator approach is a way to increase the possibility of success by funnelling...

  10. Comparing dietary macronutrient composition and food sources between native and diasporic Ghanaian adults

    Directory of Open Access Journals (Sweden)

    Rachel Gibson

    2015-11-01

    Full Text Available Background: Dietary acculturation may contribute to the increased burden of non-communicable diseases (NCDs in diasporic populations of African ancestry. Objective: To assess nutritional composition and the contribution that traditional foods make to the diets of native and UK-dwelling Ghanaian adults. Design: An observational study of Ghanaian adults living in Accra (n=26 and London (n=57 was undertaken. Three-day food records were translated to nutrient data using culturally sensitive methods and comparisons were made for energy, macronutrients, and dietary fibre between cohorts. The contribution of traditional foods to dietary intake was measured and the foods contributing to each nutrient were identified. Results: Compared to native Ghanaians, UK-Ghanaians derived a significantly higher proportion of energy from protein (16.9±3.9 vs. 14.1±2.8%, p=0.001, fat (29.9±7.9 vs. 24.4±8.5%, p=0.005, and saturated fat (8.5±3.4 vs. 5.8±3.7%, p<0.001 and a significantly lower energy from carbohydrate (52.2±7.7 vs. 61.5±9.3%, p<0.001. Dietary fibre intake was significantly higher in the UK-Ghanaian diet compared to the native Ghanaian diet (8.3±3.1 vs. 6.7±2.2 g/1,000 kcal, p=0.007. There was significantly less energy, macronutrients, and fibre derived from traditional foods post-migration. Non-traditional foods including breakfast cereals, wholemeal bread, and processed meats made a greater contribution to nutrient intake post-migration. Conclusions: Our findings show the migrant Ghanaian diet is characterised by significantly higher intakes of fat, saturated fat, and protein and significantly lower intakes of carbohydrate; a macronutrient profile which may promote increased risk of NCDs amongst UK-Ghanaians. These differences in the nutrient profile are likely to be modulated by the consumption of ‘Western’ foods observed in migrant communities.

  11. Comparing Ion Exchange Adsorbents for Nitrogen Recovery from Source-Separated Urine.

    Science.gov (United States)

    Tarpeh, William A; Udert, Kai M; Nelson, Kara L

    2017-02-21

    Separate collection of urine, which is only 1% of wastewater volume but contains the majority of nitrogen humans excrete, can potentially reduce the costs and energy input of wastewater treatment and facilitate recovery of nitrogen for beneficial use. Ion exchange was investigated for recovery of nitrogen as ammonium from urine for use as a fertilizer or disinfectant. Cation adsorption curves for four adsorbents (clinoptilolite, biochar, Dowex 50, and Dowex Mac 3) were compared in pure salt solutions, synthetic urine, and real stored urine. Competition from sodium and potassium present in synthetic and real urine did not significantly decrease ammonium adsorption for any of the adsorbents. Dowex 50 and Dowex Mac 3 showed nearly 100% regeneration efficiencies. Estimated ion exchange reactor volumes to capture the nitrogen for 1 week from a four-person household were lowest for Dowex Mac 3 (5 L) and highest for biochar (19 L). Although Dowex Mac 3 had the highest adsorption capacity, material costs ($/g N removed) were lower for clinoptilolite and biochar because of their substantially lower unit cost.

  12. Photocatalytic degradation of the dye sulforhodamine-B: A comparative study of different light sources

    Institute of Scientific and Technical Information of China (English)

    FANG Yan-fen; HUANG Ying-ping; LIU De-fu; HUANG Yang; GUO Wei; DAVID Johnson

    2007-01-01

    The photocatalytic degradation of dye pollutant sulforhodamine-B (SRB) in aqueous TiO2 dispersions was examined under three lighting regimes: UV light (330 nm<λ<380 nm), sunlight, and visible light (λ>450 nm), all investigated at pH = 2.5. Total organic carbon (TOC) and chemical oxygen demand (CODCr) assays show that the degradation rate of SRB is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRB illustrated a first-order reaction and the rate constant, k, is 0.197 min-1, 0.152 min-1, 0.027 min-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.

  13. Comparing Natural Gas Leakage Detection Technologies Using an Open-Source "Virtual Gas Field" Simulator.

    Science.gov (United States)

    Kemp, Chandler E; Ravikumar, Arvind P; Brandt, Adam R

    2016-04-19

    We present a tool for modeling the performance of methane leak detection and repair programs that can be used to evaluate the effectiveness of detection technologies and proposed mitigation policies. The tool uses a two-state Markov model to simulate the evolution of methane leakage from an artificial natural gas field. Leaks are created stochastically, drawing from the current understanding of the frequency and size distributions at production facilities. Various leak detection and repair programs can be simulated to determine the rate at which each would identify and repair leaks. Integrating the methane leakage over time enables a meaningful comparison between technologies, using both economic and environmental metrics. We simulate four existing or proposed detection technologies: flame ionization detection, manual infrared camera, automated infrared drone, and distributed detectors. Comparing these four technologies, we found that over 80% of simulated leakage could be mitigated with a positive net present value, although the maximum benefit is realized by selectively targeting larger leaks. Our results show that low-cost leak detection programs can rely on high-cost technology, as long as it is applied in a way that allows for rapid detection of large leaks. Any strategy to reduce leakage should require a careful consideration of the differences between low-cost technologies and low-cost programs.

  14. Comparative Genomic Analysis of Lactococcus garvieae Strains Isolated from Different Sources Reveals Candidate Virulence Genes

    Directory of Open Access Journals (Sweden)

    Eiji Miyauchi

    2012-01-01

    Full Text Available Lactococcus garvieae is a major pathogen for fish. Two complete (ATCC 49156 and Lg2 and three draft (UNIUD074, 8831, and 21881 genome sequences of L. garvieae have recently been released. We here present the results of a comparative genomic analysis of these fish and human isolates of L. garvieae. The pangenome comprised 1,542 core and 1,378 dispensable genes. The sequenced L. garvieae strains shared most of the possible virulence genes, but the capsule gene cluster was found only in fish-pathogenic strain Lg2. The absence of the capsule gene cluster in other nonpathogenic strains isolated from mastitis and vegetable was also confirmed by PCR. The fish and human isolates of L. garvieae contained the specific two and four adhesin genes, respectively, indicating that these adhesion proteins may be involved in the host specificity differences of L. garvieae. The discoveries revealed by the pangenomic analysis may provide significant insights into the biology of L. garvieae.

  15. Long-term Cosmetic Outcomes and Toxicities of Proton Beam Therapy Compared With Photon-Based 3-Dimensional Conformal Accelerated Partial-Breast Irradiation: A Phase 1 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Galland-Girodet, Sigolène; Pashtan, Itai; MacDonald, Shannon M.; Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Hirsch, Ariel E.; Kachnic, Lisa A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts (United States); Specht, Michelle; Gadd, Michele; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Powell, Simon N. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Recht, Abram [Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-11-01

    Purpose: To present long-term outcomes of a prospective feasibility trial using either protons or 3-dimensional conformal photon-based (accelerated partial-breast irradiation [APBI]) techniques. Methods and Materials: From October 2003 to April 2006, 98 evaluable patients with stage I breast cancer were treated with APBI (32 Gy in 8 fractions given twice daily) on a prospective clinical trial: 19 with proton beam therapy (PBT) and 79 with photons or mixed photons/electrons. Median follow-up was 82.5 months (range, 2-104 months). Toxicity and patient satisfaction evaluations were performed at each visit. Results: At 7 years, the physician rating of overall cosmesis was good or excellent for 62% of PBT patients, compared with 94% for photon patients (P=.03). Skin toxicities were more common for the PBT group: telangiectasia, 69% and 16% (P=.0013); pigmentation changes, 54% and 22% (P=.02); and other late skin toxicities, 62% and 18% (P=.029) for PBT and photons, respectively. There were no significant differences between the groups in the incidences of breast pain, edema, fibrosis, fat necrosis, skin desquamation, and rib pain or fracture. Patient-reported cosmetic outcomes at 7 years were good or excellent for 92% and 96% of PBT and photon patients, respectively (P=.95). Overall patient satisfaction was 93% for the entire cohort. The 7-year local failure rate for all patients was 6%, with 3 local recurrences in the PBT group (7-year rate, 11%) and 2 in photon-treated patients (4%) (P=.22). Conclusions: Local failure rates of 3-dimensional APBI and PBT were similar in this study. However, PBT, as delivered in this study, led to higher rates of long-term telangiectasia, skin color changes, and skin toxicities. We recommend the use of multiple fields and treatment of all fields per treatment session or the use of scanning techniques to minimize skin toxicity.

  16. FFAGS FOR MUON ACCELERATION.

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.KAHN,S.PALMER,R.TRBOJEVIC,D.JOHNSTONE,C.KEIL,Y.OGITSU,T.OHMORI,C.SESSLER,A.KOSCIELNIAK,S.

    2003-06-26

    Due to their finite lifetime, muons must be accelerated very rapidly. It is challenging to make the magnets ramp fast enough to accelerate in a synchrotron, and accelerating in a linac is very expensive. One can use a recirculating accelerator (like CEBAF), but one needs a different arc for each turn, and this limits the number of turns one can use to accelerate, and therefore requires significant amounts of RF to achieve the desired energy gain. An alternative method for muon acceleration is using a fixed field alternating gradient (FFAG) accelerator. Such an accelerator has a very large energy acceptance (a factor of two or three), allowing one to use the same arc with a magnetic field that is constant over time. Thus, one can in principle make as many turns as one can tolerate due to muon decay, therefore reducing the RF cost without increasing the arc cost. This paper reviews the current status of research into the design of FFAGs for muon acceleration. Several current designs are described and compared. General design considerations are also discussed.

  17. Comparing dietary macronutrient composition and food sources between native and diasporic Ghanaian adults

    Science.gov (United States)

    Gibson, Rachel; Knight, Annemarie; Asante, Matilda; Thomas, Jane; Goff, Louise M.

    2015-01-01

    Background Dietary acculturation may contribute to the increased burden of non-communicable diseases (NCDs) in diasporic populations of African ancestry. Objective To assess nutritional composition and the contribution that traditional foods make to the diets of native and UK-dwelling Ghanaian adults. Design An observational study of Ghanaian adults living in Accra (n=26) and London (n=57) was undertaken. Three-day food records were translated to nutrient data using culturally sensitive methods and comparisons were made for energy, macronutrients, and dietary fibre between cohorts. The contribution of traditional foods to dietary intake was measured and the foods contributing to each nutrient were identified. Results Compared to native Ghanaians, UK-Ghanaians derived a significantly higher proportion of energy from protein (16.9±3.9 vs. 14.1±2.8%, p=0.001), fat (29.9±7.9 vs. 24.4±8.5%, p=0.005), and saturated fat (8.5±3.4 vs. 5.8±3.7%, pwholemeal bread, and processed meats made a greater contribution to nutrient intake post-migration. Conclusions Our findings show the migrant Ghanaian diet is characterised by significantly higher intakes of fat, saturated fat, and protein and significantly lower intakes of carbohydrate; a macronutrient profile which may promote increased risk of NCDs amongst UK-Ghanaians. These differences in the nutrient profile are likely to be modulated by the consumption of ‘Western’ foods observed in migrant communities. PMID:26610275

  18. A Comparative View on Open-source IaaS Clouds%开源IaaS之比较研究

    Institute of Scientific and Technical Information of China (English)

    陈立民

    2014-01-01

    To process the huge amounts of data in the Big Data Era, cloud computing provides promising solutions by way of high scalable and high available paral el and distributed computing. This paper offers a comparative view on several open-source IaaS clouds. It begins with a brief introduction of cloud computing (especial y IaaS), and details some typical open source projects in this ifled. After comparing the main features of these projects, we conclude the paper with some comments and suggestions. Our results may be of some help for novice users in their deployment of the cloud infrastructure with the most suitable open-source IaaS clouds.%大数据时代,云计算以高扩展性和可用性的分布式并行计算为海量数据处理提供了技术解决方案。文章以基础设施即服务(Infrastructure as a Service,IaaS)为重点,简介云计算领域相关概念,介绍、比较、并评价了具有代表性的开源IaaS项目;给出使用建议,帮助新用户选择适应自身需求的开源工具部署其云设施。

  19. Down-ramp injection and independently controlled acceleration of electrons in a tailored laser wakefield accelerator

    CERN Document Server

    Hansson, M.; Davoine, X.; Ekerfelt, H.; Svensson, K.; Persson, A.; Wahlström, C.-G.; Lundh, O.; 10.1103/PhysRevSTAB.18.071303

    2015-01-01

    We report on a study on controlled injection of electrons into the accelerating phase of a plasma wakefield accelerator by tailoring the target density distribution using two independent sources of gas. The tailored density distribution is achieved experimentally by inserting a narrow nozzle, with an orifice diameter of only 400  μm , into a jet of gas supplied from a 2 mm diameter nozzle. The combination of these two nozzles is used to create two regions of different density connected by a density gradient. Using this setup we show independent control of the charge and energy distribution of the bunches of accelerated electron as well as decreased shot-to-shot fluctuations in these quantities compared to self-injection in a single gas jet. Although the energy spectra are broad after injection, simulations show that further acceleration acts to compress the energy distribution and to yield peaked energy spectra.

  20. Accelerator Technology Division annual report, FY 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This paper discusses: accelerator physics and special projects; experiments and injectors; magnetic optics and beam diagnostics; accelerator design and engineering; radio-frequency technology; accelerator theory and simulation; free-electron laser technology; accelerator controls and automation; and high power microwave sources and effects.

  1. Sources

    OpenAIRE

    2015-01-01

    SOURCES MANUSCRITES Archives nationales Rôles de taille 1768/71 Z1G-344/18 Aulnay Z1G-343a/02 Gennevilliers Z1G-340/01 Ivry Z1G-340/05 Orly Z1G-334c/09 Saint-Remy-lès-Chevreuse Z1G-344/18 Sevran Z1G-340/05 Thiais 1779/80 Z1G-391a/18 Aulnay Z1G-380/02 Gennevilliers Z1G-385/01 Ivry Z1G-387b/05 Orly Z1G-388a/09 Saint-Remy-lès-Chevreuse Z1G-391a/18 Sevran Z1G-387b/05 Thiais 1788/89 Z1G-451/18 Aulnay Z1G-452/21 Chennevières Z1G-443b/02 Gennevilliers Z1G-440a/01 Ivry Z1G-452/17 Noiseau Z1G-445b/05 ...

  2. Epigenetics as a source of variation in comparative animal physiology - or - Lamarck is lookin' pretty good these days.

    Science.gov (United States)

    Burggren, Warren W

    2014-03-01

    Considerable variation is inherent both within and between comparative physiological data sets. Known sources for such variation include diet, gender, time of day and season of experiment, among many other factors, but a meta-analysis of physiological studies shows that surprisingly few studies report controlling for these factors. In fact, less than 3% of comparative physiological papers mention epigenetics. However, our understanding of epigenetic influences on physiological processes is growing rapidly, and it is highly likely that epigenetic phenomena are an additional 'hidden' source of variation, particularly in wild-caught specimens. Recent studies have shown epigenetic inheritance of commonly studied traits such as metabolic rate (water fleas Daphnia magna; emu, Dromaius novaellandiae), hypoxic tolerance, cardiac performance (zebrafish, Danio rerio), as well as numerous morphological effects. The ecological and evolutionary significance of such epigenetic inheritance is discussed in a comparative physiological context. Finally, against this context of epigenetic inheritance of phenotype, this essay also provides a number of caveats and warnings regarding the interpretation of transgenerational phenotype modification as a true epigenetic phenomenon. Parental effects, sperm storage, multiple paternity and direct gamete exposure can all be confounding factors. Epigenetic inheritance may best be studied in animal models that can be maintained in the laboratory over multiple generations, to yield parental stock that themselves are free of epigenetic effects from the historical experiences of their parents.

  3. LIBO accelerates

    CERN Multimedia

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  4. Dielectric laser accelerators

    Science.gov (United States)

    England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

    2014-10-01

    The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

  5. Vibration control in accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  6. Comparative Transcriptome Analysis in the Hepatopancreas Tissue of Pacific White Shrimp Litopenaeus vannamei Fed Different Lipid Sources at Low Salinity.

    Directory of Open Access Journals (Sweden)

    Ke Chen

    Full Text Available RNA-seq was used to compare the transcriptomic response of hepatopancreas in juvenile Litopenaeus vannamei fed three diets with different lipid sources, including beef tallow (BT, fish oil (FO, and an equal combination of soybean oil + BT + linseed oil (SBL for 8 weeks at 3 practical salinity unit (psu. A total of 9622 isogenes were annotated in 316 KEGG pathways and 39, 42 and 32 pathways significantly changed in the paired comparisons of FO vs SBL, BT vs SBL, or FO vs BT, respectively. The pathways of glycerolipid metabolism, linoleic acid metabolism, arachidonic acid metabolism, glycerophospholipid metabolism, fatty acid biosynthesis, fatty acid elongation, fatty acid degradation, and biosynthesis of unsaturated fatty acid were significantly changed in all paired comparisons between dietary lipid sources, and the pathways of glycerolipid metabolism, linoleic acid metabolism, arachidonic acid metabolism and glycerophospholipid metabolism significantly changed in the FO vs SBL and BT vs SBL comparisons. These pathways are associated with energy metabolism and cell membrane structure. The results indicate that lipids sources affect the adaptation of L. vannamei to low salinity by providing extra energy or specific fatty acids to change gill membrane structure and control iron balance. The results of this study lay a foundation for further understanding lipid or fatty acid metabolism in L. vannamei at low salinity.

  7. Comparative Analysis of Human Mesenchymal Stem Cells from Umbilical Cord, Dental Pulp, and Menstrual Blood as Sources for Cell Therapy

    Directory of Open Access Journals (Sweden)

    Huaijuan Ren

    2016-01-01

    Full Text Available Although mesenchymal stem cells (MSCs based therapy has been considered as a promising tool for tissue repair and regeneration, the optimal cell source remains unknown. Umbilical cord (UC, dental pulp (DP, and menstrual blood (MB are easily accessible sources, which make them attractive candidates for MSCs. The goal of this study was to compare the biological characteristics, including morphology, proliferation, antiapoptosis, multilineage differentiation capacity, and immunophenotype of UC-, DP-, and MB-MSCs in order to provide a theoretical basis for clinical selection and application of these cells. As a result, all UC-, DP-, and MB-MSCs have self-renewal capacity and multipotentiality. However, the UC-MSCs seemed to have higher cell proliferation ability, while DP-MSCs may have significant advantages for osteogenic differentiation, lower cell apoptosis, and senescence. These differences may be associated with the different expression level of cytokines, including vascular endothelial growth factor, fibroblast growth factor, keratinocyte growth factor, and hepatocyte growth factor in each of the MSCs. Comprehensively, our results suggest DP-MSCs may be a desired source for clinical applications of cell therapy.

  8. Numerical Investigation and Experimental Reproduction of Fermi Acceleration in Laboratory Scale

    Science.gov (United States)

    Zhou, M.; Zhai, C.

    2015-12-01

    Fermi acceleration is widely accepted as the mechanism to explain power law of cosmic ray spectrum. Now this mechanism has been developed to first order Fermi acceleration and second order Fermi acceleration. In first order Fermi acceleration, also known as diffusive shock acceleration, particles are confined around the shock through scattering and accelerated by repeatedly crossing shock front. In second order Fermi acceleration, particles gain energy through statistical collisions with interstellar clouds. In this proposed work, we plan to carefully study these two kinds of acceleration numerically and experimentally. We first consider a single relativistic particle and investigate how it gains energy in Fermi-Ulam model and shock wave acceleration model respectively. We investigate collective behavior of particles with different kinds of wall-oscillation functions and try to find an optimal one in terms of efficiency of acceleration. Then, we plan to go further and consider a group of particles statistically, during which we borrow the correct generalization of Maxwell's velocity distribution in special relativity and compare the results with those in cases where we simply use Maxwell-Boltzmann distribution. To this end, we try to provide a scheme to build an accelerator applying both laser technology and mirror effect in Laboratory to reproduce Fermi acceleration, which might be a promising source to obtain high energy particles and further study the mechanism of cosmic rays acceleration.

  9. Symposium report on frontier applications of accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Parsa, Z. [ed.

    1993-09-28

    This report contains viewgraph material on the following topics: Electron-Positron Linear Colliders; Unconventional Colliders; Prospects for UVFEL; Accelerator Based Intense Spallation; Neutron Sources; and B Physics at Hadron Accelerators with RHIC as an Example.

  10. Berkeley Lab Laser Accelerator (BELLA) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Berkeley Lab Laser Accelerator (BELLA) facility (formerly LOASIS) develops advanced accelerators and radiation sources. High gradient (1-100 GV/m) laser-plasma...

  11. Acceleration and Special Relativity

    CERN Document Server

    Yahalomi, E M

    2000-01-01

    The integration of acceleration over time before reaching the uniformvelocity turns out to be the source of all the special relativity effects. Itexplains physical phenomena like clocks comparisons. The equations forspace-time, mass and energy are presented. This phenomenon complements theexplanation for the twins paradox. A Universal reference frame is obtained.

  12. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  13. Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Amini Arya

    2012-03-01

    Full Text Available Abstract Background While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. Methods This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1 and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2. Results There were 119 (39.7% patients in the ACRT group, 90 (30.0% in STRT1 and 91 (30.3% in STRT2. More patients in the ACRT group had KPS ≤ 60 (p 5% (p = 0.002, and had stage 3B disease (p Conclusions Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC.

