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Sample records for grenoble cyclotron

  1. Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

    SciTech Connect

    Thomae, R. Conradie, J.; Fourie, D.; Mira, J.; Nemulodi, F.; Kuechler, D.; Toivanen, V.

    2016-02-15

    At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.

  2. CLOVERLEAF CYCLOTRON

    DOEpatents

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

    1959-02-01

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

  3. Electron cyclotron resonance (ECR) ion sources

    SciTech Connect

    Jongen, Y.

    1984-05-01

    Starting with the pioneering work of R. Geller and his group in Grenoble (France), at least 14 ECR sources have been built and tested during the last five years. Most of those sources have been extremely successful, providing intense, stable and reliable beams of highly charged ions for cyclotron injection or atomic physics research. However, some of the operational features of those sources disagreed with commonly accepted theories on ECR source operation. To explain the observed behavior of actual sources, it was found necessary to refine some of the crude ideas we had about ECR sources. Some of those new propositions are explained, and used to make some extrapolations on the possible future developments in ECR sources.

  4. Conversion feasibility studies for the Grenoble high flux reactor

    SciTech Connect

    Mo, S.C.; Matos, J.E.

    1989-01-01

    Feasibility studies for conversion of the High Flux Reactor (RHF) at Grenoble France have been performed at the Argonne National Laboratory in cooperation with the Institut Laue-Langevin (ILL). The uranium densities required for conversion of the RHF to reduced enrichment fuels were computed to be 7.9 g/cm{sup 3} with 20% enrichment, 4.8 g/cm{sup 3} with 29% enrichment, and 2.8 g/cm{sup 3} with 45% enrichment. Thermal flux reductions at the peak in the heavy water reflector were computed to be 3% with 45% enriched fuel and 7% with 20% enriched fuel. In each case, the reactor's 44 day cycle length was preserved and no changes were made in the fuel element geometry. If the cladding thickness could be reduced from 0.38 mm to 0.30 mm, the required uranium density with 20% enrichment would be about 6.0 g/cm{sup 3} and the thermal flux reduction at the peak in the heavy water reflector would be about 7%. Significantly higher uranium densities are required in the RHF than in heavy water reactors with more conventional designs because the neutron spectrum is much harder in the RHF. Reduced enrichment fuels with the uranium densities required for use in the RHF are either not available or are not licensable at the present time. 6 refs., 6 figs., 3 tabs.

  5. 88-Inch Cyclotron newsletter

    SciTech Connect

    Stokstad, R.

    1987-02-01

    Activities at the 88-Inch Cyclotron are discussed. Increased beam time demand and operation of the ECR source and cyclotron are reported. Experimental facility improvements are reported, including improvements to the High Energy Resolution Array and to the Recoil Atom Mass Analyzer, a new capture beamline, development of a low background counting facility. Other general improvements are reported that relate to the facility computer network and electronics pool. Approved heavy nuclei research is briefly highlighted. Also listed are the beams accelerated by the cyclotron. (LEW)

  6. Cyclotron Institute Upgrade Project

    SciTech Connect

    Clark, Henry; Yennello, Sherry; Tribble, Robert

    2014-08-26

    The Cyclotron Institute at Texas A&M University has upgraded its accelerator facilities to extend research capabilities with both stable and radioactive beams. The upgrade is divided into three major tasks: (1) re-commission the K-150 (88”) cyclotron, couple it to existing beam lines to provide intense stable beams into the K-500 experimental areas and use it as a driver to produce radioactive beams; (2) develop light ion and heavy ion guides for stopping radioactive ions created with the K-150 beams; and (3) transport 1+ ions from the ion guides into a charge-breeding electron-cyclotron-resonance ion source (CB-ECR) to produce highly-charged radioactive ions for acceleration in the K-500 cyclotron. When completed, the upgraded facility will provide high-quality re-accelerated secondary beams in a unique energy range in the world.

  7. L'orologio solare a riflessione del Liceo Stendhal di Grenoble (Francia)

    NASA Astrophysics Data System (ADS)

    del Favero, Enrico

    2004-03-01

    This paper describes history and features of the great reflecting sundial involving 100 m2 of a stair wall in the Liceo Internazionale Stendhal of Grenoble, southern France. The sundial, built in 1673 by the jesuit father Jean Bonfa, contains hourly and diurnal lines of various types and also some moon-solar astronomical instruments.

  8. Spatial cyclotron damping

    NASA Technical Reports Server (NTRS)

    Olson, C. L.

    1970-01-01

    To examine spatial electron cyclotron damping in a uniform Vlasov plasma, it is noted that the plasma response to a steady-state transverse excitation consists of several terms (dielectric-pole, free-streaming, and branch-cut), but that the cyclotron-damped pole term is the dominant term for z l = c/w sub ce provided (w sub pe/w sub ce) squared (c/a) is much greater than 1. If the latter inequality does not hold, then the free-streaming and branch-cut terms persist well past z = c/w sub ce as w sub 1 approaches w sub ce, making experimental measurement of cyclotron damping essentially impossible. Considering only (w sub pe/w sub ce) squared (c/a) is much greater than 1, it is shown how collisional effects should be estimated and how a finite-width excitation usually has little effect on the cyclotron-damped part of the response. Criteria is established concerning collisional damping, measurable damping length sizes, and allowed uncertainty in the magnetic field Beta. Results of numerical calculations, showing the regions in the appropriate parameter spaces that meet these criteria, are presented. From these results, one can determine the feasibility of, or propose parameter values for, an experiment designed to measure spatial cyclotron damping. It is concluded that the electron temperature T sub e should be at least 1 ev., and preferably 10 ev. or higher, for a successful experiment.

  9. Inflation and cyclotron motion

    NASA Astrophysics Data System (ADS)

    Greensite, Jeff

    2017-01-01

    We consider, in the context of a braneworld cosmology, the motion of the Universe coupled to a four-form gauge field, with constant field strength, defined in higher dimensions. It is found, under rather general initial conditions, that in this situation there is a period of exponential inflation combined with cyclotron motion in the inflaton field space. The main effect of the cyclotron motion is that slow roll conditions on the inflaton potential, which are typically necessary for exponential inflation, can be evaded. There are Landau levels associated with the four-form gauge field, and these correspond to quantum excitations of the inflaton field satisfying unconventional dispersion relations.

  10. Cyclotron Research and Applications

    SciTech Connect

    Mach, Rostislav

    2010-01-05

    The twenty years old cyclotron U-120M was upgraded for R and D and Production of Radiopharmaceuticals. R and D on short-lived Radiopharmaceuticals production is done at this accelerator. These Radiopharmaceuticals are eventually delivered to nearby hospitals. Development of new diagnostic radiopharmaceuticals is also pursued at the facility. your paper.

  11. Cyclotrons and positron emitting radiopharmaceuticals

    SciTech Connect

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

    1984-01-01

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

  12. Ion cyclotron resonance cell

    DOEpatents

    Weller, R.R.

    1995-02-14

    An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

  13. Ion cyclotron resonance cell

    DOEpatents

    Weller, Robert R.

    1995-01-01

    An ion cyclotron resonance cell having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions.

  14. Helium cyclotron resonance within the earth's magnetosphere

    SciTech Connect

    Mauk, B.H.; McIlwain, C.E.; McPherron, R.L.

    1981-01-01

    A histogram of electromagnetic Alfven/ion cyclotron wave frequencies, sampled within the geostationary enviroment and normalized by the equatorial proton cyclotron frequency, shows a dramatic gap centered near the helium (He/sup +/) cyclotron frequency. Also, strongly cyclotron phase bunched helium ions (20--200 eV) have been observed directly within the vicinity of wave environments. These observations are interpreted as resulting from the absorption of the waves through cyclotron resonance by cool ambient populations of helium ions.

  15. ECR (Electron Cyclotron Resonance) ion sources for cyclotrons

    SciTech Connect

    Lyneis, C.M.

    1986-10-01

    In the last decade ECR (Electron Cyclotron Resonance) ion sources have evolved from a single large, power consuming, complex prototype into a variety of compact, simple, reliable, efficient, high performance sources of high charge state ions for accelerators and atomic physics. The coupling of ECR sources to cyclotrons has resulted in significant performance gains in energy, intensity, reliability, and variety of ion species. Seven ECR sources are in regular operation with cyclotrons and numerous other projects are under development or in the planning stag. At least four laboratories have ECR sources dedicated for atomic physics research and other atomic physics programs share ECR sources with cyclotrons. An ECR source is now installed on the injector for the CERN SPS synchrotron to accelerate O/sup 8 +/ to relativistic energies. A project is underway at Argonne to couple an ECR source to a superconducting heavy-ion linac. Although tremendous progress has been made, the field of ECR sources is still a relatively young technology and there is still the potential for further advances both in source development and understanding of the plasma physics. The development of ECR sources is reviewed. The important physics mechanisms which come into play in the operation of ECR Sources are discussed, along with various models for charge state distributions (CSD). The design and performance of several ECR sources are compared. The 88-Inch Cyclotron and the LBL ECR is used as an example of cyclotron+ECR operation. The future of ECR sources is considered.

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

    SciTech Connect

    Prater, R.; Lohr, J.

    1985-12-31

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

  17. BEST medical radioisotope production cyclotrons

    SciTech Connect

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

    2013-04-19

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

  18. BEST medical radioisotope production cyclotrons

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  19. FEL on slow cyclotron wave

    SciTech Connect

    Silivra, A.

    1995-12-31

    A physical mechanism of interaction of fast electromagnetic wave with slow cyclotron wave of relativistic electron beam in a FEL with helical wiggler field is described. It is shown that: (1) interaction is possible for both group of steady state electron trajectories (2) positive gain is achieved within certain interval of guide field strength (3) operation wavelength for group 1 trajectories ({Omega}{sub 0}/{gamma} < k{omega}{upsilon}{parallel}) is shorter than for the conventional FEL synchronism. A nonlinear analysis shows that efficiency of slow cyclotron FEL is restricted mainly by a breakdown of a single electron synchronism due to dependence of (modified) electron cyclotron frequency on an energy of electron. Nevertheless, as numerical simulation shows, typical efficiency of 15 % order is achieved in millimeter wavelength band for the midrelativistic ({gamma}= 3 {divided_by} 4) slow cyclotron wave FEL. Tapering of magnetic field results in a substantial increase of efficiency.

  20. Cyclotron Production of Medical Radioisotopes

    SciTech Connect

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

    2010-08-04

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

  1. Calculation of cyclotron rf systems

    NASA Astrophysics Data System (ADS)

    Van Genderen, W.; Van Der Heide, J. A.; Bräutigam, W.

    1987-08-01

    An approximate calculation of the characteristic properties of resonators for cyclotron rf systems is described. Formulas for the characteristic impedence of line segments are evaluated and an approximation for a dee-dummy dee system is given. A computer program has been written which also takes into account the capacity due to line discontinuities. The computed resonance frequency for cyclotrons in Eindhoven and Jülich agrees within 5% with experimental data. The power consumption is also computed and analyzed.

  2. Two cases of type A infant botulism in Grenoble, France: no honey for infants.

    PubMed

    Hoarau, Gautier; Pelloux, Isabelle; Gayot, Armelle; Wroblewski, Isabelle; Popoff, Michel-Robert; Mazuet, Christelle; Maurin, Max; Croizé, Jacques

    2012-03-01

    We report two severe cases of infant botulism diagnosed at Grenoble University Hospital, France, respectively in 2006 and 2009. Both cases were characterized by a delay in diagnosis, severe neurological manifestations and extended period of hospitalization in intensive care unit, but a complete recovery. Infant botulism is a rare but life-threatening disease. It primarily affects infants, and the main risk factor is honey ingestion. Diagnosis should be systematically evoked by pediatricians in infants suffering from constipation, fatigue, muscle weakness, difficult feeding and altered cry, but before the onset of generalized flaccid paralysis, so as to administer specific treatment (BabyBIG®, a human derived botulinum antitoxin) at an early stage of the disease when it is most effective. In conclusion, parents should be aware of the role of honey as a source of spores of Clostridium botulinum and therefore infant botulism in the first year of life.

  3. Atmospheric boundary layer dynamics in the Grenoble valley during strongly stable episodes

    NASA Astrophysics Data System (ADS)

    Staquet, C.; Largeron, Y.; Chollet, J.

    2013-12-01

    This paper addresses the dynamics of the atmospheric boundary layer in the Grenoble valley under strongly stable and polluted conditions. Numerical modeling is used for this purpose, along with available ground temperature measurements. Though the Grenoble valley is the most populated area in the Alps and is subjected to serious pollution episodes in winter, no such study had been conducted previously. We first analyzed ground temperature data within the valley at altitudes ranging between 220 m (valley bottom) and 1730 m during 5 months of winter 2006-2007. These data were provided by Meteo-France et by Air Rhône-Alpes, the air quality agency of Région Rhône-Alpes. Our purpose was to detect strongly stable episodes, these being defined by the episode-averaged vertical gradient of the absolute temperature being larger than the winter average during at least three days. Five episodes were selected from this criterion. We also analyzed air quality data recorded by Air Rhône-Alpes during the same winter to detect strongly polluted events for PM10 and found that the five episodes were also strongly polluted ones. To perform a more detailed analysis of these five episodes, we used the numerical code Meso-NH developed by Météo-France and the Laboratory of Aérology in Toulouse and simulated the dynamics of the atmospheric boundary layer during each episode. Four nested domains were used, the horizontal resolution of the innermost (and smallest) domain, containing the Grenoble valley, being 333 m; from comparison with the ground temperature data, we found that the vertical resolution above ground level had to be as low as 4 meters. As expected, the boundary layer dynamics in the numerical simulation for each episode was found to be decoupled from the (anticyclonic, weak) synoptic flow, consistent with the value of the Froude number associated with the inversion layer. These dynamics are controlled by thermal (mostly katabatic) winds flowing from the higher altitude

  4. Summer/winter variability of the surfactants in aerosols from Grenoble, France

    NASA Astrophysics Data System (ADS)

    Baduel, Christine; Nozière, Barbara; Jaffrezo, Jean-Luc

    2012-02-01

    Many atmospheric aerosols seem to contain strong organic surfactants likely to enhance their cloud-forming properties. Yet, few techniques allow for the identification and characterization of these compounds. Recently, we introduced a double extraction method to isolate the surfactant fraction of atmospheric aerosol samples, and evidenced their very low surface tension (≤30 mN m -1). In this work, this analytical procedure was further optimized. In addition to an optimized extraction and a reduction of the analytical time, the improved method led to a high reproducibility in the surface tension curves obtained (shapes and minimal values), illustrated by the low uncertainties on the values, ±10% or less. The improved method was applied to PM 10 aerosols from the urban area of Grenoble, France collected from June 2009 to January 2010. Significant variability was observed between the samples. The minimum surface tension obtained from the summer samples was systematically lower (30 mN m -1) than that of the winter samples (35-45 mN m -1). Sharp transitions in the curves together with the very low surface tensions suggested that the dominating surfactants in the summer samples were biosurfactants, which would be consistent with the high biogenic activity in that season. One group of samples from the winter also displayed sharp transitions, which, together with the slightly higher surface tension, suggested the presence of weaker, possibly man-made, surfactants. A second group of curves from the winter did not display any clear transition but were similar to those of macromolecular surfactants such as polysaccharides or humic substances from wood burning. These surfactants are thus likely to originate from wood burning, the dominating source for aerosols in Grenoble in winter. These observations thus confirm the presence of surfactants from combustion processes in urban aerosols reported by other groups and illustrates the ability of our method to distinguish between

  5. [Mental health, vulnerability and general practice: a study of non-profit health centers in Grenoble].

    PubMed

    Dubois-Fabing, Delphine; Pichon, Philippe; Arnevielhe, Alizée; Suscillon, Marie-Paule; Caron, Bruno; Saillard, Fabienne; François, Patrice

    2011-01-01

    Very little research has been conducted on the role of general practitioners (GPs) in mental health care among socioeconomically disadvantaged populations in France. The non-profit community health care centers in Grenoble provide populations living in sensitive urban zones with high quality primary health care that includes a medico-social and prevention dimension. The aim of this study was to measure the prevalence of mental health issues diagnosed by GPs in health care centers, to identify the factors associated with these issues and to describe treatment characteristics. This cross-sectional study focused on general practice consultations in the AGECSA Grenoble health care centers over the course of one week. At the end of each consultation, the GP collected information about the patient, including personal data, psychological disorders, vulnerability, and patient health management. Among the 451 patients included in the study, GPs found that 45.2% of patients were in vulnerable situations and 43% of patients suffered from a mental disorder, including 29% of cases of anxiety and 20% of cases of depression. 44% of patients suffered from a psychological disorder (mental disorder and/or psychological suffering). For these patients, 52.8% of the consultations lasted more than 20 minutes. Their treatment generally included a mental health care follow-up (in 76% of cases), including psychological support (59%) and treatment of functional somatic disorders (46%). The study shows the high prevalence of psychological disorders diagnosed in the patients treated by GPs working in health care centers in disadvantaged urban areas. Research shows that GPs play an important and specific role in mental health care and prevention. An analysis of the organizational methods used in health care centers is highly relevant.

  6. Electron cyclotron harmonic wave acceleration

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  7. Electron cyclotron harmonic wave acceleration

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  8. Use of cyclotrons in medicine

    NASA Astrophysics Data System (ADS)

    Qaim, S. M.

    2004-10-01

    Cyclotrons are versatile ion-accelerating machines which find many applications in medicine. In this short review their use in hadron therapy is briefly discussed. Proton therapy is gaining significance because of its capability to treat deep-lying tumours. A strong area of application of cyclotrons involves the production of short-lived neutron deficient radiotracers for use in emission tomography, especially positron emission tomography. This fast and quantitative in vivo diagnostic technique is being increasingly used in neurology, cardiology and oncology. Besides routine patient care, considerable interdisciplinary work on development of new positron emitters is under way. A short account of those efforts is given. The use of cyclotrons in the production of radionuclides for internal radiotherapy is also briefly described.

  9. Borehole Initiatives In France and Greece: The Grenoble and Corinth Gulf Vertical Arrays

    NASA Astrophysics Data System (ADS)

    Lemeille, F.; Berge-Thierry, C.; Hatzfeld, D.; Bernard, P.

    The near-surface geological site conditions in the upper tens of meters are one of the dominant factors in controlling the amplitude and variation of strong ground motion, and the damage patterns that result from large earthquakes. Our understanding of these site effects comes primarily from surface recordings. In recent years, however, the increase in the number of borehole instruments provides a significant step forward in directly measuring the effects of surface geology. In the last ten years, the IPSN has been involved in the Garner Valley Deep Accelerom- eter Project (GVDA) in Southern California in collaboration with the Nuclear Regula- tory Commission (NRC) and the University of California Santa Barbara (UCSB) both in the USA. This project has produced valuable data to study site effects and it con- stituted a milestone in terms of managing experience of a vertical array. In this way in order to study site effects in the European Community, IPSN is also collaborating in two recent projects, one in Grenoble (France), and another in the Gulf of Corinth (Greece). In the Grenoble valley, a 556 m deep borehole has been drilled. This project is also supported by the LGIT in 1999-2000 with local and ministerial funding. The ref- erence accelerometer is in the Mesozoic basement at 556 m deep. On the surface, the accelerometer is also part of the Permanent Accelerometric Network ruled by the LGIT. The borehole drilling was performed together with acoustic logging. One year of recording of accelerations is available on the Web. The LGIT, BRGM and INPG/3S carried out geophysical experiments on the site as well. In the framework of CORSEIS European program, IPSN together with ENS Paris, IPG Paris (France), AUTH and NKUA (Greece), are supporting a vertical array of accelerometers and pore pressure transducers dedicated to the study of liquefaction and nonlinearity in the Aigion harbor. These phenomena occurred during the June 15 1995 (M = 6.2) event. All transducers are

  10. [Drug supply chain safety in hospitals: current data and experience of the Grenoble university hospital].

    PubMed

    Bedouch, P; Baudrant, M; Detavernier, M; Rey, C; Brudieu, E; Foroni, L; Allenet, B; Calop, J

    2009-01-01

    Drug supply chain safety has become a priority for public health which implies a collective process. This process associates all health professionals including the pharmacist who plays a major role. The objective of this present paper is to describe the several approaches proven effective in the reduction of drug-related problem in hospital, illustrated by the Grenoble University Hospital experience. The pharmacist gets involved first in the general strategy of hospital drug supply chain, second by his direct implication in clinical activities. The general strategy of drug supply chain combines risk management, coordination of the Pharmacy and Therapeutics Committee, selection and purchase of drugs and organisation of drug supply chain. Computer management of drug supply chain is a major evolution. Nominative drug delivering has to be a prior objective and its implementation modalities have to be defined: centralized or decentralized in wards, manual or automated. Also, new technologies allow the automation of overall drug distribution from central pharmacy and the implementation of automated drug dispensing systems into wards. The development of centralised drug preparation allows a safe compounding of high risk drugs, like cytotoxic drugs. The pharmacist should develop his clinical activities with patients and other health care professionals in order to optimise clinical decisions (medication review, drug order analysis) and patients follow-up (therapeutic monitoring, patient education, discharge consultation).

  11. The Grenoble Analysis Toolkit (GreAT)-A statistical analysis framework

    NASA Astrophysics Data System (ADS)

    Putze, A.; Derome, L.

    2014-12-01

    The field of astroparticle physics is currently the focus of prolific scientific activity. In the last decade, this field has undergone significant developments thanks to several experimental results from CREAM, PAMELA, Fermi, and H.E.S.S. Moreover, the next generation of instruments, such as AMS-02 (launched on 16 May 2011) and CTA, will undoubtedly facilitate more sensitive and precise measurements of the cosmic-ray and γ-ray fluxes. To fully exploit the wealth of high precision data generated by these experiments, robust and efficient statistical tools such as Markov Chain Monte Carlo algorithms or evolutionary algorithms, able to handle the complexity of joint parameter spaces and datasets, are necessary for a phenomenological interpretation. The Grenoble Analysis Toolkit (GreAT) is an user-friendly and modular object orientated framework in C++, which samples the user-defined parameter space with a pre- or user-defined algorithm. The functionality of GreAT is presented in the context of cosmic-ray physics, where the boron-to-carbon (B/C) ratio is used to constrain cosmic-ray propagation models.

  12. The 400W at 1.8K Test Facility at CEA-Grenoble

    NASA Astrophysics Data System (ADS)

    Roussel, P.; Girard, A.; Jager, B.; Rousset, B.; Bonnay, P.; Millet, F.; Gully, P.

    2006-04-01

    A new test facility with a cooling capacity respectively of 400W at 1.8K or 800W at 4.5K, is now under nominal operation in SBT (Low Temperature Department) at CEA Grenoble. It has been recently used for thermohydraulic studies of two phase superfluid helium in autumn 2004. In the near future, this test bench will allow: - to test industrial components at 1.8K (magnets, cavities of accelerators) - to continue the present studies on thermohydraulics of two phase superfluid helium - to develop and simulate new cooling loops for ITER Cryogenics, and other applications such as high Reynolds number flows This new facility consists of a cold box connected to a warm compressor station (one subatmospheric oil ring pump in series with two screw compressors). The cold box, designed by AIR LIQUIDE, comprises two centrifugal cold compressors, a cold turbine, a wet piston expander, counter flow heat exchangers and two phase separators at 4.5K and 1.8K. The new facility uses a Programmable Logic Controller (PLC) connected to a bus for the measurements. The design is modular and will allow the use of saturated fluid flow (two phase flow at 1.8K or 4.5K) or single phase fluid forced flow. Experimental results and cooling capacity in different operation modes are detailed.

  13. NACA Researcher Examines the Cyclotron

    NASA Image and Video Library

    1951-02-21

    Researcher James Blue examines the new cyclotron at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. Researchers at NACA Lewis began postulating about the use of atomic power for propulsion immediately after World War II. The NACA concentrated its efforts on the study of high temperature materials and heat transfer since it did not have access to the top secret fission information. The military studied the plausibility of nuclear propulsion for aircraft in the late 1940s. The military program was cancelled after four years without any breakthroughs, but the Atomic Energy Commission took on the effort in 1951. The NACA Lewis laboratory was expanding its nuclear-related research during this period. In 1948, Lewis engineers were assigned to the Oak Ridge National Laboratory to obtain expertise in high temperature heat transfer and advanced materials technology. The following year a new 80-person Nuclear Reactor Division was created, and an in-house nuclear school was established to train these researchers. The cyclotron was built behind the Materials and Structures Laboratory to support thermodynamic and materials research for both nuclear aircraft and nuclear rockets. The original NACA Lewis cyclotron was used to accelerate two kinds of particles. To better match the space radiation environment, the cyclotron was later modified to accelerate particles of the newly-discovered Van Allen radiation belts.

  14. TRIUMF cyclotron vacuum system refurbishing

    NASA Astrophysics Data System (ADS)

    Sekachev, I.

    2008-03-01

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

  15. Method and apparatus for ion cyclotron spectrometry

    DOEpatents

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

    2010-08-17

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

  16. Future cyclotron systems: An industrial perspective

    SciTech Connect

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

    1995-09-01

    The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modern cyclotron-based isotope production facilities. In particular, the change to negative ion acceleration and new high power systems have resulted in dramatic improvements in reliability, increases in capacity, and decreases in personnel radiation dose. As more and more older machines are retired, decisions regarding their replacement are made based on several factors including the market`s potential and the cyclotron system`s abilities. Taking the case of the recently upgraded TR30 cyclotron at TRIUMF/Nordion, the authors investigate the requirements industrial/medical users are likely to impose on future commercial cyclotron systems and the impact this will have on cyclotron technology by the end of the century.

  17. Commercial compact cyclotrons in the 90`s

    SciTech Connect

    Milton, B.F.

    1995-09-01

    Cyclotrons continue to be efficient accelerators for radio-isotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicate a strong future for commercial cyclotrons. In this paper the authors will survey recent developments in the areas of cyclotron technology, as they relate to the new generation of commercial cyclotrons. Design criteria for the different types of commercial cyclotrons will be presented, with reference to those demands that differ from those in a research oriented cyclotron project. The authors also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA.

  18. Comparison between seismic and domestic risk in moderate seismic hazard prone region: the Grenoble City (France) test site

    NASA Astrophysics Data System (ADS)

    Dunand, F.; Gueguen, P.

    2012-02-01

    France has a moderate level of seismic activity, characterized by diffuse seismicity, sometimes experiencing earthquakes of a magnitude of more than 5 in the most active zones. In this seismicity context, Grenoble is a city of major economic and social importance. However, earthquakes being rare, public authorities and the decision makers are only vaguely committed to reducing seismic risk: return periods are long and local policy makers do not have much information available. Over the past 25 yr, a large number of studies have been conducted to improve our knowledge of seismic hazard in this region. One of the decision-making concerns of Grenoble's public authorities, as managers of a large number of public buildings, is to know not only the seismic-prone regions, the variability of seismic hazard due to site effects and the city's overall vulnerability, but also the level of seismic risk and exposure for the entire city, also compared to other natural or/and domestic hazards. Our seismic risk analysis uses a probabilistic approach for regional and local hazards and the vulnerability assessment of buildings. Its applicability to Grenoble offers the advantage of being based on knowledge acquired by previous projects conducted over the years. This paper aims to compare the level of seismic risk with that of other risks and to introduce the notion of risk acceptability in order to offer guidance in the management of seismic risk. This notion of acceptability, which is now part of seismic risk consideration for existing buildings in Switzerland, is relevant in moderately seismic-prone countries like France.

  19. Cyclotron Line Measurements with INTEGRAL

    NASA Technical Reports Server (NTRS)

    Pottschmidt, K.; Kreykenbohm, I.; Caballero, I.; Fritz, S.; Schoenherr, G.; Kretschmar, P.; Wilms, J.; McBride, V. A.; Suchy, S.; Rothschild, R. E.

    2008-01-01

    Due to its broadband energy coverage, INTEGRAL has made important contributions to observing and interpreting cyclotron lines, which are present in the 10-100 keV range of a sample of accreting pulsars. In these systems photons with energies fulfilling the resonance condition inelastically Compton scatter off electrons quantized in the accretion column above the neutron star's magnetic pole(s). This process gives rise to the broad, absorption-like lines or 'cyclotron resonant scattering features' (CRSF). The observed lines allow to directly measure the B-fields of these sources, resulting in values of a few times 1E12G. In this overview I will present recent highlights regarding CRSF observations as well as discuss current ideas and models for the physical conditions in the accretion column. Among the former are the stability of the spectrum of Vela X-1 during giant flares in 2003, the observation of three cyclotron lines during the 2004 outburst of V0332+53, the confirmation of the fundamental line at approximately 45 keV during a 2005 normal outburst of A0535-26, and the simultaneous detection of the two lines in the dipping source 4U 1907+09 (for which also a torque reversal was detected for the first time). Through these and other observations it has become increasingly apparent that two types of observations can potentially be used to constrain the accretion column geometry: the determination of energy ratios for multiple harmonic lines (only two sources with greater than 2 lines are known), was well as the evolution of the fundamental line centroid, which, for different sources, may or may not be correlated with flux. Furthermore, first steps have been taken away from the usual phenomenological description of the lines, towards a physical approach based on self-consistent CRSF modeling. Initial applications are presented.

  20. Cyclotron Line Measurements with INTEGRAL

    NASA Technical Reports Server (NTRS)

    Pottschmidt, K.; Kreykenbohm, I.; Caballero, I.; Fritz, S.; Schoenherr, G.; Kretschmar, P.; Wilms, J.; McBride, V. A.; Suchy, S.; Rothschild, R. E.

    2008-01-01

    Due to its broadband energy coverage, INTEGRAL has made important contributions to observing and interpreting cyclotron lines, which are present in the 10-100 keV range of a sample of accreting pulsars. In these systems photons with energies fulfilling the resonance condition inelastically Compton scatter off electrons quantized in the accretion column above the neutron star's magnetic pole(s). This process gives rise to the broad, absorption-like lines or 'cyclotron resonant scattering features' (CRSF). The observed lines allow to directly measure the B-fields of these sources, resulting in values of a few times 1E12G. In this overview I will present recent highlights regarding CRSF observations as well as discuss current ideas and models for the physical conditions in the accretion column. Among the former are the stability of the spectrum of Vela X-1 during giant flares in 2003, the observation of three cyclotron lines during the 2004 outburst of V0332+53, the confirmation of the fundamental line at approximately 45 keV during a 2005 normal outburst of A0535-26, and the simultaneous detection of the two lines in the dipping source 4U 1907+09 (for which also a torque reversal was detected for the first time). Through these and other observations it has become increasingly apparent that two types of observations can potentially be used to constrain the accretion column geometry: the determination of energy ratios for multiple harmonic lines (only two sources with greater than 2 lines are known), was well as the evolution of the fundamental line centroid, which, for different sources, may or may not be correlated with flux. Furthermore, first steps have been taken away from the usual phenomenological description of the lines, towards a physical approach based on self-consistent CRSF modeling. Initial applications are presented.

  1. Lawrence's Legacy : Seaborg's Cyclotron - The 88-Inch Cyclotron turns 40

    NASA Astrophysics Data System (ADS)

    McMahan, Margaret; Clark, David

    2003-04-01

    In 1958, Sputnik had recently been launched by the Russians, leading to worry in Congress and increased funding for science and technology. Ernest Lawrence was director of the "Rad Lab" at Berkeley. Another Nobel Prize winner, Glenn Seaborg, was Associate Laboratory Director and Director of the Nuclear Chemistry Division. In this atmosphere, Lawrence was phoned by commissioners of the Atomic Energy Commission and asked what they could do for Seaborg, "because he did such a fine job of setting up the chemistry for extracting plutonium from spent reactor fuel" [1]. In this informal way, the 90-Inch (eventually 88-Inch) Cyclotron became a line item in the federal budget at a cost of 3M (later increased to 5M). The 88-Inch Cyclotron achieved first internal beam on Dec. 12, 1961 and first external beam in May 1962. Forty years later it is still going strong. Pieced together from interviews with the retirees who built it, Rad Lab reports and archives from the Seaborg and Lawrence collections, the story of its design and construction - on-time and under-budget - provides a glimpse into the early days of big science. [1] remarks made by Elmer Kelly, "Physicist-in-charge' of the project on the occasion of the 40th anniversary celebration.

  2. The Warsaw K=160 cyclotron

    NASA Astrophysics Data System (ADS)

    Choinski, J.; Miszczak, J.; Sura, J.

    2001-12-01

    The overview of the Warsaw cyclotron facility is presented. The facility consists of K=160 cyclotron, 10 GHz ECR ion source, and several experimental stations. The cyclotron is of compact design with 2 straight dees. A yearly operation time is about 2900 hours on an average for the past few years. The cyclotron can deliver beams up to Ar with energy up to 10 MeV/amu to the experimental area. Experimental stations are: 1) The multidetector OSIRIS II, allows the study of exotic nuclei in the double magic 100Sn region. The experimental set-up consists of 8 HPGe detectors equipped with charged particle 4π multiplicity filter SiBall, 50 elements BGO γ-rays multiplicity filter, 4 sector polarimeter and electron conversion detector system. 2) CUDAC-Coulomb Universal Detector Scattering Chamber-an array of PIN-diodes in connection with HPGe detectors and the computer data analysis package GOSIA, maintained by the Laboratory allows investigation the Coulomb Excitation (COULEX) reactions. 3) IGISOL or Helium-jet transport system opened investigation of the reaction products by means of the online mass separator with ion-guide system. The system uses the Scandinavian-type mass separator built in INR Świerk, Poland. 4) Giant Dipole Resonance studies using experimental set-up JANOSIK developed for the detection of high-energy photons emitted in heavy-ion collisions. The set-up consists of a large NaI(Tl) detector (25 cm×29 cm) surrounded by shields: passive lead shield, active anticoincidence plastic shield and LiH shield to absorb neutrons, and a multiplicity filter of 32 small scintillator detectors (BaF2 and NaI(Tl)). 5) Laser spectroscopy stand now in test phase. The laser spectroscopy group at HIL has completed an equipment consisting of Argon ion Laser Innova 400-25W in all lines and coherent Ring Laser 669-21 as well as atomic beam apparatus.

  3. Synergy between the CIMENT tier-2 HPC centre and the HEP community at LPSC in Grenoble (France)

    NASA Astrophysics Data System (ADS)

    Biscarat, C.; Bzeznik, B.

    2014-06-01

    Two of the most pressing questions in current research in Particle Physics are the characterisation of the newly discovered Higgs-like boson at the LHC and the search for New Phenomena beyond the Standard Model of Particle Physics. Physicists at LPSC in Grenoble are leading the search for one type of New Phenomena in ATLAS. Given the rich multitude of physics studies proceeding in parallel in ATLAS, one limiting factor in the timely analysis of data is the availability of computing resources. Another LPSC team suffers from the same limitation. This team is leading the ultimate precision measurement of the W boson mass with DØ data, which yields an indirect constraint on the Higgs boson mass which can be compared with the direct measurements of the mass of the newly discovered boson at LHC. In this paper, we describe the synergy between CIMENT, a regional multidisciplinary HPC centre, and the HEP community in Grenoble in the context of the analysis of data recorded by the ATLAS experiment at the LHC collider and the D0 experiment at the Tevatron collider. CIMENT is a federation of twelve HPC clusters, of about 90 TFlop/s, one of the most powerful HPC tier-2 centres in France. The sharing of resources between different scientific fields, like the ones discussed in this article, constitutes a great asset because the spikes in need of computing resources are uncorrelated in time between different fields.

  4. Superficial Fungal Infections in a French Teaching Hospital in Grenoble Area: Retrospective Study on 5470 Samples from 2001 to 2011.

    PubMed

    Faure-Cognet, O; Fricker-Hidalgo, H; Pelloux, H; Leccia, M T

    2016-02-01

    Superficial fungal infections are predominantly caused by dermatophytes, but the spectrum of species involved is depending on geographic areas and lifestyle. Only few studies have recently described the French epidemiology of these infections, especially dermatophytosis. To determine the epidemiological situation of superficial fungal infections and the spectrum of dermatophytes in Grenoble area. A retrospective study of mycological laboratory records from January 2001 to December 2011 was carried out among patients with suspected fungal infections in the Grenoble University Hospital. Samples (skin scrapings, nail clippings and hair specimens) were collected, and mycological analyses were carried out by conventional methods. A total of 5470 samples collected from 3740 patients were analysed. Among the 1984 (36.3 %) positive cultures, dermatophytes were identified in 1348/1984 (67.9 %) samples, non-dermatophytes in 636/1984 (32.1 %) samples (yeasts 24.4 %, moulds 7.7 %). Toenails and feet were the most frequent localizations collected (2032 samples, 37.1 %, 1181 samples, 21.5 %). These data show the predominance (more than 92.6 %) of anthropophilic dermatophytes (Trichophyton rubrum, Trichophyton interdigitale and Trichophyton tonsurans). Trichophyton rubrum was the most commonly (78.6 %) isolated dermatophyte. Among zoophilic dermatophytes, Trichophyton verrucosum and Microsporum persicolor were regularly isolated.

  5. Cyclotron in the Materials and Stresses Building

    NASA Image and Video Library

    1976-11-21

    Researchers check the cyclotron in the Materials and Stresses Building at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The Materials and Stresses Building, built in 1949, contained a number of laboratories to test the strength, diffusion, and other facets of materials. The materials could be subjected to high temperatures, high stresses, corrosion, irradiation, and hot gasses. The Physics of Solids Laboratory included a cyclotron, cloud chamber, helium cryostat, and metallurgy cave. The cyclotron was built in the early 1950s to test the effects of radiation on different materials so that the proper materials could be used to construct a nuclear aircraft engine and other components. By the late 1950s, the focus had shifted to similar studies for rockets. NASA cancelled its entire nuclear program in January 1973, and the cyclotron was mothballed. In 1975 the Cleveland Clinic Foundation partnered with NASA Lewis to use the cyclotron to treat cancer patients with a new type of radiation therapy. The cyclotron split beryllium atoms which caused neutrons to be released. The neutrons were streamed directly at the patient’s tumor. Over the course of five years, the cyclotron was used to treat 1200 patients. The program was terminated in 1980 as the Clinic shifted its efforts to concentrate on non-radiation treatments. The Lewis cyclotron was mothballed for a number of years before being demolished.

  6. Recent development and progress of IBA cyclotrons

    NASA Astrophysics Data System (ADS)

    Kleeven, W.; Abs, M.; Delvaux, J. L.; Forton, E.; Jongen, Y.; Medeiros Romao, L.; Nactergal, B.; Nuttens, V.; Servais, T.; Vanderlinden, T.; Zaremba, S.

    2011-12-01

    Several cyclotron development projects were recently realized by Ion Beam Applications S.A. (IBA). This contribution presents three of them: (i) the intensity enhancement of the Cyclone 30 cyclotron, a machine mainly used for the production of SPECT isotopes. This project is related with the increased demand for 201Tl because of the shortage of Mo/Tc generators from nuclear reactors, (ii) development of a new versatile multiple-particle K = 30 isotope-production cyclotron (the Cyclone 30XP) being able to accelerate H -, D - and also α-particles. The α-beam of this cyclotron will allow the production of new therapeutic isotopes (e.g. 211At) and (iii) commissioning of the Cyclone 70 cyclotron installed for Arronax in France. This machine is similar to the C30XP but provides higher energy ( K = 70) and allows research on new types of medical isotopes.

  7. K-130 Cyclotron vacuum system

    NASA Astrophysics Data System (ADS)

    Yadav, R. C.; Bhattacharya, S.; Bhole, R. B.; Roy, Anindya; Pal, Sarbajit; Mallik, C.; Bhandari, R. K.

    2012-11-01

    The vacuum system for K-130 cyclotron has been operational since 1977. It consists of two sub-systems, main vacuum system and beam line vacuum system. The main vacuum system is designed to achieve and maintain vacuum of about 1 × 10-6 mbar inside the 23 m3 volume of acceleration chamber comprising the Resonator tank and the Dee tank. The beam line vacuum system is required for transporting the extracted beam with minimum loss. These vacuum systems consist of diffusion pumps backed by mechanical pumps like roots and rotary pumps. The large vacuum pumps and valves of the cyclotron vacuum system were operational for more than twenty five years. In recent times, problems of frequent failures and maintenance were occurring due to aging and lack of appropriate spares. Hence, modernisation of the vacuum systems was taken up in order to ensure a stable high voltage for radio frequency system and the extraction system. This is required for efficient acceleration and transportation of high intensity ion beam. The vacuum systems have been upgraded by replacing several pumps, valves, gauges and freon units. The relay based control system for main vacuum system has also been replaced by PLC based state of the art control system. The upgraded control system enables inclusion of additional operational logics and safety interlocks into the system. The paper presents the details of the vacuum system and describes the modifications carried out for improving the performance and reliability of the vacuum system.

  8. Cyclotrons: From Science to Human Health

    NASA Astrophysics Data System (ADS)

    Craddock, Michael

    2011-04-01

    Lawrence's invention of the cyclotron, whose 80th anniversary we have just celebrated, not only revolutionized nuclear physics, but proved the starting point for a whole variety of recirculating accelerators, from the smallest microtron to the largest synchrotron, that have had an enormous impact in almost every branch of science and in several areas of medicine and industry. Cyclotrons themselves have proved remarkably adaptable, incorporating a variety of new ideas and technologies over the years: frequency modulation, edge focusing, AG focusing, separate magnet sectors, axial and azimuthal injection, ring geometries, stripping extraction, superconducting magnets and rf...... Even FFAGs, those most complex members of the cyclotron (fixed-magnetic-field) family, are making a comeback. Currently there are more than 50 medium or large cyclotrons around the world devoted to research. These provide intense primary beams of protons or stable ions, and correspondingly intense secondary beams of neutrons, pions, muons and radioactive ions, for experiments in nuclear, particle and condensed-matter physics, and in the materials and life sciences. Far outnumbering these, however, are the 800 or so small and medium cyclotrons used to produce radioisotopes for medical and other purposes. In addition, a rapidly growing number of 230-MeV proton cyclotrons are being built for cancer therapy -12 brought into operation since 1998 and as many more in the works. Altogether, cyclotrons are flourishing!

  9. Electron cyclotron resonance plasma photosa)

    NASA Astrophysics Data System (ADS)

    Rácz, R.; Biri, S.; Pálinkás, J.

    2010-02-01

    In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

  10. Electron cyclotron resonance plasma photos.

    PubMed

    Rácz, R; Biri, S; Pálinkás, J

    2010-02-01

    In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

  11. Electron cyclotron resonance plasma photos

    SciTech Connect

    Racz, R.; Palinkas, J.; Biri, S.

    2010-02-15

    In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

  12. Cyclotron resonance absorption in ionospheric plasma

    NASA Astrophysics Data System (ADS)

    Villalon, Elena

    1991-04-01

    The mode conversion of ordinary polarized electromagnetic waves into electrostatic cyclotron waves in the inhomogeneous ionospheric plasma is investigated. Near resonance the warm plasma dispersion relation is a function of the angle theta between the geomagnetic field and the density gradient and of the wave frequency omega, which lies between the electron cyclotron frequency and its doubling. The differential equations describing the electric field amplitudes near the plasma resonance are studied, including damping at the second gyroharmonic. The energy transmission coefficients and power absorbed by the cyclotron waves are calculated. The vertical penetration of the plasma wave amplitudes is estimated using a WKB analysis of the wave equation.

  13. All-magnetic extraction for cyclotron beam reacceleration

    DOEpatents

    Hudson, E.D.; Mallory, M.L.

    1975-07-22

    An isochronous cyclotron can be modified to provide an initial electron stripping stage, a complete acceleration of the stripped ions through the cyclotron to a first energy state, means for returning the ions to an intermediate cyclotron orbit through a second stripping stage, further acceleration of the now higher energy stripped ions through the cyclotron to their final energy, and final extraction of the ions from the cyclotron. (auth)

  14. Method and apparatuses for ion cyclotron spectrometry

    DOEpatents

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

    2012-03-06

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

  15. Low energy cyclotron for radiocarbon dating

    SciTech Connect

    Welch, J.J.

    1985-01-01

    The author built and tested a low energy cyclotron for radiocarbon dating similar to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. The author found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. The author shows how a conventional carbon negative ion source located outside the cyclotron magnet, would produce sufficient beam and provide for quick sample changing to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

  16. Development of a Medical Cyclotron Production Facility

    SciTech Connect

    Allen, Danny R.

    2003-08-26

    Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes.

  17. Development of a Medical Cyclotron Production Facility

    NASA Astrophysics Data System (ADS)

    Allen, Danny R.

    2003-08-01

    Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes.

  18. The superconducting separated orbit cyclotron tritron

    SciTech Connect

    Trinks, U.; Assmann, W.; Dietl, L.; Hinderer, H.J.; Korner, A; Platzer, A.; Rehm, B.; Rieger, K.; Riess, C.; Savoy, R.

    1985-10-01

    At the Munich Accelerator Laboratory a booster for the existing MP-tandem-the Tritron - is under construction for acceleration of heavy ions to specific energies up to 21 MeV/u. The Tritron/sup +/ is a separated orbit cyclotron similar to the SOC but with the magnets and cavities both superconducting. The Tritron fits well into the existing laboratory. It is projected to be a prototype to demonstrate the feasibility of this type of cyclotron, which may be suited to overcome the limits of the conventional cyclotron concept. First, there are no axial focusing problems. Secondly, there is no crossing of resonances in the betatron frequency diagram, and thirdly, there are no injection and extraction problems. Thus continuous ion beams of high intensity and high quality with energies up to about 1 GeV/u seem within reach by connecting several separated orbit cyclotrons with increasing radii in series.

  19. Building 211 cyclotron characterization survey report

    SciTech Connect

    1998-03-30

    The Building 211 Cyclotron Characterization Survey includes an assessment of the radioactive and chemical inventory of materials stored within the facility; an evaluation of the relative distribution of accelerator-produced activation products within various cyclotron components and adjacent structures; measurement of the radiation fields throughout the facility; measurement and assessment of internal and external radioactive surface contamination on various equipment, facility structures, and air-handling systems; and an assessment of lead (Pb) paint and asbestos hazards within the facility.

  20. Rotatable superconducting cyclotron adapted for medical use

    DOEpatents

    Blosser, Henry G.; Johnson, David A.; Riedel, Jack; Burleigh, Richard J.

    1985-01-01

    A superconducting cyclotron (10) rotatable on a support structure (11) in an arc of about 180.degree. around a pivot axis (A--A) and particularly adapted for medical use is described. The rotatable support structure (13, 15) is balanced by being counterweighted (14) so as to allow rotation of the cyclotron and a beam (12), such as a subparticle (neutron) or atomic particle beam, from the cyclotron in the arc around a patient. Flexible hose (25) is moveably attached to the support structure for providing a liquified gas which is supercooled to near 0.degree. K. to an inlet means (122) to a chamber (105) around superconducting coils (101, 102). The liquid (34) level in the cyclotron is maintained approximately half full so that rotation of the support structure and cyclotron through the 180.degree. can be accomplished without spilling the liquid from the cyclotron. With the coils vertically oriented, each turn of the winding is approximately half immersed in liquid (34) and half exposed to cold gas and adequate cooling to maintain superconducting temperatures in the section of coil above the liquid level is provided by the combination of cold gas/vapor and by the conductive flow of heat along each turn of the winding from the half above the liquid to the half below.

  1. Low energy cyclotron for radiocarbon dating

    SciTech Connect

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

  2. Recycling and recommissioning a used biomedical cyclotron

    NASA Astrophysics Data System (ADS)

    Carroll, L. R.; Ramsey, F.; Armbruster, J.; Montenero, M.

    2001-07-01

    Biomedical Cyclotrons have a very long life, but there eventually comes a time when any piece of equipment has to be retired from service. From time to time, we have the opportunity to help find new homes for used cyclotrons which, with relatively modest overhaul and refurbishment, can have many additional years of productive service, and thus represent a very valuable asset. The reasons for retiring a cyclotron vary, of course, but in our experience it is often due to an institution's changing priorities or changing needs, rather than the due to any fundamental age-related deficiency in the cyclotron itself. In this paper we will report on the relocation and successful restoration of a used TCC CP-42 cyclotron, which was moved from M.D. Anderson Hospital in Houston to Denton, Texas in early 1998, where it is presently being used for R&D and commercial production of biomedical isotopes. Ownership of the machine has been transferred to the University of North Texas; facility, manpower, and operational resources are provided by International Isotopes, Inc.

  3. Cyclotron Provides Neutron Therapy for Cancer Patients

    NASA Image and Video Library

    1978-01-21

    A cancer patient undergoes treatment in the Neutron Therapy Treatment Facility, or Cylotron, at the National Aeronautics and Space Administration (NASA) Lewis Research Center. After World War II Lewis researchers became interested in nuclear energy for propulsion. The focused their efforts on thermodynamics and strength of materials after radiation. In 1950 an 80-person Nuclear Reactor Division was created, and a cyclotron was built behind the Materials and Structures Laboratory. An in-house nuclear school was established to train these researchers in their new field. NASA cancelled its entire nuclear program in January 1973, just as the cyclotron was about to resume operations after a major upgrade. In 1975 the Cleveland Clinic Foundation partnered with NASA Lewis to use the cyclotron for a new type of radiation treatment for cancer patients. The cyclotron split beryllium atoms which caused neutrons to be released. The neutrons were streamed directly at the patient’s tumor. The facility had a dual-beam system that could target the tumor both vertically and horizontally. Over the course of five years, the cyclotron was used to treat 1200 patients. It was found to be particularly effective on salivary gland, prostrate, and other tumors. It was not as successful with tumors of the central nervous system. The program was terminated in 1980 as the Clinic began concentrating on non-radiation treatments.

  4. Improving cancer treatment with cyclotron produced radionuclides

    SciTech Connect

    Larson, S.M. Finn, R.D.

    1992-08-04

    This report describes the author's continuing long term goal of promoting nuclear medicine applications by improving the scientific basis for tumor diagnosis treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The program has 3 interactive components: Radiochemistry /Cyclotron; Pharmacology; and Immunology. An essential strategy is as follows: novel radionuclides and radiotracers developed in the Radiochemistry/Cyclotron section under the DOE grant during the 1989--1992 grant period, will be employed in the Pharmacology and Immunology sections of the DOE grant during the 1992--1995 grant period. The development of novel radionuclides and tracers is of course useful in and of itself, but their utility is greatly enhanced by the interaction with the immunology and pharmacology components of the program.

  5. The electromagnetic ion cyclotron beam anisotropy instability

    NASA Technical Reports Server (NTRS)

    Peter Gary, S.; Schriver, David

    1987-01-01

    Electromagnetic instabilities driven by an anisotropic, relatively cool ion beam are studied for the case in which both the beam and the instabilities propagate parallel or antiparallel to a uniform magnetic field. At modest beam-core relative drift speeds, sufficiently large perpendicular-to-parallel beam temperature ratios and sufficiently large plasma beta, the mode of fastest growth rate is the ion cyclotron beam anisotropy instability. Because the right-hand polarized waves observed upstream of slow shocks in the earth's magnetotail can lead to the appropriate beam anisotropy, the ion cyclotron instability may be present and account for the left-hand polarized magnetic waves observed there. Also, because of its relatively low phase speed, the ion cyclotron beam anisotropy instability may provide the scattering necessary for ion Fermi acceleration at slow shocks of sufficiently high plasma beta.

  6. Sources and atmospheric chemistry of oxy- and nitro-PAHs in the ambient air of Grenoble (France)

    NASA Astrophysics Data System (ADS)

    Tomaz, Sophie; Jaffrezo, Jean-Luc; Favez, Olivier; Perraudin, Emilie; Villenave, Eric; Albinet, Alexandre

    2017-07-01

    Total individual concentrations (in both gaseous and particulate phases) of 80 polycyclic aromatic compounds (PACs) including 32 nitro-PAHs, 27 oxy-PAHs (polycyclic aromatic hydrocarbons) and 21 parent PAHs have been investigated over a year in the ambient air of Grenoble (France) together with an extended aerosol chemical characterization. The results indicated that their concentrations were strongly affected by primary emissions in cold period, especially from residential heating (i.e. biomass burning). Besides, secondary processes occurred in summer but also in cold period under specific conditions such as during long thermal inversion layer periods and severe PM pollution events. Different secondary processes were involved during both PM pollution events observed in March-April and in December 2013. During the first one, long range transport of air masses, nitrate chemistry and secondary nitro-PAH formation seemed linked. During the second one, the accumulation of primary pollutants over several consecutive days enhanced secondary chemical processes notably highlighted by the dramatic increase of oxy-PAH concentrations. The study of the time trends of ratios of individual nitro- or oxy-PAHs to parent PAHs, in combination with key primary or secondary aerosol species and literature data, allowed the identification of potential molecular markers of PAH oxidation. Finally, 6H-dibenzo[b,d]pyran-6-one, biphenyl-2,2'-dicarboxaldehyde and 3-nitrophenanthrene have been selected to be the best candidates as markers of PAH oxidation processes in ambient air.

  7. Impacts of land-use and land-cover changes on rockfall propagation: Insights from the Grenoble conurbation.

    PubMed

    Lopez-Saez, Jérôme; Corona, Christophe; Eckert, Nicolas; Stoffel, Markus; Bourrier, Franck; Berger, Frédéric

    2016-03-15

    Several studies have debated the incidence of global warming on the probability of rock instability, whereas the impacts of land use and land cover (LULC) changes on rockfall propagation and associated hazards have received comparably little interest. In this study we evaluate the impacts of LULC changes on rockfall hazards on the slopes above the village of Crolles (Chartreuse massif, Grenoble conurbation, French Alps) through a three-level approach: (i) diachronic landscape analysis for four different periods of the past (i.e. 1850, 1956, 1975, and 2013), (ii) computation of 3D rockfall simulations taking explicitly account of reconstructed LULC changes, and (iii) resulting changes in rockfall hazards over time. We reveal that the disappearance of viticultural landscapes (relating to the decline of cropping areas during the interwar period) and intense afforestation of the steepest upper portion of the slope resulted in a significant increase of rockfall return period associated to a gradual decrease of mean kinetic energy at the level of the urban front of Crolles. According to the Eurobloc methodology, the degree of hazard decreased significantly despite the continuous and rapid urban sprawl on the slopes. These results underline that forests can indeed have significant protection function but also call for a more systematic inclusion of LULC changes in hazard assessments in the future.