  14. Biomedical accelerator mass spectrometry

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  15. THE PRECISION AND ACCURACY OF EARLY EPOCH OF REIONIZATION FOREGROUND MODELS: COMPARING MWA AND PAPER 32-ANTENNA SOURCE CATALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Daniel C.; Bowman, Judd [School of Space and Earth Exploration, Arizona State University, Tempe, AZ (United States); Aguirre, James E., E-mail: daniel.c.jacobs@asu.edu [Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd Street, Philadelphia, PA (United States)

    2013-05-20

    As observations of the Epoch of Reionization (EoR) in redshifted 21 cm emission begin, we assess the accuracy of the early catalog results from the Precision Array for Probing the Epoch of Reionization (PAPER) and the Murchison Wide-field Array (MWA). The MWA EoR approach derives much of its sensitivity from subtracting foregrounds to <1% precision, while the PAPER approach relies on the stability and symmetry of the primary beam. Both require an accurate flux calibration to set the amplitude of the measured power spectrum. The two instruments are very similar in resolution, sensitivity, sky coverage, and spectral range and have produced catalogs from nearly contemporaneous data. We use a Bayesian Markov Chain Monte Carlo fitting method to estimate that the two instruments are on the same flux scale to within 20% and find that the images are mostly in good agreement. We then investigate the source of the errors by comparing two overlapping MWA facets where we find that the differences are primarily related to an inaccurate model of the primary beam but also correlated errors in bright sources due to CLEAN. We conclude with suggestions for mitigating and better characterizing these effects.

  16. Dosimetry of the energy of the electrons beam and virtual distance of the source of a lineal accelerator; Dosimetria de la energia del haz de electrones y distancia virtual de la fuente de un acelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, A.; Garcia, B.; Ramirez, J.; Marquina, J., E-mail: andres.gonzales@aliada.com.pe [ALIADA, Oncologia Integral, Av. Jose Galvez Barrenechea 1044, San Isidro, Lima 27 (Peru)

    2014-08-15

    The objectives of this work were to characterize, to gauge the energy of a electrons beam of 12 MeV and to find the virtual distance of the source for a lineal accelerator Trilogy-Varian. For the characterization, calibration and to find the virtual distance of the source of a lineal accelerator Trilogy-Varian, a water phantom was used (cylindrical Cuba 3-D) of Sun-Nuclear. The following values were found: R{sub 50.ion} = 4, 95 g/cm{sup 2}, R{sub 50} = 5, 04 g/cm{sup 2}, Z{sub ref} = 2,92 g/cm{sup 2}, Z{sub max} = 2, 60 g/cm{sup 2}. In the calibration was found D{sub W,Q}(Z{sub max}) = 1, 0015 c Gy/Um. In the profile In-plane was measured a symmetry and flatness of 1, 9% and 1, 6% respectively. In the profile Cross-plane a symmetry was measured and flatness of 1, 9% and 1, 3% respectively. The virtual distance regarding the source was of DFS (virtual) =105,81 cm. The electrons beam of 12 MeV was characterized and gauged satisfactorily, were carried out the In-plane and Cross-plane profiles, obtaining all the parameters inside the acceptance limit. The virtual distance of the source was of 105,81 cm. (Author)

  17. Cosmic particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Zimbardo, Gaetano; Perri, Silvia [Universita della Calabria, Dipartimento di Fisica, 87036 Rende (Italy)

    2014-07-01

    The most popular mechanism for the acceleration of cosmic rays, which is thought to operate in supernova remnant shocks as well as at heliospheric shocks, is the diffusive shock acceleration, which is a Fermi mechanism based on normal diffusion. On the other hand, in the last few years it has been shown that the transport of plasma particles in the presence of electric and magnetic turbulence can be superdiffusive rather than normal diffusive. The term 'superdiffusive' refers to the mean square displacement of particle positions growing superlinearly with time, as compared to the normal linear growth. In particular, superdiffusion is characterized by a non Gaussian statistical process called Levy random walk. We show how diffusive shock acceleration is modified by superdiffusion, and how this yields new predictions for the cosmic ray spectral index, for the acceleration time, and for the spatial profile of energetic particles. A comparison with observations of particle acceleration at heliospheric shocks and at supernova remnant shocks is done. We discuss how superdiffusive shock acceleration allows to explain the observations of hard ion spectra at the solar wind termination shock detected by Voyager 2, of hard radio spectra due to synchrotron emission of electrons accelerated at supernova remnant shocks, and how it can help to explain the observations of 'thin rims' in the X-ray synchrotron emission.

  18. Shielding high energy accelerators

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    After introducing the subject of shielding high energy accelerators, point source, line-of-sight models, and in particular the Moyer model. are discussed. Their use in the shielding of proton and electron accelerators is demonstrated and their limitations noted. especially in relation to shielding in the forward direction provided by large, flat walls. The limitations of reducing problems to those using it cylindrical geometry description are stressed. Finally the use of different estimators for predicting dose is discussed. It is suggested that dose calculated from track-length estimators will generally give the most satisfactory estimate. (9 refs).

  19. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study

    Science.gov (United States)

    Alex, Deepa; Shetty, Y. Bharath; Miranda, Glynis Anita; Prabhu, M. Bharath; Karkera, Reshma

    2015-01-01

    Background: Conventional investing and casting techniques are time-consuming and usually requires 2–4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30–40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. Materials and Methods: A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. Results: The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P < 0.001). Mean vertical gap was the maximum for Group II (53.64 μm) followed by Group IV (47.62 μm), Group I (44.83 μm) and Group III (35.35 μm). Conclusion: The Ni-Cr cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had

  20. Comparative Performance of Hybrid and Elite Inbred Rice Varieties with respect to Their Source-Sink Relationship

    Directory of Open Access Journals (Sweden)

    Md Moinul Haque

    2015-01-01

    Full Text Available Hybrid rice varieties have higher yield potential over inbred varieties. This improvement is not always translated to the grain yield and its physiological causes are still unclear. In order to clarify it, two field experiments were conducted including two popular indica hybrids (BRRI hybrid dhan2 and Heera2 and one elite inbred (BRRI dhan45 rice varieties. Leaf area index, chlorophyll status, and photosynthetic rate of flag leaf, postheading crop growth rate, shoot reserve translocation, source-sink relation and yield, and its attributes of each variety were comprehensively analyzed. Both hybrid varieties outyielded the inbred. However, the hybrids and inbred varieties exhibited statistically identical yield in late planting. Both hybrids accumulated higher amount of biomass before heading and exhibited greater remobilization of assimilates to the grain in early plantings compared to the inbred variety. Filled grain (% declined significantly at delayed planting in the hybrids compared to elite inbred due to increased temperature impaired-inefficient transport of assimilates. Flag leaf photosynthesis parameters were higher in the hybrid varieties than those of the inbred variety. Results suggest that greater remobilization of shoot reserves to the grain rendered higher yield of hybrid rice varieties.

  1. Comparing nearshore benthic and pelagic prey as mercury sources to lake fish: the importance of prey quality and mercury content.

    Science.gov (United States)

    Karimi, Roxanne; Chen, Celia Y; Folt, Carol L

    2016-09-15

    Mercury (Hg) bioaccumulation in fish poses well-known health risks to wildlife and humans through fish consumption. Yet fish Hg concentrations are highly variable, and key factors driving this variability remain unclear. One little studied source of variation is the influence of habitat-specific feeding on Hg accumulation in lake fish. However, this is likely important because most lake fish feed in multiple habitats during their lives, and the Hg and caloric content of prey from different habitats can differ. This study used a three-pronged approach to investigate the extent to which habitat-specific prey determine differences in Hg bioaccumulation in fish. This study first compared Hg concentrations in common nearshore benthic invertebrates and pelagic zooplankton across five lakes and over the summer season in one lake, and found that pelagic zooplankton generally had higher Hg concentrations than most benthic taxa across lakes, and over a season in one lake. Second, using a bioenergetics model, the effects of prey caloric content from habitat-specific diets on fish growth and Hg accumulation were calculated. This model predicted that the consumption of benthic prey results in lower fish Hg concentrations due to higher prey caloric content and growth dilution (high weight gain relative to Hg from food), in addition to lower prey Hg levels. Third, using data from the literature, links between fish Hg content and the degree of benthivory, were examined, and showed that benthivory was associated with reduced Hg concentrations in lake fish. Taken together, these findings support the hypothesis that higher Hg content and lower caloric content make pelagic zooplankton prey greater sources of Hg for fish than nearshore benthic prey in lakes. Hence, habitat-specific foraging is likely to be a strong driver of variation in Hg levels within and between fish species.

  2. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2007-01-01

    Particle Accelerator Physics is an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. Part I gathers the basic tools, recalling the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part II is an extensive primer in beam dynamics, followed in Part III by the introduction and description of the main beam parameters. Part IV is devoted to the treatment of perturbations in beam dynamics. Part V discusses the details of charged particle accleration. Part VI and Part VII introduce the more advanced topics of coupled beam dynamics and the description of very intense beams. Part VIII is an exhaustive treatment of radiation from accelerated charges and introduces important sources of coherent radiation such as synchrotrons and free-electron lasers. Part IX collects the appendices gathering useful mathematical and physical formulae, parameters and units. Solutions to many end-of-chapter problems are give...

  3. Pentaho and Jaspersoft: A Comparative Study of Business Intelligence Open Source Tools Processing Big Data to Evaluate Performances

    Directory of Open Access Journals (Sweden)

    Victor M. Parra

    2016-10-01

    Full Text Available Regardless of the recent growth in the use of “Big Data” and “Business Intelligence” (BI tools, little research has been undertaken about the implications involved. Analytical tools affect the development and sustainability of a company, as evaluating clientele needs to advance in the competitive market is critical. With the advancement of the population, processing large amounts of data has become too cumbersome for companies. At some stage in a company’s lifecycle, all companies need to create new and better data processing systems that improve their decision-making processes. Companies use BI Results to collect data that is drawn from interpretations grouped from cues in the data set BI information system that helps organisations with activities that give them the advantage in a competitive market. However, many organizations establish such systems, without conducting a preliminary analysis of the needs and wants of a company, or without determining the benefits and targets that they aim to achieve with the implementation. They rarely measure the large costs associated with the implementation blowout of such applications, which results in these impulsive solutions that are unfinished or too complex and unfeasible, in other words unsustainable even if implemented. BI open source tools are specific tools that solve this issue for organizations in need, with data storage and management. This paper compares two of the best positioned BI open source tools in the market: Pentaho and Jaspersoft, processing big data through six different sized databases, especially focussing on their Extract Transform and Load (ETL and Reporting processes by measuring their performances using Computer Algebra Systems (CAS. The ETL experimental analysis results clearly show that Jaspersoft BI has an increment of CPU time in the process of data over Pentaho BI, which is represented by an average of 42.28% in performance metrics over the six databases

  4. Utilizing Free and Open Source Software to access, view and compare in situ observations, EO products and model output data

    Science.gov (United States)

    Vines, Aleksander; Hamre, Torill; Lygre, Kjetil

    2014-05-01

    The GreenSeas project (Development of global plankton data base and model system for eco-climate early warning) aims to advance the knowledge and predictive capacities of how marine ecosystems will respond to global change. A main task has been to set up a data delivery and monitoring core service following the open and free data access policy implemented in the Global Monitoring for the Environment and Security (GMES) programme. The aim is to ensure open and free access to historical plankton data, new data (EO products and in situ measurements), model data (including estimates of simulation error) and biological, environmental and climatic indicators to a range of stakeholders, such as scientists, policy makers and environmental managers. To this end, we have developed a geo-spatial database of both historical and new in situ physical, biological and chemical parameters for the Southern Ocean, Atlantic, Nordic Seas and the Arctic, and organized related satellite-derived quantities and model forecasts in a joint geo-spatial repository. For easy access to these data, we have implemented a web-based GIS (Geographical Information Systems) where observed, derived and forcasted parameters can be searched, displayed, compared and exported. Model forecasts can also be uploaded dynamically to the system, to allow modelers to quickly compare their results with available in situ and satellite observations. We have implemented the web-based GIS(Geographical Information Systems) system based on free and open source technologies: Thredds Data Server, ncWMS, GeoServer, OpenLayers, PostGIS, Liferay, Apache Tomcat, PRTree, NetCDF-Java, json-simple, Geotoolkit, Highcharts, GeoExt, MapFish, FileSaver, jQuery, jstree and qUnit. We also wanted to used open standards to communicate between the different services and we use WMS, WFS, netCDF, GML, OPeNDAP, JSON, and SLD. The main advantage we got from using FOSS was that we did not have to invent the wheel all over again, but could use

  5. Comparing momentum and mass (aerosol source function) fluxes for the North Atlantic and the European Arctic using different parameterizations

    Science.gov (United States)

    Wróbel, Iwona; Piskozub, Jacek

    2016-04-01

    Wind speed has a disproportionate role in the forming of the climate as well it is important part in calculate of the air-sea interaction thanks which we can study climate change. It influences on mass, momentum and energy fluxes and the standard way of parametrizing those fluxes is use this variable. However, the very functions used to calculate fluxes from winds have evolved over time and still have large differences (especially in the case of aerosol sources function). As we have shown last year at the EGU conference (PICO presentation EGU2015-11206-1) and in recent public article (OSD 12,C1262-C1264,2015) there is a lot of uncertainties in the case of air-sea CO2 fluxes. In this study we calculated regional and global mass and momentum fluxes based on several wind speed climatologies. To do this we use wind speed from satellite data in FluxEngine software created within OceanFlux GHG Evolution project. Our main area of interest is European Arctic because of the interesting air-sea interaction physics (six-monthly cycle, strong wind and ice cover) but because of better data coverage we have chosen the North Atlantic as a study region to make it possible to compare the calculated fluxes to measured ones. An additional reason was the importance of the area for the North Hemisphere climate, and especially for Europe. The study is related to an ESA funded OceanFlux GHG Evolution project and is meant to be part of a PhD thesis (of I.W) funded by Centre of Polar Studies "POLAR-KNOW" (a project of the Polish Ministry of Science). We have used a modified version FluxEngine, a tool created within an earlier ESA funded project (OceanFlux Greenhouse Gases) for calculating trace gas fluxes to derive two purely wind driven (at least in the simplified form used in their parameterizations) fluxes. The modifications included removing gas transfer velocity formula from the toolset and replacing it with the respective formulas for momentum transfer and mass (aerosol production

  6. Accelerated Unification

    OpenAIRE

    Arkani-Hamed, Nima; Cohen, Andrew; Georgi, Howard

    2001-01-01

    We construct four dimensional gauge theories in which the successful supersymmetric unification of gauge couplings is preserved but accelerated by N-fold replication of the MSSM gauge and Higgs structure. This results in a low unification scale of $10^{13/N}$ TeV.

  7. An investigation of the neutron flux in bone-fluorine phantoms comparing accelerator based in vivo neutron activation analysis and FLUKA simulation data

    Energy Technology Data Exchange (ETDEWEB)

    Mostafaei, F.; McNeill, F.E.; Chettle, D.R.; Matysiak, W.; Bhatia, C.; Prestwich, W.V.

    2015-01-01

    We have tested the Monte Carlo code FLUKA for its ability to assist in the development of a better system for the in vivo measurement of fluorine. We used it to create a neutron flux map of the inside of the in vivo neutron activation analysis irradiation cavity at the McMaster Accelerator Laboratory. The cavity is used in a system that has been developed for assessment of fluorine levels in the human hand. This study was undertaken to (i) assess the FLUKA code, (ii) find the optimal hand position inside the cavity and assess the effects on precision of a hand being in a non-optimal position and (iii) to determine the best location for our γ-ray detection system within the accelerator beam hall. Simulation estimates were performed using FLUKA. Experimental measurements of the neutron flux were performed using Mn wires. The activation of the wires was measured inside (1) an empty bottle, (2) a bottle containing water, (3) a bottle covered with cadmium and (4) a dry powder-based fluorine phantom. FLUKA was used to simulate the irradiation cavity, and used to estimate the neutron flux in different positions both inside, and external to, the cavity. The experimental results were found to be consistent with the Monte Carlo simulated neutron flux. Both experiment and simulation showed that there is an optimal position in the cavity, but that the effect on the thermal flux of a hand being in a non-optimal position is less than 20%, which will result in a less than 10% effect on the measurement precision. FLUKA appears to be a code that can be useful for modeling of this type of experimental system.

  8. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977. [Planning for use for radiotherapy and as radiation source for diagnostic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Elam, S. (ed.)

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery.

  9. Comparative study on CO2 sources in soil developed on carbonate rock and non-carbonate rock in Central Guizhou

    Institute of Scientific and Technical Information of China (English)

    黎廷宇; 王世杰; 郑乐平

    2002-01-01

    In this paper, by using concentration and carbon stable isotope the.CO2 sources of soil profiles developed on limestone, dolostone and claystone basements in Central Guizhou, China are comparatively studied. The results show that CO2 concentration of soil profiles developed on different basements is different, having the following sequence: limestone>dolostone>claystone. Below the soil depth of 20 cm from the surface the δ13C value of CO2 in soil profile developed on limestone ranges from -12.811‰ - -13.492‰(PDB), that in soil profile developed on dolostone varys from -13.212‰--14.271‰(PDB) and that in soil profile developed on claystone is about -20.234‰- -21.485‰(PDB). Taking the carbon isotope of soil organic matter and carbonate rock as two isotopic endmembers, the proportion of soil C02 generated by dissolution of carbonate rock is calculated, about 21%-25% for soil profile developed on limestone basement, 19%-21% for soil profile developed on dolostone basement. There is almost no influx of

  10. A COMPARATIVE STUDY OF CASTOR AND JATROPHA OIL SOURCE AND ITS METHYL ESTER TEST ON THE DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    DEVENDRA VASHIST,

    2011-06-01

    Full Text Available Neat non-edible oils pose problems when subjected to use when used in the CI engines. These problems are attributed to high viscosity, low volatility and polyunsaturated character of these oils. Two non-edible sources of the oils were identified i.e jatropha and castor. The biodiesel was prepared from neat oils and blends preparedwith diesel. up till 20 percent of biodiesel. Produced blends were tested for their use as a substitute fuel for diesel in a single cylinder diesel engine at varying loads. The best engine operating condition based on lower brake specific fuel consumption and higher brake thermal efficiency were identified and compared. On the observed data for both the fuels, Chi square (2 statistical test was applied. The values calculated for 2 jatropha oil methyl ester (JOME = 0.0104 and 2 castor oil methyl ester (COME = 0.0524. The values concluded that there is no effect of fuel type on fuel consumption up till 20 percent biodiesel blended fuel.

  11. Sources of variability and comparability between salmonid stomach contents and isotopic analyses: study design lessons and recommendations

    Science.gov (United States)

    Vinson, M.R.; Budy, P.

    2011-01-01

    We compared sources of variability and cost in paired stomach content and stable isotope samples from three salmonid species collected in September 2001–2005 and describe the relative information provided by each method in terms of measuring diet overlap and food web study design. Based on diet analyses, diet overlap among brown trout, rainbow trout, and mountain whitefish was high, and we observed little variation in diets among years. In contrast, for sample sizes n ≥ 25, 95% confidence interval (CI) around mean δ15Ν and δ13C for the three target species did not overlap, and species, year, and fish size effects were significantly different, implying that these species likely consumed similar prey but in different proportions. Stable isotope processing costs were US$12 per sample, while stomach content analysis costs averaged US$25.49 ± $2.91 (95% CI) and ranged from US$1.50 for an empty stomach to US$291.50 for a sample with 2330 items. Precision in both δ15Ν and δ13C and mean diet overlap values based on stomach contents increased considerably up to a sample size of n = 10 and plateaued around n = 25, with little further increase in precision.

  12. Comparative study on CO2 sources in soil developed on carbonate rock and non-carbonate rock in Central Guizhou

    Institute of Scientific and Technical Information of China (English)

    黎廷宇; 王世杰; 郑乐平

    2002-01-01

    In this paper, by using concentration and carbon stable isotope the CO2 sources of soil profiles developed on limestone, dolostone and claystone basements in Central Guizhou, China are comparatively studied. The results show that CO2 concentration of soil profiles developed on different basements is different, having the following sequence: limestone>dolostone>claystone. Below the soil depth of 20 cm from the surface the ? 13C value of CO2 in soil profile developed on limestone ranges from -12.811‰ - -13.492‰(PDB), that in soil profile developed on dolostone varys from -13.212‰ - -14.271‰(PDB) and that in soil profile developed on claystone is about -20.234‰ - -21.485‰(PDB). Taking the carbon isotope of soil organic matter and carbonate rock as two isotopic endmembers, the proportion of soil CO2 generated by dissolution of carbonate rock is calculated, about 21%-25% for soil profile developed on limestone basement, 19%-21% for soil profile developed on dolostone basement. There is almost no influx of CO2 generated by the dissolution of carbonate rock in soil profile developed on claystone basement.

  13. Comparative in vitro fermentation activity in the canine distal gastrointestinal tract and fermentation kinetics of fiber sources.

    Science.gov (United States)

    Bosch, G; Pellikaan, W F; Rutten, P G P; van der Poel, A F B; Verstegen, M W A; Hendriks, W H

    2008-11-01

    The current study aimed to evaluate the variation in fermentation activity along the distal canine gastrointestinal tract (GIT, Exp. 1). It also aimed to assess fermentation kinetics and end product profiles of 16 dietary fibers for dog foods using canine fecal inoculum (Exp. 2). For Exp. 1, digesta were collected from the distal ileum, proximal colon, transverse colon, and rectum of 3 adult dogs. Digesta per part of the GIT were pooled for 3 dogs, diluted (1:25, wt/vol), mixed, and filtered for the preparation of inoculum. A fructan, ground soy hulls, and native potato starch were used as substrates and incubated for cumulative gas production measurement as an indicator of the kinetics of fermentation. In addition, fermentation bottles with similar contents were incubated but were allowed to release their gas throughout incubation. Fermentation fluid was sampled at 4, 8, 12, 24, 48, and 72 h after initiation of incubation, and short-chain fatty acids and ammonia were measured. Results showed comparable maximal fermentation rates for rectal and proximal colonic inocula (P > 0.05). Production of short-chain fatty acids was least for the ileal and greatest for the rectal inoculum (P fiber, peanut hulls, soy fiber, sugar beet fiber, sugar beet pectin, sugar beet pulp, wheat fiber, and wheat middlings. Feces of 4 adult dogs were used as an inoculum source. Similar techniques were used as in Exp. 1 except for the dilution factor used (1:10, wt/vol). Among substrates, large variations in fermentation kinetics and end product profiles were noted. Sugar beet pectin, the fructans, and the gums were rapidly fermentable, indicated by a greater maximal rate of gas production (R(max)) compared with all other substrates (P fiber were poorly fermentable, indicated by the least amount of gas produced (P fiber, sugar beet pulp, soy fiber, and wheat middlings were moderately fermentable with a low R(max). Citrus pectin and pea fiber showed a similar low R(max), but time at which

  14. Comparative study of two drying techniques used in radioactive source preparation: freeze-drying and evaporation using hot dry nitrogen jets.

    Science.gov (United States)

    Branger, T; Bobin, C; Iroulart, M-G; Lépy, M-C; Le Garrères, I; Morelli, S; Lacour, D; Plagnard, J

    2008-01-01

    Quantitative solid sources are used widely in the field of radionuclide metrology. With the aim to improve the detection efficiency for electrons and x-rays, a comparative study between two source drying techniques has been undertaken at LNE-Laboratoire National Henri Becquerel (LNE-LNHB, France). In this paper, freeze-drying using commercial equipment is compared with a system of drying using hot jets of nitrogen developed at Institute for Reference Materials and Measurements (IRMM, Belgium). In order to characterize the influence of self-absorption, the detection efficiencies for (51)Cr sources have been measured by coincidence counting and photon spectrometry.

  15. Cultivation of a thermo-tolerant microalga in an outdoor photobioreactor: influences of CO2 and nitrogen sources on the accelerated growth.

    Science.gov (United States)

    Huang, Chai-Cheng; Hung, Jia-Jang; Peng, Shao-Hung; Chen, Ching-Nen Nathan

    2012-05-01

    A photobioreactor was designed to evaluate the performance of a newly isolated thermo-tolerant microalga Desmodesmus sp. F2 in municipal wastewater under tropical outdoor conditions. The environmental parameters, levels of nutrients, and growth rates were monitored during the cultivations to elucidate the factors that contributed to accelerated growth after lag phase. Cultures bubbled with CO(2)-air had about 20% higher yields than the air-bubbled culture, and 2% of CO(2) at a flux rate of 5L/min was sufficient to reach this increased yield. In the cultures bubbled with CO(2)-air, the microalgal cells preferentially utilized ammonium and nitrate, while the air-bubbled culture made greater use of ammonium and organic nitrogen. In conclusion, the factors required for microalga Desmodesmus sp. F2 to achieve accelerated growth in tropical outdoor conditions include (1) 2% CO(2) bubbling; (2) a level of ammonium higher than 100 μM; and (3) a level of nitrate higher than 400 μM.

  16. Landing the uniformly accelerating observers

    OpenAIRE

    Rothenstein, Bernhard; Popescu, Stefan; Gruber, Ronald P.

    2006-01-01

    Observers of the uniformly accelerating observers or the observers who make up the system of uniformly accelerating observers reach the same velocity V at different times ti which depends on V and on theirs acceleration gi. Considering a platform that moves with constant velocity V, the observers can land smoothly on it. Their ages and locations in the inertial reference frame attached to the platform are reckoned and compared.

  17. Accelerator Technology Division progress report, FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Schriber, S.O.; Hardekopf, R.A.; Heighway, E.A.

    1993-07-01

    This report briefly discusses the following topics: The Ground Test Accelerator Program; Defense Free-Electron Lasers; AXY Programs; A Next Generation High-Power Neutron-Scattering Facility; JAERI OMEGA Project and Intense Neutron Sources for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Supercollider; The High-Power Microwave (HPM) Program; Neutral Particle Beam (NPB) Power Systems Highlights; Industrial Partnering; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Accelerator Theory and Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  18. What drives FDI from non-traditional sources? A comparative analysis of the determinants of bilateral FDI flows

    OpenAIRE

    2013-01-01

    Non-traditional source countries of FDI play an increasingly important role, notably in developing host countries. This raises the question of whether the determinants of FDI differ systematically between traditional and non-traditional source countries. We perform Logit and Poisson Pseudo Maximum Likelihood estimations drawing on UNCTAD's database on bilateral FDI flows, including various emerging and developing countries as sources of FDI outflows. We find that economic geography variables ...

  19. MUON ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  20. Effect of the electron transport through thin slabs on the simulation of linear electron accelerators of use in therapy: A comparative study of various Monte Carlo codes

    Energy Technology Data Exchange (ETDEWEB)

    Vilches, M. [Servicio de Fisica y Proteccion Radiologica, Hospital Regional Universitario ' Virgen de las Nieves' , Avda. de las Fuerzas Armadas, 2, E-18014 Granada (Spain)], E-mail: mvilches@ugr.es; Garcia-Pareja, S. [Servicio de Radiofisica Hospitalaria, Hospital Regional Universitario ' Carlos Haya' , Avda. Carlos Haya, s/n, E-29010 Malaga (Spain); Guerrero, R. [Servicio de Radiofisica, Hospital Universitario ' San Cecilio' , Avda. Dr. Oloriz, 16, E-18012 Granada (Spain); Anguiano, M.; Lallena, A.M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain)

    2007-09-21

    When a therapeutic electron linear accelerator is simulated using a Monte Carlo (MC) code, the tuning of the initial spectra and the renormalization of dose (e.g., to maximum axial dose) constitute a common practice. As a result, very similar depth dose curves are obtained for different MC codes. However, if renormalization is turned off, the results obtained with the various codes disagree noticeably. The aim of this work is to investigate in detail the reasons of this disagreement. We have found that the observed differences are due to non-negligible differences in the angular scattering of the electron beam in very thin slabs of dense material (primary foil) and thick slabs of very low density material (air). To gain insight, the effects of the angular scattering models considered in various MC codes on the dose distribution in a water phantom are discussed using very simple geometrical configurations for the LINAC. The MC codes PENELOPE 2003, PENELOPE 2005, GEANT4, GEANT3, EGSnrc and MCNPX have been used.

  1. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  2. Source Apportionment of Ambient PM10 in the Urban Area of Longyan City, China: a Comparative Study Based on Chemical Mass Balance Model and Factor Analysis Method

    Institute of Scientific and Technical Information of China (English)

    QIU Li-min; LIU Miao; WANG Ju; ZHANG Sheng-nan; FANG Chun-sheng

    2012-01-01

    In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry(ICP-MS).Then chemical mass balance(CMB)model and factor analysis(FA)method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan.

  3. Select Features of Diabetic Retinopathy on Swept-Source Optical Coherence Tomographic Angiography Compared With Fluorescein Angiography and Normal Eyes

    Science.gov (United States)

    Salz, David A.; de Carlo, Talisa E.; Adhi, Mehreen; Moult, Eric; Choi, WhooJhon; Baumal, Caroline R.; Witkin, Andre J.; Duker, Jay S.; Fujimoto, James G.; Waheed, Nadia K.

    2017-01-01

    IMPORTANCE Optical coherence tomographic angiography (OCTA) is a recently developed noninvasive imaging technique that can visualize the retinal and choroidal microvasculature without the injection of exogenous dyes. OBJECTIVE To evaluate the potential clinical utility of OCTA using a prototype swept-source OCT (SS-OCT) device and compare it with fluorescein angiography (FA) for analysis of the retinal microvasculature in diabetic retinopathy. DESIGN, SETTING, AND PARTICIPANTS Prospective, observational cross-sectional study conducted at a tertiary care academic retina practice from November 2013 through November 2014. A cohort of diabetic and normal control eyes were imaged with a prototype SS-OCT system. The stage of diabetic retinopathy was determined by clinical examination. Imaging was performed using angiographic 3 × 3-mm and 6 × 6-mm SS-OCT scans to generate 3-dimensional en-face OCT angiograms for each eye. Two trained Boston Image Reading Center readers reviewed and graded FA and OCTA images independently. MAIN OUTCOMES AND MEASURES The size of the foveal nonflowzone and the perifoveal intercapillary area on OCTA were measured in both normal and diabetic eyes using Boston Image Reading Center image analysis software. RESULTS The study included 30 patients with diabetes (mean [SD] age, 55.7 [10] years) and 6 control individuals (mean [SD] age, 55.1 [6.4] years). A total of 43 diabetic and 11 normal control eyes were evaluated with OCTA. Fluorescein angiography was performed in 17 of 43 diabetic eyes within 8 weeks of the OCTA. Optical coherence tomographic angiography was able to identify a mean (SD) of 6.4 (4.0) microaneurysms (95% CI, 4.4–8.5), while FA identified a mean (SD) of 10 (6.9) microaneurysms (95% CI, 6.4–13.5). The exact intraretinal depth of microaneurysms on OCTA was localized in all cases (100%). The sensitivity of OCTA in detecting microaneuryms when compared with FA was 85% (95% CI, 53–97), while the specificity was 75% (95% CI, 21

  4. Accelerators and the Accelerator Community

    Energy Technology Data Exchange (ETDEWEB)

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  5. Beam acceleration through proton radio frequency quadrupole accelerator in BARC

    Science.gov (United States)

    Bhagwat, P. V.; Krishnagopal, S.; Mathew, J. V.; Singh, S. K.; Jain, P.; Rao, S. V. L. S.; Pande, M.; Kumar, R.; Roychowdhury, P.; Kelwani, H.; Rama Rao, B. V.; Gupta, S. K.; Agarwal, A.; Kukreti, B. M.; Singh, P.

    2016-05-01

    A 3 MeV proton Radio Frequency Quadrupole (RFQ) accelerator has been designed at the Bhabha Atomic Research Centre, Mumbai, India, for the Low Energy High Intensity Proton Accelerator (LEHIPA) programme. The 352 MHz RFQ is built in 4 segments and in the first phase two segments of the LEHIPA RFQ were commissioned, accelerating a 50 keV, 1 mA pulsed proton beam from the ion source, to an energy of 1.24 MeV. The successful operation of the RFQ gave confidence in the physics understanding and technology development that have been achieved, and indicate that the road forward can now be traversed rather more quickly.

  6. Localized Ionospheric Particle Acceleration and Wave Acceleration of Auroral Ions: Amicist Data Set

    Science.gov (United States)

    Lynch, Kristina A.

    1999-01-01

    Research supported by this grant covered two main topics: auroral ion acceleration from ELF-band wave activity, and from VLF-spikelet (lower hybrid solitary structure) wave activity. Recent auroral sounding rocket data illustrate the relative significance of various mechanisms for initiating auroral ion outflow. Two nightside mechanisms are shown in detail. The first mechanism is ion acceleration within lower hybrid solitary wave events. The new data from this two payload mission show clearly that: (1) these individual events are spatially localized to scales approximately 100 m wide perpendicular to B, in agreement with previous investigations of these structures, and (2) that the probability of occurrence of the events is greatest at times of maximum VLF wave intensity. The second mechanism is ion acceleration by broadband, low frequency electrostatic waves, observed in a 30 km wide region at the poleward edge of the arc. The ion fluxes from the two mechanisms are compared and it is shown that while lower hybrid solitary structures do indeed accelerate ions in regions of intense VLF waves, the outflow from the electrostatic ion wave acceleration region is dominant for the aurora investigated by this sounding rocket, AMICIST. The fluxes are shown to be consistent with DE-1 and Freja outflow measurements, indicating that the AMICIST observations show the low altitude, microphysical signatures of nightside auroral outflow. In this paper, we present a review of sounding rocket observations of the ion acceleration seen nightside auroral zone lower hybrid solitary structures. Observations from Topaz3, Amicist, and Phaze2 are presented on various spatial scales, including the two-point measurements of the Amicist mission. From this collection of observations, we will demonstrate the following characteristics of transverse ion acceleration (TAI) in LHSS. The ion acceleration process is narrowly confined to 90 degrees pitch angle, in spatially confined regions of up to a

  7. Electrostatic accelerators fundamentals and applications

    CERN Document Server

    2005-01-01

    Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

  8. accelerating cavity

    CERN Multimedia

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  9. Impact accelerations

    Science.gov (United States)

    Vongierke, H. E.; Brinkley, J. W.

    1975-01-01

    The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

  10. Comparative value of phosphate sources on the immobilization of lead, and leaching of lead and phosphorus in lead contaminated soils.

    Science.gov (United States)

    Park, Jin Hee; Bolan, Nanthi; Megharaj, Mallavarapu; Naidu, Ravi

    2011-01-15

    The mobility and bioavailability of lead (Pb) in soils can be mitigated by its immobilization using both soluble and insoluble phosphate (P) compounds. The effectiveness of insoluble P sources on Pb immobilization depends on their rate of dissolution which can be enhanced by phosphate solubilizing bacteria (PSB). In this study, the effect of soluble (potassium dihydrogen phosphate) and insoluble (rock phosphate in the presence and absence of PSB) P compounds on the immobilization of Pb, and leaching of Pb and P was examined using both naturally contaminated (SR soil: NH₄NO₃ extractable Pb: 28.7 mg/kg, pH: 5.88, organic matter: 0.7%) and Pb spiked (AH soil: NH(4)NO(3) extractable Pb: 42.7 mg/kg, pH: 5.23, organic matter: 10.9%) soils. Phosphate compounds were added at the rate of 200 mg P/kg and 800 mg P/kg for SR and AH soils, respectively. Soluble P treatment immobilized 80% and 57% of Pb in SR and AH soils, respectively. Insoluble rock phosphate immobilized 40% and 9% of Pb without PSB, and 60% and 17% with PSB in SR and AH soils, respectively. Lead leaching was the lowest when soils were amended with rock phosphate in the presence of PSB, which reduced Pb leaching by 36% for SR soil and 18% for AH soil compared to the control. The leaching of Pb increased when the soils were amended with soluble P because soluble P treatment increased dissolved organic carbon (DOC) concentration of soil, thereby increasing Pb mobility. Soluble P treatment significantly increased P leaching and 9% of total added P was leached from low P retaining AH soil. The optimum level of P amendment is a critical issue when soluble P is used as a Pb immobilizing agent because of eutrophication resulting from excessive P leaching to surface and ground water. While the soluble P compound was effective in the immobilization of Pb, it resulted in P leaching which increased with increasing levels of P addition. However, rock phosphate amendment with PSB achieved the immobilization of Pb with

  11. Emissions From Various Biodiesel Sources Compared to a Range of Diesel Fuels in DPF Equipped Diesel Engines

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.; Burton, J.; Christensen, E.; McCormick, R. L.; Tester, J.

    2011-01-01

    The purpose of this study was to measure the impact of various sources of petroleum-based and bio-based diesel fuels on regulated emissions and fuel economy in diesel particulate filter (DPF) equipped diesel engines. Two model year 2008 diesel engines were tested with nine fuels including a certification ultra-low sulfur diesel (ULSD), local ULSD, high aromatic ULSD, low aromatic ULSD, and twenty percent blends of biodiesel derived from algae, camelina, soy, tallow, and yellow grease. Regulated emissions were measured over the heavy duty diesel transient test cycle. Measurements were also made of DPF-out particle size distribution and total particle count from a 13-mode steady state test using a fast mobility particle sizer. Test engines were a 2008 Cummins ISB and a 2008 International Maxx Force 10, both equipped with actively regenerated DPFs. Fuel consumption was roughly 2% greater over the transient test cycle for the B20 blends versus certification ULSD in both engines, consistent with the slightly lower energy content of biodiesel. Unlike studies conducted on older model engines, these engines equipped with diesel oxidation catalysts and DPFs showed small or no measurable fuel effect on the tailpipe emissions of total hydrocarbons (THC), carbon monoxide (CO) and particulate matter (PM). No differences in particle size distribution or total particle count were seen in a comparison of certification ULSD and B20 soy, with the exception of engine idling conditions where B20 produced a small reduction in the number of nucleation mode particles. In the Cummins engine, B20 prepared from algae, camelina, soy, and tallow resulted in an approximately 2.5% increase in nitrogen oxides (NO{sub x}) compared to the base fuel. The International engine demonstrated a higher degree of variability for NO{sub x} emissions, and fuel effects could not be resolved (p > 0.05). The group of petroleum diesel test fuels produced a range of NO{sub x} emissions very similar to that

  12. Accordion effect in a laser wakefield accelerator: Generating comb-like electron beams for a tunable pulsed source of polychromatic gamma-rays

    Science.gov (United States)

    Kalmykov, Serge; Davoine, Xavier; Ghebregziabher, Isaac; Shadwick, Bradley

    2016-10-01

    Trains of synchronized, fs-length GeV-scale electron bunches with a sub-micron normalized transverse emittance, brightness up to 1017 A/m2, and controlled energy spacing may be purposely produced in both plasma channels and uniform plasmas. A cavity of electron density, driven by an optimally designed multi-color stack of 10-TW-scale laser pulses, experiences expansions and contractions, periodically injecting electrons from the ambient dense plasma, accelerating them without compromising the beam quality. This periodic injection is naturally achieved in a plasma channel. The channel, however, is not a prerequisite to this effect. The number of comb components, as well as their charge and energy spacing, can be controlled in a uniform plasma by independently varying focal spots of the laser stack components. Inverse Thomson scattering from these comb-like beams produces synchronized sequences of quasi-monochromatic, fs-length gamma-ray flashes, which may become an asset to pump-probe experiments in dense plasmas. NSF Grant PHY-1535678.

  13. Comparing source of agricultural contact water and the presence of fecal indicator organisms on the surface of 'juliet' grape tomatoes.

    Science.gov (United States)

    Pahl, Donna M; Telias, Adriana; Newell, Michael; Ottesen, Andrea R; Walsh, Christopher S

    2013-06-01

    Consumption of fresh tomatoes (Solanum lycopersicum) has been implicated as the cause of several foodborne illness outbreaks in the United States, most notably in cases of salmonellosis. How the levels of fecal indicator organisms (FIOs) in water relate to the counts of these microorganisms on the tomato fruit surface is unknown, although microbial water quality standards exist for agricultural use. This study utilized four types of FIOs currently and historically used in microbial water quality standards (Enterobacteriaceae, total coliforms, fecal coliforms, and Escherichia coli) to monitor the water quality of two surface ponds and a groundwater source. The groundwater tested contained significantly lower counts of all FIOs than the two surface water sources (P tomatoes treated with overhead applications of the different water sources over the 2009 and 2010 growing seasons. The type of water source and time of year significantly affected the populations of FIOs in irrigation water (P E. coli between the water sources, there was little difference in the populations measured in washes taken from tomato fruits. This lack of association between the aforementioned FIOs present in the water samples and on the tomato fruit surface demonstrates the difficulty in developing reliable metrics needed for testing of agricultural water to ensure the effectiveness of food safety programs.

  14. A Comparative Study of News Sources in Sino-English News Reports Re-lated to Nobel Winner Mo Yan

    Institute of Scientific and Technical Information of China (English)

    徐莺

    2014-01-01

    News, by no means a neutral vehicle, is in reality ideologically driven and controlled by news values to which the use of news sources is of great help. Geis once argued that the single most important power of the press is its capacity to say what the important issues are at any particular time and to determine whose voices will be heard on any given issue (Geis, 1987:10). News sources may tell readers something, but it may also mislead readers since people cannot think about and make sense out of news events without imposing a bias on the news. It is, therefore, worth our attention and effort to understand how news source works, how it affects readers' perceptions of news events, how it is produced, how it is shaped by values and ideology.

  15. Numerical and laboratory simulations of auroral acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Gunell, H.; De Keyser, J. [1Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels (Belgium); Mann, I. [EISCAT Scientific Association, P.O. Box 812, SE-981 28 Kiruna, Sweden and Department of Physics, Umeå University, SE-901 87 Umeå (Sweden)

    2013-10-15

    The existence of parallel electric fields is an essential ingredient of auroral physics, leading to the acceleration of particles that give rise to the auroral displays. An auroral flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on auroral field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.

  16. Acceleration of microparticle

    CERN Document Server

    Shibata, H

    2002-01-01

    A microparticle (dust) ion source has been installed at the high voltage terminal of the 3.75 MV single ended Van de Graaff electrostatic accelerator and a beam line for microparticle experiments has been build at High Fluence Irradiation Facility (HIT) of Research Center for Nuclear Science and Technology, the University of Tokyo. Microparticle acceleration has been successful in obtaining expected velocities of 1-20 km/s or more for micron or submicron sized particles. Development of in situ dust detectors and analyzers on board satellites and spacecraft in the expected mass and velocity range of micrometeoroids and investigation of hypervelocity impact phenomena by using time of flight mass spectrometry, impact flash or luminescence measurement and scanning electron or laser microscope observation for metals, ceramics, polymers and semiconductors bombarded by micron-sized particles were started three years ago. (author)

  17. Assessing comparative terrestrial ecotoxicity of Cd, Co, Cu, Ni, Pb, and Zn: The influence of aging and emission source

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Holm, Peter E.; Fantke, Peter;

    2015-01-01

    Metal exposure to terrestrial organisms is influenced by the reactivity of the solid-phase metal pool. This reactivity is thought to depend on the type of emission source, on aging mechanisms that are active in the soil, and on ambient conditions. Our work shows, that when controlling for soil p...