  8. A room temperature electron cyclotron resonance ion source for the DC-110 cyclotron

    SciTech Connect

    Efremov, A. Bogomolov, S.; Lebedev, A.; Loginov, V.; Yazvitsky, N.

    2014-02-15

    The project of the DC-110 cyclotron facility to provide applied research in the nanotechnologies (track pore membranes, surface modification of materials, etc.) has been designed by the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (Dubna). The facility includes the isochronous cyclotron DC-110 for accelerating the intensive Ar, Kr, Xe ion beams with 2.5 MeV/nucleon fixed energy. The cyclotron is equipped with system of axial injection and ECR ion source DECRIS-5, operating at the frequency of 18 GHz. This article reviews the design and construction of DECRIS-5 ion source along with some initial commissioning results.

  9. Cyclotron Lines in Accreting Neutron Star Spectra

    NASA Astrophysics Data System (ADS)

    Wilms, Jörn; Schönherr, Gabriele; Schmid, Julia; Dauser, Thomas; Kreykenbohm, Ingo

    2009-05-01

    Cyclotron lines are formed through transitions of electrons between discrete Landau levels in the accretion columns of accreting neutron stars with strong (1012 G) magnetic fields. We summarize recent results on the formation of the spectral continuum of such systems, describe recent advances in the modeling of the lines based on a modification of the commonly used Monte Carlo approach, and discuss new results on the dependence of the measured cyclotron line energy from the luminosity of transient neutron star systems. Finally, we show that Simbol-X will be ideally suited to build and improve the observational database of accreting and strongly magnetized neutron stars.

  10. Physics of Cyclotron Resonance Scattering Features

    NASA Astrophysics Data System (ADS)

    Sschoenherr, Gabriele; Schwarm, Fritz-Walter; Falkner, Sebastian; Dauser, Thomas; Pottschmidt, Katja; Kretschmar, Peter; Klochkov, Dmitry; Ferrigno, Carlo; Britton Hemphill, Paul; Wilms, Joern

    2016-04-01

    Cyclotron resonant scattering features (short: cyclotron lines) are sensitive tracers of the physics of the accretion columns and mounds of X-ray pulsars. They form by interaction of X-ray photons with magnetically quantized electrons in the accreted plasma close to the neutron star. Such lines have been observed as absorption-like features for about 20 X-ray pulsars. Their energies provide a direct measure of the magnetic field strength in the line-forming region. By detailed modelling of the lines and of their parameter dependencies we can further decipher the physical conditions in the accretion column. For instance the fact that the complex scattering cross sections have a strong angle-dependence relates the phase-resolved cyclotron line shapes to parameters that constrain the systems’ still poorly understood geometry. Modelling the physics of cyclotron lines to a degree that allows for detailed and solid comparison to data therefore provides a unique access also to a better understanding of the overall picture of magnetically accreting neutron star systems.

  11. Electron-cyclotron-resonance ion sources (review)

    SciTech Connect

    Golovanivskii, K.S.; Dougar-Jabon, V.D.

    1992-01-01

    The physical principles are described and a brief survey of the present state is given of ion sources based on electron-cyclotron heating of plasma in a mirror trap. The characteristics of ECR sources of positive and negative ions used chiefly in accelerator technology are presented. 20 refs., 10 figs., 3 tabs.

  12. Tokamak startup with electron cyclotron heating

    SciTech Connect

    Holly, D J; Prager, S C; Shepard, D A; Sprott, J C

    1980-04-01

    Experiments are described in which the startup voltage in a tokamak is reduced by approx. 60% by the use of a modest amount of electron cyclotron resonance heating power for preionization. A 50% reduction in volt-second requirement and impurity reflux are also observed.

  13. Ion-cyclotron instability in magnetic mirrors

    SciTech Connect

    Pearlstein, L.D.

    1987-02-02

    This report reviews the role of ion-cyclotron frequency instability in magnetic mirrors. The modes discussed here are loss-cone or anisotropy driven. The discussion includes quasilinear theory, explosive instabilities of 3-wave interaction and non-linear Landau damping, and saturation due to non-linear orbits. (JDH)

  14. Cyclotron-based neutron source for BNCT

    SciTech Connect

    Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K.; Tanaka, H.; Sakurai, Y.; Maruhashi, A.

    2013-04-19

    Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

  15. Stability of the Electron Cyclotron Resonance

    NASA Astrophysics Data System (ADS)

    Asch, Joachim; Bourget, Olivier; Meresse, Cédric

    2015-12-01

    We consider the magnetic AC Stark effect for the quantum dynamics of a single particle in the plane under the influence of an oscillating homogeneous electric and a constant perpendicular magnetic field. We prove that the electron cyclotron resonance is insensitive to impurity potentials.

  16. Currents driven by electron cyclotron waves

    SciTech Connect

    Karney, C.F.F.; Fisch, N.J.

    1981-07-01

    Certain aspects of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of the Fokker-Planck equation is used to verify the theory of Fisch and Boozer and to extend their results into the nonlinear regime. Relativistic effects on the current generated are discussed. Applications to steady-state tokamak reactors are considered.

  17. Cyclotron resonance cooling by strong laser field

    SciTech Connect

    Tagcuhi, Toshihiro; Mima, Kunioka

    1995-12-31

    Reduction of energy spread of electron beam is very important to increase a total output radiation power in free electron lasers. Although several cooling systems of particle beams such as a stochastic cooling are successfully operated in the accelerator physics, these cooling mechanisms are very slow and they are only applicable to high energy charged particle beams of ring accelerators. We propose here a new concept of laser cooling system by means of cyclotron resonance. Electrons being in cyclotron motion under a strong magnetic field can resonate with circular polarized electromagnetic field, and the resonance take place selectively depending on the velocity of the electrons. If cyclotron frequency of electrons is equal to the frequency of the electromagnetic field, they absorb the electromagnetic field energy strongly, but the other electrons remain unchanged. The absorbed energy will be converted to transverse kinetic energy, and the energy will be dumped into the radiation energy through bremastrahlung. To build a cooling system, we must use two laser beams, where one of them is counter-propagating and the other is co-propagating with electron beam. When the frequency of the counter-propagating laser is tuned with the cyclotron frequency of fast electrons and the co-propagating laser is tuned with the cyclotron frequency of slow electrons, the energy of two groups will approach and the cooling will be achieved. We solve relativistic motions of electrons with relativistic radiation dumping force, and estimate the cooling rate of this mechanism. We will report optimum parameters for the electron beam cooling system for free electron lasers.

  18. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

    The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω+), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω+ quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω+ frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω+ frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences.

  19. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.

    PubMed

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

    2017-04-01

    The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω+), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω+ quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω+ frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω+ frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.

  20. The mirror and ion cyclotron anisotropy instabilities

    NASA Technical Reports Server (NTRS)

    Gary, S. P.

    1992-01-01

    The linear dispersion equation for fully electromagnetic waves and instabilities at arbitrary directions of propagation relative to a background magnetic field B(0) in a homogeneous Vlasov plasma is solved numerically for bi-Maxwellian particle distributions. For isotropic plasmas the dispersion and damping of the three modes below the proton cyclotron frequency are studied as functions of Beta(i) and T(e)/T(i). The transport ratios of helicity, cross-helicity, Alfven ratio, compressibility, and parallel compressibility are defined. Under the condition that the proton temperature perpendicular to B(0) is greater than the parallel temperature, the growth rates and transport ratios of the mirror instability and the ion cyclotron anisotropy instability are examined and compared. Both the proton parallel compressibility and the proton Alfven ratio are significantly different for the two growing modes.

  1. New magnet pole shape for isochronous cyclotrons

    SciTech Connect

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-06-01

    A new design has been developed for shaping pole tips to produce the radially increasing fields required for isochronous cyclotrons. The conventional solid hillpoles are replaced by poles mounted over a small secondary gap which tapers radially from maximum at the magnet edge to zero near the center. Field measurements with a model magnet and calculations with the code TRIM show an increase in field at the edge of the magnet without the usual corresponding large increase in fringing, and a radial field shape more nearly field independent than for conventional hills. The flying hills have several advantages for variable energy multiparticle cyclotrons: (1) a large reduction in the power dissipated by isochronizing trim coils; (2) a more constant shape and magnitude flutter factor, eliminating flutter coils and increasing the operating range; and (3) a sharper fall-off of the fringe field, simplifying beam extraction. 6 figures.

  2. New magnet pole shape for isochronous cyclotrons

    SciTech Connect

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-01-01

    A new design has been developed for shaping pole tips to produce the radially increasing fields required for isochronous cyclotrons. The conventional solid hill poles are replaced by poles mounted over a small secondary gap which tapers radially from maximum at the magnet edge to zero near the center. Field measurements with a model magnet and calculations with the code TRIM show an increase in field at the edge of the magnet without the usual corresponding large increase in fringing, and a radial field shape more nearly field independent than for conventional hills. The flying hills have several advantages for variable energy multiparticle cyclotrons: (1) a large reduction in the power dissipated by isochronizing trim coils; (2) a more constant shape and magnitude flutter factor, eliminating flutter coils and increasing the operating range; and (3) a sharper fall-off of the fringe field, simplifying beam extraction.

  3. Electrostatic ion cyclotron velocity shear instability

    NASA Technical Reports Server (NTRS)

    Lemons, D. S.; Winske, D.; Gary, S. P.

    1992-01-01

    A local electrostatic dispersion equation is derived for a shear flow perpendicular to an ambient magnetic field, which includes all kinetic effects and involves only one important parameter. The dispersion equation is cast in the form of Gordeyev integrals and is solved numerically. Numerical solutions indicate that an ion cyclotron instability is excited. The instability occurs roughly at multiples of the ion cyclotron frequency (modified by the shear), with the growth rate or the individual harmonics overlapping in the wavenumber. At large values of the shear parameter, the instability is confined to long wavelengths, but at smaller shear, a second distinct branch at shorter wavelengths also appears. The properties of the instability obtained are compared with those obtained in the nonlocal limit by Ganguli et al. (1985, 1988).

  4. Ion cyclotron waves observed near the plasmapause

    NASA Technical Reports Server (NTRS)

    Fraser, B. J.; Samson, J. C.; Mcpherron, R. L.; Russell, C. T.

    1986-01-01

    Pc2 electromagnetic ion cyclotron waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE-1 and -2 between L = 7.6 - 5.8 on an inbound near equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width about 1 earth radius and penetrated about 1 earth radius into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He(+) and the warm (0.1-16 keV/e) O(+) and He(+) heavy ion populations. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by multicomponent cold plasma propagation theory are identified in the wave data. The results are considered as an example of wave-particle interactions occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase.

  5. Xe/+/ -induced ion-cyclotron harmonic waves

    NASA Astrophysics Data System (ADS)

    Jones, D.

    Xenon ion sources on an ejectable package separated from the main payload during the flights of Porcupine rockets F3 and F4 which were launched from Kiruna, Sweden on March 19 and 31, 1979, respectively. The effects of the xenon ion beam, detected by the LF (f less than 16 kHz) wideband electric field experiment and analyzed by using a sonograph, are discussed. Particular attention is given to the stimulation of the ion-cyclotron harmonic waves which are usually linked to the local proton gyro-frequency, but are sometimes related to half that frequency. It was found that in a plasma dominated by O(+) ions, a small amount (1-10%) of protons could cause an effect such that the O(+) cyclotron harmonic waves are set up by the hydrogen ions, the net result being the observation of harmonic emissions separated by the hydrogen ion gyro frequency.

  6. Radiation Sources at Electron Cyclotron Harmonic Frequencies.

    DTIC Science & Technology

    1983-01-28

    KEY WORDS (Continue on reverse side it necesear and Identify by block number) Radiation source, electron cyclotron frequency, gyrotron, travelling ...investigation of gyrotron devices operating in cylindrical geometry. Specific topics include an analysis of oscillations in a gyrotron travelling wave...amplifier, the study of the effects of velocity spread and wall resistivity on gain and bandwidth in a gyrotron travell - ing wave amplifier, an

  7. Cyclotron Wave Electrostatic and Parametric Amplifiers.

    DTIC Science & Technology

    2008-02-15

    Plasma Physics Division GEORGE EwEI.• Georgia Tech Research Institute Atlanta, Georgia, 30332 February 28, 1997 Approved for public release...and transmitted to the external circuit load. Thus, as far as the input resonator is concerned, noises of the electron gun on the fast cyclotron wave...characteristics of CWESA. Engineering the permanent magnet system is often the most challenging part CWESA design at ISTOK. The plane cathode electron gun

  8. Visible and near-infrared reflectance spectroscopy of planetary analog materials. Experimental facility at Laboratoire de Planetologie de Grenoble.

    NASA Astrophysics Data System (ADS)

    Pommerol, A.; Brissaud, O.; Schmitt, B.; Quirico, E.; Doute, S.

    2007-08-01

    We have developed an original experimental facility designed to measure the bidirectional reflectance spectra of planetary analog materials. These measurements are helpful to interpret the observations of the spectrometers on board space probes in orbit around various Solar System bodies. The central part of the facility is the LPG spectrogonio- radiometer (Brissaud et al., 2004). This instrument provides measurements of samples BRDF (Bidirectional Reflectance Distribution Function) with high photometric and spectrometric accuracy in the spectral range of visible and near-infrared (0.3 - 4.8 microns). Measurements can be made at any value of incidence and emergence angle up to 80°. Azimuth angle is allowed to vary between 0 and 180°. The instrument was recently installed in a cold room allowing ambient temperatures as low as -20°C. This makes possible the measurements on different kinds of water ice samples (slab ice, frost, snow...) and mixtures of minerals and water ice with unprecedented accuracy. We also have designed and built a simulation chamber to measure spectra of samples (water ice and/or minerals) under an atmosphere with perfectly controlled temperature, pressure and composition. The main objective of this last improvement is the study of water exchange between planetary regolith analogs and atmosphere (adsorption/ desorption, condensation/sublimation). Experimental results will mainly apply to Martian water cycle and hydrated mineralogy. This simulation chamber also provides an efficient way to obtain bidirectional reflectance spectra of dry materials (removal of adsorbed water) with implications for planetary bodies without atmospheric or surface water (Titan, asteroids...). The reflectance spectroscopy facility is part of a large panel of instruments and techniques available at Laboratoire de Planetologie de Grenoble that provide complementary measurements on the same samples: infrared transmission spectroscopy of thin ice films, thick liquid and

  9. Improving cancer treatment with cyclotron produced radionuclides

    SciTech Connect

    Larson, S.M.; Finn, R.D.

    1992-08-04

    Our goal is to improve the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The grant includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. The radiochemistry group seeks to develop innovative cyclotron targetry, radiopharmaceuticals, and radiolabeled antibodies, which are then used to assess important unanswered questions in tumor pharmacology and immunology. Examples include selected positron emitting radionuclides, such as Iodine-124, and Ga-66; I-124, I-123, I-131 labeled iododeoxyuridine, C-11 colchicine, and antimetabolites, like C-11 methotrexate; and radiolabeled antibodies, 3F8, M195, A33, and MRK16 for application in the pharmacology and immunology projects. The pharmacology program studies tumor resistance to chemotherapy, particularly the phenomenon of multidrug resistance and the relationship between tumor uptake and retention and the tumor response for anti-metabolite drugs. The immunology program studies the physiology of antibody localization at the tissue level as the basis for novel approaches to improving tumor localization such as through the use of an artificial lymphatic system which mechanically reduces intratumoral pressures in tumors in vivo. Quantitative imaging approaches based on PET and SPECT in radioimmunotherapy are studied to give greater insight into the physiology of tumor localization and dosimetry.

  10. Cyclotron Requirements for Multi-disciplinary Programs

    NASA Astrophysics Data System (ADS)

    Armbruster, John M.

    2009-03-01

    As time has passed, the various Cyclotron programs have changed over the years. In the "early" times of Cyclotron operations, the emphasis was on a more single sided approach such as Clinical or Research or Production. However, as time passed, the disciplines became more interconnected until today, it is unusual to have a Cyclotron and only have a single program unless it is pure production. More and more, especially in public areas such as Universities or Health Centers, you are seeing programs that do all three types of disciplines: Production; Clinical or Patient Diagnostics and/or Treatment; and Research, either in the development and manufacture of new Radio-Isotopes, new Diagnostic or Therapeutic Compound Development, or Clinical Research involving subject testing. While all three of these disciplines have some common requirements, they also have some very different requirements that may be completely counterproductive to other requirements. For a program where all three disciplines are required to be successful, it is necessary come up with some sort of compromise that meets all the various requirements. During this talk, we will try to identify some of these different requirements for the various disciplines and how these could impact the other disciplines. We will also discuss ideas for some possible compromises that might reduce the conflict between the various disciplines.

  11. Transparency of Magnetized Plasma at Cyclotron Frequency

    SciTech Connect

    G. Shvets; J.S. Wurtele

    2002-03-14

    Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of the three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of the nonlocal plasma oscillation. The complexity of the plasma system results in an index of refraction at the cyclotron frequency that differs from unity. Lagrangian description was used to elucidate the physics and enable numerical simulation of the plasma transparency and control of group and phase velocity. This control naturally leads to applications for electromagnetic pulse compression in the plasma and electron/ion acceleration.

  12. Ion Cyclotron Heating on Proto-MPEX

    NASA Astrophysics Data System (ADS)

    Goulding, R. H.; Caughman, J. B. O.; Rapp, J.; Biewer, T. M.; Campbell, I. H.; Caneses, J. F.; Kafle, N.; Ray, H. B.; Showers, M. A.; Piotrowicz, P. A.

    2016-10-01

    Ion cyclotron heating will be used on Proto-MPEX (Prototype Material Plasma Exposure eXperiment) to increase heat flux to the target, to produce varying ion energies without substrate biasing, and to vary the extent of the magnetic pre-sheath for the case of a tilted target. A 25 cm long, 9 cm diameter dual half-turn helical ion cyclotron antenna has been installed in the device located at the magnetic field maximum. It couples power to ions via single pass damping of the slow wave at the fundamental resonance, and operates with ω 0.8ωci at the antenna location. It is designed to operate at power levels up to 30 kW, with a later 200 kW upgrade planned. Near term experiments include measuring RF loading at low power as a function of frequency and antenna gap. The plasma is generated by a helicon plasma source that has achieved ne > 5 ×1019m-3 operating with deuterium, as measured downstream from the ion cyclotron antenna location. Measurements will be compared with 1-D and 2-D models of RF coupling. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  13. Simulations of ion cyclotron anisotropy instabilities in the terrestrial magnetosheath

    NASA Technical Reports Server (NTRS)

    Gary, S. P.; Winske, Dan

    1993-01-01

    Enhanced transverse magnetic fluctuations observed below the proton cyclotron frequency in the terrestrial magnetosheath have been identified as due to the proton cyclotron and helium cyclotron instabilities driven by the T-perpendicular greater than T-parallel condition of the sheath ions. One-dimensional hybrid computer simulations are used here to examine the nonlinear properties of these two growing modes at relatively weak fluctuation energies and for wave vectors parallel to the background magnetic field. Second-order theory predicts fluctuating magnetic field energies at saturation of the proton cyclotron anisotropy instability in semiquantitative agreement with the simulation results. Introduction of the helium component enhances the wave-particle exchange rate for proton anisotropy reduction by that instability, thereby reducing the saturation energy of that mode. The simulations demonstrate that wave-particle interactions by the proton cyclotron and helium cyclotron instabilities lead to the anticorrelation observed by Anderson and Fuselier (1993).

  14. Parametric Instabilities of Electron Cyclotron Waves in Plasmas.

    DTIC Science & Technology

    1980-03-01

    tokamaks eg. PLT. In the EBT, the electron cyclotron pump of finite wavenumber 1% decays into two Bernstein modes at the second harmonic cyclotron...convective threshold with finite k, is -200 W/ . For large tokamaks , the convective threshold for various decay channels turns out to be >200 KW/cu 2...efforts on the electron cyclotron heating of large devices, eg., Elmo bumpy torus, tokamak and mirrors. In the Elmo 1bumpy torus (EBT) the microwaves

  15. The Michigan State University Cyclotron Laboratory: Its Early Years

    NASA Astrophysics Data System (ADS)

    Austin, Sam M.

    2016-01-01

    The Michigan State University Cyclotron Laboratory was founded in 1958 and over the years grew in stature, becoming the highest-ranked university-based program in nuclear science. Its K50 cyclotron had unmatched capability as a light-ion accelerator and helped to define what a modern cyclotron could do to advance our understanding of nuclei. This paper describes the first twenty years of the Cyclotron Laboratory's evolution and gives some insight into the cultural characteristics of the laboratory, and of its early members, that led it to thrive.

  16. Observations of multiharmonic ion cyclotron waves due to inverse ion cyclotron damping in the northern magnetospheric cusp

    NASA Astrophysics Data System (ADS)

    Slapak, R.; Gunell, H.; Hamrin, M.

    2017-01-01

    We present a case study of inverse ion cyclotron damping taking place in the northern terrestrial magnetospheric cusp, exciting waves at the ion cyclotron frequency and its harmonics. The ion cyclotron waves are primarily seen as peaks in the magnetic-field spectral densities. The corresponding peaks in the electric-field spectral densities are not as profound, suggesting a background electric field noise or other processes of wave generation causing the electric spectral densities to smoothen out more compared to the magnetic counterpart. The required condition for inverse ion cyclotron damping is a velocity shear in the magnetic field-aligned ion bulk flow, and this condition is often naturally met for magnetosheath influx in the northern magnetospheric cusp, just as in the presented case. We note that some ion cyclotron wave activity is present in a few similar shear events in the southern cusp, which indicates that other mechanisms generating ion cyclotron waves may also be present during such conditions.

  17. Rockfall frequency and influence of meteorological factors on a limestone cliff of the urban area of Grenoble.

    NASA Astrophysics Data System (ADS)

    D'Amato, Julie; Hantz, Didier; Baillet, Laurent; Guerin, Antoine; Jaboyedoff, Michel

    2015-04-01

    The spatial temporal frequency of rockfall events helps to quantify diffuse rockfall hazard. The influence of meteorological factors can also be studied in order to better know the failure triggering factors, and to predict dangerous periods of the year. Detection and dating of some hundreds of rockfalls has been carried out for the Saint Eynard cliff, which towers above a residential area of the town of Grenoble (French Alps), and which consists of a thinly bedded limestone cliff. The rockfalls have been detected by a diachronic comparison of digital models of the cliff, obtained from annual terrestrial laser scanning. They have been dated by means of a continuous photographic and seismic survey of the cliff. Meteorological data are given by local temperature and rain stations. These data allowed to study the influence of meteorological factors in the failure process. Six hundreds rockfalls (volume 0.005m3 to 1500m3) have been dated by periods of 2 to 11 weeks. The average frequency of the detected rockfalls for the 18 months of survey is 1.0 rockfall per day. The winter periods (with freeze-thaw cycles) clearly show a higher rockfall frequency, up to 1.9 rockfall per day for the most active winter periods. Summer periods show a lower rockfall frequency, between 0.1 and 0.5 rockfall per day. The frequency is close to 0.5 for periods with more rainfall. 126 rockfalls were dated with a precision of 10 min to several hours. For these rockfalls, the average frequency is 0.010 rockfall/h. The frequency is 0.015 rockfall/h for the freezing days (days with negative minimal temperature), 0.029 rockfall/h for the days without freeze but following a freezing day, 0.011 rockfall/h for the days with a rainfall and 0.002 rockfall/h for the other days. Rainfall and freeze-thaw events have also been determined hourly. A rainfall event begins with the beginning of a rainfall, and ends at the beginning of the next 24 hours period without rain. The 24h period has been chosen

  18. Status of the Cyclotron Institute Upgrade Project

    NASA Astrophysics Data System (ADS)

    Melconian, Dan

    2016-09-01

    The Texas A&M University Re-accelerated EXotics (T-REX) project, an upgrade to the Cyclotron Institute, will provide high-quality re-accelerated secondary beams of a unique energy range and the ability to provide primary beams to two experiments concurrently. The upgrade is nearing completion of its three major tasks: re-commissioning of the existing K150 cyclotron; construction of light- and heavy-ion guide transport systems; and charge-boosting the K150 RIB for re-acceleration using the K500 cyclotron. The light-ion guide transport system will utilize the high intensity (>= 10 μ A) proton beam from the K150 to produce rare ions via fusion-evapouration reactions or proton-induced fission fragments. These ions will be transported to an ECR charge breeder prior to injection in the K500. The heavy-ion guide will use deep inelastic, transfer and fragmentation reactions using the up to 25 MeV/u primary beams from the K150. The products will be separated by a superconducting solenoid and collected in a large gas-catcher, after which a multi-RFQ system will transport the RIB to any of: the charge-breeder and K500; the TAMU Penning Trap beamline; or an MR-TOF for beam analysis. The status of the T-REX upgrade and an overview of its capabilities will be presented Supported by DOE Grant Number DE-FG03-93ER40773 and the Robert A. Welch Foundation Grant Number H-A-0098.

  19. Electron cyclotron emission diagnostics on KSTAR tokamak

    SciTech Connect

    Jeong, S. H.; Lee, K. D.; Kwon, M.; Kogi, Y.; Kawahata, K.; Nagayama, Y.; Mase, A.

    2010-10-15

    A new electron cyclotron emission (ECE) diagnostics system was installed for the Second Korea Superconducting Tokamak Advanced Research (KSTAR) campaign. The new ECE system consists of an ECE collecting optics system, an overmode circular corrugated waveguide system, and 48 channel heterodyne radiometer with the frequency range of 110-162 GHz. During the 2 T operation of the KSTAR tokamak, the electron temperatures as well as its radial profiles at the high field side were measured and sawtooth phenomena were also observed. We also discuss the effect of a window on in situ calibration.

  20. Initial Operation of CIAE medically used cyclotron

    NASA Astrophysics Data System (ADS)

    Fan, Mingwu; Zhang, Tainjue

    1997-05-01

    CIAE medically used cyclotron is a 30 MeV fixed, isochronous field and fixed RF frequency machine with high -H beam intensity. -H beams with energy variable were obtained in December 1994 up to 0.4 mA. Two years operation has proved the design and manufacture successfully. The mapping results of magnetic field has shown the magnet perfect that would ensure the high intensity beam accelerated to the final energy. Now 7 medically useful isotopes were produced, e. g. thallium-201, cobalt-57, gallium-67, iodine-123 have been supplied for hospitals.

  1. Electron Cyclotron Heating on DIII-D

    SciTech Connect

    Prater, R.; Petty, C.C.

    2005-10-15

    Electron cyclotron heating (ECH) has proved to be a very flexible system for heating applications in DIII-D. The outstanding characteristics of ECH - controllable heating location, a high degree of localization of the power, ability to heat without introducing particles, and ability to heat only the electron fluid - have been used in a wide variety of experiments to study wave physics and transport, to control magnetohydrodynamic activity, and to improve discharges. These characteristics along with relatively easy coupling to the plasma make ECH a valuable resource for both heating and instability control in burning plasmas.

  2. [Electron cyclotron resonance (ECR) plasma film deposition

    SciTech Connect

    1999-04-01

    During the third quarter of 1995, an electron cyclotron resonance (ECR) plasma film deposition facility was constructed at the University of New Mexico. This work was conducted in support of the Los Alamos/Tycom CRADA agreement to pursue methods of improving drill bit lifetime. Work in the fourth quarter will center on the coating of drill bits and the treating and testing of various test samples. New material systems as well as treatment techniques will be attempted during this period. The following is a brief description of the various subsystems of the film deposition facility. Particular emphasis is placed on the slotted waveguide system as requested.

  3. Electron cyclotron heating in TMX-Upgrade

    SciTech Connect

    Stallard, B.W.; Hooper, E.B. Jr.

    1981-01-01

    TMX-Upgrade, an improved tandem mirror experiment under construction at LLNL, will use electron cyclotron resonance heating (ECRH) to create thermal barriers and to increase the center cell ion confining potential. Gyrotron oscillators (200 kW, 28 GHz) supply the heating power for the potential confined electron (fundamental heating) and the mirror-confined electrons (harmonic heating) in the thermal barriers. Important issues are temperature limitation and microstability for the hot electrons. Off-midplane heating can control anisotropy-driven microstability. Spacially restricting heating offers the possibility of temperature control by limiting the energy for resonant interaction.

  4. Method of enhancing cyclotron beam intensity

    DOEpatents

    Hudson, Ed D.; Mallory, Merrit L.

    1977-01-01

    When an easily ionized support gas such as xenon is added to the cold cathode in sources of the Oak Ridge Isochronous Cyclotron, large beam enhancements are produced. For example, .sup.20 Ne.sup.7+ is increased from 0.05 enA to 27 enA, and .sup.16 O.sup.5+ intensities in excess of 35 e.mu.A have been extracted for periods up to 30 minutes. Approximately 0.15 cc/min of the easily ionized support gas is supplied to the ion source through a separate gas feed line and the primary gas flow is reduced by about 30%.

  5. Cavity QED of the graphene cyclotron transition.

    PubMed

    Hagenmüller, David; Ciuti, Cristiano

    2012-12-28

    We investigate theoretically the cavity quantum electrodynamics of the cyclotron transition for Dirac fermions in graphene. We show that the ultrastrong coupling regime characterized by a vacuum Rabi frequency comparable or even larger than the transition frequency can be obtained for high enough filling factors of the graphene Landau levels. Important qualitative differences occur with respect to the corresponding physics of massive electrons in a semiconductor quantum well. In particular, an instability for the ground state analogous to the one occurring in the Dicke model is predicted for an increasing value of the electron density.

  6. Cyclotrons and FFAG Accelerators as Drivers for ADS

    DOE PAGES

    Calabretta, Luciano; Méot, François

    2015-01-01

    Our review summarizes projects and studies on circular accelerators proposed for driving subcritical reactors. The early isochronous cyclotron cascades, proposed about 20 years ago, and the evolution of these layouts up to the most recent solutions or designs based on cyclotrons and fixed field alternating gradient accelerators, are reported. Additionally, the newest ideas and their prospects for development are discussed.

  7. Cyclotrons and FFAG Accelerators as Drivers for ADS

    SciTech Connect

    Calabretta, Luciano; Méot, François

    2015-01-01

    Our review summarizes projects and studies on circular accelerators proposed for driving subcritical reactors. The early isochronous cyclotron cascades, proposed about 20 years ago, and the evolution of these layouts up to the most recent solutions or designs based on cyclotrons and fixed field alternating gradient accelerators, are reported. Additionally, the newest ideas and their prospects for development are discussed.

  8. New superconducting cyclotron driven scanning proton therapy systems

    NASA Astrophysics Data System (ADS)

    Klein, Hans-Udo; Baumgarten, Christian; Geisler, Andreas; Heese, Jürgen; Hobl, Achim; Krischel, Detlef; Schillo, Michael; Schmidt, Stefan; Timmer, Jan

    2005-12-01

    Since one and a half decades ACCEL is investing in development and engineering of state of the art particle-therapy systems. A new medical superconducting 250 MeV proton cyclotron with special focus on the present and future beam requirements of fast scanning treatment systems has been designed. The first new ACCEL medical proton cyclotron is under commissioning at PSI for their PROSCAN proton therapy facility having undergone successful factory tests especially of the closed loop cryomagnetic system. The second cyclotron is part of ACCEL's integrated proton therapy system for Europe's first clinical center, RPTC in Munich. The cyclotron, the energy selection system, the beamline as well as the four gantries and patient positioners have been installed. The scanning system and major parts of the control software have already been tested. We will report on the concept of ACCEL's superconducting cyclotron driven scanning proton therapy systems and the current status of the commissioning work at PSI and RPTC.

  9. Cyclotron resonance effects on stochastic acceleration of light ionospheric ions

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    The production of energetic ions with conical pitch angle distributions along the auroral field lines is a subject of considerable current interest. There are several theoretical treatments showing the acceleration (heating) of the ions by ion cyclotron waves. The quasi-linear theory predicts no acceleration when the ions are nonresonant. In the present investigation, it is demonstrated that the cyclotron resonances are not crucial for the transverse acceleration of ions by ion cyclotron waves. It is found that transverse energization of ionospheric ions, such as He(+), He(++), O(++), and O(+), is possible by an Electrostatic Hydrogen Cyclotron (EHC) wave even in the absence of cyclotron resonance. The mechanism of acceleration is the nonresonant stochastic heating. However, when there are resonant ions both the total energy gain and the number of accelerated ions increase with increasing parallel wave number.

  10. Ion cyclotron emission studies: Retrospects and prospects

    NASA Astrophysics Data System (ADS)

    Gorelenkov, N. N.

    2016-05-01

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfvénic cyclotron instabilities with the linear growth rate √ {n_α /n_e } driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. More recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusion devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. We discuss further prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.

  11. Ion cyclotron emission studies: Retrospects and prospects

    SciTech Connect

    Gorelenkov, N. N.

    2016-06-05

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfv,nic cyclotron instabilities with the linear growth rate similar ~ √(nα/ne) driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. Recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusion devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. Finally, we discuss prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.

  12. Ion cyclotron emission studies: Retrospects and prospects

    SciTech Connect

    Gorelenkov, N. N.

    2016-06-05

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfv,nic cyclotron instabilities with the linear growth rate similar ~ √(nα/ne) driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. Recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusion devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. Finally, we discuss prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.

  13. Ion cyclotron emission studies: Retrospects and prospects

    DOE PAGES

    Gorelenkov, N. N.

    2016-06-05

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfv,nic cyclotron instabilities with the linear growth rate similar ~ √(nα/ne) driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. Recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusionmore » devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. Finally, we discuss prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.« less

  14. Cyclotron Resonances in Electron Cloud Dynamics

    SciTech Connect

    Celata, C M; Furman, M A; Vay, J L; Grote, D P; Ng, J T; Pivi, M F; Wang, L F

    2009-05-05

    A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l{sub b} << 2{pi}{omega}{sub c}, (l{sub b} = bunch duration, {omega}{sub c} = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor {approx} 3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined density 'stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed.

  15. Cyclotron Resonances in Electron Cloud Dynamics

    SciTech Connect

    Celata, C. M.; Furman, Miguel A.; Vay, J.-L.; Ng, J. S.T.; Grote, D. P.; Pivi, M. T. F.; Wang, L. F.

    2009-04-29

    A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lb<< 2pi c/omega c (with lb = bunch length, omega c = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the electron cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor ~;;3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined vertical density"stripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

  16. Ion Cyclotron Waves in the VASIMR

    NASA Astrophysics Data System (ADS)

    Brukardt, M. S.; Bering, E. A.; Chang-Diaz, F. R.; Squire, J. P.; Longmier, B.

    2008-12-01

    The Variable Specific Impulse Magnetoplasma Rocket is an electric propulsion system under development at Ad Astra Rocket Company that utilizes several processes of ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Among these processes are parallel electric field acceleration, lower hybrid resonance heating, and ion cyclotron resonance heating. The VASIMR is capable of laboratory simulation of electromagnetic ion cyclotron wave heating during a single pass of the plasma through the resonance region. The plasma is generated by a helicon discharge of about 25 kW then passes through an RF booster stage that shoots left hand polarized slow mode waves from the high field side of the resonance. This paper will focus on the upgrades to the VX-200 test model over the last year. After summarizing the VX- 50 and VX-100 results, the new data from the VX-200 model will be presented. Lastly, the changes to the VASIMR experiment due to Ad Astra Rocket Company's new facility in Webster, Texas will also be discussed, including the possibility of collaborative experiments at the new facility.

  17. Loss cone-driven cyclotron maser instability

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Yun; Yi, Sibaek; Lim, Dayeh; Kim, Hee-Eun; Seough, Jungjoon; Yoon, Peter H.

    2013-11-01

    The weakly (or mildly) relativistic cyclotron maser instability has been successfully applied to explain the Earth's auroral kilometric radiation and other radio sources in nature and laboratory. Among the most important physical parameters that determine the instability criteria is the ratio of plasma-to-electron cyclotron frequencies, ωp/Ω. It is therefore instructive to consider how the normalized maximum growth rate, γmax/Ω, varies as a function of ωp/Ω. Although many authors have already discussed this problem, in order to complete the analysis, one must also understand how the radiation emission angle corresponding to the maximum growth, θmax, scales with ωp/Ω, since the propagation angle determines the radiation beaming pattern. Also, the behavior of the frequency corresponding to the maximum growth rate at each harmonic, (ωmax-sΩ)/Ω, where s=1,2,3,ċ , as a function of ωp/Ωis of importance for a complete understanding of the maser excitation. The present paper computes these additional quantities for the first time, making use of a model loss cone electron distribution function.

  18. Electrostatic ion cyclotron velocity shear instability

    SciTech Connect

    Lemons, D.S.; Winske, D.; Gary, S.P. )

    1992-12-01

    An electrostatic ion cyclotron instability driven by sheared velocity flow perpendicular to a uniform magnetic field is investigated in the local approximation. The dispersion equation, which includes all kinetic effects and involves only one important parameter, is cast in the form of Gordeyev integrals and solved numerically. The instability occurs roughly at multiples of the ion cyclotron frequency (but modified by the shear) with the growth rate of the individual harmonics overlapping in wavenumber. At small values of the shear parameter, the instability exists in two branches, one at long wavelength, [kappa][rho][sub i] [approximately] 0.5, and one at short wavelength, [kappa][rho][sub i] > 1.5 ([kappa][rho][sub i] is the wavenumber normalized to the ion gyroradius). At larger values of the shear parameter only the longer wavelength branch persists. The growth rate of the long wavelength mode, maximized over wavenumber and frequency, increases monotonically with the shear parameter. Properties of the instability are compared to those of Ganguli et al. obtained in the nonlocal limit.

  19. Cyclotron Production of Technetium-99m

    NASA Astrophysics Data System (ADS)

    Gagnon, Katherine M.

    Technetium-99m (99mTc) has emerged as the most widely used radionuclide in medicine and is currently obtained from a 99Mo/ 99mTc generator system. At present, there are only a handful of ageing reactors worldwide capable of producing large quantities of the parent isotope, 99Mo, and owing to the ever growing shutdown periods for maintenance and repair of these ageing reactors, the reliable supply 99mTc has been compromised in recent years. With an interest in alternative strategies for producing this key medical isotope, this thesis focuses on several technical challenges related to the direct cyclotron production of 99mTc via the 100Mo(p,2n)99mTc reaction. In addition to evaluating the 100Mo(p,2n)99mTc and 100Mo(p,x)99Mo reactions, this work presented the first experimental evaluation of the 100Mo(p,2n) 99gTc excitation function in the range of 8-18 MeV. Thick target calculations suggested that large quantities of cyclotron-produced 99mTc may be possible. For example, a 6 hr irradiation at 500 μA with an energy window of 18→10 MeV is expected to yield 1.15 TBq of 99mTc. The level of coproduced 99gTc contaminant was found to be on par with the current 99Mo/99mTc generator standard eluted with a 24 hr frequency. Highly enriched 100Mo was required as the target material for 99mTc production and a process for recycling of this expensive material is presented. An 87% recovery yield is reported, including metallic target preparation, irradiation, 99mTc extraction, molybdate isolation, and finally hydrogen reduction to the metal. Further improvements are expected with additional optimization experiments. A method for forming structurally stable metallic molybdenum targets has also been developed. These targets are capable of withstanding more than a kilowatt of beam power and the reliable production and extraction of Curie quantities of 99mTc has been demonstrated. With the end-goal of using the cyclotron-produced 99mTc clinically, the quality of the cyclotron

  20. Towards an operational integrated flood forecasting system for the Isere River basin in Grenoble: implementation of the hydrological model and assessment of the hydraulics operations impact

    NASA Astrophysics Data System (ADS)

    Claude, A.; Zin, I.; Obled, C.; Gautheron, A.; Perret, C.

    2009-04-01

    The operational flood forecasting service of French Northern Alps (called Service de Prévision des Crues - Alpes du Nord) needs to develop and implement an integrated flood forecasting system for the alpine Isere River basin in Grenoble (5720 km2). Within this framework, the semi-distributed Routing System II model (Dubois et al., 2007) has been implemented on the basin. The first issue that will be addressed concerns the sensitivity of model simulations (and in particular of the snow pack dynamics) to the accuracy of the input precipitation and the choice of the number of snow elevation bands that are used for segmentating each sub-basin. Then, the sensitivity of model predictions to the existing hydropower production infrastructures and the associated hydraulics operations will be presented.

  1. Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

    NASA Technical Reports Server (NTRS)

    Fraser, B. J.; Samson, J. C.; Hu, Y. D.; Mcpherron, R. L.; Russell, C. T.

    1992-01-01

    The first results of observations of ion cyclotron waves by the elliptically orbiting ISEE 1 and 2 pair of spacecraft are reported. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to the local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event is attributed to the modulation of this energy source by the Pc 5 waves seen at the same time.

  2. Performance of Variable Energy Cyclotron Centre superconducting cyclotron liquid nitrogen distribution system

    NASA Astrophysics Data System (ADS)

    Pal, Gautam; Nandi, Chinmay; Bhattacharyya, Tamal Kumar; Chakrabarti, Alok

    2014-01-01

    The liquid nitrogen distribution at Variable Energy Cyclotron Centre, Kolkata, India K500 superconducting cyclotron uses parallel branches to cool the thermal shield of helium vessel housing the superconducting coil and the cryopanels. Liquid nitrogen is supplied to the thermal shields from a pressurised liquid nitrogen dewar. Direct measurement of flow is quite difficult and seldom used in an operational cryogenic system. The total flow and heat load of the liquid nitrogen system was estimated indirectly by continuous measurement of level in the liquid nitrogen tanks. A mathematical model was developed to evaluate liquid nitrogen flow in the parallel branches. The model was used to generate flow distribution for different settings and the total flow was compared with measured data.

  3. Cyclotrons and positron emission tomography radiopharmaceuticals for clinical imaging.

    PubMed

    Saha, G B; MacIntyre, W J; Go, R T

    1992-07-01

    Positron emission tomography (PET) requires positron-emitting radionuclides that emit 511-keV photons detectable by PET imagers. Positron-emitting radionuclides are commonly produced in charged particle accelerators, eg, linear accelerators or cyclotrons. The most widely available radiopharmaceuticals for PET imaging are carbon-11-, nitrogen-13-, and oxygen-15-labeled compounds, many of which, either in their normal state or incorporated in other compounds, serve as physiological tracers. Other useful PET radiopharmaceuticals include fluorine-18-, bromine-75-, gallium-68 (68Ga)-, rubidium-82 (82Rb)-, and copper-62 (62Cu)-labeled compounds. Many positron emitters have short half-lives and thus require on-site cyclotrons for application, and others (68Ga, 82Rb, and 62Cu) are available from radionuclides generators using relatively long-lived parent radionuclides. This review is divided into two sections: cyclotrons and PET radiopharmaceuticals for clinical imaging. In the cyclotron section, the principle of operation of the cyclotron, types of cyclotrons, medical cyclotrons, and production of radionuclides are discussed. In the section on PET radiopharmaceuticals, the synthesis and clinical use of PET radiopharmaceuticals are described.

  4. Electron Cyclotron Resonances in Electron Cloud Dynamics

    SciTech Connect

    Celata, Christine; Celata, C.M.; Furman, Miguel A.; Vay, J.-L.; Yu, Jennifer W.

    2008-06-25

    We report a previously unknown resonance for electron cloud dynamics. The 2D simulation code"POSINST" was used to study the electron cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. An electron equilibrium density enhancement of up to a factor of 3 was found at magnetic field values for which the bunch frequency is an integral multiple of the electron cyclotron frequency. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ~;;(2 pi mec/(elb)), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics are discussed.

  5. Electron Cyclotron Emission Diagnostics on ITER

    NASA Astrophysics Data System (ADS)

    Ellis, Richard; Austin, Max; Phillips, Perry; Rowan, William; Beno, Joseph; Auroua, Abelhamid; Feder, Russell; Patel, Ashish; Hubbard, Amanda; Pandya, Hitesh

    2010-11-01

    Electron cyclotron emission (ECE) will be employed on ITER to measure the radial profile of electron temperature and non thermal features of the electron distribution as well as measurements of ELMs, magnetic islands, high frequency instabilities, and turbulence. There are two quasioptical systems, designed with Gaussian beam analysis. One view is radial, primarily for temperature profile measurement, the other views at a small angle to radial for measuring non-thermal emission. Radiation is conducted to by a long corrugated waveguide to a multichannel Michelson interferometer which provides wide wavelength coverage but limited time response as well as two microwave radiometers which cover the fundamental and second harmonic ECE and provide excellent time response. Measurements will be made in both X and O mode. In-situ calibration is provided by a novel hot calibration source. We discuss spatial resolution and the implications for physics studies.

  6. Cyclotron maser using the anomalous Doppler effect

    NASA Astrophysics Data System (ADS)

    Didenko, A. N.; Borisov, A. R.; Fomenko, G. P.; Shlapakovskii, A. S.; Shtein, Iu. G.

    1983-11-01

    The operation of an anomalous-Doppler-effect cyclotron-resonance maser using a waveguide partially filled with dielectric as the slow-wave system is reported. The device investigated is similar to that of Didenko et al. (1983) and comprises a 300-mm-long 50-mm-o.d. 30-mm-i.d. waveguide with fabric-laminate dielectric, located 150 mm from the cathode in a 500-mm-long region of uniform 0-20-kG magnetic field, and a coaxial magnetic-insulation gun producing a 13-mm-i.d. 25-mm-o.d. hollow electron beam. Radiation at 12 + or - 1 mm wavelength and optimum power 20 MW is observed using hot-carrier detectors, with a clear peak in the power-versus-magnetic-field curve at about 6.4 kG.

  7. A simple electron cyclotron resonance ion sourcea)

    NASA Astrophysics Data System (ADS)

    Welton, R. F.; Moran, T. F.; Feeney, R. K.; Thomas, E. W.

    1996-04-01

    A simple, all permanent magnet, 2.45 GHz electron cyclotron resonance ion source has been developed for the production of stable beams of low charge state ions from gaseous feed materials. The source can produce ˜1 mA of low energy (3 kV) singly charged ion current in the 10-4 Torr pressure range. The source can also be operated in a more efficient low-pressure mode at an order of magnitude lower pressure. In this latter range, for example, the ionization efficiency of Ar is estimated to be 1% with charge states up to Ar8+ present. Operation in the low-pressure mode requires low power input (˜20 W). These features make the source especially suited for use with small accelerator systems for a number of applications including ion implantation, mass spectrometry, and atomic collision experiments where multiply charged ions are desirable. Design details and performance characteristics of the source are presented.

  8. Folded waveguide coupler for ion cyclotron heating

    SciTech Connect

    Owens, T.L.; Chen, G.L.

    1986-01-01

    A new type of waveguide coupler for plasma heating in the ion cyclotron range of frequencies is described. The coupler consists of a series of interleaved metallic vanes within a rectangular enclosure analogous to a wide rectangular waveguide that has been ''folded'' several times. At the mouth of the coupler, a plate is attached which contains coupling apertures in each fold or every other fold of the waveguide, depending upon the wavenumber spectrum desired. This plate serves primarily as a wave field polarizer that converts coupler fields to the polarization of the fast magnetosonic wave within the plasma. Theoretical estimates indicate that the folded waveguide is capable of high-efficiency, multimegawatt operation into a plasma. Bench tests have verified the predicted field structure within the waveguide in preparation for high-power tests on the Radio Frequency Test Facility at the Oak Ridge National Laboratory.

  9. Shielding design of the Mayo Clinic Scottsdale cyclotron vault

    NASA Astrophysics Data System (ADS)

    Riper, Kenneth A. Van; Metzger, Robert L.; Nelson, Kevin

    2017-09-01

    Mayo Clinic Scottsdale (Scottsdale, Arizona) is building a cyclotron vault containing a cyclotron with adjacent targets and a beam line leading to an external target. The targets are irradiated by high energy (15 to 16.5 MeV) protons for the production of radioisotopes. We performed Monte Carlo radiation transport simulations to calculate the radiation dose outside of the vault during irradiation of the cyclotron and external targets. We present the Monte Carlo model including the geometry, sources, and variance reduction methods. Mesh tallies surrounding the vault show the external dose rate is within acceptable limits.

  10. Ionospheric modification at twice the electron cyclotron frequency.

    PubMed

    Djuth, F T; Pedersen, T R; Gerken, E A; Bernhardt, P A; Selcher, C A; Bristow, W A; Kosch, M J

    2005-04-01

    In 2004, a new transmission band was added to the HAARP high-frequency ionospheric modification facility that encompasses the second electron cyclotron harmonic at altitudes between approximately 220 and 330 km. Initial observations indicate that greatly enhanced airglow occurs whenever the transmission frequency approximately matches the second electron cyclotron harmonic at the height of the upper hybrid resonance. This is the reverse of what happens at higher electron cyclotron harmonics. The measured optical emissions confirm the presence of accelerated electrons in the plasma.

  11. Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs

    NASA Astrophysics Data System (ADS)

    Amaldi, U.; Bonomi, R.; Braccini, S.; Crescenti, M.; Degiovanni, A.; Garlasché, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pittà, G.; Puggioni, P.; Rosso, E.; Verdú Andrés, S.; Wegner, R.; Weiss, M.; Zennaro, R.

    2010-08-01

    Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and 'single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs.

  12. ECR Ion Source for a High-Brightness Cyclotron

    NASA Astrophysics Data System (ADS)

    Comeaux, Justin; McIntyre, Peter; Assadi, Saeed

    2011-10-01

    New technology is being developed for high-brightness, high-current cyclotrons with performance benefits for accelerator-driven subcritical fission power, medical isotope production, and proton beam cancer therapy. This paper describes the design for a 65 kV electron cyclotron resonance (ECR) ion source that will provide high-brightness beam for injection into the cyclotron. The ion source is modeled closely upon the one that is used at the Paul Scherrer Institute. Modifications are being made to provide enhanced brightness and compatibility for higher-current operation.

  13. Improving cancer treatment with cyclotron produced radionuclides. Progress report

    SciTech Connect

    Larson, S.M.; Finn, R.D.

    1993-11-01

    This report describes our continuing long term goal of promoting nuclear medicine applications by improving the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The program includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. An essential strategy is as follows: novel radionuclides and radiotracers developed in the Radiochemistry/Cyclotron section will be employed in the Pharmacology and Immunology sections during the next year. The development of novel radionuclides and tracers is of course useful in and of itself, but their utility is greatly enhanced by the interaction with the immunology and pharmacology components of the program.

  14. Radiation Monitoring System of 30 MeV Cyclotron

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Woo; Hur, Min-Goo; Jeong, Gyosung; Kim, Jongil

    2017-09-01

    A state-of-the-art radiation monitoring system was implemented at KAERI for a 30-MeV cyclotron. This system consists of several types of radiation measuring systems for ambient dose equivalent rate measurements of outside photon and neutron areas as well as inside the cyclotron, and monitors the alpha and beta particulates released from a stack, as well as the results of worker contamination at the portal of the cyclotron. In addition, an automatic alarm system is also mounted if there are alarms in the measuring systems.

  15. Cyclotron Maser Emission - Stars, Planets and Laboratory

    NASA Astrophysics Data System (ADS)

    Vorgul, Irena

    2010-11-01

    X-ray and radio observations of active stars over many years have shown that they frequently generate X-ray bursts that are quickly followed by radio bursts. In many cases the radio bursts are highly polarised. More recently, the star CU Virginis has been found to exhibit pulsar-like behaviour. In both these situations we believe that the radio emission can be best explained by a cyclotron maser type instability initiated by electron beams funnelling down converging magnetic field configurations typical of a dipole magnetic topology. Just such a geometry also exists in the Earth's auroral zone and so our model can explain the Earth's auroral kilometric radiation (AKR). Via a similar process, all the gas giant/magnetised planets in the solar system also emit radio emission. We have established a laboratory-based facility that has verified many of the details of our original theoretical description. The experiment has demonstrated, for example, that an electron beam entering a strongly converging magnetic field geometry does indeed produce a ``horse-shoe'' (or crescent-shaped) distribution in velocity space. It is the generation of this horse-shoe distribution, also observed in the Earth's auroral zone, which is vital for our theoretical model. It leads to a population inversion in the perpendicular velocity distribution and generation of electromagnetic waves close to the cyclotron frequency. We will discuss recent developments in the theory and simulation of the instability and relate these to the laboratory, space and astrophysical observations. The research was supported by UK Engineering and Physical Sciences Research Council. The input of R.A. Cairns, R. Bingham, B.J. Kellett and the experimental and computer modelling team at Strathclyde University, Glasgow is gratefully acknowledged.

  16. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K.; Gallagher, D. L.; Kozyra, J. U.

    2007-01-01

    It is well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. [2002 - 2007]. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis

  17. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.; Gallagher, D. L.; Kozyra, J. U.

    2007-01-01

    It is very well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis of modern

  18. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K.; Gallagher, D. L.; Kozyra, J. U.

    2007-01-01

    It is well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. [2002 - 2007]. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis

  19. The NSCL cyclotron gas stopper - Entering commissioning

    NASA Astrophysics Data System (ADS)

    Schwarz, S.; Bollen, G.; Chouhan, S.; Das, J. J.; Green, M.; Magsig, C.; Morrissey, D. J.; Ottarson, J.; Sumithrarachchi, C.; Villari, A. C. C.; Zeller, A.