  18. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  19. Comparation of several CUDA accelerated Gaussian filtering algorithms%几种CUDA加速高斯滤波算法的比较

    Institute of Scientific and Technical Information of China (English)

    刘进锋

    2013-01-01

    There are some image filtering algorithms based on CUDA, but some of them are not clearly described, and no one to compare the performance of these algorithms, which brings difficulties for understanding and using these algorithms. This paper discusses five different Gaussian image filters based on CUDA, they are naive method, separable share memory method, separa-ble texture memory method, FFT convolution filtering and recursive Gaussian filter. Core ideas are emphasized, time complexi-ties are compared, and performances are analyzed through experiments.%目前已有几种CUDA加速的图像高斯滤波算法,但这些算法有的描述不清楚,也没有人对它们的性能进行详尽的比较,这给理解及应用带来了困难。描述了几种CUDA加速的图像高斯滤波算法,包括直观的实现方式、使用共享内存的分离滤波器方法、使用纹理内存的分离滤波器方法、基于CUFFT的卷积滤波以及递归高斯滤波器。强调了这些算法的核心思想,比较了它们的时间复杂度,通过实验对它们的性能进行了分析。

  20. Constitutive activation and accelerated maturation of peripheral blood t cells in healthy adults in burkina faso compared to Germany: The case of malaria?

    Directory of Open Access Journals (Sweden)

    Tiba F

    2011-12-01

    Full Text Available Abstract Objective It is not exactly known how frequent exposure to Plasmodium falciparum shapes the peripheral blood T-cell population in healthy West Africans. Methods The frequency of peripheral blood CD4+ lymphocytes responding to Plasmodium falciparum merozoite surface protein 1 (PfMSP-1 by production of interferon-gamma (IFN-γ, interleukin-2 (IL-2 or tumor necrosis factor-alpha (TNF-α was determined using a commercially available flow cytometric activation assay (Fastlmmune in 17 healthy adults in Nouna, Burkina Faso. T-cell activation and maturation in peripheral blood of healthy adults in Burkina Faso (n = 40 and Germany (n = 20 were compared using immunophenotyping and three-colour flow cytometry. Results Significant numbers of PfMSV-1 -specific CD4+ lymphocytes producing IFN-γ, IL-2 and/or TNF-α were detected in 14 healthy adults in Nouna. Cytokine profiles showed predominant production of IFN-γ and TNF-α. Compared to Germans, Burkinabé showed markedly lower proportions of CCR7+ CD45RA+ naïve CD4+ cells and slightly higher frequencies of CD95+ CD4+ T-cells and of CD38+ CD8+ T-cells. The median antibody-binding capacity of CD95dim CD4+ T-cells in Burkinabé was more than twice the value observed in Germans (263 vs. 108 binding sites per cell, p Conclusions We hypothesize that an IFN-γ-induced increase in the expression level of CD95 on CD4+ lymphocytes may lower the activation threshold of resting naïve CD4+ T-cells in healthy adults living in Burkina Faso. Bystander activation of these cells deserves further study as a molecular mechanism linking strong IFN-γ responses against Plasmodium falciparum to decreased susceptibility to parasitemia observed in specific ethnic groups in West Africa.

  1. Comparing source inversion techniques for GPS-based local tsunami forecasting: A case study for the April 2014 M8.1 Iquique, Chile, earthquake

    Science.gov (United States)

    Chen, Kejie; Babeyko, Andrey; Hoechner, Andreas; Ge, Maorong

    2016-04-01

    Real-time GPS is nowadays considered as a valuable component of next generation near-field tsunami early warning systems able to provide fast and reliable source parameters. Looking for optimal methodologies and assessing corresponding uncertainties becomes an important task. We take the opportunity and consider the 2014 Pisagua event as a case study to explore tsunami forecast uncertainty related to the GPS-based source inversion. We intentionally neglect all other sources of uncertainty (observation set, signal processing, wave simulation, etc.) and exclusively assess the effect of inversion technique. In particular, we compare three end-member methods: (1) point-source fastCMT (centroid moment tensor), (2) distributed slip along predefined plate interface, and (3) unconstrained inversion into a single uniform slip finite fault. The three methods provide significantly different far-field tsunami forecast but show surprisingly similar tsunami predictions in the near field.

  2. Celeris: A GPU-accelerated open source software with a Boussinesq-type wave solver for real-time, interactive simulation and visualization

    CERN Document Server

    Tavakkol, Sasan

    2016-01-01

    In this paper, we introduce an interactive coastal wave simulation and visualization software, called Celeris. Celeris is an open source software which needs minimum preparation to run on a Windows machine. The software solves the extended Boussinesq equations using a hybrid finite volume - finite difference method and supports moving shoreline boundaries. The simulation and visualization are performed on the GPU using Direct3D libraries, which enables the software to run faster than real-time. Celeris provides a first-of-its-kind interactive modeling platform for coastal wave applications and it supports simultaneous visualization with both photorealistic and colormapped rendering capabilities. We validate our software through comparison with three standard benchmarks for non-breaking and breaking waves.

  3. Free/Open source integrated library management systems: comparative analysis of Koha, PHPMyLibrary and OpenBiblio

    OpenAIRE

    Vimal Kumar, V.

    2005-01-01

    Integrated library management systems can cut costs and enhance the efficiency of library services and therefore are absolutely necessary for the management of house keeping operations. But small and medium- size libraries face a difficult situation due to the high cost of commercial library management systems, foreign or Indian, available in the market. Naturally libraries without much financial resources need a cost effective way to automate their services. Free/Open source software was ...

  4. SHORT ACCELERATION TIMES FROM SUPERDIFFUSIVE SHOCK ACCELERATION IN THE HELIOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Perri, S.; Zimbardo, G., E-mail: silvia.perri@fis.unical.it [Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, I-87036 Rende (Italy)

    2015-12-10

    The analysis of time profiles of particles accelerated at interplanetary shocks allows particle transport properties to be inferred. The frequently observed power-law decay upstream, indeed, implies a superdiffusive particle transport when the level of magnetic field variance does not change as the time interval from the shock front increases. In this context, a superdiffusive shock acceleration (SSA) theory has been developed, allowing us to make predictions of the acceleration times. In this work we estimate for a number of interplanetary shocks, including the solar wind termination shock, the acceleration times for energetic protons in the framework of SSA and we compare the results with the acceleration times predicted by standard diffusive shock acceleration. The acceleration times due to SSA are found to be much shorter than in the classical model, and also shorter than the interplanetary shock lifetimes. This decrease of the acceleration times is due to the scale-free nature of the particle displacements in the framework of superdiffusion. Indeed, very long displacements are possible, increasing the probability for particles far from the front of the shock to return, and short displacements have a high probability of occurrence, increasing the chances for particles close to the front to cross the shock many times.

  5. MESSENGER observations of energetic electron acceleration in Mercury's magnetotail

    Science.gov (United States)

    Dewey, Ryan; Slavin, James A.; Baker, Daniel; Raines, Jim; Lawrence, David

    2016-10-01

    Energetic particle bursts within Mercury's magnetosphere have been a source of curiosity and controversy since Mariner 10's flybys. Unfortunately, instrumental effects prevent an unambiguous determination of species, flux, and energy spectrum for the Mariner 10 events. MESSENGER data taken by the Energetic Particle Spectrometer (EPS) have now shown that these energetic particle bursts are composed entirely of electrons. EPS made directional measurements of these electrons from ~30 to 300 keV at 3 s resolution, and while the energy of these electrons sometimes exceeded 200 keV, the energy distributions usually exhibited a cutoff near 100 keV. The Gamma Ray Spectrometer (GRS) has also provided measurements of these electron events, at higher time resolution (10 ms) and energetic threshold (> 50 keV) compared to EPS. We focus on GRS electron events near the plasma sheet in Mercury's magnetotail to identify reconnection-associated acceleration mechanisms. We present observations of acceleration associated with dipolarization events (betratron acceleration), flux ropes (Fermi acceleration), and tail loading/unloading (X-line acceleration). We find that the most common source of energetic electron events in Mercury's magnetosphere are dipolarization events similar to those first observed by Mariner 10. Further, a significant dawn-dusk asymmetry is found with dipolarization-associated energetic particle bursts being more common on the dawn side of the magnetotail.

  6. Shear Acceleration in Expanding Flows

    CERN Document Server

    Rieger, F M

    2016-01-01

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets of active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi-Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge ...

  7. Vertical hydraulic conductivity of a clayey-silt aquitard: accelerated fluid flow in a centrifuge permeameter compared with in situ conditions

    Directory of Open Access Journals (Sweden)

    W. A. Timms

    2014-03-01

    Full Text Available Evaluating the possibility of leakage through low permeability geological strata is critically important for sustainable water supplies, extraction of fuels from strata such as coal beds, and confinement of waste within the earth. Characterizing low or negligible flow rates and transport of solutes can require impractically long periods of field or laboratory testing, but is necessary for evaluations over regional areas and over multi-decadal timescales. The current work reports a custom designed centrifuge permeameter (CP system, which can provide relatively rapid and reliable hydraulic conductivity (K measurement compared to column permeameter tests at standard gravity (1g. Linear fluid velocity through a low K porous sample is linearly related to g-level during a CP flight unless consolidation or geochemical reactions occur. The CP module is designed to fit within a standard 2 m diameter, geotechnical centrifuge with a capacity for sample dimensions of 30 to 100 mm diameter and 30 to 200 mm in length. At maximum RPM the resultant centrifugal force is equivalent to 550g at base of sample or a total stress of ~2 MPa. K is calculated by measuring influent and effluent volumes. A custom designed mounting system allows minimal disturbance of drill core samples and a centrifugal force that represents realistic in situ stress conditions is applied. Formation fluids were used as influent to limit any shrink-swell phenomena which may alter the resultant K value. Vertical hydraulic conductivity (Kv results from CP testing of core from the sites in the same clayey silt formation varied (10−7 to 10−9 m s−1, n = 14 but higher than 1g column permeameter tests of adjacent core using deionized water (10−9 to 10−11 m s−1, n = 7. Results at one site were similar to in situ Kv values (3 × 10−9 m s−1 from pore pressure responses within a 30 m clayey sequence in a homogenous area of the formation. Kv sensitivity to sample heterogeneity was

  8. Comparation of Organic and Elemental carbon concentrations in PM2.5 in five Mexican cities: Potencial Sources

    Science.gov (United States)

    Herrera Murillo, J.; Cardenas, B.; Campos-Ramos, A.; Blanco-Jimenez, S.; Angeles-Garcia, F.

    2011-12-01

    During 2006-2010 the National Center for Environmental Research and Training of the National Institute of Ecology of Mexico, carried out several short field studies in the cities of Salamanca, Gto, Tula, Hgo; Guadalajara, Jal; Toluca, Edo Mex; and Tijuana, BC to determine concentration and chemical compositions of PM2.5. These cities, although different in size population have all important industrial and area sources that contribute to high PM2.5 concentrations and therefore potential health impacts. Chemical analyses included organic and elemental carbon for which DRI Model 2001 Thermal/Optical Carbon Analyzer (Atmoslytic Inc, Calabasas, CA, USA) was used. Highest PM2.5 mass mean concentrations were obtained in Salamanca (46 μg/m3), followed by Toluca (43 μg/m3), Guadalajara (37 μg/m3), Tula (20 μg/m3) and Tijuana (18 μg/m3). For Salamanca and Tula, annual levels exceeded the Mexican PM2.5 annual standard of 15 μg/m3. Total carbonaceous aerosol accounted for 41.4%, 41.1%, 32.3%, 29.5% and 29.1% of PM2.5 mass in Tula, Toluca, Guadalajara, Salamanca and Tijuana, respectively. Higher OC2, OC3 and OC4 carbon fractions were observed in Guadalajara, Tijuana and Toluca, indicating an important contribution of gasoline and diesel vehicles emissions in these cities. As for Tula and Salamanca, cities in which refineries and power plants are present, OC3, OC4, EC1 and EC2 represent the higher fractions which could be attributed to stationary sources that use heavy fuels for their combustion process. UNMIX and PMF analyses were used in order to identify the most important sources that contributes to OC and EC concentrations.

  9. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  10. Total gaseous concentrations in mercury in Seoul, Korea: Local sources compared to long-range transport from China and Japan

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun-Mi; Kim, Seung-Hee [Graduate School of Public Health, Department of Environmental Health, Seoul National University, Yeongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Holsen, Thomas M. [Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY 13699 (United States); Yi, Seung-Muk [Graduate School of Public Health, Department of Environmental Health, Seoul National University, Yeongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Institute of Health and Environment, Graduate School of Public Health, Seoul National University, Yeongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of)], E-mail: yiseung@snu.ac.kr

    2009-03-15

    Total gaseous mercury (TGM) and carbon monoxide (CO) were measured every 5 min and hourly, respectively, in Seoul, Korea, from February 2005 through December 2006. The mean concentrations of TGM and CO were 3.44 {+-} 2.13 ng m{sup -3} and 613 {+-} 323 ppbv, respectively. TGM and CO concentrations were highest during the winter and lowest during the summer. In total, 154 high TGM concentration events were identified: 86 were classified as long-range transport events and 68 were classified as local events. The TGM and CO concentrations were well correlated during all long-range transport events and were weakly correlated during local events. Five-day backward trajectory analysis for long-range transport events showed four potential source regions: China (79%), Japan (13%), the Yellow Sea (6%), and Russia (2%). Our results suggest that measured {delta}TGM/{delta}CO can be used to identify long-range transported mercury and to estimate mercury emissions from long-range transport. - This study identified long-range transport from China and local sources of elevated TGM concentrations in Seoul, Korea using the relationship between {delta}TGM and {delta}CO.

  11. Comparative Assessment of Heavy Metals in Drinking Water Sources in Two Small-Scale Mining Communities in Northern Ghana

    Directory of Open Access Journals (Sweden)

    Samuel J. Cobbina

    2015-08-01

    Full Text Available The study assessed levels of heavy metals in drinking water sources in two small-scale mining communities (Nangodi and Tinga in northern Ghana. Seventy-two (72 water samples were collected from boreholes, hand dug wells, dug-out, and a stream in the two mining communities. The levels of mercury (Hg, arsenic (As, lead (Pb, zinc (Zn, and cadmium (Cd were determined using an atomic absorption spectrophotometer (AAS. Mean levels (mg/l of heavy metals in water samples from Nangodi and Tinga communities were 0.038 and 0.064 (Hg, 0.031 and 0.002 (As, 0.250 and 0.031 (Pb, 0.034 and 0.002 (Zn, and 0.534 and 0.023 (Cd, respectively, for each community. Generally, levels of Hg, As, Pb, Zn, and Cd in water from Nangodi exceeded the World Health Organisation (WHO stipulated limits of 0.010 for Hg, As, and Pb, 3.0 for Zn and 0.003 for Cd for drinking water, and levels of Hg, Pb, and Cd recorded in Tinga, exceeded the stipulated WHO limits. Ingestion of water, containing elevated levels of Hg, As, and Cd by residents in these mining communities may pose significant health risks. Continuous monitoring of the quality of drinking water sources in these two communities is recommended.

  12. A large N400 but no BOLD effect--comparing source activations of semantic priming in simultaneous EEG-fMRI.

    Directory of Open Access Journals (Sweden)

    Sebastian Geukes

    Full Text Available Numerous studies have reported neurophysiological effects of semantic priming in electroencephalography (EEG and in functional magnetic resonance imaging (fMRI. Because of differing methodological constraints, the comparability of the observed effects remains unclear. To directly compare EEG and fMRI effects and neural sources of semantic priming, we conducted a semantic word-picture priming experiment while measuring EEG and fMRI simultaneously. The visually presented primes were pseudowords, words unrelated to the target, semantically related words and the identical names of the target. Distributed source analysis of the event-related potentials (ERPs successfully revealed a large effect of semantic prime-target relatedness (the N400 effect, which was driven by activations in a left-temporal source region. However, no significantly differing activations between priming conditions were found in the fMRI data. Our results support the notion that, for joint interpretations of existing EEG and fMRI studies of semantic priming, we need to fully appreciate the respective methodological limitations. Second, they show that simultaneous EEG-fMRI, including ERP source localization, is a feasible and promising methodological advancement for the investigation of higher-cognitive processes. Third, they substantiate the finding that, compared to fMRI, ERPs are often more sensitive to subtle cognitive effects.

  13. No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

    Science.gov (United States)

    Baer, Sara G; Gibson, David J; Gustafson, Danny J; Benscoter, Allison M; Reed, Lewis K; Campbell, Ryan E; Klopf, Ryan P; Willand, Jason E; Wodika, Ben R

    2014-01-01

    Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed. PMID:24567751

  14. High-efficiency high-energy Ka source for the critically-required maximum illumination of x-ray optics on Z using Z-petawatt-driven laser-breakout-afterburner accelerated ultrarelativistic electrons LDRD .

    Energy Technology Data Exchange (ETDEWEB)

    Sefkow, Adam B.; Bennett, Guy R.

    2010-09-01

    Under the auspices of the Science of Extreme Environments LDRD program, a <2 year theoretical- and computational-physics study was performed (LDRD Project 130805) by Guy R Bennett (formally in Center-01600) and Adam B. Sefkow (Center-01600): To investigate novel target designs by which a short-pulse, PW-class beam could create a brighter K{alpha} x-ray source than by simple, direct-laser-irradiation of a flat foil; Direct-Foil-Irradiation (DFI). The computational studies - which are still ongoing at this writing - were performed primarily on the RedStorm supercomputer at Sandia National Laboratories Albuquerque site. The motivation for a higher efficiency K{alpha} emitter was very clear: as the backlighter flux for any x-ray imaging technique on the Z accelerator increases, the signal-to-noise and signal-to-background ratios improve. This ultimately allows the imaging system to reach its full quantitative potential as a diagnostic. Depending on the particular application/experiment this would imply, for example, that the system would have reached its full design spatial resolution and thus the capability to see features that might otherwise be indiscernible with a traditional DFI-like x-ray source. This LDRD began FY09 and ended FY10.

  15. GPU-accelerated micromagnetic simulations using cloud computing

    Science.gov (United States)

    Jermain, C. L.; Rowlands, G. E.; Buhrman, R. A.; Ralph, D. C.

    2016-03-01

    Highly parallel graphics processing units (GPUs) can improve the speed of micromagnetic simulations significantly as compared to conventional computing using central processing units (CPUs). We present a strategy for performing GPU-accelerated micromagnetic simulations by utilizing cost-effective GPU access offered by cloud computing services with an open-source Python-based program for running the MuMax3 micromagnetics code remotely. We analyze the scaling and cost benefits of using cloud computing for micromagnetics.

  16. GPU-accelerated micromagnetic simulations using cloud computing

    CERN Document Server

    Jermain, C L; Buhrman, R A; Ralph, D C

    2015-01-01

    Highly-parallel graphics processing units (GPUs) can improve the speed of micromagnetic simulations significantly as compared to conventional computing using central processing units (CPUs). We present a strategy for performing GPU-accelerated micromagnetic simulations by utilizing cost-effective GPU access offered by cloud computing services with an open-source Python-based program for running the MuMax3 micromagnetics code remotely. We analyze the scaling and cost benefits of using cloud computing for micromagnetics.

  17. 10 MW, L-Band Klystron for Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Read, Michael [Calabazas Creek Research, Inc., San Mateo, CA (United States); Ives, Robert L. [Calabazas Creek Research, Inc., San Mateo, CA (United States); Ferguson, Patrick [Calabazas Creek Research, Inc., San Mateo, CA (United States)

    2016-03-07

    This program developed a 10 MW, pulsed, Annular Beam Klystron (ABK) for accelerator applications. This is an alternative RF source to multiple beam klystrons MBKs), which are more complex and considerably more expensive. The ABK uses a single, annular cathode and a single beam tunnel with fundamental mode cavities. The operating specifications (voltage, efficiency, power, bndwidth, duty, etc.) are the same as for comparable MBKs.

  18. Acceleration of cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Berezhko, E [Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Ave., 677980 Yakutsk (Russian Federation)], E-mail: berezhko@ikfia.ysn.ru

    2008-07-15

    Cosmic ray (CR) origin problem is briefly discussed. It is argued that CRs with energies up to 10{sup 17} eV are produced in galactic supernova remnants, whereas ultra high energy CRs are extragalactic. CR composition strongly changes within the transition from galactic to extragalactic CR component, therefore precise measurements of CR composition at energies 10{sup 17} - 10{sup 19} eV are needed for the reliable determination of this transition. The possible sources of extragalactic CRs are briefly discussed. It is argued that CR acceleration at the shock created by the expanding cocoons around active galactic nuclei has to be considered as a prime candidate for the sources of extragalactic CRs.

  19. Design of a plasma discharge circuit for particle wakefield acceleration

    CERN Document Server

    Anania, M P; Cianchi, A; Di Giovenale, D; Ferrario, M; Flora, F; Gallerano, G P; Ghigo, A; Marocchino, A; Massimo, F; Mostacci, A; Mezi, L; Musumeci, P; Serio, M; 10.1016/j.nima.2013.10.053

    2014-01-01

    Plasma wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10-100 GV m^-1), enabling acceleration of electrons to GeV energy in few centimetres. However, the quality of the electron bunches accelerated with this technique is still not comparable with that of conventional accelerators; radiofrequency-based accelerators, in fact, are limited in the accelerating field (10-100 MV m^-1) requiring therefore kilometric distances to reach the GeV energies, but can provide very bright electron bunches. Combining high brightness electron bunches from conventional accelerators and high accelerating fields reachable with plasmas could be a good compromise accelerators and high accelerating fields reachable with plasmas could be a good compromise allowing to further accelerate high brightness electron bunches coming from LINAC while preserving electron beam quality. Following the idea of plasma wave resonant excitation driven by a train of shor...

  20. Plasma Channel Guided Laser Wakefield Accelerator

    CERN Document Server

    Geddes, C G

    2005-01-01

    High quality electron beams (several 109 electrons above 80 MeV energy with percent energy spread and low divergence) have been produced for the first time in a compact, high gradient, all-optical laser accelerator by extending the interaction distance using a pre-formed plasma density channel to guide the drive laser pulse. Laser-driven accelerators, in which particles are accelerated by the electric field of a plasma wave (wake) driven by the radiation pressure of an intense laser, have over the past decade demonstrated accelerating fields thousands of times greater than those achievable in conventional radio-frequency accelerators. This has spurred interest in them as compact next- generation sources of energetic electrons and radiation. To date, however, acceleration distances have been severely limited by the lack of a controllable method for extending the propagation distance of the focused laser pulse. The ensuing short acceleration distance resulted in low-energy beams with 100 percent electron energy...

  1. Comparing an accelerated 3D fast spin-echo sequence (CS-SPACE) for knee 3-T magnetic resonance imaging with traditional 3D fast spin-echo (SPACE) and routine 2D sequences

    Energy Technology Data Exchange (ETDEWEB)

    Altahawi, Faysal F.; Blount, Kevin J.; Omar, Imran M. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Morley, Nicholas P. [Marshfield Clinic, Department of Radiology, Marshfield, WI (United States); Raithel, Esther [Siemens Healthcare GmbH, Erlangen (Germany)

    2017-01-15

    To compare a faster, new, high-resolution accelerated 3D-fast-spin-echo (3D-FSE) acquisition sequence (CS-SPACE) to traditional 2D and high-resolution 3D sequences for knee 3-T magnetic resonance imaging (MRI). Twenty patients received knee MRIs that included routine 2D (T1, PD ± FS, T2-FS; 0.5 x 0.5 x 3 mm{sup 3}; ∝10 min), traditional 3D FSE (SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝7.5 min), and accelerated 3D-FSE prototype (CS-SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝5 min) acquisitions on a 3-T MRI system (Siemens MAGNETOM Skyra). Three musculoskeletal radiologists (MSKRs) prospectively and independently reviewed the studies with graded surveys comparing image and diagnostic quality. Tissue-specific signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were also compared. MSKR-perceived diagnostic quality of cartilage was significantly higher for CS-SPACE than for SPACE and 2D sequences (p < 0.001). Assessment of diagnostic quality of menisci and synovial fluid was higher for CS-SPACE than for SPACE (p < 0.001). CS-SPACE was not significantly different from SPACE but had lower assessments than 2D sequences for evaluation of bones, ligaments, muscles, and fat (p ≤ 0.004). 3D sequences had higher spatial resolution, but lower overall assessed contrast (p < 0.001). Overall image quality from CS-SPACE was assessed as higher than SPACE (p = 0.007), but lower than 2D sequences (p < 0.001). Compared to SPACE, CS-SPACE had higher fluid SNR and CNR against all other tissues (all p < 0.001). The CS-SPACE prototype allows for faster isotropic acquisitions of knee MRIs over currently used protocols. High fluid-to-cartilage CNR and higher spatial resolution over routine 2D sequences may present a valuable role for CS-SPACE in the evaluation of cartilage and menisci. (orig.)

  2. pROC: an open-source package for R and S+ to analyze and compare ROC curves

    Directory of Open Access Journals (Sweden)

    Lisacek Frédérique

    2011-03-01

    Full Text Available Abstract Background Receiver operating characteristic (ROC curves are useful tools to evaluate classifiers in biomedical and bioinformatics applications. However, conclusions are often reached through inconsistent use or insufficient statistical analysis. To support researchers in their ROC curves analysis we developed pROC, a package for R and S+ that contains a set of tools displaying, analyzing, smoothing and comparing ROC curves in a user-friendly, object-oriented and flexible interface. Results With data previously imported into the R or S+ environment, the pROC package builds ROC curves and includes functions for computing confidence intervals, statistical tests for comparing total or partial area under the curve or the operating points of different classifiers, and methods for smoothing ROC curves. Intermediary and final results are visualised in user-friendly interfaces. A case study based on published clinical and biomarker data shows how to perform a typical ROC analysis with pROC. Conclusions pROC is a package for R and S+ specifically dedicated to ROC analysis. It proposes multiple statistical tests to compare ROC curves, and in particular partial areas under the curve, allowing proper ROC interpretation. pROC is available in two versions: in the R programming language or with a graphical user interface in the S+ statistical software. It is accessible at http://expasy.org/tools/pROC/ under the GNU General Public License. It is also distributed through the CRAN and CSAN public repositories, facilitating its installation.

  3. Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (picloram, 2,4-D, and clopyralid)

    Science.gov (United States)

    Fairchild, J.F.; Allert, A.; Sappington, L.S.; Nelson, K.J.; Valle, J.

    2008-01-01

    We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared using three procedures: standard acute toxicity testing, fractional estimates of lethal concentrations, and accelerated life testing chronic estimation procedures. The acutely lethal concentrations (ALC) resulting in 50% mortality at 96 h (96-h ALC50s) were determined using linear regression and indicated that the three herbicides were toxic in the order of picloram acid > 2,4-D acid > clopyralid acid. The 96-h ALC50 values for rainbow trout were as follows: picloram, 41 mg/L; 2.4-D, 707 mg/L; and clopyralid, 700 mg/L. The 96-h ALC50 values for bull trout were as follows: picloram, 24 mg/L; 2.4-D, 398 mg/L; and clopyralid, 802 mg/L. Fractional estimates of safe concentrations, based on 5% of the 96-h ALC50, were conservative (overestimated toxicity) of regression-derived 96-h ALC5 values by an order of magnitude. Accelerated life testing procedures were used to estimate chronic lethal concentrations (CLC) resulting in 1% mortality at 30 d (30-d CLC1) for the three herbicides: picloram (1 mg/L rainbow trout, 5 mg/L bull trout), 2,4-D (56 mg/L rainbow trout, 84 mg/L bull trout), and clopyralid (477 mg/L rainbow trout; 552 mg/L bull trout). Collectively, the results indicated that the standard surrogate rainbow trout is similar in sensitivity to bull trout. Accelerated life testing procedures provided cost-effective, statistically defensible methods for estimating safe chronic concentrations (30-d CLC1s) of herbicides from acute toxicity data because they use statistical models based on the entire mortality:concentration: time data matrix. ?? 2008 SETAC.

  4. Mixed compared with single-source proteins in high-protein diets affect kidney structure and function differentially in obese fa/fa Zucker rats.

    Science.gov (United States)

    Devassy, Jessay G; Wojcik, Jennifer L; Ibrahim, Naser H M; Zahradka, Peter; Taylor, Carla G; Aukema, Harold M

    2017-02-01

    Questions remain regarding the potential negative effects of dietary high protein (HP) on kidney health, particularly in the context of obesity in which the risk for renal disease is already increased. To examine whether some of the variability in HP effects on kidney health may be due to source of protein, obese fa/fa Zucker rats were given HP (35% of energy from protein) diets containing either casein, soy protein, or a mixed source of animal and plant proteins for 12 weeks. Control lean and obese rats were given diets containing casein at normal protein (15% of energy from protein) levels. Body weight and blood pressure were measured, and markers of renal structural changes, damage, and function were assessed. Obesity alone resulted in mild renal changes, as evidenced by higher kidney weights, proteinuria, and glomerular volumes. In obese rats, increasing the protein level using the single, but not mixed, protein sources resulted in higher renal fibrosis compared with the lean rats. The mixed-protein HP group also had lower levels of serum monocyte chemoattractant protein-1, even though this diet further increased kidney and glomerular size. Soy and mixed-protein HP diets also resulted in a small number of damaged glomeruli, while soy compared with mixed-protein HP diet delayed the increase in blood pressure over time. Since obesity itself confers added risk of renal disease, an HP diet from mixed-protein sources that enables weight loss but has fewer risks to renal health may be advantageous.

  5. A comparative study of the radiological hazard in sediments samples from drinking water purification plants supplied from different sources

    Directory of Open Access Journals (Sweden)

    Shams A.M. Issa

    2014-01-01

    Full Text Available The natural radiation level has been determined for 135 sediment samples from forty-six drinking water purification plants supplied from different sources (Nile River, Ibrahimia Canal and Bahr Yousif Canal aiming to evaluate the radiation hazard. The concentration of natural radionuclides (226Ra, 232Th and 40K has been investigated by using gamma spectrometry (NaI (Tl 3″ × 3″ detector. The results showed that the concentrations of average activity in the sediment samples collected from Nile River, Ibrahimia Canal and Bahr Yousif Canal are (29 ± 2, 30 ± 2 and 240 ± 8 Bq kg−1, (47 ± 3, 46 ± 8 and 258 ± 12 Bq kg−1 and (28 ± 2, 27 ± 3 and 219 ± 18 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The distributions of average activity concentrations of samples under investigation are within the world values although some extreme values have been determined. Radiological hazard effects such as: absorbed dose rate (D, outdoor and indoor annual effective dose equivalent (AEDE, radium equivalent activities (Raeq, hazard indices (Hex and Hin, gamma index (Iγ, excess lifetime cancer risk (ELCR and annual gonadal dose equivalent (AGDE for the corresponding samples were also estimated.

  6. Comparative proteomic analysis of Aureobasidium pullulans in the presence of high and low levels of nitrogen source.

    Science.gov (United States)

    Sheng, Long; Zhu, Guilan; Tong, Qunyi

    2014-10-29

    Pullulan, produced by Aureobasidium pullulans strain, has been broadly used in the food and medical industries. However, relatively little is known concerning the molecular basis of pullulan biosynthesis of this strain. In this paper, the effect of different concentrations of (NH4)2SO4 on pullulan fermentation was studied. Proteomics containing two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) were used to analyze the protein with different expressions of A. pullulans cells between the nitrogen limitation and nitrogen repletion. Maximum pullulan production reached 37.72 g/L when 0.6 g/L of initial (NH4)2SO4 was added. Excess nitrogen source would impel carbon flux flow toward biomass production, but decreased the pullulan production. Nitrogen limitation in A. pullulans seemed to influence the flux change of carbon flux flow toward exopolysaccharide accumulation. The findings indicated that 12 identified protein spots were involved in energy-generating enzymes, antioxidant-related enzymes, amino acid biosynthesis, glycogen biosynthesis, glycolysis, protein transport, and transcriptional regulation. These results presented more evidence of pullulan biosynthesis under nitrogen-limited environment, which would provide a molecular understanding of the physiological response of A. pullulans for optimizing the performance of industrial pullulan fermentation.

  7. Comparative Analyses of Phase Noise in 28 nm CMOS LC Oscillator Circuit Topologies: Hartley, Colpitts, and Common-Source Cross-Coupled Differential Pair

    Directory of Open Access Journals (Sweden)

    Ilias Chlis

    2014-01-01

    Full Text Available This paper reports comparative analyses of phase noise in Hartley, Colpitts, and common-source cross-coupled differential pair LC oscillator topologies in 28 nm CMOS technology. The impulse sensitivity function is used to carry out both qualitative and quantitative analyses of the phase noise exhibited by each circuit component in each circuit topology with oscillation frequency ranging from 1 to 100 GHz. The comparative analyses show the existence of four distinct frequency regions in which the three oscillator topologies rank unevenly in terms of best phase noise performance, due to the combined effects of device noise and circuit node sensitivity.

  8. Comparative analyses of phase noise in 28 nm CMOS LC oscillator circuit topologies: Hartley, Colpitts, and common-source cross-coupled differential pair.

    Science.gov (United States)

    Chlis, Ilias; Pepe, Domenico; Zito, Domenico

    2014-01-01

    This paper reports comparative analyses of phase noise in Hartley, Colpitts, and common-source cross-coupled differential pair LC oscillator topologies in 28 nm CMOS technology. The impulse sensitivity function is used to carry out both qualitative and quantitative analyses of the phase noise exhibited by each circuit component in each circuit topology with oscillation frequency ranging from 1 to 100 GHz. The comparative analyses show the existence of four distinct frequency regions in which the three oscillator topologies rank unevenly in terms of best phase noise performance, due to the combined effects of device noise and circuit node sensitivity.

  9. A comparative study of explicit and implicit modelling of subsegmental speaker-specific excitation source information

    Indian Academy of Sciences (India)

    Debadatta Pati; S R Mahadeva Prasanna

    2013-08-01

    In this paper, the explicit and implicit modelling of the subsegmental excitation information are experimentally compared. For explicit modelling, the static and dynamic values of the standard Liljencrants–Fant (LF) parameters that model the glottal flow derivative (GFD) are used. A simplified approximation method is proposed to compute these LF parameters by locating the glottal closing and opening instants. The proposed approach significantly reduces the computation needed to implement the LF model. For implicit modelling, linear prediction (LP) residual samples considered in blocks of 5 ms with shift of 2.5 ms are used. Different speaker recognition studies are performed using NIST-99 and NIST-03 databases. In case of speaker identification, the implicit modelling provides significantly better performance compared to explicit modelling. Alternatively, the explicit modelling seem to be providing better performance in case of speaker verification. This indicates that explicit modelling seem to have relatively less intra and inter-speaker variability. The implicit modelling on the other hand, has more intra and inter-speaker variability. What is desirable is less intra and more inter-speaker variability. Therefore, for speaker verification task explicit modelling may be used and for speaker identification task implicit modelling may be used. Further, for both speaker identification and verification tasks the explicit modelling provides relatively more complimentary information to the state-of-the-art vocal tract features. The contribution of the explicit features is relatively more robust against noise. We suggest that the explicit approach can be used to model the subsegmental excitation information for speaker recognition.

  10. Some Aspects of Galactic Cosmic Ray Acceleration

    CERN Document Server

    Butt, Y M

    2003-01-01

    I give a synopsis of two aspects of the Galactic Cosmic Ray (GCR) acceleration problem: the importance of the medium energy gamma-ray window, and several specific astrophysical sources which merit further investigation.

  11. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  12. Accelerated Profile HMM Searches.

    Directory of Open Access Journals (Sweden)

    Sean R Eddy

    2011-10-01

    Full Text Available Profile hidden Markov models (profile HMMs and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  13. Comparative void-volume analysis of psychrophilic and mesophilic enzymes: Structural bioinformatics of psychrophilic enzymes reveals sources of core flexibility

    Directory of Open Access Journals (Sweden)

    Bystroff Christopher

    2011-10-01

    Full Text Available Abstract Background Psychrophiles, cold-adapted organisms, have adapted to live at low temperatures by using a variety of mechanisms. Their enzymes are active at cold temperatures by being structurally more flexible than mesophilic enzymes. Even though, there are some indications of the possible structural mechanisms by which psychrophilic enzymes are catalytic active at cold temperatures, there is not a generalized structural property common to all psychrophilic enzymes. Results We examine twenty homologous enzyme pairs from psychrophiles and mesophiles to investigate flexibility as a key characteristic for cold adaptation. B-factors in protein X-ray structures are one way to measure flexibility. Comparing psychrophilic to mesophilic protein B-factors reveals that psychrophilic enzymes are more flexible in 5-turn and strand secondary structures. Enzyme cavities, identified using CASTp at various probe sizes, indicate that psychrophilic enzymes have larger average cavity sizes at probe radii of 1.4-1.5 Å, sufficient for water molecules. Furthermore, amino acid side chains lining these cavities show an increased frequency of acidic groups in psychrophilic enzymes. Conclusions These findings suggest that embedded water molecules may play a significant role in cavity flexibility, and therefore, overall protein flexibility. Thus, our results point to the important role enzyme flexibility plays in adaptation to cold environments.

  14. Compact ultrafast orthogonal acceleration time-of-flight mass spectrometer for on-line gas analysis by electron impact ionization and soft single photon ionization using an electron beam pumped rare gas excimer lamp as VUV-light source.

    Science.gov (United States)

    Mühlberger, F; Saraji-Bozorgzad, M; Gonin, M; Fuhrer, K; Zimmermann, R

    2007-11-01

    Orthogonal acceleration time-of-flight mass spectrometers (oaTOFMS), which are exhibiting a pulsed orthogonal extraction of ion bunches into the TOF mass analyzer from a continuous primary ion beam, are well-suited for continuous ionization methods such as electron impact ionization (EI). Recently an electron beam pumped rare gas excimer lamp (EBEL) was introduced, which emits intensive vacuum UV (VUV) radiation at, e.g., 126 nm (argon excimer) and is well suited as the light source for soft single photon ionization (SPI) of organic molecules. In this paper, a new compact oaTOFMS system which allows switching between SPI, using VUV-light from an EBEL-light source, and conventional EI is described. With the oaTOFMS system, EBEL-SPI and EI mass spectral transients can be recorded at very high repetition rates (up to 100 kHz), enabling high duty cycles and therefore good detection efficiencies. By using a transient recorder card with the capability to perform on-board accumulation of the oaTOF transients, final mass spectra with a dynamic range of 106 can be saved to the hard disk at a rate of 10 Hz. As it is possible to change the ionization modes (EI and SPI) rapidly, a comprehensive monitoring of complex gases with highly dynamic compositions, such as cigarette smoke, is possible. In this context, the EI based mass spectra address the bulk composition (compounds such as water, oxygen, carbon dioxide, etc. in the up to percentage concentration range) as well as some inorganic trace gases such as argon, sulfur dioxide, etc. down to the low ppm level. The EBEL-SPI mass spectra on the other hand are revealing the organic composition down to the lower ppb concentration range.

  15. Advances of Accelerator Physics and Technologies

    CERN Document Server

    1993-01-01

    This volume, consisting of articles written by experts with international repute and long experience, reviews the state of the art of accelerator physics and technologies and the use of accelerators in research, industry and medicine. It covers a wide range of topics, from basic problems concerning the performance of circular and linear accelerators to technical issues and related fields. Also discussed are recent achievements that are of particular interest (such as RF quadrupole acceleration, ion sources and storage rings) and new technologies (such as superconductivity for magnets and RF ca

  16. STATUS OF THE DIELECTRIC WALL ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, G J; Chen, Y; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Carroll, J; Cook, E; Falabella, S; Guethlein, G; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J; Weir, J

    2009-04-22

    The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.

  17. Shock-Wave Acceleration of Protons on OMEGA EP

    Science.gov (United States)

    Haberberger, D.; Froula, D. H.; Pak, A.; Link, A.; Patel, P.; Fiuza, F.; Tochitsky, S.; Joshi, C.

    2016-10-01

    The creation of an electrostatic shock wave and ensuing ion acceleration is studied on the OMEGA EP Laser System at the Laboratory for Laser Energetics. Previous work using a 10- μm CO2 laser in a H2 gas jet shows promising results for obtaining narrow spectral features in the accelerated proton spectra. Scaling the shock-wave acceleration mechanism to the 1- μm-wavelength drive laser makes it possible to use petawatt-scale laser systems such as OMEGA-EP, but involves tailoring of the plasma profile. To accomplish the necessitated sharp rise to near-critical plasma density and a long exponential fall, an 1- μm-thick CH foil is illuminated on the back side by thermal x rays produced from an irradiated gold foil. The plasma density is measured using the fourth-harmonic probe system, the accelerating fields are probed using an orthogonal proton source, and the accelerated protons and ions are detected with a Thomson parabola. These results will be presented and compared with particle-in-cell simulations. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and LLNL's Laboratory Directed Research and Development program under project 15-LW-095.

  18. Childhood exposure to DEHP, DBP and BBP under existing chemical management systems: A comparative study of sources of childhood exposure in Korea and in Denmark

    DEFF Research Database (Denmark)

    Lee, Jihyun; Lee, Jong-Hyeon; Kim, Chan-Kook

    2014-01-01

    , while Korea produces more than 0.4 million tons of the three above-mentioned phthalates each year. First, a comparative review of the existing phthalate regulations in the two countries was performed. Next, the level of childhood phthalate exposure from environmental and food sources was estimated using...... estimations based on exposure modeling and biomonitoring data. Cumulative childhood risk levels in Denmark were lower than in Korea. For both countries, risk levels from back calculation were higher than those from scenario estimation. The median cumulative risk levels from scenario estimation and back...... calculation respectively were 0.24 and up to 0.5 in Denmark while 0.52 and up to 0.95 in Korea. Food and indoor dust were the main exposure sources for all three phthalates. In order to protect human health from cumulative risks of these phthalates, the exposure scenarios in existing regulations...

  19. Elements of a dielectric laser accelerator

    CERN Document Server

    McNeur, Joshua; Schönenberger, Norbert; Leedle, Kenneth J; Deng, Huiyang; Ceballos, Andrew; Hoogland, Heinar; Ruehl, Axel; Hartl, Ingmar; Solgaard, Olav; Harris, James S; Byer, Robert L; Hommelhoff, Peter

    2016-01-01

    The widespread use of high energy particle beams in basic research, medicine and coherent X-ray generation coupled with the large size of modern radio frequency (RF) accelerator devices and facilities has motivated a strong need for alternative accelerators operating in regimes outside of RF. Working at optical frequencies, dielectric laser accelerators (DLAs) - transparent laser-driven nanoscale dielectric structures whose near fields can synchronously accelerate charged particles - have demonstrated high-gradient acceleration with a variety of laser wavelengths, materials, and electron beam parameters, potentially enabling miniaturized accelerators and table-top coherent x-ray sources. To realize a useful (i.e. scalable) DLA, crucial developments have remained: concatenation of components including sustained phase synchronicity to reach arbitrary final energies as well as deflection and focusing elements to keep the beam well collimated along the design axis. Here, all of these elements are demonstrated wit...