    2016-06-01

    Linear gas stopping cells have been used successfully at NSCL to slow down ions produced by projectile fragmentation from the 100 MeV/u to the keV energy range. These 'stopped beams' have first been used for low-energy high precision experiments and more recently for NSCLs re-accelerator ReA. A gas-filled reverse cyclotron is currently under construction by the NSCL to complement the existing stopping cells: Due to its extended stopping length, efficient stopping and fast extraction is expected even for light and medium-mass ions, which are difficult to thermalize in linear gas cells. The device is based on a 2.6 T maximum-field cyclotron-type magnet to confine the injected beam while it is slowed down in ≈100 mbar of LN2-temperature helium gas. Once thermalized, the beam will be transported to the center of the device by a traveling-wave RF-carpet system, extracted along the symmetry axis with an ion conveyor and miniature RF-carpets, and accelerated to a few tens of keV of energy for delivery to the users. The superconducting magnet has been constructed on a 60 kV platform and energized to its nominal field strength. The magnet's two cryostats use 3 cryo-refrigerators each and liquid-nitrogen cooled thermal shields to cool the coil pair to superconductivity. This concept, chosen not to have to rely on external liquid helium, has been working well. Measurements of axial and radial field profiles confirm the field calculations. The individual RF-ion guiding components for low-energy ion transport through the device have been tested successfully. The beam stopping chamber with its 0.9 m-diameter RF carpet system and the ion extraction system are being prepared for installation inside the magnet for low-energy ion transport tests.

  20. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Astrophysics Data System (ADS)

    Khazanov, G. V.; Gamayunov, K. V.; Gallagher, D. L.; Kozyra, J. U.

    2007-12-01

    It is well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. [2002 - 2007]. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis

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

    SciTech Connect

    Oosterbeek, J. W.; Buerger, A.; Westerhof, E.; Baar, M. R. de; Berg, M. A. van den; Bongers, W. A.; Graswinckel, M. F.; Hennen, B. A.; Kruijt, O. G.; Thoen, J.; Heidinger, R.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.

    2008-09-15

    An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) beam. ECE measurements are obtained during high power ECRH operation. This demonstrates the successful operation of the diagnostic and, in particular, a sufficient suppression of the gyrotron component preventing it from interfering with ECE measurements. When integrated into a feedback system for the control of plasma instabilities this line-of-sight ECE diagnostic removes the need to localize the instabilities in absolute coordinates.

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

    SciTech Connect

    Asner, D. M.; Bradley, R. F.; de Viveiros, L.; Doe, P. J.; Fernandes, J. L.; Fertl, M.; Finn, E. C.; Formaggio, J. A.; Furse, D.; Jones, A. M.; Kofron, J. N.; LaRoque, B. H.; Leber, M.; McBride, E. L.; Miller, M. L.; Mohanmurthy, P.; Monreal, B.; Oblath, N. S.; Robertson, R. G. H.; Rosenberg, L. J.; Rybka, G.; Rysewyk, D.; Sternberg, M. G.; Tedeschi, J. R.; Thummler, T.; VanDevender, B. A.; Woods, N. L.

    2015-04-20

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

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

    SciTech Connect

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

    2015-04-01

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

  4. Design Study Of Cyclotron Magnet With Permanent Magnet

    SciTech Connect

    Kim, Hyun Wook; Chai, Jong Seo

    2011-06-01

    Low energy cyclotrons for Positron emission tomography (PET) have been wanted for the production of radio-isotopes after 2002. In the low energy cyclotron magnet design, increase of magnetic field between the poles is needed to make a smaller size of magnet and decrease power consumption. The Permanent magnet can support this work without additional electric power consumption in the cyclotron. In this paper the study of cyclotron magnet design using permanent magnet is shown and also the comparison between normal magnet and the magnet which is designed with permanent magnet is shown. Maximum energy of proton is 8 MeV and RF frequency is 79.3 MHz. 3D CAD design was done by CATIA P3 V5 R18 and the All field calculations had been performed by OPERA-3D TOSCA. The self-made beam dynamics program OPTICY is used for making isochronous field and other calculations.

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

    DOE PAGES

    Asner, D. M.; Bradley, R. F.; de Viveiros, L.; ...

    2015-04-20

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

  6. Intensity limitations in compact H{sup minus} cyclotrons

    SciTech Connect

    Baartman, R.A.

    1995-12-31

    At TRIUMF, we have demonstrated 2.5 mA in a compact H{sup -} cyclotron. It is worthwhile to explore possibility of going to even higher intensity. In small cyclotrons, vertical focusing vanishes at the center. The space charge tune shift further reduces vertical focusing, thus determining an upper limit on instantaneous current. Limit on average current is of course also dependent upon phase acceptance, but this can be made quite large in an H{sup -} cyclotron. Longitudinal space charge on the first turn can reduce the phase acceptance as well. For finite ion source brightness, another limit comes from bunching efficiency in presence of space charge forces. We present methods of calculating and optimizing these limits. In particular, we show that it is possible to achieve 10mA in a 50 MeV compact H{sup -} cyclotron.

  7. Undergraduate Education with the Rutgers 12-Inch Cyclotron

    NASA Astrophysics Data System (ADS)

    Koeth, Timothy W.

    The Rutgers 12-Inch Cyclotron is a research grade accelerator dedicated to undergraduate education. From its inception, it has been intended for instruction and has been designed to demonstrate classic beam physics phenomena and provides students hands on experience with accelerator technology. The cyclotron is easily reconfigured, allowing experiments to be designed and performed within one academic semester. Our cyclotron offers students the opportunity to operate an accelerator and directly observe many fundamental beam physics concepts, including axial and radial betatron motion, destructive resonances, weak and azimuthally varying field (AVF) focusing schemes, RF and DEE voltage effects, diagnostic techniques, and perform low energy nuclear reactions. This paper emphasizes the unique beam physics measurements and beam manipulations capable at the Rutgers 12-Inch Cyclotron.

  8. Some calculations of the resonator in INR cyclotron

    SciTech Connect

    Zhang, J.; Liu, X.L.

    1985-10-01

    Some calculation methods of the resonator parameters with single dee and two coaxial transmission lines in INR variable-energy cyclotron were described. Also calculated and experimental results have been compared with the original one (two dee system).

  9. Cyclotrons for clinical and biomedical research with PET

    SciTech Connect

    Wolf, A.P.

    1987-01-01

    The purpose of this commentary is to present some background material on cyclotrons and other particle accelerators particularly with a view toward the considerations behind acquiring and installing such a machine for purely clinical and/or biomedical research use.

  10. Vacuum Control Systems of the Cyclotrons in VECC, Kolkata

    NASA Astrophysics Data System (ADS)

    Roy, Anindya; Akhtar, Javed; Yadav, R. C.; Bhole, R. B.; Pal, Sarbajit; Sarkar, D.; Bhandari, R. K.

    2012-11-01

    VECC has undertaken the modernization of the K-130 Room Temperature Cyclotron (RTC) (operational since 1978) and commissioning of K-500 Superconducting Cyclotron (SCC) at present. The control system of RTC vacuum system has been upgraded to Programmable Logic Controller (PLC) based automated system from relay based manual system. A distributed PLC based system is under installation for SCC vacuum system. The requirement of high vacuum in both the cyclotrons (1×10-6 mbar for RTC and 5 × 10-8 mbar SCC) imposes the reliable local and remote operation of all vacuum components and instrumentation. The design and development of the vacuum control system of two cyclotrons using the Experimental Physics and Industrial Control System (EPICS) distributed real-time software tools are presented.

  11. Design Study Of Cyclotron Magnet With Permanent Magnet

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Wook; Chai, Jong Seo

    2011-06-01

    Low energy cyclotrons for Positron emission tomography (PET) have been wanted for the production of radio-isotopes after 2002. In the low energy cyclotron magnet design, increase of magnetic field between the poles is needed to make a smaller size of magnet and decrease power consumption. The Permanent magnet can support this work without additional electric power consumption in the cyclotron. In this paper the study of cyclotron magnet design using permanent magnet is shown and also the comparison between normal magnet and the magnet which is designed with permanent magnet is shown. Maximum energy of proton is 8 MeV and RF frequency is 79.3 MHz. 3D CAD design was done by CATIA P3 V5 R18 [1] and the All field calculations had been performed by OPERA-3D TOSCA [2]. The self-made beam dynamics program OPTICY [3] is used for making isochronous field and other calculations.

  12. PET computer programs for use with the 88-inch cyclotron

    SciTech Connect

    Gough, R.A.; Chlosta, L.

    1981-06-01

    This report describes in detail several offline programs written for the PET computer which provide an efficient data management system to assist with the operation of the 88-Inch Cyclotron. This function includes the capability to predict settings for all cyclotron and beam line parameters for all beams within the present operating domain of the facility. The establishment of a data base for operational records is also described from which various aspects of the operating history can be projected.

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

    SciTech Connect

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

    2014-02-15

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

  14. [Towards a pedagogical e-learning approach to improve preparation for medical school curriculum in Grenoble: results over the 10 last years].

    PubMed

    Gillois, Pierre; Pagonis, Daniel; Vuillez, Jean-Philippe; Bosson, Jean-Luc; Romanet, Jean-Paul

    2013-02-01

    Before 2005, at Grenoble, the teaching of the first year of medicine satisfied neither the students, nor the teachers anxious to exempt a correctly targeted effective teaching. By 2006, the Grenoble-native teaching method was reformed in-depth with the introduction of information and communication technology (ICT) in education. Each sequence was over 4 weeks connecting: self- learning using multi-media resources, questions submitted online, meetings with teaching staff for interactive question-answer sessions in the presence of the teacher,) tutorials animated by older students for Multiple Choice Question (MCQ) training in preparation for the exams. The whole health formation was structured in 12 cycles of this same structured sequence. Since 2010, this method was extended from the faculty of medicine to the faculty of pharmacy and maieutic. Each year, more than 1600 students, 40 teachers and 140 tutors are concerned. The ICT laboratory was responsible for the production of the multi-media support, of the management of the questions online, the collection and the treatment of the evaluations of the lesson by the students. It also took part in the preparation of the MCQ trainings and after each sequence, delivered to students their personal ranking. Staffs between teachers and students are organized for the 12 cycles. The teachers' and students' opinions were analyzed to evaluate the reforms and allow teaching methods to be adapted accordingly. The expressed satisfaction' rate vary from 85% with more than 91% by students and teachers. The intensive use of new information and communication technologies is well accepted, by both sides: teachers and students. After each tutorial, students had their results and their rank, which are linked with the contest result. The mean of the 12 notes obtained during the tutorials is correlated with the note with the contest (R of Spearman=0.75). Student profiles at registration and success in the exams following the reform are

  15. Correlation electron cyclotron emission diagnostic in TCV

    NASA Astrophysics Data System (ADS)

    Fontana, M.; Porte, L.; Molina Cabrera, P.

    2017-08-01

    The correlation electron cyclotron emission diagnostic of tokamak à configuration variable has recently been upgraded. It now has the choice of three lines of sight: two horizontal lines placed on the low field side of the vessel, perpendicular to the magnetic field, and a dual-axis steerable antenna. The polarization of the radiation collected by the latter can be rotated using a universal polarizer situated in the transmission line. This line is also shared with a reflectometry system, allowing simultaneous measurements of temperature and density fluctuations in the same plasma volumes. When using this line, it is possible to choose between two dedicated front ends characterized by different local oscillator frequencies, adding flexibility in the choice of the plasma region to be studied. The intermediate frequency section is now equipped with six frequency tunable YIG filters allowing the study of turbulence properties in a wide range of radial positions. When studying fluctuations over the whole video bandwidth, the minimum detectable fluctuation level is δ Te/Te˜0.5 % . The new system has been used to measure electron temperature fluctuations over a large fraction of the plasma profiles in a series of plasmas with triangularity varying from 0.6 to -0.6 but comparable collisionality profiles.

  16. A storage ring for the JULIC cyclotron

    NASA Astrophysics Data System (ADS)

    Martin, S. A.; Prasuhn, D.; Schott, W.; Wiedner, C. A.

    1985-05-01

    The storage ring COSY is planned to provide higher intensity and resolution for nuclear structure experiments using the light heavy ion beams (p, d, τ, α) of the JULIC cyclotron and the magnet spectrograph BIG KARL. The ring contains the measuring target of BIG KARL as an internal target, two rf cavities for compensating the mean energy loss in the target and providing additional acceleration of the stored beam and an e --cooling section. In the recirculator mode, i.e., without e --cooling, a luminosity of L = 3.64 × 10 30 particles/(cm 2 s) is obtained for an experiment with 41 MeV protons and a 50 μg/cm 212C target at a spectrograph resolution p/d p = 10 4 and 100% duty factor. This corresponds to a gain in L of 546.5 in comparison with the same experiment without a storage ring. In the recirculator mode with acceleration L = 1.17 × 10 32 p/(cm 2 s) and 98.8% duty factor results for 1500 MeV protons on the same target at the same resolution. Using e --cooling L and the feasible p/d p can be enhanced, however, at a reduced duty factor.

  17. 30-cm electron cyclotron plasma generator

    NASA Technical Reports Server (NTRS)

    Goede, Hank

    1987-01-01

    Experimental results on the development of a 30-cm-diam electron cyclotron resonance plasma generator are presented. This plasma source utilizes samarium-cobalt magnets and microwave power at a frequency of 4.9 GHz to produce a uniform plasma with densities of up to 3 x 10 to the 11th/cu cm in a continuous fashion. The plasma generator contains no internal structures, and is thus inherently simple in construction and operation and inherently durable. The generator was operated with two different magnetic geometries. One used the rare-earth magnets arranged in an axial line cusp configuration, which directly showed plasma production taking place near the walls of the generator where the electron temperature was highest but with the plasma density peaking in the central low B-field regions. The second configuration had magnets arranged to form azimuthal line cusps with approximately closed electron drift surfaces; this configuration showed an improved electrical efficiency of about 135 eV/ion.

  18. Fourier transform ion cyclotron resonance mass spectrometry

    NASA Astrophysics Data System (ADS)

    Marshall, Alan G.

    1998-06-01

    As for Fourier transform infrared (FT-IR) interferometry and nuclear magnetic resonance (NMR) spectroscopy, the introduction of pulsed Fourier transform techniques revolutionized ion cyclotron resonance mass spectrometry: increased speed (factor of 10,000), increased sensitivity (factor of 100), increased mass resolution (factor of 10,000-an improvement not shared by the introduction of FT techniques to IR or NMR spectroscopy), increased mass range (factor of 500), and automated operation. FT-ICR mass spectrometry is the most versatile technique for unscrambling and quantifying ion-molecule reaction kinetics and equilibria in the absence of solvent (i.e., the gas phase). In addition, FT-ICR MS has the following analytically important features: speed (~1 second per spectrum); ultrahigh mass resolution and ultrahigh mass accuracy for analysis of mixtures and polymers; attomole sensitivity; MSn with one spectrometer, including two-dimensional FT/FT-ICR/MS; positive and/or negative ions; multiple ion sources (especially MALDI and electrospray); biomolecular molecular weight and sequencing; LC/MS; and single-molecule detection up to 108 Dalton. Here, some basic features and recent developments of FT-ICR mass spectrometry are reviewed, with applications ranging from crude oil to molecular biology.

  19. Two Dimensional Synthetic Electron Cyclotron Emission Imaging

    NASA Astrophysics Data System (ADS)

    Shi, Lei; Valeo, Ernest J.; Tobias, Benjamin J.; Kramer, Gerrit J.; Liu, Chang; Tang, William M.

    2016-10-01

    Electron Cyclotron Emission (ECE) has been widely used as a measurement of the electron temperature profile in magnetically confined plasmas. The ECE Imaging (ECEI) system provides additional vertical resolutions, and is used to measure the electron temperature fluctuations. The vertical resolution is typically a few centi-meters which is sometimes comparable to the vertical wave length of the underlying fluctuations. The ray-tracing technique used in most synthetic ECE codes to determine the origin and spatial extent of the ECE radiations is not accurate when the refraction and diffraction due to the fluctuations are important. In this presentation, we introduce a new synthetic ECEI code which solves the wave propagation up to the 2nd order of the WKB approximation, and provides full 2D information of the ECE source. We'll show that when the ECE frequency is near the cutoff, the refraction due to the fluctuations is important. A ``trapping'' of the ECE source by the density fluctuations is identified, and is potentially useful for determining the cross phase between electron temperature and density fluctuations. The new formalism is also used to study the Runaway Electrons contribution to the ECE signal, and provides insights to the measured ECE spectrum on DIII-D. This work has been funded by the US Department of Energy under Contract Number DE-AC02-09CH11466.

  20. Fourth generation electron cyclotron resonance ion sources.

    PubMed

    Lyneis, Claude M; Leitner, D; Todd, D S; Sabbi, G; Prestemon, S; Caspi, S; Ferracin, P

    2008-02-01

    The concepts and technical challenges related to developing a fourth generation electron cyclotron resonance (ECR) ion source with a rf frequency greater than 40 GHz and magnetic confinement fields greater than twice B(ECR) will be explored in this article. Based on the semiempirical frequency scaling of ECR plasma density with the square of operating frequency, there should be significant gains in performance over current third generation ECR ion sources, which operate at rf frequencies between 20 and 30 GHz. While the third generation ECR ion sources use NbTi superconducting solenoid and sextupole coils, the new sources will need to use different superconducting materials, such as Nb(3)Sn, to reach the required magnetic confinement, which scales linearly with rf frequency. Additional technical challenges include increased bremsstrahlung production, which may increase faster than the plasma density, bremsstrahlung heating of the cold mass, and the availability of high power continuous wave microwave sources at these frequencies. With each generation of ECR ion sources, there are new challenges to be mastered, but the potential for higher performance and reduced cost of the associated accelerator continues to make this a promising avenue for development.

  1. Cyclotron-based effects on plant gravitropism

    NASA Astrophysics Data System (ADS)

    Kordyum, E.; Sobol, M.; Kalinina, Ia.; Bogatina, N.; Kondrachuk, A.

    Primary roots exhibit positive gravitropism and grow in the direction of the gravitational vector, while shoots respond negatively and grow opposite to the gravitational vector. We first demonstrated that the use of a weak combined magnetic field (CMF), which is comprised of a permanent magnetic field and an alternating magnetic field with the frequency resonance of the cyclotron frequency of calcium ions, can change root gravitropism from a positive direction to negative direction. Two-day-old cress seedlings were gravistimulated in a chamber that was placed into a μ-metal shield where this CMF was created. Using this "new model" of a root gravitropic response, we have studied some of its components including the movement of amyloplasts-statoliths in root cap statocytes and the distribution of Ca 2+ ions in the distal elongation zone during gravistimulation. Unlike results from the control, amyloplasts did not sediment in the distal part of a statocyte, and more Ca 2+ accumulation was observed in the upper side of a gravistimulated root for seedlings treated with the CMF. For plants treated with the CMF, it appears that a root gravitropic reaction occurs by a normal physiological process resulting in root bending although in the opposite direction. These results support the hypothesis that both the amyloplasts in the root cap statocytes and calcium are important signaling components in plant gravitropism.

  2. Fullerenes in electron cyclotron resonance ion sources

    SciTech Connect

    Biri, S.; Fekete, E.; Kitagawa, A.; Muramatsu, M.; Janossy, A.; Palinkas, J.

    2006-03-15

    Fullerene plasmas and beams have been produced in our electron cyclotron resonance ion sources (ECRIS) originally designed for other purposes. The ATOMKI-ECRIS is a traditional ion source with solenoid mirror coils to generate highly charged ions. The variable frequencies NIRS-KEI-1 and NIRS-KEI-2 are ECR ion sources built from permanent magnets and specialized for the production of carbon beams. The paper summarizes the experiments and results obtained by these facilities with fullerenes. Continuous effort has been made to get the highest C{sub 60} beam intensities. Surprisingly, the best result was obtained by moving the C{sub 60} oven deep inside the plasma chamber, very close to the resonance zone. Record intensity singly and doubly charged fullerene beams were obtained (600 and 1600 nA, respectively) at lower C{sub 60} material consumption. Fullerene derivatives were also produced. We mixed fullerenes with other plasmas (N, Fe) with the aim of making new materials. Nitrogen encapsulated fullerenes (mass: 720+14=734) were successfully produced. In the case of iron, two methods (ferrocene, oven) were tested. Molecules with mass of 720+56=776 were detected in the extracted beam spectra.

  3. Characterization of electron cyclotron resonance hydrogen plasmas

    SciTech Connect

    Outten, C.A. . Dept. of Nuclear Engineering); Barbour, J.C.; Wampler, W.R. )

    1990-01-01

    Electron cyclotron resonance (ECR) plasmas yield low energy and high ion density plasmas. The characteristics downstream of an ECR hydrogen plasma were investigated as a function of microwave power and magnetic field. A fast-injection Langmuir probe and a carbon resistance probe were used to determine plasma potential (V{sub p}), electron density (N{sub e}), electron temperature (T{sub e}), ion energy (T{sub i}), and ion fluence. Langmuir probe results showed that at 17 cm downstream from the ECR chamber the plasma characteristics are approximately constant across the center 7 cm of the plasma for 50 Watts of absorbed power. These results gave V{sub p} = 30 {plus minus} 5 eV, N{sub e} = 1 {times} 10{sup 8} cm{sup {minus}3}, and T{sub e} = 10--13 eV. In good agreement with the Langmuir probe results, carbon resistance probes have shown that T{sub i} {le} 50 eV. Also, based on hydrogen chemical sputtering of carbon, the hydrogen (ion and energetic neutrals) fluence rate was determined to be 1 {times} 10{sup 16}/cm{sup 2}-sec. at a pressure of 1 {times} 10{sup {minus}4} Torr and for 50 Watts of absorbed power. 19 refs.

  4. Cyclotron autoresonance maser in the millimeter region

    NASA Astrophysics Data System (ADS)

    Nikolov, N. A.; Spasovski, I. P.; Kostov, K. G.; Velichkov, J. N.; Spasov, V. A.

    1990-06-01

    This paper investigates the optimal experimental conditions for a cyclotron autoresonance maser (CARM) regime realized by a nonadiabatic magnetic beam pumping in the millimeter wavelength region. In the experiment, a Blumline-type accelerator with a voltage up to 650 kV and maximal current up to 10 kA is used to generate a hollow beam with a pulse duration of 30 ns. The electron beam, emitted from a graphite cathode with a 10-mm diameter, propagates in a cylindrical drift tube of 56 mm diam and a length of 500 mm. The external magnetic field B, provided by a solenoidal magnet, is homogeneous along the drift tube up to a distance of 300 mm from the cathode. The experiment demonstrated the generation of microwave radiation in the time interval from 0.0016 to 0.0023 sec after the switch-on of the external magnetic field. Two maxima of the output microwave power (8 and 10 MW) at a wavelength of 5 and 5.5 mm, respectively, were observed.

  5. The Oak Ridge Isochronous Cyclotron Refurbishment Project

    SciTech Connect

    Mendez, II, Anthony J; Ball, James B; Dowling, Darryl T; Mosko, Sigmund W; Tatum, B Alan

    2011-01-01

    The Oak Ridge Isochronous Cyclotron (ORIC) has been in operation for nearly fifty years at the Oak Ridge National Laboratory (ORNL). Presently, it serves as the driver accelerator for the ORNL Holifield Radioactive Ion Beam Facility (HRIBF), where radioactive ion beams are produced using the Isotope Separation Online (ISOL) technique for post-acceleration by the 25URC tandem electrostatic accelerator. Operability and reliability of ORIC are critical issues for the success of HRIBF and have presented increasingly difficult operational challenges for the facility in recent years. In February 2010, a trim coil failure rendered ORIC inoperable for several months. This presented HRIBF with the opportunity to undertake various repairs and maintenance upgrades aimed at restoring the full functionality of ORIC and improving the reliability to a level better than what had been typical over the previous decade. In this paper, we present details of these efforts, including the replacement of the entire trim coil set and measurements of their radial field profile. Comparison of measurements and operating tune parameters with setup code predictions will also be presented.

  6. A small low energy cyclotron for radioisotope measurements

    SciTech Connect

    Bertsche, K.J.

    1989-11-01

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

  7. Electron cyclotron emissions from an electron cyclotron heated discharge in ISX-B

    SciTech Connect

    Elder, G.B.

    1983-01-01

    Observation of the electron cyclotron emissions (ECE) is especially effective when studying the effects of electron cyclotron heating (ECH). Two detectors were built to observe the optically thin third harmonic radiation from ISX B during the recent 28 GHz ECH experiments carried on at Oak Ridge National Laboratory. These detectors supplemented existing detectors at the fundamental frequency and at the second harmonic frequency. Observations of the three frequencies during and after the ECH was pulsed into the plasma showed an unexpected rise in their intensity, occurring after the ECH pulse was over. This rise lasted for many tens of milliseconds, well beyond estimates of the electron energy confinement time. The rise in the third harmonic intensity was frequently to an intensity 100 times greater than the pre-ECH intensity. The fundamental frequency and the second harmonic had a much milder change in their intensities. The rises were seen to depend critically on the density of the plasma and the length of the ECH pulse but only weakly on the pre-ECH temperature. A computer code that predicts the ECE from an electron distribution in ISX-B, taking into a account the effect of the plasma's dielectric response to the emissions from a single electron, was developed.

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

    NASA Astrophysics Data System (ADS)

    Slapak, Rikard; Gunell, Herbert; Hamrin, Maria

    2017-04-01

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

  9. Design of RF system for CYCIAE-230 superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Yin, Zhiguo; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

    2017-05-01

    The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push-pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

  10. Heavy ion cocktail beams at the 88 inch Cyclotron

    SciTech Connect

    Leitner, Daniela; McMahan, Margaret A.; Argento, David; Gimpel, Thomas; Guy, Aran; Morel, James; Siero, Christine; Thatcher, Ray; Lyneis, Claude M.

    2002-09-03

    Cyclotrons in combination with ECR ion sources provide the ability to accelerate ''cocktails'' of ions. A cocktail is a mixture of ions of near-identical mass-to-charge (m/q) ratio. The different ions cannot be separated by the injector mass-analyzing magnet and are tuned out of the ion source together. The cyclotron then is utilized as a mass analyzer by shifting the accelerating frequency. This concept was developed soon after the first ECR ion source became operational at the 88-Inch Cyclotron and has since become a powerful tool in the field of heavy ion radiation effects testing. Several different ''cocktails'' at various energies are available at the 88-Inch cyclotron for radiation effect testing, covering a broad range of linear energy transfer and penetration depth. Two standard heavy ion cocktails at 4.5 MeV/nucleon and 10 MeV/nucleon have been developed over the years containing ions from boron to bismuth. Recently, following requests for higher penetration depths, a 15MeV/nucleon heavy ion cocktail has been developed. Up to nine different metal and gaseous ion beams at low to very high charge states are tuned out of the ion source simultaneously and injected together into the cyclotron. It is therefore crucial to balance the ion source very carefully to provide sufficient intensities throughout the cocktail. The paper describes the set-up and tuning of the ion source for the various heavy ion cocktails.

  11. Cyclotron targets and production technologies used for radiopharmaceuticals in NPI

    NASA Astrophysics Data System (ADS)

    Fišer, M.; Kopička, K.; Hradilek, P.; Hanč, P.; Lebeda, O.; Pánek, J.; Vognar, M.

    2003-01-01

    This paper deals with some technical aspects of the development and production of cyclotronmade radiopharmaceuticals (excluding PET). In this field, nuclear chemistry and pharmacy are in a close contact; therefore, requirements of the both should be taken into account. The principles of cyclotron targetry, separation/recovery of materials and synthesis of active substances are given, as well as issues connected with formulation of pharmaceutical forms. As the radiopharmaceuticals should fulfil the requirements on in vivo preparations, there exist a variety of demands pertaining to Good Manufacturing Practice (GMP) concept, which is also briefly discussed. A typical production chain is presented and practical examples of real technologies based on cyclotron-made radionuclides are given as they have been used in Nuclear Physics Institute of CAS (NPI). Special attention is devoted to the technology of enriched cyclotron targets. Frequently used medicinal products employing cyclotron-produced active substances are characterised (Rb/Kr generators, 123I-labelled MIBG, OIH and MAB's). The cyclotron produced radioactive implants for transluminal coronary angioplasty (radioactive stents) are introduced as an example of a medical device developed for therapeutic application.

  12. Potential of cyclotron based accelerators for energy production and transmutation

    SciTech Connect

    Stammbach, T.; Adam, S.; Fitze, H.R.

    1995-10-01

    PSI operates a 590 MeV-cyclotron facility for high intensity proton beams for the production of intense beams of pions and muons. The facility, commissioned in 1974, has been partially upgraded and is now operated routinely at a beam current of 1 mA, which corresponds to a beam power of 0.6 MW. At this current, the beam losses in the cyclotron are about 0.02%. By the end of 1995 the authors expect to have 1.5 mA of protons. Extensive theoretical investigations on beam current limitations in isochronous cyclotrons were undertaken. They show that the longitudinal space charge effects dominate. Based on their experience the authors present a preliminary design of a cyclotron scheme that could produce a 10 MW beam as a driver for an {open_quotes}energy amplifier{close_quotes} as proposed by C. Rubbia and his collaborators. The expected efficiency for the conversion of AC into beam power would be about 50% (for the RF-systems only). The beam losses in the cyclotron are expected to be a few {mu}A, leading to a tolerable activation level.

  13. Cyclotron-based of plant gravisensing

    NASA Astrophysics Data System (ADS)

    Kordyum, E.; Kalinina, Ia.; Bogatina, N.; Kondrachuk, A.

    Roots exhibit positive gravitropism they grow in the direction of a gravitational vector while shoots respond negatively and grow opposite to a gravitational vector We first demonstrated the inversion of roots gravitropism from positive to negative one under gravistimulation in the weak combined magnetic field WCMF consisted of permanent magnetic field PMF with the magnitude of order of 50 mu T and altering magnetic field AMF with the 6 mu T magnitude and a frequency of 32 Hz It was found that the effect of inversion has a resonance nature It means that in the interval of frequencies 1-45 Hz inversion of root gravitropism occurs only at frequency 32 Hz 2-3-day old cress seedlings were gravistimulated in moist chambers which are placed in mu -metal shields Inside mu -metal shields combined magnetic fields have been created The magnitude of magnetic fields was measured by a flux-gate magnetometer Experiments were performed in darkness at temperature 20 pm 1 0 C We measured the divergence angle of a growing root from its horizontal position After 1 h of gravistimulation in the WCMF we observed negative gravitropism of cress roots i e they grow in the opposite direction to a gravitational vector Frequency of 32 Hz for the magnitude of the PMF applied formally corresponds to cyclotron frequency of Ca 2 ions This indicates possible participation of calcium ions in root gravitropism There are many evidences of resonance effects of the WCMF on the biological processes that involve Ca 2 but the nature of

  14. Electrostatic electron cyclotron harmonic instability near Ganymede

    NASA Astrophysics Data System (ADS)

    Tripathi, A. K.; Singhal, R. P.; Singh, K. P.; Singh, O. N.

    2014-08-01

    Jupiter's moon—Ganymede—is the largest satellite in our solar system. Galileo spacecraft made six close flybys to explore Ganymede. More information was acquired about particle population, magnetic field and plasma waves during these encounters. In this paper, our aim is to study the generation of electrostatic electron cyclotron harmonic (ECH) emissions in the vicinity of Ganymede using the observed particle data. The calculated ECH wave's growth rates are analyzed in the light of observations of plasma waves along the path of Galileo near Ganymede. Dispersion relation for electrostatic mode is solved to obtain the temporal growth rates. A new electron distribution function, fitted to distribution observed near Ganymede, is used in the calculations. A parametric study is performed to evaluate the effect of loss-cone angle and the ratio of plasma to gyro-frequency on growth rates. It is found that ECH waves growth rates generally decrease as the loss-cone angle is increased. However, the ratio plasma to gyro-frequency has almost no effect on the growth rates. These parameters vary considerably along the Galileo trajectory near Ganymede. This is the first study which relates the occurrence of ECH waves with the particle and magnetic field data in the vicinity of Ganymede. The study of ECH wave growth rate near Ganymede is important for the calculation of pitch angle scattering rates of low-energy electrons and their subsequent precipitation into the thin atmosphere of Ganymede producing ultraviolet emissions. Results of the present study may also be relevant for the upcoming JUNO and JUICE missions to Jupiter.

  15. Issues in the analysis and interpretation of cyclotron lines in gamma ray bursts

    NASA Technical Reports Server (NTRS)

    Lamb, D. Q.

    1992-01-01

    The Bayesian approach is discussed to establishing the existence of lines, the importance of observing multiple cyclotron harmonics in determining physical parameters from the lines, and evidence from cyclotron lines of neutron star rotation.

  16. 75 FR 48939 - National Superconducting Cyclotron Laboratory of Michigan State University; Notice of Decision on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-12

    ... International Trade Administration National Superconducting Cyclotron Laboratory of Michigan State University... pursuant to Section 6(c) of the Educational, Scientific, and Cultural Materials Importation Act of 1966...., NW., Washington, DC. Docket Number: 10-043. Applicant: National Superconducting Cyclotron Laboratory...

  17. Precision phase control for the radio frequency system of K500 superconducting cyclotron at Variable Energy Cyclotron Centre, Kolkata

    SciTech Connect

    Som, Sumit; Ghosh, Surajit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Roy, Suprakash

    2013-11-15

    Variable Energy Cyclotron Centre (VECC) has commissioned K500 Superconducting cyclotron (SCC) based on MSU and Texas A and M university cyclotrons. The radio frequency (RF) system of SCC has been commissioned with the stringent requirement of various RF parameters. The three-phase RF system of Superconducting cyclotron has been developed in the frequency range 9–27 MHz with amplitude and phase stability of 100 ppm and ±0.1°, respectively. The phase control system has the option to change the relative phase difference between any two RF cavities and maintain the phase stability within ±0.1° during round-the-clock cyclotron operation. The said precision phase loop consists of both analogue In-phase/Quadrature modulator to achieve faster response and also Direct Digital Synthesis based phase shifter to achieve wide dynamic range as well. This paper discusses detail insights into the various issues of phase control for the K500 SCC at VECC, Kolkata.

  18. Simultaneous observations of electrostatic oxygen cyclotron waves and ion conics

    NASA Technical Reports Server (NTRS)

    Kintner, P. M.; Scales, W.; Vago, J.; Arnoldy, R.; Garbe, G.; Moore, T.

    1989-01-01

    A sounding rocket launched to 927 km apogee during an auroral substorm encountered regions of large quasi-static electric fields (not greater than 400 mV/m), ion conics (up to 700 eV maximum observed energy), and fluctuating electric fields near the oxygen cyclotron frequency. Since the fluctuating electric fields frequently exhibited spectral peaks just above the local oxygen cyclotron frequency, and since the fluctuating electric fields were linearly polarized, they are positively identified as electrostatic oxygen cyclotron waves (EOCW). The maximum amplitude of the EOCW was about 5 mV/m rms. The EOCW closely correlated with the presence of ion conics. Because of the relatively low amplitude of the EOCW and their relatively low coherence, it cannot be concluded that they are solely responsible for the production of the ion conics.

  19. Spectra and Neutron Dosimetry Inside a PET Cyclotron Vault Room

    SciTech Connect

    Vega-Carrillo, Hector Rene; Mendez, Roberto; Iniguez, Maria Pilar; Marti-Climent, Joseph; Penuelas, Ivan; Barquero, Raquel

    2006-09-08

    The neutron field around a PET cyclotron was investigated during 18F radioisotope production with an 18 MeV proton beam. Pairs of thermoluminescent dosemeters, TLD600 and TLD700, were used as thermal neutron detector inside a Bonner Spheres Spectrometer to measure the neutron spectra at three different positions inside the cyclotron's vault room. Neutron spectra were also determined by Monte Carlo calculations. The hardest spectrum was observed in front of cyclotron target and the softest was noticed at the antipode of target. Neutron doses derived from the measured spectra vary between 11 and 377 mSv/{mu}A-h of proton integrated current, Doses were also measured with a single-moderator remmeter, with an active thermal neutron detector, whose response in affected by the radiation field in the vault room.

  20. Radiation effects testing at the 88-inch cyclotron at LBNL

    SciTech Connect

    McMahan, Margaret A.; Koga, Rokotura

    2001-10-09

    The effects of ionizing particles on sensitive microelectronics is an important component of the design of systems as diverse as satellites and space probes, detectors for high energy physics experiments and even internet server farms. Understanding the effects of radiation on human cells is an equally important endeavor directed towards future manned missions in space and towards cancer therapy. At the 88-Inch Cyclotron at the Berkeley Laboratory, facilities are available for radiation effects testing (RET) with heavy ions and with protons. The techniques for doing these measurements and the advantages of using a cyclotron will be discussed, and the Cyclotron facilities will be compared with other facilities worldwide. RET of the same part at several facilities of varying beam energy can provide tests of the simple models used in this field and elucidate the relative importance of atomic and nuclear effects. The results and implications of such measurements will be discussed.

  1. Design study of the KIRAMS-430 superconducting cyclotron magnet

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Wook; Kang, Joonsun; Hong, Bong Hwan; Jung, In Su

    2016-07-01

    Design study of superconducting cyclotron magnet for the carbon therapy was performed at the Korea Institute of Radiological and Medical Science (KIRAMS). The name of this project is The Korea Heavy Ion Medical Accelerator (KHIMA) project and a fixed frequency cyclotron with four spiral sector magnet was one of the candidate for the accelerator type. Basic parameters of the cyclotron magnet and its characteristics were studied. The isochronous magnetic field which can guide the 12C6+ ions up to 430 MeV/u was designed and used for the single particle tracking simulation. The isochronous condition of magnetic field was achieved by optimization of sector gap and width along the radius. Operating range of superconducting coil current was calculated and changing of the magnetic field caused by mechanical deformations of yokes was considered. From the result of magnetic field design, structure of the magnet yoke was planned.

  2. Alfven ion-cyclotron heating of ionospheric O(+) ions

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Sydora, R. D.; Ashour-Abdalla, M.

    1988-01-01

    Transversely heated ionospheric ions, in particular O(+) ions, are often observed flowing upward along auroral field lines. Currents observed in association with the transversely heated ions can drive shear Alfven waves and electrostatic ion-cyclotron waves unstable which can, in turn, be resonantly absorbed by the ions to produce the heating. Particle simulations are used to examine self-consistently the excitation of these waves and the associated heating. It is shown that the growth of the electrostatic ion-cyclotron waves quickly becomes suppressed as the ions become heated and the dominant wave fields are those of the shear Alfven wave. The resultant transverse ion heating is larger and faster than that produced by solely electrostatic ion-cyclotron wave heating. Due to trapping of ions by the shear Alfven wave, the temperature of the O(+) ions remains comparable to that of the H(+) ions.

  3. The electron-cyclotron maser for astrophysical application

    NASA Astrophysics Data System (ADS)

    Treumann, Rudolf A.

    2006-08-01

    The electron-cyclotron maser is a process that generates coherent radiation from plasma. In the last two decades, it has gained increasing attention as a dominant mechanism of producing high-power radiation in natural high-temperature magnetized plasmas. Originally proposed as a somewhat exotic idea and subsequently applied to include non-relativistic plasmas, the electron-cyclotron maser was considered as an alternative to turbulent though coherent wave-wave interaction which results in radio emission. However, when it was recognized that weak relativistic corrections had to be taken into account in the radiation process, the importance of the electron-cyclotron maser rose to the recognition it deserves. Here we review the theory and application of the electron-cyclotron maser to the directly accessible plasmas in our immediate terrestrial and planetary environments. In situ access to the radiating plasmas has turned out to be crucial in identifying the conditions under which the electron-cyclotron maser mechanism is working. Under extreme astrophysical conditions, radiation from plasmas may provide a major energy loss; however, for generating the powerful radiation in which the electron-cyclotron maser mechanism is capable, the plasma must be in a state where release of susceptible amounts of energy in the form of radiation is favorable. Such conditions are realized when the plasma is unable to digest the available free energy that is imposed from outside and stored in its particle distribution. The lack of dissipative processes is a common property of collisionless plasmas. When, in addition, the plasma density becomes so low that the amount of free energy per particle is large, direct emission becomes favorable. This can be expressed as negative absorption of the plasma which, like in conventional masers, leads to coherent emission even though no quantum correlations are involved. The physical basis of this formal analogy between a quantum maser and the

  4. Cyclotron motion of a charged particle with anisotropic mass

    NASA Astrophysics Data System (ADS)

    Ciftja, Orion; Livingston, Victoria; Thomas, Elsa

    2017-05-01

    The cyclotron motion of a charged particle subject to a uniform magnetic field is thoroughly described in many classical physics textbooks. Although the assumption of a particle with isotropic mass is taken for granted in classical physics, a key concept in condensed matter physics is that of particles with an effective anisotropic mass, such as electrons in the context of band structure studies of solids. Since some exposure to the concept of anisotropic mass is important within the framework of classical physics, here we consider the cyclotron motion of a charged particle with anisotropic mass in the presence of a uniform magnetic field. The exact solution of this problem exposes a broad audience of readers to concepts in condensed matter physics that are rarely mentioned within the framework of classical physics. Key ideas on the topic are illustrated in a pedagogical way by considering specific examples that show how an anisotropic mass modifies the cyclotron motion of a charged particle.

  5. The next generation of electron cyclotron emission imaging diagnostics (invited).

    PubMed

    Zhang, P; Domier, C W; Liang, T; Kong, X; Tobias, B; Shen, Z; Luhmann, N C; Park, H; Classen, I G J; van de Pol, M J; Donné, A J H; Jaspers, R

    2008-10-01

    A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T(e) profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities far beyond what has been achieved to date. These include the development of a minilens array configuration with increased sensitivity antennas, a new local oscillator pumping scheme, enhanced electron cyclotron resonance heating shielding, and a highly flexible optical design with vertical zoom capability. Horizontal zoom and spot size (rf bandwidth) capabilities are also being developed with new ECEI electronics. An interface module is under development to remotely control all key features of the new ECEI instrument, many of which can be changed during a plasma discharge for maximum flexibility.

  6. The next generation of electron cyclotron emission imaging diagnostics (invited)

    SciTech Connect

    Zhang, P.; Domier, C. W.; Liang, T.; Kong, X.; Tobias, B.; Shen, Z.; Luhmann, N. C. Jr.; Park, H.; Classen, I. G. J.; Pol, M. J. van de; Donne, A. J. H.; Jaspers, R.

    2008-10-15

    A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T{sub e} profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities far beyond what has been achieved to date. These include the development of a minilens array configuration with increased sensitivity antennas, a new local oscillator pumping scheme, enhanced electron cyclotron resonance heating shielding, and a highly flexible optical design with vertical zoom capability. Horizontal zoom and spot size (rf bandwidth) capabilities are also being developed with new ECEI electronics. An interface module is under development to remotely control all key features of the new ECEI instrument, many of which can be changed during a plasma discharge for maximum flexibility.

  7. Proton and helium cyclotron anisotropy instability thresholds in the magnetosheath

    NASA Technical Reports Server (NTRS)

    Gary, S. Peter; Convery, Patrick D.; Denton, Richard E.; Fuselier, Stephen A.; Anderson, Brian J.

    1994-01-01

    Both the protons and the helium ions of the terrestrial magnetosheath typically display T (sub perpendicular) greater than T (sub parallel), where perpendicular to and parallel to denote directions perpendicular and parallel to the background magnetic field. Observations of the highly compressed magnetosheath show an inverse correlation between these ion temperature anisotropies and the parallel proton beta. Computer simulations have demonstrated that these correlations are due to wave-particle scattering by electromagnetic ion cyclotron anisotropy instabilities. These correlations correspond to linear theory thresholds of the proton cyclotron and the helium cyclotron instabilities. This paper uses linear Vlasov theory and the assumption of a constant maximum growth rate to obtain closed-form expressions for these thresholds as a function of the relative helium density and the parallel proton beta in a parameter model of the magnetosheath.

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

    PubMed

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

    2011-05-01

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

  9. The Origin of Narrow Band Cyclotron Wave Emissions Called Chorus

    NASA Astrophysics Data System (ADS)

    Skoug, Ruth Marie

    1995-01-01

    On May 6, 1993, a sounding rocket experiment designed to study microburst electron precipitation was launched from Poker Flat, Alaska, into a morningside auroral event. This was the first sounding rocket to simultaneously detect microburst electrons and associated very low frequency (VLF) waves. Both microbursts and narrow band VLF chorus (risers) were observed throughout the flight. Waves and electron bursts were observed in association with each other, but no one-to-one correlations were seen between the two phenomena. The association between waves and particles suggests that both phenomena may be produced by a wave -particle interaction. This dissertation discusses the design of the VLF wave antenna, a magnetic search coil, and the analysis of data from this instrument. The data are compared to chorus production theories to determine the source location and mechanism of the observed waves. In this work, the observed chorus emissions are interpreted in terms of a cyclotron resonance interaction. This is the first comprehensive test of the cyclotron resonance theory applied to chorus associated with microburst precipitation. The frequency range of the risers and the observed electron energy range agree with those required to satisfy the cyclotron resonance condition. Using a criterion derived from the conservation of energy during an interaction, it is determined that a cold plasma cyclotron resonance interaction could have produced only the lower frequency portions of the observed chorus risers. We present an extension of the cyclotron resonance theory which uses a warm plasma model of the wave-particle interaction. This model assumes a two-component plasma, with an isotropic cold component and a bi-Maxwellian warm component. The addition of the warm component produces sufficient changes in the wave dispersion relation that the interaction can produce the highest frequencies observed in our data set. As predicted by theory, an anisotropic plasma is required to

  10. Electron Cyclotron Emissions from AN Electron Cyclotron Heated Discharge in Isx-B

    NASA Astrophysics Data System (ADS)

    Elder, Gerald Blaine

    1983-09-01

    Observation of the electron cyclotron emissions (ECE) at both optically thick and optically thin frequencies can be a very useful tool in studying the behavior of the electron distribution. It is especially effective when studying the effects of electron cyclotron heating (ECH). Two detectors were built to observe the optically thin third harmonic radiation from ISX-B during the recent 28 GHz ECH experiments carried on at Oak Ridge National Laboratory. These detectors supplemented existing detectors at the fundamental frequency and at the second harmonic frequency. Observations of the three frequencies during and after the ECH was pulsed into the plasma showed an unexpected rise in their intensity, occurring after the ECH pulse was over. This rise lasted for many tens of milliseconds, well beyond estimates of the electron energy confinement time. The rise in the third harmonic intensity was frequently to an intensity 100 times greater than the pre-ECH intensity. The fundamental frequency and the second harmonic had a much milder change in their intensities. The rises were seen to depend critically on the density of the plasma and the length of the ECH pulse but only weakly on the pre-ECH temperature. A computer code which predicts the ECE from an electron distribution in ISX-B, taking into account the effect of the plasma's dielectric response to the emissions from a single electron, is developed. This code is the result of combining a ray tracing technique with the emissions from a single dressed test particle and summing over the electron distribution. The code confirms the sensitivity of the third harmonic emissions to small changes in the electron distribution. A Fokker-Planck code is combined with the emission code to predict the evolution of the ECE from a perturbed electron distribution. The codes clearly show that the rises in the emissions observed by the three detectors can be reasonably explained by consideration of the effect of pitch angle scattering

  11. Backward wave cyclotron-maser emission in the auroral magnetosphere.

    PubMed

    Speirs, D C; Bingham, R; Cairns, R A; Vorgul, I; Kellett, B J; Phelps, A D R; Ronald, K

    2014-10-10

    In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's auroral region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity. We also show that the radiation is preferentially amplified along the auroral oval rather than transversely. The results are in agreement with recent Cluster observations.

  12. A 600 MeV cyclotron for radioactive beam production

    SciTech Connect

    Clark, D.J.

    1993-05-17

    The magnetic field design for a 600 MeV proton cyclotron is described. The cyclotron has a single stage, a normal conducting magnet coil and a 9.8 m outside yoke diameter. It has 8 sectors, with a transition to 4 sectors in the center region. The magnetic field design was done using 1958 Harwell rectangular ridge system measurements and was compared with recent 3-dimensional field calculations with the program TOSCA at NSCL. The center region 4--8 sector transition focussing was also checked with TOSCA.

  13. N-bursty emission from Uranus: A cyclotron maser source?

    NASA Technical Reports Server (NTRS)

    Curran, D. B.; Menietti, J. D.

    1993-01-01

    Ray tracing studies of RX-mode emission from the north polar regions of Uranus indicate that the n-bursty radio emission may have a source along field lines with footprints near the northern magnetic pole (perhaps in the cusp), but not necessarily associated with regions of strong UV emission. This is in contrast with similar studies for the Uranus nightside smooth radio emission, which are believed to be due to the cyclotron maser instability. Source regions can be found for both hollow and filled emission cones and for frequencies well above the local gyrofreuquency implying that mechanisms other than the cyclotron maser mechanism may be operating.

  14. RF cavity design for KIRAMS-430 superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Jung, In Su; Hong, Bong Hwan; Kang, Joonsun; Kim, Hyun Wook; Kim, Chang Hyeuk; Kwon, Key Ho

    2015-03-01

    The Korea Heavy Ion Medical Accelerator (KHIMA) has developed a superconducting cyclotron for the carbon therapy, which is called KIRAMS-430. The cyclotron is designed to accelerate only 12C6+ ions up to the energy of 430 MeV/u. It uses two normal conducting RF cavities. The RF frequency is about 70.76 MHz. The nominal dee voltage is 70 kV at the center and 160 kV at the extraction. The RF cavity was designed with 4 stems by using CST microwave studio (MWS). In this paper, we represent the simulation results and the optimized design of the RF cavity for the KIRAMS-430.

  15. Electron cyclotron emission diagnostics on the large helical device

    NASA Astrophysics Data System (ADS)

    Nagayama, Y.; Kawahata, K.; England, A.; Ito, Y.; Bretz, N.; McCarthy, M.; Taylor, G.; Doane, J.; Ikezi, H.; Edlington, T.; Tomas, J.

    1999-01-01

    The electron cyclotron emission (ECE) diagnostic system is installed on the large helical device (LHD). The system includes the following instruments: a heterodyne radiometer, a Michelson spectrometer, and a grating polychromator. A 63.5 mm corrugated waveguide system is fully utilized. Large collection optics and notch filters at the frequency of the LHD electron cyclotron heating (ECH) were developed for this system. In addition to these filters, the rectangular waveguide notch filters, the ECE measurement with the radiometer has been successfully performed during the ECH.

  16. Fluid equations in the presence of electron cyclotron current drive

    NASA Astrophysics Data System (ADS)

    Jenkins, Thomas G.; Kruger, Scott E.

    2012-12-01

    Two-fluid equations, which include the physics imparted by an externally applied radiofrequency source near electron cyclotron resonance, are derived in their extended magnetohydrodynamic forms using the formalism of Hegna and Callen [Phys. Plasmas 16, 112501 (2009)]. The equations are compatible with the closed fluid/drift-kinetic model developed by Ramos [Phys. Plasmas 17, 082502 (2010); 18, 102506 (2011)] for fusion-relevant regimes with low collisionality and slow dynamics, and they facilitate the development of advanced computational models for electron cyclotron current drive-induced suppression of neoclassical tearing modes.

  17. Single-Electron Detection and Spectroscopy via Relativistic Cyclotron Radiation.

    PubMed

    Asner, D M; Bradley, R F; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thümmler, T; VanDevender, B A; Woods, N L

    2015-04-24

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Although first derived in 1904, cyclotron radiation from a single electron orbiting in a magnetic field has never been observed directly. We demonstrate single-electron detection in a novel radio-frequency spectrometer. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay end point, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments.

  18. Analysis of gamma-ray burst spectra with cyclotron lines

    NASA Technical Reports Server (NTRS)

    Kargatis, Vincent; Liang, Edison P.

    1992-01-01

    Motivated by the recent developments in the cyclotron resonance upscattering of soft photons or CUSP model of Gamma Ray Burst (GBR) continuum spectra, we revisit a select database of GRBs with credible cyclotron absorption features. We measure the break energy of the continuum, the slope below the break and deduce the soft photon energy or the electron beam Lorentz factor cutoff. We study the correlation (or lack of) between various parameters in the context of the CUSP model. One surprise result is that there appears to be marginal correlation between the break energy and the spectral index below the break.

  19. Cyclotron modes of a multi-species ion plasma

    SciTech Connect

    Sarid, E.; Anderegg, F.; Driscoll, C. F.

    1995-04-15

    Cyclotron modes varying as exp(il{theta}), with l=1, 2 and 3, have been observed in an unneutralized Mg ion plasma. The l=1 mode is observed to be down-shifted from the corresponding cyclotron frequency, while the l{>=}2 modes are found to be up-shifted. Good agreement is found between the observed down-shifts of the l=1 modes of Mg{sup +} and Mg{sup ++} and the predictions of a multi-species cold plasma theory. The down-shifts depend on the composition and size of the plasma, and the relative abundance of each ion can thus be determined.

  20. Electron cyclotron heating experiments on the DIII-D tokamak

    SciTech Connect

    Prater, R.; Austin, M.E.; Bernabei, S.

    1998-01-01

    Initial experiments on heating and current drive using second harmonic electron cyclotron heating (ECH) are being performed on the DIII-D tokamak using the new 110 GHz ECH system. Modulation of the ECH power in the frequency range 50 to 300 Hz and detection of the temperature perturbation by ECE diagnostics is used to validate the location of the heating. This technique also determines an upper bound on the width of the deposition profile. Analysis of electron cyclotron current drive indicates that up to 0.17 MA of central current is driven, resulting in a negative loop voltage near the axis.

  1. Fluid equations in the presence of electron cyclotron current drive

    SciTech Connect

    Jenkins, Thomas G.; Kruger, Scott E.

    2012-12-15

    Two-fluid equations, which include the physics imparted by an externally applied radiofrequency source near electron cyclotron resonance, are derived in their extended magnetohydrodynamic forms using the formalism of Hegna and Callen [Phys. Plasmas 16, 112501 (2009)]. The equations are compatible with the closed fluid/drift-kinetic model developed by Ramos [Phys. Plasmas 17, 082502 (2010); 18, 102506 (2011)] for fusion-relevant regimes with low collisionality and slow dynamics, and they facilitate the development of advanced computational models for electron cyclotron current drive-induced suppression of neoclassical tearing modes.