  20. Experimental investigation of radiation charactristics of Ti wire X-pinch X-ray source on Yang accelerator%“阳”加速器钛丝X箍缩光源辐射特性实验研究

    Institute of Scientific and Technical Information of China (English)

    周少彤; 李军; 黄显宾; 蔡红春; 张思群; 李晶; 段书超; 周荣国

    2012-01-01

    The X-ray radiation properties of titanium wire X-pinch are investigated on the Yang accelerator at 500-800 kA peak current with a rise time of about 80 ns. The radiation power, spectrum and source size of the X-pinch X-ray source are measured and analyzed using X-ray diodes, a transmission grating spectrometer, a crystal spectrometer and a slit camera. The hot dense spot smaller than 15 ~tm emits 1 J of X-ray with an FWHM of 200 ps and a peak power of 1.5 GW distributed in the range of 1--4 keV. A method to efficiently generate a single X-ray pulse during the X-pinch implosion is demonstrated. The X-pinch presented here is useful for imaging the early stage interior structure of Z pinch as a backlight source.%为了利用x箍缩产生的点光源作为背光光源对丝阵z箍缩内爆早期的负载内部结构进行背光照相,在“阳”加速器(电流峰值为500--800kA,上升时间约80ns)上开展了钛丝(丝交叉角度为60。)x箍缩光源辐射特性的初步实验研究.通过x射线二极管探测器、透射光栅谱仪、晶体谱仪和狭缝相机等诊断设备获取了箍缩点光源的辐射功率达到1.5GW左右,辐射能量约为1J,光子能量为keV量级的辐射能谱范围主要集中在1—4keV能段,点光源尺寸小于15um,其时间尺度(辐射脉冲半高宽)达到了200ps.对光源特征信息进行了初步分析,同时掌握了有效获取钛丝x箍缩单脉冲点光源的方法.

  1. A compact tunable polarized X-ray source based on laser-plasma helical undulators

    CERN Document Server

    Luo, Ji; Zeng, Ming; Vieira, Jorge; Yu, Lu-Le; Weng, Su-Ming; Silva, Luis O; Jaroszynski, Dino A; Sheng, Zheng-Ming; Zhang, Jie

    2016-01-01

    Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because their accelerating gradients are three orders of magnitude larger than traditional accelerators. However, X-ray radiation from such devices still lacks of tunability, especially the intensity and polarization distribution. Here we propose a tunable polarized radiation source from a helical plasma undulator based on plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of $2\\times10^{19} photons/s/mm^{2}/mrad^{2}/0.1%$ bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with the ...

  2. Hadron accelerators for radiotherapy

    Science.gov (United States)

    Owen, Hywel; MacKay, Ranald; Peach, Ken; Smith, Susan

    2014-04-01

    Over the last twenty years the treatment of cancer with protons and light nuclei such as carbon ions has moved from being the preserve of research laboratories into widespread clinical use. A number of choices now exist for the creation and delivery of these particles, key amongst these being the adoption of pencil beam scanning using a rotating gantry; attention is now being given to what technologies will enable cheaper and more effective treatment in the future. In this article the physics and engineering used in these hadron therapy facilities is presented, and the research areas likely to lead to substantive improvements. The wider use of superconducting magnets is an emerging trend, whilst further ahead novel high-gradient acceleration techniques may enable much smaller treatment systems. Imaging techniques to improve the accuracy of treatment plans must also be developed hand-in-hand with future sources of particles, a notable example of which is proton computed tomography.

  3. Comparing Outcomes with Bone Marrow or Peripheral Blood Stem Cells as Graft Source for Matched Sibling Transplants in Severe Aplastic Anemia across Different Economic Regions.

    Science.gov (United States)

    Kumar, Rajat; Kimura, Fumihiko; Ahn, Kwang Woo; Hu, Zhen-Huan; Kuwatsuka, Yachiyo; Klein, John P; Pasquini, Marcelo; Miyamura, Koichi; Kato, Koji; Yoshimi, Ayami; Inamoto, Yoshihiro; Ichinohe, Tatsuo; Wood, William Allen; Wirk, Baldeep; Seftel, Matthew; Rowlings, Philip; Marks, David I; Schultz, Kirk R; Gupta, Vikas; Dedeken, Laurence; George, Biju; Cahn, Jean-Yves; Szer, Jeff; Lee, Jong Wook; Ho, Aloysius Y L; Fasth, Anders; Hahn, Theresa; Khera, Nandita; Dalal, Jignesh; Bonfim, Carmem; Aljurf, Mahmoud; Atsuta, Yoshiko; Saber, Wael

    2016-05-01

    Bone marrow (BM) is the preferred graft source for hematopoietic stem cell transplantation (HSCT) in severe aplastic anemia (SAA) compared with mobilized peripheral blood stem cells (PBSCs). We hypothesized that this recommendation may not apply to those regions where patients present later in their disease course, with heavier transfusion load and with higher graft failure rates. Patients with SAA who received HSCT from an HLA-matched sibling donor from 1995 to 2009 and reported to the Center for International Blood and Marrow Transplant Research or the Japan Society for Hematopoietic Cell Transplantation were analyzed. The study population was categorized by gross national income per capita and region/countries into 4 groups. Groups analyzed were high-income countries (HIC), which were further divided into United States-Canada (n = 486) and other HIC (n = 1264); upper middle income (UMIC) (n = 482); and combined lower-middle, low-income countries (LM-LIC) (n = 142). In multivariate analysis, overall survival (OS) was highest with BM as graft source in HIC compared with PBSCs in all countries or BM in UMIC or LM-LIC (P < .001). There was no significant difference in OS between BM and PBSCs in UMIC (P = .32) or LM-LIC (P = .23). In LM-LIC the 28-day neutrophil engraftment was higher with PBSCs compared with BM (97% versus 77%, P = .002). Chronic graft-versus-host disease was significantly higher with PBSCs in all groups. Whereas BM should definitely be the preferred graft source for HLA-matched sibling HSCT in SAA, PBSCs may be an acceptable alternative in countries with limited resources when treating patients at high risk of graft failure and infective complications.

  4. Microwave View on Particle Acceleration in Flares

    CERN Document Server

    Fleishman, Gregory D

    2013-01-01

    The thermal-to-nonthermal partition was found to vary greatly from one flare to another resulting in a broad variety of cases from 'heating without acceleration' to 'acceleration without heating'. Recent analysis of microwave data of these differing cases suggests that a similar acceleration mechanism, forming a power-law nonthermal tail up to a few MeV or even higher, operates in all the cases. However, the level of this nonthermal spectrum compared to the original thermal distribution differs significantly from one case to another, implying a highly different thermal-to-nonthermal energy partition in various cases. This further requires a specific mechanism capable of extracting the charged particles from the thermal pool and supplying them to a bulk acceleration process to operate in flares \\textit{in addition} to the bulk acceleration process itself, which, in contrast, efficiently accelerates the seed particles, while cannot accelerate the thermal particles. Within this 'microwave' view on the flare ener...

  5. Dosimetric comparison on tissue interfaces with TLD dosimeters, L-alanine, EDR2 films and Penelope simulation for a Co-60 source and linear accelerator in radiotherapy; Comparacion dosimetrica en interfaces de tejidos con dosimetros TLD, L-alanina, peliculas EDR2 y simulacion Penelope para una fuente de Co-60 y acelerador lineal en radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vega R, J. L.; Cayllahua, F.; Apaza, D. G.; Javier, H., E-mail: josevegaramirez@yahoo.es [Universidad Nacional de San Agustin, Departamento de Fisica, Av. Independencia s/n, Arequipa (Peru)

    2015-10-15

    Percentage depth dose curves were obtained with TLD-100 dosimeters, EDR2 films and Penelope simulation at the interfaces in an inhomogeneous mannequin, composed by equivalent materials to the human body built for this study, consisting of cylindrical plates of solid water-bone-lung-bone-solid water of 15 cm in diameter and 1 cm in height; plates were placed in descending way (4-2-8-2-4). Irradiated with Co-60 source (Theratron Equinox-100) for small radiation fields 3 x 3 cm{sup 2} and 1 x 1 cm{sup 2} at a surface source distance of 100 cm from mannequin. The TLD-100 dosimeters were placed in the center of each plate of mannequin irradiated at 10 Gy. The results were compared between these measurement techniques, giving good agreement in interfaces better than 97%. This study was compared with the same characteristics of another study realized with other equivalent materials to human body not homogeneous acrylic-bone-cork-bone-acrylic. The percentage depth dose curves were obtained with mini-dosimeters L-alanine of 1 mm in diameter and 3 mm in height and 3.5 to 4.0 mg of mass with spectrometer band K (EPR). The mini-dosimeters were irradiated with a lineal accelerator PRIMUS Siemens 6 MV. The results of percentage depth dose of L-alanine mini-dosimeters show a good agreement with the percentage depth dose curves of Penelope code, better than 97.7% in interfaces of tissues. (Author)

  6. The spinning disc: studying radial acceleration and its damping process with smartphone acceleration sensors

    Science.gov (United States)

    Hochberg, K.; Gröber, S.; Kuhn, J.; Müller, A.

    2014-03-01

    Here, we show the possibility of analysing circular motion and acceleration using the acceleration sensors of smartphones. For instance, the known linear dependence of the radial acceleration on the distance to the centre (a constant angular frequency) can be shown using multiple smartphones attached to a revolving disc. As a second example, the decrease of the radial acceleration and the rotation frequency due to friction can be measured and fitted with a quadratic function, in accordance with theory. Finally, because the disc is not set up exactly horizontal, each smartphone measures a component of the gravitational acceleration that adds to the radial acceleration during one half of the period and subtracts from the radial acceleration during the other half. Hence, every graph shows a small modulation, which can be used to determine the rotation frequency, thus converting a ‘nuisance effect’ into a source of useful information, making additional measurements with stopwatches or the like unnecessary.

  7. Comparative Analysis of Human Mesenchymal Stem Cells from Bone Marrow, Adipose Tissue, and Umbilical Cord Blood as Sources of Cell Therapy

    Directory of Open Access Journals (Sweden)

    Yoon Sun Yang

    2013-09-01

    Full Text Available Various source-derived mesenchymal stem cells (MSCs have been considered for cell therapeutics in incurable diseases. To characterize MSCs from different sources, we compared human bone marrow (BM, adipose tissue (AT, and umbilical cord blood-derived MSCs (UCB-MSCs for surface antigen expression, differentiation ability, proliferation capacity, clonality, tolerance for aging, and paracrine activity. Although MSCs from different tissues have similar levels of surface antigen expression, immunosuppressive activity, and differentiation ability, UCB-MSCs had the highest rate of cell proliferation and clonality, and significantly lower expression of p53, p21, and p16, well known markers of senescence. Since paracrine action is the main action of MSCs, we examined the anti-inflammatory activity of each MSC under lipopolysaccharide (LPS-induced inflammation. Co-culture of UCB-MSCs with LPS-treated rat alveolar macrophage, reduced expression of inflammatory cytokines including interleukin-1α (IL-1α, IL-6, and IL-8 via angiopoietin-1 (Ang-1. Using recombinant Ang-1 as potential soluble paracrine factor or its small interference RNA (siRNA, we found that Ang-1 secretion was responsible for this beneficial effect in part by preventing inflammation. Our results demonstrate that primitive UCB-MSCs have biological advantages in comparison to adult sources, making UCB-MSCs a useful model for clinical applications of cell therapy.

  8. Comparative analysis of CO2-based transcritical Rankine cycle and HFC245fa-based subcritical organic Rankine cycle using low-temperature geothermal source

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A detailed thermodynamic and techno-economic comparison is presented for a CO2-based transcritical Rankine cycle and a subcritical organic Rankine cycle (ORC) using HFC245fa (1,1,1,3,3-pentafluoro-propane) as the working fluid driven by the low-temperature geothermal source,in order to determine the configuration that presents the maximum net power output with a minimum investment.The evaluations of both Rankine cycles have been performed based on equal thermodynamic mean heat rejection temperature by varying certain system operating parameters to achieve each Rankine cycle’s optimum design at various geothermal source temperature levels ranging from 80oC to 120oC.The results obtained show that the optimum ther-modynamic mean heat injection temperatures of both Rankine cycles are distributed in the scope of 55% to 65% of a given geothermal source temperature level,and that the CO2-based transcritical Rankine cycle presents 3% to 7% higher net power output,84% reduction of turbine inlet volume flow rate,47% reduction of expansion ratio and 1.68 times higher total heat transfer capacity compared with the HFC245fa-based subcritical ORC.It is also indicated that using the CO2-based transcritical system can reduce the dimension of turbine design.However,it requires larger heat transfer areas with higher strength heat exchanger materials because of the higher system pressure.

  9. Comparative study of Moodle, Claroline and Dokeos open source network teaching platform%Moodle,Claroline和Dokeos开源网络教学平台的比较

    Institute of Scientific and Technical Information of China (English)

    何增颖

    2014-01-01

    Compare from awareness, basic properties, functional analysis and applications compare quartet face Moodle, Clarolin and Dodeos three mainstream open source network teaching platform for comparison. Users should be based on reality, combined with the characteristics of each platform itself, make the right choice.%从知名度、基本属性比较、功能分析和应用比较方面对Moodle,Clarolin和Dodeos三款主流开源网络教学平台进行比较。用户应从实际出发,结合各平台自身的特点,做出合适的选择。

  10. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    CERN Multimedia

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  11. Temperature-Insensitive Fibre-Optic Acceleration Sensor Based on Intensity-Referenced Fibre Bragg Gratings

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Qun; DONG Bo; WANG Yong-Xin; Evan LALLY; WANG An-Bo

    2008-01-01

    A temperature-insensitive acceleration sensor using two fibre Bragg gratings (FBGs), based on reflection spectrum intensity modulation and optical power detection, is proposed and demonstrated. A cantilever beam is used to generate acceleration-induced axial strain along two sensing gratings, which are glued on the two opposite surfaces of the beam. Because the two gratings operate within the linear spectral range of a light source, formed by a thermally-tunable extrinsic Fabry-Perot optical filter, the intensity difference of the two reflections from the gratings is proportional to the acceleration applied. This eliminates the need for sophisticated wavelength interrogation of the gratings, and it also endows the sensor with immunity to temperature variation. Compared with a commercial micromachined accelerometer, the sensor is proven to be capable of accurately detecting acceleration.

  12. Introduction to the overall physics design of CSNS accelerators

    Institute of Scientific and Technical Information of China (English)

    WANG Sheng; FANG Shou-Xian; FU Shi-Nian; LIU Wei-Bin; OUYANG Hua-Fu; QIN Qing; TANG Jing-Yu; WEI Jie

    2009-01-01

    The China Spallation Neutron Source(CSNS)is an accelerator-based facility.The accelerator of CSNS consists of a low energy linac,a Rapid Cycling Synchrotron(RCS)and two beam transport lines.The overall physits design of CSNS accelerator is described,including the design principle,the choice of the main parameters and design of each part of accelerators.The key problems of the physics design,such as beam loss and control,are also discussed.The interface between the different parts of accelerator,as well as between accelerator and target,are introduced.

  13. Summary Report of Working Group 1: Laser-Plasma Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Geddes, C.G.R.; Clayton, C.; Lu, W.; Thomas, A.G.R.

    2010-06-01

    Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with quasi-monoenergetic beams at MeV-GeV energies, making them attractive candidates for next generation accelerators. Workshop discussions included advances in control over injection and laser propagation to further improve beam quality and stability, detailed diagnostics and physics models of the acceleration process, radiation generation as a source and diagnostic, and technological tools and upcoming facilities to extend the reach of laser-plasma accelerators.

  14. Calibration of film radiochromic EBT2 for sources of I-125 encapsulated; Calibracion de pelicula radiocromica EBT2 para fuentes de I-125 encapsulado

    Energy Technology Data Exchange (ETDEWEB)

    Huerga Cabrerizo, C.; Luquero Llopis, N.; Torre Hernandez, I. de la; Ferrer Garcia, C.; Corredoira silva, E.; Serrada Hierro, A.

    2013-07-01

    This paper determines the calibration curve in absolute dose for sources of I-125 encapsulated to estimate its uncertainty. In order to assess energy dependence is compared with the obtained for an accelerator of 6MV calibration curve. (Author)

  15. Saturated Fat as Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease: A Prospective Cohort Study

    Science.gov (United States)

    Bernstein, Adam M.; Ley, Sylvia H.; Wang, Dong D.; Chiuve, Stephanie E.; Sampson, Laura; Rexrode, Kathryn M.; Rimm, Eric B.; Willett, Walter C.; Hu, Frank B.

    2015-01-01

    Background The associations between dietary saturated fat and risk of coronary heart disease (CHD) remain controversial, but few studies have compared saturated with unsaturated fats and sources of carbohydrates in relation to CHD risk. Objective This study sought to investigate associations of saturated fats as compared with unsaturated fats and different sources of carbohydrates in relation to CHD risk. Methods We followed 84,628 women (Nurses’ Health Study, 1980 to 2010), and 42,908 men (Health Professionals Follow-up Study, 1986 to 2010) who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed by semiquantitative food frequency questionnaire every 4 years. Results During 24 to 30 years of follow-up, we documented 7,667 incident cases of CHD. Higher intakes of polyunsaturated fatty acids (PUFAs) and carbohydrates from whole grains were significantly associated with lower risk of CHD (hazard ratios [HR] (95% confidence intervals [CI]) comparing the highest to the lowest quintile for PUFA: 0.80 [0.73 to 0.88], p trend saturated fats with equivalent energy intake from either PUFAs, monounsaturated fats (MUFAs), or carbohydrates from whole grains was associated with 25%, 15%, and 9% lower risk of CHD, respectively (PUFAs: 0.75 [0.67 to 0.84]; p saturated fat with carbohydrates from refined starches/added sugars was not significantly associated with CHD risk (p > 0.10). Conclusions Our findings indicate that unsaturated fats, especially PUFAs, and/or high-quality carbohydrates should replace dietary saturated fats to reduce CHD risk. PMID:26429077

  16. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  17. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  18. SuperB Progress Report for Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Buonomo, B.; Demma, T.; Drago, A.; Esposito, M.; Guiducci, S.; Mazzitelli, G.; Pellegrino, L.; Preger, M.A.; Raimondi, P.; Ricci, R.; Rotundo, U.; Sanelli, C.; Serio, M.; Stella, A.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Brachman, A.; /SLAC /Novosibirsk, IYF /INFN, Pisa /Pisa U. /Orsay, LAL /Annecy, LAPP /LPSC, Grenoble /IRFU, SPP, Saclay /DESY /Cockroft Inst. Accel. Sci. Tech. /U. Liverpool /CERN

    2012-02-14

    universities and national laboratories. In Italy these may include INFN Frascati and the University of Pisa, in the United States SLAC, LBNL, BNL and several universities, in France IN2P3, LAPP, and Grenoble, in Russia BINP, in Poland Krakow University, and in the UK the Cockcroft Institute. The construction time for this collider is a total of about four years. The new tunnel can be bored in about a year. The new accelerator components can be built and installed in about 4 years. The shipping of components from PEP-II at SLAC to Italy will take about a year. A new linac and damping ring complex for the injector for the rings can be built in about three years. The commissioning of this new accelerator will take about a year including the new electron and positron sources, new linac, new damping ring, new beam transport lines, two new collider rings and the Interaction Region. The new particle physics detector can be commissioned simultaneously with the accelerator. Once beam collisions start for particle physics, the luminosity will increase with time, likely reaching full design specifications after about two to three years of operation. After construction, the operation of the collider will be the responsibility of the Italian INFN governmental agency. The intent is to run this accelerator about ten months each year with about one month for accelerator turn-on and nine months for colliding beams. The collider will need to operate for about 10 years to provide the required 50 ab{sup -1} requested by the detector collaboration. Both beams as anticipated in this collider will have properties that are excellent for use as sources for synchrotron radiation (SR). The expected photon properties are comparable to those of PETRA-3 or NSLS-II. The beam lines and user facilities needed to carry out this SR program are being investigated.

  19. Acceleration of small astrophysical grains due to charge fluctuations

    CERN Document Server

    Ivlev, A V; Tsytovich, V N; de Angelis, U; Hoang, Thiem; Morfill, G E

    2010-01-01

    We discuss a novel mechanism of dust acceleration which dominates for particles smaller than $\\sim0.1 \\mu$m. The acceleration is caused by charge fluctuations occurring on grains during their mutual Coulomb collisions. The energy source for the acceleration are the irreversible plasma fluxes continuously absorbed by grains. In particular, this mechanism of charge-fluctuation-induced acceleration affects the rate of grain coagulation and shattering of the population of small grains.

  20. Accelerators, Colliders, and Snakes

    Science.gov (United States)

    Courant, Ernest D.

    2003-12-01

    The author traces his involvement in the evolution of particle accelerators over the past 50 years. He participated in building the first billion-volt accelerator, the Brookhaven Cosmotron, which led to the introduction of the "strong-focusing" method that has in turn led to the very large accelerators and colliders of the present day. The problems of acceleration of spin-polarized protons are also addressed, with discussions of depolarizing resonances and "Siberian snakes" as a technique for mitigating these resonances.

  1. Acceleration schedules for a recirculating heavy-ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, W.M.; Grote, D.P.

    2002-05-01

    Recent advances in solid-state switches have made it feasible to design programmable, high-repetition-rate pulsers for induction accelerators. These switches could lower the cost of recirculating induction accelerators, such as the ''small recirculator'' at Lawrence Livermore National Laboratory (LLNL), by substantially reducing the number of induction modules. Numerical work is reported here to determine what effects the use of fewer pulsers at higher voltage would have on the beam quality of the LLNL small recirculator. Lattices with different numbers of pulsers are examined using the fluid/envelope code CIRCE, and several schedules for acceleration and compression are compared for each configuration. For selected schedules, the phase-space dynamics is also studied using the particle-in-cell code WARP3d.

  2. Acceleration of injected electrons by the plasma beat wave accelerator

    Science.gov (United States)

    Joshi, C.; Clayton, C. E.; Marsh, K. A.; Dyson, A.; Everett, M.; Lal, A.; Leemans, W. P.; Williams, R.; Katsouleas, T.; Mori, W. B.

    1992-07-01

    In this paper we describe the recent work at UCLA on the acceleration of externally injected electrons by a relativistic plasma wave. A two frequency laser was used to excite a plasma wave over a narrow range of static gas pressures close to resonance. Electrons with energies up to our detection limit of 9.1 MeV were observed when 2.1 MeV electrons were injected in the plasma wave. No accelerated electrons above the detection threshold were observed when the laser was operated on a single frequency or when no electrons were injected. Experimental results are compared with theoretical predictions, and future prospects for the plasma beat wave accelerator are discussed.

  3. Accelerators and Dinosaurs

    CERN Document Server

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  4. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  5. Acceleration: It's Elementary

    Science.gov (United States)

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  6. Post-acceleration study for neutrino super-beam at CSNS

    Institute of Scientific and Technical Information of China (English)

    WU Yang; TANG Jing-Yu

    2013-01-01

    A post-acceleration system based on the accelerators at CSNS (China Spallation Neutron Source) is proposed to build a super-beam facility for neutrino physics.Two post-acceleration schemes,one using superconducting dipole magnets in the main ring and the other using room temperature magnets,have been studied,both to achieve the final proton energy of 128 GeV and the beam power of 4 MW by taking 10% of the CSNS beam from the neutron source.The main design features and the comparison for the two schemes are presented.The CSNS super-beam facility will be very competitive in long-baseline neutrino physics studies,compared with other super-beam facilities proposed in the world.

  7. OpenMP for Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, J C; Stotzer, E J; Hart, A; de Supinski, B R

    2011-03-15

    OpenMP [13] is the dominant programming model for shared-memory parallelism in C, C++ and Fortran due to its easy-to-use directive-based style, portability and broad support by compiler vendors. Similar characteristics are needed for a programming model for devices such as GPUs and DSPs that are gaining popularity to accelerate compute-intensive application regions. This paper presents extensions to OpenMP that provide that programming model. Our results demonstrate that a high-level programming model can provide accelerated performance comparable to hand-coded implementations in CUDA.

  8. 地源热泵与混合式地源热泵应用对比分析%Comparative Analysis of Ground Source Heat Pumps and Hybrid Ground Source Heat Pump

    Institute of Scientific and Technical Information of China (English)

    陈正顺

    2014-01-01

    Ground Source Heat Pumps(GSHPs) and Hybrid Ground Source Heat Pumps(HGSHPs) in-stalled in several public buildings are compared. The annual energy consumption of buildings are simulated respectively, taking selection calculation of GSHPs and HGSHPs, as well as the initial investment, annual operating costs and the comprehensive fee of two programs.%对合肥几种常见公共建筑已完全使用地埋管换热器的地源热泵系统与混合式地源热泵系统进行了比较。分别对各类型建筑进行了全年能耗模拟,对地源热泵、混合式地源热泵系统进行了选型计算,并对比了两种方案的初投资、年运行费用、年综合费用。

  9. Electromagnetic acceleration studies with augmented rails

    Energy Technology Data Exchange (ETDEWEB)

    Maruo, T.; Fujioka, K.; Nagaoka, K.; Okamoto, A.; Ikuta, K.; Nemoto, K. (Japan Steel Works Ltd., Tokyo (Japan))

    1991-01-01

    A comparative study of electromagnetic acceleration in the rail-type accelerators with two kinds of rail geometry was carried out experimentally. The accelerators were energized by 200kJ capacitor bank and the weight of loaded projectiles was about 1.3 grams with 10mm {times} 10mm square bore. The attained velocity was 4.3km/s in the augmented accelerator, while it was 3.8km/s in the classical device. In this paper these differences in attained velocity are briefly discussed. A theoretical understanding of the rail erosion is also described.

  10. Implementation of Hardware Accelerators on Zynq

    DEFF Research Database (Denmark)

    Toft, Jakob Kenn

    benchmarks, a Monte Carlo simulation of European stock options and a Telco telephone billing application. Each of the accelerators test different aspects of the Zynq platform in terms of floating-point and binary coded decimal processing speed. The two accelerators are compared with the performance...

  11. Bone marrow-derived stromal cells are more beneficial cell sources for tooth regeneration compared with adipose-derived stromal cells.

    Science.gov (United States)

    Ye, Lanfeng; Chen, Lin; Feng, Fan; Cui, Junhui; Li, Kaide; Li, Zhiyong; Liu, Lei

    2015-10-01

    Tooth loss is presently a global epidemic and tooth regeneration is thought to be a feasible and ideal treatment approach. Choice of cell source is a primary concern in tooth regeneration. In this study, the odontogenic differentiation potential of two non-dental-derived stem cells, adipose-derived stromal cells (ADSCs) and bone marrow-derived stromal cells (BMSCs), were evaluated both in vitro and in vivo. ADSCs and BMSCs were induced in vitro in the presence of tooth germ cell-conditioned medium (TGC-CM) prior to implantation into the omentum majus of rats, in combination with inactivated dentin matrix (IDM). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression levels of odontogenic-related genes. Immunofluorescence and immunohistochemical assays were used to detect the protein levels of odontogenic-specific genes, such as DSP and DMP-1 both in vitro and in vivo. The results suggest that both ADSCs and BMSCs have odontogenic differentiation potential. However, the odontogenic potential of BMSCs was greater compared with ADSCs, showing that BMSCs are a more appropriate cell source for tooth regeneration.

  12. Comparing different light-emitting diodes as light sources for long path differential optical absorption spectroscopy NO2 and SO2 measurements

    Institute of Scientific and Technical Information of China (English)

    Chan Ka-Lok; Mark Wenig; Ling Liu-Yi; Andreas Hartl; Zheng Ni-Na; Gerrit Kuhlmann; Qin Min; Sun You-Wen; Xie Pin-Hua; Liu Wen-Qing

    2012-01-01

    In this paper,we present a comparison of different light-emitting diodes (LEDs) as the light source for long path differential optical absorption spectroscopy (LP-DOAS) atmospheric trace gas measurements.In our study,we use a fiberoptic design,where high power LEDs used as the light source are coupled into the telescope using a Y shape fiber bundle.Two blue and one ultraviolet (UV) LEDs with different emission wavelength ranges are tested for NO2 and SO2 measurements.The detailed description of the instrumental setup,the NO2 and SO2 retrieval procedure,the error analysis,and the preliminary results from the measurements carried out in Science Island,Hefei,Anhui,China are presented.Our first measurement results show that atmospheric NO2 and SO2 have strong temporal variations in that area and that the measurement accuracy is strongly dependent on the visibility conditions.The measured NO2 and SO2 data are compared to the Ozone Monitoring Instrument (OMI) satellite observations.The results show that the OMI NO2 product underestimates the ground level NO2 by 45%,while the OMI SO2 data are highly influenced by clouds and aerosols,which can lead to large biases in the ground level concentrations.During the experiment,the mixing ratios of the atmospheric NO2 and SO2 vary from 8 ppbv to 36 ppbv and from 3 ppbv to 18 ppbv,respectively.

  13. Comparing different light-emitting diodes as light sources for long path differential optical absorption spectroscopy NO2 and SO2 measurements

    Science.gov (United States)

    Chan, Ka-Lok; Ling, Liu-Yi; Andreas, Hartl; Zheng, Ni-Na; Gerrit, Kuhlmann; Qin, Min; Sun, You-Wen; Xie, Pin-Hua; Liu, Wen-Qing; Mark, Wenig

    2012-11-01

    In this paper, we present a comparison of different light-emitting diodes (LEDs) as the light source for long path differential optical absorption spectroscopy (LP-DOAS) atmospheric trace gas measurements. In our study, we use a fiberoptic design, where high power LEDs used as the light source are coupled into the telescope using a Y shape fiber bundle. Two blue and one ultraviolet (UV) LEDs with different emission wavelength ranges are tested for NO2 and SO2 measurements. The detailed description of the instrumental setup, the NO2 and SO2 retrieval procedure, the error analysis, and the preliminary results from the measurements carried out in Science Island, Hefei, Anhui, China are presented. Our first measurement results show that atmospheric NO2 and SO2 have strong temporal variations in that area and that the measurement accuracy is strongly dependent on the visibility conditions. The measured NO2 and SO2 data are compared to the Ozone Monitoring Instrument (OMI) satellite observations. The results show that the OMI NO2 product underestimates the ground level NO2 by 45%, while the OMI SO2 data are highly influenced by clouds and aerosols, which can lead to large biases in the ground level concentrations. During the experiment, the mixing ratios of the atmospheric NO2 and SO2 vary from 8 ppbv to 36 ppbv and from 3 ppbv to 18 ppbv, respectively.

  14. Why productive upwelling areas are often sources rather than sinks of CO2? – a comparative study on eddy upwellings in the South China Sea

    Directory of Open Access Journals (Sweden)

    N. Jiao

    2013-08-01

    Full Text Available Marine upwelling regions are known to be productive in carbon fixation and thus thought to be sinks of CO2, whereas many upwelling areas in the ocean are actually sources rather than sinks of CO2. To address this paradox, multiple biogeochemical parameters were investigated at two cyclonic-eddy-induced upwelling sites CE1 and CE2 in the western South China Sea. The results showed that upwelling can exert significant influences on biological activities in the euphotic zone and can either increase or decrease particulate organic carbon (POC export flux depending on upwelling conditions such as the magnitude, timing, and duration of nutrient input and consequent microbial activities. At CE2 the increase of phytoplankton biomass caused by the upwelled nutrients resulted in increase of POC export flux compared to non-eddy reference sites, while at CE1 the microbial respiration of organic carbon stimulated by the upwelled nutrients significantly contributed to the attenuation of POC export flux, aggravating outgassing of CO2. These results suggest that on top of upwelled dissolved inorganic carbon release, microbial activities stimulated by upwelled nutrients and phytoplankton labile organic carbon can play a critical role for a marine upwelling area to be a source rather than a sink of CO2. Meanwhile, we point out that even though an upwelling region is outgassing, carbon sequestration still takes place through the POC-based biological pump as well as the refractory dissolved organic carbon (RDOC-based microbial carbon pump.

  15. Detection and Localization of Transient Sources: Comparative Study of Complex-Lag Distribution Concept Versus Wavelets and Spectrogram-Based Methods

    Directory of Open Access Journals (Sweden)

    Bertrand Gottin

    2009-01-01

    Full Text Available The detection and localization of transient signals is nowadays a typical point of interest when we consider the multitude of existing transient sources, such as electrical and mechanical systems, underwater environments, audio domain, seismic data, and so forth. In such fields, transients carry out a lot of information. They can correspond to a large amount of phenomena issued from the studied problem and important to analyze (anomalies and perturbations, natural sources, environmental singularities, …. They usually occur randomly as brief and sudden signals, such as partial discharges in electrical cables and transformers tanks. Therefore, motivated by advanced and accurate analysis, efficient tools of transients detection and localization are of great utility. Higher order statistics, wavelets and spectrogram distributions are well known methods which proved their efficiency to detect and localize transients independently to one another. However, in the case of a signal composed by several transients physically related and with important energy gap between them, the tools previously mentioned could not detect efficiently all the transients of the whole signal. Recently, the generalized complex time distribution concept has been introduced. This distribution offers access to highly concentrated representation of any phase derivative order of a signal. In this paper, we use this improved phase analysis tool to define a new concept to detect and localize dependant transients taking regard to the phase break they cause and not their amplitude. ROC curves are calculated to analyze and compare the performances of the proposed methods.

  16. Assessment of aortic stenosis after aortic valve replacement. Comparative evaluation of dual-source CT and echocardiography; Quantitative Evaluation der Aortenklappenoeffnungsflaeche mit der Dual-Source-CT und Korrelation mit der 2D-Echokardiografie. Initiale Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Saam, T.; Minaifar, N.; Becker, C.; Reiser, M.; Nikolaou, K. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie; Oberhoffer, M.; Rist, C.; Vogt, F.; Reichart, B. [Ludwig-Maximilians-Univ. Muenchen (Germany). Herzchirurgische Klinik und Poliklinik

    2008-06-15

    Purpose: To prospectively evaluate whether planimetric measurements of aortic valve area (AVA) with dual-source computed tomography (DSCT) correlate with measurements obtained by echocardiography and to correlate the amount of calcification of the aortic valve with AVA in a group of patients after aortic valve replacement. Materials and Method: 23 patients underwent dual-source computed tomography (DSCT) of the heart (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany), without heart rate control (heart rate 52-113 beats/minute). All patients had undergone aortic valve replacement (homografts, mean time after surgery: 7{+-}3 years). The AVA of the transplanted aortic valve graft was measured planimetrically by means of DSCT and compared with echocardiography as a standard of reference, to exclude post-surgical restenosis of the valve. Maximum AVA in systole planimetrically measured with CT was compared with calculated AVA values determined with the continuity equation, using transvalvular pressure gradients. The amount of calcification of the aortic valve was quantified and correlated (Spearman's R) with the AVA. To assess intra- and inter-reader reproducibility, the DCST data was re-analyzed by two readers 4 weeks after the initial review. Results: All DSCT datasets were of diagnostic image quality concerning valve depiction. The mean AVA as measured by DSCT was 2.7{+-}0.9 cm{sup 2} compared to 1.8{+-}0.5 cm{sup 2} by echocardiography (p<0.05). The planimetric evaluation of the CT data as compared to results of echocardiography showed a significant correlation of the results (Pearson's correlation coefficient R=0.78, p<0.001). Intra- and inter-reader reproducibility was good with intra-class correlation coefficients of 0.86 and 0.81, respectively (p<0.001). There was a significant negative correlation between the amount of aortic valve calcification and AVA as measured by echocardiography (R=-0.42; p<0.05) and as measured by DSCT (R=-0

  17. EDITORIAL: Laser and Plasma Accelerators Workshop, Kardamyli, Greece, 2009 Laser and Plasma Accelerators Workshop, Kardamyli, Greece, 2009

    Science.gov (United States)

    Bingham, Bob; Muggli, Patric

    2011-01-01

    -resolved radiobiology or chemistry. Such laser-generated beams will form the basis of the fifth generation light sources and will be compact versions of the much more expensive fourth generation XFEL, such as LCLS light sources. Laser-driven ion acceleration is also making rapid headway; one of the goals in these experiments is to produce protons and carbon ions of hundreds of MeV for oncology. These experiments are carried out using solid-target-laser interactions. There is still a number of issues to be resolved in these experiments including the origin of light ions. The paper by Willingale et al addresses this issue and demonstrates that deuteron ions originating from the front surface can gain comparable energies as those from the rear surface. Furthermore, from two-dimensional simulations they show that a proton-rich contamination layer over the surface is detrimental to deuteron ion acceleration from the rear surface but not detrimental to the front surface acceleration mechanism. Studies of different laser polarizations on ion acceleration at the rear surface were reported by Antici et al. It was shown that no real enhancement using a particular polarization was found. At higher radiation intensities, especially with the multi-petawatt lasers being planned, radiation reaction becomes important. This was reported by Chen et al who found that radiation reaction effects on ion acceleration in laser-foil interactions impeded the backward moving electrons, which enhanced the ion acceleration. An interesting new development is the use of ultra-relativistic proton beams to drive plasma wakefields. This is similar to the SLAC electron-beam-driven wakefields. However, unlike the SLAC electron beam, which is of the order of 30 fs long and matches the period of the plasma wave necessary to create the blowout or bubble regime, the ion beam is very much longer. To create shorter ion beams a magnetic compression scheme is investigated in the paper by Caldwell et al, and results for proton

  18. Nonresonant Grain Acceleration in MHD Turbulence

    CERN Document Server

    Yan, Huirong

    2009-01-01

    We discuss a new type of dust acceleration mechanism that acts in a turbulent magnetized medium. The magnetohydrodynamic (MHD) turbulence can accelerate grains through resonant as well as nonresonant interactions. We show that the magnetic compression provides higher velocities for super-Alfv\\'enic turbulence and can accelerate an extended range of grains in warm media compared to gyroresonance. While fast modes dominate the acceleration for the large grains, slow modes can be important for sub-micron grains. We provide comprehensive discussion of all the possible grain acceleration mechanisms in interstellar medium. We show that supersonic velocities are attainable for Galactic dust grains. We discuss the consequence of the acceleration. The implications for extinction curve, grain alignment, chemical abundance, etc, are provided.

  19. Acceleration profiles in elite Australian soccer.

    Science.gov (United States)

    Varley, M C; Aughey, R J

    2013-01-01

    We quantified the acceleration and high-velocity running of elite Australian soccer players. We hypothesised that high-intensity activity would be underestimated when excluding acceleration during match analysis given its high metabolic demand and occurrence at low velocities. Player movements were observed from 29 players (forwards and central and wide defenders and midfielders) during domestic Australian competition using 5-Hz global positioning system. Effort occurrence were determined for high-velocity running, sprinting and maximal accelerations. The commencement and final velocity of maximal accelerations were also identified. Players undertook an 8~fold greater number of maximal accelerations than sprints per game (65±21 vs. 8±5). Of maximal accelerations ~98% commenced from a starting velocity lower than what would be considered high-velocity running while ~85% did not cross the high-velocity running threshold. The number of efforts performed in all categories were position dependent (Psprints compared to all other positions (Pdrills.

  20. A Conceptual Description of the ESS-Bilbao Accelerator

    OpenAIRE

    Bustinduy, Ibón; Bermejo, Francisco Javier

    2014-01-01

    3rd International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS III, 31 July–3 August 2012, Bilbao, Spain & the 4th International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS IV, 23-27 September 2013, Sapporo, Hokkaido, Japa. 10 pags., 9 figs.; 1 tab. Codes: ibsimu, gpt, nigun, mad, tracewin, toutatis and rfqsim.

  1. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  2. Dynamics of pyroelectric accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ghaderi, R.; Davani, F. Abbasi, E-mail: fabbasi@sbu.ac.ir [Radiation Application Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2015-01-26

    Pyroelectric crystals are used to produce high energy electron beams. We have derived a method to model electric potential generation on LiTaO{sub 3} crystal during heating cycle. In this method, effect of heat transfer on the potential generation is investigated by some experiments. In addition, electron emission from the crystal surface is modeled by measurements and analysis. These spectral data are used to present a dynamic equation of electric potential with respect to thickness of the crystal and variation of its temperature. The dynamic equation's results for different thicknesses are compared with measured data. As a result, to attain more energetic electrons, best thickness of the crystals could be extracted from the equation. This allows for better understanding of pyroelectric crystals and help to study about current and energy of accelerated electrons.

  3. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators.

    Science.gov (United States)

    O'Shea, B D; Andonian, G; Barber, S K; Fitzmorris, K L; Hakimi, S; Harrison, J; Hoang, P D; Hogan, M J; Naranjo, B; Williams, O B; Yakimenko, V; Rosenzweig, J B

    2016-09-14

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m(-1)) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m(-1) using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m(-1). Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons.

  4. Industrial Application of Accelerators

    CERN Document Server

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Univer...

  5. Industrial Application of Accelerators

    CERN Document Server

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Uni...

  6. Transient behavior of a nuclear reactor coupled to an accelerator

    Science.gov (United States)

    Sadineni, Suresh Babu

    Accelerator Driven Systems (ADS) present one of the most viable solutions for transmutation and effective utilization of nuclear fuel. Spent fuel from reactors will be partitioned to separate plutonium and other minor actinides to be transmuted in the ADS. Without the ADS, minor actinides must be stored at a geologic repository for long periods of time. One problem with ADS is understanding the control issues that arise when coupling an accelerator to a reactor. "ADSTRANS" was developed to predict the transient behavior of a nuclear reactor coupled to an accelerator. It was based on MCNPX, a radiation transport code developed at the LANL, and upon a numerical model of the neutron transport equation. MCNPX was used to generate the neutron "source" term that occurs when the accelerator is fired. ADSTRANS coupled MCNPX to a separate finite difference code that solved the transient neutron transport equation. A cylindrical axisymmetric reactor with steel shielding was considered for this analysis. Multiple neutron energy groups, neutron precursor groups and neutron poisons were considered. ENDF/B cross-section data obtained through MCNPX was also employed. The reactor was assumed to be isothermal and near zero power level. Unique features of this code are: (1) it predicts the neutron behavior of an ADS for different reactor geometry, material concentration, both electron and proton particle accelerators, and target material, (2) it develops input files for MCNPX to simulate neutron production, runs MCNPX, and retrieves information from the MCNPX output files. Neutron production predicted by MCNPX for a 20 MeV electron accelerator and lead target was compared with experimental data from the Idaho Accelerator Center and found to be in good agreement. The spatial neutron flux distribution and transient neutron flux in the reactor as predicted by the code were compared with analytical solutions and found to be in good agreement. Fuel burnup and poison buildup were also as

  7. Status of spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    Existing and planned facilities using proton accelerator driven spallation neutron source are reviewed. These include new project of neutron science proposed from Japan Atomic Energy Research Institute. The present status of facility requirement and accelerator technology leads us to new era of neutron science such as neutron scattering research and nuclear transmutation study using very intense neutron source. (author)

  8. Development and Performance of a Proton and Deuteron ECR Ion Source

    CERN Document Server

    Dunkel, Kai; Piel, Christian; Plitzko, J

    2005-01-01

    A 5mA proton and deuteron rf source is under development at ACCEL. This source will provide the front end of our superconducting proton/deuteron linear accelerator. The design of the source is based on the proven AECL design of a 100 mA proton source. The paper will describe the design of the source and the layout of the test bench currently set up at ACCEL to characterize the source. Results of the beam dynamic simulations performed to optimize the source geometry based on KOBRA 3D will be presented and compared with first measurement results.