  2. Electron cyclotron current drive efficiency in general tokamak geometry

    SciTech Connect

    Lin-Liu, Y. R.; Chan, V. S.; Prater, R.

    2003-01-01

    Green's-function techniques are used to calculate electron cyclotron current drive (ECCD) efficiency in general tokamak geometry in the low-collisionality regime. Fully relativistic electron dynamics is employed in the theoretical formulation. The high-velocity collision model is used to model Coulomb collisions and a simplified quasi-linear rf diffusion operator describes wave-particle interactions. The approximate analytic solutions which are benchmarked with a widely used ECCD model, facilitate time-dependent simulations of tokamak operational scenarios using the non-inductive current drive of electron cyclotron waves.

  3. Performance of the beam chamber vacuum system of K = 500 cyclotron at Variable Energy Cyclotron Centre Kolkata.

    PubMed

    Pal, Gautam; DuttaGupta, Anjan; Chakrabarti, Alok

    2014-07-01

    The beam chamber of Variable Energy Cyclotron Centre, Kolkata's K = 500 superconducting cyclotron is pumped by liquid helium cooled cryopanel with liquid nitrogen cooled radiation shield. Performance of the vacuum system was evaluated by cooling the cryopanel assembly with liquid nitrogen and liquid helium. Direct measurement of beam chamber pressure is quite difficult because of space restrictions and the presence of high magnetic field. Pressure gauges were placed away from the beam chamber. The beam chamber pressure was evaluated using a Monte Carlo simulation software for vacuum system and compared with measurements. The details of the vacuum system, measurements, and estimation of pressure of the beam chamber are described in this paper.

  4. Electron-cyclotron-heating experiments in tokamaks and stellarators

    SciTech Connect

    England, A.C.

    1983-01-01

    This paper reviews the application of high-frequency microwave radiation to plasma heating near the electron-cyclotron frequency in tokamaks and stellarators. Successful plasma heating by microwave power has been demonstrated in numerous experiments. Predicted future technological developments and current theoretical understanding suggest that a vigorous program in plasma heating will continue to yield promising results.

  5. Cyclotron Resonance of Electrons Trapped in a Microwave Cavity

    ERIC Educational Resources Information Center

    Elmore, W. C.

    1975-01-01

    Describes an experiment in which the free-electron cyclotron resonance of electrons trapped in a microwave cavity by a Penning trap is observed. The experiment constitutes an attractive alternative to one of the Gardner-Purcell variety. (Author/GS)

  6. Cyclotron maser emission of auroral Z mode radiation

    NASA Technical Reports Server (NTRS)

    Melrose, D. B.; Hewitt, R. G.; Dulk, G. A.

    1983-01-01

    Results are presented suggesting that loss cone driven cyclotron maser emission by upgoing electrons, closely analogous to auroral kilometric radiation (AKR), may be the mechanism behind the observed Z mode radiation. With this hypothesis, the lack of a strong correlation between the Z mode radiation and AKR is not surprising; the ray paths for the X mode and the Z mode are markedly different, with the former directed upward and the latter downward. In addition, it is expected that the generation of the Z mode will be favored only in regions where the ratio of the plasma frequency to the electron cyclotron frequency is greater than or approximately equal to 0.3, that is, where the X mode radiation is suppressed. If the fraction of the radiation generated that crosses the cyclotron layer is large, then the argument in favor of the loss cone driven cyclotron maser as the source of the observed Z mode radiation is a strong one. The spatial growth rates are fairly large in comparison with those for the X mode, and there seems to be little doubt that Z mode radiation should be generated under conditions that differ only slightly from those for the generation of X mode radiation in AKR.

  7. Digital control in LLRF system for CYCIAE-100 cyclotron

    NASA Astrophysics Data System (ADS)

    Yin, Zhiguo; Fu, Xiaoliang; Ji, Bin; Zhang, Tianjue; Wang, Chuan

    2016-05-01

    As a driven accelerator, the CYCIAE-100 cyclotron is designed by China Institute of Atomic Energy for the Beijing Radio Ion-beam Facility project. The cyclotron RF system is designed to use two RF power sources of 100 kW to drive two half-wavelength cavities respectively. Two Dee accelerating electrodes are kept separately from each other inside the cyclotron, while their accelerating voltages are maintained in phase by the efforts of LLRF control. An analog-digital hybrid LLRF system has been developed to achieve cavity tuning control, dee voltage amplitude and phase stabilization etc. The analog subsystems designs are focused on RF signal up/down conversion, tuning control, and dee voltage regulation. The digital system provides an RF signal source, aligns the cavity phases and maintains a Finite State Machine. The digital parts combine with the analog functions to provide the LLRF control. A brief system hardware introduction will be given in this paper, followed by the review of several major characteristics of the digital control in the 100 MeV cyclotron LLRF system. The commissioning is also introduced, and most of the optimization during the process was done by changing the digital parts.

  8. Nonlinear analysis of a relativistic beam-plasma cyclotron instability

    NASA Technical Reports Server (NTRS)

    Sprangle, P.; Vlahos, L.

    1986-01-01

    A self-consistent set of nonlinear and relativistic wave-particle equations are derived for a magnetized beam-plasma system interacting with electromagnetic cyclotron waves. In particular, the high-frequency cyclotron mode interacting with a streaming and gyrating electron beam within a background plasma is considered in some detail. This interaction mode may possibly find application as a high-power source of coherent short-wavelength radiation for laboratory devices. The background plasma, although passive, plays a central role in this mechanism by modifying the dielectric properties in which the magnetized electron beam propagates. For a particular choice of the transverse beam velocity (i.e., the speed of light divided by the relativistic mass factor), the interaction frequency equals the nonrelativistic electron cyclotron frequency times the relativistic mass factor. For this choice of transverse beam velocity the detrimental effects of a longitudinal beam velocity spread is virtually removed. Power conversion efficiencies in excess of 18 percent are both analytically calculated and obtained through numerical simulations of the wave-particle equations. The quality of the electron beam, degree of energy and pitch angle spread, and its effect on the beam-plasma cyclotron instability is studied.

  9. Parametric decay of an electromagnetic wave near electron cyclotron harmonics

    SciTech Connect

    Istomin, Y.N.; Leyser, T.B.

    1995-06-01

    A system of equations describing the nonlinear coupling of high frequency electron Bernstein (EB) and upper hybrid (UH) waves near harmonics of the electron cyclotron frequency with low frequency lower hybrid (LH) waves in a homogeneous, weakly magnetized, and weakly collisional plasma is derived. The EB and UH modes are described by a single second order equation, taking into account the interaction with low frequency density fluctuations. The ponderomotive force of the high frequency oscillations increases near the cyclotron harmonics due to the resonance with the electron motion. The obtained equations are used to study the parametric decay of an infinite wavelength electromagnetic pump wave into EB or UH waves and LH waves. The threshold electric fields are sufficiently low to be exceeded in high frequency ionospheric modification experiments. However, the instability cannot be excited for pump frequencies near the cyclotron harmonics. For the decay into EB waves, the resulting forbidden frequency range depends on the harmonic number in a power law manner, consistent with observations of stimulated electromagnetic emissions in ionospheric modification experiments. Further, for sufficiently high pump electric fields the instability is also suppressed, when the frequency mismatch around the eigenfrequencies at which the interaction can occur is of the order of the frequency separation between the EB and UH modes near the cyclotron harmonics. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  10. Cyclotron targetry for production of short-lived positron emitters

    SciTech Connect

    Schlyer, D.J.

    1989-01-01

    The basic concepts of cyclotron target design are presented along with the relevant practical experience gained by workers in this field over the years. Results are presented from several recent studies on the temperature and density distribution inside gas and liquid targets. 5 refs., 3 figs.

  11. An intense alpha ion source for INRS cyclotron

    SciTech Connect

    Chen Ling,-xing; Chen Mao-bei

    1985-10-01

    An intense PIG alpha source for INRS has been developed with low arc power and low gas flow. Generally, the alpha yield of the new source is twice as much as the old one. The structure and character of the source and its experimental results both on the bench and cyclotron are described in this paper.

  12. Electron cyclotron thruster new modeling results preparation for initial experiments

    NASA Technical Reports Server (NTRS)

    Hooper, E. Bickford

    1993-01-01

    The following topics are discussed: a whistler-based electron cyclotron resonance heating (ECRH) thruster; cross-field coupling in the helicon approximation; wave propagation; wave structure; plasma density; wave absorption; the electron distribution function; isothermal and adiabatic plasma flow; ECRH thruster modeling; a PIC code model; electron temperature; electron energy; and initial experimental tests. The discussion is presented in vugraph form.

  13. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 35

    SciTech Connect

    Not Available

    1986-10-29

    Efforts are reported on the installation and checkout of cyclotron components which had been previously fabricated. Final integration of subsystems and major systems leading to internal beam tests is reported near completion. Progress is reported in relation to control system components, focus and steering magnet design, and rf system testing. (LEW)

  14. Cyclotron waves in a non-neutral plasma column

    SciTech Connect

    Dubin, Daniel H. E.

    2013-04-15

    A kinetic theory of linear electrostatic plasma waves with frequencies near the cyclotron frequency {Omega}{sub c{sub s}} of a given plasma species s is developed for a multispecies non-neutral plasma column with general radial density and electric field profiles. Terms in the perturbed distribution function up to O(1/{Omega}{sub c{sub s}{sup 2}}) are kept, as are the effects of finite cyclotron radius r{sub c} up to O(r{sub c}{sup 2}). At this order, the equilibrium distribution is not Maxwellian if the plasma temperature or rotation frequency is not uniform. For r{sub c}{yields}0, the theory reproduces cold-fluid theory and predicts surface cyclotron waves propagating azimuthally. For finite r{sub c}, the wave equation predicts that the surface wave couples to radially and azimuthally propagating Bernstein waves, at locations where the wave frequency equals the local upper hybrid frequency. The equation also predicts a second set of Bernstein waves that do not couple to the surface wave, and therefore have no effect on the external potential. The wave equation is solved both numerically and analytically in the WKB approximation, and analytic dispersion relations for the waves are obtained. The theory predicts that both types of Bernstein wave are damped at resonances, which are locations where the Doppler-shifted wave frequency matches the local cyclotron frequency as seen in the rotating frame.

  15. Ion cyclotron waves below the proton gyrofrequency in the magnetosphere

    SciTech Connect

    Gomberoff, L.; Molina, M.

    1985-02-01

    A numerical comparison between the linear theory of ion-cyclotron waves below the proton gyrofrequency and the data recorded on board the GEOS satellites is made. It is shown that the experimental data are in good agreement with the theory.

  16. Status of ECR (Electron Cyclotron Resonance) source technology

    SciTech Connect

    Lyneis, C.M.

    1987-03-01

    ECR (Electron Cyclotron Resonance) ion sources are now in widespread use for the production of high quality multiply charged ion beams for accelerators and atomic physics experiments, and industrial applications are being explored. Several general characteristics of ECR sources explain their widespread acceptance. For use with cyclotrons which require CW multiply charged ion beams, the ECR source has many advantages over heavy-ion PIG sources. Most important is the ability to produce higher charge states at useful intensities for nuclear physics experiments. Since the maximum energy set by the bending limit of a cyclotron scales with the square of the charge state, the installation of ECR sources on cyclotrons has provided an economical path to raise the energy. Another characteristic of ECR sources is that the discharge is produced without cathodes, so that only the source material injected into an ECR source is consumed. As a result, ECR sources can be operated continuously for periods of weeks without interruption. Techniques have been developed in the last few years, which allow these sources to produce beams from solid materials. The beam emittance from ECR sources is in the range of 50 to 200 ..pi.. mm-mrad at 10 kV. The principles of ECR ion sources are discussed, and present and future ECR sources are reviewed.

  17. Silicon meets cyclotron: muon spin resonance of organosilicon radicals.

    PubMed

    West, Robert; Samedov, Kerim; Percival, Paul W

    2014-07-21

    Muons, generated at a high-powered cyclotron, can capture electrons to form muonium atoms. Muon spin resonance spectra can be recorded for organosilyl radicals obtained by addition of muonium atoms to silylenes and silenes. We present a brief summary of progress in this new area since the first such experiments were reported in 2008.

  18. Axial injection and phase selection studies of the MSU K1200 cyclotron

    SciTech Connect

    Bailey, J.D. |

    1995-12-31

    Axial injection into a cyclotron through its iron yoke, a spiral inflector, and the central region electrodes couples the transverse coordinates of motion together, as well as with the longitudinal coordinates. The phase slits in the K1200 cyclotron use the r - {phi} correlations inherent in acceleration of ions in a cyclotron. Computer simulations of injection into and acceleration within the K1200 cyclotron encompassing the four transverse dimensions together with time were used to determine beam matching requirements for injection and phase selection in the K1200 cyclotron. The simulations were compared with measurements using an external timing detector.

  19. VASIMR Simulation Studies of Auroral Ion Cyclotron Heating

    NASA Astrophysics Data System (ADS)

    Brukardt, M.; Bering, E. A.; Chang-Diaz, F. R.; Squire, J. P.; Glover, T. W.; Jacobs0n, V. T.; McCaskill, G. E.; Cassady, L. D.; Bengtson, R. D.

    2006-12-01

    Plasma physics has found an increasing range of practical industrial applications, including the development of electric spacecraft propulsion systems. One of these systems, the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine, both applies and can be used to simulate several important physical processes occurring in the magnetosphere. These processes include the mechanisms involved in the ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Auroral current region processes that are simulated in VASIMR include lower hybrid heating, parallel electric field acceleration and ion cyclotron acceleration. This paper will focus on using a physics demonstration model VASIMR to study ion cyclotron heating (ICRH) similar to auroral zone processes. The production of upward moving `ion conics' and ion heating are significant features in auroral processes. It is believed that ion cyclotron heating plays a role in these processes, but laboratory simulation of these auroral effects is difficult owing to the fact that the ions involved only pass through the acceleration region once. In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) we have successfully simulated these effects. The current configuration of the VASIMR uses a helicon antenna with up to 20 kW of power to generate plasma then uses an RF booster stage that uses left hand polarized slow mode waves launched from the high field side of the resonance. The current setup for the booster uses 2 to 4 MHz waves with up to 20 kW of power. This is similar to the ion cyclotron heating in tokamaks, but in the VASIMR the ions only pass through the resonance region once. The rapid absorption of ion cyclotron waves has been predicted in recent theoretical studies. These theoretical predictions have been confirmed with several independent measurements. The ion cyclotron resonance heating (ICRH) shows a substantial increase in ion velocity. Pitch angle distribution studies

  20. Use of cyclotrons in medical research: Past, present, future

    NASA Astrophysics Data System (ADS)

    Smathers, James B.; Myers, Lee T.

    1985-05-01

    The use of cyclotrons in medical research started in the late 1930s with the most prominent use being neutron irradiation in cancer therapy. Due to a lack of understanding of the biological effect of neutrons, the results were less than encouraging. In the 1940s and 1950s, small cyclotrons were used for isotope production and in the mid 60s, the biological effect of neutrons was more thoroughly studied, with the result that a second trial of neutron therapy was initiated at Hammersmith Hospital, England. Concurrent with this, work on the use of high energy charged particles, initially protons and alphas, was initiated in Sweden and Russia and at Harvard and Berkeley. The English success in neutron therapy led to some pilot studies in the USA using physics cyclotrons of various energies and targets. These results in turn lead to the present series of machines presently being installed at M.D. Anderson Hospital (42 MeV), Seattle (50 MeV) and UCLA (46 MeV). The future probably bodes well for cyclotrons at the two extremes of the energy range. For nuclear medicine the shift is away from the use of multiple isotopes, which requires a large range of particles and energies to 11C, 13N, 15O, and 18F, which can be incorporated in metabolic specific compounds and be made with small 8-10 MeV p+ "table top" cyclotrons. For tumor therapy machines of 60 MeV or so will probably be the choice for the future, as they allow the treatment of deep seated tumors with neutrons and the charged particles have sufficient range to allow the treatment of ocular tumors.

  1. Dynamic regimes of cyclotron instability in the afterglow mode of minimum-B electron cyclotron resonance ion source plasma

    NASA Astrophysics Data System (ADS)

    Mansfeld, D.; Izotov, I.; Skalyga, V.; Tarvainen, O.; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.

    2016-04-01

    The paper is concerned with the dynamic regimes of cyclotron instabilities in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source operated in pulsed mode. The instability appears in decaying ion source plasma shortly (1-10 ms) after switching off the microwave radiation of the klystron, and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high-energy electrons along the magnetic field lines. Recently it was shown that this plasma instability causes perturbations of the extracted ion current, which limits the performance of the ion source and generates strong bursts of bremsstrahlung emission. In this article we present time-resolved diagnostics of electromagnetic emission bursts related to cyclotron instability in the decaying plasma. The temporal resolution is sufficient to study the fine structure of the dynamic spectra of the electromagnetic emission at different operating regimes of the ion source. It was found that at different values of magnetic field and heating power the dynamic spectra demonstrate common features: Decreasing frequency from burst to burst and an always falling tone during a single burst of instability. The analysis has shown that the instability is driven by the resonant interaction of hot electrons, distributed between the electron cyclotron resonance (ECR) zone and the trap center, with slow extraordinary wave propagation quasi-parallel with respect to the external magnetic field.

  2. Assessment of lichen diversity by index of atmospheric purity (IAP), index of human impact (IHI) and other environmental factors in an urban area (Grenoble, southeast France).

    PubMed

    Gombert, S; Asta, J; Seaward, M R D

    2004-05-25

    An assessment of air quality in the Grenoble area was made using the index of atmospheric purity (IAP). The survey area was divided into 198 units (0.7 x 1 km), in which 345 average lichen relevés were analyzed according to the Braun-Blanquet method. Each relevé station was characterized in the field by a subjective index of human impact (IHI) calculated according to four local environmental parameters influencing the epiphytic lichen flora: urbanization (urban, suburban or rural area), road traffic (low or high), local developments (stations located within crop fields, green areas, housing sites or car parks), and exposure (trees isolated, in rows or grouped). Eighty-three epiphytic lichen species and two algae were recorded and grouped into three ecological categories defined according to bark type and nutrient needs: nitrophytic, neutrophytic and acidophytic species. IAP values, varying from 5.9 to 71.7, were clustered into five categories in order to produce an air-quality map. The geographical pattern of the IAP map showed no clear connection with local sources of pollution, such as the vicinity of a road or an industrial plant, and was not correlated with annual mean values of SO(2), NO(2) and NO for the years 1994-1997. IAP appeared to be influenced by environmental artificiality as shown by a polynomial trend observed between IAP and IHI, even if IAP values were broadly scattered. Multivariate analysis (canonical correspondence) showed that high IAP values could be observed in stations of "natural" environments at high elevations and in stations of "artificial" environments at low elevations. It was also shown that IAP varied in relation to the relative proportion of ecological groups of lichen relevés: although a majority of neutrophytic species (>50%) with a much lower percentage of nitrophytic species generally characterized high IAP, a predominance of acidophytic or nitrophytic species led to a decrease in the IAP. A correlation between nitrophytic

  3. High Power Cyclotrons for Accelerator Driven System (ADS)

    NASA Astrophysics Data System (ADS)

    Calabretta, Luciano

    2012-03-01

    We present an accelerator module based on a injector cyclotron and a Superconducting Ring Cyclotron (SRC) able to accelerate H2+ molecules. H2+ molecules are extracted from the SRC stripping the binding electron by a thin carbon foil. The SRC will be able to deliver proton beam with maximum energy of 800 MeV and a maximum power of 8 MW. This module is forecasted for the DAEdALUS (Decay At rest Experiment for δcp At Laboratory for Underground Science) experiment, which is a neutrino experiment proposed by groups of MIT and Columbia University. Extensive beam dynamics studies have been carrying out in the last two years and proved the feasibility of the design. The use of H2+ molecules beam has three main advantages: 1) it reduces the space charge effects, 2) because of stripping extraction, it simplifies the extraction process w.r.t. single turn extraction and 3) we can extract more than one beam out of one SRC. A suitable upgraded version of the cyclotron module able to deliver up to 10MW beam is proposed to drive ADS. The accelerator system which is presented, consists of having three accelerators modules. Each SRC is equipped with two extraction systems delivering two beams each one with a power up to 5 MW. Each accelerator module, feeds both the two reactors at the same time. The three accelerators modules assure to maintain continuity in functioning of the two reactors. In normal operation, all the three accelerators module will deliver 6.6 MW each one, just in case one of the three accelerator module will be off, due to a fault or maintenance, the other two modules are pushed at maximum power of 10 MW. The superconducting magnetic sector of the SRC, as well as the normal conducting sector of the injector cyclotron, is calculated with the TOSCA module of OPERA3D. Here the main features of the injector cyclotron, of the SRC and the beam dynamic along the cyclotrons are presented.

  4. Electromagnetic ion cyclotron resonance heating in the VASIMR

    NASA Astrophysics Data System (ADS)

    Bering, E. A.; Chang-Díaz, F. R.; Squire, J. P.; Brukardt, M.; Glover, T. W.; Bengtson, R. D.; Jacobson, V. T.; McCaskill, G. E.; Cassady, L.

    2008-07-01

    Plasma physics has found an increasing range of practical industrial applications, including the development of electric spacecraft propulsion systems. One of these systems, the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine, both applies several important physical processes occurring in the magnetosphere. These processes include the mechanisms involved in the ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Auroral current region processes that are simulated in VASIMR include lower hybrid heating, parallel electric field acceleration and ion cyclotron acceleration. This paper will focus on using a physics demonstration model VASIMR to study ion cyclotron resonance heating (ICRH). The major purpose is to provide a VASIMR status report to the COSPAR community. The VASIMR uses a helicon antenna with up to 20 kW of power to generate plasma. This plasma is energized by an RF booster stage that uses left hand polarized slow mode waves launched from the high field side of the ion cyclotron resonance. The present setup for the booster uses 2 4 MHz waves with up to 20 kW of power. This process is similar to the ion cyclotron heating in tokamaks, but in the VASIMR the ions only pass through the resonance region once. The rapid absorption of ion cyclotron waves has been predicted in recent theoretical studies. These theoretical predictions have been supported with several independent measurements in this paper. The ICRH produced a substantial increase in ion velocity. Pitch angle distribution studies show that this increase takes place in the resonance region where the ion cyclotron frequency is equal to the frequency on the injected RF waves. Downstream of the resonance region the perpendicular velocity boost should be converted to axial flow velocity through the conservation of the first adiabatic invariant as the magnetic field decreases in the exhaust region of the VASIMR. In deuterium plasma, 80% efficient

  5. Ion cyclotron heating experiments in magnetosphere plasma device RT-1

    SciTech Connect

    Nishiura, M. Yoshida, Z.; Yano, Y.; Kawazura, Y.; Saitoh, H.; Yamasaki, M.; Mushiake, T.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-12-10

    The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ∼10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ∼50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

  6. Kinetic friction attributed to enhanced radiation by cyclotron maser instability

    NASA Technical Reports Server (NTRS)

    Yoon, Peter H.; Wu, C. S.

    1991-01-01

    Along the auroral field lines, a fraction of the energetic electrons injected from the magnetotail is reflected by the earth's convergent geomagnetic field. The reflected loss-cone electrons are unstable with respect to the cyclotron maser instability, resulting in the auroral kilometric radiation. This paper investigates the kinetic friction force exerted on the energetic electrons by the enhanced radiation field. It is found that the enhanced radiation results in a deceleration of reflected electrons, thereby providing an effective resistivity. In addition, the rate of decrease (increase) of effective perpendicular (parallel) kinetic temperatures is also evaluated. The analysis is carried out over various physical parameters such as the degree of loss cone, average particle energy, and the ratio of plasma frequency to cyclotron frequency.

  7. PHYSICS OF ELCTRON CYCLOTRON CURRENT DRIVE ON DIII-D

    SciTech Connect

    PETTY,CC; PRATER,R; LUCE,TC; ELLIS,RA; HARVEY,RW; KINSEY,JE; LAO,LL; LOHR,J; MAKOWSKI,MA

    2002-09-01

    OAK A271 PHYSICS OF ELCTRON CYCLOTRON CURRENT DRIVE ON DIII-D. Recent experiments on the DIII-D tokamak have focused on determining the effect of trapped particles on the electron cyclotron current drive (ECCD) efficiency. The measured ECCD efficiency increases as the deposition location is moved towards the inboard midplane or towards smaller minor radius for both co and counter injection. The measured ECCD efficiency also increases with increasing electron density and/or temperature. The experimental ECCD is compared to both the linear theory (Toray-GA) as well as a quasilinear Fokker-Planck model (CQL3D). The experimental ECCD is found to be in better agreement with the more complete Fokker-Planck calculation, especially for cases of high rf power density and/or loop voltage. The narrow width of the measured ECCD profile is consistent with only low levels of radial transport for the current carrying electrons.

  8. Nonlinear particle simulation of ion cyclotron waves in toroidal geometry

    SciTech Connect

    Kuley, A. Lin, Z.; Bao, J.; Wei, X. S.; Xiao, Y.

    2015-12-10

    Global particle simulation model has been developed in this work to provide a first-principles tool for studying the nonlinear interactions of radio frequency (RF) waves with plasmas in tokamak. In this model, ions are considered as fully kinetic particles using the Vlasov equation and electrons are treated as guiding centers using the drift kinetic equation with realistic electron-to-ion mass ratio. Boris push scheme for the ion motion has been developed in the toroidal geometry using magnetic coordinates and successfully verified for the ion cyclotron and ion Bernstein waves in global gyrokinetic toroidal code (GTC). The nonlinear simulation capability is applied to study the parametric decay instability of a pump wave into an ion Bernstein wave side band and a low frequency ion cyclotron quasi mode.

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

    PubMed

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

    2015-05-01

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

  10. Nonlinear particle simulation of ion cyclotron waves in toroidal geometry

    NASA Astrophysics Data System (ADS)

    Kuley, A.; Bao, J.; Lin, Z.; Wei, X. S.; Xiao, Y.

    2015-12-01

    Global particle simulation model has been developed in this work to provide a first-principles tool for studying the nonlinear interactions of radio frequency (RF) waves with plasmas in tokamak. In this model, ions are considered as fully kinetic particles using the Vlasov equation and electrons are treated as guiding centers using the drift kinetic equation with realistic electron-to-ion mass ratio. Boris push scheme for the ion motion has been developed in the toroidal geometry using magnetic coordinates and successfully verified for the ion cyclotron and ion Bernstein waves in global gyrokinetic toroidal code (GTC). The nonlinear simulation capability is applied to study the parametric decay instability of a pump wave into an ion Bernstein wave side band and a low frequency ion cyclotron quasi mode.

  11. Ion cyclotron instability of drifting plasma clouds. [in magnetosphere

    NASA Technical Reports Server (NTRS)

    Lin, C. S.; Parks, G. K.

    1976-01-01

    The paper is concerned with a quantitative study of the frequency dispersion characteristics of the ion cyclotron mode in a realistic dipole magnetosphere where the particles are allowed to drift azimuthally. The adopted model assumes that the particles are injected at a constant L shell in an extended region around local midnight. A drift-convoluted distribution function is used to study the spatial and temporal characteristics of the ion cyclotron instability. Two cases are examined: one in which the cold plasma density is constant and the other in which the cold particle density is allowed to vary. The resulting growth rates are presented in both the frequency versus coordinate space and the frequency versus time space. Possible inferences regarding wave emissions such as IPDP (intervals of pulsations of diminishing period) events are discussed. It is shown that the frequency dispersive effects can be produced by either the drift effects or changing the cold plasma density.

  12. Electrostatic ion-cyclotron waves in magnetospheric plasmas Nonlocal aspects

    NASA Technical Reports Server (NTRS)

    Ganguli, G.; Bakshi, P.; Palmadesso, P.

    1984-01-01

    The importance of the effect of the magnetic shear and the finite size of current channel on the electrostatic ion-cyclotron instability for the space plasmas is illustrated. A non-local treatment is used. When the channel width Lc, is larger than the shear length Ls, there is a large reduction in the growth rate along with a noteworthy reduction of the band of the unstable perpendicular wavelengths. For Lc less than or = Ls/10 the growth rate is not much altered from its local value, however for Lc/pi i less than or = 10 to the second power the growth rate starts falling below the local value and vanishes for Lc pi i. The non-local effects lead to enhanced coherence in the ion cyclotron waves. Previously announced in STAR as N84-14917

  13. Examination of the plasma located in PSI Ring Cyclotron

    NASA Astrophysics Data System (ADS)

    Pogue, N. J.; Adelmann, A.; Schneider, M.; Stingelin, L.

    2016-06-01

    A plasma has been observed inside the vacuum chamber of the PSI Ring Cyclotron. This ionized gas cloud may be a substantial contributor to several interior components having reduced lifetimes. The plasma's generation has been directly linked to the voltage that is applied to the Flat Top cavity through visual confirmation using CCD cameras. A spectrometer was used to correlate the plasma's intensity and ignition to the Flat Top cavity voltage as well as to determine the composition of the plasma. This paper reports on the analysis of the plasma using spectroscopy. The spectrometer data was analyzed to determine the composition of the plasma and that the plasma intensity (luminosity) directly corresponds to the Flat Top voltage. The results show that the plasma is comprised of elements consistent with the cyclotrons vacuum interior.

  14. Research on the high power cyclotron-wave rectifier

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyun; Tuo, Xianguo; Ge, Qing; Peng, Ying

    2017-07-01

    As a key component of a Wireless Power Transmission System, a cyclotron-wave rectifier, a high power microwave to DC converter, has received more attention from scholars. This paper comprehensively analyzes various limiting factors of the output voltage and current. The results show that high frequency breakdown, the external magnetic field, and engineering realization limit the output voltage, and the space charge force limits the beam current. On this basis, by using the equivalent circuit and particle simulation, we design a cyclotron-wave rectifier with high power. The simulation results demonstrate that working at 2.45 GHz, the rectifier can obtain an output voltage of 113 kV and an output power of 791 kW. These conclusions can provide guidance for designing and application of this device.

  15. Approach to increase beam intensity extracted from a cyclotron

    NASA Astrophysics Data System (ADS)

    Nakao, M.; Hojo, S.; Katagiri, K.; Miyahara, N.; Noda, A.; Noda, K.; Sugiura, A.; Wakui, T.; Smirnov, V.; Vorozhtsov, S.; Goto, A.

    2017-09-01

    To increase the beam intensity of cyclotrons used for producing radionuclides, beam loss during extraction must be reduced. Extraction efficiency is limited by the beam parameters in front of the deflector, especially angular distribution. Computer simulation of the second harmonic mode for 18 MeV protons, which is frequently used, has been carried out to understand beam behavior in a cyclotron. The extraction efficiency is determined by the width of the angular distribution of particles in the phase space plot at the deflector. An effective method to reduce the width is to shorten the bunch at injection. The simulation shows that the bunch phase length at injection must be ⩽30° to realize a 30 μA extraction beam current and satisfy the deflector heat limit of 200 W.

  16. Electrostatic ion-cyclotron waves in magnetospheric plasmas Nonlocal aspects

    NASA Technical Reports Server (NTRS)

    Ganguli, G.; Bakshi, P.; Palmadesso, P.

    1984-01-01

    The importance of the effect of the magnetic shear and the finite size of current channel on the electrostatic ion-cyclotron instability for the space plasmas is illustrated. A non-local treatment is used. When the channel width Lc, is larger than the shear length Ls, there is a large reduction in the growth rate along with a noteworthy reduction of the band of the unstable perpendicular wavelengths. For Lc less than or = Ls/10 the growth rate is not much altered from its local value, however for Lc/pi i less than or = 10 to the second power the growth rate starts falling below the local value and vanishes for Lc pi i. The non-local effects lead to enhanced coherence in the ion cyclotron waves. Previously announced in STAR as N84-14917

  17. Ion cyclotron heating experiments in magnetosphere plasma device RT-1

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Yoshida, Z.; Yano, Y.; Kawazura, Y.; Saitoh, H.; Yamasaki, M.; Mushiake, T.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-12-01

    The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ˜10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ˜50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

  18. Kinetic friction attributed to enhanced radiation by cyclotron maser instability

    NASA Technical Reports Server (NTRS)

    Yoon, Peter H.; Wu, C. S.

    1991-01-01

    Along the auroral field lines, a fraction of the energetic electrons injected from the magnetotail is reflected by the earth's convergent geomagnetic field. The reflected loss-cone electrons are unstable with respect to the cyclotron maser instability, resulting in the auroral kilometric radiation. This paper investigates the kinetic friction force exerted on the energetic electrons by the enhanced radiation field. It is found that the enhanced radiation results in a deceleration of reflected electrons, thereby providing an effective resistivity. In addition, the rate of decrease (increase) of effective perpendicular (parallel) kinetic temperatures is also evaluated. The analysis is carried out over various physical parameters such as the degree of loss cone, average particle energy, and the ratio of plasma frequency to cyclotron frequency.

  19. Permanent magnet electron cyclotron resonance plasma source with remote window

    SciTech Connect

    Berry, L.A.; Gorbatkin, S.M. )

    1995-03-01

    An electron cyclotron resonance (ECR) plasma has been used in conjunction with a solid metal sputter target for Cu deposition over 200 mm diameters. The goal is to develop a deposition system and process suitable for filling submicron, high-aspect ratio ULSI features. The system uses a permanent magnet for creation of the magnetic field necessary for ECR, and is significantly more compact than systems equipped with electromagnets. A custom launcher design allows remote microwave injection with the microwave entrance window shielded from the copper flux. When microwaves are introduced at an angle with respect to the plasma, high electron densities can be produced with a plasma frequency significantly greater than the electron cyclotron frequency. Copper deposition rates of 1000 A/min have been achieved.

  20. Evidence for proton cyclotron waves near Comet Giacobini-Zinner

    NASA Astrophysics Data System (ADS)

    Tan, L. C.; Mason, G. M.; Tsurutani, B. T.

    1993-02-01

    We have computed frequency spectra of power density and polarization parameters of magnetohydrodynamic waves from observations on board the ICE spacecraft as it flew past Comet Giacobini-Zinner on September 11, 1985. Since the spectral parameters are frequency dependent, we find that the analysis is best carried out in a 'wave' reference frame where one of the major axes is along the wave normal direction for each frequency component. The power density along the wave normal direction shows a systematic peak structure which we identify as belonging to cyclotron wave harmonics of pickup ions near the comet. The fundamental harmonics of the cyclotron waves are also consistent with the gyrofrequencies calculated from the magnetic field data.

  1. Heating by waves in the ion cyclotron frequency range

    SciTech Connect

    Koch, R.

    1996-03-01

    The main aspects of heating with the fast wave in the ion cyclotron range of frequencies (ICRF) are reviewed. First, the ion cyclotron resonance mechanism, fundamental and harmonics, is examined. Then the properties of fast wave dispersion are reviewed, and the principles of minority and higher cylcotron harmonic heating are discussed. An elementary coupling model is worked out in order to outline the computation of the electrical properties of ICRF antennas. Using the simple model, the antenna radiation pattern inside the plasma is computed and the effect of phasing on the k spectrum and on the antenna radiation properties is illustrated. The quasi linear-Fokker-Planck computation of the deformation of distribution functions due to Radio-Frequency (RF) and tail formation are briefly discussed. 11 refs., 5 figs.

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

    SciTech Connect

    Chu, William T.

    2005-09-01

    On August 8, 2001, Lawrence Berkeley National Laboratory celebrated the centennial of the birth of its founder (and namesake), Ernest Orlando Lawrence. For the occasion, many speeches were given and old speeches were remembered. We recall the words of the late Luis Alvarez, a Nobel Laureate and one of the Lawrence's closest colleagues: ''Lawrence will always be remembered as the inventor of the cyclotron, but more importantly, he should be remembered as the inventor of the modern way of doing science''. J. L. Heilbron and R. W. Seidel, in the introduction of their book, ''Lawrence and His Laboratory'' stated, ''The motives and mechanisms that shaped the growth of the Laboratory helped to force deep changes in the scientific estate and in the wider society. In the entrepreneurship of its founder, Ernest Orlando Lawrence, these motives, mechanisms, and changes came together in a tight focus. He mobilized great and small philanthropists, state and local governments, corporations, and plutocrats, volunteers and virtuosos. The work they supported, from astrophysics and atomic bombs, from radiochemistry to nuclear medicine, shaped the way we observe, control, and manipulate our environment.'' Indeed, all over the civilized world, the ways we do science changed forever after Lawrence built his famed Radiation Laboratory. In this editorial, we epitomize his legacy of changing the way we do medicine, thereby affecting the health and well being of all humanity. This year marks the 75th anniversary of the invention of the cyclotron by Ernest Orlando Lawrence at the University of California at Berkeley. Lawrence conceived the idea of the cyclotron early in 1929 after reading an article by Rolf Wideroe on high-energy accelerators. In the spring of 1930 one of his students, Nels Edlefsen, constructed two crude models of a cyclotron. Later in the fall of the same year, another student, M. Stanley Livingston, constructed a 13-cm diameter model that had all the features of early

  3. Cyclotron resonance in topological insulators: non-relativistic effects

    NASA Astrophysics Data System (ADS)

    Tabert, C. J.; Carbotte, J. P.

    2015-09-01

    The low-energy Hamiltonian used to describe the dynamics of the helical Dirac fermions on the surface of a topological insulator contains a subdominant non-relativistic (Schrödinger) contribution. This term can have an important effect on some properties while having no effect on others. The Hall plateaus retain the same relativistic quantization as the pure Dirac case. The height of the universal interband background conductivity is unaltered, but its onset is changed. However, the non-relativistic term leads directly to particle-hole asymmetry. It also splits the interband magneto-optical lines into doublets. Here, we find that, while the shape of the semiclassical cyclotron resonance line is unaltered, the cyclotron frequency and its optical spectral weight are changed. There are significant differences in both of these quantities for a fixed value of chemical potential or fixed doping away from charge neutrality depending on whether the Fermi energy lies in the valence or conduction band.

  4. Radiation protection aspects of the operation in a cyclotron facility

    NASA Astrophysics Data System (ADS)

    Silva, P. P. N.; Carneiro, J. C. G. G.

    2014-02-01

    The activated accelerator cyclotron components and the radioisotope production may impact on the personnel radiation exposure of the workers during the routine maintenance and emergency repair procedures and any modification of the equipment. Since the adherence of the principle of ALARA (as low as reasonable achievable) constitutes a major objective of the cyclotron management, it has become imperative to investigate the radiation levels at the workplace and the probable health effects to the worker caused by radiation exposure. The data analysis in this study was based on the individual monitoring records during the period from 2007 to 2011. Monitoring of the workplace was also performed using gamma and neutron detectors to determine the dose rate in various predetermined spots. The results of occupational radiation exposures were analysed and compared with the values established in national standards and international recommendations. Important guidelines have been developed to reduce the individual dose.

  5. LH wave absorption by mode conversion near ion cyclotron harmonics

    SciTech Connect

    Ko, K.; Bers, A.; Fuchs, V.

    1981-02-01

    Numerical studies of the dispersion relation near the lower-hybrid frequency in an inhomogeneous plasma (..delta.. n, ..delta.. T, ..delta.. B) show that portions of an incident lower-hybrid wave spectrum undergo successive but partial mode conversions to warm-plasma waves in the presence of ion cyclotron harmonics. Wave absorption beyond the first mode conversion occurs near an ion cyclotron harmonic where ion Landau damping is enhanced. A second-order dispersion relation numerically in good agreement with the full dispersion relation in the mode conversion region is derived using the condition par. delta D/par. delta k = 0. The mode conversion efficiency at each confluence is evaluated by solving the corresponding differential equation.

  6. Cyclotron Auto-Resonance Accelerator for environmental applications

    NASA Astrophysics Data System (ADS)

    Jiang, Yong; Shchelkunov, Sergey V.; Hirshfield, Jay L.

    2017-03-01

    A MW-level CW electron beam source for environmental remediation based on extensions of the scientifically-proven Cyclotron Auto-Resonance Accelerator, dubbed CARA, is described here. CARA is distinguished by its exceptionally high RF-to-beam efficiency, by its production of a self-scanning beam, and by its proportionately lower specific power loading on a beam output window. Its environmental applications include sterilization, flue gas and waste water treatment.

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

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

  8. Mode converter for electron cyclotron resonance heating of toroidal plasmas

    SciTech Connect

    Motley, R.W.; Hsuan, H.; Glanz, J.

    1980-09-01

    A method is proposed for improving the efficiency of cyclotron resonance heating of a toroidal plasma by ordinary mode radiation from the outside of the torus. Radiation not absorbed in the first pass is reflected from the inside of the torus by a corrugated surface which rotates the polarization by 90/sup 0/, so that a secondary source of extraordinary waves is created in the high field, accessible region of the plasma.

  9. Design options for an ITER ion cyclotron system

    NASA Astrophysics Data System (ADS)

    Swain, D. W.; Baity, F. W.; Bigelow, T. S.; Ryan, P. M.; Goulding, R. H.; Carter, M. D.; Stallings, D. C.; Batchelor, D. B.; Hoffman, D. J.

    1996-02-01

    Recent changes have occurred in the design requirements for the ITER ion cyclotron system, requiring in-port launchers in four main horizontal ports to deliver 50 MW of power to the plasma. The design is complicated by the comparatively large antenna-separatrix distance of 10-20 cm. Designs of a conventional strap launcher and a folded waveguide launcher that can meet the new requirements are presented.

  10. Formation of cyclotron lines in gamma-ray burst spectra

    NASA Technical Reports Server (NTRS)

    Alexander, S. G.; Meszaros, P.

    1989-01-01

    A transmission model of gamma-ray burst sources is studied using the relativistic QED magnetic-resonant opacities including multiple photon scattering, incorporated into a discrete-ordinate radiative-transport scheme. The physics of the cyclotron line-producing region is discussed in general, and the expected line profiles, relative harmonic strengths, and polarizations are indicated under various conditions. The calculated spectra for these models show good agreement with the spectra reported from Ginga for GB 880205 and GB 870303.

  11. Design options for an ITER ion cyclotron system

    SciTech Connect

    Swain, D.W.; Baity, F.W.; Bigelow, T.S.; Ryan, P.M.; Goulding, R.H.; Carter, M.D.; Stallings, D.C.; Batchelor, D.B.; Hoffman, D.J.

    1995-09-01

    Recent changes have occurred in the design requirements for the ITER ion cyclotron system, requiring in-port launchers in four main horizontal ports to deliver 50 MW of power to the plasma. The design is complicated by the comparatively large antenna-separatrix distance of 10--20 cm. Designs of a conventional strap launcher and a folded waveguide launcher than can meet the new requirements are presented.

  12. Pencil Beam Scanning System Based On A Cyclotron

    SciTech Connect

    Tachikawa, Toshiki; Nonaka, Hideki; Kumata, Yukio; Nishio, Teiji; Ogino, Takashi

    2011-06-01

    Sumitomo Heavy Industries, Ltd. (SHI) has developed a new pencil beam scanning system (PBS) for proton therapy in collaboration with National Cancer Center Hospital East (NCCHE). Taking advantage of the continuous beam from the cyclotron P235, the line scanning method is employed in order to realize continuous irradiation with high dose rate. 3D uniform and sphere field was irradiated and compared with the simulation.

  13. Electromagnetic ion beam instabilities - Growth at cyclotron harmonic wave numbers

    NASA Technical Reports Server (NTRS)

    Smith, Charles W.; Gary, S. Peter

    1987-01-01

    The linear theory of electromagnetic ion beam instabilities for arbitrary angles of propagation is studied, with an emphasis on the conditions necessary to generate unstable modes at low harmonics of the ion cyclotron resonance condition. The present results extend the analysis of Smith et al. (1985). That paper considered only the plasma parameters at a time during which harmonic wave modes were observed in the earth's foreshock. The parameters of that paper are used as the basis of parametric variations here to establish the range of beam properties which may give rise to observable harmonic spectra. It is shown that the growth rates of both left-hand and right-hand cyclotron harmonic instabilities are enhanced by an increase in the beam temperature anisotropy and/or the beam speed. Decreases in the beam density and/or the core-ion beta reduce the overall growth of the cyclotron harmonic instabilities but favor the growth of these modes over the growth of the nonresonant instability and thereby enhance the observability of the harmonics.

  14. Electrostatic ion-cyclotron waves in a nonuniform magnetic field

    NASA Technical Reports Server (NTRS)

    Cartier, S. L.; Dangelo, N.; Merlino, R. L.

    1985-01-01

    The properties of electrostatic ion-cyclotron waves excited in a single-ended cesium Q machine with a nonuniform magnetic field are described. The electrostatic ion-cyclotron waves are generated in the usual manner by drawing an electron current to a small exciter disk immersed in the plasma column. The parallel and perpendicular (to B) wavelengths and phase velocities are determined by mapping out two-dimensional wave phase contours. The wave frequency f depends on the location of the exciter disk in the nonuniform magnetic field, and propagating waves are only observed in the region where f is approximately greater than fci, where fci is the local ion-cyclotron frequency. The parallel phase velocity is in the direction of the electron drift. From measurements of the plasma properties along the axis, it is inferred that the electron drift velocity is not uniform along the entire current channel. The evidence suggests that the waves begin being excited at that axial position where the critical drift velocity is first exceeded, consistent with a current-driven excitation mechanism.

  15. Electromagnetic ion beam instabilities - Growth at cyclotron harmonic wave numbers

    NASA Technical Reports Server (NTRS)

    Smith, Charles W.; Gary, S. Peter

    1987-01-01

    The linear theory of electromagnetic ion beam instabilities for arbitrary angles of propagation is studied, with an emphasis on the conditions necessary to generate unstable modes at low harmonics of the ion cyclotron resonance condition. The present results extend the analysis of Smith et al. (1985). That paper considered only the plasma parameters at a time during which harmonic wave modes were observed in the earth's foreshock. The parameters of that paper are used as the basis of parametric variations here to establish the range of beam properties which may give rise to observable harmonic spectra. It is shown that the growth rates of both left-hand and right-hand cyclotron harmonic instabilities are enhanced by an increase in the beam temperature anisotropy and/or the beam speed. Decreases in the beam density and/or the core-ion beta reduce the overall growth of the cyclotron harmonic instabilities but favor the growth of these modes over the growth of the nonresonant instability and thereby enhance the observability of the harmonics.

  16. Cluster Observation Of Ion And Electron Cyclotron Waves Near Magnetopause

    NASA Astrophysics Data System (ADS)

    Silin, I.; Panov, E. V.

    2012-12-01

    We examine observations of electromagnetic ion cyclotron (EMIC) and electron cyclotron waves by Cluster spacecraft during a magnetopause transition near polar cusp region. The waves appear to be generated locally, on the magnetospheric side of the magnetopause current layer, due to large particle temperature anisotropy (T⊥}/T{∥ >3 for all ions and T⊥}/T{∥ ˜ 1.3 for electrons) and large plasma beta (0.5 < β < 10). The compact configuration of Cluster spacecraft and high-resolution electromagnetic field data allowed us to measure the wave vectors k by two independent methods: the wave-telescope and the polarization methods. Such measurements are essential for estimation of minimum energies of particles scattered by EMIC waves via cyclotron resonance. The results show good agreement with linear dispersion theory. The EMIC waves propagate along the magnetic field with frequencies near 1 Hz, wavelength of 260 km at speeds of ˜ 500 km/s. We discuss the implications of these results for the particle diffusion coefficients and minimum resonant scattering energies.

  17. Modern compact accelerators of cyclotron type for medical applications

    NASA Astrophysics Data System (ADS)

    Smirnov, V.; Vorozhtsov, S.

    2016-09-01

    Ion beam therapy and hadron therapy are types of external beam radiotherapy. Recently, the vast majority of patients have been treated with protons and carbon ions. Typically, the types of accelerators used for therapy were cyclotrons and synchrocyclotrons. It is intuitively clear that a compact facility fits best to a hospital environment intended for particle therapy and medical diagnostics. Another criterion for selection of accelerators to be mentioned in this article is application of superconducting technology to the magnetic system design of the facility. Compact isochronous cyclotrons, which accelerate protons in the energy range 9-30 MeV, have been widely used for production of radionuclides. Energy of 230 MeV has become canonical for all proton therapy accelerators. Similar application of a carbon beam requires ion energy of 430 MeV/u. Due to application of superconducting coils the magnetic field in these machines can reach 4-5 T and even 9 T in some cases. Medical cyclotrons with an ironless or nearly ironless magnetic system that have a number of advantages over the classical accelerators are in the development stage. In this work an attempt is made to describe some conceptual and technical features of modern accelerators under consideration. The emphasis is placed on the magnetic and acceleration systems along with the beam extraction unit, which are very important from the point of view of the facility compactness and compliance with the strict medical requirements.

  18. RF control hardware design for CYCIAE-100 cyclotron

    NASA Astrophysics Data System (ADS)

    Yin, Zhiguo; Fu, Xiaoliang; Ji, Bin; Zhao, Zhenlu; Zhang, Tianjue; Li, Pengzhan; Wei, Junyi; Xing, Jiansheng; Wang, Chuan

    2015-11-01

    The Beijing Radioactive Ion-beam Facility project is being constructed by BRIF division of China Institute of Atomic Energy. In this project, a 100 MeV high intensity compact proton cyclotron is built for multiple applications. The first successful beam extraction of CYCIAE-100 cyclotron was done in the middle of 2014. The extracted proton beam energy is 100 MeV and the beam current is more than 20 μA. The RF system of the CYCIAE-100 cyclotron includes two half-wavelength cavities, two 100 kW tetrode amplifiers and power transmission line systems (all above are independent from each other) and two sets of Low Level RF control crates. Each set of LLRF control includes an amplitude control unit, a tuning control unit, a phase control unit, a local Digital Signal Process control unit and an Advanced RISC Machines based EPICS IOC unit. These two identical LLRF control crates share one common reference clock and take advantages of modern digital technologies (e.g. DSP and Direct Digital Synthesizer) to achieve closed loop voltage and phase regulations of the dee-voltage. In the beam commission, the measured dee-voltage stability of RF system is better than 0.1% and phase stability is better than 0.03°. The hardware design of the LLRF system will be reviewed in this paper.

  19. The cyclotron laboratory and the RFQ accelerator in Bern

    SciTech Connect

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

    2013-07-18

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

  20. Improving cancer treatment with cyclotron produced radionuclides. Progress report

    SciTech Connect

    Larson, S.M.; Finn, R.D.

    1992-08-04

    Our goal is to improve the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The grant includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. The radiochemistry group seeks to develop innovative cyclotron targetry, radiopharmaceuticals, and radiolabeled antibodies, which are then used to assess important unanswered questions in tumor pharmacology and immunology. Examples include selected positron emitting radionuclides, such as Iodine-124, and Ga-66; I-124, I-123, I-131 labeled iododeoxyuridine, C-11 colchicine, and antimetabolites, like C-11 methotrexate; and radiolabeled antibodies, 3F8, M195, A33, and MRK16 for application in the pharmacology and immunology projects. The pharmacology program studies tumor resistance to chemotherapy, particularly the phenomenon of multidrug resistance and the relationship between tumor uptake and retention and the tumor response for anti-metabolite drugs. The immunology program studies the physiology of antibody localization at the tissue level as the basis for novel approaches to improving tumor localization such as through the use of an artificial lymphatic system which mechanically reduces intratumoral pressures in tumors in vivo. Quantitative imaging approaches based on PET and SPECT in radioimmunotherapy are studied to give greater insight into the physiology of tumor localization and dosimetry.

  1. Nonlinear heating of ions by electron cyclotron frequency waves

    NASA Astrophysics Data System (ADS)

    Zestanakis, P. A.; Hizanidis, K.; Ram, A. K.; Kominis, Y.

    2010-11-01

    We study the nonlinear interaction of ions with electron cyclotron (EC) wave packets in a magnetized plasma. Previous studies have shown that such interactions with high frequency electrostatic lower hybrid waves can lead to coherent energization of ions. It requires the frequency bandwidth of the wave packet to be broader than the ion cyclotron frequency [1,2]. For the electromagnetic high frequency EC waves we have developed a more general theory, based on the Lie transform canonical perturbation method [3,4]. We apply the theory to the case of two overlapping EC beams. The wave frequency of each beam is assumed to be frequency modulated with a modulation bandwidth comparable to the ion cyclotron frequency. We present results for both X-mode and O-mode and illustrate the conditions for ion energization. [4pt] [1] D. Benisti, A. K. Ram, and A. Bers, Phys. Plasmas 5, 3224 (1998). [0pt] [2] A. K. Ram, A. Bers, and D. Benisti , J. Geophys. Res. 103, 9431 (1998). [0pt] [3] J.R. Cary and A.N. Kaufman, Phys. Fluids 24, 1238 (1981). [0pt] [4] R.L. Dewar, J. Phys A-Math. Gen 9, 2043 (1976).

  2. Quench analysis of a novel compact superconducting cyclotron

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  3. High Power Ion Cyclotron Heating in the VASIMR

    NASA Astrophysics Data System (ADS)

    Longmier, B. W.; Brukardt, M. S.; Bering, E. A.; Chang Diaz, F.; Squire, J.

    2009-12-01

    The Variable Specific Impulse Magnetoplasma Rocket (VASIMR®) is an electric propulsion system under development at Ad Astra Rocket Company that utilizes several processes of ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Among these processes are parallel electric field acceleration, lower hybrid resonance heating, and ion cyclotron resonance heating. The VASIMR® is capable of laboratory simulation of electromagnetic ion cyclotron wave heating during a single pass of ions through the resonance region. The plasma is generated by a helicon discharge of 35 kW then passes through a 176 kW RF booster stage that couples left hand polarized slow mode waves from the high field side of the resonance. VX-200 auroral simulation results from the past year are discussed. Ambipolar acceleration has been shown to produce 35eV argon ions in the helicon exhaust. The effects on the ion exhaust with an addition of 150-200 kW of ion cyclotron heating are presented. The changes to the VASIMR® experiment at Ad Astra Rocket Company's new facility in Webster, Texas will also be discussed, including the possibility of collaborative experiments.