  9. A comparative study on the risk of second primary cancers in out-of-field organs associated with radiotherapy of localized prostate carcinoma using Monte Carlo-based accelerator and patient models

    Energy Technology Data Exchange (ETDEWEB)

    Bednarz, Bryan; Athar, Basit; Xu, X. George [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02108 and Department of Mechanical Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2010-05-15

    Purpose: A physician's decision regarding an ideal treatment approach (i.e., radiation, surgery, and/or hormonal) for prostate carcinoma is traditionally based on a variety of metrics. One of these metrics is the risk of radiation-induced second primary cancer following radiation treatments. The aim of this study was to investigate the significance of second cancer risks in out-of-field organs from 3D-CRT and IMRT treatments of prostate carcinoma compared to baseline cancer risks in these organs. Methods: Monte Carlo simulations were performed using a detailed medical linear accelerator model and an anatomically realistic adult male whole-body phantom. A four-field box treatment, a four-field box treatment plus a six-field boost, and a seven-field IMRT treatment were simulated. Using BEIR VII risk models, the age-dependent lifetime attributable risks to various organs outside the primary beam with a known predilection for cancer were calculated using organ-averaged equivalent doses. Results: The four-field box treatment had the lowest treatment-related second primary cancer risks to organs outside the primary beam ranging from 7.3x10{sup -9} to 2.54x10{sup -5}%/MU depending on the patients age at exposure and second primary cancer site. The risks to organs outside the primary beam from the four-field box and six-field boost and the seven-field IMRT were nearly equivalent. The risks from the four-field box and six-field boost ranged from 1.39x10{sup -8} to 1.80x10{sup -5}%/MU, and from the seven-field IMRT ranged from 1.60x10{sup -9} to 1.35x10{sup -5}%/MU. The second cancer risks in all organs considered from each plan were below the baseline risks. Conclusions: The treatment-related second cancer risks in organs outside the primary beam due to 3D-CRT and IMRT is small. New risk assessment techniques need to be investigated to address the concern of radiation-induced second cancers from prostate treatments, particularly focusing on risks to organs inside the

  10. A comparative study on the risk of second primary cancers in out-of-field organs associated with radiotherapy of localized prostate carcinoma using Monte Carlo-based accelerator and patient models

    Science.gov (United States)

    Bednarz, Bryan; Athar, Basit; Xu, X. George

    2010-01-01

    Purpose: A physician’s decision regarding an ideal treatment approach (i.e., radiation, surgery, and∕or hormonal) for prostate carcinoma is traditionally based on a variety of metrics. One of these metrics is the risk of radiation-induced second primary cancer following radiation treatments. The aim of this study was to investigate the significance of second cancer risks in out-of-field organs from 3D-CRT and IMRT treatments of prostate carcinoma compared to baseline cancer risks in these organs. Methods: Monte Carlo simulations were performed using a detailed medical linear accelerator model and an anatomically realistic adult male whole-body phantom. A four-field box treatment, a four-field box treatment plus a six-field boost, and a seven-field IMRT treatment were simulated. Using BEIR VII risk models, the age-dependent lifetime attributable risks to various organs outside the primary beam with a known predilection for cancer were calculated using organ-averaged equivalent doses. Results: The four-field box treatment had the lowest treatment-related second primary cancer risks to organs outside the primary beam ranging from 7.3×10−9 to 2.54×10−5%∕MU depending on the patients age at exposure and second primary cancer site. The risks to organs outside the primary beam from the four-field box and six-field boost and the seven-field IMRT were nearly equivalent. The risks from the four-field box and six-field boost ranged from 1.39×10−8 to 1.80×10−5%∕MU, and from the seven-field IMRT ranged from 1.60×10−9 to 1.35×10−5%∕MU. The second cancer risks in all organs considered from each plan were below the baseline risks. Conclusions: The treatment-related second cancer risks in organs outside the primary beam due to 3D-CRT and IMRT is small. New risk assessment techniques need to be investigated to address the concern of radiation-induced second cancers from prostate treatments, particularly focusing on risks to organs inside the primary beam

  11. A comparative study on electrical characteristics of crystalline AlN thin films deposited by ICP and HCPA-sourced atomic layer deposition

    Science.gov (United States)

    Altuntas, Halit; Bayrak, Turkan

    2016-12-01

    In this work, we aimed to investigate the effects of two different plasma sources on the electrical properties of low-temperature plasma-assisted atomic layer deposited (PA-ALD) AlN thin films. To compare the electrical properties, 50 nm thick AlN films were grown on p-type Si substrates at 200 °C by using an inductively coupled RF-plasma (ICP) and a stainless steel hollow cathode plasma-assisted (HCPA) ALD systems. Al/AlN/p-Si metal-insulator-semiconductor (MIS) capacitor devices were fabricated and capacitance versus voltage (C-V) and current-voltage (I-V) measurements performed to assess the basic important electrical parameters such as dielectric constant, effective charge density, flat-band voltage, breakdown field, and threshold voltage. In addition, structural properties of the films were presented and compared. The results show that although HCPA-ALD deposited AlN thin films has structurally better and has a lower effective charge density (N eff ) value than ICP-ALD deposited AlN films, those films have large leakage current, low dielectric constant, and low breakdown field. This situation was attributed to the involvement of Si atoms into the AlN layers during the HCPA-ALD processing leads to additional current path at AlN/Si interface and might impair the electrical properties.

  12. A comparative study on electrical characteristics of crystalline AlN thin films deposited by ICP and HCPA-sourced atomic layer deposition

    Science.gov (United States)

    Altuntas, Halit; Bayrak, Turkan

    2017-03-01

    In this work, we aimed to investigate the effects of two different plasma sources on the electrical properties of low-temperature plasma-assisted atomic layer deposited (PA-ALD) AlN thin films. To compare the electrical properties, 50 nm thick AlN films were grown on p-type Si substrates at 200 °C by using an inductively coupled RF-plasma (ICP) and a stainless steel hollow cathode plasma-assisted (HCPA) ALD systems. Al/AlN/ p-Si metal-insulator-semiconductor (MIS) capacitor devices were fabricated and capacitance versus voltage ( C- V) and current-voltage ( I- V) measurements performed to assess the basic important electrical parameters such as dielectric constant, effective charge density, flat-band voltage, breakdown field, and threshold voltage. In addition, structural properties of the films were presented and compared. The results show that although HCPA-ALD deposited AlN thin films has structurally better and has a lower effective charge density ( N eff ) value than ICP-ALD deposited AlN films, those films have large leakage current, low dielectric constant, and low breakdown field. This situation was attributed to the involvement of Si atoms into the AlN layers during the HCPA-ALD processing leads to additional current path at AlN/Si interface and might impair the electrical properties.

  13. Particle-accelerator decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.

    1979-12-01

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given.

  14. Accelerated cleanup risk reduction

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, R.B.; Aines, R.M.; Blake, R.G.; Copeland, A.B.; Newmark, R.L.; Tompson, A.F.B.

    1998-02-01

    There is no proven technology for remediating contaminant plume source regions in a heterogeneous subsurface. This project is an interdisciplinary effort to develop the requisite new technologies so that will be rapidly accepted by the remediation community. Our technology focus is hydrous pyrolysis/oxidation (HPO) which is a novel in situ thermal technique. We have expanded this core technology to leverage the action of steam injection and place an in situ microbial filter downstream to intercept and destroy the accelerated movement of contaminated groundwater. Most contaminant plume source regions, including the chlorinated solvent plume at LLNL, are in subsurface media characterized by a wide range in hydraulic conductivity. At LLNL, the main conduits for contaminant transport are buried stream channels composed of gravels and sands; these have a hydraulic conductivity in the range of 10{sup -1} to 10{sup -2} cm/s. Clay and silt units with a hydraulic conductivity of 10{sup -1} to 10{sup -6} cm/s bound these buried channels; these are barriers to groundwater movement and contain the highest contaminant concentrations in the source region. New remediation technologies are required because the current ones preferentially access the high conductivity units. HPO is an innovative process for the in situ destruction of contaminants in the entire subsurface. It operates by the injection of steam. We have demonstrated in laboratory experiments that many contaminants rapidly oxidize to harmless compounds at temperatures easily achieved by injecting steam, provided sufficient dissolved oxygen is present. One important challenge in a heterogeneous source region is getting heat, contaminants, and an oxidizing agent in the same place at the same time. We have used the NUFT computer program to simulate the cyclic injection of steam into a contaminated aquifer for design of a field demonstration. We used an 8 hour, steam/oxygen injection cycle followed by a 56 hour relaxation

  15. Operation of the accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, R.C.; Batzka, B.; Billquist, P.J. [and others

    1995-08-01

    Fiscal Year 1994 was the first year of seven-day operation since ATLAS became a national user facility in 1985. ATLAS made the most of the opportunity this year by providing 5200 hours of beam on-target to the research program. A record number of 60 experiments were completed and the {open_quotes}facility reliability{close_quotes} remained near the 90% level. Seven-day operation was made possible with the addition to the staff of two operator positions providing single-operator coverage during the weekend period. The normally scheduled coverage was augmented by an on-call list of system experts who respond to emergencies with phone-in advice and return to the Laboratory when necessary. This staffing approach continues but we rearranged our staffing patterns so that we now have one cryogenics engineer working a shift pattern which includes 8-hour daily coverage during the weekend. ATLAS provided a beam mix to users consisting of 26 different isotopic species, 23% of which were for A>100 in FY 1994. Approximately 60% of the beam time was provided by the Positive Ion Injector, slightly less than the usage rate of FY 1993. Experiments using uranium or lead beams accounted for 16.4% of the total beam time. The ECR ion source and high-voltage platform functioned well throughout the year. A new technique for solid material production in the source was developed which uses a sputtering process wherein the sample of material placed near the plasma chamber wall is biased negatively. Plasma ions are accelerated into the sample and material is sputtered from the surface into the plasma. This technique is now used routinely for many elements. Runs of calcium, germanium, nickel, lead, tellurium, and uranium were carried out with this technique.

  16. Industrial Applications of Accelerator Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaesang; Park, Jaewon; Lee, Chanyoung; and others

    2013-02-15

    PEFP(Proton Engineering Frontier Project) put its aim on development of high power linear proton accelerator and its beam applications. So, it has, since late 1990's, accumulated accelerator and ion source technologies, supplied beam utilization service to related industry. As of now, right after 10 year long project(PEFP), many of its low energy beam technologies seem to be successfully utilized for industrial purpose to meet the market needs, especially in improvement of production process and manufacturing performance, new substance development, etc. In this context, it is high time to carry out in-depth industrialization development on PEFP's retained ion beam technology prowess: To help them diffused profitable markets as soon as possible. So, in this work, through verification on the industrialization feasibility by experiments, it is going to get it started, with cooperation of participatory company, to enter into markets with developed technology and products.

  17. Accelerating structure with linear excitation

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J.; Srinivasan-Rao, T.

    1988-03-01

    The switched power linac (SPL) structures require a ring-shaped laser beam pulse of uniform intensity to avoid transverse field components of the accelerating field at the center. In order to also utilize the reflection of the outgoing EM wave, the switching element has to be very close to the outer edge of the structure to ensure nearly synchronous superposition at the beam hole with the original inward going wave. It is sometimes easier to produce linear (flat) laser beams, e.g., from powerful excimer lasers which have beams of rectangular cross section. Such flat beams could be used to excite linear photocathode switches or be used to produce flat electron beam pulses in electron sources. In this paper, an accelerator structure is proposed which may be considered a variant of the SPL disk structure, but could be used with linear beams. The structure utilizes a double parabolic horn. 8 refs., 9 figs.

  18. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  19. Leaky Fermi accelerators

    CERN Document Server

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  20. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  1. Production and applications of neutrons using particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Chichester, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  2. Power Converters for Accelerators

    CERN Document Server

    Visintini, R

    2015-01-01

    Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.

  3. High Gradient Accelerator Research

    Energy Technology Data Exchange (ETDEWEB)

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  4. FFAGS for rapid acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Carol J. Johnstone and Shane Koscielniak

    2002-09-30

    When large transverse and longitudinal emittances are to be transported through a circular machine, extremely rapid acceleration holds the advantage that the beam becomes immune to nonlinear resonances because there is insufficient time for amplitudes to build up. Uncooled muon beams exhibit large emittances and require fast acceleration to avoid decay losses and would benefit from this style of acceleration. The approach here employs a fixed-field alternating gradient or FFAG magnet structure and a fixed frequency acceleration system. Acceptance is enhanced by the use only of linear lattice elements, and fixed-frequency rf enables the use of cavities with large shunt resistance and quality factor.

  5. Advanced approaches to high intensity laser-driven ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Henig, Andreas

    2010-04-26

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C{sup 6+} and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C{sup 6+} spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times

  6. Comparative Characterization of Total Flavonol Glycosides and Terpene Lactones at Different Ages, from Different Cultivation Sources and Genders of Ginkgo biloba Leaves

    Directory of Open Access Journals (Sweden)

    Yong Qin

    2012-08-01

    Full Text Available The extract from Ginkgo biloba leaves has become a very popular plant medicine and herbal supplement for its potential benefit in alleviating symptoms associated with peripheral vascular disease, dementia, asthma and tinnitus. Most research on G. biloba leaves focus on the leaves collected in July and August from four to seven year-old trees, however a large number of leaves from fruit cultivars (trees older than 10 years are ignored and become obsolete after fruit harvest season (November. In this paper, we expand the tree age range (from one to 300 years and first comparatively analyze the total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of G. biloba leaves collected in November by using the validated HPLC-ELSD and HPLC-PDA methods. The results show that the contents of total terpene lactones and flavonol glycosides in the leaves of young ginkgo trees are higher than those in old trees, and they are higher in male trees than in female trees. Geographical factors appear to have a significant influence on the contents as well. These results will provide a good basis for the comprehensive utilization of G. biloba leaves, especially the leaves from fruit cultivars.

  7. Summary report of working group 3: Laser and high-gradient structure-based acceleration

    Science.gov (United States)

    Andonian, Gerard; Simakov, Evgenya

    2017-03-01

    High-gradient particle acceleration with reduced power demands is essential for miniaturization and cost reduction of future accelerators. Applications for compact accelerators span collider research for High Energy Physics, light source development for Basic Energy Sciences and National Security, and industrial accelerators for Energy and Environmental Applications. Working Group 3 discussed and surveyed the recent advances in achieving higher gradients and better acceleration efficiency in externally powered, structure-based accelerators. The topics covered in Working Group 3 included dielectric laser acceleration, millimeter-wave accelerators, breakdown phenomena, exotic topologies such as photonic band-gap structures, artificial materials, and nanostructures, and novel rf technology.

  8. Accelerating Around an Unbanked Curve

    Science.gov (United States)

    Mungan, Carl E.

    2006-02-01

    The December 2004 issue of TPT presented a problem concerning how a car should accelerate around an unbanked curve of constant radius r starting from rest if it is to avoid skidding. Interestingly enough, two solutions were proffered by readers.2 The purpose of this note is to compare and contrast the two approaches. Further experimental investigation of various turning strategies using a remote-controlled car and overhead video analysis could make for an interesting student project.

  9. Characterisation of electron beams from laser-driven particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2012-12-21

    The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

  10. A Comparative Effectiveness Study of Bone Density Changes in Women Over 40 Following Three Bone Health Plans Containing Variations of the Same Novel Plant-sourced Calcium

    Directory of Open Access Journals (Sweden)

    Gilbert R. Kaats, Harry G. Preuss, Harry A. Croft, Samuel C. Keith, Patti L. Keith

    2011-01-01

    Full Text Available Background: The US Surgeon General's Report on Bone Health suggests America's bone-health is in jeopardy and issued a “call to action” to develop bone-health plans incorporating components of (1 improved nutrition, (2 increased health literacy, and (3 increased physical activity.Objective: To conduct a Comparative Effectiveness Research (CER study comparing changes in bone mineral density in healthy women over-40 with above-average compliance when following one of three bone health Plans incorporating the SG's three components.Methods: Using an open-label sequential design, 414 females over 40 years of age were tested, 176 of whom agreed to participate and follow one of three different bone-health programs. One Plan contained a bone-health supplement with 1,000 IUs of vitamin D3 and 750 mg of a plant-sourced form of calcium for one year. The other two Plans contained the same plant form of calcium, but with differing amounts of vitamin D3 and other added bone health ingredients along with components designed to increase physical activity and health literacy. Each group completed the same baseline and ending DXA bone density scans, 43-chemistry blood test panels, and 84-item Quality of Life Inventory (QOL. Changes for all subjects were annualized as percent change in BMD from baseline. Using self-reports of adherence, subjects were rank-ordered and dichotomized as “compliant” or “partially compliant” based on the median rating. Comparisons were also made between the treatment groups and two theoretical age-adjusted expected groups: a non-intervention group and a group derived from a review of previously published studies on non-plant sources of calcium.Results: There were no significant differences in baseline BMD between those who volunteered versus those who did not and between those who completed per protocol (PP and those who were lost to attrition. Among subjects completing per protocol, there were no significant differences

  11. Technical report on the accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Bex, L. [ed.

    1995-12-31

    GANIL operation and the technical studies performed in 1994 are described. The milestones for 1994 are: SISSI (Source d`Ions Secondaires a Supraconducteurs Intense) has been in operation and used for secondary beam production with four different primary beams. The 100 kV platform for beam injection in the CO1 has been in operation for production of metallic beams which demand is increasing. Finally the SPIRAL project (Systeme de Production d`Ions Radioactifs Acceleres en Ligne) is in progress. In late 1994 the civil work has started in view of the installation of the machine in the north part of the GANIL machine building. (K.A.). 48 refs.

  12. DualSPHysics: Open-source parallel CFD solver based on Smoothed Particle Hydrodynamics (SPH)

    Science.gov (United States)

    Crespo, A. J. C.; Domínguez, J. M.; Rogers, B. D.; Gómez-Gesteira, M.; Longshaw, S.; Canelas, R.; Vacondio, R.; Barreiro, A.; García-Feal, O.

    2015-02-01

    DualSPHysics is a hardware accelerated Smoothed Particle Hydrodynamics code developed to solve free-surface flow problems. DualSPHysics is an open-source code developed and released under the terms of GNU General Public License (GPLv3). Along with the source code, a complete documentation that makes easy the compilation and execution of the source files is also distributed. The code has been shown to be efficient and reliable. The parallel power computing of Graphics Computing Units (GPUs) is used to accelerate DualSPHysics by up to two orders of magnitude compared to the performance of the serial version.

  13. Accelerators Beyond The Tevatron?

    Energy Technology Data Exchange (ETDEWEB)

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  14. COLLECTIVE-FIELD ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, Andrew M.

    1969-07-04

    Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

  15. Asia honours accelerator physicists

    CERN Multimedia

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  16. Optimization of accelerator-driven technology for LWR waste transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, C.D.

    1996-12-31

    The role of accelerator-driven transmutation technology is examined in the context of the destruction of actinide waste from commercial light water reactors. It is pointed out that the commercial plutonium is much easier to use for entry-level nuclear weapons than weapons plutonium. Since commercial plutonium is easier to use, since there is very much more of it already, and since it is growing rapidly, the permanent disposition of commercial plutonium is an issue of greater importance than weapons plutonium. The minor actinides inventory, which may be influenced by transmutation, is compared in terms of nuclear properties with commercial and weapons plutonium and for possible utility as weapons material. Fast and thermal spectrum systems are compared as means for destruction of plutonium and the minor actinides. it is shown that the equilibrium fast spectrum actinide inventory is about 100 times larger than for thermal spectrum systems, and that there is about 100 times more weapons-usable material in the fast spectrum system inventory compared to the thermal spectrum system. Finally it is shown that the accelerator size for transmutation can be substantially reduced by design which uses the accelerator-produced neutrons only to initiate the unsustained fission chains characteristic of the subcritical system. The analysis argues for devoting primary attention to the development of thermal spectrum transmutation technology. A thermal spectrum transmuter operating at a fission power of 750-MWth fission power, which is sufficient to destroy the actinide waste from one 3,000-MWth light water reactor, may be driven by a proton beam of 1 GeV energy and a current of 7 mA. This accelerator is within the range of realizable cyclotron technology and is also near the size contemplated for the next generation spallation neutron source under consideration by the US, Europe, and Japan.

  17. Comparative study of CdTe sources used for deposition of CdTe thin films by close spaced sublimation technique

    OpenAIRE

    Pinheiro,Wagner Anacleto; Falcão, Vivienne Denise; Cruz,Leila Rosa de Oliveira; Ferreira,Carlos Luiz

    2006-01-01

    Unlike other thin film deposition techniques, close spaced sublimation (CSS) requires a short source-substrate distance. The kind of source used in this technique strongly affects the control of the deposition parameters, especially the deposition rate. When depositing CdTe thin films by CSS, the most common CdTe sources are: single-crystal or polycrystalline wafers, powders, pellets or pieces, a thick CdTe film deposited onto glass or molybdenum substrate (CdTe source-plate) and a sintered C...

  18. Ion Source DECRIS-3

    CERN Document Server

    Efremov, A; Lebedev, A N; Loginov, V N; Yazvitsky, N Yu

    1999-01-01

    The ECR ion source DECRIS-3 is the copy of the mVINIS ion source which was designed and built in Dubna for the TESLA Accelerator Installation (Belgrade, Yugoslavia) in 1997. The assembly of the source was completely finished in the end of 1998 and then it was installed at the FLNR ECR test bench. The source was successfully tested with some gases and metals by using the MIVOC technique. In nearest future the source will be capable of ECR plasma heating using two different frequencies simultaneously. We are also going to use the DECRIS-3 ion source to design 1+ -> n+ technique for the DRIBs (Dubna Radioactive Ion Beams) project.

  19. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    Energy Technology Data Exchange (ETDEWEB)

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  20. The Accelerated Kepler Problem

    CERN Document Server

    Namouni, Fathi

    2007-01-01

    The accelerated Kepler problem is obtained by adding a constant acceleration to the classical two-body Kepler problem. This setting models the dynamics of a jet-sustaining accretion disk and its content of forming planets as the disk loses linear momentum through the asymmetric jet-counterjet system it powers. The dynamics of the accelerated Kepler problem is analyzed using physical as well as parabolic coordinates. The latter naturally separate the problem's Hamiltonian into two unidimensional Hamiltonians. In particular, we identify the origin of the secular resonance in the accelerated Kepler problem and determine analytically the radius of stability boundary of initially circular orbits that are of particular interest to the problem of radial migration in binary systems as well as to the truncation of accretion disks through stellar jet acceleration.