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

    NASA Astrophysics Data System (ADS)

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

    1995-09-01

    Euratom/JRC Ispra led some years ago the design of an accelerator based neutron spallation source EURAC, with special emphasis as a fusion material testing device. DENIM was involved in the development of the last version of this source. EURAC proposes to use a beam of 600 MeV or 1.5 GeV protons, produced by an effective and low cost ring cyclotron with a current of 6 mA impinging in a liquid lead, or lead-bismuth, target. It will use an advanced cyclotron technology which can be implemented in the next future, in the line of the actual technology of the upgraded SIN-type cyclotron. The adjacent rows to the target correspond to the lead, or Li17Pb83, cooled channels where the samples will be located. The available volumes there were shown enough for material testing purposes. Here, proposal of using those experimental areas to introduce small masses of radioactive wastes for testing of transmutation in spallation source is made. In addition, extrapolation of present conceptual design to make available larger volumes under flexible conditions seems to be possible. Neutrons leaking from the test zone drive a subcritical booster (< 10 MW) which could provide a thermal neutron flux trap with a liquid hidrogen moderator in the center.

  5. A Suzaku View of Cyclotron Line Sources and Candidates

    NASA Technical Reports Server (NTRS)

    Pottschmidt, K.; Suchy, S.; Rivers, E.; Rothschild, R. E.; Marcu, D. M.; Barragan, L.; Kuehnel, M.; Fuerst, F.; Schwarm, F.; Kreykenbohm, I.; Wilms, J.; Schoenherr, G.; Caballero, I.; Camero-Arranz, A.; Bodaghee, A.; Doroshenko, V.; Klochkov, D.; Santangelo, A.; Staubert, R.; Kretschmar, P.; Wilson-Hodge, C.; Finger, M. H.; Terada, Y.

    2012-01-01

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

  6. The cyclotron laboratory and the RFQ accelerator in Bern

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  7. Considerations, measurements and logistics associated with low-energy cyclotron decommissioning

    SciTech Connect

    Sunderland, J. J.; Erdahl, C. E.; Bender, B. R.; Sensoy, L.; Watkins, G. L.

    2012-12-19

    The University of Iowa's 20-year-old 17 MeV Scanditronix cyclotron underwent decommissioning in the summer of 2011. To satisfy local, state and federal regulations defining removal, transportation and long-term safe and environmentally secure disposal of the 22 ton activated cyclotron, a series of nuclear spectroscopic measurements were performed to characterize the nature and extent of proton and neutron activation of the 22-ton cyclotron, its associated targets, and the concrete wall that was demolished to remove the old cyclotron. Neutron activation of the concrete wall was minimal and below exempt concentrations resulting in standard landfill disposal. The cyclotron assessment revealed the expected array of short and medium-lived radionuclides. Subsequent calculations suggest that meaningful levels residual activity will have decayed virtually to background after 15 years, with the total residual activity of the entire cyclotron dropping below 37 MBq (1 mCi).

  8. Whistler and Alfvén Mode Cyclotron Masers in Space

    NASA Astrophysics Data System (ADS)

    Trakhtengerts, V. Y.; Rycroft, M. J.

    2008-11-01

    Preface; 1. Introduction; 2. Basic theory of cyclotron masers (CMs); 3. Linear theory of the cyclotron instability (CI); 4. Backward wave oscillator (BWO) regime in CMs; 5. Nonlinear cyclotron wave-particle interactions for a quasi-monochromatic wave; 6. Nonlinear interaction of quasi-monochromatic whistler mode waves with gyroresonant electrons in an in homogeneous plasma; 7. Wavelet amplification in an inhomogeneous plasma; 8. Quasi-linear theory of cyclotron masers; 9. Nonstationary generation regimes, and modulation effects; 10. ELF/VLF noise-like emissions and electrons in the Earth's radiation belts; 11. Generation of discrete ELF/VLF whistler mode emissions; 12. Cyclotron instability of the proton radiation belts; 13. Cyclotron masers elsewhere in the solar system and in laboratory plasma devices; Epilogue; Glossary of terms; List of acronyms; References; Index.

  9. Whistler and Alfvén Mode Cyclotron Masers in Space

    NASA Astrophysics Data System (ADS)

    Trakhtengerts, V. Y.; Rycroft, M. J.

    2012-10-01

    Preface; 1. Introduction; 2. Basic theory of cyclotron masers (CMs); 3. Linear theory of the cyclotron instability (CI); 4. Backward wave oscillator (BWO) regime in CMs; 5. Nonlinear cyclotron wave-particle interactions for a quasi-monochromatic wave; 6. Nonlinear interaction of quasi-monochromatic whistler mode waves with gyroresonant electrons in an in homogeneous plasma; 7. Wavelet amplification in an inhomogeneous plasma; 8. Quasi-linear theory of cyclotron masers; 9. Nonstationary generation regimes, and modulation effects; 10. ELF/VLF noise-like emissions and electrons in the Earth's radiation belts; 11. Generation of discrete ELF/VLF whistler mode emissions; 12. Cyclotron instability of the proton radiation belts; 13. Cyclotron masers elsewhere in the solar system and in laboratory plasma devices; Epilogue; Glossary of terms; List of acronyms; References; Index.

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

    PubMed

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

    2014-02-01

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

  11. The cyclotron maser theory of AKR and Z-mode radiation. [Auroral Kilometric Radiation

    NASA Technical Reports Server (NTRS)

    Wu, C. S.

    1985-01-01

    The cyclotron maser mechanism which may be responsible for the generation of auroral kilometric radiation and Z-mode radiation is discussed. Emphasis is placed on the basic concepts of the cyclotron maser theory, particularly the relativistic effect of the cyclotron resonance condition. Recent development of the theory is reviewed. Finally, the results of a computer simulation study which helps to understand the nonlinear saturation of the maser instability are reported.

  12. Electrostatic ion-cyclotron waves in a two-ion component plasma

    NASA Technical Reports Server (NTRS)

    Suszcynsky, David M.; Merlino, Robert L.; D'Angelo, Nicola

    1988-01-01

    The excitation of electrostatic ion cyclotron (EIC) waves is studied in a single-ended Q machine in a two-ion component plasma (Ca+ and K+). Over a large range of relative concentrations of Cs+ and K+ ions, two modes are excited with frequencies greater than the respective cyclotron frequencies of the ions. The results are discussed in terms of a fluid theory of electrostatic ion cyclotron waves in a two-ion component plasma.

  13. Microwave emission related to cyclotron instabilities in a minimum-B electron cyclotron resonance ion source plasma

    NASA Astrophysics Data System (ADS)

    Izotov, I.; Tarvainen, O.; Mansfeld, D.; Skalyga, V.; Koivisto, H.; Kalvas, T.; Komppula, J.; Kronholm, R.; Laulainen, J.

    2015-08-01

    Electron cyclotron resonance ion sources (ECRIS) have been essential in the research and applications of nuclear physics over the past 40 years. They are extensively used in a wide range of large-scale accelerator facilities for the production of highly charged heavy ion beams of stable and radioactive elements. ECRISs are susceptible to kinetic instabilities due to resonance heating mechanism leading to anisotropic electron velocity distribution function. Instabilities of cyclotron type are a proven cause of frequently observed periodic bursts of ‘hot’ electrons and bremsstrahlung, accompanied with emission of microwave radiation and followed by considerable drop of multiply charged ions current. Detailed studies of the microwave radiation associated with the instabilities have been performed with a minimum-B 14 GHz ECRIS operating on helium, oxygen and argon plasmas. It is demonstrated that during the development of cyclotron instability ‘hot’ electrons emit microwaves in sub-microsecond scale bursts at temporally descending frequencies in the 8-15 GHz range with two dominant frequencies of 11.09 and 12.59 GHz regardless of ECRIS settings i.e. magnetic field strength, neutral gas pressure or species and microwave power. The experimental data suggest that the most probable excited plasma wave is a slow extraordinary Z-mode propagating quasi-longitudinally with respect to the external magnetic field.

  14. Linear and nonlinear physics of the magnetoacoustic cyclotron instability of fusion-born ions in relation to ion cyclotron emission

    SciTech Connect

    Carbajal, L. Cook, J. W. S.; Dendy, R. O.; Chapman, S. C.

    2014-01-15

    The magnetoacoustic cyclotron instability (MCI) probably underlies observations of ion cyclotron emission (ICE) from energetic ion populations in tokamak plasmas, including fusion-born alpha-particles in JET and TFTR [Dendy et al., Nucl. Fusion 35, 1733 (1995)]. ICE is a potential diagnostic for lost alpha-particles in ITER; furthermore, the MCI is representative of a class of collective instabilities, which may result in the partial channelling of the free energy of energetic ions into radiation, and away from collisional heating of the plasma. Deep understanding of the MCI is thus of substantial practical interest for fusion, and the hybrid approximation for the plasma, where ions are treated as particles and electrons as a neutralising massless fluid, offers an attractive way forward. The hybrid simulations presented here access MCI physics that arises on timescales longer than can be addressed by fully kinetic particle-in-cell simulations and by analytical linear theory, which the present simulations largely corroborate. Our results go further than previous studies by entering into the nonlinear stage of the MCI, which shows novel features. These include stronger drive at low cyclotron harmonics, the re-energisation of the alpha-particle population, self-modulation of the phase shift between the electrostatic and electromagnetic components, and coupling between low and high frequency modes of the excited electromagnetic field.

  15. Electromagnetic cyclotron waves in the solar wind: Wind observation and wave dispersion analysis

    SciTech Connect

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

    2016-03-25

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

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

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  17. Review of Cyclotrons for the Production of Radioactive Isotopes for Medical and Industrial Applications

    NASA Astrophysics Data System (ADS)

    Schmor, Paul

    2011-02-01

    Radioactive isotopes are used in a wide range of medical, biological, environmental and industrial applications. Cyclotrons are the primary tool for producing the shorter-lived, proton-rich radioisotopes currently used in a variety of medical applications. Although the primary use of the cyclotron-produced short-lived radioisotopes is in PET/CT (positron emission tomography/computed tomography) and SPECT (single photon emission computed tomography) diagnostic medical procedures, cyclotrons are also producing longer-lived isotopes for therapeutic procedures as well as for other industrial and applied science applications. Commercial suppliers of cyclotrons are responding by providing a range of cyclotrons in the energy range of 3-70MeV for the differing needs of the various applications. These cyclotrons generally have multiple beams servicing multiple targets. This review article presents some of the applications of the radioisotopes and provides a comparison of some of the capabilities of the various current cyclotrons. The use of nuclear medicine and the number of cyclotrons supplying the needed isotopes are increasing. It is expected that there will soon be a new generation of small "tabletop" cyclotrons providing patient doses on demand.

  18. Glow plasma trigger for electron cyclotron resonance ion sources.

    PubMed

    Vodopianov, A V; Golubev, S V; Izotov, I V; Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu

    2010-02-01

    Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10(12) cm(-3), required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T(e) approximately = 20 eV.

  19. Cyclotron maser and plasma wave growth in magnetic loops

    NASA Technical Reports Server (NTRS)

    Hamilton, Russell J.; Petrosian, Vahe

    1990-01-01

    Cyclotron maser and plasma wave growth which results from electrons accelerated in magnetic loops are studied. The evolution of the accelerated electron distribution is determined by solving the kinetic equation including Coulomb collisions and magnetic convergence. It is found that for modest values of the column depth of the loop the growth rates of instabilities are significantly reduced and that the reduction is much larger for the cyclotron modes than for the plasma wave modes. The large decrease in the growth rate with column depth suggests that solar coronal densities must be much lower than commonly accepted in order for the cyclotron maser to operate. The density depletion has to be similar to that which occurs during auroral kilometric radiation events in the magnetosphere. The resulting distributions are much more complicated than the idealized distributions used in many theoretical studies, but the fastest growing mode can still simply be determined by the ratio of electron plasma to gyrofrequency, U=omega(sub p)/Omega(sub e). However, the dominant modes are different than for the idealized situations with growth of the z-mode largest for U approximately less than 0.5, and second harmonic x-mode (s=2) or fundamental o-mode (s=1) the dominant modes for 0.5 approximately less than U approximately less than 1. The electron distributions typically contain more than one inverted feature which could give rise to wave growth. It is shown that this can result in simultaneous amplification of more than one mode with each mode driven by a different feature and can be observed, for example, by differences in the rise times of the right and left circularly polarized components of the associated spike bursts.

  20. Hospital based superconducting cyclotron for neutron therapy: Medical physics perspective

    NASA Astrophysics Data System (ADS)

    Yudelev, M.; Burmeister, J.; Blosser, E.; Maughan, R. L.; Kota, C.

    2001-12-01

    The neutron therapy facility at the Gershenson Radiation Oncology Center, Harper University Hospital in Detroit has been operational since September 1991. The d(48.5)+Be beam is produced in a gantry mounted superconducting cyclotron designed and built at the National Superconducting Cyclotron Laboratory (NSCL). Measurements were performed in order to obtain the physical characteristics of the neutron beam and to collect the data necessary for treatment planning. This included profiles of the dose distribution in a water phantom, relative output factors and the design of various beam modifiers, i.e., wedges and tissue compensators. The beam was calibrated in accordance with international protocol for fast neutron dosimetry. Dosimetry and radiobiology intercomparions with three neutron therapy facilities were performed prior to clinical use. The radiation safety program was established in order to monitor and reduce the exposure levels of the personnel. The activation products were identified and the exposure in the treatment room was mapped. A comprehensive quality assurance (QA) program was developed to sustain safe and reliable operation of the unit at treatment standards comparable to those for conventional photon radiation. The program can be divided into three major parts: maintenance of the cyclotron and related hardware; QA of the neutron beam dosimetry and treatment delivery; safety and radiation protection. In addition the neutron beam is used in various non-clinical applications. Among these are the microdosimetric characterization of the beam, the effects of tissue heterogeneity on dose distribution, the development of boron neutron capture enhanced fast neutron therapy and variety of radiobiology experiments.

  1. Electromagnetic waves near the proton cyclotron frequency: Stereo observations

    SciTech Connect

    Jian, L. K.; Wei, H. Y.; Russell, C. T.; Luhmann, J. G.; Klecker, B.; Omidi, N.; Isenberg, P. A.; Goldstein, M. L.; Figueroa-Viñas, A.; Blanco-Cano, X.

    2014-05-10

    Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in the solar wind throughout the inner heliosphere. They could play an important role in heating and accelerating the solar wind. These low-frequency waves (LFWs) are intermittent but often occur in prolonged bursts lasting over 10 minutes, named 'LFW storms'. Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave analysis, we have identified 241 LFW storms in 2008, present 0.9% of the time. They are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with similar characteristics, probably due to Doppler shift of the same type of waves or waves of intrinsically different polarities. In rare cases, the opposite polarities are observed closely in time or even simultaneously. Having ruled out interplanetary coronal mass ejections, shocks, energetic particles, comets, planets, and interstellar ions as LFW sources, we discuss the remaining generation scenarios: LH ion cyclotron instability driven by greater perpendicular temperature than parallel temperature or by ring-beam distribution, and RH ion fire hose instability driven by inverse temperature anisotropy or by cool ion beams. The investigation of solar wind conditions is compromised by the bias of the one-dimensional Maxwellian fit used for plasma data calibration. However, the LFW storms are preferentially detected in rarefaction regions following fast winds and when the magnetic field is radial. This preference may be related to the ion cyclotron anisotropy instability in fast wind and the minimum in damping along the radial field.

  2. Electron cyclotron emission as a density fluctuation diagnostic

    SciTech Connect

    Lynn, A.G.; Phillips, P.E.; Hubbard, A.

    2004-10-01

    A new technique for measuring density fluctuations using a high-resolution heterodyne electron cyclotron emission (ECE) radiometer has been developed. Although ECE radiometry is typically used for electron temperature measurements, the unique viewing geometry of this system's quasioptical antenna has been found to make the detected emission extremely sensitive to refractive effects under certain conditions. This sensitivity gives the diagnostic the ability to measure very low levels of density fluctuations in the core of Alcator C-Mod tokamak. The refractive effects have been modeled using ray-tracing methods, allowing estimates of the density fluctuation magnitude and spatial localization.

  3. Ion cyclotron resonance heated conics - Theory and observations

    NASA Technical Reports Server (NTRS)

    Crew, G. B.; Chang, Tom; Retterer, J. M.; Peterson, W. K.; Gurnett, D. A.

    1990-01-01

    A general theoretical treatment of energetic oxygen ion conic formation through cyclotron resonance with magnetospheric electromagnetic plasma turbulence is presented. With suitable assumptions, there exists a similarity regime in which the process may be profitably characterized by two parameters corresponding roughly to the velocity scale and pitch angle of the ion distribution. These may be independently determined from the wave and particle observations of a conic event, as is illustrated here using typical auroral passes of the Dynamics Explorer 1 satellite. The predictions of the theory are found to be in excellent agreement with the observations.

  4. Electron-cyclotron maser instability in relativistic plasmas

    NASA Technical Reports Server (NTRS)

    Pritchett, P. L.

    1986-01-01

    The electron-cyclotron maser instability is studied for the case of an anisotropic electron velocity distribution in the regime where the relativistic corrections to the wave dispersion are significant. Solution of the linear dispersion relation reveals that when the plasma frequency-gyrofrequency ratio is less than v(te)/c, the instability is localized just below k(perpendicular)c/Omega(e) = 1. The growth rate is then strongly peaked for emission at 90 deg to the magnetic field and is considerably larger than would be the case if the cold-plasma dispersion theory were valid. These features are confirmed by EM particle simulations.

  5. Superthermal electron distribution measurements from polarized electron cyclotron emission

    SciTech Connect

    Luce, T.C.; Efthimion, P.C.; Fisch, N.J.

    1988-06-01

    Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.

  6. Personal computer based Fourier transform ion cyclotron resonance mass spectrometer

    NASA Astrophysics Data System (ADS)

    Guan, Shenheng; Jones, Patrick R.

    1988-12-01

    An IBM PC AT compatible computer is used to host the interface of a Fourier transform ion cyclotron resonance mass spectrometer or FTMS. A common fast memory bank for both ion-excitation waveform and data acquisition is reserved in the computer's system memory space. All the digital electronics circuitry is assembled on an IBM PC AT extension board. Neither an external frequency synthesizer nor a waveform digitizer is needed. Ion-excitation waveforms can be generated in either frequency-sweeping or inverse-Fourier transform modes. Both excitation and data acquisition can be carried out at eight megawords per second.

  7. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M.; Bobkov, V.; Rohde, V.; Schneider, P.; Douai, D.; Kogut, D.; Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G.; Moiseenko, V.; Noterdaeme, J.-M.; Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,ω=ω{sub H+}, and with its high cyclotron harmonics (HCH), ω=10ω{sub cH+}⋅ HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}≈0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}≈350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ⊥H} ≥1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  8. Potential applications of an electron cyclotron resonance multicusp plasma source

    SciTech Connect

    Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Stirling, W.L.

    1989-01-01

    An electron cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produced large (about 25-cm-diam), uniform (to within {plus minus}10%), dense (>10{sup 11}-cm{sup -3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Results and potential applications of this new ECR plasma source for plasma processing of thin films are discussed. 21 refs., 10 figs.

  9. Plane gyroklinotron at first and third harmonics of cyclotron frequency

    SciTech Connect

    Kurayev, A.A.; Lukashonok, D.V.; Sinitsyn, A.K. E-mail: timka86@gmail.com

    2011-07-01

    The results of gyroklinotron's parameters optimization for efficiency at f = 100 GHz with interaction on first and third harmonics of the cyclotron frequency are presented. The predicted electron gyroklinotron's efficiency reaches 70% on first harmonic and 40% on third harmonic. This is more than in usual gyrotron. Besides in contrast to usual gyrotron the width electron beam on radius of guiding centers of electron orbits in gyroklinotron may considerable exceed working wave length {lambda}. This allows to use in it considerable more power of electron beams EB then in usual gyrotron. (author)

  10. Cyclotron production of Ac-225 for targeted alpha therapy.

    PubMed

    Apostolidis, C; Molinet, R; McGinley, J; Abbas, K; Möllenbeck, J; Morgenstern, A

    2005-03-01

    The feasibility of producing Ac-225 by proton irradiation of Ra-226 in a cyclotron through the reaction Ra-226(p,2n)Ac-225 has been experimentally demonstrated for the first time. Proton energies were varied from 8.8 to 24.8 MeV and cross-sections were determined by radiochemical analysis of reaction yields. Maximum yields were reached at incident proton energies of 16.8 MeV. Radiochemical separation of Ac-225 from the irradiated target yielded a product suitable for targeted alpha therapy of cancer.

  11. Linear coupling of acoustic and cyclotron waves in plasma flows

    SciTech Connect

    Rogava, Andria; Gogoberidze, Grigol

    2005-05-15

    It is found that in magnetized electrostatic plasma flows the velocity shear couples ion-acoustic waves with ion-cyclotron waves and leads, under favorable conditions, to their efficient reciprocal transformations. It is shown that in a two-dimensional setup this coupling has a remarkable feature: it is governed by equations that are mathematically equal to the ones describing coupling of sound waves with internal gravity waves [Rogava and Mahajan, Phys. Rev. E 55, 1185 (1997)] in neutral fluids. For flows with low shearing rates a fully analytic, quantitative description of the coupling efficiency, based on a noteworthy quantum-mechanical analogy, is given and transformation coefficients are calculated.

  12. Miniature cyclotron resonance ion source using small permanent magnet

    NASA Technical Reports Server (NTRS)

    Anicich, V. G.; Huntress, W. T., Jr. (Inventor)

    1980-01-01

    An ion source using the cyclotron resonance principle is described. A miniaturized ion source device is used in an air gap of a small permanent magnet with a substantially uniform field in the air gap of about 0.5 inch. The device and permanent magnet are placed in an enclosure which is maintained at a high vacuum (typically 10 to the minus 7th power) into which a sample gas can be introduced. The ion beam end of the device is placed very close to an aperture through which an ion beam can exit into the apparatus for an experiment.

  13. Quantum non demolition measurement of cyclotron excitations in a Penning trap

    NASA Technical Reports Server (NTRS)

    Marzoli, Irene; Tombesi, Paolo

    1993-01-01

    The quantum non-demolition measurement of the cyclotron excitations of an electron confined in a Penning trap could be obtained by measuring the resonance frequency of the axial motion, which is coupled to the cyclotron motion through the relativistic shift of the electron mass.

  14. Electron cyclotron maser based on the combination two-wave resonance

    SciTech Connect

    Savilov, A. V.

    2012-11-01

    A mechanism of a combination two-wave cyclotron interaction between an electron beam and the forward/backward components of a far-from-cutoff standing wave is analyzed. This regime can be promising for the realization of high-power continuous-wave electron cyclotron masers operating in the THz frequency range.

  15. Ion-cyclotron turbulence and diagonal double layers in a magnetospheric plasma

    NASA Technical Reports Server (NTRS)

    Liperovskiy, V. A.; Pudovkin, M. I.; Skuridin, G. A.; Shalimov, S. L.

    1981-01-01

    A survey of current concepts regarding electrostatic ion-cyclotron turbulence (theory and experiment), and regarding inclined double potential layers in the magnetospheric plasma is presented. Anomalous resistance governed by electrostatic ion-cyclotron turbulence, and one-dimensional and two-dimensional models of double electrostatic layers in the magnetospheric plasma are examined.

  16. Differential turbulent heating of different ions in electron cyclotron resonance ion source plasma

    SciTech Connect

    Elizarov, L.I.; Ivanov, A.A.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-03-15

    The article considers the collisionless ion sound turbulent heating of different ions in an electron cyclotron resonance ion source (ECRIS). The ion sound arises due to parametric instability of pumping wave propagating along the magnetic field with the frequency close to that of electron cyclotron. Within the framework of turbulent heating model the different ions temperatures are calculated in gas-mixing ECRIS plasma.

  17. Plasma injection and capture at electron cyclotron resonance in a mirror system with additional rf fields

    SciTech Connect

    Golovanivskii, K.S.; Dugar-Zhabon, V.D.; Karyaka, V.I.; Milant'ev, V.P.; Turikov, V.A.

    1980-03-01

    Experiments and numerical simulations have been carried out to determine how cyclotron-resonance rf fields in an open magnetic mirror system affect the capture and confinement of a plasma injected along the axis. The results show that at electron cyclotron resonance the fields greatly improve the longitudinal plasma confinement.

  18. Method and apparatus for preventing cyclotron breakdown in partially evacuated waveguide

    SciTech Connect

    Moeller, C P

    1987-08-18

    It is an object of this invention to provide a method and apparatus for preventing cyclotron breakdown in a partially evacuated waveguide used to insert microwave energy for electron cyclotron heating in a plasma magnetic confinement device. An electrostatic field is applied along a section of such a waveguide in order to run seed electrons into the wall of the waveguide.

  19. Nonlinear theory of drift-cyclotron kinetics and the possible breakdown of gyro-kinetics

    SciTech Connect

    Waltz, R. E.; Deng Zhao

    2013-01-15

    A nonlinear theory of drift-cyclotron kinetics (termed cyclo-kinetics here) is formulated to test the breakdown of the gyro-kinetic approximations. Six dimensional cyclo-kinetics can be regarded as an extension of five dimensional gyro-kinetics to include high-frequency cyclotron waves, which can interrupt the low-frequency gyro-averaging in the (sixth velocity grid) gyro-phase angle. Nonlinear cyclo-kinetics has no limit on the amplitude of the perturbations. Formally, there is no gyro-averaging when all cyclotron (gyro-phase angle) harmonics of the perturbed distribution function (delta-f) are retained. Retaining only the (low frequency) zeroth cyclotron harmonic in cyclo-kinetics recovers both linear and nonlinear gyro-kinetics. Simple recipes are given for converting continuum nonlinear delta-f gyro-kinetic transport simulation codes to cyclo-kinetics codes by retaining (at least some) higher cyclotron harmonics.

  20. Evolution of the axial electron cyclotron maser instability, with applications to solar microwave spikes

    NASA Technical Reports Server (NTRS)

    Vlahos, Loukas; Sprangle, Phillip

    1987-01-01

    The nonlinear evolution of cyclotron radiation from streaming and gyrating electrons in an external magnetic field is analyzed. The nonlinear dynamics of both the fields and the particles are treated fully relativistically and self-consistently. The model includes a background plasma and electrostatic effects. The analytical and numerical results show that a substantial portion of the beam particle energy can be converted to electromagnetic wave energy at frequencies far above the electron cyclotron frequency. In general, the excited radiation can propagate parallel to the magnetic field and, hence, escape gyrothermal absorption at higher cyclotron harmonics. The high-frequency Doppler-shifted cyclotron instability can have saturation efficiencies far higher than those associated with well-known instabilities of the electron cyclotron maser type. Although the analysis is general, the possibility of using this model to explain the intense radio emission observed from the sun is explored in detail.

  1. Response of thermal ions to electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.

    1994-01-01

    Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

  2. Response of thermal ions to electromagnetic ion cyclotron waves

    NASA Astrophysics Data System (ADS)

    Anderson, B. J.; Fuselier, S. A.

    1994-10-01

    Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

  3. Response of thermal ions to electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.

    1994-01-01

    Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

  4. Thermal Cyclotron Absorption Coefficients. II. Opacities in the Stokes Formalism

    NASA Astrophysics Data System (ADS)

    Vaeth, H. M.; Chanmugam, G.

    1995-05-01

    We extend the discussion of the calculation of the cyclotron opacities α± of the ordinary and extraordinary mode (Chanmugam et al.) to the opacities κ, q, υ in the Stokes formalism. We derive formulae with which a can be calculated from κ, q, υ. We are hence able to compare our calculations of the opacities, which are based on the single-particle method, with results obtained with the dielectric tensor method of Tam or. Excellent agreement is achieved. We present extensive tables of the opacities in the Stokes formalism for frequencies up to 25ωc, where ωc is the cyclotron frequency, and temperatures kT = 5, 10,20, 30,40, and 50 keV. Furthermore, we derive approximate formulae with which κ, q, υ can be calculated from α± and hence use the Robinson & Melrose analytic formulae for α± in order to calculate the opacities in the Stokes formalism. We compare these opacities to accurate numerical opacities and find that the analytic formulae can reproduce the qualitative behavior of the opacities in the regions where the harmonic structure is unimportant.

  5. Mode conversion at the higher ion cyclotron harmonics

    NASA Astrophysics Data System (ADS)

    Chiu, S. C.; Chan, V. S.; Harvey, R. W.; Porkolab, M.

    1989-07-01

    It has been demonstrated that mode conversion of fast waves to ion Bernstein waves can be calculated from a reduced second order differential equation for the wave fields rather than the 4th order equations used in earlier studies near the ion-ion hybrid resonance and the second harmonic resonance. Here the underlying justification of the method is discussed. It is shown that the method works for high harmonic resonances and an analytical formula for the tunneling coefficient is derived. The result is a generalization of a previous result obtained by Ngan and Swanson and is applicable when κ⊥ρi is large. Recently, there is interest in using fast waves for current drive at high ion cyclotron harmonics frequencies in tokamaks. Generally, the fast wave will encounter ion cyclotron harmonics within the plasma cross-section. For efficient current drive, the minimization of the mode conversion processes sets restrictions to the choice of frequencies and magnetic fields. This is discussed using the derived formula.

  6. Benchmark experiments for cyclotron-based neutron source for BNCT.

    PubMed

    Yonai, S; Itoga, T; Baba, M; Nakamura, T; Yokobori, H; Tahara, Y

    2004-11-01

    In the previous study, we found the feasibility of a cyclotron-based BNCT using the Ta(p,n) neutrons at 90 degrees bombarded by 50 MeV protons, and the iron, AlF(3), Al and (6)LiF moderators by simulations using the MCNPX code. In order to validate the simulations to realize the cyclotron-based BNCT, we measured the epithermal neutron energy spectrum passing through the moderators with our new spectrometer consisting of a (3)He gas counter covered with a silicon rubber loaded with (nat)B and polyethylene moderator and the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in an acrylic phantom set behind the rear surface of the moderators. The measured results were compared with the calculations using the MCNPX code. We obtained the good agreement between the calculations and measurements within approximately 10% for the neutron energy spectra and within approximately 20% for the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in the phantom. The comparison clarified a good accuracy of the calculation of the neutron energy spectrum passing through the moderator and the thermalization in a phantom. These experimental results will be a good benchmark data to evaluate the accuracy of the calculation code.

  7. Nonlinear decay of electromagnetic ion cyclotron waves in the magnetosphere

    SciTech Connect

    Gomberoff, L.; Gratton, F.T.; Gnavi, G.

    1995-02-01

    The authors study the parametric decays of left-hand polarized electromagnetic ion cyclotron waves, propagating parallel to the external magnetic field, in the magnetosphere. They show that the presence of He{sup +} ions and a mixed population of thermal and hot protons give rise to new wave couplings. These couplings lead to a number of new instabilities. Some of the instabilities involve sound waves carried mainly by the He{sup +} ions, which can be very efficient in heating up the bulk of the He{sup +} ions via Landau damping. Other instabilities involve the branch of the left-hand polarized electromagnetic ion cyclotron waves which has a resonance at the He{sup +} ion gyrofrequency. These instabilities can also play a role in the energy transfer from the pump wave to the He{sup +} ions through resonance absorption, preferably in the direction perpendicular to the external magnetic field. The new couplings give rise to several types of parametric instabilities such as ordinary decay instabilities, beat wave instabilities, and modulational instabilities. There are also couplings where the pump wave decays into the two electromagnetic sideband waves. 42 refs., 10 figs.

  8. Superconducting Ring Cyclotron for Riken RI Beam Factory in Japan

    NASA Astrophysics Data System (ADS)

    Okuno, H.; Dantsuka, T.; Yamada, K.; Kase, M.; Maie, T.; Kamigaito, O.

    2010-04-01

    Since 1997, RIKEN Nishina Center has been constructing the Radioactive Isotope Beam Factory (RIBF) and succeeded in beam commissioning of its accelerator complex at the end of 2006. The world's first superconducting ring cyclotron (SRC) is the final booster in the RIBF accelerator complex which is able to accelerate all-element heavy ions to a speed of about 70% of the velocity of light. The ring cyclotron consists of 6 major superconducting sector magnets with a maximum field of 3.8 T. The total stored energy is 235 MJ, and its overall sizes are 19 m diameter, 8 m height and 8,300 tons. The magnet system assembly was completed in August 2005, and successfully reached the maximum field in November 2005. The first beam was extracted at the end of 2006 and the first uranium beam was extracted in March 2007. However operation of the helium refrigerator was not satisfactory although the commissioning of SRC was successful. Operation was stopped every two month due to degradation of its cooling power. In February 2008 the reason of the degradation was revealed to be oil contamination. Operation of the cryogenic system was restarted from August 2008 after hard task to clean up the helium refrigerator and to add oil separators to the compressor. After restoration long-term steady operation to keep the magnet superconducting continued for about 8 months with no sign of degradation of cooling capacity.

  9. A study of density in electron-cyclotron-resonance plasma

    SciTech Connect

    Uhm, H.S.; Lee, P.H.; Kim, Y.I.; Kim, J.H.; Chang, H.Y.

    1995-08-01

    A theory is developed for the density profile of low-temperature plasmas confined by applied magnetic field and an experiment of the electron-cyclotron-resonance (ECR) plasma is conducted to compare the theoretical prediction and experimental measurements. Due to a large electron mobility along the magnetic field, electrons move quickly out of the system, leaving ions behind and building a space charge potential, which leads to the ambipolar diffusion of ions. In a steady-state condition, the plasma generation by ionization of neutral molecules is in balance with plasma loss due to the diffusion, leading to the electron temperature equation, which is expressed in terms of the plasma size, chamber pressure, and the ionization energy and cross section of neutrals. The power balance condition leads to the plasma density equation, which is also expressed in terms of the electron temperature, the input microwave power and the chamber pressure. It is shown that the plasma density increases, reaches its peak and decreases, as the chamber pressure increases from a small value (0.1 mTorr). These simple expressions of electron temperature and density provide a scaling law of ECR plasma in terms of system parameters. After carrying out an experimental observation, it is concluded that the theoretical predictions of the electron temperature and plasma density agree remarkably well with experimental data. A large-volume plasma generated by the electron-cyclotron-resonance (ECR) mechanism plays a pivotal role in the plasma processing, including thin-film depositions and plasma etching technologies.

  10. The variable cyclotron line of GX 301-2

    NASA Astrophysics Data System (ADS)

    Kreykenbohm, I.; Wilms, J.; Coburn, W.; Kuster, M.; Rothschild, R. E.; Heindl, W. A.; Kretschmar, P.; Staubert, R.

    2004-06-01

    We present a 200 ksec observation of the High Mass X-ray Binary GX 301-2 taken in 2000 November with the Rossi X-ray Timing Explorer during the pre-periastron flare and the actual periastron passage of the neutron star. To model the spectrum we use a power law with the Fermi Dirac cutoff and a cyclotron line at higher energies plus either a reflection component or a heavily absorbed partial covering component. Although completely different, both models describe the data equally well. Phase resolved spectra show that the energy and the depth of the cyclotron resonant scattering feature vary strongly with pulse phase: It is deepest in the fall of the main pulse, the rise of the secondary pulse, and the pulse minimum in-between with τC~0.3. In the other phase bins the line is much less deep with τC~0.1. The energy of the line correlates strongly with its depth and varies by 25 % from 30.1 keV in the fall of the secondary pulse to 37.9 keV in the fall of the main pulse.

  11. Design of the ion cyclotron system for TPX

    SciTech Connect

    Swain, D.; Shipley, S.; Yugo, J.; Goulding, R.; Batchelor, D.; Stallings, D. ); Fredd, E. . Plasma Physics Lab.)

    1993-01-01

    The TPX experiment will operate for very long pulse times ([ge] 1000 s) and will require current drive of several different types to explore the advanced physics operating modes as one of its main missions. Fast wave current drive (FWCD) using ion cyclotron waves in the 40--80 MHz range will be used as one of the main current-drive mechanisms. For initial operation, 8 MW of rf will be supplied, along with 8 MW of neutral beams and 1.5 MW of lower hybrid power. The ion cyclotron (IC) system is a major part of the TPX heating and current drive system. The IC system must: supply 8 MW of power through two main horizontal ports; be upgradable to provide up to 12 MW of rf power through two ports; operate, for 1000-s pulses every 75 min; drive current using FWCD with high reliability; be bakeable to 350[degree]C for cleaning; and incorporate shielding to attenuate the neutron and gamma flux from DD operation so that hands-on maintenance can be performed exterior to the vacuum vessel. The system will consist of four modified FMIT power units that will be upgraded to deliver 2 MW each to the plasma. Two antennas, each with six current straps, will be located in adjacent ports. A sophisticated matching system is needed to provide experimental flexibility and reliability.

  12. Design of the ion cyclotron system for TPX

    SciTech Connect

    Swain, D.; Shipley, S.; Yugo, J.; Goulding, R.; Batchelor, D.; Stallings, D.; Fredd, E.

    1993-06-01

    The TPX experiment will operate for very long pulse times ({ge} 1000 s) and will require current drive of several different types to explore the advanced physics operating modes as one of its main missions. Fast wave current drive (FWCD) using ion cyclotron waves in the 40--80 MHz range will be used as one of the main current-drive mechanisms. For initial operation, 8 MW of rf will be supplied, along with 8 MW of neutral beams and 1.5 MW of lower hybrid power. The ion cyclotron (IC) system is a major part of the TPX heating and current drive system. The IC system must: supply 8 MW of power through two main horizontal ports; be upgradable to provide up to 12 MW of rf power through two ports; operate, for 1000-s pulses every 75 min; drive current using FWCD with high reliability; be bakeable to 350{degree}C for cleaning; and incorporate shielding to attenuate the neutron and gamma flux from DD operation so that hands-on maintenance can be performed exterior to the vacuum vessel. The system will consist of four modified FMIT power units that will be upgraded to deliver 2 MW each to the plasma. Two antennas, each with six current straps, will be located in adjacent ports. A sophisticated matching system is needed to provide experimental flexibility and reliability.

  13. Electron cyclotron emission measurements on the Texas Experimental Tokamak

    SciTech Connect

    Austin, M.E. Jr.

    1992-01-01

    A ten-channel grating polychromator was designed, constructed, and installed on the Texas Experimental Tokamak to monitor the second harmonic electron cyclotron emission. Electron temperature profiles were derived from measurements of the optically thick radiation for a variety of plasma confinement experiments. The radial and temporal evolution of T[sub e] has been characterized for electron cyclotron heated discharges with 150 kW of 60 GHz power. Comparisons were made of the heating efficiency of two type of ECH launchers. A focussed launcher was shown to have slightly better heating efficiency than an unfocussed launcher; however, the focussed antenna did not yield significantly higher electron temperatures as expected. A study of the time evolution of the electron temperature indicated that increased sawtooth activity limited the effectiveness of the focussed launcher. A focussing hog-horn antenna was fabricated and installed on the inboard side of the tokamak to measure emission directed towards the high-field side during ECH. Comparison of the radiation temperature profiles from low-field side and high-field side antennas indicates the creation of a nonthermal electron distribution by the heating. The results of the experiment compare favorably with theoretical predictions from a quasi-linear Fokker-Planck code of a 6 keV nonthermal population with a density about 1 percent of the thermal density.

  14. Design of the ion cyclotron system for TPX

    NASA Astrophysics Data System (ADS)

    Swain, D.; Shipley, S.; Yugo, J.; Goulding, R.; Batchelor, D.; Stallings, D.; Fredd, E.

    The TPX experiment will operate for very long pulse times (greater than or equal to 1000 s) and will require current drive of several different types to explore the advanced physics operating modes as one of its main missions. Fast wave current drive (FWCD) using ion cyclotron waves in the 40-80 MHz range will be used as one of the main current-drive mechanisms. For initial operation, 8 MW of RF will be supplied, along with 8 MW of neutral beams and 1.5 MW of lower hybrid power. The ion cyclotron (IC) system is a major part of the TPX heating and current drive system. The IC system must: supply 8 MW of power through two main horizontal ports; be upgradable to provide up to 12 MW of RF power through two ports; operate, for 1000-s pulses every 75 min; drive current using FWCD with high reliability; be bakeable to 350(degree)C for cleaning; and incorporate shielding to attenuate the neutron and gamma flux from DD operation so that hands-on maintenance can be performed exterior to the vacuum vessel. The system will consist of four modified FMIT power units that will be upgraded to deliver 2 MW each to the plasma. Two antennas, each with six current straps, will be located in adjacent ports. A sophisticated matching system is needed to provide experimental flexibility and reliability.

  15. Vacuum system of the cyclotrons in VECC, Kolkata

    SciTech Connect

    Roy, Anindya; Bhole, R.B.; Akhtar, J.; Yadav, R.C.; Pal, Sarbajit; Sarkar, D.; Bhandari, R.K. E-mail: rbb@vecc.gov.in E-mail: yadav@vecc.gov.in E-mail: dsarkar@vecc.gov.in

    2011-07-01

    The vacuum system of the K=130 Room Temperature Cyclotron (RTC) (operational since 1978) has been recently modernized and the same of the K{sub bend}=520 Superconducting Cyclotron (SCC), currently under commissioning, is being deployed for remote monitoring and control. The vacuum system of RTC is designed to achieve and maintain vacuum level of 2 X 10{sup -6} mbar inside 23 m{sup 3} volume of Resonator tank and DEE tank. This has been upgraded by replacing several valves, Freon units, gauges and pumps. The relay based manual control system has been replaced by PLC based automated system. The SCC vacuum system also has an elaborate arrangement comprising of turbo molecular pumping modules with associated isolation valves and characteristic gauges. This paper describes essential elements, typically used to obtain high (1X10{sup -7} mbar) vacuum using rotary pumps, diffusion pumps and cold traps/turbo-molecular pumps and other system components such as valves, gauges and baffles. The supervisory control methodology/scheme of both the vacuum systems, developed in-house using EPICS (Experimental Physics and Industrial Control System), a standard open-source software tool for designing distributed control system, is also elaborated here. (author)

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

    NASA Astrophysics Data System (ADS)

    Baumgarten, C.

    2013-10-01

    We discuss the possibility in principle of stripping extraction in combination with reverse bends in isochronous separate-sector cyclotrons (and/or fixed field alternating gradient accelerators). If one uses reverse bends between the sectors (instead of or in combination with drifts) and places stripper foils at the sector exit edges, the stripped beam has a reduced bending radius and it should be able to leave the cyclotron within the range of the valley—even if the beam is stripped at less than full energy. We are especially interested in stripping of H2+, as it doubles the charge to mass ratio of the ions. However the method could be applied to other ions or ionized molecules as well. For the production of proton beams by stripping extraction of an H2+ beam, we discuss possible designs for three types of machines: First, a low-energy cyclotron for the simultaneous production of several beams at multiple energies—for instance 15, 30, and 70 MeV—thus allowing beam delivery on several isotope production targets. In this case it can be an advantage to have a strong energy dependence of the direction of the extracted beam. Second, we consider a fast variable-energy proton machine for cancer therapy that should allow extraction (of the complete beam) at all energies in the range of about 70 MeV to about 250 MeV into the same beam line. Third, we consider a high-intensity high-energy machine, where the main design goals are extraction with low losses, low activation of components, and high reliability. Especially if such a machine is considered for an accelerator driven system (ADS), this extraction mechanism has advantages: Beam trips by the failure of electrostatic elements could be avoided and the turn separation would be less critical, which allows operation at lower main cavity voltages. This would in turn reduce the number of rf trips. The price that has to be paid for these advantages is an increase in size and/or field strength compared to proton machines

  17. Electron cyclotron emission imaging and applications in magnetic fusion energy

    NASA Astrophysics Data System (ADS)

    Tobias, Benjamin John

    Energy production through the burning of fossil fuels is an unsustainable practice. Exponentially increasing energy consumption and dwindling natural resources ensure that coal and gas fueled power plants will someday be a thing of the past. However, even before fuel reserves are depleted, our planet may well succumb to disastrous side effects, namely the build up of carbon emissions in the environment triggering world-wide climate change and the countless industrial spills of pollutants that continue to this day. Many alternatives are currently being developed, but none has so much promise as fusion nuclear energy, the energy of the sun. The confinement of hot plasma at temperatures in excess of 100 million Kelvin by a carefully arranged magnetic field for the realization of a self-sustaining fusion power plant requires new technologies and improved understanding of fundamental physical phenomena. Imaging of electron cyclotron radiation lends insight into the spatial and temporal behavior of electron temperature fluctuations and instabilities, providing a powerful diagnostic for investigations into basic plasma physics and nuclear fusion reactor operation. This dissertation presents the design and implementation of a new generation of Electron Cyclotron Emission Imaging (ECEI) diagnostics on toroidal magnetic fusion confinement devices, or tokamaks, around the world. The underlying physics of cyclotron radiation in fusion plasmas is reviewed, and a thorough discussion of millimeter wave imaging techniques and heterodyne radiometry in ECEI follows. The imaging of turbulence and fluid flows has evolved over half a millennium since Leonardo da Vinci's first sketches of cascading water, and applications for ECEI in fusion research are broad ranging. Two areas of physical investigation are discussed in this dissertation: the identification of poloidal shearing in Alfven eigenmode structures predicted by hybrid gyrofluid-magnetohydrodynamic (gyrofluid-MHD) modeling, and

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

    SciTech Connect

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

    2013-01-15

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

  19. Electromagnetic ion cyclotron waves in the plasma depletion layer

    NASA Technical Reports Server (NTRS)

    Denton, Richard E.; Hudson, Mary K.; Fuselier, Stephen A.; Anderson, Brian J.

    1993-01-01

    Results of a study of the theoretical properties of electromagnetic ion cyclotron (EMIC) waves which occur in the plasma depletion layer are presented. The analysis assumes a homogeneous plasma with the characteristics which were measured by the AMPTE/CCE satellite at 1450-1501 UT on October 5, 1984. Waves were observed in the Pc 1 frequency range below the hydrogen gyrofrequency, and these waves are identified as EMIC waves. The higher-frequency instability is driven by the temperature anisotropy of the H(+) ions, while the lower-frequency instability is driven by the temperature anisotropy of the He(2+) ions. It is argued that the higher-frequency waves will have k roughly parallel to B(0) and will be left-hand polarized, while the lower frequency wave band will have k oblique to B(0) and will be linearly polarized, in agreement with observations.

  20. Electromagnetic ion cyclotron waves stimulated by modest magnetospheric compressions

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Hamilton, D. C.

    1993-01-01

    AMPTE/CCE magnetic field and particle data are used to test the suggestion that increased hot proton temperature anisotropy resulting from convection during magnetospheric compression is responsible for the enhancement in Pc 1 emission via generation of electromagnetic ion cyclotron (EMIC) waves in the dayside outer equatorial magnetosphere. The relative increase in magnetic field is used to gauge the strength of the compression, and an image dipole model is used to estimate the motion of the plasma during compression. Proton data are used to analyze the evolution of the proton distribution and the corresponding changes in EMIC wave activity expected during the compression. It is suggested that enhancements in dynamic pressure pump the energetic proton distributions in the outer magnetosphere, driving EMIC waves. Waves are expected to be generated most readily close to the magnetopause, and transient pressure pulses may be associated with bursts of EMIC waves, which would be observed on the ground in association with ionospheric transient signatures.

  1. Electromagnetic ion cyclotron waves observed in the plasma depletion layer

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.; Murr, D.

    1991-01-01

    Observations from AMPTE/CCE in the earth's magnetosheath on October 5, 1984 are presented to illustrate 0.1 - 4.0 Hz magnetic field pulsations in the subsolar plasma depletion layer (PDL) for northward sheath field during a magnetospheric compression. The PDL is unambiguously identified by comparing CCE data with data from IRM in the upstream solar wind. Pulsations in the PDL are dominated by transverse waves with F/F(H+) 1.0 or less and a slot in spectral power at F/F(H+) = 0.5. The upper branch is left hand polarized while the lower branch is linearly polarized. In the sheath the proton temperature anisotropy is about 0.6 but it is about 1.7 in the PDL during wave occurrence. The properties and correlation of waves with increased anisotropy indicate that they are electromagnetic ion cyclotron waves.

  2. Resonance of relativistic electrons with electromagnetic ion cyclotron waves

    DOE PAGES

    Denton, R. E.; Jordanova, V. K.; Bortnik, J.

    2015-06-29

    Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron EMIC waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motionmore » of the hot ring current protons that drive the instability. High density due to a plasmasphere or plasmaspheric plume could possibly lead to lower minimum resonance energy by causing the He band EMIC mode to be dominant. We demonstrate these points using parameters from a ring current simulation.« less

  3. Resonance of relativistic electrons with electromagnetic ion cyclotron waves

    SciTech Connect

    Denton, R. E.; Jordanova, V. K.; Bortnik, J.

    2015-06-29

    Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron EMIC waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motion of the hot ring current protons that drive the instability. High density due to a plasmasphere or plasmaspheric plume could possibly lead to lower minimum resonance energy by causing the He band EMIC mode to be dominant. We demonstrate these points using parameters from a ring current simulation.

  4. Recent developments of cyclotron produced radionuclides for nuclear cardiology

    NASA Astrophysics Data System (ADS)

    Kulkarni, P. V.; Jansen, D. E.; Corbett, J. R.

    1987-04-01

    For over a decade myocardial perfusion imaging with thallium-201, a cyclotron product, has been routinely used in clinical medicine. Recent advances have allowed the efficient production of very high purity (> 99.8%) iodine-123. New metabolically active 123I labeled radiopharmaceuticals, including alkyl and phenyl fatty acids, and norepinephrine analogs, have been developed and are undergoing clinical trials. Fab' fragments of monoclonal antibodies to cardiac myosin have been labeled with indium-111 ( 111In) and are undergoing clinical evaluation for imaging myocardial infarcts. Monoclonal antibodies to platelets, fibrin, and the thrombolytic agent, tissue plasminogen activator (TPA), have recently been labeled with 111In. Together these developments in radiotracers and instrumentation should have a significant impact on the future of cardiovascular nuclear medicine. This manuscript will discuss developments in single photon emitting radiotracers for myocardial imaging.

  5. Electromagnetic ion/ion cyclotron instability - Theory and simulations

    NASA Technical Reports Server (NTRS)

    Winske, D.; Omidi, N.

    1992-01-01

    Linear theory and 1D and 2D hybrid simulations are employed to study electromagnetic ion/ion cyclotron (EMIIC) instability driven by the relative streaming of two field-aligned ion beams. The characteristics of the instability are studied as a function of beam density, propagation angle, electron-ion temperature ratios, and ion beta. When the propagation angle is near 90 deg the EMIIC instability has the characteristics of an electrostatic instability, while at smaller angles electromagnetic effects play a significant role as does strong beam coupling. The 2D simulations point to a narrowing of the wave spectrum and accompanying coherent effects during the linear growth stage of development. The EMIIC instability is an important effect where ion beta is low such as in the plasma-sheet boundary layer and upstream of slow shocks in the magnetotail.

  6. Alternative optical concept for electron cyclotron emission imaging

    SciTech Connect

    Liu, J. X.; Milbourne, T.; Bitter, M.; Delgado-Aparicio, L.; Dominguez, A.; Efthimion, P. C.; Hill, K. W.; Kramer, G. J.; Kung, C.; Pablant, N. A.; Tobias, B.; Kubota, S.; Kasparek, W.; Lu, J.; Park, H.

    2014-11-15

    The implementation of advanced electron cyclotron emission imaging (ECEI) systems on tokamak experiments has revolutionized the diagnosis of magnetohydrodynamic (MHD) activities and improved our understanding of instabilities, which lead to disruptions. It is therefore desirable to have an ECEI system on the ITER tokamak. However, the large size of optical components in presently used ECEI systems have, up to now, precluded the implementation of an ECEI system on ITER. This paper describes a new optical ECEI concept that employs a single spherical mirror as the only optical component and exploits the astigmatism of such a mirror to produce an image with one-dimensional spatial resolution on the detector. Since this alternative approach would only require a thin slit as the viewing port to the plasma, it would make the implementation of an ECEI system on ITER feasible. The results obtained from proof-of-principle experiments with a 125 GHz microwave system are presented.

  7. Magnetic-field measurements for the Lewis Research Center cyclotron

    NASA Technical Reports Server (NTRS)

    Fessler, T. E.

    1973-01-01

    The magnetic field of the Lewis Center cyclotron was mapped by using a Hall-effect magnetic-field transducer. Main-field Fourier coefficients were determined on a polar mesh of 40 radii for each of seven levels of main-field coil current. Incremental fields for eight sets of trim coils and two sets of harmonic coils were also determined at four of these main-field levels. A stored-program, digital computer was used to perform the measurements. The process was entirely automatic; all data-taking and data-reduction activities were specified by the computer programs. A new method for temperature compensation of a Hall element was used. This method required no temperature control of the element. Measurements of the Hall voltage and Hall-element resistance were sufficient to correct for temperature effects.

  8. Characteristics of microinstabilities in electron cyclotron and ohmic heated discharges

    SciTech Connect

    Pusztai, I.; Moradi, S.; Fueloep, T.; Timchenko, N.

    2011-08-15

    Characteristics of microinstabilities in electron cyclotron (EC) and ohmic heated (OH) discharges in the T10 tokamak have been analyzed by linear electrostatic gyrokinetic simulations with gyro[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] aiming to find insights into the effect of auxiliary heating on the transport. Trapped electron modes are found to be unstable in both OH and the EC heated scenarios. In the OH case the main drive is from the density gradient and in the EC case from the electron temperature gradient. The growth rates and particle fluxes exhibit qualitatively different scaling with the electron-to-ion temperature ratios in the two cases. This is mainly due to the fact that the dominant drives and the collisionalities are different. The inward flow velocity of impurities and the impurity diffusion coefficient decreases when applying EC heating, which leads to lower impurity peaking, consistently with experimental observations.

  9. Characteristics of microinstabilities in electron cyclotron and ohmic heated discharges

    NASA Astrophysics Data System (ADS)

    Pusztai, I.; Moradi, S.; Fülöp, T.; Timchenko, N.

    2011-08-01

    Characteristics of microinstabilities in electron cyclotron (EC) and ohmic heated (OH) discharges in the T10 tokamak have been analyzed by linear electrostatic gyrokinetic simulations with gyro [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] aiming to find insights into the effect of auxiliary heating on the transport. Trapped electron modes are found to be unstable in both OH and the EC heated scenarios. In the OH case the main drive is from the density gradient and in the EC case from the electron temperature gradient. The growth rates and particle fluxes exhibit qualitatively different scaling with the electron-to-ion temperature ratios in the two cases. This is mainly due to the fact that the dominant drives and the collisionalities are different. The inward flow velocity of impurities and the impurity diffusion coefficient decreases when applying EC heating, which leads to lower impurity peaking, consistently with experimental observations.

  10. Transport induced by ion cyclotron range of frequencies waves

    SciTech Connect

    Zhang, Debing Xu, Yingfeng; Wang, Shaojie

    2014-11-15

    The Vlasov equation, which includes the effect of the ion cyclotron range of frequencies (ICRF) waves, can be written as the Fokker-Planck equation which describes the quasilinear transport in phase space by using the Lie-transform method. The radial transport fluxes of particle, energy and parallel momentum driven by ICRF waves in the slab geometry have been derived. The results show that the ICRF-induced radial redistributions of particle, energy and parallel momentum are driven by the inhomogeneity in energy of the equilibrium distribution function, and related to the correlation between the excursion in the real space and the excursion in energy. For the case with strong asymmetry of k{sub y} spectrum, the ICRF-induced radial transport driven by the energy inhomogeneity dominates the ICRF-induced radial transport driven by the spatial inhomogeneity.

  11. Finite banana width effect on magnetoacoustic cyclotron instability

    SciTech Connect

    Chen, Y.P.; Tsai, S.T.

    1995-08-01

    The finite banana width (FBW) effect on the coupling between magnetoacoustic waves and the near harmonic gyro-oscillations of the energetic ions/{alpha} particles in tokamaks are studied. The gyrokinetic equation with FBW effect is rederived for the energetic trapped ions. The dispersion relation and growth rate of the magnetoacoustic cyclotron instability (MACI) are obtained. It is found that the coherence interaction between the energetic ion trajectory and mode field has a significant effect when the Larmor radius of energetic ions is larger than the wavelength of MACI. Near the low field side the FBW effect destabilizes the mode, while away from it the FBW gives a stabilizing effect. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  12. Grating monochromator for electron cyclotron resonance ion source operation

    SciTech Connect

    Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shouichi; Watanabe, Shin-ichi; Yamaguchi, Hidetoshi; Shimoura, Susumu; Oyaizu, Michihiro; Kase, Masayuki; Kubono, Shigeru; Hattori, Toshiyuki

    2013-07-15

    Recently, we started to observe optical line spectra from an ECR plasma using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for beam tuning because it allows the extraction of the desired ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research gives new insights into its simplification. In this paper, the grating monochromator method for beam tuning of a Hyper-ECR ion source as an injector for RIKEN azimuthal varying field (AVF) cyclotron is described.

  13. Electron cyclotron beam measurement system in the Large Helical Device

    SciTech Connect

    Kamio, S. Takahashi, H.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Ito, S.; Kobayashi, S.; Mizuno, Y.; Okada, K.; Osakabe, M.; Mutoh, T.

    2014-11-15

    In order to evaluate the electron cyclotron (EC) heating power inside the Large Helical Device vacuum vessel and to investigate the physics of the interaction between the EC beam and the plasma, a direct measurement system for the EC beam transmitted through the plasma column was developed. The system consists of an EC beam target plate, which is made of isotropic graphite and faces against the EC beam through the plasma, and an IR camera for measuring the target plate temperature increase by the transmitted EC beam. This system is applicable to the high magnetic field (up to 2.75 T) and plasma density (up to 0.8 × 10{sup 19} m{sup −3}). This system successfully evaluated the transmitted EC beam profile and the refraction.

  14. Ion cyclotron harmonics in the Saturn downward current auroral region

    NASA Astrophysics Data System (ADS)

    Menietti, J. D.; Schippers, P.; Santolík, O.; Gurnett, D. A.; Crary, F.; Coates, A. J.

    2011-12-01

    Observations of intense upgoing electron beams and diffuse ion beams have been reported during a pass by Cassini in a downward current auroral region, nearby a source region of Saturn kilometric radiation. Using the Cassini Radio and Plasma Wave Science (RPWS) instrument low frequency waveform receiver and the Cassini Plasma Spectrometer Investigation (CAPS) instrument we have been able to identify ion cyclotron harmonic waves associated with the particle beams. These observations indicate similarities with terrestrial auroral emissions, and may be a source of wave-particle interactions. We fit the observed plasma electron distribution with drifting Maxwellians and perform a linear numerical analysis of plasma wave growth. The results are relevant to ion heating and possibly to electron acceleration.

  15. Normal and anomalous Doppler effects in periodic waveguide cyclotron maser

    SciTech Connect

    Korol, M.; Jerby, E.

    1995-12-31

    A linear analysis of the periodic-waveguide cyclotron (PWC) maser shows that the PWC interaction with fast-waves possesses properties of the known anomalous Doppler resonance interaction if the wave impedance of the resonant spatial harmonic, Z{sub n}, is much smaller than the free space impedance, i.e. if Z{sub n} {much_lt} Z{sub 0}. The feasibility of a fast-wave PWC interaction in a low impedance waveguide is examined theoretically in this paper. A practical scheme of a slotted-waveguide PWC operating in the fundamental harmonic near cutoff is proposed for a future experiment. The possible advantages of the quasi-anomalous Doppler effect in the fast-wave-PWC operating regime are the alleviation of the initial electron rotation and a high-efficiency operation.

  16. Nonresonant interaction of heavy ions with electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Berchem, J.; Gendrin, R.

    1985-01-01

    The motion of a heavy ion in the presence of an intense ultralow-frequency electromagnetic wave propagating along the dc magnetic field is analyzed. Starting from the basic equations of motion and from their associated two invariants, the heavy ion velocity-space trajectories are drawn. It is shown that after a certain time, particles whose initial phase angles are randomly distributed tend to bunch together, provided that the wave intensity b-sub-1 is sufficiently large. The importance of these results for the interpretation of the recently observed acceleration of singly charged He ions in conjunction with the occurrence of large-amplitude ion cyclotron waves in the equatorial magnetosphere is discussed.

  17. Determination of the Electron Cyclotron Current Drive Profile

    SciTech Connect

    Luce, T.C.; Petty, C.C.; Schuster, D.I.; Makowski, M.A.

    1999-11-01

    Evaluation of the profile of non-inductive current density driven by absorption of electron cyclotron waves (ECCD) using time evolution of the poloidal flux indicated a broader profile than predicted by theory. To determine the nature of this broadening, a 1-1/2 D transport calculation of current density evolution was used to generate the signals which the DIII-D motional Stark effect (MSE) diagnostic would measure in the event that the current density evolution followed the neoclassical Ohm's law with the theoretical ECCD profile. Comparison with the measured MSE data indicates the experimental data is consistent with the ECCD profile predicted by theory. The simulations yield a lower limit on the magnitude of the ECCD which is at or above the value found in Fokker-Planck calculations of the ECCD including quasilinear and parallel electric field effects.

  18. Cyclotron resonant scattering and absorption. [in gamma ray bursts

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.; Daugherty, Joseph K.

    1991-01-01

    The relativistic cross-sections for first-order absorption and second-order scattering are compared to determine the conditions under which the absorption cross-section is a good approximation to the much more complex scattering cross-section for purposes of modeling cyclotron lines in gamma-ray bursts. Differences in both the cross-sections and the line profiles are presented for a range of field strengths, angles, and electron temperatures. The relative difference of the cross-sections at one line width from resonance was found to increase with field strength and harmonic number. The difference is also strongly dependent on the photon angle to the magnetic field. For the field strength, 1.7 x 10 to the 12th G, and the angle inferred from the Ginga burst features, absorption is an excellent approximation for the profiles at the first and second harmonics.

  19. Electromagnetic ion cyclotron waves observed in the plasma depletion layer

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.; Murr, D.

    1991-01-01

    Observations from AMPTE/CCE in the earth's magnetosheath on October 5, 1984 are presented to illustrate 0.1 - 4.0 Hz magnetic field pulsations in the subsolar plasma depletion layer (PDL) for northward sheath field during a magnetospheric compression. The PDL is unambiguously identified by comparing CCE data with data from IRM in the upstream solar wind. Pulsations in the PDL are dominated by transverse waves with F/F(H+) 1.0 or less and a slot in spectral power at F/F(H+) = 0.5. The upper branch is left hand polarized while the lower branch is linearly polarized. In the sheath the proton temperature anisotropy is about 0.6 but it is about 1.7 in the PDL during wave occurrence. The properties and correlation of waves with increased anisotropy indicate that they are electromagnetic ion cyclotron waves.

  20. Nonresonant interactions of electromagnetic ion cyclotron waves with relativistic electrons

    NASA Astrophysics Data System (ADS)

    Chen, Lunjin; Thorne, Richard M.; Bortnik, Jacob; Zhang, Xiao-Jia

    2016-10-01

    The dynamics of relativistic electrons traveling through a parallel-propagating, monochromatic electromagnetic ion cyclotron (EMIC) wave in the Earth's dipole field are investigated via test particle simulations. Both resonant and nonresonant responses in electron pitch angle are considered, and the differences between the two are highlighted. Nonresonant electrons, with energies below the minimum resonant energy down to hundreds of keV, are scattered stochastically in pitch angle and can be scattered into the atmospheric loss cone. The nonresonant effect is attributed to the spatial edge associated with EMIC wave packets. A condition for effective nonresonant response is also provided. This effect is excluded from current quasi-linear theory and can be a potentially important loss mechanism of relativistic and subrelativistic electrons in the radiation belts.

  1. Pulsed magnetic field-electron cyclotron resonance ion source operation

    SciTech Connect

    Muehle, C.; Ratzinger, U.; Joest, G.; Leible, K.; Schennach, S.; Wolf, B.H.

    1996-03-01

    The pulsed magnetic field (PuMa)-electron cyclotron resonance (ECR) ion source uses a pulsed coil to improve the peak current by opening the magnetic bottle along the beam axis. After demonstration of the principle of the pulsed magnetic extraction, the ion source was tested with different gases. We received promising results from helium to krypton. The influence of the current in the pulsed coil on the analyzed ion current was measured. With increased current levels within the pulsed coil not only the pulse height of the PuMa pulse, but the pulse length can also be controlled. By using the pulsed coil the maximum of the charge state distribution can be shifted to higher charge states. {copyright} {ital 1996 American Institute of Physics.}

  2. Superconducting magnet for K-500 cyclotron at VECC, Kolkata

    NASA Astrophysics Data System (ADS)

    Saha, Subimal; Choudhury, Jayanta; Pal, Gautam; Hajra, D. P.; Dey, R.; Sur, Amitava; Bhandari, R. K.

    2009-06-01

    K-500 superconducting cyclotron is in the advanced stage of commissioning at VECC, Kolkata. Superconducting magnet is one of the major and critical component of the cyclotron. It has been successfully fabricated, installed, cooled down to 4.2 K by interfacing with LHe plant and energized to its rated current on 30th April, 2005 producing magnetic field of 4.8 T at median plane of cyclotron. The superconducting magnet (stored energy of 22MJ) consists of two coils (α and β), which were wound on a sophisticated coil winding machine set-up at VECC. The superconducting cable used for winding the coils is multi filamentary composite superconducting wire (1.29 mm diameter) having 500 filaments of 40 μm diameter Nb-Ti in copper matrix which is embedded in OFHC grade copper channel (2.794 mm × 4.978 mm) for cryogenic stability. The basic structure of coil consists of layer type helical winding on a SS bobbin of 1475 mm ID × 1930 mm OD × 1170 mm height. The bobbin was afterwards closed by SS sheet to form the LHe chamber. The total weight of the coil with bobbin was about 6 tonne and the total length of the superconducting cable wound was about 35 km. Winding was done at very high tension (2000 PSI) and close tolerance to restrict the movement of conductor and coil during energization. After coil winding, all four coils (two each on upper and lower half of median plane of cyclotron) were banded by aluminium strip (2.7 mm × 5 mm) at higher tension (20,000 PSI) to give more compressive force after cool down to 4.2 K for restricting the movement of coil while energizing and thereby eliminating the chances of quench during ramping of current. After completion of coil winding by October, 2003, cryostat assembly was taken up in house. The assembly of cryostat (13 tonne) with support links (9 Nos.) refrigeration port, instrumentation port, helium vapour cooled current loads, etc. was completed by June, 2004. Meanwhile assembly of magnet frame was taken up and the cryostat

  3. A simple electron cyclotron resonance ion source (abstract)a)

    NASA Astrophysics Data System (ADS)

    Welton, R. F.; Moran, T. F.; Feeney, R. K.; Thomas, E. W.

    1996-03-01

    A simple, all permanent magnet, 2.45 GHz electron cyclotron resonance ion source has been developed for the production of stable beams of low charge state ions from gaseous feed materials. The source can produce ˜1 mA of low energy (3 kV) singly charged ion current in the 10-4 Torr pressure range. The source can also be operated in a more efficient low-pressure mode at an order of magnitude lower pressure. In this latter range, for example, the ionization efficiency of Ar is estimated to be 1% with charge states up to Ar8+ present. Operation in the low-pressure mode requires low power input (˜20 W). These features make the source especially suited for use with small accelerator systems for a number of applications including ion implantation, mass spectrometry, and atomic collision experiments where multiply charged ions are desirable. Design details and performance characteristics of the source are presented.

  4. Electromagnetic ion/ion cyclotron instability - Theory and simulations

    NASA Technical Reports Server (NTRS)

    Winske, D.; Omidi, N.

    1992-01-01

    Linear theory and 1D and 2D hybrid simulations are employed to study electromagnetic ion/ion cyclotron (EMIIC) instability driven by the relative streaming of two field-aligned ion beams. The characteristics of the instability are studied as a function of beam density, propagation angle, electron-ion temperature ratios, and ion beta. When the propagation angle is near 90 deg the EMIIC instability has the characteristics of an electrostatic instability, while at smaller angles electromagnetic effects play a significant role as does strong beam coupling. The 2D simulations point to a narrowing of the wave spectrum and accompanying coherent effects during the linear growth stage of development. The EMIIC instability is an important effect where ion beta is low such as in the plasma-sheet boundary layer and upstream of slow shocks in the magnetotail.

  5. Characteristics of surface sterilization using electron cyclotron resonance plasma

    NASA Astrophysics Data System (ADS)

    Yonesu, Akira; Hara, Kazufumi; Nishikawa, Tatsuya; Hayashi, Nobuya

    2016-07-01

    The characteristics of surface sterilization using electron cyclotron resonance (ECR) plasma were investigated. High-energy electrons and oxygen radicals were observed in the ECR zone using electric probe and optical emission spectroscopic methods. A biological indicator (BI), Geobacillus stearothermophilus, containing 1 × 106 spores was sterilized in 120 s by exposure to oxygen discharges while maintaining a temperature of approximately 55 °C at the BI installation position. Oxygen radicals and high-energy electrons were found to be the sterilizing species in the ECR region. It was demonstrated that the ECR plasma could be produced in narrow tubes with an inner diameter of 5 mm. Moreover, sterilization tests confirmed that the spores present inside the narrow tube were successfully inactivated by ECR plasma irradiation.

  6. Cyclotron resonance maser experiment in a nondispersive waveguide

    SciTech Connect

    Jerby, E.; Shahadi, A.; Drori, R.

    1996-06-01

    A cyclotron-resonance maser (CRM) oscillator experiment in which a spiraling electron beam interacts with a transverse electromagnetic wave in a nondispersive waveguide is presented. The experiment employs a low-energy low-current electron beam in a two-wire (Lecher type) waveguide. The microwave output frequency is tuned in this experiment by the axial magnetic field in the range 3.5--6.0 GHz. A second harmonic emission is observed at {approximately}7 GHz. CRM theory shows that in a free-space TEM-mode interaction, the gain might be canceled due to the equal and opposite effects of the axial (Weibel) and the azimuthal bunching mechanisms. This balance is violated in the large transverse velocity regime (V{sub {perpendicular}} {much_gt} V{sub z}) in which the experiment operates. The tunability measurements of the CRM oscillator experiment in the nondispersive waveguide are discussed in view of the CRM theory.

  7. Commercial and PET radioisotope manufacturing with a medical cyclotron

    NASA Astrophysics Data System (ADS)

    Boothe, T. E.; McLeod, T. F.; Plitnikas, M.; Kinney, D.; Tavano, E.; Feijoo, Y.; Smith, P.; Szelecsényi, F.

    1993-06-01

    Mount Sinai has extensive experience in producing radionuclides for commercial sales and for incorporation into radiopharmaceuticals, including PET. Currently, an attempt is being made to supply radiochemicals to radiopharmaceutical manufacturers outside the hospital, to prepare radiopharmaceuticals for in-house use, and to prepare PET radiopharmaceuticals, such as 2-[F-18] FDG, for outside sales. This use for both commercial and PET manufacturing is atypical for a hospital-based cyclotron. To accomplish PET radiopharmaceutical sales, the hospital operates a nuclear pharmacy. A review of operational details for the past several years shows a continuing dependence on commercial sales which is reflected in research and developmental aspects and in staffing. Developmental efforts have centered primarily on radionuclide production, target development, and radiochemical processing optimization.

  8. Project 8: Towards cyclotron radiation emission spectroscopy on tritium

    NASA Astrophysics Data System (ADS)

    Fertl, Martin; Project 8 Collaboration

    2017-01-01

    Project 8 aims to determine the neutrino mass by making a precise measurement of the beta decay of molecular tritium (Q = 18.6 keV) using the recently demonstrated the technique of cyclotron radiation emission spectroscopy (CRES). We report on results for calibration measurements performed with Kr-83m in a gas cell that fulfills the stringent requirements for a measurement using tritium: cryogenic operation, safe tritium handling, a non-magnetic design, and a good microwave guide performance. The phased program that allows Project 8 to probe the neutrino mass range accessible using molecular tritium is described. Major financial support by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics to the University of Washington under Award Number DE-FG02-97ER41020 is acknowledged

  9. Application of compact electron cyclotron resonance ion source

    SciTech Connect

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Ogawa, H.; Hojo, S.; Kubo, T.; Kato, Y.; Biri, S.; Fekete, E.; Yoshida, Y.; Drentje, A. G.

    2008-02-15

    The compact electron cyclotron resonance (ECR) ion source with a permanent magnet configuration (Kei2 source) has been developed at National Institute of Radiological Sciences for a new carbon therapy facility. The Kei2 source was designed for production of C{sup 4+} ions; its performance such as beam intensity and stability has already reached the medical requirements. Therefore, the prototype development of the source for medical use is essentially finished. Recently, we have started a few studies on other applications of the source. One is the production of fullerenes in the ECR plasma and modified fullerenes with various atoms for new materials. A second application is the production of multiply charged ions (not only carbon) for ion implantation. In this paper, some basic experiments for these applications are reported.

  10. The technology of the ion cyclotron range of frequencies

    SciTech Connect

    Hoffman, D.J.; Barber, G.C.

    1988-01-01

    Plasma heating in the ion cyclotron range of frequencies (ICRF) is the least expensive means of accomplishing auxiliary heating in fusion experiments. RF systems comprise two major elements: the transmitter and the antenna. The state of the art for the transmitter is already at the megawatt level. The technology of the antenna is strongly coupled to the plasma character. Typically, these antennas are designed to operate at a high power density (1.2 kW/cm/sup 2/) with an efficiency of 96%. ICRF technology and options have improved over the past few years, owing to development and experiments; however, the optimal combination of options can be defined only when results from confinement experiments and test facilities are in hand. 19 refs., 5 figs., 1 tab.

  11. Ring Current Ion Coupling with Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2002-01-01

    A new ring current global model has been developed for the first time that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes wave evolution of electromagnetic ion cyclotron waves (EMIC). The coupled model is able to simulate, for the first time self-consistently calculated RC ion kinetic and evolution of EMIC waves that propagate along geomagnetic field lines and reflect from the ionosphere. Ionospheric properties affect the reflection index through the integral Pedersen and Hall coductivities. The structure and dynamics of the ring current proton precipitating flux regions, intensities of EMIC, global RC energy balance, and some other parameters will be studied in detail for the selected geomagnetic storms. The space whether aspects of RC modelling and comparison with the data will also be discussed.

  12. Ring Current Ion Coupling with Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov. G. V.; Gamayunov, K. V.; Jordanova, V. K.; Six, N. Frank (Technical Monitor)

    2002-01-01

    A new ring current global model has been developed that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes wave evolution of electromagnetic ion cyclotron waves (EMIC). The coupled model is able to simulate, for the first time self-consistently calculated RC ion kinetic and evolution of EMIC waves that propagate along geomagnetic field lines and reflect from the ionosphere. Ionospheric properties affect the reflection index through the integral Pedersen and Hall conductivities. The structure and dynamics of the ring current proton precipitating flux regions, intensities of EMIC global RC energy balance, and some other parameters will be studied in detail for the selected geomagnetic storms.

  13. Excitation of Electron Cyclotron Harmonic Waves in Earth's Magnetotail

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaojia

    This dissertation investigates the generation mechanism, spatial distribution and characteristics of electrostatic electron cyclotron harmonic (ECH) waves under different plasma sheet conditions, and quantifies the role of these waves in producing the diffuse aurora. THEMIS observations from five magnetotail seasons, along with ray-tracing, and electron diffusion codes have been utilized towards that goal. By modeling the wave growth and quasi-linear pitch-angle diffusion of electrons with realistic parameters for the magnetic field, loss-cone distribution and wave intensity (obtained from observations as a function of magnetotail location), we estimate the loss-cone fill ratio and the contribution of auroral energy flux from wave-induced electron precipitation. We conclude that ECH waves are the dominant driver of electron precipitation in the middle to outer magnetotail.

  14. Integrated modeling for ion cyclotron resonant heating in toroidal systems

    NASA Astrophysics Data System (ADS)

    Jucker, M.; Graves, J. P.; Cooper, W. A.; Mellet, N.; Johnson, T.; Brunner, S.

    2011-04-01

    An integrated model capable of self-consistent Ion Cyclotron Resonant Heating (ICRH) simulations has been developed. This model includes both full shaping and pressure effects, warm contributions to the dielectric tensor, pressure anisotropy and finite orbit width. It evolves the equilibrium, wave field and full hot particle distribution function until a self-consistent solution is found. This article describes the workings of the three codes VMEC, LEMan and VENUS and how they are linked for iterated computations in a code package we have named SCENIC. The package is thoroughly tested and it is demonstrated that a number of iterations have to be performed in order to find a consistent solution. Since the formulation of the problem can treat general 3D systems, we show a quasi-axisymmetric stellarator low power test case, and then concentrate on experimentally relevant Joint European Torus (JET) 2D configurations.

  15. Peculiarities of charged particle dynamics under cyclotron resonance conditions

    SciTech Connect

    Moiseev, S. S.; Buts, V. A.; Erokhin, N. S.

    2016-08-15

    Peculiarities of the dynamics of charged particles interacting with electromagnetic radiation under nearly autoresonance conditions are analyzed. In particular, analysis of nonlinear cyclotron resonances shows that their widths increase when the autoresonance conditions are approached. In this case, however, the distance between nonlinear resonances increases even faster, due to which nonlinear resonances do not overlap and, accordingly, regimes with dynamic chaos do not occur. According to calculations, the dynamics of charged particles under the autoresonance conditions is very sensitive to fluctuations, the effect of which can be anomalously large and lead to superdiffusion. It is shown that, under the autoresonance conditions, particle dynamics on small time intervals can differ significantly from that on large time intervals. This effect is most pronounced in the presence of fluctuations in the system.

  16. Ion source and low energy injection line for a central region model cyclotron

    SciTech Connect

    Zhang Tianjue; Li Zhenguo; Lu Yinlong; Wei Sumin; Cai Hongru; Ge Tao; Wu Longcheng; Pan Gaofeng; Yao Hongjuan; Kuo, T.; Yuan, D.

    2008-02-15

    At CIAE, a 100 MeV H{sup -} cyclotron (CYCIAE-100) is under design and construction. A central region model (CRM) cyclotron was built for various experimental verifications for the CYCIAE-100 project and for research and development of high current injection to accelerate milliampere H{sup -} beam. The H{sup -} multicusp source built in 2003 has been improved recently to make the source operation more stable. A new injection line for axial low energy high current injection has been designed and constructed for the CRM cyclotron.

  17. Intelligent low-level RF system by non-destructive beam monitoring device for cyclotrons

    NASA Astrophysics Data System (ADS)

    Sharifi Asadi Malafeh, M. S.; Ghergherehchi, M.; Afarideh, H.; Chai, J. S.; Yoon, Sang Kim

    2016-04-01

    The project of a 10 MeV PET cyclotron accelerator for medical diagnosis and treatment was started at Amirkabir University of Technology in 2012. The low-level RF system of the cyclotron accelerator is designed to stabilize acceleration voltage and control the resonance frequency of the cavity. In this work an Intelligent Low Level Radio Frequency Circuit or ILLRF, suitable for most AVF cyclotron accelerators, is designed using a beam monitoring device and narrow band tunable band-pass filter. In this design, the RF phase detection does not need signal processing by a microcontroller.

  18. Design Features Of K = 100 Cyclotron Magnet For ISOL RIB Production

    SciTech Connect

    Park, Jin Ah; Gad, Kh. M. M.; Chai, Jong-Seo

    2011-06-01

    K = 100 Separated Sector Cyclotron was designed in conceptual for the ISOL driver. It has 4 separated sector magnets. Two SF cyclotrons will be used as the injectors for separated sector cyclotron. RF frequency is 70 MHz, 4th harmonics. We have designed sector magnet without trim and harmonic coils. Minimum radius of the magnet is 55 cm and maximum radius is 1.8 m. Designed magnets were calculated and simulated by OPERA 3D (TOSCA) code. Ion beam dynamics calculations have been done using particle studio code to prove the focusing properties of the designed magnets.

  19. Magnetic system of a superconducting separated-sector cyclotron for hadron therapy

    NASA Astrophysics Data System (ADS)

    Smirnov, V. L.; Vorozhtsov, S. B.

    2017-07-01

    The development of a cyclotron magnetic system based on superconducting sector magnets is discussed. The cyclotron is conceived as a booster accelerator of a source of 12C6+ ions with energy of 400MeV/nucleon for the purposes of hadron therapy. The results of preliminary investigations aimed at developing such a facility have been reported in our previous papers. In this paper, we consider various configurations of the booster's magnetic system for various field levels. We also analyze the effects of the positions and shapes of superconducting coils on the magnetic field and select the optimum configuration for the cyclotron's magnetic system.

  20. Experiments on ion cyclotron damping at the deuterium fourth harmonic in DIII-D

    SciTech Connect

    Pinsker, R.I.; Petty, C.C.; Baity, F.W.; Bernabei, S.; Greenough, N.; Heidbrink, W.W.; Mau, T.K.; Porkolab, M.

    1999-05-01

    Absorption of fast Alfven waves by the energetic ions of an injected beam is evaluated in the DIII-D tokamak. Ion cyclotron resonance absorption at the fourth harmonic of the deuteron cyclotron frequency is observed with deuterium neutral beam injection (f = 60 MHz, B{sub T} = 1.9 T). Enhanced D-D neutron rates are evidence of absorption at the Doppler-shifted cyclotron resonance. Characteristics of global energy confinement provide further proof of substantial beam acceleration by the rf. In many cases, the accelerated deuterons cause temporary stabilization of the sawtooth (monster sawteeth), at relatively low rf power levels of {approximately}1 MW.

  1. Cyclotron production of (44)Sc: From bench to bedside.

    PubMed

    van der Meulen, Nicholas P; Bunka, Maruta; Domnanich, Katharina A; Müller, Cristina; Haller, Stephanie; Vermeulen, Christiaan; Türler, Andreas; Schibli, Roger

    2015-09-01

    (44)Sc, a PET radionuclide, has promising decay characteristics (T1/2 = 3.97 h, Eβ(+)av = 632 keV) for nuclear imaging and is an attractive alternative to the short-lived (68)Ga (T1/2 = 68 min, Eβ(+)av = 830 keV). The aim of this study was the optimization of the (44)Sc production process at an accelerator, allowing its use for preclinical and clinical PET imaging. (44)CaCO3 targets were prepared and irradiated with protons (~11 MeV) at a beam current of 50 μA for 90 min. (44)Sc was separated from its target material using DGA extraction resin and concentrated using SCX cation exchange resin. Radiolabeling experiments at activities up to 500 MBq and stability tests were performed with DOTANOC by investigating different scavengers, including gentisic acid. Dynamic PET of an AR42J tumor-bearing mouse was performed after injection of (44)Sc-DOTANOC. The optimized chemical separation method yielded up to 2 GBq (44)Sc of high radionuclidic purity. In the presence of gentisic acid, radiolabeling of (44)Sc with DOTANOC was achieved with a radiochemical yield of ~99% at high specific activity (10 MBq/nmol) and quantities which would allow clinical application. The dynamic PET images visualized increasing uptake of (44)Sc-DOTANOC into AR42J tumors and excretion of radioactivity through the kidneys of the investigated mouse. The concept "from-bench-to-bedside" was clearly demonstrated in this extended study using cyclotron-produced (44)Sc. Sufficiently high activities of (44)Sc of excellent radionuclidic purity are obtainable for clinical application, by irradiation of enriched calcium at a cyclotron. This work demonstrates a promising basis for introducing (44)Sc to clinical routine of nuclear imaging using PET. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Amplitudes of electron cyclotron waves transmitted in the ionosphere

    NASA Astrophysics Data System (ADS)

    James, H. G.

    2011-07-01

    During the two-point sounding rocket experiment Observations of Electric-field Distributions in the Ionospheric Plasma-A Unique Strategy-C (OEDIPUS-C, hereinafter OC), Bernstein or electron cyclotron waves (ECWs) were transmitted over magnetic field-aligned emitter-receiver separations of hundreds of meters. Signals were observed at harmonic frequencies mfc of the electron cyclotron frequency fc, where m was 2, 3, and 4, fc ≈ 1.3 MHz, and the electron plasma frequency was less than half of fc. The electric fields at 2fc radiated by the emitting dipoles have been computed from the inhomogeneous Helmholtz wave equation. Using the full hot plasma theory to evaluate the dielectric tensor, a Green's function has been derived, based partly on numerical inversion and facilitated by some simplifications made possible by the given frequency and plasma parameters. Under the assumption of straight-line rays, it is found that the computed absolute voltage levels induced on the receiving dipoles are of the same order of magnitude as the observed levels. The electric field E radiation patterns at 2fc are found to be highly elongated along the direction of the Earth's magnetic induction field B. The component of E perpendicular to B, the radial or ρ component, is much stronger than the other two components in a cylindrical coordinate system. The prediction of strong radial E magnitudes along ray directions very close to B is consistent with the OC observations. These results enlarge our appreciation of distinct characteristics of ECW radiation and propagation that may improve understanding of the role of these electrostatic waves in ionospheric dynamics.

  3. Flash ionization signature in coherent cyclotron emission from brown dwarfs

    NASA Astrophysics Data System (ADS)

    Vorgul, I.; Helling, Ch.

    2016-05-01

    Brown dwarfs (BDs) form mineral clouds in their atmospheres, where charged particles can produce large-scale discharges in the form of lightning resulting in substantial sudden increase of local ionization. BDs are observed to emit cyclotron radio emission. We show that signatures of strong transient atmospheric ionization events (flash ionization) can be imprinted on a pre-existing radiation. Detection of such flash ionization events will open investigations into the ionization state and atmospheric dynamics. Such events can also result from explosion shock waves, material outbursts or (volcanic) eruptions. We present an analytical model that describes the modulation of a pre-existing electromagnetic radiation by a time-dependent (flash) conductivity that is characteristic for flash ionization events like lightning. Our conductivity model reproduces the conductivity function derived from observations of terrestrial gamma-ray flashes, and is applicable to astrophysical objects with strong temporal variations in the local ionization, as in planetary atmospheres and protoplanetary discs. We show that the field responds with a characteristic flash-shaped pulse to a conductivity flash of intermediate intensity. More powerful ionization events result in smaller variations of the initial radiation, or in its damping. We show that the characteristic damping of the response field for high-power initial radiation carries information about the ionization flash magnitude and duration. The duration of the pulse amplification or the damping is consistently shorter for larger conductivity variations and can be used to evaluate the intensity of the flash ionization. Our work suggests that cyclotron emission could be probe signals for electrification processes inside BD atmosphere.

  4. A fast multichannel Martin-Puplett interferometer for electron cyclotron emission measurements on JET

    SciTech Connect

    Simonetto, A.; Sozzi, C.; Garavaglia, S.; Nowak, S.; Fessey, J. A.; Collaboration: JET-EFDA Contributors

    2011-11-15

    A Martin Puplett interferometer for electron cyclotron emission (ECE) measurements from JET tokamak plasmas was extended to multichannel operation for simultaneous radial and oblique ECE measurements. This paper describes the new optics and the instrument's performance.

  5. Cyclotron-absorption measurement of the runaway-electron distribution in a tokamak

    SciTech Connect

    Zvonkov, A.V.; Suvorov, E.V.; Timofeev, A.V.; Fraiman, A.A.

    1983-03-01

    The distribution function of runaway electrons in a tokamak can be determined in the slightly relativistic region from measurements of the absorption coefficient corresponding to electron cyclotron waves. The plasma should be probed in the vertical direction.

  6. Research and development of ion surfing RF carpets for the cyclotron gas stopper at the NSCL

    NASA Astrophysics Data System (ADS)

    Gehring, A. E.; Brodeur, M.; Bollen, G.; Morrissey, D. J.; Schwarz, S.

    2016-06-01

    A model device to transport thermal ions in the cyclotron gas stopper, a next-generation beam thermalization device under construction at the National Superconducting Cyclotron Laboratory, is presented. Radioactive ions produced by projectile fragmentation will come to rest at distances as large as 45 cm from the extraction orifice of the cyclotron gas stopper. The thermalized ions will be transported to the exit by RF carpets employing the recently developed "ion surfing" method. A quarter-circle prototype RF carpet was tested with potassium ions, and ion transport velocities as high as 60 m/s were observed over distances greater than 10 cm at a helium buffer gas pressure of 80 mbar. The transport of rubidium ions from an RF carpet to an electrode below was also demonstrated. The results of this study formed the basis of the design of the RF carpets for use in the cyclotron gas stopper.

  7. Cyclotron-based nuclear science. Progress report, April 1, 1979-March 31, 1980

    SciTech Connect

    Not Available

    1980-06-01

    Research at the cyclotron institute is summarized. These major areas are covered: nuclear structure; nuclear reactions and scattering; polarization studies; interdisciplinary nuclear science; instrumentation and systems development; and publications. (GHT)

  8. Cyclotron resonance phenomena in a non-neutral multispecies ion plasma

    SciTech Connect

    Sarid, E.; Anderegg, F.; Driscoll, C.F.

    1995-08-01

    Cyclotron modes of a non-neutral Mg ion plasma were studied in a long cylindrical Penning--Malmberg trap. Several modes with angular dependence exp({ital il}{theta}), {ital l}{ge}1, are observed near the cyclotron frequencies of the various Mg ions. The {ital l}=1 modes for the majority species are downshifted from the cyclotron frequencies, with downshifts as large as four times the diocotron frequency. These large shifts are quantitatively explained by a multispecies cold-plasma theory, including the dependence on the plasma size and composition. These dependencies allow the plasma size and composition to be obtained from the measured mode frequencies. In contrast, the {ital l}=1 downshifts for minority species are generally close to twice the diocotron frequency, and remain unexplained. Cyclotron heating of the plasma ions was also observed with a surprising effect of improving the plasma confinement. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  9. Target foil rupture scenario and provision for handling different models of medical cyclotrons used in India

    PubMed Central

    Shaiju, V. S.; Sharma, S. D.; Kumar, Rajesh; Sarin, B.

    2009-01-01

    Medical cyclotron is a particle accelerator used in producing short lived radiotracers such as 18F, 11C, 15O, 13N etc. These radiotracers are labeled with suitable pharmaceuticals for use to gather information related to metabolic activity of the cell using Positron Emission Tomography (PET) scan. Target foil rupture is considered one of the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron. Recommendations have also been made to reduce personal exposure while handling the target foil rupture condition such as the use of L-Bench near the target area and participation of experienced personnel. PMID:20098564

  10. Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions

    NASA Astrophysics Data System (ADS)

    Eliasson, B.; Speirs, D. C.; Daldorff, L. K. S.

    2016-09-01

    A theoretical study is presented of the electrostatic electron cyclotron instability involving Bernstein modes in a magnetized plasma. The presence of a tenuous thermal ring distribution in a Maxwellian plasma decreases the frequency of the upper hybrid branch of the electron Bernstein mode until it merges with the nearest lower branch with a resulting instability. The instability occurs when the upper hybrid frequency is somewhat above the third, fourth, and higher electron cyclotron harmonics, and gives rise to a narrow spectrum of waves around the electron cyclotron harmonic nearest to the upper hybrid frequency. For a tenuous cold ring distribution together with a Maxwellian distribution an instability can take place also near the second electron cyclotron harmonic. Noise-free Vlasov simulations are used to assess the theoretical linear growth-rates and frequency spectra, and to study the nonlinear evolution of the instability. The relevance of the results to laboratory and ionospheric heating experiments is discussed.

  11. Target foil rupture scenario and provision for handling different models of medical cyclotrons used in India.

    PubMed

    Shaiju, V S; Sharma, S D; Kumar, Rajesh; Sarin, B

    2009-07-01

    Medical cyclotron is a particle accelerator used in producing short lived radiotracers such as (18)F, (11)C, (15)O, (13)N etc. These radiotracers are labeled with suitable pharmaceuticals for use to gather information related to metabolic activity of the cell using Positron Emission Tomography (PET) scan. Target foil rupture is considered one of the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron. Recommendations have also been made to reduce personal exposure while handling the target foil rupture condition such as the use of L-Bench near the target area and participation of experienced personnel.

  12. Excitation of low frequency waves by streaming ions via anomalous cyclotron resonance

    NASA Technical Reports Server (NTRS)

    Wu, C. S.; Dillenburg, D.; Gaffey, J. D., Jr.; Ziebell, L. F.; Goedert, J.; Freund, H. P.

    1978-01-01

    The effect of a small population of streaming ions on low-frequency waves with frequencies below the ion cyclotron frequency is analyzed for three modes of interest: Alfven waves, magnetosonic waves, and ion-cyclotron waves. The instability mechanism is the anomalous cyclotron resonance of the waves with the streaming ions. Conditions for excitation of the three types of waves are derived and expressions for the growth rates are obtained. Excitation of Alfven waves is possible even if the ratio of the densities of the streaming ions to the thermal ions is very small. For magnetosonic waves, excitation can easily occur if waves are propagating parallel or nearly parallel to the ambient magnetic field. As for ion-cyclotron waves, it is found that for the ion-whistler branch the excitation is suppressed over a broader range of wave frequencies than for the fast magnetosonic branch.

  13. Vertical-viewing electron cyclotron emission diagnostic for the DIII-D tokamak

    SciTech Connect

    James, R.; Janz, S.; Ellis, R.; Boyd, D.; Lohr, J.

    1988-08-01

    The vertical-viewing electron cyclotron emission diagnostic on DIII-D will be used to assess the nonthermal electron distributions resulting from electron cyclotron heating and electron cyclotron current drive experiments. Electron cyclotron emission along a vertical chord is collected using an ellipsoidal focusing mirror and retroreflector (the latter to minimize wall reflections). The emission is then transported approx.20 m using a quasioptical transport system composed of eight lenses and three mirrors, and detected between the 2nd and the 10th harmonics by a fast-scanning (40-Hz) Michelson interferometer. The entire system has been aligned using a Gaussian beam simulator and absolutely calibrated in situ using a cold liquid-nitrogen bath. Details of the design, installation, and calibration will be discussed.

  14. Selenogenic Ion Cyclotron Waves: ARTEMIS Observations and Implications for the Lunar Exosphere

    NASA Astrophysics Data System (ADS)

    Chi, P. J.; Wei, H. Y.; Farrell, W. M.; Halekas, J. S.

    2015-10-01

    The ARTEMIS spacecraft near the Moon have detected narrowband ion cyclotron waves during the lunar passes through the Earth’s magnetotail. The observations suggest a possible connection to the ions escaping from the lunar exosphere.

  15. Environmental Assessment: UCLA biomedical research CS-22 cyclotron replacement, University of California at Los Angeles

    SciTech Connect

    Not Available

    1992-05-01

    DOE proposes to participate in the joint funding, along with the National Institutes of Health (NIH) and private donors, of a new biomedical cyclotron research instrument for UCLA. DOE proposes to provide funding in the amount of $500,000 to UCLA for removal and disposal of the existing 19 year old CS-22 cyclotron and refitting of the existing room, plus $900,000 (of the $1.5 million total cost) for installation of a new generation Cyclone 18/9 biomedical isotope compact cyclotron. The remaining $600,000 for the new instrument would be provided by NIH and private donors. The total cost for the entire project is $2,0000,000. Operation and use of the instrument would be entirely by UCLA. The Biomedical Cyclotron Facility is a line item included on UCLA`s Broad Scope A License. The CS-22 cyclotron was turned over to UCLA`s jurisdiction by DOE in 1989 when the Laboratory of Biomedical and Environmental Sciences General Contract with DOE was changed to a Cooperative Agreement, and ``Clause B`` involving safety responsibility was terminated. In support of this, a large closeout survey was performed, licensing actions were completed, and it was agreed that environmental, health and safety compliance would be UCLA`s responsibility. Since the CS022 cyclotron was DOE property prior to the above changes, DOE proposes to provide this entire funding for its removal and disposal, and to provide partial funding for its replacement. This report describes the removal of the existing cyclotron, and the operation and installation of a new cyclotron as well as any associated environmental impacts.

  16. Rapid Current Ramp-Up by Cyclotron-Driving Electrons beyond Runaway Velocity

    SciTech Connect

    Uchida, M.; Yoshinaga, T.; Tanaka, H.; Maekawa, T.

    2010-02-12

    The toroidal current has been rapidly ramped-up after the formation of an initial closed flux surface in an electron cyclotron heated discharge in the low aspect ratio torus experiment device. A current carrying fast electron tail is developed well beyond the runaway velocity against the reverse voltage from self-induction, suggesting a forward driving force on the tail by the cyclotron absorption of high N{sub ||} electron Bernstein waves.

  17. Infra red active modes due to coupling of cyclotron excitation and LO phonons in polar semiconductor

    NASA Astrophysics Data System (ADS)

    Agrawal, Ratna; Dubey, Swati; Ghosh, S.

    2013-06-01

    Effects of free carrier concentration, external magnetic field and Callen effective charge on infra red active modes in a polar semiconductor have been analytically investigated using simple harmonic oscillator model. Callen effective charge considerably enhances reflectivity and shifts minima towards lower values of energy. Presence of magnetic field leads towards the coupling of collective cyclotron excitations with LO phonon giving rise to maximum reflectivity whereas cyclotron resonance absorption results into minimum reflectivity.

  18. Electrostatic Ion-Cyclotron Waves in Magnetospheric Plasmas: Non-Local Aspects.

    DTIC Science & Technology

    1983-10-14

    shear can completely damp the universal drift instability). Recently Waltz and Dominguez (1981), motivated by the TFR (1978) tokamak experiment, have...Drift-Wave Eigen Modes Unstable?, Phy. Rev. Lett., 40, 324, 1978. TFR Group, Ion-Cyclotron Instability in the TFR Tokamak , Phys. Rev. Lett., 41, 113...1978. Waltz, R.E. and R.R. Dominguez, Ion Cyclotron Modes in Tokamaks , Phys. Fluids, 24, 1575, 1981. 29 -%7 DISTRIBUTION LIST Director (Institute of

  19. Environmental Assessment: UCLA biomedical research CS-22 cyclotron replacement, University of California at Los Angeles

    SciTech Connect

    Not Available

    1992-01-01

    DOE proposes to participate in the joint funding, along with the National Institutes of Health (NIH) and private donors, of a new biomedical cyclotron research instrument for UCLA. DOE proposes to provide funding in the amount of $500,000 to UCLA for removal and disposal of the existing 19 year old CS-22 cyclotron and refitting of the existing room, plus $900,000 (of the $1.5 million total cost) for installation of a new generation Cyclone 18/9 biomedical isotope compact cyclotron. The remaining $600,000 for the new instrument would be provided by NIH and private donors. The total cost for the entire project is $2,0000,000. Operation and use of the instrument would be entirely by UCLA. The Biomedical Cyclotron Facility is a line item included on UCLA's Broad Scope A License. The CS-22 cyclotron was turned over to UCLA's jurisdiction by DOE in 1989 when the Laboratory of Biomedical and Environmental Sciences General Contract with DOE was changed to a Cooperative Agreement, and Clause B'' involving safety responsibility was terminated. In support of this, a large closeout survey was performed, licensing actions were completed, and it was agreed that environmental, health and safety compliance would be UCLA's responsibility. Since the CS022 cyclotron was DOE property prior to the above changes, DOE proposes to provide this entire funding for its removal and disposal, and to provide partial funding for its replacement. This report describes the removal of the existing cyclotron, and the operation and installation of a new cyclotron as well as any associated environmental impacts.

  20. Applications of Electron Cyclotron Waves in the DIII-D Tokamak

    SciTech Connect

    Prater, R.; Cengher, M.; Gorelov, I. A.; Lohr, J.; Ponce, D.

    2009-11-26

    Electron cyclotron heating (ECH) and electron cyclotron current drive (ECCD) have progressed from being the subject of experiments to being a prime tool for carrying out experiments on other topics. ECH has different characteristics than neutral beam heating: ECH heats only the electrons, heats very locally and controllably, does not inject momentum or particles, and may be arranged to drive highly localized currents or to just heat. These differences make ECH useful in a very wide range of experiments.

  1. Status of the Berkeley small cyclotron AMS (accelerator mass spectrometry) project

    SciTech Connect

    Bertsche, K.J.; Friedman, P.G.; Morris, D.E.; Muller, R.A.; Welch, J.J.

    1987-04-01

    A small, low-energy cyclotron has been designed and built at Berkeley for direct detection dating of /sup 14/C. The system combines the use of a negative ion source to reject /sup 14/N with the high resolution of a cyclotron to reject other background ions. In order to allow the dating of old and small samples, the present system incorporates a high-current external ion source and injection beamline. The system is expected to be operational by mid-1987.

  2. Saturation of cyclotron maser instability driven by an electron loss-cone distribution

    NASA Technical Reports Server (NTRS)

    Kuo, S. P.; Lee, M. C.

    1986-01-01

    The resonance diffusion of electrons in velocity space caused by the excited EM wave fields is considered to be the dominant saturation process of cyclotron maser instability that is driven by an electron loss-cone distribution. An upper bound of the saturation level is derived analytically. Since the resulting saturation level is low, the resonance diffusion is indeed responsible for the saturation of the cyclotron maser instability.

  3. Simulation, Design, and Testing of a High Power Collimator for the RDS-112 Cyclotron

    PubMed Central

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

    2015-01-01

    A high power [F-18]fluoride target package for the RDS-112 cyclotron has been designed, tested, and commercially deployed. The upgrade includes the CF-1000 target, a 1.3 kW water target with an established commercial history on RDS-111/Eclipse cyclotrons, and a redesigned collimator with improved heat rejection capabilities. Conjugate heat transfer analyses were employed to both evaluate the existing collimator capabilities and design a suitable high current replacement. PMID:25562677

  4. Coupling of electrostatic ion cyclotron and ion acoustic waves in the solar wind

    SciTech Connect

    Sreeraj, T.; Singh, S. V. Lakhina, G. S.

    2016-08-15

    The coupling of electrostatic ion cyclotron and ion acoustic waves is examined in three component magnetized plasma consisting of electrons, protons, and alpha particles. In the theoretical model relevant to solar wind plasma, electrons are assumed to be superthermal with kappa distribution and protons as well as alpha particles follow the fluid dynamical equations. A general linear dispersion relation is derived for such a plasma system which is analyzed both analytically and numerically. For parallel propagation, electrostatic ion cyclotron (proton and helium cyclotron) and ion acoustic (slow and fast) modes are decoupled. For oblique propagation, coupling between the cyclotron and acoustic modes occurs. Furthermore, when the angle of propagation is increased, the separation between acoustic and cyclotron modes increases which is an indication of weaker coupling at large angle of propagation. For perpendicular propagation, only cyclotron modes are observed. The effect of various parameters such as number density and temperature of alpha particles and superthermality on dispersion characteristics is examined in details. The coupling between various modes occurs for small values of wavenumber.

  5. Evaluation of the latent radiation dose from the activated radionuclides in a cyclotron vault

    NASA Astrophysics Data System (ADS)

    Kim, Hyunduk; Cho, Gyuseong; Kim, Sun A.; Kang, Bo Sun

    2015-02-01

    The production of short-lived radioisotopes for the synthesis of radiopharmaceuticals typically takes advantage of a cyclotron that accelerates a proton beam up to a few tens of MeV. The number of cyclotrons has been continuously increasing since the first operation of the MC-50 for the production of radiopharmaceuticals at the Korea Institute of Radiological & Medical Sciences (KIRAMS) in 1986, and currently 35 cyclotrons are under operation throughout the nation. As the number of operating cyclotrons has increased, concerns about radiation safety for the persons who are working at the facilities and dwelling in the vicinity of the facilities are becoming important issues. Radiation that could emit a time-dependent dose was shown to exist in a cyclotron vault after its shutdown. The calculation of the latent radiation dose rate was performed by using the MCNPX and the FISPACT. The calculated results for the activated long-lived radioisotopes in the concrete wall and the structural components of the cyclotron facility were compared with the measured data that were obtained by using gamma-ray spectroscopy with a HPGe detector.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10-9-10-6 ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a 12C5+ beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased.

  7. Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

    NASA Technical Reports Server (NTRS)

    Persoon, A. M.; Peterson, W. K.; Andre, M.; Chang, T.; Gurnett, D. A.; Retterer, J. M.; Crew, G. B.

    1997-01-01

    Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low- frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies.

  8. Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

    NASA Technical Reports Server (NTRS)

    Persoon, A. M.; Peterson, W. K.; Andre, M.; Chang, T.; Gurnett, D. A.; Retterer, J. M.; Crew, G. B.

    1997-01-01

    Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low-frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies.

  9. Variations of cyclotron line energy with luminosity in accreting X-ray pulsars

    SciTech Connect

    Nishimura, Osamu

    2014-01-20

    I develop a new model for changes of cyclotron line energy with luminosity based on changes in polar cap dimensions and the direction of photon propagation as well as a shock height. In X0115+63 and V0332+53, the fundamental cyclotron line energy has been observed to decrease with increasing luminosity. This phenomenon has been interpreted as a change of a shock height with luminosity. However, the rates of the observed changes are quite different, in which the line energy in V0332+53 varies slowly with luminosity compared with that in X0115+63. I demonstrate that a new model successfully reproduces the changes of the fundamental cyclotron line energies with luminosity in both X0115+63 and V0332+53. On the other hand, the cyclotron line energies in Her X–1, GX301–2, and GX304–1 were reported to increase with increasing luminosity. I discuss the positive correlation between the cyclotron line energy and luminosity based on changes in a beam pattern for Her X–1, GX301–2, and GX304–1. In addition, I discuss how a switch of the predominant, observed emission region from pole1 to pole2 influences cyclotron line energy for GX304–1 and A0535+26.

  10. Upstream proton cyclotron waves at Venus near solar maximum

    NASA Astrophysics Data System (ADS)

    Delva, M.; Bertucci, C.; Volwerk, M.; Lundin, R.; Mazelle, C.; Romanelli, N.

    2015-01-01

    magnetometer data of Venus Express are analyzed for the occurrence of waves at the proton cyclotron frequency in the spacecraft frame in the upstream region of Venus, for conditions of rising solar activity. The data of two Venus years up to the time of highest sunspot number so far (1 Mar 2011 to 31 May 2012) are studied to reveal the properties of the waves and the interplanetary magnetic field (IMF) conditions under which they are observed. In general, waves generated by newborn protons from exospheric hydrogen are observed under quasi- (anti)parallel conditions of the IMF and the solar wind velocity, as is expected from theoretical models. The present study near solar maximum finds significantly more waves than a previous study for solar minimum, with an asymmetry in the wave occurrence, i.e., mainly under antiparallel conditions. The plasma data from the Analyzer of Space Plasmas and Energetic Atoms instrument aboard Venus Express enable analysis of the background solar wind conditions. The prevalence of waves for IMF in direction toward the Sun is related to the stronger southward tilt of the heliospheric current sheet for the rising phase of Solar Cycle 24, i.e., the "bashful ballerina" is responsible for asymmetric background solar wind conditions. The increase of the number of wave occurrences may be explained by a significant increase in the relative density of planetary protons with respect to the solar wind background. An exceptionally low solar wind proton density is observed during the rising phase of Solar Cycle 24. At the same time, higher EUV increases the ionization in the Venus exosphere, resulting in higher supply of energy from a higher number of newborn protons to the wave. We conclude that in addition to quasi- (anti)parallel conditions of the IMF and the solar wind velocity direction, the higher relative density of Venus exospheric protons with respect to the background solar wind proton density is the key parameter for the higher number of

  11. Lower hybrid current drive favoured by electron cyclotron radiofrequency heating

    NASA Astrophysics Data System (ADS)

    Cesario, R.; Amicucci, L.; Cardinali, A.; Castaldo, C.; Marinucci, M.; Giruzzi, G.; Napoli, F.; Galli, A.; Schettini, G.; Tuccillo, A. A.

    2014-02-01

    The important goal of adding to the bootstrap a fraction of non-inductive plasma current, which would be controlled for obtaining and optimizing steady-state profiles, can be reached by using the Current Drive produced by Lower Hybrid waves (LHCD). FTU (Frascati Tokamak Upgrade) experiments demonstrated, indeed, that LHCD is effective at reactor-graded high plasma density, and the LH spectral broadening is reduced, operating with higher electron temperature in the outer region of plasma column (Te_periphery). This method was obtained following the guidelines of theoretical predictions indicating that the broadening of launched spectrum produced by parametric instability (PI) should be reduced, and the LHCD effect at high density consequently enabled, under higher (Te_periphery). In FTU, the temperature increase in the outer plasma region was obtained by operating with reduced particle recycling, lithized walls and deep gas fuelling by means of fast pellet. Heating plasma periphery with electron cyclotron resonant waves (ECRH) will provide a further tool for achieving steady-state operations. New FTU experimental results are presented here, demonstrating that temperature effect at the plasma periphery, affecting LH penetration, occurs in a range of plasma parameters broader than in previous work. New information is also shown on the modelling assessing frequencies and growth rates of the PI coupled modes responsible of spectral broadening. Finally, we present the design of an experiment scheduled on FTU next campaign, where ECRH power is used to slightly increase the electron temperature in the outer plasma region of a high-density discharge aiming at restoring LHCD. Consequent to model results, by operating with a toroidal magnetic field of 6.3 T, useful for locating the electron cyclotron resonant layer at the periphery of the plasma column (r/a˜0.8, f0=144 GHz), an increase of Te in the outer plasma (from 40 eV to 80 eV at r/a˜0.8) is expected by the JETTO code

  12. Lower hybrid current drive favoured by electron cyclotron radiofrequency heating

    SciTech Connect

    Cesario, R.; Cardinali, A.; Castaldo, C.; Marinucci, M.; Tuccillo, A. A.; Giruzzi, G.; Napoli, F.; Schettini, G.

    2014-02-12

    The important goal of adding to the bootstrap a fraction of non-inductive plasma current, which would be controlled for obtaining and optimizing steady-state profiles, can be reached by using the Current Drive produced by Lower Hybrid waves (LHCD). FTU (Frascati Tokamak Upgrade) experiments demonstrated, indeed, that LHCD is effective at reactor-graded high plasma density, and the LH spectral broadening is reduced, operating with higher electron temperature in the outer region of plasma column (T{sub e-periphery}). This method was obtained following the guidelines of theoretical predictions indicating that the broadening of launched spectrum produced by parametric instability (PI) should be reduced, and the LHCD effect at high density consequently enabled, under higher (T{sub e-periphery}). In FTU, the temperature increase in the outer plasma region was obtained by operating with reduced particle recycling, lithized walls and deep gas fuelling by means of fast pellet. Heating plasma periphery with electron cyclotron resonant waves (ECRH) will provide a further tool for achieving steady-state operations. New FTU experimental results are presented here, demonstrating that temperature effect at the plasma periphery, affecting LH penetration, occurs in a range of plasma parameters broader than in previous work. New information is also shown on the modelling assessing frequencies and growth rates of the PI coupled modes responsible of spectral broadening. Finally, we present the design of an experiment scheduled on FTU next campaign, where ECRH power is used to slightly increase the electron temperature in the outer plasma region of a high-density discharge aiming at restoring LHCD. Consequent to model results, by operating with a toroidal magnetic field of 6.3 T, useful for locating the electron cyclotron resonant layer at the periphery of the plasma column (r/a∼0.8, f{sub 0}=144 GHz), an increase of T{sub e} in the outer plasma (from 40 eV to 80 eV at r/a∼0.8) is

  13. Broadband terahertz-power extracting by using electron cyclotron maser.

    PubMed

    Pan, Shi; Du, Chao-Hai; Qi, Xiang-Bo; Liu, Pu-Kun

    2017-08-04

    Terahertz applications urgently require high performance and room temperature terahertz sources. The gyrotron based on the principle of electron cyclotron maser is able to generate watt-to-megawatt level terahertz radiation, and becomes an exceptional role in the frontiers of energy, security and biomedicine. However, in normal conditions, a terahertz gyrotron could generate terahertz radiation with high efficiency on a single frequency or with low efficiency in a relatively narrow tuning band. Here a frequency tuning scheme for the terahertz gyrotron utilizing sequentially switching among several whispering-gallery modes is proposed to reach high performance with broadband, coherence and high power simultaneously. Such mode-switching gyrotron has the potential of generating broadband radiation with 100-GHz-level bandwidth. Even wider bandwidth is limited by the frequency-dependent effective electrical length of the cavity. Preliminary investigation applies a pre-bunched circuit to the single-mode wide-band tuning. Then, more broadband sweeping is produced by mode switching in great-range magnetic tuning. The effect of mode competition, as well as critical engineering techniques on frequency tuning is discussed to confirm the feasibility for the case close to reality. This multi-mode-switching scheme could make gyrotron a promising device towards bridging the so-called terahertz gap.

  14. SPECE: a code for Electron Cyclotron Emission in tokamaks

    SciTech Connect

    Farina, D.; Figini, L.; Platania, P.; Sozzi, C.

    2008-03-12

    The code SPECE has been developed for the analysis of electron cyclotron emission (ECE) in a general tokamak equilibrium. The code solves the radiation transport equation along the ray trajectories in a tokamak plasma, in which magnetic equilibrium and plasma profiles are given either analytically or numerically, for a Maxwellian plasma or a non thermal plasma characterized by a distribution function that is the sum of drifting Maxwellian distributions. Ray trajectories are computed making use of the cold dispersion relation, while the absorption and emission coefficients are obtained solving the relevant fully relativistic dispersion relation valid at high electron temperature. The actual antenna pattern is simulated by means of a multi-rays calculation, and the spatial resolution of the ECE measurements is computed by means of an algorithm that takes properly into account the emission along each ray of the beam. Wall effects are introduced in the code by means of a heuristic model. Results of ECE simulations in a standard ITER scenario are presented.

  15. Electron cyclotron emission spectrometry on the Tokamak a Configuration Variable

    SciTech Connect

    Klimanov, I.; Porte, L.; Alberti, S.; Blanchard, P.; Fasoli, A.; Goodman, T.P.

    2005-09-15

    Electron cyclotron emission (ECE) measurements are an important component of the diagnostic suite on the Tokamak a Configuration Variable (TCV) [F. Hoffman et al., Plasma Phys. Controlled Fusion 36, B277 (1994)]. A recently installed, 24-channel dual-conversion heterodyne radiometer covering the radio frequency range 65-100 GHz and viewing from the low-field side (LFS) of the tokamak greatly enhances the system and, in combination with an existing radiometer viewing from the high-field side (HFS), allows simultaneous measurements of emission from the HFS and LFS. In addition, the new radiometer has multiple lines of sight that can receive the emission perpendicular to the toroidal magnetic field as well as with a finite k{sub parallel} (wave vector parallel to magnetic field). Such flexibility allows the LFS radiometer to make standard measurements of thermal emission and nonstandard measurements of nonthermal, anisotropic emission. The toroidal line of sight allows access to overdense plasma via mode converted emission. The enhanced ECE diagnostic is described and examples of measurements made in various configurations are presented.

  16. Ultradeep electron cyclotron resonance plasma etching of GaN

    DOE PAGES

    Harrison, Sara E.; Voss, Lars F.; Torres, Andrea M.; ...

    2017-07-25

    Here, ultradeep (≥5 μm) electron cyclotron resonance plasma etching of GaN micropillars was investigated. Parametric studies on the influence of the applied radio-frequency power, chlorine content in a Cl2/Ar etch plasma, and operating pressure on the etch depth, GaN-to-SiO2 selectivity, and surface morphology were performed. Etch depths of >10 μm were achieved over a wide range of parameters. Etch rates and sidewall roughness were found to be most sensitive to variations in RF power and % Cl2 in the etch plasma. Selectivities of >20:1 GaN:SiO2 were achieved under several chemically driven etch conditions where a maximum selectivity of ~39:1 wasmore » obtained using a 100% Cl2 plasma. The etch profile and (0001) surface morphology were significantly influenced by operating pressure and the chlorine content in the plasma. Optimized etch conditions yielded >10 μm tall micropillars with nanometer-scale sidewall roughness, high GaN:SiO2 selectivity, and nearly vertical etch profiles. These results provide a promising route for the fabrication of ultradeep GaN microstructures for use in electronic and optoelectronic device applications. In addition, dry etch induced preferential crystallographic etching in GaN microstructures is also demonstrated, which may be of great interest for applications requiring access to non- or semipolar GaN surfaces.« less

  17. Cyclotron Production of Radionuclides for Nuclear Medicine at Academic Centers

    NASA Astrophysics Data System (ADS)

    Lapi, Suzanne

    2016-09-01

    The increase in use of radioisotopes for medical imaging has led to the development of new accelerator targetry and separation techniques for isotope production. For example, the development of longer-lived position emitting radionuclides has been explored to allow for nuclear imaging agents based on peptides, antibodies and nanoparticles. These isotopes (64Cu, 89Zr, 86Y) are typically produced via irradiation of solid targets on smaller cyclotrons (10-25 MeV) at academic or hospital based facilities. Recent research has further expanded the toolbox of PET tracers to include additional isotopes such as 52Mn, 55Co, 76Br and others. The smaller scale of these types of facilities can enable the straightforward involvement of students, thus adding to the next generation of nuclear science leaders. Research pertaining to development of robust and larger scale production technologies including solid target systems and remote systems for transport and purification of these isotopes has enabled both preclinical and clinical imaging research for many diseases. In particular, our group has focused on the use of radiolabeled antibodies for imaging of receptor expression in preclinical models and in a clinical trial of metastatic breast cancer patients.

  18. A Michelson Interferometer for Electron Cyclotron Emission Measurements on EAST

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Stefan, Schmuck; Zhao, Hailin; John, Fessey; Paul, Trimble; Liu, Xiang; Zhu, Zeying; Zang, Qing; Hu, Liqun

    2016-12-01

    A Michelson interferometer, on loan from EFDA-JET (Culham, United Kingdom) has recently been commissioned on the experimental advanced superconducting tokamak (EAST, ASIPP, Hefei, China). Following a successful in-situ absolute calibration the instrument is able to measure the electron cyclotron emission (ECE) spectrum, from 80 GHz to 350 GHz in extraordinary mode (X-mode) polarization, with high accuracy. This allows the independent determination of the electron temperature profile from observation of the second harmonic ECE and the possible identification of non-Maxwellian features by comparing higher harmonic emission with numerical simulations. The in-situ calibration results are presented together with the initial measured temperature profiles. These measurements are then discussed and compared with other independent temperature profile measurements. This paper also describes the main hardware features of the diagnostic and the associated commissioning test results. supported by National Natural Science Foundation of China (Nos. 11405211, 11275233), and the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB106002, 2015GB101000), and the RCUK Energy Programme (No. EP/I501045), partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics (NSFC: No. 11261140328)

  19. Fourth generation electron cyclotron resonance ion sources (invited)

    SciTech Connect

    Lyneis, Claude M.; Leitner, D.; Todd, D. S.; Sabbi, G.; Prestemon, S.; Caspi, S.; Ferracin, P.

    2008-02-15

    The concepts and technical challenges related to developing a fourth generation electron cyclotron resonance (ECR) ion source with a rf frequency greater than 40 GHz and magnetic confinement fields greater than twice B{sub ECR} will be explored in this article. Based on the semiempirical frequency scaling of ECR plasma density with the square of operating frequency, there should be significant gains in performance over current third generation ECR ion sources, which operate at rf frequencies between 20 and 30 GHz. While the third generation ECR ion sources use NbTi superconducting solenoid and sextupole coils, the new sources will need to use different superconducting materials, such as Nb{sub 3}Sn, to reach the required magnetic confinement, which scales linearly with rf frequency. Additional technical challenges include increased bremsstrahlung production, which may increase faster than the plasma density, bremsstrahlung heating of the cold mass, and the availability of high power continuous wave microwave sources at these frequencies. With each generation of ECR ion sources, there are new challenges to be mastered, but the potential for higher performance and reduced cost of the associated accelerator continues to make this a promising avenue for development.

  20. Electron cyclotron resonance deposition of diamond-like films

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Pool, F. S.

    1990-01-01

    Electron cyclotron resonance (ECR) microwave plasma CVD has been developed at low pressures (0.0001 - 0.01 torr) and at ambient and high substrate temperatures (up to 750 C), to achieve large-area (greater than 4 in. diameter) depositions of diamondlike amorphous carbon (a - C:H) films. The application of a RF bias to the substrate stage, which induces a negative self-bias voltage, is found to play a critical role in determining carbon bonding configurations and in modifying the film morphology. There are two distinct types of ECR-deposited diamondlike films. One type of diamondlike film exhibits a Raman spectrum consisting of broad and overlapping, graphitic D (1360/cm, line width = 280/cm) and G (1590/cm, line width 140/cm) lines, and the other type has a broad Raman peak centered at appoximately 1500/cm. Examination of plasma species by optical emission spectroscopy shows no correlation between the CH-asterisk emission intensity and the deposition rate of diamondklike films.

  1. High current DC negative ion source for cyclotron

    NASA Astrophysics Data System (ADS)

    Etoh, H.; Onai, M.; Aoki, Y.; Mitsubori, H.; Arakawa, Y.; Sakuraba, J.; Kato, T.; Mitsumoto, T.; Hiasa, T.; Yajima, S.; Shibata, T.; Hatayama, A.; Okumura, Y.

    2016-02-01

    A filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In Cs-free operation, continuous H- beam of 10 mA and D- beam of 3.3 mA were obtained stably at an arc-discharge power of 3 kW and 2.4 kW, respectively. In Cs-seeded operation, H- beam current reached 22 mA at a lower arc power of 2.6 kW with less co-extracted electron current. The optimum gas flow rate, which gives the highest H- current, was 15 sccm in the Cs-free operation, while it decreased to 4 sccm in the Cs-seeded operation. The relationship between H- production and the design/operating parameters has been also investigated by a numerical study with KEIO-MARC code, which gives a reasonable explanation to the experimental results of the H- current dependence on the arc power.

  2. Cyclotron accelerated beams applied in wear and corrosion studies

    NASA Astrophysics Data System (ADS)

    Racolta, P. M.; Popa-Simil, L.; Ivanov, E. A.; Alexandreanu, B.

    1996-05-01

    Wear and corrosion processes are characterized by a loss of material that is, for machine parts and components, usually in a micrometer's range. That is why, in the last two decades, many direct applications in machine construction, petrochemical and metallurgical industries based on the Thin Layer Activation (TLA) technique have been developed. In this paper general working patterns together with a few examples of TLA applications carried out using our laboratory's U-120 Cyclotron are presented. The relation between the counting rate of the radiation originating from the component's irradiated zone and the loss of the worn material can be determined mainly by two methods: the oil circulation method and the remnant radioactivity measuring method. The first method is illustrated with some typical examples such as the optimization of the running-in program of a diesel engine and anti-wear features certifying of lubricant oils. There is also presented an example where the second method mentioned above has been applied to corrosion rate determinations for different kinds of unoxidable steels used in inert gas generator construction.

  3. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    NASA Astrophysics Data System (ADS)

    Tang, J. F.; Wu, D. J.; Chen, L.; Zhao, G. Q.; Tan, C. M.

    2016-05-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool for understanding FEBs and the solar plasma environment in which they propagate along solar magnetic fields. In particular, the evolution of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field during propagation can significantly influence the efficiency and properties of their emissions. In this paper, we discuss the possible evolution of the energy spectrum and velocity distribution of FEBs due to energy loss processes and the pitch-angle effect caused by magnetic field inhomogeneity, and we analyze the effects of the evolution on electron-cyclotron maser (ECM) emission, which is one of the most important mechanisms for producing solar radio bursts by FEBs. Our results show that the growth rates all decrease with the energy loss factor Q, but increase with the magnetic mirror ratio σ as well as with the steepness index δ. Moreover, the evolution of FEBs can also significantly influence the fastest growing mode and the fastest growing phase angle. This leads to the change of the polarization sense of the ECM emission. In particular, our results also reveal that an FEB that undergoes different evolution processes will generate different types of ECM emission. We believe the present results to be very helpful for a more comprehensive understanding of the dynamic spectra of solar radio bursts.

  4. Precipitation of Relativistic Electrons by Electromagnetic Ion Cyclotron (EMIC) Waves

    NASA Astrophysics Data System (ADS)

    Denton, R. E.

    2015-12-01

    We use the electromagnetic ion cyclotron (EMIC) wave fields produced in a two dimensional hybrid code simulation (full dynamics particle ions, but inertialess fluid electrons) in dipole geometry in order to investigate the effect of magnetospheric EMIC waves on relativistic electrons. The plane of the simulation includes variation in the L shell direction and along magnetic field lines. Relativistic test particle electrons are inserted into the simulation when the wave fields are near their maximum amplitude. These electrons can be scattered into the loss cone so that they precipitate into the ionosphere. We find the effective pitch angle diffusion coefficient and probability of precipitation using these test particles. The pitch angle diffusion coefficients are largest for relativistic energies greater than 2 MeV, though they may be substantial for lower energies. The probability of precipitation is highest for low energy particles at small initial equatorial pitch angle. For high initial equatorial pitch angles, the probability of precipitation increases greatly with respect to particle energy. Starting from an isotropic pitch angle distribution of relativistic electrons with a Gaussian spread in the relativistic momentum, we find only a small drop in the probability of precipitation during 13 s time as the particle energy decreases. But that result depends on the initial pitch angle distribution. Starting with a distribution of particles steeply peaked at 90° initial equatorial pitch angle, the probability of precipitation would be greater for high-energy particles. We will discuss the mechanism of pitch angle scattering.

  5. High current DC negative ion source for cyclotron

    SciTech Connect

    Etoh, H. Aoki, Y.; Mitsubori, H.; Arakawa, Y.; Sakuraba, J.; Kato, T.; Mitsumoto, T.; Hiasa, T.; Yajima, S.; Onai, M.; Hatayama, A.; Shibata, T.; Okumura, Y.

    2016-02-15

    A filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In Cs-free operation, continuous H{sup −} beam of 10 mA and D{sup −} beam of 3.3 mA were obtained stably at an arc-discharge power of 3 kW and 2.4 kW, respectively. In Cs-seeded operation, H{sup −} beam current reached 22 mA at a lower arc power of 2.6 kW with less co-extracted electron current. The optimum gas flow rate, which gives the highest H{sup −} current, was 15 sccm in the Cs-free operation, while it decreased to 4 sccm in the Cs-seeded operation. The relationship between H{sup −} production and the design/operating parameters has been also investigated by a numerical study with KEIO-MARC code, which gives a reasonable explanation to the experimental results of the H{sup −} current dependence on the arc power.

  6. Ion cyclotron transmission spectroscopy in the Tokamak Fusion Test Reactor

    SciTech Connect

    Greene, G.J.

    1993-09-01

    The propagation of waves in the ion cyclotron range of frequencies has been investigated experimentally in the Tokamak Fusion Test Reactor. A small, broadband, radiofrequency (rf) magnetic probe located outside the plasma limiter, at a major radius near that of the plasma center, was excited with a low power, frequency swept source (1--200 MHz). Waves propagating to a distant location were detected with a second, identical probe. The rf transmission spectrum revealed a region of attenuation over a band of frequencies for which the minority fundamental resonance was located between the outer plasma edge and the major radius of the probe location. Distinct, non-overlapping attenuation bands were observed from hydrogen and helium-3 minority species; a distinct tritium band should be observed in future DT experiments. Rapid spectrum acquisition during a helium-3 gas puff experiment showed that the wave attenuation involved the plasma core and was not a surface effect. A model in which the received power varied exponentially with the minority density, averaged over the resonance region, fit the time evolution of the probe signal relatively well. Estimation of a 1-d tunneling parameter from the experimental observations is discussed. Minority concentrations of less than 0.5 % can be resolved with this measurement.

  7. Ion cyclotron resonance heating in SST-1 tokamak

    SciTech Connect

    Bora, D.; Mukherjee, A.; Singh, J. P.; Gangopadhyay, S.; Kumar, Sunil; Singh RF Group, Raj

    1999-09-20

    Multimegawatt ion cyclotron resonance heating (ICRH) system is being developed for the steady state superconducting takamak SST-1 (1), which would form an important heating scheme during non-inductive steady state operation. 1.5 MW of RF power at different frequencies between 22-92 MHz is to be delivered to the plasma for pulse lengths of upto 1000 s. Water cooled antenna, interface and 9 inch Tx-line will ensure safe operation for long pulse operation. Three stages of matching would ensure maximum power coupling to the plasma. Power would be coupled to the plasma through two sets of antennae consisting of two strips in antenna box positioned 180 degree opposite to each other with capability of handling 0.8 MW/m{sup 2} heat load. Electromagnetic stress analysis of the antenna assembly shows that maximum 1.37 kNm torque would be exerted during plasma disruption operating at 3.0 T, 220 kA plasma current. Impurity generation by ICRH antennae is not so severe.

  8. Plume properties measurement of an Electron Cyclotron Resonance Accelerator

    NASA Astrophysics Data System (ADS)

    Correyero, Sara; Vialis, Theo; Jarrige, Julien; Packan, Denis

    2016-09-01

    Some emergent technologies for Electric Propulsion, such as the Electron Cyclotron Resonance Accelerator (ECRA), include magnetic nozzles to guide and expand the plasma. The advantages of this concept are well known: wall-plasma contact is avoided, it provides a current-free plume, it can allow to control thrust by modifying the magnetic field geometry, etc. However, their industrial application requires the understanding of the physical mechanisms involved, such as the electron thermodynamics at the plasma plume expansion, which is crucial to determine propulsive performances. This work presents a detailed characterization of the plasma plume axial profile in an ECR plasma thruster developed at ONERA. Langmuir, emissive, Faraday and ion energy probes are used to measure the electric potential space evolution, the current and electron energy distribution function in the plume, from the near field to the far field. The experimental results are compared with a quasi-1D (paraxial) steady-state kinetic model of a quasineutral collisionless magnetized plasma which is able to determine consistently the axial evolution of the electric potential and the electron and ion distribution functions with their associated properties.

  9. Multi-harmonic electron cyclotron instabilities. [diffuse electron aurora

    NASA Technical Reports Server (NTRS)

    Ashour-Abdalla, M.; Kennel, C. F.

    1978-01-01

    The reported investigation constitutes an extension of studies conducted by Ashour-Abdalla and Kennel (1975, 1976, 1978) with respect to a basic plasma model of Young et al. (1973). The model involves a combination of a cold Maxwellian background plasma, a hot plasma, and a 'loss cone' type of free energy source. Previous results on the first cyclotron harmonic bands are extended to multiharmonics. The significance of the obtained relations is discussed and tentative conclusions are presented. Given that the spatial growth rates of the convective modes are comparable, and that simultaneous nonconvective instability (NCI) is possible, it is concluded that multiharmonic emissions ought to be a common feature of the magnetospheric electrostatic wave observations. Since the volume of parameter space for which the first harmonic is NCI, and the volume for which the convective first harmonic mode has significant spatial growth rates, exceed those for the higher harmonics, first harmonic waves should be the most commonly observed and the higher harmonics should usually be accompanied by the first harmonic.

  10. Electron cyclotron plasma startup in the GDT experiment

    NASA Astrophysics Data System (ADS)

    Yakovlev, D. V.; Shalashov, A. G.; Gospodchikov, E. D.; Solomakhin, A. L.; Savkin, V. Ya.; Bagryansky, P. A.

    2017-01-01

    We report on a new plasma startup scenario in the gas dynamic trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) plasma heating system fires into a sufficiently dense plasma target (‘seed plasma’), which is commonly supplied by an arc plasma generator. In the reported experiments, a different approach to seed plasma generation is explored. One of the channels of the electron cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of plasma to a level suitable for NBI capture. After a short transition of approximately 1 ms the discharge becomes essentially similar to a standard one initiated by the plasma gun. This paper presents the discharge scenario and experimental data on the seed plasma evolution during ECRH, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of the consequent high-power NBI discharge are studied and differences from the conventional scenario are discussed. A theoretical model describing the ECR breakdown and the seed plasma accumulation in a large-scale mirror trap is developed on the basis of the GDT experiment.

  11. Parallel Spectral Acquisition with an Ion Cyclotron Resonance Cell Array.

    PubMed

    Park, Sung-Gun; Anderson, Gordon A; Navare, Arti T; Bruce, James E

    2016-01-19

    Mass measurement accuracy is a critical analytical figure-of-merit in most areas of mass spectrometry application. However, the time required for acquisition of high-resolution, high mass accuracy data limits many applications and is an aspect under continual pressure for development. Current efforts target implementation of higher electrostatic and magnetic fields because ion oscillatory frequencies increase linearly with field strength. As such, the time required for spectral acquisition of a given resolving power and mass accuracy decreases linearly with increasing fields. Mass spectrometer developments to include multiple high-resolution detectors that can be operated in parallel could further decrease the acquisition time by a factor of n, the number of detectors. Efforts described here resulted in development of an instrument with a set of Fourier transform ion cyclotron resonance (ICR) cells as detectors that constitute the first MS array capable of parallel high-resolution spectral acquisition. ICR cell array systems consisting of three or five cells were constructed with printed circuit boards and installed within a single superconducting magnet and vacuum system. Independent ion populations were injected and trapped within each cell in the array. Upon filling the array, all ions in all cells were simultaneously excited and ICR signals from each cell were independently amplified and recorded in parallel. Presented here are the initial results of successful parallel spectral acquisition, parallel mass spectrometry (MS) and MS/MS measurements, and parallel high-resolution acquisition with the MS array system.

  12. Electron-cyclotron maser and solar microwave millisecond spike emission

    NASA Technical Reports Server (NTRS)

    Li, Hong-Wei; Li, Chun-Sheng; Fu, Qi-Jun

    1986-01-01

    An intense solar microwave millisecond spike emission (SMMSE) event was observed on May 16, 1981 by Zhao and Jin at Beijing Observatory. The peak flux density of the spikes is high to 5 x 100,000 s.f.u. and the corresponding brightness temperature (BT) reaches approx. 10 to the 15th K. In order to explain the observed properties of SMMSE, it is proposed that a beam of electrons with energy of tens KeV injected from the acceleration region downwards into an emerging magnetic arch forms so-called hollow beam distribution and causes electron-cyclotron maser (ECM) instability. The growth rate of second harmonic X-mode is calculated and its change with time is deduced. It is shown that the saturation time of ECM is t sub s approx. equals 0.42 ms and only at last short stage (delta t less than 0.2 t sub s) the growth rate decreases to zero rather rapidly. So a SMMSE with very high BT will be produced if the ratio of number density of nonthermal electrons to that of background electrons, n sub s/n sub e, is larger than 4 x .00001.

  13. Observation of Ion Cyclotron Heating in a Fast-flowing Plasma for an Advanced Plasma Thruster

    NASA Astrophysics Data System (ADS)

    Ando, Akira; Hatanaka, Motoi; Shibata, Masaki; Tobari, Hiroyuki; Hattori, Kunihiko; Inutake, Masaaki

    2004-11-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) project in NASA, the combined system of the ion cyclotron heating and the magnetic nozzle is proposed to control a ratio of specific impulse to thrust at constant power. In order to establish the advanced plasma thruster, experiments of an ion heating and plasma acceleration by a magnetic nozzle are performed in a fast-flowing plasma in the HITOP device. A fast-flowing He plasma is produced by Magneto-Plasma-Dynamic Arcjet (MPDA) operated with an externally-applied magnetic field up to 1kG. RF waves with an ion cyclotron range of frequency (f=20-300kHz) is excited by a helically-wound antenna located downstream of the MPDA. Increases of an ion temperature and plasma stored energy measured by a diamagnetic coil clearly observed during the RF pulse. The heating efficiency is compared for various magnetic field configurations and strengths. There appears no indication of cyclotron resonance in a high density plasma where the ratio of ion cyclotron frequency to ion-ion collision one is below unity, because an ion-ion collisional effect is dominant. When the density becomes low and the ratio of ion cyclotron frequency to ion-ion collision one becomes high, features of ion cyclotron resonance are clearly appeared. The optimum magnetic field strength for the ion heating is slightly lower than that of the cyclotron resonance, which is caused by the Doppler effect due to the fast-flowing plasma. An ion energy distribution function is measured at a magnetic nozzle region by an electrostatic analyzer and increase of the parallel velocity is also observed.

  14. ARTEMIS-B: A room-temperature test electron cyclotron resonance ion source for the National Superconducting Cyclotron Laboratory at Michigan State University

    SciTech Connect

    Machicoane, G.; Cole, D.; Ottarson, J.; Stetson, J.; Zavodszky, P.

    2006-03-15

    The current scheme for ion-beam injection into the coupled cyclotron accelerator at the NSCL involves the use of two electron cyclotron resonance (ECR) ion sources. The first one is a 6.4 GHz fully superconducting that will be replaced within two years by SUSI, a third generation 18 GHz superconducting ECR ion source. The other source, ARTEMIS, is a room-temperature source based on the AECR-U design and built in collaboration with the University of Jyvaeskylae in 1999. Due to cyclotron operation constraint, very little time can be allowed to ion source development and optics studies of the cyclotron injection beam line. In this context, NSCL has decided to build ARTEMIS-B an exact replica of its room-temperature ECR ion source. The goal of this project is threefold. One is to improve the overall reliability of cyclotron operation through tests and studies of various ion source parameters that could benefit beam stability, tuning reproducibility, and of course overall extracted currents performance. Second is to implement and test modifications or upgrade made to the ion source: extraction geometry, new resistive or rf oven design, dual frequency use, liner, etc. Finally, this test source will be used to study various ion optics schemes such as electrostatic quadrupole doublet or triplet at the source extraction or the use of a correction sextupole and assess their effect on the ion beam through the use of an emittance scanner and imaging viewer that will be incorporated into ARTEMIS-B beam line. This article reviews the design and construction of ARTEMIS-B along with some initial commissioning results.

  15. Assessment of the neutron dose field around a biomedical cyclotron: FLUKA simulation and experimental measurements.

    PubMed

    Infantino, Angelo; Cicoria, Gianfranco; Lucconi, Giulia; Pancaldi, Davide; Vichi, Sara; Zagni, Federico; Mostacci, Domiziano; Marengo, Mario

    2016-12-01

    In the planning of a new cyclotron facility, an accurate knowledge of the radiation field around the accelerator is fundamental for the design of shielding, the protection of workers, the general public and the environment. Monte Carlo simulations can be very useful in this process, and their use is constantly increasing. However, few data have been published so far as regards the proper validation of Monte Carlo simulation against experimental measurements, particularly in the energy range of biomedical cyclotrons. In this work a detailed model of an existing installation of a GE PETtrace 16.5MeV cyclotron was developed using FLUKA. An extensive measurement campaign of the neutron ambient dose equivalent H(∗)(10) in marked positions around the cyclotron was conducted using a neutron rem-counter probe and CR39 neutron detectors. Data from a previous measurement campaign performed by our group using TLDs were also re-evaluated. The FLUKA model was then validated by comparing the results of high-statistics simulations with experimental data. In 10 out of 12 measurement locations, FLUKA simulations were in agreement within uncertainties with all the three different sets of experimental data; in the remaining 2 positions, the agreement was with 2/3 of the measurements. Our work allows to quantitatively validate our FLUKA simulation setup and confirms that Monte Carlo technique can produce accurate results in the energy range of biomedical cyclotrons. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  17. Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma

    SciTech Connect

    Prakash, Ved; Vijayshri; Sharma, Suresh C.; Gupta, Ruby

    2014-03-15

    Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.

  18. Focusing and bunching of ion beam in axial injection channel of IPHC cyclotron TR24

    NASA Astrophysics Data System (ADS)

    Adam, T.; Ivanenko, I.; Kazarinov, N.; Osswald, F.; Traykov, E.

    2017-07-01

    The CYRCe cyclotron (CYclotron pour la ReCherche et l’Enseignement) is used at IPHC (Institut Pluridisciplinaire Hubert Curien) for the production of radio-isotopes for diagnostics, medical treatments and fundamental research in radiobiology. The TR24 cyclotron produced and commercialized by ACSI (Canada) delivers a 16-25 MeV proton beam with intensity from few nA up to 500 μA. The solenoidal focusing instead of existing quadrupole one is proposed in this report. The changing of the focusing elements will give the better beam matching with the acceptance of the spiral inflector of the cyclotron. The parameters of the focusing solenoid are found. Additionally, the main parameters of the bunching system are evaluated in the presence of the beam space charge. This system consists of the buncher installed in the axial injection beam line of the cyclotron. The using of the grid-less multi harmonic buncher may increase the accelerated beam current and will give the opportunity to new proton beam applications.

  19. Support vector machine based fault detection approach for RFT-30 cyclotron

    NASA Astrophysics Data System (ADS)

    Kong, Young Bae; Lee, Eun Je; Hur, Min Goo; Park, Jeong Hoon; Park, Yong Dae; Yang, Seung Dae

    2016-10-01

    An RFT-30 is a 30 MeV cyclotron used for radioisotope applications and radiopharmaceutical researches. The RFT-30 cyclotron is highly complex and includes many signals for control and monitoring of the system. It is quite difficult to detect and monitor the system failure in real time. Moreover, continuous monitoring of the system is hard and time-consuming work for human operators. In this paper, we propose a support vector machine (SVM) based fault detection approach for the RFT-30 cyclotron. The proposed approach performs SVM learning with training samples to construct the classification model. To compensate the system complexity due to the large-scale accelerator, we utilize the principal component analysis (PCA) for transformation of the original data. After training procedure, the proposed approach detects the system faults in real time. We analyzed the performance of the proposed approach utilizing the experimental data of the RFT-30 cyclotron. The performance results show that the proposed SVM approach can provide an efficient way to control the cyclotron system.

  20. A REFLECTION MODEL FOR THE CYCLOTRON LINES IN THE SPECTRA OF X-RAY PULSARS

    SciTech Connect

    Poutanen, Juri; Mushtukov, Alexander A.; Tsygankov, Sergey S.; Nagirner, Dmitrij I.; Suleimanov, Valery F.; Doroshenko, Victor; Lutovinov, Alexander A.

    2013-11-10

    Cyclotron resonance scattering features observed in the spectra of some X-ray pulsars show significant changes of the line energy with the pulsar luminosity. At high luminosities, these variations are often associated with the onset and growth of the accretion column, which is believed to be the origin of the observed emission and of the cyclotron lines. However, this scenario inevitably implies a large gradient of the magnetic field strength within the line-forming region, which makes the formation of the observed line-like features problematic. Moreover, the observed variation of the cyclotron line energy is much smaller than could be anticipated for the corresponding luminosity changes. We argue here that a more physically realistic situation is that the cyclotron line forms when the radiation emitted by the accretion column is reflected from the neutron star surface, where the gradient of the magnetic field strength is significantly smaller. Here we develop a reflection model and apply it to explain the observed variations of the cyclotron line energy in a bright X-ray pulsar V 0332+53 over a wide range of luminosities.

  1. The beam commissioning of BRIF and future cyclotron development at CIAE

    NASA Astrophysics Data System (ADS)

    Zhang, Tianjue; Yang, Jianjun

    2016-06-01

    As an upgrade project of the existing HI-13 tandem accelerator facility, the Beijing Radioactive Ion-beam Facility (BRIF) is being constructed in China Institute of Atomic Energy (CIAE). This project consists of an 100 MeV proton compact cyclotron, a two-stage ISOL system, a superconducting linac booster and various experimental terminals. The beam commissioning of the cyclotron was launched by the end of 2013 and on July 4, 2014 the first 100 MeV proton beam was received on a temporary target which was positioned at the outlet of the cyclotron. The beam current was stably maintained at above 25 μA for about 9 h on July 25, 2014 and the cyclotron is now ready for providing CW proton beam on target-source for RIB production. The beam current is expected to be increased to 200-500 μA in the coming years. The installation of the ISOL system is finished and the stable ion beam test shows it can reach a mass resolution better than 10,000. It is expected to generate dozens of RIB by 100 MeV proton beam. In addition, this paper also introduces the recent progress of the pre-study of an 800 MeV, 3-4 MW separate-sector proton cyclotron, which is aimed to provide high power proton beam for various applications, such as neutron and neutrino physics, proton radiography and nuclear data measurement and ADS system.

  2. Ring Current-Electromagnetic Ion Cyclotron Waves Coupling

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.

    2005-01-01

    The effect of Electromagnetic Ion Cyclotron (EMIC) waves, generated by ion temperature anisotropy in Earth s ring current (RC), is the best known example of wave- particle interaction in the magnetosphere. Also, there is much controversy over the importance of EMIC waves on RC depletion. Under certain conditions, relativistic electrons, with energies 21 MeV, can be removed from the outer radiation belt (RB) by EMIC wave scattering during a magnetic storm. That is why the calculation of EMIC waves must be a very critical part of the space weather studies. The new RC model that we have developed and present for the first time has several new features that we have combine together in a one single model: (a) several lower frequency cold plasma wave modes are taken into account; (b) wave tracing of these wave has been incorporated in the energy EMIC wave equation; (c) no assumptions regarding wave shape spectra have been made; (d) no assumptions regarding the shape of particle distribution have been made to calculate the growth rate; (e) pitch-angle, energy, and mix diffusions are taken into account together for the first time; (f) the exact loss-cone RC analytical solution has been found and coupled with bounce-averaged numerical solution of kinetic equation; (g) the EMIC waves saturation due to their modulation instability and LHW generation are included as an additional factor that contributes to this process; and (h) the hot ions were included in the real part of dielectric permittivity tensor. We compare our theoretical results with the different EMIC waves models as well as RC experimental data.

  3. DIII-D Electron Cyclotron Heating System Status and Upgrades

    DOE PAGES

    Cengher, Mirela; Lohr, John; Gorelov, Yuri; ...

    2016-06-23

    The DIII-D Electron Cyclotron Heating (ECH) system consists of six 110 GHz gyrotrons with corrugated coaxial 31.75 mm waveguide transmission lines and steerable launching mirrors. The system has been gradually updated, leading to increased experimental flexibility and a high system reliability of 91% in the past year. Operationally, the gyrotrons can generate up to a total of 4.8 MW of rf power for pulses up to 5 seconds. The maximum ECH energy injected into the DIII-D is 16.6 MJ. The HE1,1 mode content is over 85% for all the lines, and the transmission coefficient is better than -1.1 dB formore » all the transmission lines, close to the theoretical value. A new depressed collector gyrotron was recently installed and was injecting up to 640 kW of power into the plasma during 2014-2015 tokamak operations. Four dual waveguide launchers, which can steer the RF beams ±20 degrees poloidally and toroidally, are used for real-time neoclassical tearing mode control and suppression. The launchers now have increased poloidal scanning speed and beam positioning accuracy of ~±2 mm at the plasma center. Two more gyrotrons are expected to be installed and operational in 2015- 2016. The first is a repaired 110 GHz, 1 MW gyrotron that had a gun failure after more than 11 years of operation at DIII-D. The second is a newly designed depressed collector tube in the 1.5 MW class, operating at 117.5 GHz, manufactured by Communications and Power Industries (CPI).« less

  4. Ring Current-Electromagnetic Ion Cyclotron Waves Coupling

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.

    2005-01-01

    The effect of Electromagnetic Ion Cyclotron (EMIC) waves, generated by ion temperature anisotropy in Earth s ring current (RC), is the best known example of wave- particle interaction in the magnetosphere. Also, there is much controversy over the importance of EMIC waves on RC depletion. Under certain conditions, relativistic electrons, with energies 21 MeV, can be removed from the outer radiation belt (RB) by EMIC wave scattering during a magnetic storm. That is why the calculation of EMIC waves must be a very critical part of the space weather studies. The new RC model that we have developed and present for the first time has several new features that we have combine together in a one single model: (a) several lower frequency cold plasma wave modes are taken into account; (b) wave tracing of these wave has been incorporated in the energy EMIC wave equation; (c) no assumptions regarding wave shape spectra have been made; (d) no assumptions regarding the shape of particle distribution have been made to calculate the growth rate; (e) pitch-angle, energy, and mix diffusions are taken into account together for the first time; (f) the exact loss-cone RC analytical solution has been found and coupled with bounce-averaged numerical solution of kinetic equation; (g) the EMIC waves saturation due to their modulation instability and LHW generation are included as an additional factor that contributes to this process; and (h) the hot ions were included in the real part of dielectric permittivity tensor. We compare our theoretical results with the different EMIC waves models as well as RC experimental data.

  5. DIII-D Electron Cyclotron Heating System Status and Upgrades

    SciTech Connect

    Cengher, Mirela; Lohr, John; Gorelov, Yuri; Torrezan, Antonio; Ponce, Dan; Chen, Xi; Moeller, Charles

    2016-06-23

    The DIII-D Electron Cyclotron Heating (ECH) system consists of six 110 GHz gyrotrons with corrugated coaxial 31.75 mm waveguide transmission lines and steerable launching mirrors. The system has been gradually updated, leading to increased experimental flexibility and a high system reliability of 91% in the past year. Operationally, the gyrotrons can generate up to a total of 4.8 MW of rf power for pulses up to 5 seconds. The maximum ECH energy injected into the DIII-D is 16.6 MJ. The HE1,1 mode content is over 85% for all the lines, and the transmission coefficient is better than -1.1 dB for all the transmission lines, close to the theoretical value. A new depressed collector gyrotron was recently installed and was injecting up to 640 kW of power into the plasma during 2014-2015 tokamak operations. Four dual waveguide launchers, which can steer the RF beams ±20 degrees poloidally and toroidally, are used for real-time neoclassical tearing mode control and suppression. The launchers now have increased poloidal scanning speed and beam positioning accuracy of ~±2 mm at the plasma center. Two more gyrotrons are expected to be installed and operational in 2015- 2016. The first is a repaired 110 GHz, 1 MW gyrotron that had a gun failure after more than 11 years of operation at DIII-D. The second is a newly designed depressed collector tube in the 1.5 MW class, operating at 117.5 GHz, manufactured by Communications and Power Industries (CPI).

  6. Electron-cyclotron heating in the Constance 2 mirror experiment

    SciTech Connect

    Mauel, Michael E.

    1982-09-01

    Electron cyclotron heating of a highly-ionized plasma in mirror geometry is investigated. The experimental diagnosis of the electron energy distribution and the comparison of the results of this diagnosis with a two dimensional, time-dependent Fokker-Planck simulation are accomplished in four steps. (1) First, the power balance of the heated and unheated Constance 2 plasma is analyzed experimentally. It is concluded that the heated electrons escape the mirror at a rate dominated by a combination of the influx of cool electrons from outside the mirror and the increased loss rate of the ions. (2) The microwave parameters at the resonance zones are then calculated by cold-plasma ray tracing. High N/sub parallel/ waves are launched and for these waves, strong first-pass absorption is predicted. The absorption strength is qualitatively checked in the experiment by surrounding the plasma with non-reflecting liners. (3) A simplified quasilinear theory including the effect of N/sub parallel/ is developed to model the electrons. An analytic expression is derived for the RF-induced pump-out of the magnetically-confined warm electrons. Results of the Fokker-Planck simulations show the development of the electron energy distribution for several plasma conditions and verify the scaling of the analytic expression for RF-induced diffusion into the loss cone. (4) Sample x-ray and endloss data are presented, and the overall comparison between the simulation and experiment is discussed. The x-ray signals indicate that, for greater RF power, the hot electrondensity increases more rapidly than its temperature. The time history of the endloss data, illustrating RF-enhancement, suggests the predicted scaling for warm-electron pump-out. Finally, a comparison between the measured and predicted energy distribution shows that the bulk, warm and hot components of the heated Constance 2 electrons are indeed reproduced by the simulation.

  7. Solar cycle dependence of ion cyclotron wave frequencies

    NASA Astrophysics Data System (ADS)

    Lessard, Marc R.; Lindgren, Erik A.; Engebretson, Mark J.; Weaver, Carol

    2015-06-01

    Electromagnetic ion cyclotron (EMIC) waves have been studied for decades, though remain a fundamentally important topic in heliospheric physics. The connection of EMIC waves to the scattering of energetic particles from Earth's radiation belts is one of many topics that motivate the need for a deeper understanding of characteristics and occurrence distributions of the waves. In this study, we show that EMIC wave frequencies, as observed at Halley Station in Antarctica from 2008 through 2012, increase by approximately 60% from a minimum in 2009 to the end of 2012. Assuming that these waves are excited in the vicinity of the plasmapause, the change in Kp in going from solar minimum to near solar maximum would drive increased plasmapause erosion, potentially shifting the generation region of the EMIC to lower L and resulting in the higher frequencies. A numerical estimate of the change in plasmapause location, however, implies that it is not enough to account for the shift in EMIC frequencies that are observed at Halley Station. Another possible explanation for the frequency shift, however, is that the relative density of heavier ions in the magnetosphere (that would be associated with increased solar activity) could account for the change in frequencies. In terms of effects on radiation belt dynamics, the shift to higher frequencies tends to mean that these waves will interact with less energetic electrons, although the details involved in this process are complex and depend on the specific plasma and gyrofrequencies of all populations, including electrons. In addition, the change in location of the generation region to lower L shells means that the waves will have access to higher number fluxes of resonant electrons. Finally, we show that a sunlit ionosphere can inhibit ground observations of EMIC waves with frequencies higher than ˜0.5 Hz and note that the effect likely has resulted in an underestimate of the solar-cycle-driven frequency changes described here.

  8. Terahertz Imaging of cyclotron emission from quantum Hall conductors

    NASA Astrophysics Data System (ADS)

    Komiyama, Susumu

    2006-03-01

    Microscopy of extremely weak terahertz (THz) waves via photon-counting method is reported. A quantum-dot photon detector [1] is incorporated into a scanning terahertz microscope [2]. By using a quantum Hall detector [3] as well, measurements cover the intensity dynamic range more than five orders of magnitude. The minimum intensity reaches as lo as 10̂-21^ watt (one photon per one second). Applying the measurement system to the study of semiconductor quantum Hall (QH) devices, we image cyclotron radiation emitted by non-equilibrium electrons generated in QH electron systems. Owing to the unprecedented sensitivity, a variety of new features of electron kinetics are unveiled [4]. It is stressed that the present approach is in marked contrast to the THz- wave applications recently discussed extensively in a wide variety of fields including clinic, security, and environment. In the vast majority of those applications, room-temperature operation is implicit. The intensity of treated THz radiation is hence well beyond the level of 300K black body radiation (roughly 10̂-7 watts or 10̂14 photons/s per square centimeter in a 1/10 relative band width). From the scientific viewpoint, however, detecting extremely weak THz waves from an object without external illumination such as applied in the present work is of strong importance, because the microscopic kinetics of an object can be probed only in such a passive method. Besides semiconductor electric devices studied here, we will also discuss possible applications of the present method for molecular dynamics, micro thermography, and cell activities.. [1] S. Komiyama et al., Nature 403, 405 (2000). [2] K. Ikushima et al.,. Rev. Sci. Instrum. 74, 4209 (2003). [3] Y.Kawano et al., J. Appl. Phys. 89, 4037 (2001). [4] K.Ikushima et al., Phys. Rev. Lett. 93, 146804 (2004).

  9. Theoretical determination of electron temperature in electron-cyclotron plasmas

    SciTech Connect

    Uhm, H.S.; Lee, P.H.; Kim, Y.I.; Kim, J.H.; Chang, H.Y.

    1995-12-31

    A basic theory of the plasma electron temperature in ECR plasmas has been reported in recent studies in connection with application to the plasma etching technologies. However, the previous theoretical study of the ECR plasmas is primitive and ad hoc. The authors therefore develop a theory for plasmas generated by the electron-cyclotron-resonance (ECR) mechanism and an experiment is conducted to compare the theoretical prediction and experimental measurements. Due to a large electron mobility along the magnetic field, electrons move quickly out of the system, leaving ions behind and building a space charge potential, which leads to the ambipolar diffusion of ions. In a steady-state condition, the plasma generation by ionization of neutral molecules is in balance with plasma loss due to the diffusion, leading to the electron temperature equation, which is expressed in terms of the plasma size, chamber pressure, and the ionization energy and cross section of neutrals. The electron temperature decreases as the chamber pressure increases. Based on the ambipolar diffusion of ions, a self-consistent theory of the plasma density profile is developed. The power balance condition leads to the plasma density equation, which is also expressed in terms of the electron temperature, the input microwave power and the chamber pressure. It is shown that the plasma density increases, reaches its peak and decreases, as the chamber pressure increases from a small value (0.1 mTorr). After carrying out an experimental observation, it is concluded that the theoretical predictions of the electron temperature and plasma density agree remarkably well with experimental data.

  10. Technological issues of ion cyclotron heating of fusion plasmas

    SciTech Connect

    Hwang, D.Q.; Fortgang, C.M.

    1985-07-01

    With the recent promising results of plasma heating using electromagnetic waves (EM waves) in the ion cyclotron range of frequency (ICRF) on the Princeton Large Torus (PLT) tokamak the feasibility of employing ICRF heating to a reactor-like magnetic confinement device is increasing. The high power ICRF experiments funded on JET (Joint European Torus in England) and JT-60 (in Japan) will have rf source power in the range of 10-30 MW. The time scale for the duration of the RF pulse will range from seconds up to steady-state. The development of new RF components that can transmit and launch such high power, long pulse length, EM waves in a plasma environment is a major technological task. In general, the technology issues may be divided into two categories. The first category concerns the region where the plasma comes in contact with the wave launchers. The problems here are dominated by plasmamaterial interaction, heat deposition by the plasma onto the wave launcher, and erosion of the launcher material. It is necessary to minimize the heat deposition from the plasma, the losses of the RF wave energy in the structure, and to prevent sputtering of the antenna components. A solution involves a combined design using special materials and optimal shaping of the Faraday shield (the electrostatic shields which can be used both for an EM wave polarization adjustment and as a particle shield for the launcher). Recent studies by PPPL and McDonnell Douglas Corp. on the Faraday shield designs will be discussed. The second important area where technology development will be necessary is the transmission of high power RF waves through a gas/vacuum interface region. In the past, the vacuum feedthrough has been the bottle neck which prevented high power operation of the PLT antenna.

  11. Quasi-steady, marginally unstable electron cyclotron harmonic wave amplitudes

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaojia; Angelopoulos, Vassilis; Ni, Binbin; Thorne, Richard M.; Horne, Richard B.

    2013-06-01

    Electron cyclotron harmonic (ECH) waves have long been considered a potential driver of diffuse aurora in Earth's magnetotail. However, the scarcity of intense ECH emissions in the outer magnetotail suggests that our understanding of the amplification and the relative importance of these waves for electron scattering is lacking. We conduct a comprehensive study of wave growth and quasi-linear diffusion to estimate the amplitude of loss-cone-driven ECH waves once diffusion and growth balance but before convection or losses alter the background hot plasma sheet population. We expect this to be the most common state of the plasma sheet between episodes of fast convection. For any given wave amplitude, we model electron diffusion caused by interaction with ECH waves using a 2-D bounce-averaged Fokker-Planck equation. After fitting the resultant electron distributions as a superposition of multicomponent subtracted bi-Maxwellians, we estimate the maximum path-integrated gain using the HOTRAY ray-tracing code. We argue that the wave amplitude during quasi-steady state is the inflection point on a gain-amplitude curve. During quasi-steady state, ECH wave amplitudes can be significant (~1 mV/m) at L ~ 8 but drop to very low values (<~0.1 mV/m) in the outer magnetotail (L ~ 16) and likely fall below the sensitivity of typical instrumentation relatively close to Earth mainly because of the smallness of the loss cone. Our result reinforces the potentially important role of ECH waves in driving diffuse aurora and suggests that careful comparison of theoretical wave amplitude estimates and observations is required for resolving the equatorial scattering mechanism of diffuse auroral precipitation.

  12. High power Ion Cyclotron Resonance Heating (ICRH) in JET

    SciTech Connect

    Jacquinot, J.

    1988-01-01

    Ion Cyclotron Resonance Heating (ICRH) powers of up to 17 MW have been coupled to JET limiter plasmas. The plasma stored energy has reached 7 MJ with 13 MW of RF in 5 MA discharges with Z/sub eff/ = 2. When I/sub p//B/sub /phi// = 1 MA/T the stored energy can be 50% greater than the Goldston L mode scaling. This is due to transient stabilisation of sawteeth (up to 3 s) and to a significant energy content in the minority particles accelerated by RF (up to 30% of the total stored energy). Central temperatures of T/sub e/ - 11 keV and T/sub i/ = 8 keV have been reached with RF alone. (He/sup 3/)D fusion experiments have given a 60 kW fusion yield (fusion rate of 2 /times/ 10/sup 16/ s/sup /minus/1/ in the form of energetic fast particles (14.7 MeV(H), 3.6 MeV(He/sup 4/)) in agreement with modelling. When transposing the same calculation to a (D)T scenario, Q is predicted to be between 0.l2 and 0.8 using plasma parameters already achieved. For the first time, a peaked density profile generated by pellet injection could be reheated and sustained by ICRF for 1.2 s. Electron heat transport in the central region is reduced by a factor 2 to 3. The fusion product n/sub io//tau//sub E/T/sub io/ reaches 2.2 /times/ 10/sup 20/ m/sup /minus/3//center dot/s/center dot/kev in 3 MA discharges which is a factor of 2.3 times larger than with normal density profile. 18 refs., 13 figs., 3 tabs.

  13. Heating and Current Drive by Electron Cyclotron Waves

    NASA Astrophysics Data System (ADS)

    Prater, R.

    2003-10-01

    The physics model of electron cyclotron heating (ECH) and current drive (ECCD) is becoming well validated through systematic comparisons of theory and experiment. Work has shown that ECCD can be highly localized and robustly controlled, leading to applications including stabilization of MHD instabilities like neoclassical tearing modes, control and sustainment of desired profiles of current density and plasma pressure, and studies of localized transport. These physics applications and the study of the basic physics of ECH and ECCD were enabled by the advent of the gyrotron in the 1980s and of the diamond window for megawatt gyrotrons in the 1990s. The experimental work stimulated a broad base of theory based on first principles which is encapsulated in linear ray tracing codes and fully relativistic quasilinear Fokker-Planck codes. Recent experiments use measurements of the local poloidal magnetic field through the motional Stark effect to determine the magnitude and profile of the locally driven current. The subtle balance between wave-induced diffusion and Coulomb relaxation in velocity space provides an understanding of the effects of trapping of current-carrying electrons in the magnetic well, an effect which can be used to advantage. Strong quasilinear effects and radial transport of electrons which may broaden the driven current profile have also been observed under some conditions and appear to be consistent with theory, but in large devices these are usually insignificant. Additional advantages of ECH compared with other rf heating methods are that the antenna can be far removed from the plasma and the power density can be very high. The agreement of theory and experiment, the broad base of established applications, and the technical advantages of ECH support the application of ECH in next-step tokamaks and stellarators.

  14. Optimized feed-forward neural-network algorithm trained for cyclotron-cavity modeling

    NASA Astrophysics Data System (ADS)

    Mohamadian, Masoumeh; Afarideh, Hossein; Ghergherehchi, Mitra

    2017-01-01

    The cyclotron cavity presented in this paper is modeled by a feed-forward neural network trained by the authors’ optimized back-propagation (BP) algorithm. The training samples were obtained from simulation results that are for a number of defined situations and parameters and were achieved parametrically using MWS CST software; furthermore, the conventional BP algorithm with different hidden-neuron numbers, structures, and other optimal parameters such as learning rate that are applied for our purpose was also used here. The present study shows that an optimized FFN can be used to estimate the cyclotron-model parameters with an acceptable error function. A neural network trained by an optimized algorithm therefore shows a proper approximation and an acceptable ability regarding the modeling of the proposed structure. The cyclotron-cavity parameter-modeling results demonstrate that an FNN that is trained by the optimized algorithm could be a suitable method for the estimation of the design parameters in this case.

  15. Neutron measurements in the vicinity of a self-shielded PET cyclotron.

    PubMed

    Hertel, N E; Shannon, M P; Wang, Z-L; Valenzano, M P; Mengesha, W; Crowe, Ronald J

    2004-01-01

    The radionuclides used in positron emission tomography (PET) are short-lived and generally must be produced on site using a cyclotron. A common end product of the nuclear reactions used to produce the PET radionuclides is neutron radiation. These neutrons could potentially contribute to the annual effective dose received by hospital personnel. A Bonner sphere spectrometer was used to measure neutron energy spectra at three locations near a self-shielded PET cyclotron. This cyclotron accelerates protons to 11 MeV. The neutron measurements reported were made during the production of 18F via the 18O(p,n)18F reaction (Q = -2.4 MeV). Neutron spectra were obtained with the BUMS unfolding code and converted to dose equivalent rates.

  16. Improving cancer treatment with cyclotron produced radionuclides. Comprehensive progress report, February 1, 1990--January 31, 1993

    SciTech Connect

    Larson, S.M. Finn, R.D.

    1992-08-04

    This report describes the author`s continuing long term goal of promoting nuclear medicine applications by improving the scientific basis for tumor diagnosis treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The program has 3 interactive components: Radiochemistry /Cyclotron; Pharmacology; and Immunology. An essential strategy is as follows: novel radionuclides and radiotracers developed in the Radiochemistry/Cyclotron section under the DOE grant during the 1989--1992 grant period, will be employed in the Pharmacology and Immunology sections of the DOE grant during the 1992--1995 grant period. The development of novel radionuclides and tracers is of course useful in and of itself, but their utility is greatly enhanced by the interaction with the immunology and pharmacology components of the program.

  17. Effects of Coulomb collisions on cyclotron maser and plasma wave growth in magnetic loops

    NASA Technical Reports Server (NTRS)

    Hamilton, Russell J.; Petrosian, Vahe

    1990-01-01

    The evolution of nonthermal electrons accelerated in magnetic loops is determined by solving the kinetic equation, including magnetic field convergence and Coulomb collisions in order to determine the effects of these interactions on the induced cyclotron maser and plasma wave growth. It is found that the growth rates are larger and the possibility of cyclotron maser action is stronger for smaller loop column density, for larger magnetic field convergence, for a more isotropic injected electron pitch angle distribution, and for more impulsive acceleration. For modest values of the column density in the coronal portion of a flaring loop, the growth rates of instabilities are significantly reduced, and the reduction is much larger for the cyclotron modes than for the plasma wave modes. The rapid decrease in the growth rates with increasing loop column density suggests that, in flare loops when such phenomena occur, the densities are lower than commonly accepted.

  18. Note: Control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron

    SciTech Connect

    Bhattacharyya, T. K. Pal, G.

    2015-02-15

    The Kolkata superconducting cyclotron utilises liquid helium to cool the main magnet niobium-titanium (NbTi) coil and the cryopanels. Three liquid helium cooled cryopanels, placed inside the dees of the radio-frequency system, maintain the high vacuum in the acceleration region of the superconducting cyclotron. The small cryostat placed inside the cryogenic distribution manifold located at the basement of the superconducting cyclotron building supplies liquid helium in parallel branches to three cold heads, used for cooling their associated cryopanels. The level in the cryostat has to be maintained at an optimum value to ensure uninterrupted flow of liquid helium to these three cold heads. This paper describes the transfer function of the overall system, its tuning parameters, and discusses the actual control of cryostat level by using these parameters.

  19. Ion cyclotron resonance heating (ICRH) systems for the Keda Mirror with AXisymmetry (KMAX)

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Yi, Hongshen; Lin, Munan; Wang, Yanpeng; Shi, Peiyun; Zheng, Jian; Sun, Xuan

    2017-05-01

    In this paper, we describe the engineering work involved in constructing two ion cyclotron resonance heating (ICRH) systems for use in the Keda Mirror with AXisymmetry tandem mirror experiment. Because they offer an effective and robust heating method, ICRH systems have been widely used in a variety of plasma experiments. The goal of our system is to heat the hydrogen plasma contained in the central cell using the fundamental ion cyclotron frequency. Both systems can deliver a radiofrequency power of ˜120 kW with adjustable operating frequencies that are tuned to be slightly lower than their local ion cyclotron frequencies. Two types of antennas are installed in the central cell in an attempt to launch both slow and fast waves. The heating mechanism is reliant on the magnetic beach effect for slow waves.

  20. Electrostatic ion cyclotron, beam-plasma, and lower hybrid waves excited by an electron beam

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    It is pointed out that electrostatic ion cyclotron (EIC) waves have been extensively investigated in connection with both space and laboratory plasmas. The present investigation has the objective to study the excitation of low-frequency waves in a multiion plasma by electron beams. The frequencies considered range from below the lowest gyrofrequency of the heaviest ion to about the lower hybrid frequency. It is shown that electron-beam instabilities can produce peaks in the growth rate below the cyclotron frequency of each ion species if nonzero perpendicular wave number effects are included in the ion dynamics. The dispersion relations for neutralized ion Bernstein (NIB) and pure ion Bernstein (PIB) waves are considered along with an instability analysis for a cold plasma and warm electron beam, the electron beam-plasma mode, banded ion cyclotron (EIC) waves with small perpendicular wavelengths, and the growth lengths of the waves.

  1. Coherent Cherenkov-Cyclotron Radiation Excited by an Electron Beam in a Metamaterial Waveguide

    NASA Astrophysics Data System (ADS)

    Hummelt, J. S.; Lu, X.; Xu, H.; Mastovsky, I.; Shapiro, M. A.; Temkin, R. J.

    2016-12-01

    An electron beam passing through a metamaterial structure is predicted to generate reversed Cherenkov radiation, an unusual and potentially very useful property. We present an experimental test of this phenomenon using an intense electron beam passing through a metamaterial loaded waveguide. Power levels of up to 5 MW are observed in backward wave modes at a frequency of 2.40 GHz using a one microsecond pulsed electron beam of 490 keV, 84 A in a 400 G magnetic field. Contrary to expectations, the output power is not generated in the Cherenkov mode. Instead, the presence of the magnetic field, which is required to transport the electron beam, induces a Cherenkov-cyclotron (or anomalous Doppler) instability at a frequency equal to the Cherenkov frequency minus the cyclotron frequency. Nonlinear simulations indicate that the Cherenkov-cyclotron mode should dominate over the Cherenkov instability at a lower magnetic field where the highest output power is obtained.

  2. Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    van Agthoven, Maria A.; Barrow, Mark P.; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A.; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O'Connor, Peter B.

    2015-12-01

    Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a sample. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules.

  3. Design study of an ultra-compact superconducting cyclotron for isotope production

    NASA Astrophysics Data System (ADS)

    Smirnov, V.; Vorozhtsov, S.; Vincent, J.

    2014-11-01

    A 12.5 MeV, 25 μA, proton compact superconducting cyclotron for medical isotope production has been designed and is currently in fabrication. The machine is initially aimed at producing 13N ammonia for Positron Emission Tomography (PET) cardiology applications. With an ultra-compact size and cost-effective price point, this system will offer clinicians unprecedented access to the preferred radiopharmaceutical isotope for cardiac PET imaging. A systems approach that carefully balanced the subsystem requirements coupled to precise beam dynamics calculations was followed. The system is designed to irradiate a liquid target internal to the cyclotron and to minimize the need for radiation shielding. The main parameters of the cyclotron, its design, and principal steps of the development work are presented here.

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  5. Superconducting Accelerating Structure for High-Current Cyclotrons for Accelerator-Driven Subcritical Fission

    NASA Astrophysics Data System (ADS)

    Pogue, Nathaniel; McIntyre, Peter; Sattarov, Akhdiyor

    2011-10-01

    An accelerator driven molten salt fission core is being designed to provide reliable power by subcritical nuclear fission for the next few millennia. Fission is driven by proton beams from a flux-coupled stack of three high-current cyclotrons. A key innovation in attaining the needed beam current and efficiency is a superconducting Niobium rf accelerating cavity that can accelerate bunches in the 200 orbits uniformly. The unique design allows for several cavities to be stacked, and also provides uniform acceleration and eliminates higher order modes in the cyclotron. The design and properties of the superconducting cavity will increase the efficiency of the cyclotron and the overall energy amplification from the molten salt core by an order of magnitude compared to conventional designs.

  6. Electrostatic ion cyclotron, beam-plasma, and lower hybrid waves excited by an electron beam

    SciTech Connect

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

    1985-06-01

    It is pointed out that electrostatic ion cyclotron (EIC) waves have been extensively investigated in connection with both space and laboratory plasmas. The present investigation has the objective to study the excitation of low-frequency waves in a multiion plasma by electron beams. The frequencies considered range from below the lowest gyrofrequency of the heaviest ion to about the lower hybrid frequency. It is shown that electron-beam instabilities can produce peaks in the growth rate below the cyclotron frequency of each ion species if nonzero perpendicular wave number effects are included in the ion dynamics. The dispersion relations for neutralized ion Bernstein (NIB) and pure ion Bernstein (PIB) waves are considered along with an instability analysis for a cold plasma and warm electron beam, the electron beam-plasma mode, banded ion cyclotron (EIC) waves with small perpendicular wavelengths, and the growth lengths of the waves. 39 references.

  7. Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    PubMed

    van Agthoven, Maria A; Barrow, Mark P; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O'Connor, Peter B

    2015-12-01

    Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a sample. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules. Graphical Abstract ᅟ.

  8. Electrostatic ion cyclotron, beam-plasma, and lower hybrid waves excited by an electron beam

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    It is pointed out that electrostatic ion cyclotron (EIC) waves have been extensively investigated in connection with both space and laboratory plasmas. The present investigation has the objective to study the excitation of low-frequency waves in a multiion plasma by electron beams. The frequencies considered range from below the lowest gyrofrequency of the heaviest ion to about the lower hybrid frequency. It is shown that electron-beam instabilities can produce peaks in the growth rate below the cyclotron frequency of each ion species if nonzero perpendicular wave number effects are included in the ion dynamics. The dispersion relations for neutralized ion Bernstein (NIB) and pure ion Bernstein (PIB) waves are considered along with an instability analysis for a cold plasma and warm electron beam, the electron beam-plasma mode, banded ion cyclotron (EIC) waves with small perpendicular wavelengths, and the growth lengths of the waves.

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  10. Excitation of ion-cyclotron harmonic waves in lower-hybrid heating

    NASA Astrophysics Data System (ADS)

    Villalon, E.

    1981-06-01

    The parametric excitation of ion-cyclotron waves by a lower-hybrid pump field is studied in the assumption that the magnitude of the pump is constant. The spatial amplification factor is given as a function of the wavenumber mismatch as produced by the plasma density gradient, and of the linear damping rates of the excited ion-cyclotron and sideband waves. The analysis is applied to plasma edge parameters relevant to the JFT2 heating experiment. It is found that ion-cyclotron harmonic modes are excited depending on pump frequency and plasma density. These modes are shown to have finite damping rates. The parallel refractive indices n1z of the excited sideband fields are found to be always larger than that of the driven pump field. Transition to quasi-mode decay occurs either by decreasing the pump frequency or by increasing the applied RF-power.

  11. Electromagnetic fluctuation spectrum associated with the drift Alfven-cyclotron instability

    SciTech Connect

    Rha, Kicheol; Ryu, Chang-Mo; Yoon, Peter H.

    2012-07-15

    The present paper investigates the electromagnetic fluctuation spectrum associated with the drift Alfven-cyclotron instability by means of a two-dimensional particle-in-cell simulation, which may be plausibly associated with a current disruption event. The current disruption event shows localized high-amplitude electromagnetic fluctuations. In recent theories, these fluctuation characteristics are shown to correspond to the drift Alfven-cyclotron instability. A simulation is carried out to clarify this instability. The simulation shows that the drift Alfven-cyclotron instabilities are excited in two frequency regimes, a relatively low frequency mode propagating in a quasi-perpendicular direction while the second high-frequency branch propagating in a predominantly parallel propagation direction, consistent with observations as well as with a recent theory.

  12. Method and apparatus for preventing cyclotron breakdown in partially evacuated waveguide

    DOEpatents

    Moeller, Charles P.

    1987-01-01

    Cyclotron breakdown is prevented in a partially evacuated waveguide by providing a section of waveguide having an axial cut therein in order to apply a potential across the two halves of the waveguide. This section is positioned in the waveguide crossing the area of electron cyclotron resonance. The potential applied across the waveguide halves is used to deflect seed electrons into the wall of the waveguide in order to prevent ionization of gas molecules and creation of more electron ion pairs which would result in cyclotron breakdown. Support means is also disclosed for electrically isolating the waveguide halves and transition means is provided between the section of the waveguide with the axial cut and the solid waveguide at either end thereof.

  13. Radioactive by-products of a self-shielded cyclotron and the liquid target system for F-18 routine production.

    PubMed

    Kambali, I; Suryanto, H; Parwanto

    2016-06-01

    Routine production of F-18 radionuclide using proton beams accelerated in a cyclotron could potentially generate residual radioisotopes in the cyclotron vicinity which eventually become major safety concerns over radiation exposure to the workers. In this investigation, a typical 11-MeV proton, self-shielded cyclotron has been assessed for its residual radiation sources in the cyclotron's shielding, tank/chamber, cave wall as well as target system. Using a portable gamma ray spectroscopy system, the radiation measurement in the cyclotron environment has been carried out. Experimental results indicate that relatively long-lived radioisotopes such as Mn-54, Zn-65 and Eu-152 are detected in the inner and outer surface of the cyclotron shielding respectively while Mn-54 spectrum is observed around the cyclotron chamber. Weak intensity of Eu-152 radioisotope is again spotted in the inner and outer surface of the cyclotron cave wall. Angular distribution measurement of the Eu-152 shows that the intensity slightly drops with increasing observation angle relative to the proton beam incoming angle. In the target system, gamma rays from Co-56, Mn-52, Co-60, Mn-54, Ag-110 m are identified. TALYS-calculated nuclear cross-section data are used to study the origins of the radioactive by-products.

  14. [Decommissioning of the medical cyclotron in National Center of Neurology and Psychiatry].

    PubMed

    Ito, Kimiteru; Nakata, Yasuhiro; Matsuda, Hiroshi; Sato, Noriko

    2011-05-01

    In Japan, positron emission tomography has prevailed as a useful procedure for detecting malignancy, myocardial viability, and epileptic foci. Consequently, compact medical cyclotrons have been installed in many hospitals. However, reports about the dismantling or decommissioning of compact medical cyclotrons are rare. This report describes the series of steps involved in the decommissioning of a compact medical cyclotron that had been used to produce radioactively tagged substances over a period of fifteen years at the National Center of Neurology and Psychiatry in Japan. Additionally, this report describes the manner in which the radioactive waste was disposed. The plan to decommission the cyclotron was comprised of three phases: a preliminary survey, the dismantling work, and a reports after the dismantling. We complied with the guidelines for the disposal of radioactive waste published by the Ministry of Education, Culture, Sports, Science and Technology. The most radioactive material was the vacuuming foil used in the window of the target chamber, with a dose rate of 17 microSv/h (gamma rays) and 20 x 10(3) cpm (beta rays). The detected radionuclides were mainly 22Na, 57Co, 60Co and 65Zn. The total numbers of radioactive waste containers were thirteen 200 l containers and one 50 l container. We suspect that the long shutdown period of the cyclotron (more than one year) contributed to the decay of the radioactive waste because the amount of containers was smaller than the initial estimation. The shutdown period of a cyclotron may play a significant role in reducing the amount of radioactive waste.

  15. Electron cyclotron emission at the fundamental harmonic in GDT magnetic mirror

    NASA Astrophysics Data System (ADS)

    Shalashov, A. G.; Solomakhin, A. L.; Gospodchikov, E. D.; Lubyako, L. V.; Yakovlev, D. V.; Bagryansky, P. A.

    2017-08-01

    New electron cyclotron emission (ECE) diagnostics has been installed to facilitate the successful experiment of electron cyclotron plasma heating (ECRH) in a large open magnetic trap GDT at Budker Institute. The particularities of ECE in the vicinity of the ECRH frequency were studied experimentally for a broad range of discharge scenarios. The measured thermal emission has partly validated the existing physical conceptions about microwave plasma heating in the machine. Besides the expected emission of thermal electrons, a clearly resolved non-thermal ECE was observed which unambiguously confirmed the presence of suprathermal electrons driven by high-power microwave heating.

  16. New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography

    SciTech Connect

    J. Michael Doster

    2008-12-19

    This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target technology by a factor of two to four, significantly limiting the production rate of Fluorine-18.

  17. Magnetic signatures of ion cyclotron waves during Cassini's high-inclination orbits of Saturn

    NASA Astrophysics Data System (ADS)

    Meeks, Zachary; Simon, Sven

    2017-02-01

    Based on magnetic field data from Cassini's high-inclination orbits of Saturn (radius RS = 60 , 268 km), we analyze the latitudinal distribution of ion cyclotron waves in the giant planet's magnetosphere. Our survey takes into account magnetic field data from all high-inclination orbits between 2004 and 2015. We analyze the dependency of the occurrence rate and amplitude of the ion cyclotron waves on radial distance ρ to Saturn's rotation axis, vertical distance z to Saturn's equatorial plane, and magnetic latitude λ. The occurrence rate of ion cyclotron waves is approximately 100% in Saturn's equatorial plane between the orbits of Enceladus and Dione and decreases to 50% at altitudes of | z | ≈ 0.6RS . Ion cyclotron waves were detected up to | z | = 2.0RS . The occurrence rate displays strong, non-monotonic variations with respect to ρ, z, and λ. The vertical amplitude profile of the waves exhibits an M-like pattern with two distinct peaks near z = ± 0.3RS and the central minimum at z=0. Compared to earlier observations, we find this M-like structure to be inflated in±z direction by a factor of three. The available magnetic field data provides only weak evidence for a local impact of Enceladus and Dione on the ion cyclotron wave field. Using the observed Doppler shift of the ion cyclotron wave frequency during Cassini's high-inclination orbits, we demonstrate the existence of a narrow band of bidirectional wave propagation. This band is centered around Saturn's equatorial plane and possesses a half-width of | z | = 0.15RS , which agrees well with the vertical scale height of Saturn's neutral cloud. To the north of this band, all ion cyclotron waves propagate towards the north (z > 0); and to the south, all waves propagate towards the south (z < 0). In companion with our previous study (Meeks et al., 2016), this survey provides the complete three-dimensional picture of the ion cyclotron wave field between the orbits of Enceladus and Rhea during the Cassini

  18. Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus

    DOE PAGES

    Fu, Xiangrong; Guo, Zehua; Dong, Chuanfei; ...

    2015-05-14

    An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at ω ≃ 0.5Ωe, where Ωe is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near 0.3Ωe and 0.6Ωe. Here we present a novel nonlinear mechanism for the formation of these gaps using Hamiltonian theory and test particle simulations in a homogeneous, magnetized, collisionless plasma. We find that an oblique whistler wave with frequency at a fraction of the electron cyclotron frequency can resonate with electrons, leading to effective energy exchange between the wave and particles.

  19. Neutron transport calculation for Activation Evaluation for Decommissioning of PET cyclotron Facility

    NASA Astrophysics Data System (ADS)

    Nobuhara, Fumiyoshi; Kuroyanagi, Makoto; Masumoto, Kazuyoshi; Nakamura, Hajime; Toyoda, Akihiro; Takahashi, Katsuhiko

    2017-09-01

    In order to evaluate the state of activation in a cyclotron facility used for the radioisotope production of PET diagnostics, we measured the neutron flux by using gold foils and TLDs. Then, the spatial distribution of neutrons and induced activity inside the cyclotron vault were simulated with the Monte Calro calculation code for neutron transport and DCHAIN-SP for activation calculation. The calculated results are in good agreement with measured values within factor 3. Therefore, the adaption of the advanced evaluation procedure for activation level is proved to be important for the planning of decommissioning of these facilities.

  20. Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration

    NASA Astrophysics Data System (ADS)

    Houshmandyar, S.; Yang, Z. J.; Phillips, P. E.; Rowan, W. L.; Hubbard, A. E.; Rice, J. E.; Hughes, J. W.; Wolfe, S. M.

    2016-11-01

    Calibration is a crucial procedure in electron temperature (Te) inference from a typical electron cyclotron emission (ECE) diagnostic on tokamaks. Although the calibration provides an important multiplying factor for an individual ECE channel, the parameter ΔTe/Te is independent of any calibration. Since an ECE channel measures the cyclotron emission for a particular flux surface, a non-perturbing change in toroidal magnetic field changes the view of that channel. Hence the calibration-free parameter is a measure of Te gradient. BT-jog technique is presented here which employs the parameter and the raw ECE signals for direct measurement of electron temperature gradient scale length.

  1. Development of an 18 GHz superconducting electron cyclotron resonance ion source at RCNP.

    PubMed

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2008-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has recently been developed and installed in order to extend the variety and the intensity of ions at the RCNP coupled cyclotron facility. Production of several ions such as O, N, Ar, Kr, etc., is now under development and some of them have already been used for user experiments. For example, highly charged heavy ion beams like (86)Kr(21+,23+) and intense (16)O(5+,6+) and (15)N(6+) ion beams have been provided for experiments. The metal ion from volatile compounds method for boron ions has been developed as well.

  2. A generalised formulation of beam-shadow measurement in spiral-sector superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Pradhan, Jedidiah; Dey, Malay Kanti; Chakrabarti, Alok

    2014-06-01

    A generalised analysis of coherent radial oscillation through shadow measurements on the beam in a spiral-sector, superconducting cyclotron is discussed here. Experimental measurements of shadow cast by one beam-probe on another have been used to study beam behaviour at different radial positions of the K500 superconducting cyclotron at this institute. The correlation of radial oscillation and shadow measurements as well as the motion of orbit centre are also described. The modulation of turn separation by coherent radial oscillation is used to estimate the oscillation amplitude and dee voltage.

  3. Kinetic instabilities in pulsed operation mode of a 14 GHz electron cyclotron resonance ion source

    SciTech Connect

    Tarvainen, O. Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Izotov, I.; Mansfeld, D.; Skalyga, V.

    2016-02-15

    The occurrence of kinetic plasma instabilities is studied in pulsed operation mode of a 14 GHz A-electron cyclotron resonance type electron cyclotron resonance ion source. It is shown that the temporal delay between the plasma breakdown and the appearance of the instabilities is on the order of 10-100 ms. The most important parameters affecting the delay are magnetic field strength and neutral gas pressure. It is demonstrated that kinetic instabilities limit the high charge state ion beam production in the unstable operating regime.

  4. The instability of electrostatic ion cyclotron waves in a multi-component plasma

    NASA Astrophysics Data System (ADS)

    khaira, Vibhooti; Ahirwar, G.

    2017-05-01

    The instability of electrostatic ion cyclotron wave in a plasma consisting of isotropic hydrogen ions (H+), oxygen ions (both positively and negatively charged and denoted by O+ and O-) and electron. ESIC waves with multi component plasma have been studied by kinetic approach at different plasma densities. The dispersion relation and growth rate of the electrostatic ion-cyclotron waves with multi-ion plasma has been investigated. The effect of different plasma densities on ESIC waves in multi-ions is to enhance the growth rate of ESIC waves. The results are interpreted for the space plasma parameters appropriate to the auroral acceleration region of earth’s magneto-plasma.

  5. Simulation of parameter scaling in electron cyclotron resonance ion source plasmas using the GEM code

    SciTech Connect

    Cluggish, B.; Zhao, L.; Kim, J. S.

    2010-02-15

    Although heating power and gas pressure are two of the two of primary experimental ''knobs'' available to users of electron cyclotron resonance ion sources, there is still no clear understanding of how they interact in order to provide optimal plasma conditions. FAR-TECH, Inc. has performed a series of simulations with its generalized electron cyclotron resonance ion source model in which the power and pressure were varied over a wide range. Analysis of the numerical data produces scaling laws that predict the plasma parameters as a function of the power and pressure. These scaling laws are in general agreement with experimental data.

  6. Monitoring and managing of cyclotron beam distribution on the surface of irradiated targets

    NASA Astrophysics Data System (ADS)

    Kirsanov, B. N.; Obleukhov, A. B.; Razbash, A. A.

    2016-12-01

    A system for monitoring and managing of the proton-beam distribution on the surface of the targets in the cyclotrons of the Cyclotron Co. is presented in this report. Parameters of proton beams, designs of the target and target devices, used for isotope production, and the system of the managing of the beam distribution on the target are given. The control is fulfilled via monitoring of the temperature distributions using infrared radiation from the target surface. The need in such system for increasing of the isotope productivity and reducing of the likelihood of the target damage is substantiated.

  7. Calculation of the spontaneous cyclotron emissivity using the complete relativistic resonance condition

    NASA Technical Reports Server (NTRS)

    Freund, H. P.; Wu, C. S.; Gaffey, J. D., Jr.

    1984-01-01

    An expression for the spectral emissivity of spontaneous synchrotron radiation for a plasma which consists of both thermal and suprathermal electron components is derived using the complete relativistic cyclotron resonance condition. The expression is valid over all angles of propagation. The result is applied to the study of the emission of radiation from an energetic population of electrons with a loss-cone distribution in a relatively low-density plasma (i.e., the electron plasma frequency is less than the cyclotron frequency).

  8. Gas Feeding System Supplying the U-400M Cyclotron Ion Source with Hydrogen Isotopes

    NASA Astrophysics Data System (ADS)

    Yukhimchuk, A. A.; Antilopov, V. V.; Apasov, V. A.; Vinogradov, Yu. I.; Golubkov, A. N.; Gornostaev, Ye. V.; Grishechkin, S. K.; Demin, A. M.; Zlatoustovski, S. V.; Klevtsov, V. G.; Kuryakin, A. V.; Malkov, I. N.; Musyaev, R. K.; Pustovoi, V. I.; Bekhterev, V. V.; Bogomolov, S. L.; Gulbekian, G. G.; Yefremov, A. A.; Zelenak, A.; Leporis, M.; Loginov, V. N.; Oganessian, Yu. Ts.; Pashchenko, S. V.; Rodin, A. M.; Smirnov, Yu. I.; Ter-Akopian, G. M.; Yazvitski, N. Yu.

    2005-09-01

    Automated system feeding into ion source hydrogen isotopes as molecules with preset ratio of the fluxes is described. The control system automatically maintained the working parameters and provided graphic and digital representation of the controlled processes. The radiofrequency (RF) ion source installed at the axial injection line of the cyclotron produced ion beams of HD+, HT+, DT+, D2H+, etc. At a several months DT+ beam acceleration the tritium consumption was less than 108 Bq/hr. The intensity of a 58.2 MeV triton beam (T+ ions) extracted from the cyclotron chamber was about 10 nA.

  9. FEL's with bragg reflection resonators: cyclotron auto resonance masers versus ubitrons

    SciTech Connect

    Bratman, V.L.; Denisov, G.G.; Ginzburg, N.S.; Petelin, M.I.

    1983-03-01

    FEL's based on the stimulated undulator radiation (ubitrons) are compared with those based on the stimulated cyclotron radiation (cyclotron autoresonance masers (CARM's)). If the high-current accelerators are used as electron injectors, then from the viewpoint of simplicity of oscillatory electron energy pumping, criticality with respect to electron velocity dispersion, and efficiency, CARM's seem to be more effective than ubitrons at mm and sbmm waves. For such HF generators, resonators based on selective Bragg reflection of electromagnetic waves in corrugated metallic tubes are most attractive. CARM's of this type yield 6 MW at a 4 mm wavelength and 10 MW at a 2 mm wavelength in the single-mode regime.

  10. Effects of energetic heavy ions on electromagnetic ion cyclotron wave generation in the plasmapause region

    NASA Technical Reports Server (NTRS)

    Kozyra, J. U.; Cravens, T. E.; Nagy, A. F.; Fontheim, E. G.; Ong, R. S. B.

    1984-01-01

    An expression for electromagnetic ion cyclotron convective growth rates is derived. The derivation of the dispersion relation and convective growth rates in the presence of a multicomponent energetic and cold plasma is presented. The effects that multiple heavy ions in the ring current and cold plasma produce in the growth and propagation characteristics of ion cyclotron waves are explored. Results of growth rate calculations using parameters consistent with conditions in the plasmapause region during the early recovery phase of geomagnetic storms are presented and compared with ground-based and satellite observations of waves in this region. The geophysical implications of the results are discussed.

  11. The Design of a 100 GHz CARM (Cyclotron Auto-Resonance Maser) Oscillator Experiment

    DTIC Science & Technology

    1988-09-14

    2364. (Radio Engng. Electron. Phys., 21, 78-73). 5) Ginzburg , N. S., Zarnitsyna, I. G., and Nusinovich, G. S., 1981, Theory of relativistic cyclotron...An efficient Doppler-shifted electron-cyclotron maser oscillator. Int J. Electron., 53, 555-57 1. 7) Bratman, V. L., Ginzburg , N. S., Nusinovich, G...1386-1389. (Sov. Tech. Phys. Lett., 8, 596-597). 12) Botvinnik, I. E., Bratman, V. L., Volkov, A. B., Ginzburg , N. S, Denisov, G. G., Kol’chugin, B

  12. Effects of energetic heavy ions on electromagnetic ion cyclotron wave generation in the plasmapause region

    NASA Technical Reports Server (NTRS)

    Kozyra, J. U.; Cravens, T. E.; Nagy, A. F.; Fontheim, E. G.; Ong, R. S. B.

    1984-01-01

    An expression for electromagnetic ion cyclotron convective growth rates is derived. The derivation of the dispersion relation and convective growth rates in the presence of a multicomponent energetic and cold plasma is presented. The effects that multiple heavy ions in the ring current and cold plasma produce in the growth and propagation characteristics of ion cyclotron waves are explored. Results of growth rate calculations using parameters consistent with conditions in the plasmapause region during the early recovery phase of geomagnetic storms are presented and compared with ground-based and satellite observations of waves in this region. The geophysical implications of the results are discussed.

  13. Cyclotron resonance of figure-of-eight orbits in a type-II Weyl semimetal

    NASA Astrophysics Data System (ADS)

    Koshino, Mikito

    2016-07-01

    We study the cyclotron resonance in the electron-hole joint Fermi surface of a type-II Weyl semimetal. In magnetic field, the electron and hole pockets touching at the Weyl node are hybridized to form quantized Landau levels corresponding to semiclassical 8-shaped orbits. We calculate the dynamical conductivities for the electric fields oscillating in x and y directions and find that the resonant frequencies in x and y differ by a factor of two, reflecting the figure-of-eight electron motion in real space. The peculiar anisotropy in the cyclotron resonance serves as a unique characteristic of the dumbbell-like Fermi surface.

  14. Beam-driven ion cyclotron harmonic resonances in the terrestrial foreshock

    NASA Technical Reports Server (NTRS)

    Smith, C. W.; Goldstein, M. L.; Gary, S. P.; Russell, C. T.

    1985-01-01

    A terrestrial upstream wave event which demonstrates multiple, ion cyclotron harmonic resonances between the interplanetary wave population and an observed proton beam is analyzed. The techniques and parameters employed in the data analysis are discussed, including the use of differential and band-pass filters. An upstream wave event demonstrating multiple harmonic waves is examined, and the instability analysis relevant to the ion beam observations thought to be responsible for that event is discussed. It is shown that an observed bi-Maxwellian ion beam is capable of generating right and left-hand polarized waves through ion cyclotron harmonic resonance.

  15. Anomalous magnetotransport and cyclotron resonance of high mobility magnetic 2DHGs in the quantum Hall regime

    NASA Astrophysics Data System (ADS)

    Wurstbauer, U.; Knott, S.; Westarp, C. G. v.; Mecking, N.; Rachor, K.; Heitmann, D.; Wegscheider, W.; Hansen, W.

    2010-02-01

    Low-temperature magnetotransport measurements and far-infrared transmission spectroscopy are reported in molecular beam epitaxial grown two-dimensional hole systems confined in strained InAs quantum wells with magnetic impurities in the channel. The interactions of the free holes spin with the magnetic moment of 5/2 provided by manganese features intriguing localization phenomena and anomalies in the Hall and the quantum Hall resistance. In magnetic field-dependent far-infrared spectroscopy measurements well-pronounced cyclotron resonance and an additional resonance are found that indicates an anti-crossing with the cyclotron resonance.

  16. Optimization of beam dump shielding for K-130 cyclotron at VECC.

    PubMed

    Chatterjee, S; Banerjee, K; Pandit, Deepak; Roy, Pratap; Bandyopadhyay, T; Ravishankar, R; Bhattacharya, C; Bhattacharya, S; Datta, D; Banerjee, S R

    2017-10-01

    A compact and efficient beam dump shield has been designed using Monte Carlo simulation code FLUKA to facilitate low background measurement of neutron and gamma rays using K130 cyclotron at Variable Energy Cyclotron Centre, Kolkata (VECC). Iron, lead and high density Polyethylene (HDPE) were considered in the design of the beam dump shield. Representative FLUKA simulation results have been validated using in-beam experiment performed on the same beam dump constituents. Experimental neutron and gamma-rays energy spectra have been found to be in fair agreement with the simulation results. Activation of various beam dump shield components were also carried out. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. High brightness 50 MeV Cyclotron for Accelerator-Driven Subcritical Fission

    NASA Astrophysics Data System (ADS)

    Assadi, Saeed; Badgley, Karie; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

    2011-10-01

    The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for a high-brightness, high-current cyclotron with capabilities that will be beneficial for applications to accelerator-driven subcritical fission, medical isotope production, and proton therapy. As a first embodiment of the technology, we are developing a detailed design for TAMU-50, a 50 MeV, 5 mA proton cyclotron with high beam brightness. In this presentation we present devices and beamline components for injection, extraction, controls and diagnostics. We emphasize the system integration and implementation of TAMU-50 for production of medical radioisotopes.

  18. Plasma ion dynamics and beam formation in electron cyclotron resonance ion sources

    SciTech Connect

    Mascali, D.; Neri, L.; Miracoli, R.; Gammino, S.; Celona, L.; Ciavola, G.; Gambino, N.; Chikin, S.

    2010-02-15

    In electron cyclotron resonance ion sources it has been demonstrated that plasma heating may be improved by means of different microwave to plasma coupling mechanisms, including the ''frequency tuning'' and the ''two frequency heating''. These techniques affect evidently the electron dynamics, but the relationship with the ion dynamics has not been investigated in details up to now. Here we will try to outline these relations: through the study of ion dynamics we may try to understand how to optimize the electron cyclotron resonance ion sources brightness. A simple model of the ion confinement and beam formation will be presented, based on particle-in-cell and single particle simulations.

  19. Ratchet transport of a two-dimensional electron gas at cyclotron resonance

    NASA Astrophysics Data System (ADS)

    Budkin, G. V.; Tarasenko, S. A.

    2016-02-01

    The driving of charge carriers confined in a quantum well lacking the center of space inversion by an alternating electric field leads to the formation of a direct electric current. We develop a microscopic theory of such a quantum ratchet effect for quantum wells subjected to a static magnetic field. We show that the ratchet current emerges for a linearly polarized alternating electric field as well as a rotating electric field and drastically increases at the cyclotron resonance conditions. For the magnetic field tilted with respect to the quantum well normal, the ratchet current contains an additional resonance at the first subharmonic of the cyclotron resonance.

  20. Measurement of thermal neutron fluence distribution with use of 23Na radioactivation around a medical compact cyclotron.

    PubMed

    Fujibuchi, Toshioh; Yamaguchi, Ichiro; Kasahara, Tetsuharu; Iimori, Takashi; Masuda, Yoshitada; Kimura, Ken-ichi; Watanabe, Hiroshi; Isobe, Tomonori; Sakae, Takeji

    2009-07-01

    A medical compact cyclotron produces about 10(15) neutrons per day along with 100 GBq of (18)F. Therefore, it is important to establish radiation safety guidelines on residual radioactivity for routine operation, maintenance work, and decommissioning. Thus, we developed a simple method for measuring the thermal neutrons in a cyclotron room. In order to verify the feasibility of our proposed method, we measured the thermal neutron distribution around a cyclotron by using the activation of (23)Na in salt. We installed 78 salt dosimeters in the cyclotron room with a 50 cm mesh. The photopeak of (24)Na was measured, and the neutron flux distribution was estimated. Monitoring the neutron flux distribution in a cyclotron room appears to be useful for not only obtaining an accurate estimate of the distribution of induced radioactivity, but also optimizing the shield design for radiation safety in preparation for the decommissioning process.

  1. Nonlinear Fundamental and Harmonic Cyclotron Resonant Scattering of Radiation Belt Ultra-Relativistic Electrons by Oblique Monochromatic EMIC Waves

    NASA Astrophysics Data System (ADS)

    Wang, G.; Su, Z.; Zheng, H.

    2016-12-01

    Cyclotron resonant scattering by electromagnetic ion cyclotron (EMIC) waves has been considered to be responsible for the rapid loss of radiation belt high-energy electrons. Recent studies have revealed the nonlinear character of cyclotron resonance with parallel-propagating EMIC waves. Here we investigate the fundamental and harmonic cyclotron resonance between radiation belt ultra-relativistic electrons and oblique monochromatic EMIC waves. We show that both fundamental and harmonic cyclotron resonance can exhibit significant nonlinearity for oblique EMIC waves. Higher wave obliquity allows stronger nonlinearity of harmonic resonance but weaker nonlinearity of fundamental resonance. The total transport coefficients of nonlinear resonances are found to deviate significantly from the quasi-linear predication. Increase of wave obliquity tends to reduce, to some extent, the difference between nonlinear and quasi-linear transport coefficients. These results suggest that the nonlinear resonant scattering even by oblique EMIC waves should be taken into account in future radiation belt modeling.

  2. Narrow heavy-hole cyclotron resonances split by the cubic Rashba spin-orbit interaction in strained germanium quantum wells

    NASA Astrophysics Data System (ADS)

    Failla, M.; Myronov, M.; Morrison, C.; Leadley, D. R.; Lloyd-Hughes, J.

    2015-07-01

    The spin-orbit interaction was found to split the cyclotron resonance of heavy holes confined in high-mobility, compressively strained germanium quantum wells. The interference between coherent spin-split cyclotron resonances was tracked on picosecond time scales using terahertz time-domain spectroscopy. Analysis in the time domain, or using a time-frequency decomposition based on the Gabor-Morlet wavelet, was necessary when the difference between cyclotron frequencies was comparable to the linewidth. The cubic Rashba spin-orbit coefficient β was determined via two methods: (i) the magnetic-field dependence of the cyclotron frequencies, and (ii) the spin-resolved subband densities. An enhanced β and spin polarization was created by tailoring the strain to enhance the spin-orbit interaction. The amplitude modulation of the narrow, interfering cyclotron resonances is a signature of spin coherences persisting for more than 10 ps.

  3. Generation of Electron Cyclotron Harmonic waves around the Moon

    NASA Astrophysics Data System (ADS)

    Katayama, Y.; Kojima, H.; Saito, Y.; Kasahara, Y.; Omura, Y.; Yamamoto, T.; Yokota, S.; Nishino, M. N.; Hashimoto, K.; Ono, T.; Tsunakawa, H.

    2012-12-01

    The study of the electron cyclotron harmonic(ECH) waves has been extensively made in the view point of the magnetospheric physics as well as the microscopic wave-particle interaction. The Japanese lunar satellite Kaguya provides another observation of the ECH waves around the moon. The interaction between the moon and space plasmas results in the generation of the ECH waves. We performed the detailed data analyses using the plasma wave data observed by the Kaguya as well as the linear dispersion analyses. First of all we found the close relation of the ECH wave observation and the magnetic anomaly of the night side of the moon. In order to examine the generation condition of the ECH waves, we consult the Kaguya electron data. The data show that the importance of the coexistence of of electron loss cone velocity distribution and low energy electron beams. The loss cone velocity distribution can be formed by the mirror force at the magnetic anomaly on the surface of the moon. The low energy electron beam can be realized by the acceleration due to the negative potential of the moon surface on the night side. We then assume these two kinds of electron distribution are essential to excite ECH waves. However the loss cone distribution and low energy beam are observed not only in the magnetosphere but also in the wake region, where ECH waves are not observed. This means some parametric dependence of the ECH wave generation even under the coexistence of the electron loss cone distribution and low energy electron beam. In order to make clear the parametric condition of the ECH waves around the moon, we calculate the linear growth rate by solving the kinetic plasma dispersion relation using the realistic plasma parameters of the lobe, plasma sheet and wake regions based on the KAGUYA observation. In the linear dispersion analysis, we assumed hot electrons and cold electrons, and the former have loss cone distribution and the latter has drift velocity which equivalent

  4. Neutron Beams from Deuteron Breakup at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory

    SciTech Connect

    McMahan, M.A.; Ahle, L.; Bleuel, D.L.; Bernstein, L.; Braquest, B.R.; Cerny, J.; Heilbronn, L.H.; Jewett, C.C.; Thompson, I.; Wilson, B.

    2007-07-31

    Accelerator-based neutron sources offer many advantages, in particular tunability of the neutron beam in energy and width to match the needs of the application. Using a recently constructed neutron beam line at the 88-Inch Cyclotron at LBNL, tunable high-intensity sources of quasi-monoenergetic and broad spectrum neutrons from deuteron breakup are under development for a variety of applications.

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

    PubMed

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

    2014-07-07

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

  6. Simulations of heavy ion heating by electromagnetic ion cyclotron waves driven by proton temperature anisotropies

    NASA Technical Reports Server (NTRS)

    Tanaka, M.

    1985-01-01

    Heating of heavy ions by the electromagnetic ion cyclotron (EMIC) waves, which are driven by proton temperature anisotropies, is studied by means of hybrid particle simulations. Initially, relaxation of the temperature anisotropies in the proton distribution and isotropic heating of the heavy ions are observed (phase I), followed by substantial perpendicular heating of the heavy ions (phase II). The heavy ions are distinctly gyrophase modulated by the EMIC waves. The isotropic heating in phase I is due to magnetic trapping by the excited proton cyclotron waves. The perpendicular heating in phase II is attributed to cyclotron resonance with the EMIC waves, which becomes possible by means of the preceding heating in phase I. Saturation of the EMIC instability is instead attributed to magnetic trapping of the majority ions: protons. When the proton anisotropy is very large, frequency shift (decrease) of the proton cyclotron waves to less than 1/2 Ohm(p) is observed. The present mechanism is not only relevant to He(+) heating in the dayside equator of the magnetosphere, but it also predicts hot He2(+) ions behind the earth's bow shock.

  7. Simulations of heavy ion heating by electromagnetic ion cyclotron waves driven by proton temperature anisotropies

    NASA Technical Reports Server (NTRS)

    Tanaka, M.

    1985-01-01

    Heating of heavy ions by the electromagnetic ion cyclotron (EMIC) waves, which are driven by proton temperature anisotropies, is studied by means of hybrid particle simulations. Initially, relaxation of the temperature anisotropies in the proton distribution and isotropic heating of the heavy ions are observed (phase I), followed by substantial perpendicular heating of the heavy ions (phase II). The heavy ions are distinctly gyrophase modulated by the EMIC waves. The isotropic heating in phase I is due to magnetic trapping by the excited proton cyclotron waves. The perpendicular heating in phase II is attributed to cyclotron resonance with the EMIC waves, which becomes possible by means of the preceding heating in phase I. Saturation of the EMIC instability is instead attributed to magnetic trapping of the majority ions: protons. When the proton anisotropy is very large, frequency shift (decrease) of the proton cyclotron waves to less than 1/2 Ohm(p) is observed. The present mechanism is not only relevant to He(+) heating in the dayside equator of the magnetosphere, but it also predicts hot He2(+) ions behind the earth's bow shock.

  8. Geometric analysis of phase bunching in the central region of cyclotron

    NASA Astrophysics Data System (ADS)

    Miyawaki, Nobumasa; Fukuda, Mitsuhiro; Kurashima, Satoshi; Kashiwagi, Hirotsugu; Okumura, Susumu; Arakawa, Kazuo; Kamiya, Tomihiro

    2013-07-01

    An optimum condition for realizing phase bunching in the central region of a cyclotron was quantitatively clarified by a simplified geometric trajectory analysis of charged particles from the first to the second acceleration gap. The phase bunching performance was evaluated for a general case of a cyclotron. The phase difference of incident particles at the second acceleration gap depends on the combination of four parameters: the acceleration harmonic number h, the span angle θD of the dee electrode, the span angle θF from the first to the second acceleration gap, the ratio RV of the peak acceleration voltage between the cyclotron and ion source. Optimum values of θF for phase bunching were limited by the relationship between h and θD, which is 90°/h+θD/2≤θF≤180°/h+θD/2, and sin θF>0. The phase difference with respect to the reference particle at the second acceleration gap is minimized for voltage-ratios between two and four for an initial phase difference within 40 RF degrees. Although the slope of the first acceleration gap contributes to the RF phase at which the particles reach the second acceleration gap, phase bunching was not affected. An orbit simulation of the AVF cyclotron at the Japan Atomic Energy Agency verifies the evaluation based on geometric analysis.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  10. Effect of a RF Wave on Ion Cyclotron Instability in Size Distributed Impurities Containing Plasmas

    SciTech Connect

    Sharma, A. K.; Tripathi, V. K.; Annou, R.

    2008-09-07

    The effect of a large amplitude lower hybrid wave on current driven ion cyclotron waves in a dusty plasma where dust grains are size distributed is examined. The influence of the lower hybrid wave on the stabilization of the instability is studied. The efficacy of rf is dust density dependent.

  11. Numerical study of ion-cyclotron resonant interaction via hybrid-Vlasov simulations

    SciTech Connect

    Valentini, Francesco; Iazzolino, Antonio; Veltri, Pierluigi

    2010-05-15

    Hybrid Vlasov-Maxwell numerical simulations are used to investigate the collisionless resonant interaction of ions with ion-cyclotron waves in parallel propagation with respect to a background magnetic field. In linear regime, analytical results on wave damping, obtained by integrating the linearized Vlasov equation through the well-known characteristics method, are compared with the numerical results. Then, the ion heating process and the consequent generation of temperature anisotropy in the direction perpendicular to the background magnetic field are investigated numerically in detail. In nonlinear regime, the numerical results show that the distribution of particle velocities is strongly distorted due to the resonant ion-cyclotron interaction with the formation of diffusive plateaus in the longitudinal direction (with respect to the ambient field) and significantly departs from the Maxwellian equilibrium. These results are relevant in many plasma physics environments, such as the solar wind, where the process of ion-cyclotron heating and the generation of temperature anisotropy and non-Maxwellian velocity distributions are routinely recovered in many in situ measurements, or the laboratory plasmas, where the resonant interaction of ions with ion-cyclotron waves is the primary source of auxiliary heating in the confining apparatus.

  12. Electron cyclotron harmonic resonances in high-frequency heating of the ionosphere

    SciTech Connect

    Kuo, Spencer P.

    2013-09-15

    Electron acceleration by upper hybrid waves under cyclotron harmonic resonance interaction is studied. Theory is formulated; the analytical solutions in the second and fourth harmonic cyclotron resonance cases are obtained, and in the third harmonic case, a first order differential equation governing the evolution of the electron energy is derived. The theory is applied for explaining the generation of artificial ionization layers observed in high-frequency (HF) ionospheric heating experiments. The upper hybrid waves are assumed to be excited parametrically by the O-mode HF heating wave. As the decay mode is the lower hybrid wave, the excited upper hybrid waves have wavelengths ranging from 0.25 to 0.5 m, which are short enough to effectively incorporate the finite Larmour radius effect for the harmonic cyclotron resonance interactions as well as have a frequency bandwidth of about 20 kHz, which provides an altitude region of about 10 km for continuous harmonic cyclotron resonance interaction between electrons and descending waves in the slightly inhomogeneous geomagnetic field. The numerical results on electron acceleration show that electron fluxes with energies larger than 14 eV are generated in the three harmonic cases. These energetic electrons cause impact ionizations, which are descending to form artificial ionization layers at the bottom of the ionospheric F region.

  13. Tomsk Polytechnic University cyclotron as a source for neutron based cancer treatment

    SciTech Connect

    Lisin, V. A.; Bogdanov, A. V.; Golovkov, V. M.; Sukhikh, L. G.; Verigin, D. A.; Musabaeva, L. I.

    2014-02-15

    In this paper we present our cyclotron based neutron source with average energy 6.3 MeV generated during the 13.6 MeV deuterons interactions with beryllium target, neutron field dosimetry, and dosimetry of attendant gamma fields. We also present application of our neutron source for cancer treatment.

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

    PubMed

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

    2017-04-20

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  16. Filamental quenching of the current-driven ion-cyclotron instability

    SciTech Connect

    Cartier, S.L.; D'Angelo, N.; Krumm, P.H.; Merlino, R.L.

    1985-01-01

    Experimental evidence is presented on the effect of the finite width of the current channel for the excitation of the current-driven ion-cyclotron instability. The results are in agreement with the nonlocal theory of Bakshi, Ganguli, and Palmadesso.

  17. Filamental quenching of the current-driven ion-cyclotron instability. Progress report

    SciTech Connect

    Cartier, S.L.; D'Angelo, N.; Krumm, P.H.; Merlino, R.L.

    1984-06-01

    Experimental evidence is presented on the effect of the finite width of the current channel for the excitation of the current-driven ion-cyclotron instability. The results are in agreement with the non-local theory of Bakshi, Ganguli, and Palmadesso.

  18. Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

    NASA Astrophysics Data System (ADS)

    Hellsten, T.; Johnson, T. J.; Van Eester, D.; Lerche, E.; Lin, Y.; Mayoral, M.-L.; Ongena, J.; Calabro, G.; Crombé, K.; Frigione, D.; Giroud, C.; Lennholm, M.; Mantica, P.; Nave, M. F. F.; Naulin, V.; Sozzi, C.; Studholme, W.; Tala, T.; Versloot, T.; Contributors, JET-EFDA

    2012-07-01

    The rotation of L-mode plasmas in the JET tokamak heated by waves in the ion cyclotron range of frequencies (ICRF) damped on electrons, is reported. The plasma in the core is found to rotate in the counter-current direction with a high shear and in the outer part of the plasma with an almost constant angular rotation. The core rotation is stronger in magnitude than observed for scenarios with dominating ion cyclotron absorption. Two scenarios are considered: the inverted mode conversion scenarios and heating at the second harmonic 3He cyclotron resonance in H plasmas. In the latter case, electron absorption of the fast magnetosonic wave by transit time magnetic pumping and electron Landau damping (TTMP/ELD) is the dominating absorption mechanism. Inverted mode conversion is done in (3He)-H plasmas where the mode converted waves are essentially absorbed by electron Landau damping. Similar rotation profiles are seen when heating at the second harmonic cyclotron frequency of 3He and with mode conversion at high concentrations of 3He. The magnitude of the counter-rotation is found to decrease with an increasing plasma current. The correlation of the rotation with the electron temperature is better than with coupled power, indicating that for these types of discharges the dominating mechanism for the rotation is related to indirect effects of electron heat transport, rather than to direct effects of ICRF heating. There is no conclusive evidence that mode conversion in itself affects rotation for these discharges.

  19. Status of the PHOENIX electron cyclotron resonance charge breeder at ISOLDE, CERN.

    PubMed

    Barton, Charles; Cederkall, Joakim; Delahaye, Pierre; Kester, Oliver; Lamy, Thierry; Marie-Jeanne, Mélanie

    2008-02-01

    We report here on the last progresses made with the PHOENIX electron cyclotron resonance charge breeder test bench at ISOLDE. Recently, an experiment was performed to test the trapping of (61)Fe daughter nuclides from the decay of (61)Mn nuclides. Preliminary results are given.

  20. Simulation of Median Plane Effects in the Extraction Region of the C235 Cyclotron

    SciTech Connect

    Jongen, Y.; Karamysheva, G.; Shirkov, S.

    2010-01-05

    The Study of beam dynamics in the C235 cyclotron dedicated for proton therapy is presented. Results of computer simulations of the particle motion in the measured magnetic field are given. This of the median plane effects in the extraction region was carried out. The tolerance on the radial component of the magnetic field was defined using these simulations.